Postresuscitation changes in brain free radical-mediated processes and nitric oxide synthase activity in rats: effects of individual behavior in "emotional resonance" test

Effects of 7-min cardiac arrest and individual behavior on free radical-mediated processes and nitric oxide synthase (NOS) activity was evaluated in brains of male Wistar rats one hour and one week after resuscitation. "Emotional resonance" test was used for the behavioral selection of rats. The test includes factors of significance for rats: the choice between large and lighted or small and dark space as well as signals of pain of another rat. Free radical generation (using chemiluminescence method), superoxide scavenging/generating activity, substances reacting with 2-thiobarbituric acid and NOS activity (by measuring mononitrosyl iron complex of NO with diethyl dithiocarbamate and endogenous brain Fe2+ by electron spin resonance spectroscopy) were determined in cerebral cortex, cerebellum and hippocampus. Cardiac arrest induced oxidative stress accompanied by the loss of NOS activity, as well as compensatory changes of free radical-mediated processes in cerebral cortex. Oxidative stress was also evident in cerebellum and, to a lesser extent, in hippocampus. Most of neurochemical differences between behavioral groups were induced by cardiac arrest. These differences were global, related to a specific brain region or became apparent in cerebral lateralization of biochemical indices.     

Impact of dynamic 3D transoesophageal echocardiography in the assessment of atrial septal defects and occlusion by the double-umbrella device (CardioSEAL)

Previous research has supported theoretical claims that dichotomous thinking may be a risk factor for suicide. However, the concept of dichotomous thinking is vague, and thus far, no measures of it have been developed. This study developed a coding scheme useful on Thematic Aperception Test (TAT; Murray, 1943) protocols and applicable to other verbal productions to refine the concept of dichotomous thinking and to assess its utility as a predictor of suicidality. Suicidal patients had a significantly elevated rate of a narrowly defined type of dichotomous thinking involving diametric or polarized possibilities. However, suicidal and nonsuicidal patients did not differ on weaker forms of dichotomous thinking involving nonexclusive or nonbinary alternatives. Suicidal patients produced shorter TAT stories than nonsuicidal patients, supporting other findings in the literature that suicidal patients tend to be cognitively and affectively "shut down." Traditionally designated "suicide cards" also yielded shorter stories but did not elicit higher rates of dichotomous thinking.     

陀螺测斜技术安全优化与应用

针对陀螺测斜技术现场应用中遇到的电缆起出携带大量稠油、下井仪器遭遇"油帽子"无法通过、马笼头部位电缆发生短路或断路等问题,研制了稠油井电缆清洁装置、加重装置、马笼头安全锁定密封装置。通过对陀螺测斜技术进行安全与优化,提高了陀螺现场应用效率,增强了安全性与科学性。     

氨基磺酸盐系高效减水剂概述

从官能团的角度介绍了氨基磺酸盐系高效减水剂的结构及性能的关系;阐述了目前氨基磺酸盐系高效减水主要合成工艺,并对氨基磺酸盐系高效减水剂存在的问题进行了分析,预测了氨基磺酸盐系高效减水剂的发展趋势。     

基于CATIA软件的水工钢闸门三维设计

简单介绍了三维CAD技术的应用情况,重点介绍了应用CATIA软件设计水工钢闸门的思路、过程及使用体会,总结了使用CATIA作闸门设计的优点。     

Olfactory receptor proteins. Expression, characterization and partial purification

A rat olfactory epithelium cDNA library was screened for olfactory receptor clones. One of the positively hybridizing cDNA clones was sequenced and found to encode a new member of the olfactory receptor superfamily. This cDNA, termed olp4, was used as a model of olfactory receptor for expression, both in vitro and in vivo. Expression of olp4, as well as of another previously cloned olfactory receptor (F5), was monitored by immunoprecipitation was a monoclonal antibody directed against a Flag peptide epitope tag, inserted at the N-terminus of the open reading frame, and a specific polyclonal antibody against a C-terminal peptide of olp4. Translation in vitro, followed by immunoprecipitation, showed a major olp4-specific band of 27-29 kDa. The olp4 and F5 polypeptides were found to be inserted into microsomal membranes as expected for integral membrane proteins. Expression in vivo of Flag-olp4 in Sf9 insect cells, using the baculovirus expression system, showed a specific polypeptide of the same size as the in vitro species, with an additional band of 34 kDa, which is most likely a glycosylated form. Fluorescence cytometry and immunohistochemical assays demonstrated the localization of the Flag-olp4 product on the cell surface of the infected host Sf9 cells, with the N-terminus and C-terminus in the proper orientation. Affinity chromatography was used for the partial purification of the olp4 polypeptide from infected Sf9 cells. The identification and purification of this expressed olfactory receptor polypeptide could open the way for further characterization and functional studies of the olfactory receptor superfamily members.     

Osmoregulatory function of the kidny under natural conditions: relationship between the index of osmotic concentration and reabsorption of osmotically free water]

SR 27417, a potent PAF receptor antagonist, inhibited in a dose-dependent manner the hypotensive effect of PAF in rats. It protected rats with an ED50 value of 6 +/- 2 micrograms/kg (n = 6), when given i.v., 1 min before PAF administration. After i.v. administration, SR 27417 exhibited extended duration of action, a significant protective effect was observed up to 48 h after the administration. After i.v. injection, SR 27417 (0.3, 1 and 3 mg/kg) afforded dose-dependent protection of actively sensitized rats against ovalbumin-induced hypotension but also totally reversed established antigen-induced hypotension. These results therefore confirm that PAF plays a major role in anaphylactic shock and suggest that SR 27417 may be an effective prophylactic as well as a potent curative drug in this pathology.     

The cell adhesion molecule E-cadherin is widely expressed in human atherosclerotic lesions

OBJECTIVE: Various cell adhesion molecules are expressed in atherogenesis and the significance of their involvement in atherosclerotic lesion formation is well appreciated. In the present work, we examined whether the Ca(2+)-dependent cell adhesion molecule E-cadherin is also involved in atherogenesis. METHODS: Specimens of carotid artery and aorta were obtained at operation. Expression of E-cadherin was studied by an immunohistochemical method. The nature of E-cadherin-expressing cells was examined by comparative analysis of consecutive sections and by a double immunostaining procedure. An immunohistochemical approach was also applied to examine how the accumulation of oxidised low density lipoproteins (LDL) by intimal cells is associated with E-cadherin expression. RESULTS: No E-cadherin+ cells were found in normal non-atherosclerotic intima but E-cadherin+ cells were present in 96% of the atherosclerotic lesions. In atherosclerotic intima, E-cadherin was expressed by intimal cells showing varying degrees of transformation into foam cells. These E-cadherin+ cells also contained oxidised LDL in their cytoplasm. Differing numbers of CD68+ foam cells (15% to 60%) expressed E-cadherin but all the CD68+ macrophages without signs of transformation into foam cells were negative for E-cadherin. Neither smooth muscle cells nor foam cells of smooth muscle cell origin (smooth muscle alpha-actin+) were found to be positive for E-cadherin. T-cells (CD3+) and endothelial cells (von Willebrand factor+) were also negative for E-cadherin. Only a few vascular dendritic cells (S-100+) expressed E-cadherin and their expression was weak. We also found that a large proportion (40% to 85%) of E-cadherin+ cells did not stain with any cell-type specific markers. CONCLUSIONS: The finding that E-cadherin is expressed in atherosclerotic lesions expands our knowledge of cell adhesion molecules involved in atherogenesis. That E-cadherin is expressed in intimal cells transforming into foam cells suggests that lipid accumulation might be associated with the alteration and reorganisation of cell-to-cell interactions in atherogenesis. The present observations might assist in understanding the mechanisms associated with intracellular lipid accumulation.     

The effect of exercise on the riboflavin status of adult men

Six sedentary to moderately active men with biochemical signs of riboflavin deficiency were studied under metabolic ward conditions to examine the effects of physical activity on riboflavin status. All participants were subjected to additional exercise (EXER) for an 18 d period between two maintenance (M1 and M2) periods (16 and 13 d respectively) of habitual physical activity. Energy balance and riboflavin intake were maintained throughout the study. Riboflavin status, as judged by a significant reduction in erythrocyte glutathione reductase (EC 1.6.4.2) activation coefficient (EGR-AC), improved on changing from home (1.53 (SD 0.14)) to period M1 (1.36 (SD 0.21)) diets. The exercise period, however, resulted in a significant deterioration in riboflavin status (1.57 (SD 0.31)) which persisted in the subsequent period M2 (1.54 (SD 0.15)). There was a concomitant fall in the urinary excretion of riboflavin only in the EXER period, when results were expressed as a percentage of the dietary intake of riboflavin. These results suggest an increased demand for the vitamin for selective biochemical functions during exercise. However, the energy cost of walking (treadmill 4 km/h), 50 W and 100 W work-loads (bicycle ergometer) as well as delta mechanical efficiency (DME) did not change during the three metabolic periods. The urinary excretion of riboflavin was inversely related to DME (r -0.49; P < 0.05) and directly correlated with haemoglobin levels (r 0.63; P < 0.005). The present study suggests that riboflavin status further deteriorates during a short period of increased physical activity in individuals whose riboflavin status is marginal.