医学微生物实验课的设计与管理

为了培养医学生解决实际问题的能力，训练学生树立创新的意识和严谨的科学作风以及团结协作的精神品德，本文提出了几条关于医学微生物实验课的设计原则，并且提出了几条医学微生物实验室的管理建议，以防止实验室微生物感染事件的发生。     

Dual Exposure to Sevoflurane Improves Anesthetic Preconditioning in Intact Hearts

Background: Anesthetic preconditioning (APC) with sevoflurane reduces myocardial ischemia-reperfusion injury. The authors tested whether two brief exposures to sevoflurane would lead to a better preconditioning state than would a single longer exposure and whether dual exposure to a lower (L) concentration of sevoflurane would achieve an outcome similar to that associated with a single exposure to a higher (H) concentration.

Methods: Langendorff-prepared guinea pig hearts were exposed to 0.4 mm sevoflurane once for 15 min (H1-15; n = 8) or 0.4 mm (H2-5; n = 8) or 0.2 mm sevoflurane (L2-5; n = 8) twice for 5 min, with a 5-min washout period interspersed. Sevoflurane was then washed out for 20 min before 30 min of global no-flow ischemia and 120 min of reperfusion. Control hearts (n = 8) were not subjected to APC. Left ventricular pressure was measured isovolumetrically. Ventricular infarct size was determined by tetrazolium staining and cumulative planimetry. Values are expressed as mean +/- SD.

Results: The authors found a better functional return and a lesser percentage of infarction on reperfusion in H2-5 (28 +/- 9%) than in H1-15 (36 +/- 8%; P < 0.05), L2-5 (43 +/- 6%; P < 0.05), or control hearts (52 +/- 7%; P < 0.05).     

Effect of water restrictions on the physiological parameters,psychological behavior and brain c-Fos expression in rat

1 Introduction Exposure to hostile stressors causes a series of coor- dinated responses in the body, such as alterations of neu- roendocrine secretion, immune reaction and behavioral manifestation to maintain homeostasis stability and sur-vival of the organisms. Stressors are divided into two main categories: physical, or systemic, and psychological, or emotional / processive. Each stressor might activate a spe- cific central pathway to induce a special neuroendocrine response, even cause stre…     

Morphine Preconditions Purkinje Cells against Cell Death under In Vitro Simulated Ischemia-Reperfusion Conditions

Background: Morphine pretreatment via activation of [delta]1-opioid receptors induces cardioprotection. In this study, the authors determined whether morphine preconditioning induces ischemic tolerance in neurons.

Methods: Cerebellar brain slices from adult Sprague-Dawley rats were incubated with morphine at 0.1-10 [mu]m in the presence or absence of various antagonists for 30 min. They were then kept in morphine- and antagonist-free buffer for 30 min before they were subjected to simulated ischemia (oxygen-glucose deprivation) for 20 min. After being recovered in oxygenated artificial cerebrospinal fluid for 5 h, they were fixed for morphologic examination to determine the percentage of undamaged Purkinje cells.

Results: The survival rate of Purkinje cells was significantly higher in slices preconditioned with morphine (>= 0.3 [mu]m) before the oxygen-glucose deprivation (57 +/- 4% at 0.3 [mu]m morphine) than that of the oxygen-glucose deprivation alone (39 +/- 3%, P < 0.05). This morphine preconditioning-induced neuroprotection was abolished by naloxone, a non-type-selective opioid receptor antagonist, by naltrindole, a selective [delta]-opioid receptor antagonist, or by 7-benzylidenenaltrexone, a selective [delta]1-opioid receptor antagonist. However, the effects were not blocked by the [mu]-, [kappa]-, or [delta]2-opioid receptor antagonists, [beta]-funaltrexamine, nor-binaltorphimine, or naltriben, respectively. Morphine preconditioning-induced neuroprotection was partially blocked by the selective mitochondrial adenosine triphosphate-sensitive potassium channel antagonist, 5-hydroxydecanoate, or the mitochondrial electron transport inhibitor, myxothiazol. None of the inhibitors used in this study alone affected the simulated ischemia-induced neuronal death.     

Isoflurane Preconditions Hippocampal Neurons against Oxygen-Glucose Deprivation: Role of Intracellular Ca2+ and Mitogen-activated Protein Kinase Signaling

Background: Isoflurane preconditions neurons to improve tolerance of subsequent ischemia in both intact animal models and in in vitro preparations. The mechanisms for this protection remain largely undefined. Because isoflurane increases intracellular Ca2+ concentrations and Ca2+ is involved in many processes related to preconditioning, the authors hypothesized that isoflurane preconditions neurons via Ca2+-dependent processes involving the Ca2+- binding protein calmodulin and the mitogen-activated protein kinase-ERK pathway.

Methods: The authors used a preconditioning model in which organotypic cultures of rat hippocampus were exposed to 0.5-1.5% isoflurane for a 2-h period 24 h before an ischemia-like injury of oxygen-glucose deprivation. Survival of CA1, CA3, and dentate neurons was assessed 48 later, along with interval measurements of intracellular Ca2+ concentration (fura-2 fluorescence microscopy in CA1 neurons), mitogen-activated protein kinase p42/44, and the survival associated proteins Akt and GSK-3[beta] (in situ immunostaining and Western blots).

Results: Preconditioning with 0.5-1.5% isoflurane decreased neuron death in CA1 and CA3 regions of hippocampal slice cultures after oxygen-glucose deprivation. The preconditioning period was associated with an increase in basal intracellular Ca2+ concentration of 7-15%, which involved Ca2+ release from inositol triphosphate-sensitive stores in the endoplasmic reticulum, and transient phosphorylation of mitogen-activated protein kinase p42/44 and the survival-associated proteins Akt and GSK-3[beta]. Preconditioning protection was eliminated by the mitogen-activated extracellular kinase inhibitor U0126, which prevented phosphorylation of p44 during preconditioning, and by calmidazolium, which antagonizes the effects of Ca2+-bound calmodulin.     

Parkinson''''s Disease and Smoking: An Integral Part of PD''''s Etiological Study

INTRODUCTION Parkinson抯 disease (PD), a debilitating neurodegenerative disorder, is featured with bradykinesia, resting, muscular rigidity, gait disturbances, and postural reflex impairment[1]. PD is rare before age of 50 years, but it increases dramatically with older ages, with peak onset occurring during the age of 70-85 years. In the United States, prevalence of PD in all age groups is approximately 150 per 100 000 and is roughly 30 per 100 000 at age of less than 50 years and 800 …     

青少年初始血压高者在高血压发生中的预测意义

为探讨初始血压偏高者在高血压发生中的预测意义，对汉中农村４６２３名年龄６～１５岁青少年血压，经过８年随访（末次随访率为８２．０７％）证明，基线调查收缩压百分位与８年后的收缩压相关系数，男为０．３３，女为０．２８，舒张压均为０．２０；基线调查收缩压在第７５百分位（Ｐ７５）以上者，８年后血压≥１８．７／１２．０ｋＰａ（１４０／９０ｍｍＨｇ）的机率是＜Ｐ５０以下的３．９１倍，初始血压百分位愈高相对危险性愈大；如同时初始收缩压≥Ｐ７５、体重指数≥Ｐ９０，并有高血压病家族史者，发生高血压的机率为２７．６％，是收缩压＜Ｐ７５、体重指数＜Ｐ９０和无高血压家族史者的６．５７倍。我们认为，青少年初始血压高者是成年高血压的易感人群，特别当伴有肥胖或超重及高血压家族史者，预测意义更大。     

儿童近视化长期观察及在临床治疗中的指导意义

为指导临床治疗，我们对1984～2004年间我院就诊的屈光不正的儿童87例148只眼进行了长期观察。现报道如下：[第一段]     

治疗牛皮癣的药物致骨髓重度受抑与急性再生障碍性贫血的鉴别

目的：进一步探讨临床应用牛皮癣药物导致的骨髓重度受抑与急性再生障碍性贫血（以下简称急性再障）之间的实验室鉴别诊断的主要依据。方法：药物导致的骨髓重度受抑和急性再障患者行骨髓涂片、骨髓活检和末梢血涂片瑞姬氏染色后进行骨髓象和血象的检测；另外采静脉血应用血细胞自动化分析仪进行血常规检测。结果：治疗牛皮癣药物导致的骨髓重度受抑与急性再障患者外周血象极为相似，但骨髓重度受抑患者的骨髓涂片、活检不同于急性再障患者的显示，各系、各阶段有核细胞比例大致正常，巨核细胞、血小板数量虽少但还可见；此类药物导致的骨髓重度受抑患者骨髓涂片的骨髓小粒并不少，且虽有部分空虚，但其中网络的是三系造血细胞。结论：通过了解病史和使用牛皮癣药物的治疗史，骨髓象和血象的实验室分析，可以进一步找出此类药物导致的骨髓重度受抑与急性再障之间的实验室鉴别依据。