Knowledge and attitudes of family doctors, dermatologists, and endocrinologists on sun exposure and vitamin D.

OBJECTIVES: Vitamin D is an important component of bone metabolism. Skin cells synthesize vitamin D when exposed to the sun. However, prolonged sun exposure damages the skin and increases the risk for skin cancer. The objective is to evaluate and compare the attitudes and recommendations of family doctors, dermatologists, and endocrinologists on exposure to the sun and vitamin D. METHODS: In a cross-sectional study, a questionnaire was completed by personal interview in a study population of 78 family doctors, 21 dermatologists, and 22 endocrinologists. RESULTS: On a scale of 1-10, the mean score for recommendations to reduce sun exposure was 4.7 for dermatologists, 4.2 for endocrinologists, and 6.4 for family doctors (p < 0.001). Family doctors recommended a mean daily exposure to the sun of 67.4 min compared to 41.4 by dermatologists, and 47.1 by endocrinologists (p = 0.007). Dermatologists and endocrinologists were more likely to recommend protective measures such as hats and long sleeves during sun exposure than family doctors (p < 0.0001). There were no statistically significant differences between male and female doctors for the entire study population. CONCLUSIONS: There is little consensus among these medical practitioners, whether specialists or primary care doctors, concerning sun exposure. Further studies should evaluate the optimal duration and intensity of sun exposure and doctors' recommendations should be based on the findings.

Investigation of localized delivery of diclofenac sodium from poly(D,L-lactic acid-co-glycolic acid)/poly(ethylene glycol) scaffolds using an in vitro osteoblast inflammation model.

Nonunion fractures and large bone defects are significant targets for osteochondral tissue engineering strategies. A major hurdle in the use of these therapies is the foreign body response of the host. Herein, we report the development of a bone tissue engineering scaffold with the ability to release anti-inflammatory drugs, in the hope of evading this response. Porous, sintered scaffolds composed of poly(D,L-lactic acid-co-glycolic acid) (PLGA) and poly(ethylene glycol) (PEG) were prepared with and without the anti-inflammatory drug diclofenac sodium. Analysis of drug release over time demonstrated a profile suitable for the treatment of acute inflammation with ∼80% of drug released over the first 4 days and a subsequent release of around 0.2% per day. Effect of drug release was monitored using an in vitro osteoblast inflammation model, comprised of mouse primary calvarial osteoblasts stimulated with proinflammatory cytokines interleukin-1ß (IL-1ß), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). Levels of inflammation were monitored by cell viability and cellular production of nitric oxide (NO) and prostaglandin E2 (PGE2). The osteoblast inflammation model revealed that proinflammatory cytokine addition to the medium reduced cell viability to 33%, but the release of diclofenac sodium from scaffolds inhibited this effect with a final cell viability of ∼70%. However, releasing diclofenac sodium at high concentrations had a toxic effect on the cells. Proinflammatory cytokine addition led to increased NO and PGE2 production; diclofenac-sodium-releasing scaffolds inhibited NO release by ∼64% and PGE2 production by ∼52%, when the scaffold was loaded with the optimal concentration of drug. These observations demonstrate the potential use of PLGA/PEG scaffolds for localized delivery of anti-inflammatory drugs in bone tissue engineering applications.

Directed differentiation of progenitor cells towards an islet-cell phenotype.

Exogenous insulin administration and oral anti-diabetic drugs are the primary means of treating diabetes. However, tight glycaemic control, with its inherent risk of hypoglycaemia, is required to prevent the microvascular and macrovascular complications of the disease. While islet or pancreas transplantations offer a longer-term cure, their widespread application is not possible, primarily because of a lack of donor tissue, the burden of life-long immunosuppression, and eventual graft rejection. The rapid increase in the incidence of diabetes has promoted the search for alternative cell-based therapies. Here we review recent advances in the directed differentiation of both endocrine and non-endocrine progenitors towards an islet-like phenotype.