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8043802 | [Antihistone activity of bacteria]. | For the first time an anti-histone activity of bacteria has been revealed and a method of its determination has been suggested. Bacteria used in the study and isolated from anterior section of nasal mucosa of the children have been identified on a species level and characterized in terms of their antihistone activity. With employment of light microscopic technique different stages of interaction between bacteria and nuclei of epitheliocytes of anterior section of nasal mucous membrane of children under school age were studied. A biological significance of antihistone activity of bacteria as well as a possibility of its use in biotechnology, Medicine, Ecology is discussed. |
8043800 | [The role of hypoxic-hypercapnic training in reducing local protective factors of the lung in a chronic inflammatory process in bronchopulmonary tissue under experimental conditions]. | The effect of hypoxic-hypercapnic trainings (HHT), conducted before the induction of inflammation or started at next day after foreign body bringing, was shown in experiment on rats with chronic inflammation process in bronchopulmonary tissue. HHT conducted before the induction of inflammation in general had an favourable effect. HHT conducted later had a positive effect together with expressed negative changes, in particular worsening of inflammation process in lung. |
8043801 | [Characteristics of antilysozyme activity of Staphylococcus aureus in various types of experimental infection course]. | The connection between the level of Staphylococcus Aureus anti-lysozyme activity (ALA) and the character of the experimental infection course has been revealed. The subsiding type of infection was developed by infecting by clones with the low ALA and at the same time there was a shift in the structure of population at the final stage of infectious process to the reduction of its heterogeneity in respect of ALA and the preservation of the colonies only with the zero and low ALA. The protracted form of infection was provoked by the clone with the high ALA and the dynamics of microbial dissemination had rhythmical nature and a high heterogeneity in respect of ALA in the structure of population of staphylococcus was preserved and the selection of colonies with the high ALA was observed. ALA of staphylococcus is an important link of pathogenesis of persistence as it determines the duration and dynamics of the survival of the pathogen in the organism. |
8043799 | [The effect of cytostatics on the course and outcomes of experimental herpes infection in rabbits]. | As a result of herpes simplex virus reactivation with holoxan in rabbit reconvalescents with acute primary herpetic keratoconjunctivitis, the ophthalmic herpes relapse was observed and it was characterized by a more severe and prolonged course with longterm viremia and generalization of the infection. In the survived animals the chronic, recurrent ophthalmic herpes was developed. |
8043798 | [The effect of a natural complex of cytokines on oxygen-dependent function of rat vaginal phagocytes]. | Our investigation consisted in 10-days treatment of vaginal mucous membrane wounds in white not inbred rats by introduction of natural cytokines complex into the vagina. At the same time the dynamics of vaginal phagocytes oxygen-depended function change was studied. We have ascertained the activating influence of the cytokines complex on the phagocytes chemiluminescence (CL) that found expression in 2.5-7 times fold augmentation of the CL intensity in comparison with control level (an equal portion of Medium--199 was introduced in the vagina of control-group rats). Having ended the application of the cytokines complex we have observed a rather fast normalization of the cells' activity (by the 15-17 days), consequently the cytokines did not have a distant effect on the oxygen-depended phagocytes function. We consider the activation of the phagocytes in wound as well as the bactericidal effect of the oxygen free radicals generated by the phagocytes as positive result. |
8043797 | [The sesquiterpene lactone "azerin" has memory enhancing properties]. | The memory property of Sesquiterpene Lactone Azerin, isolated from the plant species Ferula compared with placebo (PCO) and clinical well known drug Nootropyl/Piracetam (NOO) were studied on rats. The experiments showed that Azerin in 7-8 times improved the ability of rats to keep the signs of Passive Avoidance Response (PAR), when NOO only in 3-4 times. The learning and transcorneally amnesic electro-shock leaded to 100% PCO, 63% NOO and only 20% Azerin rats retrograde amnesia syndrome. Thus, the mechanisms of amnestic and antiamnestic properties of Azerin have been studied. |
8043796 | [Interaction of glucocorticoids with bone marrow lymphoblast receptors in acute leukemia]. | Two types of receptor systems for glucocorticoids: membranous and intracellular have been found on lymphoblasts of children with acute lymphoblastic leukemia by means of radioassay. They differed by localization and affinity for different glucocorticoids either. Modern radioassay needs modification because of no attention paying for interaction of hormones with different types of receptor system. |
8043795 | [Properties of glucocorticoid-sensitive alkaline proteinases of rat target organs]. | The preliminary characterization of glucocorticoid-sensitive alkaline proteinases of rats thymus and liver was carried out. The role of active serine and cysteine residues in proteolysis was estimated. The influence of Ca++, Mg++, Fe++, Fe , Cu++, EDTA and EGTA on enzymes activity was studied. It is shown that the alkaline proteinases of thymus and liver have similar properties, but are not completely identical. |
8043794 | [Effects of N-acetylasparaginic acid during frontal lobectomy in the rat: antiamnestic action and effect on monoamine level]. | Effects of N-acetyl-aspartic acid (NAA) on the behaviour models "open field", passive avoidance test and content of monoamines and their metabolites in the brain areas on the 9-th day after frontal decortication were studied. NAA (50 mg/kg), i.p., daily, 9 days) exerted antiamnestic effect in decorticated rats, evaluated in passive avoidance test. Corresponding changes in concentration of serotonin and 5-hydroxyindolacetic acid in the brain of decorticated rats were also seen. |
8043793 | [Differences in the action of serotonin 1A-receptor agonists on rotating behavior or rats with unilaterally raphe-lesioned rats]. | The differences between buspirone and 5-methoxy-N,N-dimethyltryptamine (5-MeODMT)-induced turning behaviour has been investigated in rats with unilateral lesions of the dorsal and/or medial raphe nuclei (DR, MR). 5-MeODMT caused a most intensive contralateral turning in rats with MR lesions and least intensive ones in rats with both MR and DR lesions. Effect of buspirone depended on specific raphe nuclei lesions. Rats with unilateral lesions of both raphe nuclei caused a high locomotor activity in stress situation--free run wheels, the lowest ones--rats with DR lesions. |
8043791 | [The detection of cytoplasmic creatinine phosphokinase BB in nerve cell nuclei under normal conditions, in schizophrenia, and in Alzheimer's disease patients]. | This work is devoted to the study of CPK BB content in nuclear fraction of nervous cells in normal brain and in brains of mental (schizophrenia and Alzheimer disease) patients. With the help of the immunocytochemistry and immunoblotting was detected, that the nuclear membrane fraction of brain contains significant amount of CPK BB. On the contrary, in the nuclear membrane fractions of schizophrenic and Alzheimer disease brains the content of this isoenzyme decreased. Therefore in the brain of schizophrenic and Alzheimer disease patients the content of CPK BB decreased not only in cytosolic fractions, but also in the fractions of nuclear membranes. We demonstrated also, that cytosolic CPK BB associates not only with nuclear membranes, but with synaptosomal and microsomal fractions and mitochondrias of normal brain cells. |
8043790 | [The effect of activating agents on the membrane potential of lymphocytes in hypertension patients]. | Changes of membrane potential of lymphocytes of peripheral blood under the influence of the activation agents: phytohemagglutinin, concanavalin A and Ca(2+)-ionophore A 23187 in 25 patients (men) with hypertensive disease and 8 healthy persons (men) aged 25 to 35 years have been studied. The results obtained testify to the existence of functional disturbances of lymphocytes' membrane and confirmed the wide-spread of the membrane defect in patients with hypertensive disease. |
8043789 | [Endogenous intoxication syndrome in patients in late stages of obliterating atherosclerosis in vessels of lower extremities]. | The composition of blood was evaluated (parameters of blood clinical analysis, figures of lipid peroxidation processes and system of antioxidant protection, traditional biochemical blood parameters, total proteolytic activity and peptides of blood plasma, quantity and activity of some parameters of humoral immunity) in patients with late stages of peripheral atherosclerosis. It was showed that chronic endotoxicosis appeared in these patients. The processes of chronic endotoxicosis are compensated in patients with the 3-d stage of low extremities ischemia. The quantity of endogenic toxins and markers of endogenic intoxication increased in patients with the 4-th stage of ischemia and loading on the system of detoxication was enlarged; and as a result, compensation reserves of detoxication system of organism decreased. |
8043788 | [The effect of upper urinary tract interior drainage on urodynamics and contractile function of the ureteral wall]. | S-stents were introduced to the upper urinary tracts of experimental dogs on a period from 1 week to 11 months. It was found mild ureter dilation, the increased ureter pressure, refluxes along the upper urinary tract, the lowered flow resistance during perfusion and diuretic loads. Isolated ureter wall fragments demonstrated the diminished contractility in vitro, and the mode of their contractile force adrenergic regulation was modified. The reduced ureter pressure during large flows after indwelling S-stents to the ureters may be the factor that facilitated the renal and ureter stones removing but the decreased contractility and ureter refluxes emphasized that the period of stent implantation to the upper urinary tracts must be pathogenetically and clinically evident. |
8043787 | [The blocking effect of adrenaline on the thyroid-stimulating effect of vasopressin in rats]. | Effect of various doses of oxytocin, vasopressin or adrenalin on the thyroid gland activity was studied in hypophysectomized and nonoperated rats 20 minutes after a single injection of the neurohormones. The minimal applied dose of the neurohormones stimulated increasing of their concentration in blood up to level typical for stress reaction. Injection of oxytocin led to no effect at any dose. In nonoperated rats vasopressin stimulated the thyroid gland but did not influence on TSH level in blood. In hypophysectomized rats thyrostimulating effect of vasopressin was also detected need. Adrenalin injection inhibited the thyroid gland function in both nonoperated and hypophysectomized rats. Effect of adrenalin in combination with vasopressin was like the action of adrenalin alone. Thus, it is possible to assume that under stress conditions a high blood level of adrenalin attenuates thyrostimulating effect of vasopressin. |
8043786 | [The effect of eicosapentaenoic acid and the calcium antagonist isradipin on lipid metabolism and erythrocytes in experimental hypercholesterolemia in rabbits]. | The effects of eicosapentaenoic acid (EPA) and a new dihydropyridine calcium antagonist isradipine on plasma cholesterol free fatty acids (FFA) and erythrocytes have been studied in 48 cholesterol-fed rabbits after 3-month experiment. EPA had no statistically significant reduction of total cholesterol, FFA but showed the accumulation of cholesterol in plasma and altered morphological and functional properties of erythrocytes. Isradipine revealed a dose-dependent reduction of hypercholesterolemia. levels of FFA in plasma and improved functions of erythrocytes. In this way EPA may be suitable for dietary treatment of atherosclerosis, while isradipine may be used for therapy of patients with an antisclerotic vascular system and hyperlipidemia. |
8043785 | [The mechanism of trophic effects of salivary glands on oral mucosa]. | Using standard HPLC method the catecholamines' content in submaxillary salivary glandular tissue and in oral mucous membrane non-stimulated and stimulated by pilocarpine salivary glands during desalivation and saline solution washing has been studied. In stimulated salivary glandular tissue and oral mucous membrane resulted in diminishing of noradrenaline as well. It was concluded that oral mucous membrane gets noradrenaline in period of basal secretion and spends it during stimulated secretion. |
8043784 | [Hypertensive activity of blood plasma of WKY rats with a calcium deficiency in drinking water]. | The effects of low (8.0 mg/l) and normal (80 mg/l) Ca2+ water diets on systolic blood pressure (SBP) and hypertensive plasma activity were studied. At the end of the 16-week experimental period SBP in the low-Ca2+ group of animals was higher than in the control group after the water treatment: 161 sigma 9 and 120 +/- 4 mm Hg respectively. Significant hypertensive plasma activity of the Ca(2+)-deficient rats was noted in all cases. WKY plasma of the rats of normal-Ca2+ group had no significant effect on SBP. Water correction according to the physiologically recommended levels of calcium can prevent the development of arterial hypertension and occurrence of hypertensive plasma activity. |
8043783 | [Na+ and K+ permeability of erythrocyte membranes and their phospholipid composition in hypertension patients]. | The aim of investigation is to study and to compare simultaneously the data of erythrocyte membrane permeability (by Garay and Meyer method, 1979) with the number of the basic phospholipid (method of thin-layer chromatography) in the patients with essential hypertension (EH). 10 patients with EH and 8 healthy subjects (middle age 37 years) male were studied. The general phosphor and the following phospholipids of the erythrocyte membranes were studied: lysophosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, sphingomicin, phosphatidylcholine and phosphatide acids. The quantities were expressed in mkgP/10 erythr. Data comparisons gave us a possibility to establish that the reduction of the relation of flux rate Na+ and K+ in erythrocytes in the patients with EH (1.84 +/- 0.35) in comparison with healthy subjects (3.63 +/- 0.48) is correlated with the general phosphor (P < 0.01) and phospholipid fraction (P < 0.01) reduction. |
8043782 | [Development of super-resistance to hypoxic hypoxia during adaptation to short-term stress]. | Adaptation to intermittent short-term immobilization stress exposure increases the resistance of rats to hypoxic hypoxia. This was evidenced by the fact that in acute experiments in respiration with gas-mixture containing 6% of oxygen, the mortality of control rats was 65% compared with 10% of that of adapted rats. It has been estimated that this protective cross-effect of adaptation to stress is due to more stable and efficient mobilization of external respiration in adapted animals, and to a greater extent, to the fact that adapted rats tissues have gained a capacity of extracting more oxygen from hypoxemic blood compared to control animals. The role of previously stated phenomenon of adaptive stabilization of structures in superresistance to hypoxic hypoxia is discussed. |
8043781 | [The role of posthypoxia reoxygenation in the destruction of cultured hippocampal neurons]. | A comparative quantitative analysis of neuronal death was performed on mice hippocampal cell cultures, which were subjected to hypoxia only or to hypoxia with subsequent reoxygenation during equal time. It was shown that the number of dead neurons significantly increased after 5-7 hs hypoxia followed by 3 hs reoxygenation period, comparatively with neuronal death observed after 8-10 hs hypoxia without subsequent reoxygenation. These results demonstrate that neurodestructive processes initiated by hypoxia develop more intensively during the posthypoxic reoxygenation than during the equal time of hypoxia and suggest the role of free radical and peroxide compound formation in neuronal death after renewal of oxygen access to nerve cells. |
8043780 | [The significance of feedback in accomplishing the rat hypothalamic nonapeptidergic center reaction to short-term immobilization stress]. | Stress response of oxytocin- and vasopressinergic cells in the supraoptic and paraventricular centers of the hypothalamus was studied morphometrically in rats with intact hypophysis and 7 days after hypophysectomy. Severe immobilization (for 20 min.) was applied as an unspecific short-term stress. In nonoperated rats the immobilization resulted in diminution of functional activity of vasopressinergic cells in the paraventricular nucleus exclusively: nucleolar volume of these cells reduced to 80% (P < 0.05). The same pattern of reaction of nonapeptidergic cells was revealed in the hypophysectomized rats under stress immobilization. The stress blood concentration of vasopressin, ACTH, 11-HOCS clearly increased in nonoperated rats but not in the hypophysectomized rats. TSH plasma concentration and the thyroid gland activity did not alter under stress in both groups of rats. Thus, the data evidence for the response of nonapeptidergic hypothalamic centers is not influenced by fluctuations of the hormone level in blood under short-term stress. |
8043779 | [Dynamics of changes in rat cerebral cortex electrical activity with neuropathic trigeminal neuralgia]. | The dynamics of expressivity of spontaneous epileptiformic activity, increase of evoked potentials, afterdischarges in somatosensory cortex were studied in the rats with infraorbital nerve compression in acute experiments during 6 months. It was shown that these changes were more expressed in hemisphere, contralateral to compressed nerve and were recorded during 1 week after compression already. In the course of time frequency of the recording of the spontaneous epileptiformic activity in the rat population increased while evoked potential increase and after discharges were more expressed in 3-6 weeks after compression. This dynamics is evidence the supposition about formation of central generator of pathologically increased excitation and pathological system which includes of both hemispheres. |
8043778 | [Features of mast cell status and blood coagulation during long-term administration of noradrenaline in mountain dogs]. | The total number of mast cells and their forms is increased, degranulation is weakly marked in dogs permanent of medium altitude (1650 m) in comparison with low altitude dogs (760 m) after the long-term NA injections addition with reaction similarities some differences were observed. The total number of mast cells is decreased less considerably, the number of average forms of maturity and to some extent the number of the third power degranulation are increased in altitude dogs. The decrease of the high altitude adaptive heparin level is observed, the activity of fibrinolytic system is marked facilitating the prevention of microcirculatory disturbances. Thus, mast cells and hemocoagulation systems of altitude are more resistant to the long-term noradrenaline loadings. |
8043777 | [Serotonin-producing cells during normo- and hypothermia]. | Ultrastructure of the serotonin-producing (EC) duodenum cells of a hibernant in euthermia (in summer and winter) and hypothermia has been studied. It has been found that EC cells of an active summer and spontaneously arousal animals belong to active population. This cells have protein-synthetic activity. The winter cells are characterized by the deficiency of the synthetic processes and the secretory granules disintegration. The results support the hypothesis that ES cells are an important element in the regulation of the hibernation. |
8043776 | [The role of sympathetic and parasympathetic nerves in the development of vagotomic tachycardia]. | According to some authors the vagus tonus isn't observed at all and the cause of vagotomic tachycardia is the sympathic nervous system excitement. Our investigations have found the causes of different opinions; in particular, we have showed that vagotomic tachycardia appears much earlier then sympathetic nervous system excitement. It confirms the earlier formulated idea about vagus tonus presence and it's role in the heart work regulation. The sympathic nervous system tonus isn't marked at all. |
8043775 | [The role of invertors in the mechanism of heart function regulation]. | Decrease of heart contraction function and rate, diminish of adreno- and fluoride-sensitivity of adenylate cyclase was detected under the long-time isolated rat's heart Langendorff's perfusion. Injection of rat with the Actinomycin D (an inhibitor of transcription) prevented the decline of hearts' function and adenylate cyclase activity. The addition of cytosol from cells of long-term perfused heart decreased the adrenosensitivity of adenylate cyclase of intact animal heart membranes. Actinomycin D prevented this effect. The appearance of cellular factor, which down-regulates adenylate cyclase activity (named by us an invertor) into the heart under the long-time perfusion is discussed. |
8043769 | [DSA with mechanically injected carbon dioxide. Animal experimental results]. | Carbon dioxide was used as an intra-arterial contrast medium by mechanical injection in 10 pigs. 127 angiographic examinations of 114 vascular territories were carried out and 93 were successful. A mechanism providing even gas volumes was chosen to obtain reproducible volume and pressures when using a compressible medium such as gas. Gas pressure is exponentially correlated with volume and volumes of 20-50 cm3 at 1000 mbar adequate for filling various infradiaphragmatic vascular areas. In parenchymatous organs, gas filling is seen only as far as third order arteries. The reason for this is escape of gas through preexisting arteriovenous fistulae into the efferent veins. |
8043768 | [The determination of the ovarian dosage in defecography on a digital C-arm unit]. | When using defaecography as a radiological tool for diagnosing the anorectal function in female patients, the ovaries are inevitably directly exposed. With the aim of minimising the ovarian dose applied both the area-dose product and the surface dose above the ovaries were measured during investigations of female patients with a digital C-arm unit. These values were converted into ovarian doses using tissue-air ratios. From the surface dose measured with TLD-100 a mean ovarian dose of 15.6 +/- 8.6 mGy was derived. The contributions of screening and film exposures were similar. A reduction of screening time by 10 seconds or omission of 60 film exposures results in a decrease of ovarian dose by values between 0.7 and 2 mGy. Employing a greater focus-skin distance during defaecography, however, made it possible to reduce the ovarian dose by 26%. |
8043767 | [Osteoplastic bone metastases in prostatic carcinoma: magnetic resonance tomography and bone marrow scintigraphy]. | MRI of the vertebral column was performed in 28 patients with histologically confirmed prostate carcinoma. Besides routine spin-echo sequences all patients were examined with gradient-echo sequences using the chemical shift mode. In addition, in all patients bone marrow scintigraphy (BMS) was performed, and all results were compared with routine bone scan (BS). In our study BMS was not superior to bone scan. In contrast, MRI scan revealed solitary metastases in two patients with negative BS and BMS. Osteoplastic metastases showed a contrast enhancement in the MRI and could be distinguished from benign alterations. |
8043766 | [The determination of the T2* relaxation time for characterizing trabecular bone]. | Spongy bone produces local magnetic field inhomogeneities and leads to shortening of the transverse relaxation time from bone marrow. This increased signal decay affects the T2 relaxation time. Measurements of the T2* time from the 4th lumbar vertebra were carried out in 48 normals and 20 patients with osteoporosis. A special multigradient echo technique was used, the echo times selected in relation to phase coherence of the water and fat signals. T2* times showed slight increase in relation to age. Patients with osteoporosis showed significantly increased T2* times (19.9 +/- 3.8 ms) compared to the normal control group (13.4 +/- 1.9 ms). From these findings it is possible to judge the quality of the trabecular structure. |
8043765 | [Functional spectroscopy: the limits and potentials of a new method for the study of brain activation with MR tomography]. | The possibility of examining brain activity by means of localised spectroscopy was studied in relation to its neurological basis. Measurements on 18 normals during optical stimulation showed an improvement in signal to noise ratio compared with functional imaging of almost one order of magnitude. Time dependent measurements during stimulation by a 500 ms light impulse showed definite delay of increased blood flow when compared with oxygen utilisation. The excellent signal to noise ratio and the inherent stability of the method permits reliable detection of weak effects such as are caused by finger tapping or electrical stimulation. |
8043763 | [CT and MRT in progressive multifocal leukoencephalopathy (PML)]. | Radiological findings and course of progressive multifocal leukoencephalopathy in 14 patients (1 woman, 13 men; 13 HIV seropositive, 1 chronic lymphatic leukaemia) were analysed retrospectively and correlated with clinical symptoms. A total of 21 CT and 16 MRI studies were evaluated. CT scans and MR images of 9 patients, which had been obtained in less than two weeks, could be compared to each other. MRI was superior to CT: 6 lesions with a diameter of 1 cm and below were not detected on CT scans, in 5 patients the extent of lesions was underestimated. Cortical involvement, mass effect or signs of atrophy were missing. Only 1 of 67 lesions showed a tiny enhancement after Gd injection. Due to the pattern and spread of lesions, which showed a close correlation to the neurologic symptoms, three different types of PML are suggested: 1. initial precentral demyelinisation with contralateral hemiparesis (n = 8); 2. lesions in temporo-occipital locations with visual disturbances (n = 2); 3. predominantly bilateral lesions of cerebellar white matter with ataxia (n = 4). |
8043764 | [The use of the T2-weighted turbo-spin-echo sequence in studying the neurocranium. A comparison with the conventional T2-weighted spin-echo sequence]. | T2-weighted spin-echo imaging is the standard screening procedure in MR imaging of the neurocranium. We evaluated fast spin-echo T2-weighted imaging (TT2) of the neurocranium in comparison to conventional spin-echo T2-weighted imaging (T2). Signal-to-noise and contrast-to-noise ratio of normal brain tissues (basal ganglia, grey and white matter, CSF fluid) and different pathologies were calculated. Signal-to-noise ratio and contrast-to-noise ratio were significantly higher in TT2 than in T2 (with the exception of gray-to-white matter contrast). Tissues with increased content of water protons (mobile protons) showed the highest contrast to surrounding tissues. The increased signal intensity of fat must be given due attention in fatty lesions. Because the contrast-to-noise ratio between white matter and basal ganglia is less in TT2, Parkinson patients have to be examined by conventional T2. If these limitations are taken into account, fast spin-echo T2-weighted imaging is well appropriate for MR imaging of the neurocranium, resulting in heavy T2-weighting achieved in a short acquisition time. |
8043762 | [The computed tomographic diagnosis of inflammatory abdominal aortic aneurysms]. | Amongst 1599 patients undergoing surgery for abdominal aortic aneurysm, there were 89 patients (5.6%) who showed typical features of inflammatory aneurysms of the abdominal aorta (IAAA). 37 of the 89 patients had been examined preoperatively by CT. In 73% of the cases (27/37) a correct diagnosis had been made. Localisation, width and extent of the IAAA was correctly diagnosed in all patients. Involvement of the renal arteries by the inflammatory process, the extent of thrombus and of mural calcification were accurately shown. The inflammatory tissues were typically ventral and lateral to the aorta. Frequently, there were adhesions to neighbouring structures. Aortic rupture, aortic dissection and retroperitoneal lymphoma may produce similar CT appearances; nevertheless, CT remains at present the method of choice for the diagnosis of IAAA because of its high sensitivity. |
8043761 | [Radiation-exposure studies of CT diagnosis with the standard and spiral technics]. | Comparison of the radiation exposure during CT quoted in the literature shows considerable variation; this depends on differences in apparatus, methods of examination and measurements. A systematic investigation into radiation dose during CT is therefore necessary to obtain accurate radiation doses during various examinations in order to balance risks against usefulness. The present paper deals with the radiation dose received by the patient during examinations of the cerebrum, neck, thorax, upper and lower abdomen and pelvis, using standard and spiral CT techniques. Organ doses for all organs at risk, surface dose, total body dose and dose profiles along the body axis for each type of examination have been established, which will allow the user to evaluate radiation dose. |
8043760 | [The value of the supine chest x-ray with digital luminescence radiography in relation to the experience of the observer. A ROC analysis in CT-validated cases]. | The aim of the present study was to evaluate supine chest radiographs obtained by DLR for the diagnosis of pleural and parenchymatous changes and to compare the accuracy of observers in relation to their experience. 50 examinations, which had been checked by CT, were chosen. The images were examined by 7 doctors (2 non-radiologists, 5 radiologists). Our experience indicates that DLR has high specificity but low sensitivity for the diagnosis of a pneumothorax but relatively high sensitivity and low specificity for other changes (pleural effusions, atelectases and other intrapulmonary opacities). The area under the ROC curve averaged over the 7 rater was similar for these 4 entities. There were marked differences between the observers; the radiologists were considerably better than the non-radiologists. Altogether, the diagnostic value of single DLR examinations was relatively low. In indeterminate cases, additional diagnostic methods should, therefore, be used. |
8043759 | [High-resolution CT (HRCT) of the lung in Wegener's granulomatosis]. | HRCT of the lung and plain chest X-ray were performed to reveal pulmonary manifestation in primary diagnostics or reevaluation of 35 patients with Wegener's granulomatosis. Pleural and parenchymal pathology was detected in chest X-ray of 20 (57%) and in HRCT of 30 (85.7%) patients. Granulomas with and without cavitations and with smooth or spiculated margins were deemed pathognomonic. Nonspecific findings were infiltrates, thickened interlobular septae and fibrotic changes of parenchyma and pleura. Ground glass opacities, traction bronchiectasis and small cysts were only visible on HRCT. As expected HRCT proved to be more sensitive in detecting subtle lung alterations than plain film chest X-ray. It helps to differentiate acute inflammatory and thus potentially curable processes from chronic fibrotic changes in Wegener's granulomatosis. |
8043758 | [High-resolution computed tomography (HRCT) of the lung in collagenoses: a prospective study of 73 patients]. | To determine pulmonary features of collagenous vascular diseases as assessed by high resolution computed tomography (HRCT) we performed a prospective study of 73 consecutive patients, 44 with rheumatoid arthritis (ra), 11 with progressive systemic sclerosis (pss), 8 with systemic lupus erythematosus (sle), 5 with sjögren's syndrome, 3 with dermato-/polymyositis and 2 with mixed connective-tissue disease. Pathological lung changes were demonstrated in 70% of patients with ra, 91% with pss, 63% with sle and 60% with the rest. HRCT features included: intralobular thickening (48%) with a predominance in posterior lower and middle lung areas, pleural thickening (48%) with a predominance in upper lung areas, prominent interlobular septa (37%), subpleural lines (33%), parenchymal bands (33%) with a predominance in lower and anterior lung areas, honeycombing (33%), ground glass pattern (29%) with a predominance in upper and middle, micronodules (18%) with a predominance in upper lung areas and bronchiectasis (14%). HRCT is an important means for the assessment of lung changes associated with collagenous vascular diseases and a definite diagnosis is possible in most cases. |
8043756 | Theoretical dynamics of the cyclin B-MPF system: a possible role for p13suc1. | In dividing cells, entry into mitosis is caused by maturation promoting factor (MPF), which is formed autocatalytically by activation of a complex of p34cdc2 and cyclin B. This biochemical system may oscillate, causing repeated mitosis. It is shown mathematically that the oscillatory tendency would be enhanced by a cofactor which binds to MPF and inhibits its autocatalytic action. A candidate for such a cofactor is the suc1 gene product p13, which binds to p34cdc2/cyclin B complex and inhibits MPF-induced MPF activation. At a steady rate of cyclin biosynthesis, with small amounts converted to MPF, p13suc1 would have to be titrated by MPF before autocatalysis could begin. This would have three possibly important effects: (1) it would determine the 'threshold' cyclin accumulation (and hence the corresponding time-delay) for MPF activation; (2) it would cause the accumulation of a backlog of MPF precursor (tyrosine-phosphorylated p34cdc2/cyclin B) sufficient to produce a substantial MPF pulse when MPF autocatalysis begins; (3) it would give the autocatalysis a high reaction order, which tends to destabilize the steady state, promote autonomous oscillations, and enhance the triggering property (excitability) of the system. The MPF pulse generated by this system may be essential for the proper triggering of the events of M phase, including the cyclin degradation which inactivates MPF at the end of M phase. This model offers explanations for several puzzling effects of p13suc1, including the fact that p13suc1, though an inhibitor of MPF activation, is nevertheless necessary for mitosis. |
8043755 | Rapid exploration of alternatives via chaos. | Temporary chaos facilitates a rapid exploration of alternative asymptotic possibilities. The phenomenon of alternative-exploration via chaos is shown to have a finite probability of occurrence for a class of dynamical systems, the evolution of which is described by (complex) analytic maps. The ability to explore alternatives confers an adaptive advantage, and the possible relevance of temporary chaos to rapid mutations is discussed. |
8043754 | What determines the basal metabolic rate of vertebrate cells in vivo? | Do vertebrate cells dictate basal metabolic rate or does the organism have some influence over this decision? In this paper we advance the idea that the rate of delivery of essential nutrients to cells could be a key regulatory mechanism, a concept which originates for Coulson (Comp. Biochem, Physiol., 84A, 1986, 217-229) that we have extended to the delivery of substrates to enzymes at the intracellular level. |
8043753 | Optimization by trees on simple adaptive landscapes. | We evaluate the optimizing ability (rate of adaptation) of trees on simple adaptive landscapes. At points away from a peak, there is a strong negative relationship between rate of adaptation and tree precision P, a relationship that is independent of the size of the tree. P measures the variability among trial solutions generated by the tree: high precision trees have low variability, low precision trees have high variability. Near a peak, the situation reverses, with high precision trees showing higher rates of adaptation than low precision trees; however, for all trees, the absolute rate of adaptation is uniformly low. On multiple-peak landscapes, the probability of crossing an adaptive valley from a lower peak to a higher peak is also negatively correlated with tree precision. These results suggest that under a wide range of conditions, trees with low precision are, on average, the best optimizers. |
8043752 | Learning synergy in a multilevel neuronal architecture. | An artificial worlds model of the brain has been developed that integrates memory, intraneuronal dynamics and multilevel evolutionary learning. The model includes two major subsystems. The first is a memory-manipulation scheme, called the reference neuron system, that serves to orchestrate a repertoire of neurons with different input-output capabilities. Signals impinging on these neurons are integrated by a cytoskeletal structure that is simulated as a cellular automation. The second subsystem is an evolutionary learning scheme, called the selection circuits system, that serves to train the neurons in the repertoire by varying the cytoskeletal proteins that control signal flow or readouts. The integrated system comprises two layers of cytoskeletally controlled neurons and two layers of reference neurons. Evolution can occur at the level of readout enzymes in neurons, at the level of proteins that control the flow of signals in the cytoskeleton and at the level of reference neurons that orchestrate the repertoire. The integrated system controls the motion of a modeled organism that is embedded in an artificial environment consisting of barriers, food and a target. The organism effectively learns to use patterns of barriers in its local environment to find the target, using food as a reward. Experiments with the model show that the integrated system enjoys significant computational synergies that make it more powerful than the component systems standing alone, that interactions between different levels at which variation can occur exert significant control over the tempo of evolution, that the synergies between different components and levels becomes more important as the environment becomes more complex and that mutation strategies that significantly slow down the rate of learning significantly decrease the degrading effects of environmental noise on performance. |
8043743 | [Lyme disease: a multisystemic condition]. | While Lyme's Disease is clinically well known since 1920, its complete ascertainment and its etiological agent, as well as the details of its transmission mechanisms and multisystemic clinical manifestations (mainly dermatological, cardiac, neurological and articular) have been only recently known. In Spain, the number of papers published on this affection has increased lately, although its understanding is still not as generalized as it should be. This review focuses mainly on our country's experience, as well as on its clinical characteristics. We think that it is a very important affection, since its estimated incidence is 500 cases per year, a significant figure compared to other European countries. |
8043742 | [Maxillary sinus lymphoma associated with HIV infection]. | We present the case of a patient with positive antibodies against the human immunodeficiency virus, erroneously diagnosed, on the basis of conventional radiology and clinical signs, as right maxillary sinusitis. CT showed a tumoral mass at the maxillary sinus, with histology of highly malignant Non-Hodgkin's Lymphoma (NHL). The chemotherapy (CHOP) resulted in clinical remission, but the appearance of acute myelodepression forced the staggering of cycles, resulting in recurrency of the disease. The addition of G-CSF allowed to continue chemotherapy at full doses, again with positive responses. The lymphoma located at the maxillary sinus is extremely rare in patients with AIDS. Chemotherapy is complicated by myelodepression and the frequent development of opportunistic infections. The use of stimulant factors of the hematopoietic growth facilitates the management of AIDS-associated neoplasias. |
8043741 | [Adult respiratory distress syndrome secondary to varicella pneumonia in an immunocompetent male]. | We present a case of varicellous pneumonia in a 40-year-old patient without immunitary compromise, who quickly evolved to respiratory distress in the adult and required sustained ventilatory support. We review the literature, with special mention to the indications of the antivirical treatment with Aciclovir. |
8043740 | [Varicella pneumonia in a healthy adult. Review of risk factors and treatment]. | We present the case of a healthy adult patient without underlying risk factors, who developed bilateral pneumonia and respiratory failure during an outbreak in his family of infection by the Varicella-Zoster virus. IV. acyclovir treatment was begun with good clinical and radiological response and improvement in blood-oxygen levels. We review below risk factors and patients susceptible to treatment with acyclovir. |
8043739 | [Wilm's tumor in adults. Review of the literature on prognostic factors and treatment]. | The incidence of adult Wilms' tumor is difficult to determine but the lesion is rare. The prognosis is poorer than in children, but in adults is often diagnosed at a higher clinical stage and with an unfavorable histologic type. There may be other reasons for the poor prognosis as well. A 33-year-old woman with metastatic disease (bilateral kidney tumors, pulmonary and multiples lymph nodes metastases) is described. Treatment with chemotherapy consisted of doxorubicin, ifosfamide and etoposide which resulted in complete remission that persisted for only three months. The factors that probably contributed to rapid progression included un favorable histology (predominant nodular blastematous elements which were anaplastic) and advanced disease. The precise histologic diagnosis was late precluding to plan the correct treatment. |
8043738 | [Self-induced Cushing's syndrome due to dexamethasone abuse in nasal spray: clinical and biochemical study]. | We studied a 55-year-old woman with remarkable cushingoid features, which presented biochemical evidence of suppression of the hypothalamus-hypophysis-adrenal axis. In the detailed anamnesis, we discovered that the patient had used during more than two years a nasal spray containing dexamethasone. In the initial assessment of the suprarenal function, in addition to suppressed concentrations of cortisol and ACTH, we observed the absence of response to acute stimulus (insulinic hypoglycemia and short ACTH test), as well as a normal response to sustained ACTH stimulus. After discontinuing the intranasal administration of dexamethasone, the patient remained asymptomatic; the basal concentrations of ACTH and cortisol, as well as the levels of urinary free cortisol, were normal at 3 months and the responses of cortisol and ACTH to their stimulus were restored to normal levels at 6 months. We conclude that in the cases of Cushing's syndrome with suppression of the hypothalamus-hypophysis-adrenal axis, it is necessary to conduct a detailed investigation on the consumption of glucocorticoids through unusual ways. The presence of a normal response to the sustained stimulus with ACTH may be a quick recovery index of the suprarenal function. |
8043737 | [Effects of low doses of desmopressin (DDAPV) on gonadal and adrenal development, and on the testicular function and sperm motility]. | The present study proved that desmopressin (DDAVP) (1 microgram DDAVP/12 h/5 días) does not affect ovary, testis and adrenal development in immature Wistar rats (17 days old), because the DDAVP does not modify the weight of the aforementioned organs as compared with the control group. Nevertheless, the male adults Wistar rats (80 days old) showed lower serum testosterone concentrations than the control group, after injection of 4 micrograms/day (2 micrograms/12 h) or 8 micrograms/day (4 micrograms/12 h) of DDAVP during a 5 days period time. Moreover, paradoxical significant lower concentrations of serum testosterone were found in 4 micrograms DDAVP/day-treated rats than in 8 micrograms DDAVP/day-treated ones. The former also showed a decreased number of spermatozoa as compared with the latter and with the control group. The percentage of mobile spermatozoa was lower in rats treated with both concentrations of DDAVP as compared with the control group. Therefore, desmopressin does not delay gonadal and adrenal growth in immature rats, but, at low doses, it affects the testicular function and the mobility of the spermatozoa in male adult rats. |
8043736 | [Pyogenic liver abscess. Study of 20 patients treated with percutaneous drainage]. | We conducted a descriptive study of pyogenous hepatic abscesses (PHA) and their treatment with percutaneous drainage and antibiotherapy in the general hospital of Galdácano between 1989 and 1992. We assessed prevalence, clinical characteristics, responses to treatment, evolution and complications. We studied 20 PHAs in adults confirmed through puncture guided with echography and/or computerized tomography. We considered as causal germs those isolated in the abscess and/or hemocultures. All the patients were treated with catheter drainage and antibiotics. After discharge, follow-up and regular TC controls were performed at least for 6 months. The average age of the patients was 56 +/- 3 years and the men/women rate was 2.5:1. The most frequent origin of the infection was cholecystitis/cholangitis in 50% of patients and hydatidic cysts in 20%. Twelve patients had isolated abscess and 8 patients, multiple abscesses. The diagnostic sensitivity was 95% for the echography and 100% for CAT. The most frequent germs were E. Coli, Streptococcus, K. pneumoniae and Salmonella spp. In three cases, it was not possible to bacteriologically identified the germ. After drainage, the abscesses disappeared in 16 patients. The average duration of percutaneous drainage was 10 days. Three patients required surgery after drainage due to complications or incomplete drainage; two other patients required extirpation of hydatidic cysts. The mortality rate was 10%, although it was not related to PHA. We did not observe any differences between isolated or multiple abscesses with regard to prognosis. The drainage guided by echography and/or CT, associated to antibiotic therapy, is a successful technique for the treatment of PHAs in most patients.(ABSTRACT TRUNCATED AT 250 WORDS) |
8043735 | [Intestinal tuberculosis in patients with and without HIV infection]. | To Study the main characteristics of intestinal tuberculosis (ITB), comparing patients with and without infection by HIV (HIV and non-HIV, respectively). The clinical records of patients diagnosed of this disease in the past five years in our center, were retrospectively reviewed. We used as inclusion criteria the histological and/or microbiological corroboration of the intestinal anatomical piece or the bacteriological and/or histological corroboration of tuberculosis at any other location with clinical and radiological signs compatible with intestinal affection. Two groups were established according to the serological results for HIV: HIV and non-HIV. We studied seven cases, three of them infected by the HIV. The mean age of HIV patients was 23 years, whereas the mean age of non-HIV patients was 49 years. Three non-HIV patients referred pulmonary tuberculosis when they were young. The interval between the onset of symptoms and the diagnosis in HIV patients was 45 days, ranging in the non-HIV patients between one month and four years. All the patients had abdominal pain. Six patients, including three HIV, had fever and constitutional syndrome. Thoracal radiography showed tuberculosis activity, bacteriologically demonstrated, in a HIV patient and in a non-HIV patient. Except one HIV-patient, the remainder were laparotomized. In all the HIV patients, intestinal tuberculosis was suspected upon admission, but this was not the case in the four non-HIV patients. CAT was the most useful of all the supplementary explorations conducted. Retrospectively, only four laparotomies were justified, although before this procedure, four patients were incorrectly oriented, one of them infected by the HIV. All the patients showed a good response to an specific treatment. Laparotomy is still a frequent diagnostic method. The characteristics of the HIV patients are similar to the ones of the non-HIV patients. The main differences are: younger ages and shorter time of evolution until diagnosis in the HIV group, and evidence of former or current pulmonary tuberculosis in the non-HIV group. |
8043734 | [Addition of ritanserin to the treatment with propranolol in cirrhotic patients: effects on portal pressure]. | The use of vasodilators to prevent the rupture of esophagic varices (EV) due to portal hypertension (PH) would reduce the portal pressure (PP) as the result of increased portocolateral flow. Rinsaterine, a 5-HT2 receptor blocker, reduces PP in experimental models of PH. This pilot study was designed to verify if ritanserine has a sustained and additive effect to propranolol on PP in cirrhotic patients with PH. Ten chronic patients with EV, under prophylactic therapy with propranolol and with a suprahepatic venous pressure gradient (SVPG) > 12 mm Hg, received ritanserine (0.11-0.14 mg/kg/day). One patients completed one month of treatment due to drug intolerance. Nine patients completed one month of treatment; SVPG did not show any significant variation in four patients and decreased 3 mm Hg in five patients, which were treated during 70 days more. After then, HVPG returned to its previous values except in one patient. The long-term association between ritanserine and propranolol does not improve the results of propranolol. However, the initial response observed in all of these patients supports the role of the serotoninergic system in the PH and states the need for further studies on 5-HT2 blocking for the prophylaxis of EV rupture. |
8043732 | Illiteracy among Medicaid recipients and its relationship to health care costs. | Poor literacy is associated with poor health status, but whether illiteracy is also linked to higher medical care costs is unclear. We characterized the literacy skills of 402 randomly selected adult Medicaid enrollees to determine if there was an association between literacy skills and health care costs. Each subject's literacy skills were measured with a bilingual (English/Spanish) reading-assessment instrument. We also reviewed each subject's health care costs over the same one-year period. The mean reading level of this Medicaid population was at grade 5.6. Mean annual health care costs were $4,574 per person. There was no significant relationship between literacy and health care costs. While there are compelling reasons to improve poor reading skills among Medicaid enrollees, illiteracy in this population does not appear to contribute to the high cost of providing government-sponsored care. |
8043731 | Evaluation of a managed care program for the non-Medicaid urban poor. | In 1988, Detroit and surrounding Wayne County, Michigan, began CountyCare, an innovative managed care program designed to deliver health care services to the very poor while reducing excessive emergency-room and inpatient care. We interviewed 279 former CountyCare participants to assess differences in off-program utilization, use of clinical services, hospitalization, and patient satisfaction among respondents assigned to one of four CountyCare provider groups. Patients responded favorably to CountyCare, although off-program utilization was substantial and emergency-room and inpatient care were not significantly reduced. We conclude that how such a program is managed and administered, and a provider's degree of motivation, govern the extent to which it succeeds in reducing health care costs and increasing patient satisfaction. |
8043730 | Saving rural health care: strategies and solutions. | Health care for rural populations has been threatened in recent years by a significant number of hospital closures and a scarcity of primary care providers. While some factors that influence hospital closures lie beyond the reach of individual facilities, others, such as low occupancy rates and poor management, can and should be addressed through hospital networking, strategic planning, and well-focused marketing. To recruit and retain physicians, communities should develop financial-incentive packages and such alternatives to the traditional fee-for-service medical practice as recruiting older providers, establishing a community-based health maintenance organization, or founding a community-owned and -operated medical clinic staffed by primary care providers. Improving rural health care requires community involvement and commitment, and good planning. |
8043726 | Does subsidizing rural community health centers hurt private practice physicians? | One reason for the shortage of primary care physicians in rural areas may be these physicians' reluctance to compete for patients with federally subsidized Community Health Centers (CHCs). Yet little is known about the relationship between private practice physicians and physicians in federally subsidized practices who share service areas. We used surveys from a two-state subset of a nationally representative sample to compare practice characteristics of three types of physicians: those who work in CHCs; those in private practice within CHC service areas; and private practice physicians in other rural areas. We found that rural physicians who compete with CHCs earn incomes comparable to physicians in rural areas who do not compete with CHCs, and that the percentage of Medicaid and uninsured patients seen in private physician practices does not increase when a CHC is not in the county. We conclude that CHCs do not provide competitive barriers to physicians in private practice, although we do not know if the presence of a CHC inhibits new private physicians from entering practices in these communities. |
8043725 | Access to infant immunizations for poor, inner-city families: what is the impact of managed care? | California plans to enroll half of its Medicaid population, 75 percent of which are children, into managed care. To measure the impact of managed care on utilization of preventive services, we surveyed 867 families in two inner-city areas of Los Angeles and assessed the relationship between insurance type, source of care, and access to immunization services. Compared to children in public health clinics, those in private physicians' offices or health maintenance organizations (HMOs) had odds of being up-to-date on immunizations of 0.43 (p < .01) and 0.24 (p < .01), respectively. We conclude that in the absence of meaningful financial incentives to encourage private physicians and HMOs to provide immunizations to inner-city children, managed care is unlikely to improve immunization rates among this vulnerable population. |
8043723 | [Cesarean section with subsequent craniotomy in the area of the posterior cranial fossa]. | We report on a 31-year old pregnant patient with von-Hippel-Lindau syndrome who presented to the emergency room with symptoms of increased intracranial pressure. She was found in premature labour with a normal foetus of 29 weeks' gestational age in breech presentation. We discuss an anaesthetic and neurosurgical management during emergent craniotomy and Caesarean section. Caesarean section and posterior fossa craniotomy with resection of an angioblastoma are performed in one setting. Following rapid sequence induction with thiopentone and succinylcholine, anaesthesia is maintained with fentanyl, flunitrazepam and pancuronium; nitrous oxide and volatile anaesthetics are avoided. The advantages of this technique include haemodynamic stability and maintenance of intracranial pressure. Neonatal depression is likely with this technique and requires resuscitative measures. The indications for rapid sequence induction in pregnant patients with raised intracranial pressure at risk for aspiration are discussed. Different options for monitoring during this procedure are described. |
8043722 | [Implications of concomitant therapy with psychotropic drugs in emergency care. Discussion of current literature with reference to a case report]. | This case report deals with an acute psychotic suicidal patient who stabbed two nail-scissors straight into his eyes. The extent of the trauma was unknown primarily during emergency treatment, and an intracranial trauma had to be considered. Furthermore, there was no information on the patient's history including medical therapy or abuse of psychotropic drugs like monoamine oxidase inhibitors, tri- or tetracyclic antidepressants, neuroleptic agents, or lithium salts which could have consequences for subsequent drug administration. The emergency aid management of psychotic patients with the possibility of both an intracranial trauma and an existing psychotropic drug therapy is discussed in this case report. |
8043716 | [Accidental anesthetic overdose caused by anesthesia respirators Servo 900 C and D]. | When working with the anaesthetics vaporizers/respirators of the type Siemens Servo 900 C/D we found differences between the values adjusted at the instrument and those measured by the anaesthetic gas monitor (Sirecust 734 G). Control measurements yielded differences of inspiratory concentrations of halothane and isoflurane that were in excess by up to 80%. We found that the reason for this was the absence of reducing valves at the respirator that would reduce the static pressure of central gas supply from 5.3-5.5 bar to the values of not more than 4.0 bar that are permissible for the vaporizer. It is pointed out that the operation of respirators of this type is safe only provided the prescribed gas supply pressures are observed, if necessary with the help of the appropriate reducing valves, to ensure accurate dosage of volatile anaesthetics. |
8043714 | [Safety and tolerance of a new dipeptide-containing amino acid solution DP-Gln 20 versus a conventional amino acid solution Vamin 18EF in patients after elective colon surgery]. | Recent studies have demonstrated the important role of glutamine in postoperative metabolism. Using dipeptide-containing amino acid solutions it is possible to enhance glutamine supply. Safety and tolerance of DP-Gln 20 (gly-gln, gly-tyr) and Vamin 18EF were investigated in an open, prospective, randomised study. 16 patients received isonitrogenous parenteral nutrition over 4 days. There was no difference in clinical and biochemical patterns between both groups. Complications and adverse events due to the infused amino acid solutions were not observed. |
8043715 | [In vitro study of the formation of NO2 in inhalation of nitrogen monoxide]. | Nitric oxide (NO), an endogenous endothelium-derived relaxing factor, produces profound relaxation of vascular smooth muscle. Thus, inhaled NO is a potent and selective pulmonary vasodilator that may be useful for treatment of pulmonary hypertension of different aetiologies. However, the main danger of NO inhalation is spontaneous formation of toxic nitrogen dioxide (NO2) if NO is added to an oxygen-containing gas mixture. This chemical reaction depends on the time available for the oxidation and the concentration of NO and oxygen. The aim of this study was to assess in vitro the spontaneous formation of NO2 during administration of various NO concentrations with a ventilator. A modified ventilator system is described which can deliver NO within clinically relevant concentrations avoiding excessive formation of toxic NO2. The system was evaluated using an artificial lung. NO and NO2 concentrations were measured by chemiluminescence at the proximal and distal end of the inspiratory limb. In-vitro NO2 formation was assessed during administration of 10, 20, 40, 80 ppm NO while ventilating with an FiO2 of 0.25, 0.5 and 0.75, an inspiratory minute volume of 5, 7.5 and 10 l/min (IMV) and a respiratory rate of 12/min. NO2 concentration correlated with increasing FiO2 and NO concentration and was inversely correlated to IMV. While ventilating with 5-40 ppm NO, an FiO2 of 0.25-0.75 and an IMV of 10 l per minute, the NO2 formation was measured to be less than 0.2 ppm and thus not clinically relevant. During administration of 80 ppm NO the NO2 formation increased to 0.3-0.6 ppm. We conclude that for patients safety concentrations less than 80 ppm of inhaled NO should be used with this ventilator system. In addition, online monitoring of the NO2 concentration in the inspiratory limb should always be performed. |
8043713 | [Fats in parenteral nutrition]. | This paper aims at presenting the properties and actions of individual lipids, as determined via various animal experiments, on the organ systems of the area of the splanchnicus and the lung that are of particular relevance for the intensive-care physician, and to derive possible therapeutic options form these data. Although so far no data are available on newly introduced kinds of fat such as fish oil used in parenteral feeding of critically ill patients, it will be the aim of future therapeutic concepts to arrive at optimal combinations for the individual patient of the pharmacological, energetic and essential properties of the individual classes of fatty acids. Structured lipids may possibly be suitable for this task in an ideal manner, the glycerol molecule of which is esterified with linoleic acid as an essential constituent of food, a medium-chain fatty acid as energy carrier, and an omega-3 fatty acid as immunomodulator. The question as to whether such mixtures can eventually be administered in a not too distant future to parenterally fed patients after trauma and during septic condition for their benefit, can be answered only by means of clinical studies that will have to be conducted in years to come. |
8043711 | Metabolic implications of low-dose triiodothyronine administration in rats: relevance to the adjunctive use of triiodothyronine in the treatment of depression. | The adjunctive use of triiodothyronine (T3) with tricyclic antidepressants is generally believed to augment the efficacy of the tricyclic medications in unipolar, bipolar, and treatment-resistant depression. In the small subset of depressed patients with evidence for overt or subclinical hypothyroidism, the efficacy of supplementary T3 is logically presumed to derive from the amelioration of the hypothyroidism. It is, however, uncertain why adjunctive T3 therapy is often effective in the initially euthyroid depressed patient and if such therapy induces subclinical hyperthyroidism. To determine the metabolic state induced by low-dose T3 treatment, rats were administered nonpulsatile, submaintenance doses of T3 to achieve marked but incomplete suppression of the serum thyroxine (T4) (to 25%-50% of control levels) and serum thyrotropin (TSH) concentrations over a 10-week interval. No statistically significant change in the serum T3 was observed. At sacrifice, multiple parameters of peripheral metabolic status (growth rate, heart rate, organ weights, and tissue alpha-glycerophosphate dehydrogenase activities) in cerebrum, liver, kidney, spleen, and testes were consistent with euthyroidism. Thus, in a centrally regulated T3-predominant environment such as accompanies treatment with submaintenance doses of T3, originally euthyroid animals appear to remain in a euthyroid metabolic state. |
8043710 | Olfactory sensitivity in major depressive disorder and obsessive compulsive disorder. | Olfactory sensitivity to two odorants, isoamyl acetate and androsterone, was assessed in 14 obsessive compulsive disorder (OCD) patients, nine major depressive disorder (MDD) patients, and 16 sex- and age-matched healthy controls. Tests were performed during a drug-free period, and 3 and 6 weeks after initiation of antidepressant drug therapy. No difference in olfactory sensitivity, to either odorant, was found between OCD patients and controls at any time. In MDD patients, a significant increase in the sensitivity to isoamyl acetate was observed 6 weeks after initiation of treatment, compared to controls. |
8043709 | Effects of sleep on the antidepressant response to sleep deprivation. | The effect of a 90-min nap period on mood was studied in 22 sleep-deprived patients with a diagnosis of major depression. All patients remained awake from 7 AM until 12 noon the following day at which time they were permitted to nap while being monitored by sleep encephalography. Fifteen subjects showed a significant response to sleep deprivation as defined by a 35% improvement on the Hamilton Rating Scale for Depression. After the nap a relapse of depressive symptoms occurred which was significantly related to the amount of non-rapid eye movement sleep time. |
8043708 | Persistent effects of antidepressants: EEG sleep studies in depressed patients during maintenance treatment. | Electroencephalographic (EEG) sleep studies represent a research tool that can be used to examine depressed patients over different phases of their illness. We examined the long-term effects of imipramine on EEG sleep in 27 subjects who completed 3 years of maintenance treatment on imipramine without experiencing a recurrence. The analyses were performed on EEG sleep data collected prior to acute treatment, after 3 months in maintenance, and every 3 months thereafter. The major aim was to examine specific changes in rapid eye movement (REM) and slow-wave sleep (SWS) as they unfolded over the course of illness and recovery during long-term drug maintenance. The acute changes in the sleep profile produced by antidepressants remained essentially the same throughout the entire period of drug administration. The REM sleep parameters, which were affected immediately, remained essentially unchanged thereafter, even as long as 3 years into maintenance treatment. A rapid redistribution of slow-wave sleep in the first part of the night was also observed without an increase in the total amount of slow-wave sleep throughout the night. The application of spectral analysis confirmed that the sleep changes following drug administration remained stable throughout all phases of drug treatment. Thus, it appears that sustained clinical improvement is accompanied by persistent sleep alterations on tricyclic antidepressant medication. |
8043707 | CSF neuroactive steroids in affective disorders: pregnenolone, progesterone, and DBI. | Recently several steroid compounds have been discovered to act as neuromodulators in diverse central nervous system (CNS) functions. We wondered if neuroactive steroids might be involved in affective illness or in the mode of action of mood-regulating medications such as carbamazepine. Levels of the neuroactive steroids pregnenolone and progesterone, as well as the neuropeptide diazepam binding inhibitor (DBI) (known to promote steroidogenesis), were analyzed from cerebrospinal fluid (CSF) obtained by lumbar puncture (LP) from 27 medication-free subjects with affective illness and 10 healthy volunteers. Mood-disordered subjects who were clinically depressed at the time of the LP had lower CSF pregnenolone (n = 9, 0.16 ng/ml) compared with euthymic volunteers (n = 10, 0.35 ng/ml; p < 0.01). In addition, pregnenolone was lower in all affectively ill subjects (n = 26, 0.21 ng/ml), regardless of mood state on the LP day, than healthy volunteers (p < 0.05). No differences were found for progesterone or DBI levels by mood state or diagnosis. Progesterone, pregnenolone, and DBI did not change significantly or consistently in affectively ill subjects after treatment with carbamazepine. CSF pregnenolone is decreased in subjects with affective illness, particularly during episodes of active depression. Further research into the role of neuroactive steroids in mood regulation is warranted. |
8043706 | Platelet monoamine oxidase B activity and vitamin B12 in dementia. | The activity of platelet monoamine oxidase B (MAO-B) was highly correlated with the severity of dementia in 39 patients suffering from probable dementia of the Alzheimer type and in 18 age-matched controls. There was no association between a low vitamin B12 level and high MAO-B activity in our sample of patients, who are living in a geriatric hospital where the balanced nutrition of inpatients is controlled by diet assistants. |
8043705 | Increased serum soluble interleukin-2 receptors in Caucasian and Korean schizophrenic patients. | Recent studies have identified immunologic abnormalities in some schizophrenic subjects. This experiment replicates previous findings that serum soluble interleukin-2 receptors (SIL-2Rs) are elevated in schizophrenic patients, and is the first study to describe this phenomenon in non-Caucasian patients. Despite differences between Korean and Caucasian schizophrenic patients in absolute serum SIL-2R levels, both groups were significantly elevated when compared with their respective ethnic control groups (477 +/- 171 U/ml versus 354 +/- 172 U/ml and 763 +/- 347 U/ml versus 567 +/- 231 U/ml, respectively). Neither age, gender, medication status, nor duration of illness correlated with SIL-2R levels. These findings are further evidence that immune activation is present, regardless of ethnic origin, in some schizophrenic patients. |
8043704 | The effects of prolonged lithium exposure on the immune system of normal control subjects: serial serum soluble interleukin-2 receptor and antithyroid antibody measurements. | The purpose of this study was to begin evaluating the effects of lithium carbonate on in vivo immune function in normal controls. We postulated that lithium carbonate would stimulate lymphocytes but would not affect the production of antithyroid antibodies. Twenty-seven normal controls had blood samples drawn for measurements of serum soluble interleukin-2 receptors (SIL-2Rs), antithyroglobulin antibodies, and antimicrosomal antibodies prior to and after approximately 1 and 4 weeks of treatment with lithium carbonate at therapeutic blood levels. Subjects had a small but statistically significant increase in serum SIL-2Rs after 4 weeks of lithium treatment (446.3 +/- 177.2 U/ml versus 497.6 +/- 232.3 U/ml, p = 0.033). There was no increase in the prevalence of antithyroglobulin or antimicrosomal antibodies with lithium treatment nor did lithium act as an adjuvant to increase the titers in subjects with preexisting antithyroid antibodies. |
8043702 | Lung gas volumes and expiratory time constant in immature newborn rabbits treated with natural or synthetic surfactant or detergents. | Immature newborn rabbits delivered at a gestational age of 27 days were tracheotomized and treated, via the tracheal cannula, with clinically recommended doses of natural or synthetic surfactant (Curosurf and Exosurf, respectively). Littermates received 0.1% tyloxapol, 5% Tween 20, or saline. The dose volume of Curosurf was 2.5 ml/kg, that of the other materials 5 ml/kg. Animals were kept in a multiplethysmograph system and ventilated for 30 min with a standardized sequence of insufflation pressures. End-expiratory lung gas volume was calculated at the end of the experiment from measurements of lung weight and total lung volume. Tidal volumes were significantly improved in all groups of animals receiving surfactant or detergents. However, expiratory time constant (determined from the tidal volume tracing) was significantly longer, and end-expiratory gas volume significantly larger, in animals treated with Curosurf than in those receiving Exosurf or detergents. These differences were confirmed by semiquantitative evaluation of alveolar air expansion in histological sections. In addition, airway epithelial necrosis was reduced in animals receiving Curosurf, Exosurf, or Tween 20, but not in animals treated with tyloxapol. The discrepancy between improvements in tidal volume, expiratory time constant, and end-expiratory gas volume reflects failure of lung stabilization in animals treated with Exosurf or detergents, probably due to absence of specific hydrophobic proteins in the synthetic products. |
8043701 | Effects of phenobarbital on cerebral blood flow during hypoxia. | Phenobarbital (PB), at anticonvulsant dosages, has been used in an attempt to reduce hypoxic brain injury in asphyxiated newborn infants. The effects of PB pretreatment on the cerebral blood flow (CBF) response in hypoxia were studied in 15 curarized and mechanically ventilated piglets: 7 animals were pretreated with 20 mg/kg of PB (group 1) and 8 served as untreated controls (group 2). Successive aliquots (25 ml) of carbon monoxide were introduced into a closed ventilator circuit and CBF (measured with radiolabelled microspheres), arterial blood pressure, blood gases, arterial pH and PaO2 were subsequently determined at different levels of hypoxia. The amount of hemoglobin available for oxygen transport (i.e. total Hb-HbCO) was used to express hypoxic aggression and decreased from grade I (> 2 mmol/l) to grade II (1-2 mmol/l) to grade III (< 1 mmol/l). In the control group, CBF increased during grade-I hypoxia and continuously remained above baseline values during grade-II and grade-III hypoxia. In pretreated animals, however, only grade-II hypoxia was associated with a significant increase in CBF above baseline. In addition during grade-III hypoxia, CBF decreased to the prehypoxic values despite a fall in cerebral oxygen delivery and cardiac index. These data suggest that PB should be used with caution to prevent brain damage in the asphyxiated newborn infants. |
8043700 | Effect of blood volume expansion on basal plasma atrial natriuretic factor and adrenocorticotropic hormone secretions in the fetal rat at term. | The effect of a blood volume expansion (1-1.5% of body weight) on atrial natriuretic factor (ANF) and adrenocorticotropic hormone (ACTH) secretions were investigated in 21-day-old rat fetuses injected intravenously through the umbilical vein with 50 microliters of isotonic saline. Basal ANF and ACTH concentrations were determined in the plasma with specific radioimmunoassays over a 30-min observation period. The basal plasma ANF concentration increased rapidly 1 min after blood volume expansion and then decreased to the control value 5 min later. The basal plasma ACTH concentration decreased during the first 10 min after injection and then increased to the control value 30 min after intravascular volume load. The results suggest that the fetal rat in late gestation is able to respond to blood volume expansion by increasing ANF secretion. |
8043699 | Adrenocortical stimulation of stomach development in the prenatal pig. | Development of the porcine gastric proteases (chymosin, pepsin A, B and C) has been studied in the fetal pig in the last third of gestation (term 115 days). The possibility that the prepartum rise in circulating cortisol is involved in gastric maturation was investigated by infusing immature fetuses with cortisol (osmotic minipumps implanted at 82-90 days of gestation). Concentrations of prochymosin in fundic tissue and stomach contents increased before term, correlated positively with log10 plasma cortisol values (r = 0.68-0.76, p < 0.001), and were stimulated by cortisol infusion (p < 0.001). The pH of stomach contents decreased (from pH 7 to 3), correlated negatively with log10 plasma cortisol values (r = -0.69, p < 0.001), and was reduced by cortisol infusion (p < 0.05). Only trace amounts of pepsinogens could be detected in fetal pigs. By immunohistochemistry, it was shown that cortisol increased the number and distribution of prochymosin-containing cells in the fundic gland. Stimulating effects were also observed for the small populations of pepsinogen-reactive cells present in some of the fetal pigs. The results suggest that endogenous cortisol stimulates the rise in prochymosin synthesis and secretion together with increased gastric acidity in the prenatal period of the pig. |
8043698 | Cerebral blood flow autoregulation after moderate hypoxemia in the newborn piglet. | The isotope-labelled microsphere method was used to study blood flow autoregulation in the brainstem (BS), cerebellum (CBL), cerebrum (CBR) and choroid plexus (ChPl) in 21 newborn piglets exposed to hypoxemia and/or hypovolemia. One group of piglets (n = 7) was made hypoxemic by breathing 10% O2 for 10 min, a second group (n = 8) was studied during hypoxemia (10% O2, 10 min), followed by hypovolemia (bleeding 20% of estimated blood volume). A third group of piglets (n = 6) was made hypovolemic by bleeding 20%. Hypoxemia significantly impaired the autoregulatory capacity in CBL and CBR resulting in a pressure-passive flow pattern. Hypovolemia alone did not produce any significant cerebral vascular response in BS, CBL and CBR, not even when hypovolemia was preceded by hypoxemia, indicating a rapid restoration of the autoregulatory capacity of the cerebral vasculature after hypoxemia of moderate duration. The hypotension seen both during hypoxemia and hypovolemia was gradually compensated for and normalized within 60 min. However, animals exposed to both hypoxemia and hypovolemia were still hypotensive 60 min after the hypoxemic insult. Cardiac output (CO) was not affected by hypoxemia, but was consistently reduced in hypovolemia. We therefore speculate that in the newborn a reduced CO might be a more specific parameter for hypovolemia than a low blood pressure. |
8043697 | Value of examination of the gastric aspirate for the diagnosis of neonatal infection. | To evaluate the interest of examination of the gastric aspirate (GA) as a contribution to decision making of initial antimicrobial therapy, all 3,989 neonates delivered in Orléans Maternity Hospital in 1990 have been studied. Microscopic examination: polymorphonuclear leukocytes (PMN) were, respectively, absent/present/abundant in 180/130/25 treated (T) and in 2,567/1,032/90 untreated (NT) newborns. PMN were demonstrated in 2/5 documented, 4/6 obvious, 2/2 suspected and 34/58 possible infections. Bacteria were, respectively, absent/present/abundant in 201/109/46 T newborns and in 2,722/877/56 NT newborns. Bacteria were demonstrated in 3/5 documented, 4/6 obvious, 2/2 suspected and 32/58 possible infections. Culture: the number of initially T and NT newborns was, respectively, for each bacterial species: Enterobacteriaceae 33/294, streptococci B (GBS), D and alpha-hemolytic 60/107, 12/110 and 18/70, Streptococcus pneumoniae 2/2, anaerobes 12/402, Listeria 3/0, Haemophilus species 4/4, Staphylococcus aureus 5/7, coagulase-negative staphylococci 25/1335, Lactobacillus 14/345, corynebacteria 10/196. In the 5 newborns with documented early onset meningitis and/or septicemia, 3 grew with GBS, Escherichia coli and Listeria. In the 4 newborns (2 meningitis and 2 urinary tract infections) with late-onset infection, no positive GA could be demonstrated. Although microscopic examination and cultures were statistically more frequently positive in T newborns, with variations dependent on the species of bacteria, more newborns without infection were colonized whatever the bacteria. Thus, bacteriological results of GA, if considered out of the clinical context, cannot be an argument for treatment. |
8043696 | Abnormal cortical plate (polymicrogyria), heterotopias and brain damage in monozygous twins. | We report 5 cases of abnormal cortical plate (polymicrogyria or microgyric-like pattern) and heterotopias associated with hypoxic-ischemic brain injuries in monochorionic diamniotic twin fetuses of respectively 22, 26, 28, 31, 32 weeks gestation. These fetuses belonged to a series of 5 pairs of patients (10 cases) presenting with the characteristic features of the twin-to-twin transfusion syndrome. Three of them (2 donors and 1 recipient) were macerated and the brains were not available for study. Two (most likely recipient twins) survived. In the remaining 5 fetuses (3 donors and 2 recipients) with neuropathological study there were cortical plate abnormalities. In 2 cases, the cortex was dysmorphic and consisted of focal nodular distribution or vertical stripes of neurons. True polymicrogyria was focal in 2 cases and involved almost the entire surface of the hemispheres in another one. Heterotopias of immature cells were found in 4 cases, either in the white matter or in the cortex or in both sites. There was a focal laminar necrosis only in 2 cases. The morphological pattern of the anomalies depends on the time of occurrence of the insult and on its severity. These abnormalities, although similar to those already described in singleton fetuses, illustrate the variety of cortical dysmorphia which may be associated with fetal hypoxic-ischemic injuries and emphasize the particular vulnerability of the brain in monozygotic twins, whether it belongs to the donor or the recipient. |
8043695 | [The effect of high pressure on induced lipid peroxidation processes in liposome membranes]. | The effect of high pressure on the Fe-ascorbate-induced lipid peroxidation in liposome suspensions has been studied. It was found that hydrostatic or helium pressure up to 140 bar increases the rate of MDA accumulation in this model system. This effect is assumed to be connected with the gain in polarity of the lipid bilayer under hyperbaric conditions. |
8043693 | [Medicinal activation and inhibition of function of glucocorticoid receptors as the basis for regulation of the glucocorticoid effect]. | On the basis of Scatchard and Lineweaver-Burk analysis, it was demonstrated that a series of drugs either activated or inhibited the function of types II and III glucocorticoid receptors. Analgine (0.04-10.0 mM) and sodium salicylate (12.5-50.0 mM) suppress the type II glucocorticoid receptor function of rat liver cytosol. Maradol (5.0 mM) increases the type II glucocorticoid receptors density but decreases the measurable constant for the [3H]acetonide triamsinolone interaction with type II glucocorticoid receptors. Analgine (1.25-10.0 mM) and sodium salicylate (0.62-10.0 mM) increase the type III glucocorticoid receptor function of rat liver cytosol. Maradol (0.25-1.0 mM) suppresses the type III glucocorticoid receptor function. The mechanism of regulation of the glucocorticoid effect by nonsteroid drugs influencing upon the function of types II and III glucocorticoid receptors is discussed. |
8043694 | [The effect of cholesterol level in liposomes on the interaction with blood serum lipoproteins]. | The effect of the cholesterol content in liposomes on their interaction with blood serum lipoproteins has been studied. It was shown that phosphatidyl choline liposomes without cholesterol did not interact selectively with any class of serum lipoproteins. At the same time, addition of high cholesterol concentrations to liposomes confers to them a new feature, namely the ability to interact selectively with the serum low density lipoproteins. Up to 90% of such lipoproteins can interact with liposomes. This finding was confirmed by "in vivo" data. The observed effect of "address" properties given to liposomes by a native lipid may be of interest in search for new possibilities to use liposomes for selective delivery of drugs. |
8043692 | [A comparative analysis of the protein composition of human skeletal and cardiac muscle by two-dimensional electrophoresis]. | Using a modified O'Farrell 2DE technique, the protein composition of human skeletal muscles was compared to that of human myocardium. The variability of protein composition was analysed in nine types of skeletal muscle tissue. A number of skeletal and heart muscles proteins were identified on the electrophoregrams. Both common and tissue-specific groups of muscle tissue polypeptides were revealed. |
8043691 | [Study of human lymphocyte proteins using two-dimensional electrophoresis]. | Using O'Farrell 2DE modified method, a panel of human lymphocyte proteins have been studied. A 2-D map involving 273 fractions characterized in M(r)/pI coordinates has been developed. Some proteins were identified on the map and some comparability of experimental results to the Celis et al. data demonstrated. Ten protein fractions displaying some variability in a sample of 30 patients were revealed. A change in the amount of the E2 fraction M(r)/pI -51.0/5.70 was found among patients with chromosome 5 short arm deletion and translocation. |
8043690 | [Na+/H+- and Na+/Na+-countertransport in human, rabbit, and rat erythrocytes: evidence for the existence of two independent ion-transporting systems]. | The activity and regulatory features of the Na+/H(+)- and Na+/Na(+)-exchange were studied in human, rabbit and rat red blood cells. No basal activity of the Na+/H(+)-exchange (the amyloride-inhibited component of the 22Na+ influx) in erythrocytes of these species was observed. The rate of 22Na+ influx increased rapidly when the experiments were carried out on acid-loaded cells in an alkaline (pH0 = 8.0) incubation medium (delta mu H(+)-induced Na+/H(+)-exchange). The ratio of delta mu H(+)-induced Na+/H(+)-exchange activities in human, rabbit and rat red blood cells was 1.0 : 1.1 : 2.3, respectively, whereas that of the Na+/Na(+)-exchange activities (the phloretin-inhibited component of the 22Na+ influx) in erythrocytes of these species was 1.0 : 4.6 : 0.2. The osmotic shrinkage of rat and rabbit erythrocytes led to the stimulation of the Na+/H(+)- (but not Na+/Na+) exchange. Amyloride (1 mM) inhibited the shrinkage-induced 22Na+ entry as well as the delta mu H(+)-induced 22Na+ entry--by 95 and 10-20%, respectively. Heat treatment (10 min, 49-51 degrees C), disturbing the membrane cytoskeleton suppressed both the shrinkage-induced activation and the delta mu H(+)-induced activation of the Na+/H(+)-exchange. The data obtained indicate that the both transport systems are mediated by two distinct transport carriers. It may be suggested that the delta mu H(+)-induced Na+/H(+)-exchange, on the one hand, and the shrinkage-induced Na+/H(+)-exchange, on the other, are mediated by two different Na+/H(+)-exchanger subtypes. |
8043689 | [A new property of known proteins: specific binding of thyroid hormones by human plasma apolipoproteins]. | The thyroid hormones--thyroxine (T4) and triiodothyronine (T3)--are capable of associating with human plasma high (HDL), low (LDL) and very low density lipoprotein particles (VLDL). Apolipoproteins (apo) act as the hormone-binding components of the lipoprotein particles. The thyroid hormone binding to apolipoproteins is a time-dependent, reversible, saturable and sensitive to specific inhibitors interaction with the structurally isolated site in the protein which is complementary to the ligand. The number of such sites per macromolecule varies from one (apoA-I) to three (apoB-100). Low affinities (Ka approximately 10(5)-10(6) M-1) for T4 are characteristic of apoA-II, apoA-IV, apoE and apoB-100, while apoA-I and its lipid complex, apoA-I-HDL display sufficiently high affinities for the hormone (Ka approximately 10(7)-10(8) M-1). The active site of apoA-I-HDL contains a chemical group interacting with the ionized phenolic ring hydroxy-group of T4, includes cavities capable of accommodating iodine atoms of the ligand molecule, has a hydrophobic nature and low stereospecificity and is located close to the surface of the protein globule in the N-terminal part of polypeptide chain conformationally associated with the polar surface monolayer of the lipid matrix. Three hormone-binding sites in apoB-100 are located in different regions of the polypeptide chain which are distant from each other and lie outside the sites of heparin and cellular LDL receptor binding. ApoB-100 and apoE stimulate T4 entry into fibroblasts, while apoA-I inhibits the interaction of T4 and T3 with human placental plasma membranes. |
8043688 | [Study of hydrogen bonds in the "catalytic triad" of trypsin by NMR spectra at 1H, 13C, and 15N nuclei]. | The 1H and 13C NMR of trypsin stabilized by chemical modification with a hydrophilic polymer have been obtained in a wide range of pH (1.0-11.0). The spectral features referred to some nuclei of the "catalytic triad" have been identified using different NMR techniques as well as chemical modification with selective reagents. It was found that the monoprotonation of this system results in a quasi-symmetrical hydrogen bond formed between the basic groups which provided explanation for the discrepancies between the experimental findings obtained by different authors concerning the protonation site in this catalytic system. Simulation of the catalytic triad by a 15N-labelled low molecular model suggests that an increase in the OH-group acidity is unaccompanied by a discrete double proton transfer; however, a smooth shift of the bridging protons from one basic atom to another occurs with quasi-symmetrical hydrogen bonds formed in intermediate cases. On the basis of experimental data a new concept has been proposed for the mechanism of acid-base catalysis performed by pains of weak basic groups, such as His-Im and Asp(Glu)-COO- (pKa = 3-7) which are not capable of proton abstraction from alcoholic or water OH-groups (pKa > 13). The catalysis may consist in changing the charge densities on the reacting groups due to strong H-bonding and, on the other hand, in facilitating the free movement of a proton in the field of several basic atoms when going along the reaction coordinate. The energy of very strong hydrogen bonds thus formed diminishes the activation energy of the reaction. |
8043671 | Control of microwave heating of peritoneal dialysis solutions. | To determine if microwave heating of dialysis solutions to 37 degrees C produced focal overheating (hot spots) and caramelization of dextrose. In vitro determination of conditions for controlling time, temperature, and procedures. Bags had been stored at ambient room temperature. Solution and external bag surface temperature determinations. Dextrose degradation products determined spectrophotometrically. Microscopy for potential caramel precipitates. A microwave oven with no rotation tray produced uneven heating of bags of two commercially available concentrations of dialysis solutions. The greatest hot spots were evident in spike ports. External bag surface temperatures were within 0.20 degrees C of reservoir temperatures. Initial solution temperatures correlated with temperatures of the solutions after microwave heating (r = 0.895). No statistically significant differences were found between dextrose degradation product concentrations of unheated and heated solutions, including hot spots. No precipitates were observed microscopically. Despite the presence of solution hot spots in bag infusion ports, 37 degrees C temperatures were achievable in the bag reservoirs with no evidence of increased glucose degradation. This outcome is assured if the initial temperature and the microwave conditions (procedure, time, mixing of solution) are held constant, and the external bag temperatures are measured after heating. |
8043670 | Cytogenetic analyses reveal "atypical cells" in the peritoneal dialysis effluent. | Cytogenetic analyses were performed on dividing cells from the peritoneal effluent of 26 patients undergoing chronic peritoneal dialysis (CPD). Numerical and structural abnormalities of karyotype served as the diagnostic criteria for "atypical cells." The following cytogenetic abnormalities were observed in 7 patients: hyperdiploidy (in 6 patients), hypodiploidy (in 2 patients), and marker chromosomes (in 2 patients). In 3 patients more than one chromosome abnormality was present. Dividing cells with normal mitoses were observed in 11 patients, while in the remaining 8 patients no dividing cells could be found. There were no differences in age, sex, duration of dialysis, and peritonitis incidence between patients with pathological mitoses and those without it. The question whether this unexpected finding is a consequence of immunosuppressed uremic status, dialysis procedure, or some other factor remains to be elucidated. |
8043669 | Careful patient selection and dialysis prescription are required for effective nightly intermittent peritoneal dialysis. | To evaluate the adequacy of dialysis in patients on nighttime intermittent peritoneal dialysis (NIPD). Retrospective review of prospectively collected data. Seven patients on NIPD. The fast peritoneal equilibration test (PET) was used to determine peritoneal membrane permeability for small solutes. Adequacy of dialysis measured by 24-hour collections of dialysate and urine for weekly KT/V and creatinine clearance in liters/week/1.73 m2 was assessed in patients with (n = 3) and without (n = 4) residual renal function and evaluated in concert with the patient's clinical status. Outcome for each patient was also noted. Five of the patients had a high-average dialysate/serum creatinine by PET ( > 0.66). Despite a weekly KT/V of 1.7 or more, four of the seven patients on NIPD were uremic and either transferred to hemodialysis or continuous cycling peritoneal dialysis (CCPD). A fifth patient had a KT/V of 1.4 and was also uremic on NIPD. The patient who was clinically well and continued on NIPD had significant residual renal function. NIPD should be restricted to patients with high-average dialysate/serum creatinine as determined by PET and residual renal function or those with high dialysate/serum creatinine. Extended dialysis time and large volumes of dialysate are required for successful NIPD in patients without residual renal function. Accepted parameters of dialysis adequacy used for patients on continuous peritoneal dialysis are not appropriate for intermittent forms of peritoneal dialysis. |
8043668 | In vitro study of the effect of osmotic solutes on the interactions between cells from the peritoneum and peritoneal cavity. | To study how the presence of osmotic solutes in medium affects growth of the peritoneal mesothelial cells and fibroblasts and how osmotic solutes influence the production of factors regulating growth of these cells. The proliferation of mesothelial cells and fibroblasts was evaluated by measuring the incorporation of 3H-thymidine into the cells. Cells were exposed to osmotic solutes; the concentration of the latter in the medium was continuously lowered over the time of the experiment to simulate changes of their concentration in the dialysate. The synthesis of factors influencing the proliferation of the mesothelial cells or fibroblasts, by mesothelial cells or fibroblasts themselves, or by peritoneal leukocytes, was tested by the characteristics of the "conditioned" medium. The conditioned medium was produced by exposing standard medium to mesothelial or fibroblasts monolayer or to peritoneal leukocytes over 24 hours; following filtration it was applied to growing test cells for the study of growth factors. The effect of osmotic solutes on the growth of mesothelial cells is less inhibitory when their concentration is gradually lowered over the time of the study, compared to previous findings with a constant concentration. Peritoneal leukocytes produce growth factors for mesothelial cells and fibroblasts. Glucose and amino acids inhibit production of peritoneal leukocyte-derived growth factors for mesothelial cells, while glycerol increases synthesis of such growth factors for fibroblasts. Mesothelial cells produce factors stimulating the proliferation of mesothelial cells and fibroblasts. In the presence of glycerol or amino acids synthesis of mesothelium-derived growth factors for fibroblasts is augmented. Finally, fibroblasts produce factors that inhibit the proliferation of the mesothelial cells, and this effect is potentiated in the presence of amino acids. Cytotoxicity of the osmotic solutes measured by the inhibition of growth of the mesothelial cells or their increased damage is significantly reduced during in vitro kinetic study when the concentration of these solutes is gradually lowered. Presence of osmotic solutes in the medium affects synthesis of growth factors derived from mesothelium, fibroblasts, or peritoneal leukocytes, which affect the proliferation of mesothelial cells or fibroblasts. |
8043667 | A comparison of clearances on tidal peritoneal dialysis and intermittent peritoneal dialysis. | To compare the small molecule clearances on tidal peritoneal dialysis (TPD) and intermittent peritoneal dialysis (IPD), controlling for dialysate flow rate. Alternating 8-hour treatments on IPD and TPD (2 of each in 6 patients), each treatment separated by 3 or more days [patients returning to continuous ambulatory peritoneal dialysis (CAPD) in the interim] were performed. IPD treatments consisted of 15 exchanges with 2 L/exchange for a total of 30 L/treatment. TPD treatments consisted of 29 exchanges, with an initial fill volume of 2 L, followed by 1 L tidal volume for the subsequent exchanges (reserve volume of 1 L) for a total of 30 L/treatment. Six patients, with a mean dialysate/plasma (D/P) creatinine as determined by the peritoneal equilibration test (PET) of 0.64 +/- 0.10, were studied. Four had a low-average D/P creatinine, while 2 had a high-average D/P creatinine. Urea nitrogen, creatinine, phosphate, and potassium clearances on TPD and IPD were compared using the paired t-test. The dialysate flow rates were 3.7 +/- 0.1 L/hour for IPD and 3.8 +/- 0.2 L/hour for TPD. The mean dialysate dextrose was 1.9 +/- 0.5 g/dL for both. The creatinine clearances were 9 +/- 2 versus 10 +/- 3 mL/minute, the urea nitrogen clearances 19 +/- 3 versus 20 +/- 3 mL/minute, and phosphate clearances 10 +/- 3 versus 11 +/- 3 mL/minute for IPD and TPD, respectively (all not different). The ultrafiltration rates were 2.9 +/- 0.9 mL/minute on IPD and 3.3 +/- 1.6 mL/minute on TPD (not different). On both IPD and TPD the clearances of urea nitrogen, creatinine, and phosphate for the 2 patients with high-average D/P creatinine were higher than for the 4 patients with low-average D/P creatinine. When the dialysate flow rate is controlled and a TPD prescription of 1 L reserve and tidal volumes is used, the small molecule clearances on IPD are similar to those on TPD. |
8043666 | Risk factors for peritoneal dialysis-related infections. | To identify factors associated with peritoneal dialysis-related infections at one center. The study was a retrospective study of a 3-year time period with relatively stable treatment patterns. A single center experienced academic peritoneal dialysis program. Patients (N = 163) receiving peritoneal dialysis (PD) from January 1989 to December 1991 who had received treatment at home for at least one month. None. Catheter-related infection and peritonitis were the main outcome measures. Variables affecting infection rates that were assessed included age, time on PD, prior end-stage renal disease (ESRD) therapy, diabetic status, catheter type, exchange device, nasal carriage of S. aureus, and prophylactic rifampin therapy. Data were analyzed with univariate as well as with a fixed-effects and a mixed-effects gamma-Poisson multiple regression model. Variables associated with an increased risk of new peritonitis included age under 20 years (p < 0.009; rate ratio 4.54) and nasal carriage of S. aureus (p < 0.04; rate ratio 1.75). Decreased new peritonitis risk was associated with the ULTRA Set exchange system (p < 0.008; risk ratio 0.38) and intermittent prophylactic rifampin therapy (p < 0.001; rate ratio 0.99 for each 1% time on therapy). Catheter-related infections were increased in patients who had double-cuff catheters (p < 0.003) and nasal carriage of S. aureus (p < 0.04; rate ratio 1.82). Decreased catheter-related infections were noted in older patients (p < 0.02; rate ratio 0.983/year) and increasing months of study follow-up (p < 0.03; rate ratio 0.97/month). In our program nasal carriage of S. aureus increased the risk of peritonitis and catheter-related infection. Prophylactic rifampin significantly decreased peritonitis, as did use of the ULTRA Set. Single-cuff opaque catheters had the lowest catheter infection rate. Analysis of the relationships between clinical and demographic variables and peritoneal dialysis-related infection rate can identify significant contributing or protective variables and allow peritoneal dialysis programs to develop preventive strategies to minimize the risk of infection. |
8043665 | Cancer antigen 125 is locally produced in the peritoneal cavity during continuous ambulatory peritoneal dialysis. | The local production of cancer antigen (CA) 125 in the peritoneal cavity of 14 continuous ambulatory peritoneal dialysis patients was studied. In addition, the relationship between the concentration of mesothelial cells and CA 125 in the peritoneal dialysate effluent was examined. The median results and ranges were as follows: plasma CA 125 14 U/mL (range 10-23), dialysate CA 125 18 U/mL (range 5.2-76), dialysate/plasma ratio 1.9 (range 0.61-5.4), and number of mesothelial cells 400/mL (range 10-5000). Peritoneal concentrations of mesothelial cells and CA 125 were positively correlated (r = 0.50, p < 0.01). Using a monoclonal antibody, CA 125-positive cells were found in the cytospin preparations of the cells of dialysis effluents. All these CA 125 positive cells were also positive for cytokeratin used as a mesothelial cell marker. In vitro experiments using mesothelial cells in monolayers showed a linear increase in CA 125 concentration both in time and in relation to the number of mesothelial cells. From these experiments a production rate of 24 U/hour/10(6) cells could be calculated. It is therefore concluded that CA 125 is locally produced in the peritoneal cavity during CAPD and that the mesothelial cells are the major source of this CA 125. |
8043664 | Insulin therapy in uremic diabetic patients on continuous ambulatory peritoneal dialysis; comparison of intraperitoneal and subcutaneous administration. | To compare, in diabetic uremic patients on continuous ambulatory peritoneal dialysis (CAPD), the effects of two patterns of insulin administration, four times daily subcutaneous (SC) injections and intraperitoneal (IP) route, on blood glucose, insulin, lactate, beta-hydroxybutyrate and glycerol levels. We examined 6 uremic insulin-dependent diabetic patients on CAPD. The two insulin regimens, SC and IP, were tested successively in randomized sequence in each patient. At the end of each treatment period we determined the 24-hour profiles of blood glucose, free insulin, lactate, beta-hydroxybutyrate, and glycerol. Mean blood glucose over 24 hours (SC 7.21 +/- 0.61 mmol/L, IP 7.49 +/- 0.93 mmol/L), Schlichtkrull's M value, an index of glycemic control and stability (SC 10 +/- 3, IP 10 +/- 5), and the blood intermediate metabolites beta-hydroxybutyrate, lactate, and glycerol were similar in both groups. Mean serum free insulin was significantly higher during subcutaneous treatment (SC 257.4 +/- 127.2 pmol/L, IP 170.4 +/- 83.4 pmol/L, p < 0.001). Insulin requirements were 2.5 times greater for the intraperitoneal route (SC 51 +/- 4 U/24 hours, IP 130 +/- 43 U/24 hours). In uremic diabetic patients on CAPD, good glycemic control may be achieved either with subcutaneous intensive insulin therapy or with intraperitoneal insulin administration. The latter method allows reduction of circulating free insulin levels, but requires a higher dose of insulin per day. |
8043663 | The effect of serum albumin at the start of continuous ambulatory peritoneal dialysis treatment on patient survival. | To analyze the effect of serum albumin using immunoturbidimetry, demographic, biochemical, and kinetic factors on survival of continuous ambulatory peritoneal dialysis (CAPD) patients. A review of prospectively collected data in a 2-year follow-up study of peritoneal transport kinetics. University medical center. Sixty-one patients, evaluated within 3 months after the start of CAPD. Covariables used in the survival analysis were plasma urea, and creatinine, albumin, hemoglobin, mass transfer area coefficient of creatinine, peritoneal albumin clearance, 4-hour peritoneal albumin loss, net ultrafiltration, age, blood pressure, body mass index, difference between actual and ideal bodyweight, and presence or absence of systemic disease. Overall survival was 64% at 2 years. Median serum albumin was 30.9 g/L, range 18.1-43.9 g/L. Patients with a serum albumin below the median had a lower survival rate than those higher than the median (2-year survival 49% vs 79%, p = 0.01). Using the Cox model, survival was related to systemic disease (p = 0.004), age (p = 0.02), hemoglobin (p = 0.03), and serum albumin (p = 0.1). The results confirm the strength of serum albumin as predictor of survival. However, in this study serum albumin merely reflected the presence of a systemic disease, which was the most important risk factor for patient survival. |
8043658 | The adhesive protein cDNA of Mytilus galloprovincialis encodes decapeptide repeats but no hexapeptide motif. | A mussel is attached to hard surfaces by its byssus, which consists of a bundle of threads, each with a fibrous collagenous core coated with adhesive proteins. We constructed a cDNA library from RNA isolated from the foot of the mussel Mytilus galloprovincialis sampled in Japan. The library was probed with a nucleotide sequence corresponding to a part of the decapeptide repeat motif in the major adhesive protein of the closely related species M. edulis, and a clone including the whole coding region of the same adhesive protein of M. galloprovincialis was isolated. The sequences of the signal and nonrepetitive regions of the protein of M. galloprovincialis were homologous to those of M. edulis, despite several substitutions and a deletion of 18 amino acids. The repetitive region included a tetradecapeptide sequence and 62 repeats of the same decapeptide motif as in M. edulis, but hexapeptide sequences present in M. edulis were absent in the protein of M. galloprovincialis. In the decapeptide motif, two tyrosine residues, two lysine residues, and one of the two proline residues were highly conserved, but other residues were frequently substituted. In some residues in the decapeptide motif, specific codon usages were observed, suggesting that the nucleotide sequence itself has a function. |
8043657 | Biological characteristics and biomedical applications of the squid Sepioteuthis lessoniana cultured through multiple generations. | Providing squids--especially their giant axons--for biomedical research has now been achieved in 10 mariculture trials extending through multiple generations. The noteworthy biological characteristics of Sepioteuthis lessoniana are (1) this species is behaviorally and morphologically well suited to the laboratory environment; (2) the life cycle is completed in 4-6 months; (3) growth is rapid (12% and 5% wet body weight d-1 for 100 d and for the life span, respectively), with adult size ranging from 0.4-2.2 kg; (4) feeding rates are high (30% wet body weight d-1), and a variety of live crustaceans and fishes are eaten; (5) crowding is tolerated (about 4 squids m-3); (6) the incidence of disease and cannibalism is low; and (7) reproduction in captivity allows culture through three successive generations. Engineering factors contributed to culture success: (1) physical design (i.e., size, shape, and painted pattern) of the culture tanks; (2) patterns of water flow in the culture tanks; (3) water filtration systems; and (4) spawning substrates. Initial production (a few hundred squids per year) suggests that large-scale culture will be able to supply the needs of the biomedical research community. The size (> 400 microns in diameter) and characteristics of the giant axons of Sepioteuthis are appropriate for experimentation, and other studies indicate that the eye, oculomotor/equilibrium system, olfactory system, blood, and ink are equally suitable for research. |
8043656 | Excitatory actions of FMRFamide-related peptides (FaRPs) on the neurogenic Limulus heart. | The actions of FMRFamide-related peptides (FaRPs) on the neurogenic heart of the horseshoe crab, Limulus polyphemus, were investigated. Excitatory chronotropic effects were produced by application of TNRNFLRFamide, SDRNFLRFamide, GYNRS-FLRFamide, or pQDPFLRFamide to the intact heart preparation. Effects were dose-dependent with a threshold of 10(-9) M or less. TNRNFLRFamide and SDRNFLRFamide increased the burst rate of the isolated Limulus cardiac ganglion. Synthetic FaRPs produced inotropic excitation of the heartbeat as well. GYNRSFLRFamide, TNRNFLRFamide, SDRNFLRFamide, and pQDPFLRFamide increased heart contraction strength at a threshold dose of approximately 10(-8) M. TNRNFLRFamide and SDRNFLRFamide enhanced electrically evoked contractions of the Limulus myocardium, elicited contracture in some preparations, and increased the excitability of cardiac muscle fibers. The presence of cardioactive FaRPs in the Limulus central nervous system was suggested by reverse phase HPLC of acidified methanol extracts of Limulus nervous tissue. Four peaks of FaRP-like bioactivity were detected with the Busycon radula protractor muscle bioassay. These peaks also contained FaRP-like immunoreactivity. Two of these partially purified peaks produced excitatory chronotropic effects on the intact Limulus heart preparation similar to those produced by synthetic FaRPs. |
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