Lee C.Y.,Sunway University
Clinical and Experimental Pharmacology and Physiology | Year: 2013
Psychosocial stress is reported to be one of the main causes of obesity. Based on observations in studies that relate stress and gut inflammation to obesity, the present study hypothesized that chronic stress, via inflammation, alters the expression of nutrient transporters and contributes to the development of metabolic syndrome. Rats were exposed to restraint stress for 4 h/day for 5 days/week for eight consecutive weeks. Different segments of rat intestine were then collected and analysed for signs of pathophysiological changes and the expression of Niemann-Pick C1-like-1 (NPC1L1), sodium-dependent glucose transporter-1 (SLC5A1, previously known as SGLT1) and facilitative glucose transporter-2 (SLC2A2, previously known as GLUT2). In a separate experiment, the total anti-oxidant activity (TAA)-time profile of control isolated intestinal segments was measured. Stress decreased the expression of NPC1L1 in the ileum and upregulated SLC5A1 in both the jejunum and ileum and SLC2A2 in the duodenum. Inflammation and morphological changes were observed in the proximal region of the intestine of stressed animals. Compared with jejunal and ileal segments, the rate of increase in TAA was higher in the duodenum, indicating that the segment contained less anti-oxidants; anti-oxidants may function to protect the tissues. In conclusion, stress alters the expression of hexose and lipid transporters in the gut. The site-specific increase in the expression of SLC5A1 and SLC2A2 may be correlated with pathological changes in the intestine. The ileum may be protected, in part, by gut anti-oxidants. Collectively, the data suggest that apart from causing inflammation, chronic stress may promote sugar uptake and contribute to hyperglycaemia. © 2013 Wiley Publishing Asia Pty Ltd.
Saravanan M.,Sunway University |
Rao K.P.,CSIR - Central Leather Research Institute
Carbohydrate Polymers | Year: 2010
Microencapsulations using pectin and alginate by complex coacervation with gelatin were studied using metronidazole hydrochloride (MH), diclofenac sodium (DS) and indomethacin (IM) as core material. MH was poorly encapsulated (4-7% w/w) than DS (49-53% w/w) and IM (62-66% w/w). Pectin produced coacervation with gelatin with all acidifiers but alginate produced coacervation only with acetic acid. Addition of sodium carboxymethyl cellulose reduced aggregation between the microparticles. FT-IR confirmed the complexation between pectin or alginate with gelatin and intact nature of encapsulated drug. Microencapsulation of MH produced microspheres and DS/IM resulted in irregular particles. Alginate-gelatin produced smaller microparticles than pectin-gelatin. DSC of microcapsules revealed change in physical nature of DS whereas IM produced no changes. The microcapsules showed low drug release in gastric fluid and sustained release in intestinal fluid. Alginate was better than pectin for coacervation with gelatin in terms of less aggregation, smaller particle size and easy dispersion. © 2009 Elsevier Ltd. All rights reserved.
Choy M.-K.,University of Cambridge |
Phipps M.E.,Sunway University
Trends in Molecular Medicine | Year: 2010
The human major histocompatibility complex class I chain-related gene A (MICA) is one of the genes in the HLA class I region of chromosome 6. Unlike HLA classical class I gene products, MICA does not present any antigen but acts as a ligand for several immune cells including natural killer (NK) cells bearing NKG2D receptors. MICA is the member of the non-classical class I family that displays the greatest degree of polymorphism. MICA alleles can be divided into two large groups with the polymorphisms found in α3 domains. This division could be explained by a possible polyphyletic origin that is in line with recent findings from evolutionary, population and functional studies of this gene. MICA polymorphisms are associated with a number of diseases related to NK activity, such as viral infection, cancer and allograft rejection or graft-versus-host disease (GVHD). The mechanisms underlying these associations include NK cell-mediated cytotoxicity and MICA shedding to produce immunosuppressive soluble MICA particles. The MICA-induced humoral response has attracted interest recently because of its possible role in graft rejection in solid organ transplantation. Here, we discuss the genetics and biology of the MICA gene and its products, and their importance in disease. © 2010 Elsevier Ltd. All rights reserved.
Chan C.K.Y.,Sunway University |
Cameron L.D.,University of Auckland
Journal of Behavioral Medicine | Year: 2012
Self-regulation theory and research suggests that different types of mental imagery can promote goaldirected behaviors. The present study was designed to compare the efficacy of approach imagery (attainment of desired goal states) and process imagery (steps for enacting behavior) in promoting physical activity among inactive individuals. A randomized controlled trial was conducted with 182 inactive adults who received one of four interventions for generating mental images related to physical activity over a 4-week period, with Approach Imagery (approach versus neutral) and Process Imagery (process versus no process) as the intervention strategies. Participants received imagery training and practiced daily. Repeated measures ANOVAs revealed that Approach Imagery: (1) increased approach motivations for physical activity at Week 4; (2) induced greater intentions postsession, which subsequently induced more action planning at Week 4; (3) enhanced action planning when combined with process images at post-session and Week 1; and (4) facilitated more physical activity at Week 4 via action planning. These findings suggest that inducing approach orientation via mental imagery may be a convenient and low-cost technique to promote physical activity among inactive individuals. © Springer Science+Business Media, LLC 2011.
Bonsu K.O.,Sunway University
Systematic reviews | Year: 2013
Statins are known to reduce cardiovascular morbidity and mortality in primary and secondary prevention studies. Subsequently, a number of nonrandomised studies have shown statins improve clinical outcomes in patients with heart failure (HF). Small randomised controlled trials (RCT) also show improved cardiac function, reduced inflammation and mortality with statins in HF. However, the findings of two large RCTs do not support the evidence provided by previous studies and suggest statins lack beneficial effects in HF. Two meta-analyses have shown statins do not improve survival, whereas two others showed improved cardiac function and reduced inflammation in HF. It appears lipophilic statins produce better survival and other outcome benefits compared to hydrophilic statins. But the two types have not been compared in direct comparison trials in HF. We will conduct a systematic review and meta-analysis of lipophilic and hydrophilic statin therapy in patients with HF. Our objectives are:1. To determine the effects of lipophilic statins on (1) mortality, (2) hospitalisation for worsening HF, (3) cardiac function and (4) inflammation.2. To determine the effects of hydrophilic statins on (1) mortality, (2) hospitalisation for worsening HF, (3) cardiac function and (4) inflammation.3. To compare the efficacy of lipophilic and hydrophilic statins on HF outcomes with an adjusted indirect comparison meta-analysis.We will conduct an electronic search of databases for RCTs that evaluate statins in patients with HF. The reference lists of all identified studies will be reviewed. Two independent reviewers will conduct the search. The inclusion criteria include:1. RCTs comparing statins with placebo or no statin in patients with symptomatic HF.2. RCTs that employed the intention-to-treat (ITT) principle in data analysis.3. Symptomatic HF patients of all aetiologies and on standard treatment.4. Statin of any dose as intervention.5. Placebo or no statin arm as control.The exclusion criteria include:1. RCTs involving cerivastatin in HF patients.2. RCTs with less than 4 weeks of follow-up. We will perform an adjusted indirect comparison meta-analysis of lipophilic versus hydrophilic statins in patients with HF using placebo or no statin arm as common comparator.