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Biomedical subjects

H Yasui

Publications and source records attributed to H Yasui.

At least 235 records · Page 13Linked to original sources
PubMed1994

[Endopyelotomy for ureteropelvic junction obstruction: results and complications].

We treated eleven cases of primary ureteropelvic junction obstruction with percutaneous endopyeltomy. Endopyelotomy was successful in nine of the eleven cases. Complications during and after endopyelotomy occurred in three cases, two of which had pyelonephritis and the other severe postoperative hemorrhage requiring blood transfusion due to incision of a posterior crossing vessel. In this last case, the kidney was supplied by three arteries. The lower segmental artery passed behind the ureter. We emphasized that angiography should be performed to rule out the presence of a posterior crossing vessel before endopyelotomy, when it is doubtful if an extrinsic cause of ureteropelvic junction obstruction is present.

Adolescent↗
PubMed1994

[Reoperation for transposition of the great arteries: mid-term results and reoperation after arterial switch operation].

The arterial switch operation for transposition of the great arteries is now widely accepted as the therapeutic method of choice. As of December 1993, a total of 162 patients underwent the arterial switch. There were 100 patients with transposition and intact ventricular septum, 48 with a ventricular septal defect, 14 with ventricular septal defect and arch anomalies (coarctation: 11, interruption: 3). Early and late mortality were 3.7% (6 patients) and 4.5% (7 patients), respectively. Postoperative pulmonary stenosis (> 30 mmHg) was noted in 33 patients (22%), aortic regurgitation (> mild) in 20 (13%), supravalvular aortic stenosis (> 20 mmHg) in 5 (3%) and mitral regurgitation (> mild) in 5 (3%). Reoperation was performed in 27 patients with no mortality. Mean interval between the switch and the reoperation was 30 months. Twenty-three patients with pulmonary stenosis underwent patch plasty of pulmonary artery. Two children with severe aortic regurgitation underwent aortic valve replacement. Two patients who had undergone one-staged repair for interruption complex were reoperated due to supravalvular aortic stenosis and pulmonary stenosis. Actuarial survival and freedom from reoperation at 9 years were 90% and 69%, respectively.

Aortic Valve Stenosis↗
PubMed1993

Synergism between IFN-gamma and IL-1 alpha/beta in growth inhibition of an allografted tumor.

Soluble effector molecules involved in the rejection of allografted mouse Meth A (3-methylcholanthrene-induced ascites type tumor) cells were examined. A potent antiproliferative activity against the tumor cells was detected in the culture supernatant of leukocytes that had infiltrated into the peritoneal cavity of C57BL/6 mice on days 6-8 after transplantation, when the i.p. transplanted Meth A cells were undergoing rejection. Studies with neutralizing antibodies indicated that both IFN-gamma and IL-1 alpha/beta were required for the activity but that TNF-alpha was not. Actually, mouse rIFN-gamma and rIL-1 alpha/beta used, at the concentrations found in the culture supernatant determined by ELISA, were able to reconstitute the potent antiproliferative activity, although each cytokine alone had a weak growth inhibitory activity against Meth A cells. The half-maximal inhibition was observed with 0.02-0.03 U/ml of rIL-1 alpha/beta at 1-100 U/ml of rIFN-gamma. The synergistic growth inhibitory effect of these cytokines also was observed with four of 15 mouse transformed cell lines tested, indicating that the effect was not specific to Meth A cells. These findings suggest that IFN-gamma and IL-1 alpha/beta participate as soluble effector molecules in the rejection of some allografted tumor cells including Meth A cells.

Animals↗
PubMed1993

Measurement of recombination frequencies between two homologous DNA segments embedded in a YAC vector.

We measured the frequencies of recombination in a yeast host between two homologous segments of DNA that had been inserted with the same polarity in a yeast artificial chromosome (YAC) vector. Three kinds of YAC clones were constructed in which the gene encoding neomycin(Nm) resistance was sandwiched between two homologous segments of DNA, such as the IS3 elements of Escherichia coli or human Alu sequences. Frequencies of homologous recombination in yeast were measured in terms of loss of resistance to Nm. In the case of IS3 fragments, homologous recombination between them did occur at a relatively high frequency (5 x 10(-4). In contrast, recombination between two Alu sequences did not occur at a detectable level during a 30-day incubation. Thus, the frequency was less than 10(-5). These results indicate that the Alu sequences do not sufficiently promote the frequency of recombination between two homologous fragments in yeast as to induce rearrangements of DNA in a substantial fraction of YAC clones in libraries.

Base Sequence↗
PubMed1993

Revised technique of cardiopulmonary bypass in one-stage repair of interrupted aortic arch complex.

Twenty infants with interrupted aortic arch associated with various intracardiac anomalies underwent primary complete repair using pulsatile high-flow cardiopulmonary bypass with a short period of circulatory arrest. Age at repair ranged from 11 to 126 days (mean age, 43 days). Weight ranged from 2.2 to 5.5 kg (mean weight, 3.4 kg). Associated cardiac lesions included ventricular septal defect (14 patients), truncus arteriosus (3), transposition of the great arteries (2), and aortopulmonary window (1 patient). Left ventricular outflow tract obstruction was relieved in 2 patients. The aortic arch was reconstructed with a polytetrafluoroethylene graft in 7 patients and by direct anastomosis in the most recent 11 patients. An arterial cannulation method has been devised to facilitate direct anastomosis between the ascending aorta and the descending aorta, to lessen circulatory arrest time, and to prevent dangerous laceration and postoperative narrowing of the thin, small ascending aorta at the cannulation site. Two patients died, a surgical mortality rate of 10%. There has been one late death, which was due to severe truncal valve insufficiency. The other patients are doing well with a mean follow-up of 3 years 6 months. Restenosis of the direct anastomosis has not been noted in any patient. However, subaortic stenosis with pressure gradients of 30 to 40 mm Hg developed in 3 patients. In conclusion, one-stage repair including direct anastomosis for the aortic arch reconstruction and repair of all coexisting intracardiac defects is thought to be the treatment of choice.

Anastomosis, Surgical↗
PubMed1993

Trans-ventricular septal defect approach for resection of accessory mitral valve tissue.

Accessory mitral valve tissue is a rare cause of left ventricular outflow tract obstruction, which can be difficult to recognize. Surgical resection by the conventional transaortic approach with or without left atriotomy is extremely difficult in infants with a small aorta. When a ventricular septal defect is present, it may be the best way to approach the accessory mitral valve tissue, because the ventricular septal defect is located just in front of it. Five infants underwent resection of accessory mitral valve tissue together with repair of other intracardiac malformations. In 3 infants, resection of accessory mitral valve tissue was easily performed through the ventricular septal defect, which required enlargement in 2 patients.

Female↗
PubMed1993

T cell receptor-extracellular constant regions as hetero-cross-linkers for immunoglobulin variable regions.

The T cell receptor alpha and beta chains are covalently linked via a disulfide bond in their extracellular constant regions. To use these domains as specific hetero-cross-linkers of two different polypeptides, we created genetic constructs encoding a chimeric antibody Fab fragment in which mouse immunoglobulin constant regions from a phosphorylcholine-specific antibody were substituted for human alpha beta-T cell receptor (TCR) extracellular constant regions (for solubilization, the transmembrane- and cytoplasmic-regions of the receptor were deleted). These constructs, i.e., chimeric heavy (VHC beta C kappa) and light (VLC alpha) chains, were cotransfected into murine SP2/0 myeloma cells for expression. Cells transfected with the genes expressed mRNAs for chimeric heavy and light chains. Without CD3 molecules, the two chimeric chains specifically associated via a disulfide bond to form a chimeric Fab fragment in the cells. These data indicate that the TCR C alpha- and C beta-regions might be used as potent specific hetero-cross-linkers for protein engineering.

Amino Acid Sequence↗
PubMed1993

Improved flow injection analysis (FIA) method for determining selenium in biological samples, and the effect of captopril administration on selenium levels and glutathione peroxidase activity in rat.

An improved flow injection analysis (FIA) method has been developed for the determination of trace selenium in biological samples, and this method has been applied to investigate the effect of captopril, an antihypertensive drug having a thiol group, on selenium concentrations in the rat blood, liver and urine. After oral administration of captopril, selenium levels in the blood decreased, while those in the liver increased significantly. However, no pronounced effect was observed on the urinary excretion rate. The glutathione peroxidase activities in the blood and the liver were comparable to the changes in the selenium levels.

Administration, Oral↗
PubMed1993

Synthetic study on selenocystine-containing peptides.

N-9-Fluorenylmethoxycarbonyl-Se-4-methoxybenzylselenocysteine++ + [Fmoc-Sec(MBzl)-OH] was synthesized from selenocystine and successfully applied to Fmoc-based solid-phase peptide synthesis. The stability and the deprotection conditions of the Se-MBzl group were examined. The diselenide bond of a peptide was directly and effectively established between Sec(MBzl) residues by treatment with iodine or the dimethyl sulfoxide-trifluoroacetic acid system. Reduction kinetics of diselenide and disulfide in model peptides by reduced glutathione were also studied comparatively.

Amino Acid Sequence↗
PubMed1993

[The effect of perioperative portal venous inoculation with donor lymphocytes in combination with immunosuppressive agents on rat cardiac allograft survivals].

The synergistic effects of inoculation with donor lymphocytes via portal vein (PV) in combination with FK506 or monoclonal anti-T lymphocyte antibody (OX19) on cardiac allograft survival were investigated in rat heart transplant model (Lewis engrafted BN heart). The recipients were divided into the six groups. A) Control B) FK506 group C) PV group D) FK506+PV group E) OX19 group F) OX19+PV group. The recipients of PV group and FK506 group displayed a prolongation of cardiac allograft survival [MST: 11.2 +/- 1.0 and 12.4 +/- 1.0 days] compared with control group [MST: 7.3 +/- 0.3 days]. However, MST of FK506+PV group was 10.6 +/- 0.8 days, showing no synergistic effect of FK506 with PV administration. Significant prolongation of the graft survivals was not observed between OX19 group and OX19+PV group [MST: 17.2 +/- 2.1 and 15.0 +/- 1.2 days]. Serum from PV-treated hosts on day 7 after transplantation had suppressor effect (92.7%) on the MLR of Lewis responder cells toward donor BN cells. On the other hand, suppressor effect of serum from FK506+PV group was significantly reduced (5.8%) compared with PV alone. These results indicate that FK506 might inhibit the generation of suppressor factor which was induced in the serum after administration of donor lymphocytes, and that generation of suppressor factor might be dependent on T cell.

Animals↗
PubMed1993

[A case of acute hepatitis A associated with acute renal failure from the onset].

A 42-year-old female was admitted to a hospital, because of acute hepatitis A. Laboratory data were GOT 8210mU/ml. GPT 4650mU/ml, LDH 11860mU/ml, total bilirubin 4.7mg/dl, BUN 19.5mg/dl and creatinine 1.9mg/dl. Urinalysis showed proteinuria 3+ and occult blood 1+. Soon after admission, she suffered from anuric acute renal failure and was transferred to our hospital for hemodialysis. Her urine-volume was under 20 ml per day. Urinalysis showed proteinuria 4+, occult blood 1+ and casts. Laboratory data showed BUN 58.2mg/dl and creatinine 8.5mg/dl. She was treated by hemodialysis for 35 days, before recovering from renal failure. However, her renal function did not recover perfectly and her 24-hour creatinine clearance remained at 50ml/min after 6 months. Renal biopsy was performed on the 17th day after admission. Examination by light microscopy revealed the findings of acute tubular necrosis and examination by immunofluorescence antibody method was negative. Urinalysis of 8 patients with acute hepatitis A showed that all patients had proteinuria at the onset. Patients with acute hepatitis A have symptoms of appetite-loss, nausea, vomiting and/or diarrhea. These symptoms cause hypovolemia, and hepatic dysfunction causes discontrol of vasoactive hormones, which gives rise to disturbance of renal circulation. Subsequently, acute tubular necrosis and acute renal failure occur.

Acute Disease↗
PubMed1993

Pulmonary vascular disease and operative indications in complete atrioventricular canal defect in early infancy.

Pulmonary vascular disease was morphometrically analyzed in 67 patients (mean age, 19 months) with isolated complete atrioventricular canal defect. Complete obstruction of the small pulmonary arterial lumen resulting from acute fibrous proliferation and atrophy of the peripheral arterial media, which were considered absolute operative contraindications, were characteristic in six patients with Down's syndrome. Morphometric analysis of medial thickness revealed that thinning of the media of the small pulmonary arteries is generally observed at around 6 months of age in patients with complete atrioventricular canal defect and that the media in patients who have complete atrioventricular canal defect and Down's syndrome was thinner than that in such patients without Down's syndrome. These results suggest that thinning of the media as a result of two factors--Down's syndrome and aging--facilitates the rapid occurrence of fibrous intimal proliferation. Therefore intracardiac repair is desirable within 6 months of life, before medial thinning, in patients with complete atrioventricular canal defect and Down's syndrome. Excluding patients with absolute operative contraindications, the scores of the index of pulmonary vascular disease in operative survivors were below 2.0 and death occurred when scores were more than 2.2. The pulmonary vascular resistances measured in room air and by the oxygen inhalation and tolazoline tests in patients with operative contraindications were more than 7.3, 3.8, and 6.6 units.m2, respectively. We thus conclude that lung biopsy should be undertaken for patients in whom pulmonary vascular resistance is beyond these values to determine the appropriateness of surgical intervention.

Child↗
PubMed1993

Anomalous origin of the left coronary artery from the right pulmonary artery: report of a case.

A 1-year-old boy was referred to our hospital for further investigation of mitral regurgitation. Color-Doppler echocardiography revealed the site of the anomalous origin of the left coronary artery which was confirmed by a cineangiographic study. This case is interesting for several reasons: the first is that the anomalous left coronary artery originated from the right pulmonary artery; the second is that two-dimensional echocardiographic findings can be misleading, i.e., a vessel-like structure which seemed to be the left coronary artery arising normally from the aorta was visualized; and the last is that a two-dimensional color-Doppler echocardiogram was useful in the diagnosis of the anomalous origin of the left coronary artery. The patient underwent implantation of the anomalous left coronary artery as well as Kay's plasty of the mitral valve, and has been doing well since then.

Coronary Vessel Anomalies↗
PubMed1992

Clonal growth of hepatitis B virus-integrated hepatocytes in cirrhotic liver nodules.

A total of 83 cirrhotic nodules (pseudolobules) individually collected from 11 cirrhotic livers of hepatitis B virus carrier patient were analyzed for the frequency and mode of hepatitis B virus integration as well as histological features. Southern blot analysis disclosed discrete bands at higher molecular weight region in 26 of 83 nodules (31.3%), indicating a clonal growth of hepatocytes with viral integration. Considerable variation (0-75%) existed in the positive rates for discrete bands in nodules among livers. Molecular cloning revealed the sequence flanking an integrated viral sequence to be host DNA and thus confirmed true integration. Histological analysis, however, did not reveal any neoplastic-appearing foci of growth within nodules, despite the fact that the detection sensitivity would predict clones of more than 10(5) cells to give rise to clonal integration patterns on Southern blot analysis. The question of whether clonal expansion of hepatocytes reflects any viral integration-associated growth advantage and/or a preneoplastic condition awaits future studies.

Adult↗