Objective To evaluate the in vitro biological safety of acellular spinal cord scaffold so as to provide theoretical basis for constructing the ideal tissue engineering scaffold of spinal cord.Methods A piece of thoracic spinal cord for 2 cm removed from SD rats was harvested and then was treated by freezing and thawing and chemical extraction with 3% sodium deoxyeholate and 1 KU/ml DNaseI and RNaseA. Gross observation and histological examination of the acellular spinal cord scaffold were carried out to learn the condition of the extracellular matrix scaffold. The biological safety of the acellular spinal cord scaffold was evaluated. Results In cross section, network of the extracellular matrix was presented in the scaffold. The cells, myelin and axons disappeared after the spinal cord was treated with sodium deoxycholate, DNaseI and RNaseA. Typical network of empty tubes were viewed in longitudinal sections. General toxic reaction, pyrogen test, hemolysis test and cytotoxicity test were conforming to the standard of materials. Conclusion As neotype tissue engineering material, the acellular spinal cord scaffold has satisfactory biological safety.

Objective To compare the effect of 2 decellularizing methods,sodium deoxycholate plus Triton X-100 or plus DNase and Rnase,in the preparation of acelluar allograft spinal cord scaffold in order to provide an ideal natural spinal cord scaffold to bridge the nerve gap.Methods Spinal cord was removed from health rats,and then decellularized by the method of freeze thawing(immersing in 3% sodium deoxycholate followed by the mixture of 1?103 U/ml DNase and RNase),or by chemical extraction(immersing in 1% Triton X-100 and then 1% sodium deoxycholate).HE staining,myelin staining and scanning electron microscopy(SEM) were employed to evaluate the spinal cord scaffold after the 2 methods of decellularization.Results Both cells and myelin were completely decellularized with the 2 methods.In cross section,network of the extracellular matrix was presented without axon,sheath and cells nucleus being seen in the scaffold.Typical network of empty tubes were viewed in longitudinal sections.Conclusion An ideal spinal cord scaffold can be produced with these 2 decellularizing methods in tissue engineering.The scaffold made by the 2 methods have similar three dimensional structure with normal spinal cord,so can be used as a graft to bridge the nerve gap directly or as a scaffold to implant the seeding cells in spinal cord tissue engineering.

[Objective]Using a procedure of chemical agent to remove the cells and myethin in spinal cord of rat and to prepare the scaffold of extracellular matrix,so as to obtain an ideal natural spinal cord scaffold to bridge the nerve gap.[Method]Rat spinal cord was cut and treated using the method of freeze thawing and chemical extraction(3%sodiumdeoxycholate and 1KU/ml DNaseI,RNaseA).Histology was exploited to evaluate the degree of acellular and the structure of the spinal cord scaffold.[Result]In cross section,network of the extracellular matrix was presented in the scaffold.The cells,myethin and axons disappeared after the spinal cord was treated with sodium deoxycholate and DNaseI,RNaseA.Typical network of empty tubes were viewed in longitudinal sections.[Conclusion]An ideal spinal cord scaffold can be produced with the method designed in authors experiment.This scaffold has similar three dimensional structure with normal spinal cord,which can be used as a graft to bridge the nerve gap directly or as a scaffold to implant the seeding cells in spinal cord tissue engineering.The experiment indicates that cells and myethin can be removed and the three dimensional structure be reserved by chemical extraction with 3% sodium deoxycholate and 1KU/ml DNaseI,RNaseA.Chemical extraction is an ideal method to prepare tissue engineer scaffold of spinal cord.

[Objective] To investigate the immunogenicity of the acellular spinal cord scaffold and to provide theoretical basis for its further application in tissue engineering.[Method]Acellular spinal cord(freeze thawing +3%sodiumdeoxycholate + DNaseI 、RNaseA)and fresh spinal cord of rats were implanted into paravertebral muscles of rats.The tissue was obtained at 1、2、3 and 4w after the operation,then the inflammatory reaction was evaluated by HE stain and the immunogenicity of acelular scaffold was tested by immunohistochemical examination of the intensity of CD3+ 、CD4+ and CD8+ cells that infiltrated the allografts.[Result]The bistological examination indicated that acellular spinal cord scaffold was surrounded by a amount of neutrophilic cells and lymphocytes one week postoperatively,yet two weeks postoperatively,there was only small amount of lymphocytes infiltration.Fresh spinal cord allograft elicited an intense acute inflammatory infiltrate,and two weeks later,there still had a mount of lymphocytes infiltration.The intensity of CD3+、CD4+ and CD8+ T cells that infiltrated the allografts was greatly lower in acellular spinal cord than that in fresh spinal cord.The mild cell-mediated host-graft immune rejection in acellular spinal cord was observed.[Conclusion]The acellular spinal cord scaffold has mild inflammatory reaction and immune rejection,suggestting it is qualified for some biological properties and it may be a potential alternative scaffold of tissue engineering.

AIM: To monitor the concentration of tacrolimus in whole blood in liver transplant recipients and establish an optimal therapeutic window of tacrolimus, in order to provide information for rational usage in clinic. METHODS: The whole blood concentrations of tacrolimus were measured by ELISA. The levels of tacrolimus in 1190 samples from 138 liver transplant recipients were compared and studied. RESULTS: The whole blood concentration of tacrolimus is gradually decreased with time after operation. The optimal therapeutic window of tacrolimus for liver transplant recipients was 8-15 ?g?L -1 within 1 month after operation, 6-12 ?g?L -1 from the 2nd to 3rd months, 5-10 ?g?L -1 from the 4th to 6th months and 3-8 ?g?L -1 after 6 months, respectively. CONCLUSION: It is necessary to routinely monitor blood concentration of tacrolimus. The satisfying therapeutic effects will be obtained if dosage regimens will be individualized according to optimal therapeutic window.

Objective To investigate the mechanisns of motivating blood circulation and removing blood stasis decoction for anti- hepatic fibrosis. Methods The hepatic fibrosis rats were fed with motivating blood circulation and removing blood stasis decoction, PC- NA and a-SMA expression of liver tissue were observed by means of immunohistochemical technique Results Motivating blood circula- tion and removing blood stasis decoction inhibited ?-SMA expression of HSC compared with the self-restore grounp (P

Objective To investigate the biological effects of low intensity pulsed ultrasound (LIPUS) on the proliferation and osteogenic differentiation of adipose tissue-derived stem cells (ADSCs) in vitro.Methods Primary ADSCs were harvested from the inguinal fat pads of 4-week-old female Sprague-Dawley rats,cultured in vitro and purified by magnetic-activated cell sorting.Surface ADSC markers were identified by flow cytometry.LIPUS at 100 mW/cm2 was used to stimulate the cultured cells.Flow cytometry was performed for cell cycle analysis.Cellular proliferation was evaluated via CCK8 chromatometry,and a proliferation index was calculated.ADSCs were assigned to 4 groups:a negative control group,a LIPUS group,an osteoinduction group and a LIPUS plus osteoinduction group,and treated accordingly.Alkaline phosphatase (ALP) activity was determined at the 7th and 14th day in each group,and calcium nodes were marked by Von Kossa staining.The levels of osteogenic differentiation in the different groups were evaluated.Results The ADSCs of passage 3 expressed CD 34low,and CD29high CD44high,which was consistent with the characteristics of ADSC surface markers.Proliferation was upregulated significantly in the LIPUS group compared with the negative control group.ALP activity was also elevated significantly and it resulted in mine-ralization.The highest mineralization rate was observed in the LIPUS plus osteoinduction group.Conclusions LIPUS not only can stimulate the proliferation of rat ADSCs,it also promotes their osteogenic differentiation.

Objective: To compare the pharmacokinetics and bioavailability of verapamil hydrochloride pulsed release tablets with core tablets. Methods: Latin test was employed in the single oral administration of the Ⅲ,Ⅳ type of pulsed release tablets and core tablets in 8 volunteers. The pharmaceutics behavior of the tablet in vivo was evaluated by the lag time, c max ,AUC and so on. Results: The pharmacokinetics results demonstrated that the Ⅲ type of pulsed tablet in humans could be released after about 4 h lag time. In a proper range, pulsed release tablets only changed the beginning time while c max and AUC were not different from the core tablets. Conclusion: A new system to reduce the early morning symptoms of ischemic heart disease is prepared. [

A simple,reliable RPHPLC method on ODS column with UV detector for deter-mination of the anticoagulant rodenticide coumatetralyl in animal tissue was developed.1,1′-Bi-(2-Naphthol)was used as an internal standard to check the process ofexperiments.The mean recoveries from the spiked rabbit liver were around 90% atthe levels of 0.4-16mg/kg.The coeffecint of variation of 5 determination was 3.2%.The results showed that this method has a satisfactory reproducibility.The methodis practical for examining poisons in poisoning cases.

Nine Rabbits were orally administrated with a single dose of 25mg/kg,100mg/kgcoumatetralyl to establish poisoning model.Poisoning sympton and pathological changes were observed.Coumatetralyl content in main internal organsand muscle was determined by RPHPLC method.The results were discussed.