Finite-element model of the human head: scalp potentials due to dipole sources

Three-dimensional finite-element models provide a method to study the relationship between human scalp potentials and neural current sources inside the brain. A new formulation of dipole-like current sources is developed here. Finiteelement analyses based on this formulation are carried out for both a threeconcentric-spheres model and a human-head model. Differences in calculated scalp potentials between these two models are studied in the context of the forward and inverse problems in EEG. The effects of the eye orbit structure on surface potential distribution are also studied.     

Human Peripheral Eosinophils with Receptors for IgM: Demonstration and Ultrastructural Morphology

Receptors for IgM were detected on peripheral blood human eosinophils by a rosette technique with ox red blood cells coated with the IgM fraction of the specific immunserum. Between 14 % and 43 % (mean 27 %) FcµR positive cells were found after an overnight incubation period at 37°C by using this technique. The specificity of the receptors for IgM was assessed by studying the inhibitory capacity of purified human IgM in the rosette assay. From an ultrastructural point of view, the EA^M rosette-forming cells are mature eosinophlic granulocytes characterized by a nucleus with a variable number of lobes and a certain number of «first type» granules partially or totally devoid of their content.     

Solubilization and Stabilization of an Anti-HIV Thiocarbamate,NSC 629243, for Parenteral Delivery,Using Extemporaneous Emulsions

The O-alkyl-N-aryl thiocarbamate, I, (2-chloro-5-[[(l-methyl-ethoxy)thioxomethyl]amino]benzoic acid, 1-methylethylester, NSC 629243, also known as Uniroyal Jr.) is an experimental anti-HIV drug with very low water solubility (1.5 µg/mL). Early clinical studies required an injectable solution at 15 mg/mL, representing a solubility increase of 10⁴-fold. Adequate solubilization of this hydrophobic drug was achieved in 20% lipid emulsions. Extemporaneous emulsions were prepared by adding a concentrated drug solution to a commercially available parenteral emulsion. Various methods of preparation to minimize drug precipitation during its addition and enhance redissolution of precipitated drug were evaluated. The stability and mechanism(s) of decomposition of NSC 629243 in both 20% lipid emulsions and in natural oil vehicles were examined. In lipid emulsions, the shelf life at 25°C varied from 1 to >10 weeks, depending on the extent to which air was excluded from the preparation. The shelf life of 50 mg/mL solutions in natural oils at 25°C varied from <1 to >100 days depending on the oil and its supplier. A qualitative correlation was found between the initial rate of oxidation and the peroxide concentration in the oil. The primary degradation product in both systems was shown to be a disulfide dimer, II, formed via oxidation. Oxidation was inhibited by vacuum-sealing of emulsion formulations or incorporation of an oil-soluble thiol, thioglycolic acid (TGA), into oil formulations. TGA may inhibit oxidation by consuming free radicals or peroxide initiators or by reacting with the disulfide, II, to regenerate the starting drug.     

Effect of prostaglandin E1 on preservation injury of canine liver grafts preserved in UW solution

This study investigated whether prostaglandin E₁ (PGE₁) could reduce hepatic injury to the liver graft caused by harvesting and 24-h preservation in University of Wisconsin (UW) solution in a canine model. The PGE₁-treated group was intravenously administered 0.5 g/kg per minute of PGE₁ for 30 min before harvesting, as well as a concentration of 1 mg/l PGE₁ in the washout and UW solutions. In both the PGE₁-treated and the control group, all recipients survived for 1 week or more after transplantation. Arterial ketone body ratio (AKBR) remained over 1.0 in the early postoperative period. The PGE₁ group showed significant reductions in guanase, GOT, and LDH during the early postoperative period compared to the untreated control group. Histological examination disclosed partial mitochondrial swelling, hepatocyte vacuolation, and necrosis in the control group, while such abnormalities were rarely seen in the PGE₁ group. These results suggest that PGE₁ can effectively reduce hepatic injury to liver grafts preserved in UW solution prior to transplantation.     

小容量高渗氯化钠溶液/琥珀酰明胶复苏犬失血性休克

目的:研究复合应用高渗氯化钠溶液和琥珀酰明胶对失血性休克犬的血流动力学和氧转运的影响。方法:18只犬麻醉后气管内插管,自主呼吸空气。经股动脉放血至平均动脉压为6.7kPa并维持2h。分为3组,每组6只。氯化钠溶液组:于5min内输入失血量10%的75g·L-1NaCl;高渗氯化钠溶液/琥珀酰明胶组:于5min内输入失血量10%的75g·L-1NaCl/琥珀酰明胶;乳酸钠林格氏液组:于20min内输入2.5倍失血量的乳酸钠林格氏液。结果:3组的血流动力学参数在治疗后都有显著的改善。高渗氯化钠溶液/琥珀酰明胶对血流动力学和氧供的作用时间较HSC持久。高渗氯化钠溶液/琥珀酰明胶组的胶体渗透压明显高于其它两组。各组氧摄取率和血浆乳酸浓度无显著差异。结论:失血性休克早期应用小容量75g·L-1NaCl/琥珀酰明胶可改善血流动力学和氧供需平衡。     

添加生长激素肠外营养对短肠大鼠代谢效应的影响

目的　研究单纯肠外营养 (PN)与添加生长激素 (GH)的PN对短肠大鼠的代谢作用。方法　建立PN短肠大鼠模型 ,随机分成普通肠外营养组 (STD组 )及添加GH的肠外营养组 (rhGH组 )。测各组大鼠每日体重及氮平衡 ,计算其累积氮平衡。实验结束后测各组织器官重量变化 ,并测大鼠总体水、脂肪及蛋白含量。结果　PN结束后rhGH组大鼠体重、每日氮平衡及累积氮平衡均显著高于STD组 ,P <0 .0 1。各器官重量分析显示rhGH组大鼠腓肠肌重量显著高于STD组 ,P <0 .0 5 ,但与对照组无明显差异。机体组成分析表明rhGH组大鼠总体蛋白及所占机体百分比较STD组显著升高 ,而总体脂肪则明显下降 ,P <0 .0 5。结论　PN时辅助添加rhGH具有显著的促代谢合成作用 ,蛋白合成增加是rhGH作用的显著特点。     

重型颅脑损伤早期肠内营养的临床研究

目的　探讨重型颅脑损伤早期肠内营养的合理性与临床价值。方法　GCS≤ 8的重型颅脑损伤患者随机分为两组 :A组 32例 ,早期肠内营养 ;B组 36例 ,早期全胃肠外营养。两组营养支持均在伤后或术后 2 4小时开始 ,观察两组患者营养状况 ,胃肠道并发症及其他并发症的发生率及预后。结果　EEN组的营养状况优于TPN组 ,胃肠道并发症及其他并发症的发生率低于TPN组 (P <0 .0 5) ,预后亦较TPN组有明显改善 (P<0 .0 5)。结论　重型颅脑损伤后早期肠内营养可改善患者营养状况 ,减少并发症的发生 ,并改善预后。