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Biomedical subjects

M Chiba

Publications and source records attributed to M Chiba.

At least 379 records · Page 21Linked to original sources
PubMed1982

Immunity to cytopathic agents associated with Crohn's disease: a negative study.

Serum and peripheral blood lymphocytes from 10 patients with Crohn's disease and 10 healthy subjects were examined for immunological reactivity against chick embryo cell cultures displaying cytopathic effects after inoculation with 0.2 micro filtrates prepared from Crohn's disease intestinal tissues. Although the assay systems (indirect immunofluorescence, lymphocyte transformation, and cytotoxicity) yielded positive results using well-characterized cytopathic viruses (mumps, measles), neither Crohn's disease nor healthy subjects showed immune reactivity to the chick embryo cell cultures inoculated with Crohn's disease intestinal tissues in any of the assay systems. These experiments provide evidence against the hypothesis that the in vitro cytopathic effect on chick embryo cell cultures produced by Crohn's disease intestinal filtrates are caused by a replicating virus or viruses.

Adult↗
PubMed1982

Insulin response to glucagon with or without tolbutamide in normal and diabetic subjects.

In order to investigate insulin response to glucagon, eight normal subjects and thirty diabetic patients were studied. According to fasting blood glucose, diabetic patients were classified into three groups; mild, moderate and severe. An oral glucose tolerance test, a glucagon test and a tolbutamide-glucagon test were performed at intervals of several days. In the glucose tolerance test, insulin response was reduced in the patients with moderate or severe diabetes. Plasma insulin increased and reached a peak 3 min after glucagon injection (glucagon 1) in the normal controls (66.1 +/- 9.9 microunits/ml), while plasma insulin response to glucagon 1 was reduced in the three diabetic groups (35.8 +/- 7.3, 33.2 +/- 9.7 and 22.9 +/- 5.0 microunits/ml, respectively). In the normal subjects glucagon injected 60 min after tolbutamide (glucagon 2) caused a rise in insulin (72.0 +/- 4.9 microunits/ml). In the diabetic groups, glucagon 2 caused a reduced response of plasma insulin (38.6 +/- 8.9, 49.5 +/- 17.4 and 34.8 +/- 11.3 microunits/ml, respectively). Glucagon with or without tolbutamide produced a far greater maximal response of plasma insulin in all the diabetic groups than in the normal subjects, while glucose produced a not significantly different increment of plasma insulin between the normal subjects and the mild diabetics. The present study demonstrates the glucagon injection with or without tolbutamide could clearly discriminate the insulin response in diabetics from that in normal subjects.

Adult↗
PubMed1981

Characterization of structural properties for morphological differentiation of melanosomes: I. Purification of tyrosinase by tyrosine affinity chromatography and its characterization in B16 and Harding Passey melanomas.

To characterize how structural properties are related to the morphological differentiation of melanosomes, two forms of melanosomes, commonly seen in mammals, were isolated from B16 and Harding Passey (HP) mouse melanomas. From these morphologically different melanosomes, tyrosinase was solubilized by BRIJ-35 and purified by affinity chromatographies substituted with tyrosinase substrates. We found that tyrosine ethyl ester (TEE) and dopa are effective and specific in retaining tyrosinase as an affinity media and that enzyme retrieval with approximately 100% recovery is possible by a substrate, TEE, or a competitive inhibitor, N-acetyl L-tyrosine. The purified tyrosinase of B16 and HP melanosomes possessed a common antigenic site and revealed little difference in size and the Mikaelis constant for dopa utilization. It is likely that tyrosinase is involved in melanosome morphogenesis only through melanization, and that it is not directly related to the architecture, i.e., lamellar and granular patterns, of the inner matrix.

Animals↗
PubMed1981

Human colonic intraepithelial and lamina proprial lymphocytes: cytotoxicity in vitro and the potential effects of the isolation method on their functional properties.

Colonic mucosal lymphoid cells, selectively enriched for intraepithelial (IEL) or lamina proprial lymphocytes (LPL), were isolated by sequential EDTA-collagenase treatment of resected human colons. Cytotoxic activities of colonic and peripheral blood lymphoid cells (PBL) were tested in three different assays, using chicken erythrocytes (CRBC) and Chang cells as targets. Antibody-dependent cell-mediated cytotoxicity (ADCC) and PHA-induced cytotoxicity (MICC) for both targets were shown by all the isolates of PBL, as was spontaneous cell-mediated cytotoxicity (SCMC) for Chang cells. However, no SCMC or ADCC for Chang cells was found with LPL, and IEL showed minimal or no activity in either assay. PBL, LPL and IEL demonstrated MICC for Chang cells but, contrasting with PBL and LPL, IEL showed no MCC for CRBC. No significant differences were found between the cytotoxic capabilities of colonic lymphoid cells from patients with inflammatory bowel disease and those from patients with other colonic diseases. Importantly, control studies with PBL showed that SCMC for Chang cells and ADCC for CRBC and Chang cells were reduced by collagenase treatment used in the isolation, of LPL. Also, SCMC for Chang cells was reduced by the treatment of PBL with EDTA. In contrast, neither EDTA nor collagenase reduced MICC for CRBC or Chang cells. Both forms of treatment induced variable degrees of cell losses in the PBL. By analogy, it can be implied that the isolation of intestinal mononuclear cells using EDTA and collagenase may influence some of their cytotoxic activities in vitro. This raises an important caveat in the interpretation of such studies.

Adolescent↗
PubMed1981

Further observations of the digital plethysmography in response to auditory stimuli and its clinical applications.

Further observations of the digital plethysmography with auditory stimuli and its clinical applications were performed in patients with vibration disease and heart diseases. The responsive pattern to the auditory stimuli in the digital plethysmogram could be faithfully reproducible if it elapses more than 5 minutes apart between the first stimulus and the second one. The responsive patterns were divided into four types: normal (N), hyperreactive (I and D) types and hyporeactive (P) type. The values of urinary catecholamine increased in parallel to the activity level of the autonomic nerve. The hyperreactive type (D) had the highest value of urinary catecholamine, and vice versa. With regard to the age, the elderly was prone to show hyporeactive (P) type, and the young tended to be hyperreactive (D) type. Psychologic factors were examined by Cornell medical index. Neurosis was not necessarily related to the hyperreactive type. In clinical applications, it was observed by this method that the autonomic imbalance in patients with vibration disease, angina pectoris, or hypertension was recovered by the treatment, and the abnormal types of the response recovered to N type. In conclusion, the digital plethysmography with auditory stimuli as one of the autonomic nerve function tests would be much useful and non-invasive method for observation of clinical course and decision of the severity.

Adult↗