Biomedical subjects
Publications and source records attributed to H Masuda.
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To study the morphological changes in the endothelial surface of the artery induced by wall shear stress load, an arterio-venous shunt was constructed between the common carotid artery and the external jugular vein in 21 dogs. The ultrastructural changes in the endothelial surface were observed by scanning electron microscopy after the measurement of the hemodynamic parameters. In acute experiments (3 days or 1 week postoperative), the clear ultrastructural changes, such as the disturbance of the smooth folds, the find transverse wrinkles, the small spindle swellings, the splitting of the intercellular junction of the endothelial cells and occasionally the desquamation of the endothelial cells, were significantly observed as proportional to the elevated flow rate ratio (fs/fc, fs: flow rate of the shunted artery, fc: flow rate of the control artery). In subacute experiments (2 or 4 weeks postoperative), the small spindle swellings were observed in the shunted artery with high flow rate ratio. In chronic experiments (5 or 6 months postoperative), these changes were less proportional to the flow rate ratio. These morphological changes were significant in the disturbance of the endothelial barrier in acute experiments and they were significant in adaptive regulatory change in the chronic experiments. These support our previous observation (Am. J. Physiol. 239, H14-21, 1980). The possibility of the wall shear stress for atherogenesis was discussed.
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Of 1,749 volunteers in a screening program for gastric cancer in Japan, 206 men and 181 women received a systematic gastroscopic examination and responded to a dietary questionnaire estimating their quantitative intake of 33 food items during the past weeks. When diet was correlated with intestinal metaplasia (a precursor lesion of gastric carcinoma) found in gastroscopic biopsies, it was observed that more dried fish consumption and less vitamin A intake increased the extent of intestinal metaplasia in men. For women, there was a significant negative association of ume (pickled plum) intake with intestinal metaplasia. The implications of these findings were discussed in relation to gastric cancer.
Recently, a new antibiotic of cephamycins, cefmetazole (CMZ) has been developed. In our clinic, CMZ was used to examine its clinical effect and adverse reactions, and the results were herein reported. The CMZ was administered to 8 patients for the prevention of postoperative infections, 7 with genitourinary infections and 1 with maxillitis complicated with uremia. For these patients, a daily dose of 1 to 6 g of CMZ was intravenously given for a period of 4 to 12 days. Among the 8 patients who received CMZ for the prevention of postoperative infections, there were 1 case with urinary tract infection, 1 with wound infection and 2 with fever of over 38 degrees C, but they had no serious infections. In the clinical observations on 3 cases with pyelonephritis, the CMZ showed marked effectiveness in 2 cases and effectiveness in 1 case. It must be noted that CMZ was proved to be markedly effective for pyelonephritis caused by Serratia marcescens. In the cases with acute epididymitis and prostatitis, a good effect of CMZ was obtained. Similarly in the case with maxillitis complicated with uremia, the maxillitis was improved by the effect of CMZ and hemodialysis. No cases with hepatic or renal dysfunction were observed after using CMZ. It is concluded that satisfactory effect of CMZ was obtained clinically.
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One-hundred-fifteen patients with cervical cancer were treated by placing bleomycin, carbazilquinone (Carboquone), and 5-fluorouracil suppositories in contact with cancer lesions located in the vaginal portion of the uterus or by inserting them into the cervical canal, twice a week, one to 14 times. The cancer lesions disappeared form 17 to 33 patients with Stage 0 lesions and 9 of 42 with Stage IA lesions. The remaining lesions were principally found in the deep portion of the cervical glands and tended to decrease the more often the suppositories were applied. This led to the presumption that if this local therapy had been carried on longer it would have eradicated even the remaining lesions from the patients with Stage 0 and IA lesions. The optimal per administration dose of bleomycin appeared to be 30 mg. The use of Witepsol (Dynamit Nobel Aktiengesellschaft, F.R.G.) suppository base was accompanied by frequent adverse reactions to it, which hindered the local therapy from being repeated over long periods of time. An equal amount mixture of hydroxypropyl cellulose and carbomer (Carbopol 934) as the suppository base was accompanied by relatively less adverse reactions, which permitted the prolonged local therapy with the suppositories. A trace of bleomycin was also found in the ovaries, but it did not cause microscopically evident histologic changes, nor did it affect the menstrual cycle. If early cancer can be treated completely by local therapy, it will be useful for the younger patient with early cervical cancer.
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Inducibility of chromosomal aberrations, cell survival, and mutation to 8-azaguanine (8AG) resistance in cultured V79 cells by 1-phenyl-3,3-dimethyltriazene (PDMT), 1-phenyl-3,3-diethyltriazene (PDET), and 1-(pyridyl-3)-3,3-diethyltriazene (PyDET) were examined with or without metabolic activation. Chromosomal aberrations were induced in a dose-dependent manner by all 3 triazenes in a direct treatment for 24 h. Chromosomal aberrations were also induced by PDMT with metabolic activation system for 3 h, and little differences in the incidences were observed compared with those obtained by a direct treatment. All 3 triazenes were slightly mutagenic in a direct treatment for 24 h. In metabolic activation experiments, however, PDMT and PyDET were highly mutagenic. The mutagenicity, when compared with the cytotoxicity, was significantly higher in a metabolic activation system than in a direct treatment.
Because of 4-nitroquinoline 1-oxide (4-NQO) selectively induces lung tumors in offspring of ICR/Jcl inbred mice, unscheduled DNA synthesis (UDS) induced by 4-NQO was investigated with use of confluent primary cultures of cells from six different organs of ICR/Jcl mouse embryos. The UDS level of lung-derived cells (lung cells), as measured with hydroxyurea-resistant incorporation of [3H]thymidine into cellular DNA in the presence of 4-NQO, was at least threefold lower than levels in cells from skin, intestine, kidney, liver, and brain, when compared at equitoxic doses of 4-NQO of equimolar binding of 4-NQO to DNA Autoradiographic studies also revealed that the percentage of UDS-positive nuclei in lung cells was about one-fifth of other cell types. Cytotoxic examinations showed that the lung cells were the most sensitive to the lethal action of 4-NQO. These results suggest that the capacity of cells from the target organ to repair 4-NQO damage is intrinsically much lower than the capacity of cells from nontarget organs.
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