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991.
Cyclosporine A (CsA) is an immunosuppressive agent that also causes hypertension. The effect of CsA on vascular responses was determined in Sprague-Dawley rats and isolated rat aortic rings. Male rats weighing 250 to 300 g were given either CsA (25 mg. kg-1. d-1) in olive oil or vehicle by intraperitoneal injection for 7 days. CsA administration produced a 42% increase (P<0.001) in mean arterial pressure (MAP) that reached a plateau after 3 days. Conversely, the levels of both nitrate/nitrite, metabolites of nitric oxide (NO), and cGMP, which mediates NO action, decreased by 50% (P<0.001) and 35% (P<0.001), respectively, in the urine. Thoracic aortic rings from rats treated with CsA and precontracted with endothelin (10(-9) mol/L) showed a 35% increase (P<0.001) in tension, whereas endothelium-dependent relaxation induced by acetylcholine (ACh, 10(-9) mol/L) was inhibited 65% (P<0.001) compared with that in untreated rats. This response was similar to that of endothelium-denuded aortic rings from untreated rats in which ACh-induced relaxation was completely abolished (P<0.001), but relaxation induced by S-nitroso-N-acetylpenicillamine (SNAP, 10(-8) mol/L) was unaffected (P<0.001). ACh-induced formation of both nitrate/nitrite and cGMP by both denuded and CsA-treated aortic rings was inhibited 95% (P<0.001) and 65% (P<0.001), respectively, compared with intact aortic rings. The effects of CsA were reversed both in vivo and in vitro by pretreatment with L-arginine (10 mg. kg-1. d-1 IP), the precursor of NO. There were no changes in MAP and tension in rats treated with L-arginine alone. In summary, CsA inhibits endothelial NO activity, with resulting increases in MAP and tension, and this inhibition can be overcome by parenteral administration of L-arginine. 相似文献
992.
GU H?glinger J Sautter M Meyer C Spenger RW Seiler WH Oertel HR Widmer 《Canadian Metallurgical Quarterly》1998,813(2):313-322
The method of analysis described permits the determination of 2,4-dinitrobenzoic acid down to the lower microg l(-1) range in the urine of persons exposed to dinitrotoluene. 2,4-Dinitrobenzoic acid is the main metabolite of 2,4-dinitrotoluene and technical dinitrotoluene. After acidic hydrolysis, which served to release the conjugated part of the 2,4-dinitrobenzoic acid, the analyte was selectively separated from the urine matrix via various extraction steps and then derivatised to the methyl ester. Quantitative analysis was carried out using capillary gas chromatography and mass selective detection. 3,5-Dinitrobenzoic acid was used as an internal standard. The detection limit was 1 microg l(-1) urine. The relative standard deviations of within-series imprecision were between 5 and 6%. The relative recoveries were between 91 and 110% depending on the concentration. The analytical method developed as part of this study was used to investigate a collective consisting of 82 urine samples from persons working in the area of explosives disposal. The concentrations of 2,4-dinitrobenzoic acid determined ranged from the detection limit to 95 microg l(-1) urine. The method allowed the quantification of low-level internal exposure to dinitrotoluene. 相似文献
993.
A Cogo AW Lensing MM Koopman F Piovella S Siragusa PS Wells S Villalta HR Büller AG Turpie P Prandoni 《Canadian Metallurgical Quarterly》1998,316(7124):17-20
OBJECTIVE: To evaluate the safety of withholding anticoagulant treatment from patients with clinically suspected deep vein thrombosis but normal findings on compression ultrasonography. DESIGN: Compression ultrasonography was done with a simplified diagnostic procedure limited to the common femoral vein in the groin and the popliteal vein extending down to the trifurcation of the calf veins. Patients with normal ultrasonography findings at presentation were retested 1 week later. MAIN OUTCOME MEASURE: The incidence of venous thromboembolic complications during follow up for 6 months in patients in whom anticoagulant treatment was withheld on the basis of normal results on two ultrasonography tests 1 week apart. SETTING: University research centres in four hospitals. RESULTS: A total of 1702 patients were included in the study. Abnormal results on compression ultrasonography at presentation or at 1 week were found in 400 and 12 patients, respectively, for a prevalence of deep vein thrombosis of 24%. None of the patients were lost to follow up. Venous thromboembolic complications during the week of serial testing occurred in a single patient and in eight patients during 6 months' follow up, resulting in a cumulative rate of venous thromboembolic complications of 0.7% (95% confidence interval 0.3% to 1.2%). The mean number of extra hospital visits and additional tests required per initially referred patient was 0.8. CONCLUSION: It is safe to withhold anticoagulant treatment from patients with clinically suspected deep vein thrombosis who have a normal result on compression ultrasonography at the time of presentation and at 1 week. 相似文献
994.
EB Gottlin AE Rudolph Y Zhao HR Matthews JE Dixon 《Canadian Metallurgical Quarterly》1998,95(16):9202-9207
The phospholipase D (PLD) superfamily includes enzymes of phospholipid metabolism, nucleases, as well as ORFs of unknown function in viruses and pathogenic bacteria. These enzymes are characterized by the invariant sequence motif, H(X)K(X)4D. The endonuclease member Nuc of the PLD family was over-expressed in bacteria and purified to homogeneity. Mutation of the conserved histidine to an asparagine in the endonuclease reduced the kcat for hydrolysis by a factor of 10(5), suggesting that the histidine residue plays a key role in catalysis. In addition to catalyzing hydrolysis, a number of phosphohydrolases will catalyze a phosphate (oxygen)-water exchange reaction. We have taken advantage of this observation and demonstrate that a 32P-labeled protein could be trapped when the enzyme was incubated with 32P-labeled inorganic phosphate. The phosphoenzyme intermediate was stable in 1 M NaOH and labile in 1 M HCl and 1 M hydroxylamine, suggesting that the enzyme forms a phosphohistidine intermediate. The pH-stability profile of the phosphoenzyme intermediate was consistent with phosphohistidine and the only radioactive amino acid found after alkaline hydrolysis was phosphohistidine. These results suggest that the enzymes in the PLD superfamily use the conserved histidine for nucleophilic attack on the substrate phosphorus atom and most likely proceed via a common two-step catalytic mechanism. 相似文献
995.
JR Benz HR Black A Graff A Reed S Fitzsimmons Y Shi 《Canadian Metallurgical Quarterly》1998,12(12):861-866
OBJECTIVE: This study compares the antihypertensive efficacy and tolerability of valsartan, a novel angiotensin II antagonist, given with hydrochlorothiazide (HCTZ) vs placebo or vs valsartan or HCTZ alone. DESIGN: 871 adult out-patients with essential hypertension participated in this double-blind study. Patients were randomised in equal number to receive either combination therapy of valsartan (80 mg or 160 mg) and HCTZ (12.5 mg or 25 mg), or valsartan (80 mg or 160 mg) or HCTZ (12.5 mg or 25 mg) alone, or placebo. Patients were treated once daily for 8 weeks and assessed at 2, 4 and 8 weeks after randomisation. MAIN OUTCOME MEASURES: The primary efficacy variable was change from baseline in mean sitting diastolic blood pressure (MSDBP) at end-point. The secondary variable was change in mean sitting systolic blood pressure (MSSBP) from baseline to end-point. RESULTS: All active treatments produced a statistically significant difference in MSDBP (P < 0.001) from baseline to end-point compared with placebo. Similar results were obtained for MSSBP. All combination regimens produced a statistically significantly greater reduction in MSDPB and MSSBP than the corresponding monotherapies. Dizziness and headache were the most common treatment-related adverse experiences reported. Hypokalaemia, associated with the use of thiazide diuretics, was more commonly reported in the higher dose HCTZ 25 mg groups. CONCLUSIONS: Valsartan 80 mg and 160 mg act additively with HCTZ 12.5 mg or 25 mg to lower MSDBP and MSSBP in patients with essential hypertension. The addition of HCTZ to valsartan 80 mg or 160 mg was well tolerated. 相似文献
996.
997.
HR Axelrod JS Kim CB Longley E Lipka GL Amidon R Kakarla YW Hui SJ Weber S Choe MJ Sofia 《Canadian Metallurgical Quarterly》1998,15(12):1876-1881
PURPOSE: The objective was to investigate the ability of a glycosteroid (TC002) to increase the oral bioavailability of gentamicin. METHODS: Admixtures of gentamicin and TC002 were administered to the rat ileum by injection and to dogs by ileal or jejunal externalized ports, or PO. Bioavailability of gentamicin was determined by HPLC. 3H-TC002 was injected via externalized cannulas into rat ileum or jejunum, or PO and its distribution and elimination was determined. The metabolism of TC002 in rats was evaluated by solid phase extraction and HPLC analysis of plasma, urine and feces following oral or intestinal administration. RESULTS: The bioavailability of gentamicin was substantially increased in the presence of TC002 in both rats and dogs. The level of absorption was dependent on the concentration of TC002 and site of administration. Greatest absorption occurred following ileal orjejunal administration. TC002 was significantly more efficacious than sodium taurocholate, but similar in cytotoxicity. TC002 remained primarily in the GI tract following oral or intestinal administration and cleared rapidly from the body. It was only partly metabolized in the GI tract, but was rapidly and completely converted to its metabolite in plasma and urine. CONCLUSIONS: TC002 shows promise as a new drug transport agent for promoting intestinal absorption of polar molecules such as gentamicin. 相似文献
998.
P Wiegand HR Schneider M Schürenkamp M Kleiber B Brinkmann 《Canadian Metallurgical Quarterly》1998,111(4):180-182
A case of microcytic anemia, leukopenia (with lymphocytic reduction prevalence) and light thrombocytopenia is reported. The case occurred to a 63-year old diabetic woman suffering from Basedow's disease. The thyropathy was diagnosed first and the patient did not undergo to any previous treatment with antithyroid agents. The bone marrow aspiration only showed slight dyserythropoietic notes, with slight reduction of myeloid-erythroid ratio. The blood cell indexes rapidly normalized as soon as euthyroidism was achieved by radioiodine therapy (I131, 4mCi), and this led to think there was a relationship between thyropathy and blood modifications. The patient was subsequently treated with levothyroxine because of the occurrence of a iatrogenic hypothyroidism. Two years later, during a follow-up, all the hematologic parameters were normal, as well as the serum concentration of thyroid hormones and TSH (during opotherapy). We report the hematologic alterations most frequently observed in hyperthyroidism and underline the peculiarity of this case as it shows the simultaneous alterations of different cellular lines in the same patient. 相似文献
999.
HR Silvers PJ Lewis LS Suddaby HL Asch DE Clabeaux LE Blumenson 《Canadian Metallurgical Quarterly》1996,9(4):287-293
The objective of this pilot study was to evaluate the safety and efficacy of cervical discectomy with fusion performed on an outpatient basis. The experimental group (50 consecutive patients) was studied prospectively and the outcomes were compared with 53 consecutive, retrospectively analyzed, admitted controls who underwent the same procedure. Outcomes for both groups were assessed by patient-response questionnaires and clinical examination. At follow-up times of 1.3 (outpatient) and 1.6 (inpatient) years, outcomes (outpatient/inpatient) expressed as percent successful were as follows: Relief of arm pain (80/70%); relief of neck pain (78/68%); relief of arm muscle weakness and atrophy (94/96%); return to normal activities (64/70%); return to work (65/68%); and satisfaction with the results of surgery (86/83%). No statistically significant differences between outpatients and inpatients were found for any of the outcome parameters studied. There was no mortality and the operative complication rate was 2% for each study group. The results indicate that conversion of cervical discectomy with fusion from an admitted to an ambulatory practice did not compromise the safety or efficacy of the surgical procedure. Potential economic savings to overall health costs of the United States that might result from such conversion could exceed $100 million annually. 相似文献
1000.
MG Ortega-Pierres L Yepez-Mulia W Homan HR Gamble PL Lim Y Takahashi DI Wassom JA Appleton 《Canadian Metallurgical Quarterly》1996,18(6):273-284
In order to characterize immunodominant components of T. spiralis a workshop was organized. In this the reactivity of monoclonal and polyclonal antibodies, provided by different research groups, towards total extracts from adult, new born larvae and muscle larvae as well as to excretory/secretory components of muscle larvae were tested by ELISA, Western blot and immunoprecipitation assays. As a result of this workshop T. spiralis ML antigens have been classified into eight groups (TSL-1-TSL-8) according to their recognition by monoclonal and polyclonal antibodies. Among them, TSL-1 antigens have been the most extensively characterized both biochemically and immunologically. These antigens are stage specific, originate in the muscle stichosome and are abundant in both E/S and on the larval cuticular surface. The TSL-1 antigens share an immunodominant carbohydrate epitope (tyvelose), which is unique for Trichinella and is not associated with phosphorylcholine. The data collected in this workshop has allowed both the unification of the nomenclature for T. spiralis antigens and their biochemical characterization. It also has provided a platform for further studies on the characterization of other T. spiralis antigens and indeed for other Trichinella species. 相似文献