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Biomedical subjects

M Homma

Publications and source records attributed to M Homma.

At least 433 records · Page 24Linked to original sources
PubMedDate not supplied

Systematic analysis of post-administrative saiboku-to urine by liquid chromatography to determine pharmacokinetics of traditional Chinese medicine.

To disclose the mystery of a traditional Chinese medicine and to identify biologically active components, we analysed post-administrative urine for Saiboku-To, an anti-asthmatic Chinese herbal remedy. Systematic analysis of the components appearing in the urine was carried out by high-performance liquid chromatography (HPLC) with normal- and reversed-phase modes in combination. beta-D-glucuronidase-treated urine was subjected to rapid-flow fractionation (RFF) to achieve fractional extraction of lipophilic components with exhaustive recovery rates. The extracts were analysed by HPLC equipped with a multi-channel UV-detector. In the first stage of HPLC, we conducted a normal-phase mode run to find magnolol derived from Magnolia officinalis, as the most hydrophobic component showing minimum retention time among the urinary products of Saiboku-To. In the next stage, mobile phase solvent composition for reversed-phase HPLC was optimized so as to retain magnolol up to 60 min. Under these conditions, other Saiboku-To urinary products, which were more polar than magnolol, appeared within 60 min. Our HPLC method used marker compounds like magnolol and could indicate the terminal peak position on the reversed-phase chromatography. We found a total of eight components in the post-administrative Saiboku-To urine. Structure identification of the isolated pure materials was achieved using nuclear magnetic resonance (NMR)-, mass (MS)- and UV-spectra, and HPLC retention profiles. They were magnolol and 8,9-dihydroxydihydromagnolol stemming from M. officinalis, medicarpin and liquiritigenin from Glycyrrhiza glabra, baicalein, wogonin, and oroxylin A from Scutellaria baicalensis, and davidigenin of an unknown origin. The pharmacological mystery of Saiboku-To should be disclosed by resolving the pharmacokinetics and pharmacodynamics of these urinary products independently and synergistically.

Adult↗
PubMedDate not supplied

Chiral resolution of four major flavanones in post-administrative urine of Chinese herbal medicines by HPLC on macroporous silica gel coated with cellulose tris(3,5-dimethylphenylcarbamate).

Direct chiral resolution of four major flavanones recovered from post-administrative urine of the traditional Chinese medicines Daisaiko-to and Shosaiko-to was achieved by high-performance liquid chromatography (HPLC) on macroporous silica gel coated with cellulose tris(3,5-dimethylphenylcarbamate), Chiralcel OD. Chromatographic conditions were optimized so as to attain satisfactory enantiomeric resolution of the polysubstituted flavanones. Urinary liquiritigenin and naringenin were considerable mixtures of R and S-enantiomers, while S-enantiomers of dihydrowogonin and dihydrooroxylin A were predominantly excreted. Our chiral HPLC techniques can be applied to pharmacokinetical evaluation of the chiral flavanone enantiomers following oral administration of the herbal medicines.

Administration, Oral↗
PubMedDate not supplied

Clinical manifestations of tularemia in Japan--analysis of 1,355 cases observed between 1924 and 1987.

A total of 1,355 cases of tularemia observed between 1924 and 1987 in Japan were viewed on the basis of clinical manifestations and the results were compared with those in the United States. The incubation period varied from one day to over one month. In 75.5% of cases, the symptoms of illness appeared within seven days with the peak on the third day. A sudden onset of flu-like symptoms was generally observed, and 92% of cases was followed by regional lymph node swelling which mostly appeared in axillary and cubital regions. They were observed predominantly at the left rather than the right side. In contrast with the cases in the United States, the number of cases of ulceroglandular type in Japan was only one third of those of glandular type. None of the pleuropulmonary cases or fatal tularemia have been reported in Japan. The number of oropharyngeal cases has remarkably increased after World War II, and is still on the rise, presumably because of the change of dietary habits in Japan. All these characteristics of Japanese tularemia are assumed to be caused by low virulence of Japanese strains of Francisella tularensis.

Axilla↗
PubMedDate not supplied

Arterial dynamic appearance of common bile duct carcinoma by helical CT on angiography (angio-HCT): four operated cases.

We present four cases of common bile duct carcinoma in which both angiographic helical CT (angio-HCT) and pancreatoduodenectomy were done in the 3 years since 1995. Angio-HCT was performed with direct infusion of the contrast medium through the gastroduodenal artery inserted on angiography. Angio-HCT displayed the tumors as lower density areas in contrast to the strong enhancement of the circumferential nontumorous areas, including the pancreas and duodenum.

Adenocarcinoma↗
PubMedDate not supplied

Overexpression of the human melanoma-associated antigen ME491 partially suppresses in vivo malignant phenotypes of H-ras-transformed NIH3T3 cells in athymic nude mice.

H-ras-transformed NIH3T3 cells that overexpressed a human melanoma-associated antigen ME491 (44-3H) were generated by transfection with the cloned ME491 antigen gene followed by a 'panning' selection, and effects of the antigen overexpression on H-ras-mediated malignant phenotypes were studied. Although in vitro growth properties of the 44-3H overexpresser cells, both anchorage-dependent and -independent, were practically the same as those of the 44-1C control cells, 44-3H cells exhibited less malignant phenotypes in athymic nude mice (in vivo), i.e. decreased tumourigenicity after subcutaneous inoculation and prolonged survival time after intraperitoneal inoculation, compared with 44-1C cells. These results suggested that overexpression of ME491 antigen partially suppressed malignant phenotypes of H-ras-transformed NIH3T3 cells in athymic nude mice through co-operating with a factor(s) or mechanism(s) that exist in vivo but not in vitro. Thus, ME491 antigen might act as a tumour suppressor under some circumstances.

3T3 Cells↗