实验动物屏障系统微生物动态状况

目的研究运行中的实验动物屏障系统微生物的情况。方法采用沉降菌法、棉拭子法等方法,研究运行中的屏障系统不同区域、不同环境指标下屏障系统内微生物的状况。结果动态下的屏障系统微生物情况与国标GB14925-2001中静态环境有较大不同,动物饲养室和动物实验室沉降菌浓度远高于静态要求;辅助区域在规范化消毒及严格管理的情况下,能达到国标要求。屏障系统的微生物情况存在一定的昼夜变化规律,在晚间出现峰值。结论合适的换气次数可有效控制实验动物屏障系统的沉降菌浓度;加强消毒及硬件的管理,是屏障系统内环境稳定的保障。     

长爪沙鼠高胆固醇血症模型的建立与辛伐他汀的作用

目的探索长爪沙鼠高胆固醇血症模型建立及辛伐他汀的影响。方法在饲喂长爪沙鼠高脂饲料的同时给予不同浓度辛伐他汀抑制胆固醇生物合成,通过观察肝脏颜色,测量体重、肝重、TC、LDL-C及HDL-C等血脂和肝功能指标判断高脂饲料和辛伐他汀对血脂和肝脏功能的影响。结果动物体重、肝重和肝脏指数没有显著变化。高脂饲料能够促进脂肪在肝脏的沉积,但是对AST和ALT等肝脏功能指标影响不显著;辛伐他汀能够有效抑制TC、LDL-C、HDL-C、TBA和GLU的升高,但对其他指标影响不明显。结论高脂饲料能够快速建立长爪沙鼠高胆固醇血症模型;辛伐他汀能够抑制内源性胆固醇的合成从而有效抑制血浆胆固醇（TC）、LDL-C和HDL-C的升高。结果表明,特殊的反馈调节机制导致长爪沙鼠无法在大量摄入胆固醇时终止内源性胆固醇的合成。长爪沙鼠特殊的反馈调节机制可能是易发高胆固醇血症的一个主要原因。     

In-depth analysis of the human CSF proteome using protein prefractionation

The identification of disease markers in human body fluids requires an extensive and thorough analysis of its protein constituents. In the present study, we have extended our analysis of the human cerebrospinal fluid (CSF) proteome using protein prefractional followed by shotgun mass spectrometry. After the removal of abundant protein components from the mixture with the help of immunodepletion affinity chromatography, we used either anion exchange chromatography or sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) to further subfractionate the proteins present in CSFs. Each protein subfraction was enzyme digested and analyzed by tandem mass spectrometry and the resulting data evaluated using the Spectrum Mill software. Different subfractionation methods resulted in the identification of a grant total of 259 proteins in CSF from a patient with normal pressure hydrocephalus. The greatest number of protein, 240 in total, were identified after prefractionating the CSF proteins by immunodepletion and SDS-PAGE. Immuno-depletion combined with anion exchange fractionation resulted in 112 proteins and 74 proteins were found when only immunodepletion of the CSF samples was carried out. All methods used showed a significant increase in the number of identified proteins as compared with nondepleted and unfractionated CSF sample analysis, which yielded only 38 protein identifications. The present work establishes a platform for future studies aimed at a detailed comparative proteome analysis of CSFs from different groups of patients suffering from various psychiatric and neurological disorders.     

Visualization of comparative genomic analyses by BLAST score ratio

Background  

The first microbial genome sequence, Haemophilus influenzae, was published in 1995. Since then, more than 400 microbial genome sequences have been completed or commenced. This massive influx of data provides the opportunity to obtain biological insights through comparative genomics. However few tools are available for this scale of comparative analysis.     

GeneKeyDB: A lightweight,gene-centric,relational database to support data mining environments

Background  

The analysis of biological data is greatly enhanced by existing or emerging databases. Most existing databases, with few exceptions are not designed to easily support large scale computational analysis, but rather offer exclusively a web interface to the resource. We have recognized the growing need for a database which can be used successfully as a backend to computational analysis tools and pipelines. Such database should be sufficiently versatile to allow easy system integration.     

Association of alpha-amylase and the R1 protein with starch granules precedes the initiation of net starch degradation in turions of Spirodela polyrhiza

In turions of Spirodela polyrhiza (L.) Schleiden, net degradation of storage starch is controlled by a special low fluence response of phytochrome requiring illumination for several days. This light effect has been used to study protein-starch interactions that occur prior to and during net degradation of starch. Following various pretreatments on S. polyrhiza turions, native starch granules were isolated and two fractions of starch-related proteins were distinguished: proteins enclosed within the starch particles (starch-internalized proteins) and those attached to the surface (starch-associated proteins). The pattern of starch-associated proteins as resolved by SDS-PAGE was more complex than that of starch-internalized proteins and varied depending upon the pretreatment of the turions. Two starch associated proteins were identified immunochemically as alpha-amylase (EC 3.2.1.1) and the R1 protein (Lorberth et al. (1998) Nature Biotechnology 16: 473-477). Dark-pretreatment of non-dormant turions does not induce starch net degradation. Under these conditions, alpha-amylase and R1 were bound to the surface of the starch granules. Continuous illumination with red light induces a rapid degradation of starch. Within the first 24 h of illumination the level of starch-associated alpha-amylase transiently increased and subsequently decreased rapidly. Similarly, the amount of the starch-associated R1 also decreased during illumination. The dissociation of both alpha-amylase and R1 from the starch granules preceded the decrease in starch content. However, binding of the two proteins to starch granules remained unchanged when the turions did not perform net starch degradation (as observed during continuous darkness, orthophosphate deficiency, or dormancy of the turions). Thus, during net starch degradation, so far unidentified changes are postulated to occur at the surface of the starch particles that are relevant for protein binding. This conclusion was supported by in vitro studies in which the binding of purified beta-amylase (EC 3.2.1.2) to starch granules isolated from turions following various pretreatments was monitored. The enzyme did bind to starch granules prepared from dark-stored turions (in which starch degradation had not been initiated), but not to those isolated from illuminated (starch degrading) turions.