元认知能力在医学生临床实习中的培养

元认知能力在医学生临床实习过程中起着非常重要的作用。培养医学生的元认知能力 ,必须丰富医学生的元认知知识 ,强化医学生的元认知体验 ,促进医学生加强元认知监控 ,从而使他们成为独立自主、有创造力的学习者。     

重庆地区驾驶员血液中乙醇浓度与驾驶能力的关系

目的　探讨重庆地区驾驶员血液中乙醇浓度 (BAC)和驾驶能力的关系 ,为交通安全立法提供科学依据。　方法　随机选择重庆地区 59名驾驶员志愿者 ,建立饮酒后驾车模型、科学的BAC测定以及驾驶能力评价体系 ,对不同BAC下驾驶能力进行测评。　结果　受试者出现驾驶能力损害时的BAC均数为 685.9mg/L ,最小值 190 .0mg/L ,最大值 152 0 .0mg/L ,总体均数 95%可信区间为 60 2 .4～ 70 9.5mg/L。汉族和土家族间、汉族男性和女性间、2 3～ 3 5岁和 3 6～ 56岁年龄组间差异无显著性意义 (P >0 .0 5) ,而既往饮酒量不同的三个组别间差异有显著性意义 (P <0 .0 5)。随着BAC增高 ,驾驶能力受损人数增加。在 2 0 0 .0mg/L有 3 % (2 / 59)的受试者驾驶能力降低 ,80 0 .0mg/L则达到 68% (40 / 59)。　结论　随着BAC增高 ,重庆地区驾驶员驾驶能力受损人数比例增加 ,出现驾驶能力明显损害时BAC为 60 2 .4～ 70 9.5mg/L ,既往酒量较大人群中该值较高     

The Relationship between maternal education and mental retardation in 10-year-old children

We conducted a case-control study of mental retardation (MR) in which case children (aged 10 years) were identified from existing records at multiple sources, primarily the public school systems. Control children were drawn from a roster of public school students not receiving special education services. We found that maternal educational level at the time of delivery was strongly and inversely related to a form of MR not accompanied by other serious neurologic conditions. For this isolated form of MR, maternal educational level was by far the most important predictor from among seven sociodemographic variables examined. There was a significant race-education interaction that indicated a steeper gradient in risk among white mothers than among black mothers. Relative to children of white mothers with 12 years of education, all children of black mothers, except those whose mothers had 16 or more years of education, were at increased risk. The results may be useful as a guide for selecting high-risk groups as candidates for early childhood intervention programs.     

A hole in the T cell repertoire specific for a pigeon cytochrome c related peptide associated with amino acid substitutions on I-Ab molecules.

When C57BL/10(B10) mice were immunized with a pigeon cytochrome c related peptide, 50V (AEGFSYTVANKNKGIT), two helper T cell populations with different specificity were activated. A major T cell population reacted with a 50V analog, 50V54A (AEGFSYTVANKAKGIT), more potently than with the immunogen, 50V, in a heteroclitic fashion, whereas the other minor T cell population responded only to 50V. By contrast, when bm12 mice were immunized with 50V, the minor T cell population responding only to 50V could hardly be demonstrated. The apparent deletion of the minor T cell population in bm12 mice seems to be attributable to negative selection under the influence of I-Abm12 molecules, since the minor T cell population was undetectable in both I-Ab and I-Abm12 restricted T cells from (B10 x bm12)F1 mice. Thus, three mutant points on the I-A molecule in bm12 mice appear to be involved in the seemingly negative selection of the certain T cell repertoire. The present finding demonstrates that a T cell repertoire generated under the influence of a MHC product (Ab) on one parental strain is eliminated by a different MHC product (Abm12) on the other parental strain of F1 cross. The mechanism underlying the apparent negative selection is discussed.     

自行下体负压训练器的研制

目的 研制一种自行下体负压训练器。方法 自行下体负压训练器由若干环形钢圈及涂胶布材料构成的密闭完整的空腔壳体，可上下随意伸缩。上表面安装有单向排气阀门、可调进气阀门、把手及肩带。沿筒体纵轴进行屈／伸膝关节运动，使之被动扩张产生负压。结果 进气阀门完全关闭、打开1／4、1／2至完全打开时，训练器负压峰值逐渐降低，分别为-58、-46、-38和-26mmHg。结论 自行下体负压训练器集体育锻炼和下体负压于一体，安全可靠，使用方便，可望应用于对抗失重生理影响和飞行员抗荷生理训练。     

Autoimmune progesterone dermatitis: absence of contact sensitivity to glucocorticoids, oestrogen and 17-α-OH-progesterone

Autoimmune progesterone dermatitis is a rare condition, characterized by recurrent premenstrual exacerbations of a dermatosis, in which sensitivity to progesterone can be demonstrated. The sensitizing mechanism is unknown. The aim of this study was to test the hypothesis that cross-sensitivity between steroid groups could induce allergy to endogenous progesterone in these patients. 5 patients with autoimmune progesterone dermatitis and 1 with oestrogen-sensitive dermatitis have been patch tested with a corticosteroid series, conjugated oestrogen 1% in petrolatum (pet.), and 17-α-OH-progesterone 2% pet. There were no immediate or delayed reactions at 2 and 4 days to any steroid group. We have therefore been unable to demonstrate steroid cross-sensitivity, or a use for 17-α-OH-progesterone in the investigation of oestrogen - and progesterone-sensitive dermatoses.     

Expression of Na+/HCO3− co‐transporter proteins (NBCs) in rat and human skeletal muscle

Aim: Sodium/bicarbonate co‐transport (NBC) has been suggested to have a role in muscle pH regulation. We investigated the presence of NBC proteins in rat and human muscle samples and the fibre type distribution of the identified NBCs. Methods and results: Western blotting of muscle homogenates and sarcolemmal membranes (sarcolemmal giant vesicles) were used to screen for the presence of NBCs. Immunohistochemistry was used for the subcellular localization. The functional test revealed that approximately half of the pH recovery in sarcolemmal vesicles produced from rat muscle is mediated by bicarbonate‐dependent transport. This indicates that the NBCs are preserved in the vesicles. The western blotting experiments demonstrated the existence of at least two NBC proteins in skeletal muscle. One NBC protein (approximately 150 kDa) seems to be related to the kidney/pancreas/heart isoform NBC1, whereas the other protein (approximately 200 kDa) is related to the NBC4 isoform. The two NBC proteins represent the electrogenic isoforms named NBCe1 and NBCe2. Membrane fractionation and immunofluorescence techniques confirmed that the two NBCs are located in the sarcolemmal membrane as well as in some internal membranes, probably the T‐tubules. The two NBCs localized in muscle have distinct fibre type distributions. Conclusions: Skeletal muscle possesses two variants of the sodium/bicarbonate co‐transporter (NBC) isoforms, which have been called NBCe1 and NBCe2.     

PCBP1:一种在多水平上参与基因表达调控的蛋白因子

多聚胞嘧啶结合蛋白1 (poly C binding protein-1,PCBP1),属于RNA结合蛋白亚家族,因其具有同RNA的多聚胞嘧啶(poly C)区域特异的结合活性而得名.目前该亚家族共有5个成员:hnRNP K(heterogeneous nuclear ribonucleoprotein K)、PCBP1、PCBP2、PCBP3和PCBP4.PCBP1蛋白在多个水平参与基因的表达调控,如转录、mRNA加工、mRNA的转运、mRNA稳定以及翻译水平调控等.本文对PCBP1基因的结构和生物学功能进行了综述.