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Biomedical subjects

G Watanabe

Publications and source records attributed to G Watanabe.

At least 343 records · Page 19Linked to original sources

[A rare case of successful surgical treatment of dissecting aortic aneurysm (DeBakey IIIb) associated with total obstruction of the abdominal aorta and acute complicated renal failure].

A rare case of successful surgical management of dissecting aortic aneurysm (DeBakey IIIb) is presented. A fifty-year-old male was admitted to our hospital with a complaint of severe backache and both leg pain. A diagnosis of acute renal failure and assessed total obstruction of the abdominal aorta was made angiographically. Immediate hemodialysis was carried out. After 50 days, a right subclaviafemoral bypass was performed. However, on the 60th postoperative day, plasma creatinine and BUN levels were significantly elevated. A left renal revascularization was performed using saphenous vein graft from the right common iliac artery. The postoperative course was excellent and the creatinine and BUN levels were immediately reduced. And there was no need of hemodialysis postoperatively. Because of difficult management of this kind of complication, extra-anatomic bypass is preferable, instead of total replacement of the dissecting aortic aneurysm. And weaning from such a long term hemodialysis by revascularization of one-kidney is very rare.

Acute Kidney Injury↗

Pulsatile luteinizing hormone (LH) release during the progesterone-induced LH surge in the female rhesus monkey.

LH pulses during the progesterone (P)-induced LH surge were examined in ovariectomized and estrogen-treated female monkeys. Animals received a 2.5-mg P or oil injection 24 h after administration of 30 micrograms estradiol benzoate. The animals were fitted with jugular catheters connected to a tether-swivel system. Blood samples were collected at 10-min intervals starting 3-4 h before and ending 12-20 h after P or oil injection. Plasma LH was measured by both bioassay and RIA. LH pulses were determined by the PULSAR program. P administration induced a BIA-LH surge with a latency of 71 +/- 10 min in all seven animals. The P-induced bioassayable LH (BIA-LH) surge consisted of an ascending phase (204 +/- 24 min), a plateau period (174 +/- 32 min), and a descending phase (376 +/- 60 min). Oil injection did not cause a LH surge (n = 4). BIA-LH release before P and that during the P-induced LH surge were pulsatile. Pulse intervals of BIA-LH before P treatment (57.1 +/- 5.2 min) were not different from those before (55.0 +/- 11.7 min) and after (62.9 +/- 16.3 min) oil injection. In contrast, pulse intervals during the ascending phase (35.0 +/- 4.0 min), plateau period (34.6 +/- 2.6 min), and descending phase (45.0 +/- 3.1 min) were significantly shorter (P less than 0.02) than those before P. Pulse amplitudes of BIA-LH during the ascending phase (125.3 +/- 28.7 ng/ml) and plateau period (253.9 +/- 27.0 ng/ml) were significantly (P less than 0.001) higher than those (44.7 +/- 12.6 ng/ml) before P and during the descending phase (66.9 +/- 11.1 ng/ml). Radioimmunoassayable LH results were quite similar to those for BIA-LH, except that amplitude changes in radioimmunoassayable LH after P treatment were smaller than those in BIA-LH. It was concluded, therefore, that both the frequency and amplitude of pulsatile LH release increase during the P-induced LH surge, especially during the ascending phase and plateau period, in female rhesus monkeys. Furthermore, the present results support our previous conclusion that P facilitates pulsatile LHRH release with increases in frequency and amplitude in ovariectomized and estrogen-treated monkeys.

Animals↗

Inhibin activity and secretion of gonadotropin during the period of follicular maturation.

To evaluate the relative contributions of the ovarian inhibin and estradiol-17 beta (E) on the regulation of FSH secretion, inhibin and E in ovarian venous plasma (OVP) and FSH and LH in peripheral plasma were simultaneously measured using superovulating rats with special reference to follicular maturation. By the transplantation of a pituitary gland from adult male rats under the kidney capsule between 1100 and 1200 hr on diestrus-1 in cyclic rats, superovulation was successfully induced on the morning of the next estrus without any additional treatment with human chorionic gonadotropin (hCG). The number of maturing follicles capable of ovulating in response to hCG significantly increased at 12 hours after the grafting as compared with sham-operated controls and further increases occurred until the afternoon of proestrus. In the superovulating rat, first and second surges of FSH were completely blocked and an LH surge was also partially suppressed during the periovulatory period when surges of FSH and LH were normally observed in controls. Contents of FSH as well as LH in the animal's own pituitary gland were suppressed significantly after the grafting as compared with controls. A marked increase in inhibin activity in OVP of rats with a pituitary transplant occurred concomitantly with an increase in the number of follicles capable of ovulating whereas E levels in OVP did not so. Inhibin activity in OVP at each point was much higher in the pituitary grafted rats than in controls but this was not true for E levels. These results suggest that ovarian inhibin derived from the maturing follicles rather than E may be a primary factor for regulation of FSH secretion, and high levels of endogenous inhibin can suppress synthesis of LH as well as FSH in the pituitary gland of the female rat.

Animals↗

Initiation of ovarian follicular maturation without a surge of FSH in cyclic rats treated with antiserum to LH-releasing hormone.

The relationship between a surge of FSH and the initiation of follicular maturation was examined using rats with a 4-day oestrous cycle. When antiserum against LH-releasing hormone (LHRH-AS) was given at 13.00 h on the day of pro-oestrus (day 0), surges of FSH and LH were blocked. Plasma FSH and LH were maintained at low basal levels without a surge release until the next spontaneous surge occurred on the afternoon of day 4, the predicted day of pro-oestrus. Follicular responsiveness to an injection of human chorionic gonadotrophin (hCG) indicated that preovulatory follicles, present at the time of treatment with LHRH-AS, were capable of ovulating on day 1 but had regressed by day 2. Subsequently, as shown by the ovulatory response to hCG, a new set of follicles had begun to mature by the morning of day 3 without a preceding surge of FSH. Changes in oestradiol-17 beta levels in the plasma throughout the oestrous cycle were the same in rats injected with LHRH-AS or non-immune control serum. The mature follicles in the rats treated with LHRH-AS thus retained the capacity to ovulate after losing their ability to secrete oestrogen. These results suggest that an FSH surge is not essential for initiation of follicular maturation and that basal levels of FSH may be enough to initiate follicular maturation in the absence of newly formed corpora lutea.

Animals↗

[Surgical experience in arteriovenous fistula following disk surgery].

A 21 year-old woman was admitted to our hospital due to congestive heart failure with severe leg edema. A continuous murmur was heard around the lumbar spine close to a surgical scar after laminectomy of the L4-L5 and L5-S1 disc that the patient had undergone six months before. Aortography demonstrated an arteriovenous fistula between the right common iliac artery and the inferior vena cava. At operation, we found the moderate sized venous defect and it corresponded with the angiographic finding. It was repaired by direct suture from inner side of the right common iliac artery. Arterial reconstruction was made with a 8mm woven dacron graft. Postoperative course was uneventful. The cardiac silhouette diminished in size and cardiac output improved from 12.5l/min. to 8l/min. after surgery. This report is the fourth case of successful repair for the arteriovenous fistula after disc surgery in Japan.

Adult↗

[A family with multiple endocrine neoplasia type I presenting prolactinoma, Zollinger-Ellison syndrome and hyperparathyroidism].

A family of multiple endocrine neoplasia type I with five confirmed cases in three generations is described. All of them have primary hyperparathyroidism in common. The propositus is 51 year-old male. After a year of symptoms of gastroduodenal ulcer, he was found to have elevated levels of serum gastrin and PTH. The serial imaging studies revealed a tumor in pancreatic head, and Zollinger-Ellison syndrome was diagnosed. The gastrin level was reduced into normal range after extirpation of the tumor, but post surgical elevation of Calcium put the patient under parathyroidectomy, which normalized serum PTH and Calcium levels. His two sisters (I and II), the mother of them, and the daughter of sister I, had neither signs nor symptoms until family study showed hypercalcemia in all. Sister I is a 54 year-old female with enlarged parathyroid. The hyperparathyroidism is of chemical type, but no other endocrinological abnormality is found. The Calcium level decreased after parathyroidectomy. Sister II is a 56 year-old female. The only sign was galactorrhea. Serum PTH and Calcium decreased after parathyroidectomy. The prolactinoma was diagnosed by the increased prolactin levels and enhanced mass lesion in sella turcica. Her serum prolactin levels is now within normal range since she is on bromocryptine. The mother of the above three siblings and the daughter of the sister I are now under further study.

Female↗

Induction of selective release of FSH in castrated male rats bearing an ovarian transplant by the administration of human chorionic gonadotrophin.

The present study was undertaken to determine whether hypothalamic differentiation is involved in the selective release of FSH during the periovulatory period using adult male rats castrated and implanted with an ovary. Adult male rats (70-90 days old) were castrated and an ovary obtained from a prepubertal female rat (26 days old) was immediately grafted subcutaneously. Four weeks later, human chorionic gonadotrophin (hCG, 10 i.u.) was injected i.v. into the experimentally manipulated rats to induce ovulatory changes in the grafted ovaries. Another group of similarly prepared rats was injected with 0.9% (w/v) NaCl solution as controls. After injection of hCG, plasma concentrations of FSH increased significantly by 6 h, reached peak values at 12 h and declined to control levels at 36 h. On the other hand, plasma concentrations of LH were reduced by 6 h and decreased further during the next 36 h. An abrupt fall in plasma concentrations of oestradiol-17 beta occurred within 3 h of the administration of hCG. Histological examination revealed that ovulatory changes and luteinization of follicles were induced in grafted ovaries by 18 h after the injection of hCG. Thirty-six hours after treatment with hCG, a set of newly formed corpora lutea was observed in grafted ovaries and plasma concentrations of progesterone were raised. Treatment with oestradiol-17 beta did not inhibit the selective release of FSH after the administration of hCG, suggesting that the abrupt decrease in secretion of oestradiol-17 beta from the grafted ovary is not involved in the occurrence of the FSH surge.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Development of surgery for carcinoma of the esophagus.

During the period from October 1972 to January 1983, 462 patients with squamous cell carcinoma of the esophagus were admitted to Toranomon Hospital. Those patients with carcinoma of the hypopharynx, cervical esophagus, or cardia extending to the esophagus were excluded from the study. Resection and reconstruction were carried out in 295 patients with a resectability rate of 63.9 percent and an operative mortality rate of 1.7 percent. The 5 year survival rate for 101 patients who had resection with minimum 5 year follow-up was 34.7 percent. Although the ultimate outcome is largely influenced by the tumor type representing malignancy, it is worthwhile to make all efforts to resect the tumor with a negative surgical margin and to resect concomitant lesions if there are any. Surgeons should not be discouraged by the length or size of a tumor. The extent of positive lymph node is closely related to long-term results. However, systemic lymph node dissection should be carried out because 5 year survival can then be expected, even when positive nodes are dissected from various areas.

Carcinoma, Squamous Cell↗

The inferior right hepatic vein: ultrasonic demonstration.

The inferior right hepatic vein (IRHV) was demonstrated sonographically in 27 out of 269 patients (10%). It was shown to be thicker than the right hepatic vein in 8 (3%). In 2 patients, two accessory right hepatic veins were demonstrated, with one being the IRHV and the other the middle right hepatic vein. Delineation of the IRHV is significant in hepatectomy, detection of tumor thrombus in hepatocellular carcinoma, Budd-Chiari syndrome, and dilatation of the intrahepatic bile ducts.

Bile Ducts, Intrahepatic↗

Ultrasonic characteristics of the small hepatocellular carcinoma.

Fifty five small hepatocellular carcinoma less than 5 cm in diameter among 41 patients were examined by linear arrayed electronic scanning system with 3.5 MHz transducer. Characteristics of the sonogram were enhanced posterior echoes of the tumor, mosaic pattern of internal echoes, halo and lateral shadows. These findings are appeared in 69%, 64%, 35% and 22% of tumors respectively. Among 45 tumors from 2.1 cm to 5 cm in diameter, these findings are appeared in 81%, 73%, 40% and 24% respectively. Among 10 tumors less than 2 cm in diameter, these characteristics were rare and these minimal hepatocellular carcinomas were demonstrated as a simple low echo area. Fifty tumors in 39 patients were resected. Lobulation of the hepatocellular carcinoma on the cut surface of the resected specimen and mosaic pattern on the sonogram are closely connected with each other. Thin fibrous capsule of the hepatocellular carcinoma corresponded to halo and lateral shadows. Posterior echo enhancement was due to the softness of the hepatocellular carcinoma. By those four characteristics, hepatocellular carcinoma can be differentiated from hemangioma and metastatic liver tumor.

Carcinoma, Hepatocellular↗