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Biomedical subjects

M Hirabayashi

Publications and source records attributed to M Hirabayashi.

At least 73 records · Page 4Linked to original sources
PubMed1990

Intracerebroventricular infusions of insulin increase vasopressin release in rats.

1. The role of cerebral insulin or insulin-like immunoreactive substance (ILI) on arginine-vasopressin (AVP) release using rats was investigated. Feeding rats with a high salt diet for 4 weeks significantly decreased the contents of ILI in both the hypothalamus and pituitary gland. Intracerebroventricular infusions of insulin (4 and 40 micrograms/min for 30 min) increased plasma AVP concentrations dose-dependently without hypoglycaemia, but decreased hypothalamic and pituitary contents of AVP. 2. These results indicate that ILI in the brain may play a role in the secretion of AVP, and that this mechanism could be operated to control a water-sodium balance.

Animals↗
PubMed1990

Intracerebroventricular injections of endothelin increase arterial pressure in conscious rats.

We investigated the possible effects of endothelin (ET) on the central regulation of arterial pressure by injecting ET intracerebroventricularly (ICV) into conscious rats. ICV injections of ET caused dose-dependent elevation of arterial pressure and increase of heart rate. The first reaction was abolished by bunazosin, an alpha 1-adrenergic blocker, injected intravenously. However, the increase in arterial pressure and heart rate caused the rats, injected with ET ICV, to roll to the left on their long axis for 20-30 min, followed by prolonged sedation. Furthermore, the pressor responses and tachycardia were significantly attenuated by the ICV pretreatment with nicardipine, a calcium channel blocker, and nicorandil, a nitrate derivative, respectively. These results suggest that ET may elevate the intracellular Ca2+ concentration ([Ca2+]i) of sympathetic nerve activity regulatory neurons of the brain, leading to an accelerated outflow of sympathetic nerve activity and cause the elevation of arterial pressure.

Adrenergic alpha-Antagonists↗
PubMed1990

[Estimating the quality of life in childhood cancer survivors from parent questionnaires].

Multidisciplinary clinical research on childhood cancer has achieved a marked improvement in survival rate during the last two decades. Due to the increase of long-term survivors, the survey of quality of life (QOL) of cured children is essential. But methods to estimate QOL of children have not been established. We attempted to estimate the QOL of surviving patients from the responses to a questionnaire filled out by their parents. The total number of patients treated at the National Children's Hospital from 1965-1987 was 937, of which 296 patients are still surviving. Among these survivors 108 patients were selected to be surveyed because they were being followed up by our attending physicians. The originally elaborated questionnaire was sent to parents in June 1989. Seventy-eight parents responded. The questionnaire consisted of four major questions. The first was how the QOL of the child compared to that of an ordinary child. The parents circled the appropriate level of QOL determined by our scale (1 lower, 4 the same as ordinary child, 7 excellent). The average score was 5.61 showing that parents felt their child's QOL is superior to an ordinary child. The second question concerned how the present status of the child was influenced by the experience of cancer. Answers were divided into five categories as follows: 1) Good or positive (10%); 2) nothing in particular (49%); minimum (29%); negative (9%); and other (7%). The third question concerned any anxieties. Most parents had numerous anxieties about the relapse, late effects, education, job prospects, marriage and offspring and getting the latest information. The fourth question dealt with what to tell the child as to their true diagnosis. Answers were divided as follows: absolutely no (56%); yes, but in the future (23%); yes, already done (10%); and yes, through our physician; (13%). After studying the questionnaires we interviewed the parents. We noticed that the parent/child relationship was very close. A meeting was conducted with parents and all the staff (doctors, psychologists and nurses). In conclusion, the QOL in surviving childhood cancer patients is considered to be better than that of ordinary children by their parents. This result is likely due to the excellent parent/child relationship.

Adolescent↗
PubMed1989

High-resolution electron microscopy study on crystal structures of high-Tc superconductors.

Recent studies of high-resolution electron microscopy on the high-Tc superconductors of Y-Ba-Cu-O and Bi-Ca-Sr-Cu-O are presented. The observed images of crystals thinner than 3 nm, taken under conditions that approached the Scherzer defocus condition, directly show the arrangements of cations and oxygen-vacant positions. The results reveal structural characteristics of the atomic scale; this offers important insights into the origin of the high-Tc superconductivity. The usefulness of high-resolution electron microscopy for studying complicated crystal structures is demonstrated for the high-Tc oxides.

Bismuth↗
PubMed1989

[Prognostic factors of common epithelial ovarian cancer treated by surgery and cisplatin based combination chemotherapy].

Retrospective analysis of prognostic factors in 171 patients who had common epithelial ovarian cancer (WHO) and treated by surgeries and cisplatin based combination chemotherapies were performed by survival assay and multivariate analysis. In FIGO stage 3, the estimated parameter values were in following order: residual tumour age grade performance status histological type. On analysing Stage patients, histological grading and histological typing had an effect on prognosis. Patients with grade 2 or tumours had a worse prognosis than did those with grade 1 tumours, and patients with clear-cell carcinoma or undifferentiated adenocarcinoma showed a poor prognosis.

Adult↗
PubMed1988

Serum testosterone level in the peripheral vein and the perigastric draining vein of patients with gastric carcinoma.

The serum testosterone level (STL) was determined in 181 patients with gastric carcinoma, 128 male and 53 female, and in 98 patients with benign diseases, 67 male and 31 female. As in our previous report, the preoperative STL of the cancer group was significantly lower than that of the control group, in both male and female patients (P less than 0.001). In the present study, the STL of the perigastric vein draining the stomach was determined and compared with the STL of the blood obtained at the same time from the peripheral vein during the operation. It was found that, in the male patients, the STL of the blood obtained from the perigastric vein draining a stomach with carcinoma was significantly lower than that of the peripheral vein in the same patient (P less than 0.001); however, there was no difference between these STL in the control group. On the contrary, in the female patients during operation, no such phenomenon was confirmed. Analysis classifying the patients by histological type revealed almost the same results for all patients as those shown for the cancer group, i.e. there was a proven significant difference in male patients and no significant difference in female patients. It was therefore considered that the mechanism of decrease in preoperative peripheral STL was not always the same in male patients as in female patients, although the STL decrease was observed to be similar in both sexes before surgery.

Adenocarcinoma↗
PubMed1987

Complementation studies with clinical and biochemical characterizations of a new variant of multiple sulphatase deficiency.

A patient with a new variant of multiple sulphatase deficiency (MSDv) is reported. Unlike the usual type, onset was late and progress was slow. The phenotypic changes were those usually seen in multiple sulphatase deficiency but much milder. Cytoplasmic accumulations were found in skin fibroblasts, and urinary mucopolysaccharides and sulphatides were high. Arylsulphatases A, B and C (ASA, B and C), heparan N-sulphatase sulphoiduronate sulphatase, and N-acetylgalactosamine 6-sulphatase all had low activity in lymphocytes and cultured skin fibroblasts. Complementation for ASA activity was found in hybrids between MSDv and metachromatic leukodystrophy (MLD) as well as between multiple sulphatase deficiency (MSD) and MLD. Complementation for ASC activity was also seen in hybrids between MSDv and X-linked ichthyosis (XLI), and between MSD and XLI. However, neither ASA nor ASC activity increased in hybrid cells of MSDv and MSD. These results suggested that the mutations of MSDv and of MSD were allelic, although of different phenotypes.

Adult↗
PubMed1987

Facial reconstruction with latissimus dorsi myocutaneous island flap following total maxillectomy.

Following total maxillectomy for maxillary cancer, facial reconstruction was performed using a latissimus dorsi myocutaneous island flap. Postreconstructive deformity was studied in 10 patients. In 5 patients, after simple total maxillectomy the inner raw surface of the facial skin and orbito was covered by the flap, and the other extended total maxillectomy patients where the orbital contents and facial skin were involved, reconstruction was by means of the folded flap. In the patients with simple total maxillectomy, cicatricial contracture of the facial skin and cicatricial ectropion of the lower eyelid were quite small, and in the patients with extended total maxillectomy, reconstructed facial skin did not give rise to cicatricial contracture.

Cicatrix↗
PubMed1987

Strain differences in the reverse tolerance to methamphetamine and changes in catecholaminergic neurons in mice.

The effect of methamphetamine (MAP) on ambulatory activity and neurochemical changes in catecholaminergic neurons in the brain were investigated in dd and C57BL/6 strains of male mice. The mice were given repeatedly MAP at 2 mg/kg, s.c., 10 times at a fixed interval of 4 days. Single MAP markedly increased the ambulatory activity in both strains of mice. The ambulation-increasing effect was progressively enhanced without accompanying stereotyped behaviors when the drug was repeatedly given. The dd mice showed higher susceptibility not only to single MAP but also to the enhancing effect of the drug (reverse tolerance) that the C57BL/6 mice. On the other hand, non-treated dd mice exhibited lower maximum densities of 3H-spiperone binding sites in the striatum and 3H-WB4101 binding sites in the cortex and hippocampus than non-treated C57BL/6 mice. In contrast, the dd mice exhibited higher noradrenaline turnover than the C57BL/6 mice in the brain regions examined. The repeated administration of MAP produced decrease in the densities of both 3H-spiperone and 3H-WB4101 binding sites in the corresponding regions with increase in catecholamine turnover in dd mice. However, the similar changes were observed only in 3H-WB4101 binding sites and noradrenaline turnover in C57BL/6 mice. These results suggest that the ambulation-increasing effect of MAP is positively correlated with catecholamine turnover, while it was correlated negatively with the densities of catecholamine binding sites. Furthermore, the enhancing effect of MAP is supposed to have been partially elicited by changes in brain catecholaminergic systems, in particular an increase in catecholamine turnover.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1987

Age-related morphological changes in auditory middle-latency response.

Age-related changes in the waveforms of the middle latency response (MLR) were investigated in 9 adults and 28 children aged between 4 and 14 years. The children were classified into three groups according to their age. For obtaining characteristic configurations in the responses for each group, composite group averaging was performed by summating the individual recordings in each group. With high-pass digital filtering at 20 Hz, composite MLR for adults showed a well-defined Na-Pa-Nb-Pb complex with peak latencies at about 17, 30, 45 and 63 ms, respectively. The composite response for children aged 4-7 years was characterized by a broad positive deflection (Pa) followed by a negative peak (Nb) at about 40 and 60 ms after stimulus onset, respectively. The peak latency of Pa was close to the adult value in the composite MLR for subjects aged 8-11 years, while the complete adult pattern in the later part of the response was not reached even in the composite response for subjects aged 12-14 years.

Adolescent↗
PubMed1987

Early gastric cancer and a concomitant pregnancy.

Gastric cancer associated with pregnancy is most often associated with a poor prognosis because the cancer stage is usually advanced at the time of diagnosis. The symptoms are frequently masked by factors related to the normal pregnancy and diagnostic approaches are restricted by physical and psychological clinical events. The authors treated a 30-year-old woman at 35 weeks of gestation. She had episodes of hematemesis and a prompt diagnosis of early gastric cancer was made following observations using a gastroduodenal fiberscope. A living normal child was delivered following oxytocin-induced labor and, 18 days later, curative resection for the gastric cancer was done. The patient has been doing well for over 16 months at this writing, with no evidence of recurrence. Based on the author's experience and a review of the literature, they conclude that early gastric cancer detected during pregnancy has a satisfactory prognosis and that use of the gastrofiberscope facilitates an early diagnosis in a pregnant subject with untoward symptoms of the GI tract.

Adenocarcinoma↗
PubMed1987

Postoperative mechanical ventilation preventing the occurrence of pleural effusion after hepatectomy.

To determine factors leading to pleural effusion after hepatectomy, the frequency of pleural effusion was investigated in 68 patients who underwent hepatic resection, with or without dissection of the right coronary ligament. In 36 of 44 patients (81.8%) who underwent hepatic resection with complete dissection of the right coronary ligament, and in two of 24 (8.3%) who underwent the procedure without dissection of this ligament, pleural effusion developed in the right hemithorax (p less than 0.001). Difference in pressure between the abdominal and thoracic cavities was considered to lead to ascites in the chest via the diaphragmatic triangular area (where there is no parietal peritoneum). While investigating the preventive effect of mechanical ventilation following hepatic resection on the occurrence of pleural effusion in 12 patients, we concluded that effusion could be prevented with use of mechanical ventilation--an approach that retained the intrathoracic pressure in a positive state.

Adult↗