415 research outputs found

    Obesity-related perivascular adipose tissue damage is reversed by sustained weight loss in the rat

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    Objective – Perivascular adipose tissue (PVAT) exerts an anticontractile effect in response to various vasoconstrictor agonists and this is lost in obesity. A recent study reported that bariatric surgery reverses the damaging effects of obesity on PVAT function. However, PVAT function has not been characterised following weight loss induced by caloric restriction, which is often the first line treatment for obesity. Approach and Results – Contractility studies were performed using wire myography on small mesenteric arteries with and without PVAT from control, diet-induced obese, calorie restricted and sustained weight loss rats. Changes in the PVAT environment were assessed using immunohistochemistry. PVAT from healthy animals elicited an anticontractile effect in response to norepinephrine. This was abolished in diet-induced obesity through a mechanism involving increased local TNFα and reduced nitric oxide bioavailability within PVAT. Sustained weight loss led to improvement in PVAT function associated with restoration of adipocyte size, reduced TNFα and increased nitric oxide synthase function. This was associated with reversal of obesity-induced hypertension and normalisation of plasma adipokine levels, including leptin and insulin. Conclusions – We have shown that diet-induced weight loss reverses obesity-induced PVAT damage through a mechanism involving reduced inflammation and increased nitric oxide synthase activity within PVAT. These data reveal inflammation and nitric oxide synthase, particularly eNOS, as potential targets for the treatment of PVAT dysfunction associated with obesity and the metabolic syndrome

    Improving the effectiveness of psychological interventions for depression and anxiety in the cardiac rehabilitation pathway using group-based metacognitive therapy (PATHWAY Group MCT) : study protocol for a randomised controlled trial

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    BACKGROUND: Anxiety and depression are prevalent among cardiac rehabilitation patients but pharmacological and psychological treatments have limited effectiveness in this group. Furthermore, psychological interventions have not been systematically integrated into cardiac rehabilitation services despite being a strategic priority for the UK National Health Service. A promising new treatment, metacognitive therapy, may be well-suited to the needs of cardiac rehabilitation patients and has the potential to improve outcomes. It is based on the metacognitive model, which proposes that a thinking style dominated by rumination, worry and threat monitoring maintains emotional distress. Metacognitive therapy is highly effective at reducing this thinking style and alleviating anxiety and depression in mental health settings. This trial aims to evaluate the effectiveness and cost-effectiveness of group-based metacognitive therapy for cardiac rehabilitation patients with elevated anxiety and/or depressive symptoms. METHODS/DESIGN: The PATHWAY Group-MCT trial is a multicentre, two-arm, single-blind, randomised controlled trial comparing the clinical- and cost-effectiveness of group-based metacognitive therapy plus usual cardiac rehabilitation to usual cardiac rehabilitation alone. Cardiac rehabilitation patients (target sample n = 332) with elevated anxiety and/or depressive symptoms will be recruited across five UK National Health Service Trusts. Participants randomised to the intervention arm will receive six weekly sessions of group-based metacognitive therapy delivered by either cardiac rehabilitation professionals or research nurses. The intervention and control groups will both be offered the usual cardiac rehabilitation programme within their Trust. The primary outcome is severity of anxiety and depressive symptoms at 4-month follow-up measured by the Hospital Anxiety and Depression Scale total score. Secondary outcomes are severity of anxiety/depression at 12-month follow-up, health-related quality of life, severity of post-traumatic stress symptoms and strength of metacognitive beliefs at 4- and 12-month follow-up. Qualitative interviews will help to develop an account of barriers and enablers to the effectiveness of the intervention. DISCUSSION: This trial will evaluate the effectiveness and cost-effectiveness of group-based metacognitive therapy in alleviating anxiety and depression in cardiac rehabilitation patients. The therapy, if effective, offers the potential to improve psychological wellbeing and quality of life in this large group of patients. TRIAL REGISTRATION: UK Clinical Trials Gateway, ISRCTN74643496 , Registered on 8 April 2015

    Detectable Clonal Mosaicism from Birth to Old Age and its Relationship to Cancer

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    Clonal mosaicism for large chromosomal anomalies (duplications, deletions and uniparental disomy) was detected using SNP microarray data from over 50,000 subjects recruited for genome-wide association studies. This detection method requires a relatively high frequency of cells (>5–10%) with the same abnormal karyotype (presumably of clonal origin) in the presence of normal cells. The frequency of detectable clonal mosaicism in peripheral blood is low (<0.5%) from birth until 50 years of age, after which it rises rapidly to 2–3% in the elderly. Many of the mosaic anomalies are characteristic of those found in hematological cancers and identify common deleted regions that pinpoint the locations of genes previously associated with hematological cancers. Although only 3% of subjects with detectable clonal mosaicism had any record of hematological cancer prior to DNA sampling, those without a prior diagnosis have an estimated 10-fold higher risk of a subsequent hematological cancer (95% confidence interval = 6–18)

    Impaired flow-induced arterial remodeling in DOCA-salt hypertensive rats

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    Arteries from young healthy animals respond to chronic changes in blood flow and blood pressure by structural remodeling. We tested whether the ability to respond to decreased (-90%) or increased (+100%) blood flow is impaired during the development of deoxycorticosterone acetate (DOCA)-salt hypertension in rats, a model for an upregulated endothelin-1 system. Mesenteric small arteries (MrA) were exposed to low blood flow (LF) or high blood flow (HF) for 4 or 7 weeks. The bioavailability of vasoactive peptides was modified by chronic treatment of the rats with the dual neutral endopeptidase (NEP)/endothelin-converting enzyme (ECE) inhibitor SOL1. After 3 or 6 weeks of hypertension, the MrA showed hypertrophic arterial remodeling (3 weeks: media cross-sectional area (mCSA): 10 +/- 1 x 10(3) to 17 +/- 2 x 10(3) mu m(2); 6 weeks: 13 +/- 2 x 10(3) to 24 +/- 3 x 10(3) mu m(2)). After 3, but not 6, weeks of hypertension, the arterial diameter was increased (empty set: 385 +/- 13 to 463 +/- 14 mu m). SOL1 reduced hypertrophy after 3 weeks of hypertension (mCSA: 6 x 10(3) +/- 1 x 10(3) mu m(2)). The diameter of the HF arteries of normotensive rats increased (empty set: 463 +/- 22 mu m) but no expansion occurred in the HF arteries of hypertensive rats (empty set: 471 +/- 16 mu m). MrA from SOL1-treated hypertensive rats did show a significant diameter increase (empty set: 419 +/- 13 to 475 +/- 16 mu m). Arteries exposed to LF showed inward remodeling in normotensive and hypertensive rats (mean empty set between 235 and 290 mu m), and infiltration of monocyte/ macrophages. SOL1 treatment did not affect the arterial diameter of LF arteries but reduced the infiltration of monocyte/ macrophages. We show for the first time that flow-induced remodeling is impaired during the development of DOCA-salt hypertension and that this can be prevented by chronic NEP/ECE inhibition. Hypertension Research (2012) 35, 1093-1101; doi:10.1038/hr.2012.94; published online 12 July 201

    Modulation of vascular reactivity by perivascular adipose tissue (PVAT)

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    Purpose of Review: In this review we discuss the role of perivascular adipose tissue (PVAT) in the modulation of vascular contractility and arterial pressure, focusing on the role of the renin-angiotensin-aldosterone system and oxidative stress/inflammation. Recent Findings: PVAT possesses an relevant endocrine-paracrine activity, which may be altered in several pathophysiological and clinical conditions. During the last two decades it has been shown PVAT may modulate vascular reactivity. It has also been previously demonstrated that inflammation in adipose tissue may be implicated in vascular dysfunction. In particular, adipocytes secrete a number of adipokines with various functions, as well as several vasoactive factors, together with components of the renin-angiotensin system which may act at local or at systemic level. It has been shown that the anticontractile effect of PVAT is lost in obesity, probably as a consequence of the development of adipocyte hypertrophy, inflammation, and oxidative stress. Summary: Adipose tissue dysfunction is interrelated with inflammation and oxidative stress, thus contributing to endothelial dysfunction observed in several pathological and clinical conditions such as obesity and hypertension. Decreased local adiponectin level, macrophage recruitment and infiltration, and activation of renin-angiotensin-aldosterone system could play an important role in this regards

    Susceptibility to multiple cutaneous basal cell carcinomas: significant interactions between glutathione S-transferase GSTM1 genotypes, skin type and male gender.

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    The factors that determine development of single and multiple primary cutaneous basal cell carcinomas (BCCs) are unclear. We describe a case-control study firstly, to examine the influence of allelism at the glutathione S-transferase GSTM1 and GSTT1 and cytochrome P450 CYP2D6 loci on susceptibility to these tumours and, secondly, to identify interactions between genotypes and relevant individual characteristics, such as skin type and gender. Frequency distributions for GSTM1 genotypes in cases and controls were not different, although the frequency of GSTM1 A/B was significantly lower (P = 0.048) in the multiple BCCs than in controls. We found no significant differences in the frequencies of GSTT1 and CYP2D6 genotypes in cases and controls. Interactions between genotypes were studied by comparing multinomial frequency distributions in mutually exclusive groups. These identified no differences between cases and controls for combinations of the putatively high risk GSTM1 null, GSTT1 null, CYP2D6 EM genotypes. Interactions between GSTM1 A/B and the CYP2D6 PM and GSTT1-positive genotypes were also not different. Frequency distributions of GSTM1 A/B with CYP2D6 EM in controls and multiple BCCs were significantly different (P = 0.033). The proportion of males in the multiple BCC group (61.3%) was greater than in controls (47.0%) and single BCC (52.2%), and the frequency of the combination GSTM1 null/male gender was significantly greater in patients with multiple tumours (P = 0.002). Frequency distributions of GSTM1 null/skin type 1 were also significantly different (P = 0.029) and the proportion of subjects who were GSTM1 null with skin type 1 was greater (P = 0.009) in the multiple BCC group. We examined the data for interactions between GSTM1 null/skin type 1/male gender by comparing frequency distributions of these factors in the single and multiple BCC groups. The distributions were almost significantly different (exact P = 0.051). No significant interactions between GSTT1 null or CYP2D6 EM and skin type 1 were identified. Comparisons of frequency distributions of smoking with the GSTM1 null, GSTT1 null and CYP2D6 EM genotypes identified no differences between patients with single and multiple tumours

    Investigation and Management of Resistant Hypertension:British and Irish Hypertension Society Position Statement

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    People living with resistant hypertension (RH) are at high risk of adverse cardiovascular events. The British and Irish Hypertension Society has identified suspected RH as a condition for which specialist guidance may improve rates of blood pressure control and help clinicians identify those individuals who may benefit from specialist review. In this position statement we provide a practical approach for the investigation and management of adults with RH. We highlight gaps in the current evidence and identify important future research questions. Our aim is to support the delivery of high-quality and consistent care to people living with RH across the UK and Ireland
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