Flow cytometric analysis of cell proliferation dynamics in the B cell compartment of the mouse

Using a method which allows simultaneous flow cytometric detectionof cell surface markers and 5-bromo-2'-deoxyuridine (BrdU) incorporation,the distribution and proliferative behavior of B lineage subpopulationswas studied in intact adult mice. In the bone marrow we coulddefine two subsets of B cells on the basis of differential expressionof the pan-B cell marker B220 and of membrane-associated µand immunoglobulin heavy chains. B220^dullµ^+– Bcells were found to emerge from rapidly dividing cells and probablyrepresent B cells recently generated from B220^dullµ^–pie-B cells. In contrast, oniy few, If any, of the B220^brightµ⁺⁺B cells were labeled with BrdU after a period of 8 days, suggestingthat these cells represent long-lived B cells residing in thebone marrow. Analysis of BrdU-Incorporation into splenic B cellsshowed that only 20% of these cells had gone through cell divisionduring the preceding 8 days. Almost none of the B cells in theperitoneum, a large fraction of which belongs to the Ly1 B subset,were labeled with BrdU over a period of 7 days in 8-month-oldanimals.     

Molecular epidemiology of hepatitis C virus infection amongst intravenous drug users in rural communities

The prevalence of hepatitis C virus (HCV) infection amongst a group of intravenous drug users (IVDUs) resident in West Suffolk (East Anglia, England) was investigated and compared with the prevalence of infection with hepatitis B virus (HBV) and human immunodeficiency virus (HIV). In addition, both the level of HCV persistence, as defined by detection of viral RNA, and the HCV genotypes present in this population were determined. It was found that HCV antibodies were present in 59% of those tested; by comparison 22% had antibodies to HBV and 1% antibodies to HIV. HCV RNA was found in 44% of those with HCV antibody. HCV genotype 1 was the most prevalent within this population although both genotypes 2 and 3 were also represented. © 1995 Wiley-Liss, Inc.     

Treatment of atypical leishmaniasis with interferon γ resulting in progression of Kaposi's sarcoma in an AIDS patient

Visceral leishmaniasis (kala-azar) affecting HIV-infected patient is being reported in increasing frequency. A 40-year-old German bisexual patient with full-blown AIDS is described who presented with Kaposi's sarcoma, epigastric pain, diarrhea, and weight loss but without fever.Leishmania amastigotes were initially found in biopsies from stomach, duodenum, and a cutaneous Kaposi's sarcoma lesion but were later also recovered from bone marrow and lymph node. The patient received three courses of a combination of pentavalent antimony and interferon-. In addition to the common side effects such as fever, thrombocytopenia, and elevated amylase and lipase, a vivid progression of the Kaposi's sarcoma was noted. Tumor progression was temporally closely associated with treatment with interferon-. Because this phenomemon has also been observed in other patients, we advise caution when using interferon- in patients with Kaposi's sarcoma.Abbreviations AIDS acquired immunodeficiency syndrome - HIV human immunodeficiency virus - KS Kaposi's sarcoma Correspondence to: H. Albrecht     

Electron microscopic evidence of a viral nature for osteoclast inclusions in Paget's disease of bone

Circumstantial evidence from electron microscopic and immunological studies support the view that Paget's disease of bone represents a slow virus infection. However, there is only limited information available regarding its electron microscopic, enzyme and immunocytochemical characteristics. Two cases were studied using electron microscopy with particular emphasis on the inclusions in osteoclasts. Detailed ultrastructural and cytochemical studies including immuno-electron microscopy were performed. Some osteoclasts demonstrated specific virus-like structures composed of aggregations of microtubules in the nucleus and cytoplasm. The structures were easily digested by trypsin or protease, and were sensitive to RNase, which provided substantial evidence of a proteinaceous nature and inclusion of ribonucleic acid. Immunocytochemical examination identified binding of anti-respiratory syncytial virus and anti-measles virus antibodies in the tissue obtained from one of the two cases examined. The presence of viral antigens in structures in the cytoplasm of Pagetic osteoclasts supports the theory of paramyxovirus involvement in this disease.     

Hemopoietic and Lymphoid Progenitor Cells in Human Umbilical Cord Blood

Human umbilical cord blood, which in the past was discarded with the placental tissue, provides a convenient source of fetal hemopoietic cells for scientific analysis and clinical use. Cord blood cells are immature compared to analogous populations in adult peripheral blood. Cord blood B lymphocytes display unique phenotypic and functional characteristics. The antigens CD1C, CD38, CD5, and CD23, although normally expressed on only a small percentage of circulating B cells in adults, are highly expressed on cord blood B cells. Recent studies have demonstrated that whereas cord blood B cells are functionally naive, their potential is similar to that of adult B cells if optimal T-cell help is available. Thus, the failure of B-cell responses in cord blood is due to the T cells. The functional abnormalities of T cells from newborns can be summarized as a dominance of the effects of TH0 cells. Thus, the cytokines produced are immunosuppressive rather than mediating helper activity for B cells. NK activity in cord blood is also depressed compared to that in adults. Cord blood is a very rich source of hemopoietic progenitor cells. The spectrum of progenitors shows a predominance of early progenitor cells when compared with bone marrow. These cells provide an alternative source to adult bone marrow for stem cells to use for hemopoietic reconstitution and as targets in the treatment of hereditary deficiencies by gene therapy. These features make cord blood a unique research tool to investigate hemopoietic ontogeny and a unique clinical tool for transplantation.     

Detection of Epstein-Barr virus in a case of undifferentiated nasopharyngeal carcinoma by in situ hybridization with digoxigenin-labelled PCR-generated probes

A case of nasopharyngeal carcinoma is presented. Epstein-Barr viral genome was identified in the neoplastic cells by in situ hybridization with digoxigeninlabelled polymerase chain reaction-generated probes. We report the development of this technique in paraffinembedded sections and propose that such identification may prove valuable for the diagnosis of this tumour in routine material.P. Delvenne is a research associate of the National Fund for Scientific Research (Belgium)     

Variable regions of antibodies to synthetic polypeptides--I. Characterization of an idiotope expressed on antibodies and T-cell factors

Spleen cells from a Lewis rat immunized with affinity-purified B10 anti-(T,G)-A-L antibody were fused with the non-secreting murine hybridoma SP2/0. Cell lines secreting monoclonal antibodies specific for mu- and kappa-chains, as well as an idiotope on anti-(T,G)-A-L antibodies, were isolated and characterized. The anti-mu and -kappa antibodies, are true anti-isotypes, reacting with sera from all strains of mice tested. The anti-idiotope antibodies recognize a determinant on antibodies binding a GT-containing epitope. The proportion of anti-GAT antibody bearing the idiotope varies markedly in different murine strains. A 1000-fold higher level of antibody from Igha mice than from Ighb and Ighe mice is required to give an equivalent inhibition of the idiotope-anti-idiotope reaction. Analysis of monoclonal antibodies expressing the idiotope indicates that the affinity of binding between idiotope and anti-idiotope can vary by as much as two orders of magnitude. Immunoadsorbants prepared with anti-idiotope antibody bind suppressor factor secreted by a GAT-specific T-cell hybridoma.     

Bacillary angiomatosis in a German patient with AIDS

Summary A 52-year old male homosexual patient with acquired immunodeficiency syndrome (AIDS) presented in our clinic with multiple nodular papules (more than 100) spread over the whole body which had developed within 3 months. Bacillary angiomatosis was suspected, which is a bacterial infectious disease recognized recently mainly in patients with AIDS. Histological and immunohistochemical examinations of extirpated skin lesions were in agreement with the diagnosis, and the detection of rod-shaped bacteria in the lesions by Warthin-Starry silver stain confirmed it. The patient was treated with 2 × 100 mg doxycycline per day. The fever disappeared, and the cutaneous lesions showed a slight tendency to improve. However, after 5 days of therapy the patient showed increasing weakness, with muscle and bone pain. The patient died 10 days after the doxycyline therapy had been started. The cutaneous lesions in bacillary angiomatosis may resemble Kaposi's sarcoma and may therefore be misdiagnosed. The disease may be fatal, but timely antibiotic treatment is usually effective; therefore the diagnosis of bacillary angiomatosis is important. Although many cases have been reported from the United States, only one case is known from Europe. Our finding of bacillary angiomatosis in a German AIDS patient supports the concept of a worldwide distribution of this bacterial agent.Abbreviations HIV human immunodeficiency virus type 1 - AIDS acquired immunodeficiency syndrome     

常见呼吸道病毒分子鉴别诊断技术的建立

目的 建立一种常见呼吸道感染病毒的快速检测方法,为尽早诊断、减少疾病的传播以及为临床提供良好的治疗依据.方法 采用液体芯片检测技术结合靶向多重RT-PCR技术建立可以同时检测13种呼吸道病原的检测技术.结果 该方法特异性方面检测13种常见呼吸道病毒没有交叉,标本的检出率为100%;灵敏度方面达到10e2-10e1（pfu/ml）.结论 该分子鉴别诊断可应用常见呼吸道病毒的检测,协助诊断病毒引起的病毒性呼吸道感染.     

结核分枝杆菌Ag85B与IL-12基因真核共表达质粒的构建及表达

目的 :构建结核分枝杆菌Ag85B和鼠IL 12基因的共表达载体pBud85B IL12。方法 :将结核分枝杆菌Ag85B基因和鼠IL 12基因同时克隆入含多启动子的共表达载体pBudCE4 .1中 ,构建真核共表达质粒pBud85B IL12。以pBud85B IL12转染COS 7细胞 ,通过RT PCR及ELISA方法检测目的基因的表达。结果 :在COS 7细胞中同时可检测到Ag85B和IL12的表达。结论 :pBud85B IL12共表达质粒的成功构建 ,为对其免疫原性、免疫反应性及免疫保护作用的进一步研究奠定了基础