Biomedical subjects
Publications and source records attributed to M Sakamoto.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Under ultrasound guidance, we treated 25 cases of renal cyst with 99% ethanol instillation to prevent the recurrence of this disease from January 1985 to June 1987. Patients' age was from 17 to 85 years old with the average age of 63 years. Twelve cases were men, and 13 cases were women. Among the 25 cases, eleven were asymptomatic and 14 showed clinical features of lumbago, microhematuria, hypertension or proteinuria. The aspirated site was the right side in 9, left side in 14 and bilateral kidneys in 2 cases. Subsequently, cyst puncture was carried out 27 times. We encountered 12 complications following puncture. These complications were derived from the puncture itself or caused by the ethanol instillation. Flank pain caused by the injection of ethanol, nausea, causalgia or a feeling of drunkenness appeared immediately after the inoculation procedure. However, no serious complications such as pneumothorax, perirenal hematoma or infection were recognized. Some complications arose in 7 cases of 9 examples (77.8%) following more than 50 ml of ethanol injection, but the complications were observed in only 5 cases of 18 examples (22.8%) following less than 50 ml of administration. Based on these findings, ethanol injection in renal cysts appears to be useful for the treatment of this disease. In case of huge cysts when more than 50 ml of ethanol, is instilled the case should be followed up carefully after the instillation procedure.
Explore the source record for details and available documents.
This study clarifies the correlation between guanidino compounds and other laboratory findings including peroxidative markers in the sera of patients undergoing regular haemodialysis. The concentration of guanidine, for example, correlates significantly with iron, ferritin, and malondialdehyde. Guanidine is synthesized from various guanidino compounds such as arginine, guanidinoacetic acid, creatinine, creatine, methylguanidine, guanidinosuccinic acid, and canavanine in vitro by the hydroxyl radical. These results suggest that guanidine is synthesized as a result of active oxygen, and demonstrates the importance of guanidine as an indicator of the peroxidative state in patients with uraemia.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A 3-year-old boy, with left testicle absent, a 3-year-old boy with right testicle absent and a 5-year-old with left testicle absent visited our clinic. On operation the testes and the vas could not be found in the inguinal canal or in the retroperitoneal space in all 3 cases. These three cases are reported along with embryological studies.
The quantitative changes of cytoplasmic vesicles and vacuoles in lymphatic endothelial cells of the mongolian jirds associated with Brugia pahangi infections were observed by transmission electron microscopy. The present study revealed a decrease in the proportion of cytoplasm occupied by vesicles and in the number of cytoplasmic vesicles in endothelial cells from lymphatic vessels harboring B. pahangi at 3, 4, and 10 mo after infection (3.55, 3.36, and 2.55 vesicles/micron 2, respectively) when compared with cells from uninfected control vessels (7.03 vesicles/micron 2). On the contrary, there was an increase in the area of vacuoles in endothelial cells of jirds at 3, 4, and 10 mo postinfection. The mean +/- SD diameter of vesicles in cells from lymphatic vessels at 10 mo after infection was significantly smaller (78.6 +/- 5.6 nm) compared to vesicles in uninfected vessels (87.5 +/- 9.7 nm).
Explore the source record for details and available documents.
Pharmacological doses of niacin and its analogues were given intraperitoneally to rats with and without coadministration of a hepatocarcinogenic dose of diethylnitrosamine (DEN), and their effects on the induction of ornithine decarboxylase (ODC, EC 4.1.1.17) activity in the rat liver were studied. The induction of ODC activity by DEN was inhibited by 74.3, 85.5, 94.6, 97.6, 72.6 and 55.2% by nicotinamide, nicotinic acid, 3-hydroxymethylpyridine, beta-picoline, pyridine-3-aldehyde and ethylnicotinate respectively. When given alone, these analogues did not induce ODC activity. All these compounds are known to have a niacin effect. DEN-induced ODC activity was also inhibited by 84.0, 93.3, 52.8 and 75.9% by 6-aminonicotinamide, picolinic acid, pyridine-3-sulfonic acid and thionicotinamide, respectively, but, peculiarly, they induced ODC activity by their administration alone. These niacin analogues are known to have anti-niacin effects. Tryptophan, N'-methylnicotinamide and isonicotinic acid hydrazide did not affect the DEN-induced ODC activity but could induce ODC by themselves. Tryptophan belongs to the former group and isonicotinic acid hydrazide to the latter group. The reason for these discrepancies is discussed.
Based on the observation that congenic haired and hairless mice differ in the hyperkeratinizing/hyperproliferative epidermal response following topical exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in vivo, it has been proposed that this response in mice segregates with the Ah locus (which controls for the Ah receptors) and the hr locus (for hairlessness) (Knutson and Poland, 1982). In the present studies this hypothesis was tested by comparing the response of epidermal keratinocytes derived from genotypically segregated newborn haired and hairless HRS/J mice to TCDD exposure in in vitro cultures. the parameters monitored were stimulation of cell proliferation (as measured by protein content and rate of tritiated thymidine incorporation in cultures), epidermal transglutaminase activity, cornified cell envelope formation, and keratin staining with Rhodanile blue. Results suggested that the sensitivity of HRS/J haired and hairless mouse epidermal keratinocyte cultures to TCDD exposure in vitro was very similar. In both cell cultures all parameters monitored were stimulated by TCDD exposure in a similar dose-dependent manner. This suggests that physiologic factors beyond the epidermal cells may be involved in expression of the different responses seen in the skin of mice to TCDD in vivo.
Using a radioimmunoassay for alpha-rat atrial natriuretic polypeptide (alpha-rANP), tissue levels of alpha-rANP-like immunoreactivity (-LI) in the rat spinal cord and autonomic ganglia were investigated. The alpha-rANP-LI level was higher in the more caudal parts of the spinal cord and the highest in the sacral spinal cord. alpha-rANP-LI was also detected in the superior cervical and coeliac ganglia. Gel permeation chromatographic analysis showed that the major peak of alpha-rANP-LI in the spinal cord was a low molecular weight form co-eluted with synthetic alpha-rANP. Reverse-phase high performance liquid chromatographic analysis revealed that alpha-rANP-LI with a low molecular weight in the spinal cord consisted of several components, two major components of which co-migrated with synthetic alpha-rANP (4-28) and alpha-rANP (5-28), whereas little immunoreactivity was eluted at the position of alpha-rANP. These findings suggest the involvement of ANP in the function of the spinal cord and autonomic nervous system.
Explore the source record for details and available documents.