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Biomedical subjects

K Usui

Publications and source records attributed to K Usui.

At least 55 records · Page 3Linked to original sources

Life span of Japanese male medical doctors.

There have been few reports with regard to the life spans of medical doctors. The status of the medical doctors graduating from 1926 to 1974, alive or dead as of October 1996, was ascertained on the basis of the list of graduates from the School of Medicine, Hokkaido University. Excluding data on female doctors and those who died in battle during World War II, data on a total of 3,982 doctors were available for study. Their mortality as of October 1996 decreased in parallel with the graduation year. Their mean future life span at graduation was estimated to be about 52.88 years (95% CI, 52.45-53.31) through linear regression (r = 0.992). Their mean age at graduation was 25.17 years. This was not different from the future life expectancy at 25 years of age of the general population (52.35 years). The future life span of surgeons and gynecologists-obstetricians was shorter than that of the doctors of basic medical sciences and internal medicine. This difference might be accounted for by factors peculiar to each speciality (e.g., exposure to blood) or by the degree of stress from work.

Age Factors↗

A case of antiphospholipid antibody syndrome diagnosed after thrombosis of an arteriovenous shunt.

A 32-year-old male dialysis patient with lupus nephritis was admitted because of shunt obstruction. The arteriovenous fistula was reconstructed, but obstruction recurred twice within several hours after surgery. A high blood level of anticardiolipin beta2-glycoprotein I antibody suggested that shunt obstruction was caused by a thrombotic tendency related to the antiphospholipid antibody syndrome. Accordingly, for the third shunt procedure, antiplatelet therapy (which had been commenced for systemic lupus erythematosus) was combined with dalteparin sodium from before surgery and warfarin was added postoperatively. This regimen prevented shunt obstruction. In conclusion, hemodialysis patients who suffer repeated shunt obstruction should be examined for antiphospholipid antibody syndrome.

Adult↗

Preparation of Anisotropic Gold Particles Using a Gemini Surfactant Template.

Anisotropic gold particles were prepared in a gemini cationic surfactant solution by reduction of HAuCl4 with UV irradiation. With increasing concentrations of both HAuCl4 and the surfactant, fibrous gold particles were obtained and their length increased. These results suggest that the gemini surfactant which provides threadlike micelles operates as a soft template for anisotropic gold particles. Copyright 1998 Academic Press.

Journal Article↗

The effect of low intensity bicycle exercise on the insulin-induced glucose uptake in obese patients with type 2 diabetes.

OBJECTIVE: The present study was undertaken to reveal the effect of low intensity bicycle exercise on the insulin-induced glucose uptake in obese patients. SUBJECTS AND METHODS: Seven obese men with Type 2 diabetes (OBDM) and seven healthy young men (HY) participated in this study. The glucose infusion rate (GIR) was determined by glucose clamp procedure at an insulin infusion rate of 40 mU m-2 min-1 (plasma insulin concentrations: 700-800 pmol l-1). Confirming stabilized GIR, a 30-min bicycle exercise was performed during the glucose clamp which was continued for 120 min after exercise. RESULTS: Average GIR in OBDM for last 30 min prior to exercise were significantly lower than HY (28.3 +/- 1.7, 47.4 +/- 1.8 mumol kg-1 min-1 respectively, P < 0.05). GIR abruptly increased during exercise and gradually decreased after exercise to the nadir almost at the time from 30 to 60 min in recovery period in both groups. GIR in OBDM, however, gradually increased significantly over pre-exercise levels (P < 0.05), following exercise and reached the same levels compared to HY after 80 min of recovery period. CONCLUSION: These results indicated that in obese Type 2 diabetes, 30 min of low intensity bicycle exercise significantly enhances the lower level of insulin-induced glucose uptake shortly after exercise and might be useful for the treatment of post-prandial hyperglycemia.

Adult↗

From behavior to development: genes for sexual behavior define the neuronal sexual switch in Drosophila.

The isolation and analysis of Drosophila mutants with altered sexual orientation lead to the identification of novel branches in the sex-determination cascade which govern the sexually dimorphic development of the nervous system. One such example is the fruitless (fru) gene, the mutation of which induces male-to-male courtship and malformation of a male-specific muscle, the muscle of Lawrence (MOL). Since the MOL is formed in wild-type flies when the innervating nerve is male, regardless of the sex of the MOL itself, the primary site of Fru function is likely to be the motoneurons controlling the MOL. The fru gene produces multiple transcripts including sex-specific ones. A female-specific mRNA from the fru locus has a putative Transformer (Tra) binding site in its 5' untranslated region, suggesting that fru is a direct target of Tra. The fru transcripts encode a set of proteins similar to the BTB (Bric à brac, Tramtrack and Broad-complex)-Zn finger family of transcription factors. Mutations in the dissatisfaction (dsf) gene result in male-to-male courtship and reduced sexual receptivity of females. The dsf mutations also give rise to poor curling of the abdomen in males during copulation and failure of egg-laying by females. The latter phenotypes are ascribable to aberrant innervation of the relevant muscles. A genetic analysis reveals that expression of the dsf phenotypes depends on Tra but not on Doublesex (Dsx) or Fru, suggesting that dsf represents another target of Tra. Taken together, these findings suggest that the sex-determination protein Tra has at least three different targets, dsx, fru and dsf, each of which represents the first gene in a branch of the sex-determination hierarchy functioning in a mutually-exclusive set of neuronal cells in the Drosophila central nervous system.

Animals↗

Disproportional response between refractory period and blood flow to alpha 1- and beta-adrenoceptor blockade in canine ischemic myocardium.

We investigated the response of refractory periods and blood flow to blockade of alpha 1- and beta-adrenoceptors alone, or in combination on endocardium and epicardium, during myocardial ischemia. Dogs were anesthetized with alpha-chloralose and divided into bunazosin (an alpha 1-blocking agent)-treated (0.1-0.2 mg/kg, i.v., n = 14), propranolol-treated (0.2 mg/kg, i.v., n = 12), and vehicle-control (n = 10) groups. The diagonal branches of the left anterior descending artery were ligated. The refractory period (ERP) and blood flow (RMBF) were determined by an S1-S2 extrastimulus method and a nonradioactive microsphere technique, respectively. The duration of regional electrograms (DRE) was measured in the endocardial and epicardial sites. Bunazosin alone reversed the ischemia-related shortening of ERPs at both the endocardial and epicardial sites, with a greater effect seen epicardially (P < .05). Subsequent administration of propranolol further prolonged ERPs in both sites, although the effect was greater in the epicardial surface (P < .05). Bunazosin reduced RMBF to a greater degree at the endocardial site than at the epicardial site in the ischemic zone (P < .01 and P < .05, respectively), but the magnitude of the reduction in RMBF and the difference in RMBF between sites were similar to the control group (P < .01). Propranolol alone and subsequent administration of bunazosin prolonged the ERP more at the epicardial site (P < .01) than at the endocardial sites in the ischemic zone. Propranolol produced no significant difference in RMBF between both sites. DREs in animals treated with bunazosin and propranolol alone, or in combination, were similar to those in animals treated with vehicle. These results suggest that differences in ERPs between endocardium and epicardium with blockade of alpha 1- and/or beta-adrenoceptor are not due to concomitant alterations in RMBF, but to differences in electrophysiological properties of the endocardial and epicardial cells during the acute phase of myocardial ischemia.

Adrenergic alpha-1 Receptor Antagonists↗

Prevalence of ischemic heart disease among patients with sleep apnea syndrome.

We investigated the prevalence of ischemic heart disease (IHD) in sleep apnea syndrome (SAS) and the presence of coronary risk factors involved in the onset of IHD in 386 subjects with suspected SAS due to heavy snoring. The prevalence of IHD among patients with untreated SAS was found to be 23.8%, and the percentage of patients having SAS complicated with IHD was high among those with moderate or severe SAS. Sleep apnea syndrome patients with IHD also showed high prevalences of hypertension and hyperlipidemia. It appears that sleep apnea aggravates the factors that cause coronary vascular disorders, and is involved in the onset of IHD.

Comorbidity↗

[Primary Sjögren's syndrome with pulmonary hypertension].

A 50-year-old woman was admitted to our hospital because of dyspnea on exertion. A chest X-ray film showed cardiomegaly and echocardiography revealed right-heart overload. Right heart catheterization studies revealed pulmonary hypertension and no signs of pulmonary embolism or vasculitis. The patient had complained of Raynaud's phenomenon since 6 years before admission. She did not notice eye or mouth dryness, but examination of a lip-biopsy specimen showed infiltration of lymphocytes into the salivary glands. Laboratory findings showed hypergammaglobulinemia and hemolytic anemia. Primary Sjögren's syndrome with pulmonary hypertension was diagnosed. Her general condition improved with steroid pulse therapy followed by oral administration of corticosteroids and cyclophosphamide.

Anemia, Hemolytic↗

Pemphigus vulgaris associated with transient acanthosis nigricans like lesion.

A patient with pemphigus vulgaris was treated with predonisolone and cyclosporin. At the sites of healing erosions, hyperkeratotic, hyperpigmented plaques developed; they were clinically and histologically similar to acanthosis nigricans. These lesions regressed after a few months. This case and others described in the literature suggest that such dermatoses might be caused by immunologically as well as mechanically mediated epidermal injury.

Acanthosis Nigricans↗

Differences in refractory-period response of canine subendocardium and subepicardium to bunazosin, an alpha1-adrenoceptor antagonist, and propranolol during myocardial ischemia.

Our objective was to investigate the effects of alpha1- or beta-adrenoceptor blockers on endocardial and epicardial refractory-period changes during myocardial ischemia in alpha-chloralose-anesthetized dogs. The first and second diagonal branches of the left anterior descending coronary artery were ligated. The refractory period was determined by an S1-S2 extrastimulus method. Dogs were treated with the alpha1-blocker bunazosin (0.1-0.2 mg/kg, i.v.; n = 16), the beta-blocker propranolol (0.2 mg/kg, i.v.; n = 15), or saline (n = 11). Dogs that developed ventricular tachycardia/fibrillation (VT/VF) during the experiment were excluded from the statistical assessment in refractory periods. In all groups, coronary ligation produced a significant shortening of the refractory period of ischemic epicardial tissue (p < 0.05) but only minimal shortening of ischemic endocardial refractory periods, resulting in an increased difference in repolarization time between the endo- and epicardial sites. Treatment with bunazosin ameliorated this ischemia-related shortening of refractory periods at both the endo- and epicardial sites, with a greater effect seen epicardially (p < 0.05), resulting in values similar to those in the nonischemic tissue. Treatment with propranolol prolonged refractory periods more in the epicardial (p < 0.01) than in endocardial sites, exacerbating the disparity in the refractory period between the endo- and epicardial sites (p < 0.05). Propranolol also prolonged the refractory period of nonischemic tissue (p < 0.05 and p < 0.01 in endo- and epicardial sites, respectively), resulting in a significant difference between the ischemic and normal myocardium at the endocardial site (p < 0.05). Results suggest that the alpha1-blocker bunazosin reduces the refractory-period disparity between the ischemic and normal myocardium without increasing the disparity between the endo- and epicardial surfaces, whereas propranolol produces a greater disparity.

Adrenergic alpha-1 Receptor Antagonists↗

[Study on coagulation fibrinolytic systems in predialysis patients with chronic renal failure--comparison between patients with chronic glomerulonephritis and patients with diabetic nephropathy].

To clarify the abnormalities of coagulation and fibrinolytic systems on predialysis patients with chronic renal failure, we measured indices of coagulation and fibrinolytic systems in 33 predialysis patients whose creatinine (Cr) levels were over 3.0 mg/dl. We termed twenty-four patients with chronic glomerulonephritis the "CGN group". We also termed nine patients wit diabetes mellitus the "DM group". We measured thrombin.antithrombin III complex (TAT), alpha 2-plasmin inhibitor plasmin complex (PIC), D-dimer, protein C, protein S, thrombomodulin (TM), vitronectin, tissue plasminogen activator.plasminogen activator inhibitor-1 complex (tPAI-C) in theses two groups. Furthermore, we measured the same indices after 6 months in the CGN group. As a result, the plasma levels of both TAT, PIC, TM/Cr ration in the DM group were significantly higher that those in the CGN group, changes in both protein S activities and plasma levels of tPAI-C were reduced significantly after 6 months. In conclusion, the abnormalities of coagulation and fibrinolytic systems in predialysis diabetic patients were stronger than those in predialysis patients with CGN. Furthermore, these abnormalities were worsened after 6 months in predialysis patients with chronic renal failure.

Adult↗

Sexual orientation in Drosophila is altered by the satori mutation in the sex-determination gene fruitless that encodes a zinc finger protein with a BTB domain.

We have isolated a new Drosophila mutant, satori (sat), the males of which do not court or copulate with female flies. The sat mutation comaps with fruitless (fru) at 91B and does not rescue the bisexual phenotype of fru, indicating that sat is allelic to fru (fru(sat)). The fru(sat) adult males lack a male-specific muscle, the muscle of Lawrence, as do adult males with other fru alleles. Molecular cloning and analyses of the genomic and complementary DNAs indicated that transcription of the fru locus yields several different transcripts. The sequence of fru cDNA clones revealed a long open reading frame that potentially encodes a putative transcription regulator with a BTB domain and two zinc finger motifs. In the 5' noncoding region, three putative transformer binding sites were identified in the female transcript but not in male transcripts. The fru gene is expressed in a population of brain cells, including those in the antennal lobe, that have been suggested to be involved in determination of male sexual orientation. We suggest that fru functions downstream of tra in the sex-determination cascade in some neural cells and that inappropriate sexual development of these cells in the fru mutants results in altered sexual orientation of the fly.

Alleles↗

Leiomyoma of the lesser omentum: report of a case.

The case of a 67-year-old Japanese woman with leiomyoma arising from the lesser omentum is reported herein. Although the patient had no abdominal symptoms, findings of a routine abdominal ultrasound examination suggested a mass between the stomach and the lateral segment of the liver. Subsequent magnetic resonance imaging (MRI) demonstrated a 6-cm well-encapsulated tumor in the lesser omentum, and this was confirmed intraoperatively. Resection of the tumor was performed without any other procedure and the histological diagnosis was confirmed as leiomyoma. The patient has been well for the 6 months since her operation. To our knowledge, this is the first report in the English literature of leiomyoma arising from the lesser omentum.

Aged↗

Hepatocyte growth factor in nephronophthisis-medullary cystic disease complex.

A 13-year-old Japanese girl presented with severe anemia and renal dysfunction. The nephronophthisis-medullary cystic disease complex was diagnosed from the results of renal biopsy and a family study. Immunohistochemical detection of hepatocyte growth factor in the epithelial cells of dilated renal tubules suggested that it may have a role in the development of the tubular cystic changes which are characteristic of this disease.

Adolescent↗