Individual Differences in Plasma Catecholamine and Corticosterone Stress Responses of Wild-Type Rats: Relationship With Aggression

Plasma noradrenaline (NA), adrenaline (A), and corticosterone (CS) responses to social and nonsocial stressors were studied in male members of a strain of wild-type rats, widely differing in their level of aggression. The aggressiveness was preliminarily established by measuring the latency time to attack (ALT) a male intruder in a standard resident-intruder test. Animals were then provided with a jugular vein cannula for blood sampling during stress exposure. Implanted rats were randomly assigned to 3 experimental treatments: social stress (defeat experience, SD), nonsocial stress (presentation of a shock-prod, SP) and control (animals undisturbed in their home cages, CTR). A significant correlation was found between ALT and the amount of time spent in burying the probe in SP rats: the more aggressive the animal, the higher the rate of burying behavior. SD induced a much stronger effect on plasma NA, A, and CS concentrations than SP. A significant negative correlation was found between ALT scores and values of the area under the response time curve for NA and A, in both SD and SP situations: the more aggressive the animal, the higher the catecholaminergic reactivity to the stressors. On the contrary, no evidence of a correlation between aggressiveness and plasma corticosterone responses was found, neither in SD nor in SP rats. These findings in an unselected strain of wild-type rats confirmed that an aggressive/active coping strategy is associated with a high sympathetic-adrenomedullary activation and support the concept of individual differentiation in coping styles as a coherent set of behavioral and neuroendocrine characteristics.     

Thromboresistant properties of hydrophilic gels

The thromboresistant properties of hydrophilic gels based on copolymers of nitrogen-containing heterocyclic vinyl compounds with vinyl monomers were investigated. The hydrophilic gels were shown to prevent adsorption of fibrinogen, activation of procoagulants, and adhesion of platelets. Hydrogen surfaces possess selective affinity for plasma albumin. The authors consider that the thromboresistant effect of hydrophilic gels is due to the competitive action of plasma albumin. Modification of hydrophilic gels increases their thromboresistant properties.Laboratory of Thromboresistant Materials, Institute of Transplantation of Organs and Tissues, Ministry of Health of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. M. Chernukh.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 89, No. 3, pp. 296–298, March, 1980.     

Fast-induced changes in plasma glucose, insulin and free fatty acid concentration compared in rats during the night and day

Changes in PG, PI and PFFA were examined and compared in fed rats or after 0 to 12 hours of fasting, during the night or during the day. At night, a progressive decrease in PG and PI and an increase in PFFA were induced by 0 to 12 hours of food deprivation. During the light period a decrease in PG occurred only from the 6th hour of fasting. A slight, progressive increase in PFFA levels was induced from 0 to 12 hours of fasting, while no significant variation of PI levels was observed. The results are discussed in terms of relationships between blood glucose, PFFA levels, and food intake in control rats over the circadian cycle.     

等离子体表面改性涤纶材料的血浆蛋白吸附与血小板黏附行为研究

采用等离子体表面接枝改性技术在涤纶 (聚对苯二甲酸乙二醇酯 ,PET)材料表面接枝不同分子量的聚乙二醇 (PEG) ,从表面能与界面自由能的角度分析了血浆蛋白 (纤维蛋白原和白蛋白 )在材料表面的竞争吸附关系 ,结果表明接枝了 PEG长链分子的 PET材料具有优先吸附白蛋白的性质 ,其中接枝 PEG6 0 0 0的 PET优先吸附倾向最明显。预接触白蛋白和纤维蛋白原的 PET材料表面的血小板黏附实验表明 :吸附白蛋白的表面能够显著抑制血小板的黏附和聚集 ,表现出好的血液相容性 ,而吸附了纤维蛋白原的材料表面具有降低血液相容性的性质。     

超氧自由基和血液粘度的相关性研究

本文对69名体检人员进行过氧化脂质(LPO)血液流变性和血脂检测,应用电子计算机和医用统计软件进行数据分析.直线回归分析表明,LPO与全血和血浆粘度无显著相关;进行多元逐步回归分析表明,LPO在全血粘度比值中则列为第3受选因子,说明LPO对血浆粘度有一定影响.     

Hormone changes induced by 37.5-h head-down tilt (−6°) in humans

Endocrine regulation of hormones and electrolytes during 37.5 h of –6° head down tilt (HDT) was studied in 13 men. The acute effects of simulated weightlessness are today well documented, but no study has been made concerning the hormone changes between 12 h and 2 days of HDT. Plasma volume showed a maximal increase of 9.23 (SEM 1.97) % after 6.5 h (P<0.01) and had returned to prestudy levels after 13.5 h of HDT. From 1.5 h to 4 h of HDT, C-terminus and N-terminus atrial natriuretic peptide (ANP) concentrations in plasma were increased by about 50% (P<0.01) and thereafter declined to pre-HDT levels. Plasma renin activity (PRA) was decreased by 47% (P<0.05) after 4 h of HDT; PRA increased after 23.5 h to 60%; noradrenaline concentration decreased immediately and remained low up to 37.5 h. Diuresis and natriuresis were evident during the 1st day of HDT, resulting in a marked increase in the urinary Na⁺. These results showed that the initial hormone (ANP, PRA) changes during HDT did not last more than 13.5 h and that after 24 h a new state would seem to have been established to adapt the body to hypovolaemia.     

Thermal gradients in microtitration plates. Effects on enzyme-linked immunoassay

Temperature studies of microtitration plates demonstrate that the use of a common bacteriology incubator for heating the plates can cause a phase lag of over 30 min for the fluid in the wells to reach 37°C from ambient temperature, and that a temperature gradient of as much as 1.6°C can exist between the peripheral and center wells. This gradient is a cause of the ‘rim’ or edge effect noted in enzyme immunoassay using microtitration plates. The problem is corrected by the use of a specially designed forced air microtitration plate incubator.     

Monoclonal antibodies against human granulocytes and myeloid differentiation antigens

Monoclonal antibodies (MCA) were obtained by immunizing BALB/c mice with 99% pure granulocytes from normal donors or with a whole leukocyte suspension obtained from a chronic myelogenous leukemia (CML) patient, and then fusing the mouse spleen cells with a 315–43 myeloma cell clone. Four MCA were selected and studied using ELISA, immunofluorescence, cytotoxicity assays, and FACS analysis. Antibodies 80H.1. 80H.3. and 80H.5 (from normals) and 81H.1 (from CML) detected antigens expressed on neutrophils. Antibodies 80H.1 and 80H.3 (lgG) also reacted with monocytes but not with other blood cell subsets. Antibodies 80H.5 and 81H.1 (lgM) were cytotoxic and reacted strongly with most of the cells of the neutrophil maturation sequence. i.e., myeloblasts, promyelocytes, myelocytes, and mature granulocytes. Antibodies 80H.5 and 81H.1 also inhibited BFU-GM and CFU-E. Antigens recognized by 80H.3. 80H.5, and 81H.1 were expressed both on a proportion of cells from HL.60, KG.1, ML.1, and K562 myeloid cell lines, and on a proportion of blast cells isolated from patients with acute myelogenous leukemia. They were not found on lymphoid cell lines or lymphoid leukemia cells. These MCA recognize either late differentiation antigens expressed on mature neutrophils and monocytes (80H.1 and 80H.3) or early differentiation antigens (80H.5 and 81H.1) specific to the granulocytic lineage. They may be useful for a better definition of those antigens specific to hematopoietic stem cells and their relationship with normal or neoplastic hematopoiesis.     

Comparison of radioimmunoassay and ELISA methods for detection of antibodies to chromatin components

A solid phase radioimmunoassay has been compared with an enzyme-linked immunosorbent assay (ELISA) for efficacy in measuring anti-chromatin antibodies. The low backgrounds achieved with the radioimmunoassay method produced a high signal-to-noise ratio and enabled detection of the human test antiserum at a dilution of 1:102,400. By contrast, the ELISA could detect the same antiserum only at a dilution of 1:3200 and above. The radioimmunoassay was consistently more sensitive than the ELISA for detection of anti-chromatin antibodies in a number of human and mouse sera and ascites fluid containing a monoclonal antibody. Factors affecting sensitivity in both assays are discussed.