BET 2: Should children with sport-related concussion observe strict physical rest until symptom-free?

A short cut review was carried out to establish whether strict physical rest following sports related concussion in children is better than normal activity in reducing post-concussional symptoms. two recent systematic reviews presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. It is concluded that children who present with a sport-related concussion should have a brief period of cognitive and physical rest followed by a gradual increase in activity. Further studies should examine the length of the brief rest period, however at this time 24-48 hours of rest should be recommended.

1alpha,25(OH)2-Vitamin D3 stimulation of secretion via chloride channel activation in Sertoli cells.

Sertoli cell secretory activities are highly dependent on ion channel functions and critical to spermatogenesis. The steroid hormone 1alpha,25(OH)2-vitamin D3 (1,25(OH)2-D3) stimulates exocytosis in different cell systems by activating a nongenotropic vitamin D receptor (VDR). Here, we described 1,25(OH)2-D3 stimulation of secretion via Cl(-) channel activation in the mouse immature Sertoli cell line TM4. 1,25(OH)2-D3 potentiation of chloride currents was dependent on hormone concentration, and correlated with a significant increase in whole-cell capacitance within 20-40 min. In addition, Cl(-) currents were potentiated by the nongenomic VDR agonist 1alpha,25(OH)2 lumisterol D3 (JN), while 1,25(OH)2-D3 potentiation of channels was suppressed by nongenomic VDR antagonist 1beta,25(OH)2-vitamin D3 (HL). Treatment of TM4 cells with PKC and PKA activators PMA and forskolin respectively, increased Cl(-) currents significantly, while PKC and PKA inhibitors Go6983 and H-89, respectively, abolished 1,25(OH)2-D3 stimulation of Cl(-) currents, suggesting phosphorylation pathways in 1,25(OH))2-D3 mediated channel responses. RT-PCR demonstrated the expression of outwardly rectifying ClC-3 channels in TM4 cells. Taken together, our results demonstrate a PKA/PKC-dependent 1,25(OH)2-D3/VDR nongenotropic pathway leading to Cl(-) channel and exocytosis activation in Sertoli cells. We conclude that 1,25(OH)2-D3 appears to be a modulator of male reproductive functions at least in part by stimulating Sertoli cell secretory functions.