幽门螺杆菌疫苗免疫机制的研究进展

幽门螺杆菌(H.pylori)是定植于人体胃粘膜的重要致病菌,而粘膜疫苗以其有效的保护性免疫成为防治H.pyiori的热点,但对相应的免疫机制的认识目前尚不明确.故本文对H.pyiori疫苗的保护性免疫机制中的抗原递呈机制,抗体的作用以及TH细胞反应的作用等研究进展做一概要介绍.     

The early phase of experimental acute renal failure

Experiments were conducted to establish whether diminished solute reabsorption in the loop of Henle during acute renal failure could explain the loss of urinary concentration and participate in generating a tubuloglomerular feedback-mediated reduction in filtration rate. The electrolyte content of the fluid in the ascending limb of the loop of Henle was determined in situ by monitoring its electrical conductivity after propulsion into the distal tubule with a sudden burst perfusion. The value of the minimum electrolyte concentration decreased exponentially with increasing equilibration time, reaching a steady-state value equivalent to 27±9 mM NaCl in normal kidneys, 34±15 mM in mercuric chloride kidneys and 53±22 mM following ischaemia. A mathematical model was derived to describe the process of sodium chloride dilution from which it was possible to calculate both the permeability and transport velocity of the cortical thick ascending limb. In the normal kidney, the transport velocity was calculated to be 4.65±0.92 ·10^–5 cm/s, a value not significantly different from that of the mercuric chloride or ischaemic kidneys, and the estimated permeability was 1.13±0.52·10^–5 cm/s, not different from that of the mercuric chloride kidneys but significantly lower than that calculated for the ischaemic kidneys. It is concluded that for the more severely damaged ischaemic model, the loss of urinary concentrating ability was accompanied by a reduction in diluting ability of the ascending limb of the short loop of Henle, which appears to be due, at least in part, to an elevation of the passive permeability to sodium chloride in this segment.     

人格特征与防御方式的相关研究

目的 :尝试用防御机制解释EPQ各维度的特征。方法 :采用EPQ人格问卷、DSQ防御方式问卷、16PF中的G量表对 2 2 0例成人进行测试。结果 :本样本中EPQ各维度与成熟防御方式均无显著相关 (P >0 .0 5 ) ,N维度和P维度均与不成熟防御方式、中间型防御方式有显著正相关 (P <0 .0 0 1)。结论 :本研究显示 ,可以用防御机制解释EPQ各维度的某些特征。     

齿龈内阿米巴的致病作用与致病机制的研究

在注射免疫抑制剂 1周后的大白鼠龈缘涂抹齿龈内阿米巴 (Emtamoebagingivalis ,E .g .) ,5天后 ,牙龈组织出现溃疡、牙周脓肿形成、脓液查见活E .g .、牙槽骨吸收等牙周炎病症。电镜术与生化分析发现 :E .g .伪足活跃、有丰富的溶酶体 ,所含水解酶与ACP显著较健康组高 (P <0 0 1) ,可使牙周组织溶解与受损。SOD较健康组显著性低 (P <0 0 1) ,MDA显著性增高 (P <0 0 1) ,说明E .g .感染产生较多氧自由基可使细胞膜受损 ,加上口腔共生菌的协同作用使免疫力低下的宿主发生牙周炎。     

Effects of ultrasound,the polyene antibiotic amphotericin B,and their combination on biomembranes of yeastlikeCandida fungi

Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 116, N ^o 10, pp. 391–393, October, 1993     

Involvement of a Na−Ca exchange mechanism in contraction induced by low-Na solution in isolated guinea-pig aorta

The possibility of involvement of a Na–Ca exchange mechanism in the contractile responses induced by a reduction of external Na concentration ([Na]₀) has been studied in isolated guinea-pig aorta. Low-Na (11.9 mM) solution (Lisubstituted) produced a contraction in ouabain-treated muscles in the presence of phentolamine (10^–6 M). The magnitude of the contraction was dependent on the duration of the pretreatment with ouabain (2×10^–5 M). Ca-free solution, but not verapamil (10^–6 M), abolished the contraction induced by low-Na solution. The muscles were loaded with various amounts of Na by incubating the tissue with ouabain and varying [Na]₀ (11.9–148.7 mM) in the absence of Ca. The magnitude of the contractions induced in these muscles by low-Na solution containing Ca (2.5 mM) was dependent on the cellular Na content. Loss of cellular Na into low-Na solution followed a single exponential time course and the rate coefficient of Na-loss in the presence of external Ca was about twice as great as in the absence of Ca. Cellular⁴⁵Ca uptake in low-Na solution was significantly greater in Na-loaded tissues (pretreated with ouabain for 3 h) than in normal tissues. The⁴⁵Ca uptake in low-Na solution was not inhibited by verapamil. These results suggest that the contraction induced by low-Na solution is caused by a Ca influx which is dependent on internal Na (a Na–Ca exchange mechanism).     

TNF inhibits malaria hepatic stages in vitro via synthesis of IL-6

We examined the capacity of murine recombinant tumor necrosis factor (rmTNF) to induce an inhibitory effect at the hepatic stage on malaria induced by Plasmodium yoelii sporozoites. When injected three times, 1.0 micrograms of rmTNF was found to protect 78% of mice against a sporozoite challenge. In contrast, whatever the dose and the schedule of administration, no inhibition was observed when purified hepatocyte cultures were infected with P. yoelii. The addition of non-parenchymal hepatic cells to hepatocyte cultures restored the capacity of TNF to modulate hepatic stage development, leading to up to 44% inhibition. Antibodies to interleukin 6 reversed the anti-parasite activity in the co-culture system.     

国际典型综合类科技期刊公众传播特点及对我国综合类科技期刊公众传播能力建设的启示

【目的】 分析国际顶级综合类科技期刊公众传播模式及特点,为我国科技期刊公众传播能力建设提供建议。【方法】 以Altmetric Top 100入选论文数量最多的Nature、Science和PNAS三刊为研究对象,剖析其在公众传播产品、媒体传播体系和新闻媒体人才支撑等方面的模式和特征。对照分析我国最有影响力的综合类科技期刊《国家科学评论》和《科学通报》的公众传播特点。【结果】 以《国家科学评论》和《科学通报》为代表的我国综合类科技期刊的公众传播能力提升迅速,但仍存在新闻传媒人才短缺、期刊集约化程度不高、公众传播机制尚未建立等问题。【结论】 我国综合类科技期刊需要着力增强传媒人才培育、集约化品牌发展、公众传播机制建设,以促进我国科技期刊公众传播能力提升。