ABSTRACT
Objective To evaluate regenerative nerve and functional recovery of target muscle in rats with sciatic nerve defect bridged by acellular nerve allograft made through chemical extraction.Methods Sciatic nerve of SD rats was processed in a volume fraction of 3％ Triton X-lO0 solution and 40 g/L sodium deoxycholate solution.Morphology of myelin sheath,axons and basal lamina tubes of sciatic nerve segments was observed under the light microscopy before and after the chemical processing.Twenty-five Wistar rats were divided into acellular nerve allograft group (n =10),autograft group (n =10) and normal control group(n =5) according to the random number table.A 1 cm sciatic nerve defect was created in acellular nerve allograft group and autograft group,and was respectively bridged by acellular nerve allograft and autograft.Sciatic nerve function index (SFI) was measured every two weeks.Twelve weeks after surgery,nerve conduction velocity (NCV),recovery rate of compound muscle action potential (CMAP) and recovery rate of muscle force were measured in each group.Results Cellular components including myelin sheath and axons were removed thoroughly,but the basal lamina tubes were preserved completely.At postoperative 2,4,6,8,10 and 12 weeks,SFI in normal control group (-1.7±5.9,-0.3 ±2.5,0.8 ±4.1,-1.4±3.6,-2.5 ±5.7 and-2.1±3.2) was superior over autograft group (-94.3±3.7,-90.1±4.1,-63.7±7.8,-51.9±8.2,-48.8±8.6 and -44.3 ± 10.5) and acellular nerve allograft group (-97.1 ± 5.3,-91.2 ± 6.1,-70.6 ± 5.5,-60.4±6.2,-58.2 ±10.2 and-56.4 ±8.0) (P ＜0.01).At postoperative 6,8,10 and 12 weeks,SFI in autograft group were better than those in acellular nerve allograft group (P ＜0.05).NCV [(61.6 ± 8.1) m/s],recovery rate of CMAP[(98.7 ± 5.9) ％] and recovery rate of muscle force [(101.8 ± 6.6) ％] in normal control group were higher than those in acellular nerve allograft group [(22.3 ± 4.7) m/s,(40.3 ± 9.2) ％ and (43.8 ± 9.3) ％] and those in autograft group [(29.0 ±5.5) m/s,(52.5 ± 10.6) ％ and (54.3 ± 10.5) ％] (P ＜ 0.01).NCV,recovery rate of CMAP and recovery rate of muscle force in autograft group were better than those in acellular nerve allograft group (P ＜ 0.05).Conclusions Acellular nerve segments are harvested satisfactorily by chemical extraction.Sciatic nerve defect in rats can be cured with the acellular nerve allograft,but the repair effect of autograft is relatively better.
ABSTRACT
Objective To detect mutations in the PTPN11 gene in a family with LEOPARD syndrome (LS).Methods Clinical data were collected from a 7-year-old boy patient with LS.Peripheral blood was obtained from the patient,both of his parents,and 50 healthy controls.All the exons and their flanking sequences of the PTPN11 gene were amplified by PCR followed by direct DNA sequencing.Results A heterozygous missense mutation c.836A ＞ G,which resulted in a substitution of TAT by TGT at codon 279,was found in exon 7 of the PTPN11 gene in the patient.No mutation was detected in the unaffected parents or healthy controls.Conclusion The missense mutation c.836A ＞ G may be the cause of the phenotype of LS in this family.
ABSTRACT
Objective: Our aims were to study the expression of p73 protein in giant cell tumor of bone, and to investigate its function in the carcinogenesis and development of giant cell tumor of bone. Methods: The expression of p73 was detected by using S-P immunohistochemical method in 40 cases of paraffin-embedded sections of giant cell tumor of bone. Results: The positive rate of p73 in 40 patients with giant cell tumor of bone was 30.0%,and 20.0% in osteochondroma.The difference between them was not significant(P<0.05). There was significant difference between the expression of p73 in different stages of giant cell tumor of bone(P>0.05). Conclusion: The expression of p73 in giant cell tumor of bone increased prominently in this experiment. It suggests that p73 may play an important role in the carcinogenesis and development of giant cell tumor of bone, and p73 may also have a certain value for the diagnosis of giant cell tumor of bone.