Activation of the langendorff perfused rat heart depolarized by increased external potassium concentration

Myocardial activation under depolarized conditions was studied in spontaneously beating Langendorff perfused hearts from albino rats. Depolarization was obtained by increasing external potassium concentration in steps (5.4, 7.4, 10, 10.5, 11 and 11.5 mM) in the perfusing solution with or without adrenaline (Adr). Left ventricle isovolumic systolic pressure and coronary flow did not change as external potassium increased, albeit being larger with Adr in the perfusing solution. Atrial and ventricular rates decreased, the latter showing a larger decline. The same behaviour was displayed by perfused hearts, with higher rates being developed by the group with Adr. PR interval and QRS complex duration increased as a function of external potassium. PR intervals were the same in both groups but QRS duration was larger in the Adr group, indicating that AV conduction was not changed in presence of Adr but intraventricular conduction was delayed in that situation. It was also observed that in the great majority of perfused hearts, differing from isolated preparations, ventricular mechanical activity ceased at around 11.5 mM external potassium.     

慢性阻塞性肺疾病呼吸驱动影响因素分析

目的:探讨慢性阻塞性肺疾病(COPD)病人呼吸驱动与肺功能、血气及静息能量代谢之间的关系.方法:26例COPD和21例正常对照者分别测定口腔阻断压P0.1、呼吸肌功能[最大吸气压(PIMAX)、最大呼气压(P EMAX)]、肺通气功能[努力肺活量(FVC)、一秒率(FEV,%)]、残气(RV/TLC)、弥散功能(DLCO)、静息能量代谢(REE)、呼吸商(RQ)、血气分析及Borg分级等.结果:COPD组P0.1和P0.1/PIMAX高于对照组(P＜0.01).相关分析COPD组P0.1与PaO2、SaO2负相关(r分别为-0.62,-0.53,P均＜0.05),而与PaCO2相关性不明显.Borg分级与P0.1正相关(r=0.63,P＜0.05),P0.1与FVC、FEV1%、RV/TLC、DLCO以及RQ无相关性,P0.1/PIMAX与REE有正相关关系(r=0.41,P＜0.05).结论:COPD呼吸驱动增高,不仅与PaO2,SaO2相关,还与静息能量代谢及Borg分级等相关.     

Basic principles of immunology (immune response) for hemapheresis practitioners

Advances in medical knowledge and technology have identified the essential elements involved in the human immune system, their relationships and interactions, and offer more advanced concepts in the design, function, and maintenance of immune response. Immune response begins with the earliest progenitor cell and transfers its legacy of protection through white blood cells and the complement system. A basic understanding of immunology is essential to the hemapheresis practitioner as new treatment regimens requiring hemapheresis interventions develop. © 1992 Wiley-Liss, Inc.     

Immune activation during pregnancy in mice leads to dopaminergic hyperfunction and cognitive impairment in the offspring: a neurodevelopmental animal model of schizophrenia.

BACKGROUND: Maternal viral infection is associated with increased risk for schizophrenia. It is hypothesized that the maternal immune response to viruses may influence fetal brain development and lead to schizophrenia. METHODS: To mimic a viral infection, the synthetic double strand RNA polyriboinosinic-polyribocytidilic acid (poly I:C) was administered into pregnant mice. Behavioral evaluations (thigmotaxis, methamphetamine [MAP]-induced hyperactivity, novel-object recognition test [NORT]), sensorimotor gating (prepulse inhibition [PPI]), and biochemical evaluation of the dopaminergic function of the offspring of phosphate-buffered saline (PBS)-treated dams (PBS-mice) and that of poly I:C-treated dams (poly I:C-mice) were examined. RESULTS: In juveniles, no difference was found between the poly I:C-mice and PBS-mice. However, in adults, the poly I:C-mice exhibited attenuated thigmotaxis, greater response in MAP-induced (2 mg/kg) hyperlocomotion, deficits in PPI, and cognitive impairment in NORT compared with the PBS-mice. Cognitive impairment in the adult poly I:C-mice could be improved by subchronic administration of clozapine (5.0 mg/kg) but not haloperidol (.1 mg/kg). Increased dopamine (DA) turnover and decreased receptor binding of D2-like receptors, but not D1-like receptors, in the striatum were found in adult poly I:C-mice. CONCLUSIONS: Prenatal poly I:C administration causes maturation-dependent increased subcortical DA function and cognitive impairment in the offspring, indicating a neurodevelopmental animal model of schizophrenia.     

心肌缺血患者白细胞计数动态变化及其活性研究

目的:探讨心肌缺血患者外周血白细胞计数及活性与心肌缺血发生发展的相关性。方法:对74例心肌缺血患者进行回顾性统计,以白细胞计数lO×109/L分组,大于此数患者归于异常组,小于此数则属于正常组.把心肌缺血患者分为两组.一组为心肌梗死组,另一组为心绞痛组,以健康体检者为对照组,分别就患者组与健康对照组在ld～3d/4d~6d/7d—lOd/lld—14d分四个阶段进行白细胞计数及活性测定。结果:心肌梗死组的白细胞计数明显高于冠心病组及正常对照组;随着病情的减轻白细胞计数逐渐下降,其白细胞活性与其记数呈正相关;且心肌梗死组白细胞教异常的病例数明显高于冠心病组及正常对照组。结论:白细胞数及活性的升高参与了心肌缺血的病理生理过程。     

Least-square conformal brain mapping with spring energy

The human brain cortex is a highly convoluted sheet. Mapping of the cortical surface into a canonical coordinate space is an important tool for the study of the structure and function of the brain. Here, we present a technique based on least-square conformal mapping with spring energy for the mapping of the cortical surface. This method aims to reduce the metric and area distortion while maintaining the conformal map and computation efficiency. We demonstrate through numerical results that this method effectively controls metric and area distortion, and is computational efficient. This technique is particularly useful for fast visualization of the brain cortex.     

血小板活化与冠心病关系的研究进展

病理性血小板活化与血栓性疾病密切相关,在心血管疾病中,这一病理生理过程不仅与冠心病的发生、发展有着非常重要的联系,而且对于该病的治疗策略的优化和近、远期预后等方面都有直接的影响。     

Body composition in young female adults with Type 1 diabetes mellitus. A prospective case-control study.

AIMS: Overweight is common during late puberty in female patients with Type 1 diabetes. The aim of this study was to examine the change in body composition from late puberty to early adulthood in such female patients in comparison with age-matched control subjects. METHODS: Eighteen females with Type 1 diabetes and 19 healthy female control subjects were recruited for a case-control study at the age of 16-19 years (baseline). Six years later, 16 of the diabetic females and 17 of the control subjects were re-examined (follow-up). Body composition was assessed by dual energy X-ray absorptiometry. RESULTS: Body mass index (BMI) and fat mass index (total fat mass/height2) were significantly higher at baseline in the diabetic patients than in the control subjects (26.4 +/- 2.6 vs. 23.9 +/- 3.7 kg/m2, P < 0.05, and 10.0 +/- 2.4 vs. 8.0 +/- 2.8 kg/m2, P = 0.04, respectively). At follow-up, these parameters still tended to be higher in the diabetic group (27.8 +/- 4.9 vs. 24.6 +/- 5.7 kg/m2, P = 0.09, and 11.8 +/- 5.6 vs. 8.7 +/- 4.9 kg/m2, P = 0.05, respectively). BMI at baseline was strongly correlated to BMI at follow-up in both diabetic patients (r = 0.60; P < 0.05) and control subjects (r = 0.83; P < 0.01). CONCLUSIONS: Increased fat mass in pubertal girls with Type 1 diabetes seems to persist in young adulthood. This study emphasizes the need for new strategies to prevent the development of overweight during puberty in diabetic girls.     

Characterization of Latent Transforming Growth Factor-β From Human Seminal Plasma

PROBLEM : Human seminal plasma is known to exhibit immunosuppressive activity. Transforming growth factor β (TGF-β) has been identified as an immunosuppressive factor in human seminal plasma. Biologically active TGF-β represents a family of 25-kDa homodimeric proteins linked with disulfide bonds. TGF-β associates with high molecular weight proteins noncovalently to form a type of latency that is biologically inactive. Quantitative distribution of active form of TGF-β versus inactive latent form of TGF-β, and mechanism of the TGF-β activation in human seminal plasma remain to be elucidated. PURPOSE : To characterize seminal plasma latent form of TGF-β, including its concentration, and the mechanism underlying the activation of TGF-β. METHOD : Gel filtrations on ACA-34 and Biogel P-60 were used to fractionate seminal plasma. TGF-β was measured by enzyme immunoassay using antibodies specific for TGF-β₁ and TGF-β₂, respectively. Radioreceptor assay with recombinant human [¹²⁵I]-TGF-β₁ was applied to qualitatively identify TGF-β₁. Kinetic experiments with various pH, temperature and time, along with protease inhibitors, were performed to delineate the activation mechanism of latent TGF-β. RESULTS : Human seminal plasma contained both TGF-β₁ and TGF-β₂, predominantly in latent form. The total concentration of TGF-β₁ averaged 238 ng/ml versus an average of 18 ng/ml for TGF-β₂. The in vitro activation or release of TGF-β₁, from latent TGF-β₁ was achieved only at acidic pH of <4.0, and was time and temperature dependent. At pH 3.7 and 37°C, a significant activation of latent TGF-β₁ was achieved after an incubation of only 15 min, reached the maximum at 120 min, and the activated TGF-β₁ remained relatively stable for at least 24 h. The activation was not inhibitable by a series of protease inhibitors examined, alone or in combination (e.g., phenylmethylsulfonyl fluoride, E-64, pepstatin, leupeptin, ethylenediamine tetraacetic acid). Competitive radioreceptor assay established the functional identity of TGF-β₁ in human seminal plasma with recombinant human TGF-β₁. CONCLUSION : Human seminal plasma TGF-β is biologically activated from high molecular weight latent TGF-β by acid pH. The acidic environment of female lower genital tract could represent an in vivo physiological condition for activation of seminal plasma TGF-β that may immunologically protect the integrity of sperm.     

营养缺乏及补充维生素A对大鼠肺巨噬细胞功能的影响

采用Ｗｉｓｔａｒ大鼠，从怀孕１６天进行限食喂养直到生后４５天，干预组从生后第３６天及第４２天分别给予维生素Ａ灌胃，每次２０００ＩＵ。结果表明，补充维生素Ａ可明显增加大鼠的胸腺重量、肺巨噬细胞的数目、巨噬细胞的吞噬功能及ＮＯ－２的分泌。维生素Ａ可部分纠正营养缺乏导致的免疫缺陷、胸腺萎缩，活化肺巨噬细胞功能，其作用机制有待于进一步研究。