Erythrocyte's aging in microgravity highlights how environmental stimuli shape metabolism and morphology.

The determination of the function of cells in zero-gravity conditions is a subject of interest in many different research fields. Due to their metabolic unicity, the characterization of the behaviour of erythrocytes maintained in prolonged microgravity conditions is of particular importance. Here, we used a 3D-clinostat to assess the microgravity-induced modifications of the structure and function of these cells, by investigating how they translate these peculiar mechanical stimuli into modifications, with potential clinical interest, of the biochemical pathways and the aging processes. We compared the erythrocyte's structural parameters and selected metabolic indicators that are characteristic of the aging in microgravity and standard static incubation conditions. The results suggest that, at first, human erythrocytes react to external stimuli by adapting their metabolic patterns and the rate of consumption of the cell resources. On longer timeframes, the cells translate even small differences in the environment mechanical solicitations into structural and morphologic features, leading to distinctive morphological patterns of aging.

The natural history of prehypertension. A 20-year follow-up.

OBJECTIVE: According to the JNC7 report, prehypertension category includes subjects with systolic blood pressure between 120 and 139 mmHg and/or diastolic blood pressure between 80 and 89 mmHg that would be at risk for developing hypertension and its untoward sequelae as myocardial infarction and cerebrovascular disease. Moreover, ambulatory blood pressure monitoring made it possible to detect subjects with masked hypertension, who are at risk of greater target organ damage than those with normal ambulatory or home blood pressure. The aim of this study was to evaluate the risk of cardiac, cerebral and vascular events in a group of prehypertensive subjects, with and without masked hypertension. PATIENTS AND METHODS: We studied 204 consecutive asymptomatic prehypertensive subjects without history and signs of cardiovascular disease or diabetes. All the subjects underwent clinical evaluation, electrocardiogram, routine laboratory tests and ambulatory blood pressure monitoring. They were followed-up for a maximum of 237 months or until a cardiovascular event occurred. RESULTS: Twenty-seven cardiovascular events (13.2%) occurred, including 4 abdominal aortic aneurysms. Age (p<0.0001), total cholesterol (p=0.004), smoking (p=0.03) and clinically overt hypertension development (p=0.011) were related to cardiovascular events. Prognosis was not related to masked hypertension. CONCLUSIONS: The results of this study suggest that, in subjects with prehypertension, followed for 20 years, traditional cardiovascular risk factors and development of clinically overt hypertension could be more relevant than ambulatory hypertension in the prediction of an adverse outcome.

Effects of dark chocolate on endothelial function in patients with non-alcoholic steatohepatitis.

BACKGROUND AND AIM: Oxidative stress plays a pivotal role in inducing endothelial dysfunction and progression from simple fatty liver steatosis (FLD) to non-alcoholic steatohepatitis (NASH). Polyphenols could reduce oxidative stress and restore endothelial function by inhibiting the nicotinamide-adenine-dinucleotide-phosphate (NADPH) oxidase isoform Nox2. The aim of this study was to assess endothelial function and oxidative stress in a population affected by simple FLD and NASH. Furthermore, we analysed the effect of high vs low content of cocoa polyphenols on endothelial function and oxidative stress in patients with NASH. METHODS: In a cross-sectional study we analysed endothelial function, as assessed by flow-mediated dilation (FMD), and oxidative stress, as assessed by Nox2 activation, serum isoprostanes and nitric oxide bioavailability (NOx), in patients with NASH (n = 19), FLD (n = 19) and controls (n = 19). Then, we performed a randomized, cross-over study in 19 subjects with NASH comparing the effect of 14-days administration of 40 g of chocolate at high (dark chocolate, cocoa >85%) versus low content (milk chocolate, cocoa <35%) of polyphenols on FMD and oxidative stress. Compared to controls, NASH and FLD patients had higher Nox2 activity and isoprostanes levels and lower FMD and NOx, with a significant gradient between FLD and NASH. The interventional study showed that, compared to baseline, FMD and NOx increased (from 2.9 ± 2.4 to 7.2 ± 3.0% p < 0.001 and from 15.9 ± 3.6 to 20.6 ± 4.9 µM, p < 0.001, respectively) in subjects given dark but not in those given milk chocolate. A simple linear regression analysis showed that Δ (expressed by difference of values between before and after 14 days of chocolate assumption) of FMD was associated with Δ of Nox2 activity (Rs = -0.323; p = 0.04), serum isoprostanes (Rs: -0.553; p < 0.001) and NOx (Rs: 0.557; p < 0.001). CONCLUSIONS: Cocoa polyphenols improve endothelial function via Nox2 down-regulation in NASH patients.

Evaluation of hand circulation with CardioWaves photoplethysmograph device during Allen test in healthy volunteers.

OBJECTIVE: Radial artery occlusion is a potential complication of transradial procedures and its occurrence ranges from 0.8 to 30%. It is virtually always asymptomatic but the functional and sensorial consequences of a long acting hand hypoperfusion could go underestimated. CardioWaves is a novel photoplethysmograh device that allows us to detect the pulse wave amplitude of the blood flowing to the hand. Our objective was to assess in normal subjects the hand blood flow supplied by radial arteries and ulnopalmar arches, respectively, by using CardioWaves device during modified Allen's test (MAT). PATIENTS AND METHODS: MAT was performed on both hands of 60 normal subjects, age ranging 21 to 66 years, without any cardiovascular factor risk. RESULTS: Photoplethysmograh and MAT showed a high positive linear correlation (r=0.93). Despite that, MAT tends to give a higher reading by between 1.05 and 1.6 sec. 11 of 120 readings (9%) by CardioWaves showed values of radial/ulnar pulse amplitude ratio more than mean + 1 SD, suggesting a significant decrease in ulnopalmar arterial circulation when radial blood flow supply would ceased. CONCLUSIONS: The CardioWaves device allows us an accurate reading of the flow because of its independency from respiratory changes. Furthemore, the evaluation of radial and ulnar pulse wave amplitude and the ratio between them would reveal an insufficient blood flow supply by the ulnar artery irrespective of the MAT results. We suggest that their assessment before performing coronary angiography and interventions may reduce potential complication of transradial access.

Blood pressure control and clustering of cardiovascular risk factors in Mediterranean post-menopausal hypertensive women.

BACKGROUND: Control of hypertension is unsatisfactory among older women. Data about Mediterranean countries are not currently reported. AIM: The aim of the present study was to describe the features of blood pressure (BP) control and the clustering of other cardiovascular (CV) risk factors in Mediterranean post-menopausal hypertensive women. PATIENTS AND METHODS: We consecutively selected 516 post-menopausal female patients (mean age 69±11 years) with drug-treated essential hypertension (ESH/ESC grade 1 and 2) for this cross-sectional study. All patients were divided in 4 groups: < 60 years; 60-69 years; 70-79 years; ≥ 80 years. RESULTS: The Kruskal-Wallis analysis of variance showed a significant difference among the 4 age groups both for systolic BP (p < 0.001) and diastolic BP (p < 0.01). Mann-Whitney test for multiple comparisons of each age group vs. octogenarians demonstrated that there is a significant incremental trend of SBP through the age decades. Mean diastolic BP values were significantly higher in younger patients (age decades < 60 and 60-69 years, p < 0.01 and p < 0.05 respectively), while in patients aged 70-79 years there was no difference vs. octogenarians. Dyslipidemia was the more prevalent clustered risk factor with a peak rate of 49% in patients aged 60-69 years, statistically different (p < 0.05) from octogenarians. Global BP control (i.e. treated BP < 140/90 mmHg) was low (33.5% in the whole population) and there was no trend through age decades. CONCLUSIONS: BP control varied across age groups, but was poor. Nevertheless, the studied population appeared to be at low cardiovascular risk, due to a modest clustering of traditional risk factors.

PON1 L55M polymorphism is not a predictor of coronary atherosclerosis either alone or in combination with Q192R polymorphism in an Italian population.

BACKGROUND: The present study evaluated the role of the PON1 L55M polymorphism independently and in conjunction with the Q192R polymorphism on the risk of coronary atherosclerosis in an Italian population. MATERIALS AND METHODS: Three hundred and ninety-one subjects with significant coronary stenosis (> 50%) (coronary artery disease-positive; CAD+), 196 subjects with normal coronary arteries (< 10% stenosis) (CAD-) and 178 healthy controls were screened using a combination of polymerase chain reaction and restriction enzyme digestion. RESULTS: In the pooled population, the frequencies of L and M alleles were 0.63 and 0.37, respectively; the most common haplotypes were QQ/LM (24.2%) and QR/LL (21.8%) and a strong linkage disequilibrium between L/55 and R/192 alleles was observed (D' = -0.91; P < 0.0001). CAD+ subjects did not show any significant differences in the distribution of PON1-55 genotypes as compared to CAD- subjects and population controls (chi2 = 1.5, P = 0.8). After controlling for other risk factors, the low-concentration M allele was not associated with a significant change of CAD risk (OR 1.02; 95% CI 0.80-1.29; P = 0.87). Moreover, the L55M polymorphism did not show any interaction with other risk factors such as smoking, diabetes, hypertension, low levels of high-density lipoprotein (HDL) or high ratios of low-density to high-density lipoproteins. The combination of L55M with the Q192R polymorphism did not show any effect on CAD risk. However, a marginal decrease in myocardial infarction risk was detected when QQ/MM carriers (OR 0.51; 95% CI 0.26-0.99; P = 0.048), but not LL/RR carriers, were compared with subjects not homozygous for an L or R allele. CONCLUSIONS: These findings did not indicate a major effect of the PON1 L55M polymorphism, either alone or in combination with the Q192R polymorphism, on CAD risk. Additional studies are needed for a better evaluation of the role of the 55/192 PON1 genotypes in combination on myocardial infarction risk.

Modified autonomic balance in offsprings of diabetics detected by spectral analysis of heart rate variability.

This study was performed to evaluate the influence of family history for non-insulin-dependent diabetes mellitus (NIDDM) on autonomic balance. The latter was assessed by spectral analysis of heart rate variability (SA-HRV) and by analyzing the relative contribution of low-frequency (LF) and high-frequency (HF) components. Twenty glucose normotolerant offsprings of NIDDM parents and 20 controls underwent a 1-hour continuous electrocardiogram (ECG). LF and HF (mean +/- SEM in normalized units [NU]), respectively increased and decreased in offspring versus controls. The LF/HF ratio (mean +/- SEM) significantly increased (LF/HF = 3.25 +/- 0.7 v 1.45 +/- 0.5, P <.0001 offsprings v controls). To test a stimulated response, a passive tilting (+ 90 degrees ) after 30 minutes of bed rest (0 degrees ) was performed in a subsample of subjects (10 offsprings v 10 controls). During bed rest, we found significantly higher values of the LF/HF ratio in offsprings versus controls (1.93 +/- 0.3 v 1.08 +/- 0.2, P <.05), whereas in the head-up position, the LF/HF ratio value increased to the same levels in the 2 groups (6.48 +/- 1.3 v 6.89 +/- 1.4, not significant [NS]). NIDDM family history is characterized in the basal condition by an imbalance of the autonomic system, which, compared with controls, is expressed by a higher weight of sympathetic and a lower weight of parasympathetic components. No significant differences can be found under stimulated conditions.

The common mutations in the lipoprotein lipase gene in Italy: effects on plasma lipids and angiographically assessed coronary atherosclerosis.

The present study evaluated the role of the common lipoprotein lipase (LPL) mutations on the risk of dyslipidemia and coronary atherosclerosis in an Italian population. Cohorts of 632 patients undergoing coronary angiography, as well as 191 healthy controls, were screened by a combination of PCR and restriction enzyme digestion. In the pooled population, the frequencies of LPL D9N and N291S were 4.1%, with no homozygous carriers, whereas that of LPL S447X was 21% with 19.6% heterozygous and 1.4% homozygous carriers. Compared to non-carriers, LPL N291S carriers showed higher plasma triglycerides (TG) (p < 0.03) and increased risk of high TG phenotype (odds ratio [OR] 2.49, 95% Cl 1.06-5.81; p < 0.03). When this LPL mutation was associated with high body mass index (BMI) ( > 25 Kg/m2) or fasting, plasma insulin (> 10.6 mU ml(-1)) significantly reduced HDL-C levels were also observed. Carriers of the S447X mutation presented with higher HDL-C concentrations (p < 0.05) as compared to non-carriers; they also showed a significantly reduced risk of high TG/low HDL-C dyslipidemia (OR 0.34, 95%, Cl 0.12-0.99; p < 0.05). The favourable effect of the LPL S447X variant was even more pronounced in lean subjects and in those with low insulin levels. No significant influence on plasma lipids by the LPL D9N was observed. None of LPL variants was a significant predictor of angiographically assessed coronary atherosclerosis. At most, the risk was borderline, increased in N291S carriers and possibly decreased in S447X carriers.

A common mutation of the insulin receptor substrate-1 gene is a risk factor for coronary artery disease.

Insulin resistance is associated with increased risk of atherosclerosis. Insulin receptor substrate-1 (IRS-1) plays a key role in tissue insulin sensitivity. A common mutation (G972R) of the IRS-1 gene has been shown to impair IRS-1 function, and it has been associated with reduced insulin sensitivity and lipid abnormalities. This led us to investigate the role of the G972R mutation in predisposing individuals to coronary artery disease (CAD). The DNA of 318 subjects with angiographically documented coronary atherosclerosis (>50% stenosis) and 208 population control subjects was analyzed for the presence of the G972R mutation. This mutation was detected by nested polymerase chain reaction and BstNI restriction enzyme digestion. The frequency of the G972R mutation was significantly higher among patients with CAD than controls (18. 9% versus 6.8%, respectively; P<0.001). After controlling for other coronary risk factors, the relative risk of CAD associated with the G972R mutation was 2.93 (95% CI 1.30 to 6.60; P<0.02) in the entire cohort. This risk was found to be even higher in the subgroups of obese subjects (odds ratio [OR] 6.97, 95% CI 2.24 to 21.4; P<0.001) and subjects with clinical features of insulin resistance syndrome (OR 27.3, 95% CI 7.19 to 104.0; P<0.001). The IRS-1 gene variant was associated with a higher frequency of diabetes mellitus (14.9% among carriers versus 6.5% among noncarriers; P<0.01) and with a 60% increase of plasma total triglycerides (P<0.001). Also, plasma concentrations of total cholesterol and the ratio of total cholesterol to HDL cholesterol were significantly (P<0.001) higher among carriers than noncarriers, although to lesser a extent. These effects were independent of CAD status. The G972R mutation in the IRS-1 gene was found to be a significant independent predictor of CAD. Moreover, this mutation greatly increased the risk of CAD in obese subjects and in patients with the cluster of abnormalities of insulin resistance syndrome. Besides the increased frequency of diabetes, carriers showed a more atherogenic lipid profile, suggesting a potential role of the IRS-1 gene in the pathogenesis of lipid abnormalities associated with CAD.

The gln-Arg192 polymorphism of human paraoxonase gene is not associated with coronary artery disease in italian patients.

Serum paraoxonase (PON) is an HDL-bound enzyme protecting LDL from oxidation. A common polymorphism of the paraoxonase gene (PON1) involving a Gln-to-Arg interchange at position 192 has been demonstrated to modulate PON activity toward paraoxon, a nonphysiological substrate; Arg192 (allele B) is associated with higher activity than Gln192 (allele A). This polymorphism has been proposed as a genetic marker of risk for coronary artery disease (CAD). However, the relationships between codon 192 PON1 genotypes, coronary atherosclerosis, and the occurrence of myocardial infarction (MI) are still controversial. PON1 genotypes were determined in 472 consecutive subjects (>40 years old) who underwent coronary angiography. CAD (>50% stenosis) was detected in 310 subjects (CAD+); 162 subjects with <10% stenosis served as controls (CAD-). We also evaluated 204 randomly selected individuals as population controls. PON1 genotypes were determined by PCR and AlwI restriction enzyme digestion. Frequencies of alleles A and B were 0. 70 and 0.30 in angiographically assessed subjects and 0.73 and 0.27 in population controls, respectively (chi2=2.0; P<0.3). Distribution of PON1 genotypes in CAD+ were not significantly different from those in CAD- (chi2=2.10; P<0.3). Similarly, no differences were observed in the subgroup of CAD+ with MI nor in that at higher oxidative risk (smokers and/or diabetics). After controlling for other coronary risk factors, no association was found between PON1 alleles and the presence of CAD. PON1 AA genotype was associated with reduced concentration of apolipoprotein B-containing triglyceride-rich lipoproteins. This study did not provide evidence of a significant association between codon 192 PON1 genotypes and coronary atherosclerosis in Italian patients. However, it did confirm that the PON1 low-activity allele is associated with a less atherogenic lipid profile.

Angiotensin-converting enzyme gene polymorphism is not associated with coronary atherosclerosis and myocardial infarction in a sample of Italian patients.

BACKGROUND: The deletion (D) allele of the angiotensin-converting enzyme (ACE) gene has been proposed as a genetic marker of the risk of ischaemic heart disease. However, the relationships between ACE genotypes, the development of coronary atherosclerosis and the occurrence of major coronary events are still controversial. METHODS: To investigate whether the ACE I/D (insertion/deletion) polymorphism predicts the risk of coronary stenosis and myocardial infarction (MI), ACE genotypes were determined in 394 consecutive patients who underwent coronary angiography. The presence determined in 394 consecutive patients who underwent coronary angiography. The presence of coronary artery disease (CAD) (defined by > 50% stenosis) was detected in 236 patients (CAD+); 85 of these individuals had a history of MI. Patients with coronary stenosis < 10% (n = 158) served as controls (CAD-). ACE genotypes were determined by agarose gel sizing after polymerase chain reaction (PCR) amplification. RESULTS: The distribution of ACE genotypes in CAD+ patients was not significantly different from that in CAD-patients (chi 2 = 2.63, P < 0.27). After controlling for other coronary risk factors, no significant increase in risk of CAD or MI was found to be associated with the D allele, regardless of whether the D allele was assumed to have a dominant, a codominant or a recessive effect. Similar results were observed in CAD+ patients at lower risk because of low body mass index and apolipoprotein B concentrations. Smoking, apolipoprotein B and history of hypertension were found to be independent predictors of CAD and MI. CONCLUSION: Our study did not provide evidence of a significant association between ACE genotypes and the development of coronary atherosclerosis. It also failed to support a role of ACE I/D polymorphism in favouring the conversion of coronary stenosis to MI.

Interleukins 6 and 8 as mediators of acute phase response in acute myocardial infarction.

The present study provides evidence that interleukin (IL)-6 and IL-8 are the main endogenous mediators of acute phase response in patients with myocardial infarction. This conclusion was supported by the observation of a strict relation between IL-6 elevation and the extent of myocardial tissue damage and rise in body temperature.