血清电解质紊乱对ICU慢性阻塞性肺疾病患者预后的影响

目的探讨血清电解质紊乱对慢性阻塞性肺疾病（COPD）预后的影响。方法将广西医科大学第一附属医院ICU2007年7月~2008年1月收治的213例慢性阻塞性肺疾病患者,按血清电解质水平分为非电解质紊乱组86例和电解质紊乱组127例,分析不同电解质水平与COPD预后之间的关系。结果两组患者年龄、性别无显著差异性,两组的住院时间、发生酸碱失衡、接受机械通气治疗时间及病死率比较差异有显著性（P〈0.05）。电解质紊乱组经治疗后,得以纠正者治疗有效率高于纠正无效者,两者差异有统计学意义。结论 COPD合并电解质紊乱较非电解质紊乱患者的住院时间及入住ICU接受机械通气治疗时间长,前者病死率较后者高。电解质紊乱可以作为判断慢性阻塞性肺疾病病情预后的指标之一。     

Large-scale profiling and identification of potential regulatory mechanisms for allelic gene expression in colorectal cancer cells

Allelic variation in gene expression is common in humans and this variation is associated with phenotypic variation. In this study, we employed high-density single nucleotide polymorphism (SNP) chips containing 13,900 exonic SNPs to identify genes with allelic gene expression in cells from colorectal cancer cell lines. We found 2 monoallelically expressed genes (ERAP2 and MYLK4), 32 genes with an allelic imbalance in their expression, and 13 genes showing allele substitution by RNA editing. Among a total of 34 allelically expressed genes in colorectal cancer cells, 15 genes (44.1%) were associated with cis-acting eQTL, indicating that large portions of allelically expressed genes are regulated by cis-acting mechanisms of gene expression. In addition, potential regulatory variants present in the proximal promoter regions of genes showing either monoallelic expression or allelic imbalance were not tightly linked with coding SNPs, which were detected with allelic gene expression. These results suggest that multiple rare variants could be involved in the cis-acting regulatory mechanism of allelic gene expression. In the comparison with allelic gene expression data from Centre d'Etude du Polymorphisme Humain (CEPH) family B cells, 12 genes showed B-cell specific allelic imbalance and 1 noncoding SNP showed colorectal cancer cell-specific allelic imbalance. In addition, different patterns of allele substitution were observed between B cells and colorectal cancer cells. Overall, our study not only indicates that allelic gene expression is common in colorectal cancer cells, but our study also provides a better understanding of allele-specific gene expression in colorectal cancer cells.     

加替沙星对小鼠肠道菌群的影响

目的 了解加替沙星正常剂量用药和非正常剂量用药方式对小鼠肠道菌群的影响.方法 24只昆明小鼠随机分为3组,每组8只,对照组只灌胃生理盐水,另外2组分别按正常剂量和正常剂量的一半给小鼠灌胃加替沙星溶液,7 d后无菌采取小鼠粪便,观察各组小鼠粪便中双歧杆菌、类杆菌、乳酸杆菌、大肠埃希菌及肠球菌数量.结果 加替沙星灌胃7 d后,与给药前相比,肠杆菌和肠球菌药敏结果无明显变化.灌胃前后肠杆菌对CIP、LEV、GAT、AM、CRO、AMK、NOR均敏感,肠球菌对AM、LEV、VA、GAT均敏感,对NOR、CIP、CRO敏感性不同.2种用药方式可导致大肠埃希菌数量显著减少(P＜0.05),肠球菌数量稍有增加(P＞0.05).而双歧杆菌、乳酸杆菌和类杆菌数量无明显变化(P＞0.05).结论 加替沙星2种用药方式短时期对肠道菌群影响不大(肠杆菌除外),不易产生耐药性.其杀灭肠杆菌的作用远大于对厌氧菌的作用.     

Inferring the parameters of the neutral theory of biodiversity using phylogenetic information and implications for tropical forests

We develop a statistical method to infer the parameters of Hubbell's neutral model of biodiversity using data on local species abundances and their phylogenetic relatedness. This method uses the approximate Bayesian computation (ABC) approach, where the data are summarized into a small number of informative summary statistics. We used three statistics: the number of species in the sample, Shannon H index of evenness and Shao and Sokal's B ₁ index of phylogenetic tree imbalance. Our approach was found to outperform previous methods, illustrating the potential of ABC methods in ecology. Applying it to four large tropical forest tree data sets, the best-fit immigration rates m were found to be two orders of magnitude smaller and regional diversities θ larger than previously reported for the same data. This implies that neutral-compatible regional pools of tropical trees should extend over continental scales, and that m measures, in this context, mostly the frequency of long-distance dispersal events.     

口腔微生态失衡导致口腔异味的研究

目的介绍口腔微生态失调与口腔疾病的关系,口腔疾病出现口腔气味异常的机制。综合分析口腔微生态与口腔健康的研究动态及意义。展望口腔微生态调整在口腔疾病治疗中的作用研究,尤其在消除口腔异昧的积极作用。方法由第一、二作者应用计算机通过pubmed检索NCBI数据库1992年至2007年相关文献,检索词为“Micro ecology”,限定语言种类为“English”;同时检索CNKI全文数据库、维普全文数据库1995年至2007年相关文献,检索词为“微生态”,限定语言种类为中文。纳入标准：文章内容与口腔微生态相关的研究、以及在口腔疾病研究领域有关。排除标准：较陈旧的文献和重复研究。结果共收集到106篇相关文献,21篇文献纳入本文,其中,19篇为综述和述评类文献,19篇为中文杂志,2篇为外文杂志。结论致病菌大量生长繁殖,口腔微生态失调,菌斑内微生物之间以及机体与菌斑之间相互作用分解蛋白产生硫化物,这些代谢产物包括H2S、CH3SH、CH3SCH3、吲哚、甲基吲哚、挥发脂肪酸和聚胺等发出刺激性气味,产生口腔异味。治疗口腔异味应该考虑平衡口腔微生态,调整口腔菌群。口腔异味的治疗又有利于口腔菌群平衡。提示我们治疗口腔疾病应该考虑口腔微生态平衡。     

四君子汤对急性肝损伤伴发菌群失调及内毒素血症的保护作用

目的　观察急性肝损伤时肠道微生态学、血内毒素含量变化及四君子汤的保护作用。方法　小白鼠腹腔注射D-氨基半乳糖( D- Ga L N) ,制备肝损伤模型,观察中药对肠道正常细菌,组织二胺氧化酶( DAO)活性,血内毒素( L PS)含量的影响及肝脏病理学影响。结果　急性肝损伤时肠杆菌、肠球菌数量明显上升,乳酸杆菌、双歧杆菌数量显著下降,DAO活性下降,L PS含量明显上升,病理学显示,肝细胞大片状、多灶性坏死,大量炎细胞浸润。而中药治疗组上述指标得到明显改善,差异有非常显著性( P<0 .0 0 1)。结论　中药四君子汤对肠道微生态失衡有调整作用,能够减少内毒素的产生和吸收,对肝脏具有保护作用     

Differential responses of cellular immunity in patients undergoing neoadjuvant therapy followed by surgery for carcinoma of the oesophagus

Background  To compare immune responses following neoadjuvant chemoradiation therapy in combination with hyperthermia plus surgery to those induced by surgery alone in patients with oesophageal cancer. Methods  Thirty-two patients with histopathologically proven oesophageal cancer, scheduled for potentially curative transhiatal or transthoracic oesophagectomy with (neo, n = 20) or without (control, n = 12) neoadjuvant thermochemoradiation therapy (ThCR) were included. Peripheral blood samples were obtained before ThCR, after 2 weeks of ThCR, 1 day before surgery, on postoperative days 1, 3, 7, and 6 weeks after surgery, for white blood cell counts, lymphocyte subsets and T helper type 1 (Th1) and type 2 (Th2) lymphocyte responses. Results  Neo patients showed a significant decrease in granulocytes and lymphocyte subsets, and T cell cytokines after 2 weeks of ThCR. Only CD8+ (cytotoxic) T cells recovered after ThCR to reach normal levels prior to surgery. In contrast, CD4+ T (helper) cells, and NK- and B cells in neo patients did not recover prior to surgery (all P < 0.05). Oesophagectomy induced a significant increase in granulocytes and a decrease in lymphocytes (and subsets). Only those subsets that had not recovered after ThCR (CD4+ T cells, NK and B cells but not CD8+ T cells), were significantly lower (all P < 0.05) during the entire postoperative study period. Postoperatively, the stimulated cytokine production capacity of Th1 and Th2 cells, corrected for number of T cells, was not significantly different between the groups. Conclusion  Neoadjuvant thermochemoradiation for oesophageal cancer caused significant disturbances of host cellular immunity with reduced T, NK and B cell counts, and differential recovery of cytotoxic and helper T cells leading to prolonged T cell imbalance that extends beyond the time of surgery. The functional and anti-tumour consequences of this immunodisturbance need further investigation, as recovery of T helper cytokine production towards surgery was less impaired than T helper cell counts.     

Effects of peptides, with emphasis on feeding, pain, and behavior A 5-year (1999-2003) review of publications in Peptides

Novel effects of naturally occurring peptides are continuing to be discovered, and their mechanisms of actions as well as interactions with other substances, organs, and systems have been elucidated. Synthetic analogs may have actions similar or antagonistic to the endogenous peptides, and both the native peptides and analogs have potential as drugs or drug targets. The journal Peptides publishes many leading articles on the structure–activity relationship of peptides as well as outstanding reviews on some families of peptides. Complementary to the reviews, here we extract information from the original papers published during the past five years in Peptides (1999–2003) to summarize the effects of different classes of peptides, their modulation by other chemicals and various pathophysiological states, and the mechanisms by which the effects are exerted. Special attention is given to peptides related to feeding, pain, and other behaviors. By presenting in condensed form the effects of peptides which are essential for systems biology, we hope that this summary of existing knowledge will encourage additional novel research to be presented in Peptides.     

Severity of chronic Chagas disease is associated with cytokine/antioxidant imbalance in chronically infected individuals

Understanding the pathogenic mechanisms in chronic Chagas disease, a major cause of morbidity and mortality in Latin America, is essential for the design of rational therapeutic strategies. In this paper we show that the development of Chagas disease is a consequence of a long-term and complex relationship between parasite persistence and maladapted homeostatic mechanisms in the host which leads to pathologic changes. We performed a retrospective study on 50 patients with chronic Chagas disease and 50 healthy control individuals. The specific immune response was detected by ELISA and IHA tests using autochthonous antigens, inflammatory process with the cytokine tumour necrosis factor (TNF)-alpha and nitric oxide (NO), and antioxidant protection with glutathione peroxidase and superoxide dismutase (SOD) levels. We developed generalised linear modelling procedures to assess simultaneously which explanatory variables and/or their interactions better explained disease severity in patients. Our results show the existence of a strong relationship between anti-Trypanosoma cruzi levels and chronic Chagas disease (P<0.0001). Taken together, the statistical data indicate both cumulative and complementary effects, where the increase in TNF-alpha (P=0.004) and NO (P=0.005) levels correlated with a reduction in glutathione peroxidase (P=0.0001) and SOD (P=0.01) levels drives the disease pathology in chronically infected patients. Our findings may have important implications for understanding host susceptibility to develop severe chronic infectious disease. In addition we show putative targets for the design of new therapeutic strategies to prevent disease progression, considering both specific treatment against the aetiological agent and modulation of the different immunopathological reactions in chronically infected individuals with chronic Chagas disease.     

中药"神曲"对肠道菌群失调小鼠调整和保护作用的观察

目的研究中药"神曲"在肠道微生态失调中的调整和保护作用.方法使用中药大黄煎剂给小鼠灌胃8 d,造成肠道菌群失调病理模型,将菌群失调小鼠分为5组模型组、自然恢复组、丽珠肠乐组、同仁堂神曲组和复方神曲组.实验动物经不同因素处理后,取结肠内容物、粪便进行菌群培养;取回肠组织进行各项病理指标的测定;取各组小鼠肝脏和结肠标本进行光镜观察.结果治疗组肠道菌群与正常对照组相比无明显变化,与自然恢复组相比差异有显著性(P＜0.05);各治疗组超氧化物歧化酶(superoxide dismutase,SOD)、丙二醛(methyl-di-alde-hyde,MDA)、黄嘌吟氧化酶(xanthine oxidase,XOD)和一氧化氮(NO)水平与正常组相比差异无显著性,与自然恢复组相比差异有显著性(P＜0.05);治疗组肝脏和结肠与正常对照组相比无明显变化,其与自然恢复组相比差异有显著性.结论中药"神曲"对肠道菌群失调动物具有调整和保护作用.