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Biomedical subjects

N Uchiyama

Publications and source records attributed to N Uchiyama.

77 records · Page 5Linked to original sources
PubMedDate not supplied

Sex difference in metabolism of simvastatin by rat hepatic microsomes.

Metabolism of simvastatin (SV), a new cholesterol-lowering agent, by hepatic microsomes from male and female rats was investigated. After incubation of [14C]-SV with hepatic microsomes, radioactive metabolites were detected by HPLC. The main metabolite was 3' alpha-hydroxy-SV in male rats and the hydroxy open acid form of SV (SVA) in females. The 3"-hydroxy-SV and 3',3"-dihydroxy-SV which were observed in male rats were hardly detected in females. Specific activity for the metabolism of SV in male rats (3.97 nmol/mg protein/min) was about 9-times higher than that in females. Metabolic activity of hepatic microsomes in male rats was essentially unchanged with increase in age, whereas that in females decreased age-dependently and was very low or negligible after 7 weeks of age. Formation of 3"-hydroxy-SV and 3',3"-dihydroxy-SV in male rats was markedly increased with age, and that in females was negligible at all ages examined.

Aging↗
PubMedDate not supplied

Interaction between non-ionic contrast medium and prostaglandin E1 incorporated in lipid microspheres: in-vitro comparative study of direct and non-direct mixing.

PURPOSE: To examine whether there is any interaction between non-ionic contrast medium and prostaglandin E1 incorporated in lipid microspheres (Lipo-PGE1) in direct and non-direct mixing. MATERIALS AND METHODS: Iopamidol 300 and 370 mgI/ml, iohexol 300 and 350 mgI/ml, and iopromide 300 and 370 mgI/ml were mixed with Lipo-PGE1. In the direct mixing test, both agents were mixed directly in a tube. The appearance of the mixture, average size of the Lipo-PGE1 particles, and changes in pH were observed. In the non-direct mixing test, both agents were poured one after the other into a narrow luminal glass tube. The appearance of the mixture was observed. Lipo-PGE1 and the contrast agent were discharged sequentially via a catheter placed in 5 L of physiological saline. The appearance of the physiological saline was observed. RESULTS: In the direct mixing test, no interaction was observed between iopamidol, iohexol, or iopromide 300 mgI/ml and Lipo-PGE1. Aggregation and creaming were observed in the mixture of iopromide 370 mgI/ml and Lipo-PGE1, and average particle size increased over time. However, there was no apparent change in pH. In the non-direct mixing test, none of the test contrast agents interacted with Lipo-PGE1. CONCLUSION: The test non-ionic contrast media, even if they interacted with Lipo-PGE1 when mixed directly, did not appear to interact with Lipo-PGE1 when mixed in a non-direct manner, which represents the clinically used prescription in pharmacoangiography.

Alprostadil↗
PubMedDate not supplied

Radiographic features of invasive lobular carcinoma of the breast.

PURPOSE: To evaluate the radiographic features of invasive lobular carcinoma of the breast. METHODS: We evaluated the radiographic features of 61 cases of histopathologically documented invasive lobular carcinoma. Mammography was performed in all cases. In seven of 61 cases, helical CT with contrast medium was also carried out. Mammographic findings were analyzed to determine true-positive and false-negative rates for the detection of neoplasm. Further, the diameter of the tumor as determined on mammography and helical CT was noted for comparison with the pathologic size. RESULTS: Mammographic features were divided into six types: spiculated mass (38%), indistinct mass (5%), obscured mass (23%), asymmetric opacity (16%), architectural distortion (16%), and no findings (2%). Microcalcifications were present in 12 cases (20%). The overall sensitivity rate was 59%. However, 20 (56%) of 36 cases that were diagnosed as detectable on mammography were underestimated in terms of tumor size compared with the histopathologic findings. Four cases examined by helical CT with contrast medium were compared with the histopathologic findings in terms of extent of the lesion. In three cases, helical CT was more precise than mammography, but the histopathologic findings showed lesions beyond the region evaluated by helical CT. CONCLUSION: Invasive lobular carcinoma is difficult to detect radiographically, and the extent of the lesion tends to be underestimated.

Adult↗
PubMedDate not supplied

Chemical sclerosis of the gallbladder. An experimental study in pigs of the effect of absolute ethanol and polidocanol on gallbladder epithelium.

Chemical ablation of the gallbladder with absolute ethanol and polidocanol 3% was attempted in 23 and 10 pigs, respectively, after open transhepatic cholecystostomy. Absolute ethanol caused complete necrosis of the gallbladder epithelium in 10 pigs and partial necrosis with focally present gallbladder epithelium in 9. An intact epithelium was observed in 4 pigs but it was not possible to determine whether this epithelium was the original one, not affected by the ethanol, or regenerated after previous damage. Gallbladders with hemorrhage and hydrops were frequently encountered. Gallbladders treated with polidocanol all had an intact epithelium.

Animals↗