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11.
We undertook an immunohistochemical analysis of human bronchopulmonary epithelial neoplasms and pleural mesotheliomas using a monoclonal antibody which recognizes ras oncogene products (p21ras). The monoclonal antibody, RAP-5, recognizes both unaltered and certain mutated p21ras. Formalin fixed and paraffin embedded tissue samples of 187 lung epithelial tumors and 27 pleural mesotheliomas were investigated; normal and bronchiectatic lungs were similarly studied. Normal lung and pleural tissue did not immunostain except for occasional type II pneumocytes. Reactive type II pneumocytes adjacent to carcinomas and bronchiectasis immunostained consistently. Twenty four/34 (71%) squamous carcinomas immunostained. Only 8/50 (16%) adenocarcinomas immunostained focally and weakly whereas 19/24 (79%) bronchioloalveolar carcinomas immunostained. Eleven/18 (61%) large cell carcinomas immunostained with variable intensity. Eleven/13 (85%) carcinoids, 6/7 (85%) well differentiated neuroendocrine carcinomas, and 18/21 (86%) intermediate cell neuroendocrine carcinomas immunostained while none of 20 small cell neuroendocrine carcinomas immunostained. Only a few mesotheliomas were immunostained focally. Two/14 (14%) epithelial type and 1/9 (11%) biphasic type mesotheliomas immunostained weakly; none of 4 spindle cell mesotheliomas immunostained. We conclude that while at least occasional cases of most types of pulmonary epithelial neoplasms express p21ras, the frequency and intensity of the expression are distinctly greater in certain tumor types such as squamous, bronchioloalveolar, and neuroendocrine neoplasm except for the small cell type. Contrary to these lung epithelial neoplasms, most mesotheliomas did not immunostain for p21ras. Whether the enhanced p21ras expression may point to a different mechanism of transformation or may merely reflect differentiation features remains undetermined.  相似文献   
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Subcutaneous administration of caerulein (100-500 micrograms/kg) significantly reduced the development of picrotoxin (8 mg/kg) seizures in male mice. The same doses of caerulein inhibited 3H-flunitrazepam binding in in vivo experiments. Proglumide, an antagonist of cholecystokinin receptors, in low dose (5 mg/kg) potentiated the effects of caerulein (100 micrograms/kg), whereas the administration of proglumide in high dose (25 mg/kg) reduced the action of caerulein on 3H-flunitrazepam binding and picrotoxin seizures. Caerulein (5-1000 nM) decreased 3H-flunitrazepam binding in in vitro experiments only after supplementation of the binding medium with 120 mM NaCl and 5mM KCl. The results suggest the possible interaction of caerulein with chloride ionophor. It seems probable that the direct interaction of caerulein with chloride ionophor in involved in the inhibitory effect of caerulein on picrotoxin seizures and 3H-flunitrazepam binding.  相似文献   
14.
Adult rats subjected to repeated peritoneal saline lavage show a rapid depletion of mast cells in the peritoneal fluid, but the mast cells in mesentery and omentum are not significantly reduced. The residual mast cells are predominantly young elements, histochemically belonging to stages 1 and 2 of maturation. Regeneration of mast cells is rapid with return to the normal density and distribution accomplished within 3 -- 4 weeks after cessation of lavage. The origin, nature and factors influencing the regeneration of mast cells is to be further investigated.  相似文献   
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蔡玉荣  燕超  孔云逸  张刚  刘东晓  李勇 《病毒学报》2021,37(5):1148-1157
为了解内蒙古地区蜱虫病毒组学的本底数据,采用病毒宏基因组学方法对在内蒙古阿拉善盟左旗、右旗和四子王旗地区3个采样点采集骆驼和羊体表寄生的1789只蜱虫样品进行病毒宏基因组学分析,并对特定病毒进行巢式PCR扩增和测序,通过Clustal W和MEGA7.0等生物信息学软件对获得的病毒基因序列进行遗传进化分析.数据显示,蜱虫样品携带包括植物、脊椎动物和非脊椎动物等来源的17个病毒科和一些未分类的病毒;其中,2株弹状病毒具有丰富的遗传多样性,与新疆地区和长江地区的弹状病毒的同源性达到98.5%和96.26%,提示蜱虫弹状病毒可能是通过羊和骆驼等动物贸易导致了新疆和内蒙古地区,以及内地的跨区域传播;细小病毒仅在羊来源的蜱虫中检测到,与中国河北地区的山羊血清中的细小病毒形成同一进化分支,我们推测蜱虫细小病毒在国内不同地区间可跨区域传播,在进化分析过程中,发现这种病毒与多种的细小病毒的同源性都不低于50%,提示细小病毒可能具有遗传稳定性;Tamdy病毒与来自阿塞拜疆、乌兹别克斯坦和美国的Tamdy病毒均具有极高的同源性,结果显示该病毒在内蒙古地区已经出现,并存在潜在流行的可能,有必要对Tamdy病毒进行进一步的监测;在本研究中,我们鉴定的白蛉病毒与来自新疆的亚洲璃眼蜱所携带的博乐蜱虱病毒形成同一个进化分支,与新型布尼亚病毒和Heartland virus病毒的同源性达到50%以上,该结果提示,我们发现的蜱虫白蛉病毒可能具有潜在的致病性,需要对其流行情况和致病性进行监测和研究.本研究为完善内蒙古部分地区蜱虫病毒的多样性和本底情况提供了重要的基础数据.  相似文献   
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马勇  凌旋  童昀 《生态学报》2021,41(19):7542-7554
以典型旅游城市三亚市为案例地,利用2006-2018年4期Landsat遥感影像数据,借助ENVI、ArcGIS平台定量识别土地利用演变特征,在1km×1km格网尺度下估算旅游地生态系统服务价值,并结合空间探索性数据分析揭示生态系统服务价值时空分异特征及其与旅游地发展的时空耦合关系。结果表明:(1)2006-2018年间,三亚市生态系统服务价值总量呈逐年下降趋势,由6.73×109元降至5.76×109元,累计减少9.78×108元;(2)空间格局上,三亚市呈"南低北高"空间分异格局,2006-2018年增值区域连片分布于崖州区、天涯区、吉阳区南部区域,且呈逐年减少趋势,减值区域集聚于天涯区东北部、海棠区;(3)空间集聚上,生态系统服务价值截面各年份均呈显著空间正相关且相关性先降后增。高高集聚区位于天涯区北部区域,低低集聚区分布于沿海、海湾地区;(4)旅游发展与生态系统服务价值时空演化特征关联性较强。三亚市天涯区北部林地生态环境良好,生态系统服务价值略有下降但绝对数值稳定,是生态系统服务价值主要来源;旅游发展较为迅速的三亚湾、崖州湾以及海棠湾,相对增值区域较多,但绝对生态系统服务价值损失显著,严重滞后于其他区域。  相似文献   
18.
Addition of ethanol to rat brain homogenate containing opiate receptors inhibits at a concentration of 50 mM the stereospecific binding of 3H-naloxone at 37 degrees C but not at 0 degree C, with the ID50 being 462 mM under these conditions. The temperature-dependent inhibition of the ligand binding suggests that ethanol does not compete with naloxone for specific binding sites of opiate receptors and changes the structure of lipids in biological membranes. Scatchard's analysis has demonstrated that apart from a decrease in the number of highly affinity binding sites of 3H-naloxone, the total amount of the binding sites remains unchanged both in the presence and absence of ethanol and constitutes 453 and 549 fmol/mg protein. It is assumed that ethanol might interconvert highly and low-affinity binding sites. Analysis of the effect of ethanol on 3H-naloxone binding with opiate receptors contained by synaptic membranes obtained from animals with varying predisposition to voluntary alcoholization has shown that ethanol inhibits to a greater degree ligand binding with membranes obtained from rats predisposed to alcoholization. The possibility of the involvement of receptors in the biochemical mechanisms by which the initial alcoholic motivation is effected is under discussion.  相似文献   
19.
7-dehydrocholesterol (7-DHC) and cholesterol (CHOL) are biomarkers of Smith-Lemli-Opitz Syndrome (SLOS), a congenital autosomal recessive disorder characterized by elevated 7-DHC level in patients. Hair samples have been shown to have great diagnostic and research value, which has long been neglected in the SLOS field. In this study, we sought to investigate the feasibility of using hair for SLOS diagnosis. In the presence of antioxidants (2,6-ditert-butyl-4-methylphenol and triphenylphosphine), hair samples were completely pulverized and extracted by micro-pulverized extraction in alkaline solution or in n-hexane. After microwave-assisted derivatization with N,O-Bis(trimethylsilyl)trifluoroacetamide, the analytes were measured by GC-MS. We found that the limits of determination for 7-DHC and CHOL were 10 ng/mg and 8 ng/mg, respectively. In addition, good linearity was obtained in the range of 50–4000 ng/mg and 30–6000 ng/mg for 7-DHC and CHOL, respectively, which fully meets the requirement for SLOS diagnosis and related research. Finally, by applying the proposed method to real hair samples collected from 14 healthy infants and two suspected SLOS patients, we confirmed the feasibility of hair analysis as a diagnostic tool for SLOS. In conclusion, we present an optimized and validated analytical method for the simultaneous determination of two SLOS biomarkers using human hair.  相似文献   
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