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Biomedical subjects

N Miyamoto

Publications and source records attributed to N Miyamoto.

At least 145 records · Page 8Linked to original sources
PubMed1991

Hyperbaric diuresis is associated with decreased antidiuretic hormone and increased atrial natriuretic polypeptide in humans.

When men are exposed to a hyperbaric environment, urine flow increases. In order to elucidate the mechanism of this hyperbaric diuresis, a dry saturation dive experiment was carried out. Five male subjects were exposed to a 16-21 ATA (atmospheric pressure absolute) helium-oxygen (He-O2) environment for 4 days. Five blood samples were obtained in the early morning (0600-0630 h): once at predive 1 ATA air, 3 times at 16-21 ATA He-O2, and once at postdive 1 ATA air. Eight-hour timed urine samples, 0600-1400 h, 1400-2200 h, and 2200-0600 h (night urine), were collected throughout the experimental period. Urine flow markedly increased by the exposure to hyperbaria in the presence of constant creatinine clearance. The increase was mostly attributable to the urine flow during 2200-0600 h. The secretion of antidiuretic hormone (ADH) was suppressed at daytime and night during the exposure. On the other hand, the secretion of atrial natriuretic polypeptide (ANP) increased solely at night during hyperbaria and correlated with the increases of both the nocturnal urine flow and the nocturnal urinary excretion of sodium. These results suggest that both suppressed ADH secretion and stimulated ANP secretion cause hyperbaric diuresis.

Adult↗
PubMed1991

[A case of ruptured aneurysm of the descending thoracic aorta associated with active Behçet's disease].

A 63-year-old male receiving steroid for active Behçet's disease was admitted of massive hemoptysis. A pseudoaneurysm of about 5 cm in diameter caused by rupture of the aortic wall penetrating into the lung was detected on the descending thoracic aorta. Operation was performed using left atrium-femoral artery bypass with centrifugal pump. The technique of graft interposition was selected rather than patch closure to prevent postoperative anastomotic aneurysm. We consider that in the treatment of inflammatory aneurysm, use healthy aortic wall for suture and end-to-end anastomosis are very important. In spite of steroid supplementation, the inflammatory reaction get worse postoperatively and the dosage of steroid had to be increased to control inflammation. The patient is well 20 months after surgery.

Aorta, Thoracic↗
PubMed1991

[Squamous cell carcinoma of the thymus].

A 68-year-old woman was admitted with cough and dyspnea. Her chest X-ray showed right pleural effusion and a mediastinal tumor. She underwent mediastinotomy following a preoperative diagnosis of invasive thymoma. A tumor originating from the thymus had invaded the right middle lobe and pericardium, and multiple pleural dissemination was also found. Therefore, considering the patient's age and pulmonary function, we performed only subtotal resection of the tumor. The pathological diagnosis was poorly differentiated squamous cell carcinoma. The patient received irradiation and chemotherapy including Cisplatin after surgery, but she died 1 year later because of rapid progression of distant metastases.

Aged↗
PubMed1990

Primate's p53 inhibits SV40 DNA replication in vitro.

Previous reports indicated that rodent p53 inhibits simian virus 40 (SV40) DNA replication in vitro as well as in vivo while that from primate cells does not (1-4). Here we report the evidence that p53 of primate origin also inhibits SV40 DNA replication in vitro. p53-SV40 large tumor antigen (T antigen) complex purified from SV40 infected COS-1 cells had little replication activity and inhibited SV40 DNA replication in vitro. These results suggest that inhibition of SV40 DNA replication by p53 should be regarded as general property of the protein and does not determine the mode of species specific replication of SV40 DNA.

Animals↗
PubMed1990

Pathologic characteristics of human T-cell lymphotropic virus (HTLV)-related extranodal orofacial lymphomas.

Eleven cases of extranodal orofacial lymphomas (EOFL), consisting of four HTLV-related and seven HTLV-unrelated EOFL, were investigated with respect to the immunohistochemical and clinical features. HTLV-related EOFL were of T-cell phenotype and were associated with a poorer prognosis than HTLV-unrelated EOFL, most of which were of B-cell origin. The appearance of giant cells with cerebriform nuclei was helpful in identifying HTLV-related EOFL. The relatively high incidence of T-cell type EOFL in our series was considered to be related to the high percentage of HTLV carriers in our district, an area endemic for adult T-cell leukemia-lymphoma.

Adult↗
PubMed1990

Serum levels of glycated albumin in non-diabetic and insulin-dependent diabetic children.

The serum levels of glycated albumin (GA) in 83 non-diabetic children and 26 children with insulin-dependent diabetes mellitus (IDDM) were measured by high-performance liquid chromatography (HPLC). In non-diabetic children over one year, the GA levels were found to be uninfluenced by age, while the fructosamine (FRA) levels increased with age. The mean level of GA in IDDM children was 39.1 +/- 9.1%, which was significantly higher than in non-diabetic children with values of 16.1 +/- 1.1% (p less than 0.01). The GA levels of non-diabetic and IDDM children did not overlap, whereas their FRA levels did overlap. The GA levels correlated with HbAlc levels (r = 0.74, p less than 0.01) and FRA levels (r = 0.66, p less than 0.01) in IDDM children. The GA levels were more closely correlated than the FRA levels with the blood glucose two and three weeks previously. Thus, the GA level is a useful indicator of short-term control in diabetes mellitus.

Adolescent↗
PubMed1990

Assembly of nascent DNA into nucleosome structures in simian virus 40 chromosomes by HeLa cell extract.

A soluble system was developed that could support DNA replication in simian virus 40 (SV40) chromosomes. DNA synthesis in this system required the presence of purified SV40 large tumor antigen, SV40 chromosomes prepared from virus-infected monkey cells, a crude extract from HeLa cells, and several low-molecular-weight components. In comparison to the replication of purified SV40 form I DNA, the rate of DNA synthesis was 15 to 20% in this system. DNA synthesis started near the replication origin of SV40 and proceeded bidirectionally in a semiconservative manner. Micrococcal nuclease digestion experiments revealed that the replicated DNA produced in this system became organized into a regularly spaced array of nucleosome core particles when an appropriate amount of purified HeLa core histones was added to the reaction mixture. SV40 form I DNA replicating under the same conditions was also assembled into nucleosomes, which were arranged in a rather dispersed manner and formed an aberrant chromatin structure.

Cell Line↗
PubMed1990

Mechanisms of atrial natriuretic peptide (ANP) secretion by rat hearts perfused in vitro--Ca2(+)-dependent signal transduction for ANP release by mechanical stretch.

Effects of temperature, contraction frequency, and intraatrial pressure on immunoreactive ANP release were investigated in isolated rat hearts perfused in Langendorff or working mode. A reduction of temperature from 37 C to 27 degrees C caused a decrease of ANP release by 64% indicating its marked temperature-dependency (Q10 = 2.92). An increase of atrial contraction frequency from 300 to 500/min in Langendorff-perfused hearts did not cause a significant change in the ANP release. An elevation of left atrial filling pressure of working hearts from 8 to 18 and 28 cmH2O was associated with pressure-dependent, and reversible increase of the ANP release. This pressure-induced release of ANP was inhibited in a low calcium (50% Ca2+) medium or by nifedipine (10(-7) M). N-(6-aminohexyl)-5-chloro-1-naphthalene-sulfonamide (W-7, 10(-7)M), a potent calmodulin inhibitor, or ryanodine (10(-8)M) had similar inhibitory action against the pressure-induced increase of ANP release. These results indicate that ANP secretion is primarily regulated by mechanical stretch or distension of the atrial wall, while the atrial contraction frequency is less important as a physiological stimulus for the secretion. The stretch-induced ANP secretion may require an influx of calcium through the voltage-dependent Ca2+ channels. It was also suggested that Ca2+ release from the sarcoplasmic reticulum leading to an activation of calcium-calmodulin kinase may be included in the intracellular processes of ANP release by mechanical stretch.

Animals↗
PubMed1990

[Results of surgery in non-small cell lung cancer].

Two hundred and nine patients with non-small cell lung cancer underwent surgical treatment from January, 1978 to December, 1987 at the Kochi Municipal Hospital. There were 126 men and 83 women, varying in age from 36 to 85 years. The post-surgical stage distribution was as follows: 121 patients with Stage I, 22 with Stage II, 43 with Stage IIIA, 14 with Stage IIIB and 9 with Stage IV. The 5 year survival rate was 54% for all patients and only 3 patients of them (1.4%) died within the first month following operation. The 5 year survival rate was 71% for Stage I, 22% for Stage II, 38% for Stage IIIA, 36% for Stage IIIB and 25% for Stage IV. The 5 year survival rate was 66% for absolutely curative operation, 46% for relatively curative operation, 55% for relatively noncurative operation and 19% for absolutely noncurative operation. This series have 41 patients (19.6%) over 70 years old, and the 3 year and the 5 year survival rates for this high age group were 58% and 40%, respectively. Statistically, there was no significant difference in survival rate between this high age group and the younger group. Our successful experiences of the bronchoplastic procedures, extended resections and limited operations were also reported.

Adult↗
PubMed1990

[Report on clinico-pathological examinations in Meikai University (formerly Josai Dental University) Hospital (4)].

This clinico-pathological study was conducted to examine biopsies and surgical specimens for histopathological diagnosis from April 1983 to March 1988 in Meikai University (formerly Josai Dental University) Hospital. The following statistical results were obtained: 1) The total number of the specimens examined was 2705, 2026 from the dental clinic and 679 from the medical clinic. 2) Concerning age distribution, most specimens from the dental clinic were from patients in the 40's age bracket, whereas most from the medical clinic were from those under 10 years of age. With regard to sex distribution, the difference between males and females was not so much in the dental clinic specimens, but the number from the medical clinic was greater for males than for females. 3) Concerning classification of the tumors from the dental clinic, 181 cases were benign; and of them 41 were odontogenic and 140 were non-odontogenic tumors. Among the odontogenic tumors, ameloblastoma, cementoma, and odontoma were the most numerous. Among non-odontogenic tumors, fibroma was the most common, followed by pleomorphic adenoma. Malignant tumors comprised 77 cases. Of them squamous cell carcinoma was the most commonly found, with the grade-2 type being most numerous. Of the medical clinic tumors, nevus was the most common benign tumor observed; and adenocarcinoma, the most common malignant one. 4) Concerning the distribution of main lesions in the dental clinic specimens, most specimens were cysts or cystic lesions, followed by inflammatory lesions and tumors. Among medical clinic specimens, inflammatory lesions were the most common. 5) Regarding the dental clinic specimens, the most frequently observed case was the radicular cyst (301 samples) among the odontogenic cysts (514 samples); and among non-odontogenic cysts (290 samples), the most common was the mucous cyst (159 samples). 5) In terms of the distribution by location, tissue or organ, most tumors from the dental clinic were from the jaws, followed in descending frequency by those from gingiva and alveolar mucosa, maxillary sinus, lip, buccal mucosa, and tongue. Among the medical clinic tumors, the paranasal cavity and tonsils were the most frequent locations.

Adult↗
PubMed1990

[Analysis of T1N0M0 nonsmall cell lung cancer undergoing surgical resection without mediastinal lymph node dissection].

Eleven patients of T1N0M0 non-small cell lung cancer underwent relatively non-curative surgical resection without mediastinal lymph node dissection (the undissected group). The 5 year survival rate of this group was 70.7% and no significant difference in survival was found between the undissected group and the patients of T1N0M0 non-small cell lung cancer undergoing absolutely curative surgical resection (the dissected group). No patient died of pneumonia in the undissected group, while 4 aged patients in the dissected group died of pneumonia. This may suggest that mediastinal lymph node dissection is also injurious in distant period after surgery, especially in the aged patient. So "simple lobectomy" without mediastinal lymph node dissection may be considered as an elective procedure in the poor risk patient such as the aged, who has an early staged non-small cell lung cancer.

Adult↗
PubMed1990

[Effect of controlled freezing-point storage of hearts--combined effect of controlled freezing-point storage and verapamil].

Controlled Freezing-point Storage (CF Storage) is a new method of preserving foods in minus non-frozen temperature range. Therefore, the authors tried to apply this method to organ preservation. We investigated the effect of controlled freezing-point storage of hearts on ventricular function in isolated perfused rat heart (male, Sprague dawley strain, body weight about 300 g), and the combined effect of controlled freezing-point storage and Verapamil (0.5 mg/l). The hearts were perfused by working heart mode for 10 min, and received infusion of cardioplegic solution which was followed by 4 hours of cardiac arrest. The hearts were stored for 4 hours in Euro-Collins solution at 4 degrees C (4 degrees C group) and minus non-frozen temperature (CF storage group), and were stored for 4 hours in Euro-Collins solution containing Verapamil at minus non-frozen temperature (CF-Ve storage group). Then, the aerobic reperfusion by working heart mode was continued for an additional 30 min. The recovery rate of cardiac output was 33.5%, 62.5% and 74.2% respectively of the preischemic value in 4 degrees C group, CF storage group and CF-Ve storage group. The recovery rate of cardiac output in 4 degrees C group was significantly lower than that in CF storage group and CF-Ve storage group (p less than 0.01), and significant difference was noted between CF storage group and CF-Ve storage group (p less than 0.05). ATP activity after 4 hours of cardiac arrest was 13.9 micrograms/mg, 18.7 micrograms/mg and 18.3 micrograms/mg in 4 degrees C group, CF storage group and CF-Ve storage group respectively. ATP activity after 4 hours of cardiac arrest in 4 degrees C group was significantly lower than that in CF storage group and CF-Ve storage group (p less than 0.05). These data suggest that CF storage of hearts has a protective effect against an ischemic insult upon myocardial cell during hypothermic cardiac arrest, and the best metabolic and functional protection appeared when the hearts were stored in Euro-collins solution containing Verapamil at minus non-frozen temperature.

Animals↗
PubMed1990

[Orofacial lymphomas in seropositive patients manifesting the type I human lymphotropic virus (HTLV-I)].

Eleven cases of extranodal orofacial lymphomas (EOFL), consisting of 4 HTLV related and 7 HTLV unrelated EOFLs, have been investigated with regard to their immunohistological and clinical features. The HTLV related EOFLs were found to be of the T-cell phenotype and were associated with a poorer prognosis than the HTLV unrelated EOFLs, most of which were of B-cell origin. The comparatively high incidence of T-cell type in our series was considered to be related to the high percentage of HTLV carriers in our district, an area in which adult T-cell leukemia lymphoma has been found to be endemic.

Adult↗
PubMed1990

[Doppler echocardiographic measurement of flow velocity in cases with a Björk-Shiley aortic prosthesis and diagnosis of prosthetic valve dysfunction].

115 patients with a Björk-Shiley aortic valve prosthesis were studied by means of the ultrasonic Doppler method. The maximum flow velocity at the prosthetic valve was measured by the continuous wave Doppler method, and the velocity at the left ventricular outflow tract was measured by the pulsed wave Doppler method. In addition, flow velocity measured by Doppler method was compared to the valve opening angle obtained by cinefluoroscopy. 1) The maximum velocities at the prosthetic valve in the patients with normally functioning prosthesis were 3.1 +/- 0.4, 2.7 +/- 0.5, 2.2 +/- 0.4, 1.9 +/- 0.3, 1.7 +/- 0.3 m/sec for valve sizes of 21, 23, 25, 27, and 29 mm, respectively. Statistical differences were recognized between the valve size groups. In a case with a thrombosed valve, the maximum velocity was faster than in cases with normally functioning valves and it reached 4.5 m/sec. 2) Flow velocities at the left ventricular outflow tract in patients with normally functioning valves were 0.86 +/- 0.15, 0.86 +/- 0.16, 0.79 +/- 0.14, 0.82 +/- 0.16, 0.75 +/- 0.18 m/sec for valve sizes of 21, 23, 25, 27, 29 mm, respectively. No statistical difference was recognized. In the patients with perivalvular leakage, velocity was faster than in the patients with normally functioning valves. But, in the case with thrombosed valve, it remained within the normal range. 3) No significant correlation was observed between flow velocities and valve opening angles in the cases with normally functioning valves. But, in the cases with malfunctioning valves, flow velocities were faster than normal.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Age- and sex-specific cumulative rate and risk of ATLL for HTLV-I carriers.

We have surveyed the incidence of adult T-cell leukemia/lymphoma (ATLL) in an endemic area of 290,464 inhabitants for 7 years. We now revise our previous results on the basis of additional findings and estimate the age- and sex-specific cumulative rate for HTLV-I carriers, the adoption of which is recommended by current cancer epidemiology as a new age-standardized incidence rate. An unequivocal age-dependent increase in seroprevalence was observed for both sexes with a characteristic predominance in females. The age-dependent seroconversion in females may be partly explained by additional infection from infected husbands to their wives but the reason for men remains obscure. The mean annual number of incident cases of ATLL was 11.4, giving 3.9 ATLL patients annually per 10(5) inhabitants, 6.1 per 10(5) inhabitants aged over 30, and 85.0 per 10(5) seropositives aged over 30. Crude annual incidence rate of ATLL among 10(5) male seropositives aged over 30 was 145.3 and that for females was 55.2 and 95% confidence intervals of ATLL incidence rates were 34.8 to 255.7 for males and 6.4 to 104.1 for females, respectively. Although the sex ratio of 80 ATLL patients was 1.35, males are more prone to the disease (46 male patients among 4,522 male seropositives aged over 30 vs 34 female patients among 8,801 female seropositives aged over 30; p less than 0.001) for unknown reason(s). Morbidity in male seropositives aged over 30 is 2.6 times as high as that of females. Decennial incidence rates in males in their fifties and sixties were significantly higher than those in females. The remarkable male preponderance in oncogenicity of HTLV-I may be due to the fact that men are more prone to the disease and the number of female carriers in the denominator used to calculate the incidence rate is larger than that of males. The whole life span (0-79) cumulative risk for males was 6.9% and significantly higher than that of females (2.95%).

Age Factors↗
PubMed1989

Potentiation of atrial natriuretic peptide-stimulated cyclic guanosine monophosphate formation by glucocorticoids in cultured rat renal cells.

1. The effect of steroid hormones on atrial natriuretic peptide (ANP)-stimulated cyclic guanosine monophosphate (cyclic GMP) formation was studied in cultured rat renal cells. 2. ANP increased cyclic GMP formation in a dose-dependent manner, while cyclic AMP was not changed by ANP. 3. Steroid hormones did not affect basal cyclic GMP levels in cultured rat renal cells. 4. Dexamethasone at 10(-8) M increased ANP (human and rat ANP)-stimulated cyclic GMP dose-dependently in cultured rat renal cells. Cortisol, corticosterone and aldosterone at a concentration of 10(-7) M also potentiated ANP-stimulated cyclic GMP formation, although triiodothyronine, oestradiol and testosterone were ineffective. Potentiation of ANP action by these steroids seems to parallel glucocorticoid activity. 5. Dexamethasone did not affect cyclic GMP formation stimulated by sodium nitroprusside which stimulates soluble guanylate cyclase in the cytosol. Therefore, the potentiating action of dexamethasone may be mediated through the action on particulate guanylate cyclase at the plasma membrane. 6. It is suggested that the diuretic action of glucocorticoids may, at least in part, be mediated through the potentiating effect of glucocorticoids on cyclic GMP response to ANP.

Animals↗
PubMed1989

Alterations in fructosamine and glycated albumin levels during childhood.

Age-related changes in the blood concentrations of glycated proteins during childhood and adolescence were examined by measuring the blood fructosamine (FA), glycated albumin (GA), glucose levels and total serum protein levels in 611 healthy children (325 boys and 286 girls) aged 0-18 years old. These levels were compared with those of 130 healthy adults. GA was measured by a newly developed, highly precise method of high-performance liquid chromatography (inter-assay coefficient of variation, 4.9%). The FA values of all groups of up to 15 years old (grouped in two year age brackets) were significantly lower than those of adults. The mean serum concentrations of GA in infants up to four years old were also significantly lower than in adults. A slight but statistically significant positive correlation was found between age and values of FA (r = 0.36, P less than 0.001), but not of GA (r = 0.04). Levels of total serum proteins showed a positive correlation with those of FA (r = 0.47, P less than 0.001) but a weak correlation with those of GA (r = 0.29). These results suggest that age should be taken into account when the FA levels of children and the GA values of infants are evaluated.

Adolescent↗