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15546249 | Comparison of lifestyle risk factors by family history for gastric, breast, lung and colorectal cancer. | To assess the theoretical impact of lifestyle of a cancer family history in first-degree relatives (CFH) and clarify interactions between CFH and lifestyle factors, hospital-based comparison and case-reference studies were conducted in Nagoya, Japan. Totals of 1988 gastric, 2455 breast, 1398 lung and 1352 colorectal cancer patients, as well as 50,706 non-cancer outpatients collected from 1988 to 1998, were checked for lifestyle factors, which included dietary and physical exercise habits, as well as smoking/drinking status. General lifestyle factors with non-cancer outpatients did not differ by the CFH status. Case-reference analyses showed that frequent intake of fruits, raw vegetables, carrots, pumpkin, cabbage and lettuce, as well as frequent physical exercise, were associated with decreased risk for all four sites of cancer, while habitual smoking increasing the risk of gastric, and more particularly, lung cancer. Interestingly, the study revealed the magnitude of odds ratios for the above lifestyle factors obtained from CFH positives to be similar to those from CFH negatives for these four sites of cancer. There were no significant interactions between CFH and any particular lifestyle factor. In conclusion, our results suggest no appreciable influence of CFH on lifestyle related risk factors for gastric, breast, lung, and colorectal cancer. Habitual smoking increased, while frequent physical exercise and raw vegetables intake decreased cancer risk, regardless of the CFH status. |
15546248 | Mortality report of malignant tumors in SheXian, Hebei Province, China, from the 1970's to the present. | Investigations into mortality from malignant tumors were initiated in the 1970's in Hebei Province, China, and especially for esophageal cancer the rates were high, Shexian county ranking in first place of the towns that were surveyed. Since the 1970's, a register system for all causes of death has been in place. Data for the decades of the 1970's, 1980's, 1990's and 2000's century were here checked and analyzed by SPSS software. From the decades of the 1970's onward, the mortality rates of malignant tumors/100,000 were 272.0, 260.1, 211.7 and 180.1, respectively, with significant differences over time (x2 =240.5, P<0.001). The main malignant tumors were esophageal, gastric, liver, lung and cervix cancers. The sum of their percentages of all cancer deaths were 92.1% in the 1970's, 91.6% in the 1980's, 92.1% in the 1990's and 93.9% in the 21st century. The sex ratios (male vs female) were 1.5, 1.5, 1.7 and 2.0 respectively, with an ascending trend. Mortality rates of malignant tumors increased with age, with an obvious geographic distribution. The highest mortality of malignant tumors was evident in the area where the Qingzhang and Zhuozhang rivers join. From 1970's to the beginning of the 21st century, the mortality rate of malignant tumors has shown a declining trend. The main responsible cancers are in the esophagus, stomach, liver, and lung. Through great efforts for prevention, obvious decrease for esophageal cancer and cervix cancer has been achieved, but the mortality rate for gastric cancer remains high. |
15546247 | A pilot study on genotype announcement to induce smoking cessation by Japanese smokers. | Genotype announcements related to susceptibility to hazardous effects of smoking may be effective to induce smoking cessation. Subjects were municipal government employees, 63 young smokers employed in the previous year and 59 smokers with more than 45 pack-years, who were invited to educational sessions against smoking held in December 2003 and February 2004, respectively. In the session, those who wished genetic susceptibility tests (GSTM1, GSTT1, and NQO1 C609T) were enrolled in the study. The smoking habit was ascertained three times: at the session, one month later, just before the genotype announcement, and at the follow-up three months after the announcement. Fifty eight (92.1%) and 49 (83.1%) smokers participated in the study, respectively. One out of 58 smokers was not a habitual smoker, so was not included in the analysis. The smoking cessation rates were 15.8% (9 participants) and 6.1% (3 participants) just before the genotype announcement, and 7.0% (4 participants) and 10.2% (5 participants) at the follow-up, respectively. All subjects were satisfied with the genotype testing except for two who rather regretted participating, but one of whom actually quit smoking. The present pilot study without controls indicated that the effects of genotype announcements in this framework on smoking cessation were less than might have been expected. The temporary effect of the session on younger smokers may have been due to the participation per se. The potential effects of genotype announcements for heavy smokers should now be examined in studies with adequate controls. |
15546246 | Prostate specific antigen for screening for prostate cancer: an appraisal of Thai reports. | Prostate cancer is the most common cancer in male populations in many parts of the world. It is a slowing growing deadly cancer with very few signs and symptoms in the early stage. For screening, prostate specific antigen (PSA) has been proposed as a marker in the serum. It is widely employed in western countries, but use of PSA for prostate cancer screening in developing Asian countries is not generalized. Here, the author performed an appraisal on the diagnostic properties of serum PSA in screening prostate cancer among the Thais. Four reports from the literature were recruited for further metanalysis of a total of 1,321 cases. The overall diagnostic activity with regard to sensitivity, specificity, false positive and false negative rates, values being 95.8 %, 66.2 %, 33.8 % and 4.2 %, respectively. Therefore the test has good sensitivity, and sufficiently good diagnostic properties for screening when compared to digital rectal examination (DRE). However, serum PSA cannot be used for a definitive diagnosis, for which pathological confirmation is also necessary. |
15546245 | Cumulative risk and trends in prostate cancer incidence in Mumbai, India. | Information relating to cancer incidence trends in a community forms the scientific basis for the planning and organization of prevention, diagnosis and treatment of cancer. We here estimated the cumulative risk and trends in incidence of prostate cancer in Mumbai, India, using data collected by the Bombay Population-based Cancer Registry from the year 1986 to 2000. During the 15 year period, a total of 2864 prostate cancer cases (4.7% of all male cancers and 2.4% of all cancers) were registered by the Bombay Population-based Cancer Registry. For evaluation of the trend, we applied a linear regression model based on the logarithm of the observed incidence rates. The annual percentage changes were also computed for the evaluation. Cumulative incidence rates percentages were calculated by adding up the age specific incidence rates at single ages and then expressed as a percentage. Analysis of the trends in age-adjusted incidence rates of prostate cancer during the period 1986 to 2000 showed no statistically significant increase or decrease and the rates proved stable across the various age groups (00-49, 50-69 and 70+) also. The probability estimates indicated that one out of every 59 men will contract a prostate cancer at some time in his whole life and 99% of the chance is after he reaches the age of 50. The stability in age adjusted-incidence rates indicates that there are no changes in the etiological factors for prostate cancer in Mumbai, India. These findings may be of general interest because changes in diagnostic practices are confounded in the time trends of prostate cancer change in many western countries preventing inferences on the changes in risk. |
15546244 | A case-control study of colorectal cancer in relation to lifestyle factors and genetic polymorphisms: design and conduct of the Fukuoka colorectal cancer study. | A case-control study was designed to elucidate roles of dietary and other behavioral influences, in combination with genetic susceptibility factors (genetic polymorphisms), in colorectal carcinogenesis. Both cases and controls were residents in Fukuoka City and three adjacent areas. Cases were patients undergoing surgery for a first diagnosis of colorectal cancer at 8 hospitals in the study area, and controls were randomly selected in the community by frequency-matching with respect to the expected distribution by sex, age (10-year class), and residence. Dietary and other lifestyle factors were ascertained by in-person interview, and venous blood was obtained for genotyping and possible biochemical measurements. The cases were interviewed at each hospital during the period from 2000 to 2003, and controls were surveyed during the period from 2001 to 2002. A total of 840 cases of colorectal cancer and 833 controls were interviewed with participation rates of 80% for the cases and 60% for the controls. Informed consent to genotyping was obtained from 685 cases and 778 controls. Further details of the design and conduct are described with respect to methodological aspects. |
15546243 | A study of cancer patterns among inpatients of public hospitals in Iran. | Cancer is becoming an increasingly important cause of premature mortality in developing countries as their populations expand and their lifestyle becomes westernized. The aim of this study was to determine the frequency distribution of various neoplasms among Iranian inpatients, their demographic status and length of stay involved in hospitals during 2000-2002. Records of 17447 inpatients who were hospitalized with malignant tumors in Iranian public hospitals during 2000-2002 were studied. The neoplasms had been coded and classified according to International Classification of Diseases, 10th Revision (ICD-10). The frequency distribution of cancer patients was evaluated by age, sex, place of residence and the length of stay at hospital. There were 9470 male patients (54.3%) and 7977 females (45.7%). The mean +/- sd age was 51.2+/-20.6 with a median of 55 years. The average for females (49.4+/-19.2 yrs) was significantly lower than that for males (52.8+/-21.7 yrs) (p<0.001). The five most common cancer sites were the digestive organs (27.6%) followed by lymphoid and haematopoitic tissues (21.4%), breast (10.2%), respiratory and intrathoracic organs (8.8%) and skin (6%). These accounted for 74% of all malignancies. Some 31% of women's cancers were found in breast or genital organs compared to only 7.6% for males. The male/female ratio was 1.19 with the highest being 2.85 for respiratory organs and the lowest being 0.04 for breast. Mean age of male patients with cancer of the digestive organs, respiratory and intrathoracic organs and skin was significantly lower than that of females (p<0.001). The median length of stay of patients in hospitals each time they were admitted was 6 days. Of the cancer patients, 77.7% lived in urban areas which include only 64.5% of the population. Rural patients with skin cancer accounted for 32.1%. In conclusion, the results of this study carry important implications for future health planning strategies and provide a baseline for further studies on the evaluation of malignancies in Iran. |
15546242 | Co-risk factors for HPV infection in Northeastern Thai women with cervical carcinoma. | HPV infection is the main cause of cervical cancer; however, factors that promote and maintain HPV infection are still unclear. This study was designed to search for factors responsible for the HPV infection in Northeastern Thai women. A total of 190 volunteers with a normal histopathologic appearance of cervix as controls (n=100) and with squamous cell cervical carcinoma (SCCA) (n=90) were the subjects. Variables of risk factors including sexual behaviors, history of reproduction, history of sexually transmitted diseases and smoking were conducted with self-report and direct interview. Number of sexual partners and smoking history increased the likelihood of high-risk HPV infection. Multiple sexual partners showed significantly higher 3.94-fold risk for HPV infection (95% CI = 1.82-8.82, p-value<0.001). Smoking history of partner increased the risk for HPV infection 3.03-fold (95%CI=1.42-6.58, p-value< 0.002). After OR were adjusted, significant difference was still observed in the number of sexual partners (p-value <0.0001) and smoking history of the partner (p-value<0.005). To decrease the incidence of cervical cancer, we should prevent HPV dissemination and be on the alert for having multiple sexual partners and a partner's smoking habit, which must be included in our public health planning. |
15546241 | Hodgkin's disease: assessment of treatment and survival rates in Iran. | Each year an estimated of 7,500 new cases of Hodgkin's disease are reported in the United States. It is a type of malignancy, where 75% of patients can recover and be cured with modern therapeutic approaches if presentation is in an early stage. While primary prevention is not a focus of attention, prevention of mortality is thus possible. The main objective of this investigation was to assess the current situation with the disease in Iran, with determination of 5- and 10-year-survival rates. This retrospective, descriptive, analytical and cross-sectional study was performed on patients identified in Tabriz Shahid Ghazi hospital. The information obtained through medical files was organized and the rate of response to treatment and overall survival (OS) were computed. Resulting data were analyzed using SPSS10 and Chi-square software. Overall, there were 121 male patients (67%) and 59 females (33%). The patient age (with a median of 31.8+/-17.1 years) did not show any effect on survival rate. Neck masses were the most common (40%) complaint among new patients, mostly classified as stage III. Mixed cellularity (47.2%) accounted for the most common histological subtype. Complete remission was achieved with the ABVD chemotherapy regimen, included in 37.6% of overall chemotherapy regimens. The five- and 10-year-survival rates were determined to be 65 and 61.3 percent respectively. Chemotherapy was a significantly more effective treatment compared to other modalities, and provided complete remission in 52.7% of patients. Overall, 5- and 10-year-survivals were shown to be highest in patients treated with ABVD and a variant of the MOPP regimen, respectively. As general conclusions, early diagnosis, on time management of the patients, and use of appropriate treatment modalities provide significant prevention of mortality in Hodgkin's disease patients. |
15546240 | Do Japanese take more folate from traditional Japanese dish than is conventionally estimated?-Actual folate contents in hospital diets and marketed lunch boxes. | Folic acid deficiency is very rare in Japan. However, recent concerns in relation to causal relationships between cancer and low folic acid levels necessitate information on actual folate intake by Japanese, which has hitherto not been well studied. We therefore evaluated folate contents of a hospital diet for 7 consecutive days and of 16 lunch boxes purchased at convenience stores. Dietary intake was assessed for weighed food items after cooking using our previously published data on folate contents of various foods and also by using Standard Tables of Food Composition in Japan (STFCJ). Mean daily folate intake from the hospital diet was 723.9 microg/day using our data but only 359.2 microg/day if calculated using the STFCJ. Twenty-nine % of the total daily folate intake was through rice. Mean folate intake through lunch boxes was 491.7 microg/day by our tabulation and 139.5 microg/day with the STFCJ. Folic acid intake of Japanese is far above the levels taken in other countries and over half of this amount is taken from rice. Levels of folic acid contents (especially in rice) listed in the STFCJ are too low and revision is strongly suggested. |
15546239 | An epidemiological study of HBV, HCV and HTLV-I in Sherpas of Nepal. | An epidemiological study of hepatitis viruses type B (HBV) and type C (HCV) and human T-cell leukemia virus type I (HTLV-I) was carried out among 103 residents (male:female=61:42) regarded as Sherpas, at Lukla (Solukhumbu district), Nepal in 2004. Blood was drawn from apparently healthy volunteers at ages of 28.8+12.3 (range 15-66) years. HBsAg, HBsAb, HBcAb, and HCV Ab were measured by microparticle enzyme-immunoassay, and HTLV-I Ab was measured by particle agglutination. Prevalence of HBsAg(+), HBsAb(+), HBcAb(+), and HBsAb(+) or HBcAb(+) were 1.9% 22.3%, 24.3%, and 28.2%, respectively. For HCV Ab, only a borderline reaction was observed in one sample, and for HTLV-I Ab all samples were negative. Nucleotide sequencing of the PreS1, PreS2, and S genes revealed that HBV among Sherpas to be of the A' (or Aa) genotype, which is prevalent among Nepalese but rare in native Tibetans, suggesting transmission within Nepal rather than association with ancestors' migration from Tibet as the origin. This is the first report of Himalayan Sherpas' state of infection with HBV, HCV, and HTLV-I. |
15546238 | Knowledge of the effects of sun exposure of Turkish high school students and their sun bathing habits. | Cancer, long a serious problem in developed countries, is now becoming a serious health concern throughout the world. There has been an alarming increase in the number of new cases of melanoma each year, this cancer increasing at a faster rate than any other neoplasm in some regions. This may be a result of depletion of the ozone layer. An association between non-melanocytic skin cancer and exposure to the sun appears to have first been suggested in 1894; it was not until about 1952 that it was argued that exposure to the sun also causes melanoma. It is commonly believed that skin cancers develop only after long-term exposure to UVR. At the individual level, people who live in sunnier climates comparatively have a higher risk for skin cancer than do people who live in colder climates. This is particularly the case for migrant populations with a fair skin. The present study was conducted to evaluate the knowledge of the young generation in Turkey related to the side effects of sun exposure, and their sun bathing habits. Sun sensitivity, use of sunscreens, sunbathing habits and protective behaviours were determined for a total of 1244 high school students from the answers to a questionnaire completed by them. Data from 627 (50.4 %) females and 617 (49.6 %) males were evaluated. All were aged between 15 and 18 years. Sunscreen use was found to be higher in female students (59 %) than in their male counterparts (45.8 %). The wearing of sunglasses was reported by 36.7 %, whereas the incidence of hat wear was found to be 55.1% overall. The results of this study indicate that, although most high school students are aware of the side effects of sun exposure, they do not pay sufficient attention to protective behaviour. A further study should now be conducted to evaluate the use of sunscreens in a large group. |
15546237 | Allelic variation of GSTT1, GSTM1 and GSTP1 genes in North Indian population. | Glutathione S-transferase (GST) enzymes are involved in detoxification of many potentially carcinogenic compounds. Homozygous deletions or null genotypes of GSTT1 and GSTM1 genes and an A to G substitution at nucleotide 313 in GSTP1 have been reported in different populations. Intra-ethnic as well as interethnic differences are known to exist in the frequencies of the above GST genes. The present study was therefore undertaken to determine the prevalence of GSTM1 and GSTT1null alleles, as well as the GSTP1 gene polymorphism, in 370 healthy individuals in a North Indian population. Genotyping of M1 and T1 was performed using a multiplex polymerase chain reaction and the GSTP1 polymorphism was determined by the polymerase chain reaction/restriction fragment length polymorphism (PCR-RFLP) method. The frequencies of GSTM1 and GSTT1 null alleles in normal healthy individuals were observed to be 33.0% and 18.4% respectively. In 7.0% of individuals' concomitant lack of M1 and T1 genes were observed. For GSTP1, wild (Ile/Ile), heterozygous (Ile/Val) and mutant (Val/Val) genotypes were observed for 44.3%, 50.3% and 5.4% of individuals respectively. The prevalence of the M1 null allele is significantly lower than those documented for English, Turkish, Chinese, Caucasians, Japanese and white (Brazilian and American) populations. However, a significantly higher frequency for T1 null was reported in Chinese and Japanese population. Furthermore, Japanese and African American populations have exhibited significantly higher frequencies of wild and mutant P1 genotypes, respectively, than the Indian population. Thus, our results signify an impact of ethnicity and provide a basis for future epidemiological and clinical studies. |
15546236 | Cervical cancer in the asian pacific-epidemiology, screening and treatment. | Squamous cell carcinoma (SCC) of the cervix continues to be a major problem in many areas of the Asian-Pacific, particularly in the Indian subcontinent and Papua New Guinea, and to a lesser extent in South-East Asia, Korea and Mongolia. In contrast, levels in the developed countries of the region are low, as is also the case for the Muslim countries of Western Asia, and mainland China. Incidence generally mirrora associated mortality, although with some exceptions reflecting facilities and infrastructure for early detection. Over the last 25 years there has been a marked decrease in incidence rates across most of the Asian Pacific, although less pronounced in India than elsewhere, and there are exceptions where the incidence is on the increase. The predominant risk factor is well established to be persistent infection with a high risk 'oncogenic' type of human papilloma virus (HPV), along with multiple partners, other sexually transmitted diseases and smoking. Consumption of vegetables, in contrast, appears to be protective. Hormonal factors may also play some role. Modifying factors may either impact on neoplasia by directly influencing the processes underlying carcinogenesis, or indirectly by affecting persistence of viral infections. For primary prevention, avoidance of repeated infections and smoking, as well as a high antioxidant intake may be beneficial. Vaccines against HPV also have promise for the future, but a better understanding of the mechanisms underlying spontaneous clearance of both infection and cervical intraepithelial neoplasia (CIN) of different grades is also essential for optimal intervention. For screening, the choice of whether the PAP smear, HPV testing or some form of visual inspection are utilized depends on the resources which are available, all approaches having their own advantages and disadvantages, but with similar sensitivity and specificity. One complication is the increase in adenocarcinoma of the cervix which has been reported in some countries, for which risk factors and most effective screening may differ from the SCC case. A focus on high risk groups like sex workers might be warranted where financial and technical support are limited. If cervical intraepithelial neoplasias are detected then cryotherapy or the loop electrosurgical excision procedure (LEEP) are effective for their removal. Control of cancer of the cervix, however, demands that a comprehensive approach to screening and management is adopted, necessitating major training of personnel and provision of appropriate resources. |
15546234 | Gender and the natural history of self-rated health: a 59-year longitudinal study. | Self-ratings of health are uniquely predictive of morbidity and mortality, and they encompass people's evaluations of many medical, psychological, and social conditions in their lives. However, the longitudinal trajectory of self-rated health has not been evaluated to date. In the present study, 59-year longitudinal multilevel analyses (1940-1999) of data from 1,411 men and women revealed that self-rated health was relatively stable until age 50 and then began to decrease in an accelerating fashion through the rest of the life course. Men had higher self-rated health throughout most of adulthood than did women but had steeper linear rates of decline. As a result, the gender difference in self-rated health disappeared by late adulthood. |
15546233 | Repression and high anxiety are associated with aberrant diurnal cortisol rhythms in women with metastatic breast cancer. | Previous research has provided evidence of autonomic, endocrine, and immunological dysregulation in repressers and a possible association with cancer incidence and progression. Recently published data from the authors' laboratory demonstrated that flatter diurnal cortisol slopes were a risk factor for early mortality in women with metastatic breast cancer. In the current analysis of this same sample (N=91), the authors tested differences at baseline between groups scored using the Weinberger Adjustment Inventory on diurnal cortisol slope and mean cortisol levels. When compared with self-assured and nonextreme groups, the represser and high-anxious groups had a significantly flatter diurnal slope. Diurnal slope was similar for repressers and high-anxious groups. Groups did not differ on mean cortisol levels, nor did they differ on intercept (morning) values. |
15546232 | Relationships among health factors and everyday problem solving in african americans. | This study examined whether measures of health status enhance the prediction of performance on everyday problem solving in adult African Americans. The sample consisted of 209 community-dwelling African American adults with a mean age of 66.82 years (SD=7.95). The following variables were included in the analysis: Everyday Problems Test (EPT), summary index of chronic illnesses (cardiovascular disease, hypertension, arthritis, stroke, and diabetes), self-rated health (current health, health in the past month, health compared with others, health compared with 5 years ago), and demographic information. Using hierarchical regression and follow-up communality analysis, the authors found that the number of chronic illnesses and self-rated health as compared with 5 years prior were significant and unique predictors of performance on the EPT but did not account for all of the demographic-related variance. The results indicate that health indices contribute to the variability in everyday cognition in this understudied population. |
15546231 | Hostility and distraction have differential influences on cardiovascular recovery from anger recall in women. | This study investigated the relation of dispositional hostility to cardiovascular reactivity during an anger-recall task and of hostility and distraction to posttask recovery in 80 healthy women (ages 18-30). Half were randomly assigned to distraction during recovery. Hostility predicted slower systolic blood pressure and preejection period during recovery. Distraction was related to faster cardiac recovery, higher high-frequency (HF) power, lower low-frequency (LF) power and LF:HF ratios, and lower state anger and rumination during recovery. These results indicate deleterious influences of hostility on cardiovascular recovery but not during anger recall. The findings also show beneficial effects of distraction in expediting cardiovascular recovery, possibly through reducing rumination and anger. |
15546230 | Psychological response to test results in an ovarian cancer screening program: a prospective, longitudinal study. | To identify the psychological impact of receipt of an abnormal yet benign screening test result, the authors examined the response to a transvaginal ultrasound screening (TVS) test for ovarian cancer (OC) in asymptomatic women (N=540) undergoing an initial TVS screening test. Interviews were conducted prior to undergoing TVS screening and at 2 weeks and 4 months following this baseline. Women receiving an abnormal yet benign TVS test result (n=33) reported elevated OC-specific, but not general, distress at 2-week follow-up. Distress returned to baseline levels at 4-month follow-up. Consistent with the monitoring process and cognitive-social health information processing models, response to an abnormal TVS result was moderated by a monitoring coping style, low optimism, and a family history of OC. |
15546229 | Latent growth curve analyses of peer and parent influences on smoking progression among early adolescents. | Social influences on smoking uptake were examined in latent growth curve analyses of data from 1,320 youths assessed 5 times during 6th to 9th grade. Initial smoking stage predicted increases in number of friends who smoked, indicating selection; however, initial number of friends who smoked did not predict smoking stage progression, indicating no significant effect of socialization. Associations over time among smoking stage progression, affiliation with friends who smoke, and parenting behaviors were significant, suggesting dynamic, reciprocal relationships. Parental involvement, monitoring, and expectations provided direct protective effects against smoking progression as well as indirect effects, by limiting increases in number of friends who smoke. These results are consistent with the peer selection hypothesis, confirm the powerful association over time of social influences with smoking, and provide the first evidence that parenting behavior may protect against smoking progression by limiting increases in number of friends who smoke. |
15546228 | Is it beneficial to involve a family member? A meta-analysis of psychosocial interventions for chronic illness. | Links between chronic illness and family relationships have led to psychosocial interventions targeted at the patient's closest family member or both patient and family member. The authors conducted a meta-analytic review of randomized studies comparing these interventions with usual medical care (k=70), focusing on patient outcomes (depression, anxiety, relationship satisfaction, disability, and mortality) and family member outcomes (depression, anxiety, relationship satisfaction, and caregiving burden). Among patients, interventions had positive effects on depression when the spouse was included and, in some cases, on mortality. Among family members, positive effects were found for caregiving burden, depression, and anxiety; these effects were strongest for nondementing illnesses and for interventions that targeted only the family member and that addressed relationship issues. Although statistically significant aggregate effects were found, they were generally small in magnitude. These findings provide guidance in developing future interventions in this area. |
15546227 | Finding benefit in breast cancer during the year after diagnosis predicts better adjustment 5 to 8 years after diagnosis. | Cancer patients experience positive as well as adverse consequences from diagnosis and treatment. The study reported here examined longer term reverberations of such experiences. A set of benefit-finding items along with measures of well-being were completed by 230 early-stage breast cancer patients in the year postsurgery. Four to 7 years later, 96 of them again completed measures of well-being. Controlling for initial distress and depression, initial benefit finding in this sample predicted lower distress and depression at follow-up. |
15546226 | Relationship of social support and social burden to repeated breast cancer screening in the women's health initiative. | Direct and interactive effects of social support, social burden (caregiving, negative life events, and social strain), education, and income on repeated use of breast cancer screening among a large (N=55,278), national sample of postmenopausal women participating in the Women's Health Initiative observational study were examined. Repeated screening decreased as emotional/informational support and positive social interactions decreased (ps<.01). Repeated mammography decreased with frequent caregiving (p<.01). Less social strain reduced the frequency of repeated breast self-examinations (BSEs; ps<.01), but frequent caregiving and more negative life events increased repeated use of BSE (ps<.01). Interactive effects suggested that emotional/informational but not tangible support is associated with repeated mammography and clinical breast examinations (ps<.01) and may be particularly important among low-income older women, especially those burdened by caregiving. |
15546225 | Psychological and social predictors of changes in fruit and vegetable consumption over 12 months following behavioral and nutrition education counseling. | This study assessed psychological and social factors predicting 12-month changes in fruit and vegetable consumption achieved by 271 men and women from a low-income population randomized to brief behavioral and nutrition education counseling. Greater increases in fruit and vegetable intake were achieved in the behavioral than in the nutrition education condition (1.49 vs. 0.87 portions per day, p=.021). Increases were predicted by baseline social support for dietary change but not by baseline psychological measures. However, short-term (8-week) changes in dietary self-efficacy, encouragement, anticipated regret, perceived benefits, and knowledge of recommended intake predicted 12-month changes in fruit and vegetable consumption independently of gender, age, ethnicity, income, and baseline intake. These factors accounted for 51% of the superiority of behavioral counseling over nutrition education. |
15546224 | A longitudinal analysis of the course of depressive symptomatology in geriatric patients with cancer of the breast, colon, lung, or prostate. | This study mapped the trajectory of depression and its components (depressive mood, somatic expression of depression, and lack of positive affect) for 1 year after an initial cancer diagnosis, revealing the complex nature of the psychological response to the cancer experience. The analysis was based on 4 waves of panel data from 860 older patients with incident breast, colon, lung, or prostate cancer. Predictors of depressive symptoms included cancer site; stage; comorbidities; sociodemographic characteristics; and indicators of physical functioning, symptom severity, and treatment. Patients' overall depressive symptoms declined, especially depressive mood and somatic indicators. By contrast, the sense of well-being did not recover; in fact, it would have deteriorated without improvements in physical functioning and physical symptoms. The present findings show the importance of psychological assessments and symptom management during cancer treatment. |
15546223 | Written emotional disclosure buffers the effects of social constraints on distress among cancer patients. | The aims of the present study were to examine whether written emotional disclosure would reduce distress among cancer patients and whether it would buffer the effects of high levels of social constraint (negative social responses to patients' expressions of emotion regarding their cancer) on distress. Cancer patients (N=104) were randomly assigned to write about their emotions regarding their cancer 20 min a day for 3 days or to write about a nonemotional topic. They completed questionnaires at baseline and 6 months postintervention. Results showed that written disclosure buffered the effects of social constraints on stress at the 6-month follow-up and that avoidance partly mediated these effects. The present data reinforce the notion that interventions should be tailored to patients' needs. |
15546222 | Quality improvement in the continuum of care: impact of atherothrombosis in managed care pharmacy. | To review the clinical and economic impact of atherothrombosis, the use of antiplatelet therapy for patients with atherothrombosis, and the impact of disease management programs on quality improvement and health care costs. Atherothrombosis is a new term that describes the formation of a thrombus on an existing atherosclerotic plaque. While simple, this pathophysiologic mechanism underlies a vast array of vascular diseases, including myocardial infarction, ischemia, peripheral arterial disease, vascular death, and many forms of stroke. In fact, atherothrombosis is the leading cause of death worldwide. Treatment approaches include lifestyle modification and the use of pharmacologic agents such as lipid-lowering therapy, antihypertensive agents, hypoglycemic therapy, ACE inhibitors, and beta-blockers. Despite these treatments, studies have indicated that not all patients receive recommended therapies. The continuing upward spiral in health care costs in the United States has spurred numerous initiatives aimed at improving the quality of care while maintaining or reducing costs. Among these approaches to quality improvement are programs that promote adherence to evidence-based clinical data, including published guidelines, and improve the appropriate use of pharmaceuticals. Although expenditures for prescription drugs are rising, they remain a minority of overall health care expenditures, and evidence suggests that improved usage of medications can reduce other direct costs, such as hospitalizations and inpatient care, which may account for a far greater proportion of total costs. The utilization of quality improvement techniques and disease management tools can be used to improve the quality of care of patients with atherothrombosis. A key component of this strategy is pharmacologic therapy. The appropriate use of prescription drugs involves several key factors, including the proper selection of the agent based on available clinical evidence, choosing regimens that enhance patient compliance, and sound methodologies to evaluate outcomes. Improvements in the quality of care for patients with atherothrombosis can have a significant impact on the overall quality of health care as well as total costs. |
15546221 | Targeted therapies in the treatment of colorectal cancer: what managed care needs to know. | This review is designed to explore the disease, its current treatment, the expanding field of antiangiogenic treatments, and the implications of these advances for the managed care patient. This article is based, in part, on presentations given by the authors in a continuing education symposium presented during the Academy of Managed Care Pharmacy.s 16th Annual Meeting and Showcase, April 1, 2004, in San Francisco. Colorectal cancer (CRC) is the third most common cancer in the United States, and the second-leading non.gender-specific cause of cancer deaths. If the cancer is caught soon enough (before node involvement and metastasis occur), there is a strong chance of survival; however, only slightly more than one third of cases are detected that soon. Emerging treatments that target only the cancer cells are increasing the length of survival for those who are diagnosed at later stages of the disease. |
15546220 | Estimating the number of bound waters in Gd(III) complexes revisited. Improved methods for the prediction of q-values. | Two literature computational methods for the prediction of the number of inner-sphere aqua ligands, q, have been applied to a test set of seven Gd(aminocarboxylate) complexes. The first method is based on the hypothesis that q should be proportional to the solvent-accessible surface area of the ligand-complexed Gd ion (Castonguay, L. A., Treasurywala, A. M., Caulfield, T. J., Jaeger, E. P., and Kellar, K. E. (1999) Prediction of q-Values and Conformations of Gadolinium Chelates for Magnetic Resonance Imaging. Bioconjugate Chem. 10, 958). The second method is based on the hypothesis that q-values can be deduced by examining series of steric energy versus ionic radii plots as a function of coordination number (Reichert, D. E., Hancock, R. D., and Welch, M. J. (1996) Molecular Mechanics Investigation of Gadolinium(III) Complexes. Inorg. Chem. 35, 7013). This study identifies deficiencies in these methods and, with respect to the first method, describes some apparent errors. Although neither method was reliable at predicting q, two alternate approaches based on either molecular mechanics strain thresholds or exposed Gd surface area thresholds are shown to predict observed q-values for all Gd aminocarboxylate complexes in the test set. |
15546219 | Targeted molecular imaging agents for cellular-scale bimodal imaging. | Molecular imaging is a powerful tool that has the ability to elucidate biochemical mechanisms and signal the early onset of disease. Overexpression of the peripheral benzodiazepine receptor (PBR) has been observed in a variety disease states, including glioblastoma, breast cancer, and Alzheimer's disease. Thus, the PBR could be an attractive target for molecular imaging. In this paper, the authors report cellular uptake and multimodal (MRI and fluorescence) imaging of PBR-overexpressing C6 glioblastoma (brain cancer) cells using a cocktail administration approach and a new PBR targeted lanthanide chelate molecular imaging agent. |
15546218 | Synthesis and properties of fluorescent NF-kappa B-recognizing hairpin oligodeoxyribonucleotide decoys. | Intramolecular fluorescence quenching of cyanine dyes was investigated using a model hairpin oligonucleotide decoy encoding a NF-kappaB p50 subunit binding site. Two types of hairpin oligonucleotides were synthesized: (1) 5'-(6-aminohexyl)- and 3'-(3-aminopropyl)-linked (I); (2) 5'-(6-aminohexyl)- and 3'-[3-(3-hydroxypropyldithio)propyl]-linked (II). Oligonucleotide I was covalently modified using monofunctional either Cy3- or Cy5.5-N-hydroxysuccinimide esters. Using reverse-phase HPLC, mono-and dicyanineamide derivatives of I were isolated. Mono-Cy3-modified derivatives of I, but not the mono-Cy5.5-modified derivatives, showed a 2-fold higher Cy3 fluorescence intensity compared to the free dye. There was no detectable difference in fluorescence between the di-Cy3 derivative of I and the free dye at the same concentration. However, there was a 4-fold quenching of fluorescence in the case of the di-Cy5.5 derivative of the same hairpin oligonucleotide. The quenching of Cy5.5 fluorescence could not be explained by the interaction of Cy5.5 with nucleotide bases as demonstrated by incubating free Cy5.5 dye with oligonuclotides. The quenching effect was further investigated using an oligonucleotide bearing a cleavable 3'-amino-terminated linker bearing an S-S bond (III). After modification of the 5'- and 3'-end of oligonucleotide III with a Cy5.5 monofunctional hydroxysuccinimide ester, a 70-75% quenching of fluorescence was observed. Fluorescence was 100% dequenched after the reduction of S-S bond. The obtained result unequivocally demonstrates that the formation of intramolecular Cy5.5 dimers is the dominant mechanism of fluorescence quenching in symmetric dye-dye hairpin decoy beacons. |
15546217 | Evidence of antisense tumor targeting in mice. | Even though increased accumulations of radiolabeled antisense DNAs compared to control DNAs are becoming a routine observation in cultured tumor cells, trustworthy evidence of tumor targeting in vivo by an antisense mechanism remains elusive. The goal of this study was to obtain convincing evidence of antisense tumor targeting in nude mice by using two different tumors and both intratumoral (i.t.) and intravenous (i.v.) administration of radiolabeled antisense and control sense DNAs. Both the MDR++ cell line KB-G2 and its parent MDR+ cell line KB-31 were used in this study. The antisense (AS) DNA was directed against the AUG start codon of the MDR1 mRNA and, along with the sense (S) control DNA, was a uniform phosphorothioate administered naked. In previous cell culture studies from our laboratories, the accumulation of this AS DNA was strikingly high in KB-G2 cells and only average in KB-31 cells, a fact we attribute to the 1000-fold higher expression by RT-PCR of MDR1 mRNA in the former cell line. In this study, both DNAs were radiolabeled with (99m)Tc via MAG3 and administered i.t. or i.v. at 1 microg (100 microCi) per animal 24 h prior to sacrifice and dissection in mice bearing thigh tumors of about 1 g. Following i.t. administration, no statistically significant differences (Student's t test, p < 0.05, N = 4) between the AS and S DNA biodistributions in normal tissues were observed except in the KB-G2 mice in which muscle levels were lower for the S control. In contrast, tumor levels in the KB-G2 animals were significantly higher for the AS DNA vs S DNA (14.7 vs 8.5% ID/g) while this difference (8.6 vs 4.3% ID/g) was insignificant in the KB-31 animals. The whole body images obtained just prior to sacrifice clearly show improved targeting of AS DNA vs S DNA in the KB-G2 but not the KB-31 animals. Calculations based on these results show that about 60 000 AS DNAs accumulated specifically (i.e. AS DNA - S DNA) per KB-G2 tumor cell following i.t. administration. When administered i.v. rather than i.t., higher tumor levels in KB-G2 animals compared to KB-31 were not observed, most likely because of the lower dosage reaching the tumors. When the KB-G2 and KB-31 results are combined, no statistically significant differences between the AS and S DNA biodistributions in normal tissues were observed except in blood in which S DNA levels were higher and in spleen in which they were lower. In contrast, tumor levels were significantly higher for the AS DNA vs S DNA (0.100 vs 0.063% ID/g). Calculations based on these results show that about 400 AS DNAs accumulated specifically per tumor cell following i.v. administration. Therefore evidence for tumor targeting in vivo by an antisense mechanism has been obtained in that statistically higher tumor accumulations of the (99m)Tc-AS DNA were observed compared to the control (99m)Tc-S DNA both following i.t. and i.v. administrations. The successful localization of AS DNA in tumor demonstrates that in vivo AS targeting of tumor is feasible although improvements in tumor delivery and normal tissue clearance are needed for practical antisense imaging. |
15546216 | Radiopharmaceuticals for assessment of multidrug resistance P-glycoprotein-mediated drug transport activity. | Multidrug resistance (MDR) mediated by overexpression of MDR1 P-glycoprotein (Pgp) is one of the best characterized transporter-mediated barriers to successful chemotherapy in cancer patients. Thus, noninvasive interrogation of Pgp-mediated transport activity in vivo would be beneficial in guiding therapeutic choices. Both small organic medicinals as well as metal complexes characterized as transport substrates for Pgp are amenable to incorporation of PET or SPECT radionuclides and may enable noninvasive imaging of Pgp in cancer patients. Toward this objective, clinically approved agents, exemplified by (99m)Tc-Sestamibi and (99m)Tetrofosmin, have already shown promise for the functional evaluation of Pgp-mediated transport activity in human tumors in vivo. In addition, selected agents from an upcoming class of substituted Schiff-base gallium(III) complexes containing an N(4)O(2) donor core in their organic scaffold and capable of generating both SPECT and PET radiopharmaceuticals have also been shown to be promising for noninvasive assessment of Pgp activity in vitro and in vivo. |
15546215 | Streptavidin in antibody pretargeting. 4. Site-directed mutation provides evidence that both arginine and lysine residues are involved in kidney localization. | The in vivo application of the protein streptavidin is limited by its propensity to localize to kidney, particularly when it is used as a carrier of radionuclides in Targeted Radionuclide Therapy. Our previous studies demonstrated that modification of recombinant "core" streptavidin (rSAv) by reaction of lysine residues with succinic anhydride and arginine residues with 1,2-cyclohexanedione dramatically decreases the kidney concentrations over that obtained with wild-type rSAv. In this investigation, we explored the role of lysine and arginine residues in kidney localization further by evaluating site-directed mutants of rSAv. In the five mutants studied, the four lysine residues found in each subunit of rSAv were replaced (independently) with an alanine (K80A, K121A, K132A, K134A), and a specific arginine was replaced with a histidine (R59H). The rSAv mutants were prepared from a "core" rSAv construct produced by expression in E. coli that had 124 amino acids (residues 13-136). Another rSAv construct that had 127 amino acids (residues 13-139), used in most of our previous studies, was also included for comparison. As an additional comparison, succinylated rSAv was prepared and evaluated. The rSAv proteins were radioiodinated and injected into athymic mice that were on a biotin-free diet for 5-7 days prior, and biodistribution data were obtained (for most proteins) at 1, 4, 24, and 48 h postinjection. The data obtained show large differences in kidney localizations of the wild-type rSAv and some rSAv mutants. The largest difference in the kidney concentration was noted for the rSAv-K134A mutant (1.90 +/- 0.22%ID/g; 24 h pi) as compared to the wild-type rSAv (31.83 +/-5.26%ID/g) at the same time point. The concentration of rSAv-K134A mutant in kidney was slightly lower than that obtained with succinylated rSAv. At the 24 h time point, the kidney concentrations of the rSAv-R59H mutant (8.95 +/- 2.94%ID/g) and the rSAv-K121A mutant (11.86 +/- 1.61%ID/g) were lower than wild-type rSAv, but the rSAv mutants rSAv-K80A (27.95 +/- 1.82%ID/g) and rSAv-K132A (32.50 +/- 10.09%ID/g) were essentially the same. The data suggests that specific lysine and arginine residues are involved in kidney localization. Possible mechanisms for the observed kidney localization are discussed. |
15546214 | 18F-fluorothiols: a new approach to label peptides chemoselectively as potential tracers for positron emission tomography. | [(18)F]Fluorothiols are a new generation of peptide labeling reagents. This article describes the preparation of suitable methanesulfonyl precursors and their use in no-carrier-added radiosyntheses of (18)F-fluorothiols. The preparations of (3-[(18)F]fluoropropylsulfanyl)triphenylmethane, (2-[2-[2-(2-[(18)F]fluoroethoxy)ethoxy]ethoxy]ethylsulfanyl)triphenylmethane, and 4-[(18)F]fluoromethyl-N-[2-triphenylmethanesulfanyl)ethyl]benzamide starting from the corresponding methanesulfonyl precursors were investigated. Following the removal of the triphenylmethane protecting group, the (18)F-fluorothiols were reacted with the N-terminal chloroacetylated model peptide ClCH(2)C(O)-LysGlyPheGlyLys. The corresponding radiochemical yields of (18)F-labeled isolated model peptide, decay-corrected to (18)F fluoride, were 10%, 32%, and 1%, respectively. These results indicate a considerable potential of (18)F-fluorothiols for the chemoselective labeling of peptides as tracers for positron emission tomography (PET). |
15546213 | Preparation and properties of 99mTc(CO)3+-labeled N,N-bis(2-pyridylmethyl)-4-aminobutyric acid. | Labeling biomolecules with (99m)Tc(CO)(3)(+) ((99m)Tc tricarbonyl) is attracting increasing attention. Although histidine is often considered an ideal bifunctional chelator for (99m)Tc (or (188)Re) tricarbonyl, the family of dipicolylamine carboxylate chelators may be a useful alternative because of the expected ease of synthesis and because the structure provides a pendent carboxylate for potential conjugation to biomolecules. The dipicolylamine chelator N,N-bis(2-pyridylmethyl)-4-aminobutyric acid (BPABA) was synthesized using 4-aminobutyric acid in place of glycine or aminopropionic acid in the literature, to avoid possible involvement of the carboxylate in the complex formation process by forming five- or six-membered chelation rings. Using a commercial tricarbonyl kit (Mallinckrodt), the complex formation properties of both BPABA and commercial histidine with (99m)Tc tricarbonyl were investigated, and the in vitro complex stabilities in saline and in serum were compared. Stability in vivo was also examined following i.v. administration to normal mice. BPABA was synthesized simply and quantitatively by reacting picolyl chloride with aminobutyric acid in one step. On RP HPLC, the product eluted essentially in one peak and the structure was confirmed by ESI-MS. After labeling, both BPABA and histidine were shown by RP HPLC to form tricarbonyl complexes. In both cases, after incubation at 100 degrees C for 20 min, only one predominant peak of (99m)Tc(CO)(3)(+)-histidine or (99m)Tc(CO)(3)(+)-BPABA was apparent, and both complexes were stable at room temperature in saline for at least 24 h. After incubation for 24 h in 37 degrees C serum, by SE HPLC, 20% of the (99m)Tc(CO)(3)(+)-histidine was bound to serum protein compared to less than 10% for (99m)Tc(CO)(3)(+)-BPABA. A 5000 molar excess of histidine at 100 degrees C for 6 h was unable to dissociate (99m)Tc(CO)(3)(+)-BPABA. By contrast, BPABA easily dissociated (99m)Tc(CO)(3)(+)-histidine under the same conditions. Both complexes were stable in vivo in mice, and (99m)Tc(CO)(3)(+)-BPABA showed rapid and specific hepatobiliary clearance while (99m)Tc(CO)(3)(+)-histidine was cleared through the kidneys. In conclusion, BPABA was easily synthesized and was shown to possess properties comparable to histidine for labeling of biomolecules with (99m)Tc tricarbonyl. However, it was found that the chelator concentration required for quantitative (99m)Tc tricarbonyl labeling with both BPABA and histidine were 2 orders higher than that required with more conventional labeling using MAG(3). Finally, the complex (99m)Tc(CO)(3)(+)-BPABA itself was found to clear exclusively via the hepatobiliary pathway and may have value as a potential hepatobiliary imaging agent. |
15546212 | Cyclen-based phenylboronate ligands and their Eu3+ complexes for sensing glucose by MRI. | Novel cyclen-based phenylboronate ligands and their corresponding Eu(3+) complexes have been examined as glucose sensors using chemical exchange saturation transfer (CEST) MR imaging for detection. Two isomeric bis-phenylboronate complexes, Eu(4) and Eu(10), and a mono-phenylboronate complex, Eu(12), had been prepared and characterized by UV and circular dichroism spectroscopy, mass spectrometry, and CEST imaging. Both the free ligands and their Eu(3+) complexes bind to simple sugars, but their selectivity and binding affinities vary with sugar structure. Interestingly, the free ligands, 4 and 10, are selective for fructose over glucose, but this selectivity order switches in the respective Eu(3+) complexes. Of the complexes examined, Eu(4) shows the highest selectivity and binding affinity for glucose (2275 +/- 266 M(-)(1) at pH 10.2 and 339 +/- 29 M(-)(1) at pH 7). Glucose acts as a "capping"moiety in the Eu(4).glucose binary complex and modulates water exchange between a single Eu(3+)-bound water molecule and bulk water, an effect that can be detected by CEST imaging. Thus, Eu(4) represents a new class of metabolite-specific imaging agents that may allow mapping of metabolites by MRI of the bulk water signal. |
15546211 | PEG-g-poly(GdDTPA-co-L-cystine): a biodegradable macromolecular blood pool contrast agent for MR imaging. | Biodegradable PEGylated Gd-DTPA l-cystine copolymers, PEG-g-poly(GdDTPA-co-l-cystine), were prepared and tested as a blood pool contrast agent in mice. The biodegradable macromolecular agent was designed to be broken down into smaller Gd complexes by endogenous thiols via the disulfide-thiol exchange reaction to facilitate the clearance of Gd complexes after the contrast-enhanced MRI examination. Gd-DTPA l-cystine copolymers were synthesized by condensation polymerization of l-cystine and DTPA-dianhydride in water followed by chelating with Gd(OAc)(3). MPEG-NH(2) (MW = 2000) was then conjugated to the polymeric backbone in different ratios. The macromolecular contrast agent was readily degraded with the incubation of l-cysteine. It also demonstrated superior contrast enhancement in the heart and blood vessels as compared to a low molecular weight control agent, Gd-(DTPA-BMA). At 1 h postcontrast, the PEGylated macromolecular agent still showed prominent enhancement, while little contrast enhancement was detectable in the blood pool by the control agent. PEG-g-poly(GdDTPA-co-l-cystine) shows promise as an MR blood pool imaging agent. |
15546210 | A new high affinity technetium analogue of bombesin containing DTPA as a pharmacokinetic modifier. | The bombesin (BN)/gastrin-releasing peptide (GRP) receptor is expressed in high density on the cell surface of a variety of tumors. This makes the receptors accessible as a molecular target for the detection of lesions in which they are expressed. In this study, we describe a high affinity hydrophilic (99m)Tc-labeled BN analogue, [DTPA(1), Lys(3)((99m)Tc-Hx-DADT), Tyr(4)]BN, having diethylenetriaminepentaacetic acid (DTPA), as a build-in pharmacokinetic modifier, to direct its excretion through the urinary system in order to lower abdominal background activity. In vitro binding studies using [(125)I-Tyr(4)]BN (K(d), 0.1 nM) and human prostate cancer PC-3 cell membranes showed that the inhibition constant (K(i)) of [DTPA(1), Lys(3)((99)Tc-Hx-DADT), Tyr(4)]BN was 19.9 +/- 8.0 nM. Biodistribution studies in normal mice showed fast blood clearance (0.15 +/- 0.01% ID/g, 4 h postinjection), low intestinal accumulation (9.16 +/- 2.35% ID/g, 4 h postinjection), and significant uptake in BN/GRP receptor rich tissues such as the pancreas (21.83 +/- 2.88% ID/g, 15 min postinjection). The pancreas/blood, pancreas/muscle, and pancreas/liver ratios were highest at 2 h postinjection at 23, 74, and 8.4, respectively. The uptake in the pancreas could be blocked by BN (11.96 +/- 1.17 vs 0.65 +/- 0.16% ID/g), partially blocked by neuromedin B (11.96 +/- 1.17 vs 6.66 +/- 0.51% ID/g), but not affected by somatostatin (11.96 +/- 1.17 vs 12.91 +/- 2.53% ID/g), indicating that the binding of [DTPA(1), Lys(3)((99m)Tc-Hx-DADT), Tyr(4)]BN to the receptors was specific. Scintigraphic imaging of human PC-3 prostate cancer xenografts in SCID mice gave a high target to nontarget ratio on the image. Thus, [DTPA(1), Lys(3)((99m)Tc-Hx-DADT), Tyr(4)]BN has the potential for imaging BN/GRP receptor-positive lesions. |
15546209 | Synthesis and characterization of poly(L-glutamic acid) gadolinium chelate: a new biodegradable MRI contrast agent. | Most currently evaluated macromolecular contrast agents for magnetic resonance imaging (MRI) are not biodegradable. The goal of this study is to synthesize and characterize poly(l-glutamic acid) (PG) gadolinium chelates as biodegradable blood-pool MRI contrast agents. Two PG chelates of gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) were synthesized through the use of difunctional and monofunctional DTPA precursors. The conjugates were characterized with regard to molecular weight and molecular weight distribution, gadolinium content, relaxivity, and degradability. Distributions of the polymeric MRI contrast agents in various organs were determined by intravenous injection of (111)In-labeled polymers into mice bearing murine breast tumors. MRI scans were performed at 1.5 T in mice after bolus injection of the polymeric chelates. PG-Hex-DTPA-Gd, obtained from aminohexyl-substituted PG and DTPA-dianhydride, was partially cross-linked and was undegradable in the presence of cathepsin B. On the other hand, PG-Bz-DTPA-Gd synthesized directly from PG and monofunctional p-aminobenzyl-DTPA(acetic acid-tert-butyl ester) was a linear polymer and was degradable. The relaxivities of the polymers at 1.5 T were 3-8 times as great as that of Gd-DTPA. Both polymers had high blood concentrations and were primarily accumulated in the kidney. However, PG-Bz-DTPA-Gd was gradually cleared from the body and had significantly less retention in the blood, the spleen, and the kidney. MRI with PG-Bz-DTPA-Gd in mice showed enhanced vascular contrast at up to 2 h after the contrast agent injection. The ability of PG-Bz-DTPA-Gd to be degraded and cleared from the body makes it a favorable macromolecular MRI contrast agent. |
15546208 | Developing a peptide-based near-infrared molecular probe for protease sensing. | Recently near-infrared (NIR) molecular probes have become important reporter molecules for a number of types of in vivo biomedical imaging. A peptide-based NIR fluorescence probe consisting of a NIR fluorescence emitter (Cy5.5), a NIR fluorescence absorber (NIRQ820), and a protease selective peptide sequence was designed to sense protease activity. Using a MMP-7 model, we showed that NIRQ820 efficiently absorbs the emission energy of Cy5.5 resulting in a low initial signal. Upon reacting with its target, MMP-7, the fluorescence signal of the designed probe was increased by 7-fold with a K(cat)/K(m) of 100 000 M(-)(1) s(-)(1). The described synthetic strategy should have wide application for other NIR probe preparations. |
15546207 | Irreversible engineering of the multielement-binding antibody 2D12.5 and its complementary ligands. | Engineering the permanent formation of a receptor-ligand complex has a number of potential applications in chemistry and biology, including targeted medical imaging and therapy. Starting from the crystal structure of the rare-earth-DOTA binding antibody 2D12.5 (Corneillie, T. M., Fisher, A. J., and Meares, C. F. (2003) J. Am. Chem. Soc. 125, 15039-15048), we used the site-directed incorporation of cysteine nucleophiles at the periphery of the antibody's binding site, paired with the chemical design of a weakly electrophilic ligand, to produce a receptor-ligand pair that associates efficiently and permanently. Protein residues proximal to the ligand's side chain were identified for engineering cysteine mutants. Fab fragments incorporating a cysteine at position 54, 55, or 56 of the heavy chain (complementarity determining region 2) were designed from the structure and then cloned, expressed in Drosophila S2 cells, and tested for reactivity with mildly electrophilic DOTA-yttrium ligands. All showed permanent binding activity, indicating that there is some tolerance for the location of the reactive mutant on the protein surface near the binding site. The G54C Fab mutant displayed the highest expression levels and permanent binding activity in initial experiments and was produced in high yield for further study. Upon examining the behavior of the G54C mutant with a small set of electrophilic ligands, differences in reactivity were observed which indicated that the substituents near the electrophilic atom can be important determinants of permanent binding. The G54C mutant permanently attaches to Y(3+) complexes of (S)-2-(4-acrylamidobenzyl)-DOTA with a half-time of approximately 13 min at 37 degrees C, making it potentially useful for in vivo pretargeting applications. |
15546206 | Converting weak binders into infinite binders. | Monoclonal antibody 2D12.5 binds DOTA chelates of all the rare earths with K(d) approximately 10(-)(8) M, making it useful for the capture of probe molecules with a variety of properties. To make 2D12.5 even more useful for biological applications, we have engineered a single cysteine residue at position 54 of the heavy chain, a site proximal to the protein's binding site, so that weakly electrophilic metal complexes of (S)-2-(4-acrylamidobenzyl)-DOTA (AABD) may bind and form permanent linkages. At 37 degrees C, pH 7.5, all of the rare earth-AABD complexes bind permanently to the 2D12.5 G54C mutant within 5 min, in yields that correlate with their relative binding affinities. Surprisingly, indium-AABD also binds permanently in >50% yield within 5 min, despite the fact that changing the metal to indium reduces the affinity approximately 100x; even copper-AABD, which has approximately 10 000x lower binding affinity than the rare earths, binds permanently in >70% yield within 2 h. However, acrylamido compounds with no measurable affinity do not bind permanently. The important practical implication is that the G54C mutant of 2D12.5 may be used for applications that include not only the rare earths, but also an unexpected range of other elements as well. This infinite binding system can exhibit selective and permanent attachment with a remarkable range of structurally related ligands, albeit at slower rates as affinities decrease. |
15546205 | Multimodality in vivo molecular-genetic imaging. | Multimodality imaging is increasingly being used in molecular-genetic studies in small animals. The coupling of nuclear and optical reporter genes represents the beginning of a far wider application of this technology. Optical imaging and optical reporter systems are cost-effective and time-efficient, they require less resources and space than PET or MRI, and they are particularly well suited for small animal imaging and for in vitro assays to validate different reporter systems. However, optical imaging techniques are limited by depth of light penetration and scatter and do not yet provide optimal quantitative or tomographic information. These issues are not limiting for PET- or MRI-based reporter systems, and PET- and MRI-based animal studies are more easily generalized to human applications. Many of the shortcomings of each modality alone can be overcome by the use of dual- or triple-modality reporter constructs that incorporate the opportunity for PET, fluorescence and bioluminescence imaging. We optimistically expect that some form of tomographic, small animal optical imaging capability will be developed soon, and that this will provide the opportunity for the colocalization of optical signals to anatomical structures provided by tomographic CT and MR imaging. |
15546204 | In vitro cytotoxicity and in vivo distribution after direct delivery of PEG-camptothecin conjugates to the rat brain. | Low water solubility and rapid elimination from the brain inhibits local delivery via implants and other delivery systems of most therapeutic drugs to the brain. We have conjugated the chemotherapy drug, camptothecin (CPT), to poly(ethylene glycol) (PEG) of molecular weight 3400 using previously established protocols. These new conjugates are very water-soluble and hydrolyze at a pH-dependent rate to release the active parent drug. We have studied the uptake of these conjugates by cells in vitro and quantified their cytotoxicity toward gliosarcoma cells. These conjugates were loaded into biodegradable polymeric controlled-release implants, and their release characteristics were studied in vitro. We implanted similar polymeric disks into rat brains and used a novel sectioning scheme to determine the concentration profile of CPT in comparison to conjugated CPT in the brain after 1, 7, 14, and 28 days. We have found that PEGylation greatly increases the maximum achievable drug concentration and greatly enhances the distribution properties of CPT, compared to corelease of CPT with PEG. Although only one percent of CPT in the conjugate system was found in the hydrolyzed, active form, drug concentrations were still significantly above cytotoxic levels over a greater distance for the conjugate system. On the basis of these results, we believe that PEGylation shows great promise toward increasing drug distribution after direct, local delivery in the brain for enhanced efficacy in drug treatment. |
15546203 | Design of metalloporphyrin-carbohydrate conjugates for a new superoxide dismutase mimic with cellular recognition. | Metalloporphyrin-carbohydrate conjugates have been synthesized as superoxide dismutase (SOD) mimics with cellular recognition. To synthesize the conjugates, aliphatic primary amino groups for conjugation were introduced, with the cationic pyridyl groups for the SOD activity of porphyrin preserved. The reductive amination between introduced amino groups and the reducing end of lactose was then carried out. The resulting conjugates consisting of manganese (Mn)-porphyrin surrounded by several lactose molecules possessed significant SOD activity and low cytotoxicity. Compared with metalloporphyrins having no lactose molecule, the recognition of the resulting conjugates by human hepatoma HepG2 cells increased. The cellular recognition was inhibited by competitors of beta-galactose. These results suggest that the Mn-porphyrin-lactose conjugates recognized the hepatic lectin on the cell surface. |
15546202 | Synthesis and biological activity of water-soluble maleimide derivatives of the anticancer drug carboplatin designed as albumin-binding prodrugs. | Four platinum (II) complexes (13-16) were synthesized by reacting either [Pt trans-DACH](NO(3))(2) with a 6-maleimidocaproic acid, a 15-maleimido-4,7,10,13-tetroxapentadecanoic acid, and a 6-maleimido-4-oxacaproic ester derivative of cyclobutane-1,1-dicarboxylic acid (CDBA) or [Pt(NH(3))(2)](NO(3))(2) with a 6-maleimido-4-oxacaproic ester derivative of CBDA. Both complexes containing the 6-maleimido-4-oxacaproic ester (15, 16) showed good water solubility (>/=8 mg/mL) and CE experiments revealed rapid binding to human serum albumin and the formation of biadducts with dGMP and dAMP. In the MaTu xenograft model in nude mice, both complexes showed an improved antitumor effect at their maximum tolerated dose (2 x 50 mg/kg carboplatin equivalents) compared to therapy with carboplatin at equimolar dose or at its optimal dose (2 x 75 mg/kg). |
15546201 | DNA complexing lipopolythiourea. | We present a neutral lipopolythiourea (DTTU) as a potential DNA-binding agent. Light scattering experiments showed that mixing a lipopolythiourea with dipalmitoylphosphatidylcholine (DPPC/DTTU) led to small particles with sizes ranging from 100 to 150 nm at optimum conditions. Setting a fixed DNA amount, an increasing amount of DTTU/DPPC or DPPC lipids was added. Particle size increased only with DTTU/DPPC, indicating that interaction occurred between the DTTU/DPPC particles and DNA. In the same way, only DTTU/DPPC limited the ethidium bromide accessibility to plasmid DNA. These data suggest that DTTU/DPPC liposomes associate to DNA, which was confirmed by agarose gel experiments. To prove the active part of the DTTU lipid itself in DNA compaction, pegoylated-lipid was used. Cholesterol-PEG(2000) alone was not able to condense DNA. In contrast, DTTU/PEG-cholesterol was able to retain plasmid DNA on an agarose gel. In vivo injection of DTTU/DPPC/complexes was studied. Circulation time increase for noncationic particles as compared to cationic. More obvious was the lack of nonspecific accumulation in the lung, where a gain of 3 to 40 fold was measured. |
15546200 | Novel NMR platform for detecting gene transfection: synthesis and evaluation of fluorinated phenyl beta-D-galactosides with potential application for assessing LacZ gene expression. | Gene therapy holds great promise for the treatment of diverse diseases, but widespread implementation is hindered by difficulties in assessing the success of transfection. The development of noninvasive reporter techniques based on appropriate molecules and imaging modalities may help to assay gene expression. Fluorophenyl-beta-d-galactopyranosides provide a novel class of NMR active molecules, which are highly responsive to the action of beta-galactosidase (beta-gal), the product of the lacZ gene. The reporter molecules are stable in solution and with respect to wild-type cells, but the enzyme causes liberation of the aglycon, a fluorophenol, accompanied by distinct color formation and a (19)F NMR chemical shift of 5-10 ppm, depending on pH. Synthetic strategy, experimental methods, and molecular and (19)F NMR characteristics are reported for a series of molecules in solution, blood, and tumor cells. This class of molecules presents a new strategy for assaying gene expression with a highly versatile molecular structural platform. |
15546199 | Synthesis of poly(ethylene glycol)-based saquinavir prodrug conjugates and assessment of release and anti-HIV-1 bioactivity using a novel protease inhibition assay. | Various poly(ethylene glycol)(PEG)-based prodrug conjugates of the HIV-1 protease inhibitor (PI) saquinavir (SQV) were prepared using several types of chemical groups potentially capable of modifying its pharmacokinetic properties. These prodrug conjugates included SQV-cysteine-PEG3400, SQV-cysteine-PEG3400-biotin, SQV-cysteine(R.I.CK-Tat9) [a cationic retro-inverso-cysteine-lysine-Tat nonapeptide]-PEG3400, and SQV-cysteine(R.I.CK(stearate)-Tat9)-PEG3400. SQV was linked to cysteine to form a releasable SQV-cysteine ester bond in all of the conjugates. The amino group of the cysteine moiety provided an attachment site for a slower-degrading amide bond with N-hydroxysuccinimide-activated forms of PEG- and PEG-biotin. Disulfide bonds were used to attach the cationic peptides, R.I.CK-Tat9 and R.I.CK(stearate)-Tat9 to the cysteine moiety in order to provide cell-specific release. An assay was established and validated for measuring the activity of SQV and other protease inhibitors in biological samples. In this assay, cleavage of an internally quenched fluorescent substrate, Arg-Glu(EDANS)-Ser-Gln-Asn-Tyr-Pro-Ile-Val-Gly-Lys(DABCYL)-Arg by HIV-1 protease was inhibited by SQV in a dose-dependent manner at concentrations of 0.05-0.5 microM. All prodrug conjugates were shown to be inactive in this assay until the ester bond was cleaved and active SQV was released. The prodrug reconversion half-lives in 0.1 N HCl, phosphate-buffered saline (PBS) at pH 7.4 and in spiked plasma at 37 degrees C were 9, 14, and 0.9 h, respectively. The anti-HIV-1 activity (ED(50)) of the PEG-based SQV prodrug conjugates was evaluated in MT-2 cells using an MTT assay. The activity of conjugated SQV was reduced (ED(50) = 900 nM) for the PEG only conjugate, but restored with the addition of biotin (ED(50) = 125 nM), R.I.CK-Tat9 (ED(50) = 15 nM), and R.I.CK(stearate)-Tat9 (ED(50) = 62 nM) as compared to maximum achievable anti-HIV-1 activity (unconjugated SQV, control, ED(50) = 15 nM), suggesting enhanced cellular uptake of conjugates. Cytotoxicity (LD(50)) was assessed for all prodrug conjugates using non-HIV-1 infected cells and was found to be in the micromolar range. The difference between the LD(50) and ED(50) suggests a favorable therapeutic index for the prodrug conjugates. In conclusion, these promising initial results demonstrate that the reconversion of the conjugate prodrugs was complete and that active SQV was released. Since the major delivery advantages of PEG prodrug conjugates can only be observed in vivo, issues of reconversion and elimination half-lives in plasma will have to be further studied in an in vivo model. The current results also demonstrate that the protease inhibition assay is a simple yet effective bioanalytical tool that can be used to assess the release and anti-HIV-1 activity of HIV-1 PIs from their prodrug forms. |
15546198 | Peptide nucleic acid (PNA) amphiphiles: synthesis, self-assembly, and duplex stability. | Peptide amphiphiles comprising a class of conjugates of peptide nucleic acid (PNA), natural amino acids, and n-alkanes were synthesized and studied. These PNA amphiphiles (PNAA) self-assemble at concentrations between 10 and 50 muM and exhibit water solubilities above 500 muM. The highly specific, stable DNA binding properties of PNAs are preserved by these modifications, with no significant differences between the thermodynamics of DNA binding of the PNA peptide and the PNA amphiphile. Proper solubilization of the PNAA required the attachment of (Lys)(2) and (Glu)(4) peptides to PNAs, which affected the PNAA-DNA duplex stability by electrostatic interactions between these charged amino acids and the negatively charged DNA backbone. These electrostatic effects did not affect the specificity of DNA binding, however. Electrostatic effects are screened with added salt, in a manner consistent with previous studies of PNA-DNA duplex stability and predictions from a charged-cylinder model for the duplex. |
15546197 | Prediction of the viscosity radius and the size exclusion chromatography behavior of PEGylated proteins. | Size exclusion chromatography (SEC) was used to determine the viscosity radii of equivalent spheres for proteins covalently grafted with poly(ethylene glycol) (PEG). The viscosity radius of such PEGylated proteins was found to depend on the molecular weight of the native protein and the total weight of grafted PEG but not on PEG molecular weight, or PEG-to-protein molar grafting ratio. Results suggest grafted PEG's form a dynamic layer over the surface of proteins. The geometry of this layer results in a surface area-to-volume ratio approximately equal to that of a randomly coiled PEG molecule of equivalent total molecular weight. Two simple methods are given to predict the viscosity radius of PEGylated proteins. Both methods accurately predicted (3% absolute error) the viscosity radii of various PEG-proteins produced using three native proteins, alpha-lactalbumin (14.2 kDa MW), beta-lactoglobulin dimer (37.4 kDa MW), and bovine serum albumin (66.7 kDa MW), three PEG reagents (2400, 5600, and 22500 MW), and molar grafting ratios of 0 to 8. Accurate viscosity radius prediction allows calculation of the distribution coefficient, K(av), for PEG-proteins in SEC. The suitability of a given SEC step for the analytical or preparative fractionation of different PEGylated protein mixtures may therefore be assessed mathematically. The methods and results offer insight to several factors related to the production, purification, and uses of PEGylated proteins. |
15546196 | Reversible photocontrol of peptide helix content: adjusting thermal stability of the cis state. | Cross-linking reagents based on an azobenzene core can be used to reversibly photoregulate secondary structure when introduced as intramolecular bridges in peptides and proteins. Photoisomerization of the azobenzene core in the trans to cis direction is triggered by photon absorption but isomerization from cis to trans occurs thermally as well as photochemically. The rate of the thermal process effectively determines the half-life of the cis form as well as the extent to which the trans form can be recovered. We designed and characterized a series of methanethiosulfonate (MTS)-bearing thiol-reactive azo-benzene-based cross-linkers. These cross-linkers are shown to permit photoregulation of helix content in a test peptide with half-lives for the cis conformation ranging from 11 s to 43 h at 25 degrees C. The cross-linkers described here thus broaden the range of reagents available for reversible photocontrol of peptide and protein conformation. |
15546195 | Enhanced anti-rotavirus action of human cystatin C by site-specific glycosylation in yeast. | The cDNA encoding human cystatin C (HCC) was subjected to site-specific substitution of alanine for serine at the position 37, to obtain the Asn(35)-Lys(36)-Ser(37) sequence that is a signal for asparagine-linked (N-linked) glycosylation of protein in eukaryotes, and was transformed into Pichia pastoris X33. As a result, 1.2 mg/L oligomannosyl HCC with a carbohydrate chain of Man(10)GlcNAc(2) was produced by the Pichia transformant. The oligomannosyl HCC was more stable at the low ionic strength condition of 50 mM potassium phosphate buffer, pH 7.0, than the wild-type. In addition, the oligomannosylation substantially improved the molecular stability of cystatin against an aspartic proteinase, cathepsin D, in which the susceptibility decreased to less than 50% of nonglycosylated one. The anti-rotavirus activity of HCC was substantially enhanced by the site-directed glycosylation using the yeast expression system. A MA-104 cell line was used as a host cell for human rotavirus type-2 Wa strain in this study, to which both the wild-type and oligomannosyl HCCs did not show cytotoxicity at a concentration of 100 mug/mL. More than 80% viability of the host cell infected with 1.0 x 10(5) PFU/mL of rotavirus was conserved under the condition coexisting with 75 mug/mL of the oligomannosyl HCC, which was 15.2% higher than that of wild-type HCC. Thus, the in vitro anti-rotavirus assay indicated that the supplement of a proper amount of the oligomannosyl HCC could be used as an anti-rotavirus agent. |
15546194 | Acid-degradable particles for protein-based vaccines: enhanced survival rate for tumor-challenged mice using ovalbumin model. | Acid-degradable protein-loaded polymer particles show promise for antigen-based vaccines due to their ability to activate cytotoxic T lymphocytes (CTLs) in vitro. Protein loadings and cytotoxic T lymphocyte activation efficiencies have now been enhanced through novel delivery vehicle designs. In particular, the use of a more hydrophilic acid-degradable cross-linker leads to increased water dispersibility and increased protein loading efficiency for the particles. A 2.5-fold increase in protein encapsulation allows the delivery of more protein antigen to antigen presenting cells (APCs) leading to a 20-fold rise in antigen presentation levels. The mechanism by which APCs internalize these particles was explored using the phagocytosis inhibitor, cytochalasin B. In addition, preliminary in vivo experiments were conducted to investigate the ability of the protein-loaded particles to provide immunity against tumors in mice, and an enhanced survival rate over the use of protein alone was observed, indicating that this vaccine delivery strategy has great practical potential. |
15546193 | Sequence-selective cleavage of oligoribonucleotides by 3d transition metal complexes of 1,5,9-triazacyclododecane-functionalized 2'-O-methyl oligoribonucleotides. | 2'-O-Methyl oligoribonucleotides bearing a 3'-[2,6-dioxo-3,7-diaza-10-(1,5,9-triazacyclododec-3-yl)decyl phospate conjugate group have been shown to cleave in slight excess of Zn(2+) ions complementary oligoribonucleotides at the 5'-side of the last base-paired nucleotide. The cleavage obeys first-order kinetics and exhibits turnover. The acceleration compared to the monomeric Zn(2+) 1,5,9-triazacyclododecane chelate is more than 100-fold. In addition, 2'-O-methyl oligoribonucleotides having the 1,5,9-triazacyclododec-3-yl group tethered to the anomeric carbon of an intrachain 2-deoxy-beta-d-erythro-pentofuranosyl group via a 2-oxo-3-azahexyl, 2,6-dioxo-3,7-diazadecyl, or 2,9-dioxo-3,10-diazatridecyl linker have been studied as cleaving agents. These cleave as zinc chelates a tri- and pentaadenyl bulge opposite to the conjugate group approximately 50 times as fast as the monomeric chelate and show turnover. The cleavage rate is rather insensitive to the length of linker. Interestingly, a triuridyl bulge remains virtually intact in striking contrast to a triadenyl bulge. Evidently binding of the zinc chelate to a uracil base prevents its catalytic action. Replacement of Zn(2+) with Cu(2+) or Ni(2+) retards the cleaving activity of all the cleaving agents tested. |
15546192 | Site-specifically traced drug release and biodistribution of a paclitaxel-antibody conjugate toward improvement of the linker structure. | Tumor-directed drug delivery is a promising strategy in cancer treatment, and in this field, monoclonal antibodies constitute an important class of targeting vehicles. A critical issue in the design of targeting conjugates is the timing of the release of the cytotoxic payload, with the ideal situation being the release at the maximum tumor uptake of the targeting molecule. A site-specific radiolabeling technique was used to elucidate the biodistribution and in vivo drug release pattern of an antibody conjugate of paclitaxel (PTX, 1, Figure 1) in which the drug and the antibody moieties were connected by a succinate (SX) linker. In this new method, a metabolite of PTX, 3'-(4-hydroxyphenyl)paclitaxel (3'-OH-PTX, 2, Figure 1) was used as a tyrosine mimic for the synthesis of the drug site-labeled conjugate (DSL, [(125)I]-3'-OH-PTXSXC225). This was achieved by iodogen (125)I-labeling of 3'-OH-PTXSX and subsequent conjugation to C225. The antibody site-labeled conjugate (ASL, PTXSX-[(125)I]-C225) was prepared by direct radioiodination of PTXSXC225. Biodistribution of these compounds was studied in Balb/c nude mice bearing DU-145 human prostate carcinoma xenografts. While the 4 and 24 h tumor uptake (in percent injected dose per gram of tissue, %ID/g) for [(125)I]-3'-OH-PTXSXC225 were 3.3 +/- 1.5 and 1.7 +/- 0.6%ID/g, the PTXSX-[(125)I]-C225 showed tumor uptake values of 3.8 +/- 4.2 and 14.8 +/- 4.2%ID/g at these time points. This difference in the tumor uptake over time indicates an early cleavage of the drug with respect to the antibody tumor localization. This was further confirmed by an in vitro drug release kinetics study leading to a half-life of about 2 h for PTXSXC225 under physiological conditions. To increase the stability of the PTX-MAb bond, a new conjugate (PTXGLC225) with glutaric acid (GL) as the linker was synthesized. Under the same conditions, the PTXGLC225 showed a 16-fold increase in the half-life (t(1/2)) of the drug release. The effect of the increased t(1/2) of this compound on the antitumor activity of the conjugate was tested in a DU-145 human prostate tumor-implanted mouse model. In comparison to a previous similar experiment with PTXSXC225, better antitumor activity was observed for the PTXGLC225 conjugate as compared to controls. These results demonstrated the first time use of radioiodinated 3'-OH-PTX for in vivo tracing of a paclitaxel conjugate and application of the resulting information to the design of a therapeutically more useful PTX-MAb linker. |
15546191 | Acetals as pH-sensitive linkages for drug delivery. | pH-Sensitive linkages designed to undergo hydrolysis at mildly acidic pH can trigger the release of therapeutics selectively at targets such as tumor and inflammatory tissues and in the endosomes and lysosomes of cells. Acetals have the potential to be used as linkages for a range of alcohol functionalities, and, by altering their chemical structure, it is possible to tune their hydrolysis rate. The syntheses of four conjugates of model drug molecules with PEO using acetals of varying chemical structure are described herein. Primary and secondary alcohols, as well as syn-1,2-diols, were incorporated in the conjugates. The hydrolysis kinetics were investigated by HPLC, and the conjugates had half-lives ranging from less than 1 min to several days at pH 5.0, with slower hydrolysis at pH 7.4 in all cases. These acetal linkages are therefore promising for use in a variety of drug delivery applications ranging from polymer-drug conjugates to pH-sensitive micelles and nanoparticulate systems. |
15546190 | Protein cargo delivery properties of cell-penetrating peptides. A comparative study. | Application of cell-penetrating peptides for delivering various hydrophilic macromolecules with biological function into cells has gained much attention in recent years. We compared the protein transduction efficiency of four cell-penetrating peptides: penetratin, Tat peptide, transportan, and pVEC and studied the effects of various medium parameters on the uptake. Depletion of cellular energy and lowering of temperature strongly impaired the internalization of protein complexed with cell-penetrating peptides, confirming the endocytotic mechanism of peptide-mediated protein cellular transduction. Peptide-induced protein association with HeLa cells decreased 3-6-fold in energy-depleted cells. Inhibition of clathrin-dependent endocytosis by the hyperosmolar medium decreased the uptake of peptide-avidin complexes 1.5-3-fold and the removal of cholesterol from the plasma membrane 1.2-2-fold, suggesting that both clathrin-dependent and independent endocytosis were involved in peptide-induced cellular delivery of avidin. However, even under conditions of cellular energy depletion, ceasing of cellular traffic, and partial depolarization of plasma membrane, peptide-protein complexes associated with HeLa cells, as observed by FACS analysis and spectrofluorimetry. Among the studied peptides, pTat and transportan revealed higher protein transduction efficiency than penetratin or pVEC. |
15546189 | Binding behavior of aliphatic oligopeptides by bridged and metallobridged bis(beta-cyclodextrin)s bearing an oxamido bis(2-benzoic) carboxyl linker. | beta-Cyclodextrin dimers bearing an oxamido bis(2-benzoic) carboxyl linker (1) or its metal complexes (2 and 3) were newly synthesized, and their inclusion complexation behavior with a series of representative aliphatic oligopeptides, i.e., Leu-Gly, Gly-Leu, Gly-Pro, Glu-Glu, Gly-Gly, Gly-Gly-Gly, and Glu(Cys-Gly), was elucidated by means of UV/vis, circular dichroism, fluorescence, and 2D NMR spectroscopy in Tris-HCl buffer solution (pH 7.4) at 25 degrees C. The results obtained indicated that metallobridged bis(beta-cyclodextrin)s 2 or 3 could significantly enhance the original molecular binding abilities of parent bis(beta-cyclodextrin) 1 toward model substrates through the cooperative binding of two cyclodextrin moieties and the additional chelation effect supplied by the coordinated metal centers. It is interesting that hosts 2 and 3 displayed an entirely different fluorescence behavior upon complexation with guest oligopeptides. Among the guest peptides examined, 3 showed the highest complex formation constant of 68 200 M(-)(1) for Glu-Glu, up to 510-fold as compared with 1 (135 M(-)(1)), while 1 gave excellent molecular selectivity for Glu(Cys-Gly)/Glu-Glu pair, up to 51-fold. The molecular binding ability and selectivity were discussed from the viewpoints of the induced-fit and multiple recognition mechanism between host and guest. |
15546188 | Tuning of intercalation and electron-transfer processes between DNA and acridinium derivatives through steric effects. | A series of acridinium derivatives 1-6, wherein steric factors have been varied systematically through substitution at the 9 position of the acridine ring, have been synthesized and their DNA interactions have been investigated by various biophysical techniques. The unsubstituted and methylacridinium derivatives 1 and 2 and the o-tolylacridinium derivative 6 exhibited high fluorescence quantum yields (Phi(f)() congruent with 1) and lifetimes (tau = 35, 34, and 25 ns, respectively), when compared with the arylacridinium derivatives 3-5. The acridinium derivatives 1 and 2 showed high DNA binding affinity (K = 7.3-7.7 x 10(5) M(-)(1)), when compared to the arylacridinium derivatives 3-5 (K = 6.9-10 x 10(4) M(-)(1)). DNA melting and viscosity studies establish that in the case of the aryl-substituted systems, the efficiency of DNA binding is in the order, phenyl > p-tolyl > m-tolyl >>>> o-tolyl derivative. The increase in steric crowding around the acridine ring hinders the DNA binding interactions and thereby leads to negligible binding as observed in the case of 6 (o-tolyl derivative). These results indicate that a subtle variation in the substitution pattern has a profound influence on the photophysical and DNA interactions. Further, they demonstrate that pi-stacking interactions of the ligands with DNA are essential for efficient electron transfer between the DNA bases and the ligands. These water soluble and highly fluorescent molecules which differ in their DNA binding mode can act as models to study various DNA-ligand interactions. |
15546187 | Hydrotropic dendrimers of generations 4 and 5: synthesis, characterization, and hydrotropic solubilization of paclitaxel. | Polyglycerol dendrimers (PGDs) with 4-5 generations were synthesized and used to investigate the effect of dendritic architecture and its generation on aqueous solubilization of paclitaxel (PTX), a poorly water-soluble drug. Chemical and physical properties of the PGDs were characterized by NMR, MALDI-TOF mass, GPC, viscosity, and dynamic light scattering measurements. The PTX solubility in all the solutions of PGDs, even below 10 wt %, was much higher than that in PEG400 that is commonly used as a cosolvent or a hydrotropic agent. Increase in the PTX solubility by PGDs was dependent on the dendrimer generation. The dendritic structure was the reason for the enhanced solubility of PTX even at low concentrations. (1)H NMR spectra of PTX before and after mixing with PGDs in D(2)O suggested that the aromatic rings and some methyne groups of PTX were surrounded by PGDs. PGDs, which do not require hydrophobic segment as in polymeric micelles, provide an alternative method of hydrotropic solubilization of poorly soluble drugs. |
15546186 | Poly(3-guanidinopropyl methacrylate): a novel cationic polymer for gene delivery. | A cationic polymethacrylate with a guanidinium side group was designed in order to create a polymer with cell membrane-penetrating properties such as Tat or other arginine-rich peptides. The polymer, poly(3-guanidinopropyl methacrylate), abbreviated as pGuaMA, was synthesized by free radical polymerization. The DNA-condensing properties of pGuaMA (Mw 180 kDa) were investigated via dynamic light scattering and zeta potential measurements, and small, positively charged particles (110 nm, +37 mV) were found. It was shown that polyplexes based on pGuaMA were able to transfect COS-7 cells efficiently in the absence of serum, while under the same conditions poly(arginine) (pArg) polyplexes did not show detectable transfection levels. Addition of a membrane-disrupting peptide, INF 7, derived from the influenza virus, to preformed pGuaMA polyplexes did result in approximately 2 times increased transfection levels. DLS, zeta potential measurements, gel electrophoresis, and ethidium bromide displacement measurements indicated that serum induced aggregation of the polyplexes at high polymer/plasmid ratios, while at low polymer/plasmid ratios the polarity of the polyplexes reversed likely due to adsorption of negatively charged proteins on their surface. Likely, the unfavorable interactions of pGuaMA polyplexes with serum proteins is the reason for the absent transfection activity of these polyplexes in the presence of serum. Confocal laser scanning microscopy indicated cellular internalization via endocytosis of both polyplexes and free polymer. Thus, pGuaMA polyplexes enter cells, as reported for other polyplexes, by endocytosis and not, as hypothesized, via direct membrane passage. |
15546185 | Synthetic biocompatible cyclodextrin-based constructs for local gene delivery to improve cutaneous wound healing. | The localized, sustained delivery of growth factors for wound healing therapy is actively being explored by gene transfer to the wound site. Biocompatible matrices such as bovine collagen have demonstrated usefulness in sustaining gene therapy vectors that express growth factors in local sites for tissue repair. Here, new synthetic biocompatible materials are prepared and shown to deliver a protein to cultured cells via the use of an adenoviral delivery vector. The synthetic construct consists of a linear, beta-cyclodextrin-containing polymer and an adamantane-based cross-linking polymer. When the two polymers are combined, they create an extended network by the formation of inclusion complexes between the cyclodextrins and adamantanes. The properties of the network are altered by controlling the polymer molecular weights and the number of adamantanes on the cross-linking polymer, and these modifications and others such as replacement of the beta-cyclodextrin (host) and adamantane (guest) with other cyclodextrins (hosts such as alpha, gamma, and substituted members) and inclusion complex forming molecules (guests) provide the ability to rationally design network characteristics. Fibroblasts exposed to these synthetic constructs show proliferation rates and migration patterns similar to those obtained with collagen. Gene delivery (green fluorescent protein) to fibroblasts via the inclusion of adenoviral vectors in the synthetic construct is equivalent to levels observed with collagen. These in vitro results suggest that the synthetic constructs are suitable for in vivo tissue repair applications. |
15546184 | Influence of pendant arms bearing ligating groups on the structure of bismuth porphyrins: implications for labeling immunoglobulins used in medical applications. | The synthesis of two picket bismuth(III) porphyrins is reported, and their crystal structures are compared. The influence of the nature of the pickets, as well as their number, is discussed in terms of stability, kinetics of metalation, structure, and distortion of the porphyrin. Unexpectedly, the results indicate that the coordination sphere of bismuth is not affected by different types of distortion nor is the stability of the complex. For both types of complexes, the X-ray crystallography revealed that a single arm is actually in direct interaction with the bismuth cation, thereby allowing further functionalization on the porphyrin core as the linkage with immunoglobulins or anti-rabbit antibodies (both noted IgG), which have been used in diagnostic or therapeutic applications. |
15546183 | Synthesis and evaluation of a triplex-forming oligonucleotide-pyrrolobenzodiazepine conjugate. | In most cases, unmodified oligonucleotides designed as antigene molecules are incapable of binding to DNA with sufficient stability to prevent gene expression. To stabilize binding to a polypurine tract in the HER-2/neu promoter, a triplex forming oligonucleotide (TFO) was conjugated to a pyrrolo[1,4]benzodiazepine (PBD), desmethyltomaymycin, and site-specific DNA binding was evaluated. An activated ester of the PBD moiety was conjugated by an acylation reaction to a free primary amine on a 50-atom aliphatic linker at the 5' end of the TFO. This long aliphatic linker was designed to provide a bridge from the major groove binding site of the TFO to the minor groove binding site of the PBD. Triplex formation by the resulting TFO-PBD conjugate occurred more slowly and with a nearly 30-fold lower affinity compared to an unconjugated TFO. PBD binding to the triplex target was demonstrated by protection from restriction enzyme digestion, and covalent binding to the exocyclic amino group of guanine was inferred by substituting specific guanines with inosines. Although the binding of the TFO was less efficient, this report demonstrates that in principle, TFOs can be used to direct the binding of a PBD to specific location. Further optimization of TFO-PBD conjugate design, likely involving optimization of the linker and perhaps placing a PBD at both ends of the TFO, will be needed to make gene modification robust. |
15546182 | Synthesis and in vitro testing of J591 antibody-dendrimer conjugates for targeted prostate cancer therapy. | Targeted therapeutics using antibodies are an attractive option over conventional cancer chemotherapeutics due to their potential to deliver a therapeutic specifically to cancer tissue without damaging normal tissue. However, there are known problems with immunoconjugates such as decreased immunoreactivity and poor solubility. Using dendrimers as carriers for these agents has the potential to resolve these issues. We synthesized J591 anti-PSMA (prostate specific membrane antigen) antibody dendrimer conjugates containing fluorophores on the dendrimer. The in vitro studies of these conjugates show that they specifically bind to cells expressing PSMA. Confocal microscopy experiments document the binding and internalization of these conjugates. This research encourages the further study of antibody-dendrimer-drug conjugates for use in targeted therapeutics. |
15546181 | Cytosolic delivery of macromolecules. 3. Synthesis and characterization of acid-sensitive bis-detergents. | A serious limitation that precludes utilization of single-tailed, pH-sensitive detergents for the cytosolic delivery of macromolecules is their low limit of incorporation in stable liposomal formulations. To address this issue, we have prepared two Gemini surfactants or 'bis-detergents' by cross-linking the headgroups of single-tailed, tertiary amine detergents through oxyethylene (BD1) or acid-labile acetal (BD2) moieties. The membrane-bound pK(a) of the twin tertiary amine headgroups was determined to be 6.37 +/- 0.36 using a fluorescence-based assay. As evidenced by thin-layer chromatography, BD2was hydrolyzed under acidic conditions (pH 5.0) with an approximate half-life of 3 h at 37 degrees C, while BD1 remained stable. Low pH-induced collapse of liposomes containing acid-labile BD2 into micelles was more facile than that of BD1. With BD1, the process appeared to be reversible in that aggregation of micelles was observed at basic pH. The irreversible lamellar-to-micellar transition observed with BD2-containing liposomes can possibly be attributed to acid-catalyzed hydrolysis of the acetal cross-linker, which generates two detergent monomers within the bilayer. Liposomes composed of 75 mol % bis-detergent and 25 mol % phosphatidylcholine were readily prepared and could entrap macromolecules such as polyanionic dextran of MW 40 kDa with moderate efficiency. The ability of BD2-containing liposomes to promote efficient cytosolic delivery of antisense oligonucleotides was confirmed by (a) their diffuse intracellular distribution seen in fluorescence micrographs, and (b) the up-regulation of luciferase in an antisense functional assay. The low pH-responsive, bis-detergent constructs described herein are suitable for triggered release strategies targeted to acidic intracellular or interstitial environments. |
15546180 | Targeting malaria with polyamines. | During the asexual cycle of Plasmodium falciparum within the host erythrocyte, the parasite induces a stage-dependent elevation in the levels of polyamines by increased metabolism and uptake of extracellular pools. Polyamine amides of N-methylanthranilic acid have been synthesized which have embedded within them putrescine, spermidine, or spermine and from a charge perspective mimic natural polyamines. The interaction of these polyamine conjugates with human erythrocytes infected with malaria is described using fluorescent microscopy. The fluorescent spermine mimic was the only probe to show measurable intracellular accumulation. This was observed in late stage development but not in the ring stages or in uninfected erythrocytes. |
15546179 | Synthesis of phosphate-branched oligonucleotides. | A solid-phase synthesis for phosphate-branched oligonucleotides is described. The method is based on coupling of a single nucleoside phosphorodiamidite to terminal hydroxyl functions of two solid-supported oligonucleotides. After oxidation of the phosphite triester obtained to a phosphate triester, the third branch is assembled by conventional phosphoramidite chemistry. |
15546177 | Identification of the gonad-specific anion transporter SLCO6A1 as a cancer/testis (CT) antigen expressed in human lung cancer. | Serological analysis of recombinant cDNA expression libraries (SEREX) has led to the identification of many of the antigens recognized by the immune system of cancer patients, which are collectively referred to as the cancer immunome. We used SEREX to screen a testicular cDNA expression library with sera obtained from non-small cell lung cancer patients and isolated cDNA clones for 82 antigens. These included a total of 31 antigens previously identified by SEREX, and 51 that did not match entries in the Cancer Immunome Database and were considered newly identified antigens. Overall, the antigens comprised 62 known proteins and 20 uncharacterized gene products. Six antigens (NY-TLU-6, -37, -39, -57, -70, -75) were identified as putative cell surface proteins that are potential targets for monoclonal antibody-based immunotherapy. Of these, the gonad-specific anion transport protein SLCO6A1 (NY-TLU-57) was shown to be tissue-restricted. RT-PCR showed it to be expressed strongly only in normal testis, and weakly in spleen, brain, fetal brain, and placenta. In addition, NY-TLU-57 mRNA was found in lung tumor samples (5/10) and lung cancer cell lines (6/11), as well as bladder (5/12) and esophageal (5/12) tumor samples. These data suggest that SLCO6A1 is a putative cancer/testis (CT) cell surface antigen of potential utility as a target for antibody-based therapy for a variety of tumor types. The analysis also permits us to estimate the eventual size of the SEREX-defined cancer immunome at around 4000 genes. This emphasizes the importance of continued SEREX screening to define the cancer immunome. |
15546176 | Preoperative imaging of chronic sinusitis by multislice computed tomography. | The aim of this study was to evaluate whether multislice CT enables quality improvement and dose reduction in the imaging of the paranasal sinuses, especially when using secondary reconstructions. We compared the imaging quality of direct CT scans and secondary reconstructions of single-slice CT (SSCT) as a criterion standard with multislice CT (MSCT) of the paranasal sinuses in 80 patients suspected of having chronic sinusitis. Coronary secondary reconstructions were calculated from all transversal CT data sets. Coronary reconstructions of transversal MSCT showed a significantly better image quality compared with coronary reconstructions of SSCT. Because of the absence of dental metal artifacts, coronary reconstructions of MSCT were superior even to direct coronary images of SSCT. MSCT offered a superior examination quality compared to SSCT. A halving of radiation dosage can be reached by eliminating one examination plane. |
15546175 | Steroid injection to vocal nodules using fiberoptic laryngeal surgery under topical anesthesia. | Since 1990, we have performed steroid injection into the vocal fold by fiberoptic laryngeal surgery (FLS) under local anesthesia. In this study, the usefulness of this method was evaluated in 28 patients with vocal nodules. Under monitoring using a fiberoptic laryngoscope, a curved injection needle was inserted via the oral cavity and steroid was injected. Endoscopic findings showed that the vocal nodule had disappeared in 17 patients of the 27 patients and decreased in 10 after injection. The maximum phonation time was 10.9 s before operation and 13.9 s after operation, showing a significant increase (P<0.05), and the mean flow rate also showed a significant improvement (P<0.05). The patients self-rating concerning hoarseness demonstrated great improvement after injection. This technique can be performed under local anesthesia in combination with voice therapy on an outpatient basis, and it is considered to be useful for treating vocal nodules. |
15546174 | Incidental metastases of well-differentiated thyroid carcinoma in lymph nodes of patients with squamous cell head and neck cancer: eight cases with a review of the literature. | The examination of a large series of cervical lymph nodes in patients with head and neck cancer revealed the presence of incidental metastases of occult thyroid carcinoma in eight patients, of which six cases were squamous cell carcinoma of glottic and supraglottic sites of the larynx and two cases were pyriform sinus and tongue carcinomas. Three patients had two lymph nodes and the remaining patients had one lymph node each involved. The nodal chains affected were the jugular (n=5; level IV), Kuttner (level II), supraomohyoid (level III) and supraclavicular (level VI). In four cases, a subtotal thyroidectomy or unilateral lobectomy was performed during laryngectomy (for surgical reasons) or after histologic nodal examination; a minimal focus of thyroid papillary carcinoma was detected in one patient. Three of eight patients died from recurrence of the squamous cell carcinoma; no case presented clinical evidence of thyroid malignancy. The differential diagnosis from benign thyroid heterotopia was based on the presence of minimal nuclear atypia. The choice of treatment of patients with a coexisting neoplasm characterized by poor prognosis is difficult, and contrasting opinions exist regarding the use of radical thyroidectomy and the subsequent management. As reported in the literature (66 cases), the more aggressive squamous cell carcinoma will determine the prognosis of these patients; in fact, only one of the referred cases died of cerebellar metastases of the thyroid cancer. Our results emphasize the importance of an accurate re-evaluation and follow-up of patients with incidental occult metastases for detection of a primary thyroid tumor. In the general population, this incidental nodal involvement may be related to a minimal occult thyroid carcinoma. |
15546163 | Suppression of distant pulmonary metastasis of MDA-MB 435 human breast carcinoma established in mammary fat pads of nude mice by retroviral-mediated TIMP-2 gene transfer. | Previous studies have shown that TIMP-2 overexpression is a useful therapeutic tool for inhibiting tumor growth and invasion in animals. However, it has not been reported whether genetic manipulation for TIMP-2 overexpression can induce an inhibitory effect on spontaneous metastasis from the primary tumor site to other organs such as lungs or lymph nodes in an animal model. The present studies describe the effects of retrovirus-mediated TIMP-2 gene transfer into human breast cancer cell lines on the in vitro invasion of the tumor cells or the in vivo growth in nude mouse. Here we also used retroviral-mediated TIMP-2 overexpression by intratumoral injection for suppression of metastasis in human breast carcinoma established in the mammary fat pad of nude mice. As expected, overexpression of TIMP-2 inhibited matrix metalloprotenase (MMP) activity and invasion of the tumor cells. Also, the growth rate of tumors grafted with the breast cancer cells transduced with the retrovirus vector encoding TIMP-2 cDNA was significantly slower than the growth rate of tumors grafted with the breast cancer cells transduced with a control retrovirus vector. Furthermore, single intratumoral injection of the TIMP-2 retrovirus-producing cells into human breast tumor tissue established in mammary fat pads of nude mice showed a dramatic decrease in size and number of lung metastatic tumors. Retrovirus-mediated TIMP-2 gene transfer into human breast cancer cells is able to down-regulate invasion and show that tumor-derived angiogenesis is reduced. In this model, retroviral-mediated transduction of TIMP-2 cDNA into a limited population of human tumor cells inhibits tumor growth and prevents distant pulmonary metastasis. These results indicate that it may not be necessary to deliver and express these genes in every single tumor cell as long as the level of expression in a limited number of transduced cells is sufficient to prevent the excessive breakdown of the extracellular matrix. |
15546162 | pDUAL, a multipurpose, multicopy vector capable of chromosomal integration in fission yeast. | A novel series of plasmid vectors named pDUAL have been developed. These vectors enable one to introduce not only multicopies of genes with episomal maintenance but also a single copy with chromosomal integration into the fission yeast, Schizosaccharomyces pombe. The multicopy plasmids can be easily converted to fragments for chromosomal integration by digestion of the plasmids with a certain restriction endonuclease before transformation of the yeast cells. The resultant fragments, lacking the autonomously replicating sequence, are designed for targeting into the chromosomal leu1 locus by homologous recombination. Whether the transformants are the results of episomal maintenance of the plasmid or homologous gene targeting can be readily checked by their requirement for uracil or leucine, or by the PCR diagnostic analysis. Furthermore, we propose the use of pDUAL derivatives for PCR-based chromosomal tagging of a gene to introduce several tags into 5'-terminus of a gene, employing a set of primers. Using these all-in-one vectors, a suitable mode of expression of a cloned gene can be selected for individual analysis without any complicated subcloning processes. |
15546161 | Surgeon's recommendation, perceived operative efficacy and age dictate treatment choice by Chinese women facing breast cancer surgery. | to identify factors influencing Chinese women's choices between breast-conserving therapy (BCT), mastectomy (MRM) or MRM followed by breast reconstruction (MRM+R). of 405/443 Hong Kong Chinese women receiving surgery for early breast cancer who were interviewed one week post-surgery about their pre-surgical consultation, available treatment alternatives, whether their surgeons had indicated a surgical preference, perceived efficacy of the surgical options and considerations influencing their treatment decisions (TDM), 198 (49%) reported they were offered a choice of surgery. among women offered a choice of surgery, BCT was chosen by 34/43 (79%) of women whose surgeons recommended BCT but by only 34/96 (37%) of women whose surgeons expressed no treatment recommendation. Multivariate adjustment showed women choosing MRM were influenced more by avoiding both cancer recurrence (p = 0.003) and further treatment (p = 0.009) when choosing surgical option than women choosing BCT. In contrast, women choosing MRM+R and BCT, placed more emphasis on appearance (p < 0.001) and body image (p < 0.001) concerns as influencing treatment choice than did women who chose MRM. survival concerns rather than physical appearance, age and lack of recommendation push Chinese women to choose MRM as BCT is, incorrectly often seen as less efficacious. Recommending BCT increases BCT choice. |
15546160 | Bone marrow cells engraft within the epidermis and proliferate in vivo with no evidence of cell fusion. | In adults, bone marrow-derived cells (BMDC) can contribute to the structure of various non-haematopoietic tissues, including skin. However, the physiological importance of these cells is unclear. This study establishes that bone marrow-derived epidermal cells are proliferative and, moreover, demonstrates for the first time that BMDC can localize to a known stem cell niche: the CD34-positive bulge region of mouse hair follicles. In addition, engraftment of bone marrow cells into the epidermis is significantly increased in wounded skin, bone marrow-derived keratinocytes can form colonies in the regenerating epidermis in vivo, and the colony-forming capacity of these cells can be recapitulated in vitro. In some tissues this apparent plasticity is attributed to differentiation, and in others to cell fusion. Evidence is also provided that bone marrow cells form epidermal keratinocytes without undergoing cell fusion. These data suggest a functional role for bone marrow cells in epidermal regeneration, entering known epidermal stem cell niches without heterokaryon formation. |
15546159 | Impact of regulatory labeling for troglitazone and rosiglitazone on hepatic enzyme monitoring compliance: findings from the state of Ohio medicaid program. | Troglitazone, the first drug of the thiazolidinediones class for type II diabetes, was first marketed in March 1997 and was removed from the U.S. market 36 months later after 90 cases of liver failure were reported despite multiple warnings containing liver enzyme monitoring recommendations. Rosiglitazone has been available since June 1999 and is still on the market. The purpose of this study was to evaluate the impact of labeled hepatic enzyme monitoring for troglitazone and rosiglitazone. Drug cohorts were assembled, using population-based fee-for-service Medicaid claims, for patients between 18 and 65 years of age who had received at least one troglitazone (n = 7226) or rosiglitazone (n = 1480) prescription between 1 April, 1997, and 21 March, 2000. The outcome of interest was the percentage of patients, based on their first treatment episode, who had baseline and post-baseline liver enzyme testing. Overall baseline testing was under 9% before regulatory actions, increased to 14% after the first two 'Dear Doctor' letters issued by the FDA in October and December 1997, and peaked to about 26% afterwards. Coincident with the marketing of rosiglitazone and the fourth 'Dear Doctor' letter issued in June 1999, baseline testing dropped to 18%. Baseline testing increased 2.5-fold (race-sex-age adjusted) after regulatory action. Achieving 50% post-baseline testing took approximately 6 months for both drugs. Regulatory actions had only modest effects on the incidence of liver monitoring. More effective and timely communication strategies, health provider prescribing interventions and modification of health provider behaviors to enhance compliance with recommended risk management measures need to be identified, evaluated and implemented. |
15546158 | Over-expression of TGF-beta1 in Smad4-deficient human oral carcinoma cells causes tumour regression in vivo by mechanisms that sensitize cells to apoptosis. | We have shown previously that transforming growth factor-beta (TGF-beta) is a potent tumour suppressor in Smad4-deficient human malignant oral keratinocytes but the mechanism by which this occurs is unknown. In the present study, we show that over-expression of TGF-beta1 causes regression of tumours derived from Smad4-deficient oral keratinocytes transplanted orthotopically to athymic mice. Further, tumour regression is associated with the induction of apoptosis without changes in cell proliferation. In vitro, TGF-beta1 did not induce apoptosis directly in these cells but sensitized cells to cisplatin, but not Fas, -induced cell death. The data suggest that TGF-beta1 induces tumour regression in vivo by Smad4-independent pathways that sensitize keratinocytes to mitochondrial-mediated apoptosis. |
15546157 | Disregarded use of herbal medical products and dietary supplements among surgical and medical patients as estimated by home inspection and interview. | More and more patients use herbal medical products (HMP) and dietary supplements (DS). Due to the possibility of drug interactions and side effects, it is important that physicians are aware of the use. The aim of the present cross sectional survey was to analyse the consumption of HMP and DS among patients recently discharged from two hospital departments. Patients were visited within 1 week after discharge and interviewed about their use of HMP and DS. Stored products were inspected and registered. Hospital files and discharge letters were examined to establish the frequency of registration. Totally, 83 surgical and 117 medical patients were included (n = 200), 139 patients (70%) were women. 53 patients (27%) stored no HMP or DS, whereas the home inventories of 147 patients (74%) comprised 343 products. 116 patients (58%) used HMP or DS daily and 25 patients (13%) used the products on demand. The most frequently used product was multivitamins (82 patients = 41%). Totally, 61% of the products were used on the patients' own initiative. In 3% of the used products, patients were aware of possible side effects. No patients were aware of possible drug interactions. Only 21% of the 211 HMP and DS used daily prior to admission were recorded in the hospital files. The use of HMP and DS was frequent among surgical and medical patients. The use was often not recorded in the hospital files and patients' knowledge of possible side effects and drug-interactions was minimal. |
15546155 | Neuroglial activation and neuroinflammation in the brain of patients with autism. | Autism is a neurodevelopmental disorder characterized by impaired communication and social interaction and may be accompanied by mental retardation and epilepsy. Its cause remains unknown, despite evidence that genetic, environmental, and immunological factors may play a role in its pathogenesis. To investigate whether immune-mediated mechanisms are involved in the pathogenesis of autism, we used immunocytochemistry, cytokine protein arrays, and enzyme-linked immunosorbent assays to study brain tissues and cerebrospinal fluid (CSF) from autistic patients and determined the magnitude of neuroglial and inflammatory reactions and their cytokine expression profiles. Brain tissues from cerebellum, midfrontal, and cingulate gyrus obtained at autopsy from 11 patients with autism were used for morphological studies. Fresh-frozen tissues available from seven patients and CSF from six living autistic patients were used for cytokine protein profiling. We demonstrate an active neuroinflammatory process in the cerebral cortex, white matter, and notably in cerebellum of autistic patients. Immunocytochemical studies showed marked activation of microglia and astroglia, and cytokine profiling indicated that macrophage chemoattractant protein (MCP)-1 and tumor growth factor-beta1, derived from neuroglia, were the most prevalent cytokines in brain tissues. CSF showed a unique proinflammatory profile of cytokines, including a marked increase in MCP-1. Our findings indicate that innate neuroimmune reactions play a pathogenic role in an undefined proportion of autistic patients, suggesting that future therapies might involve modifying neuroglial responses in the brain. |
15546154 | Blue light differentially alters cellular redox properties. | Blue light (lambda = 380-500 nm) historically has been used to initiate polymerization of biomaterials and recently has been proposed as a therapeutic agent. New evidence suggests that cell-type-specific responses result from redox changes induced by exposure to blue light. Cultured cells were exposed to defined doses of blue light, equivalent to exposure times of 10 s and 2 min, to achieve energies of 5 J/cm2 and 60 J/cm2, respectively, after which (a) viable cell number, (b) cellular protein profiles, (c) mitochondrial succinate dehydrogenase (SDH) activity, (d) total reactive oxygen species (ROS), and (e) induction of apoptosis were compared to that of nonexposed control cultures. Results showed that blue-light exposure arrested monocyte cell growth and increased levels of peroxiredoxins. SDH activity of normal epidermal keratinocytes (NHEK) was slightly enhanced by blue light, whereas identical treatment of OSC2 oral tumor cells resulted in significant suppression of SDH activity. Blue-light exposure generally induced higher levels of total ROS in OSC2 cells than in NHEK. Finally, only OSC2 cells exhibited signs of apoptosis via Annexin V staining following exposure to blue light. These data support the central hypothesis that blue light induces an oxidative stress response in cultured cells resulting in cell-type-specific survival outcomes. The identification of oxidative stress as a mediator of the effects of blue light is a critical first step in defining its biological risks and therapeutic opportunities. |
15546153 | Mechanistic and epidemiologic considerations in the evaluation of adverse birth outcomes following gestational exposure to statins. | The cholesterol-lowering "statin" drugs are contraindicated in pregnancy, but few data exist on their safety in human gestation. We reviewed case reports for patterns suggesting drug-related effects on prenatal development and considered a variety of mechanisms by which such effects, if confirmed, might occur. This uncontrolled case series included all FDA reports of statin exposures during gestation, as well as others from the literature and from manufacturers. Exposures and outcomes were reviewed and were tabulated by individual drug. Age-specific rates of exposure to each drug among women of child-bearing age were estimated. Of 214 ascertained pregnancy exposures, 70 evaluable reports remained after excluding uninformative cases. Among 31 adverse outcomes were 22 cases with structural defects, 4 cases of intrauterine growth restriction, and 5 cases of fetal demise. There were two principal categories of recurrent structural defects: cerivastatin and lovastatin were associated with four reports of severe midline CNS defects; simvastatin, lovastatin, and atorvastatin were all associated with reports of limb deficiencies, including two similar complex lower limb defects reported following simvastatin exposure. There were also two cases of VACTERL association among the limb deficiency cases. All adverse outcomes were reported following exposure to cerivastatin, simvastatin, lovastatin, or atorvastatin, which are lipophilic and equilibrate between maternal and embryonic compartments. None were reported following exposure to pravastatin, which is minimally present in the embryo. Statins reaching the embryo may down-regulate biosynthesis of cholesterol as well as many important metabolic intermediates, and may have secondary effects on sterol-dependent morphogens such as Sonic Hedgehog. The reported cases display patterns consistent with dysfunction of cholesterol biosynthesis and Sonic Hedgehog activity. Controlled studies are needed to investigate the teratogenicity of individual drugs in this class. |
15546152 | Humoral and contact interactions in astroglia/stem cell co-cultures in the course of glia-induced neurogenesis. | Astroglial cells support or restrict the migration and differentiation of neural stem cells depending on the developmental stage of the progenitors and the physiological state of the astrocytes. In the present study, we show that astroglial cells instruct noncommitted, immortalized neuroectodermal stem cells to adopt a neuronal fate, while they fail to induce neuronal differentiation of embryonic stem cells under similar culture conditions. Astrocytes induce neuron formation by neuroectodermal progenitors both through direct cell-to-cell contacts and via short-range acting humoral factors. Neuron formation takes place inside compact stem cell assemblies formed 30- 60 h after the onset of glial induction. Statistical analyses of time-lapse microscopic recordings show that direct contacts with astrocytes hinder the migration of neuroectodermal progenitors, while astroglia-derived humoral factors increase their motility. In non-contact co-cultures with astrocytes, altered adhesiveness prevents the separation of frequently colliding neural stem cells. By contrast, in contact co-cultures with astrocytes, the restricted migration on glial surfaces keeps the cell progenies together, resulting in the formation of clonally proliferating stem cell aggregates. The data indicate that in vitro maintained parenchymal astrocytes (1) secrete factors, which initiate neuronal differentiation of neuroectodermal stem cells; and (2) provide a cellular microenvironment where stem cell/stem cell interactions can develop and the sorting out of the future neurons can proceed. In contrast to noncommitted progenitors, postmitotic neuronal precursors leave the stem cell clusters, indicating that astroglial cells selectively support the migration of maturing neurons as well as the elongation of neurites. |
15546151 | New Huntington disease mutation arising from a paternal CAG34 allele showing somatic length variation in serially passaged lymphoblasts. | The analysis of somatic CAG triplet variation in lymphoblastoid cell lines from subjects carrying alleles of intermediate length (IA(33CAG) and IA(34CAG)) in Huntington disease (HD) gene disclosed instability in the DNA of the person, from whom a new expansion mutation of 45 triplets originated. The triplet size increased after about 30 passages in cell cultures in lymphoblasts with the IA(34) genotype. Lymphoblasts may provide an appropriate model for studying repeat instability in subjects with poly(CAG) repeat disorders. HD shows somatic, in addition to germ-line instability, highlighting the propensity to somatic CAG variation in human cells even with repeat numbers under the expanded edge. Factors potentially cis acting with the mutation, other than those reported in this study (CCG polymorphic stretch, the deletion of the glutamic acid residue at position 2642 and the 4-codon segment between CAG and CCG polymorphisms), should be searched for and analyzed. |
15546150 | Mammalian cell delivery via aerosol deposition. | The objective of this study was to test the hypothesis that bovine dermal fibroblasts can survive aerosol delivery via an airbrush with mean cell survival rates greater than 50%. This technology has great implications for burn and other wound therapies, for delivery of genetically altered cells in gene therapies, and for tissue engineering with tissue scaffolds. Bovine dermal fibroblasts were suspended at a concentration of 200,000 cells/mL in Hank's Balanced Salt Solution, and delivered into six-well tissue culture plates using a Badger 100G airbrush. Cells were delivered through three nozzle diameters (312, 484, and 746 microm) at five different air pressures (41, 55, 69, 96, and 124 kPa). Nine repetitions were performed for each treatment group, and cell viability was measured using trypan blue exclusion assay. Mean cell viability ranged from 37 to 94%, and depended on the combination of nozzle diameter and delivery pressure (p < 0.0001). Linear regression analysis was used to develop a stochastic model of cell delivery viability as a function of nozzle diameter and delivery air pressure. This study demonstrates the feasibility of using an airbrush to deliver viable cells in an aerosol to a substrate. |
15546149 | Lipopolysaccharide affects Golli expression and promotes proliferation of oligodendrocyte progenitors. | Proliferation of oligodendrocyte progenitor cells (OPCs) is important for initial myelination as well as for remyelination in demyelinating diseases. Previously, we showed that numerous OPCs and activated microglia, are present around multiple sclerosis lesions, and that they accumulate Golli proteins. Golli proteins, present in both neuronal and immune cells, might have a role in the immune processes, as well as in development of neurons and oligodendrocytes. We hypothesize that Golli proteins, generated by microglia in response to inflammation, promote proliferation of OPCs. To test this hypothesis, we induced inflammation in neonatal mouse brain slice culture with bacterial endotoxin lipopolysaccharide (LPS). Treated slices showed an increase in the number of OPCs. Several results support the notion that this effect of LPS is conveyed through activation of microglia and upregulation of Golli proteins. First, LPS-treated brain slices have increased expression of Golli proteins observed by immunofluorescence and Western blot analysis. Second, Golli proteins were demonstrated only in the conditioned medium from LPS-treated microglial cell cultures (LPS-MCM), and were absent in either the conditioned media from LPS-treated astrocytes or the control media. Third, proliferation of purified OPCs was promoted with LPS-MCM or Golli proteins, but not with LPS alone. Taken together, these results demonstrate that microglia and/or microglia secreted factors, are necessary for the LPS-promoted proliferation of OPCs and suggest possible involvement of Golli proteins as one of mediators in this process. |
15546148 | In search of the molecular mechanism by which small stress proteins counteract apoptosis during cellular differentiation. | Many differentiation programs are accompanied by an increase in small heat shock proteins (sHsps) level. Most of the time transient, this accumulation takes place during the early phase of the process and is correlated with the growth arrest that precedes the differentiation. Important biochemical modifications of sHsps occur, such as changes in phosphorylation and oligomerization. The fact that these proteins are induced independently of the signal that triggers differentiation, of the differentiation type, and of the cell type strongly suggests their involvement in fundamental mechanisms of cellular differentiation. Moreover, impairment of sHsps accumulation leads to abortion of the differentiation program and, subsequently, to a massive commitment to cell death. Recent advances in this field of research are presented as well as the hypothesis that should be tested to unravel the mode of action of these proteins during cellular differentiation. |
15546147 | Validation of a behavioral health treatment outcome and assessment tool designed for naturalistic settings: The Treatment Outcome Package. | In 1994, the American Psychological Association and the Society for Psychotherapy Research convened a Core Battery Conference to develop a set of criteria for the selection of a universal core battery that could be used as a common outcome tool across all outcome studies. The Treatment Outcome Package (TOP) is a behavioral health assessment and outcome battery with modules for assessing a wide array of behavioral health symptoms and functioning, demographics, case-mix, and treatment satisfaction. It was developed to follow the design specifications set forth by the Core Battery Conference, but also to ensure the battery's applicability to naturalistic treatment settings in which randomization may be impossible. In this article we discuss a number of studies that evaluate the initial psychometrics of the items that comprise the mental health symptom and functional modules of the TOP. We conclude that the TOP has an excellent factor structure, good test-retest reliability, promising initial convergent and discriminant validity, measures the full range of pathology on each scale, and has some ability to distinguish between behavioral health clients and members of the general population. |
15546146 | Maintaining psychology's scientific and professional credibility and ethical responsibility to self-regulate: a comment on "validations" of mental health assessment instruments. | Recent growth of "managed" mental health care in the United States has spawned huge demand for products that draw on one of psychology's most well developed subdisciplines, tests and measurement. The commercial potential of mental health assessment instruments intended for widespread use, to meet what Kraus, Seligman, and Jordan (this volume) describe as "an industry-wide surge in outcome evaluations in naturalistic ... settings," necessarily raises conflict of interest dilemmas for those who develop and market them. The American Psychological Association has devoted intensive effort to the preceding issue as it pertains to other aspects of the science and practice of clinical psychology. Comparable attention has not been focused recently on the development and marketing of assessment instruments. This Comment highlights the issue and suggests types of self-regulatory actions that might be taken, e.g., requiring and publishing full disclosure statements of authors' relationships to companies that market instruments like the Treatment Outcome Package in psychometric articles in which they are evaluated. |
15546145 | Origins of bidirectional replication of Epstein-Barr virus: models for understanding mammalian origins of DNA synthesis. | Epstein-Barr virus (EBV), provides unique advantages to understand origins of replication in higher eukaryotes. EBV establishes itself efficiently in infected B lymphocytes, where it exists as a 165 kb, circular chromosome which is duplicated once per cell cycle (Adams [1987] J Virol 61:1743-1746). Five to twenty copies of the EBV chromosome are usually present in each cell, increasing the signal/noise ratio for mapping and analyzing its replication origins. Remarkably only one viral protein is required for the synthesis and partitioning of the viral chromosomes: EBV nuclear antigen-1, or EBNA1. EBV uses distinct origins related to the ARS1 origin of Saccharomyces cerevisiae and to that of the dihydrofolate reductase (DHFR) locus in Chinese hamster ovary (CHO) cells [Bogan et al., 2000]. We shall review the properties and the regulation of these two kinds of origins in EBV and relate them to their cellular cousins. |
15546144 | Cognitive-behavioral therapy for PTSD in the real world: do interpersonal relationships make a real difference? | The goal of this effectiveness study was to investigate the role of pre-treatment interpersonal relationship functioning in two forms of group cognitive-behavioral treatment (CBT) for veterans with PTSD. Analysis of data from 45 veterans who completed either trauma- or skills-focused CBT indicated no overall differences between the two treatments in PTSD symptomatology, alcohol abuse, or violence perpetration at four months post-treatment. However, there was a stronger inverse relationship between intimate relationship functioning and violence outcomes in the trauma-focused group versus the skills-focused group. While no differences in violence outcomes were found between the treatments at poorer levels of pre-treatment intimate relationship functioning, those receiving trauma-focused treatment with better pre-treatment intimate relationships reported less violence. Extended relationship functioning and violence outcomes were less strongly associated in the trauma-focused group versus the skills-focused group. The theoretical implications of these results, as well as the clinical opportunities to improve CBT for PTSD by capitalizing on patients' relationships, are discussed. |
15546143 | Psychological mindedness and awareness of self and others. | The major goal of this study was to explore the relationship among psychological mindedness (PM) and several facets of awareness, including a general sense of mindfulness (Mindful Attention Awareness Scale; Brown & Ryan, 2003), as well as more specific awareness of self (self-consciousness scale; Fenigstein, Scheier, & Buss, 1975) and others (Interpersonal Reactivity Index; Davis, 1980). Participants were 103 undergraduate students at an urban liberal arts college. Results indicated that PM (PM Scale; Conte, Plutchik, Jung, Picard, Karasu, & Lotterman, 1990) is related to mindfulness (r = .41, p < .01), private self-consciousness (r = .27, p < .05), as well as cognitive (r = .30, p < .01) and affective (r = .35, p < .01) indices of empathy. Self-consciousness and empathy explained a significant amount of variance in PM in a simultaneous-entry multiple regression. These findings support theoretical claims that PM involves awareness of self and others. |
15546142 | Trafficking and localization of platinum complexes in cisplatin-resistant cell lines monitored by fluorescence-labeled platinum. | Cisplatin is a chemotherapeutic agent commonly used in the treatment of a wide variety of malignant tumors. Resistance to cisplatin represents a major obstacle to effective cancer therapy because clinically significant levels of resistance quickly emerge after treatment. Based on previous studies indicating abnormal plasma membrane protein trafficking in cisplatin-resistant (CP-r) cells, Fluorescence (Alexa Fluor)-labeled cisplatin was used to determine whether this defect altered the trafficking and localization of cisplatin by comparing drug sensitive KB-3-1 and KB-CP-r cells. Alexa Fluor-cisplatin was readily internalized and localized throughout the KB-3-1 cells, but overall fluorescence decreased in KB-CP-r cells, as detected by flow cytometry (FACS) and confocal microscopy. Only punctate cytoplasmic staining was observed in KB-CP-r cells with less fluorescence observed in the nucleus. Colocalization experiments with a Golgi-selective stain indicate the involvement of Golgi-like vesicles in initial intracellular processing of Alexa Fluor conjugated cisplatin complexes. As detected using an antibody to Alexa Fluor-cisplatin, cisplatin complex-binding proteins (CCBPs) were reduced in membrane fractions of single-step cisplatin-resistant KB-CP.5 cells, and increased in the cytoplasm of KB-CP.5 cells compared to KB-3-1 cells. CCBPs localized to lower density fractions in KB-CP.5 cells than in KB-3-1 cells as determined by iodixanol gradient centrifugation. In summary, inappropriate trafficking of CCBPs might explain resistance to cisplatin in cultured cancer cells, presumably because membrane binding proteins for cisplatin are not properly located on the cell surface in these cells, but are instead trapped in low density vesicles within the cytoplasm. |
15546141 | An investigation into the effectiveness of bibliotherapy and minimal contact interventions in the treatment of panic attacks. | The present study investigated the effectiveness of bibliotherapy and minimal therapist-contact interventions in the treatment of panic attacks. Individuals were randomly assigned to one of three conditions: (1) bibliotherapy alone (BT); (2) bibliotherapy plus phone contact (BT+PC); or (3) phone contact alone (PC). Assessment (pre- and post-treatment) and treatment (8 weeks in duration) were conducted via mail and phone. Individuals receiving BT and BT+PC exhibited significant reductions from pre- to post-treatment on panic cognitions and fear of having a panic attack. Individuals receiving BT+PC exhibited significant reductions from pre- to post-treatment on panic symptoms and avoidance. In addition, individuals in the BT and BT+PC groups were more likely to exhibit clinically significant improvement on most dependent measures relative to PC alone. On some measures, individuals in the BT+PC group did clinically better than individuals in the BT group. Results of the present study also suggest that diagnosis may play some role in outcome. |
15546140 | Stat1-mediated cytoplasmic attenuation in osteoimmunology. | Signal transducer and activator of transcription 1 (Stat1) is a critical mediator of gene transcription in type I interferon (IFN-alpha/beta) signaling that is essential for host defense against viruses. In the skeletal system, type I IFNs (IFN-alpha/beta) also play an important physiological role in the inhibition of receptor activator of NF-kappaB ligand (RANKL)-induced osteoclast differentiation and bone resorption: mice deficient in IFN signaling exhibit decreased bone mass accompanied by the activation of osteoclastogenesis. On the other hand, an unexpected increase in bone mass was observed in Stat1-deficient mice, indicating that Stat1 has a hitherto unknown function in the regulation of bone formation. Indeed, Stat1 was found to have a unique, non-canonical function as a cytoplasmic attenuator of Runx2, a key transcription factor for osteoblast differentiation. Thus, the loss of Stat1 results in excessive activation of Runx2 and osteoblast differentiation, thereby tipping the balance in favor of bone formation over bone resorption. This is an interesting example in which a latent transcription factor attenuates the activity of another transcription factor in the cytoplasm, and reveals a novel regulatory mechanism of bone remodeling by immunomodulatory molecules. Here, we summarize recent advances in the study of Stat1 and IFNs in the context of osteoimmunology, including latest reports that question whether the inhibitory function of Stat1 in chondrocytes is responsible for dwarfism in achondroplasia. |
15546139 | DNA methylation and chromatin structure: the puzzling CpG islands. | DNA methylation is the epigenetic modification, which introduces 5mC as fifth base onto DNA. As for the distribution of 5mCs, it is well known that they distribute themselves in a non-random fashion in genomic DNA so that methylation pattern is characterized by the presence of methylated cytosines on the bulk of DNA while the unmethylated ones are mainly located within particular regions termed CpG islands. These regions represent about 1% of genomic DNA and are generally found in the promoter region of housekeeping genes. Their unmethylated state, which is an essential condition for the correct expression of correlated genes, is paradoxical if one considers that these regions are termed CpG islands because they are particularly rich in this dinucleotide, which is the best substrate for enzymes involved in DNA methylation. Anomalous insertion of methyl groups in these regions generally leads to the lack of transcription of correlated genes. An interesting scientific problem is to clarify the mechanism(s) whereby CpG islands, which remain protected from methylation in normal cells, are susceptible to methylation in tumor cells. How the CpG moieties in CpG islands become vulnerable or resistant to the action of DNA methyltransferases and can thus lose or maintain their characteristic pattern of methylation is still an open question. Our aim is to gather some mechanisms regarding this intriguing enigma, which, despite all energy spent, still remains an unresolved puzzle. |
15546138 | Sulindac and its metabolites inhibit invasion of glioblastoma cells via down-regulation of Akt/PKB and MMP-2. | Non-steroidal anti-inflammatory drug (NSAID), sulindac has chemopreventive and anti-tumorigenic properties, however, the molecular mechanism of this inhibitory action has not been clearly defined. The Akt/protein kinase B, serine/threonine kinase is well known as an important mediator of many cell survival signaling pathways. In the present study, we demonstrate that down-regulation of Akt is a major effect of anti-invasiveness property of sulindac and its metabolites in glioblastoma cells. Myristoylated Akt (MyrAkt) transfected U87MG glioblastoma cells showed increase invasiveness, whereas DN-Akt transfected cells showed decrease invasiveness indicating that Akt potently promoted glioblastoma cell invasion. MMP-2 promoter and enzyme activity were up-regulated in Akt kinase activity dependent manner. Sulindac and its metabolites down-regulated Akt phosphorylation, inhibited MMP-2 production, and significantly inhibited invasiveness of human glioblastoma cells. In addition, sulindac and LY294002, a selective inhibitor of phosphoinositide 3-kinase (PI3K), synergistically inhibited the invasion of glioblastoma cells. Furthermore, only celecoxib showed Akt phosphorylation reduction and an anti-invasivness in glioblastoma cells, whereas aspirin, ketoprofen, ketorolac, and naproxen did not. In conclusion, our results provide evidence that down-regulation of Akt pathway and MMP-2 may be one of the mechanisms by which sulindac and its metabolites inhibit glioblastoma cell invasion. |
15546137 | Prognostic factors in oral cavity and oropharyngeal squamous cell carcinoma. | The survival of patients with head and neck squamous cell carcinoma (HNSCC) remains unaffected despite recent therapeutic advances. To reverse this trend, reliable and clinically applicable markers of tumor aggressiveness must be identified. One such marker may be the tumor-associated macrophage content. The authors hypothesized that tumor-associated macrophages contribute to HNSCC aggressiveness, and the objective of the current study was to prove this hypothesis using mRNA expression analysis and a large cohort of clinical specimens. Oligonucleotide microarray analysis was performed on a prospective cohort of 20 patients with previously untreated oral cavity or oropharynx squamous cell carcinoma (OC/OP SCCA) and on normal oropharyngeal mucosa from 4 patients. After determining whether macrophage chemoattractants were produced by tumors, conditioned media from three HNSCC cell lines were used to quantify macrophage migration in an in vitro assay. A high-density tissue microarray of 102 patients with previously untreated OC/OP SCCA was stained immunohistochemically for CD68 to identify tissue macrophages, and the results were correlated with clinicopathologic data and survival. Monocyte chemoattractant protein 1 was up-regulated significantly in tumors compared with normal mucosa (P=0.0025; fold change=1.89). All University of Michigan SCC tumor cell line conditioned media caused a significant increase in macrophage migration (P <0.05). Tissue microarray data revealed that macrophage content of the primary tumor was associated strongly with lymph node metastasis (P <0.0001), extracapsular lymph node spread (P=0.0001), and advanced clinical disease stage (P=0.0002). When it was evaluated along with other clinicopathologic data, the macrophage content was found to be an independent predictor of lymph node metastasis (P <0.0001). Primary tumor macrophage content is a strong predictor of tumor aggressiveness in HNSCC. |
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