The molecular regulation of Chinook salmon gonadotropin β-subunit gene transcription

Expression of the gonadotropin β-subunit genes is tightly regulated both cell-specifically and by the regulatory hormones to achieve the appropriate gonadotropic hormone levels required for reproductive development and function. Although the cDNA sequences of these genes are highly conserved across species, their promoter sequences are not and few functional studies have been carried out to understand the molecular mechanisms through which their expression is regulated. We and others have carried out several studies on the LHβ gene promoter of Chinook salmon (Oncorhynchus tschawytscha), and also isolated the FSHβ gene from the same species. We present here a review of these studies and also novel data pertaining to both genes, in an attempt to collate the current understanding of the molecular regulation of the gonadotropin β-subunit genes in these fish.     

The regulatory environment: a source of job (dis)satisfaction for early childhood professionals?

This article extends current understandings of sources of job (dis)satisfaction for childcare staff by investigating the hypothesis that early childhood professionals' satisfaction with regulatory requirements is a predictor of job satisfaction. Findings show that for early childhood professionals in New South Wales, Australia, satisfaction with the regulatory environment is related to the extent these requirements are perceived to support autonomous professional practices conducive to quality care. Considerable dissatisfaction with regulatory requirements was found among study participants. Nonetheless, this level of dissatisfaction did not predict job (dis)satisfaction. The lack of correlation may be indicative of the study's sample, however, and does not preclude a greater connection between the two constructs. Implications of a possible nexus between job satisfaction and satisfaction with regulatory requirements are discussed, and further research is called for.     

Inhibition of lactate export by quercetin acidifies rat glial cells in vitro

The relationship between glial lactate release and glial intracellular pH (pH_i) regulation is studied using C6 glioma cells and rat astrocytes in vitro, and the lactate transport inhibitors quercetin and α-cyano-4-hydroxycinnamate (CHC). pH_i is measured using 2′,7′-bis(carboxyethyl)-5,6-carboxyfluorescein (BCECF). The results show that lactate release is mediated partly by a specific lactate transport system inhibitable by quercetin (50 μM), but not by CHC (5 mM). Inhibition by quercetin results in a significant 3–4-fold increase of intracellular lactate and a decrease of intracellular pH to 6.9. A participation of quercetin-inhibitable lactate transport in glial pH_i-regulation is suggested by the observation that pH_i-homeostasis after acidification by diffusion of undissociated lactic acid into the cell is inhibited by quercetin. The existence of a system controlling lactate release in glial cells may also reflect a function of astrocytes to supply neurons with lactate.     

尊重患者知情权减少医疗纠纷

《医疗事故处理条例》的确规定了病人享有知情权,医疗机构及服务人员应将患者病情,医疗措施、医疗风险等告知患者。但在告知的过程中,需根据病情及病人具体情况采用不同方式,本文对此提出的探讨。     

内皮型一氧化氮合酶重组腺病毒表达载体的构建及其在食管平滑肌细胞中的表达和调控

背景：一氧化氮(N0)是一种重要的抑制性神经递质，其合成障碍与多种胃肠道动力障碍性疾病的发生密切相关。目的：构建四环素调控的内皮型一氧化氮合酶(eNOS)重组腺病毒表达载体，实现eNOS在食管平滑肌细胞(ESMC)中表达的精确调控。方法：可调控重组腺病毒表达载体的构建分为3个步骤：首先，将编码目的基因eNOS的全长cDNA定向克隆于穿梭质粒pTRE—Shuttle中，获得一个能被四环素或其类似物强力霉素调控的表达盒(Tet—responsive expression cassette)；然后，将表达盒与腺病毒DNA(Adeno—X^tm Viral DNA)体外连接，形成重组腺病毒质粒Ad—eNOS；最后，Ad—eNOS转染人胚肾293细胞后被包装成有感染能力的重组腺病毒颗粒Adeno-x—TRE—eNOS。用Adeno-x—TRE—eNOS和调控病毒Adeno—X—Tet-off共感染体外培养的ESMC，采用逆转录聚合酶链反应(RT—PCR)和western blot评价eNOS在靶细胞中的表达以及强力霉素对表达强度的调控情况。结果：体外连接法成功构建了可调控重组腺病毒表达载体Adeno-x—TRE—eNOS，其与调控病毒共感染ESMC后，RT—PCR和western blot出现阳性结果。加入不同浓度的强力霉素可以抑制eNOS基因的转录强度，其抑制作用呈剂量-效应关系，强力霉素浓度达到0．01μg／m1时可以完全关闭目的基因的表达。结论：采用体外连接法成功构建了可调控的eNOS重组腺病毒表达载体，并介导了eNOS在体外培养的ESMC中的表达和调控，为进一步利用eNOS进行基因治疗奠定了基础。     

电阻抗成像中变差正则化算法的研究

我们将变差函数作为罚函数项引入到电阻抗逆问题的正则化重构算法中，形成了变差正则化算法，与常用Tikhonov正则化算法不同，该算法在重构中不仅能够保证逆问题解适定，同时还能够很好地提高重构图像的对比度和锐度，使所得重构图像目标区域与背景区域之间边界更加清晰，定位更加准确，进而使EIT重构图像与医学图像更加吻合，对EIT成像技术早日走上实用化有积极意义。     

外源多胺对大鼠再生肝细胞鸟氨酸脱羧酶基因转录的调节

目的 研究天然多胺(腐胺、精脒和精胺)对大鼠再生肝细胞鸟氨酸脱羧酶(ODC)基因转录的调节,探讨多胺在肝再生中的作用.方法 大鼠部分肝切除术诱导再生肝,采用原位杂交技术分析ODC mRNA的表达量,外源多胺(溶于0.9%NaCl)的处理用皮下注射法.结果 外源多胺处理后,再生肝ODC mRNA水平的变化趋势与对照组相似,但不同种类、剂量的多胺,结果差异明显.在所观察到的整个肝再生期间,高剂量腐胺(20 mg/kg体重)处理组mRNA水平始终低于对照组,特别在部分肝切除后2、4和10 h与对照组相比具有显著性差异(P＜0.05);低剂量(0.02 mg/kg体重)的腐胺处理组,只在4 h和12 h显著高于对照组.高剂量精脒(0.15 mg/kg体重)处理组的ODC mRNA水平始终低于对照组(在10 h例外);而低剂量(0.03 mg/kg体重)处理组则不同,ODC mRNA水平表现出先抑制(在2 h)后促进(在4 h和6 h)的特点.精胺的作用与精脒相似.结论 不同浓度的多胺(主要是精脒和精胺)对大鼠再生肝细胞ODC基因转录存在着反馈调节作用.