ABSTRACT
Tau protein, a microtubule-associated protein, has a high specific expression in neurons and axons. Because traumatic spinal cord injury mainly affects neurons and axons, we speculated that tau protein may be a promising biomarker to reflect the degree of spinal cord injury and prognosis of motor function. In this study, 160 female Sprague-Dawley rats were randomly divided into a sham group, and mild, moderate, and severe spinal cord injury groups. A laminectomy was performed at the T8 level to expose the spinal cord in all groups. A contusion lesion was made with the NYU-MASCIS impactor by dropping a 10 g rod from heights of 12.5 mm (mild), 25 mm (moderate) and 50 mm (severe) upon the exposed dorsal surface of the spinal cord. Tau protein levels were measured in serum and cerebrospinal fluid samples at 1, 6, 12, 24 hours, 3, 7, 14 and 28 days after operation. Locomotor function of all rats was assessed using the Basso, Beattie and Bresnahan locomotor rating scale. Tau protein concentration in the three spinal cord injury groups (both in serum and cerebrospinal fluid) rapidly increased and peaked at 12 hours after spinal cord injury. Statistically significant positive linear correlations were found between tau protein level and spinal cord injury severity in the three spinal cord injury groups, and between the tau protein level and Basso, Beattie, and Bresnahan locomotor rating scale scores. The tau protein level at 12 hours in the three spinal cord injury groups was negatively correlated with Basso, Beattie, and Bresnahan locomotor rating scale scores at 28 days (serum: r = -0.94; cerebrospinal fluid: r = -0.95). Our data suggest that tau protein levels in serum and cerebrospinal fluid might be a promising biomarker for predicting the severity and functional outcome of traumatic spinal cord injury.
ABSTRACT
Objective To optimize the extraction technology of total triterpenoid from root of Rose odorata var.gigantean (TTROG) by orthogonal test combined with the contraction effect of TTROG on the isolated intestinal smooth muscle of rats in vitro.Methods UV spectrophotometric method was used to determine the contents of total triterpenoids in the TTROG extractive at the wavelength of 550 nm by taking ursolic acid as standard substance,and vanillin acetic acid as chromogenic reagent.The extraction rate of total triterpenoids was used as index to evaluate the technology based on single factor test,in which three factors were considered as follows:the concentration of extraction solvent,ratio of material to liquid,extraction time,and their interaction on extraction were studied by orthogonal experimental design.The inhibition effect of different extracts obtained from the optimized extraction process on the contraction of intestinal smooth muscle were recorded by tension transducer to the BL-420 biological experimental multi-channel physiological signal acquisition and processing system.The extraction process of TTROG was evaluated by the combination of biological activity and extraction rate with weighting method.Results The optimal extraction conditions of TTROG were as follows:extraction solvent 80％ ethanol,solid-liquid ratio 1∶10,extraction time for 2 h,three times and extraction temperature of 80 ℃.The optimized extraction rate could reach 42.12 mg/g.TTROG obtained using the optimized method showed significantly contraction effect on rat intestinal smooth muscle with dose effect dependence,and the effect on jejunum was the strongest,and the inhibition rate was 41.96％.Conclusion The optimized extraction technology is stable and effective with high extraction rate.TTROG showed the significant inhibitory function on contraction of isolated rat intestinal smooth muscle.
