转移及非转移肿瘤移植后615小鼠血液流变学变化的研究

血道高转移瘤株FC、淋巴合并血道高转移瘤株U14、淋巴道高转移瘤株H22、非转移瘤株P615分别接种于336只纯系近交615小鼠.不同时间取血并处死动物,进行组织学及血液流变学检查.将转移瘤发展过程分为潜伏期、侵袭期、转移早、中、晚期,非转移瘤发展过程分为潜优期、增殖期、囊腔形成期及中心坏死期.本实验结果显示,不同转移能力及途径肿瘤发展的不同时期血液流变学变化规律不同,因而表明肿瘤侵袭、转移与血液流变学变化之间存在互为因果的紧密关系.其临床诊断及治疗意义被讨论.     

DM891129菌株对沙土鼠高胆固醇血症的影响

本项研究的目的是通过动物实验来观察由健康人分离出的肠球菌DM891129菌株的降血脂作用。本实验选42只沙土鼠(gerible),雌雄各半,随机分为3组,第1组13只为正常组;第2组13只,在正常饮食中 5％胆固醇饲喂1周;第3组16只,在第2组饮食的基础上,每天以肠球菌(DM891129)菌悬液(10~9个细菌/ml)0.5ml/次,Bid灌胃一周。3组沙土鼠以眼球采血,分别检测血清胆固醇、甘油三酯和胆酸水平及粪便中肠球菌和肠杆菌水平。结果表明:第2组胆固醇水平较第1组明显升高(P<0.001)。第3组胆固醇水平较第2组明显降低(P<0.001)。相应的、第3组鼠粪便肠球菌水平明显高于第1、2组(P<0.05),而1、2组之间无显著性差异,第2、3组肠杆菌水平明显高于第1组(P<0.02、P<0.05),2、3组肠杆菌水平无显著性差异。胆酸、甘油三酯水平3组之间无显著性差异。可见DM891129菌株对沙土鼠高胆固醇饮食所致的高胆固醇血症具有明显的降低作用而对血甘油三酯、胆酸水平无显著性影响。现在对DM891129菌株体内降血胆固醇水平的机制尚不清楚,有待于进一步研究。     

抑菌生的研究总结报告

本文报告一种由枯草杆菌制成的生态制剂,并命名为抑菌生(Subtilobiogen)。该制剂对创、烧伤感染有治疗作用。经过安全试验、急性毒性试验、Ames试验和微核试验证明,该制剂是一种无害、无毒和有致突变作用的活菌制剂。抑菌生有膏剂、乳剂及粉剂3种剂型。抑菌生在试管和体内对金黄色葡萄球菌、绿脓杆菌和大肠杆菌均具有抑菌作用。临床观察证明,将抑菌生喷洒在创面上,对浅Ⅱ°度、深Ⅱ°度及混合型烧伤感染均具有明显疗效。实验组(181例)与对照组(174例)相比较,在统计学上具有显著性差异。抑菌生的作用机制,经过初步试验证明,与营养争夺和占位性保护有关,因为枯草杆菌的生长速度超过金黄色葡萄球菌、绿脓杆菌和大肠杆菌的生长速度。     

Chronobiologic approach to beat-to-beat variations of cultured murine myocardial cells

An earlier demonstration of a circadian rhythm in rat atria by others is complemented herein by observations in culture: A single murine myocardial cell and two sets of grouped cells beating in culture for several days reveal several features of an anticipated, presumably built-in spectrum of multifrequency rhythms and trends, the chronome. Circadian and about 12-h (circasemidian) components are modulated by an approximately 84-h (circasemiseptan) component, which cannot be separated from trends in view of the brevity of the series. The circumstance under which the culture is aging and in which fibroblasts proliferate is a further complication that limits the findings to a single cycle reproduced in three separate cultures. Whether it is a rhythm that repeats itself or a response to placement into culture, an approximately 3.5-d component in the beating of myocardial cells in culture is to be aligned with a very prominent similar component found in the incidence of 85,819 human myocardial infarctions.     

pH-sensitive liposomes containing polymerized phosphatidylethanolamine and fatty acid.

With the ultimate aim of targeting cancer drugs to malignant tissues, liposomes containing polymeric phosphatidylethanolamine and a fatty acid were prepared. For this purpose diacetylenic phosphatidylethanolamine (DAPE), a phosphatidylethanolamine containing diacetylene, was synthesized. Liposomes containing DAPE, fatty acid, and either phosphatidylethanolamine (PE) or phosphatidylethanolamine-beta-oleoyl-gamma-palmitoyl (POPE) were then prepared. Polymerization of DAPE was effected by UV illumination. The polymeric liposomes so obtained were stable at physiological pH but became leaky below pH 6.5. Of various compositions studied, the greatest pH-sensitivity was found with liposomes composed of 35 mol% DAPE, 35 mol% POPE, and 30 mol% saturated fatty acid. The presence of blood plasma albumin decreased vesicle stability while apolipoprotein A-I (apo A-I) had the opposite effect and plasma as a whole had a slightly stabilizing effect.     

Acetic acid formation in Escherichia coli fermentation

Theoretical analysis of cellulase product inhibition (by cellobiose and glucose) has been performed in terms of the mathematical model for enzymatic cellulose hydrolysis. The analysis showed that even in those cases when consideration of multienzyme cellulase system as one enzyme (cellulase) or two enzymes (cellulase and beta-glucosidase) is valid, double-reciprocal plots, usually used in a product inhibition study, may be nonlinear, and different inhibition patterns (noncompetitive, competitive, or mixed type) may be observed. Inhibition pattern depends on the cellulase binding constant, enzyme concentration, maximum adsorption of the enzyme (cellulose surface area accessible to the enzyme), the range in which substrate concentration is varied, and beta-glucosidase activity. A limitation of cellulase adsorption by cellulose surface area that may occur at high enzyme/substrate ratio is the main reason for nonlinearity of double-reciprocal plots. Also, the results of calculations showed that material balance by substrate, which is usually neglected by researchers studying cellulase product inhibition, must be taken into account in kinetic analysis even in those cases when the enzyme concentration is rather low. (c) 1992 John Wiley & Sons, Inc.     

Centrally acting endogenous hypotensive substances in rats subjected to endotoxic shock.

Cerebroventricular perfusate (CVP) from rats subjected to endotoxic shock was infused into the lateral ventricle of the naive rat. This procedure produced a hypotensive response in the recipient rat which could be reversed by the intravenous injection of the opioid antagonist naltrexone. The degree of endotoxemic hypotension in the donor rat was attenuated by perfusing the cerebroventricular system with mock CSF. The results suggest the existence of endogenous hypotensive substances in rat central nervous system, possibly opioid in nature, which may play a critical role in the pathogenesis of endotoxic shock.