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Biomedical subjects

E Okamoto

Publications and source records attributed to E Okamoto.

At least 253 records · Page 14Linked to original sources
PubMed1983

Increase in muscarinic acetylcholine receptors in mouse intestine by hexamethonium treatment.

The effects of hexamethonium (C6) administration on muscarinic acetylcholine receptors (mACh-R) in the intestine and brain of mice were investigated. Mice were treated with C6 with an osmotic mini-pump (330 mg/kg/day) for one week and then the binding of 3H-quinuclidinylbenzilate (3H-QNB) in the intestine and brain were assayed. This treatment increased the maximum specific binding (Bmax) of 3H-QNB from 160 to 320 fmoles/mg protein in the ileum and from 190 to 340 fmoles/mg protein in the rectum, without affecting the KD values in these regions. On the contrary, C6 treatment did not change the Bmax or KD value in brain tissues. This C6 treatment increased the sensitivity of the contractile response of the intestine to muscarinic agonists, possibly by increasing mACh-R.

Animals↗
PubMed1983

Computed tomography in the detection of small hepatocellular carcinomas.

Thirty-two patients with hepatocellular carcinoma less than 5 cm in diameter were examined by computed tomography. At the examination 26 patients (81%) were correctly diagnosed. A common type of CT image series was detectable as low density on the precontrast scan, a positive or mixed pattern on dynamic scan, and visible on postcontrast scan. In 10 patients with minute tumors (less than 2 cm), 7 were correctly diagnosed. CT was valuable for diagnosis of the small hepatocellular carcinomas larger than 1 cm by using the dynamic study after an intravenous bolus injection of the contrast medium.

Adult↗
PubMed1983

Simultaneous radical surgical treatment for membranous obstruction of the inferior vena cava and the coincident hepatocellular carcinoma--the first successful case.

To our knowledge, this is the first report of a patient for whom a successful radical treatment for both membranous obstruction of the inferior vena cava (MOVC) and coincident hepatocellular carcinoma (HCC) were simultaneously carried out. A 36 year old Japanese man with Budd-Chiari syndrome due to MOVC was found to have HCC in the right hepatic lobe during a shunt operation between the inferior vena cava (IVC) and the right atrium (RA), using a vascular prosthetic graft. He was referred to us from another institute for further operative procedures. Both the mediastinum and the abdomen were entered through a long midline incision with longitudinal splitting of the sternum. The graft that had been occluded by thrombus was removed. Transcardiac membranotomy was achieved by manual manipulation and then by Tubb's dilator. The hepatic tumor with an abundant surgical margin of the liver was resected. The tumor of 2.5 X 2.5 X 2.0 cm was a well differentiated clear cell type HCC associated with congestive liver cirrhosis. Postoperative contrast and pressure studies through IVC showed satisfactory results. Serum alfa-fetoprotein levels decreased from 503 to 12 ng/ml. The patient is well at least for 44 months after the surgery without any recurrence at the time of completion of this writing.

Adult↗
PubMed1983

Serum and erythrocyte acetylcholine esterase in Hirschsprung's disease.

Determination of acetylcholine esterase in serum (S-AChE) and erythrocytes (E-AChE) was carried out in nine patients with Hirschsprung's disease and 16 normal controls. S-AChE was significantly elevated in patients with Hirschsprung's disease, while no significant difference was observed in E-AChE in these two groups. In 17 patients with Hirschsprung's disease, S-AChE and E-AChE were determined after definitive operation. Twelve of these patients underwent a Duhamel type procedure in which a small part of the aganglionic bowel segment remained unresected. Five patients were treated by Swenson's procedure performing complete resection of the aganglionic bowel segment. S-AChE in patients treated by the Duhamel type procedure remained elevated, while it was as low as that in normal controls in patients who underwent Swenson's procedure. There was no significance in E-AChE in both groups. This study suggests a close relation of the level of S-AChE to the extent of the aganglionic bowel segment in Hirschsprung's disease.

Acetylcholinesterase↗
PubMed1983

[Cytogenetic studies of multiple ovarian dermoid cysts in a single host].

To investigate the pathogenesis of gonadal teratoma, sixteen ovarian dermoid cysts obtained from four patients were examined by using chromosomal Q and R heteromorphisms, HLA antigens and enzyme polymorphisms of phosphoglucomutase-1 and esterase-D. The results obtained were as follows: 1) Karyotypes of 16 tumors were 46,XX. 2) In thirteen tumors, chromosomal heteromorphisms were homozygous for the homologous chromosomes, being heterozygous in the hosts. In 9 of them, all gene markers analyzed were also homozygous, but in the remaining 4 tumors some gene markers showed heterozygous combination. These findings indicate that these 13 tumors arose from a germ cell after the first meiotic division by suppression of the second meiotic division or by fusion of polar body II with the oocyte. 3) In three tumors, chromosomal heteromorphisms showed heterozygous patterns as in the hosts. In 2 of them, some gene markers were homozygous, and in the remaining one tumor the gene markers were all heterozygous. These findings suggest that these three tumors arose from a germ cell before the first meiotic division. It is concluded that multiple ovarian dermoid cysts in a single host originate from different germ cells with diverse mechanisms.

Adult↗
PubMed1983

[Second-look operation for childhood solid malignancy].

Forty-four cases with childhood solid malignancy during the period from 1973 to 1982, were analysed. 11 cases underwent second-look operation, including 4 neuroblastomas, 4 hepatoblastomas, 1 malignant teratoma, 1 nephroblastoma, and 1 rhabdomyosarcoma. Two cases of hepatoblastoma in second-look operation are surviving over two years with no evidence of disease, and one case survived 5 years 8 months. For one patient of initially unresectable neuroblastoma, second-look operation was successfully performed by complete resection followed by paraortic-lymphonode dissection. In two cases of Wilms' tumor and malignant teratoma, second-look operations were performed for the purpose of treatment decision after radical operation. In the unresectable tumors or recurrent tumors or metastatic lesions, complete cure can be expected by aggressive surgical approach and combination chemotherapy followed by second-or third-look operation.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1983

[Pathohistological evaluation of hepatic artery ligation (HAL) or transcatheter arterial embolization (TAE) on primary carcinoma of the liver].

Ischemic effect of interruption of hepatic artery upon the expansively growing primary carcinoma of the liver was studied on six resected specimens obtained by hepatectomy having been carried out 10 to 35 days after HAL or TAE. Both HAL and TAE were found to bring about an extensive coagulative necrosis in the main tumor. No substantial difference was observed between the two in the degree or the mode of necrosis produced. Complete necrosis of the tumor was observed in a case of a nodular type hepatoma in the visceral aspect of the right posterior segment. An incomplete necrosis was obtained in the main tumor of remaining 5 cases. The necrotized region was clearly demarcated from the viable portion in the tumor by the septal formation which was probably used to be the part of the capsule around the tumor. This suggested that the compartment in the tumor separated by these septa is supplied by the different artery independently. Therefore, if the interruption therapy is chosen as the sole procedure, it is stressed that complete hepatic dearterialization is mandatory for the treatment of liver cancer.

Carcinoma, Hepatocellular↗
PubMed1983

[The significance of hepatic lobectomy as the surgical treatment for primary hepatocellular carcinoma].

Since most patients with primary hepatocellular carcinoma (HCC) in Japan have cirrhosis, indication of hepatectomy is now tending to be limited to a single segment or subsegment for small HCC. However, pathologic examinations on the resected specimens have revealed that intrahepatic metastases were associated in more than 50% of HCC smaller than 5 cm, indicating that hepatic resection is required in these patients to be as extensive as possible within the limit of hepatic reserve. Our multiple regression equation provided for the preoperative prediction of an early prognosis of hepatectomized patient has successfully reduced the incidence of postoperative fatal liver failure from 17% before 1980 to 6% after 1981. The sequential volumetric CT measurements of the remaining liver after hepatectomy in humans has revealed an ability of the cirrhotic liver to regenerate nearly as normal liver in patient who has well tolerated hepatic resection. Ligation or embolization of the portal vein of an affected side in patients with unresectable HCC has rapidly induced a compensatory hypertrophy in the contralateral lobe to be remained, indicating the potential usefulness of this procedure to relatively reduce the loss of functioning liver mass by the proposed lobectomy.

Carcinoma, Hepatocellular↗
PubMed1983

[Mechanism of bile outflow in cholecystectomized patients].

Intraluminal manometric and cine-cholangiomanometric studies were carried out on the movement of the sphincter of Oddi at the time of excretion of bile into the duodenum in 12 patients after cholecystectomy for gallstone. Two phases were observed in the sphincteric movement; the resting phase without any contraction and active phase with vigorous contraction. On stimulation with CCK-PZ 0.5 u/kg (bolus injection) in a active phase, a prompt transition from the active phase to the resting phase was observed in 4 to 8 minutes. On cine-cholangiomanometric study, the contrast medium injected into the common bile duct did not flow into the duodenum at the resting phase, but in the active phase. In the active phase, the excretion of the contrast medium was observed at the end of each contraction of the sphincter of Oddi. These observations have led a conclusion that bile excretion occurs in the active phase of the sphincter of Oddi in the cholecystectomized patients.

Adult↗
PubMed1983

[Multiple regression equation evaluating the resectability for liver tumors].

In order to avoid postoperative liver failure after resection of the liver associated with chronic injury, an accurate evaluation of resectability should be established based on available preoperative factors. This paper reports our multiple regression analysis of the correlation between the prognosis (Y) after hepatectomy and the seventeen sorts of preoperative factors (X) to obtain a multiple regression equation predicting the prognosis. The analysis was employed on 36 patients who underwent hepatectomy of varying extent. The prognosis (Y) was represented in our scoring system (0-100 point) determined by the degree of postoperative liver failure. As a result, the following multiple regression equation, consisting of four prognostic factors, was derived. Y = -110 + 0.942X1 + 1.36 X2 + 1.17 X X3 + 5.94 X X4 (X1 = resection rate of the liver tissue calculated by C.T. Scan, X2 = retention rate of ICG (15)%, X3 = age, X4 = maximal removal rate of ICG (mg/kg/min). The Y-score of 36 patients computed by this equation revealed that: Y-scores of the 8 patients with fatal liver failure had wholly more than fifty points, and Y-scores of the remaining 28 patients with a favourable course had less than fifty points. The validity of this equation was ascertained through the predetermined Y-score, in which critical point is set about fifty points or more, for other 49 patients. By this equation, accurate evaluation of resectability for liver tumors has been made possible.

Adult↗
PubMed1983

The proposed Japanese TNM classification of primary liver carcinoma in infants and children.

The TNM classifications of neuroblastoma, nephroblastoma and soft tissue sarcoma were adopted at the International Conference for TNM Classification (UICC) held in May 1980. There is no TNM system under contemplation, however, for primary liver carcinoma in childhood. Accordingly, we have formulated the proposed Japanese TNM system for this carcinoma in children and examined its validity in 136 cases of hepatoblastoma seen in the listed 14 institutions. The basic policy of the Committee on the Japanese TNM Classification is not to include the resectability of the tumor and regional lymph nodes or any other status of the disease resulting from therapeutic intervention as a component of the pTNM system. This is a feature which makes our proposed system widely divergent from the accepted classification scheme for the three types of tumor cited above.

Adolescent↗
PubMed1982

Use of medium-chain triglycerides in feeding the low-birth-weight infant.

Intestinal fat absorption and anthropometric and clinical variables were monitored weekly in 21 low-birth-weight (LBW) infants fed either a whey-predominant cow's-milk formula (formula 1) or identical formulas with medium-chain triglycerides (MCTs) comprising 40% (formula 2) or 80% (formula 3) of the fat content. Fat absorption of infants fed formula 1 averaged 86.7% of intake, whereas that of infants fed formulas 2 and 3 averaged 93.8% and 95.4%, respectively. However, no differences in weight, length, head circumference, or skin fold thickness were observed. Moreover, intestinal symptoms were encountered more frequently in infants fed formulas 2 and 3. This demonstrated failure of the resulting small increase in fat absorption incident to MCTs either to promote enhanced growth or to confer obvious clinical benefit does not support the increasing use of MCT formulas for routine feeding of LBW infants.

Diet Therapy↗
PubMed1982

Diminution of chemically induced lung neoplasia in mice by phenobarbital pre-treatment.

Pre-treatment of 21-day-old ICR/Jcl mice with 75 micrograms/g of phenobarbital significantly reduced the yields of lung tumors induced by 4-nitroquinoline-1-oxide (4NQO) and furylfuramide. Dimethylbenz[a]anthracene (DMBA)- and urethane-induced lung tumorigenesis was also reduced, but was not significantly different from that in mice receiving only the carcinogen. However, 6 consecutive treatments with phenobarbital (40 micrograms/g) in adult mice greatly reduced urethane-induced lung tumorigenesis. Post-treatment with an equal dose of phenobarbital showed neither diminution nor enhancement of tumorigenesis.

4-Nitroquinoline-1-oxide↗
PubMed1982

Is DNA methylation responsible for mammalian X chromosome inactivation?

MOHANDAS et al. (1981) have proposed that mammalian X chromosome inactivation involves segmental methylation of cytosine residues in the DNA at multiple sites along the X chromosome. Using antibodies specific for 5-methylcytosine, we have found no detectable difference in the extent of methylation of the DNA in the two X chromosomes of owl monkey or human females. Thus inactivation (facultative heterochromatization) of the X chromosome is not due to, or associated with, intense DNA methylation comparable to that seen in most constitutive heterochromatin.

5-Methylcytosine↗
PubMed1982

Histologic and embryologic studies on the innervation of the pelvic viscera in patients with Hirschsprung's disease.

On the specimens taken at autopsy from three newborns with Hirschsprung's disease and three newborns in the control group, the innervation of the pelvic organs was histologically studied. The authors found that all the pelvic organs, except for the rectum in patients with Hirschsprung's disease, preserved a completely normal innervation not only of pelvic autonomic nerve plexuses, but also of sensory nerves of spinal origin. Even in the wall of the aganglionic rectum, the extrinsic sympathetic as well as parasympathetic nerve fibers were preserved, which showed a marked proliferative change due to the absence of target nerve cells upon which they otherwise terminated. An additional embryologic study was performed upon 20 human embryos. The results revealed that the pelvic nerve plexuses were formed during the six to ten gestational week period by neural cells migrating along the pelvic visceral branches of sacral nerves, while none of these neural cells was found to enter the rectum. The enteric plexuses of the rectum were formed later by neural cells that migrated down along the alimentary tract in a craniocaudal manner. The two separate origins, the sacral for the pelvic nerve plexuses and the vagal for the enteric plexuses of the rectum, seem to be the reason why innervation of the genitourinary organs, which are located in front of the aganglionic rectum, is normal in those patients with Hirschsprung's disease.

Autonomic Nervous System↗