PubMed Health⌕ Search

Biomedical subjects

T Takechi

Publications and source records attributed to T Takechi.

68 records · Page 4Linked to original sources
PubMed1987

Catalase gene of the yeast Candida tropicalis. Sequence analysis and comparison with peroxisomal and cytosolic catalases from other sources.

A clone harbouring the genomic DNA sequence for the peroxisomal catalase of an n-alkane-utilizable yeast, Candida tropicalis, has been isolated by the hybrid-selection method and confirmed with a probe of catalase partial cDNA. Nucleotide sequence analysis of the cloned DNA disclosed that the gene fragment coding for catalase had a length of 1455 base pairs (corresponding to 485 amino acids; m = 54937 Da), and that the size of this enzyme was the smallest among all catalases reported hitherto. No intervening sequence was found in this coding region and some portions coincided with the amino acid sequences obtained from the analysis of the purified catalase. The comparison with three peroxisomal catalases from rat liver, bovine liver and human kidney, and one cytosolic catalase from Saccharomyces cerevisiae has revealed that catalase from C. tropicalis was more homologous to the peroxisomal enzymes than to the cytosolic one. C. tropicalis used the codons of the high-expression type. Amino acid residues were all conserved at the active and heme-binding sites. In the N and C-terminal regions there was no characteristic signal sequence or consensus sequence. However, a noticeable region, which can be discriminated between peroxisomal and cytosolic catalases, was proposed.

Amino Acid Sequence↗
PubMed1986

Two acyl-coenzyme A oxidases in peroxisomes of the yeast Candida tropicalis: primary structures deduced from genomic DNA sequence.

We report the complete nucleotide sequence of two genes encoding major peroxisomal polypeptides (PXPs) of Candida tropicalis. One, POX4, encodes PXP-4, which is the most abundant polypeptide in cells grown on oleic acid, and the other, POX5, is the gene for PXP-5. Each of the two polypeptides was found to be the subunit of a distinct long-chain acyl-coenzyme A oxidase: acyl-CoA oxidase II (PXP-4) or acyl-CoA oxidase I (PXP-5). Both the genes had no intron and gave a single open reading frame. The NH2-terminal sequences, except the initiator methionine, and the calculated molecular weights of the deduced polypeptides were consistent with those of the respective PXPs. Well-conserved sequences of 12 and 16 hydrophobic amino acids were present in the middle of the polypeptide, instead of at the NH2 terminus, and may be internal signal sequences for the peroxisomal location of PXPs. Although the two polypeptides were significantly homologous throughout their sequences, the local homologies in two regions out of five were markedly diverged from the average (63%); the homology in the second region was 93%, whereas that in the fourth one was only 24%. The implications of this finding are discussed in respect to the multiplicity of peroxisomal enzymes and the presence of multifunctional proteins in peroxisomes.

Acyl Coenzyme A↗
PubMed1983

[Usefulness of contrast echoangiographic diagnosis of congenital tricuspid stenosis].

Congenital tricuspid stenosis is an uncommon congenital anomaly and usually associated with other lesions such as severe pulmonic stenosis or atresia. Sometimes, it is difficult to diagnose this malformation non-invasively, but the differential diagnosis from tricuspid atresia is essential for the surgical considerations. Described here were three patients with congenital tricuspid stenosis who were successfully diagnosed by contrast echoangiography using peripheral venous injection of the contrast medium. Contrast echoes appeared in the right atrium initially and then in the right ventricle through the stenotic tricuspid valve. In conclusion, contrast echoangiography is mandatory in the diagnosis of this entity.

Child, Preschool↗
PubMed1982

Fate of coronary aneurysms in Kawasaki disease: serial coronary angiography and long-term follow-up study.

Between January 1973 and December 1979, 290 patients with Kawasaki disease were evaluated with coronary angiography after the acute stage of illness. Of these patients, 43 (15 percent) were diagnosed as having coronary aneurysms. Forty-two patients have been followed up for an average of 4 years (range 15 months to 8 years). One 8 month old girl died of myocardial infarction after 4 months of illness. Follow-up coronary angiography was performed in 42 patients 5 to 18 months after the acute illness. Four groups can be distinguished. Group I: In 21 (50 percent) of 42 patients angiography showed that the coronary aneurysms had regressed, so that no observable lesions were seen. During convalescence, electrocardiography, exercise stress testing and thallium scintigraphy were within normal limits. In the other 21 patients abnormal findings persisted on follow-up angiography. Group II: Ten patients showed persistent coronary aneurysms, although reduced in size. Group III: In seven patients the aneurysms had disappeared, but complete obstruction or marked stenosis of coronary arteries was found. Group IV: In four patients, irregularities of the coronary arterial wall without stenosis were seen. Among patients with abnormal angiographic findings myocardial infarction and mitral regurgitation were also seen. Early initiation of aspirin therapy aneurysms show regression on angiography in 1 or 2 years in about half of patients. The remaining patients are at risk for ischemic heart disease. Thus, Kawasaki disease should be considered an important cause of ischemic heart disease in children and a possible risk factor of premature coronary atherosclerosis.

Cardiac Output↗
PubMed1982

[Two-dimensional echocardiographic study of coronary artery lesion in Kawasaki disease: a new approach to visualize the right coronary artery].

Recently nonivasive visualization of the left main coronary artery by two-dimensional echocardiography has developed. However, previous reports has described the difficulty to evaluate a right coronary aneurysm and coronary stenosis or obstruction. Therefore two-dimensional echocardiographic studies using 5 MHz linear scanner were performed in 48 patients of Kawasaki disease, and the findings were compared with coronary angiographic findings. Their ages ranged from 3 months to 15 years (mean 3.2 years of age). In coronary angiographic findings, the left main coronary aneurysm was demonstrated in 23 cases, and stenosis of the left coronary artery in 2 cases. While a right coronary aneurysm was demonstrated in 17 cases, and stenosis or obstruction of the right coronary artery in 7 cases. The diagnosis of a coronary aneurysm by linear scanner two-dimensional echocardiography was established in 22 of 23 (96%) patients on the left main coronary artery and in all 17 patients on the right coronary artery. Stenosis or obstruction of the left and right coronary arteries was demonstrated in 1 of 2 (50%) patients and 6 of 7 (86%) patients, respectively. These results were superior to the results of the two-dimensional echocardiographic study by 3.5 mHz sector scanner. The right coronary artery was visualized effectively and extensively by the linear scanner than the sector scanner. We conclude that two-dimensional echocardiography using high frequency linear scanner is a very useful method to diagnose stenotic lesions as well as aneurysmal formation in the right and left coronary arteries and to follow up aneurysms in acute phase and inspect the growth of coronary aneurysms.

Adolescent↗
PubMed1982

[Echocardiographic assessment of anatomical detail in patients with hypoplastic left heart syndrome].

Hypoplastic left heart syndrome is a disease with poor prognosis, which is characterized by severe heart failure in early neonatal period. However, there are some patients who survive for relatively longer period. In the light of this fact, 18 patients with this syndrome were studied by echocardiography, and the anatomical and functional classification was attempted. Hypoplastic left heart syndrome was classified into three types: type I was mitral atresia and aortic atresia, type II was mitral atresia and aortic stenosis, and type III was mitral atresia with an abnormality of cono-truncal relationship, respectively. M-mode echocardiography was performed in 15 of the 18 patients, and two-dimensional echocardiograms were recorded in seven cases. Heart catheterization was performed in all patients. Autopsy was performed on 14 of the 18 patients, and its findings were compared with the findings obtained by echocardiography. Two-dimensional echocardiographic classification of this syndrome was possible in all the patients using above-mentioned criteria. Patent ductus arteriosus was detected in two of six cases having this syndrome, and foramen ovale in 4 of 5 cases. The morphological evaluation of both the interatrial and interventricular septum was made by two-dimensional echocardiography, and it contributed to decide the indication of balloon-atrial septostomy. The patients with type I had the poorest prognosis, and the patients with type III survived longer period. Anatomical classification of this syndrome and detection of associated anomalies by two-dimensional echocardiography are recommended to consider the prognostic and surgical considerations.

Adolescent↗
PubMed1981

[Two-dimensional echocardiographic diagnosis of aortic arch by suprasternal approach (author's transl)].

Two-dimensional echocardiographic studies of the aortic arch and proximal descending aorta were performed in 6 cases with coarctation of the aorta, 40 normal subjects and 9 cases of coarctectomy approached by the suprasternal notch. In cases with the normal aortic arch and proximal descending aorta, the ascending aorta, aortic arch, descending aorta and right pulmonary artery were visualized clearly. The diameter of the aortic lumen is consistent throughout the plane of the scan. The origins of the left carotid artery and the left subclavian artery were seen clearly. In 3 of 7 normal newborns a localized area of a slightly aortic narrowing (diameter of aortic narrowing area / diameter of proximal descending aorta greater than 0.75) was visualized. In 5 of 6 cases with coarctation of the aorta a localized area of an aortic narrowing distal to the origin of the left subclavian artery is visualized which corresponded to the angiographic appearance of the coarctation. In 1 of 6 cases with coarctation of the aorta a more diffuse area of aortic obstruction beginning from distal portion of the left carotid artery to distal portion of the left subclavian artery was visualized. In this case, aortic valve stenosis, ventricular septal defect, patent ductus arteriosus, and hypertrophy of the interventricular septum and left ventricular posterior wall were associated. In 9 coarctectomy cases a localized area of an aortic narrowing distal to the origin of the subclavian artery was enlarged after operation. Two-dimensional echocardiogram approached by the suprasternal notch may offer a useful noninvasive method for direct visualization of the aortic arch and proximal descending aorta.

Adolescent↗
PubMed1981

[Fetal echocardiography: structural evaluation of the fetal heart and prenatal diagnosis of congenital heart disease (author's transl)].

Two-dimensional echocardiography has developed to the routine examination to diagnose congenital heart disease. In this study, we studied the value of two-dimensional echocardiography for evaluating the development of the fetal heart and for prenatal diagnosis of congenital heart disease. We studied 100 fetuses whose gestational ages were 16-40 weeks of pregnancy. The examination was performed with Toshiba Sonolayer-V model SSL-53M. The scanners were the 2.25 MHz linear and sector transducers. The images were recorded on videotapes. Changing the scanner direction according to the fetal position, we recorded the left ventricular long-axis view, short-axis view of great arteries and four-chamber view. In the four-chamber view, diameters of the tricuspid and mitral valve rings were measured. In the short-axis view of great arteries, the diameters of the aorta and pulmonary artery were measured. We identified the right and left ventricles by detecting both the great arteries and attaching sites of the atrioventricular valves. The identification of the aorta was made by detecting the arch and the identification of the pulmonary artery was made by depicting its two branches. Cardiac structures were identified on the fetus over five months of pregnancy. In many instances recordings were obtained in 7 months fetuses. The success rate to get clear recordings was 88% of all cases in the four-chamber view, 75% in the short-axis view of great arteries and 71% in the left ventricular long-axis view, respectively. The average ratio of the mitral to tricuspid valvular diameter and that of the pulmonary arterial to aortic diameter were both less than 1, suggesting the right ventricular dominance in fetal hearts. From these findings, it might be possible to diagnose prenatally certain congenital heart diseases such as atrioventricular valve atresia and semilunar valve atresia which require the critical evaluation and management in the neonatal periods.

Echocardiography↗
PubMed1980

[Laboratory and clinical studies on cefoperazone in pediatrics treatment (author's transl)].

Laboratory and clinical studies of cefoperazone (CPZ), a new semisynthetic cephalosporin, were investigated and following results were obtained. (1) Blood level: CPZ was given intravenous dose of 25 mg/kg and 50 mg/kg to each 3 children. In the former, the blood level of 15 minutes after injection was 194.2 mcg/ml on average and the half life was 106.2 minutes. In the latter, the blood level was 320.0 mcg/ml on average and half life was 102.2 minutes. (2) Urinary concentration: In the cases of the dose of 25 mg/kg, 35.9% of CPZ was recovered on average from the urine within 6 hours after injection, and the urinary concentration reached to 2,148.6 mcg/ml (0 approximately 2 hours). And in the cases of the dose of 50 mcg/kg, the recovery rate in urine was 43.6%, and the urinary concentration was 3,008.3 mcg/ml. (3) Cerebrospinal fluid level: CSF level was determined in a patient with bacterial meningitis by S. pneumoniae. Ninety mg/kg of CPZ were given intravenous injection. After 60 minutes CSF level was 3.35 mcg/ml, and after 80 minutes the blood level was 192.0 mcg/ml. (4) Bacteriological evaluation: Against 164 strains isolated clinical specimens, the bacteriological evaluation on CPZ was performed in comparison with cefotaxime (CTX), cefazolin (CEZ) and piperacillin (PIPC) by inoculum size of 10(8) cells/ml. CPZ showed antibacterial activity against Gram-negative bacteria almost similar to CTX and PIPC. (5) CLINICAL RESULTS: CPZ was given 48.3 approximately 360 mg/kg/day (average 146.1 mg/kg/day) by intravenous route to 46 patients with various infection. The overall efficacy rate was 80.4%. The rate of bacteriological effectiveness was 78.9% in 19 cases. (6) Side effects: As side effects, diarrhea, fever, rash, urticaria, leukopenia, eosinophilia, elevation of GOT, GPT, and LDH were observed, but not seriously.

Adolescent↗
PubMedDate not supplied

Thymidylate synthetase and dihydropyrimidine dehydrogenase levels in gastric cancer.

The measurement of thymidylate synthetase (TS) and dihydropyrimidine dehydrogenase (DPD) enzymatic activities and mRNA levels in tumors may be useful in predicting tumor sensitivity to 5-fluorouracil (5-FU). Forty-one patients with advanced gastric cancer gave informed consent and were enrolled in this study. Biopsy specimens of gastric cancer were obtained preoperatively through gastrofiberscopy and used to determine TS and DPD mRNA levels. We also measured TS and DPD enzymatic activities and mRNA levels in surgically resected gastric cancer samples, as well as in adjacent normal gastric mucosa. TS and DPD activities were measured using the TS-binding assay and a radioenzymatic assay, respectively, while mRNA levels were measured by semi-quantitative reverse transcription-PCR (RT-PCR) co-amplified with glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as an internal standard. In resected tumor specimens, TS and DPD activities ranged from 7.1 to 176.6 fmol/mg protein and from 3.6 to 99.8 pmol/min/mg protein, respectively, while TS and DPD mRNA levels ranged from 0.50 to 21.12 and from 0.014 to 7:22, respectively. There were no significant correlations between TS/DPD levels and other clinicopathological factors, except for low DPD mRNA levels in undifferentiated carcinoma. Both TS activity and mRNA levels were significantly higher in tumor tissues compared to normal adjacent mucosa. In contrast, there was no significant difference between tumoral and non-tumoral DPD activity, although tumor tissue showed significantly lower DPD mRNA levels than non-tumoral tissue. High tumoral TS mRNA levels in preoperative biopsy specimens from patients with stage III/IV was associated with poor survival outcome after surgery compared with patients with low tumoral TS mRNA levels. In contrast, DPD levels had no influence on prognosis. We conclude that high tumoral TS levels and low tumoral DPD mRNA may indicate the selective cytotoxicity of 5-FU on gastric cancer, and that tumoral TS mRNA levels may be a prognostic factor for patients with stage III/IV gastric cancer.

Aged↗
PubMedDate not supplied

Roles of thymidylate synthase and dihydropyrimidine dehydrogenase in tumor progression and sensitivity to 5-fluorouracil in human gastric cancer.

BACKGROUND: The role of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) enzyme activities in tumor progression and sensitivity to 5-fluorouracil (5-FU) were evaluated. MATERIALS AND METHODS: TS and DPD activities were measured in 81 clinical samples of gastric cancer. TS and DPD activities were determined by 5-fluorodeoxyuridine monophosphate binding assay and by radioenzymatic assay, respectively. Sensitivity to 5-FU was determined by in vitro ATP assay. RESULTS: There was no correlation between TS activity and sensitivity to 5-FU. However, a weak correlation was found between DPD activity and sensitivity to 5-FU. In a subgroup of patients who did not receive adjuvant chemotherapy, overall survival was poorer in patients with high TS activity (p=0.0265). Conversely, in a subgroup of patients who received 5-FU-based adjuvant chemotherapy, overall survival was poorer in patients with high DPD activity (p=0.0465). CONCLUSION: These results suggest that TS has an important role in tumor progression and DPD may be the dominant predictor of 5-FU sensitivity in gastric cancer.

Adult↗
PubMedDate not supplied

Antitumor effect of S-1 on DMH induced colon cancer in rats.

The aim of this study was to establish an autochthonous colon cancer model in the rat as an in vivo secondary screen for the general evaluation of new anticancer agents against colorectal cancer, and also to evaluate practically the antitumor activity of 1M tegafur-0.4M 5- chloro-2,4-dihydroxypyridine-1M potassium oxonate(S-1), a new p.o. fluoropyrimidine. Thirty-two Sprague-Dawley rats received dimethlhydrazine(40 mg/kg) s.c. once weekly for 10 weeks to induce colon cancer.20 weeks after beginning the carcinogen treatment, a barium enema was performed to visualize tumors. The animals were divided into a control group and S-1 treatment group. After 5 weeks of treatment, the barium enema was repeated. The mean doubling time of 24 tumors in the control group was 19.0 + 8.4 (SD) days. Response to S-1 was judged as effective when the doubling time exceeded 35.8 days, calculated from the mean + 2SDs in the control group. The response rate of S-1 was 55%, 34% of the tumors were decreased in size after treatment. This figure was higher than that of clinically-used 5-fluorouracil(5-FU) derivatives; 5-FU;6%, Tegafur(FT):6%, 1M tegafur-4M uracil(UFT):14%, reported in our previous study. An autochthonous colon cancer model is useful to evaluate the clinical therapeutic efficacy of drugs for colorectal cancer, and S-1 is expected to have a high therapeutic effect on human colorectal cancer.

1,2-Dimethylhydrazine↗