Direct mechanical heart massage

Biomedical Engineering -     

Molecular subtyping of Vibrio cholerae O1 and O139 by pulsed-field gel electrophoresis in Hong Kong: correlation with epidemiological events from 1994 to 2002

Two hundred twenty isolates of Vibrio cholerae O1 and O139 collected from 1994 to 2002 in Hong Kong were analyzed by pulsed-field gel electrophoresis (PFGE). Chromosomal DNAs from all V. cholerae isolates in agarose plugs were digested with the restriction enzyme NotI, resulting in 20 to 27 bands. Sixty distinctive PFGE patterns in the range of 10 to 300 kb were noted among 213 isolates typeable by PFGE. By comparing the common PFGE patterns obtained from four well-defined outbreaks of V. cholerae O1 and O139 with those obtained from other, epidemiologically unrelated isolates during the study period, indistinguishable and similar PFGE patterns were identified, indicating their close relatedness, in agreement with the results of epidemiological investigations. Heterogeneous PFGE patterns (with four to six banding differences), however, were identified among strains that were imported from other parts of Asia, including Indonesia, India, and Pakistan. Correlations with epidemiological information further support the usefulness of PFGE as an epidemiological tool in laboratory investigations of suspected outbreaks. Standardization of PFGE methodology will allow international comparison of fingerprint patterns and will form the basis of a laboratory network for tracking V. cholerae.     

Transport of Ca2+ ions in the mitochondria of Ehrlich's ascites tumor cells

The pattern of Ca²⁺ accumulation by tumor mitochondria (MC) was investigated under various experimental conditions. In the absence of penetrating anions tumor MC were shown to take up Ca²⁺ in only one fifth the amount taken up by liver MC. In the presence of acetate this difference was greater still. Inorganic phosphate (P_in) abolished the observed defects of Ca²⁺ transport and increased the Ca²⁺ capacity of the tumor MC considerably. By contrast with liver MC, P_in also had a stabilizing effect on membrane permeability of the tumor MC; this may be the cause of the increasee Ca²⁺ capacity of these MC.Department of Bioenergetics, Institute of Biological Physics, Academy of Sciences of the USSR, Pushchino-on-Oka. (Presented by Academician of the Academy of Medical Sciences of the USSR S. E. Severin.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 84, No. 8, pp. 202–205, August, 1977.     

Interaction between mitogenic lectins and plasma membranes of lymphocytes

Mitogenic signals from concanavalin A and phytohemagglutinin were shown to undergo summation in time under conditions when each mitogen separately, if the duration of contact with lymphocytes during the experiment was the same (14 or 20 h), did not induce mitogenesis. The results are discussed from the standpoint of cell-cell interaction between lymphocytes. It is suggested that the ability of these signals to undergo time summation lies at the basis of the nonspecific mechanism of protection against tolerance.Laboratory of Physical Chemistry of Biological Membranes, Biological Faculty, M. V. Lomonosov Moscow University. (Presented by Academician of the Academy of Medical Sciences of the USSR V. N. Orekhovich.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 7, pp. 89–91, July, 1979.     

Significance of methods for purification of oligodeoxyribonucleotide probes for the efficiency of gene diagnosis by real-time PCR

Analysis of the use of real-time PCR with fluorescent registration of results for gene diagnosis of infectious diseases showed that the sensitivity and reliability of quantitative evaluation of DNA targets directly depended on the method of purification of oligonucleotide probes. Chromatographic behavior of synthetic probes carrying various fluorophores and fluorescence quenchers was analyzed. Approaches to optimization of purification methods are proposed enabling elimination of previously undetectable admixtures. The importance of these studies is explained by the need in extending the armory of methods for the development and production of diagnosticums for detection of infectious and hereditary diseases, identification of genetically modified organisms, and for a wide spectrum of research in molecular biology and medicine. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 3, pp. 280–284, March, 2008     

心脏组织工程瓣脉动流培养系统的设计与构建

自行设计和制造平面和三维立体培养室及贮液室等构件,用医用硅胶管连接;转子泵作为动力源,贮液室通气口供给5%CO2 95%空气,恒温水浴箱保持构件37℃恒温,这样组成了种植细胞与生物瓣支架复合体的脉动培养系统,并进行生物力学和生物相容性测试,为心脏组织工程瓣的体外构建提供研究器材。结果显示,该装置密闭性能好,内环境能保持37±1℃、CO2浓度5%±1%、pH值6.8～7.5;流量在0.125～6.0L/min的范围内任意调节;同种瓣膜上的内皮细胞经2周培养后扩增约10倍;瓣膜支架的细菌和霉菌培养均为阴性,说明我们构建的脉动流培养系统能有效地模拟体内脉动流场实现种植细胞在体外的增殖、重塑,为心脏组织工程瓣的体外构建提供了一种新的实验方法。     

Comparison of deltaFVC between patients with allergic rhinitis with airway hypersensitivity and patients with mild asthma.

BACKGROUND: In asthmatic individuals, airway sensitivity and maximal airway response are increased. Airway sensitivity is usually evaluated by measuring the provocation concentration of inhaled methacholine or histamine that causes a decrease in forced expiratory volume in 1 second of 20% (PC20). The percentage decrease in forced vital capacity at the PC20 (deltaFVC) has been proposed as a surrogate marker for maximal airway response. Individuals with allergic rhinitis and no clinical evidence of asthma frequently exhibit airway hypersensitivity. OBJECTIVE: To compare the deltaFVC between patients with allergic rhinitis and mild asthmatic patients with a similar degree of airway hypersensitivity. METHODS: A retrospective analysis of methacholine challenge test data from 72 children with allergic rhinitis and airway hypersensitivity (methacholine PC20 < 16 mg/mL) (rhinitis group) and from 72 children with mild atopic asthma matched to the rhinitis group regarding the methacholine PC20 (asthma group). The deltaFVC was calculated on the concentration-response curve to methacholine. RESULTS: The mean +/- SD deltaFVC was significantly lower in the rhinitis group (15.0% +/- 3.6%) vs the asthma group (17.4% +/- 5.3%) (P = .002). There was no significant correlation between the deltaFVC and PC20 in the rhinitis (r = -0.101; P = .41) and asthma (r = -0.023; P = .85) groups when 2 patients with PC20 less than 1 mg/mL were excluded from each group. CONCLUSIONS: Patients with allergic rhinitis and airway hypersensitivity had a significantly lower deltaFVC than methacholine PC20-matched mild asthmatic patients, suggesting that the level of maximal airway response in patients with allergic rhinitis is lower than that in mild asthmatic patients with a similar degree of airway hypersensitivity.     

致癌物分子结构识别中的一种特征提取方法

本文论述基于拓扑参数的致癌物分子结构识别中的一种特征参数－－特征片段的提取方法；对一组活性已知的分子训练集，将其分子结构用ＫＬＮ编码法进行编码并输入计算机，在三个约束条件下用深度第一法对各分子进行结构分解，生成片段文件，并汇总成片段总库，然后用统计检验和聚类分析提取和优化特征片段，从而为识别模型提供合理有效的特征参数。