排序方式: 共有455条查询结果,搜索用时 15 毫秒
51.
The triflates and pivalates of 3 alpha-hydroxymethyl-6-substituted-2,2-dimethylpenam sulfones 3, 5; methyl and benzyl 6-substituted penicillanates 6-9 and 3-exo-methylene-6-substituted-2,2-dimethylpenam sulfone 4 were synthesized. These novel compounds were evaluated as elastase inhibitors using porcine pancreatic elastase. The effects that structural modifications of substituents on C-3 and C-6 in the penam nucleus have on elastase activity were examined and several similarities and distinctions were identified when compared to the reported penicillin esters and amides elastase inhibitors. 相似文献
52.
OA Ayangbile JP Fontenot PP Graham DJ Kirk VG Allen 《Canadian Metallurgical Quarterly》1998,76(3):686-693
Exacerbations of asthma have been associated with exposure to ozone or particles with a 50% cut-off aerodynamic diameter of 10 microm (PM10). We postulated in this study that the association of summertime air pollution (i.e. ozone and PM10) with acute respiratory symptoms, medication use and peak expiratory flow differs among patients grouped according to asthma severity. During the summer of 1995, effects of ambient air pollution on these parameters were studied in a panel of 60 nonsmoking patients with intermittent to severe persistent asthma. These patients were recruited from our Pulmonary Out-patient Clinic. Subgroup analysis was performed on the degree of hyperresponsiveness and lung steroid use before the start of the study, as indictors for the severity of asthma. Associations of the parameters studied with ozone, PM10, nitrogen dioxide (NO2), sulphur dioxide (SO2) and black smoke were evaluated using time series analysis. Several episodes with increased summertime air pollution occurred during the 96 day study period. Eight hour average ozone concentrations exceeded the World Health Organization (WHO) Air Quality Guidelines (120 microg x m(-3)) on 16 occasions. Daily mean levels of PM10 were moderately elevated (range 16-98 microg x m(-3)). Levels of the other measured pollutants were low. There was a consistent, positive association of the prevalence of shortness of breath (maximal relative risk (RRmax) 1.18) with ozone, PM10, black smoke and NO2. In addition, bronchodilator use was associated with both ozone and PM10 levels (RRmax 1.16). Stratification by airway hyperresponsiveness and steroid use did not affect the magnitude of the observed associations. No associations with peak expiratory flow measurements were found. We conclude that the severity of asthma is not an indicator for the sensitivity to air pollution. 相似文献
53.
OA Sutochnikova MV Samsonova AV Cherniak AL Cherniaev AS Sokolov AG Chuchalin 《Canadian Metallurgical Quarterly》1996,68(3):48-50
11 patients with severe bronchial asthma entered a randomized trial of glucocorticosteroid budesonide of Russian produce. Of them 6 patients received inhalations of budesonide (800 micrograms/day for 6 months), 5 control patients did not receive the drug. As shown by investigations of external respiration and bronchoalveolar lavage with estimation of cytogram, metacholine provocative tests, fiber bronchoscopy, budesonide inhalations relieved clinical symptoms of asthma, bronchial hyperreactivity and inflammation. 相似文献
54.
IuG Parkhomenko OA Tishkevich TG Barkhina SN Potekaev NS Potekaev 《Canadian Metallurgical Quarterly》1998,60(5):66-68
A unique case of generalized bacillary angiomatosis (BA) in a patient who died of HIV infection is described. Apart from widely spread skin lesions there were also manifestations in the brain, lungs, heart, esophagus and intestine. Gram-negative bacteria were found in the histological sections. Oval and roundish bacteria with a predominantly perivascular location were found electron microscopically in the archives material. 相似文献
55.
OA Kiseleva AG Travkin VS Grishina TKh Petrova OG Davydova 《Canadian Metallurgical Quarterly》1998,114(6):15-17
Condition was studied of collective specific immunity against diphtheria in vaccinated children who ranged from 2 to 15 years old, living in the industrial region of Pridneprovye, with special reference for the degree of the technogenous environmental pollution. To determine specific cellular sensibilization to diphtherial antigen. LAIT was used for the first time. The studies made showed that in a region under health-hazard conditions lower level of antitoxic antidiphtherial immunity occurs more frequently than in non-polluted areas (twice as much of the values), which fact suggests that technologeous pollution may have a suppressive effect on formation of postvaccinal immunity. Apart from measuring the level of specific antibodies for control of the formation of the immune responsiveness to be monitored you may use LAIT and measure levels of R-proteins. 相似文献
56.
VM Kodentsova OA Vrzhesinskaia SN Denisova AA Sokol'nikov NA Beketova VA Isaeva OK Netrebenko VB Spirichev 《Canadian Metallurgical Quarterly》1993,39(4):27-31
Values of hour excretion of vitamins B1, B2, B6 and PP with urine in children of 9-13 years, studied under conditions of normal consumption of these vitamins, were estimated considering the correlation between the vitamins B concentration in blood and excretion of their metabolites with urine as well as using these parameters dependence on content of the vitamins in daily ration; for this purpose 35 adult persons and 31 children of both sexes were examined. Normal rate of riboflavin excretion with urine constituted 10-11 micrograms/h in children of this age, while of thiamine-11-12 micrograms/h. Under conditions of normal thiamine consumption, activity of erythrocyte transketolase, measured after preinactivation of transaldolase, exceeded 35 mumol/h/I ml of erythrocytes. Rates of excretion with urine of 4-pyridoxic acid and I-methyl nicotinamide were similar both in children and in adult persons and were equal to more than 40 micrograms/h and 400-600 micrograms/h, respectively. 相似文献
57.
M2, an acid-activated ion channel, is an influenza A virus membrane protein required for efficient nucleocapsid release after viral fusion with the endosomal membrane. Recombinant M2 slows protein traffic through the Golgi complex (Sakaguchi, T., Leser, G. P)., and Lamb, R. A. (1996) J. Cell Biol. 133, 733-47). Despite its critical role in viral infection, little is known about the subcellular distribution of M2 or its fate following delivery to the plasma membrane (PM). We measured the kinetics of M2 transport in HeLa cells, and found that active M2 reached the PM considerably more slowly than inactive M2. In addition, M2 delayed intra-Golgi transport and cell surface delivery of influenza hemagglutinin (HA). We hypothesized that the effects of M2 on transport through non-acidified compartments are due to inefficient retrieval from the trans-Golgi of machinery required for intra-Golgi transport. In support of this, acutely activated M2 had no effect on intra-Golgi transport of HA, but still slowed HA delivery to the PM. Thus, M2 has an indirect effect on early transport steps, but a direct effect on late steps in PM delivery. These findings may help explain the conflicting and unexplained effects on protein traffic observed with other perturbants of intraorganelle pH such as weak bases and inhibitors of V-type ATPases. 相似文献
58.
59.
RC King OA Binns RC Kanithanon JT Cope RL Chun KS Shockey CG Tribble IL Kron 《Canadian Metallurgical Quarterly》1997,63(5):1398-1404
BACKGROUND: Reperfusion injury is a significant cause of early allograft dysfunction after lung transplantation. We hypothesized that direct pulmonary arterial infusion of an intravascular nitric oxide donor, sodium nitroprusside (SNP), would ameliorate pulmonary reperfusion injury more effectively than inhaled nitric oxide without causing profound systemic hypotension. METHODS: Using an isolated, ventilated, whole-blood-perfused rabbit lung model, we studied the effects of both inhaled and intravascular nitric oxide during lung reperfusion. Group I (control) lungs (New Zealand White rabbits, 3 to 3.5 kg) were harvested en bloc, flushed with Euro-Collins solution, and then stored inflated for 18 hours at 4 degrees C. Lungs were then reperfused with whole blood and ventilated with 60% oxygen for 30 minutes. Groups II, III, and IV received pulmonary arterial infusions of SNP at 0.2, 1.0, and 5.0 micrograms.kg-1.min-1, respectively, whereas group V was ventilated with 60% oxygen and nitric oxide at 80 ppm during reperfusion. RESULTS: Pulmonary arterial infusions of SNP even at 0.2 microgram.kg-1.min-1 (group II) showed significant improvements in pulmonary artery pressure (31.35 +/- 0.8 versus 40.37 +/- 3.3 mm Hg; p < 0.05) and pulmonary vascular resistance (38,946 +/- 1,269 versus 52,727 +/- 3,421 dynes.s/cm-5; p < 0.05) when compared with control (group I) lungs after 30 minutes of reperfusion. Infusions of SNP at 1.0 microgram.kg-1.min-1 (group III) showed additional significant improvements in dynamic airway compliance (1.98 +/- 0.10 versus 1.46 +/- 0.02 mL/mm Hg; p < 0.05), venous-arterial oxygenation gradient (116.00 +/- 24.4 versus 34.43 +/- 2.5 mm Hg; p < 0.05), and wet-to-dry ratio (6.9 +/- 0.9 versus 9.1 +/- 2.2; p < 0.05) when compared with control (group I) lungs. Lungs that received inhaled nitric oxide at 80 ppm (group V) were significantly more compliant (1.82 +/- 0.13 versus 1.46 +/- 0.02 mL/mm Hg; p < 0.05) than control (group I) lungs. CONCLUSIONS: Pulmonary arterial infusion of low-dose SNP during lung reperfusion significantly improves pulmonary hemodynamics, oxygenation, compliance, and edema formation. These effects were achieved at doses of SNP that did not cause profound systemic hypotension. Direct intravascular infusion of SNP via pulmonary arterial catheters could potentially abate reperfusion injury immediately after allograft implantation. 相似文献
60.
The effect of illumination on intracellular free calcium concentration, [Ca2+]i, was studied in a cell line (WiDr cells) derived from a primary adenocarcinoma of the rectosigmoid colon. In these cells the biosynthesis of protoporphyrin IX was stimulated by 5-aminolevulinic acid to reach levels of 600-700 pmol of protoporphyrin IX per mg cell protein. A brief (1-min) exposure of the cells to light (70% of light energy at 340-380 nm) resulted in an increase in [Ca2+]i. This increase was not reversible over a period of at least 20 min following illumination. Elevation of [Ca2+]i most probably represented an influx of calcium ions from the medium to the cell, since it was completely abolished in the presence of extracellular EGTA. The increased [Ca2+]i did not reflect general membrane damage, as determined by trypan blue staining as well as measurement of the intercalation of ethidium bromide into cellular DNA, and neither did the sustained elevation of [Ca2+]i lead to any substantial loss of clonogenicity following illumination of protoporphyrin-containing cells. Together these results indicate that an increased [Ca2+]i level is not per se a cause of cell death during photodynamic therapy. 相似文献