Membrane lipids of B16 melanoma cells and heat-resistant variants

Membrane lipid composition and fluidity of a series of B16 melanoma cell variants with increased resistance to heat were analysed for changes within the lipid component that may contribute to the acquisition of heat resistance. Within one series of heat-resistant lines the cholesterol content of the cells decreased as their heat resistance increased. The most heat-resistant line, WH75, had 40 per cent less cholesterol than the parent line. No change in the composition of phospholipid fatty acids was found. An increased level of membrane fluidity in WH75 was demonstrated by electron paramagnetic resonance using 5- or 12-doxyl stearic acid. When challenged by heat the increase in membrane fluidity was similar for WH75 and for the parent line. Thus the increased heat resistance of the variants is probably not due to their ability to adapt to heat challenge by increasing membrane thermostability. The inverse relationship between heat resistance and cholesterol content was not demonstrated in two other series of heat-resistant variants. The cholesterol decrease, therefore, is not a universal response of cells as they acquire heat resistance.     

抗凝血酶Ⅲ测定在评价肝脏功能中的应用

测定110例肝病的抗凝血酶Ⅲ(AT-Ⅲ)活性,62例低于正常(56.4％),均值为60.1±38.2％。50例正常对照为100.0±26.7％。重症肝炎、慢性活动性肝炎及失代偿期肝硬化活性显著下降,均值分别为12.9±13.0％、51.0±34.6％、43.3±29.6％.AT-Ⅲ活性在评价肝脏功能方面较凝血酶原时间敏感,具有一定的实用意义。     

Accuracy of allometrically predicted pharmacokinetic parameters in humans: role of species selection.

A general equation was derived, which directly describes the mathematical relationship between the allometrically predicted pharmacokinetic (PK) parameters in humans and the body weights of animal species (along with their corresponding measured PK parameters). It was shown, with use of the derived equation, that the predicted values in humans, based on combinations of animal species commonly used in allometry, are heavily dependent on certain species, for example, the dog. In contrast, parameter values from the rat made no contribution to the predicted human values, as long as the rat was not the smallest species used. Monte Carlo simulations were further performed to examine the species or weight dependence. The cost-effective combinations of animal species, in terms of number and species type, were theoretically examined through simulations. Finally, literature data demonstrated the species or weight dependence predicted from the equation and as illustrated through the Monte Carlo simulations. Appreciation of this species or weight dependence should guide researchers in selecting animal species and designing optimal experiments in the application of allometric scaling.     

截瘫患者医院感染的监测及预防措施

目的了解截瘫患者医院感染的病原菌对药物敏感情况. 方法回顾分析我院自1996年9月～2003年11月,316例截瘫患者的有关临床资料. 结果 98例患者发生医院感染,医院感染率为31.01%,感染部位主要以呼吸道、皮肤软组织、手术切口、泌尿道感染为多;医院感染的病原菌主要是条件致病菌,以G-菌为主.结论医护人员必须严格无菌操作,根据细菌药敏结果合理选用抗菌药物,加强营养,提高患者机体抵抗力.     

Soluble polystyrene derivatives of metal bis(3,4-dicarboxybenzoyl)phthalocyaninates: Synthesis,thermal analysis,and sensitivity towards toxic gases

Polystyrene-bound metal [2,9 or 2,10 (or 2,16 or 2,17) bis(3,4-dicarboxybenzoyl)]phthalocyaninates were synthesized by Friedel-Crafts reaction of polystyrene with the corresponding metal phthalocyaninates. Co(II) and Cu(II) [2,9 or 2,10 (or 2,16 or 2,17) bis(3,4-dicarboxybenzoyl)]-phthalocyaninate (PS-CodaPc and PS-CudaPc) contained 0,13 mmol · g^?1 (12,4 wt.-%) and 0,13 mmol · g^?1 (12,8 wt.-%) of CodaPc and CudaPc, respectively. They were soluble in N,N'-dimethylformamide, but only partially soluble in chloroform, tetrahydrofuran (THF), dimethyl sulfoxide, N-methyl-2-pyrrolidone, and pyridine. The THF extracts contained 0,12 mmol · g^?1 (11,4 wt.-%) and 0,18 mmol ? g^?1 (17,2 wt.-%) of PS-CodaPc and PS-CudaPc, respectively. The thermal stability of the polymers was studied using thermogravimetric and differential thermal analysis in nitrogen and synthetic air atmosphere. The contents of MdaPc(M: metal) in THF-extracted polymers calculated from the data of residue in thermogravimetric analysis are 0,12 mmol · g^?1 for PS-CodaPc and 0,19 mmol · g^?1 for PS-CudaPc. In addition, the sensitive properties of the polymers towards toxic gases were also investigated by quartz microbalance transducers. The results show that the quartz microbalance sensors coated with both polymers were sensitive to NO₂ and chlorinated hydrocarbons, i.e. chloroform and perchloroethylene. The sensitivity to NO₂ was 6,53 · 10^?7 m³ · mL^?1 · s^?1 for PS-CodaPc and 1,90 · 10^?6 m³ · mL^?1 · s^?1 for PS-CudaPc, and that to chloroform and perchloroethylene was 2,33 · 10^?8 and 4,60 · 10^?8 m³ · mL^?1 · s^?1, respectively, for PS-CodaPc and 4,79 · 10^?8 and 9,51 · 10^?7 m³ · mL^?1 · s^?1 for PS-CudaPc.     

甾体避孕药不增加血栓栓塞性疾病危险(病例对照研究)

本文采用1:3病例对照研究方法,对甾体避孕药的使用与血栓栓塞性疾病(急性心肌梗塞、脑栓塞、脑血栓形成和深静脉血栓形成)间的关联进行多因素分析。结果提示在我国广泛应用的甾体避孕药(主要为国产Ⅰ号避孕药)并不增加血栓栓塞性疾病的危险性。用药和停药时间的长短与血栓栓塞性疾病的发生无关,并与高血压病之间亦不存在协同作用。     

穿透性角膜移植术后角膜内皮细胞之命运

地２组猴行５。５→５．０ｍｍ穿透性角膜移植术，异种组４只，同种组４只，术前用冷冻创伤＾３Ｈ－ＴｄＲ标记法标记受生角膜内皮细胞，术后１４周摘除眼球，用放射自显影法显示银颗粒的分布。     

Monitoring the protective effects of minocycline treatment with radiolabeled annexin V in an experimental model of focal cerebral ischemia.

Minocycline is an antibiotic now recognized to have antiapoptotic and antiinflammatory properties. Because of these properties, minocycline may be of benefit in reducing neuronal apoptosis from ischemia and subsequent postischemic inflammation if administered soon after a stroke. We now explore the feasibility of using (99m)Tc-annexin V, an in vivo marker of apoptosis, with SPECT to monitor the antiapoptotic effects of minocycline therapy. METHODS: CB6/F1 adult male mice underwent unilateral distal middle cerebral artery occlusion (dMCA) occlusion and were imaged and sacrificed at 1, 3, 7, or 30 d after injury. Animals were given minocycline (or vehicle) 30 min and 12 h after dMCA occlusion and then given 22.5 mg/kg twice daily for up to 7 d. Before imaging, behavioral tests were performed to evaluate the neurologic function. After imaging, brains were collected for histology and assessed for the degree of apoptosis and microglial activation. RESULTS: (99m)Tc-Annexin V uptake in injured hemispheres was significantly decreased 2- to 3-fold by minocycline at all time points. Minocyline reduced infarct size as seen histologically and improved behavioral indices as late as 30 d. Infarct volume as seen histologically correlated with radiolabeled annexin V uptake seen by SPECT. In situ fluorescent microscopy demonstrated that annexin V bound primarily to neurons at 1 and 3 d, with a shift toward microglia by 7 and 30 d. CONCLUSION: We found that minocycline significantly reduces neuronal apoptosis and infarct size and improves neurologic outcome in mice after acute focal cortical ischemia.