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Biomedical subjects

M Azuma

Publications and source records attributed to M Azuma.

At least 379 records · Page 21Linked to original sources

Negative inotropic effects of halothane, enflurane, and isoflurane in papillary muscles from diabetic rats.

Myocardial contractile responses to halothane, enflurane, and isoflurane were studied in papillary muscles isolated from streptozotocin-induced diabetic rats and in those from age-matched control rats. The developed tension in diabetic papillary muscles electrically paced at a constant rate was not different from that in control muscles, but both the time to peak tension and the relaxation time of the isometric contraction were significantly prolonged in diabetic muscles. Halothane, enflurane, and isoflurane all produced negative inotropic effects in both diabetic and control muscles. However, the negative inotropic effects were significantly less in the muscles from diabetic rats than in the muscles from control rats throughout the range of concentrations. In muscles from both the diabetic and control rats, the negative inotropic effects of these anesthetics were accompanied by decreases in the time to peak tension and in relaxation time. The results suggest that the myocardium from the diabetic rat is less sensitive to the negative inotropic action of volatile anesthetics than is the myocardium of normal hearts.

Animals↗

[Studies on small thyroid carcinoma in dialysis patients with hyperparathyroidism].

For twenty long-term hemodialysis patients with medically uncontrolled hyperparathyroidism, subtotal parathyroidectomy (PTX) was performed and histological examination was done for 17 out of them, suspected of thyroid disease from operative findings. Thyroid carcinomas were found in 5 out of 17 patients by biopsied specimens of thyroids. Histological findings of carcinomas were follicular (2 cases) and papillary types (3 cases). In all cases, carcinomas were in occult state and the sizes of carcinomas of 4 cases were small being a diameter less than 10 mm. Among others, findings of follicular adenoma (2 cases) and chronic thyroiditis (1 case) were obtained. The incidence rate of thyroid carcinoma in this report seemed to be rather high as the incidence diagnosed from biopsied specimen at operation. Several factors such as immunological incompetence accompanied by renal failure, metabolic abnormalities of cells induced by parathyroid dysfunction and accelerated aging are considered to be involved as a cause of increased incidence of thyroid carcinoma in hemodialysis patients with hyperparathyroidism.

Adenocarcinoma↗

Effect of dibutyryl cyclic AMP on morphologic features and biologic markers of a human salivary gland adenocarcinoma cell line in culture.

Dibutyryl cyclic AMP (dB-cAMP) has marked effects on the growth, morphologic features, and biologic markers of a human salivary gland adenocarcinoma cell line in culture. A cell line with ultrastructure and biologic markers specific to the intercalated duct cells of human salivary glands was cultivated in the presence of dB-cAMP. Major alterations, such as process formation and expression of myofilaments and oxytocin receptor in addition to myosin and S-100 protein, were observed in those cells with a phenotype similar to myoepithelial cells. Both the anchorage-independent and anchorage-dependent growths were markedly suppressed in the presence of dB-cAMP. After the removal of dB-cAMP from the culture, the treated cells returned rapidly to the phenotype of the untreated cells. These findings indicate that reversible differentiation into the myoepithelial cells of a human salivary gland adenocarcinoma cell line occurs in growth medium containing dB-cAMP.

Adenocarcinoma↗

Recurrent intraoral herpes simplex virus infection.

A 48-year-old female had primary herpetic gingivostomatitis, followed by recurrent intraoral herpes simplex virus (HSV) disease; HSV isolates were obtained from the swabs of primary and recurrent lesions; restriction endonuclease cleavage analysis of the viral DNAs extracted from Vero cells infected with the HSV isolates according to the method of Hirt was carried out. The viral DNAs were cleaved by restriction endonucleases such as BamHI, KpnI and SalI and resolved by agarose gel electrophoresis, followed by staining with ethidium bromide. Consequently, their cleavage patterns were very similar to one another and were identified as HSV type 1. From these findings, it can be concluded that primary and recurrent lesions of this case are caused by the same virus.

Complement Fixation Tests↗

Immunohistochemical demonstration of carcinoembryonic antigen (CEA) on tissue sections from squamous cell head and neck cancer and plasma CEA levels of the patients.

45 squamous cell head and neck cancers including 36 with carcinoma of the oral cavity and 9 with carcinoma of the maxillary sinus were examined immunohistochemically for the presence of CEA. 12 of 30 carcinomas of the oral cavity and 7 of the 9 carcinomas of the maxillary sinus had tumors containing CEA. This difference in the occurrence of CEA was statistically significant. The mean plasma CEA level of 36 patients with carcinoma of the oral cavity and 7 patients with carcinoma of the maxillary sinus was 1.95 +/- 1.72 ng/ml and 3.70 +/- 3.53 ng/ml, respectively. Significant elevation of plasma CEA levels was found only in the stage-IV group patients with carcinoma of the oral cavity as compared with the stage-I group patients. In the 3 patients having plasma CEA values exceeding 5 ng/ml at the time of pretherapy, plasma CEA levels were decreased to below 2.5 ng/ml with the cancer treatment followed by the complete remission. These findings indicate that plasma CEA as a tumor marker in squamous cell head and neck cancer is meaningful in a small proportion of the cancer patient population.

Aged↗

Interferon activity and its characterization in the sera of patients with premalignant lesions arising in oral mucosa.

The interferon (IFN) assay of the sera from the 26 patients with premalignant lesions such as lichen planus and leukoplakia arising in oral mucosa was performed by the plaque-reduction assay with vesicular stomatitis virus in FL cells derived from human amniotic membrane. When the serum IFN activity was characterized by acid treatment, significant increase of acid-stable IFN in the patients was found as compared with those in the normal controls. The titers of gamma-like IFN defined by anti-HuIFN-alpha and anti-HuIFN-beta in the sera of patients of 50-79 years age group (n = 17, P less than 0.002) showed a highly significant increase as compared with the relevant normal controls (n = 20). All of the 26 patients were treated with topical administration of HuIFN-beta. When the correlation between prognosis of the disease and titers of serum IFN was investigated by measuring gamma-like IFN and acid-stable IFN in the sera of patients, all of 13 patients with good prognosis after the HuIFN-beta therapy showed significantly decreased levels of gamma-like IFN (P less than 0.01), whereas the serum level of acid-stable IFN after HuIFN-beta therapy showed a significant increase compared to that before the therapy (P less than 0.05). These findings indicate that the endogenous IFN system may be associated with the pathophysiology in patients with the oral mucosal lesions.

Adult↗

Application of immune adherence hemagglutination test in the screening of blood donors carrying a high titer antibody to varicella-zoster virus.

The immune adherence hemagglutination (IAHA) test was compared with the complement fixation (CF) test and fluorescent antibody (FA) test to measure the antibody titer to varicella-zoster virus (VZV) in 70 sera of convalescents 2 to 8 weeks after herpes zoster onset. The IAHA titer correlated with the FA titer, but not with the CF titer which was lower than the IAHA and FA titers. Then, the IAHA test was used for screening of blood donors with a high titer (higher than 64 units) of antibody to VZV from 2,592 blood donors. About 14% of the sera from the donors aged 16 to 19 years had an antibody titer higher than 64 units, about 10% of sera from the donors aged 20 to 49 years, and 5.6% of sera from the donors older than 50 years. An average positive rate was about 9%, indicating that an enough VZV immune plasma with a high titer of antibody might be obtained from blood donors.

Adolescent↗

Enhancement of interferon-gamma production in glycyrrhizin-treated human peripheral lymphocytes in response to concanavalin A and to surface antigen of hepatitis B virus.

The effects of glycyrrhizin, a component of licorice (Glycyrrhiza glabra) roots, on the production of interferon-gamma in human peripheral lymphocyte-macrophage cultures by concanavalin A (Con A) was examined. Interferon-gamma production in normal lymphocyte-macrophage cultures treated with 10 to 100 micrograms/ml of glycyrrhizin at 37 degrees C for 12 hr or longer, and then treated with 10 micrograms/ml of Con A, was enhanced four to eight times compared to control cell cultures. Lymphocyte-macrophage cultures treated with 10 to 100 micrograms/ml of glycyrrhizin alone did not produce interferon. No significant difference in the adsorption of [3H]Con A to glycyrrhizin-treated and control lymphocyte-macrophage cultures was found, but RNA and protein synthesis of the treated lymphocytes was increased compared to control cells; DNA synthesis, however, was reduced. Collaboration between enriched T-lymphocytes and macrophages, both treated with glycyrrhizin, was needed for the enhancement of interferon-gamma production. A smaller increase in interferon production was also observed in the glycyrrhizin-treated peripheral lymphocyte-macrophage cultures derived from an asymptomatic carrier of hepatitis B virus, in response to Con A and surface antigen of hepatitis B virus.

Cells, Cultured↗

Emergence of differentiated subclones from a human salivary adenocarcinoma cell clone in culture after treatment with sodium butyrate.

A human salivary gland adenocarcinoma cell line, which has ultrastructure and biological markers specific to the intercalated duct cells of human salivary glands, was cultured in 5 mM sodium butyrate for 12 days; then the cells were trypsinized, subcultured for an additional 16 days, and then transferred to growth medium without sodium butyrate. Morphological changes appeared about 1 wk after return to growth medium without sodium butyrate; cells being spindle or stellate in shape appeared in the treated cells, whereas the untreated cells were polygonal in shape. This morphologically altered phenotype persists after more than 14 mo of culture in growth medium without sodium butyrate. Of 40 subclones isolated, 2 clonal cell lines were established from the subculture and characterized. The other 38 subclones were accompanied by cell death during the subcultures. The clonal lines exhibited a phenotype similar to myoepithelial cells such as myosin, beta-chain of S-100 protein, myofilaments, and oxytocin receptor in addition to decreased tumorigenicity and anchorage-independent growth. These findings indicate that commitment to differentiation into myoepithelial cells and conversion from malignant to normal phenotype occur in a human salivary gland adenocarcinoma cell line following the sodium butyrate treatment.

Adenocarcinoma↗

Induction of cells with a myoepithelial cell phenotype by treatment with dibutyryl cyclic AMP in human salivary adenocarcinoma cells 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 dibutyryl cyclic AMP (dB-cAMP) at a final concentration of 1 mM daily for 28 days and examined morphologically and immunohistochemically. The dB-cAMP treatment resulted in a marked suppression of tumor growth. In addition, tumor nests with a myoepithelial cell phenotype characterized by the presence of microfilament systems reactive with antimyosin and anti-S-100 protein sera were often observed in the treated tumors, but not in untreated controls. These findings lead us to suggest that neoplastic intercalated duct cells can be induced to differentiate into myoepithelial cells and that levels of cAMP within the cells may regulate this cytodifferentiation.

Actin Cytoskeleton↗

Therapeutic effect of human fibroblast interferon on premalignant lesions arising in oral mucosa. A pilot study.

Human fibroblast interferon (HuIFN-beta) was topically administered to 20 premalignant lesions histopathologically showing epithelial dysplasia such as leukoplakia and lichen planus which arose in the oral mucosa. HuIFN-beta was prepared in the water-soluble gel form containing 2% carboxymethylcellulose, 45% glycelin, 0.1 M citrate buffer (pH 4.5) and 0.2% SDS as stabilizing agents. This preparation was found to be effective for herpetic gingivostomatitis and zostal lesions arising along the intercostal nerve. Thus, the HuIFN-beta preparation (10(4) to 5 X 10(3) IU) was applied to the oral mucosal lesion for 1 h twice a week. The lesion with topical administration of HuIFN-beta was covered tightly with the mucosal bandage which was coated with carboxymethylcellulose, glycelin and CaCl2 on vinyl acetate matrix. The 14 oral lesions with erosion or ulcer formation accompanied by severe pain by touch, had complete remission after approximately 10 successive applications of this preparation. Although subjective symptoms such as irritation pain in the other 6 patients with severe hyperkeratotic lesion subsided, white coatings and streaks could not be completely removed by this therapy. No other side-effects excluding slight pain and reddish swelling which occurred intermittently during HuIFN-beta administration were observed.

Administration, Topical↗

Adsorption of poly rI:rC on cell membrane participating and nonparticipating in interferon induction.

PR-RK cells, which were derived from RK-13 cells by repeated treatment with a copolymer of polyriboinosinic acid and polyribocytidylic acid (poly rI:rC), were resistant to the cytotoxic effect of poly rI:rC, and could not produce interferon when exposed to poly rI:rC alone. These characteristics of PR-RK cells have not reversed for more than 40 passages of the cells in medium without poly rI:rC. Poly rI:rC was adsorbed on PR-RK cells at a rate of 60 to 70% of its adsorption to RK-13 cells. On the other hand, PR-RK cells could produce a low level of interferon when they were induced by a poly rI:rC-DEAE dextran complex, by poly rI:rC and metabolic inhibitors (superinduction), by poly rI:rC and pretreatment with interferon (priming), and by Newcastle disease virus. Interferon production in RK-13 cells in response to poly rI:rC or poly rI:rC-DEAE dextran complex was inhibited by pretreatment of the cells with anti-RK-13 cell serum and anti-RK-13 cell serum absorbed with PR-RK cells. These results suggest that PR-RK cells are deficient in the receptor for poly rI:rC, and that poly rI:rC can adsorb onto the cell membrane nonspecifically, acting as a weak inducer when transcriptional control in cells is affected by superinduction or priming. Only about 30% of the poly rI:rC adsorbed on RK-13 cells may be specific binding, participating in normal interferon induction.

Adsorption↗