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Biomedical subjects

Y Yoshimura

Publications and source records attributed to Y Yoshimura.

At least 505 records · Page 28Linked to original sources
PubMed1988

[Effects of experimental salpingoplasty on fertility in the rabbit].

The present study was undertaken to determine the functional capacity of oviduct following distal ampullar salpingostomy and tubal anastomosis. In the first experiment using 6 rabbits, the left fimbria of an oviduct and adjoining ampulla were resected, and then the remaining distal ampulla was subjected to cuff salpingostomy. The contralateral oviduct of each rabbit served as a control. Ovulation was induced at 3 weeks after surgery. The mean number of corpora lutea per ovary in the salpingostomy oviduct (5.00 +/- 0.37) did not differ significantly from that observed in the control oviduct (5.17 +/- 0.31). Five of 6 salpingostomy oviducts contained ovulated ova. However, the retrieval rate was significantly (p less than 0.01) reduced in the salpingostomy oviducts (36.7%), as compared to that found in the control oviducts (93.5%). Scanning electron microscopy of the fimbria revealed morphological features of both ciliated and secretory cells that were comparable to those of the contralateral intact fimbria. The second experiment assessed pregnancy outcome following tubal anastomosis in 6 rabbits. Pregnancy was established in both oviducts of all rabbits. The rate of implantation did not differ significantly between anastomosis sides (75.0 +/- 8.9%) and contralateral controls (93.9 +/- 3.9%). The present data demonstrated that fimbriectomized rabbit oviduct can retrieve ovulated ova, albeit less efficiently than normally. However, information that the retrieval rate of ova after salpingostomy is lower than that found in anastomosis also suggests a significant role of fimbria in ovum retrieval.

Anastomosis, Surgical↗
PubMed1987

Formation of 6-O-alpha-maltosylcyclomalto-oligosaccharides by transfer action of three debranching enzymes.

O-Maltosylcyclomaltohexaoses (G2-cG6) were formed in yields of 24.3 and 23.2 mmol from 40 mmol of alpha-maltosyl fluoride (alpha-G2F) and 90 mmol of cyclomaltohexaose (cG6) by the transfer action of pullulanase from Aerobacter aerogenes (A-pullulanase) and isoamylase from Pseudomonas amyloderamosa, respectively. These yields were three times that given by pullulanase from Bacillus acidopullulyticus (B-pullulanase). The yields of O-maltosylcyclomalto-oligosaccharides were changed according to the origin of the enzymes and the kind of cyclomalto-oligosaccharide (cG6, cG7, or cG8) used as the acceptor. By the reaction with 40 mmol of alpha-G2F and 90 mmol of cG6, 20 mmol of alpha-G2F and 30 mmol of cG7, or 40 mmol of alpha-G2F and 90 mmol of cG8, the amounts of O-maltosylcyclomalto-oligosaccharides produced and the transfer ratios of alpha-G2F to the acceptors were as follows. By A-pullulanase, 24.3 mmol of G2-cG6 was produced in a 60.8% transfer ratio, whereas the yields of G2-cG7 and G2-cG8 were 1.7 mmol (8.5%) and 8.4 mmol (21.0%), respectively. The yields of G2-cG6, G2-cG7, and G2-cG8 by B-pullulanase were 8.8 mmol (22.0%), 1.2 mmol (6.0%), and 11.7 mmol (29.3%), respectively. In the case of isoamylase, G2-cG7 (9.2 mmol, 46.0%) and G2-cG8 (20.9 mmol, 52.3%) were produced, as much as for G2-cG6 (23.2 mmol, 58.0%). It was suggested that the difference in the amounts of G2-cG6 produced by these three debranching enzymes is based on the difference in the mode of action on the alpha-G2F used as the substrate, either a transfer action or a hydrolytic action.

Bacillus↗
PubMed1987

[The effects of carbamylation of hormones on their biological activities--with reference to 3,5,3'-L-triiodothyronine and insulin].

It has been demonstrated that the binding of cyanic acid, formed from urea which is increased in renal failure, to hemoglobin (Hb) results in the formation of HbA1. The combination of Hb and cyanic acid is called carbamylation, a nonspecific reaction between protein and cyanic acid. It is theoretically considered that like glycation, carbamylation may occur between cyanic acid and not only Hb but also various peptides and proteins. In the present study, hormones were subjected to carbamylation, and the effects of carbamylation on the biological activity of the hormones, i.e. 3,5,3'-L-triiodothyronine (T3) and insulin, were investigated. Carbamylated T3 and carbamylated insulin were synthesized in vitro, using KCNO. The carbamylated hormones were isolated by high-performance liquid chromatography (HPLC). The biological activities of carbamylated T3 and carbamylated insulin were assayed by employing the metamorphosis of tadpoles (Rana nigromaculata) and the glucose oxidation of fat cells or the receptor binding capacity of rat hepatocytes, respectively. The biological activity of carbamylated T3 was less than about 1/13 of that of T3, and the binding activity of carbamylated insulin was 1/5 of that of insulin. Therefore, carbamylation of hormones may be an important factor in the analysis of clinical conditions, especially the endocrine condition in renal failure.

Animals↗
PubMed1987

The effects of proteolytic enzymes on in vitro ovulation in the rabbit.

The involvement of proteolytic enzymes in follicle rupture was assessed by use of the in vitro perfused rabbit ovary. Streptokinase (10 and 100 units/ml) induced ovulation in the absence of gonadotropin. Ovulation failed to occur in contralateral control ovaries. The time of ovulation in streptokinase- and human chorionic gonadotropin--treated ovaries was similar, but significantly more ova from streptokinase-treated ovaries were immature (p less than 0.001). Other ovaries were pretreated with trans-4-(aminomethyl)-cyclohexane-carboxylic acid, an inhibitor of the conversion of plasminogen to plasmin, and then perfused with human chorionic gonadotropin (50 IU). Ovulatory efficiency was significantly reduced by trans-4-(aminomethyl)-cyclohexane-carboxylic acid at 10 or 1 mmol/L (p less than 0.001), but ovum maturity was unaffected. Aprotinin (100 or 10 micrograms/ml), a potent inhibitor of plasmin, significantly inhibited human chorionic gonadotropin-induced ovulation (p less than 0.001) but did not affect oocyte maturation. Scanning electron microscopy of detergent-treated streptokinase-perfused ovaries revealed loosening and decomposition of collagen in the tunica albuginea. These results suggest proteolytic enzyme involvement in follicle rupture.

Animals↗
PubMed1987

Hemodynamic changes during dental extraction and post-extraction bleeding in patients with prosthetic heart valves.

Hemodynamic changes during dental extraction and postextraction bleeding were retrospectively evaluated in patients with prosthetic heart valves. It was found that the rate pressure product had a higher value in the period of anesthesia and during dental extraction. There was a tendency for a high RPP difference corresponding to an increased incidence of ECG changes, such as ST-T, QRS, P, and tachycardia. ECG changes were frequently observed high in procedures which required high doses of local anesthetic at one time or when multiple dental extractions were undertaken, whereas they seemed to have no positive relation to the number of heart valves replaced. Approximately 87% of the extractions were carried out under continuous anticoagulant therapy with a pretreatment coagulability level, of which 32% had bleeding during the first 24 h.

Adult↗
PubMed1987

The subcutaneous pedicle flap: widening of its applications.

The subcutaneous pedicle flap is useful for reconstruction of a relatively small defect, and there have been many reports on its use in the facial region. With careful manipulation and thought given to the selection of the patient, it is also applicable to the trunk and extremities. During the last 7 years, we have treated 80 patients who had subcutaneous pedicle flaps applied to various parts of the body (57 on the face, 12 on the trunk, and 11 on the extremities). Eleven representative patients are presented in this article. Based on our experience, we are now confident that the subcutaneous pedicle flap is useful to reconstruct a free border or transient area of different tissues, such as the eyebrow, eyelid, lip, and nose. In the trunk, e.g., in the buttock and the breast, it is useful to reconstruct the natural convexity. We prefer using the V-Y advancement type of subcutaneous pedicle flap rather than the transposition flap. To increase the mobility of the advancement flap, the distal portion of the flap is undermined just below the layer of the subdermal plexus. This may prevent postoperative bulkiness and facilitate the reconstruction of natural contour.

Adolescent↗
PubMed1987

Scalp graft for elevation of the reconstructed auricle.

Use of a split-thickness scalp graft for coverage of the retroauricular area after elevation of a reconstructed auricle is reported. Because there is no morbidity of the donor site and the color and texture match is excellent, the scalp can be an ideal donor site for coverage of the retroauricular area of the reconstructed auricle.

Adult↗
PubMed1987

Carbamylation of insulin and its biological activity.

A nonspecific binding reaction between cyanic acid formed from urea and protein or peptide is called carbamylation. In the present study, insulin, a peptide hormone, was subjected to carbamylation and the activity of carbamylated insulin was determined. Both immunological and biological activities of insulin changed on carbamylation. The decrease in biological activity in respect to glucose oxidation of fat cells or receptor-binding capacity of rat hepatocytes was greater than that in immunological activity.

Adipose Tissue↗
PubMed1987

Effect of aromatase inhibitors on the histology of the cycling rat ovary.

Two aromatase inhibitors, 4-hydroxyandrostenedione (4-OHA) and testololactone (Teslac), were tested to determine their effects on folliculogenesis, particularly ovarian histologic alterations, in the cycling rat. Adult, female Sprague-Dawley rats were treated with continuous infusion of both inhibitors at concentrations of 10(-8), 10(-4), and 10(-2) M for 30 days. The effect of the inhibitors on cultured granulosa cells harvested on proestrus was determined in vitro. The in vivo administration of each inhibitor induced significant reduction in ovarian-vein estradiol levels. Estradiol synthesis in cultured granulosa cells was inhibited by both aromatase inhibitors in a dose-dependent fashion. These observations indicate that 4-OHA and Teslac significantly inhibit basal estradiol synthesis in vivo and in vitro. This effect on estrogen synthesis was not reflected in alteration of the ovarian histology in the cycling rat.

Androstenedione↗
PubMed1987

Are ovarian steroids required for ovum maturation and fertilization? Effects of cyanoketone on the in vitro perfused rabbit ovary.

An isolated perfused rabbit ovary preparation was used to determine the effects of cyanoketone, a potent inhibitor of 3 beta-hydroxysteroid dehydrogenase, on ovulation, ovum maturation and fertilizability, and steroid production. In the first experiment, cyanoketone (10(-4) M) was added to the perfusate of one ovary. The contralateral control ovary was perfused with medium alone. Thirty minutes after the onset of perfusion, hCG (50 IU) was added to the perfusate of both ovaries. The ovulatory efficiency of ovaries treated with cyanoketone plus hCG (82.3 +/- 4.6%) was similar to that of ovaries treated with hCG alone (84.8 +/- 4.4%). No difference was observed in the degree of ovum maturity or degeneration between control and cyanoketone-treated ovaries. Progesterone and estradiol production were significantly reduced by cyanoketone treatment; concentrations in the perfusate of ovaries treated with cyanoketone were 9.7% and 8.0% of the control values, respectively, 2 h after exposure to hCG. The concentration of 17-hydroxypregnenolone was not affected by cyanoketone treatment. Exposure to cyanoketone resulted in a significant (P less than 0.005) reduction in the fertilizability of ova ovulated and fertilized in vitro. In the second experiment, the percentage of ova that showed evidence of normal fertilization was significantly (P less than 0.025) increased in ovaries perfused with cyanoketone plus estradiol (64.5%) compared to that in ovaries perfused with cyanoketone alone (32.4%). In the third experiment, the addition of progesterone to the perfusate did not affect fertilizability of ovulated ova in ovaries perfused with cyanoketone plus estradiol. These results suggest that the presence of estradiol in the ovarian steroid environment may be essential for fertilizability of ova, but not for the processes of ovulation or meiotic maturation.

3-Hydroxysteroid Dehydrogenases↗
PubMed1987

Protective effect of 4,6-O-ethylidene glucose against the cytotoxicity of streptozotocin in pancreatic beta cells in vivo: indirect evidence for the presence of a glucose transporter in beta cells.

Ethylidene glucose (4,6-O-ethylidene glucose; EG) is known to bind the outer surface of the glucose transporter in the membranes of human erythrocytes and other mammalian cells. If a glucose transport system is present on pancreatic beta cells and recognizes the glucose moiety of streptozotocin (STZ), EG should protect beta cells from the cytotoxicity of STZ when it is administered with STZ. This possibility was examined in in-vivo experiments in rats. When EG and STZ were injected into rats together the animals did not become diabetic, as judged by their blood glucose levels, response in a glucose-tolerance test, and insulin secretion in response to feeding. These results suggest that there is a glucose transporter present in beta cells and also the transport of streptozotocin into beta cells through this system.

Animals↗
PubMed1987

Orally active 1-(cyclohexyloxycarbonyloxy)alkyl ester prodrugs of cefotiam.

Orally active 1-(alkyl substituted cyclohexyloxycarbonyloxy)alkyl ester prodrugs (9b-h) of 7 beta-[2-(2-aminothiazol-4-yl)acetamido]-3- [[[1-(2-dimethylaminoethyl)-1H-tetrazol-5-yl]thio]-methyl]ceph+ ++-3- em-4-carboxylic acid (cefotiam, CTM) have been studied as well as the thia (9i) and aza (9j) analogs. These represent derivatives of the 1-(cyclohexylacetoxy)ethyl ester (2) of CTM. The syntheses and oral bioavailability (BA) in mice are described. Among them, the 1-(cyclohexyloxycarbonyloxy)butyl ester (9h) gave the highest BA, 93.5%; the esters having a cyclohexyloxy group in the ester moiety gave BAs of more than 75%, although the BA of the 1-(ethoxycarbonyloxy)ethyl ester (9a) was only 23.9%. The thia analog showed a moderate BA, 46%, but the aza analog, 9j, did not show a BA of CTM. These results indicate that the 1-(substituted cyclohexyloxycarbonyloxy)alkyl group was the suitable promoiety to improve the oral BA of CTM. Chiral 1-(alkoxycarbonyloxy)alkyl groups used as the ester moiety, gave an almost 1: 1 mixture of diastereoisomeric esters. These were tested as such. However, an experiment in which the separated isomers of the 1-(cyclohexyloxycarbonyloxy)ethyl ester (9d) were administered orally confirmed that both diastereoisomers gave identical BAs.

Administration, Oral↗
PubMed1987

The effect of a carbon dioxide pneumoperitoneum on rabbit follicular oocytes and early embryonic development.

The effect of a carbon dioxide (CO2) pneumoperitoneum and its duration on rabbit follicular oocytes was assessed by evaluating fertilization and subsequent embryonic development rates. CO2 may cross the plasma membrane and form carbonic acid, which liberates H+, thus lowering the intracellular pH. There were no significant differences in arterial pH and [HCO3-] between CO2 and air treatment groups, whereas arterial pCO2 and pO2 were significantly increased in the CO2 treatment group. We found that the duration of pneumoperitoneum, irrespective of type of gas used, was negatively correlated with success of embryonic development. These findings necessitate that more attention be given to the gas used for creation of a pneumoperitoneum during egg retrieval for in vitro fertilization and an attempt be made to minimize duration of the pneumoperitoneum.

Animals↗
PubMed1987

[Ovulation induction with a combination of LHRH analogue and hMG pulsatile subcutaneous administration in PCO patients].

The pulsatile subcutaneous administration of hMG (hMG therapy) and treatment with a combination of luteinizing hormone releasing hormone analogue (Buserelin) and hMG (combined therapy) were used to induce ovulation in 9 patients with polycystic ovary syndrome (PCO). Ovulation was observed in all twelve treatment cycles in the combined therapy, and two cases (delivery at term, and abortion) of pregnancy were confirmed. In the hMG therapy, ovulation occurred in 22 cycles of 26 treatment cycles. Ovarian hyperstimulation occurred in one cycle in the combined therapy and in 5 cycles (3 ovulated patients) in the 26 hMG therapy. The total dose per cycle of hMG required to induce ovulation in the combined therapy (1,700 +/- 203IU) was significantly lower than in the hMG therapy (2,344 +/- 223IU). In response to Buserelin administration, LH and FSH increased transiently and then declined to the normal range observed in the early follicular phase. The reduced LH level was sustained throughout the hMG administration. The concentration of FSH increased in response to hMG administration, resulting in a change in the LH/FSH ratio. The LH/FSH ratio in the combined therapy was significantly lower than in the hMG therapy. The present data demonstrated that pulsatile subcutaneous administration of hMG associated with Buserelin was effective in inducing ovulation in patients with PCO with a low incidence of serious side effects.

Administration, Intranasal↗