一种简化的去大鼠大脑方法

本文介绍一种简化的行之有效的去大鼠大脑方法。与传统方法相比,本法不需结扎颈总动脉或其分支,可简化手术程序,缩短手术时间,避免因手术操作对颈动脉窦区参与呼吸循环功能反射性调节的重要感受器及其传入神经的可能损伤。用此法去大脑后,动物的呼吸频率、心率、动脉血压等可稳定10小时以上,并能成功地进行延髓细胞内记录和标记。本法可用于研究脑干调控功能的急性动物实验。     

Interleukin-6 predicts hypoalbuminemia, hypocholesterolemia, and mortality in hemodialysis patients

Low serum albumin and low serum cholesterol levels are among the most consistent predictors of mortality in patients with end-stage renal disease (ESRD) undergoing hemodialysis. Hypoalbuminemia is often interpreted as a marker of poor nutrition, but serum albumin and cholesterol levels can also be low as part of a cytokine-mediated acute-phase reaction to acute or chronic inflammation. Here we report the results from a 900-day prospective study designed to determine whether tumor necrosis factor-alfa (TNF-alpha) and interleukin-6 (IL-6) predict serum albumin and cholesterol levels and mortality in a group of 90 ambulatory, adult hemodialysis patients with no acute infection, hospitalization or surgery, and no known acquired immunodeficiency syndrome (AIDS), malignancy, or liver disease. Measurable levels of TNF-alpha and/or IL-6 were found in 89 of 90 patients. Significant relationships were found between TNF-alpha and IL-6 and the degree of hypoalbuminemia and dyslipoproteinemia. IL-6 was the strongest predictor of mortality in univariate and multivariate analysis, followed by age, albumin level, and body mass index (BMI). Although the cause of hypercytokinemia was not addressed in this study, the data support the view that hypoalbuminemia and hypocholesterolemia are negative acute-phase responses to inflammatory stimuli. These results suggest that efforts to identify the nature of the stimuli for cytokine production and to lower cytokine levels in hemodialysis patients might be effective in improving the survival of patients undergoing hemodialysis.     

全固态乌头碱电化学检测器的研制及其在流动注射分析中的应用

报道一种新型结构的全固态乌头碱电化学检测器的研制及其在流动注射分析中的应用。采用流动注射分析法对川乌、草乌及其中成药(小活络丸)中剧毒成分(双酯型生物碱)进行了测试,方法简便快速,结果同光度法接近。本文还提出了电化学法研究乌头碱水解动力学原理。在pH 6.5,温度98℃的条件下测得乌头碱水解成苯甲酰乌头碱的速度常数为1.36×10^-2min^-1。     

CHRONIC ETHANOL CONSUMPTION AMELIORATES THE MATURITY-ONSET DIABETES-OBESITY SYNDROME IN CBA MICE

The effects of a chronic ethanol drinking schedule (20% solutionfor 6 weeks) on energy balance and carbohydrate and lipid metabolismhave been investigated in lean (32–36 g) and obesediabetic(40–44 g) CBA/Ca mice. The untreated obesediabetic miceexhibited hyperglycaemia, hypertriglyceridaemia, hyper-insulinaemiaand insulin resistance. The chronic ethanol treatment, whichyielded plasma ethanol levels of between 1 and 11 mM, loweredthe blood glucose, plasma insulin and tnacylglycerol levelstowards normal in the obese mice, but did not affect these parametersin the lean mice. The body weight of the obese mice tended toreturn to normal during the 6-week drinking period, althoughtheir total energy intake (9.2–10.0 kJ/g/week, food plusethanol-denved calories) was almost double that of the leanmice (4.8–5.4 kJ/g/week). The blood glucose response toacute insulin injection, which was significantly reduced inthe obese mice, became indistinguishable from the response ofnormal mice after chronic ethanol treatment. Soleus muscle glycogensynthesis in both lean and obese mice was not significantlyaltered by ethanol drinking, but brown adipose tissue lipogenesiswas significantly increased (by 50%) in the obese mice. It isproposed that ethanol is acting chronically to restore insulinsensitivity in the obese diabetic mice at doses which have littleor no effect in normal lean animals. This action is exerted,at least in part, at the level of brown adipose tissue lipogenesis.     

Transfected leukocyte integrin CD11b/CD18 (Mac-1) mediates phorbol ester-activated, homotypic cell:cell adherence in the K562 cell line

The CD11b/CD18 leukocyte integrin molecule mediates diverse neutrophil adherence-related functions, including cell:cell and cell:extracellular matrix attachments. To study the individual role of this leukocyte integrin in cell adherence in hematopoietic cells, we expressed the CD11b/CD18 complex on the surface of K562 cells, a cell line derived from an individual with chronic myelogenous leukemia in blast crisis. We used an amphotrophic retroviral vector designated LCD18SN, harboring the complete coding sequence for the CD18 subunit, to transfer the CD18 cDNA into K562 cells and select stable cell lines. The CD11b subunit in the expression plasmid pREP4 was transfected into these K562/CD18 cells by electroporation and stable cell clones were selected. These K562 cells possessed RNA and intracellular protein for each subunit, and they expressed the CD11b/CD18 heterodimer on the cell surface. When CD11b/CD18 expressing K562 cells were stimulated with phorbol myristate acetate (50 ng/mL) for 24 to 48 hours, these K562 cells formed dense cell:cell aggregates. This homotypic aggregation required both activation of the CD11b/CD18 complex and the induction of the counter- receptor for CD11b/CD18 on the conjugate cell. This cell line will (1) enable the structure-function relationships between cell activation and homotypic adherence to be assessed, (2) provide the opportunity to identify accessory molecules required for activation of the CD11b/CD18 complex, and (3) facilitate the identification of novel ligands for the CD11b/CD18 complex.     

全固态乌头碱电化学检测器的研制及其在流动注射分析中的应用

报道一种新型结构的全固态乌头碱电化学检测器的研制及其在流动注射分析中的应用。采用流动注射分析法对川乌、草乌及其中成药(小活络丸)中剧毒成分(双酯型生物碱)进行了测试,方法简便快速,结果同光度法接近。本文还提出了电化学法研究乌头碱水解动力学原理。在pH 6.5,温度98℃的条件下测得乌头碱水解成苯甲酰乌头碱的速度常数为1.36×10~(-2)min~(-1)。