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7785990
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Primary structure of OXA-3 and phylogeny of oxacillin-hydrolyzing class D beta-lactamases.
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We determined the nucleotide sequence of the blaOXA-3(pMG25) gene from Pseudomonas aeruginosa. The bla structural gene encoded a protein of 275 amino acids representing one monomer of 31,879 Da for the OXA-3 enzyme. Comparisons between the OXA-3 nucleotide and amino acid sequences and those of class A, B, C, and D beta-lactamases were performed. An alignment of the eight known class D beta-lactamases including OXA-3 demonstrated the presence of conserved amino acids. In addition, conserved motifs composed of identical amino acids typical of penicillin-recognizing proteins and specific class D motifs were identified. These conserved motifs were considered for possible roles in the structure and function of oxacillinases. On the basis of the alignment and identity scores, a dendrogram was constructed. The phylogenetic data obtained revealed five groups of class D beta-lactamases with large evolutionary distances between each group.
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7785988
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Activities of roxithromycin against Mycobacterium avium infections in human macrophages and C57BL/6 mice.
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The activity of roxithromycin against three clinical isolates of Mycobacterium avium was compared with that of clarithromycin both in a model of infection of human monocyte-derived macrophages and in a model of established infection of C57BL/6 mice. In the cell culture model, roxithromycin and clarithromycin were bactericidal for strains MO-1 and N-92159 and bacteriostatic for strain N-93043. For the three strains, the differences between the intracellular activities of roxithromycin and clarithromycin were not singificant after 7 days of treatment. Mice were infected with the MO-1 strain. Drugs were given by gavage at a dosage of 200 mg/kg of body weight 6 days per week for 16 weeks starting 5 weeks after infection. At the end of treatment, clarithromycin was more effective than roxithromycin in lungs; roxithromycin was as effective as clarithromycin in spleens. Thus, the activity of roxithromycin was comparable to that of clarithromycin both in vitro and in vivo.
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7785987
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Erythromycin shortens neutrophil survival by accelerating apoptosis.
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Erythromycin is reported to have an anti-inflammatory action, which may account for its clinical effectiveness in the treatment of chronic inflammatory diseases such as diffuse panbronchiolitis. To evaluate the anti-inflammatory action of erythromycin, we examined the survival of isolated neutrophils with and without erythromycin. Erythromycin shortened neutrophil survival in a dose-dependent fashion, with a maximum effect at 10 micrograms/ml [corrected] and above. Survival at 24 h was 63.4% in medium with 10 micrograms of erythromycin per ml compared with 82.7% in control medium (P < 0.01). This shortening of survival was brought about by acceleration of apoptosis, as evidenced by transmission electron microscopy. In a manner similar to that of erythromycin, other macrolide antibiotics, i.e., clarithromycin, roxithromycin, and midecamycin, also shortened neutrophil survival, but neither the beta-lactams ampicillin and cefazolin nor the aminoglycoside gentamicin affected their survival. Erythromycin increased intracellular levels of cyclic AMP (cAMP) to 150% of control levels in neutrophils. Forskolin, rolipram, and dibutyryl-cAMP, which are known to increase intracellular cAMP levels, also shortened neutrophil survival. H-89, an inhibitor of cAMP-dependent protein kinase A, partially blocked the survival-shortening effect of erythromycin. Our findings suggest that erythromycin shortens neutrophil survival at least in part through elevation of intracellular cAMP levels.
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7785986
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In vitro activity of D0870 compared with those of other azoles against fluconazole-resistant Candida spp.
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We compared the in vitro activity of a new triazole, D0870, with those of fluconazole, itraconazole, and ketoconazole against 41 clinical isolates of fluconazole-resistant Candida belonging to nine different species. The 50% inhibitory concentrations (IC50s) were determined by a microdilution method with morpholinopropanesulfonic acid (MOPS)-buffered RPMI medium and an inoculum of approximately 10(4) yeasts per ml. After incubation for 48 h at 37 degrees C the optical density at 550 nm was measured. The IC50 was the lowest drug concentration which reduced the optical density at 550 nm by > or = 50% compared with that for a drug-free control. D0870 had significant activity against many of the isolates. Its activity was comparable to that of ketoconazole, slightly superior to that of itraconazole, and markedly superior to that of fluconazole against Candida albicans. Against Candida glabrata, Candida krusei, and Candida inconspicua, it had activity similar to those of itraconazole and ketoconazole but had activity superior to that of fluconazole. D0870 IC50s for some isolates were increased. This may be due to cross-resistance mechanisms because the IC50s of both itraconazole and ketoconazole for these isolates were often high. When IC50s and IC80s were compared there was a marked organism and drug variation. With C. glabrata much higher endpoints for itraconazole were observed when an IC80 endpoint was used. For C. albicans there was also a significant shift upward in endpoints for itraconazole and ketoconazole. Values were changed little when IC50 and IC80 endpoints of D0870 were compared. For 35 of 41 isolates tested the D0870 IC50 was less than the 2.5-mg/liter breakpoint threshold proposed previously. Therefore, D0870 may be a useful agent for the therapy of infections caused by fluconazole-resistant Candida spp.
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7785985
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Alterations in penicillin-binding protein 2B from penicillin-resistant wild-type strains of Streptococcus pneumoniae.
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The 1.5-kb transpeptidase-encoding region (TER) of penicillin-binding protein (PBP) 2B was amplified and sequenced from 18 penicillin-resistant isolates of Streptococcus pneumoniae, with each isolate representing a different DNA fingerprint profile of the TER. PBP 2B TERs from penicillin-resistant isolates revealed extensive sequence divergence from the penicillin-susceptible R6 strain, differing by up to 170 nucleotide substitutions and resulting in up to 38 alterations in the amino acid sequence of the protein. All penicillin-resistant isolates showed sequence divergence within a +/- 300-bp area at the center of the PBP 2B TER. Although a number of amino acid substitutions were found within this central area of PBP 2B, only two substitutions were common to all resistant isolates, namely, Thr-252 replacement by Ala and Glu-282 replacement by Gly. These two substitutions appear to be essentially associated with a decreased affinity of PBP 2B for penicillin. A second block of divergent nucleotide sequence was prominent amongst isolates with high levels of resistance. This was a +/- 100-bp area of the TER around nucleotide 1300 and included the substitution of Gly for Asp-431, which was the only amino acid substitution within this area that was common to all isolates. These data may assist in the definition of the structural changes in the penicillin-binding site of PBP 2B associated with penicillin resistance in S. pneumoniae.
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7785984
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Evaluation of maduramicin and alborixin in a SCID mouse model of chronic cryptosporidiosis.
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Two polyether ionophores, maduramicin and alborixin, were evaluated for anticryptosporidial activity in a severe combined immune deficient (SCID) mouse model of cryptosporidiosis. Groups of SCID mice were inoculated with 10(6) oocysts of bovine origin by oral gavage. Maduramicin or alborixin was administered beginning 4 weeks postinfection at 3 mg/kg of body weight per day. Maduramicin treatment resulted in a 96% reduction in fecal parasite load over the 3-week treatment period (P < 0.003). This reduction correlated with decreases in tissue parasite loads observed in histological sections of the small intestine (P < 0.000002) and the colon (P < 0.000006). A significant decrease in oocyst shedding was also observed after a 3-week treatment with alborixin (71% reduction, P < 0.01). Maduramicin was also evaluated in a relapsing model of cryptosporidiosis in which the infection was observed to recur after treatments were discontinued. Some toxicity, as demonstrated by weight loss, was observed with both maduramicin and alborixin. Both drugs exhibited significant anticryptosporidial activities with concomitant moderate toxicity. These polyether ionophores should be valuable as positive controls in compound evaluation studies and as lead compounds for chemical optimization (modification).
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7785982
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Antiviral effect of oryzacystatin, a proteinase inhibitor in rice, against herpes simplex virus type 1 in vitro and in vivo.
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Oryzacystatin (OC) is the first-described cystatin originating from rice seed; it consists of two molecular species, OC-I and OC-II, which have antiviral action against poliovirus in vitro (H. Kondo, S. Ijiri, K. Abe, H. Maeda, and S. Arai, FEBS Lett. 299:48-50, 1992). In the experiments reported here, we investigated the effects of OC-I and OC-II on the replication of herpes simplex virus type 1 (HSV-1) in vitro and in vivo. HSV-1 was inoculated onto monolayers of monkey kidney epithelial cells (CV-1 cells) at a multiplicity of infection of 0.1 PFU per cell. After adsorption of the virus onto cells, the cultures were incubated in the presence of either OC-I or OC-II in the concentration range of 1.0 to 300 microM, and the supernatant virus yield was quantitated at 24 h. The effective concentration for 90% inhibition of HSV-1 was 14.8 microM, while a cytotoxic effect on CV-1 cells without infection of HSV-1 was not observed below 500 microM OC-I. Therefore, the apparent in vitro chemotherapeutic index was estimated to be more than 33. In the mouse model of HSV-1-induced keratitis and encephalopathy, topical administration of OC-I to the mouse cornea produced a significant decrease in virus production in the cornea (mean virus yields: 3.11 log10 PFU in the treated group and 4.37 log10 PFU in the control group) and significant improvement in survival rates (P = 0.01). The in vivo antiherpetic effect of OC-I was comparable to that of acyclovir, indicating that topical treatment of HSV-1 infection in humans with OC-I might be possible. Our data also suggest the importance of some thiol proteinases, which may be derived from either the host's cells or HSV-1, during the replication process of HSV-1.
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7785983
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In vitro activity of A-86719.1, a novel 2-pyridone antimicrobial agent.
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This study evaluated the in vitro activity of A-86719.1, a novel 2-pyridone antimicrobial agent. The drug inhibited all tested members of the family Enterobacteriaceae at < or = 0.5 microgram/ml and all tested Pseudomonas aeruginosa, Burkholderia (Pseudomonas) cepacia, and Xanthomonas maltophilia strains at < or = 2 micrograms/ml. All but two strains of gram-positive bacteria were inhibited by < or = 1 microgram of the new drug per ml, including isolates highly resistant to ciprofloxacin.
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7785981
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Quantitation of slow drug release from an implantable and degradable gentamicin conjugate by in vivo magnetic resonance imaging.
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A biodegradable model hydrogel containing a covalently bound aminoglycoside in which drug release can be monitored by magnetic resonance imaging (MRI) in vivo was developed. The hydrogel consists of the bishydroxysuccinimide ester of polyethylene glycol disuccinate cross-linked albumin, to which gentamicin and Gd-diethylenetriaminepentaacetic acid are covalently attached in stochiometric quantities. MRI allowed us to depict the three-dimensional structure of implanted gels, to accurately calculate their volumes, and thus to calculate the concentration of hydrogel-bound gentamicin. The correlation coefficient for the concentration of released gentamicin and the hydrogel volume was 0.965. Free and hydrogel-released gentamicin conjugates had similar antibiotic efficacies when tested in microbiological agar diffusion assays. In vivo, hydrogel-released gentamicin had a longer half-life in plasma than unaltered gentamicin (5.6 versus 0.7 h), presumably because of residual bound polyethylene glycol residues. Hydrogel implants into rats resulted in a prolonged (7 to 10 days) release of gentamicin and a decreased 24-h mortality in mice infected with a lethal dose of Pseudomonas aeruginosa. The results indicate the feasibility of imaging and quantitating therapeutic drug concentrations in vivo by MRI.
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7785980
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Tolerability, kinetics, and efficacy of subconjunctival pefloxacin in pigmented rabbits.
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Pefloxacin has been shown to have good intraocular penetration when given systemically. In order to extend its clinical use, we have assessed the tolerability, kinetics, and efficacy of subconjunctival pefloxacin in phakic pigmented rabbits. The tolerability of a single subconjunctival injection of pefloxacin (0.8, 1.6, 8, or 16 mg in 0.2 ml) in the right eyes of eight rabbits was evaluated by clinical and histopathological examination. The 0.8-mg dose of pefloxacin was well tolerated. The kinetics was evaluated after a single subconjunctival injection of 0.8 mg in 18 rabbits. Animals were sacrificed at 1, 3, 5, 7, 12, or 18 h postinjection. Drug concentrations were measured by high-performance liquid chromatography. Pefloxacin was found in the cornea (maximum concentration, 18.13 micrograms/ml; half-life, 3.92 h) and in the aqueous humor (maximum concentration, 3.40 micrograms/ml; half-life, 2.14 h). Pefloxacin did not penetrate into the vitreous humor by this route. The efficacy was evaluated in an experimental model of staphylococcal corneal ulcers in eight rabbits which received two subconjunctival injections of 0.8 mg of pefloxacin at 16 and 24 h after intrastromal inoculation. The results (expressed as mean log10 CFU per milliliter +/- standard deviation) showed that pefloxacin significantly (P < 0.001) reduced the bacterial counts (4.39 +/- 0.97) compared with those in control eyes (6.46 +/- 0.69). For phakic eyes, subconjunctival pefloxacin might be of value for the treatment of corneal ulcers. Further studies are required to determine its penetration into the vitreous humor of aphakic eyes.
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7785978
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Plasmid-mediated dissemination of the metallo-beta-lactamase gene blaIMP among clinically isolated strains of Serratia marcescens.
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The distribution of strains producing metallo-beta-lactamase among 105 strains of Serratia marcescens was investigated. All of these strains were isolated in seven general hospitals located in Aichi Prefecture, Japan, from April to May 1993. Southern hybridization analysis suggested that four S. marcescens strains, AK9373, AK9374, AK9385, and AK9391, had a metallo-beta-lactamase genes similar to the blaIMP gene found by our laboratory (E. Osano, Y. Arakawa, R. Wacharotayankun, M. Ohta, T. Horii, H. Ito, F. Yoshimura, and N. Kato, Antimicrob. Agents Chemother. 38:71-78, 1994), and these four strains showed resistance to carbapenems as well as to the other broad-spectrum beta-lactams. In particular, strains AK9373, AK9374, and AK9391 showed an extraordinarily high-level resistance to imipenem (MICs, > or = 64 micrograms/ml), whereas strain AK9385 demonstrated moderate imipenem resistance (MIC, 8 micrograms/ml). The imipenem resistance of AK9373 was transferred to Escherichia coli CSH2 by conjugation with a frequency of 10(-5). The DNA probe of the blaIMP gene hybridized to a large plasmid (approximately 120 kb) transferred into the E. coli transconjugant as well as to the large plasmids harbored by AK9373. On the other hand, although we failed in the conjugational transfer of imipenem resistance from strains AK9374, AK9385, and AK9391 to E. coli CSH2, imipenem resistance was transferred from these strains to E. coli HB101 by transformation. A plasmid (approximately 25 kb) was observed in each transformant which acquired imipenem resistance. The amino acid sequence at the N terminus of the enzyme purified from strain AK9373 was identical to that of the metallo-beta-lactamase IMP-1. In contrast, strains ES9348, AK9386, and AK93101, which were moderately resistant to imipenem (MICs, > or = 4 to < or = 8 micrograms/ml), had no detectable blaIMP gene. As a conclusion, 19% of clinically isolated S. marcescens strains in Aichi Prefecture, Japan, in 1993 were resistant to imipenem (MICs, > or = 2 micrograms/ml), and strains which showed high-level imipenem resistance because of acquisition of a plasmid-mediated blaIMP-like metallo-beta-lactamase gene had already proliferated as nosocomial infections, at least in a general hospital.
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7785979
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Inducible and constitutive expression of resistance to glycopeptides and vancomycin dependence in glycopeptide-resistant Enterococcus avium.
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A clinical isolate of Enterococcus avium, Ea1, which exhibited inducible, low-level resistance to vancomycin and teicoplanin, and two mutants selected from this strain, Ea3 and Ea31, were studied. Ea3 was vancomycin dependent and derived from Ea1, while Ea31 was not vancomycin dependent, was constitutively resistant, and was derived from Ea3. Hybridization studies revealed that vanA was present in Ea1 and suggested that it was located on a high-molecular-weight plasmid. In the absence of induction, Ea1 synthesized only the natural UDP-MurNAc-pentapeptide precursor, and after induction it synthesized an additional precursor identified as UDP-MurNAc-tetrapeptide-D-lactate. The latter was the only precursor found in Ea3 and Ea31, even after precursor accumulation. From these results, we infer that (i) the low level of resistance to glycopeptides in strain Ea1 may be in part due to the residual synthesis of the normal precursor and (ii) the vancomycin dependence of mutant Ea3 could be due to the fact that this strain does not produce any peptidoglycan precursor in the absence of induction.
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7785977
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Increasing antimicrobial resistance of Shigella isolates in Israel during the period 1984 to 1992.
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Recent (1984 to 1992) trends in the antimicrobial resistance of Shigella isolates in Israel were studied by analyzing the results of 106,000 stool cultures, 3,511 of which yielded Shigella spp. Over the study period, resistance to trimethoprim-sulfamethoxazole (TMP-SMX) increased from 59 to 92% (P = 0.0038) and that to ampicillin increased from 13 to 86% (P < 0.0001). Resistances to nalidixic acid, chloramphenicol, and broad-spectrum cephalosporins remained low. Shigella sonnei, which currently accounts for 90% of Shigella infections, was more resistant than S. flexneri to TMP-SMX (81 versus 57%, P < 10(-6)), ampicillin (42 versus 32%, P < 10(-5)), and tetracycline (38 versus 28%, P < 10(-5)). S. boydii and S. dysenteriae were relatively rare. Seasonality in antimicrobial resistance was found, with summer isolates being less resistant to TMP-SMX, ampicillin, or both than isolates obtained over the rest of the year (P < 10(-5)). We conclude that the resistance of shigellae, especially S. sonnei, to TMP-SMX and ampicillin is increasing to approximately 90%. Resistance should be recorded locally, and empiric therapy for suspected shigellosis should be changed accordingly.
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7785976
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Target for bacteriostatic and bactericidal activities of beta-lactam antibiotics against Escherichia coli resides in different penicillin-binding proteins.
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The relationship between cell-killing kinetics and penicillin-binding protein (PBP) saturation has been evaluated in the permeability mutant Escherichia coli DC2 in which the antimicrobial activity of beta-lactams has been described as being directly related to the extent of saturation of the PBP target(s). Saturation of a single PBP by cefsulodin (PBP 1s), mecillinam (PBP 2), and aztreonam (PBP 3) resulted in a slow rate of killing (2.5-, 1.5-, and 0.8-log-unit decreases in the number of CFU per milliliter, respectively, in 6 h). Saturation of two of the three essential PBPs resulted in a marked increase in the rate of killing, which reached the maximum value when PBPs 1s and 2 were simultaneously saturated by a combination of cefsulodin and mecillinam (4.7-log-unit decrease in the number of CFU per milliliter in 6 h). Inactivation of all three essential PBPs by the combination of cefsulodin, mecillinam, and aztreonam further increased the killing kinetics (5.5-log-unit decrease in the number of CFU per milliliter), and this was not significantly changed upon additional saturation of the nonessential PBPs 5 and 6 by cefoxitin. Similar relationships between PBP saturation and killing kinetics were obtained with imipenem and meropenem at concentrations which inhibited only one PBP (PBP 2), only two PBPs (PBP 1s and 2), or all three essential PBPs. Saturation of one or more PBPs also resulted in a different rate of bacteriolysis, the highest rate being obtained by the cefsulodin-mecillinam combination and by 5 micrograms of either imipenem or meropenem per ml. All of these conditions caused saturation of PBP 2 and saturation or extensive binding of PBP 1s. However, none of these conditions caused determined the fastest possible rate of killing, which occurred only when all three essential PBPs were saturated. It was concluded that the actual killing effect of beta-lactams is reflected by killing rates that approach the fastest possible rate for the given microorganism and that the targets for the bactericidal activity are precisely those PBPs whose saturation or binding occurs under conditions.
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7785975
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Effect of atovaquone and atovaquone drug combinations on prophylaxis of Pneumocystis carinii pneumonia in SCID mice.
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The prophylactic efficacies of atovaquone (ATQ) alone and in combination with azithromycin, clarithromycin, rifabutin, proguanil, PS-15, trimethoprim, co-trimoxazole, or dapsone were investigated in a SCID mouse model of Pneumocystis carinii pneumonia (PCP). ATQ alone was shown to have a significant dose-related effect, and at 200 mg/kg of body weight per day administered orally, the efficacy of ATQ was comparable to that of Septrin (co-trimoxazole). Of the drugs investigated orally in combination with ATQ, only dapsone (25 mg/kg/day) and to a lesser extent PS-15 (5 mg/kg/day) had any noteworthy antipneumocystis activity (at the doses examined) when administered alone. ATQ drug combinations affected the prophylactic efficacy of a subcurative dosage of ATQ (50 mg/kg/day given orally) in the following ways: dapsone (25 mg/kg/day) or co-trimoxazole (25 mg of sulfamethoxazole plus 5 mg of trimethoprim per kg/day) had no significant effect on ATQ, azithromycin (200 mg/kg/day) or clarithromycin (200 mg/kg/day) had a slight additive effect with ATQ, trimethoprim (100 mg/kg/day) or PS-15 (5 mg/kg/day) had an additive effect with ATQ, and proguanil (25 mg/kg/day) or rifabutin (200 mg/kg/day) had a marked synergistic effect on ATQ. The last result was particularly noteworthy as neither proguanil nor rifabutin was effective against PCP when administered alone. None of the drugs examined antagonized the prophylactic activity of ATQ in experimental PCP in SCID mice. The results suggest that clinical trials of ATQ with synergistic drug combinations may now be justified, particularly if such drug combinations improve ATQ's efficacy and broaden its spectrum of activity.
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7785970
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Ribosylation by mycobacterial strains as a new mechanism of rifampin inactivation.
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Several fast-growing Mycobacterium strains were found to inactivate rifampin. Two inactivated compounds (RIP-Ma and RIP-Mb) produced by these organisms were different from previously reported derivatives, i.e., phosphorylated or glucosylated derivatives, of the antibiotic. The structures of RIP-Ma and RIP-Mb were determined to be those of 3-formyl-23-[O-(alpha-D-ribofuranosyl)]rifamycin SV and 23-[O-(alpha-D-ribofuranosyl)]rifampin, respectively. To our knowledge, this is the first known example of ribosylation as a mechanism of antibiotic inactivation.
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7785969
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Pharmacokinetics of high-dose intravenous ciprofloxacin in young and elderly and in male and female subjects.
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The effects of age and gender on the pharmacokinetics of high-dose intravenous ciprofloxacin in a healthy volunteer study were investigated. Plasma ciprofloxacin concentrations were higher in the elderly than in the young, and the pharmacokinetic parameters were not significantly different between the genders. Ciprofloxacin was well tolerated, with the majority of adverse events related to local reactions at the IV site.
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7785968
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Poliovirus neutralizing antibody persistence after vaccination with the Sabin vaccine: a follow-up study.
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In 1976, a cohort survey on the persistence of neutralizing antibodies in children regularly immunized 1 to 4 years earlier with the Sabin attenuated vaccine (OPV) was undertaken in the Venice mainland. Subsequent serological evaluations in the same cohort were carried out in 1983 and 1993. A macroneutralization test using a 1:4 initial serum dilution was utilized in the 1976 and 1983 survey years. In the 1993 survey a microneutralization test using a 1:2 initial dilution was utilized. In this survey, however, sera were tested using both the latter microneutralization test and the former test. Using the former method, the results indicate that the OPV-induced humoral immunity to poliovirus 1 and 2 remain fairly stable after the initial decrease, whereas antibodies to poliovirus 3 are further declining. Using the latter more sensitive method the seropositivity rates were found to be equal or close to 100 percent. The results of our follow-up survey thus indicate that the OPV-induced humoral immunity is long-lasting when tested with a highly sensitive and reproducible method. The clinical protection that ensues after OPV-immunization is probably lifelong similar to that which follows the natural infection.
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7785966
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Myoglobin clearance as an early indicator for rhabdomyolysis-induced acute renal failure.
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Two cases are described to illustrate the use of the myoglobin clearance rate as a predictor of acute renal failure (ARF). Both patients suffered extensive skeletal muscle injury characterized by high total creatinine kinase and urine myoglobin. In the first case, a high myoglobin clearance at admission (27 mL/min) was accompanied by normal serum creatinine and creatinine clearances. This patient recovered without renal complications. The second case also had normal serum creatinine and creatinine clearances at the initial presentation of symptoms, but was accompanied by a very low myoglobin clearance (0.64 mL/min). Within 48 h, this patient developed acute renal failure, with creatinine rising from 1.5 to 5.8 mg/dL, and creatinine clearance dropping from 270 to 2.8 mL/min. Because myoglobin has been recognized as a cause of ARF, these cases help illustrate how the myoglobin clearance rate might be used in evaluating patients with rhabdomyolysis for the development ARF.
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7785967
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Cytogenetic characterization of three cell lines derived from primary cervical tumors.
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Braun et al established three cell lines from keratinizing and nonkeratinizing cervical carcinomas. These cell lines were subsequently analyzed for growth properties and physical state of the human papillomavirus type 16 genome. It was found that these cell lines have distinct growth properties in vitro and in vivo. Furthermore, they differ in the physical state of the viral genome. TC-140/7, derived from a keratinizing cervical tumor, contains primarily human papillomavirus type 16 in the episomal state. Both TC-146A and TC-146B, derived from a nonkeratinizing large-cell cervical carcinoma, contain exclusively human papillomavirus type 16 in the integrated state. The chromosomes of these three cell lines were characterized in the present study using GTG-banding analysis. The most striking chromosomal abnormalities noted in the TC-140/7 cell line were the presence of a small metacentric consistent with the morphology of an i(12p) or i(5p), an isochromosome 8q and multiple copies of chromosome 9. For TC-146A, the most notable chromosomal abnormalities were in the presence of a derivative chromosome 7 with additional material present on its long arm, an i(8q) and derivative chromosome 19's. For cell line 146B, the most notable chromosomal abnormalities were found to be a marker resembling a derivative X chromosome, a derivative chromosome 7 with additional material on its long arms, an i(8q), an i(16q) and one or more copies of a marker with morphology resembling i(17q). Fluorescent in situ hybridization experiments using select probes further corroborate the results of the conventional cytogenetic studies.
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7785964
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Cell proliferation and apoptosis during development and aging of the rabbit corpus luteum.
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Corpora lutea (CL) are endocrine ovarian structures that regulate fundamental reproductive events in mammals. The functional lifespan of these structures is finite as CL regress and cease secreting progesterone after species-dependent intervals during nonfertile postovulatory cycles or pregnancy. The signals that regulate CL aging are poorly understood. This study investigates cell growth and programmed cell death or apoptosis in corpora lutea of New Zealand White rabbits. To study cell growth, CL were obtained at various postovulatory days (POD) from animals injected with the deoxyribonucleic acid (DNA) precursor analog bromodeoxyuridine (BUdR). The BUdR-labeled cells were identified by avidin-biotin-complex immunocytochemistry, and the mean proliferation index area computed by image analysis. Apoptotic cells were scored and further identified by in situ demonstration of DNA fragmentation. Proliferation in parenchymal, stromal, and endothelial CL cells was significantly elevated at POD 3, 5, 18, and 21 and highest at POD 3 (P < 0.001). The number of apoptotic cells was elevated (P < 0.001) at POD 18 and 21, while 1 percent or less of CL cells were apoptotic at POD 3, 5, and 12. Apoptosis was accompanied by shrinkage or vacuolization of CL cells and increased mean number (P < 0.001) of heterophilic leucocytes at POD 18. These data demonstrate that cell growth is more intense during early luteal development and that cell deletion via apoptosis plays an important role in CL regression. The role of paracrine signals such as microphagic cytokines in CL aging remains to be elucidated.
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7785965
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An enzyme-linked immunosorbent assay for urinary screening of fentanyl citrate abuse.
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An enzyme-linked immunosorbent assay (ELISA) for quantitation of urinary fentanyl was evaluated as a screening tool for detecting abuse of this potent narcotic. The assay was found to have reproducible calibration curves from 0.5 to 10 ng/mL and a limit of detection of 0.5 ng/mL. Interference by proteins, glucose, or pH was negligible. The assay was specific for fentanyl with little cross-reactivity against despropionyl fentanyl and norfentanyl metabolites, other analgesics and common drugs of abuse. To evaluate its use in humans, urines were collected from 57 normal individuals, 48 patients seen in the Emergency Department, and 18 surgical patients receiving either low (50 micrograms) or moderate fentanyl dosage (200 and 250 micrograms) for routine anesthesia. In patients receiving 50 micrograms (a dose consistent with early abuse), urinary fentanyl was detectable for 3 to 10 h post administration. In patients receiving 200 or 250 micrograms (a dose more consistent with addiction), urinary fentanyl was detectable for longer time periods (> 24 h). These results indicate that the ELISA is sensitive for the detection of recent fentanyl exposure under conditions likely to mimic those in abuse and addiction. The assay is simple to perform, reliable, and can be used to screen urine specimens prior to gas chromatography/mass spectrometry (GC/MS) confirmation.
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7785963
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The influence of zinc on apoptosis.
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This review summarizes the evidence that apoptosis is modulated by intracellular excess or deficiency of Zn2+, considers mechanisms whereby Zn2+ may influence apoptosis, and delineates gaps in current knowledge and opportunities for research. The experimental evidence supports four major conclusions: [1] Zinc deficiency, resulting from dietary deprivation of mice, or exposure of cultured cells to membrane-permeable Zn(2+)-chelators, can induce apoptosis; [2] Zinc supplementation, either by pretreating mice with ZnSO4, or adding Zn2+ to the media of cell cultures, can prevent apoptotic death. Zn2+ protects against the apoptosis induced by diverse physical, chemical, or immunologic stimuli in cultured cells of lymphoid, hepatic, or neoplastic origin; [3] Zn2+ does not affect the triggering events or earliest signs of apoptosis, but acts later in the apoptotic pathway, preventing endonucleosomal fragmentation and subsequent cytolysis; and [4] An intracellular pool of chelatable Zn2+ plays a critical role in apoptosis, possibly by modulating the activation or activity of endonuclease(s). These conclusions should alert pharmacologists and physicians to the potential therapeutic applications of zinc compounds and zinc chelators in clinical disorders and diseases that involve apoptosis, and to the relevance of zinc nutrition in such conditions.
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7785962
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Renal function in the elderly.
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Renal size and volume decrease with age, accompanied by intrarenal vascular changes. The number of glomeruli decreases and the mass of the juxtamedullary nephrons falls. The result is a decrease in the filtration area of the glomerular basement membrane and decreased permeability. The glomerular filtration rate (GFR) is reduced with aging. The GFR is approximated by the endogenous creatinine clearance, which falls in parallel with the inulin clearance (the true measure of GFR) and is always greater because of tubular excretion of creatinine. Analytical methods for serum and urine creatinine overestimate its concentration and suffer, to varying degrees, from interferences, making the normal range method dependent. A further uncertainty arises from the use of a correction to standard surface area. Serum creatinine concentration is an insensitive indicator of renal function in the elderly. Deduction of creatinine clearance from serum creatinine concentration, weight and age using one of many formulae gives only approximate values, usually too high, and is unsuitable for debilitated and seriously ill patients. Tubular function, in general, is decreased in the elderly. The ability of the kidney to concentrate urine maximally after water deprivation decreases with age, as does the ability to excrete a water and salt load, particularly during the night. Nocturnal polyuria is common in the elderly. The aged kidney can maintain acid-base balance under normal conditions, but not when subjected to an acid load.
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7785961
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Diseases related to oxygen-derived free radicals.
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Oxygen-derived free radicals are very important mediators of cell injury and death. Not only are these highly reactive chemical species important in the aging process, but they are either directly or indirectly involved in a wide variety of clinical disorders, such as atherosclerosis, reperfusion injury, pulmonary toxicity, macular degeneration, cataractogenesis, and cancer. In addition, they play an important role in chronic granulomatous disease and act as secondary sources of cellular injury in chronic granulomatous disease and act as secondary sources of cellular injury in chronic inflammatory processes and several disorders of the central nervous system. Furthermore, a wide variety of drugs and xenobiotics are themselves either converted to, or stimulate the formation of, free radicals. Prevention and/or treatment of many of these disorders may be possible by appropriate antioxidant therapy, either currently available or to be discovered through continued research.
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7785952
|
Lower values for immunoglobulin M in cerebrospinal fluid when sampled with an atraumatic Sprotte needle compared with conventional lumbar puncture.
|
Immunoglobulin M (IgM) has a very low concentration in cerebrospinal fluid (CSF) compared with serum, and therefore determinations of IgM in CSF are highly sensitive to pre-analytical errors caused by contamination with serum or interstitial fluid. Capillary attraction causes a thin layer of liquid containing serum proteins to be formed inside a conventional (Quincke) needle during penetration of tissue. To investigate this source of pre-analytical error, 35 patients had lumbar punctures using a 22 G atraumatic (Sprotte) or 25 G conventional (Quincke) needle according to a randomized scheme, and the IgM concentrations in CSF and serum were determined. The CSF IgM concentrations for samples taken with a Sprotte needle were significantly lower than those taken with a Quincke needle (P < 0.05), whereas the corresponding serum IgM concentrations and CSF erythrocyte counts did not differ significantly. The difference indicates that CSF IgM concentrations determined after conventional sampling may be falsely increased by contamination. We conclude that IgM concentrations in CSF samples taken with the atraumatic technique are more accurate, and recommend the use of this technique when CSF IgM is to be determined.
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7785949
|
D-dimer tests detect both plasmin and neutrophil elastase derived split products.
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Both plasmin and elastase, a protease released from neutrophil granulocytes, are known to degrade fibrin(ogen). This raises the possibility that elevated plasma levels of split products such as D-dimer may in part result from elastase action. After incubation in vitro of fibrinogen and fibrin clots with elastase, a clearcut increase of D-dimer immunoreactivity was demonstrated by two commercial ELISA kits. In the plasma of 79 patients with inflammatory bowel disease, D-dimer values measured by one of the ELISA kits were correlated significantly not only with markers of thrombin and plasmin activation, but also with elastase-alpha 1-antitrypsin complexes (r = 0.3555; P = 0.014). Thus, the findings of this study suggest that indeed the D-dimer levels in patients with inflammatory disorders are influenced by neutrophil elastase. New tests discriminating effects of activated haemostasis from proteolysis by neutrophil enzymes might be helpful in differential diagnosis and monitoring of therapy.
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7785950
|
Measurement of markers of tobacco smoking in patients with coronary heart disease.
|
591 patients with a history of coronary heart disease had one or more biochemical markers of tobacco smoking measured. 26% were self reported smokers and a further 4% were apparent 'smoking deceivers'. The urinary nicotine metabolite concentration is an excellent marker for tobacco smoking; breath CO would be a suitable alternative for busy clinics. Half the patients were subjected to regular advice on risk factor management but there was no evidence that this contributed effectively to smoking cessation. Overall smoking cessation rate was poor.
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7785948
|
The cryopreservation of skin biopsies--a technique for reducing workload in a cell culture laboratory.
|
A method is described for the cryopreservation of skin biopsies at -70 degrees C for subsequent possible reculture. Biopsies stored up to 1 year could be successfully recultured without affecting the time to achieve confluence or the culture failure rate. This technique has been in operation in our department for over 3 years and has resulted in a demonstrable reduction in cell culture costs and a greater flexibility in the acceptance of skin biopsies for culture.
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7785947
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Evaluation of a first-line spectrophotometric screening test for increased urine porphyrin excretion.
|
We compared a spectrophotometric screening test for urine porphyrin concentration with a high performance liquid chromatography (HPLC) method. The screening test gave lower values than those obtained by HPLC, but the overall correlation was good. Occasionally, spectrophotometry failed to detect porphyrins in the urine which were detected by HPLC. The type of porphyria had no influence on the efficacy of the screening method. Receiver operating characteristic plot analysis of the screening test led to a cut-off value of 110 nmol/24 h with a sensitivity of 96% and a specificity of 86%. We conclude that the spectrophotometric screening method is useful for detection of increased total urine porphyrin concentration.
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7785946
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Long-term physical exercise and lipoprotein(a) levels in a previously sedentary male and female population.
|
We investigated the effect of long-term physical exercise on serum lipoprotein(a) levels. 21 sedentary men and 15 sedentary women were trained three to four times a week with increasing intensity during 9 months. After 24 weeks all subjects ran a 15 km race and after 36 weeks a half marathon run (21 km). Blood samples were drawn before the training programme, 5 days before both races and 5 days after the half marathon run. Median (interquartile range) pre-training values in the male group were 32 (11-63) mg/L and in the female group 65 (23-199) mg/L. After 24 weeks of training, serum lipoprotein(a) concentrations had risen significantly in both male and female groups. Moreover, after 36 weeks of training, in preparation for the half marathon competition, median serum lipoprotein(a) rose almost twofold in both groups and was still elevated 5 days later. This study demonstrates that an exercise programme which includes running of increasing distances significantly increases serum lipoprotein(a) concentration.
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7785945
|
An improved method for the quantitation of apolipoprotein B and apolipoprotein A-1 in dried blood spots.
|
An extraction protocol has been developed to elute apolipoprotein B (apo B) and apolipoprotein A-1 (apo A-1) from dried blood spots with assay of the extracted apolipoproteins by automated immunoturbidimetry. Various extraction media were investigated to assess their elution efficiency and the optimum medium was found to be deionized water. Studies on the rate of elution suggested both apolipoproteins were eluted readily in less than an hour with a recovery of 71% for apo B and 65% for apo A-1. Extracted apo B but not aop A-1 was found to be stable for 24 h when kept at 4 degrees C. The within-batch coefficients of variation (CV) for the combined extraction and assay of apo B were found to be 5.9% and 8.5% at 0.6 g/L and 1.2 g/L respectively. The CVs for apo A-1 were found to be 7.4% at 0.7 g/L and 8.9% at 1.5 g/L. Antiserum from three sources (Immuno, Incstar and Bayer) was investigated for immunoreactivity with apo B and apo A-1 and cross-reactivity with red blood cells was also assessed. Although the antisera from the three companies showed similar immunoreactivity towards apo B and apo A-1, antiserum from Bayer was found to cross-react with red cells.
|
7785944
|
A rapid method for measurement of the susceptibility to oxidation of low-density lipoprotein.
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Oxidation of low-density lipoprotein (LDL) may be important in the pathogenesis of atherosclerosis. We describe a method which measures the oxidation resistance of LDL isolated by a rapid procedure without added antioxidants. LDL was isolated from heparinized plasma by density gradient ultracentrifugation and desalted by gel filtration. The protein concentration was standardized to 50 mg/L and oxidation was promoted by copper (2 mumol/L) at 37 degrees C. The total sample preparation time was 2.5 h. Conjugated diene production was monitored at lambda = 234 nm with computation of the lag time. LDL oxidation was inhibited by EDTA but not heparin. Albumin inhibited LDL oxidation but only in concentrations greater than 50 mg/L. LDL was stable in frozen plasma (-70 degrees C) for 10 weeks, but unstable in the isolated and desalted state. The lag time for LDL from patients treated with the antioxidant probucol was markedly prolonged compared to normal subjects.
|
7785943
|
Determination of aluminium in serum, dialysate fluid and water by inductively coupled plasma optical emission spectrometry.
|
Methods for the determination of aluminium in serum, dialysate fluid and water by inductively coupled plasma optical emission spectrometry are described and validated. Aluminium was measured at 167 nm using an argon purged monochromator. Matrix effects in serum and dialysate fluid were overcome by using an yttrium internal standard. Serum was found to have a complicated background in the region of 167 nm: careful selection of the wavelength used for background correction is therefore a pre-requisite for accurate analysis. The method for serum was validated by comparison with electrothermal atomization atomic spectrometry and the limit of agreement determined to be +/- 0.3 mumol/L. Routine performance in a quality assessment scheme has been highly satisfactory for a period of 1 year. The method is ideal for fast and accurate monitoring of patients potentially at risk from aluminium toxicity.
|
7785942
|
Rapid diagnosis of long chain and medium chain fatty acid oxidation disorders using lymphocytes.
|
A method based on the release of tritiated water from [9,10(n)-3H] palmitic and myristic acids previously described for fibroblasts, was adapted for lymphocytes for the rapid diagnosis of fatty acid oxidation disorders. Optimal concentrations for both substrates and linearity of the assay were established. Normal values were established in control subjects of different age groups (58 children and 117 adults) and 16 patients with known fatty acid oxidation disorders were tested. Tritiated water production from patients' lymphocytes was expressed as a ratio between residual oxidations of palmitate and myristate and the results show that this method allows good differentiation between long chain and medium chain fatty acid oxidation defects.
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7785941
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Screening for drugs of abuse. I: Opiates, amphetamines and cocaine.
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(1) In order to provide an efficient and reliable service for drugs of abuse screening in urine, the laboratory should analyse 20-30 samples per week, and the staff should include a scientist with special expertise in the subject. (2) Turnaround times should be between 2-3 days of sample collection. To achieve this aim it may be necessary to make special arrangements for the delivery of samples to the laboratory. Results should preferably be transmitted by electronic mail or facsimile with the necessary precautions for security and confidentiality: hardcopy reports may also be required. (3) Good communications between the requesting clinician and the laboratory are essential. An advisory service should be provided by the laboratory and clinicians should be encouraged to discuss requests and results with laboratory staff. It is important that the laboratory inform doctors of the range of substances detected and the sensitivity and specificity of laboratory assays. (4) Assays should be performed according to the manufacturer's protocols, or by modified methods that have been rigorously validated. Quality control samples should be included in each analytical run and participation in an external quality assessment scheme, e.g. UKNEQAS, is essential to provide independent confirmation and confidence that results compare with those from other laboratories. Other requirements include adequate training and supervision of staff, and careful recording of samples and results. (5) Drugs to be tested will depend on the drug 'scene' in the area but should include those drugs regularly prescribed for maintenance therapy (e.g. methadone, dihydrocodeine, benzodiazepines), and drugs frequently misused (e.g. heroin, buprenorphine, amphetamines, cocaine). (6) Positive results obtained by preliminary screening methods e.g. EMIT, should be confirmed by another analytical technique, e.g. TLC, GC or GC-MS. If there are potentially serious or legal implications, and in employment and preemployment testing, confirmation of positive results is mandatory. In some cases, e.g. checking for methadone or benzodiazepine compliance, it may be considered unnecessary to confirm positive results although possible spiking of samples cannot be excluded without checking for the presence of metabolites by a chromatographic procedure.
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7785936
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[Scopulariopsis brevicaulis otomycosis after tympanoplasty].
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We report a case of otomycosis due to Scopulariopsis brevicaulis in a patient who has undergone tympanoplasty 3 months before. Mycological finding led us to consider this fungus as the causative agent. Whereas in vitro studies show a better efficiency of azole derivatives, cure was obtained with nystatine after two treatment failures in our patient.
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7785935
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[Contribution of L lactate and amino-acid enzymatic biosensors for the analysis of Frey syndrome].
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Twelve patients with Frey's syndrome after total parotidectomy for plemorphic adenoma were analysed using simultaneously 2 biosensors. Biosensors allowed for detection of L lactate and amino acid level on intact skin. The assay procedure and the results achieved with the simultaneous use of these 2 biosensors are presented. The L lactate biosensor appears to be an interesting tool for Frey's syndrome analysis. The sensibility of the amino acid biosensor is not sufficient enough to allow its use at time of Frey's syndrome analysis.
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7785934
|
[Dysphonia in adults caused by unilateral pseudohypertrophy of the ventricular band with deformation of the thyroid cartilage. Apropos of three cases].
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The association of dysphonia appearing in adulthood with unilateral bulging of the false cord associated with a convex deformation of the overlying thyroid cartilage is to be remarked in three cases. The origin, which was presumably acquired by gradual deformation of the thyroid cartilage with age, is discussed in the light of the literature and the clinical history. A past traumatic cause can also be implicated (1 case). CT-Scan is essential for the diagnostic of the cartilage deformation and eliminates laryngeal tumors. In one of the cases reported, we were able to demonstrate the possibility of treatment by CO2 laser resection of the false cord hypertrophy.
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7785933
|
[Malignant transformation of inverted papilloma of the nasal sinuses.. Apropos of a series of 7 cases].
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Seven cases of malignant inverting papillomas are presented (6 men and 1 woman) with ages ranging from 31 to 72 years (mean age: 58 years); the minimum follow up was 37 months. The diagnosis was based on the histopathologic analysis of biopsy in five patients. In two patients the diagnosis was confirmed by the pathological analysis of the specimen. Treatment was always surgical: lateral rhinotomy and total ethmoidectomy. Neoadjuvant chemotherapy was given to four patients. Post operative radiation therapy was delivered in five patients. Five patients on seven died: local recurrence and systemic metastases: 3; systemic metastases: 1; second primary: 1. Reports from the literature are discussed. The authors emphasize the treatment modalities based on complete tumor removal through lateral rhinotomy.
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7785932
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[Role of modern imaging (tomodensitometry and MRI) in cochlear implantation in children].
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Since 1989, 40 patients have received implants in the O.R.L. ward of the Hôpital d'Enfants Armand Trousseau (Paris). Over the past 2 years, 17 children have undergone radiological assessment combining M.R.I. anf high resolution C.T scanning. Imagery is not the essential stage, and is only used after assessment by a multidisciplinary team. However, the imagery results influence the choice of implant, and sometimes the side to be implanted. C.T is always the first stage as it detects congenital abnormalities, and, for children with a history of bacterial meningitis, it can detect signs of labyrinthine ossification which contraindicate cochlear implantation. These signs are not always visible using tomodensitometry, especially when fibrosis within the canal has not yet ossified. This examination also provides for post-operative confirmation of implant position in case of failure or complication. Over the past 3 years, Magnetic Resonance Imagery has been combined with tomodensitometry, especially with children having a past medical history of meningitis. This examination provides a basis for evaluating the liquid nature of the labyrinth. A G.E. Sygna 1.5 T was used by the authors, employing sequences of volumetric acquisition (S.S.F.P. with 1.5 mm image slices and an angle of 15 to 35 degrees). Hence, modern imagery plays an important role when the decision to implant has already been taken, particularly in the case of profoundly deaf children. M.R.I. is always used in combination with a scanner in cases involving children with a past medical history of meningitis.
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7785931
|
[Short-term reproducibility of acoustic oto-emissions induced by clicks in adults].
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Otoacoustic emissions (OAE) are sounds emitted by the cochlea and recordable in the external ear canal by a miniature microphone. The OAE reflect the existence of an active mechanism within the cochlea. Development of the OAE has spurred much interest because they may used as a valid test for screening and monitoring cochlear changes. The OAE were recorded in 8 normal hearing subjects (15 ears) during nine test sessions under similar conditions. The aim of this work was to study the short-term variability in the amplitude of the emissions. Results of the study indicate that response levels are stable over time in the same ear therefore changes in the response level can be associated with changes in the cochlea.
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7785930
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[Clinical development of acute noise-induced acoustic trauma. An evaluation of a study of 250 cases].
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Traumatic damage on Cochlea (250 cases) induced by assault gun (F.A.M.A.S.) consists in tinitus and hearing impairement on 6000 Hz. Noise's effects are specific to one Cochlea. Dissociated developments of both tinitus and hearing loss show that their anatomical sites are different. Acoustic injury entails definitive haire cells lesions, cellular biochemical and vascular changes. The treatment that reestablishes or raises cochlear blood flow entails recovery in 80% of cases provided that it is given within 48 hours after the trauma.
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7785929
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[Implantation on the cochlear nucleus. Apropos of a patient with bilateral neuroma].
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A new auditory brainstem implant (ABI), manufactured by Cochlear, was implanted in a young patient suffering from a large bilateral acoustic neuroma, associated with multiple other tumors due to a tuberor sclerosis of Bourneville. The operating procedure and the first results are described. A short historical summary, the anatomical basis and the difficulties due to side effects of stimulation are exposed.
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7785928
|
[Benign paroxysmal positional vertigo. Apropos of 51 cases].
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51 cases of benign paroxysmal vertigo have been investigated in 3 years. The findings put in evidence: the particular frequency of this pathology (18% of BPPV in a vestibulometry consultation), its opportunist character and the possible association with other more severe pathologies (meningiomas, multiple sclerosis, cerebellar venous angioma, vascular cerebral infarction) or more benign pathologies (labyrinth malformation, middle fossa atrophia). Sémont liberatory maneuver revealed to be much efficient (50% of patients free of disease after a single repositioning manoeuvre). Only 3 cases remaining unchanged after 2 years and intractable were proposed for surgery. We mention 7% of bilateral forms and 5% of alternating recurrent forms (sometimes on the right and sometimes on the left side). The recurrence is noted in 50% of BPPV followed at least during one year. We describe a particular topographic form concerning probably a cupulolithiasis of the external canal. 53% of cases beneficiated of CT-scan or of magnetic resonance imaging. The frequency and the possibility of pathological associations with BPPV bring to a particular vigilance for the diagnosis and to a particular care in the affirmation of the benignity in the case of long lasting vertigo (superior to 6 months), or when the nystagmus duration in Hallpike position is superior to 60 seconds.
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7785924
|
Structure of the osteopontin gene and its promoter.
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We cloned the hOPN gene and its 5' upstream region, and analyzed its exon-intron structure and potential regulatory sequences of the promoter region in comparison with those of mouse and porcine homologues. The hOPN gene consists of 7 exons that are similar to those of the mouse gene, although the hOPN gene is longer than the mouse homologue. This difference is attributable to an insertion of about 1750 bp immediately before exon 4 in the hOPN gene. A region of approximately 285 bp immediately upstream of the hOPN transcription initiation site was highly conserved and contained a number of potential cis regulatory consensus sequences. CAT analysis using SCC-3 cells demonstrated that nucleotides at positions -439 to -270, -124 to -80, and -55 to -39 contained cis-acting enhancing elements, in which the -124 to -80 element was much more active than the others. Deletion of the sequences between -474 and -270 localized the cis elements to the sequence at position -439 to -410, whereas the deletion between -124 to -80 localized it to -124 to -115, and -94 to -80 (data not shown). Gel shift analysis using synthesized double-stranded oligonucleotides corresponding to the 30 bp at position -439 to -410 (data not shown), and 10 and 15 bp regions at positions -124 to -115 and -94 to -80, respectively, as probes revealed that each probe formed one or two bands complexed with a nuclear protein prepared from SCC-3 cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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7785911
|
Expression of osteopontin in a macrophage cell line and in transgenic mice with pulmonary fibrosis resulting from the lung expression of a tumor necrosis factor-alpha transgene.
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The expression level of osteopontin (OPN) mRNA was found to be increased in a macrophage cell line in the presence of recombinant tumor necrosis factor-alpha (TNF-alpha). OPN mRNA level was also explored in the lungs of transgenic mice which were expressing TNF-alpha in type II pneumocytes, a condition leading to pulmonary alveolitis and progressive fibrosis. OPN mRNA was significantly increased in the lungs of these transgenic mice. In situ hybridization showed that it was localized mostly in alveolar macrophages. Since OPN can be induced in macrophages by TNF-alpha stimulation and since on the other hand osteopontin appears to decrease the level of nitric oxide synthase, and thus the production of nitric oxide, osteopontin might also indirectly have an antifibrotic effect. The role played by osteopontin in fibrotic lesions resulting from the release of TNF-alpha deserves further study, since it may be involved in the balance of opposite effects eventually leading to local tissue damage ending in fibrosis.
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7785899
|
Osteopontin and related phosphorylated sialoproteins: effects on mineralization.
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Osteopontin is one of a family of phosphorylated sialoproteins found in the extracellular matrices of mineralized connective tissues. Solution studies from a variety of laboratories have shown that while some of these proteins (e.g., osteopontin, dentin sialoprotein) inhibit calcium phosphate production, others, such as bone sialoprotein, can act as a nucleator of calcium phosphate formation. The differences in the behaviors of these proteins can be related to their interactions with mineral crystal nuclei and crystal growth sites. The specificity of these interactions, in turn, can be related to differences in the primary structures of the sialoproteins and to the extent to which they are phosphorylated. In vitro systems for the study of osteopontins and osteopontin-related protein effects on mineral deposition are described, along with mechanisms explaining the contrasting abilities of the polyglutamate-containing bone sialoprotein to act as a nucleator, while the polyaspartate-containing osteopontin and dentin sialoproteins inhibit calcium phosphate formation and growth.
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7785896
|
Regulation of osteopontin expression in osteoblasts.
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Osteopontin (OPN) is a prominent bone matrix protein that is synthesized by osteoblastic cells. To elucidate the function of OPN in bone we studied the regulated expression of the rat OPN protein during bone formation in vivo and in vitro. OPN mRNA is expressed by preosteoblastic cells early in bone formation, but the highest expression is observed in mature osteoblasts at sites of bone remodelling. A low-phosphorylated, 55-kDa form of OPN is produced by the preosteoblastic cells, whereas osteoblasts produce a highly phosphorylated, 44-kDa protein; the two forms of OPN corresponding to pp69 and pp62 in transformed rat cells. The synthesis of the 55-kDa OPN correlates with the formation of a 'cement' matrix that is synthesized prior to bone deposition, whereas the 44-kDa OPN synthesized by osteoblasts associates rapidly with hydroxyapatite, possibly regulating crystal growth, and may also provide a substratum for osteoclast attachment. Expression of OPN mRNA is upregulated by growth and differentiation factors (PDGF, EGF, TGF-beta and BMP-7/OP-1) and by mechanical stress, which promote bone formation, as well as by osteotropic hormones (retinoic acid and vitamin D3), which can promote bone resorption and remodelling. However, OPN mRNA is down-regulated by bisphosphonates, which abrogate bone resorption. Regulation of OPN expression is, therefore, consistent with a multiplicity of functions for OPN that involve specific structural motifs in both the synthesis and resorption of bone.
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7785893
|
Localization and expression of osteopontin in mineralized and nonmineralized tissues of the periodontium.
|
To summarize results from various studies focusing on determining the expression/localization of BSP and OPN during tooth root development, there is general agreement that OPN is expressed/localized to the root surface during cementogenesis and is also seen throughout the PDL region. The expression/localization of OPN to odontoblasts and its role in dentinogenesis is less apparent. Recent studies directed at establishing odontoblast cell lines should help to resolve this conflict. Studies on BSP expression during tooth root formation indicate a very precise expression and localization of this molecule during cementogenesis indicating that this molecule may play an important role in the formation of this mineralized tissue. However, as with OPN, the expression of BSP and its role in dentin formation is not clearly defined.
|
7785894
|
Osteopontin and the bone remodeling sequence. Colloidal-gold immunocytochemistry of an interfacial extracellular matrix protein.
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Relative to other noncollagenous, extracellular matrix proteins in mineralized tissues, colloidal-gold immunocytochemistry has demonstrated that the ultrastructural distribution of osteopontin (OPN) is unique in that this protein preferentially accumulates at mineralized tissue interfaces. In bone, this protein is present as a major component of cell-matrix and matrix-matrix interfacial structures called cement lines and laminae limitantes. In the present article, the implications of this distinct tissue distribution are discussed in terms of the bone remodeling sequence, and a detailed account of the secretion, accumulation and potential role of OPN is presented and related to current theory on the cellular and extracellular matrix events associated with basic multicellular unit (BMU)-based bone remodeling. In this context, a proposal is made describing the production of this protein as one of the earliest, and latest, secretory activities of the osteoblastic lineage, and that this activity manifests itself morphologically as a cement line ('plane') and a lamina limitans, respectively, at bone matrix interfaces. When integrated with other, known functional characteristics of this protein, the present morphological and compositional data indicate that OPN in cement lines and laminae limitantes may participate in initial and late extracellular matrix organization and mineralization, matrix-matrix/mineral adhesion and/or cell adhesion at bone interfaces.
|
7785890
|
Osteopontin expression in cardiovascular diseases.
|
Adhesive interactions are recognized requirements for cellular proliferation, migration and differentiation during normal morphogenesis as well as disease. By differential cloning, osteopontin was identified as an adhesive protein upregulated during vascular remodeling and neointima formation in both rat models and human vascular diseases including atherosclerosis and restenosis. In functional studies, purified osteopontin promoted adhesion, focal contact formation, and migration of vascular smooth muscle and endothelial cells. Utilizing neutralizing antibodies, three integrin-type receptors, alpha v beta 3, alpha v beta 1, and alpha v beta 5 were found to support cellular adhesion to osteopontin. In contrast, only cells containing the alpha v beta 3 integrin could migrate towards an osteopontin gradient, demonstrating for the first time that different functions of osteopontin are mediated via distinct receptors. These results suggest a model whereby osteopontin, via its integrin-type receptors, contributes to vascular remodeling during development and disease by facilitating smooth muscle migration and simultaneously promoting endothelial coverage of the affected area.
|
7785891
|
Conformational analyses on soluble and surface bound osteopontin.
|
Immunohistology of calvarial sections revealed that staining with monoclonal anti-osteopontin antibodies (clone MPIIIB10) is minimal unless sections are first treated with EDTA. In contrast, following treatment of sections with EDTA, strong staining of mineralizing osteoid areas and osteoblast-like cells was noted (Fig. 1B). Immunostaining for osteopontin appeared to be specific in that controls which substituted rabbit IgG or normal mouse ascites fluid for monoclonal antibody, or which omitted monoclonal antibody uniformly gave background results (Fig. 1C). In an effort to circumvent problems of antibody accessibility we examined the immunoreactivity of OP when adsorbed to plastic and hydroxyapatite surfaces. Although OP bound to plastic surfaces is reactive with MPIIIB10 antibodies, OP adsorbed to hydroxyapatite crystal surfaces is not recognized by these antibodies as assessed by two detection methods. These results demonstrate that most or all of OP bound to hydroxyapatite exhibits a different conformation than when bound to plastic surfaces. On the basis of immunohistologic results with calvarial sections, we suggest that the conformation of native OP in bone and of isolated OP adsorbed to hydroxyapatite may be similar. Finally, solution circular dichroism and Fourier-transformed infrared spectroscopic studies indicate that the conformation of bone OP is dependent upon its concentration, and, secondarily to the presence or absence of calcium ion. With both spectroscopic methods, addition of calcium appeared to increase the extent of disordered structure. We suggest that these findings support our hypothesis that bone matrix proteins exhibit a different conformation when adsorbed on hydroxyapatite crystal surfaces. Assumption of a more organized secondary structure in concentrated OP solutions (i.e., 15 mg/ml) is consistent with these results in that local concentrations of OP within a semisolid matrix may approach or exceed levels used here.
|
7785889
|
Regulation and function of osteopontin in ras-transformed cells.
|
Transformation of nontumorigenic NIH 3T3 fibroblasts with an activated ras oncogene produces malignant cells that can metastasize. This induction of malignant behavior is due to changes in gene expression induced by Ras-mediated signal transduction. Osteopontin expression is induced in response to Ras, due to increased osteopontin transcription mediated by Ras-responsive regions in the osteopontin gene promoter. The increased expression of osteopontin contributes functionally to the malignant ability of the cells. Ras-transformed cells that express antisense osteopontin RNA show markedly reduced ability to form tumors and to metastasize in experimental animals. Increased osteopontin expression in human tumors thus may also contribute to increased malignancy. Site-directed mutagenesis of recombinant osteopontin protein indicates that an intact RGD sequence is required for cell adhesion and induction of chemotaxis, consistent with the idea that integrin-mediated signal transduction is a consequence of osteopontin binding to cells. Osteopontin may contribute to malignancy by inducing responses in host and/or tumor cells.
|
7785876
|
Peptic hemoglobin hydrolysis in an ultrafiltration reactor at pilot plant scale generates opioid peptides.
|
Two hemorphins, peptides with opioid activity, have been isolated from a pepsin hydrolysate of bovine hemoglobin, by use of gel permeation (GP) and reverse phase (RP) high-performance liquid chromatography (HPLC). Their primary structure and accurate molecular weights, determined by amino acid analysis and fast atom bombardment (FAB) mass spectrometry, were identical to fragments 31-40 (LVV-hemorphin-7) and 32-40 (VV-hemorphin 7) of the beta-chain of bovine hemoglobin. Two other peptides, 34-40 (hemorphin-7) and 34-41 (hemorphin-8) of the beta-chain of bovine hemoglobin, have been synthesized and studied. The opioid potency of these peptides, exhibited by the use of electrically stimulated muscle of isolated guinea pig ileum (GPI), were significant and comparable with some others previously described. Studies of opioid activities and primary structure of hemorphins led us to postulate the important role of arginine and phenylalanine in opioid potency.
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7785857
|
A multifunctional flow-injection biosensor for the simultaneous determination of ammonia, creatinine, and urea.
|
A strategy for the multifunctionalization of the FIA biosensor was developed. The described multifunctional FIA system offers a fast and simple method for the simultaneous determination of ammonia, creatinine, and urea. The hydrolysis of creatinine by creatinine deiminase (CRDI) or of urea by urease forms ammonia, which is amperometrically detected by an oxygen electrode, based on an enzyme conversion system, glutamate dehydrogenase (GLDH)/glutamate oxidase (GLOD). The split of the stream into three after sample injection and confluence before the GLDH reactor resulted in a three-channel system, into which were set three parallel columns, respectively, filled with immobilized CRDI, urease, and CPG. A triple-peak recording was obtained by putting two delay coils at the channels involving CRDI and urease. Thus the interfering of the endogenous ammonia on the creatinine and urea assay is simultaneously compensated. Furthermore, the problem of great difference in concentration between urea and the other two components is resolved by taking advantage of the differentiated dilution effect for each channel caused from the split-stream, flow-injection system. Linear calibration ranges for ammonia, creatinine, and urea were 0.1-5, 0.2-10, and 2-40 mM, respectively. One run was finished within 5 minutes, and the system was reproducibility good (3 to 5%). The results of the urine assay obtained by the present method will be described in the near future.
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7785836
|
Reaction mechanism for the conversion of 5-monosubstituted hydantoins to enantiomerically pure L-amino acids.
|
The specific conversion of D,L-5-monosubstituted hydantoins to optically pure L-amino acids by resting cells of Arthrobacter sp. DSM 7330 has been evaluated. A new nonstereoselective hydantoinase from Arthrobacter sp. DSM 7330 was isolated and characterized. When whole cells were tested, the conversion of D,L-5-methylthioethylhydantoin (D,L-5-MTEH) led to the optically pure intermediate D-carbamoylmethionine (D-CM) and to the optically pure amino acid L-methionine. After purification of the hydantoin hydrolyzing enzyme, the probable reaction mechanism of the conversion of 5-monosubstituted hydantoins to enantiomerically pure L-amino acids could be enlightened.
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7785834
|
Ototoxicity assessment of a gentamicin sulfate otic preparation in dogs.
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Vestibulotoxic and ototoxic effects often are seen after long-term, high-dose systemic treatment with gentamicin, but toxic effects after topical use have not been reported in animals, to the authors' knowledge. Vestibular and auditory effects of twice daily otic gentamicin treatment for 21 days were evaluated in 10 dogs with intact tympanic membranes and in the same 10 dogs after experimental bilateral myringotomy. Each dog served as its own control; 7 drops of gentamicin sulfate (3 mg/ml in a buffered aqueous vehicle) were placed in 1 ear, and 7 drops of vehicle were placed in the opposite ear. Treatment and control ears were reversed after myringotomy. Vestibular function was evaluated daily by neurologic examination and behavioral assessment. Auditory function was evaluated twice weekly by determination of brain stem auditory evoked potentials. Gentamicin sulfate placed in the ear of clinically normal dogs with intact or ruptured tympanic membranes, in the quantities used in this study, did not induce detectable alteration of cochlear or vestibular function. Serum gentamicin concentration after 21 days of treatment was detectable in only 2 dogs and was an order of magnitude below documented toxic concentrations.
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7785833
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Laparoscopic anatomy of the equine abdomen.
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Laparoscopy was performed on 6 horses (2 mares, 2 geldings, 2 stallions) to determine the normal laparoscopic anatomy of the equine abdomen. After withholding feed for 36 hours, horses were examined from the left and right paralumbar fossae, and the visceral anatomic structures were recorded by videotape and photography. One mare developed emphysema located subcutaneously at the primary laparoscopic portal; otherwise, there were no complications. The anatomic structures of diagnostic importance that were observed in the left half of the abdomen were the hepatic duct; left lateral and quadrate lobes of the liver; stomach; spleen; left kidney with the associated nephrosplenic ligament; segments of jejunum, descending colon, and ascending colon; left side of the male and female reproductive tracts; urinary bladder; vaginal ring; and mesorchium. Important structures observed in the right side of the abdomen were portions of the common hepatic duct; left lateral, quadrate, and right lobes of the liver; caudate process of the liver; stomach; duodenum; right dorsal colon, epiploic foramen; omental bursa; right kidney; base of the cecum; segments of jejunum, descending colon, and ascending colon; urinary bladder; right half of the male and female reproductive tracts; and rectum.
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7785832
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Adrenocortical function in neonatal and weanling beagle pups.
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Adrenocortical function was assessed in 27 Beagle pups at 2, 4, 6, 8, 10, and 12 weeks of age by determination of plasma sodium, potassium, and chloride concentrations; serum aldosterone and cortisol concentrations; and plasma ACTH concentrations. Serum cortisol concentration was measured before and 1 and 2 hours after IM administration of 2.2 IU of ACTH/kg of body weight. Serum progesterone concentration also was determined for all pups at 2, 4, and 6 weeks of age. Mean baseline cortisol concentration was lower for pups 8 weeks old or younger than for mature dogs. Nevertheless, mean serum ACTH-stimulated cortisol concentration in dogs of all age groups increased into the adult reference range after administration of ACTH. For pups 4 weeks old or younger, increase in cortisol concentration was maximal at 2 hours after ACTH administration. However, in pups between 6 and 12 weeks of age, the increase in cortisol concentration was maximal 1 hour after ACTH administration in about a third of the pups, whereas the remaining pups had peak values at 2 hours. Mean plasma sodium, potassium, and chloride concentrations for each age group were within the reference ranges established for mature dogs, with the exception of lower mean plasma sodium and chloride concentrations in pups 4 weeks old or younger. Mean serum aldosterone concentration in pups of each age group was substantially higher than the range of aldosterone concentrations for clinically normal mature dogs. Median progesterone concentration was uniformly less than 0.2 ng/ml for all pups 6 weeks old or younger.(ABSTRACT TRUNCATED AT 250 WORDS)
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7785830
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Pharmacokinetics and residues of enrofloxacin in chickens.
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The pharmacokinetic properties of enrofloxacin were determined in broiler chickens after single IV and orally administered doses of 10 mg/kg of body weight. After IV and oral administrations, the plasma concentration-time graph was characteristic of a two-compartment open model. The elimination half-life and the mean +/- SEM residence time of enrofloxacin for plasma were 10.29 +/- 0.45 and 9.65 +/- 0.48 hours, respectively, after IV administration and 14.23 +/- 0.46 and 15.30 +/- 0.53 hours, respectively, after oral administration. After single oral administration, enrofloxacin was absorbed slowly, with time to reach maximal plasma concentration of 1.64 +/- 0.04 hours. Maximal plasma concentration was 2.44 +/- 0.06 micrograms/ml. Oral bioavailability was found to be 64.0 +/- 0.2%. Statistically significant differences between the 2 routes of administration were found for the pharmacokinetic variables--half-lives of the distribution and elimination phase and apparent volume of distribution and volume of distribution at steady state. In chickens, enrofloxacin was extensively metabolized into ciprofloxacin. Residues of enrofloxacin and the major metabolite ciprofloxacin in fat, kidney, liver, lungs, muscles, and skin were measured in chickens that received an orally administered dose of 10 mg/kg once daily for 4 days. The results indicate that enrofloxacin and ciprofloxacin residues were cleared slowly. Mean muscle, liver, and kidney concentrations of the metabolite ciprofloxacin ranging between 0.020 and 0.075 micrograms/g persisted on day 12 in chickens after dosing. However, at the time of slaughter (12 days), enrofloxacin residues were only detected in liver and mean +/- SEM concentration was 0.025 +/- 0.003 micrograms/g.
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7785831
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Eicosanoid concentrations in digital venous blood from horses with chronic laminitis.
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The eicosanoids are a family of lipid-derived autocoids that are released in response to a variety of physical and hormonal stimuli. In this study, prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) were measured in the digital veins of clinically normal horses and horses with chronic laminitis to determine whether these arachidonic acid metabolites have a role in mediating signs of hoof pain and lesions associated with chronic laminitis. Horses were evaluated at rest and after a brief exercise period, to determine whether eicosanoids are released into the circulation after mild concussion. Digital vein eicosanoid concentrations in horses with signs of hoof pain attributable to chronic laminitis were not different than those in clinically normal horses. There was no difference in resting and postexercise PGE2 or LTB4 concentrations. Mean digital vein PGE2 concentration for the 2 groups was 187.18 pg/ml, whereas mean digital vein LTB4 concentration for the 2 groups was 74.71 pg/ml. These data do not support the hypothesis that PGE2 and LTB4 have a role in mediating the signs of pain and pathologic features of chronic laminitis.
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7785829
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Cardiovascular effects of epidurally administered morphine and a xylazine-morphine combination in isoflurane-anesthetized dogs.
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Cardiovascular effects of epidurally administered morphine, a morphine-xylazine combination, and saline solution (control) during isoflurane-maintained anesthesia were assessed in 6 healthy dogs. Anesthesia was induced with isoflurane in O2 and was maintained at 2.0% end-tidal isoflurane concentration. Ventilation was controlled to maintain PaCO2 at 35 to 45 mm of Hg. The dorsal pedal artery was cannulated for measurement of systolic, mean, and diastolic pressures, and for blood sample collection. Arterial blood pH and gas tensions were determined every 30 minutes. Cardiac output was determined by thermodilution. The ECG, heart rate, body temperature, central venous pressure, mean pulmonary artery pressure, pulmonary capillary wedge pressure, end-tidal isoflurane concentration, and CO2 tension were monitored. Systemic and pulmonary vascular resistance, arterial HCO3- concentration, base excess, and cardiac index were calculated. After baseline measurements were taken, morphine (0.1 mg/kg of body weight) in 5 ml of isotonic saline solution, morphine and xylazine (0.1 mg of morphine and 0.02 mg of xylazine/kg) in 5 ml of isotonic saline solution, or 5 ml of isotonic saline solution was injected into the lumbosacral epidural space. Data were recorded at 5, 15, 30, 45, 60, 75, 90, 105, and 120 minutes after epidural injection. Statistical analysis included ANOVA for repeated measures. Significance was set at P < 0.05. None of the measured variables was significantly different among the 3 treatments at any time. Results of the study indicated that epidural administration of morphine or morphine and xylazine is not associated with significant cardiovascular side effects during isoflurane-maintained anesthesia in dogs.
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7785828
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High-performance liquid chromatography method for determination of flunixin in bovine plasma and pharmacokinetics after single and repeated doses of the drug.
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A high-performance liquid chromatography method was developed for determination of flunixin in bovine plasma. The extraction procedure was easily performed and made it possible to detect low concentrations of flunixin with high accuracy. The limit of quantitation was 7 ng/ml (relative standard deviation = 18% n = 10). The analytic method permits processing of 60 samples/d. Flunixin, as well as the internal standard (diclofenac sodium), belong to the group of nonsteroidal anti-inflammatory drugs, which are known to have a high degree of binding to plasma proteins. Therefore, an evaluation of several buffer systems was undertaken to optimize analytic conditions. Cattle were given 2.2 mg of flunixin melgumine/kg of body weight. In experiment 1, single injections were administered IV to 1 cow and IV and IM to 1 heifer (7 days apart), and pharmacokinetic variables were calculated. The IV data were best described by a two-compartment model. The half-life after single IV or IM administration was around 4.0 hours. In experiment 2, the decreasing flunixin concentration was determined after the last of either 4 IM injections daily (n = 3 cows) or 2 IM injections daily (n = 3 cows) administered during a 14-day postpartum period. The half-life, determined between 48 and 96 hours after the last dose, was approximately 26 hours in both groups, and flunixin could be detected in plasma up to 8 days, on average. The protein binding of flunixin was studied, using the method of equilibrium dialysis.(ABSTRACT TRUNCATED AT 250 WORDS)
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7785827
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Effect of methacholine on mucociliary transport in bovine trachea in vitro.
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A method is described to evaluate pharmacologic influence on bovine tracheal mucus transport in vitro. In this model, cholinergic agonist methacholine stimulated transport velocity. Methacholine at concentration of 10(-6)M increased velocity by 13.6%, whereas 10(-5)M increased velocity by 26%. Stimulation was inhibited by atropine.
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7785826
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Ceftiofur distribution in serum and milk from clinically normal cows and cows with experimental Escherichia coli-induced mastitis.
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Eight Holstein cows, 4 inoculated intracisternally in 1 quarter of the mammary gland with Escherichia coli and 4 noninfected controls, were administered ceftiofur sodium (3 mg/kg of body weight, IV, q 12 hours) for 24 hours, beginning at 14 hours after inoculation of infected cows. All challenge-exposed cows became infected, with mean +/- SEM peak log10 bacterial concentration in milk of 5.03 +/- 0.69 colony-forming units/ml. The infection resulted in systemic signs (mean peak rectal temperature, 41.5 +/- 0.3 C; anorexia; signs of depression) and local inflammation (mean peak albumin concentration in milk, 7.89 +/- 1.71 mg/ml). Ceftiofur was detectable in milk from all challenge-exposed cows, compared with only 1 of 4 noninfected cows, and the mean period after inoculation that ceftiofur was detectable in milk was longer (P < 0.05) in infected (147.7 +/- 27.5 hours) than noninfected cows (1.3 +/- 1.3 hours). However, maximal ceftiofur concentration attained in milk for all cows was 0.28 microgram/ml, and was 0.20 microgram/ml or less for all but 2 milk samples collected for 10 days after challenge exposure. Mean serum concentration of ceftiofur peaked at 1.0 +/- 0.3 microgram/ml and 0.7 +/- 0.1 microgram/ml for infected and noninfected cows, respectively. After each ceftiofur dose, mean peak and trough concentrations of ceftiofur in serum did not differ between groups; however, concentration of ceftiofur in serum was higher at 7 hours after each dose in noninfected cows, suggesting more rapid clearance of the drug in infected cows.(ABSTRACT TRUNCATED AT 250 WORDS)
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7785825
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Articular chondrocalcinosis of the humeral head in greyhounds.
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Of 143 Greyhounds necropsied consecutively, 6 (4%) had chondrocalcinosis of the scapulohumeral joint; lesions were identified in 6 additional dogs. Lesions were seen exclusively in the humeral head, mainly in the plateau region. The lesions in the dogs of the initial group were unilateral, but 2 of the 6 additional dogs had bilateral lesions. Focal mineralization of articular cartilage appeared as a white raised nidus, sometimes surrounded by a translucent halo in the opaque cartilage. Circular, small translucent cartilage foci, with or without beginning mineralization, were adjacent to definitive chondrocalcinosis lesions. Chondrocyte necrosis and matrix degradation were considered to antedate appearance of matrical mineral granules; mineralization of the cartilage was considered a secondary process, but not necessarily an epiphenomenon. Scanning electron microscopy indicated that the chondrocalcinosis lesion was composed of deposits of irregularly fused stone material that, in scanning and transmission electron micrographs, was composed of irregular spheroids, 0.05 to 0.5 micron in diameter. The spheroids contained poorly formed needle-like crystals of apatite. Sparse transformation of the mineral phase into hydroxyapatite was considered to be attributable to a biological mechanism that inhibited phase transition. Cartilage degeneration and chondrocalcinosis of the plateau region of the humeral head appear to be unique lesions that develop in young Greyhounds. It is possible that these lesions are the result of the biomechanical stress of training and racing.
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7785824
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Comparative treatment of mares susceptible to chronic uterine infection.
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Four intrauterine treatment strategies were evaluated for effectiveness in mares that were confirmed to be susceptible to chronic uterine infection. Pretreatment samples were obtained at detection of estrus, and a genital strain of Streptococcus zooepidemicus was infused into the uterus when a preovulatory (> 35 mm) follicle was detected. At 12 hours after inoculation, mares were assigned to 1 of 4 selected treatment groups: autologous plasma, 100 ml (n = 5); potassium penicillin, 5 million U in 100 ml of phosphate-buffered saline solution (PBSS; n = 5); 10 mg of prostaglandin F2 alpha in 100 ml of PBSS (n = 5)' and large-volume lavage with normal saline solution (1,000 ml increments). A fifth group, treated with vehicle alone (100 ml of PBSS), served as a negative control (n = 7). All treatments were administered into the uterus. To assess the effectiveness of the treatment, samples for culture and cytologic examination were collected at 96 hours after bacterial inoculation. An effect of treatment was observed on the number of uterine neutrophils (P = 0.02) and growth of S zooepidemicus (P < 0.01). Intrauterine treatment with potassium penicillin, prostaglandin F2 alpha, and large-volume uterine lavage significantly reduced the growth of S zooepidemicus (P < 0.01) as well as the number of neutrophils (P < 0.02). Autologous plasma reduced the number of neutrophils (P < 0.05), but not growth of S zooepidemicus. There was significant correlation between the number of uterine neutrophils and growth of S zooepidemicus for each treatment group (r = 0.57; P < 0.05).
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7785823
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Efficacy of lufenuron against developmental stages of fleas (Ctenocephalides felis felis) in dogs housed in simulated home environments.
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Twenty-four, adult, female Beagles were arranged by body weight from greatest to least and allocated to 2 groups of 12 dogs, using random numbers. Dogs were housed collectively in 2 adjacent metal buildings, each divided into 4 rooms measuring 2.1 x 3.7 m. Each room was paneled and carpeted and had an access door to the outside with a connecting run that measured 2.1 x 9.1 m. Each run had a surface consisting of 5 cm of pea gravel overlaying 5 cm of sand, and was partially covered by an awning that provided shade at its proximal end. For placement in room/run units, dogs in each of the treated and control groups were alloted to 4 subgroups of 3 dogs each. Each subgroup of dogs was placed in a separate room/run unit. Units containing treatment or control subgroups were alternated to avoid placing identically treated subgroups adjacent to each other. Dogs of subgroups A, C, E, and G were treated with lufenuron monthly at a minimal target dosage of 10 mg/kg of body weight; those of subgroups B, D, F, and H were treated with excipient tablets. Dogs were treated on study days 7, 37, 68, and 98. Each dog was infested with 100 newly emerged, unfed, insectary-reared, adult Ctenocephalides felis on each of study days 0 and 2. Thereafter, infestations on all dogs were dependent on continued development of fleas either in the indoor or outdoor environment. Numbers of fleas on each of the treated and control dogs were determined, using a nondestructive counting technique on days 6, 14, 21, 28, 35, 56, 70, 84, 98, 112, and 119.(ABSTRACT TRUNCATED AT 250 WORDS)
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7785822
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Efficacy of injectable doramectin against natural Boophilus microplus infestations in cattle.
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Three experiments were conducted in Latin America--1 in Brazil, 1 in Venezuela, and 1 in Argentina--using a common protocol to investigate the efficacy of a single SC injection of doramectin (200 micrograms/kg of body weight) for treatment and control of Boophilus microplus infestations in grazing cattle. In each experiment, 2 groups of 20 to 27 cattle were allocated on the basis of tick burdens present 24 hours before treatment to a treated or control group, which received saline solution (1 ml/50 kg). All cattle were injected in the mid-dorsal cervical region and examined on treatment day and on posttreatment days (PTD) 8, 14, 21, and 28. On each observation day, the number of engorged and semiengorged ticks on half of each animals was counted and recorded. Doramectin was highly efficacious in removing tick burdens and controlling reestablishment of B microplus under field conditions of continuous reinfestation. Compared with tick counts in the control group, doramectin-treated cattle began to eliminate ticks after treatment and efficacy improved on subsequent observation days. In Brazil, efficacy was 91% at PTD 8 and 14, and increased to 99% or higher at PTD 21 and 28. In Venezuela, efficacy was 100% at PTD 8, 14, and 21 and 92% at PTD 28. In Argentina, efficacy progressed from 94.5% at PTD 8 to 99 and 98.5% at PTD 21 and 28, respectively. The reduction of the number of ticks in the doramectin-treated cattle was significant (P < 0.05) at each observation day.(ABSTRACT TRUNCATED AT 250 WORDS)
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7785821
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Specific antibodies in serum and vaginal mucus of heifers inoculated with a vaccine containing Tritrichomonas foetus.
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Thirty-five heifers were allotted to 3 groups. Group 1 (control) consisted of 10 heifers that were not vaccinated and were challenge exposed by breeding to infected bulls. Group 2 (natural challenge exposure) consisted of 10 heifers that were vaccinated and challenge exposed by breeding to infected bulls. Group 3 (experimental challenge exposure) consisted of 15 heifers that were vaccinated and challenge exposed by breeding to infected bulls and by intravaginal inoculation with 10(7) Tritrichomonas foetus. Total immunoglobulin concentrations and specific trichomonal antibodies were determined in serum and vaginal secretions of heifers, using radial immunodiffusion and ELISA procedures. Control heifers remained infected for a mean of 10.6 weeks (range, 0 to 18 weeks), and heifers of the natural and experimental challenge-exposure groups remained infected for 3.2 and 5.0 weeks, respectively (range, 0 to 12 weeks). Total serum and cervicovaginal mucus concentrations of IgM, IgA, IgG1, and IgG2 did not change significantly after vaccination or challenge exposure. However, ELISA titers of total trichomonal antibodies increased up to 1:10,000 (range, 1:400 to 1:10,000) in serum after vaccination, and increased approximately tenfold above background in cervicovaginal mucus. In serum, the predominant trichomonal antibody isotype was IgG1, although trichomonal IgA and IgM antibodies also increased. The predominant trichomonal antibody detected in cervicovaginal mucus was IgA. Antibody titers in serum and cervicovaginal mucus of vaccinated heifers were not increased by infection. However, in control heifers, the total local trichomonal antibody response increased three- to fivefold after infection.(ABSTRACT TRUNCATED AT 250 WORDS)
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7785820
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Effect of selenium supplementation on colostral IgG concentration in cows grazing selenium-deficient pastures and on postsuckle serum IgG concentration in their calves.
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Effects of selenium (Se) deficiency and supplementation on production of colostral immunoglobulins by beef cows and transfer of antigen-specific and nonspecific immunoglobulins to their calves were examined. Eight beef cows, with marginal to deficient Se status (blood Se concentration, 50 micrograms/L), were allotted by breed and age to 1 of 4 Se treatment groups (n = 20/group): no supplemental Se; parenteral administration of 0.1 mg of Se and 1 mg of vitamin E/kg of body weight; ad libitum consumption of 120 mg of Se/kg of salt-mineral mix (SMM); and parenteral administration of 0.1 mg of Se and 1 mg of vitamin E/kg plus ad libitum consumption of 120 mg of Se/kg of SMM. All cows were inoculated IM with lysozyme. Cows consumed Se-deficient pastures or hay (21 to 62 micrograms/kg) during the study that began at mid-gestation and ended at postpartum hour 24. Although the concentration of specific lysozyme antibodies was not affected, cows given 120 mg of Se/kg of SMM (treatments 3 and 4) had higher colostral IgG concentration (P < 0.002) than did Se-deficient cows (treatments 1 and 2). Calves from cows in treatments 3 and 4 had higher postsuckle serum concentrations of IgG (P < 0.01) than did calves from cows in treatments 1 and 2. Colostral IgM and calf serum IgM concentrations did not differ among treatments.
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7785819
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Detection of bovine immunodeficiency virus in blood and milk-derived leukocytes by use of polymerase chain reaction.
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Bovine immunodeficiency virus (BIV) is prevalent in beef and dairy cattle, yet the mode(s) of BIV transmission are undefined. Using polymerase chain reaction, which specifically targeted a 235-bp, highly conserved region of the BIV pol gene, BIV-infected leukocytes were detected in the blood and milk of BIV-seropositive cows. These data confirm the presence of BIV in milk and identify the potential for lactogenic transmission of this virus.
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7785817
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Complement component C3b and immunoglobulin Fc receptors on neutrophils from calves with leukocyte adhesion deficiency.
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Receptors for opsonins, such as complement component C3b (CR1) and immunoglobulins, Fc receptors, interact with adhesion glycoproteins in mediating immune functions. Defects in expression of the adhesion glycoproteins CD11/CD18 results in severely hampered in vitro and in vivo adherence-related functions of leukocytes. Little is known regarding the effect of leukocyte adhesion deficiency (LAD) on ligand binding and receptor expression. We investigated the binding and expression of CR1 and Fc receptors by bovine neutrophils isolated from dairy calves suffering from LAD, compared with clinically normal (hereafter referred to as normal) age-matched calves. Neutrophils were also assayed for endogenously bound IgG and IgM and for exogenous binding of C3b, IgG1, IgG2, IgM, and aggregated IgG (aIgG), using flow cytometry. Luminol-enhanced chemiluminescence (CL) production in response to IgG2 opsonized zymosan was studied, and specific inhibition of CL was used to determine the specificity of IgG2 binding. Activation of protein kinase C with phorbol myristate acetate was used to determine the effect of cellular activation on expression of CR1. A greater percentage of neutrophils from normal calves bound C3b than did neutrophils from LAD-affected calves. Receptor expression was similar. Activation with phorbol myristate acetate resulted in increased expression of CR1 on neutrophils from normal and LAD-affected calves, but expression was almost twofold greater on neutrophils from normal calves. There was no difference between LAD-affected and normal calves in percentage of neutrophils that bound endogenous IgG and IgM. A greater percentage of neutrophils from normal calves bound exogenous IgM than did neutrophils from LAD-affected calves.(ABSTRACT TRUNCATED AT 250 WORDS)
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7785816
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Risk of feline infectious peritonitis in cats naturally infected with feline coronavirus.
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A longitudinal survey of 820 cats in 73 households was conducted over a period of 6 years to establish the fate of pet cats that were seropositive after natural exposure to feline coronavirus (FCoV). In particular, their risk of developing feline infectious peritonitis (FIP) was determined. The seropositive cats were assigned to 1 of 3 groups: cats from households in which FIP had recently been diagnosed; cats from households in which FIP had not been diagnosed, but from which kittens had been relocated and subsequently died of FIP; and cats from households in which FIP had not been diagnosed. Cats in the first group were not at greater risk of developing FIP than were cats in the other 2 groups. Consequently, any household in which seropositive cats live must be considered a potential source of FCoV that can cause FIP. There was no evidence that the enhanced disease, which has been described after experimentally induced infection of seropositive cats, exists in nature. Thus, analysis of the survival of the seropositive cats over periods of up to 36 months indicated that their risk of developing FIP decreased with time, suggesting the development of immunity rather than increased susceptibility to disease. In addition, of 56 cats deemed to have been naturally reinfected because their anti-FCoV antibody titers decreased and subsequently increased, only 3 developed FIP.
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7785815
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Tissue and serum enzyme activities in the yellow rat snake (Elaphe obsoleta quadrivitatta).
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Activities of diagnostically important enzymes were measured in serum and lysates of liver, kidney, skeletal muscle, heart, intestine, lung, and pancreatic tissues from wild-caught yellow rat snakes, Elaphe obsoleta quadrivitatta. All samples were analyzed for alkaline phosphatase, lactate dehydrogenase (LD), aspartate transaminase (AST), alanine transaminase, gamma-glutamyltransferase, and creatine kinase (CK) activities. The major enzyme activities found in the liver were LD and AST. The kidney had moderate activities of LD, AST, alanine transaminase, and CK. Skeletal muscle and heart contained high CK activity. Intestine, lung, and pancreas had low activities for most enzymes analyzed. Little to no gamma-glutamyltransferase activity was found in serum or tissues analyzed. Serum enzyme activities in yellow rat snakes were similar to those described for other reptile species, except for serum CK activity, which was increased in rat snakes.
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7785813
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Comparison of the sensitivity of the caudal fold skin test and a commercial gamma-interferon assay for diagnosis of bovine tuberculosis.
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A study to determine and compare the sensitivity of the caudal fold tuberculin test (CFT) and a commercial gamma-interferon (gamma-IFN) assay for diagnosis of bovine tuberculosis was conducted. A dairy herd with approximately a third of the cattle infected with Mycobacterium bovis was chosen for this study. All cattle from this herd were slaughtered, and tissue specimens for bacteriologic culturing and histologic examination were collected. Results of the CFT and gamma-IFN assay were compared with results of bacteriologic culturing and histologic examination to determine test sensitivity. Results were analyzed, using each of the following 4 standards to classify cattle as infected: positive test result by bacteriologic culturing only; histologic examination only; bacteriologic culturing and histologic examination; and bacteriologic culturing or histologic examination. Sensitivity of the CFT ranged from 80.4 to 84.4%, depending on the standard of comparison. Sensitivity of the gamma-IFN assay ranged from 55.4 to 97.1%, depending on the standard of comparison and on the method of interpretation. The CFT was significantly (P < 0.001) more sensitive than the gamma-IFN assay for diagnosis of bovine tuberculosis when the gamma-IFN assay was conducted and interpreted as instructed by the manufacturer. Maximum overall sensitivity was achieved when results of the CFT and gamma-IFN assay were interpreted in parallel.
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7785814
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Body weight, heart weight, and heart-to-body weight ratio in greyhounds.
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Heart and body weights were obtained from 230 Greyhounds during necropsy. Sex and age were recorded for each Greyhound. Twenty-nine racing and 21 nonracing Greyhounds among the 230 dogs were compared. Heart-to-body weight ratio was calculated. Statistical analysis was done to determine the effects of age, sex, and racing on heart and body weights and heart-to-body weight ratio. In adult Greyhounds, mean +/- SD body weight was 28.4 +/- 3.1 and 31.5 +/- 2.8 kg, heart weight was 355.6 +/- 52.8 and 381.4 +/- 50.8 g, and heart-to-body weight ratio was 1.3 +/- 0.2 and 1.2 +/- 0.2% for females and males, respectively. Heart and body weights were significantly different between sex and age groups and among nonracing and racing males. However, heart-to-body weight ratio was not significantly different among age, sex, or racing groups.
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7785812
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Enzyme-linked immunosorbent assay for apolipoprotein A-I in the serum of cattle.
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An ELISA was developed to evaluate the concentration of apolipoprotein A-I, a major apoprotein in high-density lipoprotein, in the serum of cattle. Serum apolipoprotein A-I was purified electrophoretically, and antibodies to this protein were raised in rabbits. The specificity of the antiserum was assessed by use of several immunologic techniques including western blotting. The ELISA was sensitive (detection limit was 70 ng of apolipoprotein A-I/ml) and reliable (coefficients of variance were in the range of 3.5 to 8.2%). By use of this method, the serum apolipoprotein A-I concentration was higher in 2- to 6-year-old Holstein cows (mean +/- SD, 0.580 +/- 0.304 mg/ml) than in 7- to 15-month-old heifers (0.339 +/- 0.237 mg/ml), 6-month-old heifers (0.238 +/- 0.188 mg/ml), and 6-month-old steers (0.173 +/- 0.146 mg/ml). The concentration, however, is not largely different in cows in early, middle, and late lactation and in non-lactating stages. Results also indicated that apolipoprotein A-I concentration was decreased in cows with hepatic lipidosis (fatty liver) induced by administration of ethionine, suggesting that this method is a useful tool for the pathophysiologic study of lipid metabolism and its impairment in cattle.
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7785811
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In defense of the guidance theory of palatal canine displacement.
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From the foregoing debate it will be quite clear that Peck et al. have provided ample evidence that may be used to fuel the arguments of both sides: 1. Their material does not contradict the possibility that environmental factors may give rise to palatal displacement of canines generated by genetic anomaly of the adjacent teeth. 2. The buccally displaced canine finds itself similarly environmentally compromised by the different factor of crowding which leads to its characteristic buccally ectopic guidance pattern. 3. (a) Canines that are transposed with the premolar, (b) others that have erupted ectopically, high in the buccal sulcus and in the absence of crowding, and (c) certain palatal canines whose root apex is located markedly distant from their designated site, may all be labeled as genetically controlled with a fair degree of confidence. 4. In between these clearly defined entities there exists a "gray area" in which it is probable that the etiology of the individual displaced teeth may be linked to a combination of circumstances that obey premise number 1 and premise number 2, to varying degrees. The guidance theory cannot provide the complete answer to the etiology of the palatally displaced canine. Were this so, we would find PDC every time there was an anomalous or missing lateral incisor. Equally, it may not yet be discounted out of hand and certainly not on the basis of the evidence provided in the article in question.
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7785810
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Case report MH. Class II, Division 1 malocclusion with anterior openbite.
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This case report was presented at a regular meeting of the Southern California Component of the Edward H. Angle Society in 1994. It demonstrates the value of two-phase treatment which resulted in effective vertical control.
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7785806
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Statistical analysis of differential lissajous EMG from normal occlusion and Class III malocclusion.
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The method of differential lissajous electromyography (DL-EMG) was applied to investigate the relationship among the integrated EMG activity, timing, and coordination of the bilateral superficial anterior temporal and masseter muscle activities in normal occlusion and Class III malocclusion subjects. In both Class III malocclusion and normal occlusion subjects, the working side muscles showed a higher mean cumulative voltage (MCV) and mean maximum peak voltage (MMPV) compared with the balancing side. In addition, a higher MCV and MMPV of the working side masseter was observed in the normal occlusion group compared with that seen in the Class III group during both right and left side chewing (p < 0.01). Discriminant analysis applied to examine the distribution, the size and the shape of DL-EMG pattern further indicated a statistical difference between subject groups (p < 0.01). Finally, there was a significantly higher percentage of clockwise DL-EMG pattern-generation in the normal group compared with that seen for Class III subjects (p < 0.01). These data indicate that, compared with normal subjects, patients with a Class III malocclusion have a demonstrably abnormal masticatory muscle balance which is well characterized by the DL-EMG method.
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7785805
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Remodeling mechanisms of transseptal fibers during and after tooth movement.
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The remodeling mechanisms of transseptal fibers during and after tooth movement were investigated histologically. An autoradiographic study was conducted to assess the synthetic response. One hundred fifty male Wistar strain growing rats were divided into three groups--one control and two experimental groups. Animals in the experimental groups were subjected to tooth movement with 25 g and 150 g of force. Maxillary first and second molars were separated and retained mechanically. Transseptal fibers were stretched in proportion to the amount of force applied for up to 2 days. Dynamic remodeling with proliferation of fibroblasts during tooth movement and slow rearrangement during retention periods occurred in both experimental groups. Collagen phagocytosis within the fibroblasts was observed ultrastructurally during the experimental periods. The number of silver grains in fibroblasts in the collagen fibers increased 160% the first day and 206% during the first 3 days. Proliferating fibroblasts remodeled the transseptal fibers through the synthesization and degradation of collagen fibers.
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7785804
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Orthodontic bone remodeling in relation to appliance decay.
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This study examined alveolar bone turnover and orthodontic tooth movement after appliance decay. One group of rats (N = 54) received orthodontic force (40 g initial activation) while the other (N = 36) was sham-treated. Groups of six rats were sacrificed at various times following activation. Tooth movement and appliance decay were monitored cephalometrically, and bone turnover was monitored locally by histomorphometry and phosphatase chemistries and systemically by serum phosphatase and osteocalcin changes. A significant association was found between spring forces assessed by direct measurement and by cephalometric images (R2 = 0.784; p = 0.02). The cephalometric method indicated appliances were at least 93% deactivated by day 16. Tooth movement continued beyond the point of appliance decay (p < 0.001). This was accompanied by a dramatic decline in osteoblast surface (p < 0.0001) and an increase in osteoclast surface to control levels (p < 0.001). A significant peak in bone formation rate was also noted around appliance decay (p = 0.005). Serum acid phosphatase and osteocalcin also increased after appliance decay (p < 0.05), but alkaline phosphatase did not. Bone acid phosphatase was characterized by a peak after appliance decay (p = 0.0004), but alkaline phosphatase remained depressed (p < 0.0001). These data demonstrate that significant amounts of alveolar bone turnover continue for an indeterminant period following appliance decay.
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7785803
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Biomechanical behavior of the periodontium before and after orthodontic tooth movement.
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This study was designed to investigate the biomechanical behavior of the periodontium including the periodontal ligament (PDL) in terms of tooth mobility. Tooth mobility was measured in the canines of 10 adolescent patients before and after distal movement. Distal movement of the canines was carried out by use of a calibrated sectional archwire exerting an initial retraction force of 200 g. Tooth mobility was measured immediately before and after canine retraction by use of a noncontact displacement sensor when varying distal forces of 0 to 500 g were applied to the mesial of the canine. Before tooth movement, tooth mobility exhibited a substantial increase in loading with forces ranging from 50 to 150 g. The rate of increase gradually decreased up to 500 g. A nonlinear change in tooth mobility was similarly observed at the end of tooth movement or 24 days after the initiation of movement. Tooth mobility, however, was significantly greater when forces above 200 g were loaded. The periodontal tissues--the PDL and alveolar bone in particular--become more flexible at the end of tooth movement, indicating reduced support by the periodontal tissues. These findings suggest that the elastic nature of the PDL and alveolar bone may decrease substantially at the end of tooth movement.
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7785802
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Comparisons of the thermodynamic properties of three nickel-titanium orthodontic archwires.
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The unique memory property of thermodynamic wire is only partially understood. It is believed to result from the wire's inherent capability to markedly alter its atomic bonding forces as a function of temperature. This shape recovery phenomenon may be the result of a transition in crystal structure that occurs by deformation and cooling. When the transition is reversed, by heating, the structure reverts to its original form and abrupt property changes occur. The purpose of this study was to determine the transition temperature ranges (TTR) of three commercially available thermodynamic archwires and to determine the rate of recovery of the wires when bent to a uniform shape. A jig was constructed to hold the wires and was suspended in a water bath within a plexiglass box. The temperature of the water bath was gradually increased. A program was written to acquire a single video frame from a running video tape and then allow the operator to graphically overlay the position of each wire specimen. The results indicate that the TTRs for the three commercially available thermodynamic wires are of similar magnitudes (x = 6.7 degrees C, 6.2 degrees C and 6.7 degrees C). The greatest differences were in the standard deviations (1.3 degrees C, 2.2 degrees C and 3.7 degrees C) which may be a function of manufacturing during alloying of the wire and/or its heat treatment.
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7785801
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In vitro release of nickel and chromium from different types of simulated orthodontic appliances.
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Five identical samples, each consisting of a fixed appliance, a headgear and a quad-helix for one-half of a dental arch, were immersed in 0.9% sodium chloride for 2 hours, 24 hours and 7 days. A control appliance was subjected to dynamic test conditions in a specially built "oral simulator" under similar test conditions. A significant release of nickel was detected from the quad-helix during the first two hours in static conditions, whereas during the following two periods significantly less nickel was released from the quad-helix than from the other appliances. The fixed appliance with simulated function showed a significantly higher cumulative release of nickel than the similar appliance in static conditions, 44.2 micrograms (SD 22.8) and 17.1 micrograms (SD 3.4). The total amounts of chromium released from the fixed appliance were significantly lower than those of nickel. No difference in the release of chromium was seen between the static and dynamic conditions. The results indicate certain differences in the amount and pattern of nickel release from different stainless steel orthodontic appliances in vitro. The release rate of nickel from dynamically loaded fixed appliances was found to be accelerated compared with that released under static conditions. Caution should be exercised when applying the results to the in vivo situation.
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7785800
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Enamel surfaces after orthodontic bracket debonding.
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The enamel surfaces of extracted teeth were studied clinically and with a scanning electron microscope following debonding of orthodontic attachments and subsequent polishing. Excess orthodontic resin was removed with tungsten carbide burs and abrasive discs. Several combinations of polishing agents were evaluated. The no. 30 fluted tungsten carbide bur appeared to be the most efficient method of removing highly filled resin, and it produced the least amount of scarring. A polishing sequence was developed which used resin points and cups followed by a water slurry of fine pumice and brown and green cups. This procedure was tested clinically and appeared to return the enamel to an acceptable condition. This procedure is fast, efficient, and comfortable for the patient.
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7785799
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Cerebral dural sinus thrombosis. A case report.
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Cerebral dural sinus thrombosis is an uncommon syndrome that a patient presents with severe headache, which may be associated with complex physical and neurologic findings. The authors present a thirty-two-year-old woman with severe headache, focal motor seizures, and subsequent hemiparesis when she was ten weeks pregnant, diagnosed as having a dural sinus thrombosis by magnetic resonance imaging and magnetic resonance angiography. In this report, the application of magnetic resonance techniques, including angiography to diagnose and monitor therapy for dural sinus thrombosis, is presented.
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7785798
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Heart block in dextrocardia with situs inversus. A case report.
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The authors report a case of a forty-one-year-old white woman with dextrocardia with situs inversus who presented episodes of prolonged sinus arrest and syncopal episodes secondary to possible idiopathic degeneration of the conduction system, managed successfully with a permanent bicameral pacemaker. In their literature review they found that this case represents a very rare association.
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7785797
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Transesophageal echocardiography combined with magnetic resonance imaging for detecting venous anomalies in dextrocardia. A case report.
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A fifty-six-year-old woman was admitted to Osaka Rosai hospital because of dyspnea, chills, and fatigue. The patient was diagnosed by transthoracic echocardiography as having congestive heart failure due to severe biatrioventricular valve regurgitation, and cardiac surgery was proposed. Preoperative transesophageal echocardiography (TEE) revealed a dilatation of the coronary sinus (CS), a right-sided hemiazygos vein (R-AZ), and another great vessel lying between the CS and the R-AZ. Magnetic resonance imaging (MRI) was also performed, and this showed a persistent right superior vena cava (PRSVC) entering the left atrium via the dilatated CS. However, the site of connection between the R-AZ and the PRSVC could not be detected by MRI because of inadequate slice acquisition. Each method has its limitations, particularly with regard to visualizing the extracardiac vascular system. Therefore, the authors demonstrated that the combination of TEE and MRI might be more useful than each alone, and the combination is as a valuable method as digital subtraction angiography for the diagnosis of extracardiac venous anomalies.
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7785796
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Myocardial infarction secondary to coronary aneurysm in systemic lupus erythematosus. An autopsy case.
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The authors report a thirty-seven-year-old woman with systemic lupus erythematosus (SLE), a coronary aneurysm, and myocardial infarction. SLE was diagnosed at twenty-three years of age and treated with prednisolone. Seven years later, she developed inferior myocardial infarction, and coronary angiography showed an aneurysm in the proximal right coronary artery without associated stenosis. At the age of thirty-seven years, she died from cerebral infarction and sepsis. Autopsy revealed an aneurysm (6 mm in diameter) in the proximal right coronary artery and an old inferior myocardial infarction. Histologic examination showed recanalization and fibrosis in the media of the aneurysm wall. This case suggests that coronary aneurysm may cause myocardial infarction in SLE and that aneurysm formation may be a sequela of arteritis.
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7785795
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Acute myocardial infarction shortly after a normal exercise stress test. Case reports.
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The authors describe 3 cases of AMI occurring shortly after a negative bicycle ergometer stress test. These cases represent an unfortunate but extremely rare complication of a relatively safe diagnostic procedure. The authors also focus on the pathogenesis of the ischemic event, which may be attributed either to intraplaque hemorrhage or to platelet aggregation, both exercise-induced. The prevalence of AMI in this paper (0.06%) is similar to the data described in literature.
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7785794
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Refractory cardiogenic shock and complete heart block after verapamil SR and metoprolol treatment. A case report.
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A seventy-eight-year-old woman presented with complete heart block and refractory hypotension two days after a therapeutic dose of sustained-release verapamil with concomitant use of metoprolol. The patient continued to remain hypotensive with complete heart block, even with multiple uses of intravenous atropine as well as high doses of pressor agents such as dopamine and dobutamine. However, shortly after the use of intravenous calcium chloride, the refractory hypotension and complete heart block resolved.
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7785793
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Atrial natriuretic peptide and antihypertensive action due to beta-blockade in essential hypertensive patients.
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The effects of beta-blocker treatment on hemodynamics were studied in relation to plasma atrial natriuretic peptide (ANP) levels in 17 outpatients with essential hypertension. Administration of propranolol for twelve weeks to untreated subjects resulted in a significant (P < 0.001) rise in plasma ANP levels (from 37.9 +/- 21.2 to 66.7 +/- 46.2 pg/mL, mean +/- SD). Systolic and diastolic blood pressures were significantly decreased (P < 0.05 and P < 0.01, respectively). Heart rate was also significantly decreased (P < 0.001). On the other hand, a significant reduction of cardiac index was detected (from 4.12 +/- 1.34 to 2.96 +/- 0.75 L/min/m2, P < 0.01) with chronic administration of propranolol, suggesting a reflection of decreased cardiac function. A significant negative correlation was observed between %changes in systolic blood pressure and %changes in plasma ANP (r = -0.594, P < 0.05). These results suggest that the increased plasma ANP levels may contribute to the antihypertensive effect with propranolol.
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7785792
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Percutaneous balloon valvuloplasty in severe pulmonary valvular stenosis.
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Percutaneous balloon pulmonary valvuloplasty (PBPV) was achieved successfully in 20 of 22 patients with severe pulmonary valvular stenosis, aged two days to ten years (median four years and two months). The diameters of the balloon for PBPV were 88-125% (mean +/- SD = 109.5 +/- 10.0%) of the pulmonary valve annulus. PBPV failed in 2 patients because of the inability of the cardiac catheters to cross the stenotic valve. A significant reduction of right ventricle-pulmonary artery (RV-PA) pressure gradient occurred in all 20 patients (mean +/- SD = 72.1 +/- 10.3%). The mean RV-PA pressure gradient was reduced from 93.2 +/- 33.1 to 26.3 +/- 15.6 mmHg (P < 0.0001) and the mean right ventricular peak systolic pressure fell from 117.2 +/- 32.4 to 51.6 +/- 17.3 mmHg (P < 0.0001). Five (25%) of 20 patients had an infundibular gradient before PBPV. Two (10%) developed a new infundibular stenosis immediately after PBPV. Four (20%) presented with cyanosis, which disappeared after the successful PBPV. Two patients (10%) who showed a residual RV-PA pressure gradient of more than 40 mmHg had a significant infundibular obstruction initially. Two patients underwent recatheterization fifteen months after PBPV owing to a significant residual RV-PA pressure gradient and had no reductions in right ventricular pressure and RV-PA pressure gradient, but resolution of infundibular obstruction was noted in both. Repeat PBPV was successfully performed on these 2 patients. No significant complications were noted in any patient.(ABSTRACT TRUNCATED AT 250 WORDS)
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7785791
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Unstable angina of crescendo pattern vs new onset: a clinical, coronary arteriographic and hemodynamic study.
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Unstable angina includes a variety of clinical presentations with a different level of risk for an unfavorable outcome. In this study the authors investigated the prognostic significance of crescendo angina and new-onset angina to discuss management strategies, paying attention to the relevance of baseline clinical characteristics, coronary artery lesions, and left ventricular function, as well as their alterations during atrial pacing. Accordingly coronary arteriographic anatomy and changes in left ventricular volumes and ejection fraction before and during atrial pacing were studied by means of digital subtraction ventriculography in 18 patients with crescendo angina and in 18 patients with new-onset angina. Triple-vessel disease was more frequently observed in crescendo angina (56%; P < 0.05) as compared with the patients with new-onset angina (11%). Complex coronary morphology was statistically more likely to be found in crescendo angina. The angiographic evidence of intracoronary thrombi was found in 33% (P < 0.05) patients with crescendo angina and in 4% patients with new-onset angina. Compared with the patients with new-onset angina, patients with crescendo angina had higher end-diastolic and end-systolic volumes and lower ejection fraction at rest. At peak pacing, ejection fraction was significantly (P < 0.05) lower in crescendo angina (0.48 +/- 0.06) than in new-onset angina (0.66 +/- 0.04). In crescendo angina, during pacing, the magnitude of velocity of circumferential fiber shortening was significantly decreased as compared with new-onset angina.(ABSTRACT TRUNCATED AT 250 WORDS)
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7785789
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In vivo measurement of regional large artery compliance by intravascular ultrasound under pentobarbital anesthesia.
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The presence of smooth muscle fibers on the wall of large arteries would suggest that arterial compliance might change in response to vasoactive substances. The purpose of this study is to determine the basal level of vasomotor tone in these arteries in a commonly used animal preparation and to learn whether the compliance of large conductance arteries can be altered in vivo by vasoactive agents. Proximal iliac arterial compliance was measured in 7 pentobarbital-anesthetized pigs, before and during local infusions of adenosine and norepinephrine. Luminal area was measured every forty milliseconds by means of a 30 MHz intravascular ultrasound catheter and an automatic edge detection program. Simultaneous high-fidelity pressure measurements were obtained by means of a catheter-tipped pressure microtransducer positioned at the origin of the iliac artery. Linear regression analysis of the area/pressure relationship in two consecutive cardiac cycles (systolic phase only) was performed before and during adenosine and norepinephrine infusions. The slope of the area/pressure regression line was defined as an index of arterial compliance. Measurements after three minutes of infusions of adenosine (5-5000 micrograms/minute) and norepinephrine (0.001-10 micrograms/minute) were compared with the control measurements. Even at the highest infusion rate, adenosine did not significantly increase arterial compliance as compared with baseline (25 +/- 7 vs 19 +/- 4 mm2/mmHg x 10(-3), respectively, P = ns). In contrast, norepinephrine decreased arterial compliance as compared with the second baseline control (13 +/- 3 vs 20 +/- 3 mm2/mmHg x 10(-3), respectively, P < 0.01). In this animal model with pentobarbital anesthesia, arterial compliance may be modified more by the acute infusion of norepinephrine than by adenosine in large conductance arteries such as the proximal iliac. Thus, in this preparation, smooth muscle tone tends to be minimal and arterial compliance near maximal (ie, mostly a passive phenomenon). However, in response to norepinephrine, arterial compliance can decrease significantly as smooth muscle tone increases. Intravascular ultrasound allows continuous and accurate monitoring of these changes of arterial dimensions, suggesting that this technique may be useful in the evaluation of pharmacologically induced changes in the compliance of large arteries by vasoactive agents.
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7785790
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Relation between postpacing T wave changes and myocardial scintigraphic characteristics in patients with ventricular demand pacemaker.
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The aim of this study was to elucidate the cause of T wave changes after ventricular pacing using thallium 201 single photon emission computed tomography (Tl-SPECT). Tl-SPECT was performed in 20 patients with sick sinus syndrome who had negative T wave after ventricular pacing and had had a ventricular demand pacemaker (VVI) implanted. Patients who have stenotic coronary arteries were excluded from the study. From the analysis of Tl-SPECT, extent score was calculated as the ischemic region. Data in patients with SSS were compared with those in 20 normal controls (NC). Thallium perfusion defects in patients with VVI were observed and distributed mainly in apex and inferior regions on the polar map. The extent score in patients with VVI was significantly higher than that in NC (56.4 +/- 21.6% vs 3.2 +/- 6.4%, P < 0.01). The washout rate of thallium 201 in the defect area was significantly lower in patients with VVI than in NC (27.4 +/- 10.2% vs 46.8 +/- 12.3%, P < 0.01). These results suggest that T wave changes after ventricular pacing are closely related to myocardial ischemia.
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7785788
|
Brain infarction developed in hypertensive and normotensive patients during hospitalization--hemodynamic factors.
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To determine the effects of changes in blood pressure (BP) on the development of ischemic stroke, 17 patients who developed acute brain infarction during hospitalization were analyzed in relation to the vascular risk factors such as hypertension, previous stroke, diabetes mellitus, and hyperlipidemia. Their BPs were retrospectively referred to the onset of stroke. The average values of mean arterial blood pressure (MABP) on admission were 137 mmHg in hypertensive patients (HT; n = 9) and 101 mmHg in normotensives (NT; n = 8). HT patients received antihypertensive treatment after admission and MABP decreased by 22 mmHg (14%) prior to the ictus (three to sixty-five days after admission). MABP in NT patients remained constant before the attack (-1.4 mmHg, four to one hundred ten days after admission). Similarly, MABP decreased by 17 mmHg (four to ninety-three days) before the ictus in patients with previous stroke (n = 9), whereas it changed only a little in patients without history of stroke (n = 8). BP in each group elevated immediately after the stroke and gradually decreased to 90% of the resting level after two weeks. An excessive reduction of BP may induce brain infarction in HT or chronic stroke patients or cause it to recur.
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