Anticonvulsant effect of melatonin through ATP-sensitive channels in mice.

Melatonin is a neurohormone secreted principally by the pineal gland. This molecule has various pharmacological properties including improving immune system, prevent cancer, anti-aging, and anti-oxidant effects. The anticonvulsant effects of melatonin have been proved by previous studies. Adenosine triphosphate (ATP)-sensitive potassium (KATP ) channels are considered as an important target in the seizure modulation. The aim of the present study was to investigate the anticonvulsant effect of melatonin in pentylenetetrazole (PTZ)-induced seizures in mice, focusing on its ability to regulate KATP channels. Acute intraperitoneal administration of melatonin (40 and 80 mg/kg) increased clonic seizure threshold induced by intravenous administration of PTZ. Melatonin (40 and 80 mg/kg) increased the latency of clonic seizure and reduced its frequency in mice receiving an intraperitoneal injection of PTZ. Administration of glibenclamide, a KATP channels blocker, before intravenous injection of PTZ reduced melatonin anticonvulsant effect. Diazoxide and cromakalim, as KATP channels openers, increased antiseizure effect of melatonin in PTZ model of seizures. These findings suggest that the antiseizure effect of melatonin probably is gained through increasing the opening of KATP channels.

Clinical and functional outcomes of vascularized bone graft in the treatment of scaphoid non-union.

INTRODUCTION: Scaphoid non-union is a challenging and complex problem. Various methods have been proposed for the management of patients with scaphoid non-union and to reduce the risk of complications. In this study, our aim was to evaluate the clinical and functional outcomes of using a vascularized bone graft in the treatment of scaphoid non-union. METHODS: Patients with scaphoid non-union who underwent 1,2 intercompartmental supraretinacular artery pedicled vascularized bone graft between January 2005 and January 2011 were enrolled. The parameters assessed included clinical and functional outcomes, radiological measures, and potential risk factors. RESULTS: Forty-one patients were finally included. Thirty patients achieved union (73%) and 11 did not. Smoking was a significant risk factor for non-union after the surgery. In patients who achieved union, grip strength and radioulnar abduction were greater in comparison to that in patients who did not achieve union. Functional measures, including the Disabilities of Arm and Shoulder score and the Modified Mayo Wrist Score, improved in patients with scaphoid union. The scaphoid length also improved significantly postoperatively in these patients. CONCLUSION: Surgical treatment of scaphoid non-union using vascularized bone graft led to a high union rate with good clinical and functional outcomes. Smoking is a risk factor for non-union, even with the use of a vascularized bone graft. Avascular necrosis was not associated with an increased risk for non-union.