Genomic approach to identification of Mycobacterium bovis diagnostic antigens in cattle

Differential delayed-type hypersensitivity skin testing with tuberculin purified protein derivatives from Mycobacterium bovis and M. avium is the standard for diagnosing bovine tuberculosis. However, improved tests based on defined, specific antigens are urgently needed. In the present study, a combination of bioinformatics, molecular biology, and bovine models of infection were used to screen mycobacterial proteins for their potential as diagnostic reagents which could be used in a whole-blood assay for diagnosis of tuberculosis. Initial screening of 28 proteins selected in silico and expressed as recombinants in Escherichia coli indicated that CFP-10, ESAT-6, TB27.4, TB16.2, TB15.8, and TB10.4 induced strong gamma interferon responses in experimentally infected cattle. A more thorough investigation over time in two groups of animals infected with a high (10(6) CFU) and a low (10(4) CFU) dose of M. bovis revealed that, for both groups, the strength of the in vitro response to individual antigens varied greatly over time. However, combining the results for ESAT-6, CFP-10, and TB27.4, possibly supplemented with TB10.4, gave sensitivities at different infection stages close to those obtained with M. bovis purified protein derivative. Importantly, while responsiveness to ESAT-6 and CFP-10 correlated strongly for individual samples, the same was not the case for ESAT-6 and TB27.4 responsiveness. The results suggest that combinations of specific antigens such as these have great potential in development of optimized diagnostic systems for bovine tuberculosis.     

Characterization of antimicrobial resistance among Escherichia coli O111 isolates of animal and human origin

Fifty isolates of Escherichia coli serogroup O111 recovered from humans and various animal species over a 24-year period (1976-1999) were examined for typical virulence-associated factors and susceptibilities to antimicrobials of human and veterinary significance. Nine H (flagellar) types were identified including nonmotile (n = 24), 32 (n = 12), negative (n = 5), and 56 (n = 3). Thirty-five (70%) isolates possessed at least one Shiga-toxin-producing E. coli (STEC)-associated virulence determinants (eae, stxl, stx2, hlyA) via PCR analysis. Of these 35 isolates, 20 possessed eae, stxl, and hlyA genes, whereas three isolates possessed eae, stxl, stx2, and hylA genes. Multiple antibiotic resistance was observed in 70% of the 50 E. coli O111 isolates. The majority of isolates displayed resistance to streptomycin, sulfamethoxazole, tetracycline, and kanamycin. Bacterial resistance to ampicillin, gentamicin, chloramphenicol, trimethoprim and apramycin was also observed. Integrons were identified in 23 (46%) of the E. coli isolates assayed, with a 1-kb amplicon being most frequently observed. DNA sequencing of these integrons revealed the presence of the aadA gene, encoding resistance to streptomycin. Two integrons of 1.5 and 2 kb contained the aadA2 and either dfrI or dfrXII genes, encoding resistance to streptomycin and trimethoprim, respectively. Integrons were also identified from isolates dating back to 1982. Isolates were further genetically characterized via ribotyping, which identified 15 distinct ribogroups, with 62% of isolates clustering into four major ribogroups. Certain riboprint patterns from different animal species, including humans, were observed in isolates spanning the 24-year collection period, suggesting the dissemination of specialized pathogenic O111 clones.     

中国胰岛素依赖性糖尿病病人（HLA－DR9）的HLA－DQB1基因顺序分析

用血清学方法研究显示中国人胰岛素依赖性糖尿病（ＩＤＤＭ）与ＨＬＡ－ＤＲ９相关。鉴于白种人中的研究显示ＩＤＤＭ与ＨＬＡ－ＤＱβ链第５７位氨基酸相关，Ａｓｐ－５７对ＩＤＤＭ呈抗性，ｎｏｎ－Ａｓｐ与ＩＤＤＭ易感性相关。我们用ＰＣＲ技术扩增了中国人中血清学ＤＲ９纯合的ＩＤＤＭ患者和正常对照的ＨＬＡ－ＤＱＢ１基因第二外显子并测定了核苷酸顺序，结果未发现ＩＤＤＭ特异ＨＬＡ－ＤＱＢ１等位基因，但发现ＩＤＤＭ病人ＨＬＡ－ＤＱＢ１５７位均为天冬氨酸。表明中国ＩＤＤＭ患者中的ＨＬＡ－ＤＱＢ１５７位天冬氨酸不一定具有保护个体抵抗ＩＤＤＭ的足够能力。ＩＤＤＭ易感性可能涉及多个基因位点的变化，另外还可能与其它遗传因素及环境因素有关。     

北京市新入监罪犯人格特点及心理卫生状况

目的:调查新入监罪犯的人格特点及心理卫生状况.方法:采用人格诊断问卷(PDQ-4 )、症状自评量表(SCL-90)和Zung氏抑郁自评量表(SDS)对1,511名新入监罪犯进行测试,并进行相关分析.结果:罪犯的PDQ-4 总分明显高于常模,暴力和财产犯罪者的反社会型和攻击型得分高于性犯罪者(P<0.01);暴力和性犯罪者的表演型得分高于财产犯罪者;而财产和性犯罪者的回避型、强迫型和被动攻击型的得分高于暴力犯罪者,差异均有统计学显著意义(P<0.05).所有罪犯的SCL-90总分和各因子分,SDS总分均明显高于正常人群.结论:新入监罪犯的心理问题较为严重,人格缺陷较为突出.     

Comparison of ethanol versus formalin fixation on preservation of histology and RNA in laser capture microdissected brain tissues

Although RNA can be retrieved from formalin-fixed, paraffin-embedded (FFPE) tissues, the yield is low, and the RNA is fragmented. Recent advances in gene expression profiling underscore the importance of identifying a fixative that preserves histology and mRNA. We demonstrated that, for immersion fixation of brains, 70% ethanol is superior to formalin for mRNA preservation. RNA yield from ethanol-fixed tissues was 70% of the yield from fresh frozen specimens, but only a negligible quantity was recovered from formalin-fixed tissues. RNA from ethanol-fixed brains showed integrity comparable to RNA from fresh frozen tissues, and RT-PCR using RNA from ethanol-fixed tissues was consistently successful. RNA from FFPE tissues composed of low-molecular weight fragments, and their use in RT-PCR failed repeatedly. The yield and quality of RNA from ethanol-fixed brains were unaffected after immersion at 4 degrees C for 2 weeks. In a blinded comparison to FFPE tissues, ethanol-fixed specimens were judged to show comparable histology and superior immunostaining. After laser capture microdissection (LCM), we failed to recover mRNA from FFPE tissues but retrieved mRNA from ethanol-fixed tissues for RT-PCR and cDNA microarray analysis. We conclude that 70% ethanol preserves RNA integrity and is suitable for expression profiling of brain tissues by LCM and cDNA microarray.     

Progressive decrease of proinsulin secretion in sulphonylurea-treated type 2 diabetes

Progressive deterioration of beta-cell function is proposed as a disease-related factor of sulphonylurea (SU) failure in type 2 diabetes. If it gradually worsens over time then disease duration may mirror the progressive beta-cell deterioration. The aim of the present study is to assess whether or not disease duration is influential in remodelling the secretion pattern of insulin-like molecules and in glucose control of SU-treated type 2 diabetes. A research model is used to investigate proinsulin secreting capacity over time, using two groups of patients: i) disease duration <5 years (n=62), comprising SU responders (SUr; n=48) and SU failures (SUf; n=14); and ii) disease duration > or = 5 years (n= 37), comprising an SUr group (n=17) and an SUf group (n=20). Blood samples are taken at 0 h, 0.5 h 1 h, 2 h and 3 h during a standard oral glucose tolerance test and measured for glucose, total proinsulin (TPI), intact proinsulin (IPI) and specific insulin (SI) concentrations. Pairwise comparison of estimated marginal means of blood glucose, SI, IPI and TPI levels at each time point are carried out between groups and subgroups. (SUr vs. SUf). Homa insulin resistance index (IR index) is applied to analyse IR between the groups. It was found that patients with shorter disease duration had higher proinsulin (TPI and IPI) levels at all time points (P<0.05), together with a lower glucose level at 2 h and 3 h (P<0.05). Homa insulin index analysis showed no difference between the two groups (P=0.26). Results also showed that the SUr group had a significantly lower glucose level at Oh and 3h (P<0.05), although no significant difference in insulin and proinsulin levels was found between the SUr and SUf groups. In conclusion, proinsulin may play an important role in glucose control in SU-treated type 2 diabetes, but the effect is reduced in SUf patients.     

Two patients with chromosome 6q terminal deletions with breakpoints at q24.3 and q25.3.

We report on 2 patients with de novo terminal deletion of 6q. The first was a 4-month-old boy whose karyotype was 46,XY,del(6)(q24.3); the second a 2-year-old girl whose karyotype was 46, XX, del(6)(q25.3). The main anomalies in both patients included mental retardation, minor craniofacial and cerebral anomalies, and cardiac defects. The characteristic manifestations were imperforate anus in the first patient, and retinitis proliferans and a triatrial heart in the other. Comparison of clinical findings of our 2 patients with those of 18 previously reported patients with similar phenotypes suggests that terminal deletion of the 6q23 or 6q25 band is critical in producing the main anomalies of del(6q) syndrome.     

Characterization of a neurotoxigenic Clostridium butyricum strain isolated from the food implicated in an outbreak of food-borne type E botulism.

Neurotoxigenic Clostridium butyricum was isolated from the food implicated in an outbreak of clinically diagnosed type E botulism in China. PCR assay showed that the isolate (LCL 155) contained the type E botulinum toxin gene. This appears to be the first report of neurotoxigenic C. butyricum causing food-borne botulism.     

GDNF-induced seminomatous tumours in mouse--an experimental model for human seminomas?

Glial-cell-line-derived neurotrophic factor (GDNF) is a distant member of the transforming growth factor superfamily. It binds to and activates a receptor complex consisting of GFR-alpha1 and Ret receptor tyrosine kinase. In testis, GDNF is expressed by Sertoli cells. We have shown by transgenic loss- and gain-of-function mouse models that GDNF regulates the cell fate decision of undifferentiated spermatogonia. In the GDNF +/- mice, the spermatogonia differentiate in excess leading to the depletion of germ cells. In the mice overexpressing GDNF in testes, undifferentiated spermatogonia accumulate in the tubules, no sperm is produced, and the mice are infertile. After a year, the GDNF overexpressing mice frequently (89%) develop testicular tumours, and most of them are bilateral (56%). All these tumours show the same histological pattern. They are composed of round spermatogonial/gonocytic cells with only a scant cytoplasm. The tumours are locally invasive but do not metastasise. They express germ line markers, are positive for alkaline phosphatase, and aneuploid with a triploid peak. Thus, by several histological, molecular, and histochemical characteristics, the GDNF-induced tumours mimic classical seminomas in men, but the precursor lesions are apparently different in mouse and man.     

颅脑肿瘤术后并发静脉血栓栓塞症危险因素的Meta分析

目的明确颅脑肿瘤术后患者发生静脉血栓栓塞症(VTE)的危险因素。方法检索中国知网、万方、维普、中国生物医学文献、PubMed、The Cochrane Library、Web of Science、EMbase等数据库建库至2021年11月1日颅脑肿瘤术VTE危险因素的队列研究或病例对照研究。由两名研究人员独立进行文献筛选、资料提取以及文献质量评价。使用RevMan 5.4软件对纳入文献进行Meta分析。结果共纳入14篇文献,合计样本量40 552例,发生VTE1 801例。Meta分析结果显示,年龄＞45岁、术前D-二聚体升高、肥胖、女性、术前日常生活活动能力处于依赖状态、术前呼吸机依赖、术前曾患脓毒血症、高级神经胶质瘤、手术时间＞3.05 h、术后D-二聚体升高、术后下肢运动功能障碍、术后卧床不起、术后并发尿路感染为颅脑肿瘤术后患者发生VTE的危险因素。结论颅脑肿瘤术后VTE发生与多种因素有关。建议构建颅脑肿瘤术后VTE风险预测模型,关注高风险人群,落实规范化静脉血栓风险评估,注重血栓评估过程管控。