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Biomedical subjects

O Kobayashi

Publications and source records attributed to O Kobayashi.

At least 145 records · Page 8Linked to original sources
PubMed1986

[An experimental study of the healing of velour grafts].

An experimental study of implantation of velour grafts in the abdominal aorta or the external iliac artery of dogs was conducted with the object of evaluating the type of velour surface best fit for small-caliber artery implantation. Velour grafts measuring 4mm in diameter with differing velour surfaces were used as materials. Velour grafts now available on the market differ not only in velour surface but also in structure, notably in porosity and wall thickness. Hence each of the grafts used was reversed (i.e. inside out) and thus new grafts were prepared. These grafts were considered most suitable for making a comparative study of the effects of velour surface on healing. Macroscopic and histological findings revealed that each graft was good healing with the rate of patency as high as 84 percent. However, like Vasculour-D grafts, crimped grafts which preserve the crimp after implantation was significantly thicker at the internal valley than other grafts. Based on the findings of this experimental study non-crimped velour grafts were considered to be best fit for small-caliber artery implantation.

Animals↗
PubMed1985

The acute effects of prostaglandin E1 on the pulmonary circulation and oxygen delivery in patients with the adult respiratory distress syndrome.

Prostaglandin E1 was administered intravenously to 10 patients who had the adult respiratory distress syndrome associated with severe infection in order to investigate its hemodynamic effects. Infusion of PGE1 significantly decreased the mean pulmonary arterial pressure, mean systemic arterial pressure, pulmonary vascular resistance and systemic vascular resistance, and increased the cardiac index, oxygen delivery and oxygen consumption. No significant difference was noted in the intrapulmonary shunt fraction. These results indicate that administration of PGE1 improves pulmonary hemodynamics and tissue oxygenation in patients with acute respiratory distress syndrome, by reducing right ventricular afterload and increasing the cardiac index.

Aged↗
PubMed1985

AFP-producing Sertoli-Leydig cell tumor of the ovary.

A tumor of the right ovary in a 21-year-old single woman is reported. Secondary amenorrhea, hirsutism, acne and deepening of the voice were associated with the tumor. Light and electron microscopic examinations showed that the tumor was composed of cells resembling Sertoli and Leydig cells of the testis in their cytology features and growth patterns. High levels of circulating dehydroepiandrosterone, androstenedione, testosterone and alpha-fetoprotein (AFP) were found preoperatively. Preoperative estrogen and progesterone levels were all slightly above the upper limits of normal for females. These hormone and AFP levels fell to within the normal range after removal of the tumor. Direct hormone and AFP production of this tumor was confirmed by immunohistochemical techniques and long-term cell cultures in vitro. This is possibly the first report on a Sertoli-Leydig cell tumor in which AFP has been identified in the patient's plasma, in part of the tumor cells and the culture fluid.

Adult↗
PubMed1985

Effect of dithiothreitol on activity and protein structure of human urine urokinase.

Human urine urokinase [EC 3.4.21.31] was found to be inactivated by dithiothreitol (DTT) much more severely than by 2-mercaptoethanol at the same concentration on the basis of -SH groups. Removal of DTT by dialysis restored the activities of esterase toward acetyl-glycyl-L-lysine methyl ester, plasminogen activation, and amidase toward 7-(glutaryl-glycyl-L-arginine-amido)-4-methyl coumarin. But the restoration of amidase activity was much less than that of esterase activity. The addition of DTT mediated the conversion of high molecular weight urokinase to low molecular weight urokinase, releasing several peptides. This suggests that the urokinase consists of several polypeptides linked by disulfide bonds. The molecular weight of urokinase produced with DTT was smaller than that of low molecular weight urokinase obtained by autodigestion of high molecular weight urokinase. The autodigestion was also accompanied by liberation of some peptides. But, those peptides released on autodigestion of high molecular weight urokinase were different from those appearing in the presence of DTT.

Amidohydrolases↗
PubMed1985

Asymptomatic low molecular weight proteinuria: a report on 5 cases.

In children with asymptomatic proteinuria, a high proportion of low molecular weight (LMW) proteins is an indicator of tubular malfunction. In a routine screening program covering the last 15 years and involving 280,000 children, aged between 3 and 19 years, we have identified 5 boys with LMW proteinuria. In 4 of these, renal biopsy was histologically normal on the first presentation. Follow-up for 4-16 years showed normal growth curves, but further evidence of tubular dysfunction appeared: glycosuria and hypophosphatemia in 2 patients; one of them had also aminoaciduria and rising serum creatinine (greater than 1.2 mg/100 ml). Another patient had only increased serum creatinine. The other two, still less than 13 years old, show so far no other abnormality than persistent LMW proteinuria. It is suggested that early identification of LMW proteinuria may presage gradual development of progressive tubular dysfunction with age and that such patients should be followed up indefinitely.

Adolescent↗
PubMed1984

Uropepsinogen in human urine: its protein nature, activation and enzymatic properties of activated enzyme.

Uropepsinogen (UPG) in human urine was highly purified by chromatography on columns of DEAE-lignocellulose, elastin-celite, etc. The purified UPG was composed of two electrophoretically distinguishable components (UPG I and UPG II), and they were isolated in the pure state, respectively. UPG I and UPG II were the same in molecular weight (3.9 X 10(4)) and in N-terminal (leucine) and C-terminal (alanine) amino acid residues. Also, they were quite similar in amino acid composition. They were activated to uropepsin (UP I and UP II, molecular weight, 3.3 X 10(4), respectively), but the activated enzymes were the same in the various properties examined, suggesting that the difference between UPG I and UPG II is due to only a minor change in the peptide segment, perhaps by deamidation. The activation of UPG I and UPG II occurred at acid pHs, the best pH being at 2.0. Both the proenzymes previously incubated with pepstatin at pH 6.8, however, were not activated even in the following incubation at acid sides. The results obtained are discussed in regard to the origin of the proenzyme and its properties before and after activation.

Amino Acid Sequence↗
PubMed1984

[Study on follow-up procedure for postmolar patients].

Since 1974, in Chiba prefecture patients with trophoblastic disease have been registered with the Department of Obstetrics and Gynecology, Chiba University School of Medicine as the registration and management center. An original follow-up system for postmolar patients has been used and following results obtained. From 1974 to 1981 (8 years), 1544 hydatidiform mole patients were registered. The number of deliveries was 582,641. The incidence of hydatidiform mole in deliveries was 1:377. Postmolar patients whose hCG titers were greater than 10,000 IU/l, 1,000 IU/l and 100 IU/l at the fifth, eighth and twelfth week respectively, were treated as trophoblastic sequelae. In these check points, 155 cases (10.0%) were treated as sequelae, namely, 9 cases (0.6%) of choriocarcinoma, 54 cases (3.5%) of invasive mole and 94 cases undetermined (6.1%). At the fifth week after molar evacuation, there were 96 cases whose hCG titers were from 1,000 to 10,000 IU/l, and at the eight week, 86 cases were from 100 to 1,000 IU/l. Among the former there were 30 cases (31.2%) and among the latter, 36 cases (41.9%) of spontaneous remission. By using this follow-up system, 66 cases (36.3%) were able to avoid over treatment.

Chorionic Gonadotropin↗
PubMed1983

[Studies on enzymeimmunoassay for human chorionic gonadotropin and its clinical application].

Two enzyme immunoassays for hCG were developed and compared with HAR and RIA by using many urine and serum samples. The EIA was characterized by management of trophoblastic disease. 1. An EIA by hCG-beta antibody immobilized on a microplate and hCG antibody conjugated with HRP enzyme quantified hCG from 0.5 to 100ng/ml, while the other by biotinyl hCG antibody and avidine-HRP conjugate quantified hCG from 0.1 to 20ng/ml. Both of them had a good correlation with RIA; y = 1.02x + 2.3, r=0.99 and Y=0.96x-0.38. The C.V.S. were 1.8 and 5.2% (intraassay), or 5.8 and 9.5% (interassay), respectively. 2. The EIA was carried out to test hCG patients whose urinary hCG by HAR was under the LH level. The values in 371 samples were under 2ng/ml, but those in 40 samples were higher than 2ng/ml (Max 15.8 ng/ml). Diagnosis by EIA distinguished recurrence from remission 2 month earlier than by HAR. The EIA was useful in the management of the disease.

Adult↗
PubMed1983

[Histological study of urinary bladder tumor: DNA of rat urinary bladder tumor caused by N-butyl-N-(4-hydroxybutyl) nitrosamine and that of human bladder tumor].

Male Fisher rats were treated with 0.5% BBN, and the appearance of cancer in the rat's bladder was observed successively. The quantities of DNA in the normal and tumorous tissues were compared with those in the bladder cancer excised from man; and, the bladder cancer produced in the rat and that occurring in man were compared. 96 rats were divided into 4 groups, and given 8, 16, 24 or 32 weeks of treatment with BBN. Papillomas appeared after administration for 8 weeks, and with subsequent increase in the period of administration the rate of canceration increased. The cancerous tissue proliferated papillarily , the malignancy was grade 1 to 2, no case showed infiltration into the muscle layer, and the quantity of DNA scarcely changed with time, always showing a peak near 2c. In the papillary type of bladder cancer in man, the quantity of DNA showed little change at any stage, and little tendency of infiltration; and, the growth pattern was similar to that of the BBN-induced cancer in rats. On the other hand, non-papillary cancer in man showed a flat histogram of DNA, had a strong tendency of infiltration, and showed a growth pattern different from that of the BBN-induced cancer in rats, thus the BBN-induced cancer in the rat cannot be used as a model of non-papillary infiltrative cancer.

Animals↗