Synergistic effect of melatonin on exercise-induced neuronal reconstruction and functional recovery in a spinal cord injury animal model.

Nitric oxide (NO) may aggravate neuronal damage after spinal cord injury (SCI). We hypothesized that NO produced by inducible nitric oxide synthase (iNOS) accelerates secondary damage to spinal tissue, which may be reversed by the neuroprotectant, melatonin. This study investigated the effects of combination therapy with melatonin (10 mg/kg) and exercise (10 m/min) on recovery from SCI caused by contusion. We examined locomotor recovery, iNOS gene expression, autophagic and apoptotic signaling, including Beclin-1, LC3, p53 and IKKalpha protein expression and histological alterations in the ventral horn of the spinal cord. Melatonin in combination with exercise resulted in significantly increased hindlimb movement (P < 0.05), a reduced level of iNOS mRNA (P < 0.05) and more motor neurons in the ventral horn, versus control SCI and SCI plus exercise alone, with no effect on the other signaling molecules examined. This study shows that combined therapy with melatonin and exercise reduces the degree of secondary damage associated with SCI in rats and supports the possible use of melatonin in combination with exercise to reduce the side effects related to exercise-induced fatigue and impairment.

Comparison of the clinicopathologic features between flat and polypoid adenoma.

OBJECTIVE: Several reports have suggested that flat colorectal adenomas might exhibit a higher potential for malignancy compared to polypoid adenomas. Although the clinical importance of the shape of polyps is stressed, the controversy surrounding the malignant potential of flat adenomas continues. The aim of this study was to compare the clinicopathologic characteristics, including degree of dysplasia and malignancy, between flat and polypoid adenomas 5 mm in size or larger. MATERIAL AND METHODS: A total of 3263 polyps (254 flat adenomas and 3009 polypoid adenomas), >/=5 mm in size, diagnosed in 1883 patients by colonoscopy were analyzed. RESULTS: Flat adenomas were found in 10% of patients, which represented 7.8% of all adenomas removed. The flat adenomas were larger in diameter than the polypoid adenomas (14.8+/-12.6 mm versus 8.6+/-5.0 mm, p <0.01), had a higher rate of villous components (18.5% versus 11.4%, p <0.01), a higher rate of high-grade dysplasia (9.4% versus 4.2%, p <0.01), and a higher rate of malignancy (10.2% versus 3.6%, p <0.01) than polypoid adenomas. However, there was no difference in the rate of high-grade dysplasia or carcinoma between flat and polypoid adenomas of equal size. It was shown by multivariate analysis that rectosigmoid location, larger size, and presence of a villous component were associated with a higher rate of malignancy, but not with flat morphology. CONCLUSIONS: Flat adenomas, which were of a relatively large size in this study, were not associated with a higher risk for high-grade dysplasia and carcinoma compared with polypoid adenomas.