C反应蛋白检测在感染性和非感染性发热鉴别中的作用

目的：探讨C反应蛋白（C reactive protein,CRP）在感染性和非感染性发热鉴别中的作用。方法：对758例以发热为主要症状的患者进行各项检查,并在入院24小时内采集静脉血用免疫比浊法检测CRP,计算特异度、灵敏度、准确度、阳性预测值、阴性预测值、阳性似然比、阴性似然比。结果：758例患者中,确诊为感染性发热的患者616例,占81.27%,非感染性发热患者142例,占18.73%。感染性发热患者的CRP值显著高于非感染性发热患者,差异具有统计学意义（P〈0.05）。CRP检验的特异度、灵敏度、准确度、阳性预测值、阴性预测值、阳性似然比和阴性似然比的值分别为87.32%、97.89%、95.91%、97.10%、90.51%、7.72和0.02。结论：CRP的检测能有效鉴别感染性发热与非感染性发热。     

The rickettsia surface cell antigen 4 applies mimicry to bind to and activate vinculin

Pathogenic Rickettsia species cause high morbidity and mortality, especially R. prowazekii, the causative agent of typhus. Like many intracellular pathogens, Rickettsia exploit the cytoskeleton to enter and spread within the host cell. Here we report that the cell surface antigen sca4 of Rickettsia co-localizes with vinculin in cells at sites of focal adhesions in sca4-transfected cells and that sca4 binds to and activates vinculin through two vinculin binding sites (VBSs) that are conserved across all Rickettsia. Remarkably, this occurs through molecular mimicry of the vinculin-talin interaction that is also seen with the IpaA invasin of the intracellular pathogen Shigella, where binding of these VBSs to the vinculin seven-helix bundle head domain (Vh1) displaces intramolecular interactions with the vinculin tail domain that normally clamp vinculin in an inactive state. Finally, the vinculin·sca4-VBS crystal structures reveal that vinculin adopts a new conformation when bound to the C-terminal VBS of sca4. Collectively, our data define the mechanism by which sca4 activates vinculin and interacts with the actin cytoskeleton, and they suggest important roles for vinculin in Rickettsia pathogenesis.     

Analysis of potential virulence genes and competence to transformation in Haemophilus influenzae biotype aegyptius associated with Brazilian Purpuric Fever

Brazilian Purpuric Fever (BPF) is a hemorrhagic pediatric illness caused by Haemophilus influenzae biogroup aegyptius (Hae), a bacterium that was formerly associated with self-limited purulent conjunctivitis. BPF is assumed to be eradicated. However, the virulence mechanisms inherent to Hae strains associated with BPF is still a mystery and deficient in studies. Here, we aim to analyze the role of the autotransporter genes related to adherence and colonization las, tabA1, and hadA genes through RT-qPCR expression profiling and knockout mutants. Relative quantification by real-time PCR after infection in human cells and infant rat model suggests that las was initially downregulated probably duo to immune evasion, tabA1, and hadA were overexpressed in general, suggesting an active role of TabA1 and HadA1 adhesins in Hae in vitro and in vivo. Transformation attempts were unsuccessful despite the use of multiple technical approaches and in silico analysis revealed that Hae lacks genes related to competence in Haemophilus, which could be part of the elucidation of the difficulty of genetically manipulating Hae strains.     

肺部感染铜绿假单胞菌的临床特点

目的:分析肺部感染铜绿假单胞菌的临床特点。方法:对我院呼吸科2012年1月-2013年12月住院患者的痰标本中分离出的铜绿假单胞菌的病例资料进行回顾性分析。结果:检出铜绿假单胞菌85株;患者的平均年龄为(59.93±12.46)岁;平均住院天数为(13.32±6.66)天;慢性基础性肺疾病、广谱抗生素的应用、机体免疫力低下可增加该菌的感染率;发热率为43.53%,表现为低热和中等度热;发热患者与体温正常的患者相比,白细胞计数差异具有统计学意义(x2=7.6656,P=0.00560.05),中性粒细胞百分比差异具有统计学意义(x2=3.9027,P=0.04820.05)。发热患者的WBC平均为(12.53±6.16)×109/L,G%平均为为(78.85±9.10)%;敏感率65%的抗生素有哌拉西林/他唑巴坦钠、头孢他啶、头孢哌酮/舒巴坦钠、头孢吡肟、亚胺培南、环丙沙星、左氧佛沙星,其均可作为肺部感染铜绿假单胞菌的经验性治疗药物;有无按药敏调整药物及疾病的预后,差异无统计学意义,应继续增加样本量。结论:肺部感染铜绿假单胞菌的患者临床特点变化多样。治疗时应重视感染该菌的危险因素,根据药敏结果用药。     

Exposure of sheep to mosquito bites: possible consequences for the transmission risk of Rift Valley Fever in Senegal

Rift Valley Fever (RVF) is a growing health problem in West Africa. In northern Senegal, the candidate vectors of this arbovirosis are Aedes (Aedimorphus) vexans Meigen and Culex (Culex) poicilipes Theobald (Diptera: Culicidae). Domestic ruminants are the reservoirs of the virus. A study was undertaken during the 2002 rainy season to assess spatial and temporal variations in exposure to mosquito bites in sheep herds, and to evaluate the possible consequences on the risk of RVF transmission to sheep. Mosquitoes were collected with sheep-baited traps. The number of Ae. vexans females (the predominant species during the 2002 rainy season) trapped per trap-night was the dependent variable in statistical analyses. The trapping periods were divided into six series of two to five consecutive days, from July to November 2002. Three temporary ponds were selected according to their ecological features: depth, bank slope, size and vegetation cover. Traps were laid on the pond bank and in the nearest available compound, close to the sheep night pen. Data were analysed using mixed-effects Poisson models. The explanatory variables were the trapping period, the pond, and the capture site. The exposure to mosquito bites varied according to the pond type, suggesting that the risk of transmission was spatially heterogeneous. However, there was no obvious trend in transmission risk due to the effect of the distance from the compound to the pond. The period with the highest exposure was in October, i.e. when transhumant herds left the Ferlo to relocate to their dry-season settlement. It is thus hypothesized that transhumance, the seasonal movements of herds, plays a significant role in the dissemination of RVF virus in the region.     

Intravenous alpha-MSH reduces fever in the squirrel monkey

alpha-MSH reduces fever in rabbits when administered IV, ICV, or by gavage; however, the applicability of this finding to higher species, specifically to primates, has not been determined. In this study, we chose the squirrel monkey as an appropriate primate model since it responds reliably to peripheral administration of bacterial endotoxins that cause fever in man. From pilot studies, doses of S. typhosa endotoxin necessary to produce maximum fever and doses of alpha-MSH which did not cause hypothermia were determined for each animal. In the main experiments endotoxin was given via an indwelling catheter in the saphenous vein, followed by alpha-MSH injections when the rectal temperature increased 0.3 degrees C. alpha-MSH (100-400 micrograms) reduced the area under the fever curve an average of 50.0%, but had no effect on afebrile temperature. Molar equivalent amounts of the antipyretic drug acetaminophen had little effect on fever. These findings support the idea, based on research on rabbits, that alpha-MSH has a role in central modulation of fever.     

The genome of Theileria parva: some structural properties

The DNA of the protozoan Theileria parva, the causal agent of the bovine East Coast Fever, has been prepared at least 99% pure from the intra-erythrocytic form of the parasite. Its buoyant density was found to be 1.696 g/cm3 and its calculated G + C content was 36.7%. Fragmentation of T. parva by the restriction enzyme EcoRI provides some evidence of the presence of repetitive DNA sequences.     

应用原位杂交及免疫组化检测肝活检组织中流行性出血热病毒RNA及抗原

本文应用原位杂交及免疫组化技术对25例流行性出血热(EHF)患者肝活检组织进行了病毒RNA及其囊膜G_2蛋白的定位检测,结合光镜,认为肝细胞的变性、胞浆疏松化、点状坏死是EHF病毒直接侵犯并在其胞浆内增殖表达所致,肝组织的灶状坏死则主要是肝窦狭窄、枯否氏细胞增生导致微循环障碍引起的缺血性梗死。急性脂褐素沉积是病毒侵犯肝细胞的间接证据。研究还发现,肝细胞内病毒的多少与病程关系不明确,而与临床分型有一定相关,为探讨EHF的发病机制提供了分子水平的依据。     

斑点杂交检测肾综合征出血热病毒核酸的研究

本研究用非放射性标记物—地高辛碱性磷酸酶标记肾综合征出血热病毒（ＨＦＲＳＶ）ｃＤＮＡ制备探针,检测恙螨、鼠肺中ＨＦＲＳＶＲＮＡ的ＲＴＰＣＲ扩增产物中目的片段。结果表明：ＨＦＲＳＶ抗原阳性鼠体螨５０只组、１０只组,游离螨５０只组、１０只组,ＨＦＲＳＶ抗原阳性鼠肺１０００ｍｇ、５００ｍｇ,抗原阴性鼠肺１０００ｍｇ检测结果为阳性,呈现明显紫褐色斑点,而ＲＴＰＣＲ检测时未能扩增出ＨＦＲＳＶ抗原阴性鼠肺１０００ｍｇ和游离螨１０只组中的目的条带。实验结果说明,斑点杂交检测方法比ＲＴＰＣＲ敏感。     

Febrile tolerance develops in response to repeated administration of bacterial lipopolysaccharide but not of interleukin-1β in rats

Changes of abdominal temperature in response to intraperitoneal injections of 100 μg/kg bacterial lipopolysaccharide (LPS), repeated three times in intervals of 3 days were measured in rats. Only after the first injection of LPS a pronounced fever developed, a small fever was recorded after the second injection, while the response to the 3rd injection of LPS was almost the same as to an administration of solvent (0.9 % saline) to naive rats. Levels of bioactive cytokines (tumor necrosis factor α, TNFα, and interleukin-6, IL-6), measured 60 min after the 1st, 2nd or 3rd injection of LPS, were progressively attenuated. Changes of abdominal temperature in response to intraperitoneal injections of recombinant rat-interleukin-1β (rr IL-1β), also repeated three times in intervals of 3 days were measured in another group of rats. The febrile responses to the 1st, 2nd and 3rd injection of rr IL-1β were amost identical. The results of this study show that febrile tolerance develops in response to repeated injections of LPS, but not of its putative endogenous mediator, IL-1β, in rats.