In quiescent IBD, IBS-like symptoms related to persistent subclinical inflammation associated with increased colonic paracellular permeability. A persistent increase in TNF-α in colonic mucosa may contribute to the epithelial barrier defects associated with abdominal pain in quiescent IBD, but not in IBS. Optimisation of anti-inflammatory therapy may be considered in quiescent IBD with IBS-like symptoms.

The shorter wavelengths of the visible light spectrum have been recently reported to induce a long-lasting hyperpigmentation but only in melano-competent individuals. Here, we provide evidence showing that OPN3 is the key sensor in melanocytes responsible for hyperpigmentation induced by the shorter wavelengths of visible light. The melanogenesis induced through OPN3 is calcium dependent and further activates CAMKII followed by CREB, extracellular signal-regulated kinase, and p38, leading to the phosphorylation of MITF and ultimately to the increase of the melanogenesis enzymes: tyrosinase and dopachrome tautomerase. Furthermore, blue light induces the formation of a protein complex that we showed to be formed by tyrosinase and dopachrome tautomerase. This multimeric tyrosinase/tyrosinase-related protein complex is mainly formed in dark-skinned melanocytes and induces a sustained tyrosinase activity, thus explaining the long-lasting hyperpigmentation that is observed only in skin type III and higher after blue light irradiation. OPN3 thus functions as the sensor for visible light pigmentation. OPN3 and the multimeric tyrosinase/tyrosinase-related protein complex induced after its activation appear as new potential targets for regulating melanogenesis but also to protect dark skins against blue light in physiological conditions and in pigmentary disorders.

Airway remodelling refers to the structural changes that occur in both large and small airways relevant to miscellaneous diseases including asthma. In asthma, airway structural changes include subepithelial fibrosis, increased smooth muscle mass, gland enlargement, neovascularization and epithelial alterations. Although controversial, airway remodelling is commonly attributed to an underlying chronic inflammatory process. These remodelling changes contribute to thickening of airway walls and, consequently, lead to airway narrowing, bronchial hyper-responsiveness, airway edema and mucous hypersecretion. Airway remodelling is associated with poor clinical outcomes among asthmatic patients. Early diagnosis and prevention of airway remodelling has the potential to decrease disease severity, improve control and prevent disease expression. The relationship between structural changes and clinical and functional abnormalities clearly deserves further investigation. The present review briefly describes the characteristic features of airway remodelling observed in asthma, its clinical consequences and relevance for physicians, and its modulation by therapeutic approaches used in the treatment of asthmatic patients.

Background: Epidemiological studies suggest a link between vitamin D deficiency in early life and development of asthma in later life. Aim: The aim of this study was to measure serum vitamin D levels in asthmatic children and to compare these to healthy non-asthmatic controls. Methods: Asthmatic (n = 483) and healthy control (n = 483) children were recruited from the Pediatric Allergy-Immunology Clinics of Hamad General Hospital and the Primary Health Care Clinics in Qatar from October 2009 to July 2010. All children were below 16 years of age and asthma was diagnosed by a physician. Parents of all children completed extensive questionnaires documenting demographics, child’s feeding practice and vitamin D intake. Serum vitamin D (25-hydroxyvitamin D), calcium, phosphorus, alkaline phosphatase, magnesium, creatinine and parathyroid hormone assays were performed. Subjects with serum containing less than 20 ng/ml vitamin D were deemed deficient. Results: Asthmatic children had significantly reduced serum vitamin D levels compared to non-asthmatic children (p < 0.001); 68.1% of all asthmatics were vitamin D deficient. Asthmatic children had significantly higher degrees of moderate (41.8 vs. 25.1%) and severe (26.3 vs. 11.0%) vitamin D deficiency compared to healthy controls (p < 0.001). Positive familial history of vitamin D deficiency (35.6%, p = 0.005) and asthma (36.4%, p = 0.009) were significantly higher in asthmatic children. Along with vitamin D deficiency, asthmatics also had reduced phosphorus (p < 0.001) and magnesium (p = 0.001) levels but elevated serum alkaline phosphatase (p < 0.001) and IgE (p < 0.001). The majority of asthmatic children had less exposure to sunlight (66.7%, p = 0.006) and less physical activity (71.3%, p < 0.001). Vitamin D deficiency was the strongest predictor of asthma in this population (OR 4.82; 95% CI 2.41–8.63, p < 0.001). Conclusion: The present study revealed that the majority of asthmatic children had vitamin D deficiency compared to control children. Vitamin D deficiency was the major predictor of asthma in Qatari children.