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Biomedical subjects

E Okamoto

Publications and source records attributed to E Okamoto.

At least 235 records · Page 13Linked to original sources
PubMed1985

Qualitative and quantitative analysis of muscarinic acetylcholine receptors in the piebald lethal mouse model of Hirschsprung's disease.

Cholinergic innervation in the aganglionic bowel of the piebald lethal mouse model of Hirschsprung's disease was investigated by analysis of muscarinic acetylcholine receptors before and after administration of hexamethonium. After hexamethonium administration in the normal rectum, the maximum specific binding (Bmax) of [3H]quinuclidinyl benzilate increased from 196.6 to 346.2 fmol/mg protein without affecting the dissociation constant. This increase of muscarinic acetylcholine receptors was associated with a decrease in the 50% effective dose (ED50) of contractile response to oxotremorine from 3.8 X 10(-7) M to 6.5 X 10(-8) M. In the aganglionic rectum, hexamethonium administration did not change the Bmax (166.4 fmol/mg protein) or dissociation constant value. The ED50 of contractile response to acetylcholine and oxotremorine (4.3 X 10(-8) M, 6.5 X 10(-8) M) was lower than that in the normal rectum (1.9 X 10(-7) M, 2.0 X 10(-7) M), but it was not changed by hexamethonium. It is concluded that cholinergic innervation is congenitally absent in the aganglionic rectum in piebald lethal mice.

Acetylcholine↗
PubMed1985

Consistency of human liver.

Liver consistency was measured biomechanically on the left lobe during laparotomy (n = 52) and on the resected specimen (n = 24) using a specially devised technique. Its relationship with histological findings and hepatic functions was also investigated. Instrumentation included a venipuncture needle with a closed tip and a round latex microballoon attached at a side hole. The needle was connected to a pressure transducer and infusion pump with a polyethylene tube. After the needle was introduced into the liver tissue, liver consistency was measured as delta P/delta V (cm H2O/ml) from the slope of pressure rise on a Pressure (P)-Volume (V) curve obtained at constant saline infusion. Liver consistency increased proportionally with the degree of hepatic fibrosis: 589 +/- 191 (cm H2O/ml) for nonfibrosis (n = 25), 869 +/- 139 for periportal fibrosis (n = 14), 1030 +/- 116 for incomplete cirrhosis (n = 15), and 1250 +/- 206 for fully developed cirrhosis (n = 22). Correspondingly, liver consistency correlated closely with morphometrically estimated hepatic fiber content (r = 0.82, P less than 0.01). With the exception of albumin, liver function tests including prothrombin time, gamma-globulin fraction, zinc turbidity, and indocyanine green retention rate showed significant correlations with liver consistency (0.41 less than magnitude of r less than 0.68, P less than 0.001). However, correlation was much less than that between liver consistency and hepatic fiber content. The present study demonstrates that liver consistency measured by this technique can be a predictive index of hepatic fiber gradings.

Adult↗
PubMed1985

[Transformation of ovarian yolk sac tumor to immature teratoma following chemotherapy].

The patient, a 28-year-old woman, in her ninth week of pregnancy, was operated on for stage Ia, mixed germ cell tumor (grade 3 immature teratoma + yolk sac tumor) of AFP decreased to the normal level. Eight months later, an intrapelvic mass and raised AFP were found. The extirpated recurrent tumor in the pouch of Douglas was a grade 2 immature teratoma with no yolk sac element. FAM chemotherapy was given again, and the patient is alive and well after taking oral UFT. As in testicular germ cell tumors, ovarian germ cell tumors can be converted to a more differentiated tumor following chemotherapy.

Adult↗
PubMed1985

[Treatment of patients with hepatoma and esophageal varices].

Fifty-nine patients with hepatoma associated with advanced esophageal varices who received a variety of therapeutic modalities in the past 10 years at our department were reviewed. Our therapeutic modalities are hepatic resection, hepatic artery ligation (HAL) and trans-arterial embolization (TAE) for those with hepatoma and non-shunting treatment (NST; esophageal transection or Hassab's procedure) and endoscopic sclerotherapy (ST) for those with esophageal varices. A patient selection was made by our own criterial developed by a multiple regression analysis for the hepatoma and KICG value for esophageal varices. Out of 59.16 underwent hepatic resection and NST. Eight survived more than 2 years. The longest survivor has been living for 4 yr and 4 months. Two-year survival rate is 69.8%. Another 16 underwent HAL and NST. Two-year survival was 14.6%. Another 7 underwent ST following hepatic resection or HAL. Five of the 7 received an emergency ST. Hemostasis was achieved in all of them. Two-year survival was 21.8%. The remaining 20 underwent ST and TAE; 13 received an emergency ST with 85% of hemostasis rate. None of them survived more than 2 years. From these data, it is suggested that a proper selection of patients for a proper therapeutic modality improves the prognosis even in those with hepatoma associated with advanced esophageal varices.

Carcinoma, Hepatocellular↗
PubMed1985

[Pathophysiology of defecatory disturbance in the patient with Hirschsprung's disease and chronically constipated patients with simple megarectum].

The disturbance of defecation in the patient with Hirschsprung's disease and the pathophysiology of constipation in the constipated patient with simple megarectum were investigated. In Hirschsprung's disease, an existence of aganglionosis and the sphincter achalasia are two main factors which cause clinical symptoms such as chronic constipation and megacolon. As a surgical treatment, we have routinely performed our modified Duhamel's operation. Postoperative followup study indicated that the most cases in our series have gained a satisfactory defecatory function 1 to 3 years after operation. In chronically constipated patient with simple megarectum, on the other hand, it was found manometrically that the most of them had significantly high anal canal pressure and incomplete anal relaxation after rectal stimulation. These findings indicate that those patients have hypertonic and achalasic sphincter. Therefore, the authors propose "high anal pressure syndrome (HAPS)" for such constipated patient with simple megarectum. As to the surgical treatment, 6 patients with simple megarectum had a complete posterior internal sphincterotomy and the postoperative results were excellent or good in our series.

Adolescent↗
PubMed1984

High-resolution studies in patients with aniridia-Wilms tumor association, Wilms tumor or related congenital abnormalities.

We attempted to determine whether all cases of AWTA (anirida-Wilms tumor association) or any of the following groups of patients show 11p deletion: cases of Wilms tumor with congenital abnormalities other than aniridia, those without any congenital abnormalities, tumor itself in cases of Wilms tumor without constitutional 11p deletion and cases of aniridia or hemihypertrophy without Wilms tumor. We studied a total of 29 index patients including five cases of AWTA, four cases of Wilms tumor with various congenital abnormalities, 16 cases of Wilms tumor without other abnormalities, three cases of aniridia in one of which Wilms tumor developed later and a case of hemihypertrophy. In all five cases of AWTA and in a case of aniridia who later developed Wilms tumor, 11p deletion involving the p13 band was detected. The mother of the latter also showed an identical 11p deletion. The common segment of deletion was the middle part of the p13. Two possible hypotheses on the mechanism through which Wilms tumor might develop were evaluated, based on the distribution of break points. All other cases, including five with tumor culture, showed a normal karyotype.

Adolescent↗
PubMed1984

An experimental study on the mechanism of rectosphincteric reflex in special reference to Hirschsprung's disease.

In order to clarify the mechanism of rectosphincteric reflex (RSR), an experimental study was performed using mongrel canine models. The RSR exists in normal anesthetized mongrel dogs. It does not disappear in dogs with isolation of the rectoanal portion from the surrounding tissues. The RSR disappeared after circular transection of the rectal muscle coat at the level between the rectum and the anal canal, and also after selective destruction of the myenteric plexus of the rectum. These data suggest that the RSR is a local reflex contained within the rectoanal wall and its regulating center and neural pathway are in the myenteric plexus of the rectum.

Anal Canal↗
PubMed1984

Role of taurine in feeding the low-birth-weight infant.

Plasma and urinary taurine concentrations, growth, nitrogen balance, duodenal bile salt concentration and pattern, fecal bile acid excretion, and intestinal fat absorption were determined in appropriate for gestational age low-birth-weight infants fed either a whey-predominant cow milk formula or the same formula supplemented with taurine (45 mumol/kg/day). Mean plasma taurine concentration in the two groups did not differ. Mean urinary taurine concentration in the control and supplemented groups over the entire study period were 2.67 +/- 0.69 and 12.41 +/- 5.20 mumol/dl, respectively (P less than 0.05). Urinary taurine concentration in the supplemented infants, however, decreased significantly during the study period. Neither growth nor nitrogen retention differed between the two groups. Mean duodenal concentrations of taurine as well as glycine conjugates of both cholate and chenodeoxycholate were higher in supplemented infants. Total duodenal bile salt concentration correlated positively with taurine status as reflected by urinary taurine excretion (r = 0.71); this correlation plus the lower duodenal cholesterol concentration in supplemented infants suggests that conversion of cholesterol to bile acids was greater in supplemented infants. Mean intestinal fat absorption in control and supplemented infants, however, did not differ.

Bile Acids and Salts↗
PubMed1984

Endoscopic extraction of foreign bodies from the duodenum: four cases in infancy.

Four cases of foreign bodies in the duodenum were treated using a flexible fibre-optic panendoscope. All the patients were boys and eight months to four years of age. The ingested foreign materials were an injection needle, a marking pin, a hairpin and a curtain hook. Endoscopic extraction was attempted, because the ingested objects might cause perforation or obstruction of the gastrointestinal tract. Until recently, they had to be carefully watched or prophylactic operation suggested. Under general anaesthesia, duodenal endoscopy was easily performed and extraction of foreign bodies was not found to be difficult during infancy. This is considered to be a safer and less hazardous way than careful watching or prophylactic operation.

Child, Preschool↗
PubMed1984

A multiple regression equation for prediction of posthepatectomy liver failure.

This article reports a multiple regression equation for prediction of posthepatectomy liver failure. In phase I, using the correlations between 17 preoperative parameters (Xi) and the postoperative course scored (Y) of the past 36 hepatectomized patients, we proposed the following multiple regression equation: Y = -110 + 0.942 X resection rate (%) + 1.36 X ICG retention rate (%) + 1.17 X patient's age + 5.94 X ICG maximal removal rate (mg/kg/min). With the equation, the calculated Y value (prediction score) of these patients revealed that prediction scores of the eight nonsurvivors with liver failure were more than 50 points while those of the 28 survivors were 50 points or less. In phase II, the relationships between early prognosis and a precalculated prediction score were prospectively found the same as that seen in phase I. These findings indicate that our formula is a useful prognostic index for prediction of posthepatectomy liver failure.

Adult↗
PubMed1984

Malignant pheochromocytoma with ACTH production.

An autopsy case of a 54-year-old woman with malignant pheochromocytoma and ectopic ACTH production was reported. Noradrenaline was increased in 24 hour urine and in the blood sample from the left adrenal vein. Hormone assay studies of the tumor tissue and plasma revealed abnormally high levels of ACTH. Formaldehyde fume induced fluorescence method demonstrated biogenic amine in the tumor cytoplasm. Electron microscopic examinations also disclosed numerous neurosecretory granules in the tumor cytoplasm. These findings confirmed that this pleomorphic carcinoma of the left adrenal gland was one of the APUDoma originating from the adrenal medulla, so-called pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1984

Prediction of the safe limits of hepatectomy by combined volumetric and functional measurements in patients with impaired hepatic function.

By use of computed tomography measurements, preoperative estimations of the safe limits of hepatic resection have been attempted in 38 patients with primary hepatocellular carcinoma who underwent hepatectomies of varying degrees. Twenty eight (73.7%) of these 38 patients had cirrhosis. Preoperative computed tomography estimations of volume of liver and hepatocellular carcinoma have been compared with measured volume of the resected specimens. The average differences between the estimated and actual volumes of resected liver and hepatocellular carcinoma were within 10% and 7%, respectively. To quantify the extent of hepatectomy, the "parenchymal hepatic resection rate" (formula: see text) was provided. As an indicator of functional impairment of the liver, the retention rate 15 minutes after an intravenous injection of indocyanine green dye (ICG) at 0.5 mg/kg (ICG R15) was used. A close correlation was observed between the parenchymal hepatic resection rate and ICG R15 relative to the patients' outcome, indicating their potential use in the prediction of the safe limits of hepatectomy and the probable development of posthepatectomy liver failure.

Carcinoma, Hepatocellular↗
PubMed1983

[Distribution of C cells in the human thyroid gland].

The distribution of C-cells was reviewed in a series of human thyroid glands from 84 autopsies. The C-cells were demonstrated by the Grimelius method modified by De Grandi [10] and immunohistochemically using anticalcitonin by the method of Sternberger et al. [43]. The immunohistochemical method proved to be considerably more useful than the silver reaction. In half the cases C-cells were found symmetrically in both lateral lobes, concentrated around an axis running in a cranial-lateral-dorsal to caudal-medial-ventral direction. In about a quarter of the cases the C-cells were only approximately symmetrical in distribution, and rarely was no symmetry visible in their distribution. A completely homogeneous distribution of C-cells throughout the thyroid was never demonstrated. C-cells are normally concentrated in the upper and the middle thirds of the thyroid, but in cases with hyperplasia they were found predominantly in the middle and lower thirds of the lateral lobes. Exceptionally, some C-cells were present in the isthmic region or no C-cells were found in the entire thyroid at all. Thyroid nodules are generally free of C-cells. The number of C-cells seems to be more or less constant when the thyroid is of normal weight. In large goiters, however, the number of C-cells increases. Since the distribution of C-cells was rather irregular all the cases considered, thyroid biopsies are of little help in generally evaluating their reactive state. This does not apply to C-cell tumors, i.e. medullary carcinoma of the thyroid, where cytologic examination has been proven to be a valuable diagnostic method.

Adolescent↗