An experimentally supported, mathematical explanation of the gas chromatographic elution behaviour of the long-chain carbon members of the homologous series

By substituting the saturated vapour phase tension of the pure normal hydrocarbons described by the Clausius-Clapeyron law into the accepted expression of the specific retention volume (V_g,T), a theoretically coherent and relatively simple mathematical evidence of the elution behaviour of the homologous members has been deduced. It gives exponential retention time dependence on carbon number for isothermal, and nearly equidistant (i.e., approximately linear retention-time dependence on carbon number) elution for linear temperature programmed gas chromatographic runs. The final equations are in close correlation with the experimental results. Special emphasis is placed on the fact that a good approximation—not strict physical laws—have been found.     

严重慢性阻塞性肺疾病患者食管切除术围手术期并发症及处理

目的 探讨重度慢性阻塞性肺疾病简称慢阻肺病人食管切除术围手术期常见并发症及其处理。方法 45例重度慢阻肺的病人在全麻联合硬膜外阻滞下进行开胸食管切除手术，围手术期处理包括术前戒烟、胸部理疗、预防和控制呼吸道感染、解痉化痰、呼吸功能锻炼、营养支持和氧疗；术后硬膜外镇痛、早期锻炼、保持呼吸道通畅，部分病人予以呼吸支持。结果 术中3例出现低氧血症。术后所有病人PaO2均有不同程度的下降，6例出现肺部感染，6例行纤维支气管镜吸痰，2例通过气管插管给予呼吸机支持，2例行气管切开术，1例酸碱平衡紊乱使用盐酸精氨酸治疗。所有病人均痊愈出院。结论 重度慢阻肺病人并非开胸食管切除手术的绝对禁忌证，积极的术前准备和严格的术后管理可减少和控制术后急性发作，有助于确保此类病人的围手术期安全和康复。     

三磷酸腺苷结合盒运转体A1与颈动脉粥样硬化斑块的关系

目的 探讨三磷酸腺苷结合盒运转体A1(ATP binding cassette transporter A1,ABCA1)在人颈动脉粥样硬化斑块中的表达变化及作用机制.方法 收集24例人颈动脉粥样硬化斑块标本和10例肠系膜动脉标本(对照组),采用RT-PCR测定ABCA1 mRNA和视黄酸X受体α(RXRα)mRNA表达水平,并采用Western Blot检测ABCA1及RXRα的蛋白表达水平.24例人颈动脉粥样硬化斑块标本按病理分级,比较病理组织为Ⅲ级和Ⅰ级动脉粥样硬化组织间ABCA1 mRNA、RXRαmRNA表达水平及蛋白表达水平.结果 颈动脉粥样硬化斑块组的ABCA1 mRNA(0.79±0.04)和RXRα mRNA(0.73±0.04)表达与对照组相比上调,差异有统计学意义(P＜0.05);ABCA1 mRNA与RXRα mRNA增加水平相关(P＜0.05);颈动脉粥样硬化斑块的ABCA1蛋白表达(0.22±0.03)下调水平与对照组(0.53±0.03)相比差异有统计学意义(P＜0.05);Ⅲ级和Ⅰ级动脉硬化斑块ABCA1mRNA、RXRα mRNA及蛋白表达水平差异有统计学意义(P＜0.05).结论 ABCA1及RXRα蛋白表达水平下调可能是进展性动脉粥样硬化损害的关键因素.     

磺柳酸法在Array360全自动特定蛋白分析仪尿液测定中的应用

目的探讨磺柳酸法在Array360全自动特定蛋白分析仪尿液测定中的应用价值。方法用磺柳酸法对离心后的尿液样本中的蛋白质进行半定量测定,并用Array360全自动特定蛋白分析仪测定α1微球蛋白α1-MG、白蛋白(ALB)、转铁蛋白(TRF)、免疫球蛋白G(IgG)在各个稀释度的测定范围,结合尿液蛋白质半定量结果和各个项目在不同稀释度的测定范围设定初始的标本稀释度。结果蛋白质半定量结果不同的尿液标本用Ar-ray360进行测定时,各个项目有其合适的初始标本稀释度。结论磺柳酸法在Array360全自动特定蛋白分析仪尿液的测定中有重要的应用价值,可大幅度节约试剂成本,缩短测定时间。     

甘草酸及肾十方治疗慢性马兜铃酸肾病26例疗效观察

目的观察甘草酸及复方中药肾十方对慢性马兜铃酸肾病的疗效。方法26例符合慢性马兜铃酸肾病的患者，给予甘草酸二铵150mg加中药复方汤剂肾十方治疗3个疗程。观察治疗前后尿素氮（BUN）、血肌酐（SCr）、尿酶及24h尿蛋白排泄量，血红蛋白、红细胞压积。结果治疗后患者临床症状有显著改善，总有效率80.76％；BUN、SCr、尿N-乙酰葡萄胺酶（NAG）、β2-微球蛋白（β2-MG）均显著下降（P〈0．05），血红蛋白、红细胞压积较治疗前升高（P〈0．05）。结论甘草酸及复方中药肾十方对慢性马兜铃酸肾病有确切的疗效。     

Poly-lactic acid and agarose gelatin play an active role in the recovery of spinal cord injury

Objective To investigate the role of poly-lactic acid and agarose gelatin in promoting the functional recovery of the injured spinal cord. Methods Poly-lactic acid ( PLA) or agarose was embedded in the space between two stumps of the hemisectioned spinal cord. Immunohistochemistry was used to show astroglia proliferation and the infiltration of RhoA-positive cells. Locomotor activity recovery was evaluated by testing the function of hindlimbs. Results Astrogli-as and RhoA labeled non-neuronal cells accumulated in the area adjacent to the implant, while the number of RhoA-positive cells was decreased dramatically in the absence of implant. Animals implanted with agarose gelatin recovered more quickly than those with PLA, concomitant with a higher survival rate of the neurons. Conclusion Both PLA and agarose gelatin benefited the recovery of spinal cord after injury by providing a scaffold for astroglia processes. Modulation of the rigidity, pore size and inner structure of PLA and agarose gelatin might make these biodegradable materials more effective in the regeneration of the central nervous system (CNS).     

Blunted renal dopaminergic system activity in puromycin aminonucleoside-induced nephrotic syndrome.

BACKGROUND: A primary tubular sodium handling abnormality has been implicated in the edema formation of nephrotic syndrome. Dopamine synthesized by renal proximal tubules behaves as an endogenous natriuretic hormone by activating D(1)-like receptors as a paracrine/autocrine substance. METHODS: We examined the time courses of the urinary excretion of sodium, protein and dopamine in puromycin aminonucleoside (PAN)-treated and control rats. The rats were sacrificed during greatest sodium retention (day 7) as well as during negative sodium balance (day 14) for the evaluation of renal aromatic l-amino acid decarboxylase (AADC) activity, the enzyme responsible for the synthesis of renal dopamine. Also, the influence of volume expansion (VE) and the effects of the D(1)-like agonist fenoldopam (10 microg/kg bw/min) on natriuresis and on proximal tubular Na(+),K(+)-ATPase activity were examined on day 7. RESULTS: The daily urinary excretion of dopamine was decreased in PAN-treated rats, from day 5 and beyond. This was accompanied by a marked decrease in the renal AADC activity, on days 7 and 14. During VE, the fenoldopam-induced decrease in proximal tubular Na(+),K(+)-ATPase activity was more pronounced in PAN-treated rats than in controls. However, the urinary sodium excretion during fenoldopam infusion was markedly increased in control rats but was not altered in PAN-treated animals. CONCLUSION: PAN nephrosis is associated with a blunted renal dopaminergic system activity which may contribute to enhance the proximal tubular Na(+),K(+)-ATPase activity. However, the lack of renal dopamine appears not to be related with the overall renal sodium retention in a state of proteinuria.     

Digestive properties of the venom of the Australian Coastal Taipan, Oxyuranus scutellatus (Peters, 1867).

The digestive properties of Australian elapid snake venoms have not been studied to any great extent. To address this, the in vitro digestive properties of Oxyuranus scutellatus (Australian Coastal Taipan) venom were investigated in a simulation of the in vivo conditions using the parameters reported for the stomach of snakes and representative prey for this species. The amount of soluble protein released was measured over time using a bicinchoninic acid (BCA) assay. Dismembered mouse hindlegs were injected intramuscularly with 0.1 ml O. scutellatus venom (concentration 10 mg/ml) and maintained in a micro-anaerobic, acidic environment (pH approximately 1.2-1.7) at 25 degrees C. The bathing liquid was sampled every 24 h for 7 days, and assayed for soluble protein. Statistical analysis revealed that O. scutellatus venom increased the rate at which proteins were released when compared to a negative control suggesting the potential importance of envenomation in the digestion of whole prey.     

非胰岛素依赖型糖尿病患者血清唾液酸的改变

测定20例NIDDM伴有心脑血管病变的患者、20例单纯NIDDM患者的血清唾液酸（SA）水平，并与20例正常人进行比较。结果发现所有NIDDM患者的血清SA水平均显著增高（P＜0．01），其中伴有心脑血管疾病患者的血清SA水平显著高于单纯NIDDM患者（P＜0．05），同时血清SA水平与血清胰岛素及C肽水平、收好压之间存在相关。提示血清SA水平与NIDDM患者的心脑血管疾病关系密切，可能是心脑血管并发症发生的一个危险因素。