Interferon-gamma increases expression of chemokine receptors CCR1, CCR3, and CCR5, but not CXCR4 in monocytoid U937 cells

Chemokine receptors (CR), which can mediate migration of immune cells to the site of inflammation, also function as coreceptors for human immunodeficiency virus (HIV) entry into CD4+ T lymphocytes and antigen-presenting cells. We demonstrate here that interferon-gamma (IFN-gamma) increases the expression of chemokine receptors CCR1, CCR3, and CCR5 in monocytoid U937 cells as detected by cell surface molecule labeling and mRNA expression, as well as by intracellular calcium mobilization and cell migration in response to specific ligands. The increased expression of these chemokine receptors also results in an enhanced HIV-1 entry into cells. Our data provide evidence for a relationship of cellular pathways that are induced by IFN-gamma with those that regulate chemokine receptor expression.     

Toxicity of inhaled 91YCl3 in dogs

Few systematic studies have been devoted to investigating the role of Ca2+ as an intracellular messenger in prokaryotes. Here we report an investigation on the potential involvement of Ca2+ in signalling in Bacillus subtilis, a Gram-positive bacterium. Using aequorin, it is shown that B. subtilis cells tightly regulate intracellular Ca2+ levels. This homeostasis can be changed by an external stimulus such as hydrogen peroxide, pointing to a relationship between oxidative stress and Ca2+ signalling. Also, B. subtilis growth appears to be intimately linked to the presence of Ca2+, as normal growth can be immediately restored by adding Ca2+ to an almost non-growing culture in EGTA containing Luria broth medium. Addition of Fe2+ or Mn2+ also restores growth, but with 5-6 h delay, whereas Mg2+ did not have any effect. In addition, the expression of alkyl hydroperoxide reductase C (AhpC), which is strongly enhanced in bacteria grown in the presence of EGTA, also appears to be regulated by Ca2+. Finally, using 45Ca2+ overlay on membrane electrotransferred two-dimensional gels of B. subtilis, four putative Ca2+ binding proteins were found, including AhpC. Our results provide strong evidence for a regulatory role for Ca2+ in bacterial cells.     

Diagnostic role of Mantoux test site biopsy in neurosarcoidosis

We discuss a patient with sarcoidosis presenting with cranial neuropathy and a cerebral mass lesion evident on imaging. Also, we review from the literature six patients with sarcoidosis presenting with cerebral mass lesion. We emphasize the diagnostic role of Mantoux test site biopsy in patients with dominant or isolated neurologic presentation because the involved sites are not easily accessible and Kveim's test antigen is not commercially available.     

Immunohistochemical demonstration of carcinogen-DNA adducts in tissues of rats given 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP): detection in paraffin-embedded sections and tissue distribution

A polyclonal antibody against 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-DNA adducts was raised for their immunohistochemical demonstration in paraffin-embedded sections. Specificity of this antibody was confirmed by competitive ELISA. Positive signals were immunohistochemically detected in acetone-fixed but not in formalin- or ethanol-fixed sections from F344 rats treated by gavage with a single dose of PhIP at 37.5-300 mg/kg and killed at 1, 2, and 7 days thereafter. Dose-dependent positive staining was observed in almost all organs of both sexes, including the colon, prostate, and mammary gland but largely independent of the tumor response. Repair activity, judged by disappearance of adducts with time, differed according to the organ or cell type. One exception was hepatocytes, the liver incidentally being a nontarget organ. The results suggest that the generated antibody is applicable for detection of cells targeted by PhIP in paraffin-embedded sections and also for the investigation of the mechanisms of PhIP-carcinogenesis.     

European surveillance of infectious diseases: the case of AIDS and tuberculosis

In 1992, the Maastricht treaty gave specific responsibilities to the European Community in the field of research, information and health education. Several European surveillance systems for infectious diseases have been organised. The surveillance of AIDS was set up in 1984 after the emergence of this new disease. Seven western European countries participated initially. The system currently covers 48 of the 51 countries of the WHO European region. Based on a common case definition, it enables analysis of trends and comparisons which considerably facilitate the understanding of the epidemic and its determinants, and the evaluation of preventive actions. European countries have now decided to set up a reporting system for HIV infection. The surveillance of tuberculosis started in 1996 in response to the reversal of trends in reported cases observed in western Europe and to the threat of multi-drug resistant tuberculosis epidemics. Common recommendations on definitions and data collection procedures facilitated its establishment. Most countries of the WHO European region participated in the first year, revealing a very heterogeneous epidemiological situation. The next objective is to set up a surveillance system for antituberculosis drug resistance. The European surveillance of AIDS and tuberculosis are examples of systems adapted to the specific characteristics of Europe: similarities in diagnostic procedures, similarities in access to treatments, and common requirements regarding both the exchange of information and the coordinated response to public health threats. They are not simply looking for a common denominator. They are creating a real momentum among participating countries towards a better quality and a higher level of pertinence of the information.     

A method providing bidirectional control of coil delivery in occlusions of patent ductus arteriosus with shallow ampulla and Pott's shunts

A novel method using a snare and bioptome to provide bidirectional control of a Gianturco coil for occlusion of a patent ductus arteriosus with a shallow ampulla and Pott's shunts is presented. This method greatly reduces the risk of coil embolization and optimizes coil position in difficult cases.     

Role of Fas ligand and receptor in the mechanism of T-cell depletion in acquired immunodeficiency syndrome: effect on CD4+ lymphocyte depletion and human immunodeficiency virus replication

Direct killing of CD4+ lymphocytes by human immunodeficiency virus-1 (HIV-1) probably cannot account for the magnitude of the loss of these cells during the course of HIV-1 infection. Experimental evidence supports a pathophysiologic role of the apoptotic process in depletion of CD4 cells in acquired immunodeficiency syndrome (AIDS). The Fas-receptor/Fas-ligand (Fas-R/Fas-L) system mediates signals for apoptosis of susceptible lymphocytes and lympoblastoid cell lines. A number of investigators have recently reported increased expression of the Fas receptor in individuals with HIV infection, along with increased sensitivity of their lymphocytes to anti-Fas antibody mimicking Fas ligand. We attempted to determine the role of Fas-mediated apoptosis in disease progression and viral replication. Increased Fas-receptor (CD95) expression on CD4+ and CD8+ lymphocytes was found in a large group of HIV-1-infected patients compared with normal controls; individuals with a diagnosis of AIDS and a history of opportunistic infection had significantly more Fas receptor expression than did asymptomatic HIV-infected persons and normal blood donor controls (P < .01). Triggering of the Fas-R by agonistic anti-Fas monoclonal antibody, CH11, was preferentially associated with apoptosis in the CD4+ cells; this effect was more pronounced in lymphocytes derived from HIV+ individuals. Soluble and membrane-bound forms of Fas-L were produced in greater amounts in peripheral blood mononuclear cells (PBMC) cultures and in plasma obtained from HIV-1-infected persons than from normal controls. Furthermore, triggering of lymphocytes from HIV-infected persons by CH11 increased levels of interleukin-1beta converting enzyme (ICE), a protein associated with apoptosis. When PBMC were cultured in the presence of CH11, p24 production per number of viable cells was decreased as compared with the same PBMC without CH11 (P < .01). These findings suggest that multiple mechanisms, including increased production of Fas-L by infected PBMC, increased Fas-R expression, and induction of a protease of ICE family, may play roles in the apoptotic depletion of CD4+ cells in HIV infection.     

BT之后是电驴——网际快车3．0电驴功能实测

我们知道,BT下载的优点是下载速度快、资源分布广、对服务器造成的负担较小,但缺点是每一个BT资源都有时效性.例如:两个月前的BT资源,现在多半是无效的,也就是通常说的"没种子了".而电驴(eMule)则不然,它的特点就是可使用多个途径搜索下载的资料源.由ED2K、来源交换、Kad共同组成一个可靠的网络结构.虽然速度上可能不及BT,但可以搜索得到更多的资源(包括一些N年前的东东).快车在其3.0版中加入对电驴的支持,无疑又将其可用性提高了一大截.至此,快车下载软件可以支持BT、eMule、FTP、HTTP等绝大部分下载方式.     

Isolation of a bioactive Ca(2+)-mobilizing complex lipid from bovine vitreous body

We have been undertaking the gene therapy for a 6 year-old boy with ADA deficiency and performed 11 cycles of the infusion of the peripheral T cells transduced with retroviral vector LASN since August 8th 1995. The percentage of the peripheral blood lymphocytes carrying the transduced ADA gene has remained stable at 10% to 20% since the 4th infusion. ADA enzyme activity in his circulating T cells increased to levels comparable to 1/3 of a heterozygous carrier individual and was associated with increased T lymphocytes counts and improvement in both humoral and cellular immune function. The results obtained in this clinical study support the usefulness of T lymphocyte-directed gene transfer in the treatment of ADA deficiency.