[Posterior pituitary lobe and ACTH secretion].
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Biomedical subjects
Publications and source records attributed to A Okuno.
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Hypoxic changes in the cholinergic neurons of the pedunculopontine nucleus (PPN) and the laterodorsal tegmental nucleus (LDT) were studied morphologically using immunohistochemistry for choline acetyltransferase (ChAT). Fifty-three postnatal day (PND) 7 Sprague-Dawley rats were subjected to a hypoxic load of 8% oxygen for 5 h. The rats which survived were later sacrificed at PND 14 or 28 for histological analysis. The results were compared with those obtained from control rats. Three weeks after hypoxic load, a decrease in the number of ChAT immunoreactive cells, especially in the caudal PPN, was found, although no remarkable changes were detected in cell morphology. Since several studies support the possibility that the cholinergic system from PPN/LDT is responsible for both REM generation and the general motor inhibition during REM sleep, our results may account, in part, for the clinical features of hypoxic brain damage such as sleep disorders and abnormal muscle tonus.
Unstable expansion of the CTG repeats in the 3' untranslated region encoding a member of the protein kinase family in the q13.3 band on chromosome 19 is a mutation specific for myotonic dystrophy. To examine the correlation between clinical expression and CTG trinucleotide repeat length, we carried out Southern blot analysis in a family with myotonic dystrophy. In this pedigree, the expanded CTG repeats were transmitted maternally. The mother had three female children. The mother had about 200 CTG repeats, and the number of repeats for each child was about 800, 1500 and 1600 in birth order. The mother and the patient with 800 repeats were unaware of muscle weakness or myotonia. Symptoms were present from age 3 years in the patient with 1500 repeats and from birth in the one with 1600 repeats. Although the mother menstruated regularly, the patients with 800 and 1500 repeats both menstruated irregularly, and the one with 1600 repeats has never menstruated. The age of onset and severity of the disease were correlated with the size of the expanded repeats. Endocrinological studies revealed that the basal levels of the gonadotropins, PRL and E2 were within normal range, and a pituitary response to LHRH was observed. These data suggest that the amenorrhea and menstrual irregularities were caused by a suprahypophyseal dysfunction. When expanded CTG repeats are transmitted maternally, abnormal products resulting from the metabolic disturbance in the affected mother may harm the fetus in utero. A heterozygous fetus, who has more CTG repeats, may be unable to metabolize the pathologic products sufficiently and therefore may become more severely affected. This may explain the exclusive maternal transmission of congenital myotonic dystrophy.
To investigate the prevalence of mitochondrial DNA mutations among Japanese children with IDDM as well as in those with NIDDM, a total of 155 patients with IDDM and 30 patients with NIDDM who were younger than 15 years of age at onset were studied for the following mtDNA mutations: 1) the A-->G mutation at position 3243 of mitochondrial leucine transfer RNA (3243 mutation); 2) the G-->A mutation at position 3316 of mitochondrial leucine transfer RNA (3316 mutation), and 3) The T-->C mutation at position 3394 of the mitochondrial NADH dehydrogenase subunit (3394 mutation). None of the 155 IDDM patients had the 3243 mutation. Although two of the 155 IDDM patients had homoplasmy of 3316 and five had 3394 mutations, these frequencies were not significant compared with healthy controls. None of the 30 NIDDM patients had the 3243, 3316 or 3394 mutation. The presence of these mutations even in control subjects suggests that the effect of the 3316 or 3394 mutation on mitochondrial function is relatively mild. It seems that 3316 and 3394 mutations contribute to the manifestation of diabetes together with other genetic and/or environmental factors.
BACKGROUND/AIMS: Patients with advanced gallbladder carcinoma have usually been considered nonresectable, leading to a very poor outcome. This study was aimed to evaluate the results of our aggressive surgical approaches in certain cases of advanced gallbladder carcinoma. METHODOLOGY: Ninety-one patients with advanced gallbladder carcinoma of stages pT3 and pT4 who underwent surgery at our institution were the subjects of this study. Fifty-eight of 91 patients had surgical excision; 44 by hepatic resection and 14 by hilar resection. Post-operative outcome was evaluated. Advanced gallbladder carcinomas were classified according to our previously reported classification: type I hepatic; type II biliary; type III hepatobiliary; type IV others. RESULTS: Curative resection was obtained at a more increased rate in type I tumor patients than in types II and III (91% vs. 29%, p < 0.01). The surgical mortality rate was 17%. Survival rates of resected patients were significantly higher that those of nonresected patients: 45%, 31%, 22%, 17%, 13% at 1, 2, 3, 4, 5 years vs. 9%, 9%, 0% at 1, 2, 3 years (p < 0.01). Survival rates of type I tumor patients after curative resection were remarkably higher than those of type II and III tumor patients, (69%, 64%, 56%, 48%, 39% at 1, 2, 3, 4, 5 years vs. 17%, 17%, 0% at 1, 2, 3 years). CONCLUSIONS: Aggressive surgical approaches might bring about improved prognosis in advanced gallbladder carcinoma, especially for patients with type I tumors.
BACKGROUND/AIMS: This study assesses the treatment of biliary obstruction in patients with hilar malignancies by metallic stents. METHODOLOGY: Twenty-one consecutive patients with unresectable malignant biliary obstruction at the hepatic hilum (Bismuth type II, III and IV) were treated with percutaneous transhepatic placement of self-expandable metallic endoprostheses. The endoprostheses were successfully inserted in all patients. In 12 patients all segments of the liver were drained and in 9 patients partial segments of the liver were drained. RESULTS: Seventeen patients (81%) showed relief from jaundice and could be freed of external drainage tubes. Ten patients (48%) showed no recurrent symptoms due to stent obstruction until death. Overall survival was 4.86+/-4.15 (mean+/-SD) months, stent patency was 3.76+/-3.64 months and comfort index representing a ratio of well-being was 70.5+/-38.3%. There was no significant difference in survival rate, stent patency or comfort index between the groups with complete and those with partial drainage. CONCLUSIONS: Even in patients with complicated hepatic hilar biliary occlusions, internal drainage using metallic stents can relieve jaundice and leave patients free of external tubes with a comfortable quality of life.