PubMed Health⌕ Search

Biomedical subjects

S Takishita

Publications and source records attributed to S Takishita.

At least 19 recordsLinked to original sources

Angiotensin-converting enzyme (ACE) insertion/deletion polymorphism and survival in a cohort of chronic hemodialysis patients.

BACKGROUND: There are conflicting reports regarding the relationship between the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism and the initiation and progression of cardiovascular disease. Moreover, there is no report regarding the relationship between the ACE I/D polymorphism and the prognosis of chronic dialysis patients. METHODS: We examined the frequency of the ACE I/D polymorphism in 727 chronic hemodialysis patients in Okinawa, Japan, and observed the prognosis over 2 years in 407 men and 320 women with mean age (SD) of 55.5 (13.9) years with a mean duration of dialysis of 84.3 (66.6) months. RESULTS: Genotype frequencies were 42.1% for II, 43.2% for ID, and 14.7% for DD. The relative risks of death were examined by Cox-proportional hazards analysis after adjusting for age, sex, age at the start of dialysis, presence of diabetes mellitus and hypertension and total cholesterol and serum albumin levels. The adjusted hazard ratio (95% confidence interval) was 1.03 (0.38 - 2.85) for DD genotype and 1.50 (0.83 - 2.70) for DD+ID genotype when compared to II genotype. CONCLUSION: ACE I/D polymorphism appears to have no relation to the short-term prognosis in chronic hemodialysis patients.

Adult↗

Cause of residual hypertension after adrenalectomy in patients with primary aldosteronism.

The cause of residual hypertension after adrenalectomy for primary aldosteronism (PA) is unknown. The purpose of this study is to investigate the characteristic pathological kidney features associated with PA. Between 1977 and 1999 at our hospital, 26 patients with PA caused by a unilateral adrenal cortical adenoma (Conn's syndrome) underwent unilateral adrenalectomy with concurrent open-wedge renal biopsy. Patients were categorized into two groups: (1) those with normotension with diastolic blood pressure less than 90 mm Hg who were not administered antihypertensive drugs, and (2) those with residual hypertension with diastolic blood pressure of 90 mm Hg or greater who were administered medication for 6 months after surgery. Thirteen patients were cured of hypertension postoperatively, and 12 patients were administered antihypertensive medications. Glomerulosclerosis, renal arteriolosclerosis, and preoperative left ventricular mass (LVM) index were worse in the group with residual hypertension than in that with normotension (17.8% +/- 7.8% versus 9.6% +/- 3.8%; P = 0.01; 2.5 +/- 0.5 versus 1.6 +/- 0.4, Bader's grade; P = 0.005; and 165 +/- 31 versus 139 +/- 24 g/m(2); P = 0.02, respectively). Severity of tubulointerstitial injury, preoperative duration of hypertension, preoperative severity of proteinuria, plasma aldosterone level, and serum potassium concentration were not significantly different between the two groups. In conclusion, severity of glomerulosclerosis and arteriolosclerosis and LVM are related to blood pressure after adrenalectomy in patients with PA.

Adenoma↗

Molecular forms of plasma and urinary adrenomedullin in normal, essential hypertension and chronic renal failure.

OBJECTIVES: Human adrenomedullin precursor is converted to glycine-extended adrenomedullin (AM-Gly), an intermediate inactive form of adrenomedullin. Subsequently, AM-Gly is converted to active form of mature adrenomedullin (AM-m). The aim of the present study was to investigate (i) whether sex or age influences plasma and urinary AM-m and AM-Gly levels in normal subjects; (ii) the daytime variability of plasma AM-m and AM-Gly levels in normal subjects; (iii) AM-m and AM-Gly levels and its ratio in plasma and urine in normal subjects, individuals with essential hypertension (HT), and chronic renal failure (CRF); and (iv) the ratio of AM-m and AM-total (T) in plasma of various veins and aorta. METHODS: We measured plasma levels and urinary excretions of AM-m, AM-Gly and AM-T (AM-m + AM-Gly) by recently developed immunoradiometric assay in normal subjects (n = 81), HT (n = 28) and CRF (n = 30). We also determined the molecular forms of plasma adrenomedullin taken from various sites during angiography in patients with suspected renovascular hypertension (n = 9). RESULTS: There were no differences in plasma and urinary excretions of two molecular forms of adrenomedullin among sexes or ages in normal subjects. There was no daytime variation of plasma two molecular forms of adrenomedullin in normal subjects. Plasma AM-m, AM-Gly and AM-T levels were increased in patients with HT and CRF compared with normal subjects, whereas urinary AM-m, AM-Gly and AM-T excretions were decreased in patients with HT and CRF compared with normal subjects. Urinary AM-m: AM-T ratios were significantly higher than plasma AM-m: AM-T ratios. Plasma AM-m and AM-T levels taken from various veins were similar, and they were significantly higher than those of aorta, although there were no differences in plasma AM-Gly levels between aorta and veins. CONCLUSIONS: These results suggest that in normal subjects, and individuals with HT and CRF: (i) plasma and urinary excretions of AM-m and AM-Gly are not affected by age or sex; (ii) AM-m in parallel with AM-Gly is increased; (iii) urine contains a higher percentage of active adrenomedullin than plasma; and (iv) plasma AM-m may be partly metabolized in the lung.

Adrenomedullin↗

Treatment of severe hypothyroidism reduced serum creatinine levels in two chronic renal failure patients.

Short-term hypothyroidism has been associated with a reversible rise in serum creatinine levels in patients with normal renal function. A remarkable decline in serum creatinine levels associated with a treatment of severe and prolonged hypothyroidism has rarely been reported so far. We present here 2 patients with chronic renal failure in whom treatment for hypothyroidism resulted in a significant and sustained reduction of their serum creatinine levels. These cases indicate that because hypothyroidism may aggravate the serum creatinine levels, TSH should be considered in screening procedures of patients with chronic renal failure presenting with recent accelerated aggravation of renal function. Hypothyroidism per se, one of its complications or one of its associated autoimmune diseases might play a role in modifying the underlying renal problem.

Adult↗

Pregnancy outcome in nephrotic syndrome with mixed connective tissue disease.

We describe two pregnancies of a young woman with mixed connective tissue disease. In June 1983, she was diagnosed as having Raynaud's phenomenon, arthralgia, and proteinuria. She then developed nephrotic syndrome. Methylprednisolone was initially prescribed at a large dose of 1 g/day which was slowly tapered to 5 mg/day. The proteinuria disappeared. During both pregnancies (the first beginning in December 1988 and the second in May 1992), the patient was placed on a prednisolone maintenance dose (5 mg/day). Both neonates were born healthy at term with no complications. Continuing prednisolone may be useful in pregnant women, and aggressive treatment to prevent mixed connective tissue disease exacerbation may be appropriate during pregnancy.

Adult↗

Alterations of intrarenal adrenomedullin and its receptor system in heart failure rats.

Calcitonin receptor-like receptor/receptor activity-modifying protein 2 (CRLR/RAMP2) and CRLR/RAMP3 complexes have been reported to be specific adrenomedullin (AM) receptors. In the present study, we evaluated the pathophysiological significance of renal AM and its receptor system in aortocaval shunt (ACS) rats. Renal AM levels were measured serially during 5 weeks after the operation. Renal gene expressions of AM, CRLR, RAMP2, and RAMP3 were measured at 2 weeks (decompensated phase) and 5 weeks (compensated phase) after the operation. Immunohistochemical localizations of renal AM were also evaluated. Furthermore, the relations between urinary sodium excretion (UNaV) and renal AM levels were evaluated. Renal AM levels were higher in ACS than in control animals only at 1, 2, and 3 weeks after the operation. At 2 weeks after the operation, renal AM mRNA expression was also higher in ACS than in control animals. CRLR, RAMP2, and RAMP3 mRNAs were expressed in the kidney, but there were no differences between the 2 groups. Immunohistochemistry revealed the positive AM immunostaining within the renal tubular cells, and it was more intense in ACS than in control animals. There were significant correlations between UNaV and renal AM levels. At 5 weeks after the operation, there were no differences in mRNA levels of AM, CRLR, RAMP2, and RAMP3 between the 2 groups. There was a significant correlation between UNaV and medullary AM levels. The present findings suggest that increased renal AM levels in decompensated heart failure, presumably due to increased AM production in renal tubules, in part, are involved in the regulation of sodium excretion.

Adrenomedullin↗

High heart rate relates to clustering of cardiovascular risk factors in a screened cohort.

Increased heart rate (HR) is a predictor of cardiovascular mortality, so the present study used a screened cohort to investigate whether the clustering of cardiovascular risk factors is associated with increased HR. Individuals who were receiving medication for hypertension or heart disease and those who did not have an ECG record or who had a record of arrhythmia were excluded. In total, 8,508 subjects (5,299 men, 3,209 women; age range, 18-89 years) were studied. Subjects were divided into 2 HR classes using the value of mean HR+ 1 SD as the cut-off point: low HR (HR < 77 beats/min, n=7,320) and high HR (HR > or = 77 beats/min, n=1,188). For logistic regression analysis, the dependent variable was HR class and the independent variables were the number of risk factors (ie, hypertension, diabetes mellitus, and hypertriglyceridemia each of which was associated positively with HR class by multivariate analysis). The odds ratios and 95% confidence intervals for the number of risk factors were 1.412 (1.216-1.640) for 1 risk factor, 2.800 (2.269-3.455) for 2, and 4.582 (2.815-7.459) for 3. Multivariate regression analyses showed that the number of risk factors from 0 to 3 correlated positively with high HR. HR increased significantly with clustering of risk factors even with low HR (regression coefficient was 1.147, p<0.0001). Modifying the risk factors may lower HR and reduce cardiovascular mortality.

Adolescent↗

Significance of hyperuricemia on the early detection of renal failure in a cohort of screened subjects.

A high level of serum creatinine (S-Cr) is a predictor of end-stage renal disease (ESRD), but only a few studies have investigated the prevalence of high S-Cr and its correlates in a large population. We analyzed the data collected from 6,403 subjects (4,222 men and 2,181 women) who participated in the Okinawa General Health Maintenance Association (OGHMA) screening both at 1997 and 1999. The computer-saved data included sex, age, blood chemistries, blood pressure, medical histories, and lifestyles. Multivariate Cox proportional hazard analyses were performed to identify the correlates of developing high S-Cr levels: > or = 1.4 mg/dl in men and > or = 1.2 mg/dl in women. The prevalence of high S-Cr was 3.0% (N=193), which was 4.1% in men (N=175) and 0.8% in women (N=18), and increased with age in both sexes at the 1997 screening. Among those who showed normal levels of S-Cr in 1997 (N=6,210), 241 subjects (223 men and 18 women) developed high S-Cr. The 2-year cumulative incidence of high S-Cr was 5.5% in men and 0.8% in women. Other than sex, serum uric acid was the most significant correlate for developing high S-Cr. The adjusted relative risk (95% confidence interval) of those with serum uric acid 8.0 mg/dl and over was 2.91 (1.79-4.75) in men and 10.39 (1.91-56.62) in women when compared to those with serum uric acid less than 5.0 mg/dl. Prevalence of high levels of S-Cr was relatively high in men. Other than gender, serum uric acid was a significant positive correlate of developing high S-Cr in this sample of the Japanese population.

Adult↗

[Antihypertensive drug therapy: adverse effects and drug interactions].

The number of classes of antihypertensive drugs has been growing. The options of choice of the drugs now are so great that it seems not to be difficult to reduce blood pressure effectively. Newly developed classes have been shown to provide beneficial effects in variety of hypertension-related processes. However, each drug shows significant differences in adverse effects, incidental properties and interactions with non-antihypertensive drugs. To improve quality of life, compliance with medication, and beneficial effects on pathophysiological and cardiovascular risk conditions of patients, we should be well acquainted with adverse effects and possible disadvantages produced by antihypertensive drugs in particular situations.

Angiotensin-Converting Enzyme Inhibitors↗

Interaction of alcohol and an alpha1-blocker on ambulatory blood pressure in patients with essential hypertension.

Ingestion of alcohol acutely decreases vascular resistance and blood pressure (BP) with activation of the sympathetic nervous system in Orientals. Although alpha1-blockers are widely used in the treatment of hypertension, the possible interaction between alcohol and alpha1-blockers has not been clarified. We examined the effects of prazosin on the alcohol-induced BP changes in Japanese men with mild hypertension. Ten hypertensive patients (54 +/- 3 years, mean +/- SE) were given 1 mL/kg of alcohol or isocaloric control drink with a light meal in the evening before and 5 to 7 days after treatment with prazosin (1 mg three times daily). Ambulatory BP monitoring was carried out every 30 min for 24 h in each period using Colin ABPM-630. Blood samples were obtained before and 2 h after intake of alcohol or control drink. Before prazosin treatment, alcohol ingestion decreased BP for several hours with a significant reduction in average 24-h BP, whereas it increased heart rate, plasma norepinephrine, and plasma renin activity. Treatment with prazosin caused a significant decrease in 24-h BP (136.3 +/- 4.0/82.8 +/- 2.5 v 131.6 +/- 3.2/80.0 +/- 2.3 mm Hg). The alcohol-induced hypotension at 2-4 h after ingestion was enhanced by prazosin (-18.0 +/- 3.7/-11.8 +/- 2.7 v -24.4 +/- 4.9/-17.8 +/- 2.8 mm Hg, P < .05 for diastolic BP). These results suggested that inhibition of the sympathetic nervous system with alpha1-blockers accentuates alcohol-induced hypotension. Ingestion of alcohol may cause a marked BP reduction in hypertensive Orientals treated with alpha1-blockers.

Adrenergic alpha-Antagonists↗

Effects of cilnidipine, a novel dihydropyridine calcium antagonist, on autonomic function, ambulatory blood pressure and heart rate in patients with essential hypertension.

AIMS: The aim of the present study was to evaluate the effects of cilnidipine, a novel dihydropyridine calcium antagonist, on autonomic function, ambulatory blood pressure and heart rate in patients with essential hypertension. METHODS: Ten inpatients with mild to moderate essential hypertension (four men and six women; age: 44-64 years) underwent a drug-free period for 7 days and a treatment period with cilnidipine 10 mg orally for another 7 days, in a randomized crossover study. On the sixth day of each period, they underwent autonomic function tests including a mental arithmetic test, a cold pressor test and a Valsalva manoeuvre. After these tests, 24 h ambulatory blood pressure, heart rate, and the electrocardiogram R-R intervals were monitored every 30 min. A power spectral analysis of R-R intervals was performed to obtain the low-and high-frequency components. RESULTS: Cilnidipine significantly decreased the 24 h blood pressure by 6.5 +/- 1.7 mm Hg systolic (mean +/- s.e.mean; P < 0.01) and 5.0 +/- 1.1 mmHg diastolic (P < 0.01), whereas cilnidipine did not change heart rate or any indices of power spectral components. During the cold pressor test, the maximum change in systolic blood pressure and percentage changes in both systolic and diastolic blood pressures were significantly lower during the treatment period with cilnidipine than during the drug-free period. The baroreflex sensitivity measured from the overshoot phase of the Valsalva manoeuvre did not differ significantly between the two periods. CONCLUSIONS: Cilnidipine is effective as a once-daily antihypertensive agent and causes little influence on heart rate and the autonomic nervous system in patients with mild to moderate essential hypertension. Moreover, it is suggested that cilnidipine has an additional clinical benefit in the inhibition of the pressor response induced by acute cold stress.

Adult↗

Effects of a low-energy diet and an insulin-sensitizing agent on ambulatory blood pressure in overweight hypertensive patients.

OBJECTIVE: To clarify the role of insulin resistance and hyperinsulinaemia in the pathogenesis of obesity-related hypertension. DESIGN: An open study comparing the effects of weight reduction by low-energy diet and treatment with troglitazone, an insulin-sensitizing agent. SETTING: A tertiary teaching hospital. PATIENTS: Thirty overweight hypertensive patients (15 men and 15 women, mean age 61 years, mean body mass index 29.1 kg/m2). INTERVENTIONS: Fifteen patients were assigned to a weight-reduction programme by low-energy diet (3360 kJ/day) for 3 weeks; the remaining 15 patients were treated with troglitazone (400 mg/day) for 8 weeks. MAIN OUTCOME MEASURES: Casual and ambulatory blood pressures, glucose and lipid metabolism, and insulin sensitivity. RESULTS: The baseline values of body mass index, fasting and post-glucose plasma insulin, and casual and ambulatory blood pressures were comparable between the two groups. Weight reduction (4.1 +/- 0.3 kg, mean +/- SEM) was associated with significant decreases in plasma insulin, blood glucose, homeostasis model assessment (HOMA) insulin resistance index, serum triglyceride, casual blood pressure (7.7 +/- 2.3/ 3.9 +/- 1.4 mmHg) and 24 h blood pressure (8.3 +/- 1.9/ 4.3 +/- 1.1 mmHg). Treatment with troglitazone caused comparable decreases in the metabolic parameters and HOMA index, but did not change casual or 24 h blood pressure (0.8 +/- 3.4/0.8 +/- 2.1 and 1.5 +/- 2.4/ 1.0 +/- 1.9 mmHg, respectively). CONCLUSIONS: Insulin resistance/hyperinsulinaemia may not have an important role in the pathogenesis of obesity-related hypertension. The antihypertensive effect of weight reduction seems to be mediated mainly by other mechanisms.

Adult↗

Effect of a hypocaloric diet on adrenomedullin and natriuretic peptides in obese patients with essential hypertension.

We examined the effect of a hypocaloric diet on adrenomedullin (AM), atrial natriuretic peptide (ANP), and brain natriuretic peptide (BNP) in 12 obese patients with essential hypertension (age, 48-81 years; body mass index, 26-34 kg/m2). For the initial week, a standard diet of 2000 kcal/day was given, followed by 3 weeks of a hypocaloric diet of 850 kcal/day, with a constant intake of sodium. The patients lost 3.7 +/- 0.2 kg body weight during the hypocaloric diet period (p < 0.0001). The decrease in blood pressure during the study period was 10.3 +/- 3.6 mmHg systole (p = 0.017) and 4.2 +/- 3.2 mmHg diastole (NS). Plasma AM concentration was decreased significantly from 4.88 +/- 0.46 to 3.97 +/- 0.38 pmol/l by the hypocaloric diet (p = 0.004). Plasma ANP and BNP concentrations were also decreased significantly by the hypocaloric diet (p = 0.042 for each). These results demonstrate, for the first time, that plasma AM concentration as well as plasma ANP and BNP concentrations are decreased by a hypocaloric diet in obese patients with essential hypertension. These vasodilator peptides may act against further elevation in blood pressure in obese patients with essential hypertension.

Adrenomedullin↗