Differential regulation of dual NADPH oxidases/peroxidases, Duox1 and Duox2, by Th1 and Th2 cytokines in respiratory tract epithelium

Partially reduced metabolites of molecular oxygen, superoxide (O2-) and hydrogen peroxide (H2O2), are detected in respiratory tract lining fluid, and it is assumed that these are key components of innate immunity. Whether these reactive oxygen species (ROS) are produced specifically by the respiratory epithelium in response to infection, or are a non-specific by-product of oxidant-producing inflammatory cells is not well characterized. Increasing evidence supports the hypothesis that the dual function NAD(P)H oxidases/peroxidases, Duox1 and Duox2, are important sources of regulated H2O2 production in respiratory tract epithelium. However, no studies to date have characterized the regulation of Duox gene expression. Accordingly, we examined Duox1 and Duox2 mRNA expression by real-time PCR in primary respiratory tract epithelial cultures after treatment with multiple cytokines. Herein, we determined that Duox1 expression was increased several-fold by treatment with the Th2 cytokines IL-4 and IL-13, whereas Duox2 expression was highly induced following treatment with the Th1 cytokine IFN-gamma. Duox2 expression was also elevated by polyinosine-polycytidylic acid (poly(I:C)) and rhinovirus infection. Diphenyleneiodonium (DPI)-inhibitable apical H2O2 production was similarly increased by the addition of Th1 or Th2 cytokines. These results demonstrate for the first time the regulation of Duox expression by immunomodulatory Th1 and Th2 cytokines, and suggest a mechanism by which ROS production can be regulated in the respiratory tract as part of the host defense response.     

Brain development in mice lacking L1-L1 homophilic adhesion

A new mouse line has been produced in which the sixth Ig domain of the L1 cell adhesion molecule has been deleted. Despite the rather large deletion, L1 expression is preserved at normal levels. In vitro experiments showed that L1-L1 homophilic binding was lost, along with L1-alpha5beta1 integrin binding. However, L1-neurocan and L1-neuropilin binding were preserved and sema3a responses were intact. Surprisingly, many of the axon guidance defects present in the L1 knockout mice, such as abnormal corticospinal tract and corpus callosum, were not observed. Nonetheless, when backcrossed on the C57BL/6 strain, a severe hydrocephalus was observed and after several generations, became an embryonic lethal. These results imply that L1 binding to L1, TAG-1, or F3, and L1-alpha5beta1 integrin binding are not essential for normal development of a variety of axon pathways, and suggest that L1-L1 homophilic binding is important in the production of X-linked hydrocephalus.     

以儿童呼吸道感染为主的非典型EBV感染报道

目的报道儿童EBV感染所致的临床疾病谱与年龄特点,以进一步提高对EBV感染诊治水平.方法回顾性分析了EBV-VCA-IgM或EBV-DNA-PCR诊断的690例儿童EBV感染的疾病分布和年龄分布特点.结果EBV感染儿童非典型传染性单核细胞增多症患儿422例,占61.16%,非典型EBV感染268例,占38.84%.非典型EBV感染中以呼吸道感染最为多见,为191例,占非典型EBV感染的71.27%.其他为皮炎或口炎、血小板减少性紫癜、腹泻病、川畸病、肠系膜或颈淋巴结炎、肾炎或肾病和CNS感染等.EBV感染致传染性单核细胞增多症和呼吸道感染在各年龄组的分布差异无显著性,EBV感染男女比为1.79：1.结论儿童EBV感染所致疾病多样,累及系统多,非典型表现以呼吸道感染为主.传染性单核细胞增多症和呼吸道感染在各年龄组间差异无显著性.     

光肩星天牛体内纤维素酶活性及其与寄主选择的关系（英文）

为了揭示光肩星天牛Anoplophora glabripennis Motschulsky纤维素酶与寄主选择的关系, 以4种不同寄主树种（新疆杨Populus alba var. pyramidalis Bunge、箭杆杨Populus nigra var. thevestina (Dode) Bean、合作杨Populus simonii × Populus pyramidalis cv. opera Hsu和漳河柳Salix matsudana f. lobato-glandulosa Faug et Liu来源的光肩星天牛幼虫, 和以取食5种不同树种（臭椿Ailanthus altissima、毛白杨Populus tomentosa、合作杨、旱柳Salix matsudana Koidz.和复叶槭Acer negundo Linn.）的光肩星天牛成虫为实验对象, 测定其纤维素酶活性。结果表明: 不同寄主来源的光肩星天牛幼虫内切-β-1,4-葡聚糖酶活性在1.36~2.71 μmol葡萄糖/ (g FW·h)之间, β-葡萄糖苷酶活性在2.57~4.86 μmol葡萄糖/(g FW·h)之间;取食不同树种的光肩星天牛成虫内切-β-1,4-葡聚糖酶活性在4.08~9.27 μmol葡萄糖/(g FW·h)之间, β-葡萄糖苷酶活性在2.87~6.08 μmol葡萄糖/ (g FW·h)之间。不同寄主树种来源的光肩星天牛幼虫体内纤维素酶活性无显著性差异, 取食与否以及取食树种的不同对光肩星天牛成虫纤维素酶活有较大影响。     

Nutritional composition and digestibility by ocelots (Leopardus pardalis) of whole animals and a commercial diet

Felids are adapted to eat whole prey, but in North American zoos are usually fed processed diets based on muscle meat. We analyzed proximate nutrient composition and digestibility by ocelots of a commercial processed diet and whole animals of five species. The processed diet did not differ significantly from the whole animals in proximate composition, although it was at one end of the range of results for all nutrients. Domestic chicks were significantly lower than all other dietary items tested in digestibility of energy and fat, and lower than rabbits and quail in digestibility of dry matter. There were no other significant differences. These results suggest that the commercial diet tested provides an appropriate nutritional environment for ocelots with respect to proximate constituents. Studies of vitamin and mineral composition and digestibility and comparisons to wild prey species should be conducted to permit a full evaluation. Zoo Biol 29:753–759, 2010. © 2009 Wiley‐Liss, Inc.     

泌尿道感染动物模型制作研究现状

建立与人类泌尿道感染相似的可靠动物模型,对探讨泌尿道感染发病机制和研究治疗方法十分必要。本文介绍了急性肾盂肾炎,慢性肾盂肾炎,腺性膀胱炎等泌尿道感染模型制作研究现状,并从菌种,品系等角度进行探讨。     

儿童泌尿系感染的病原学分析

探讨目前儿童泌尿系感染病原体的变化趋势,为临床治疗提供实验依据。分析2008年1月至2009年10月住院治疗的357例尿细菌培养、支原体体外培养、衣原体检测阳性的泌尿系感染患儿病原体的分布情况。结果显示,尿细菌培养和支原体体外培养、衣原体检测前未应用过抗生素的患儿其阳性率为82.2%,而应用过抗生素的患儿其阳性率为31.8%,两者相比具有统计学意义(P0.01)。在检测的357例阳性标本中,革兰阴性杆菌占74.7%,其中以大肠埃希菌为主,占46.2%;革兰阳性球菌占14.8%,其中肠球菌占10.9%;真菌占3.1%,支原体占4.8%,衣原体占2.5%。临床要密切关注儿童泌尿系感染病原体的分布变迁情况,以便于为临床的诊断和治疗提供可靠的实验依据。     

Interactions between PTB RRMs Induce Slow Motions and Increase RNA Binding Affinity

Polypyrimidine tract binding protein (PTB) participates in a variety of functions in eukaryotic cells, including alternative splicing, mRNA stabilization, and internal ribosomal entry site-mediated translation initiation. Its mechanism of RNA recognition is determined in part by the novel geometry of its two C-terminal RNA recognition motifs (RRM3 and RRM4), which interact with each other to form a stable complex (PTB1:34). This complex itself is unusual among RRMs, suggesting that it performs a specific function for the protein. In order to understand the advantage it provides to PTB, the fundamental properties of PTB1:34 are examined here as a comparative study of the complex and its two constituent RRMs. Both RRM3 and RRM4 adopt folded structures that NMR data show to be similar to their structure in PRB1:34. The RNA binding properties of the domains differ dramatically. The affinity of each separate RRM for polypyrimidine tracts is far weaker than that of PTB1:34, and simply mixing the two RRMs does not create an equivalent binding platform. ¹⁵N NMR relaxation experiments show that PTB1:34 has slow, microsecond motions throughout both RRMs including the interdomain linker. This is in contrast to the individual domains, RRM3 and RRM4, where only a few backbone amides are flexible on this time scale. The slow backbone dynamics of PTB1:34, induced by packing of RRM3 and RRM4, could be essential for high-affinity binding to a flexible polypyrimidine tract RNA and also provide entropic compensation for its own formation.