Gender differences in the effect of auditory stimuli on ventricular repolarization in healthy subjects.

Introduction: Gender differences in the incidence of ventricular arrhythmias have been reported and torsade de pointes associated with long-QT syndrome (LQTS) is more common in women than men. Although auditory stimulation has been recognized as an important trigger of torsade de pointes in LQT2 patients, the normal response and gender differences in ventricular repolarization induced by auditory stimuli remained to be evaluated systematically.

Methods: Holter ECGs were recorded in 30 healthy volunteers (14 men aged 25 +/- 4 years and 16 women aged 23 +/- 2 years).

Early atorvastatin therapy improves cardiac function in patients with acute myocardial infarction.

Background: A number of experimental and clinical studies have demonstrated a cardioprotective effect of statins; however, the effect of atorvastatin on cardiac function in patients with an acute myocardial infarction (AMI) has not been established.

Methods And Results: Thirty consecutive patients with an AMI (16 males and 14 females) were enrolled. All the patients underwent successful percutaneous coronary intervention in the early phase after the onset of an AMI.

Hepatocyte growth factor levels are associated with the results of 123I-metaiodobenzylguanidine myocardial scintigraphy in patients with type 2 diabetes mellitus.

Elevated hepatocyte growth factor (HGF) levels and cardiovascular autonomic dysfunction are associated with a high mortality rate in patients with type 2 diabetes mellitus. We tested the hypothesis that elevated HGF is associated with insulin resistance and cardiovascular autonomic dysfunction in patients with type 2 diabetes mellitus not receiving insulin treatment. The study group consisted of 21 type 2 diabetes mellitus patients with high HGF levels (>0.

Correlations of visceral fat accumulation and atherosclerosis in Japanese patients with type 2 diabetes mellitus.

We tested the hypothesis that increased abdominal visceral fat accumulation (VFA) is associated with insulin resistance and aortic stiffness in patients with type 2 diabetes mellitus not receiving insulin treatment. The study consisted of 22 Japanese patients with type 2 diabetes mellitus and high VFA (> or =100 cm(2); age, 61 +/- 7 years; high VFA group) and a control group of 18 age-matched patients with normal VFA (<100 cm(2); age, 60 +/- 8 years; normal VFA group). Brachial-ankle pulse wave velocity (BaPWV) was measured by automatic oscillometric method.

Correlations between homocysteine levels and atherosclerosis in Japanese type 2 diabetic patients.

Elevated total plasma homocysteine (tHcy) level and aortic stiffness are associated with high mortality in type 2 diabetic patients. We tested the hypothesis that tHcy correlates with aortic stiffness and insulin resistance in type 2 diabetic patients. The study consisted of 40 Japanese patients with type 2 diabetes mellitus and high tHcy levels (mean age +/- SD, 57 +/- 7 years) and a control group of 45 age-matched patients with normal tHcy levels (mean age +/- SD, 57 +/- 6 years).

Hyperthermia treatment prevents angiotensin II-mediated atrial fibrosis and fibrillation via induction of heat-shock protein 72.

We tested the hypothesis that atrial fibrosis and atrial fibrillation (AF) evoked by angiotensin II (AII) could be prevented by the induction of heat-shock protein 72 (HSP72) by hyperthermia (HT). In cultured atrial fibroblasts isolated from male Sprague-Dawley rats, HT (42 degrees C) was applied for 30 min. AII (100 nmol/L) was added to the medium 8 h later.

Correlations of high-sensitivity C-reactive protein and atherosclerosis in Japanese type 2 diabetic patients.

Background: The elevated level of high-sensitivity C-reactive protein (HSCRP) and aortic stiffness are associated with high mortality in type 2 diabetic patients. We tested the hypothesis that the HSCRP correlates with aortic stiffness and insulin resistance in type 2 diabetic patients.

Material And Methods: The study consisted of 46 Japanese patients with type 2 diabetes and high HSCRP group (0.

Predictors for silent cerebral infarction in patients with chronic renal failure undergoing hemodialysis.

In patients with chronic renal failure undergoing hemodialysis (HD), silent cerebral infarctions (SCIs) are associated with high mortality. Levels of hepatocyte growth factor (HGF) increase with renal dysfunction and may be a novel predictor of cerebrovascular events. We examined if HGF is a predictor of SCI in HD patients.

Abdominal visceral fat accumulation is associated with the results of (123)I-metaiodobenzylguanidine myocardial scintigraphy in type 2 diabetic patients.

Purpose: We tested the hypothesis that increased abdominal visceral accumulation (VFA) is associated with insulin resistance and cardiovascular autonomic dysfunction in type 2 diabetic patients not receiving insulin treatment.

Methods: The fat distribution was evaluated by measuring the VFA by abdominal computed tomography at the umbilical level. The study group consisted of 24 type 2 diabetic patients with high VFA (> or =100 cm(2), age 60 +/- 8 years, high VFA group).

Receptor-mediated suppression of cardiac heat-shock protein 72 expression by testosterone in male rat heart.

The impact of testosterone on cardiac expression of heat-shock protein 72 (HSP72) remains to be elucidated. Male Sprague Dawley rats 10 wk of age (adult) were castrated. Four weeks later, testosterone (10 mg/kg, ip) was administered as a single dose, followed by the application of hyperthermia (HT) (43 C) at 6 h after testosterone administration.

Correlations of urinary albumin excretion and atherosclerosis in Japanese type 2 diabetic patients.

Microalbuminuria and aortic stiffness are associated with high mortality in type 2 diabetic patients. We tested the hypothesis that the presence of microalbuminuria correlates with aortic stiffness and insulin resistance in type 2 diabetic patients. The study consisted of 36 Japanese patients with type 2 diabetes and microalbuminuria (age: 56+/-9 years, mean+/-S.

Smoking is associated with urinary albumin excretion: an evaluation of premenopausal patients with type 2 diabetes mellitus.

Cigarette smoking and an increase in urinary albumin excretion are associated with high mortality in patients with type 2 diabetes mellitus. We tested the hypothesis that the presence of a smoking habit correlates with increased urinary albumin excretion in premenopausal Japanese women with type 2 diabetes mellitus. The study consisted of 20 premenopausal Japanese patients with type 2 diabetes mellitus in the current-smokers group (age, 45 +/- 4 years, mean +/- SD).

[Evaluation of autonomic function using posture change].

There are several examinations to evaluate cardiac autonomic function. Autonomic neuropathy is a common complication of diabetes mellitus and is associated with increased mortality. Baroreflex sensitivity (BRS) is a marker for the ability to augment vagal activity.

Homocysteine levels are associated with the results of 123I-metaiodobenzylguanidine myocardial scintigraphy in type 2 diabetic patients.

Purpose: Elevated total plasma homocysteine (tHcy) levels and cardiovascular autonomic dysfunction are associated with a high mortality in type 2 diabetic patients. We tested the hypothesis that hyperhomocysteinemia is associated with insulin resistance and cardiovascular autonomic dysfunction in type 2 diabetic patients not receiving insulin treatment.

Methods: The study group consisted of 17 type 2 diabetic patients with high tHcy levels (>15 mmol/l, age 58+/-5 years, high tHcy group).

Pioglitazone but not glibenclamide improves cardiac expression of heat shock protein 72 and tolerance against ischemia/reperfusion injury in the heredity insulin-resistant rat.

We tested the hypothesis that pioglitazone could restore expression of heat shock protein (HSP)72 in insulin-resistant rat heart. At 12 weeks of age, male Otsuka Long-Evans Tokushima Fatty (OLETF) rats and control (LETO) rats were treated with pioglitazone (10 mg x kg(-1) x day(-1)) or glibenclamide (5 mg x kg(-1) x day(-1)) for 4 weeks. Thereafter, hyperthermia (43 degrees C for 20 min) was applied.

Diazoxide-induced cardioprotection via DeltaPsim loss depending on timing of application.

Although the role of mitochondrial ATP-sensitive potassium (mitoKATP) channels in cardioprotection is widely accepted, it remains unclear when their opening is critical for protection. We tested the hypothesis that the mitoKATP channel acts as a trigger or mediator of protection against apoptosis through loss of mitochondrial inner membrane potential (DeltaPsim). Exposure of neonatal rat cardiomyocytes to H2O2 (0.

Influence of menstrual cycle on QT interval dynamics.

Objectives: The aim of this study was to investigate the effects of the menstrual cycle on QT interval dynamics and the autonomic tone in healthy women.

Methods: Holter ECGs were recorded in 11 healthy women aged 18-32 years during the follicular and luteal phases of their regular menstrual cycle. The interval from QRS onset to the apex (QaT) and to the end of the T-wave (QeT), the interval between the apex and the end of the T-wave (Ta-e), and RR intervals were measured automatically in the course of 24 hours by Holter ECGs.

Phosphatidylinositol 3-kinase-dependent activation of akt, an essential signal for hyperthermia-induced heat-shock protein 72, is attenuated in streptozotocin-induced diabetic heart.

We tested the hypothesis that phosphatidylinositol 3-kinase (PI 3-kinase)-dependent activation of Akt is essential for the expression of cardiac heat-shock protein 72 (HSP72) and that this pathway is impaired in the streptozotocin (STZ)-induced diabetic heart. STZ-induced male diabetic rats were treated with insulin (STZ-insulin group, n = 26) or vehicle (STZ-vehicle group, n = 61) for 3 weeks. Whole-body hyperthermia (43 degrees C for 20 min) was applied, and the heart was isolated 24 h later.

Hyperhomocysteinemia is a significant risk factor for silent cerebral infarction in patients with chronic renal failure undergoing hemodialysis.

In patients with chronic renal failure undergoing hemodialysis (HD), the presence of silent cerebral infarction (SCI) is associated with high mortality. Plasma total homocysteine (tHcy), which increases with renal dysfunction, has been flagged as a novel predictor for cerebrovascular events. We tested the hypothesis that the presence of SCI correlates with tHcy in HD patients.

Effects of valsartan and perindopril combination therapy on left ventricular hypertrophy and aortic arterial stiffness in patients with essential hypertension.

Objective: To compare the effects of combined therapy of an angiotensin II receptor blocker (ARB; valsartan) and an angiotensin converting enzyme inhibitor (ACEI; perindopril) on blood pressure (BP), metabolic profiles, plasma brain natriuretic peptide (BNP) levels, echocardiographic findings, and aortic pulse wave velocity (PWV) with those of respective monotherapy in never-treated patients with essential hypertension.

Methods: This was a prospective randomized trial, in which there were 31 patients with essential hypertension and left ventricular hypertrophy (LVH) who visited the outpatient clinic of Oita Red Cross Hospital (14 women and 17 men; mean+/-SD age, 59+/-5 years). Each patient was randomly assigned to receive valsartan (160 mg/day, V group, n=10), perindopril (8 mg/day, P group, n=11), or a combination of valsartan (80 mg/day) and perindopril (4 mg/day, V+P group, n=10) for 40 weeks.

Heterogeneous expression of connexin 43 in the myocardium of rabbit right ventricular outflow tract.

The right ventricular outflow tract (RVOT) has been demonstrated as an important focus in idiopathic ventricular arrhythmias. However, the role of the gap junction in this region in arrhythmic events has not been fully investigated. The purpose of this study was to evaluate the expression and distribution of the gap junction protein connexin 43 (Cx43) in the myocardium of the RVOT area of normal adult rabbits.

Gender differences in autonomic modulation of ventricular repolarization in humans.

Background: Gender differences in the incidence of ventricular arrhythmias have been reported and torsades de pointes associated with long QT syndrome are more common in women than men. Although increased sympathetic tone has an important role in vulnerability to arrhythmia, little is currently known regarding gender differences in the dynamic electrophysiological response to sympathetic stimulation. Therefore, we investigated whether there is a gender difference in humans with respect to the dynamic response of ventricular repolarization to beta-adrenergic stimulation and to autonomic blockade.

Estrogen inhibits hyperthermia-induced expression of heat-shock protein 72 and cardioprotection against ischemia/reperfusion injury in female rat heart.

There is still controversy as to whether estrogen inhibits or enhances heat-shock protein (HSP72) expression in the heart. To evaluate the gender difference, whole-body hyperthermia (HT, 43 degrees C for 20 min) or normothermia (NT, 37 degrees C for 20 min) was applied to both male and female rats. Twenty-four hours after each thermo-treatment, the heart was isolated for either Western blot analysis or isolated-perfused heart experiments.