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K Tenner-Racz

Publications and source records attributed to K Tenner-Racz.

52 records · Page 3Linked to original sources
PubMed1993

Cytotoxic effector cell granules recognized by the monoclonal antibody TIA-1 are present in CD8+ lymphocytes in lymph nodes of human immunodeficiency virus-1-infected patients.

A novel monoclonal antibody (mAB) TIA-1, which recognizes a 15-kd granule-associated protein of cytotoxic T lymphocytes and natural killer cells, has been applied to sections of lymph nodes with human immunodeficiency virus (HIV)-induced lymphadenopathy (follicular hyperplasia and lymphocyte depletion). The protein recognized by this mAB induces apoptosis in permeabilized lymphocytes in vitro. While this mAB reacted with approximately 46% of paracortical CD8+ cells in control nodes, it reacted with 75% of such cells in HIV-induced follicular hyperplasia. Germinal centers of the control nodes contained few TIA-1 + cells; in follicular hyperplasia caused by HIV-1, almost all germinal center CD8+ cells were TIA-1 +. Both in the control nodes and in HIV-induced follicular hyperplasia the majority of TIA-1 + cells coexpressed CD45R0. A marked loss of CD8+TIA-1+ cells was seen in lymphocyte-depleted nodes of patients with AIDS. The loss of these cytotoxic T lymphocytes may have a significant impact on the progression of the disease.

Acquired Immunodeficiency Syndrome↗
PubMed1991

[Histologic classification of HIV-1 induced lymphadenopathy. Current results on the pathogenesis of germinal center changes].

At the IV International Conference on AIDS in Stockholm, a Symposium on the pathology of HIV-related diseases was organized. During this Symposium the "European Study Group on HIV-Pathology" presented a histological classification of lymph node alterations seen in HIV-associated lymphadenopathy. The goal of the Study group was to offer a common terminology for histologic changes previously described with different terms by different authors. In the present review the most important histological criteria used in the proposed classification are summarized. Since the classification is based on the conspicuous changes of the follicles, a brief review of the possible pathogenic mechanisms leading to disintegration of the germinal centers will also be given.

AIDS-Related Complex↗
PubMed1990

Lymphatic tissue changes in AIDS and other retrovirus infections: tools and insights.

Based on immunohistochemistry, in situ hybridization, and electron microscopy, lymphatic tissue changes in human immunodeficiency virus (HIV) and other retroviral infections represent different stages of a dynamic process progressing from hyperplasia to atrophy. The germinal centers (GC) function early as a virus reservoir in both HIV and feline leukemia virus infection, which also produces lymphadenopathy, severe immune impairment, and death from opportunistic infections. Core proteins of HIV can be detected on the surface of follicular dendritic cells, electron microscopy reveals cell-free HIV and virus replication in the same location, and in situ hybridization shows that the majority of cells with mRNA of HIV can be found in germinal centers (GC). Double immunohistochemical labeling of lymphocyte populations suggests that one of the most important events in HIV lymphadenitis with explosive follicular hyperplasia is the accumulation of CD8+CD45R0+ lymphocytes in the lymph nodes. Their clustering in the vicinity of the FDC network could play a key role in disintegration of GC and lymphocyte depletion as the disease progresses.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Experimental infection of rhesus monkeys with SIV isolated from African green monkeys.

To establish an animal model for AIDS, 6 juvenile rhesus monkeys were infected intravenously with cell-free SIVagmTYO-1, 5, or 7. One animal was infected with SIV of known pathogenicity isolated from a sooty mangabey (SIVsmm). The 2 animals infected with TYO-1, 1 of 2 infected with TYO-7 and the 1 infected with SIVsmm seroconverted within 4-8 weeks after infection and infectious virus could be recovered 8-10 or 44 weeks after infection. Three of the 4 seroconverted monkeys developed a persistent lymphadenopathy 12 weeks after infection. Rhesus monkeys infected with SIVagm could serve as a model to study HIV infection and for vaccine trials.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Sulfide silver amplification of ferritin iron cores in blood and bone marrow cells. Methods, adaptations to microphysical analyses, and the impact of advanced iron overload.

A short exposure of cell suspensions to gaseous hydrogen sulfide, appropriate fixations, and subsequent physical development of silver shells around sulfidated insoluble metals were used to amplify ferritin iron cores in blood and bone marrow cells. The methods described are suitable for both light microscopy and transmission electron microscopy. These techniques made it possible to visualize Prussian Blue stainable ferritin and haemosiderin, as well as a large variety of isoferritin iron and other smaller particles beyond the sensitivity of Prussian Blue staining. Admixtures of sulfidatible zinc and traces of other heavy metals had to be taken into consideration. For further research, adaptations of sulfide silver staining to microphysical analyses were developed. However, conventional energy dispersive X-ray analysis was not sensitive enough to signalize the presence of Fe in sulfide silver amplified iron cores of a single or a few ferritin molecule(s). Proton-induced X-ray emission was used to measure Fe and Zn down to 1 fg/single cell in unstained or sulfide silver stained smears on thin foils. However, multielement analysis of homogeneous cell concentrates was much easier to perform and far more sensitive. In advanced iron overload, highly increased sulfide silver staining was found in peripheral blood cells including lymphocytes, monocytes, eosinophils, basophils, and--in extreme cases--also in neutrophils and platelets.

Blood Cells↗
PubMed1986

HTLV-III/LAV viral antigens in lymph nodes of homosexual men with persistent generalized lymphadenopathy and AIDS.

The presence of core antigens of retrovirus HTLV-III/LAV, referred to as "AIDS-related virus" (AV), has been sought in lymph node samples of patients with persistent generalized lymphadenopathy (PGL, 28 patients), prodromal AIDS (1 patient) and AIDS with Kaposi sarcoma (3 patients). In 30 patients the deposition of viral antigens, detected by monoclonal antibodies to HTLV-III and LAV, could be observed within the germinal centers (GCs) primarily within the extracellular network of immune complexes, and the two patients who were negative were atypical. No AV could be found in normal tonsil or in samples with follicular hyperplasia of unknown etiology (20 cases). These findings, taken together with the ultrastructural identification of typical retrovirus particles in all 9 PGL and 2 AIDS cases studied, indicates that the network of follicular dendritic (FD) cells is an important reservoir of AV virus antigen at this site. The persistence of this retrovirus inside the GCs helps explain how the follicular hyperplasia affecting FD cells and B blasts in PGL may in progressive cases be accompanied by destruction of FD cells and gradual development of T4+ lymphopenia. T4+ T cells may circulate through the GCs and become infected with AV there. In addition, the identification of retrovirus antigen in situ may be of diagnostic value.

Acquired Immunodeficiency Syndrome↗
PubMed1985

[AIDS fatalities in Hamburg (status: February 1985)--legal medicine aspects].

The registration of patients with acquired immune deficiency syndrome (AIDS) and AIDS deaths is centralized for medical research. A short review of the epidemiological state of AIDS in Hamburg is given (situation as of February 1985), and the autopsy results of seven postmortem examinations are referred to. Kaposi's sarcoma was seen in four patients and opportunistic infections in all cases, especially as a result of Pneumocystis carinii and cytomegalovirus. Due to the constellation of groups with an increased risk of acquiring AIDS--homosexual males, intravenous drug abusers and prostitutes--forensic implications have to be expected.

Acquired Immunodeficiency Syndrome↗
PubMed1983

Immunopathologic aspects in human onchocercal lymphadenitis.

Lymph nodes (LN) from 50 patients with generalized onchocerciasis with or without diethylcarbamazine treatment and LN of patients with untreated localized onchocerciasis were studied. Light and electron microscopic examinations and immunostaining (PAP) were performed. In both forms of the disease the majority of microfilariae were degenerated and surrounded either by eosinophils or macrophages. In addition increased number of mast cells and plasma cells was observed. A direct contact between eosinophils and microfilariae, degranulation of eosinophils and free eosinophil granules in the electron dense material around the degenerating microfilariae were registered. The majority of plasma cells produced IgE or IgG. A positive staining for IgE was also present on the surface of mast cells. An extensive hyperplasia of the follicles was a characteristic feature in localized as well as treated generalized onchocerciasis. After anti-IgE staining a heavy intercellular deposition suggesting trapping of immune complexes by dendritic reticular cells developed in the light parts of the germinal centres. Not seldom, IgE producing blast cells were found in the follicles.

Diethylcarbamazine↗
PubMedDate not supplied

Are follicular dendritic cells, macrophages and interdigitating cells of the lymphoid tissue productively infected by HIV?

Numerous data demonstrate that lymphoid tissues represent a major HIV reservoir and sites of virus replication. To gain more information about the phenotype of cells in which HIV replicates in the lymphoid tissue, we applied HIV RNA hybridization technique in combination with immunohistochemistry on 10 lymph nodes and 2 lymphoepithelial cysts (LEC) of the parotid gland. In addition, to determine whether or not follicular dendritic cells (FDC) are important targets for HIV, we also analysed isolated and sorted FDC from 4 lymph nodes. The tissues showed follicular hyperplasia and heavy RNA signals in the germinal centres (GC), where diffuse labelling in the light zone as well as single cells with > 50 silver grains were present. The extrafollicular parenchyma contained only a few productively infected cells. The diffuse labelling was intimately related to the FDC network. However, electron microscopic examination and in situ hybridization on isolated FDC did not provide convincing evidence for virus replication in these cells. Virus-producing cells in the GC were almost exclusively CD45RO+, CD57- T cells. Macrophages with HIV RNA were mainly found in LEC of the parotid gland. S-100+ interdigitating cells of the T-dependent zone were HIV RNA-. However, some large S-100+ cells in the squamous epithelium covering the LEC or lying subepithelial did express HIV RNA. These findings suggest that local factors (cytokines?) in the lymphoid tissue probably influence the expression of HIV.

Dendritic Cells↗