Intra-Arterial Blood Pressure Response in Hypertensive Subjects during Low- and High-Intensity Resistance Exercise

OBJECTIVE:

The aim of this study was to describe blood pressure responses during resistance exercise in hypertensive subjects and to determine whether an exercise protocol alters these responses.

INTRODUCTION:

Resistance exercise has been recommended as a complement for aerobic exercise for hypertensive patients. However, blood pressure changes during this kind of exercise have been poorly investigated in hypertensives, despite multiple studies of normotensives demonstrating significant increases in blood pressure.

METHODS:

Ten hypertensive and ten normotensive subjects performed, in random order, two different exercise protocols, composed by three sets of the knee extension exercise conducted to exhaustion: 40% of the 1-repetition maximum (1RM) with a 45-s rest between sets, and 80% of 1RM with a 90-s rest between sets. Radial intra-arterial blood pressure was measured before and throughout each protocol.

RESULTS:

Compared with normotensives, hypertensives displayed greater increases in systolic BP during exercise at 80% (+80±3 vs. +62±2 mmHg, P<0.05) and at 40% of 1RM (+75±3 vs. +67±3 mmHg, P<0.05). In both exercise protocols, systolic blood pressure returned to baseline during the rest periods between sets in the normotensives; however, in the hypertensives, BP remained slightly elevated at 40% of 1RM. During rest periods, diastolic blood pressure returned to baseline in hypertensives and dropped below baseline in normotensives.

CONCLUSION:

Resistance exercise increased systolic blood pressure considerably more in hypertensives than in normotensives, and this increase was greater when lower-intensity exercise was performed to the point of exhaustion.     

Hypertension, cerebral vascular changes and stroke in Ghana. 1. Microaneurysm formation and stroke

A modification of the post-mortem arteriographic technique of Ross Russell was used to study the brains of 284 consecutive autopsy cases dying from non-traumatic causes; and made up of 159 hypertensives and 125 normotensives. Microaneurysms were demonstrated in 30.8 per cent of the hypertensives compared with 9.6 per cent normotensives. Haemorrhagic stroke was the cause of death in 37.6 per cent of the hypertensives, the majority of which were in younger age groups compared with hypertensive strokes in whites. The much lower incidence of microaneurysms in the brain of black hypertensives (even those with haemorrhagic strokes) compared with that found by workers among white hypertensives further emphasized the different nature of hypertension in blacks. It is suggested that, in the absence of significant structural differences in the cerebral vasculature between blacks and whites, the high incidence of haemorrhagic strokes occurring in the relatively younger subjects in Ghana may be due to the direct effect of high blood pressures on small intracerebral vessels and that microaneurysm formation may not be as important as in the much older white subjects dying of haemorrhagic strokes.     

Social Supports, Perceived Stress, and Health: The Black Experience in Medical School��A Preliminary Study

Black medical students perceived significantly more stressors than white medical students in a predominantly white medical school environment (P=0.001). Black medical students perceived fewer social supports than white medical students, but not significantly fewer (P=0.224). There was no significant difference between mean systolic and diastolic blood pressure levels for the low and high stress groups (P=0.302 and 0.844, respectively). The total degree of perceived stressors did not predict systolic and diastolic blood pressure when controlling for potential confounders (0.05<P<0.1). The interaction of total degree stressors and total degree of social supports did not significantly predict systolic and diastolic blood pressures when controlling for potential confounding variables (P>0.25 and 0.1<P<0.25, respectively).     

Intercostal and forearm muscle deoxygenation during respiratory fatigue in patients with heart failure: potential role of a respiratory muscle metaboreflex

The purpose of this study was to determine the effect of respiratory muscle fatigue on intercostal and forearm muscle perfusion and oxygenation in patients with heart failure. Five clinically stable heart failure patients with respiratory muscle weakness (age, 66±12 years; left ventricle ejection fraction, 34±3%) and nine matched healthy controls underwent a respiratory muscle fatigue protocol, breathing against a fixed resistance at 60% of their maximal inspiratory pressure for as long as they could sustain the predetermined inspiratory pressure. Intercostal and forearm muscle blood volume and oxygenation were continuously monitored by near-infrared spectroscopy with transducers placed on the seventh left intercostal space and the left forearm. Data were compared by two-way ANOVA and Bonferroni correction. Respiratory fatigue occurred at 5.1±1.3 min in heart failure patients and at 9.3±1.4 min in controls (P<0.05), but perceived effort, changes in heart rate, and in systolic blood pressure were similar between groups (P>0.05). Respiratory fatigue in heart failure reduced intercostal and forearm muscle blood volume (P<0.05) along with decreased tissue oxygenation both in intercostal (heart failure, -2.6±1.6%; controls, +1.6±0.5%; P<0.05) and in forearm muscles (heart failure, -4.5±0.5%; controls, +0.5±0.8%; P<0.05). These results suggest that respiratory fatigue in patients with heart failure causes an oxygen demand/delivery mismatch in respiratory muscles, probably leading to a reflex reduction in peripheral limb muscle perfusion, featuring a respiratory metaboreflex.     

Two-dimensional speckle-tracking echocardiography assessment of left ventricular remodeling in patients after myocardial infarction and primary reperfusion

Introduction

Left ventricular remodeling (LVR) is the most prognostically important consequence of acute myocardial infarction (AMI). The aim of the study was to assess the value of speckle tracking echocardiography in the prediction of left ventricular remodeling in patients after AMI and primary coronary angioplasty (PCI).

Material and methods

Eighty-eight patients (F/M = 31/57 patients; 63.6 ±11 years old) with coronary artery disease (CAD) and successful PCI were enrolled and divided into group I with ST-elevation myocardial infarction or non-ST elevation myocardial infarction and group II with stable angina pectoris. Conventional and speckle tracking echocardiography was performed 3 days (baseline), 30 days and 90 days after PCI. Patients were divided into 2 groups based on the presence of LVR (increase of LV end-diastolic and/or end-systolic volume > 20%) at 3 months follow-up.

Results

At initial presentation, 2-chamber longitudinal strain (9.4 ±3.5% vs. –11.6 ±3.6%, p < 0.04) and 4-chamber transverse strain (10.4 ±8.2% vs. 15.6 ±8%, p < 0.003) were lower in the LVR+ group compared to the LVR– group. LV wall motion score index did not differ between the two groups. After 30 days, circumferential apical and basal strain (–15.58 ±8.9% vs. –25.53 ±8.8%, p < 0.001; –15.02 ±5.6 vs. –19.78 ±6.3, p < 0.008), radial apical strain (9.96 ±8.4% vs. 14.15 ±5.5%, p < 0.03), 4-chamber longitudinal strain (–8.7 ±5.8% vs. –13.47 ±3.9%, p < 0.005), 4-chamber transverse strain (10.5 ±8.1% vs. 16.7 ±8.3%, p < 0.03), apical rotation (3.84 ±2.5° vs, 5.66 ±3.2°, p < 0.04) and torsion (6.15 ±4.1° vs. 8.98 ±4.6°, p < 0.03) were significantly decreased in the LVR+ group compared to the LVR– group. According to ROC analysis, circumferential apical strain > –15.92% (sensitivity 93%, specificity 59%, positive predictive value 90%) was the most powerful predictor of remodeling after primary PCI in AMI.

Conclusions

Our results suggest that impaired indices of LV deformation detected 3 days and 30 days after AMI may provide important predictive value in LV remodeling and patients’ follow-up.     

Temporal stability of task-induced cardiovascular, adrenergic, and psychological responses: The effects of race and hypertension

This study examined the test-retest reliability of task-induced responses of blood pressure, heart rate, norepinephrine, epinephrine, anger, and anxiety in 98 black and white normotensive and hypertensive individuals. Subjects completed three laboratory tasks (standing, mental arithmetic, and cold pressor) on two occasions 10 days apart. For all subjects, all baseline and test-retest correlation coefficients were significant (rs = .23–.71; median = .58). Baseline-adjusted (residual scores) reactivity test-retest correlation coefficients were consistently smaller (rs = .02–.55; median = .36). In contrast to the white hypertensives, white normotensives, and black normotensives, the black hypertensives showed no significant baseline-adjusted test-retest correlation coefficients (rs =?.21–.40; median = .12). Epinephrine responses revealed a significant session by race interaction; blacks had 20% higher mean values and whites had 10% lower mean values upon retesting. The data suggest that race and hypertension may interact to affect the temporal stability of task-induced responses to stressors.     

Effect of Allium Cepa and Allium Sativum on Some Immunological Cells in Rats

Extracts of some spices have been reported to play a contributory role in enhancing immune function. We evaluated and compared the effect(s) of single and combined oral administration of fresh aqueous onion (Allium cepa) and garlic (Allium sativum) extracts at different concentrations on some immunological determinants in rats. CD₄ cells of the rats were estimated using Partec flow cytometric technique, while total and differential white blood cell (WBC) counts were estimated using the Sysmsex® automated haematology analyzing technique. Our findings revealed that, CD4 and total WBC counts were significantly increased (P≤0.05) in a dose-dependent manner in both onion (250mg/Kg/d: 349±11cell/ul and 2.75±0.15X10³cell/l; 500mg/Kg/d: 389±10cells/µl and 3.05±0.05 X10³cell/l; 750mg/Kg/d: 600±11cell/µl and 3.25±0.05X10³cells/l) and garlic (250mg/Kg/d: 410±10cell/ul and 2.85±0.15X10³cell/l; 500mg/Kg/d: 494±32cells/µl and 3.30±0.10 X10³cell/l; 750mg/Kg/d: 684±11cell/µl and 3.55±0.05X10³cells/l) treated rats when compared to the zero control (200±11cells/µl and 1.55±0.05X10³cells/l, respectively). Extract of garlic at 750mg/Kg/d had significantly increased the CD4 cells and total white cell count when compared to other concentrations (P≤0.05). However, no significant effect was observed on these parameters when extracts were combined (250mg/Kg/d: 252±21cell/µl and 1.80±0.10X10³cells/l; 500mg/Kg/d: 315±21cells/ul and 2.10±0.10X10³cells/l; 750mg/Kg/d: 368±10cells/µl and 2.35±0.05X10³cells/l, respectively), the differential WBC count showed a significant increase in the proportion of cell types (lymphocytes, neutophils and monocytes) (P≤0.05). The results from this study revealed the immune boosting capabilities of Allium cepa and Allium sativum, but underscored their synergistic activities.     

Experimental Benign and Malignant Nephrosclerosis

Aortic ligation between the renal arteries in Sprague-Dawley rats weighing 150-200 g resulted in the prompt development of either the malignant (MHY) or benign (BHY) forms of hypertension. Evolution of hypertension and vascular disease was studied in groups of MHY and BHY animals killed at 12,21 and 30 days after ligation. At 12 days MHY and BHY animals showed equally elevated mean arterial pressure (MHY: 184±6; BHY: 189±2 mmHg). MHY animals, however, were characterized by markedly increased plasma renin activity (PRA:MHY: 565±129; BHY: 85±13; sham-operated (SHAM-OP): 15±2 ng angiotensin I (AI)/ml/h) and widespread necrotizing arteritis with massive fibrinoid deposition. At 21 days fibrinoid deposits had extended to the non-ischaemic kidney, where the initiation of intimal proliferation in interlobular arteries was also present. Elevated PRA in 30-day MHY animals (MHY: 152±20; BHY: 25±2; SHAM-OP: 19±2 ng/AI/ml/h) was accompanied by generalized necrotizing arteritis, malignant nephrosclerosis and elevated blood urea nitrogen (BUN:MHY: 50±7 mg/dl; BHY: 29±1 mg/dl; P<0.025). In benign hypertensives, despite similarly elevated blood pressure necrotizing lesions were not observed. Although no MHY survived beyond 41 days of hypertension, 108 BHY were alive 60 days after aortic ligation. BHY animals studied at this time were characterized by increased blood pressure (BHY: 177±6; SHAMOP: 112±2 mmHg), normal body wt (BHY: 344±5; SHAM-OP: 353±8 g), normal PRA (BHY: 8±1; SHAM-OP: 9±1 ng AI/ml/h), normal levels of BUN (BHY: 18±2; SHAM-OP: 20±2 mg/dl) and the absence of necrotizing vascular disease in the kidney or other organs. These experiments indicate that aortic ligation in animals of this size results in the development of MHY in a significant proportion of the population (36%). This system permits the study of animals which sustain a close replica to the malignant or benign form of the human disease. Furthermore, the pathogenic mechanisms operating in one form of hypertension may be compared to those occurring in animals following the opposite course of the disease.     

Heart function disturbances in chronic kidney disease – echocardiographic indices

Introduction

In chronic kidney disease (CKD) patients left ventricular (LV) diastolic dysfunction occurs frequently and is associated with heart failure (HF) and higher mortality. Left ventricular systolic dysfunction is associated with coronary artery disease (CAD) and is a major determinant of prognosis. The aim of this study was to assess indices of LV diastolic dysfunction in CKD patients.

Material and methods

Study included 118 CKD patients. All patients underwent transthoracic echocardiography. Diastolic function based on E and A, E/A ratio and pulmonary vein flow velocities as well as EF%, deceleration time, RA, LA volume were assessed. In dialysis patients examination was carried out before and after dialysis.

Results

In CKD patients the stage of renal failure was associated with the significant increase in LV mass (268.0 ±47.6 CKD I/II vs. 432.7 ±122.4 CKD V/dialysis, p < 0.0001), systolic LV (37.3 ±4.5 vs. 51.2 ±8.9, p < 0.0001) and diastolic LV (CKD I–II 44.7 ±4.1 vs. CKD III 48.5 ±6.7 vs. CKD IV 47.1 ±5.6; p = 0.004) dimensions and in the size of the LA (40.4 ±2.0 vs. 41.9 ±2.7 vs. 42.3 ±3.2 vs. 44.8 ±3.1; p < 0.0001). The increase the E/E’ ratio between groups of patients (6.7 ±1.5 vs. 8.9 ±2.4 vs. 11.5 ±4.0 vs. 13.5 ±5.0; p < 0.0001) was seen in this study. The reduction in deceleration time (247.2 ±34.5 in CKD I/II vs. 197.4 ±61.0 in CKD IV, p = 0.0005) along with the decrease in estimated glomerular filtration rate was also observed in this study.

Conclusions

Early identification of factors involved is necessary to prevent this devastating process. Many indexes of contractility are used and each of them has imperfections. It seems that TVI, E, E/A and E/E’ are good instruments for the early detection of left ventricular hypertrophy and diastolic dysfunction.     

Racial differences in the relaxation response of hypertensives.

Racial differences in the relaxation response of hypertensives maintained on diuretic were investigated by comparing blood pressure, muscle tension, and hand temperature changes occurring with biofeedback assisted relaxation. Resting blood pressures were not different in blacks compared with whites. Both black and white subjects decreased diastolic blood pressure significantly from baseline values, but only whites significantly decreased systolic blood pressure. Though both blacks and whites significantly decreased forehead muscle tension, black subjects showed no changes in finger temperature while whites increased temperature significantly. The lack of change in finger temperature in blacks may be a reflection of the increased peripheral resistance previously associated with the greater incidence of hypertension in the American black population.     

Unmasking Myocardial Dysfunction in Patients Hospitalized for Community-Acquired Pneumonia Using a 4-Chamber 3-Dimensional Volume/Strain Analysis

Lower respiratory infection was reported as the most common fatal infectious disease. Community-acquired pneumonia (CAP) and myocardial injury are associated; yet, true prevalence of myocardial injury is probably underestimated. We assessed the rate and severity of myocardial dysfunction in patients with CAP. Admitted patients diagnosed with CAP were prospectively recruited. All the patients had C-reactive protein (CRP), brain natriuretic peptide (BNP), and high-sensitivity cardiac troponin (hs-cTnl) tests added to their routine workup. 2D/3D Doppler echocardiography was done on a Siemens Acuson SC2000 machine ≤ 24 h of diagnosis. 3D datasets were blindly analyzed for 4-chamber volumes/strains using EchobuildR 3D-Volume Analysis prototype software, v3.0 2019, Siemens-Medical Solutions. Volume/strain parameters were correlated with admission clinical and laboratory findings. The cohort included 34 patients, median age 60 years (95% CI 55–72). The cohort included 18 (53%) patients had hypertension, 9 (25%) had diabetes mellitus, 7 (21%) were smokers, 7 (21%) had previous myocardial infarction, 4 (12%) had chronic renal failure, and 1 (3%) was on hemodialysis treatment. 2D/Doppler echocardiography findings showed normal ventricular size/function (LVEF 63 ± 9%), mild LV hypertrophy (104 ± 36 g/m²), and LA enlargement (41 ± 6 mm). 3D volumes/strains suggested bi-atrial and right ventricular dysfunction (global longitudinal strain RVGLS =  − 8 ± 4%). Left ventricular strain was normal (LVGLS =  − 18 ± 5%) and correlated with BNP (r = 0.40, p = 0.024). The patients with LVGLS >  − 17% had higher admission blood pressure and lower SaO₂ (144 ± 33 vs. 121 ± 20, systolic, mmHg, p = 0.02, and 89 ± 4 vs. 94 ± 4%, p = 0.006, respectively). hs-cTnl and CRP were not different. Using novel 3D volume/strain software in CAP patients, we demonstrated diffuse global myocardial dysfunction involving several chambers. The patients with worse LV GLS had lower SaO₂ and higher blood pressure at presentation. LV GLS correlated with maximal BNP level and did not correlate with inflammation or myocardial damage markers.     

Predictors of Increased Left Ventricular Filling Pressure in Dialysis Patients with Preserved Left Ventricular Ejection Fraction

Aim

To study the left and right ventricular function and to assess the predictors of increased left ventricular (LV) filling pressure in dialysis patients with preserved LV ejection fraction.

Methods

This study included 63 consecutive patients (age 57 ± 14 years, 57% women) with end-stage renal failure. Echocardiography, including tissue Doppler measurements, was performed in all patients. Based on the median value of the ratio of transmitral early diastolic velocity to early myocardial velocity (E/E’ ratio), patients were divided into 2 groups: the group with high filling pressure (E/E’>10.16) and the group with low filling pressure (E/E’≤10.16).

Results

Compared with patients with low filling pressure, the group of patients with high filling pressure included a higher proportion of diabetic patients (41% vs 13%, P = 0.022) and had greater LV mass index (211 ± 77 vs 172 ± 71 g/m³, P = 0.04), lower LV lateral long axis amplitude (1.4 ± 0.3 vs 1.6 ± 0.3 cm, P = 0.01), higher E wave (84 ± 19 vs 64 ± 18cm/s, P < 0.001), lower systolic myocardial velocity (S’:8.6 ± 1.5 vs 7.0 ± 1.3 cm/s, P < 0.001), and lower diastolic myocardial velocities (E’: 6.3 ± 1.9 vs 9.5 ± 2.9 cm/s, P < 0.001; A’: 8.4 ± 1.9 vs 9.7 ± 2.5 cm/s, P = 0.018). Multivariate analysis identified LV systolic myocardial velocity – S’ wave (adjusted odds ratio, 1.909; 95% confidence interval, 1.060-3.439; P = 0.031) and age (1.053; 1.001-1.108; P = 0.048) as the only independent predictors of high LV filling pressure in dialysis patients.

Conclusions

In dialysis patients with preserved left ventricular ejection fraction, reduced systolic myocardial velocity and elderly age are independent predictors of increased left ventricular filling pressure.Cardiovascular disorders are the main cause of mortality and morbidity in patients with end-stage renal failure who are in regular hemodialysis programs (1,2). The left ventricular (LV) hypertrophy is a common finding in these patients. It reflects a physiological response to pressure and volume overload (3) and positively correlates with cardiovascular mortality (4). LV hypertrophy is frequently associated with LV dilatation and reduced systolic function (5). An increased incidence of atherosclerotic cardiovascular events in these patients has also been reported (6). Systolic dysfunction and LV hypertrophy have been identified as the best predictors of outcome in dialysis patients (4,7,8). However, the conventional systolic dysfunction appears in the late stages of the chronic renal failure (9).In contrast to conventional echocardiography, tissue Doppler imaging of the myocardial velocities overcomes the load dependence of diastolic parameters (10). The ratio of transmitral early diastolic velocity (E) to early myocardial velocity (E’) (E/E’ ratio) has been shown to be an accurate method of the LV filling pressure estimation (8) and the best predictor of LV diastolic filling in various cardiac pathologies (11,12), thereby serving as one of the best predictors of outcome in heart failure patients (13-15) and patients with end-stage renal disease (16).The aims of this study were to investigate the left and right ventricular function in patients with end-stage renal disease and preserved LV ejection fraction and to assess the predictors of increased LV filling pressure in these patients.     

Hepatopulmonary syndrome: the role of intra-abdominal hypertension and a novel mouse model

Objective: Hepatopulmonary syndrome (HPS) is considered as a triad of chronic liver disease, pulmonary vascular ectasia and severe hypoxemia. The study aims to investigate the pathological mechanism of intra-abdominal pressure (IAP) in HPS and establish a novel mouse model. Methods: Fifty male ICR mice were randomly divided into experimental and control group, receiving subcutaneous injection of carbon tetrachloride and water, respectively. Mice in experimental group were then divided into 4 sub-groups with the intraperitoneal injection of different volume of albumin to form different IAP (0, 5, 10 and 20 cmH₂O). All the mice were then sacrificed 24 hours later and blood gas analysis was conducted. In addition, liver and lung histopathology was also examined. Results: Blood gas analysis in different IAP suggested the respiratory alkalosis. Arterial partial pressure of oxygen significantly decreased in the IAP=10 cmH₂O (68.13 ± 3.56, P<0.01) and 20 cmH₂O (66.00 ± 3.78, P<0.01). Alveolar-arterial oxygen pressure difference increased markedly in the IAP=10 cmH₂O (54.60 ± 6.80, P<0.001) and 20 cmH₂O (57.04 ± 5.60, P<0.001). According to lung histopathology, macrophages were found to accumulate in the alveolar spaces and the widened alveolar walls were detected. In addition, there was visible blood stasis in the alveolar walls and numerous red blood cells extravasated into air space in the IAP=10 and 20 cmH₂O. Conclusions: Our study suggested that intra-abdominal hypertension was a significant pathological mechanism of HPS. Meanwhile, we have established a novel mouse model that will now be optimized with further investigation of the mechanism and therapeutic targets of HPS.     

Levels of vitamin D receptor and CYP24A1 in patients with end-stage renal disease

ObjectiveThis study was performed to detect the expression of vitamin D receptor (VDR) and cytochrome P450, family 24, subfamily A, polypeptide 1 (CYP24A1) in 24 end stage renal disease (ESRD) patients and 24 healthy controls.MethodIn this study, 24 ESRD patients and 24 healthy controls were included.ResultsIn our study, the levels of VDR in patients with ESRD were reduced when compared with those from healthy controls (5.20±0.32 vs 8.59±1.03; P<0.01). However, the levels of CYP24A1 in ESRD patients were increased than those from healthy controls (50.18±21 vs 7.78±1.31; P<0.01). Correlation analysis showed that VDR levels were negatively correlated with CYP24A1 (r=−0.723; P<0.01).ConclusionVDR levels were reduced and CYP24A1 levels were increased in patients with ESRD, and VDR levels were negatively correlated with CYP24A1.     

Comparison of heart rate response and heart rate recovery after step test among smoker and non-smoker athletes

BackgroundExercise performance depend on the ability of the cardiovascular system to respond to a wide range of metabolic demands and physical exertion.ObjectivesTo investigate the habitual smoking effects in heart rate response and heart rate recovery after step test in athletes.MethodsSeventy-eight physically healthy active athletes (45 non-smokers and 33 smokers) aging 27±8 years old, participated in this study. All participants completed the International Physical Activity Questionnaire and performed the six-minute step test. Cardiovascular parameters such (resting heart rate, peak heart rate, heart rate at 1 min after testing, heart rate recovery, recovery time, blood pressure at rest, and post-testing blood pressure) were recorded.ResultsSmoker-athletes had higher resting heart rate (76 ± 9bpm vs. 72 ± 10bpm, p<0.05), maximum heart rate (154 ± 18bpm vs. 147 ± 17bpm, p<0.05) and recovery time (7min 25sec ± 6min 31sec vs. 4min 21sec ± 4min 30sec, p<0.05) than non-smoker athletes. Scores from the IPAQ were approximately the same (M=7927 ± 10303, M= 6380 ± 4539, p<0.05).ConclusionSmoking was found to affect athletes'' cardiovascular fitness. The change of the athletes'' heart rate recovery and recovery time contributes to the adaptation of cardiovascular function in training requirements.     

Tumor growth reduction is regulated at the gene level in Walker 256 tumor-bearing rats supplemented with fish oil rich in EPA and DHA

We investigated the effect of fish oil (FO) supplementation on tumor growth, cyclooxygenase 2 (COX-2), peroxisome proliferator-activated receptor gamma (PPARγ), and RelA gene and protein expression in Walker 256 tumor-bearing rats. Male Wistar rats (70 days old) were fed with regular chow (group W) or chow supplemented with 1 g/kg body weight FO daily (group WFO) until they reached 100 days of age. Both groups were then inoculated with a suspension of Walker 256 ascitic tumor cells (3×10⁷ cells/mL). After 14 days the rats were killed, total RNA was isolated from the tumor tissue, and relative mRNA expression was measured using the 2^-ΔΔCT method. FO significantly decreased tumor growth (W=13.18±1.58 vs WFO=5.40±0.88 g, P<0.05). FO supplementation also resulted in a significant decrease in COX-2 (W=100.1±1.62 vs WFO=59.39±5.53, P<0.001) and PPARγ (W=100.4±1.04 vs WFO=88.22±1.46, P<0.05) protein expression. Relative mRNA expression was W=1.06±0.022 vs WFO=0.31±0.04 (P<0.001) for COX-2, W=1.08±0.02 vs WFO=0.52±0.08 (P<0.001) for PPARγ, and W=1.04±0.02 vs WFO=0.82±0.04 (P<0.05) for RelA. FO reduced tumor growth by attenuating inflammatory gene expression associated with carcinogenesis.     

A single resistance exercise session improves myocardial contractility in spontaneously hypertensive rats

Resistance training evokes myocardial adaptation; however, the effects of a single resistance exercise session on cardiac performance are poorly understood or investigated. This study aimed to investigate the effects of a single resistance exercise session on the myocardial contractility of spontaneously hypertensive rats (SHRs). Male 3-month-old SHRs were divided into two groups: control (Ct) and exercise (Ex). Control animals were submitted to sham exercise. Blood pressure was measured in conscious rats before the exercise session to confirm the presence of arterial hypertension. Ten minutes after the exercise session, the animals were anesthetized and killed, and the hearts were removed. Cardiac contractility was evaluated in the whole heart by the Langendorff technique and by isometric contractions of isolated left ventricular papillary muscles. SERCA2a, phospholamban (PLB), and phosphorylated PLB expression were investigated by Western blot. Exercise increased force development of isolated papillary muscles (Ex=1.0±0.1 g/mg vs Ct=0.63±0.2 g/mg, P<0.05). Post-rest contraction was greater in the exercised animals (Ex=4.1±0.4% vs Ct=1.7±0.2%, P<0.05). Papillary muscles of exercised animals developed greater force under increasing isoproterenol concentrations (P<0.05). In the isolated heart, exercise increased left ventricular isovolumetric systolic pressure (LVISP; Δ +39 mmHg; P<0.05) from baseline conditions. Hearts from the exercised rats presented a greater response to increasing diastolic pressure. Positive inotropic intervention to calcium and isoproterenol resulted in greater LVISP in exercised animals (P<0.05). The results demonstrated that a single resistance exercise session improved myocardial contractility in SHRs.     

Partial baroreceptor dysfunction and low plasma nitric oxide bioavailability as determinants of salt-sensitive hypertension: a reverse translational rat study

This study determined whether clinical salt-sensitive hypertension (cSSHT) results from the interaction between partial arterial baroreceptor impairment and a high-sodium (HNa) diet. In three series (S-I, S-II, S-III), mean arterial pressure (MAP) of conscious male Wistar ChR003 rats was measured once before (pdMAP) and twice after either sham (SHM) or bilateral aortic denervation (AD), following 7 days on a low-sodium (LNa) diet (LNaMAP) and then 21 days on a HNa diet (HNaMAP). The roles of plasma nitric oxide bioavailability (pNOB), renal medullary superoxide anion production (RMSAP), and mRNA expression of NAD(P)H oxidase and superoxide dismutase were also assessed. In SHM (n=11) and AD (n=15) groups of S-I, LNaMAP-pdMAP was 10.5±2.1 vs 23±2.1 mmHg (P<0.001), and the salt-sensitivity index (SSi; HNaMAP−LNaMAP) was 6.0±1.9 vs 12.7±1.9 mmHg (P=0.03), respectively. In the SHM group, all rats were normotensive, and 36% were salt sensitive (SSi≥10 mmHg), whereas in the AD group ∼50% showed cSSHT. A 45% reduction in pNOB (P≤0.004) was observed in both groups in dietary transit. RMSAP increased in the AD group on both diets but more so on the HNa diet (S-II, P<0.03) than on the LNa diet (S-III, P<0.04). MAP modeling in rats without a renal hypertensive genotype indicated that the AD*HNa diet interaction (P=0.008) increases the likelihood of developing cSSHT. Translationally, these findings help to explain why subjects with clinical salt-sensitive normotension may transition to cSSHT.     

Relationship between plasma homocysteine and blood pressure in hypertensive Northern-Nigerians

AimThe study sought to determine whether there is any relationship between plasma homocysteine and blood pressure levels in Nigerians with essential hypertension.MethodIt was a cross-sectional analytical study done on 120 randomly selected hypertensive patients and 120 normal healthy controls seen at the large Conference hall of the Ahmadu Bello University (ABU) Medical Centre, Zaria as well as the ABU Teaching Hospital, Zaria, Northern-Nigeria. Pearson''s Correlation and Binary Logistic Regression analysis determined the relationship between homocysteine and hypertension.ResultsHyperhomocysteinaemia found in the hypertensive patients (22.8 ± 6.6 µmol/L) differed significantly (p<0.001) from controls (10.9 ± 2.8 µmol/L) with significant (p<0.001), blood pressure difference between both groups. Homocysteine significantly positively correlated with systolic (r = 0.51, p<0.001) and diastolic (r = 0.47, p<0.001) blood pressures in hypertensive subjects. The relation of plasma hcy to hypertension was statistically significant for SBP; OR: 1.08 (95% CI, 1.05–1.11) and DBP; OR: 1.08 (95% CI, 1.03–1.13) in the unadjusted model. When adjusted for confounding variables, hcy was significantly related to SBP; OR: 1.1 (95% CI, 1.04–1.18) but not DBP (p=0.25; OR: 1.06 (95 % CI, 0.96–1.18). The mean plasma folate level was high (115.2 ± 48.0 ng/mL) in the hypertensive subjects. The hyperhomocysteinaemic subjects showed a 2.8 times Odds of developing hypertension.ConclusionThis study showed higher mean plasma homocysteine levels in hypertensives than controls not accounted for by sub-optimal folate levels. Hyperhomocysteinaemia showed a positive relationship to systolic hypertension after adjusting for confounders.     

The impact of paracentesis flow rate in patients with liver cirrhosis on the development of paracentesis induced circulatory dysfunction

Background/Aims

Ascites is a dreadful complication of liver cirrhosis associated with short survival. Large volume paracentesis (LVP) is used to treat tense or refractory ascites. Paracentesis induced circulatory dysfunction (PICD) develops if no plasma expanders are given with ominous complications. To study the effect of ascites flow rate on PICD development.

Methods

Sixty patients with cirrhosis and tense ascites underwent LVP of 8 L were randomized into 3 equal groups of different flow rate extraction; group I (80 mL/minute), group II (180 mL/minute) and group III (270 mL/minute). Plasma renin activity (PRA) was measured baseline and on day six. PICD was defined as increase in PRA >50% of the pretreatment value.

Results

In group I through 3; the mean age was (52.5±9.4 vs. 56.4±8.5 vs. 55.8±7.1 years; P>0.05), mean arterial pressure (81.4±5.6 vs. 81.5±7 vs. 79.5±7.2 mmHg; P>0.05), MELD (17.6±4.1 vs. 15.8±4.1 vs. 14.7±4.5). Baseline PRA was comparable (1,366.0±1244.9 vs. 1,151.3±1,444.8 vs. 951.9±1,088 pg/mL; P>0.05). There was no statistically significant (P>0.05) flow mediated changes (Δ) of creatinine (0.23±0.27 vs. 0.38±0.33 vs. 0.26±0.18 mg/dL), MELD (1.25±5.72 vs. 1.70±2.18 vs. 1.45±2.21) or PRA (450.93±614.10 vs. 394.61±954.64 vs. 629.51±1,116.46 pg/mL). PICD was detected in a similar frequency in the three groups (P>0.05). On univariate logistic analysis only female sex was a fairly significant PICD predictor (Wald 3.85, odds ratio 3.14; P=0.05).

Conclusions

The ascites flow rate does not correlate with PICD development.