Stem Cells in the Intestine: Possible Roles in Pathogenesis of Irritable Bowel Syndrome

Irritable bowel syndrome is one of the most common functional gastrointestinal (GI) disorders that significantly impair quality of life in patients. Current available treatments are still not effective and the pathophysiology of this condition remains unclearly defined. Recently, research on intestinal stem cells has greatly advanced our understanding of various GI disorders. Alterations in conserved stem cell regulatory pathways such as Notch, Wnt, and bone morphogenic protein/TGF-β have been well documented in diseases such as inflammatory bowel diseases and cancer. Interaction between intestinal stem cells and various signals from their environment is important for the control of stem cell self-renewal, regulation of number and function of specific intestinal cell types, and maintenance of the mucosal barrier. Besides their roles in stem cell regulation, these signals are also known to have potent effects on immune cells, enteric nervous system and secretory cells in the gut, and may be responsible for various aspects of pathogenesis of functional GI disorders, including visceral hypersensitivity, altered gut motility and low grade gut inflammation. In this article, we briefly summarize the components of these signaling pathways, how they can be modified by extrinsic factors and novel treatments, and provide evidenced support of their roles in the inflammation processes. Furthermore, we propose how changes in these signals may contribute to the symptom development and pathogenesis of irritable bowel syndrome.

Modified Parkinson's Disease Sleep Scale (MPDSS) in Thai Parkinson's disease patients.

BACKGROUND: Parkinson's Disease Sleep Scale (PDSS) has been recently developed for clinical evaluation of sleep problems in PD. The modified PDSS (MPDSS) has been developed in the presented study. OBJECTIVE: To evaluate the usefulness of MPDSS and sleep problems in Thai PD patients. MATERIAL AND METHOD: A cross sectional study in 50 PD patients was conducted at King Chulalongkorn Memorial Hospital. Sleep problems were assessed by the MPDSS, which has more items to cover more aspects of sleep problems in PD than PDSS. RESULTS: MPDSS showed good reliability (Cronbach's Alpha = 0.842). Some Problems regarding the clinical use of MPDSS in Thai patients were detected especially related to the meaning of visual analogue scale. Self-assessment of sleep in PD patients reveal sleep problems only 58%, while MPDSS probed sleep problems in 76% of PD patients. Nocturnal motor symptoms, snoring, sleep initiation and maintenance problem and nocturia were common in Thai PD patients. Disease staging had significant correlation with MPDSS. Prevalence of sleep disorders and trend of each score in PDSS were similar to previous studies in Western countries. CONCLUSION: MPDSS is useful for screening and evaluation of sleep problems in Thai PD patients. Nevertheless, some modifications, especially the visual analogue scale, may be needed to simplify its practical utility. Prevalence and trend of sleep problems in Thai PD patients were similar to the previous studies in Western countries.