结核感染T细胞斑点试验在结核诊断与筛查中的价值

目的 探讨结核感染T细胞斑点试验(T-SPOT.TB)在结核诊断与筛查中的价值.方法 对2013年1月至2016年12月在南通市第一人民医院就诊的266个患者分为结核组、非结核组及生物制剂组,抽取静脉血应用结核感染T细胞斑点试验进行检测,同时部分患者进行了结核菌素检测.结果 T-SPOT.TB法诊断TB患者的敏感度为87.9％,阳性预测价值和阴性预测价值分别是43.2％和88.5％,TB组T-SPOT.TB检测阳性率明显高于非TB组(P ＜0.001)和生物制剂组(P＜0.001)的阳性率.而TST试验结果中,TB组阳性率与非TB组、非TB组阳性率与生物制剂组差异均没有统计学意义(P＞0.05),而TB组阳性率与生物制剂组差异有统计学意义(P＜0.05).在所有受试者T-SPOT.TB检测和TST试验的一致性为70.3％(K =0.397),生物制剂组中两者一致性为59.5％ (K=0.313).在TB组和非TB组中,两种方法一致性更高,分别为83.7％(K=0.486)和77.1％ (K=0.437).T-SPOT.TB法中TB组的斑点数显著高于非TB组(P ＜0.001)和生物制剂组(P＜0.001),而非TB组和生物制剂组的斑点数差异没有统计学意义(P＞0.05).结论 T-SPOT.TB检测比结核菌素试验有更高的灵敏度及阴性预测价值,并且不受环境分枝杆菌和BCG接种的影响,使得T-SPOT.TB在结核感染的诊断与筛查中具有较好的临床应用价值.     

结核感染T细胞斑点试验与肺部CT表现的相关性

目的:探讨活动性肺结核患者结核感染T细胞斑点试验（T-SPOT.TB）数值测定与高分辨CT（HRCT）征象评分的相 关性。方法:回顾分析52例肺结核患者,对其外周血液标本进行T-SPOT.TB数值测定,并根据其HRCT的7种典型征象分 布及范围行对上述患者的肺部CT表现进行评分,利用结核感染T-SPOT.TB数值与HRCT征象评分进行散点图绘制,统计 学软件进行相关性分析,讨论两者有无相关性。结果:52例患者肺部HRCT评分分值分布在2~52。微结节分值最大,总 分为254,平均4.88;最小为空洞,总分10,平均0.19,分值整体上成正态分布;52 例患者T-SOPT.TB所测值A抗原孔阴性 （测得值为0~5）17例,阳性（测得值>5）35例,B孔抗原阴性（测得值为0~5）14例,阳性（测得值>5）38例,T-SPOT.TB表现为 阴性所对应的HRCT征象评分均值与阳性所对应均值对比无统计学差异（不论A孔或者B孔）;从散点图看T-SOPT.TB所 测A抗原孔及B抗原孔值与HRCT征象评分值之间存在一定相关性,利用统计学计算相关系数分别为0.27（P<0.05）和 0.17（P<0.05）,提示T-SOPT.TB测定值与HRCT征象评分为正相关性。结论:T-SOPT.TB与肺部CT所示肺结核病变范围 大小及程度有一定相关性。     

独立医学实验室的发展现状及展望

独立医学实验室将标本集中检测,形成规模,降低检验成本,达到双赢及多赢,论文介绍了独立医学实验室的国内外发展现状、存在问题,指出了未来发展趋势,并提出发展措施和建议.     

Validation of increased blood storage times with the T-SPOT.TB assay with T-Cell Xtend reagent in individuals with different tuberculosis risk factors

We compared the performance of the T-SPOT.TB assay with blood used within 0 to 3.5 h after collection (control) to its performance with blood stored for 0 to 3.5, 5 to 8, 18 to 21, or 31 to 33 h with the addition of T-Cell Xtend (experimental), using samples from 154 participants. The 95.4% concordance between paired specimens indicated that blood can be stored for up to 33 h prior to T-SPOT.TB testing.     

Recovery of Histoplasma capsulatum from BACTEC TB media.

From 1990 through 1994, we fortuitously isolated Histoplasma capsulatum from six patients with AIDS whose specimens of blood were processed by the BACTEC system using Middlebrook broth selective for acid-fast bacilli (13A medium). Growth indices became positive after an average of 17 days of incubation (range, 11 to 20 days). No acid-fast bacilli were seen, but small budding yeasts characteristic of H. capsulatum were present.     

The campaign against TB: governments must commit themselves. TB in Africa

This article presents an interview with Pierre Chaulet on the campaign against tuberculosis (TB) in Africa. Chaulet noted during the 9th IUATLD Conference of the Africa Region that the national TB control programs have taken on a new commitment in Africa since the declaration of TB as a global emergency in the 1990s. The TB control program package consists of five principal components: 1) political will of the government and its commitment to support the program; 2) case detection; 3) initiation of short course chemotherapy among detected cases; 4) ensuring the regular supply of essential anti-TB drugs; and 5) establishing a registry and reporting system for program monitoring and evaluation. Of the 40 African countries participating in the conference, 30 have efficient programs. Comparing the management of National TB Control Programs in Francophone and Anglophone Africa, it is noted that both are complementary, although generally, public health issues are more easily integrated into the medical training in the Anglophone countries than they are in the Francophone. Anglophone uses a more comprehensive approach to public health while countries in the Francophone practiced a more traditional university centralization. Finally, Chaulet gives his comment on the role of WHO in addressing concerns over the financial issues involved in TB Control Programs, particularly in the mobilization of resources from nongovernmental organizations and international institutions.     

Variation in Antisperm Antibody Results Using Different Assays

PROBLEM: The detection of various types of antisperm antibodies (ASA) in the serum varies among different assays. This variation may influence the diagnosis and management of infertile couples who are tested for such immunologic factors. This prospective study was conducted to determine the variation in the results of ASA as measured by the sperm immobilization (SI), sperm agglutination (SA), and the indirect immunobead (IB) assays. METHOD: The sera of 79 patients that tested positive for ASA by at least one of the assays listed above were concurrently tested with all three assays. RESULTS: Using an individual ASA assay, 66 (84%), 26 (33%) or 36 (46%) of sera tested positive by the SA, SI, or IB assays, respectively. However, using a combination of assays, 67 (85%), 78 (99%) or 40 (51%) of sera tested positive using either the SA+SI, SA+IB or SI+IB assays, respectively. CONCLUSION: These findings suggest that the utilization of different assays to detect ASA may detect sera that are positive for ASA with more reliability than single assay testing.     

Sequence Variation within Three Important Cytomegalovirus Gene Regions in Isolates from Four Different Patient Populations

We determined the nucleotide (nt) and amino acid (aa) heterogeneities of three distinct regions of the human cytomegalovirus (CMV) genome for 46 low-passage CMV isolates from four different patient populations (congenitally infected infants, children attending day-care centers, renal transplant recipients, and human immunodeficiency virus-infected individuals) and for two laboratory strains (CMV Ad169 and Towne). The gene regions for the major immediate-early (MIE) exon 4 gene (nt positions 1702 to 1982, aa positions 152 to 244), the DNA polymerase gene (nt positions 2797 to 3046, aa positions 713 to 795), and the glycoprotein B (gB) gene (nt positions 1698 to 1884, aa positions 567 to 628) were sequenced. The sequence information was used to design sets of nested PCR primers directed against the most highly conserved regions identified. MIE was the most variable gene region compared to the variability of the DNA polymerase and gB gene regions. Comparison of the sequences of all 46 isolates with that of Ad169 revealed nt and aa sequence homologies of 87.9 and 87.2%, respectively, within the MIE gene compared to 92.8 and 100% homologies, respectively, within the DNA polymerase gene and 93 and 95.2% homologies, respectively, within the gB gene. Within the MIE gene, compared to the Ad169 nt sequence the homology at the nt level among isolates obtained from children attending day-care centers was high (96.4%), while it was lower (90%) among isolates obtained from the other three patient populations. Preliminary results of a nested PCR with oligonucleotide primers selected from the DNA polymerase gene region with a low level of nt sequence variation indicates that primers selected from this region might be more powerful for use in PCR than primers selected from the MIE gene region.     

Variation in the Susceptibility of Drosophila to Different Entomopathogenic Nematodes

Entomopathogenic nematodes (EPNs) in the genera Heterorhabditis and Steinernema are lethal parasites of insects that are of interest as models for understanding parasite-host interactions and as biocontrol agents for insect pests. EPNs harbor a bacterial endosymbiont in their gut that assists in insect killing. EPNs are capable of infecting and killing a wide range of insects, yet how the nematodes and their bacterial endosymbionts interact with the insect immune system is poorly understood. Here, we develop a versatile model system for understanding the insect immune response to parasitic nematode infection that consists of seven species of EPNs as model parasites and five species of Drosophila fruit flies as model hosts. We show that the EPN Steinernema carpocapsae, which is widely used for insect control, is capable of infecting and killing D. melanogaster larvae. S. carpocapsae is associated with the bacterium Xenorhabdus nematophila, and we show that X. nematophila induces expression of a subset of antimicrobial peptide genes and suppresses the melanization response to the nematode. We further show that EPNs vary in their virulence toward D. melanogaster and that Drosophila species vary in their susceptibilities to EPN infection. Differences in virulence among different EPN-host combinations result from differences in both rates of infection and rates of postinfection survival. Our results establish a powerful model system for understanding mechanisms of host-parasite interactions and the insect immune response to parasitic nematode infection.     

Variation in human rotavirus electropherotypes occurring between rotavirus gastroenteritis epidemics in central Australia.

The changes in human rotavirus electropherotypes, occurring during a period including two rotavirus gastroenteritis epidemics in 1976 and 1979 in relatively remote Central Australia, were determined by polyacrylamide gel electrophoretic analysis of the rotavirus genome ribonucleic acid. A number of different electropherotypes were present during each of the epidemics, although a single type was predominant in each one. The predominant electropherotype of the first epidemic persisted in the area for approximately 2 years afterwards. Apart from this electropherotype, only three others were recognized in the 3 years between the two epidemics. One of these, first seen 1 year before the second epidemic, bore a very close similarity to the predominant type of the second epidemic. Altogether, 12 different electropherotypes were recognized during the period of the survey. No type common to both areas was found when rotavirus electropherotypes recognized in Central Australia were compared with those detected in a 1973-to-1979 survey in Melbourne, Australia.     

Protection and pathology in TB: learning from the zebrafish model

Zebrafish has earned its place among animal models of tuberculosis. Its natural pathogen, Mycobacterium marinum, shares major virulence factors with the human pathogen Mycobacterium tuberculosis. In adult zebrafish, which possess recombination-activated adaptive immunity, it can cause acute infection or a chronic progressive disease with containment of mycobacteria in well-structured, caseating granulomas. In addition, a low-dose model that closely mimics human latent infection has recently been developed. These models are used alongside infection of optically transparent zebrafish embryos and larvae that rely on innate immunity and permit non-invasive visualization of the early stages of developing granulomas that are inaccessible in other animal models. By microinjecting mycobacteria intravenously or into different tissues, systemic and localized infections can be induced, each useful for studying particular aspects of early pathogenesis, such as phagocyte recruitment, granuloma expansion and maintenance, vascularization of granulomas, and the phagocyte-mediated dissemination of mycobacteria. This has contributed to new insights into the mycobacteria-driven mechanisms that promote granuloma formation, the double-edged role of inflammation, the mechanisms of macrophage cell death that favor disease progression, and the host-protective role of autophagy. As a result, zebrafish models are now increasingly used to explore strategies for adjunctive therapy of tuberculosis with host-directed drugs.     

Variation in prescribing of hypnotics, anxiolytics and antidepressants between 61 general practices.

BACKGROUND. Although the desirability of reducing prescribing of hypnotics and anxiolytics has long been recognized, variation between practices in patterns of psychotropic drug prescribing has received little attention; factors underlying such variation are poorly understood. AIM. The study aimed to describe the extent of variation between general practices in the prescribing of hypnotics, anxiolytics and antidepressants; it also aimed to analyse the influence of measures of practice population and general practice and general practitioner characteristics on any variation in prescribing volumes. METHOD. Routinely collected prescribing data and practice population data, from April 1992 to March 1993, from all 61 practices in the Cambridge and Huntingdon Health Commission were analysed. Prescribing was measured as annual defined daily doses per 1000 practice population for each drug class. Data on variables relating to practice structure and general practitioner characteristics were obtained and analysed. Potentially influencing variables were investigated by multiple regression. RESULTS. Between the highest and lowest prescribing practices there was an 11-fold difference, a 13-fold difference and an eightfold difference in the annual defined daily doses per 1000 practice population prescribed for hypnotics, for anxiolytics and for antidepressants, respectively. Strong positive correlations existed between volumes of prescribing of each drug class. The drugs prescribed in the greatest volumes were hypnotics. Practice population structure had some influence on psychotropic drug prescribing with high prescribing being associated with the proportions of temporary residents and women aged 65 years and over in the practice for all three classes of drug. Other factors, including presence of a practice counsellor, were not found to have a significant influence on psychotropic drug prescribing. CONCLUSION. The degree of variation in prescribing volumes of psychotropic drugs between practices raises serious concerns. Further study is needed, but progress will be hampered until there is more clarity over the effectiveness and appropriateness of using these substances in the various illness, symptom and life-stress presentations seen in primary care.     

Variation in chromosome 19.

Variations in centromeric staining of chromosome 19 appear to be an uncommon polymorphism inherited in a Mendelian manner and easily seen in G-banded cells. It should not be misinterpreted as a structural cytogenetic abnormality.     

Variation in periodontal floras.

Statistical analyses indicated (i) that the floras of individual samples taken from the depth of sulci with nickel-plated Morse 00 scalers were highly reproducible and representative of the flora present at any given time, (ii) that the different compositions of floras of different people with similar clinical signs were statistically highly significant, and (iii) that floras of different affected sites may differ significantly in some (two of three) people at any one time or may differ from week to week in other people (one of three). Thus the flora composition of individual sites appears to be in dynamic flux, probably in response either to environmental changes or to host responses. There was no evidence that double sampling per se (two single passes with 00 scalers) changed the composition of the flora. Repeat samples taken after 1 week were slightly more similar to the initial samples than were samples taken after 3 weeks.     

CD156 transgenic mice. Different responses between inflammatory types.

CD156 (ADAM8) is part of the ADAM family of proteins with the catalytic site consensus sequence of metalloprotease and disintegrins. To examine the role of CD156 in vivo, we generated mutant CD156 (eCD156) transgenic mice expressing the ectodomain of CD156 under the control of the alpha1-antitrypsin (AT) promoter. One of the transgenic mice designated ATMS2-TG18 expressed a 1.84 kb mRNA which was predicted to be a truncated CD156. The expression of the transgenic CD156 mRNA in ATMS2-TG18 mice was abundant in the liver and slight in kidney. Turpentine oil (TO) and lipopolysaccharide (LPS) markedly upregulated the expression. Soluble CD156 (sCD156) was produced constitutively, and increased after the treatment with TO. Casein-induced peritoneal leukocyte infiltration was significantly less extensive in ATMS2-TG18 than non-transgenic mice. The expression of L-selectin in neutrophils (PMN) from peripheral blood leukocytes (PBL) was more strongly downregulated in ATMS2-TG18 than non-transgenic mice, suggesting that L-selectin in PMN from ATMS2-TG18 mice was shed by sCD156. In contrast, oxazolone (Ox)-induced contact hypersensitivity reactions (CHR) were more marked in ATMS2-TG18 than non-transgenic mice. The expression of E-selectin mRNA was detected in inflammatory skin sites from ATMS2-TG18, but not non-transgenic mice, suggesting that sCD156 may activate the endothelial cells and lead to the upregulation of E-selectin. These results suggest that CD156 regulates leukocyte infiltration directly or indirectly.     

Independent movement of surface immunoglobulin from Fc receptors on lymphocyte membranes.

The majority of surface immunoglobulin-positive lymph node cells possess Fc receptors detectable by a rosette technique. The movement of surface immunoglobulin to form caps does not alter the distribution of Fc receptors, although Fc rosette-forming indicator cells collect over the immunoglobulin cap under capping conditions.     

Performance of Clinical Laboratories in South African Parasitology Proficiency Testing Surveys between 2004 and 2010

Performance in proficiency testing (PT) schemes is an objective measure of a laboratory's best performance. We examined the performance of participants in two parasitology PT schemes in South Africa from 2004 through 2010. The average rates of acceptable scores over the period were 58% and 66% for the stool and blood parasite schemes, respectively. In our setting, participation in PT alone is insufficient to improve performance; a policy that provides additional resources and training seems necessary.