Measles virus replication in lungs of hispid cotton rats after intranasal inoculation.

Hispid cotton rats were inoculated intranasally with either measles virus (MV) Edmonston, a multipassaged, tissue culture-adapted strain of MV, or with one of three clinical MV isolates that had limited passages (three to five times) in tissue culture cells. MV Edmonston was recovered from the lungs of every (n = 37) hispid cotton rat inoculated with this virus for at least 7 days after virus inoculation. Peak pulmonary titers occurred on Day +4 (3.3-4.4 log10/g lung). Scattered areas of inflammation were observed interstitially in lung sections from infected animals stained with hematoxylin and eosin, and a similar pattern of diffuse fluorescence was seen in cryostat sections stained with an indirect fluorescent antibody procedure specific for virus antigens. Fluorescent antibody and virus isolation studies on lung lavage cells both suggested that lung leukocytes were a primary target of the virus. In contrast to these findings, virus was isolated only sporadically from hispid cotton rats inoculated with any of the clinical measles virus isolates. Despite the restricted growth of MV in these animals, cotton rats may be useful for studying certain aspects of measles virus pathogenesis and for screening potential antiviral compounds in vivo.     

Characterization of boreholes by Octopus dofleini in the bivalve Saxidomus giganteus

Octopus dofleini (Wulker) drills holes in mollusc shells, enabling it to introduce venom. Boreholes in the bivalve Saxidomus giganteus (Deshayes) were generally irregular. Thick shells were more likely to have incomplete boreholes, and the diameter of completed boreholes was larger than in thin shells. A comparison of boreholes to fractured and artificially drilled surfaces suggests that O. dofleini employs chemical dissolution of the shell during drilling.     

Evaluating automated infrared thermography and vulva exposure tracking as components of an estrus detection platform in a commercial dairy herd

The primary objective of this study was to develop an automated infrared thermography platform (Estrus BenchMark) capable of measuring skin temperature and tail movements as a means of identifying cows in estrus. The secondary objective was to evaluate the accuracy of Estrus BenchMark to detect estrus compared to in-line milk progesterone (P₄) analysis (Herd Navigator System) in a commercial dairy herd managed under a robotic milking system. Data were collected on forty-six cows from 45 to 120 d after calving. Cows were flagged in estrus when milk P₄ fell below 5 ng/mL. The Estrus BenchMark true positive estrus alerts (Sensitivity; Se%) were compared to Herd Navigator System estrus alerts at different time-windows (±12 h, ±24 h, ±48 h, and ±72 h) relative to the Estrus BenchMark estrus alerts for all the estrus alerts (AE) and confidence-quality estrus (CQE; >80% quality) alerts identified by Herd Navigator System. The Estrus BenchMark captured skin temperature and tail movements resulting in vulva exposure (left tail movements, LTail; right tail movements, RTail; and pooled tail movements, PTail) for each milking event. Skin temperature tended to increase when the milk P₄ concentration (Least-Squares Means ± SE) dropped for AE (estrus day [d 0]; P₄; 3.51 ± 0.05 ng/mL, Skin temperature; 33.31 ± 2.38 °C) compared with d ?7 (P₄; 20.22 ± 0.73 ng/mL; Skin temperature: 32.05 ± 3.77 °C). The increase in skin temperature, however, was significant in cows with CQE > 80% at d 0 (32.75 ± 0.29 °C) compared to d ?7 (31.80 ± 0.28 °C). The prevalence of tail movements to expose vulva was greater (P = 0.01) in AE at d 0 (LTail: 62.50%; PTail; 68.75%; and RTail: 56.25%) compared with d ?7 (LTail: 18.75%; PTail: 9.37%: and RTail: 9.37%), and d +4 (LTail: 9.37%; PTail: 9.37%; and RTail: 12.5%). Moreover, the higher prevalence of tail movements at d 0 was observed in cows with CQE > 80% (LTail; 65%, PTail; 80%, and RTail; 70%) compared to those with CQE < 80%. The highest Estrus BenchMark Youden index (YJ; 0.45), diagnostic odds ratio (DOR; 9.04), and Efficiency (0.77) were achieved for AE in a ±48 h window and at ±72 h window for CQE (YJ; 0.66, DOR; 25.29, and Efficiency 0.76) relative to Herd Navigator System estrus alerts. The highest Estrus BenchMark resulted in 58% estrus detection rates for AE and 80% for cows with CQE compared to the Herd Navigator System.     

重组hPRL-1的表达纯化及其理化和酶学性质研究

目的:表达纯化hPRL-1重组蛋白,分析其理化性质及酶学特性。方法:热激法将重组pET15b质粒转化入E.coli BL21中,IPTG诱导表达出His-tagged hPRL-1蛋白。使用Ni-NTA亲和层析法结合Mono Q离子交换层析法纯化。用SDS-PAGE法和Western Blot法进行表达情况的定性定量分析,并使用HPLC法鉴定蛋白纯度,计算出蛋白分子量,圆盘等电聚焦电泳分析重组蛋白等电点。比较分析以pNPP、4-MUP和DiFMUP为底物时的酶促反应动力学。同时以pNPP为底物测定酶的最适pH值;以4-MUP为底物测定酶的最适温度,分析探讨缓冲液离子强度与蛋白酪氨酸酶通用抑制剂钒酸钠对酶活力的影响。结果:以亲和层析和离子交换层析结合,可以纯化得到纯度约为95%的蛋白。测得蛋白分子量为24.54kD,等电点为9.11。以pNPP、4-MUP和DiFMUP为底物时Km分别为3720μmol/L,130μmol/L和50μmol/L。酶的最适pH值为7.6,最适温度为34℃。结论:纯化所得蛋白为目的蛋白hPRL-1;两步纯化相结合可以得到纯度较高的蛋白;三种底物特异性依次为DiFMUP>4-MUP>pNPP。     

Neglected tropical diseases in Uganda: the prospect and challenge of integrated control

So-called 'neglected tropical diseases' (NTDs) are becoming less neglected, with increasing political and financial commitments to their control. These recent developments were preceded by substantial advocacy for integrated control of different NTDs, on the premise that integration is both feasible and cost-effective. Although the approach is intuitively attractive, there are few countrywide experiences to confirm or refute this assertion. Using the example of Uganda, this article reviews the geographical and epidemiological bases for integration and assesses the potential opportunities for, and operational challenges of, integrating existing control activities for several of these diseases under an umbrella vertical programme.     

Sigma Factor SigB Is Crucial to Mediate Staphylococcus aureus Adaptation during Chronic Infections

Staphylococcus aureus is a major human pathogen that causes a range of infections from acute invasive to chronic and difficult-to-treat. Infection strategies associated with persisting S. aureus infections are bacterial host cell invasion and the bacterial ability to dynamically change phenotypes from the aggressive wild-type to small colony variants (SCVs), which are adapted for intracellular long-term persistence. The underlying mechanisms of the bacterial switching and adaptation mechanisms appear to be very dynamic, but are largely unknown. Here, we analyzed the role and the crosstalk of the global S. aureus regulators agr, sarA and SigB by generating single, double and triple mutants, and testing them with proteome analysis and in different in vitro and in vivo infection models. We were able to demonstrate that SigB is the crucial factor for adaptation in chronic infections. During acute infection, the bacteria require the simultaneous action of the agr and sarA loci to defend against invading immune cells by causing inflammation and cytotoxicity and to escape from phagosomes in their host cells that enable them to settle an infection at high bacterial density. To persist intracellularly the bacteria subsequently need to silence agr and sarA. Indeed agr and sarA deletion mutants expressed a much lower number of virulence factors and could persist at high numbers intracellularly. SigB plays a crucial function to promote bacterial intracellular persistence. In fact, ΔsigB-mutants did not generate SCVs and were completely cleared by the host cells within a few days. In this study we identified SigB as an essential factor that enables the bacteria to switch from the highly aggressive phenotype that settles an acute infection to a silent SCV-phenotype that allows for long-term intracellular persistence. Consequently, the SigB-operon represents a possible target to develop preventive and therapeutic strategies against chronic and therapy-refractory infections.     

以MyD88 TIR二聚化为靶点的抗炎抑制剂筛选模型的建立

MyD88是IL-1R/TLR受体超家族向细胞内转导胞外信号时募集到受体胞浆尾部的重要接头蛋白．由TIR结构域介导的MyD88分子同源二聚化是它招募到受体胞浆尾部的前提,然后二聚化的MyD88再募集下游信号分子,传递信号,引发促炎基因的表达．本研究旨在建立一种模型,以实现活细胞原位的、基于荧光信号变化的MyD88二聚化抑制物的高通量筛选．我们分别构建了MyD88 TIR与GFP和RFP的融合蛋白表达质粒,瞬时转染HeLa细胞,在488 nm激发光下,转染GFP-MyD88 TIR和RFP-MyD88 TIR细胞,检测到绿色荧光与红色荧光间的共振能量转移(FRET)．而当细胞转染GFP-MyD88 TIR和RFP或RFP-MyD88 TIR和GFP,因TIR二聚化不能实现,FRET效率受到严重影响．实验结果提示,依赖双阳性表达GFP-MyD88 TIR和RFP-MyD88 TIR的细胞株,检测不同化合物对于荧光FRET效率的影响,可以建立MyD88 TIR二聚化抑制药物的筛选模型．此外,我们构建了原核表达质粒,利用纯化的His-MyD88 TIR分别与GST或GST-MyD88 TIR蛋白进行体外结合实验,发现GST-MyD88 TIR(而非GST)可以与His-MyD88 TIR相互结合．结果的差异性提示,利用His-MyD88 TIR和GST-MyD88 TIR体外结合实验分析,可以进一步确定抑制物是否直接阻断了TIR的相互作用．结合真核细胞的荧光FRET阻断结果和原核表达的重组蛋白相互作用分析,可确定MyD88 TIR二聚化的抑制物．利用这一模型可以对商品化的小分子库、自行制备的天然产物组分进行广泛的筛选,从中获得有效抑制MyD88二聚化的化合物,参与对MyD88信号通路依赖的慢性炎症、自身免疫性疾病的药物治疗．     

FREUDEIA KASZAB, A NEWLY RECORDED GENUS AND A NEW SPECIES FROM CHINA (COLEOPTERA, TENEBRIONIDAE,TENTYRIINI)

报道中国鳖甲族1新纪录属及1新种:异颚弗鳖甲Freudeia heteromaxillaria sp.nov.,描述了新种的形态特征并附鉴别特征图和整体照片.新种模式标本保存于中国科学院西北高原生物研究所和河北大学博物馆.