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991.
Kari Hemminki Xinjun Li 《Journal of occupational and environmental medicine / American College of Occupational and Environmental Medicine》2003,45(4):456-461
Epidemiologic data on pleural mesothelioma are scarce on regional and occupational time trends, which would monitor the effects of changes in exposure to asbestos. We aim to characterize time trends, regional, socioeconomic, and occupational risk factors for pleural mesothelioma in Sweden in the years from 1961 to 1998. The Swedish Family-Cancer Database was used to identify patients with pleural mesothelioma. Age-standardized incidence rates and standardized incidence ratio (SIR) were calculated for the population in the Database. A total of 1298 male and 233 female pleural mesotheliomas were retrieved. Age-standardized incidence of the disease was highest, and the trend increased in residents of large industrial and shipbuilding cities. In the last follow-up period, the male rate exceeded the female rate about 10-fold. Among male socioeconomic groups, manual workers showed the highest and ever-increasing SIR. No female socioeconomic group was at risk. For men, plumbers and seamen had the highest risk of 4.56 and 2.83, respectively, but the risks appeared to be decreasing for plumbers, whereas no clear trend was noted for seamen, probably because of indirect expose in ships. Farmers showed an SIR of 0.28, indicating that the population at large was at four times higher risk than farmers. The SIRs of many academic/college-educated groups were two to six times higher than those of farmers, suggesting indirect exposure to asbestos in these groups. 相似文献
992.
P J Hayden C J Welsh Y Yang W H Schaefer A J Ward J L Stevens 《Chemical research in toxicology》1992,5(2):232-237
Nephrotoxic cysteine conjugates derived from a variety of halogenated alkenes are enzymatically activated via the beta-lyase pathway to yield reactive sulfur-containing metabolites which bind covalently to cellular macromolecules. Mitochondria contain beta-lyase enzymes and are primary targets for binding and toxicity. Previously, mitochondrial protein and/or DNA have been considered as molecular targets for cysteine conjugate metabolite binding. We now report that metabolites of nephrotoxic cysteine conjugates form covalent adducts with rat kidney mitochondrial phospholipids. Rat kidney mitochondria were incubated with the 35S-labeled conjugates S-(1,1,2,2-tetrafluoroethyl)-L-cysteine (TFEC), S-(2-chloro-1,1,2-trifluoroethyl)-L-cysteine (CTFC), S-(1,2-dichlorovinyl)-L-cysteine, and S-(1,2,3,4,4-pentachlorobutadienyl)-L-cysteine. Quantitation of metabolite binding to whole mitochondria and to mitochondrial protein and lipid fractions revealed that as much as 42% of the 35S-label associated with the mitochondria was found in the lipid fraction. Total lipids were also extracted from 35S-treated mitochondria and separated by thin-layer chromatography. 35S-Containing metabolites were found in the lipid fractions from mitochondria treated with each of the conjugates. Lipids from both [35S]CTFC- and [35S]-TFEC-treated mitochondria contained major 35S-labeled lipid adducts which had similar mobility by thin-layer chromatography. Fatty acid analysis, 19F and 31P NMR spectroscopy, and mass spectrometric analyses confirmed that the major TFEC and CTFC adducts are thioamides of phosphatidylethanolamine. 相似文献
993.
F Rulli M Muzi M Lazzari M L Capitanucci P Cipriani A Giordano A Magni 《Journal of chemotherapy (Florence, Italy)》1992,4(4):216-220
Pulmonary infection complicating intra-abdominal sepsis is a major clinical problem. An experimental model for intra-abdominal sepsis was created with implantation of gelatin capsules, containing 3 x 10(8) cfu E. coli strain no. 2554, in the peritoneal cavity of 20 rats (10 animals received and 10 did not receive antibiotic therapy with ceftriaxone) in order to verify the role of the primary site of infection in the pathogenesis of pneumonia. Ten rats were sacrificed to determine the relative pulmonary weight and 10 were submitted to simple laparotomy and insertion of a germ-free capsule (sham-operated group). In this group of animals there was only one death (10%). All the rats that received antibiotic therapy survived until sacrifice while all the rats that did not receive ceftriaxone died, 7 within the 2nd and 3 on the 6th postoperative day. Pneumonia and peritonitis developed only in the animals that did not receive ceftriaxone. Bacteriological findings of material obtained from peritoneal and pleural cavities revealed the same strain of E. coli used for the experiment, suggesting that bacteria involved in the pleuro-pulmonary infections may originate in the primary site of infection and that antibiotic therapy started at the moment of contamination, can prevent this major complication. 相似文献
994.
995.
Premalignant lesions and nonsquamous malignancy of the penis and carcinoma of the scrotum. 总被引:2,自引:0,他引:2
P F Schellhammer G H Jordan E L Robey J T Spaulding 《The Urologic clinics of North America》1992,19(1):131-142
Premalignant lesions of the penis include cutaneous horn, balanitis xerotica obliterans, and leukoplakia. The true incidence of progression of each of these to squamous-cell carcinoma is unknown. Bowenoid papulosis, erythroplasia of Queyrat, and Bowen's disease are histologically identical to in situ carcinoma. Although the first is consistently benign, the latter two regularly evolve into invasive cancer. Malignant scrotal lesions include squamous-cell carcinoma, liposarcoma, leiomyosarcoma, basal-cell carcinoma, extramammary Paget's disease, erythroplasia of Queyrat, malignant melanoma, and metastases. Hemangioma can be confused with carcinoma. 相似文献
996.
997.
The purpose of this study was to measure the muscle activity during performance of the anti-G straining maneuver (AGSM) at high sustained acceleration stress (+Gz = head-to-foot inertial loading). Ten males were exposed on three separation occasions to a rapid onset rate of 6 + Gz. Subjects wore standard United States Air Force (USAF) anti-G trousers and performed the AGSM until perceived fatigue or until achieving light loss criteria. During each exposure, surface electromyography (EMG) was recorded from the erector spinae, external oblique, bicep femoris, vastus lateralis, and lateral gastrocnemius muscles. The normalized root-mean squares (RMS) and mean power frequency (MPF) for each muscle were calculated and tested for significant differences with an analysis of variance (ANOVA) procedure. The results of this study showed that mean amplitude decreased during the AGSM (35.40%) while MPF showed no significant change. The EMG amplitude of lower extremity muscles decreased (61.45%) while the amplitude of trunk muscles decreased slightly (3.45%). These results indicate that during the performance of the AGSM, motor unit recruitment in lower extremity muscles decrease without evidence of fatigue. 相似文献
998.
用小鼠败血症系统感染模型,以感染小鼠肾匀浆活菌计数为标准,以庆大霉素为对照药,探讨日剂量单次与分两次给药两种方案对新氨基糖苷类抗生素89—07体内抗留作用的影响。结果表明大肠杆菌90-020、绿脓假单胞菌3—374、金葡球菌90—506对抗生素89—07和庆大霉素均敏感(MIC范围0.0625~2mg/L);抗生素89—07和庆大霉素日剂量单次给药组(OD)3株实验菌的肾匀浆活菌计数值由给药前的4.94±0.09、4.60±0.27、4.86±0.101gcfu/ml分别降至1.94±0.19、1.84±0.25、1.88±0.251gcfu/ml(给药后7~8h).日剂量分两次给药组(BID)则分别降至2.95±0.48、2.87±0.37、3.44±0.271gcfu/ml。OD组对3株实验菌的最大杀菌作用Emax分别为3.02、2.97和2.851gcfu/ml,OD给药方案的体内杀菌作用明显优于BID方案。 相似文献
999.
Van Landeghem G; Haese P; Lamberts L; Barata J; DeBroe M 《Nephrology, dialysis, transplantation》1997,12(8):1692-1698
Background: The association between aluminium and
dialysis encephalopathy and deterioration of the neurological state during
desferrioxamine treatment of dialysis patients is well established. At
present little is known about the speciation and the mechanisms underlying
the element's neurotoxicity. Methods. Aluminium speciation was performed in
cerebrospinal fluid samples of acutely aluminium-intoxicated dialysis
patients using a recently developed high-performance liquid
chromatographic/electro-thermal atomic absorption spectrometric hybrid
method. Results: Baseline cerebrospinal fluid
aluminium levels of samples taken shortly after the intoxication were low
but elevated (5.0±2.0 &mgr;g/l, n=3) as compared to subjects
with normal renal function (<1 &mgr;g/l). In contrast to the
situation noted in serum and to the iron speciation in cerebrospinal fluid,
aluminium was not bound to transferrin but appeared as two distinct
compounds, the main fraction eluting at the elution volume of aluminium
citrate/silicate. The second compound was not identified. Forty-four hours
after desferrioxamine administration the cerebrospinal fluid aluminium
levels had increased up to a concentration of 10.3±2.5
&mgr;g/l (n=3). This was accompanied by a change in the speciation
profile with aluminium appearing at the elution volume of aluminoxamine.
Conclusion: Our findings may contribute to a better
understanding of the neurotoxic effects of aluminium and its
desferrioxamine chelate in dialysis patients. 相似文献
1000.
Maria A. Giovino Robert J. Hawley Matt W. Dickerson Roseann Glaser Deborah H. Meshulam Robert Ardtsini Margaret D. Rosa Rod L. Monroy 《Xenotransplantation》1997,4(2):112-119
Abstract: Establishment of mixed bone marrow chimerism in pig-to-primate transplantation, as a means of inducing specific immune tolerance, will require that both immune and nonimmune barriers be overcome. As a preliminary step in evaluating nonimmune barriers in this system, we have developed an in vitro model of engraftment in which long-term culture of porcine bone marrow-derived hematopoietic cells is supported on preformed primate bone marrow stromal layers. In the absence of cytokine supplementation, primate stromal cells were unable to support long-term porcine hematopoiesis in these cultures. Supplementation with porcine Steel Factor was required for long-term maintenance of hematopoietic progenitor cell content and total hematopoietic activity. Addition of porcine IL-3, in combination with porcine Steel Factor, increased long-term progenitor cell content and hematopoietic activity on primate stroma to levels comparable to that obtained in cultures on porcine stroma. The combination of porcine GM-CSF and Steel Factor increased progenitor cell content and hematopoietic activity early in the cultures, but had little effect in long-term cultures. The Steel Factor and IL-3 combination was species-specific in its action in these cultures, as the corresponding human cytokines were unable to effectively support long-term porcine hematopoiesis. Likewise, the combination of porcine cytokines had only minimal effects on long-term bone marrow culture of primate CD34+ cells I on primate stroma. 相似文献