Age-Related Impairment in Insulin Release The Essential Role of beta(2)-Adrenergic Receptor

In this study, we investigated the significance of β(2)-adrenergic receptor (β(2)AR) in age-related impaired insulin secretion and glucose homeostasis. We characterized the metabolic phenotype of β(2)AR-null C57Bl/6N mice (β(2)AR(-/-)) by performing in vivo and ex vivo experiments. In vitro assays in cultured INS-1E β-cells were carried out in order to clarify the mechanism by which β(2)AR deficiency affects glucose metabolism. Adult β(2)AR(-/-) mice featured glucose intolerance, and pancreatic islets isolated from these animals displayed impaired glucose-induced insulin release, accompanied by reduced expression of peroxisome proliferator-activated receptor (PPAR)γ, pancreatic duodenal homeobox-1 (PDX-1), and GLUT2. Adenovirus-mediated gene transfer of human β(2)AR rescued these defects. Consistent effects were evoked in vitro both upon β(2)AR knockdown and pharmacologic treatment. Interestingly, with aging, wild-type (β(2)AR(+/+)) littermates developed impaired insulin secretion and glucose tolerance. Moreover, islets from 20-month-old β(2)AR(+/+) mice exhibited reduced density of β(2)AR compared with those from younger animals, paralleled by decreased levels of PPARγ, PDX-1, and GLUT2. Overexpression of β(2)AR in aged mice rescued glucose intolerance and insulin release both in vivo and ex vivo, restoring PPARγ/PDX-1/GLUT2 levels. Our data indicate that reduced β(2)AR expression contributes to the age-related decline of glucose tolerance in mice

Blood pressure control in Italy: analysis of clinical data from 2005-2011 surveys on hypertension

Introduction: Blood pressure (BP) control is poorly achieved in hypertensive patients, worldwide. Aim: We evaluated clinic BP levels and the rate of BP control in hypertensive patients included in observational studies and clinical surveys published between 2005 and 2011 in Italy. Methods: We reviewed the medical literature to identify observational studies and clinical surveys on hypertension between January 2005 and June 2011, which clearly reported information on clinic BP levels, rates of BP control, proportions of treated and untreated patients, who were followed in different clinical settings (mostly in general practice, and also in outpatient clinics and hypertension centres). Results: The overall sample included 158 876 hypertensive patients (94 907 women, mean age 56.6 +/- 9.6 years, BMI 27.2 +/- 4.2 kg/m(2), known duration of hypertension 90.2 +/- 12.4 months). In the selected studies, average SBP and DBP levels were 145.7 +/- 15.9 and 87.5 +/- 9.7 mmHg, respectively; BP levels were higher in patients followed in hypertension centres (n = 10 724, 6.7%; 146.5 +/- 17.3/88.5 +/- 10.3 mmHg) than in those followed by general practitioners (n = 148 152, 93.3%; 143.5 +/- 13.9/84.8 +/- 8.9 mmHg; P < 0.01). More than half of the patients were treated (n = 91 318, 57.5%); among treated hypertensive patients, only 31 727 (37.0%) had controlled BP levels. Conclusion: The present analysis confirmed inadequate control of BP in Italy, independently of the clinical setting. Although some improvement was noted compared with a similar analysis performed between 1995 and 2005, these findings highlight the need for a more effective clinical management of hypertension

Cerebral embolic lesions detected with diffusion-weighted magnetic resonance imaging following carotid artery stenting: a meta-analysis of 8 studies comparing filter cerebral protection and proximal balloon occlusion.

OBJECTIVES: The aim of this meta-analysis was to evaluate and compare the efficacy of the 2 different neuroprotection systems in preventing embolization during carotid artery stenting (CAS), as detected by diffusion-weighted magnetic resonance imaging (DW-MRI). BACKGROUND: Data from randomized and nonrandomized studies comparing both types of embolic protection devices revealed contrasting evidence about their efficacy in neuroprotection, as assessed by the incidence of new ischemic lesions detected by DW-MRI. METHODS: Eight studies, enrolling 357 patients, were included in the meta-analysis. Our study analyzed the incidence of new ischemic lesions/patient, comparing filter cerebral protection and proximal balloon occlusion. RESULTS: Following CAS, the incidence of new ischemic lesions/patient detected by DW-MRI was significantly lower in the proximal balloon occlusion group (effect size [ES]: -0.43; 95% confidence interval [CI]: -0.84 to -0.02, I(2) = 70.08, Q = 23.40). Furthermore, following CAS, the incidence of lesions at the contralateral site was significantly lower in the proximal protection group (ES: -0.50; 95% CI: -0.72 to -0.27, I(2) = 0.00, Q = 3.80). CONCLUSIONS: Our meta-analysis supports the concept that the use of proximal balloon occlusion compared with filter cerebral protection is associated with a reduction of the amount of CAS-related brain embolization. The data should be confirmed by a randomized clinical tria

Endovascular treatment of lower extremity arteries is associated with an improved outcome in diabetic patients affected by intermittent claudication

BACKGROUND: Lower extremity peripheral arterial disease (LE-PAD) is a highly prevalent condition among diabetic patients, associated with reduced walking capacity and a high incidence of cardiovascular events. Endovascular revascularization of lower extremities arteries improves walking performance and quality of life of diabetic patients affected by intermittent claudication, but few studies evaluated the impact of revascularization on cardiovascular outcome in this high-risk population. Accordingly, in the present study we evaluated if leg-ischemia resolution by effective lower limbs percutaneous revascularization can also impact cardiovascular outcome in a homogeneous group of diabetic patients affected by intermittent claudication. METHODS: 236 diabetic patients affected by LE-PAD at stage II of Fontaine's classification, with ankle/brachial index ≤ 0.90 and one or more hemodynamically significant stenosis in at least one artery of the ileo-femoro-popliteal axis were enrolled in the study. According to the Trans-Atlantic Inter Society Consensus II recommendations, 123 (52.1%) underwent percutaneous transluminal angioplasty (PTA group), while 113 (47.9%) underwent conservative medical therapy only (MT group). The incidence of major cardiovascular events (cardiovascular death, myocardial infarction, ischemic stroke, coronary or carotid revascularization) was prospectively analyzed with Kaplan-Meier curves and the risk of developing a cardiovascular event calculated by Cox analyses. RESULTS: No baseline difference in cardiovascular risk factors were observed between the PTA and MT groups, except for a lower prevalence of males in PTA group (74.8% vs. 85.8%, p=0.034). Furthermore, patients in the PTA group showed a worse walking capacity as expressed by maximum walking distance (108.7 ± 300.9 vs 378.4 ± 552.3 meters, p<0.001). During a median follow-up of 20 months (12.0-29.0), the incidence of cardiovascular events was markedly lower in patients in the PTA group with respect to patients in the MT group (7.3% vs. 22.1%, p=0.001), and patients of the MT group had at Cox analysis a 3.9 increased risk with respect to PTA group, after adjustment for potential confounding factors (95% CI 1.1-15.3, p=0.049). CONCLUSIONS: The present study shows that lower limbs revascularization of diabetic patients affected by intermittent claudication, in addition to improve walking performance, is associated with a reduction in the incidence of future major cardiovascular events

Experimental Evolution of Extreme Resistance to Ionizing Radiation in Escherichia coli after 50 Cycles of Selection.

In previous work (D. R. Harris et al., J Bacteriol 191:5240-5252, 2009, https://doi.org/10.1128/JB.00502-09; B. T. Byrne et al., Elife 3:e01322, 2014, https://doi.org/10.7554/eLife.01322), we demonstrated that Escherichia coli could acquire substantial levels of resistance to ionizing radiation (IR) via directed evolution. Major phenotypic contributions involved adaptation of organic systems for DNA repair. We have now undertaken an extended effort to generate E. coli populations that are as resistant to IR as Deinococcus radiodurans After an initial 50 cycles of selection using high-energy electron beam IR, four replicate populations exhibit major increases in IR resistance but have not yet reached IR resistance equivalent to D. radiodurans Regular deep sequencing reveals complex evolutionary patterns with abundant clonal interference. Prominent IR resistance mechanisms involve novel adaptations to DNA repair systems and alterations in RNA polymerase. Adaptation is highly specialized to resist IR exposure, since isolates from the evolved populations exhibit highly variable patterns of resistance to other forms of DNA damage. Sequenced isolates from the populations possess between 184 and 280 mutations. IR resistance in one isolate, IR9-50-1, is derived largely from four novel mutations affecting DNA and RNA metabolism: RecD A90E, RecN K429Q, and RpoB S72N/RpoC K1172I. Additional mechanisms of IR resistance are evident.IMPORTANCE Some bacterial species exhibit astonishing resistance to ionizing radiation, with Deinococcus radiodurans being the archetype. As natural IR sources rarely exceed mGy levels, the capacity of Deinococcus to survive 5,000 Gy has been attributed to desiccation resistance. To understand the molecular basis of true extreme IR resistance, we are using experimental evolution to generate strains of Escherichia coli with IR resistance levels comparable to Deinococcus Experimental evolution has previously generated moderate radioresistance for multiple bacterial species. However, these efforts could not take advantage of modern genomic sequencing technologies. In this report, we examine four replicate bacterial populations after 50 selection cycles. Genomic sequencing allows us to follow the genesis of mutations in populations throughout selection. Novel mutations affecting genes encoding DNA repair proteins and RNA polymerase enhance radioresistance. However, more contributors are apparent

PREVALENCE OF 'BORDERLINE' VALUES OF CARDIOVASCULAR RISK FACTORS IN THE CLINICAL PRACTICE OF GENERAL MEDICINE IN ITALY: RESULTS OF THE BORDERLINE STUDY.

INTRODUCTION: The prevalence of patients with 'borderline' levels of cardiovascular risk factors has been rarely investigated, being often reported in studies evaluating abnormal values of these parameters. The BORDERLINE study represents a pilot experience to primarily identify the prevalence of 'high-normal' conditions, such as pre-hypertension, lipid and glucose levels in the upper range of normality in the setting of general practice in Italy. AIM: The aim of this study was to evaluate the prevalence of patients with 'borderline' values of cardiovascular risk factors in Italy. METHODS: Involved physicians were asked to evaluate the first 20 outpatients, consecutively seen in June 2009. Data were collected in a study-designed case-report form, in which physicians identified thresholds rather than reported absolute values of several clinical parameters. High-normal values were defined as follows: blood pressure (BP) 130-140/85-90 mmHg; total cholesterol 180-200 mg/dL; low-density lipoprotein cholesterol (LDL-C) 130-150 mg/dL; high-density lipoprotein cholesterol (HDL-C) 30-40 mg/dL in males and 40-50 mg/dL in females; triglycerides 130-150 mg/dL and fasting glucose 100-110 mg/dL. RESULTS: Fifty-three Italian physicians provided valuable clinical data on 826 individual outpatients, among which 692 (83.7%, 377 women, mean age 60.9 ± 13.2 years, body mass index 26.6 ± 5.0 kg/m2) were included in the present analysis. Prevalence of borderline values of systolic BP and total cholesterol levels were at least comparable with those in the normal limits of the corresponding parameters, whereas prevalence of borderline diastolic BP, LDL-C, HDL-C, triglycerides and fasting glucose levels was significantly lower than that of normal values, but higher than that of abnormal values of the corresponding parameters. CONCLUSIONS: Using this sample of healthy subjects in the setting of general practice in Italy, our results demonstrated a relatively high prevalence of borderline values of cardiovascular risk factors, which was at least comparable with that of normal, but significantly higher than that of abnormal thresholds. These preliminary findings may prompt more extensive investigations in the area of 'borderline' cardiovascular risk. This information may, in fact, potentially enable the design of more effective prevention strategies in the future to limit the burden of cardiovascular disease in the general population in Italy

GRK2 Levels in Umbilical Arteries of Pregnancies Complicated by Gestational Hypertension and Preeclampsia

BACKGROUND G-Protein coupled receptor kinase 2 (GRK2) represents a regulator of cell function in different cardiovascular conditions, including high blood pressure. The relationship between elevated GRK2 levels and impaired vasorelaxant responses is causative of hypertension through the increase in vascular resistances. The aim of this study is to ascertain if this feature is present in the fetal placental vasculature of pregnancies complicated by hypertensive disorders. METHODS We have assessed GRK2 levels in the umbilical arteries (UA) of 21 preeclamptic or gestational hypertensive and 23 normotensive women at time of delivery. RESULTS GRK2 levels were increased in the hypertensive group (0.83 +/- 0.14 vs. 0.48 +/- 0.06 densitometry units; P < 0.05). GRK2 levels were in correlation and in linear regression with systolic, diastolic, and mean arterial pressure (P < 0.05, r(2) = 0.12, r(2) = 0.11, r(2) = 0.12). Correlations did not reach a significant value for other clinical parameters such as gestational age at birth, umbilical artery pulsatility index, maternal proteinuria, and neonatal birth weight. Out of the 21 hypertensive women, 7 who developed a preeclampsia associated with early preterm delivery (before 34 weeks) had a significantly lower GRK2 levels compared to the remaining 14 (0.51 +/- 0.12 vs. 1.08 +/- 0.20 densitometry units, P < 0.05). CONCLUSIONS We conclude that elevated GRK2 levels in the umbilical vasculature is correlated to elevated blood pressure levels, with a likely compensatory rather than causative role since the lack of protective effect of elevated GRK2 levels may negatively affect the outcome of the hypertensive state

Predictors of carotid occlusion intolerance?during proximal protected?carotid artery?stenting.

OBJECTIVES: The aim of this study was to identify predictors of occlusion intolerance (OI) developing during proximal protected carotid artery stenting (CAS). BACKGROUND: The use of proximal embolic protection devices, such as endovascular occlusion, during CAS has been demonstrated to be particularly safe and effective. However, endovascular occlusion can expose the ipsilateral hemisphere to hypoperfusion and produce transient neurological symptoms (OI). METHODS: From March 2010 to March 2012, 605 consecutive patients underwent proximal protected CAS at our institution. To identify independent predictors of OI, a multivariate logistic regression model was developed that included all patients' clinical/angiographic and procedural characteristics. RESULTS: OI developed in a total of 184 patients (30.4%). Compared with patients in whom OI did not develop, those who experienced OI had lower occlusion pressure (OP) (42.3 ± 12.7 mm Hg vs. 61.9 ± 15.4 mm Hg, p < 0.001). Receiver-operating characteristic curve analysis demonstrated that OP was the most consistent predictor of OI with a C-statistic of 0.85 (95% confidence interval [CI]: 0.82 to 0.88) with best cutoff being ≤40 mm Hg (sensitivity, 68.5%; specificity, 93.3%). By logistic regression analysis, the most powerful independent predictor of OI developing was an OP ≤40 mm Hg (odds ratio: 33.2, 95% CI: 19.1 to 57.7) and the most powerful clinical predictor of such OP was the presence of contralateral internal carotid artery occlusion (odds ratio: 3.1, 95% CI: 1.5 to 6.2). CONCLUSIONS: OI may occur in as many as one-third of the patients undergoing proximal protected CAS. This event is more common in those patients with an OP ≤40 mm Hg. Patients presenting with concomitant occlusion of the contralateral internal carotid artery more frequently have an OP ≤40 mm Hg

Blood pressure control in Italy: analysis of clinical data from 2005-2011 surveys on hypertension

INTRODUCTION: Blood pressure (BP) control is poorly achieved in hypertensive patients, worldwide. AIM: We evaluated clinic BP levels and the rate of BP control in hypertensive patients included in observational studies and clinical surveys published between 2005 and 2011 in Italy. METHODS: We reviewed the medical literature to identify observational studies and clinical surveys on hypertension between January 2005 and June 2011, which clearly reported information on clinic BP levels, rates of BP control, proportions of treated and untreated patients, who were followed in different clinical settings (mostly in general practice, and also in outpatient clinics and hypertension centres). RESULTS: The overall sample included 158 876 hypertensive patients (94 907 women, mean age 56.6 ± 9.6 years, BMI 27.2 ± 4.2 kg/m(2), known duration of hypertension 90.2 ± 12.4 months). In the selected studies, average SBP and DBP levels were 145.7 ± 15.9 and 87.5 ± 9.7 mmHg, respectively; BP levels were higher in patients followed in hypertension centres (n = 10 724, 6.7%; 146.5 ± 17.3/88.5 ± 10.3 mmHg) than in those followed by general practitioners (n = 148 152, 93.3%; 143.5 ± 13.9/84.8 ± 8.9 mmHg; P < 0.01). More than half of the patients were treated (n = 91 318, 57.5%); among treated hypertensive patients, only 31 727 (37.0%) had controlled BP levels. CONCLUSION: The present analysis confirmed inadequate control of BP in Italy, independently of the clinical setting. Although some improvement was noted compared with a similar analysis performed between 1995 and 2005, these findings highlight the need for a more effective clinical management of hypertension