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Query: UMLS:C1275122 (TEM)
 21,810 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Infection with herpes simplex virus type 1 (HSV-1) induces different morphological changes in different cell lines. This is demonstrated by comparative scanning (SEM and transmission (TEM) electron microscopic investigations of cell cultures prepared under identical conditions. SEM of HSV-1 infected HEp-2 cells reveals a slightly altered cell surface: only the number of the microvilli is reduced. Large amounts of released virions are detectable adhering to the outer plasma membrane. Ultra-thin sections show typical virus maturation steps in the nuclei (formation of nucleocapsids and virus budding from the inner lamella of the nuclear membrane) and in the cytoplasm (egress of enveloped nucleocapsids through membranous structures). HSV-infected primary chick embryo fibroblast (CEF) cells are characterized by crumpled and rough surfaces without virus particles adhering to the membrane. Ultra-thin sections exhibit atypical virus maturation with many unenveloped nucleocapsids within the cytoplasm. The distribution of HSV-induced antigen(s) on the surface of the infected cells is identical in the two cell systems as determined by the peroxidase labelling technique. The c.p.e. (as seen by phase contrast light microscopy) is similar in both HEp-2 and CEF cells: both fusion and rounding up is induced in the infected cells.
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PMID:Differences in the morphology of herpes simplex virus infected cells: I. Comparative scanning and transmission electron microscopic studies on HSV-1 infected HEp-2 and chick embryo fibroblast cells. 23 Feb 92

The immunocytological identification of the mycosis fungoides cell was carried out on cells extracted from the tumorous nodules of a patient suffering from typical mycosis fungoides. Various techniques, such as E and IgM-EAC rosettes and examination for surface membrane immunoglobulins, were performed on the peripheral blood cells and the tumour cell. Membrane staining with a specific anti-T lymphocyte serum conjugated with peroxidase confirmed the thymodependent origin of the mycosis fungoides cell. However, the immunolabelling (with Fab peroxidase conjugate was found constantly negative.
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PMID:Immunocytological characterization of the mycosis fungoides tumour cell. 30 33

Mononuclear cells from seven patients with hairy cells leukaemia were examined for features suggestive of either a lymphocytic or monocytic origin. Immunofluorescent staining of both methanol fixed and incubated cells, using monospecific antisera, revealed a predominant cell-associated immunoglobulin in each case. Three were positive for mu and kappa chains, two for gamma and kappa chains, one for delta and kappa chain determinants and one reacted only with antigamma chain serum. Formation of EAC rosettes, a feature of both B lymphocytes and monocytes, was variable. T cells, as judged by E rosettes, were not elevated in any patient. Phytohaemagglutinin reactivity was normal in six and depressed in one case. With the exception of minimal activity in assays for glass adherence and latex particle phagocytosis, none of the cells showed features typical of monocytes. Hairy cells were negative by peroxidase stain and lacked the electron microscopic characteristics of monocytes. They did not react in either rosette or phagocytic assays with anti-A or anti-D coated erythrocytes nor did they elaborate granulocyte colony stimulating factor, a monocyte-derived in vitro granulopoietin. Although unequivocal classification of these abnormal cells is not possible, the data storngly suggests that this represents a variant of a B lymphocytic neoplasm.
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PMID:Hairy cell leukaemia: seven cases with probable B-lymphocytic origin. 30 39

Among glass-adherent peritoneal exudate cells (gaPEC), induced by an inoculation of 1% glycogen solution, about 4.5% were classified as antibody-forming cell precursors (AFCP) on the first day of culture by means of anti-mouse B-cell antibody (anti-B-Ab). They proliferated and differentiated into IgG-forming plasma cells when cultured with antigen and thymic RNA in vitro. Pretreatment of PEC with anti-B-Ab and complement suppressed the formation of plasma cells. AFCP had receptors for IgM-antigen complexes and for complement, both of which were independent of Ca++ and MG++ and resistant to treatment by pronase or phospholipase C. Cells bearing detectable receptors for EA (IgM) an EAC diminished by the 6th day when gaPEC were cultured with thymic RNA, but persisted longer in cultures without thymic RNA. The same percentages of cells demonstrated tartrate-resistant acid phosphatase activities but were devoid of esterase. Twenty to thirty percent of anti-B-Ab sensitive cells ingested latex particles. The proliferation kinetics of IgG-forming cells were studied through the 21st day of culture by means of peroxidase-labeled antibody staining methods.
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PMID:Antibody forming cell precursors among glass-adherent peritoneal exudate cells. 30 30

A distinctive subpopulation of nonphagocytic, tightly adherent cells (NPAC) comprised approximately 6% of the adherent peritoneal cells from untreated mice, and about 18% of those from mice previously given BCG i.p. A separation procedure based on adherence and lack of phagocytosis was devised. Isolated NPAC were morphologically intermediate between small lymphocytes and macrophages. They were positive for nonspecific esterase, negative for peroxidase, positive for surface IgM, and negative for surface IgG1, IgG2 and IgA. When capped, their surface IgM regenerated in vitro. NPAC had demonstrable Fc receptors but not EAC receptors. They resisted killing by an anti-macrophage serum, were negative by immunofluorescence with an anti-T cell reagent, and incorporated increased amounts of thymidine in response to LPS but not to PHA. They were more readily killed with anti-Ia serum and complement than macrophages, but less readily than splenic B cells. NPAC appeared to represent a subpopulation of B lymphocytes which contaminates some preparations previously regarded as "macrophages" and which may be ressponsible for some of the activities previously ascribed to "macrophages".
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PMID:Characterization of the nonphagocytic adherent cell from the peritoneal cavity of normal and BCG-treated mice. 32 54

The present resolution (75-100 A) of the conventional scanning electron microscope (SEM) and its ability to image the surfaces of large numbers of whole cells in situ permits the approach of problems such as viral and cell surface antigen localization by immunological labeling with visual markers. Identification of virus and cell surface antigens in situ has been accomplished in indirect reactions by conjugated and unconjugated markers. Hemocyanin (Hcy) from whelk, Busycon canniculatum, has been developed as an immunospecific marker for virion and cell surface labeling in the electron microscope. Its size (approximately 30 x 50 nm) and distinct cylindrical shape permit easy visualization in the SEM and TEM. The Hcy method involves the preparation of antisera to Hcy in appropriate hosts for use in an unlabeled antibody macromolecular procedure based exclusively on antigen-antibody affinity to couple the macromolecule to the antigen site. Further correlative data from fluorescence microscopy can be obtained from similarly labeled samples by binding fluorescein to the bridging antibodies used in the Hcy technique. The usefulness of the Hcy marker system was demonstrated using antisera to the major envelope and cell surface glycoprotein (gp70) of Rauscher murine leukemia virus (R-MuLV), a type C retrovirus. The antiserum was shown to bind to the virion and cell surfaces of virus-infected cells in the homologous virus-infected cell system. It also demonstrated the expression of R-MuLV gp70-related antigens on a murine cell line Mm5mt/c1 which produces mouse mammary tumor virus (MuMTV), A type B retrovirus. Furthermore, when used in the Hcy marker system this antiserum was able to distinguish type B from type C budding virus on the same cell. Examples of other marker systems (ferritin, peroxidase, colloidal gold, and latex) used to show anti-gp70 serum reactivity will be presented to demonstrate their applicability to cell surface labeling studies. Methods for the preparation of immunoreagents and labeling of cells are discussed.
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PMID:Immunologic techniques for the identification of virion and cell surface antigens by correlative fluorescence, transmission electron and scanning electron microscopy. 39 19

The TEAG rosette test was not devised as an immediate diagnostic indicator, but in order to detect gross differences over a period of time between the lymphocytes of patients with conditions where immune complexes may be formed, and those of normal people. In summary these results indicate that:- 1. Percentage TEAG rosettes were highly significantly increased in patients with SLE, active chronic hepatitis and carcinoma of lung compared with normal controls, when the tests were performed on suspensions, containing over 90% lymphocytes, separated from peripheral blood. 2. Estimates of mean B lymphocytes plus blood monocytes in the separated suspensions, as measured by EAC rosettes (and peroxidase and differential counts for monocytes) are exceeded by TEAG-rosetting cells in the patients tested. 3. Tests on patients with chronic autoimmune conditions (e.g. ACH and SLE) do not show a highly significant difference from normal controls with respect to mean total cells forming E-rosettes. 4. It may be speculated that some TEAG rosettes are formed by T-cells which could have immune complexes or autologous anti-lymphocyte globulin on their surface and that such a condition may account for the depressed T-cell function found in these conditions.
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PMID:Lymphocyte surface-attached immunoglobulins in some clinical conditions. 108 63

With an aim to better understand the pathogenesis of nerve damage in leprosy, peripheral nerve biopsies from six untreated leprosy cases (3 BT/TT and 3 BL/LL) were studied by electronmicroscopy and immuno-histology. In addition to routine histopathology for diagnosis, infiltrating cells of granuloma were characterized after preparation of single cell suspension. The lymphocytes in the lesion were characterized by E and EAC rosetting and macrophage phagocytic system (MPS) cells were studied using histochemical markers like esterase and peroxidase. The results indicate that the lymphocyte content was significantly greater in tuberculoid neural granuloma compared to lepromatous nerves and these formed rosettes with sheep erythrocytes (E) and expressed HLA-DR antigen suggesting that they are activated T cells. Infiltrating macrophages in both the tuberculoid and lepromatous neural granuloma were esterase positive, peroxidase negative and did not form rosettes with sheep erythrocytes or EAC. Ultrathin sections of tuberculoid granuloma showed lymphocytes clearly associated to epithelioid macrophages having well developed Golgi apparatus and rough endoplasmic reticulum. Correlation of these immunological and ultrastructural characters suggests that hypersensitivity mechanisms are possibly responsible for nerve damage in tuberculoid leprosy. Ultrastructural examination of lepromatous nerves, on the other hand, showed the predominance of macrophages with large nucleus, heavily bacillated Schwann cells, and a few lymphocytes. The correlation of immuno-histological and ultrastructural characters indicates that the mechanism(s) of nerve damage in lepromatous leprosy are basically different wherein hypersensitivity appears to play a very limited role.
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PMID:A preliminary study of correlation of immuno-histological and ultrastructural characteristics of neural granuloma in leprosy patients. 133 75

It has been suggested that matrix molecules like fibronectin and laminin influence the differentiation and migration of embryonic cells. We investigated the role of these two glycoproteins in somitogenesis as well as in the differentiation and migration of the avian Wolffian (pronephric and mesonephric) duct. At first, we described essential steps in the development of these two organ anlagen by light microscopy, SEM and TEM. To localize fibronectin and laminin more exactly in the actual stages, we used the indirect immunoperoxidase reaction at the light microscopic level and the peroxidase-antiperoxidase technique at the ultrastructural level. Fibronectin was found at the surface of the unsegmented paraxial mesoderm, increasing in the cranial direction, and in the basal laminae of somites and Wolffian duct. The mesenchymal tip of the duct contains a moderate amount of fibronectin. In the two investigated organ anlagen, laminin was found mainly in the basal laminae. The role of fibronectin and laminin was investigated further by using synthetic peptides that mimic the main cell binding domain of either fibronectin or laminin, and that competitively inhibit their cell surface receptors. Thus, the pentapeptides GRGDS, YIGSR, and for control, SHLVE were micro-injected under the ectoderm of 2-day-old embryos. After treatment with GRDS, the Wolffian duct and the segmental plate are more compact. The rounded cells exhibit only short processes and narrow intercellular spaces. At the side of injection the duct shows a delay in migration. After treatment with YIGSR the Wolffian duct migrated laterally over the somatopleure. The basal laminae seem to be incomplete. SHLVE had no effect. Our results suggest that fibronectin is a prerequisite for the migration of the Wolffian duct, and that laminin probably plays a role in guiding the duct. The epithelialization during somitogenesis and differentiation of the duct is a more complex process involving also fibronectin and laminin.
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PMID:The role of fibronectin and laminin in development and migration of the avian Wolffian duct with reference to somitogenesis. 186 90

By the production of microbicidal agents, such as reactive oxygen species, activated PMN are capable of inducing tissue damage in the host. TNF-alpha was recently shown to be a potent activator of PMN oxidative metabolism. To further evaluate the interaction between activated PMN with physiological target cells, the effect of human PMN on cultured bovine aortic and human umbilical vein endothelial cells (EC) upon stimulation with human TNF-alpha was investigated by ultrastructural techniques: Scanning and transmission electron microscopy (SEM and TEM resp.) and ultrastructural detection of H2O2 production. When isolated PMN were added to EC in the presence of recombinant human TNF-alpha (10(3) U/ml) the EC-monolayer was disrupted within 4 h and EC changed their shape by exhibiting a spindle-like structure. PMN were seen in the intercellular spaces. Release of H2O2 was observed at the surface of the PMN plasma membrane, the luminal part of the small intracytoplasmic vacuoles in the PMN as well as in the contact zone between PMN and EC, but not within the EC. Scavengers of reactive oxygen species, such as superoxide dismutase and catalase or D-mannitol failed to block the effect of TNF-alpha-stimulated PMN on EC. In contrast, addition of NaN3 (0.1 mM), an inhibitor of myeloperoxidase activity, almost completely inhibited the disruption of EC-monolayers. Subsequent addition of NaN3-insensitive horseradish peroxidase reconstituted the effect. The results obtained suggest that TNF-alpha-stimulated PMN effectively cause the disruption of EC monolayers by an adherence-dependent mechanism which is mediated by the release of myeloperoxidase. The results may be of major importance for the pathogenesis of inflammatory vascular reactions.
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PMID:Interaction of granulocytes and endothelial cells upon stimulation with tumor necrosis factor-alpha: an ultrastructural study. 209 2


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