丙泊酚或七氟醚复合瑞芬太尼麻醉对机体蛋白质分解代谢的影响

比较丙泊酚或七氟醚复合瑞芬太尼全麻维持,对行经腹会阴联合直肠癌根治术（Miles 手术）患者机体蛋白质分解代谢的影响。选择40例将要行 Miles 手术的患者,年龄25岁～65岁,ASA Ⅰ级～Ⅱ级,随机分为两组：一组接受丙泊酚复合瑞芬太尼全麻维持（P 组,n＝20）;另一组接受七氟醚复合瑞芬太尼全麻维持（S 组,n＝20）。尿标本自手术开始切皮（0h）每小时收集一次,检测尿液中3-甲基组氨酸（3-M H）与肌酐（Cr）的比值（3-M H／Cr）。呼吸商（RQ）从手术切皮（0h）以后每小时检测一次。结果 P 组与 S 组 T2（1h ～2h）、T3（2h ～3h）的3-M H ／Cr 值与 T0（0h）、T1（0h ～1h）相比,明显升高,且 P 组 T2和 T3的3-M H／Cr 值和 RQ 均比 S 组低。丙泊酚脂肪乳中的甘油三酯可能会作为供能物质被机体分解利用,从而减少体内蛋白质的分解。     

冠心病患者微量白蛋白尿与C反应蛋白的关系

研究冠心病患者微量白蛋白尿与血清C反应蛋白(CRP)相关性.研究对象为接受冠状动脉造影确诊为冠心病的住院患者87例,检测其尿白蛋白/肌酐浓度值(ACR)、血清C反应蛋白水平及其他指标,并与35例冠状动脉造影为非冠心病的患者进行比较.冠心病组lgACR及lgCRP水平明显高于正常对照组(P＜0.05).lgACR与lgCRP呈正相关(r=0.275,P=0.005),且均为冠心病的独立预测因素.冠心病患者微量白蛋白尿与血清C反应蛋白均明显增加.ACR、CRP均为冠心病的独立预测因素.在微量白蛋白尿的发生过程中可能有低度炎症(CRP)的参与.     

The associations of the Five Factor Model of personality with inflammatory biomarkers: A four-year prospective study

This study evaluated the associations of the Five Factor Model of personality with two inflammation biomarkers, C-reactive protein and fibrinogen, and the possible moderating effects of common health-related behaviors (physical activity and smoking) concurrently and over four years, while adjusting for socio-demographic and health status. Participants were individuals who underwent a health examination at two points of time, T1 (n = 1709) and T2 (n = 923), about four years apart. Regression analyses uncovered positive associations between Neuroticism and Extraversion with two inflammatory biomarkers at baseline (T1) and over time (T2) and increases in their levels over time. Additionally, a synergistic interaction of neuroticism and physical inactivity was associated with higher levels of inflammation biomarkers at both time periods. Openness was negatively associated with inflammation biomarkers at T1 and T2, but not with changes in their levels. No significant associations were found for Agreeableness and Conscientiousness. The results suggest that personality traits might be involved in the inflammatory process both concurrently and over time, and thus indicate a possible mechanism by which personality traits might influence health, especially cardiovascular disease risk.     

K-ras基因与结直肠腺癌关系研究进展

肿瘤的发生涉及癌基因的激活及抑癌基因的失活,K-ras基因是与肿瘤形成关系较为密切的一种癌基因,其功能异常能够影响细胞的生长、增殖、分化和凋亡等。研究已发现K-ras基因的突变激活是结直肠癌变过程中的重要事件之一。本文拟对K-ras基因的生物学特性、对细胞信号转导的影响及在结直肠腺癌形成与治疗中的作用作一综述。     

循证医学在ICU中的应用

循证医学(Evidence-Based Medicine,EBM)是指慎重、准确而明智地应用当前所能获得的最佳的研究证据,同时结合医生个人的专业技能和临床经验,并考虑患者的价值和愿望,将三者完美地结合起来制定出对患者最有利的临床决策。然而,ICU中的各项治疗措施常缺乏大规模随机对照试验(RCT)的证据;对于已经实施的RCT同样存在着概念方面的错误,尤其是很多被认为已经RCT验证过的措施实际上并无RCT的证据。尽管如此,但近年来我们终于在临床试验结果方面有了更多积极的进步,一些干预措施已被证明可改善患者的预后。     

Alzheimer amyloid beta-peptide inhibits the late phase of long-term potentiation through calcineurin-dependent mechanisms in the hippocampal dentate gyrus

The perforant path projecting from the entorhinal cortex to the hippocampal dentate gyrus is a particularly vulnerable target to the early deposition of amyloid beta (Abeta) peptides in Alzheimer's brain. The authors previously showed that brief applications of Abeta at subneurotoxic concentrations suppressed the early-phase long-term potentiation (E-LTP) in rat dentate gyrus. The current study further examines the effect of Abeta on the late-phase LTP (L-LTP) in this area. Using multiple high-frequency stimulus trains, a stable L-LTP lasting for at least 3 h was induced in the medial perforant path of rat hippocampal slices. Bath application of Abeta(1-42) (0.2-1.0 microM) during the induction trains attenuated both the initial and late stages of L-LTP. On the other hand, Abeta(1-42) perfusion within the first hour following the induction primarily impaired the late stage of L-LTP, which resembled the action of the protein synthesis inhibitor emetine. Blockade of calcineurin activity with FK506 or cyclosporin A completely prevented Abeta-induced L-LTP deficits. These results suggest that Abeta(1-42) impaired both the induction and maintenance phase of dentate L-LTP through calcineurin-dependent mechanisms. In the concentration range effective for inhibiting L-LTP, Abeta(1-42) also reduced the amplitude of NMDA receptor-mediated synaptic currents in dentate granule cells via a postsynaptic mechanism. In addition, concurrent applications of Abeta(1-42) with the protein synthesis inhibitor caused no additive reduction of L-LTP, indicating a common mechanism underlying the action of both. Thus, inhibition of NMDA receptor channels and disruption of protein synthesis were two possible mechanisms contributing to Abeta-induced L-LTP impairment.     

蛋白质化学与分子生物学携手前进

蛋白质化学的发展历经了几次重大的转变,分析仪器的商品化使蛋白质从实验室走向市场;一级结构信息促进了多肽的合成与改造;分子生物学技术的成熟使人们从设计改造功能蛋白转向设计基因,并尝试进行基因治疗和ＤＮＡ免疫。这些转变,使蛋白质化学技术与分子生物学技术成为人们手中的工具,为人们研究生命拓宽了思路。     

视剥夺及视剥夺学习后Jun样蛋白在雏鸡两侧半球中不同表达的研究

该实验利用免疫组化技术,在已有实验的基础上进一步观察比较了左眼视剥夺及单眼学习后,Ｊｕｎ样蛋白在雏鸡两侧半球ＨＶ和ＬＰＯ中表达的差异。实验结果表明：１．视剥夺２、２４、４８、７２小时后观测到Ｊｕｎ样蛋白在左、右半球ＨＶ和ＬＰＯ中的表达逐渐增高,并且于视剥夺４８小时表达到达峰值。同时仅在视剥夺２小时后观测到两半球ＬＰＯ中Ｊｕｎ样蛋白的表达存在差异,在其余各视剥夺时程中两侧半球的ＬＰＯ、ＨＶ中Ｊｕｎ样蛋白的表达均无显著差异。２．视剥夺２小时和２４小时后均在学习后７０分钟组中观测到Ｊｕｎ样蛋白在左、右半球的ＨＶ和ＬＰＯ中表达的显著升高,而在视剥夺２小时学习后１０分钟只观测到左半球ＨＶ和ＬＰＯ中Ｊｕｎ样蛋白表达的显著升高,在视剥夺２４小时学习后１０分钟中仅观测到左半球ＬＰＯ中Ｊｕｎ样蛋白的显著升高。同时也仅在视剥夺２小时学习后１０分钟观测到两侧半球ＨＶ、ＬＰＯ中Ｊｕｎ样蛋白表达的显著性差异。３．无论单纯视剥夺组还是单眼学习组,各组同侧半球中ＬＰＯＪｕｎ样蛋白的表达显著高于ＨＶ的Ｊｕｎ样蛋白的表达现象在视剥夺４８小时后消失。     

Long-term rod dark adaptation in man. Threshold measurements, rhodopsin regeneration and allosteric sensitivity regulation. An evaluation

Recent evidence strongly suggests that the relationship between threshold elevation ( T ) and fraction of bleached rhodopsin ( B ), obtained during a major, middle period of long-term rod dark adaptation in man, is well described by a power function, i. e., T = k · Bⁿ , where k is a multiplicative constant and n is the exponent. Due primarily to the low reliability of measurements of rhodopsin regeneration, however, the exponent n of the power function cannot, at present, be given an exact value. Available information indicates that the value of the exponent ranges between 2.4 and 4. Implications of this uncertainty are discussed within the framework of the allosteric, tetrameric model of rod dark adaptation. It is concluded that this model in its simplest form may only offer a first approximation of the real system implicated in the process.     

一日龄小鸡的不同记忆阶段中Jun样蛋白在脑内HV和LPO的表达

以一日龄小鸡为研究对象,采用一次性动回避反应试验和免疫组织化学结合的方法,选择六个时间点对Ｊｕｎ样蛋白在小鸡左右侧脑内ＨＶ和ＬＰＯ两部位的表进行了探讨。