Vanadium toxicity in the thymic development

The purpose of this study was to define the toxic effects of vanadium on thymic development in broilers fed on diets supplemented with 0, 5, 15, 30, 45 and 60 mg/kg of vanadium for 42 days. We examined the changes of relative weight, cell cycle phase, apoptotic cells, and protein expression of Bcl-2, Bax, and caspase-3 in the thymus by the methods of flow cytometry, TUNEL (terminal-deoxynucleotidyl transferase mediated nick end labeling) and immunohistochemistry. The results showed that dietary high vanadium (30mg/kg, 45mg/kg and 60mg/kg) caused the toxic effects on thymic development, which was characterized by decreasing relative weight, increasing G₀/G₁ phase (a prolonged nondividing state), reducing S phase (DNA replication) and proliferating index (PI), and increasing percentages of apoptotic thymocytes. Concurrently, the protein expression levels of Bax and caspase-3 were increased, and protein expression levels of Bcl-2 were decreased. The thymic development suppression caused by dietary high vanadium further leads to inhibitive effects on T lymphocyte maturity and activity, and cellular immune function. The above-mentioned results provide new evidences for further understanding the vanadium immunotoxicity. In contrast, dietary 5 mg/kg vanadium promoted the thymic development by increasing relative weight, decreasing G₀/G₁ phase, increasing S phase and PI, and reducing percentages of apoptotic thymocytes when compared to the control group and high vanadium groups.     

Hepatitis B virus core antigen as a carrier for Chlamydia trachomatis MOMP multi-epitope peptide enhances protection against genital chlamydial infection

Chlamydia trachomatis (Ct) is the leading cause of sexually transmitted diseases worldwide. There is no safe and effective vaccine to control the spread of Ct. In development of Ct vaccine, selection of appropriate candidate antigens and an effective delivery system may be the main challenges. Multi-epitope of major outer membrane protein (MOMPm) is the most suitable candidate for a Ct vaccine, while hepatitis B virus core antigen (HBcAg) has unique advantages as vaccine delivery system. Therefore, in this study, we evaluated the immunogenicity and protective immune response of a novel candidate vaccine in a murine model of chlamydial genital infection. This candidate vaccine comprises MOMPm peptide delivered with HBcAg. Our results of Ct-specific serum IgG and secretory IgA assay, cytokine assay, and cytotoxic T-lymphocyte assay revealed that immunogenicity of the candidate vaccine was much better than that of the corresponding synthetic MOMPm peptide. Furthermore, the protective effect of the candidate vaccine was also shown much better than that of the synthetic peptide by calculating the isolation of Chlamydia from vaginal swabs and histopathological analysis. Taken together, our results indicate that HBcAg carrying Ct MOMPm could be an effective immune prophylactic for chlamydial infection.     

GB virus type C E2 protein inhibits human immunodeficiency virus type 1 Gag assembly by downregulating human ADP-ribosylation factor 1

GB virus type C (GBV-C) glycoprotein E2 protein disrupts HIV-1 assembly and release by inhibiting Gag plasma membrane targeting, however the mechanism by which the GBV-C E2 inhibits Gag trafficking remains unclear. In the present study, we identified ADP-ribosylation factor 1 (ARF1) contributed to the inhibitory effect of GBV-C E2 on HIV-1 Gag membrane targeting. Expression of GBV-C E2 decreased ARF1 expression in a proteasomal degradation-dependent manner. The restoration of ARF1 expression rescued the HIV-1 Gag processing and membrane targeting defect imposed by GBV-C E2. In addition, GBV-C E2 expression also altered Golgi morphology and suppressed protein traffic through the secretory pathway, which are all consistent with a phenotype of disrupting the function of ARF1 protein. Thus, our results indicate that GBV-C E2 inhibits HIV-1 assembly and release by decreasing ARF1, and may provide insights regarding GBV-C E2''s potential for a new therapeutic approach for treating HIV-1.     

神经内科病房环境的微生物学特征与患者感染的关系

目的 了解神经内科感染患者与其病房环境微生物学特征,进一步分析两者之间的关系.方法 选取2009年4月-2010年9月神经内科住院患者中发生感染的110例作为研究对象,于感染发生＜24 h对其病房环境标本和感染部位标本进行采集、培养、菌种鉴定及药敏试验.结果 病房标本中病原菌主要为革兰阳性菌伴有少量革兰阴性杆菌,以藤黄微球菌、表皮葡萄球菌、枯草芽胞杆菌黑色变种芽胞较为常见,感染患者标本中检出19种病原菌,主要为革兰阴性杆菌和革兰阳性球菌,以肺炎克雷伯菌、铜绿假单胞菌、金黄色葡萄球菌较为常见,病房环境与患者感染病原菌种类分布比较,差异无统计学意义.结论 神经内科病房环境与感染患者的菌种分布具有相对一致性,病房环境是患者发生感染的重要感染源.     

医务人员工作服病原菌调查

目的 了解医务人员工作服的病原菌污染情况,提出医务人员工作服的管理措施,加强医务人员医院感染预防控制意识.方法 采集医院7个科室医师及护士工作服共182件,在袖口部进行病原菌污染检测.结果 被检工作服均受病原菌污染,以微球菌属所占比例最高,其次是凝固酶阴性葡萄球菌,未检出金黄色葡萄球菌,科室以急诊科污染最严重,其次是呼吸内科,以ICU最轻微;工作服穿着3d后,袖端平均含菌量为3.6 CFU/cm2,有7.7％的工作服含菌量超标,穿着7d平均含菌量为6.2 CFU/cm2,有19.2％超标,穿着14 d平均含菌量＞13.0CFU/cm2,有60.0％超标.结论 工作服袖口污染严重,医务人员要加强工作服换洗意识;医院总体上可以实行一周换洗1次的制度,但重点科室及个别污染严重的科室需要缩短周期;各个科室要做好消毒隔离等措施,要保持通风;医院需要加强医务人员工作服的清洁及消毒的管理,杜绝医院感染的发生.     

Thyroid function and related hepatic enzymes in the germfree rat

The adult germfree rat has a low metabolic rate, and the activity of various hepatic enzymes differs substantially from values found in the conventional animal. To promote understanding of the shifts in intermediary metabolism apparent in the germfree rodent, parameters of thyroid function and the activity of three enzyme systems presumably influenced by thyroid function were determined in 40-, 60-, and 100-day-old male germfree and conventional Lobund rats of Wistar origin.Serum thyroxine concentrations generally increased with age. They were below normal levels in 40- and 60-day-old germfree rats but appeared normal in the 100-day-old germfree animal. Serum thyroxine-binding protein saturation levels were significantly reduced in germfree rats of all age groups, but the reduction was least in the 100-day-old group.Mitochondrial succinate oxidase and α-glycerophosphate dehydrogenase activities were lower in livers of germfree rats of all age groups, although the significance of the difference in succinic oxidase activity became less in older animals. Monoamine oxidase activity was similar in germfree and conventional animals.Although the data suggest a hypofunction of the thyroid in the immature germfree rat, no definite relation between thyroid function and the characteristic metabolic anomalies of the germfree rat could be established.     

肠缺血再灌注时肠道菌群变化及胃肠多肽的作用

目的探讨肠缺血再灌注(IIR)后猕猴肠道菌群变化的原因。方法将10只健康成年猕猴分为对照组和IIR组,每组各5只。IIR组肠系膜上动脉夹闭60 min,松解再灌注24 h,造成缺血再灌注损伤。对照组行假手术。观察动物肠道大体形态改变,测定胃pH值;细菌培养分析回肠菌群的变化;免疫组化定位测定回肠局部胃肠多肽的分布,并用放射免疫分析法定量测定其水平变化,并在体外将胃肠多肽与肠道细菌共向孵育,观察两者有无相互作用。结果猕猴IIR损伤后,回肠内细菌较正常增加约106倍,以大肠杆菌等需氧菌为优势菌群;小肠明显充血扩张;胃内pH值由2.80±0.84增至7.20±0.84,伴有胆汁反流;全回肠组织中胃肠多肽(生长抑素、血管活性肠肽、P物质)明显增加,而黏膜中生长抑素及血管活性肠肽的浓度却减少;胃肠多肽与肠道细菌共同培养后,胃肠多肽的含量及细菌数量均无明显变化。结论猕猴IIR后,小肠细菌过度生长可能由小肠动力降低直接或间接导致。小肠肌间神经丛中的生长抑素及血管活性肠肽增加可能是此刻小肠动力降低的启动因素。     

Microbiologic Findings in Relation to Risk Assessment for Periodontal Disease: A Cross‐Sectional Study

Background: In this study, an association between a computerized risk calculator and microbiologic testing is examined in patients with periodontitis. Methods: Seventy‐four patients with moderate and severe periodontitis were selected from patients receiving treatment at Tufts University School of Dental Medicine. Their periodontal risk was analyzed with a periodontitis risk assessment tool, and microbiologic testing was performed. Periodontitis risk assessment and microbiologic testing were examined for a possible association. The data were evaluated by the χ² test at P <0.05 levels. Results: Forty‐six patients scored as having a “very high” risk of periodontitis and 22 patients scored as having a “high” risk of periodontitis by the risk assessment tool. Patients with a risk score of very high risk showed a higher detection of each bacterium except Capnocytophaga species than the rest of the study population. Treponema denticola and Prevotella intermedia (P = 0.01 and P = 0.02, respectively) were two bacteria that showed a statistically significant difference between patients at very high risk and those at high risk. Conclusions: Patients with periodontitis were identified as high risk and very high risk compared with the rest of the risk categories by the risk assessment tool. The study population, categorized mostly as very high risk, showed high detection of putative periodontal bacteria.     

T lymphocyte abnormalities in disseminated histoplasmosis

Disseminated histoplasmosis is associated with depression of T cell-mediated immunity and in some cases anergy. In this report, two patients with disseminated disease are described. Both had a depression of T cell-mediated immunity as well as other abnormalities of immune response. In one, a patient with relapse, a marked depression in the ratio of T helper to T suppressor cells was noted. Neither patient had any predisposing condition known to be associated with disseminated disease.