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Biomedical subjects

A Okuda

Publications and source records attributed to A Okuda.

At least 55 records · Page 3Linked to original sources
PubMed1994

Somatic mutations at T-cell antigen receptor and glycophorin A loci in pediatric leukemia patients following chemotherapy: comparison with HPRT locus mutation.

Frequencies of somatic mutations in pediatric patients with leukemia were evaluated following intensive treatment at three different loci: the hypoxanthine-guanine phosphoribosyl transferase (HPRT), T-cell antigen receptor (TCR), and glycophorin A (GPA) gene. Thirty-two children with acute lymphoblastic leukemia (ALL), nine children with acute myelogenous leukemia (AML), and 20 age-matched healthy controls were included in the study of mutant frequencies (Mfs) at the HPRT and TCR loci. Among these patients and controls, individuals with heterozygous MN blood type, i.e., 14 children with ALL, three children with AML, and nine healthy controls, served for the further assessment of variant frequency (Vf) at the GPA locus. In ALL patients, geometric mean Mfs and Vfs at these loci were significantly higher than in healthy controls. The high Mf value at the HPRT locus persisted for up to 8 years after the end of chemotherapy. On the other hand, the Mf values at the TCR locus and Vf values at the GPA locus declined gradually with time. In AML patients, on the other hand, the geometric mean Mf only at the TCR locus was significantly higher than in the controls, albeit to a lesser degree than in ALL patients. These data suggest that anti-cancer therapy induces somatic mutations at various loci and that ALL patients are more susceptible to mutagenic intervention than are AML patients.

Adolescent↗
PubMed1994

Successful surgical management for multiple cerebral mycotic aneurysms involving both carotid and vertebrobasilar systems in active infective endocarditis.

Mycotic aneurysm is usually found in the middle cerebral artery associated with infective endocarditis. Previous reports we have identified include only 4 cases of vertebrobasilar aneurysm. We report on a 29-year-old female who had multiple mycotic aneurysms involving both the carotid and vertebrobasilar systems complicated by intracranial hemorrhage with infective endocarditis, in whom staged operations, mitral valve replacement and craniotomies, were successfully performed.

Adult↗
PubMed1994

In vivo administration of granulocyte colony-stimulating factor promotes neutrophil survival in vitro.

We recently showed that recombinant human granulocyte-colony stimulating factor (rhG-CSF) maintained the viability of human neutrophils in incubation for up to 72 hours. However, it is not known whether rhG-CSF can enhance neutrophil survival in in vivo situations. To clarify this issue, we investigated neutrophil survival in vitro following in vivo injection of rhG-CSF. Neutrophils were obtained from 4 pediatric patients with malignancies and healthy adult volunteers before and after rhG-CSF administration. Neutrophils obtained before rhG-CSF treatment started to undergo apoptosis after 24 h of incubation. In contrast, the survival of neutrophils drawn after rhG-CSF administration increased by approximately 24 h. Concomitantly, the appearance of typical ladder-like DNA fragmentation was delayed. Such an increase in neutrophil survival was inhibited by co-incubation with either H 7 (10 mumol/l) or H 8 (20 mumol/l), which worked as protein kinase C inhibitors. Although our study did not measure neutrophil survival in vivo directly, it provides us with further evidence that rhG-CSF may function to prolong neutrophil life expectancy in vivo.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1994

[A successful case of transaortic coronary patch angioplasty for left coronary ostial stenosis in a middle-aged woman].

A 46-year-old woman was admitted to our hospital because of effort angina. Electrocardiogram on exercise showed a significant ST depression in I, II, III, aVF, and V3-6 201Thallium myocardial scintigram demonstrated a low uptake lesion on effort and redistribution in anterior wall of left ventricle. Coronary angiography showed a 50% stenosis only in the left coronary ostium. Operation was carried out by transaortic patch angioplasty using autologous pericardium fixed with 0.25% glutaraldehyde. Her postoperative course was uneventful. Anginal discomfort disappeared, and favorable results was obtained. Recent reports suggest that an isolated coronary ostial stenosis is a distinct clinical entity which is different from the usual atherosclerotic ischemic heart disease. The transaortic patch angioplasty might be useful operative method for the isolated coronary ostial stenosis.

Constriction, Pathologic↗
PubMed1994

[An experience of successful valve repair for acquired mitral and tricuspid regurgitation in dextrocardia, situs inversus, bilateral vena cava, and hemiazygos continuation].

A 56-year-old woman was admitted to our department because of congestive heart failure. Chest X-ray showed dextrocardia with situs inversus. The echocardiography revealed severe mitral regurgitation due to prolapse of posterior leaflet and secondary Venography demonstrated the bilateral superior vena cava, huge coronary sinus and hemiazygos continuation with hypoplastic inferior vena cava. Mitral valve regurgitation was repaired by Carpentier's and Burr's technique, and tricuspid valve regurgitation was repaired by Kay's technique. Her postoperative course was uneventful. Valve surgery for acquired valvular lesion in dextrocardia with situs inversus is rare. Although valve repair is easily performed even in mirror-image heart as well as in normal, levo-position heart, preoperative evaluation of systemic venous return is important in the case of dextrocardia with systemic venous anomalies.

Azygos Vein↗
PubMed1994

[A case of coronary artery bypass grafting for single coronary artery complicated by effort angina].

A case of coronary artery bypass grafting (CABG) for single coronary artery (SCA) complicated by effort angina pectoris was reported. A 52-year-old man was admitted complaining of effort angina. Coronary arteriography demonstrated a single coronary artery originated in left coronary sinus bifurcated to the left anterior descending artery (LAD) and the circumflex artery (CX) which extended around the atrio-ventricular fold to send a branch down the posterior small branches extend to posterior surface of the right ventricle. This type single coronary artery was classified to Smith's type I. Other findings included 75% stenosis in LAD #6 and #7, 90% stenosis in CX #11. CABG was carried out using left internal thoracic artery graft and saphenous vein graft. His postoperative course was uneventful. Anginal discomfort disappeared, and favorable results was obtained. SCA might be vulnerable to ischemic insult, so that coronary revascularization should be recommended in selected cases before the onset of serious complications.

Angina Pectoris↗
PubMed1994

[A successful case of left heart bypass with biocompatible bypass circuit and minimal heparin for severe heart failure after open mitral commissurotomy].

A successful case of left heart bypass (LHB) for severe heart failure after mitral commissurotomy is presented. A 44-year-old woman underwent surgery for mitral and tricuspid regurgitation, then could not be weaned from cardiopulmonary bypass because of low cardiac output and intractable ventricular arrhythmia. The LHB from right-sided left atrium to ascending aorta was instituted with anti-thrombogenic centrifugal pump system (Carmeda). During initial 6 hours of LHB, any anticoagulant drugs were not employed, thereafter the local administration of heparin into left ventricle was started with a dose of 200 unit per hour. The LHB was successfully weaned at 26 hours after institution. Her postoperative course was uneventful. The left heart bypass without systemic heparinization utilizing anti-thrombogenic material might be a safe and useful method for postcardiotomy cardiogenic shock.

Adult↗
PubMed1994

[A left atrial appendage thrombus without mitral stenosis--a successful case of removal].

Successful thrombectomy for left atrial ball thrombus without mitral stenosis is presented. A 62-year-old man was admitted to our department because of intermittent claudication. Arteriography demonstrated complete occlusion in bilateral superficial femoral arteries, however, the arterial wall was much smooth, suggesting thrombo-embolism rather than arteriosclerosis obliterans. The transthoracic echocardiography revealed no abnormal lesion in mitral apparatus and in left atrial cavity. The bypass operation was carried out for arterial occlusion, when the intraoperative transesophageal echocardiography showed the ball thrombus in left atrial appendage. The urgent operation was successfully carried out on 14th postoperative day after bypass operation. The thrombus occupied almost all the left atrial appendage, and its size was 24 x 19 x 13 mm. The transesophageal echocardiography was useful in diagnosis for left atrial appendage thrombus. Once the diagnosis was made for large and movable left atrial thrombus, immediate surgical therapy should be recommended to avoid serious complications and sudden death.

Echocardiography, Transesophageal↗
PubMed1994

[A successful case of valve-sparing surgery for tricuspid valve endocarditis].

A successful repair for infective endocarditis of the tricuspid valve is presented. A 35-year-old man was referred to our hospital complaining of high fever despite antibiotic chemotherapy. Lung scan showed multiple thromboembolism. Blood cultures revealed staphylococcus aureus. Echocardiography showed vegetations attached to the tricuspid valve and severe tricuspid regurgitation. Conservative surgery such as vegetectomy and DeVega's annuloplasty was successfully carried out. The patient's postoperative course was uneventful. The conservative surgery might provide a satisfactory result in the selected cases with localized vegetation and minimum valve involvement.

Adult↗
PubMed1993

Identification of the specific labile sites in the 180 kDa catalytic polypeptide of the Drosophila melanogaster DNA polymerase alpha-primase complex.

The immunoaffinity-purified DNA polymerase alpha-primase complex from Drosophila melanogaster Kc cells contains three high molecular weight polypeptides besides the 180 kDa catalytic polypeptide. These polypeptides are immunologically cross-reactive with the 180 kDa polypeptide. When the immunoaffinity-purified complex was kept at 4 degrees C for about four weeks, the amounts of the three polypeptides increased, while the 180 kDa polypeptide completely disappeared. Sodium bisulfite inhibited the decrease in the 180 kDa polypeptide. The N-terminal amino acid sequences of all the polypeptides were all assigned to ones present in a portion close to the N-terminus of the 180 kDa polypeptide. The N-terminal residue of all the three polypeptides was Ser. The cleavage sites were Phe130-Ser131, Thr180-Ser181, and Phe237-Ser238. These results show that the three polypeptides are cleavage products of the 180 kDa catalytic polypeptide, the cleavage occurring at specific labile sites including a Ser residue. The amino acid residues at the sites are quite different from those (Lys-Lys) in the human 180 kDa catalytic polypeptide.

Amino Acid Sequence↗
PubMed1993

[A case of impending rupture of acute aortic dissection with thrombosed false lumen in early phase].

A 73-year-old patient with acute aortic dissection in delayed shock state following sudden onset of chest-back pain and left sided hemothorax was successfully operated. Contrast enhanced CT demonstrated a crescent-shaped low density area in the descending aorta. Aortography showed ulcer-like projection (ULP) with minor leakage into left thorax, however, a flow in false lumen was not visualized. These findings suggested that the false lumen of type III aortic dissection was thrombosed in its early phase. The aneurysm was transected on left heart bypass through left thoracotomy. The entry of false lumen was found in proximal portion of descending aorta, in which fresh thrombus was filled. A graft was anastomosed and reinforced with felt strips in end-to-end. The postoperative course was uneventful. The ULP by aortography provides a possible sign of rupture in clinical course of aortic dissection.

Aged↗
PubMed1992

Functional analysis of nucleosome assembly protein, NAP-1. The negatively charged COOH-terminal region is not necessary for the intrinsic assembly activity.

A nucleosome assembly protein (NAP-1) of Saccharomyces cerevisiae facilitates the association of histones with DNA to form nucleosomes in vitro at physiological ionic conditions. The cloned gene was expressed in Escherichia coli using a T7 expression system, and the protein (417 amino acid residues) was purified by Mono Q column chromatography. Various deletion fragments of NAP-1 protein were also produced, and their nucleosome assembly activity was examined by supercoiling assay. The internal fragment containing the residues 43-365 was necessary and sufficient for the activity, and a long stretch of negatively charged region near the carboxyl terminus was dispensable. This minimal size fragment could form the 12 S NAP-1-histone complex as the whole protein could, whereas deleted fragments on either side could bind with core histones only to form aggregates.

Animals↗
PubMed1992

Etiopathogenesis of feline dental resorptive lesions.

There are several factors in the etiopathology of feline resorptive lesions. They may be considered as local immune-response mediating cell and humoral factors; release of biochemical components in dental and paradental tissues to attract odontoclasts; mechanical stress, including occlusal mechanism; and local and systemic calcium regulation, including remodeling of mineralized tissue and dietary intake of calcium.

Animals↗
PubMed1992

Induction of DNA synthesis by fibroblast growth factor in temperature-sensitive cell-cycle mutants of rat 3Y1 fibroblasts arrested at restrictive temperature.

Four temperature-sensitive cell-cycle mutants of rat 3Y1 clonal fibroblasts representing separate complementation groups (3Y1tsD123, 3Y1tsF121, 3Y1tsG125 and 3Y1tsH203) are arrested at restrictive temperature, primarily with a G1-phase DNA content (temperature arrest). We examined various factors affecting signal transduction for activity which induces DNA synthesis at the restrictive temperature when added to the temperature-arrested cultures of these mutants. The factors examined were theophylline, dibutyryl cyclic AMP, cholera toxin (CT), dibutyryl cyclic GMP, sodium nitroprusside, phorbol 12-myristate 13-acetate, 1-oleoyl 2-acetylglycerol, bombesin, vasopressin, basic fibroblast growth factor (FGF), platelet-derived growth factor, A23187, monensin, epidermal growth factor (EGF), insulin and fetal calf serum (FCS). None of these factors induced DNA synthesis in 3Y1tsH203. In one mutant (3Y1ts121), FGF, EGF and FCS individually induced DNA synthesis. In the other 2 mutants (3Y1tsD123 and 3Y1tsG125), FGF and CT individually induced DNA synthesis. The FGF-induced DNA synthesis was suppressed by islet-activating protein (IAP) in 3Y1tsD123 and 3Y1tsG125, but not in 3Y1tsF121. The CT-induced DNA synthesis was also suppressed by IAP, as previously shown. When temperature-arrested cultures were shifted to a permissive temperature, all 4 mutants initiated DNA synthesis in the presence of IAP. These results suggest that (1) a cell can prepare for the initiation of DNA synthesis by using several independent signal transduction pathways, and (2) in a given situation, the cell uses a particular pathway because of its availability, which depends on the culture conditions.

Animals↗
PubMed1992

Analysis of glutathione transferase P gene regulation with liver cells in primary culture.

Glutathione transferase P (GST-P) gene is specifically and highly activated during rat chemical hepatocarcinogenesis. We have previously cloned the GST-P gene and have identified putative regulatory regions. To further explore regulatory mechanisms, deletion constructs of the GST-P gene fused to the chloramphenicol acetyltransferase (CAT) structural gene were introduced into primary cultured rat hepatocytes by electroporation, and their activity was determined. The expression of the GST-P-CAT fusion gene is quite low in these cells as compared to that in both a rat fibroblast cell line, 3Y1 cells, and a rat hepatoma cell line, dRLh84. The presence of the strong enhancer GPEI did not elicit any enhancing activity at its original position, or when it was located 3' of the CAT gene, although this element does enhance CAT activity significantly when located adjacent to the promoter. Cotransfection of neither c-jun nor c-fos expression vector, nor both vectors, could enhance the CAT activity, even though GPEI consists of two phorbol ester response element-like sites. Furthermore, the expression of jun family gene was not correlated with GST-P gene expression either in primary cultured hepatocytes or in hepatoma cell lines.

Animals↗
PubMed1992

Biodegradation of aniline and abundance of potential degraders in river waters.

Total dissolved organic carbon (TOC), number of colony forming units (CFU), and total direct count (TDC) were compared to the biodegradation of aniline and the number of potential degraders in water samples from head waters to down stream of the Ina River and several other sites of rivers traversing Osaka city. The results indicate that aniline degrading populations of these various microbial communities exhibit different activities probably depending on the extent of adaptation to pollutants to which the microbes are exposed. The number of aniline degraders found in river water samples was in agreement with other parameters which were used to demonstrate the degree of pollution in river water even though higher biodegradability was evident in waters which show comparatively low TOC and CFU. These results suggest that biodegradation of aniline and enumeration of its potential degraders may serve as valuable indicators for the assessment of pollution in river waters.

Aniline Compounds↗
PubMed1991

Silencer binding proteins function on multiple cis-elements in the glutathione transferase P gene.

The glutathione transferase P (GST-P) gene is specifically expressed during chemical hepatocarcinogenesis of the rat, whereas mRNA of this gene is virtually undetectable in normal liver. We have previously identified a stretch of DNA, that acted negatively in transcription, at 400 bp upstream from the cap site of the rat GST-P gene. Further characterization has revealed that this negative fragment functions in an orientation and position independent manner, suggesting that it is acting as a silencer. This silencer consists of multiple negative elements to which nuclear factors bind. This silencer is active not only in rat non-hepatoma and hepatoma cells but also in human and mouse cell lines, suggesting that these elements function as general regulators of basal gene expression. At least two proteins bind to this silencer fragment, one of which, designated SF-A (Silencer Factor A), has been partially purified. SF-A binds to several regions in this silencer, and likely plays an important role on negative regulation of this gene.

Animals↗