Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038362 (stomatitis)
 8,852 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Synthesized N protein of vesicular stomatitis virus (VSV) is associated with replicated viral genomes in the infected cells. The cytoplasmic side of cell membranes was examined by quick-freezing and deep-etching replica method, in order to clarify the localization of VSV genomes. Control or infected monolayer Vero cells were fixed in 2% paraformaldehyde, scraped and centrifuged to make pellets. A drop of the cell pellet was put between two glass coverslips, which were coated with 3-aminopropyl triethoxy silane and glutaraldehyde. The cells were consequently split open and postfixed in the mixture of glutaraldehyde and paraformaldehyde. Some inside-out cell membranes on the coverslips were immunostained with anti-N monoclonal antibody directly coupled to gold particles. Others were immunostained with anti-N monoclonal antibody and rabbit anti-mouse IgG coupled to peroxidase and fixed again in glutaraldehyde. They were incubated in diaminobenzidine and hydrogen peroxide solution for 1 min. All of them were infiltrated with 10% methanol in distilled water and quickly frozen in a mixture of isopentane and propane cooled by liquid nitrogen. Such preparations were deep-etched and shadowed by platinum and carbon. Although many cell organelles were found to be associated with the cytoplasmic side of cell membranes in the normal Vero cells, few cell organelles were attached to it in the infected cells. On the contrary, special strand structures were identified, which could be immunostained with anti-N monoclonal antibody. It is concluded that platinum replicas have sufficient resolution to identify the VSV genomes coated with N protein and that these nucleocapsids can be associated with the cytoplasmic side of cell membranes in the infected cells.
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PMID:Immunocytochemical study on the cytoplasmic side of cell membranes infected with vesicular stomatitis virus by quick-freezing and deep-etching replica method. 299 6

We have used defined subcellular fractions to reconstitute in a cell-free system vesicle fusions occurring in the endocytic pathway. The endosomal fractions were prepared by immuno-isolation using as antigen an epitope located on a foreign protein, the transmembrane glycoprotein G (G-protein) of vesicular stomatitis virus. The G-protein was first implanted in the cell plasma membrane and subsequently endocytosed for 15 to 30 min at 37 degrees C. The endosomal fractions were immuno-isolated on a solid support using as antigen the cytoplasmic domain of the G-protein in combination with a specific monoclonal antibody. For comparative studies the plasma membrane was immuno-isolated from cells in the absence of G internalization with a monoclonal antibody against the exoplasmic domain of the G-protein. The immuno-isolated endosomal vesicles contained 70% of horseradish peroxidase internalized in the endosome fluid phase, exhibited an acidic luminal pH as shown by acridine orange fluorescence and differed in their protein composition from the immuno-isolated plasma membrane fraction. The fusion of endocytic vesicles originating from different stages of the pathway was studied in a cell-free assay using both a bio-chemical and a morphological detection system. These well defined endosomal vesicles were immuno-isolated with the G-protein on the solid support and provided the recipient compartment of the fusion (acceptor). They were mixed with a post-nuclear supernatant containing endosomes loaded with exogenous lactoperoxidase (donor) at 37 degrees C. Fusion delivered the donor peroxidase to the lumen of acceptor vesicles permitting fusion-specific iodination of the G-protein itself. The fusion of vesicles required ATP and was detected only with an endosomal fraction prepared after internalization of the G-protein for 15 min at 37 degrees C but not with a plasma membrane or with an endosomal fraction prepared after 30 min G-protein internalization.
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PMID:Reconstitution of vesicle fusions occurring in endocytosis with a cell-free system. 302 71

The influence of low extracellular pH on endocytosis was studied in baby hamster kidney cells. When the extracellular medium was adjusted to pH 5.7, the intracellular pH decreased within 2 min to pH 6.2 and the endocytosis of horseradish peroxidase (HRP) in the fluid phase dropped to an undetectable level. With an external pH of 6.3, the internal pH dropped to pH 6.8 and HRP was internalized at a normal rate for 5 min but accumulation during longer incubation times did not occur. Morphologically, HRP was visualized in the lumen of a subpopulation of tubular and vesicular endosomes. These observations were confirmed by subcellular fractionation studies using free flow electrophoresis. Low extracellular pH also had an effect on the endocytosis of the membrane-spanning glycoprotein G of vesicular stomatitis virus which was implanted into the plasma membrane. The internalization of G-protein was quantitated by a surface fluoroimmunoassay. The endocytosis of G-protein was not affected when the external pH was dropped to 6.3, but was reduced at an external pH of 5.7. The intracellular ATP was not depleted and the reduction of endocytosis was reversible upon return to physiological pH. Clathrin coated pits were detected by electron microscopy at the plasma membrane of the low-pH-treated cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Two threshold values of low pH block endocytosis at different stages. 342 67

The clinical and pathological study was performed in order to determine the histopathological and cytoimmunological characteristics of denture stomatitis. All specimens were biopsy materials from seventeen patients with denture stomatitis. Normal palatal mucosae from ten patients served as the control. In addition to the usual staining methods, naphtol AS-D chloroacetate esterase stain and peroxidase-antiperoxidase method were used to detect mast cells and plasma cells. Denture stomatitis could be divided into atrophic and hyperplastic types. The former showed a smooth and atrophic mucosa. The latter showed a large number of exophytic projections which were composed of marked acanthosis and submucosal fibrosis, and was further subdivided into granular and papillary subtype according to the size of projections. In the present study, there were six cases of the atrophic type, and eleven cases of the hyperplastic type (consisting of seven granular and four papillary subtypes). The hyperplastic type was more frequently observed in patients with partial dentures compared with complete dentures and was associated frequently with ill fitting of the denture base as well as agglutination of denture plaque. Cytoimmunological study revealed that there was a pronounced increase of plasma cells, especially IgG- and IgA-producing cells, and a moderate increase of lymphocytes as well as mast cells in both types of denture stomatitis. Mast cells were always noted in the area with marked plasma cell infiltration, suggesting an intimate relation between both cells. These findings suggest that the immunological reactions play some role in the pathogenesis of denture stomatitis.
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PMID:Clinico-pathological study on denture stomatitis. 348 90

Two xenotropic murine leukaemia virus (XMuLV)-related proteins--a major envelope glycoprotein gp70 and a 90K protein (probably corresponding to the uncleaved envelope precursor)--were expressed on the surface of mouse L cells as demonstrated by lactoperoxidase-catalysed iodination and immunoprecipitation with anti-XMuLV serum. These two proteins out of many labelled cell surface proteins were selectively incorporated into vesicular stomatitis virus (VSV) virions. Significant differences were found in the amounts of labelled XMuLV-related proteins between L cells and two cell lines infected with XMuLV (rabbit SIRC and lamb LKC cells). The two viral antigens represented only a small proportion of radioactivity on L cells. While in XMuLV-infected SIRC and LKC cells, the gp70 was the major labelled surface protein no detectable amounts of XMuLV-related 90K protein or of cell-specific proteins were found in these cells.
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PMID:Assembly of xenotropic murine leukaemia virus-related antigens from the surface of mouse L cells by vesicular stomatitis virus. 613 28

alpha 2-Macroglobulin (alpha 2 M) was adsorbed to colloidal gold and used as a new tool in the study of receptor-mediated endocytosis. alpha 2 M-gold is easy to prepare and is clearly visualized at the electron microscope level. When cells were incubated with alpha 2 M-gold at 0 degrees C, gold was visualized both diffusely over the cell surface and concentrated in coated pits. After cells to which alpha 2 M-gold had been bound at 0 degrees C were warmed, the gold was rapidly internalized into uncoated vesicles, previously termed receptosomes. After 30 min of incubation or longer, gold was found in small lysosomes and, later, in large lysosomes and very small vesicles in the region of the Golgi complex. This pattern of localization is similar to that previously described, using peroxidase-labeled anti-alpha 2 M antibodies. By incubating cells with both alpha 2 M-gold and vesicular stomatitis virus (VSV), we studied the internalization of these two markers simultaneously. VSV and alpha 2 M-gold rapidly clustered in the same coated pits and were internalized in the same receptosomes. Proteins and hormones adsorbed to gold may be useful in the study of receptor-mediated endocytosis.
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PMID:alpha 2-macroglobulin adsorbed to colloidal gold: a new probe in the study of receptor-mediated endocytosis. 616 81

alpha 2-Macroglobulin (alpha 2M), epidermal growth factor (EGF), and vesicular stomatitis virus (VSV) each enter cultured fibroblasts by receptor-mediated endocytosis. The present study defines some basic ionic requirements in the cell culture medium which are necessary for the maximal rate of endocytosis of these three ligands. Na+ and HCO-3 were both necessary for maximal endocytosis of 125I-alpha 2M, 125I-EGF, and 35S-VSV at 37 degrees C. The ion specificities for both the anion and cation requirements were established. The binding of 125I-alpha 2M to its cellular receptors at 4 degrees C was unaffected by the absence of Na+ and HCO-3 in the culture medium. In addition, the absence of Na+ and HCO-3 in the culture medium did not reduce cellular uptake of horseradish peroxidase by fluid phase endocytosis. Na+ and HCO-3 may be general requirements in receptor-mediated endocytosis.
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PMID:Involvement of Na+ and HCO-3 in receptor-mediated endocytosis of alpha 2-macroglobulin, epidermal growth factor, and vesicular stomatitis virus. 618 77

Infection of baby hamster kidney cells with vesicular stomatitis virus (VSV) caused a reduced rate of pinocytosis (as judged by the uptake of horseradish peroxidase) after 1 h, and maximum inhibition (60-80%) was observed at 4-6 h. This inhibition occurred 2-3 h before release of virus or changes in cell morphology. Analytical cell fractionation of homogenates of VSV-infected cells indicated that the horseradish peroxidase taken up by pinocytosis was transferred to lysosomes. The inhibition of pinocytosis required viral gene expression: little or no inhibition was detected in cells infected with UV-irradiated virus, wild-type virus in the presence of cycloheximide, or a temperature-sensitive mutant which failed to synthesize viral proteins. When cells were infected with temperature-sensitive viruses with mutations in the five VSV genes, an inhibition of pinocytosis was observed only when the viral transmembrane glycoprotein was present on the surface of the cells.
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PMID:Rapid inhibition of pinocytosis in baby hamster kidney (BHK-21) cells following infection with vesicular stomatitis virus. 619 65

Simple, sensitive, and reproducible assay systems for measurement of the biological activity of interferon are described. The methods used are based on the quantification of cell membrane-bound viral and cellular antigens in interferon-treated cells by enzyme immunoassays. To measure the antiviral activity, samples of human interferon are titrated in microplates with human or bovine cells. After incubation with challenge virus (vesicular stomatitis or herpes simplex virus) the cells are fixed with glutaraldehyde and assayed for viral antigens by enzyme-labeled antibodies. This assay permits the detection of less than 0.1 unit of interferon per milliliter, after optimization of several factors, such as type of cell, multiplicity of infection, temperature, and period of incubation. The effect of interferon on cellular antigens is measured in a similar way, by using peroxidase-labeled antibodies directed against beta 2-microglobulin. The two types of assays described appear suitable for kinetic experiments and for detection of interferons of different specificities in body fluids.
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PMID:Bioimmunoassays (BIAs) of human interferon. 619 51

A sensitive enzyme immunoassay (EIA) for determining the biological activity of human interferon was developed. Green monkey kidney (Vero) cells and human embryonic lung (HEL) cells were grown in microtitre plates, treated with leukocyte interferon (IFN alpha) and infected with vesicular stomatitis virus (VSV). Cells were fixed with paraformaldehyde and permeabilized with Triton X-100. Viral antigen synthesis was measured by labelling the cells with VSV antiserum followed sequentially by protein A horseradish peroxidase conjugate and o-phenylenediamine. Interferon activity was detected as a lowering of the absorbance value from that of the virus control wells, reflecting the inhibition of virus protein synthesis by interferon. The minimum amount of interferon producing statistically significant (P less than 0.01) decrease of absorbance in Vero cells was 1-5 international units (I.U.)/ml as in the standard plaque reduction test the detection limit was 7.5 I.U./ml or more. In HEL cells the detection limit was 1 I.U./ml measured by EIA. The EIA for interferon activity is at least as sensitive as the traditional plaque reduction test. It is reproducible, easy to automatise and requires 7-10 times less cell culture materials than the plaque reduction test. We find it preferential especially when large numbers of specimens with limited volumes are to be analysed for interferon activity.
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PMID:Sensitive interferon assay based on immunoenzymatic quantification of viral antigen synthesis. 629 74


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