Objective: We explored the extent to which these age-dependent physiological changes correlated with alterations in gene transcription in murine Pgc-1β-/- atria.
Methods and Results: RNA isolated from murine atrial tissue samples from young (12-16 weeks) and aged (>52 weeks of age), wild type (WT) and Pgc-1β-/- mice were studied by pre-probed quantitative PCR array cards. We examined genes encoding sixty ion channels and other strategic atrial electrophysiological proteins. Pgc-1β-/- genotype independently reduced gene transcription underlying Na+-K+-ATPase, sarcoplasmic reticular Ca2+-ATPase, background K+ channel and cholinergic receptor function. Age independently decreased Na+-K+-ATPase and fibrotic markers. Both factors interacted to alter Hcn4 channel activity underlying atrial automaticity. However, neither factor, whether independently or interactively, affected transcription of cardiac Na+, voltage-dependent K+ channels, surface or intracellular Ca2+ channels. Nor were gap junction channels, β-adrenergic receptors or transforming growth factor-β affected.
Conclusion: These findings limit the possible roles of gene transcriptional changes in previously reported age-dependent pro-arrhythmic electrophysiologial changes observed in Pgc-1β-/- atria to an altered Ca2+-ATPase (Atp2a2) expression. This directly parallels previously reported arrhythmic mechanism associated with p21-activated kinase type 1 deficiency. This could add to contributions from the direct physiological outcomes of mitochondrial dysfunction, whether through reactive oxygen species (ROS) production or altered Ca2+ homeostasis.
MATERIALS AND METHODS: Five groups of rats (n=6) were administered orally once daily for 7 days with 8% Tween 80 (negative control), 100 mg/kg ranitidine (positive control), or MEMC (100, 250 or 500 mg/kg), followed by the ulcer induction via ligation of the pyloric part of the rat's stomach. This was followed by the macroscopic analysis of the stomach, evaluation of gastric content parameters, and quantification of mucus content. The antioxidant (measured using the superoxide anion and 2,2-diphenyl-1-picrylhydrazyl (DPPH)-radical scavenging, oxygen radical absorbance capacity (ORAC) and total phenolic content (TPC) assays), anti-inflammatory (evaluated using the in vitro lipoxygenase and xanthine oxidase assays), phytoconstituents and HPLC analysis of MEMC were also carried out.
RESULTS: The MEMC significantly (p<0.05) reduced gastric lesion in this model. Furthermore, the extract also significantly (p<0.01) reduced the volume of gastric content whereas the total acidity was significantly (p<0.05) reduced in the doses of 100 and 500 mg/kg MEMC. Moreover, the mucus content increased significantly (p<0.01) in MEMC-treated rats. The extract also showed high antioxidant and anti-inflammatory activities in all assays tested, and demonstrated the presence of high tannins and saponins followed by flavonoids.
CONCLUSION: The MEMC exerted gastroprotective effect via several mechanisms including the anti-secretory, antioxidant and anti-inflammatory activities. These activities could be attributed to the presence of tannins, saponins and flavonoids (e.g. rutin, quercitrin, fisetin and dihydroquercetin).
AIM: The main aim of this study was to translate and validate the Malaysian versions of Perceived Diabetes Self-Management Scale (PDSMS), Medication Understanding and Use Self-Efficacy Scale (MUSE), and to revalidate 8-Morisky Medication Adherence Scale (MMAS-8) by Partial Credit Rasch Model (Modern Test Theory).
MATERIALS AND METHODS: Permission was obtained from respective authors to translate the English versions of PDSMS, MUSE and MMAS-8 into Malay language according to established standard international translation guidelines. In this cross-sectional study, 62 adult DM patients were recruited from Hospital Kuala Lumpur by purposive sampling method. The data were extracted from the self-administered questionnaires and entered manually in the Ministeps (Winsteps) software for Partial Credit Rasch Model. The item and person reliability, infit/outfit Z-Standard (ZSTD), infit/outfit Mean Square (MNSQ) and point measure correlation (PTMEA Corr) values were analysed for the reliability analyses and construct validation.
RESULTS: The Malay version of PDSMS, MUSE and MMAS-8 found to be valid and reliable instrument for the Malaysian diabetic adults. The instrument showed good overall reliability value of 0.76 and 0.93 for item and person reliability, respectively. The values of infit/outfit ZSTD, infit/outfit MNSQ, and PTMEA Corr were also within the stipulated range of the Rasch Model proving the valid item constructs of the questionnaire.
CONCLUSION: The translated Malay version of PDSMS, MUSE and MMAS-8 was found to be a highly reliable and valid questionnaire by Partial Credit Model. The Malay version was conceptually equivalent to original version, easy to understand and can be used for the Malaysian adult diabetic patients for future studies.