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Biomedical subjects

M Okada

Publications and source records attributed to M Okada.

At least 1,351 records · Page 75Linked to original sources
PubMed1987

The effect of biological response modifiers on chronic and latent murine cytomegalovirus infections.

Host-mediated antiviral effect of 2 biological response modifiers (BRM), OK-432, and PS-K, against murine cytomegalovirus (MCMV) was evaluated in chronically or latently infected mice. In the early stage of chronic MCMV infection, the BRM-induced resistance was evidenced by decrease in infectious viruses replicated in the salivary glands and by augmented cytotoxic activity of the spleen cells against YAC-1 cells and MCMV-infected mouse embryonic fibroblasts (MEF). In the late stage of chronic MCMV infection, the BRM treatment did not eliminate MCMV from the mice, but did prevent exacerbation of MCMV infection in the salivary glands induced by administration of cyclophosphamide (CY). In mice latently infected by MCMV, BRM treatment suppressed CY-induced reactivation of MCMV in the salivary glands. It was suggested that the antiviral effect of BRM against MCMV in chronically or latently infected mice was based on activation of natural killer (NK) cells and cytotoxic T lymphocytes (CTL).

Animals↗
PubMed1987

Application of a new medium supplement for propagation and storage of human cytomegalovirus.

A new medium supplement, NU-SERUM, was evaluated for cultivation of human embryonic lung fibroblasts (HEL) and for propagation and storage of human cytomegalovirus (HCMV). NU-SERUM was comparable to fetal bovine serum (FBS) in promoting rapid growth of HEL if they were seeded at a sufficient density. HCMV replicated quite satisfactorily in HEL cultured with media supplemented with NU-SERUM as well as FBS. Inactivation of HCMV at 37 C occurred similarly when the medium contained FBS or NU-SERUM. However, at -70 C, HCMV was less stable in NU-SERUM-containing medium than in FBS-containing medium. Sorbitol added to the NU-SERUM-containing medium improved the unstableness of HCMV at -70 C, and HCMV was storable with such medium. Thus, NU-SERUM is useful as an alternative to FBS not only for growth of HEL but also for propagation and storage of HCMV.

Animals↗
PubMed1987

Nephritogenic glycoprotein. XII. Focal glomerulonephritis with myeloid bodies produced in rats by synthetic analogues of the glycopeptide, nephritogenoside.

Glomerular lesions were successfully induced in rats by a single footpad injection of synthetic analogues of nephritogenoside [alpha-Glc-(1----6)-alpha-Glc-(1-NHCO-Asn, and -Gln)]. Characteristic morphological changes of these glomerular lesions are (1) focal glomerulonephritis (FGN) and (2) the appearance of myeloid bodies in the epithelial cells of the podocytes. FGN produced by a single injection of the synthetic analogues of nephritogenoside may provide an experimental animal model of this potentially diffuse disease, since morphological changes in the early stage of sclerosing glomerulonephritis (end-stage kidney) induced by a single footpad injection of natural nephritogenoside are often identical to those of FGN.

Animals↗
PubMed1987

Interleukin-2 receptor-inducing factor(s) in adult T cell leukemia.

The expression of the interleukin-2 receptor (IL-2-R) is regulated by transcriptional and post-transcriptional mechanisms. IL-2-R gene expression is induced by pharmacological agents including calcium ions, phorbol esters such as phorbol myristate acetate (PMA) and forskolin (FK), a direct activator of adenylate cyclase. HTLV-I(+) leukemic T cells and T cell lines from patients with adult T cell leukemia (ATL) continuously expressed IL-2-R without production of IL-2. However, there was no abnormality of the structural gene for IL-2-R in these cell lines as well as in fresh leukemic cells of ATL. We have detected that many HTLV-I(+) T4(+) T cell lines constitutively produce a non-IL-2 lymphokine named ATL-derived factor (ADF), which induced the expression of the high-affinity IL-2-R on a variety of cells including HTLV-I(+) T cells, myeloid leukemia cells and YT cells. IL-2-R-inducing agents such as ADF and FK were shown to induce elevation of the mRNA levels for IL-2-R through transcriptional enhancement of the IL-2-R gene. The possible involvement of IL-2-R-inducing cytokines in the physiological lymphocyte activation and the leukemogenesis in ATL and other T cell leukemias is discussed.

Antibodies, Monoclonal↗
PubMed1987

Retinal pigment epithelial cells produce fibronectin.

Antichick fibronectin antiserum, noncross-reactive to bovine fibronectin, was prepared to determine the production of fibronectin by cultured chick retinal pigment epithelial cells which were grown in the presence of fetal bovine serum. The typical fibrillary net pattern of fibronectin was observed by an indirect immunofluorescent technique when this specific antiserum reacted with cultured chick retinal pigment epithelial cells. Cultured chick retinal pigment epithelial cells were shown to produce fibronectin.

Animals↗
PubMed1987

Cell components in proliferative vitreoretinopathy: immunofluorescent double staining of cultured cells from proliferative tissues.

Intermediate filament proteins in cultured cells from epiretinal membranes of 5 cases of proliferative vitreoretinopathy and subretinal strands of 2 cases were immunohistologically characterized. Double staining technique after colcemid treatment revealed that either keratin-positive or vimentin-positive cells were found with different ratios depending on the cases. Both positive and both negative cells were also observed. Desmin and glial fibrillary acidic protein were totally negative.

Adult↗
PubMed1987

Correlative analysis of longitudinal changes in bronchoalveolar lavage, 67gallium scanning, serum angiotensin-converting enzyme activity, chest X-ray, and pulmonary function tests in pulmonary sarcoidosis.

Despite the relatively high cost and complicated procedures, Gallium-67 (67Ga) scanning and bronchoalveolar lavage (BAL) are increasingly advocated as more sensitive indicators of disease activity in sarcoidosis than chest X-ray and serum angiotensin-converting enzyme activity (SACE). To evaluate the clinical usefulness of 67Ga scanning and BAL, we followed 31 patients with pulmonary sarcoidosis, using these four parameters, at 9- to 24-month intervals over periods of 9 to 48 months. We obtained 68 complete evaluations. Close correlations were observed among chest X-ray, 67Ga scanning, SACE, and the percentage of lymphocytes in BAL fluid (p less than 0.1 to 0.001). Longitudinal changes were also well correlated in these four parameters (p less than 0.001) and paralleled the changes in vital capacity (p less than 0.01 to 0.001). However, we were unable to predict the patients' outcome from the initial evaluation of these four parameters. These results suggest that, in terms of their usefulness for estimating disease activity, the differences among these four indicators are negligible. We therefore conclude that chest X-ray and SACE sufficiently reflect disease activity and that, at present, routine evaluation by 67Ga scanning and BAL are not necessarily indicated in the long-term management of pulmonary sarcoidosis.

Adult↗
PubMed1987

Activation of N-nitrosodialkylamines by near-ultraviolet irradiation: formation of directly-acting mutagens and DNA-damaging products.

On near-ultraviolet (UVA) irradiation in a phosphate buffer, N-nitrosomorpholine (NMOR) and N-nitrosopyrrolidine (NPYR) were converted into directly-acting mutagens. The activated NPYR was fractionated, and the active product was isolated. The compound was shown to be identical to alpha-phosphonooxy NPYR on the basis of several properties: retention times in high-performance liquid chromatograms, mutagenic specificity and potency, ultraviolet spectrum, and inactivation by phosphatase treatment. Photoactivation was inhibited by superoxide dismutase, and therefore superoxide is implicated as playing a key role in mutagen formation. N-Nitrosoproline (NPRO) and eighteen other N-nitrosodialkylamines were irradiated with UVA in the presence of phi X174 RFI DNA. The DNA underwent single-strand breaks to give RFII DNA, indicating that N-nitrosodialkylamines in general have this property. DNA chain cleavage was inhibited both by superoxide dismutase and hydroxyl-radical scavengers. These results provide new information on the genotoxic mechanism of action of N-nitrosodialkylamines.

Bacteriophage phi X 174↗
PubMed1987

Urinary metabolites of N-nitrosodibutylamine and N-nitrodibutylamine in the rat: identification of N-acetyl-S-alkyl-L-cysteines.

N-Acetyl-S-butyl-L-cysteine, N-acetyl-S-3-oxobutyl-L-cysteine and N-acetyl-S-3-hydroxybutyl-L-cysteine have been isolated and identified (as their methyl esters) from the urine of rats given N-nitrosodibutylamine (NDBA), N-nitrodibutylamine (NO2DBA) and their 1-acetoxy derivatives. Greater amounts of these N-acetyl-S-alkyl-L-cysteines were detected in the urine after administration of NDBA than of NO2DBA, and greater urinary excretion of the three N-acetyl-S-alkyl-L-cysteines was observed with 1-acetoxy NDBA than with 1-acetoxy NO2DBA. This suggests that the markedly different biological activities of NDBA and NO2DBA might be due, in part, to a difference in their alkylating abilities in vivo.

Alkylation↗