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71.
Microsomal monooxygenases catalyze the biosynthesis of epoxides from olefinic and aromatic compounds whilst microsomal epoxide hydratase and cytoplasmic glutathione S-transferases are responsible for their further biotransformation. Although catalytically very efficient the cytoplasmic glutathione S-transferases play, due to their subcellular localization, a minor role in the inactivation of epoxides derived from large lipophilic compounds and were, therefore, not included in this study. It was shown with such a lipophilic compound, benzo(a)pyrene, as a model substance and with liver enzyme mediated bacterial mutagenesis as biological endpoint that species and strain differences in epoxide hydratase and monooxygenases are reflected in very dramatic differences in mutagenicity of benzo(a)pyrene which varied from extremely potent to a degree which could easily be overlooked. In order to investigate whether the differences in enzyme activities were causally linked to the observed differences in mutagenicity, the enzyme activities were modulated by inhibition and induction. These manipulations were always accompanied by the corresponding changes in mutagenicity.It is concluded that species such as mice which possess high monooxygenase activity but very low epoxide hydratase activity are much more susceptible than man to those toxic effects which are mediated by metabolically formed epoxides which are substrates of epoxide hydratase. In this regard, it is especially noteworthy that mice possess a much lower hepatic epoxide hydratase activity than man.Presented at the Symposium Influence of Metabolic Activations and Inactivations on Toxic Effects held at the 18th Spring Meeting of the Deutsche Pharmakologische Gesellschaft, Section Toxicology, D-6500 Mainz, March 15, 1977 相似文献
72.
Abstract: There is evidence to indicate that opioid compounds with mixed μ agonist/δ antagonist properties are analgesics with low propensity to produce tolerance and physical dependence. A chimeric peptide containing the potent and selective μ agonist H‐Dmt‐D‐Arg‐Phe‐Lys‐NH2 ([Dmt1]DALDA) (Dmt = 2′,6′‐dimethyltyrosine) and the potent and selective δ antagonist H‐Tyr‐TicΨ[CH2‐NH]Cha‐Phe‐OH (TICP[Ψ]) (Cha = cyclohexylalanine), connected ‘tail‐to‐tail’ via a short linker, was synthesized using a combination of solid‐phase and solution techniques. The resulting peptide, H‐Dmt→D‐Arg→Phe→Lys‐NH‐CH2‐CH2‐NH‐Phe←Cha[NH‐CH2]ΨTic←Tyr‐H, showed the expected μ agonist/δ antagonist profile in the guinea‐pig ileum and mouse vas deferens assays. Its μ and δ receptor binding affinities were in the low nanomolar range, as determined in rat brain membrane binding assays. 相似文献
73.
B(a)P诱导小鼠前胃癌过程中组织病理学变化 总被引:1,自引:0,他引:1
目的:探讨B(a)P诱导小鼠前胃癌过程中胃组织形态学的动态改变。方法:小鼠用5mg/ml的B(a)P灌胃,每周两次,共4周。以后每隔4周处死一部分小鼠,对胃组织进行病理组织学观察。结果:从第17周开始小鼠前胃开始出现肉眼可见的肿瘤,前胃组织由局部腺体增生、排列紊乱逐步发展为腺体普遍异常增生,形成早期胃癌,进一步发展出现进展期胃癌。结论:B(a)P诱导的小鼠前胃癌的潜伏期大约3个月左右,前胃组织病理学动态变化过程是萎缩性胃炎、不典型增生、胃癌。 相似文献
74.
Andrés Redondo Sánchez Javier de Castro Carpeño Manuel González Barón 《Clinical & translational oncology》2003,5(5):239-248
Esophageal cancer has a dismal prognosis and the surgical treatment only cures a small percentage of patients. The survival achieved by traditional surgical procedures is being improved with extended resections, but at the cost of greater morbidity. Concurrent radiochemotherapy can obtain results similar to those of surgery. Nowadays, locally advanced esophageal cancer should have a multimodal approach, because neoadjuvant chemotherapy, with or without radiotherapy, has demonstrated to improve the survival of chemosensitive patients. Recently, the role of hyperfractionated radiotherapy and new drugs such as paclitaxel, docetaxel and irinotecan in neoadjuvant treatment is being evaluated. 相似文献
75.
Alvarez B Doménech N Alonso F Sánchez C Gómez del Moral M Ezquerra A Domínguez J 《Xenotransplantation》2000,7(4):258-266
Abstract: We describe in this report the production and characterization of monoclonal antibodies (mAb) to the swine homologues of CD11a and CD18 antigens, and their use for phenotypic and functional analysis of porcine leukocytes. Monoclonal antibodies BL1H8 and BL2F1 precipitated two bands of approximately 170 and 95 kDa, whereas mAb BA3H2 brought down three bands of 170, 155 and 95 kDa, from alveolar macrophage lysates. Clearance of macrophage lysates with mAbs BL1H8 and BL2F1 resulted in complete removal of the 170-kDa band. The cell distribution of the molecules recognized by these mAbs was similar to that of human LFA-1. It was found on all leukocytes, although its expression varied among the different leukocyte subpopulations, with monocytes, granulocytes and a subset of CD8+ cells expressing the highest levels. Cross-blocking studies showed that these antibodies recognize different epitopes on porcine LFA-1. Both anti-LFA-1 mAbs strongly inhibited the mitogenic response of PBMC to ConA, whereas the anti-CD18 mAb had no effect. These anti-LFA-1 mAbs also inhibited the mixed lymphocyte reaction (MLR) and the NK cell-mediated lysis of K-562 cells. 相似文献
76.
经上颌窦前壁钻孔行鼻窦内窥镜术30例报告 总被引:1,自引:0,他引:1
报告经上颌窦前壁钻孔行鼻窦内窥镜手术30例,疗效较好。与鼻腔、鼻窦内窥镜手术比较,该术式具有观察方便,出血少,反应轻,操作方便,并发症少,术后复发率低等优点。 相似文献
77.
AKIN IN RAMAZAN YIITO ALI ONA NUREDDIN VURGUN ZEKI ARI PELIN ERTAN AHMET ZEKI ENGIL 《Pediatrics international》1998,40(1):47-51
The lipid profile is known to alter in patients with infection, but there has not been a study of the apolipoprotein levels in serum of otherwise healthy children during infection. Lipids, lipoproteins, apolipoproteins A-l and B and lipoprotein (a) were evaluated prospectively in 31 consecutive children, aged4–15 years, who were admitted to the hospital with bacterial pharyngitis. The degree of dyslipidemia associated with bacterial pharyngitis was assessed using each child as his/her own control and by comparison with 79 healthy children who had not had an infection during the past 3 months. Serum total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, apolipoprotein A-l and apolipoprotein B levels were significantly decreased during the symptomatic phase of the disease, whereas the serum triglyceride level was slightly elevated. Serum lipoprotein (a) concentration did not change significantly. In conclusion, it is suggested that serum lipids, lipoproteins and apolipoproteins should not be assessed during infection because of the possible transient changes of these parameters during infection or inflammation. 相似文献
78.
Prosopo-thoracopagus twins are united from the face down to the umbilicus, none with union in the brain but all with visceral
anomalies intermediate between those of cephalopagus and thoracopagus. In a review of over 1200 cases of conjoined twins reported
during the past 100 years, there were 14 that illustrate the continuum between cephalopagus and thoracopagus, including three
that were united only from the cervical region to the umbilicus. Classic cephalopagus twins are joined from the top of the
head to the umbilicus, sharing a single foregut as well as two relatively normal hearts, the “posterior” one often diminished.
Typical thoracopagus, however, are conjoined only from the upper thorax to the umbilicus, each twin with a normal foregut
but both sharing a single complex multiventricular heart. The intermediate cases shared either a single very abnormal heart
or two hearts united by double aortic arches, and all except one had a single foregut. It is these cases intermediate between
cephalopagus and thoracopagus which are the subject of this report.
Received September 11, 1996; accepted December 16, 1996 相似文献
79.
简要回顾了朱潮早期的革命生涯和战斗经历,着重介绍了他在全国解放后的数十年来从事全国医药教育管理领导工作上所取得的主要业绩和重要贡献。同时,还对他的工作精神、思想作风和为人处事等作了简述。 相似文献
80.