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Biomedical subjects

J Watanabe

Publications and source records attributed to J Watanabe.

At least 487 records · Page 27Linked to original sources

Glucose 6-phosphatase activity in pregnant and lactating mammary glands of the mouse.

Glucose 6-phosphatase activity was studied in the secretory epithelial cell and other cell types composing alveoli of the mammary gland (cytochemical study) and in the whole mammary gland (biochemical study) of pregnant and lactating mice. The reaction product for the enzyme activity was seen in the endoplasmic reticulum and nuclear envelope in secretory epithelial cells from all animals examined (days 7 and 14 of pregnancy, and days 0, 3, 10, and 20 of lactation. The amounts of the reaction product appeared scarce at day 7 of pregnancy, moderate at day 14 of pregnancy and day 0 of lactation, and abundant at days 3 and 10 of lactation. The reaction product, however, became generally scarce at day 20 of lactation. Biochemical activity was relatively low at days 7 and 14 of pregnancy and days 0 and 20 of lactation, while it was high at days 3 and 10 of lactation. The increased activity is probably related to functions of secretory epithelial cells in the lactating gland.

Animals↗

Significance of the increase in glucose 6-phosphatase activity in skeletal muscle cells of the mouse by starvation.

The effects of starvation on glucose 6-phosphatase (G6Pase; EC 3.1.3.9., D-glucose 6-phosphate phosphohydrolase) and glycogen phosphorylase (EC 2.4.1.1.) activities, and on glycogen content, were studied in skeletal muscles (m. rectus femoris) of mice. In the muscle cells from fed animals, the cytochemical reaction product for G6Pase activity was observed in moderate amounts in the terminal cisternae of sarcoplasmic reticulum and in small amounts in the nuclear envelope, and was rare or absent in the intermyofibrillar sarcoplasmic reticulum. After 4 days of starvation, however, the reaction product became abundant in all of the terminal cisternae, intermyofibrillar sarcoplasmic reticulum, and nuclear envelope. Biochemical G6Pase and glycogen phosphorylase a (active form) activities were higher in the muscles of starved mice than in those of fed animals. The glycogen content decreased markedly in the muscles of starved mice. The results suggest that the role of the increased G6Pase in skeletal muscle cells of starved mice is to release glucose into the blood by hydrolyzing glucose 6-phosphate produced through the increased phosphorylase activity.

Animals↗

Plasma fibronectin and platelet aggregation in diabetes mellitus.

Plasma fibronectin (FN) is a high-molecular weight glycoprotein produced by endothelial cells, fibroblasts, and other mesenchymal cells. Plasma FN levels were measured in non-insulin-dependent diabetics (NIDDM) (n = 42) and compared with age-matched control subjects (n = 20). Plasma FN levels were significantly higher in the NIDDM patients (44.2 +/- 2.2 mg/dl, mean +/- SE) than in the control subjects (31.2 +/- 2.2 mg/dl). In addition, the rate of platelet aggregation was studied in 23 of the 42 NIDDM patients. Interestingly, the plasma FN levels were significantly elevated, particularly in diabetic patients with enhanced platelet aggregation. It is suggested that elevated plasma FN may be closely related to the abnormality of platelet function in diabetics, which leads to diabetic vascular lesions.

Adult↗

Electronystagmographic assessment of cerebellar lesions.

Remarkable progress has been achieved in the neurophysiological study of the cerebellum. Based on these neurophysiological data, electronystagmographic (ENG) assessment of cerebellar lesions was made to ascertain to what extent cerebellar lesions could be diagnosed. In 13 patients out of 17 whose lesions were mainly localized on one side through CT, cerebellar lesions could be diagnosed by electronystagmographic findings. In the 1 patient with amyotrophic lateral sclerosis of the remaining 4, asymptomatic cerebellar infarction was detected unexpectedly through CT. In the remaining 3 patients, differential diagnosis from brainstem lesions was difficult to evaluate on the basis of ENG findings. In 13 patients showing cerebellar signs and symptoms, pursuit eye movements, optokinetic nystagmus (OKN), and fixation-suppression of caloric nystagmus were impaired on both sides, suggesting large mass effects upon the bilateral brainstem. However, either rebound nystagmus or opposing positioning nystagmus characteristic of cerebellar lesions was detected in 13 patients (81%). The same was true in patients with bilateral cerebellar lesions. ENG test, however, could not detect any patients who showed neither cerebellar signs nor symptoms. Further investigations are needed to supplement the gap between basic and clinical research.

Cerebellar Diseases↗

Reduced serum-stimulatory activity on prostacyclin production by cultured aortic endothelial cells in diabetes mellitus.

Reduced prostacyclin (PGI2) production by the vascular wall has been proposed as a possible cause of macro- or microangiopathy in diabetes mellitus. In the present study, we confirmed the stimulatory activity on PGI2 (PSA) production in plasma-derived serum (PDS) by cultured aortic endothelial cells. Furthermore, the abnormality of PSA was examined in diabetic PDS. PSA in PDS from non-insulin-dependent diabetics significantly decreased as compared with that in PDS from age-matched control subjects. There was no difference in PSA in PDS between diabetic patients with and without vascular complications such as retinopathy and nephropathy. In addition, after treatment with dialysis, PSA in diabetic PDS was still not restored to that in normal PDS. These findings suggest that relatively heat-stable (56 degrees C, 30 min) and nondialyzable PGI2 stimulatory substance(s) may decrease in diabetic PDS. It is concluded that a reduction in PDS-stimulated PGI2 production by the vascular wall can play an important role in the pathogenesis of vascular lesions in diabetes mellitus.

6-Ketoprostaglandin F1 alpha↗

High and testosterone-dependent glucose 6-phosphatase activity in epithelium of mouse seminal vesicle.

For study of the mechanism of seminal fructogenesis, glucose 6-phosphatase activity was examined cytochemically (a method modified from that of Wachstein and Meisel) and biochemically (the method of Leskes et al.) in seminal vesicles from normal, castrated, and castrated and testosterone-treated mice. The reaction product for the activity was localized in the endoplasmic reticulum and nuclear envelope of all cell types composing the seminal vesicle. In normal seminal vesicle, the reaction product was apparently more abundant in columnar and basal cells than in other cell types. Ten, 20, and 30 days after castration, the abundant amount of reaction product in columnar and basal cells decreased to the level in other cell types. In animals treated with testosterone after castration, however, the reaction product in columnar and basal cells remained abundant. If fructose 6-phosphate was added to the reaction medium in place of glucose 6-phosphate, the amount and pattern of deposition of the reaction product did not change. Changes in biochemical activity in castrated or castrated and testosterone-treated animals paralleled the cytochemical results. The results show that the high activity in columnar and basal cells is under the control of testosterone, and the role of this enzyme is probably to release fructose into the seminal fluid.

Animals↗

Role of mandibular striated duct in salivary excretion of urea in dogs.

The role of mandibular striated duct in salivary excretion of endogenous urea was studied by a technique of retrograde ductal injection of HgCl2 and a stop flow analysis. (1) It was verified in this study that treatment with HgCl2 markedly inhibited Na+ reabsorption in the striated duct so that water reabsorption driven by the Na+ reabsorption would be inhibited substantially. (2) The saliva/plasma concentration ratios (S/P ratios) of urea in HgCl2-treated saliva (about 0.71) were significantly higher than those in untreated saliva (about 0.37). (3) The excretion rate of urea in HgCl2-treated saliva (about 0.02 mg/min/kg) was also significantly higher than those in untreated saliva (about 0.01 mg/min/kg) despite the same flow rate for both saliva samples. Furthermore, (4) The S/P ratios of urea in the second (0.25-0.50 ml) poststop-flow saliva (about 0.65) were significantly higher than those in prestop-flow saliva (about 0.35). These results suggest a possibility that salivary urea is reabsorbed in the dog mandibular striated duct and that the enhancement of the S/P ratio as well as the salivary level of urea by the pre-treatment with HgCl2 may be due to the inhibition of urea reabsorption.

Animals↗

Effects of preload alteration on the degree of ischemia and function of ischemic myocardium under constant mean aortic pressure, coronary perfusion pressure and heart rate in isolated perfused canine heart.

We examined the effects of preload alteration on global and regional (i.e., non-ischemic and ischemic areas) function in the presence of regional myocardial ischemia and on the degree of ischemia using 18 isolated, metabolically supported canine left ventricles. For this purpose, cardiac output (CO), systolic segment length change (SL), myocardial CO2 tension (PmCO2) and ST level of epicardial ECG were measured at 3 levels of left ventricular end-diastolic pressure (LVEDP), i.e., approximately 7 (low LVEDP), 11 (middle LVEDP), and 16 mmHg (high LVEDP) without and with left circumflex artery (LCx) stenosis under a constant mean aortic pressure (90 mmHg), mean coronary perfusion pressure (90 mmHg) and heart rate. In the Pre-ischemic stage, CO and SL increased significantly when LVEDP was elevated in a stepwise fashion by changing the height of the reservoir connected to the left atrium. There were no significant changes in PmCO2 or ST level. On the other hand, with LCx stenosis, CO did not show a subsequent increase at higher LVEDPs (i.e., from 796 +/- 103 ml/min at middle LVEDP to 931 +/- 153 ml/min at high LVEDP). Furthermore, there was no significant SL response in the LCx area following alterations of LVEDP, although there was considerable lengthening of end-diastolic length. Both increased PmCO2 and ST level of the LCx area, following LCx stenosis, further increased significantly with elevation of LVEDP. These results suggest the possibility that considerable elevation of LVEDP worsens the degree of ischemia and does not significantly augment ischemic regional myocardial function or global function, while mild elevation of preload improves or tends to improve simultaneously regional ischemic and global functions without aggravating the ischemic injury significantly. Therefore, we conclude that the preload level is quite important in managing ischemia induced myocardial dysfunction.

Animals↗

The changes in ECG ST segment and mechanical function of regional ischemic myocardium during afterload reduction in isolated dog hearts with coronary stenosis.

By measuring ECG ST segment deviation and regional mechanical dysfunction, we assessed the effects of an alteration in afterload pressure on regional myocardial ischemia due to a partial coronary occlusion of the left circumflex coronary artery (CFX). Eight isolated, perfused and paced dog hearts were loaded with an artificial arterial system which simulated the aortic input impedance of the dog arterial tree. Afterload pressure was altered by stepwise changes in peripheral resistance (Rp), while left ventricular end-diastolic pressure (LVEDP) and heart rate were kept constant. Coronary perfusion pressure (CPP) was kept equal to mean aortic pressure (AoP). ECG and myocardial systolic segment shortening (SS) were measured in both areas perfused by the CFX and the left anterior descending coronary artery (LAD). In the presence of CFX stenosis, mean AoP decreased from 96 +/- 7 to 46 +/- 7 mmHg following a decrease in Rp and cardiac output increased progressively from 465 +/- 30 to 1055 +/- 100 ml/min. In this situation, CFX coronary blood flow decreased from 75 +/- 2 to 28 +/- 6 ml/100 g/min. Epicardial ECG in the ischemic region showed two types of ST segment deviation after CFX stenosis: ST segment elevation and ST segment depression. Moreover, following afterload reduction, these individual ECG ST segment changes showed further deviations. The levels of mean AoP, below which further ST segment deviations significantly occurred, were as follows: 71 +/- 6 mmHg in ST segment elevation cases and 52 +/- 7 mmHg in ST segment depression cases. Myocardial systolic segment shortening in the ischemic region also significantly decreased following CFX stenosis (91 +/- 8% of pre-ischemic control, p less than 0.05). Then, during afterload reduction, SS in the CFX area appeared to be bimodal and it definitely decreased when mean AoP was 46 +/- 7 mmHg. To enhance the sensitivity of detection of further mechanical dysfunction throughout afterload reduction following regional myocardial ischemia, we calculated percentage values of the SS in the CFX area to the SS in the LAD area at each Rp. By this normalization, mechanical dysfunction was found when mean AoP was below 67 +/- 5 mmHg. These results suggest that reduction in afterload pressure below a certain level aggravated the regional ischemia, despite an increase in cardiac output, and to detect this change in the ischemic region during afterload reduction, ECG ST segment deviation seems to be a useful indicator.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Effects of major coronary artery stenosis on the pressure-flow relationship of an adjacent intact coronary artery branch in isolated supported canine left ventricle.

We investigated whether the relationship between the mean left anterior descending and septal coronary blood flow and the mean perfusion pressure varies with left circumflex coronary stenosis. We used excised, perfused canine heart preparations (n = 10), in which variables to influence the myocardial oxygen demand and supply relation can be fairly well controlled. The results showed that coronary blood flow in the adjacent, non-stenosed coronary artery increased significantly following LCX stenosis; this increased flow was found at the same values of heart rate, left ventricular end-diastolic pressure and perfusion pressure, as those in the preischemic state. Moreover, this increased flow was also observed when the values of peak left ventricular pressure and pressure-length loop area were similar between the pre-ischemic and ischemic states. Thus, contributions of neurohumoral factors or alterations in mechanical factors determining the myocardial oxygen demand and supply relation are negligible. This increased flow may be important in maintaining overall cardiac function in cases of acute coronary stenosis or coronary occlusion.

Animals↗

[Detection of pyloric Campylobacter in patients with gastroduodenal diseases].

We report a study of 127 patients examined with esophago-gastroduodenoscopy and with a diagnosis of chronic gastritis (by biopsy), and gastric peptic ulcer and duodenal peptic ulcer (endoscopically). Brushing samples and biopsies were taken from the esophagus, stomach, and duodenum. Gram stains of brush-collected samples, culture of brush samples and biopsies were performed in order to detect the presence of PC. In cases of chronic active gastritis, PC was found in 91% of patients. It was found in 73% and 84%, respectively, of cases of gastric and duodenal ulcer. PC was found with equal frequency in the cardia and body as in the antrum of infected individuals, but no confirmed cases of colonization of the esophagus or duodenum were found. The most efficient methods for identifying PC colonization were (in descending order of efficiency), silver stain of biopsies, Gram stain of brushings, hematoxylin-eosin stain of biopsies, culture of biopsies, and culture of brushings. In some cases, we have identified PC in the esophagus and duodenum by gram stain and culture, but no not by silver stain or H&E stain of biopsies, suggesting that contamination from other areas of the stomach may be an occasional problem in sampling these areas for PC.

Adolescent↗

[Transcatheter embolization in the management of pain from metastatic uroepithelial cancer].

Arterial embolization was performed for the relief of pain in 4 patients with symptomatic osseous metastases associated with extensive soft tissue tumors. Two patients had metastatic transitional cell carcinoma of the bladder and renal pelvis, and 2 had metastatic renal cell carcinoma. Three of the 4 patients experienced significant relief of pain and improved performance status. Decrease of tumor size or healing of osteolytic metastasis did not occur. Errant embolization occurred in one patient but did not become a serious problem. In 3 patients post-infarction pain occurred, but subsided within 36 hours. This therapeutic approach may be useful to control the pain associated with a massive advanced uroepithelial cancer.

Aged↗

Human myeloid leukemia cells metabolize 25-hydroxyvitamin D3 in vitro.

Human promyelocytic leukemia cells (HL-60) converted 25-hydroxyvitamin D3 to two more polar metabolites during in vitro incubations. A two-step high pressure liquid chromatography system revealed two unique elution positions of those leukemic cell-derived metabolites that exactly co-migrated with the elution positions of 5(Z)-19-nor-10-oxo-25-hydroxyvitamin D3 and 5(E)-19-nor-10-oxo-25-hydroxyvitamin D3, respectively. These unique metabolites did not bind specifically to a protein receptor for 1,25-dihydroxyvitamin D3.

Animals↗