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T Yasuoka

Publications and source records attributed to T Yasuoka.

At least 37 records · Page 2Linked to original sources
PubMed1998

Arginine vasotocin receptor in the vagina of the oviduct of the hen.

The presence of receptor for arginine vasotocin (AVT) in the vagina of the oviduct of the hen was demonstrated by the use of radioligand binding assays on membrane fractions of the tissue. The binding to [125I]AVT was highly competitive with unlabeled AVT. Scatchard analysis revealed that the binding sites are of a single class. The equilibrium dissociation constant (Kd) was 0.48+/-0.05 nM (x+/-SEM; n = 6) in laying hens holding a hard-shelled egg in the uterus (shell gland) and 1.01+/-0.02 nM (n = 6) in nonlaying hens. The maximum binding capacity (Bmax) was 0.41+/-0.04 pmol/mg protein (n = 6) in laying hens and 0.81+/-0.01 pmol/mg protein (n = 6) in nonlaying hens. The Kd value of the laying hens varied from 0.39 to 1.20 nM during an oviposition cycle, showing an increase just prior to oviposition, and the Bmax value also varied from 0.30 to 0.66 pmol/mg protein, showing a gradual increase after 6 h prior to oviposition. In the nonlaying hen, both values were almost constant during a 24-h day. The changes in the binding affinity and capacity of AVT receptor of the vagina may be related to oviposition in the hen.

Animals↗
PubMed1998

Calcitonin receptor binding properties in bone and kidney of the chicken during the oviposition cycle.

The binding property of calcitonin (CT) in the membrane fraction of calvaria and kidney of egg-laying and nonlaying hens was analyzed using a [125I] CT binding assay system. Binding properties of CT receptors in both tissues satisfy the authentic criteria of a receptor-ligand interaction in terms of specificity, reversibility, and saturation. Scatchard plots revealed a single class of binding sites. Values of the equilibrium dissociation constant (Kd) and binding capacity (Bmax) in laying hens showed a decrease during the period between 3 h before and 2 h after oviposition. No change was observed in nonlaying hens. In vivo administration of 17beta-estradiol or progesterone caused the decrease in Kd and Bmax values. The results suggest that the binding affinity and capacity of the CT receptor in the calvaria and the kidney of the hen may be modulated by the ovarian steroid hormone.

Animals↗
PubMed1997

Mesotocin receptor binding of cortical and medullary kidney tissues of the hen.

[125I]Mesotocin (MT) binding of membrane fractions of the cortical tissue and the medullary tissue (medullary cone) of the kidney of nonlaying hens was measured by the use of radioligand binding assays to determine the distribution of two distinct MT receptors within the hen kidney. The binding to [125I]MT in the medullary tissue was found to be highly competitive with unlabeled MT. In the cortical tissue, the binding was competitive with both unlabeled MT and arginine vasotocin. Kinetic and Scatchard analyses of specific binding revealed that the binding affinity was higher in the cortical tissue than in the medullary tissue, but the binding capacity was less in the cortical tissue. The localization of two distinct MT receptor having different binding properties may be related to the biphasic action of MT within the tissue of the kidney of the hen.

Animals↗
PubMed1997

Appearance of an arginine vasotocin receptor of large molecular size in the uterus (shell gland) of the hen at oviposition.

The molecular mass of the arginine vasotocin receptor in membrane fractions of the uterus (shell gland) of hens was estimated by autoradiography of [125I]-labelled arginine vasotocin binding protein after SDS-PAGE. A band of approximately 67 kDa was found in all of the samples taken from laying hens before and after oviposition and from nonlaying hens. In addition to this band, another band of approximately 95 kDa was found in samples from laying hens taken immediately before and after oviposition. Both bands were reduced by the presence of unlabelled arginine vasotocin or mesotocin, but the reduction was greater by arginine vasotocin than by mesotocin. These two bands were not reduced by chicken luteinizing hormone-releasing hormone-I (Gln8-GnRH), chicken luteinizing hormone-releasing hormone-II (His5,Trp7,Tyr8-GnRH) and chicken angiotensin-II (Val5-angiotensin-II). The appearance of the arginine vasotocin receptor of the larger molecular size may be related to oviposition in hens.

Analysis of Variance↗
PubMed1997

Direct action of melatonin on hen ovarian granulosa cells to lower responsiveness to luteinizing hormone.

The presence of a melatonin-binding component in the membrane fraction of the ovarian granulosa cells of hens that has characteristics of a receptor such as high affinity, limited capacity, reversible binding, and binding specificity was demonstrated by radioligand binding assays. When the cells were incubated in vitro with various concentrations of luteinizing hormone (LH) in the presence and absence of melatonin (1 and 5 nM), the dose-response curve for the LH-stimulated progesterone production was shifted to a higher concentration of LH: ED50 of LH was approximately two times greater in the presence of melatonin. The results suggest a direct action of melatonin on the ovarian granulosa cells of the hen to lower the responsiveness to LH for progesterone production.

Animals↗
PubMed1996

Changes in parathyroid hormone receptor binding affinity during egg laying: implications for calcium homeostasis in chicken.

Parathyroid hormone (PTH) receptor bindings were examined in the membrane fraction of the calvaria and the kidney of the hen by the use of [125I]PTH-related protein (PTHrP) binding assays. The binding specificity, reversibility, and saturation of the receptor were demonstrated. The equilibrium dissociation constant (Kd) and the maximum binding capacity (Bmax) were obtained by Scatchard analyses. In both calvaria and kidney, Kd and Bmax values decreased at 3 h before oviposition in egg-laying hens, but not in nonlaying hens. Administration of 17 beta-estradiol or progesterone in vivo caused a decrease in the Kd and Bmax values. Ionized calcium concentrations in the blood plasma showed a decrease at 13 h before oviposition. The results suggest that the PTH receptor binding in the calvaria and the kidney is affected by ovarian steroid hormones and may play a role in maintaining the calcium homeostasis in the egg-laying hen.

Analysis of Variance↗
PubMed1996

The effect of ovariectomy on the temporomandibular joints of growing rats.

PURPOSE: This investigation studied the effects of ovariectomy, on the temporomandibular joints (TMJ) of young rats. MATERIALS AND METHODS: Four-week-old female Wistar rats were ovariectomized and killed at the intervals of 1, 2, 4, and 8 weeks postoperatively. Histomorphometric study of the TMJ was performed in a synchronous manner with an age-matched sham-operated control group. The serum levels of estrogen, calcitonin, and C-terminus parathyroid hormone were also determined. RESULTS: In the sham-operated control group, the serum levels of estrogen and calcitonin increased with age. An increase of the bone volume, with a concomitant increase of the osteoid surface, was observed at 12 weeks. Thickness of the articular soft tissue was decreased with increasing age. In the ovariectomized animals, serum estrogen was not detected during the experiment. A biphasic change in the parathyroid hormone level, with decreases at 1 and 2 weeks after the ovariectomy and increases at 4 and 8 weeks postoperatively, was observed, whereas a constant value was noted in the calcitonin level. Thickness of the articular soft tissue was increased in the anterior and central portions of the condyle at 1, 2, and 4 weeks after the ovariectomy, whereas no appreciable changes were observed in the posterior portion. The bone volume was decreased during the experiment, particularly in the posterior portion. An osteophyte in the anterior region was also observed 8 weeks postoperatively. CONCLUSIONS: Estrogen deficiency in rats during puberty predisposes to alterations of the TMJ through changes in serum calcitonin and parathyroid hormone levels.

Analysis of Variance↗
PubMed1996

Mesotocin binding to receptors in hen kidney plasma membranes.

Radioligand assays were performed to demonstrate the presence of a receptor for mesotocin (MT) in the membrane fractions of the kidney of the hen. Specific [125I]MT bindings were decreased by the presence of Mg2+ and Ca2+, increased by the presence of EDTA, increased during the first 4 h of incubation and then reached a plateau, and increased with the increase in the protein concentration from 2.5 to 20 micrograms. The membrane fraction showed binding specificity to [125I]MT. The Scatchard plot revealed a curvilinear profile that indicated the presence of two classes of binding sites: a high affinity site and a low affinity site. The equilibrium dissociation constant was 0.08 +/- 0.01 nM (mean +/- SEM; n = 5) in the high affinity site and 0.87 +/- 0.08 nM (n = 5) in the low affinity site. The maximum binding capacity of the high and low affinity sites was 42 +/- 4 and 129 +/- 6 fmol/mg protein, respectively. The results suggest the presence of two distinct MT receptors in the kidney of the hen.

Animals↗
PubMed1995

A vasoactive intestinal peptide binding component in hen granulosa cells.

In radioligand assays, the vasoactive intestinal peptide (VIP) binding component in the membrane fraction of granulosa cells of the ovary of the hen was shown to possess characteristic properties of a receptor, such as reversible binding, binding specificity, high-affinity, and limited capacity. The binding site was of a single class. The binding affinity was higher in the largest (F1) and the second largest follicle (F2) than in the third largest follicle (F3), and the binding capacity was greater in F2 and F3 than in F1. During the ovulatory cycle, changes in affinity and capacity were observed only in F1 shortly before ovulation. The results suggest the presence of VIP receptor in the hen granulosa cells and its binding is assumed to be related to the follicular growth and ovulation.

Animals↗
PubMed1995

Diuretic and antidiuretic effects of mesotocin as compared with the antidiuretic effect of arginine vasotocin in the hen.

Mesotocin and arginine vasotocin were injected intravenously once at various dosage levels (.0025 to 25 micrograms/kg body weight) immediately after an intravenous injection of 15 mL/kg body weight saline solution into hens in which an artificial anus had been surgically created, and the volume of urine excreted during a 5-h period, following the injection, was measured. Arginine vasotocin caused a monophasic, dose-dependent decrease in urine volume. By contrast, mesotocin was biphasic: at .025 and .25 micrograms/kg body weight it decreased urine volume with the same efficacy as arginine vasotocin, whereas it dramatically increased urine volume at the higher doses (2.5 and 25 micrograms/kg body weight).

Animals↗
PubMed1993

[Deep peroneal nerve palsy associated with hypothyroidism].

Carpal tunnel syndrome is well known to be associated with hypothyroidism, but other mononeuropathies have been rarely reported. We report a 65-year-old male who showed right deep peroneal nerve palsy caused by hypothyroidism. The patient was admitted to our hospital because of general fatigue and right drop foot. On admission, bilateral pretibial pitting edema was observed, predominant on the right side. There was no muscle contraction in the right anterior tibial muscle and extensor hallucis longus in addition to slight weakness of the proximal muscles; whereas, muscle atrophy of the anterior tibial muscle was not noted. There was no sensory disturbance. On an electrophysiological examination, there was no muscle action potentials by the stimulation of the right deep peroneal nerve. Other nerves showed normal results both in the conduction velocity and in the compound action potential. Two months after the administration of levothyroxine sodium (0.025 mg/day), the right deep peroneal nerve palsy was completely recovered, associated with disappearance of pretibial edema. It is not yet determined which of axonopathy or demyelination is dominantly responsible for neuropathy associated with hypothyroidism. These results suggested a conduction block in deep peroneal nerve associated with focal edema. It is necessary to consider hypothyroidism as well as trauma, diabetes mellitus, and vasculitis when investigating mononeuropathy of deep peroneal nerve.

Action Potentials↗
PubMed1993

[Surgical treatment of the primary cardiac rhabdomyoma in the neonate--a case report].

A successful surgical treatment of intracardiac rhabdomyoma in a 12-day-old female is reported. The neonate was first noted to have a cardiac murmur and she was diagnosed cardiac tumor by two dimensional echocardiography. It showed multiple cardiac tumors which occupied the right ventricular outflow tract and interventricular septum. Under the routine cardiopulmonary bypass the tumor of the right ventricular outflow tract was removed. Histological examination revealed a rhabdomyoma. Follow-up evaluation 7 years after operation showed normal growth and development of the patient. A repeated two dimensional echocardiogram revealed no sign of recurrence and the left ventricular cavity was not obstructed by the residual tumor in the interventricular septum. We reviewed 10 cases treated surgically in infancy including three neonate in Japan.

Echocardiography↗
PubMed1993

[Clinical use of an expanded polytetrafluoroethylene sheets (GORE-TEX SHEETS) as a pericardial substitute after aorto coronary bypass grafting].

Reoperation after cardiovascular surgical procedures are often accompanied by the possibility of injuring the heart the great vessels, and extracardiac grafts during resternotomy. To reduce the risk associated with resternotomy and to facilitate dissection of intrapericardial adhesion, we have used GORE-TEX SHEET as pericardial substitute since January, 1989. In case GORE-TEX SHEET are implanted in the mediastinum, prolongation of the foreign body reaction, mediastinitis, increasing postoperative hemorrhage should be in mind. In this study, the biocompatibility of GORE-TEX SHEET was examined clinically. The following postoperative indices such as duration of fever, change of the WBC counts, WBC fraction, CRP, mediastinal hemorrhage are evaluated. These results showed no statistical significance between GORE-TEX SHEET group and autologous pericardial group by the randomized study. We recommend use of GORE-TEX SHEET as a pericardial substitute in cases of major cardiovascular operation using median sternotomy.

Aged↗
PubMed1992

Breast angiosarcoma metastatic to the maxillary gingiva. Case report.

A case of breast angiosarcoma metastatic to the maxillary gingiva is reported. A review of the literature revealed only three previously reported cases. Angiosarcomas often present as benign lesions. The surgeon should maintain a high level of vigilance when patients present with oral lesions and a history of breast tumor.

Breast Neoplasms↗
PubMed1991

Histomorphometric study of trabecular bone remodeling during condylar process fracture healing in the growing period: experimental study.

Trabecular bone remodeling during condylar fracture healing in the growing period was analyzed by histomorphometry with a synchronous system. Data from the study showed displacement of the fractured condyle was compensated by the changes in remodeling ascribed to the pubertal spurt of growth, and that such remodeling still continued even after clinical healing. The regional acceleratory phenomenon, evolved to potentiate tissue healing, was observed 1 week after induction of the fracture. Mesenchymal cells were presumably modulated into chondroblasts that promoted endochondral ossification. It was concluded that trabecular bone remodeling plays an important role in healing of condylar fractures during the growth period.

Animals↗
PubMed1989

The platysma myocutaneous flap for oral reconstruction. Experience with MacFee's cervical incision.

The present study was performed to demonstrate and evaluate the effectiveness of the Platysma Myocutaneous Flap in conjunction with MacFee's cervical incision (MacFee, 1960) for reconstruction after oral cancer excision. Ten squamous cell carcinoma cases were provided for postoperative evaluation of tongue movement and aesthetic problems of the cervical skin. It was found that the thickness of the skin island was adequate for covering the oral defects and was not a hindrance to proper postoperative function. MacFee's incision improved the condition of the scar caused by flap elevation. The procedure for preparing the muscle pedicle beneath the cervical skin tunnel was carried out without much difficulty by carefully preparing the surgical field.

Adult↗