A randomised placebo controlled trial of VSL#3® probiotic on biomarkers of cardiovascular risk and liver injury in non-alcoholic fatty liver disease.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is associated with increased cardiovascular risk irrespective of conventional risk factors. The role of gut-liver interaction is implicated in its development. We investigated the effects of VSL#3® probiotic supplementation on biomarkers of cardiovascular risk and liver injury in patients with NAFLD. METHODS: A randomised, double-blinded, placebo-controlled, proof-of-concept study was undertaken. Patients with NAFLD were randomly allocated to take 2 sachets VSL#3® probiotic or placebo twice daily for 10 weeks. Measurements of endothelial function (digital photoplethysmography, sVCAM-1 and cGMP), oxidative stress (glutathione ratio and LHP), inflammation (hsCRP), insulin resistance (HOMA-IR) and liver injury [transaminases, fibrosis risk score and acoustic structure quantification (ASQ)] were undertaken before and after intervention. Difference in baseline characteristics between the treatment groups was analysed using independent t-test or Mann Whitney U test for non-parametric data. Independent t-test was used to compare the outcomes at the end of the study between the two treatment groups. Wilcoxon Signed Rank test was used to determine the difference in fibrosis risk scores before and after treatment. Spearman's correlation was used to determine any association between cardiovascular and hepatic markers at baseline. RESULTS: Thirty-five patients completed the study (28 males and 7 females) with a mean age of 57 ± 8 years, body mass index of 32.6 ± 5.0 kg/m2 and a relatively short duration of NAFLD (median duration 0.3 IQR 2.0 years). No significant difference was observed in biomarkers of cardiovascular risk and liver injury following VSL#3® supplementation. Significant correlations were noted between sVCAM-1 and hsCRP (rho = 0.392, p = 0.01), and HOMA-IR and AST (rho = 0.489, p < 0.01) at baseline. CONCLUSIONS: This is the first study to evaluate the effect of VSL#3® on ASQ in patients with NAFLD. VSL#3® did not significantly improve markers of cardiovascular risk and liver injury in patients with NAFLD. However, the study supports an association between endothelial dysfunction and inflammation in patients with NAFLD and suggests that NAFLD is linked with insulin resistance. TRIAL REGISTRATION: ISRCTN05474560 ( https://doi.org/10.1186/ISRCTN05474560 ) Registered 9 August 2012 (retrospectively registered).

Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) in Human Lung Microvascular Endothelial Cells Controls Oxidative Stress, Reactive Oxygen-Mediated Cell Signaling and Inflammatory Responses.

BACKGROUND: Perturbation of endothelial function in people with cystic fibrosis (CF) has been reported, which may be associated with endothelial cell expression of the cystic fibrosis transmembrane conductance regulator (CFTR). Previous reports indicate that CFTR activity upregulates endothelial barrier function, endothelial nitric oxide synthase (eNOS) expression and NO release, while limiting interleukin-8 (IL-8) release, in human umbilical vein endothelial cells (HUVECs) in cell culture. In view of reported microvascular dysfunction in people with CF we investigated the role of CFTR expression and activity in the regulation of oxidative stress, cell signaling and inflammation in human lung microvascular endothelial cells (HLMVECs) in cell culture. METHODS: HLMVECs were cultured in the absence and presence of the CFTR inhibitor GlyH-101 and CFTR siRNA. CFTR expression was analyzed using qRT-PCR, immunocytochemistry (IHC) and western blot, and function by membrane potential assay. IL-8 expression was analyzed using qRT-PCR and ELISA. Nrf2 expression, and NF-κB and AP-1 activation were determined using IHC and western blot. The role of the epidermal growth factor receptor (EGFR) in CFTR signaling was investigated using the EGFR tyrosine kinase inhibitor AG1478. Oxidative stress was measured as intracellular ROS and hydrogen peroxide (H2O2) concentration. VEGF and SOD-2 were measured in culture supernatants by ELISA. RESULTS: HLMVECs express low levels of CFTR that increase following inhibition of CFTR activity. Inhibition of CFTR, significantly increased intracellular ROS and H2O2 levels over 30 min and significantly decreased Nrf2 expression by 70% while increasing SOD-2 expression over 24 h. CFTR siRNA significantly increased constitutive expression of IL-8 by HLMVECs. CFTR inhibition activated the AP-1 pathway and increased IL-8 expression, without effect on NF-κB activity. Conversely, TNF-α activated the NF-κB pathway and increased IL-8 expression. The effects of TNF-α and GlyH-101 on IL-8 expression were additive and inhibited by AG1478. Inhibition of both CFTR and EGFR in HLMVECs significantly increased VEGF expression. The antioxidant N-acetyl cysteine significantly reduced ROS production and the increase in IL-8 and VEGF expression following CFTR inhibition. CONCLUSION: Functional endothelial CFTR limits oxidative stress and contributes to the normal anti-inflammatory state of HLMVECs. Therapeutic strategies to restore endothelial CFTR function in CF are warranted.

Effects of collagen-derived bioactive peptides and natural antioxidant compounds on proliferation and matrix protein synthesis by cultured normal human dermal fibroblasts.

Nutraceuticals containing collagen peptides, vitamins, minerals and antioxidants are innovative functional food supplements that have been clinically shown to have positive effects on skin hydration and elasticity in vivo. In this study, we investigated the interactions between collagen peptides (0.3-8 kDa) and other constituents present in liquid collagen-based nutraceuticals on normal primary dermal fibroblast function in a novel, physiologically relevant, cell culture model crowded with macromolecular dextran sulphate. Collagen peptides significantly increased fibroblast elastin synthesis, while significantly inhibiting release of MMP-1 and MMP-3 and elastin degradation. The positive effects of the collagen peptides on these responses and on fibroblast proliferation were enhanced in the presence of the antioxidant constituents of the products. These data provide a scientific, cell-based, rationale for the positive effects of these collagen-based nutraceutical supplements on skin properties, suggesting that enhanced formation of stable dermal fibroblast-derived extracellular matrices may follow their oral consumption.

Azo compounds in colon-specific drug delivery.

Azo compounds have the potential to act as drug carriers that facilitate the selective release of therapeutic agents to the colon, and also to effect the oral administration of those macromolecular drugs that require colon-specific drug delivery. With some further research-driven refinements, these materials may lead to more efficient treatments for local conditions, such as colonic cancer or inflammatory bowel disease. This article provides an overview of the azo-based systems developed to date, identifies the requirements for an ideal carrier, and highlights the directions for further developments in the field of azo group-facilitated colonic delivery.

Orally administered, colon-specific mucoadhesive azopolymer particles for the treatment of inflammatory bowel disease: An in vivo study.

Radiolabeled congeners of a series of azopolymers have been synthesized and characterized. The in vivo (rat) gastrointestinal transit profile of millimeter-sized particles of these azopolymers has been determined and used to facilitate the selection of a candidate material for therapeutic applications. The efficacy of the selected material as a protective coating for the colonic mucosa has been tested in a hapten-reactivated, in vivo model of inflammatory bowel disease: 7 days after reactivation of the condition, the myeloperoxidase activity of animals that had received doses of the selected azopolymer was determined to be at the same level as that of healthy animals or that of the negative control group, highlighting the therapeutic promise of this material.

Attitudes to concept maps as a teaching/learning activity in undergraduate health professional education: influence of preferred approach to learning.

Pre-prepared concept maps that organise knowledge in a non-linear fashion appeal to a variety of cognitive learning styles and may thus represent an educational tool that supports 'teaching to all types'. However, another central cognitive factor, learning approach, may have a bearing on student take-up of this learning resource. Student attitudes to pre-prepared concept maps introduced in Stage 2 MPharm and BSc Pharmacology lectures were therefore examined in relation to the principal learning orientations according to Duff's 30-item revised approaches to study inventory (RASI). Approximately one half of students (49.6 +/- 4.5%) reported pre-prepared concept maps to be useful to their learning (n = 121). When preferred learning approach was examined, derived from the highest RASI score per individual and excluding ties, 31.9 +/- 4.3%, 29.3 +/- 4.2% and 38.8 +/- 4.5% of students demonstrated a preference for the deep approach (DA), strategic approach (STA) and surface approach (SUA), respectively (P > 0.05, chi2 goodness-of-fit test, n = 116). There was a weak but statistically significant association between preferred learning approach identified by Duff's 30-item RASI and the self-reported usefulness of concept maps (P < 0.05, chi2 test of independence; Cramer's V = 0.235; lambda = 0.193). In contrast, gender was not significantly associated with attitude to concept maps in this student cohort. A preliminary analysis of standardised residuals based on observed and expected frequencies revealed that the greatest contributions to this significant association were: a positive influence of DA and a negative influence of STA, respectively, on attitude to concept maps. These data now indicate a contribution of the principal learning orientations vis-à-vis student attitudes to pre-prepared concept maps when employed alongside more traditional teaching/learning activities in medical and biomedical science education, and may further suggest a role for concept maps in the support of deep learning.

The effects of garlic extract upon endothelial function, vascular inflammation, oxidative stress and insulin resistance in adults with type 2 diabetes at high cardiovascular risk. A pilot double blind randomized placebo controlled trial.

BACKGROUND AND AIMS: Endothelial dysfunction, vascular inflammation and oxidative stress have been integrally linked to the pathogenesis of both type 2 diabetes and cardiovascular disease. Aged Garlic Extract (AGE), a potent antioxidant, has been shown in previous studies to attenuate these novel risk factors in a non-diabetic population. AIMS: This study tested the hypothesis that AGE may improve endothelial function, oxidative stress, vascular inflammation and insulin resistance in high risk cardiovascular subjects with type 2 diabetes. METHODS: A double blind, placebo controlled crossover pilot study was performed in 26 subjects with type 2 diabetes who received 1200 mg of AGE or placebo daily for 4 weeks with a 4 week washout period. Plasma HsCRP was measured as a marker of inflammation. Plasma TAOS, blood GSH/GSSG and plasma LHP were measured as markers of oxidative stress/anti-oxidant defense. Insulin resistance was measured using the HOMA-IR method. Endothelial function was measured using change in the reflective index (RI) post-salbutamol using digital photoplethysmography and urinary albumin/creatinine ratio was measured as a biochemical surrogate. Measurements were taken at baseline and after intervention with AGE or placebo. RESULTS: Of the 26 patients studied (male 17, female 9), age was 61 ± 8 years (mean ± 1 SD), HbA1c 7.2 ± 1.1%, BP 130/75 ± 15.9/9.8 mmHg, total cholesterol 4.2 ± 0.81 mmol/l, triglyceride 2.11 ± 1.51 mmol/l, and HDL cholesterol 1.04 ± 0.29 mmol/l. The majority of patients were being treated with metformin (59%), aspirin (50%) and statin (96%) therapy. 36% were treated with an ACEI. There were no changes in these therapies throughout the study. Treatment with AGE had no significant effect upon the above metabolic parameters including insulin resistance. Treatment with AGE also had no significant effect on markers of endothelial function (plethysmography), oxidative stress (TAOS, GSH/GSSG, LHP) or inflammation (HsCRP). CONCLUSION: In this group of type 2 diabetic patients at high cardiovascular risk, 4 weeks treatment with AGE did not significantly improve endothelial function, vascular inflammation, oxidative stress or insulin resistance.

Therapeutic inhibition of the renin angiotensin aldosterone system.

BACKGROUND: Inhibitors of the renin angiotensin aldosterone system (RAAS) represent some of the most widely prescribed, successful and well-tolerated therapeutics of recent times and are of proven worth in the management/prevention of cardiovascular disease and diabetic nephropathy. However, as knowledge has grown about the RAAS and its manifold alternate pathways, loci of action and dynamic response to inhibition, so has the clinical debate as how to best use existing therapeutics as well as how best to conceptualise and design RAAS inhibitors of the future. OBJECTIVE: To provide an overview of the several points of therapeutic anti-RAAS intervention, many of which have already been exploited from 'upstream' renin inhibition to 'midstream' ACE inhibition to 'downstream' angiotensin AT1 receptor blockade. METHODS: A search of patents for RAAS inhibitors recorded in 2008 was conducted along with a relevant literature search. RESULTS/CONCLUSION: Each intervention has merits and demerits with implications for RAAS 'escape' phenomena, 'dual inhibition' therapy, long-term clinical efficacy and adverse drug reactions. Renin inhibitors offer the most complete RAAS inhibition, but more downstream interventions are likely to recruit supplementary anti-RAAS mediators and receptor signalling pathways. Furthermore, managing hyperkalaemia-stimulated aldosterone escape during combined ACE inhibitor and angiotensin receptor blocker treatment may realise the full clinical potential of dual inhibition therapy.

Attitudes to concept maps as a teaching/learning activity in undergraduate health professional education: influence of preferred learning style.

Concept maps that integrate and relate concepts in a nonlinear fashion are widely accepted as an educational tool that can underpin meaningful learning in medical education. However, student take-up may be affected by a number of cognitive and non-cognitive influences. In the present study, student attitudes to pre-prepared concept maps introduced in Stage 2 conjoint MPharm and BSc Pharmacology lectures were examined in relation to preferred learning styles according to the Felder-Silverman model. There was no statistically significant influence of dichotomous learning style dimension (sensing/intuitive; visual/verbal; active/reflector; sequential/global) on the self-reported utility of such concept maps to learning. However, when strength of preference was analysed within each dimension, moderate/strong verbal learners were found to be significantly less likely to self-report concept maps as useful relative to mild verbal learners. With this important exception, these data now suggest that student attitudes to concept maps are broadly not influenced by preferred learning styles and furthermore highlight the potential of concept maps to address a variety of different learning styles and thereby facilitate 'teaching to all types'. Concept maps could therefore potentially assist motivation, engagement and deep learning in medical and biomedical science education when used as a supplement to more traditional teaching/learning activities.

Nitrate tolerance and the links with endothelial dysfunction and oxidative stress.

Identification of nitric oxide as the molecule responsible for endothelial dependant vasodilatation has led to an explosion of interest in endothelial function. Oxidative stress has been identified as an important factor in the development of tolerance to organic nitrates. This review examines the evidence supporting this recently developed theory and how mechanisms of nitrate tolerance may link with the wider picture of primary nitric oxide resistance.