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Biomedical subjects

T Omae

Publications and source records attributed to T Omae.

At least 181 records · Page 10Linked to original sources
PubMed1987

Effect of angiotensin converting enzyme inhibitor (captopril) on cerebral blood flow in hypertensive patients without a history of stroke.

The effect of the angiotensin converting enzyme inhibitor, captopril, on cerebral blood flow (CBF) was studied in 11 hypertensives without a history of stroke. Mean hemispheric CBF (mCBF) was measured in each patient by Xe-133 inhalation method before and after 7 days of captopril administration. Blood pressure (BP) both in the control state and at the time of CBF measurement decreased significantly after drug administration. mCBF, however, did not show any significant change. When percent changes in mCBF before and after the administration were plotted against those of mean arterial BP, significant inverse correlations were obtained in both hemispheres; the larger the BP decrease, the more increase in CBF was observed. It is concluded that captopril lowers systemic BP without concomitant decrease in CBF in hypertensive subjects with no history of stroke. Furthermore, the results suggest that captopril may have a vasodilating action on cerebral blood vessels.

Adult↗
PubMed1987

Side effects and metabolic effects of converting enzyme inhibitors.

Captopril Research Group of Japan made an evaluation of clinical usefulness of captopril in the treatment of mild to moderate essential hypertension. A relatively low frequency of side effects manifested as clinical symptoms was observed when the daily dose of captopril used was 37.5-112.5 mg. Antihypertensive effect was well maintained in this dose range. Follow-up surveillance of captopril also confirmed this. Abnormalities in blood chemistry were also found to be very less frequent. Untoward metabolic effects of ACE inhibitors such as alteration of serum electrolytes, lipid profiles or glucose metabolism were reported to be minimal or not actually observed. Side effects and untoward metabolic effects may appear more frequently when the same dose was given in patients with renal impairment. ACE inhibitors can be used as the first choice of drugs in the treatment of essential hypertension with no renal function impairment.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1987

A sensitive method for precise measurement of endogenous angiotensins I, II&III in human plasma.

We measured endogenous angiotensins (ANGs) I, II&III using a system of extraction by Sep-Pak column followed by high performance liquid chromatography (HPLC) combined with radioimmunoassay (RIA). An excellent separation of ANGs was obtained by HPLC. The recovery of ANGs I, II&III was 80-84%, when these authentic peptides were added to 6 ml of plasma. The coefficient of variation of the ANGs was 0.04-0.09 for intra-assay and 0.08-0.13 for inter-assay, thereby indicating a good reproducibility. Plasma ANGs I, II&III measured by this method in 5 normal volunteers were 51,4.5 and 1.2 pg/ml. In the presence of captopril, ANGs II&III decreased by 84% and 77%, respectively, while ANG I increased 5.1 times. This method is therefore useful to assess the precise levels of plasma ANGs.

Angiotensin I↗
PubMed1987

Physiological and biochemical changes in ageing--based on a population survey in a Japanese community, Hisayama.

Biophysical and biochemical characteristics of the aged were studied in a general population sample of 1,621, 2,008 or 2,146 Hisayama residents aged 40 or over, which were screened at 1961, 1973-74 or 1983, respectively. In addition, 769 consecutive autopsy-cases of the Hisayama residents were examined to elucidate age-related reduction in weight of various organs. Body-mass index for both sexes decreased with advancing age-decade, and this trend was more prominent for males. A slight acceleration in the biennial changes in body-mass index for males was found during the fifth decade of life and a slight attenuation during the seventh decade, although the magnitude of the change is small. Reduction in weight of brain, liver or kidneys of the autopsied cases aged 30 or over, was in progress with a decade of increasing age. Both systolic and diastolic blood pressures rose with increasing age until the 7th decade. Thereafter, systolic pressure continued to rise while diastolic pressure began to drop in advanced age for both sexes. A standard deviation of average systolic pressure in both borderline cases and normotensives became larger along the time-course in the aged. This variation is probably due to the difference in age-related changing pattern of systolic pressure each by each, particularly in borderline hypertensives. Changes in blood chemical constituents by age-decade varied according to sex, namely, each constituent had its own pattern of ageing by sex. Based on the results from the present study, basic morphology or physiology related to ageing was discussed.

Adult↗
PubMed1987

Circaseptan rhythm in sodium and potassium excretion in salt-sensitive and salt-resistant Dahl rats.

Six salt-sensitive (S) and six salt-resistant (R) male Dahl rats were housed in metabolic cages under LD 12:12 (L 0600-1800). High-salt (8%) and low-salt (0.4%) diets were available to half the S and R rats, respectively for 4 hr during a 24-hr span (feeding 1800-2200). Urine was collected at 4-hr intervals for 30 days. Sodium and potassium were determined by ion-specific electrode. Apart from circadian rhythmicity, a circaseptan rhythm in sodium and potassium excretion came to the fore in the rats on the high-salt diet only, with a phase difference of about 180 degrees between sodium and potassium. These rhythms were not detectable in the animals eating their usual-low salt diet. The ability to induce circaseptan variations in renal function may lend itself to the chronotherapeutic utilization of such cycles in achieving optimal therapeutic effects or minimizing undesirable side effects of different forms of treatment.

Animals↗
PubMed1986

Regulation of atrial natriuretic peptide receptors in cultured vascular smooth muscle cells of rat.

To elucidate the regulation of vascular receptors for atrial natriuretic peptide (ANP), we have studied the binding capacity of 125I-labeled rat (r) ANP using cultured vascular smooth muscle cells from rat aorta. After preincubation with 3.2 X 10(-8) M rANP at 37 degrees C, the binding capacity decreased as a function of time; the maximal receptor loss (70-75%) occurred after 4 hrs and persisted for 24 hrs. Pretreatment with cycloheximide (20 micrograms/ml) and actinomycin D (2 micrograms/ml) similarly caused a dramatic reduction (approximately 80%) of the binding capacity after 24 hrs; the half-life (t1/2) of the receptor loss was approximately 7-8 hrs. Following removal of rANP, the "down-regulated" ANP receptors fully recovered in the presence of 10% fetal calf serum, but not in combination with either actinomycin D or cycloheximide. Concanavalin A dose-dependently inhibited the binding. The binding capacity also decreased with time in the presence of tunicamycin (1 microgram/ml) with t1/2 of approximately 30 hrs. These data indicate that protein and carbohydrate moieties are essential for the functional integrity of the vascular receptor binding sites for ANP, and suggest that the recovery of the receptor loss by "down-regulation" requires concomitant RNA and protein synthesis.

Animals↗
PubMed1986

Circadian characteristics of urinary melatonin from clinically healthy young women at different civilization disease risks.

Rhythm characteristics in the about-daily (circadian) and about-yearly (circannual) frequency ranges were assessed for urinary melatonin. Clinically healthy women in Minnesota, USA, and Kyushu, Japan, were sampled around the clock once in 1-4 seasons. Possible differences that could reflect the large difference in breast cancer incidence in these two geographic locations were investigated. Each subject's risk of developing breast cancer, cardiovascular diseases resulting from an elevated blood pressure, and emotional conditions was numerically evaluated according to epidemiologic questionnaires. A prominent circadian rhythm characterizes urinary melatonin in both populations, peaking in the middle of the night. The American women exhibit a larger circadian rhythm-adjusted mean (mesor) than do the Japanese women. A circannual rhythm is also apparent in the North American women, but not in the Japanese women. The circadian mesor of urinary melatonin correlates negatively with the risk score of emotional depression and positively with that of developing cardiovascular diseases.

Adolescent↗
PubMed1986

Plasma atrial natriuretic polypeptide and polyuria during paroxysmal tachycardia in Wolff-Parkinson-White syndrome patients.

The human atrial natriuretic polypeptide (hANP) concentration in plasma was measured during paroxysmal supraventricular tachycardia provoked in 2 patients with Wolff-Parkinson-White syndrome. A 10- to 20-fold increase in plasma hANP concentration was observed during the tachycardia: from 12 to 291 pg/ml in 1 case and from 14 to 174 pg/ml in the other. Although polyuria was associated with the tachycardia, urinary sodium excretion as well as urinary osmolality were decreased. The urinary arginine vasopressin was appreciably decreased during the tachycardia. These results suggest that hANP released by paroxysmal tachycardia might not act as a natriuretic factor in this range of plasma concentration. Polyuria during paroxysmal tachycardia was attributed mainly to the inhibition of arginine vasopressin release.

Adult↗
PubMed1986

Controlled trial of combined urokinase and dextran sulfate therapy in patients with acute cerebral infarction.

In this multiinstitute cooperative study, 143 patients were treated with either urokinase (UK) or combination of urokinase and dextran sulfate (UK-DS) within one to seven days following acute onset of cerebral thrombotic infarction. Of these, 81 randomized cases received a single dose of UK (2.83 X 10(5) units) by six-hour intravenous drip infusion and the remaining 62 received a combined dose of UK (2.84 X 10(5) units) and DS (3000 mg) for only one day. Moderate to marked clinical improvements assessed during the seven-day study period were observed in 30.9% of the patients treated with UK and in 61.3% of those with UK-DS, the latter being significantly higher. Hemorrhagic phenomena appeared in 3.2% of the cases treated with UK-DS and in none of those with UK alone, but mortality was 1.6% in the former and 2.5% in the latter. UK-DS produced a prompt and sustained increase in plasma fibrinolytic activity with transient and relatively minor disturbance of the blood coagulation system. The results indicate that combined therapy with UK and DS is more effective than UK alone for acute cerebral thrombotic infarction.

Acute Disease↗
PubMed1986

Is renin secreted by exocytotic mechanism through mature renin granules from juxtaglomerular cells?

Mature renin granules were isolated by the combination of discontinuous and continuous Percoll density gradient centrifugation. Stored renin in the renin granules was found to consist of isoelectrically seven different forms. The seven different isoelectric points (pIs) were 5.6, 5.35, 5.2, 5.0, 4.8, 4.6 and 4.4. Approximately 70% of the stored renin as the total enzymatic activities from all isoelectric peaks was found in a peak which pI corresponded to be 5.35. Renin secreted from isolated glomeruli was also focused into seven peaks possessing identical values. However, the distribution pattern of renin peaks was quite different from that of stored renin. In the secreted renin, peaks of 5.35 (pI) and 5.2 (pI) showed high renin activity and each had approximately 30% of released renin as the total recovered. These results indicate multiple forms of renin are stored and secreted by rat kidney. As the distribution pattern of enzymatic activities in renin peaks between stored renin and secreted renin are different, it is probable that renin may not secreted through mature renin granules by exocytotic mechanism.

Animals↗
PubMed1986

Blood pressure and sympathetic nervous function in spontaneously hypertensive rats derived from breeders on low sodium diet.

We investigated the effect of dietary salt restriction in spontaneously hypertensive rat (SHR) breeders to determine if the development of hypertension of offspring would be blunted. Weaning SHRs (F-0) were divided into 3 groups and were given a diets containing sodium of 0.4% (G 1), 0.05% (G 2), or 0.4% plus mefruside 0.001% (G 3) with distilled water. Potassium content was 0.75% and the other ingredients except chloride were identical in all the diets. Offsprings (F-1) were derived from selective inbreeding within each group. Systolic blood pressure rose over 160 mmHg by 8 weeks of age in all the male rats of all the groups in both F-0 and F-1. There was no difference in blood pressure between G 1 and G 2 at any age, while in G 3 blood pressure was significantly lower than in G 1 at 12 and 20 weeks of age in F-1. The findings in pressure were ascertained by heart-body weight ratio determined at autopsy, which was similar between G 1 and G 2, and was smaller in G 3 than the others at 20 weeks of age. Aldostrone excretion rate was markedly higher in G 2 than G 1 and G 3 at all study points, whereas plasma renin content was similar between G 1 and G 2, and higher in G 3. Plasma concentrations of noradrenaline and adrenaline did not differ among the 3 groups at any age in both F-0 and F-1.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1986

Total body fluid volume determination based on urea kinetics in hemofiltration as an index of basal body weight in uremic patients.

Assuming that urea is distributed uniformly within the total body water, urea-space or total body fluid volume was determined in six uremic patients based on urea kinetics in hemofiltration. The total body fluid volume before hemofiltration was 36.0 +/- 3.6 L (61.8 +/- 2.6% BW) and after hemofiltration 32.5 +/- 3.4 L (59.3 +/- 2.8% BW), suggesting that the total body fluid volume was nearly normalized by hemofiltration. It is concluded that urea-space, easily measurable based on urea kinetics during hemofiltration, is useful in evaluating the fluid balance in patients undergoing artificial kidney therapy.

Blood↗
PubMed1985

Coronary atherosclerosis and antecedent risk factors: pathologic and epidemiologic study in Hisayama, Japan.

The pathologic and epidemiologic study of coronary atherosclerosis was performed on 281 autopsy subjects aged 40 years and older during the period between 1971 and 1981, in Hisayama, Kyushu Island, Japan. During this interval, the autopsy rate was about 80%. Grading of coronary atherosclerosis was made by the degree of luminal stenosis. Seven selected factors such as age, gender, mean arterial blood pressure, serum total cholesterol, body mass index, alcohol intake and cigarette smoking were all given attention. The severity of coronary atherosclerosis revealed age-related progression. Coronary atherosclerosis correlated positively with antecedent elevated blood pressure and with higher serum total cholesterol levels. In multivariate analysis, factors that significantly (p less than 0.05) and positively correlated with coronary atherosclerosis were age, mean arterial blood pressure, serum total cholesterol, gender and body mass index in this order. The overall contribution of 7 selected factors to coronary atherosclerosis was nearly 33.5% of the total variation by the analysis of multiple regression model.

Adult↗
PubMed1985

Adrenocorticosteroid therapy and gastroduodenal lesions.

Gastroduodenoscopy was performed in 25 patients with various disorders, such as liver cirrhosis, nephrotic syndrome, and ulcerative colitis, to assess the effects of corticosteroids on the stomach and duodenum. The main criterion for entry into the trial was the absence of open ulcer, healed ulcer, erosion, or bleeding from the stomach or duodenum on pretreatment endoscopy performed within 48 hours before administration of corticosteroids. Endoscopy repeated at 2 to 4 weeks disclosed gastroduodenal lesions in 11 cases (44%)and no lesion in 14 cases (56%). The gastroduodenal lesions observed in 11 cases are as follows: one gastric ulcer (4.0%), six gastric erosions (24.0%), two gastroduodenal erosions (8.0%), and two duodenal erosions (8.0%). A lack of correlation between the patients' subjective complaints and endoscopic findings indicates the unreliability of patients' complaints and the importance of endoscopy in assessing gastroduodenal lesions. There were no differences in the total and average daily doses of corticosteroid between a group with gastric and/ or duodenal lesions and a group without such lesions. Corticosteroids may produce gastroduodenal lesions, regardless of the dose.

Adolescent↗