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S Ohmori

Publications and source records attributed to S Ohmori.

300 records · Page 17Linked to original sources
PubMedDate not supplied

Elemental concentrations in hair of inhabitants of a cadmium-polluted area.

To investigate the present situation of inhabitants living in the cadmium-polluted area of Toyama Prefecture, 95 hair samples were analyzed instrumentally by the neutron activation method. The concentrations were compared with nonpolluted samples. The concentrations of Cd, Cu, Zn, and Cu/Zn in hair were compared with those in some reported organs. The values of Cu/Zn were significantly lower (p less than 0.001) in hair of both female groups, but only somewhat lower (p less than 0.05) in hair of the male group. Causes of these facts are discussed. Results obtained from principal component analysis are also mentioned.

Adolescent↗
PubMedDate not supplied

Water-diluted local anesthetic for trigger-point injection in chronic myofascial pain syndrome: evaluation of types of local anesthetic and concentrations in water.

BACKGROUND AND OBJECTIVES: We have recently demonstrated that a mixture of 1% lidocaine with water in a 1:3 ratio has less injection pain and is more effective than unaltered 1% lidocaine in treating chronic myofascial pain syndromes. Yet, the most suitable local anesthetic and the most effective dilution in water have not been evaluated. METHODS: Various mixtures of local anesthetics and water or saline were injected intramuscularly into the shoulder of 40 female volunteers, and pain scores on injection were evaluated in a randomized and double-blinded manner. In another portion of the study, 0.25% or 0.2% lidocaine in water were injected randomly into 1 side of 21 outpatients with chronic neck, shoulder, or lumbar myofascial pain to the same degree in both sides. The other solution was injected into the other side of the same patients. RESULTS: Less injection pain was experienced with the water-diluted 0.25% lidocaine and water-diluted 0.25% mepivacaine than the saline-diluted 0.25% lidocaine and water-diluted 0.0625% bupivacaine. Also, less injection pain was experienced with the water-diluted 0.25% and 0.2% lidocaine than the water-diluted 0.3% and 0.15% lidocaine. In the other study, there were no differences in either the effectiveness or duration of analgesia between the 0.25% and 0.2% water-diluted lidocaine. CONCLUSIONS: The suitable type of local anesthetic may be lidocaine or mepivacaine, and the most effective water-diluted concentration is considered to be 0.2% to 0.25%.

Adult↗
PubMedDate not supplied

Natural course of cavernous hepatic hemangioma.

Cavernous hepatic hemangiomas are benign liver tumors and present as incidental findings on sonographic examinations, but little is known concerning their natural course. Therefore, we performed a clinical and imaging follow-up of 64 cases of cavernous hepatic hemangioma in 50 patients during an average 18.8 month period. One case presented a symptom of slightly right upper quadrant pain and two cases showed thrombocytopenia. In one of the thrombocytopenia cases, cavernous hepatic hemangioma was resected because of Kasabach-Merrit syndrome. No case increased in size during follow-up, but one case decreased and disappeared. These results suggested that prolonged clinical and imaging follow-up of cavernous hepatic hemangiomas may be needed.

Adult↗
PubMedDate not supplied

Comparison of screening methods for hepatocellular carcinomas in patients with cirrhosis.

To determine the most suitable screening methods for hepatocellular carcinomas (HCCs), we investigated 45 cases with HCCs. Ultrasonography, computed tomography (CT) scan and measurement of alpha-fetoprotein (AFP) were regularly performed. Thirty-two cases (72%) were detected initially by ultrasonography. Fourteen out of 23 cases (61%) with tumors 20 mm or less in diameter and 11 out of 12 cases (91%) with 21-30 mm tumors were detected initially by.ultrasonography. For the initial detection of tumors sized 20 mm or less, the mean interval of ultrasonography was 3.54 months, unlike the 5.67 months for tumors sized over 21 mm. There was no significant difference between tumor size and measurement interval in AFP levels or CT scan examinations. From these results, we suggest that a suitable screening schedule would be every three months by ultrasonography.

Aged↗
PubMedDate not supplied

Cytochrome P450 isozymes involved in propranolol metabolism in human liver microsomes. The role of CYP2D6 as ring-hydroxylase and CYP1A2 as N-desisopropylase.

Oxidative metabolic pathways of propranolol consist of naphthalene ring-hydroxylations (at the 4-, 5-, and 7-positions) and side-chain N-desisopropylation in mammals. We characterized cytochrome P450 isozymes responsible for propranolol metabolism, especially N-desisopropylation and 5-hydroxylation, in human liver microsomes. 4-Hydroxy, 5-hydroxy-, and N-desisopropylpropranolol were detected as primary metabolites, whereas 7-hydroxypropranolol was in trace amounts. Good correlations were obtained for activities of propranolol 4- and 5-hydroxylases with immunochemically determined CYP2D6 content, whereas correlations of these activities with CYP1A2, CYP2C, or CYP3A4 content were relatively low. The activities also correlated highly with debrisoquine 4-hydroxylase, compared with other metabolic activities such as phenacetin O-deethylase, hexobarbital 3'-hydroxylase, and testosterone 6 beta-hydroxylase, which are typical reactions for CYP1A2, CYP2C, and CYP3A4, respectively. Propranolol N-desisopropylase activity in the samples highly correlated with CYP1A2 content and phenacetin O-deethylase activity, but not with the other P450 isozyme contents or metabolic activities. Quinidine, a specific inhibitor of CYP2D6, inhibited propranolol 4- and 5-hydroxylase activities selectively and in a concentration-dependent manner. alpha-Naphthoflavone, a potent inhibitor of CYP1A2, inhibited all of the propranolol oxidation activities, and the IC50 value for N-desisopropylase activity was much smaller than the values for ring-hydroxylase activities. Antibody directed to CYP2D inhibited propranolol 4- and 5-hydroxylase activities by 70% at an antibody/microsomal protein ratio of 1.0. Anti-CYP2C9 antibody did not inhibit any activity determined. These results indicate that propranolol 5-hydroxylation, as well as 4-hydroxylation, is mainly catalyzed by CYP2D6 in human liver microsomes.(ABSTRACT TRUNCATED AT 250 WORDS)

Benzoflavones↗
PubMedDate not supplied

Rat liver microsomal cytochrome P-450 responsible for reductive metabolism of zonisamide.

The reductive metabolism of 1,2-benzisoxazole-3-methanesulfonamide (zonisamide) to 2-sulfamoylacetylphenol (SMAP) was observed in liver microsomes from female rats, as well as male rats, but the SMAP-producing activity in female rats was 4-fold lower than that found in male rats. In addition, the reductive metabolism of zonisamide in liver microsomes was induced by the treatment of male rats with phenobarbital. However, the SMAP-producing activity did not correlate positively with the amounts of P-450 2B1 and P-450 2C11 immunochemically determined. In contrast, the reductive metabolism of zonisamide was also found to be induced by the pretreatment of male rats with pregnenolone 16 alpha-carbonitrile, triacetyloleandomycin, and dexamethasone. Furthermore, the SMAP-producing activity correlated highly with the amount of P-450 cross-reactive with antihuman P-450 3A4 antibody, suggesting that P-450 3A1/2 may function in the reductive metabolism of zonisamide. In addition, the P-450 PCNa (3A2) exhibited the SMAP-producing activity in a reconstituted system. The antihuman P-450 3A4 antibody inhibited markedly the formation of SMAP from zonisamide in male rat liver microsomes. These results indicate that cytochrome(s) P-450 belonging to P-450 3A subfamily may be predominantly responsible for the reductive metabolism of zonisamide in rat liver microsomes.

Anaerobiosis↗
PubMedDate not supplied

Characterization of cytochrome P-450 2B6 in human liver microsomes.

A cytochrome P-450 (P-450) enzyme of the CYP2B subfamily was partially purified from human liver microsomes and characterized with respect to immunochemical properties, N-terminal amino acid sequence, and catalytic activities toward typical P-450 substrates. P-450 enzymes were monitored in chromatographic fractions by immunoblotting analysis using antibodies raised against a monkey P-450 2B, as well as several purified human P-450 enzymes. The final P-450 2B preparation thus obtained was contaminated with P-450 3A4, but an N-terminal amino acid sequence matching the sequence predicted from the CYP2B6 cDNA was obtained. The apparent M(r) of this protein was 48 kDa, and the migration on sodium dodecyl sulfate-polyacrylamide gel electrophoresis was the same as that of the P-450 2B6 protein expressed in a human lymphoblast cell line. Immunoblotting analysis of 50 human liver samples revealed that the protein band considered to be P-450 2B6 was detected in only 12 samples, with four of these having relatively high levels. Several activities toward typical P-450 substrates were determined in a reconstituted monooxygenase system containing partially purified P-450 2B6 and compared with those obtained using a highly purified preparation of P-450 3A4 enzyme; we found that most of the activities were similar in these preparations, except that the partially purified P-450 2B6 showed high rates of activation of the mutagens 6-aminochrysene and 3-methoxy-4-aminoazobenzene to genotoxic metabolites in Salmonella typhimurium NM2009 strain.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMedDate not supplied

Effects of clarithromycin and its metabolites on the mixed function oxidase system in hepatic microsomes of rats.

Clarithromycin and its metabolites have been examined for their abilities to induce specific form(s) of cytochrome P-450 and metabolite complex formation in rats. Pretreatment of rats with clarithromycin,N-demethyl clarithromycin, clarithromycin N-oxide, and decladinosyl clarithromycin resulted in 48-75% decreases in the amount of 2C11 and 100-600% increases in the amount of 3A1. Clarithromycin and N-demethyl clarithromycin, but not decladinosyl clarithromycin, produced a metabolite complex with cytochrome P-450 in vivo. Activities of testosterone 2 beta- and 6 beta-hydroxylases were increased by administration of clarithromycin and N-demethyl clarithromycin when these activities were measured in the presence of ferricyanide, but not significant induction was observed when measured in the absence of ferricyanide. Clarithromycin N-oxide treatment resulted in the increase in hydroxylation of testosterone not only at the 2 beta- and 6 beta-positions (430 and 190%, respectively), but also at 7 alpha-position (60%), regardless of the presence or absence of ferricyanide. In vitro experiments with hepatic microsomes of dexamethasone-pretreated rats indicated that the metabolites that were modified at the tertiary amino group more efficiently produced the metabolite complex with cytochrome P-450 compared with the parent compound. In contrast, decladinosyl and hydroxylated metabolites had similar or lower capacities for metabolite complex formation than did the parent compound. Clarithromycin and its N-modified metabolites were able to induce 3A1 and form a metabolite complex with cytochrome P-450 in vivo in varying extents. Decladinosyl clarithromycin has a weak inducibility of 3A1 and did not form a metabolite complex with cytochrome P-450 in vivo.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗