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Biomedical subjects

K Tayama

Publications and source records attributed to K Tayama.

101 records · Page 6Linked to original sources
PubMed1992

[Coronary artery bypass grafting in a patient with Kawasaki disease].

A 3-year-girl admitted because of angina at rest. She had been diagnosed as Kawasaki disease at the age of 3 months. At that time, a coronary aneurysm was detected by echocardiogram and aspirin had started to administer. At the age of 4 months, a cardiac arrest occurred after severe heart attack because of inferior myocardial infarction. At the age of 2 years and 6 months, she started to complain of a chest pain even at rest. Coronary angiography was performed, and it showed total occlusion of RCA and LAD. However, LAD was vaguely filled by collateral flow from diagonal branch, and 201Tl scintigraphy showed myocardial viability of anteroseptal area. At operation, the size of ITA was 1.2 mm in diameter. Coronary artery bypass grafting to LAD by ITA was performed. Three weeks postoperatively, graft patency was confirmed by coronary angiography. The girl discharged with good ability of exercise. The ITA seemed to be the first choice of conduit for CABG even in a small child, and to be useful for progressive surgical treatment of Kawasaki disease.

Child, Preschool↗
PubMed1991

Cloning and sequencing of the gene cluster encoding two subunits of membrane-bound alcohol dehydrogenase from Acetobacter polyoxogenes.

The membrane-bound alcohol dehydrogenase (ADH) from Acetobacter polyoxogenes NBI1028 is composed of a 72 kDa subunit and a 44 kDa cytochrome c subunit. The amino acid sequences of the two regions of the 72 kDa subunit were determined to prepare oligonucleotides for the purpose of amplification of a DNA fragment corresponding to the intermediate region by the polymerase chain reaction. A 0.5 kb DNA fragment thus amplified was used as the probe to clone a 7.0 kb PstI fragment coding for the whole 72 kDa subunit. Nucleotide sequencing and immunoblot analysis revealed that the cloned fragment contained the full structural genes for the 72 kDa and the 44 kDa subunits and they were clustered with the same transcription polarity. The predicted amino acid sequence of the gene for the 72 kDa subunit showed homology with that of the 72 kDa subunit from ADH of A. aceti and those of methanol dehydrogenase from methylotrophic bacteria. The 72 and 44 kDa subunits contained one and three typical haem binding sequences, respectively.

Acetobacter↗
PubMed1989

Cloning of the Membrane-Bound Aldehyde Dehydrogenase Gene of Acetobacter polyoxogenes and Improvement of Acetic Acid Production by Use of the Cloned Gene.

A genomic clone bank of Acetobacter polyoxogenes NBI1028 constructed in Escherichia coli by use of the expression vector pUC18 was screened with antibody raised against membrane-bound aldehyde dehydrogenase (ALDH; 75 kilodaltons [kDa]) from A. polyoxogenes NBI1028. A clone that synthesized a 41-kDa protein cross-reactive with anti-ALDH antibody was isolated. For cloning of the full-length ALDH structural gene, a cosmid gene bank was screened by Southern blot hybridization with the cloned DNA as a probe, and subcloning from the positive cosmid clone was performed with shuttle vector pMV24. Plasmid pAL25, containing the full-length ALDH structural gene, was isolated and expressed in both E. coli and Acetobacter aceti to produce a fused protein (78 kDa) with a short NH(2)-terminal beta-galactosidase peptide. pAL25 conferred ALDH production on a mutant of A. aceti lacking the enzyme activity. Transformation of A. aceti subsp. xylinum NBI2099 with pAL25 caused 2- and 1.4-fold increases in the production rate and in the maximum concentration of acetic acid in submerged fermentation, respectively.

Journal Article↗
PubMed1988

Effect of buthionine sulfoximine on orthophenylphenol-induced hepato- and nephrotoxic potential in male rats.

A single oral administration of orthophenyl-phenol (OPP, 1400 mg/kg; about half the LD50) to male Fischer 344 rats produced an elevation of serum transaminase activity 24 h later. Pretreatment with L-buthionine-S,R-sulfoximine (BSO, 900 mg/kg) in the OPP-treated rats potentiated the hepatic and renal damage which was accompanied by necrosis. Six hours after the administration of OPP (700 or 1400 mg/kg), hepatic and renal glutathione (GSH) levels decreased with increasing dosage. Hepatic GSH depletion with OPP was enhanced with BSO pretreatment and the recovery of GSH in both organs was slow in the high-dose OPP group. These results suggest that hepatic and renal damage is associated with a serious and prolonged GSH depletion. When either phenyl-p-benzoquinone (PBQ) or phenylhydroquinone (PHQ), which are intermediates of OPP, was administered orally to rats at 700 or 1400 mg/kg, the mortality with the high dose of PBQ was 75% at 24 h. The serum transaminase activity and UN level increased with the low dose of PBQ, accompanied by necrotic hepatocytes. The toxic effects of PHQ on kidney or liver were less than those on PBQ. These observations suggest that the liver and kidney may be target organs for toxic actions of a large dose of OPP and its intermediate, PBQ.

Alanine Transaminase↗
PubMed1988

Nephrotoxicity of butylated hydroxytoluene in phenobarbital-pretreated male rats.

A single large dose of butylated hydroxytoluene (BHT, 1000 mg/kg) in male Fischer 344 rats produced some renal damage, reduced accumulation of p-aminohippuric acid in renal slices, proteinuria and enzymuria, in addition to hepatic damage. Further, prior administration of phenobarbital (80 mg/kg, i.p., daily for 4 days) in the high-dose BHT-treated male rats produced renal damage accompanied by slight tubular necrosis. The renal damage was confirmed by biochemical and histological changes. These changes were dose dependent, with a maximum at 24 h after BHT administration, but had returned to the normal range by 48 h. Female rats, on the other hand, were less susceptible to BHT-induced renal and hepatic damage than male rats. The results indicate sex differences in BHT-induced renal or hepatic damage.

Animals↗
PubMed1986

[Comparison of characteristics between F344 and Slc:Wistar rats--Slc:Wistar rats cannot be distinguished from the F344 strain].

With respect to F344/DuCrj and Slc: Wistar rats, both widely used in Japan, it was found that there is a close similarity in the changes of body weights and survival rates, and in the organ distribution and incidence of spontaneous tumors. To examine the degree of homozygosity between F344 and Slc: Wistar strains, tumor transplantation and skin grafting were performed. The bladder carcinomas that originated from F344/DuCrj rats grew subcutaneously in the other F344 strains and Slc: Wistar rats, but did not grow in the other Wistar-derived strains. The skin grafts between F344/DuCrj or F344/NSlc and Slc: Wistar rats were accepted, but those between F344/DuCrj or Slc: Wistar and the other Wistar-derived strains were rejected. These results suggest that Slc: Wistar rats cannot be distinguished genetically from the F344 strain of rats.

Animals↗
PubMed1985

Effect of cobaltous chloride on butylated hydroxytoluene-induced hepatic necrosis in rats.

Although a single dose of butylated hydroxytoluene (BHT); 1000 mg/kg to rats induced a hepatic injury accompanying centrilobular necrosis, the pretreatment with cobaltous chloride, an inhibitor of cytochrome P-450 synthesis, could inhibit the damage. The marked elevations of serum transaminase activities and bile acid content induced by BHT were diminished to nearly the control level by pretreatment with cobaltous chloride. The protective effect of cobaltous chloride on BHT-induced hepatotoxicity is discussed.

Animals↗
PubMed1984

On the mechanism of butylated hydroxytoluene-induced hepatic toxicity in rats.

The relations between serum transaminase activity and the hepatic contents of glutathione and lipid peroxide were examined following oral administration to rats of butylated hydroxytoluene (BHT; 500 or 1000 mg/kg). The glutathione level rapidly diminished and reached a minimum at 6 hr after BHT administration. The period of depletion was dependent on dose: restoration of the glutathione level took longer in high-dose rats than in low-dose rats. The content of hepatic lipid peroxide was not markedly changed by BHT throughout the experimental period. The activity of glutathione S-transferase was not affected until 12 hr after BHT administration but, thereafter, it increased with time and was accompanied by elevation of the glutathione level. Though the activities of serum glutamate-oxaloacetate transaminase and glutamate-pyruvate transaminase were not affected by low-dose BHT, they increased rapidly in the high-dose rates after a lag period of about 6 hr and reached a maximum at 24 hr after administration; at that time, the livers of the high-dose rats showed centrilobular necrosis. The results indicate that acute hepatic injury was induced by the high-dose BHT. Pretreatment with cobaltous chloride inhibited the increase in the activities of the serum transaminases produced by the high-dose of BHT accompanying the depletion of microsomal cytochrome P-450 content and the induction of glutathione content. These observations suggest that hepatic damage was associated with prolonged depletion of glutathione rather than with lipid peroxidation in the liver, and that the activated metabolites of BHT rather than the parent compound induced the tissue damage.

Alanine Transaminase↗
PubMedDate not supplied

Clinical usefulness of doxazosin in patients with type 2 diabetes complicated by hypertension: effects on glucose and lipid metabolism.

This uncontrolled study investigated the effects of using the alpha 1-blocker doxazosin (2 mg or 4 mg daily for 3 months) to treat 21 hypertensive patients with type 2 diabetes, including eight obese individuals (body mass index [BMI] > or = 25.0 kg/m2). A significant reduction in systolic and diastolic blood pressure, beginning after 1 month of treatment, was seen. There was no significant change in BMI. Although there was no obvious improvement in glucose metabolism, doxazosin treatment noticeably reduced insulin resistance and significantly lowered triglyceride and free fatty acid levels. No significant changes were found in total cholesterol, high- or low-density lipoprotein-cholesterol, atherosclerotic index, or small or large subfractions of low-density lipoprotein-cholesterol. None of the patients showed any adverse effects. The beneficial effects of doxazosin on blood pressure and lipid and glucose metabolism shown in this study suggest that this drug is clinically useful as an anti-hypertensive agent for patients with diabetes.

Antihypertensive Agents↗
PubMedDate not supplied

Chemotherapy for advanced non-small cell lung cancer.

Less than 20% of all cases of non-small cell lung cancer are operable. The treatment option available for such patients is either radiotherapy or chemotherapy. Various combinations of chemotherapeutic agents have been tried. The combination of cisplatin and 5-fluorouracil (5-FU) has been proved to have a synergistic antitumour effect in many experimental and clinical studies. In this paper the authors report the results of a trial using tegafur (which is a prodrug of 5-FU; 1-[2-tetrahydrofuryl]-5-FU) and uracil along with cisplatin in inoperable non-small cell lung cancer. Thirty-one patients were entered into the study, all of whom were less than 75 years old (mean age 61 years). The patients (except for 2) had either stage IIIB (12) or stage IV (17) disease with adenocarcinoma and squamous cell carcinoma in equal proportions (15 each). A combination of uracil and tegafur (400 mg/m2) in 100 mg capsules (100 mg tegafur and 224 mg of uracil), was given orally for 21 days. Most of the patients received 300 mg of the combination tablets twice a day. Cisplatin (80 mg/m2) was given as an infusion over 90 minutes on day 8 after adequately hydrating the patients. This cycle was repeated every 4 weeks. At least 2 treatment cycles were given, unless there was disease progression or toxicity. The response and survival rates were assessed after a follow up period which ranged between 9 and 30 months. The patients received 1 to 4 cycles of therapy and the response rates were: complete response--nil,partial response--11, no change--11 and disease progression--9. The overall response rate was 35% (95% CI: range 19-52%). Five patients achieved at least 50% tumour reduction after 2 cycles. Of the 11 patients who showed partial response, 5 (35%) had stage IV disease and 6 (36%) had other stages; 6 (40%) had squamous cell carcinomas and 5 (31%) had tumours of other histological types. The median duration of response was 6 months (3-13 months). In stage III disease, the 1-year survival rate was 31%, with a median survival time of 11 months, while in stage IV disease it was 29% with a median survival time of 8 months. There was a low incidence of toxicity, with anaemia (10%), leukopenia (6%) and thrombocytopenia (6%) being the most common side-effects. There were also no treatment-related deaths. The authors concluded that oral uracil and tegafur were as effective as other combinations with cisplatin. They also caused very few side-effects. They suggest that a larger trial needs to be carried out.

Antineoplastic Combined Chemotherapy Protocols↗