Objectives To detect expressions of heat shock protein 70 (HSP70) and glial fibrillary acidic protein (GFAP) , and to estimate the post-injury interval after concussion of brain via the ratios of percentage of HSP70/GFAP-positive cells. Methods We established a brain concussion model of rat. Tissue levels of HSP70 and GFAP were determined by immunohistochemical staining at different time points after injury. Finally, the relationship between the ratio of percentage of HSP70/GFAP-positive cells and the post-injury interval was measured. Results The ratio of percentage of positive cells (increased from 7.15 to 11.73) and the percentage of HSP70-positive cells (P<0.05, compared with control group) increased, and the percentage of GFAP-positive cells did not change remarkably (P<0.05, compared with control group); the post-injury interval was between 0.5 hour and 3 hours. High ratio (>6.66) and high percentage of HSP70 and GFAP-positive cells (P<0.05, compared with control group) indicated the post-injury interval was between 3 and 12 hours. A low ratio (<6.66) and high percentage of HSP70 and GFAP-positive cells (P<0.05, compared with control group) suggested that the post-injury interval was later than 12 hours. Conclusion By analyzing the variation rule of the ratio of percentage positive cells after brain concussion, the post-injury interval after concussion of brain could be estimated.
Objective To study the relationship between the expression ratio of heat shock protein (HSP) 70 to C-fos in organs outside the brain after brain concussion and the time of injury in rats, in order to provide a new visual angle for determining injury time of brain concussion. Methods The model of brain concussion was established through free falling method. Then the rats were executed at 30 minutes, 1 hour, and 3, 6, 12, 24, 48, 96, 168, 240, 336 hours after injury. Immunohistochemistry staining of C-fos and HSP70 were used in the materials from the main organs including heart, liver, spleen, lung and kidney. All related experiment results were studied by using a microscope with image analytical system and homologous statistics. Results From 30 minutes to 6 hours after injury, the proportion of HSP70 immuno-positive cells increased slowly, while the proportion of C-fos immuno-positive cells increased rapidly, and the ratio of HSP70/C-fos positive cells was on the decline. From 6 to 12 hours after injury, the proportion of HSP70 immuno-positive cells rose continuously, while the proportion of C-fos immuno-positive cells started to decrease, and the HSP70/C-fos ratio showed a rising tendency. From 12 to 336 hours after injury, the proportion of HSP70 immuno-positive cells decreased slowly, while the proportion of C-fos immuno-positive cells decreased rapidly, and the HSP70/C-fos ratio was still on the rise. Conclusions The proportion of positive cells and ratio of the two markers in the main organs including heart, liver, spleen, lung and kidney are similar to those in the brain of rats after brain concussion. Observing the proportion of positive cells of the two markers together with their ratio in the main organs outside the brain may provide a reference for the determination of injury time after brain concussion.
Objective To observe the result of reconstructing quadriceps femoris function in the paraplegia rats by using the 7th cervical nerve root (C7) transposition with autologous and allogeneic neural transplantation. Methods Twenty16-week-old SPF male Wistar rats were adopted to prepare frozen sciatic nerve. Thirty-six Wistar rats were divided into 2 groups (group A and group B, n=18). The left paraplegia model was establ ished with left spinal cord hemisection by the micro scissors under the operation microscope. After the model establ ishment, the homolateral autologous sciatic nerve was bridged with the femoral nerve root by the translocation of C7 in group A, while the allogeneic sciatic nerve was bridged with the femoral nerve root by the translocation of C7 in group B. At 16 weeks and 24 weeks after operation, 9 rats in each group were selected for the neuroelectric-physiological test and then the histomorphology of the nerves was observed under the microscope and the electron microscope. The fresh weight recovery rate of quadriceps femoris was calculated. Results At 16 and 24 weeks after operation, the nerve action-evoked potential (NAP) was (1.14 ± 0.07) mV and (1.21 ± 0.07) mV in group A, and (0.87 ± 0.06) mV and (0.99 ± 0.05) mV in group B; the nerve conduction velocity (NCV) was (17.34 ± 2.15) m/s and (19.00 ± 3.02) m/s in group A, and (11.23 ± 1.45) m/s and (12.54 ± 1.59) m/s in group B, respectively, indicating significant differences (P lt; 0.05) between 2 groups. At 16 and 24 weeks after operation, HE staining and Bielschowsky staining showed that group A had a large number of nerve fiber regeneration, with a regular arrange of axons; while group B had l ittle nerve fiber regeneration with a scattered arrange of axons. At 24 weeks after operation, images in TEM showed a large number of regeneration myel inated nerve fibers and a small number of unmyel inated nerve fibers through the transplanted nerve in two groups. At 16 weeks after operation, the number of myel inated nerve fibers in group A and group B was (438 ± 79) and (196 ± 31) / vision, the areas of myel inated nerve fiberswere (5 596.00 ± 583.94) and (4 022.63 ± 615.75) μm2 / vision; after 24 weeks, the number of myel inated nerve fibers in groups A and B were (642 ± 64) and (321 ± 75)/vision, the areas of myel inated nerve fibers were (6 689.50 ± 1 142.10) and ( 4 733.00 ± 982.22) μm2/vision, indicating significant differences between two groups (P lt; 0.05). There was no statistically significant difference (P gt; 0.05) in the wet weight recovery rate of quadriceps between group A and group B at 16 weeks (87.96% ± 4.93% vs. 86.47% ± 7.47%) and at 24 weeks after operation (90.10% ± 4.22% vs. 87.66% ± 3.14%). Conclusion C7 transposition combined with autograft and allograft of sciatic nerve can reconstruct the partial function of the quadriceps femoris in paraplegia rats. The effect of graft is better than that of graft obviously.