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T Okasora

Publications and source records attributed to T Okasora.

16 recordsLinked to original sources
PubMed1994

Extensive dissection at the porta hepatis for biliary atresia.

Dissection at the porta hepatis is the crucial step in surgery for biliary atresia. The authors describe their procedure for extensively dissecting the porta hepatis. The technique is based on an anatomic cast corrosion of the human liver, and the portal vein serves as the landmark for dissection. Lateral dissection at the hepatic hilus is critical to the procedure. On the right side, the anterior portal branches are dissected to the bifurcation of the S5 and S7 segmental portal branches, over the bifurcation of the anterior and posterior portal branches. On the left side, the liver parenchyma, which bridges the umbilical point, is sectioned, and the left portal branch is dissected to the umbilical point over the pars transversalis and taped. The fibrous mass that lies within the confines of the portal branches, including the dorsal aspect, is transected completely. This procedure was performed in 16 infants; the jaundice cleared in 93.7%.

Biliary Atresia↗
PubMed1994

[Studies on cholinergic nerve function of the aganglionic colon in murin model].

The true role of the extrinsic cholinergic nerve fibers proliferating abundantly in the aganglionic colon of Hirschsprung's disease has not yet been established. Electrophysiological and pharmacological studies using superfusion method were carried out on rectal muscle strips of piebald lethal mice, one of murine models of Hirschsprung's disease and their siblings as a control. The muscle strips were preincubated with [3H] choline in Krebs solution. The contractions and the release of [3H] acetylcholine evoked by electrical transmural stimulation of the muscle strips were measured. In addition, the contractility of muscle strips treated with acetylcholinesterase blocking agents were recorded. In the aganglionic colon, as in the normal colon, the release of [3H] acetylcholine evoked by electrical transmural stimulation was recognized. However, no contractions were evoked in the aganglionic colon. The uptake of [3H] choline in the aganglionic colon was larger than in the normal colon presumably due to the proliferated extrinsic cholinergic nerve fibers. On the other hand, the release of [3H] acetylcholine evoked by electrical transmural stimulation was smaller in the aganglionic colon. In the aganglionic colon, no contractions were evoked by acetylcholinesterase blocking agents, indicating that there is no spontaneous release of acetylcholine. In the presence of low concentration of acetylcholinesterase blocking agents, the form of contractions evoked by electrical transmural stimulation in the aganglionic colon was different from those in the normal colon. These results have indicated that in the murine aganglionic colon, the proliferated extrinsic cholinergic nerve fibers may not directly regulate the smooth muscles through the functional neuro-muscular junction. In conclusion, the proliferated extrinsic cholinergic nerve fibers is not related to the narrowing of the aganglionic colon.

Acetylcholine↗
PubMed1992

Suppressive effect of superoxide dismutase on adriamycin nephropathy.

A single intravenous injection of adriamycin (ADR) results in marked proteinuria and glomerular morphological changes that are similar to minimal-change disease in humans. We examined the effect of superoxide dismutase (SOD) on ADR-induced proteinuria. ADR in a dose of 7.5 mg/kg body weight significantly increased urinary protein by day 14; proteinuria rapidly increased thereafter. Concurrent administration of SOD (50 mg/kg) over 30 min prior to and 30 min following ADR injection markedly reduced proteinuria. Twenty-one days after the treatment with SOD, the amount of urinary protein was 108.6 +/- 43.1 mg/24 h in the experimental animals, while it was 221.6 +/- 102.9 mg/24 h in the ADR control group (p less than 0.05). There were also less severe glomerular morphologic changes in the SOD group versus ADR controls. The protective effects of SOD provide indirect evidence that oxygen free radicals are important mediators of ADR-induced proteinuria.

Animals↗
PubMed1991

Altered localization of antigen recognized by proteinuria-inducing monoclonal antibody in experimental nephrosis.

Change in the localization of the antigen recognized by the proteinuria-inducing monoclonal antibody (MA) 5-1-6 in experimental nephrosis was studied by indirect and biotin-avidin immunofluorescence, and immunoperoxidase at light and electron microscopical levels. The proteinuric state was induced by the administration of the aminonucleoside of puromycin (PAN) or adriamycin. The antigen decreased in quantity and/or its distribution changed with an increase in the amount of protein excreted in both experimental models. Recovery from the alterations observed during the development and proteinuria appeared to occur when PAN-induced proteinuria subsided. This antigenic molecule may thus be essential for maintaining the normal permselectivity of glomerular capillary walls.

Animals↗
PubMed1990

[Study on function of aganglionic colon musculature of Hirschsprung's disease murine model].

This study examined the function in vitro of aganglionic colon musculature in mice with hereditary aganglionosis--a strain of animals used as a model of Hirschsprung's disease. Double sucrose gap recordings from the muscle strips of both normal and aganglionic colon showed bursts of spike potentials with muscle contraction. Intracellular recordings of the membrane potentials of the circular muscle cells of normal, aganglionic and oligo-ganglionic colon had no statistical difference. Microelectrode recordings from the circular muscle cells of normal siblings, in the presence of nifedipine, irregular ongoing fluctuations in membrane potential, which were abolished by tetrodotoxin and reduced by d-tubocurarine or apamin. The fluctuations were less effected by atropine. These observations suggest that there is ongoing inhibitory neural activity to the circular smooth muscle of normal colon. These ongoing fluctuations were not recorded from the cells of aganglionic and oligo-ganglionic colon of affected animals. Although transmural stimulation of the intrinsic nerves produced cholinergic excitatory and inhibitory junction potentials in normal colon, no junction potentials were evoked by transmural stimulation in aganglionic colon. It was concluded that the ongoing tonic inhibitory activity may contribute to the compliance of the normal mouse colon and lack of the compliance may affect functional intestinal obstruction of the aganglionic colon in Hirschsprung's disease.

Animals↗
PubMed1989

[Late complications after successful Kasai's operation for biliary atresia].

The late complications in 25 patients more than 3 years after successful Kasai's operation for biliary atresia were presented. Nine (36%) of these 25 patients had episodes of variceal hemorrhage with portal hypertension, and biliary reobstruction in 3 (12%), bleeding from duodenal ulcer in 2, bleeding from gastric erosion in one, and diffuse pulmonary arterio-venous shunt in one were observed. Recently esophageal varices have been well controlled by endoscopic sclerotherapy, and the surgical treatment may be indicated in older children complicated with severe hypersplenism and marked splenomegaly, which are resistant for sclerotherapy. As a surgical procedure, splenectomy with periesophago-gastric devascularization (Hassab's operation) seems to be very useful for portal hypertension by biliary cirrhosis. The reoperation, hepaticoenterostomy, was performed in 3 patients with biliary reobstruction. All three patients are alive and well, and two of them are at 19 years (university student) and 24 years (married life) of age. Hepatic Rehepaticoenterostomy is well indicated rather than liver transplantation, if biliary reobstruction is incurable with conservative therapy. Many of the patients with complications were able to carry on an almost normal life, if suitable treatments for complications were taken.

Adolescent↗
PubMed1989

[Usefulness of ultrasonography and transcranial Doppler flowmetry in evaluation of infantile bacterial meningitis].

A 40-day-old girl with B-group streptococcal meningitis was examined with ultrasonography (US) and transcranial Doppler flowmeter. Transfontanelle US with a 7.5 MHz probe showed a dilatation of the extracerebral space (ECS). The flow velocity in the middle cerebral artery increased remarkably in the acute phase, and thereafter returned to normal. The superficial arterial velocity on the left side could not be recorded in the period of fluid collection in the left ECS. These two methods are useful procedures in the evaluation of infantile bacterial meningitis and its complications.

Female↗
PubMed1986

Projections of enteric motor neurons in the mouse distal colon.

This study examined the projections in vitro of excitatory and inhibitory colonic motor nerves in the unaffected siblings of mice with hereditary aganglionic colon--a strain of animals used as a model of Hirschsprung's disease. Microelectrode recordings from the circular muscle layer showed ongoing fluctuations in membrane potential (presumably junction potentials) that were sensitive to tetrodotoxin. Transmural electrical stimulation of the intrinsic nerves produced cholinergic excitatory and inhibitory junction potentials. The latter responses were more prolonged when recorded aboral to the stimulating electrodes. Apamin reduced, but did not block, these inhibitory potentials. Cholinergic excitatory junction potentials were abolished by d-tubocurarine when recording 2 mm from the stimulating electrodes; inhibitory junction potentials were recorded up to 10 mm in the presence of this drug. Thus, the intrinsic excitatory cholinergic motor neurons have relatively short projections to the circular smooth muscle compared with the projections of the inhibitory motor neurons.

Animals↗
PubMed1986

Electrophysiological and pharmacological study on innervation of the aganglionic colon in Hirschsprung's disease of human and murine model.

A true role of extrinsic nerve fibres proliferating abundantly in the aganglionic colon of Hirschsprung's disease has not yet been established. Electrophysiological and pharmacological studies were carried out on rectal muscle strips of piebald lethal mice and their siblings. Muscle strips of both aganglionic and normal colon obtained from fifteen patients with Hirschsprung's disease were also investigated for the purpose of determining whether these extrinsic nerve fibres innervate the smooth muscle cells in the aganglionic colon or not. Junction potentials and contractile tensions evoked by electric stimulations were recorded employing the double-sucrose gap method, and examined the effects of nerve blocking agents on junction potentials. In the normal colon, excitatory junction potentials and inhibitory junction potentials were recorded following stimulation in both man and mouse. Excitatory junction potentials were accompanied by muscle contraction and abolished by atropine or tetrodotoxin. Inhibitory junction potentials were resistant to phentolamine and propranolol, and abolished by tetrodotoxin. It was concluded that the normal colon of both mouse and man is innervated by cholinergic excitatory and non-adrenergic inhibitory nerves. In the aganglionic colon, on the other hand, neither junction potentials nor contractions were evoked by stimulations in both mouse and man. These evidences led to the conclusion that in the aganglionic colon in Hirschsprung's disease of man and murine model, there may be a deficiency in neuronal regulation.

Adolescent↗
PubMed1984

Esophageal perforation in a neonate associated with gastroesophageal reflux.

This is the first report of a neonate with esophageal perforation in whom an association of gastroesophageal reflux (GER) was detected by esophagraphy and esophageal pH monitoring. The patient was successfully treated for both esophageal perforation of GER by thoracic drainage and fundoplication. In this patient, GER seemed a likely cause of esophageal perforation.

Esophageal Fistula↗
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↗
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

[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↗