The full-length genome analysis of a street rabies virus strain isolated in Yunnan province of China

The epidemic of rabies has rapidly increased and expanded in Yunnan province in recent years.In order to further analyze and understand the etiological reasons for the rapid expansion of rabies in Yunn...     

Polysaccharides serve as scaffold of biofilms formed by mucoid Pseudomonas aeruginosa

Chronic lung infection by mucoid Pseudomonas aeruginosa is one of the major pathologic features in patients with cystic fibrosis. Mucoid P.?aeruginosa is notorious for its biofilm forming capability and resistance to immune attacks. In this study, the roles of extracellular polymeric substances from biofilms formed by mucoid P.?aeruginosa were investigated. Alginate is not an essential structure component for mucoid P.?aeruginosa biofilms. Genetic studies revealed that Pel and Psl polysaccharides serve as essential scaffold and mediate macrocolony formation in mucoid P.?aeruginosa biofilms. The Psl polysaccharide is more important than Pel polysaccharide in mucoid P.?aeruginosa biofilm structure maintenance and phagocytosis resistance. The polysaccharides were further found to protect mucoid P.?aeruginosa strain from host immune clearance in a mouse model of acute lung infection.     

Cell origins and diagnostic accuracy of interleukin 27 in pleural effusions

The objective of the present study was to investigate the presence of interleukin (IL)-27 in pleural effusions and to evaluate the diagnostic significance of pleural IL-27. The concentrations of IL-27 were determined in pleural fluids and sera from 68 patients with tuberculous pleural effusion, 63 malignant pleural effusion, 22 infectious pleural effusion, and 21 transudative pleural effusion. Flow cytometry was used to identify which pleural cell types expressed IL-27. It was found that the concentrations of pleural IL-27 in tuberculous group were significantly higher than those in malignant, infectious, and transudative groups, respectively. Pleural CD4(+) T cells, CD8(+) T cells, NK cells, NKT cells, B cells, monocytes, macrophages, and mesothelial cells might be the cell sources for IL-27. IL-27 levels could be used for diagnostic purpose for tuberculous pleural effusion, with the cut off value of 1,007 ng/L, IL-27 had a sensitivity of 92.7% and specificity of 99.1% for differential diagnosing tuberculous pleural effusion from non-tuberculous pleural effusions. Therefore, compared to non-tuberculous pleural effusions, IL-27 appeared to be increased in tuberculous pleural effusion. IL-27 in pleural fluid is a sensitive and specific biomarker for the differential diagnosing tuberculous pleural effusion from pleural effusions with the other causes.     

葛根素对糖尿病心肌细胞的保护及其机制研究

观察葛根素（Puerarin）对链脲佐菌素（streptozotocin,STZ）诱导的糖尿病大鼠心肌细胞的保护作用,并探讨血小板反应素1（Thrombospondin-1,TSP-1）的表达改变及其作用。雄性SD大鼠45只随机分为三组（n=15）：糖尿病组和葛根素治疗组采用一次腹腔注射链脲佐菌素（STZ）65mg／kg制备糖尿病模型,其中葛根素治疗组于造模后葛根素腹腔注射4周（100mg/kg/day）,正常对照组仅腹腔注射等量生理盐水（6ml／kg）,同样喂养4周。四周后各组大鼠处死。H—E染色及透射电子显微镜观察三组大鼠心肌细胞纤维显微结构和超微结构的病理改变．免疫组化和实时荧光定量PCR法观察大鼠心肌细胞中TSP-1蛋白和mRNA表达的变化．同时利用Langendorff离体心脏灌流法测定各组大鼠心室肌细胞功能。结果发现葛根素治疗组较糖尿病组大鼠的体重增加明显,同时血糖下降,有显著性差异（P〈0．01）。H—E染色显示糖尿病大鼠多处心肌肌丝紊乱伴少量炎症细胞浸润,电镜下发现有线粒体嵴消失溶解,肌丝排列紊乱等病理改变,而葛根素治疗组大鼠偶见上述病理变化。免疫组化显示葛根素治疗组心肌内TSP-1阳性细胞密度小于糖尿病大鼠,TSP-1 mRNA表达也比糖尿病大鼠要低。此外葛根素治疗组大鼠的左室收缩末压（LVSEP）、左心室舒张末期压（LVEDP）等心功能指标均明显低于正常组（P〈0．01）,但较糖尿病组有显著改善（P〈0．01）。上述结果显示葛根素能保护糖尿病大鼠心肌细胞的高糖损伤和维持心室肌细胞的功能,而该机制可能与抑制心肌细胞TSP-1表达的水平有关。     

南宁地区唐氏综合征患者的细胞遗传学研究

为了探讨中国南宁地区唐氏综合征患者染色体核型分布及其特点, 对广西壮族自治区妇幼保健院1994年以来的500例疑似唐氏综合征(Down syndrome, DS)患者进行外周血染色体核型分析, 130例确诊为DS患者。其中, 单纯型21-三体为86.15%(112/130); 易位型为8.46%(11/130); 嵌合型为5.39%(7/130)。在单纯型21-三体中性别比为女∶男=1∶1.8; 93.08% 的唐氏综合征患儿由年轻母亲(<35岁)所生, 另有6.92% 由高龄产妇所生。结果表明, 南宁地区86% 以上唐氏综合征患者的染色体核型是单纯型21-三体, 男性唐氏综合征患儿明显高于女性患儿。     

Two new antibacterial sesquiterpenoids from Centipeda minima

Two new guaiane-type sesquiterpene lactones, compounds 1 and 2, along with three known guaianolide- or pseudoguaianolides, were isolated from Centipeda minima (whole plant). Their structures were identified by spectroscopic and mass-spectrometric analyses. The configuration at C5 of the guaiane framework of 1 was rationalized by quantum-mechanical calculations (Table 2). All compounds were found to be active against eight different microbial pathogens (Table 3), with MIC values in the range of 6.25-100 microg/ml.     

Fluorescent substrate analog for monitoring chain elongation by undecaprenyl pyrophosphate synthase in real time

Farnesyl pyrophosphate (FPP) is a common substrate for a variety of prenyltransferases for synthesizing isoprenoid compounds. In this study, (2E,6E)-8-O-(N-methyl-2-aminobenzoyl)-3,7-dimethyl-2,6-octandien-1-pyrophosphate (MANT-O-GPP), a fluorescent analog of FPP, was synthesized and demonstrated as a satisfactory substrate for Escherichia coli undecaprenyl pyrophosphate synthase (UPPS) with a K_m of 1.5 μM and a k_cat of 1.2 s⁻¹ based on [¹⁴C]IPP consumption. Interesting, we found that its emission fluorescence intensity at 420 nm increased remarkably during chain elongation, thereby useful for real-time monitoring kinetics of UPPS to yield a K_m of 1.1 μM and a k_cat of 1.0 s⁻¹, consistent with those measured using radiolabeled substrate. Using this assay, the IC₅₀ of a known UPPS inhibitor farnesyl thiopyrophosphate (FsPP) was confirmed. Our studies provide a convenient and environmentally friendly alternative for kinetics and inhibition studies on UPPS drug target.     

Genome sequencing and comparison of two nonhuman primate animal models, the cynomolgus and Chinese rhesus macaques

The nonhuman primates most commonly used in medical research are from the genus Macaca. To better understand the genetic differences between these animal models, we present high-quality draft genome sequences from two macaque species, the cynomolgus/crab-eating macaque and the Chinese rhesus macaque. Comparison with the previously sequenced Indian rhesus macaque reveals that all three macaques maintain abundant genetic heterogeneity, including millions of single-nucleotide substitutions and many insertions, deletions and gross chromosomal rearrangements. By assessing genetic regions with reduced variability, we identify genes in each macaque species that may have experienced positive selection. Genetic divergence patterns suggest that the cynomolgus macaque genome has been shaped by introgression after hybridization with the Chinese rhesus macaque. Macaque genes display a high degree of sequence similarity with human disease gene orthologs and drug targets. However, we identify several putatively dysfunctional genetic differences between the three macaque species, which may explain functional differences between them previously observed in clinical studies.