An animal model of SARS produced by infection of Macaca mulatta with SARS coronavirus

A new SARS animal model was established by inoculating SARS coronavirus (SARS-CoV) into rhesus macaques (Macaca mulatta) through the nasal cavity. Pathological pulmonary changes were successively detected on days 5-60 after virus inoculation. All eight animals showed a transient fever 2-3 days after inoculation. Immunological, molecular biological, and pathological studies support the establishment of this SARS animal model. Firstly, SARS-CoV-specific IgGs were detected in the sera of macaques from 11 to 60 days after inoculation. Secondly, SARS-CoV RNA could be detected in pharyngeal swab samples using nested RT-PCR in all infected animals from 5 days after virus inoculation. Finally, histopathological changes of interstitial pneumonia were found in the lungs during the 60 days after viral inoculation: these changes were less marked at later time points, indicating that an active healing process together with resolution of an acute inflammatory response was taking place in these animals. This animal model should provide insight into the mechanisms of SARS-CoV-related pulmonary disease and greatly facilitate the development of vaccines and therapeutics against SARS.     

Fatal avian influenza A (H5N1) in a child presenting with diarrhea followed by coma

In southern Vietnam, a four-year-old boy presented with severe diarrhea, followed by seizures, coma, and death. The cerebrospinal fluid contained 1 white cell per cubic millimeter, normal glucose levels, and increased levels of protein (0.81 g per liter). The diagnosis of avian influenza A (H5N1) was established by isolation of the virus from cerebrospinal fluid, fecal, throat, and serum specimens. The patient's nine-year-old sister had died from a similar syndrome two weeks earlier. In both siblings, the clinical diagnosis was acute encephalitis. Neither patient had respiratory symptoms at presentation. These cases suggest that the spectrum of influenza H5N1 is wider than previously thought.     

Oxygen-dependent up-regulation of mucoid exopolysaccharide (alginate) production in Pseudomonas aeruginosa.

We previously showed substantial differences in Pseudomonas aeruginosa exopolysaccharide production in vitro at oxygen tensions reflective of the right versus left cardiac circuits in vivo (40 versus 80 mm Hg, respectively; A. S. Bayer, T. O'Brien, D. C. Norman, and C. C. Nast, J. Antimicrob. Chemother. 23:21-35, 1989). However, those studies did not specifically confirm this exopolysaccharide to be the characteristic P. aeruginosa mucoid alginate seen in patients with cystic fibrosis. With a murine monoclonal antibody prepared against P. aeruginosa alginate, strongly positive immunofluorescence (IF) staining of a nonmucoid P. aeruginosa strain (PA-96) was seen after its exposure in vitro to oxygen tensions (pO2) of approximately 80 mm Hg; the intensity of the IF staining under these conditions was similar to that observed with a phenotypically mucoid P. aeruginosa strain (C1712M) from a cystic fibrosis patient. In contrast, the same nonmucoid strain (PA-96), after exposure to pO2 of approximately 40 mm Hg, showed little IF staining for alginate. Following enzyme treatment with alginase, PA-96 cells previously exposed to the higher pO2 and exhibiting enhanced alginate production, as determined by IF staining, now showed no IF staining. Moreover, treatment of the oxygen-up-regulated PA-96 cells with alginase released amounts of unsaturated alginate breakdown products (uronic acids) quantitatively similar to those released by typically mucoid strains treated with the same enzyme. These data indicated that the P. aeruginosa exopolysaccharide in our studies was, indeed, mucoid alginate and that variations in oxygen tensions represent one of the trigger mechanisms for the up-regulation of mucoid exopolysaccharide production.     

一种新型的脱细胞组织工程血管支架的构建和评价

本研究的目的是制备一种免疫原性较小、生物相容性较好、力学性能优良的组织工程血管支架。新鲜获得的犬主动脉,置于三蒸水中4℃过夜，使血管细胞由于渗透压差较大而破裂；随后经过多聚环氧化合物家族的乙二醇缩水甘油醚（EX-810）的作用。进一步促进细胞破裂的同时。对血管支架的纤维结构起交联作用；最后应用物理超声的方法清除支架内的细胞碎片残留。用这种方法处理的犬主动脉内几乎没有可见的核染，基本消除了血管支架的免疫原性。同新鲜的血管相比较。这种组织工程血管支架的各种力学指标与新鲜的犬主动脉没有显著差异。说明处理后的支架仍然保持新鲜血管的力学特征。同时它还表现出极低的细胞毒性。分别在支架上种植内皮细胞和平滑肌细胞，扫描电镜检测结果表明，两种细胞在支架上生长良好，且局部已经融合成片。 相容性     

维拉帕米对失血性休克犬心脏的保护作用及机制

杂种犬１１只，由股动脉放血使平均动脉压（ＭＡＰ）维持在６．０ｋＰａ９０ｍｉｎ后回输全部血液，继续观察１５０ｍｉｎ。在休克３０ｍｉｎ后，对照组和维拉帕米处理组（Ｖｅｒ组）分别静脉滴注生理盐水和Ｖｅｒ溶液［（１０μｇ／ｋｇ·ｍｉｎ）１５ｍｉｎ］，液体总量为３ｍｌ／ｋｇ。对照组犬在失血后心率（ＨＲ）加快，左室ｄｐ／ｄｔｍａｘ显著降低，回输血液后ＭＡＰ虽有回升，但仍低于基础值，左室ｄｐ／ｄｔｍａｘ无明显改善；Ｖｅｒ使休克犬ＨＲ减慢，血液回输后ＭＡＰ缓慢恢复至基础值，左室ｄｐ／ｄｔｍａｘ显著高于对照组；电镜观察可见对照组心肌肌原纤维和线粒体等有明显的损伤，而Ｖｅｒ组心肌超微结构基本正常。结果还显示：Ｖｅｒ组犬心肌中丙二醛含量、黄嘌呤氧化酶活性低于对照组，而超氧化物歧化酶活性高于对照组。结果表明：Ｖｅｒ对失血性休克犬的心脏具有保护作用，其机制可能与其阻滞膜Ｃａ２＋内流、抑制脂质过氧化有关。     

脑室注射促甲状腺素释放激素对电针镇痛及脑内亮氨酸脑啡肽含量的影响

实验用大鼠76只,用辐射热-甩尾法测痛,以电针后痛阈变化的百分率评价镇痛效应;用放射免疫分析法测定脑内L-Enk含量。发现脑室注入三肽-促甲状腺素释放激素(TRH)后,能显著降低电针镇痛效果;提高丘脑内L-Enk含量,但痛阈与脑内L-Enk含量的变化无相关关系。本文证明,TRH在电针镇痛过程中是对抗作用。已知针刺镇痛与脑内多种神经质和肽类有关,在不利于针刺镇痛的因素中,TRH是新添的“一员”。     

Gründe für die Ablehnung behördlicher Empfehlungen und Maßnahmen zum Schutz vor SARS-CoV-2 – eine qualitative Studie auf Basis von Beiträgen in sozialen Medien

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Um die Ausbreitung von SARS-CoV‑2 (schweres akutes Atemwegssyndrom-Coronavirus-Typ 2) zu verlangsamen, haben Bund...     

雷公藤多甙片加益肾活血法治疗IgM相关性肾小球疾病

目的探讨IgM相关性肾小球疾病的治疗。方法53例患者分为雷公藤多甙片组(A组)和雷公藤多甙片＋中药益肾活血(B组)治疗,疗程2个月。结果两组治疗前后尿蛋白均下降（P＜0．05）,组间比较则B组降低更明显(P＜0．05)。尿红细胞均有减少,A组P＞0．05,B组P＜0．05;组间比较P＜0．05。结论雷公藤多甙片＋中药益肾活血法治疗IgM相关性肾小球疾病较单用雷公藤多甙片疗效显著提高。认为辨病辨证相结合组方用药,能够提高疗效。     

黄芪多糖对糖尿病大鼠微血管病变的作用及机制的研究

目的：探讨黄芪多糖（APS）对糖尿病大鼠微血管病变的影响以及对糖尿病的治疗作用及机制。方法：成年,健康SD大鼠40只,雌雄不限,分成四组：正常对照组,糖尿病组（腹腔注射四氧嘧啶200mg/kg),APS组（造模成功后用APS治疗）,优降糖组（造模成功后用优降糖治疗）。治疗两周时测一次血糖,四周后,测血糖;颈动脉取血测定血清胰素水平,NO和MDA含量。应用形态定量的方法比较各组的心肌病理变化。结果：腹腔注射alloxan(200mg/kg)后的SD大鼠血糖浓度显升高,血清NO,MDA,胰岛素水平明显改变。APS治疗四周后,血糖浓度明显下降,与优降糖治疗组无明显差异,血清NO较未治疗组明显升高（P＜0．01）,血清MDA较未治疗组明显减少（P＜0．01）,血清胰岛素水平升高（P＜0．05）,光镜下观察,糖尿病大鼠的心肌毛细血管数量减少,基底膜增厚,微血管与心肌纤维的比率显减低,这些改变都可被APS改善.结论：APS有降低血糖和保护血管内皮细胞的作用,这可能与APS减轻氧自由基的损伤,影响NO的产生以及促进胰岛B细胞的损伤的恢复有关。     

制备工艺对ATO超细粉体导电性能的影响

采用化学共沉淀法制备锑掺杂二氧化锡（ATO）超细导电粉体,研究了反应温度,滴定终点pH值,掺锑量及锻炼温度对粉体导电性的影响,并对实验结果进行了讨论。