Search PubMed⌕ Search

Biomedical subjects

H Yamabe

Publications and source records attributed to H Yamabe.

287 records · Page 16Linked to original sources
PubMed1974

Effects of dietary sodium and of acute saline infusion on the interrelationship between dopamine excretion and adrenergic activity in man.

The effects of dietary sodium and of saline infusion on urinary dopamine and norepinephrine and on the relationship of these catecholamines to adrenergic activity were determined. In seven normal subjects on a 9-meq sodium intake, urinary dopamine and norepinephrine were 136+/-18 (SE) and 37.4+/-5.3 mug/day, respectively. When sodium intake was increased to 209 or 259 meq/day, urinary dopamine increased to 195+/-20 mug/day (P<0.01) whereas urinary norepinephrine decreased to 21.1+/-3.0 mug/day (P<0.01). Infusion of saline in seven subjects increased sodium excretion and urinary dopamine (from 2.18+/-0.22 to 2.79+/-0.19 mug/20 min, P<0.01), but decreased plasma dopamine-beta-hydroxylase by 33% and urinary norepinephrine insignificantly. The clearance of inulin and p-aminohippurate did not change significantly and filtration fraction was the same. The data indicate that an increase in dietary sodium or infusion of saline results in an apparent decrease in adrenergic activity and an increase in urinary dopamine. Dopamine excretion would thus appear to relate inversely to adrenergic activity and to parallel sodium excretion. These findings suggest a possible role for dopamine and norepinephrine in the regulation of renal sodium excretion.

Adult↗
PubMedDate not supplied

Effect of L-arginine administration on myocardial thallium-201 perfusion during exercise in patients with angina pectoris and normal coronary angiograms.

OBJECTIVES: We tested the hypothesis that an exogenous supplement of L-arginine could alleviate coronary perfusion abnormality during exercise in patients with angina pectoris and normal coronary arteries. METHODS AND RESULTS: Twelve patients underwent exercise thallium-201 scintigraphy without medication (control) and after intravenous administration of L-arginine. Exercise time was prolonged in the L-arginine study compared with the control (482 s vs 540 s, P < .05). TI-201 extent score was improved in the L-arginine study (0.33 vs 0.26, P < .05), and the severity score was also improved (23.7 vs 16.9, P < .05). In 7 of the 12 patients whose TI-201 redistribution disappeared in the L-arginine study, the percent increase in serum L-citrulline concentration during exercise was larger than that of the remaining 5 patients (18% vs 0.9%, P < .01). The percent reduction in epicardial coronary diameter in response to acetylcholine was also greater in the former group (28.3% vs 11.1%, P < .05). CONCLUSION: Exogenous L-arginine improved myocardial perfusion during exercise in a subset of patients with angina pectoris and normal coronary arteries, probably by increasing production of nitric oxide.

Acetylcholine↗
PubMedDate not supplied

Yolk sac tumor of the ovary: radiologic-pathologic correlation in four cases.

We report the radiologic and pathologic features of yolk sac tumor (endodermal sinus tumor) of the ovary in four patients. Yolk sac tumors were shown as well-enhancing solid tumors on both CT and MR studies and were associated with prominent signal voids on MRI. A hypervascular nature was confirmed on microscopic studies. Areas of hemorrhage were another common characteristic. These imaging findings seem to have an important implication for the diagnosis of this tumor.

Adolescent↗
PubMedDate not supplied

Immunohistochemical studies on the localization of cancer associated antigens DU-PAN-2 and CA19-9 in carcinomas of the digestive tract.

The immunohistochemical localization of DU-PAN-2 antigen and CA19-9 antigen in carcinomas of the digestive tract was studied using an immunoperoxidase technique. Staining for DU-PAN-2 antigen and CA19-9 antigen was observed in 104 (79%) and 96 (73%) of 131 carcinomas of the digestive tract, respectively. Diffuse staining (more than 20% of carcinoma cell stained) for DU-PAN-2 was detected in 14 of 21 (67%) pancreatic carcinomas and 11 of 19 (58%) carcinomas of the biliary tract (including cholangiocarcinoma). Diffuse staining for CA19-9 was detected in 15 (71%) of pancreatic carcinomas and nine (47%) of the carcinomas of the biliary tract. In colon carcinomas, no diffuse staining for DU-PAN-2 was observed, whereas diffuse staining for CA19-9 was found in 41%. There was a positive correlation between the differentiation degree (or grade) of the adenocarcinomas of the colon and the expression of CA19-9, but not that of DU-PAN-2. These immunohistochemical studies showed that DU-PAN-2 antigen is expressed diffusely in most cases of adenocarcinoma of the pancreas and biliary tract and is more specific for adenocarcinomas of the pancreas and biliary tract than CA19-9.

Adenocarcinoma↗
PubMedDate not supplied

Regulation of tissue plasminogen activator production in cultured human fetal mesangial cells.

Glomerular fibrin deposition is thought to be one of the factors causing progressive glomerular injury and may be related to defective intraglomerular fibrinolysis. Recently, it was shown that tissue plasminogen activator (t-PA) is produced by mesangial cells and is associated with degradation of the extracellular matrix. This study was designed to clarify the factors regulating t-PA production in human mesangial cells. The levels of t-PA activity, t-PA antigen and t-PA inhibitor-1 (PAI-1) antigen were estimated in the supernatants of cultured human fetal mesangial cells incubated for 72 h with thrombin, IL-Ibeta, IL-6, IL-10, and transforming growth factor-beta (TGF-beta). The t-PA activity was measured by an amidolytic assay, and the levels of t-PA antigen and PAI-1 antigen were also measured by enzyme-linked immunosorbent assay. Thrombin increased t-PA activity and TGF-beta decreased it in parallel with t-PA antigen level, although these agents did not affect the synthesis of PAI-1. Incubation with IL-1beta, IL-6 and IL-10 did not change the t-PA activity. It was concluded that the release of t-PA from human fetal mesangial cells was stimulated by thrombin and inhibited by TGF-beta in parallel with that of t-PA antigen. These factors may participate in the glomerular fibrin deposition and the accumulation of extracellular matrix.

Cells, Cultured↗
PubMedDate not supplied

The role of oxygen extraction in peripheral tissues in exercise capacity in chronic heart failure.

To elucidate the role of oxygen extraction during exercise in chronic heart failure (CHF), 26 patients underwent the symptom-limited maximal exercise. Hemodynamics, oxygen uptake (VO2) and blood gas were examined during exercise. Group I (n = 16, VO2max less than 20 ml/min/kg) showed severe cardiac dysfunction during exercise compared with group II (n = 10, VO2max greater than or equal to 20 ml/min/kg). Though VO2 was similar in both groups at rest and with a 25-watt load, oxygen extraction was significantly higher in group I than in group II. At the maximal work load, VO2max was significantly lower in group I, whereas there was no significant difference in oxygen extraction between the two groups. With a 25-watt load, mixed venous partial oxygen tension was similar, however, oxygen saturation was significantly lower in group I. It was concluded that oxygen extraction during exercise rapidly increased in group I, and this may play an important role in the maintenance of exercise capacity during mild physical activity in CHF.

Adult↗
PubMedDate not supplied

Follicular center cell lymphoma of childhood in Japan.

Following a histologic review of 108 patients with childhood lymphoma from 20 hospitals in the Osaka, Hyogo, Nara, and Kyoto prefectures of Japan during the period 1964-1989, 16 cases (15%) were classified as follicular center cell (FCC) lymphomas. None had a follicular pattern of proliferation. The age range was from 2 to 15 years (median 10) with no peak incidence. The male/female ratio was 1.3:1. Presentation was nodal in 10 patients and extranodal in 6. Chronic infection and other predisposing factors for the development of FCC lymphomas in childhood are discussed, with a review of the literature.

Adolescent↗
PubMedDate not supplied

Production of monocyte chemoattractant protein-1 by cultured glomerular epithelial cells: inhibition by dexamethasone.

Glomerular epithelial cells (GECs) have been shown to be one class of target cells in immunological and nonimmunological glomerular injury of glomerulonephritis, some cases of which are accompanied by infiltration of glomeruli by monocytes/macrophages. In this study we tested whether GECs in culture produce monocyte chemoattractant protein-1 (MCP-1), a potential molecule responsible for monocyte recruitment in inflammation, and whether the production is inhibited by glucocorticoid. GECs were obtained from outgrowth of rat glomeruli. Levels of MCP-1 mRNA and protein were determined by Northern blot analysis and ELISA, respectively. Northern blot analysis revealed the expression of MCP-1 mRNA in cytokine-treated GECs. The expression of MCP-1 mRNA was inhibited by dexamethasone. Quantitative analysis by ELISA confirmed the production of MCP-1 protein by GECs and the inhibitory effect of dexamethasone. These results indicate that cytokine-treated GECs produce and secrete MCP-1 and that the MCP-1 production is inhibited by dexamethasone. We suggest that MCP-1 produced by GECs may play a role in the recruitment of monocytes/macrophages in glomerulonephritis and that the therapeutic effect glucocorticoid on the disease might include the inhibition of the production of MCP-1.

Animals↗