重症肺炎影响极低出生体重儿血小板及凝血功能的研究

目的:通过观察我院收治的极低出生体重新生儿肺炎的临床治疗,研究重症肺炎对该类疾病患儿的血小板及凝血功能的影响,探讨其临床研究价值.方法:将47例一般肺炎的极低出生体重新生儿设为对照组,45例重症肺炎的极低出生体重新生儿设为实验组,对比分析两组患儿的血小板参数的检测指标并行患儿凝血功能检查.结果:在血小板参数方面,实验组在MPV和PDW的数据较对照组高,而在PLT明显较低;在凝血功能方面,实验组在PT、APTT和TT等方面的数据较对照组高,而在FIB方面明显较低.结论:临床上对动态监测重症肺炎患儿血小板的变化情况,对判断该疾病患儿的预后具有积极的参考与预警意义,而对重症肺炎患儿出现凝血系统功能紊乱及时把握具体发病机制,对症进行凝血功能恢复治疗,值得临床进一步研究与探讨.     

肠道微生物对肠道屏障功能完整性的维护机制研究概况

肠道微生物群是一个稳定且复杂的生态系统,可以通过形成菌膜屏障或促进肠道上皮细胞增殖分化等方式形成保护屏障,并在肠道病原菌感染和威胁期间维持和促进免疫稳态中起积极作用。本文重点叙述宿主-肠道微生物相互作用过程中抗病原菌感染的方式,以及肠道微生物参与合成抗菌化合物抵御肠道病原菌入侵和威胁的机制,为调控肠道微生物解决临床胃肠道疾病及其相关症状提供理论参考依据。     

细胞色素P450酶的结构、功能与应用研究进展

细胞色素P450 (cytochrome P450,CYP)酶是广泛存在于微生物、动植物及人体中与膜结合的血红蛋白类酶,具有氧化、环氧化、羟化、去甲基化等多种生物催化活性。CYP酶在药物、类固醇、脂溶性维生素和许多其他类型化学物质的代谢中具有重要作用,其在异源物质的解毒、药物相互作用和内分泌功能等领域的研究是热点问题。本综述对CYP的结构、功能、临床应用与开发前景进行了概述,并对其最新的研究现状和发展前景进行探讨。     

猪流行性腹泻病毒经其附属蛋白抑制细胞凋亡

【背景】orf3位于猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV) s基因与e基因之间,是目前发现的PEDV唯一一个附属基因,编码附属蛋白(ORF3蛋白)。我们前期研究初步发现ORF3蛋白对PEDV诱导的细胞凋亡有影响。【目的】研究ORF3蛋白在PEDV侵染复制过程中的毒力作用机制。【方法】实验用3种PEDV:rDR13att-?ORF3 (orf3基因全部敲除)、DR13-ORF3att (携带有C端截短orf3)、rDR13att-ORF3wt(携带全长orf3基因)感染Vero细胞,观察病变情况,再用活细胞成像仪、流式细胞仪、 DNA断裂的原位末端标记法[terminaldeoxynucleotidyltransferase(TDT)-mediated dUTP nick end labeling,TUNEL]等方法检测不同感染时间点的细胞凋亡情况,然后用蛋白质印迹方法分析PEDV感染宿主细胞中主要凋亡相关蛋白(如Caspase-3)的活化或裂解,最后进行转录组测序研究病毒感染细胞中差异基因的表达情况,再用荧光定量PCR验证转录组结果。【结果】rDR13att-?ORF3引起较多的细胞病变,活细胞成像仪的动态观察结果显示,3种病毒侵染的细胞凋亡水平随着时间的延长均高于正常阴性细胞,但敲除orf3的病毒感染细胞后细胞凋亡率比其他两种病毒更高;敲除orf3病毒感染细胞凋亡率显著高于其他两种病毒;病毒rDR13att-?ORF3感染细胞后TUNEL阳性细胞数比DR13-ORF3att和rDR13att-ORF3wt更多;表达ORF3蛋白的重组PEDV可以抑制Caspase-3的活化;ORF3蛋白对受感染细胞Heat shock 70 kD protein 1B (HSP70)基因转录有促进作用,荧光定量PCR结果表明rDR13att-ORF3wt感染细胞的HSP70表达量高于rDR13att-?ORF3感染细胞。【结论】PEDV通过ORF3蛋白抑制细胞凋亡,而且这种作用可能是通过抑制Caspase-3的活化或增加HSP70的产生来完成的。     

微生物降解石油烃的功能基因研究进展

微生物对石油烃的降解在自然衰减去除土壤和地下水石油烃污染的过程中发挥了重要作用。微生物通过其产生的一系列酶来利用和降解这类有机污染物,其中,编码关键降解酶的基因称为功能基因。功能基因可作为生物标志物用于分析环境中石油烃降解基因的多样性。因此,研究石油降解功能基因是分析土著微生物群落多样性、评价自然衰减潜力与构建基因工程菌的重要基础。本文主要介绍了烷烃和芳香烃在有氧和无氧条件下的微生物降解途径,重点总结了烷烃和芳香烃降解的主要功能基因及其作用,包括参与羟化作用的单加氧酶和双加氧酶基因、延胡索酸加成反应的琥珀酸合酶基因以及中心中间产物的降解酶基因等。     

Late Miocene Erinaceinae from the Teruel Basin (Spain)

Classifying fossil teeth of Erinaceinae (spiny hedgehogs) is a challenging task, because of their scanty record and systematic treatment that heavily relies on skull characteristics. In this paper we describe the complete set of isolated dental elements of Erinaceinae from the upper Miocene sediments of the Teruel Basin (eastern Central Spain). Four different species were recognized: Postpalerinaceus cf. vireti, Atelerix aff. depereti, Atelerix steensmai nov. sp., and a form classified as Erinaceinae genus and species indet. All four are relatively derived in showing multi-purpose dentitions, not showing only adaptations to insectivory, but also to carnivory, herbivory and possibly durophagy/malacophagy. The temporal occurrence of spiny hedgehogs during the middle to late Miocene in the Teruel Basin and neighboring Calatayud-Montalbán Basin peaks within periods of relative aridity, a correlation consistent with modern geographic distribution. Messinian cooling is the best candidate for explaining a remarkable demise of Erinaceinae at 7 Ma.     

A disintegrin and metalloproteinase-12 (ADAM12): Function,roles in disease progression,and clinical implications

Background

A disintegrin and metalloproteinase-12 (ADAM12) is a member of the greater ADAM family of enzymes: these are multifunctional, generally membrane-bound, zinc proteases for which there are forty genes known (21 of these appearing in humans). ADAM12 has been implicated in the pathogenesis of various cancers, liver fibrogenesis, hypertension, and asthma, and its elevation or decrease in human serum has been linked to these and other physiological/pathological conditions.

Scope

In this review, we begin with a brief overview of the ADAM family of enzymes and protein structure. We then discuss the role of ADAM12 in the progression and/or diagnosis of various disease conditions, and we will conclude with an exploration of currently known natural and synthetic inhibitors.

Major conclusion

ADAM12 has potential to emerge as a successful drug target, although targeting the metalloproteinase domain with any specificity will be difficult to achieve due to structural similarity between the members of the ADAM and MMP family of enzymes. Overall, more research is required to establish ADAM12 being as a highly desirable biomarker and drug target of different diseases, and their selective inhibitors as potential therapeutic agents.

General significance

Given the appearance of elevated levels of ADAM12 in various diseases, particularly breast cancer, our understanding of this enzyme both as a biomarker and a potential drug target could help make significant inroads into both early diagnosis and treatment of disease.     

A Modified Valley Restrained Monte Carlo Method to Efficiently Search the Low Energy Structures of Peptides

Abstract

A new Monte Carlo sampling scheme, namely the Modified Valley Restrained Monte Carlo procedure, is used to obtain the global energy minimum conformations for polypeptides, such as Met-enkephalin and Melittin. For each peptide, we found close agreement with previous results from both theoretical and experimental studies. The simple idea for controlling the step size according to the Valley Function, provides useful suggestions in searching the global energy minimum structures, and furthermore helps solve the multiple minima problem.     

TIME-OF-DAY EFFECTS ON THE INTERNAL SIMULATION OF MOTOR ACTIONS: PSYCHOPHYSICAL EVIDENCE FROM POINTING MOVEMENTS WITH THE DOMINANT AND NON-DOMINANT ARM

It is well known that circadian rhythms modulate human physiology and behavior at various levels. However, chronobiological data concerning mental and sensorimotor states of motor actions are still lacking in the literature. In the present study, we examined the effects of time-of-day on two important aspects of the human motor behavior: prediction and laterality. Motor prediction was experimentally investigated by means of imagined movements and laterality by comparing the difference in temporal performance between right and left arm movements. Ten healthy participants had to actually perform or to imagine performing arm-pointing movements between two targets at different hours of the day (i.e., 08:00, 11:00, 14:00, 17:00, 20:00, and 23:00?h). Executed and imagined movements were accomplished with both the right and left arm. We found that both imagined and executed arm pointing movements significantly fluctuated through the day. Furthermore, the accuracy of motor prediction, investigated by the temporal discrepancy between executed and imagined movements, was significantly better in the afternoon (i.e., 14:00, 17:00, and 20:00?h) than morning (08:00 and 11:00?h) and evening (23:00?h). Our results also revealed that laterality was not stable throughout the day. Indeed, the smallest temporal differences between the two arms appeared at 08:00 and 23:00?h, whereas the largest ones occurred at the end of the morning (11:00?h). The daily variation of motor imagery may suggest that internal predictive models are flexible entities that are continuously updated throughout the day. Likewise, the variations in temporal performance between the right and the left arm during the day may indicate a relative independence of the two body sides in terms of circadian rhythms. In general, our findings suggest that cognitive (i.e., mental imagery) and motor (i.e., laterality) states of human behavior are modulated by circadian rhythms. (Author correspondence: charalambos.papaxanthis@u-bourgogne.fr)     

Seasonal Effect on Infants' Sleep Regulation: A Preliminary Study in a Mediterranean Climate

Infants' sleep-wake rhythms are influenced by multiple factors, including developmental and contextual aspects, as well as circadian cycles. Empirical studies that address the seasonal impact on infants' sleep are scarce. The present study examined aspects of sleep schedule and quality, comparing summer and winter months in a Mediterranean climate. This report is based on a convenience sample of 34 healthy 7-mo-olds, an age in which sleep is well consolidated and regulated compared with the first few months of life. Sleep was measured with actigraphy, in the home context. It was found that compared with winter, in the summer months, sleep onset occurred at a later hour, and more motor activity during sleep was detected. Although the overall sleep quality, as defined by sleep efficiency score, was similar in the two seasons, in the summer, more active sleep was observed. The authors discuss the finding in terms of circadian rhythms, developmental characteristics, as well as possible environmental factors and family routines, and call for more studies, in different climates and geographical zones, and in different developmental periods. (Author correspondence: cohen.dini@gmail.com or anats@edu.haifa.ac.il)