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Biomedical subjects

M Azuma

Publications and source records attributed to M Azuma.

At least 361 records · Page 20Linked to original sources
PubMed1988

Study on the apparent resistant strains of herpes simplex virus type 1 against 9-beta-D-arabinofuranosyladenine.

The appearance of drug resistant strains of herpes simplex virus type 1 (HSV-1) against 9-beta-D-arabinofuranosyladenine (araA), in comparison with 5-iodo-2'-deoxyuridine (IUdR) and 9-(2-hydroxyethoxymethyl)guanine (acycloguanosine, ACG), has been investigated in green monkey kidney cell cultures (Vero) and human embryo lung cell cultures (HEL). Growth curves of HSV-1 in Vero cells and HEL cells in the presence or absence of 20 micrograms/ml of araA showed that not only the viruses produced by these cells in the presence of araA but also the viruses produced in the absence of araA were resistant to the same concentration of araA. However, both viruses were unable to grow in the presence of a combination of 20 micrograms/ml of araA and 3 micrograms/ml of erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA) which is an inhibitor of adenosine deaminase. On the other hand, the viruses produced only in the presence of IUdR or ACG were resistant to each drug. All virus clones obtained from five serial clonings in the presence of araA alone or araA and EHNA in combination were not resistant to araA. These results show that the strain of HSV-1 resistant to araA is an apparently resistant strain, and a truly resistant strain to araA may not be established as easily as the truly resistant strains to IUdR and ACG.

Acyclovir↗
PubMed1988

Effect of B-factor and its analogues on rifamycin biosynthesis in Nocardia sp.

B-Factor, 3'-(1-butylphosphoryl)adenosine, which was isolated from yeast extract, is an inducer of rifamycin production in a rifamycin non-producing Nocardia mutant. Feeding of B-factor to the mutant culture demonstrated that the induction process was triggered during early stationary phase. Rifamycin production in the mutant was also induced by an exogenous supply of 3-amino-5-hydroxybenzoic acid, an intermediate of the antibiotic pathway, suggesting that a step upstream from the intermediate is regulated by B-factor. B-Factor analogues, i.e., alkylesters of 3'-AMP with alkyl side chains of C(2) approximately C(12) and n-butyl esters of 3'-GMP and 2'-AMP all showed the B-factor activity. Among these n-octyl ester of 3'-AMP showed the lowest effective concentration of approximately 3 x 10(-10) M. An intrinsic substance of the Nocardia sp. with potent B-factor activity and a UV absorption maximum at 260 nm was isolated from the cells of the parental strain.

Adenosine Monophosphate↗
PubMed1988

Correlation between augmented resistance to influenza virus infection and histological changes in lung of mice treated with trehalose-6,6'-dimycolate.

Mice inoculated intravenously with trehalose-6,6'-dimycolate (TDM), a glycolipid component of the cell wall of Mycobacterium, in an oil-in-water emulsion (TDM emulsion) acquired a high resistance to intranasal infection by influenza virus. Athymic nude mice inoculated with TDM emulsion could not acquire such an augmented resistance to influenza virus infection. The augmented antiviral resistance of TDM emulsion-treated mice was diminished by prior intravenous inoculation of silica particles, which selectively impair macrophage functions. In vitro experiments showed that macrophage cultures treated with TDM emulsion released an activator(s) of T lymphocytes. Histological studies of the lung of TDM emulsion-inoculated mice revealed that a typical granuloma and severe perivascular lymphocyte infiltration appeared, though no such histological change was observed in the lung of control emulsion-inoculated mice. The lungs from TDM emulsion-treated athymic nude mice and the lungs from silica particle- and TDM emulsion-treated mice showed fewer and smaller granulomata and milder perivascular lymphocyte infiltration than a typical granuloma and lymphocyte infiltration in the lungs of TDM emulsion-treated mice. These and earlier results suggest that an acquired antiviral resistance of TDM emulsion-treated mice was caused by elicitation of macrophages with TDM, then activation of T lymphocytes, leading to granuloma formation and an amplified earlier interferon production in response to influenza virus infection.

Animals↗
PubMed1988

Studies on murine IgE with monoclonal antibodies. I. Characterization of rat monoclonal anti-IgE antibodies and the use of these antibodies for determinations of serum IgE levels and for anaphylactic reactions.

Rat monoclonal antibodies were constructed by fusion of immunized rat spleen cells with a nonsecreting mouse myeloma cell. Two monoclonal antibodies (6HD5 and HMK-12) were selected for further study. Both reacted with various IgE molecules of different specificities and different allotypes, but did not react with immunoglobulins of other isotypes and with light chains. These antibodies were therefore anti-isotypic (IgE) and not anti-allotypic or anti-idiotypic. It was shown by competition studies that these antibodies recognize different epitopes on the FcR epsilon fragment. A sensitive ELISA for the quantitation of murine IgE was developed with these monoclonal antibodies; the sensitivity was between 2 and 250 ng/ml for detection of serum IgE levels. Good correlation was obtained with protein amounts as determined by enzyme-linked immunosorbent assay (ELISA) and passive cutaneous anaphylaxis (PCA) activities. Both monoclonal antibodies were used to study anaphylactic reactions elicited by IgE antibodies. Both could inhibit PCA reactions and both could elicit reverse PCA reactions.

Animals↗
PubMed1988

Monoclonal antibody to the streptococcal preparation OK-432: tissue OK-432 localization and analysis of interaction between OK-432 and macrophages or NK cells in human salivary adenocarcinoma-bearing nude mice given OK-432.

An immunoglobulin M mouse monoclonal antibody (MAb) to the streptococcal preparation OK-432, TS-1, was generated. The TS-1 antigen is a carbohydrate epitope. This antigen is stable upon fixation and embedding in paraffin. The tissue and cellular OK-432 localization in human salivary adenocarcinoma-bearing nude mice given OK-432 intratumorally was examined by various methods according to the immunological procedures using the purified TS-1 MAb. The presence of OK-432 antigen recognized by TS-1 MAb was clearly observed in the tumor as well as the spleen and lung 24 or 48 h after OK-432 administration, whereas transfer of OK-432 from the site of injection to the organs, such as liver and kidney, was rarely seen. The presence of OK-432 antigen in some immunocompetent cells, as defined by Mac-1 antigen or asialo GM1 antigen, was observed by the double-antibody labeling technique in the tumor and spleen from tumor-bearing nude mice. Moreover, interaction between OK-432 and macrophages or natural killer (NK) cells in relation to expression of interferon (IFN) in tumor-bearing nude mice given OK-432 was observed. Consequently, significant increases of Ia-positive or Ia-negative macrophages, NK cells as well as IFN-alpha/beta- or IFN-gamma-positive cells in the tumor and/or spleen were found when compared with those without OK-432 administration.

Adenocarcinoma↗
PubMed1987

Escherichia coli H+-ATPase. Glutamic acid 185 in beta subunit is essential for its structure and assembly.

The uncD gene for the beta subunit of Escherichia coli H+-ATPase was cloned downstream of the lac promoter and mutagenized (Glu-185----Gln or Lys) by an oligonucleotide-directed procedure. The recombinant plasmid was introduced into a strain in which the unc operon for subunits of H+-ATPase was deleted. The wild-type or mutant beta subunit synthesized amounted to about 10% total cell protein and was mainly found in the cytoplasmic fraction. These subunits could be purified to almost homogeneity by conventional procedures. The wild-type and two mutant beta subunits had essentially the same Kd values for 8-anilinonaphthalene-1-sulfonate, aurovertin, and ATP, although the fluorescence intensities of 8-anilinonaphthalene-1-sulfonate and aurovertin were significantly less when bound to the two mutant beta subunits than when bound to the wild-type subunit. The three beta subunits showed essentially the same circular dichroism spectra, indicating alpha-helical contents of about 16-18%. Thus, the mutations did not cause marked change of the secondary structure of the subunit. However, measurements of theta 208 during linear increase in temperature suggested that replacement of Glu-185 by Gln or Lys slightly changed the stability of the secondary structure. Only trace amounts of alpha beta gamma complexes could be reconstituted using the two mutant beta subunits. These results suggest that Glu-185 or the region in its vicinity may be essential for subunit assembly. The methods developed in this study should be useful for further studies on the beta subunit.

Circular Dichroism↗
PubMed1987

Regulation of murine IgE production in SJA/9 and nude mice. Potentiation of IgE production by recombinant interleukin 4.

Serum IgE levels were determined in different strains of mice with enzyme-linked immunosorbent assay by using rat monoclonal anti-murine IgE antibodies in normal and in Nippostrongylus brasiliensis-infected mice. After infection, serum IgE levels were high in BALB/c and CB-20, low in SJL/J and SJA/20 mice, and not detected at all in SJA/9 and nude mice. Surface IgE-positive cells were greatly increased in BALB/c and SJL/J mice after infection, but not in SJA/9 and nude mice. Most surface IgE-positive spleen cells were also surface IgM- and surface IgD-positive. When spleen cells from SJA/9 or nude mice were stimulated in vitro with lipopolysaccharide and recombinant interleukin 4 (formerly B cell-stimulating factor 1), IgE was produced and detected in the supernatants of these cultures. In addition, surface IgE-positive cells could be detected in these cultures. Most of the surface IgE-positive cells were surface IgM- and surface IgD-negative, unlike those seen in the spleens of Nippostrongylus-infected BALB/c and SJL/J mice. These observations show that SJA/9 and nude mice have IgE-producing precursor B cells, and after appropriate stimulation interleukin 4 can induce them to secrete IgE.

Animals↗
PubMed1987

Small cell undifferentiated carcinoma of the minor salivary gland containing exocrine, neuroendocrine, and squamous cells.

The light microscopic, electron microscopic and immunohistochemical features of a small cell undifferentiated carcinoma of the minor salivary gland are presented. The tumor was composed predominantly of undifferentiated small cells with focally admixed neuroendocrine, exocrine and squamous cells, occasionally arranged in an organoid manner. The presence of vasoactive intestinal polypeptide in the tumor was found immunohistochemically. In addition, the tumor cells stained with Grimelius' impregnation. Immunohistochemically the tumor contained cells that reacted positively with the antibodies to carcinoembryonic antigen, 66K keratin polypeptide, or human salivary amylase. These findings indicate that a small cell undifferentiated carcinoma of the minor salivary gland, reported here, exhibits focally multidirectional differentiation as well as neuroendocrine cell derivation.

Amylases↗
PubMed1987

Induction of cells with acinar cell phenotype including presence of intracellular amylase. Treatment with 12-O-tetradecanoyl-phorbol-13-acetate in a neoplastic human salivary intercalated duct cell line grown in athymic nude mice.

The adenocarcinoma produced by transplantation into nude mice of a neoplastic human salivary intercalated duct cell line was treated with 0.1 ml of minimal essential medium (MEM) containing 12-O-tetradecanoyl-phorbol-13-acetate (TPA) at a final concentration of 10(-7) mol/l daily for 28 days and examined morphologically and immunohistochemically. The TPA treatment resulted in an enhancement of tumor growth. In addition, tumor cells containing secretory granules positively reactive to antiamylase serum were observed in the treated tumors, but not in untreated controls. These findings lead us to suggest that neoplastic intercalated duct cells treated with TPA can be induced to differentiate into acinar cells in heterotransplanted athymic nude mice.

Adenocarcinoma↗
PubMed1987

5-Azacytidine induction of stable myoepithelial and acinar cells from a human salivary intercalated duct cell clone.

A neoplastic human salivary intercalated duct cell clone was cultured in 5 microM 5-azacytidine for 5 days at 37 degrees C; then the cells were trypsinized and subcultured in growth medium without 5-azacytidine. Thereafter, subclones were cloned from the subculture. Of 12 subclones isolated, 7 clonal cell lines were established and characterized. The two subclones composed of cells which were spindle shaped or stellate exhibited phenotypes similar to those of myoepithelial cells such as microfibrils and myosin and formed a myoepithelioma upon transplantation of the cells into nude mice. The other five subclones were composed of polygonal cells with numerous secretory granules in their cytoplasm and containing amylase that seems to be specific to acinar cells; transplantation of these cells into nude mice resulted in production of acinic cell carcinoma. These findings indicate that a neoplastic human salivary intercalated duct cell is capable of at least bidirectional differentiation.

Adenocarcinoma↗
PubMed1987

Role of interferon in the augmented resistance of trehalose-6,6'-dimycolate-treated mice to influenza virus infection.

Mice inoculated intravenously with 10 to 100 micrograms trehalose-6,6'-dimycolate in an oil-in-water emulsion (TDM emulsion) acquired high resistance to intranasal infection by influenza virus at 7 to 14 days, but not at 1 day, after treatment. Mice inoculated with an oil-in-water emulsion without TDM (control emulsion) did not resist infection. The activity of the reticuloendothelial system of mice inoculated with TDM emulsion or control emulsion was greatly stimulated 1 day and 14 days after treatment. Interferon production in response to influenza virus was augmented in lung and serum of TDM emulsion-treated mice. The augmented interferon production was greatly diminished in the TDM emulsion-treated mice by treatment with anti-Thy-1.2 monoclonal antibody. Production of haemagglutination-inhibiting antibody in the TDM emulsion-treated or control emulsion-treated mice was higher than that in untreated mice, although no difference was observed between the TDM emulsion-treated and control emulsion-treated mice. On the other hand, TDM emulsion treatment of mice did not influence the appearance of antibody-producing cells, nor the activity of natural killer cells in the mice. The enhanced resistance of mice was diminished by inoculating anti-interferon-alpha/beta serum before influenza virus infection. No detectable interferon activity was observed in lung and blood of mice inoculated with anti-interferon-alpha/beta serum prior to influenza virus infection. These results suggest that the augmented early interferon production in T-lymphocytes of TDM emulsion-treated mice in response to influenza virus may play an important role in the enhanced resistance.

Animals↗
PubMed1987

Expression of vasoactive intestinal polypeptide and amylase in a human parotid gland adenocarcinoma cell line in culture.

A neoplastic epithelial cell line initially established in culture from a human parotid gland adenocarcinoma grown in athymic nude mice with a BALB/c genetic background, which has an ultrastructure similar to that of the intercalated duct cell of the salivary glands, was examined for the expression of amylase and vasoactive intestinal polypeptide (VIP). The cultured cells were found by the peroxidase-antiperoxidase (PAP) method to express amylase and ultrastructurally to have secretory granules showing positive immunoreaction with anti-amylase serum. In addition, the cells were found to secrete amylase into the culture medium. The expression of VIP in the cultured cells was observed by the PAP method, immunofluorescent staining method, or immunoelectron microscopy. Moreover, the presence of the polypeptide reactive to antibodies directed against VIP in the cultured cells was confirmed by immunoblotting and radioimmunoassay. These findings indicate that the cells proliferating in culture express both amylase and VIP.

Adenocarcinoma↗