The rabbit enteropathogenic E. coli (rEPEC) strain RDEC-1 possesses a lifA homologue adjacent to the LEE pathogenicity island. To study the entire nucleotide sequence and biological function of lifA,the DNA sequence and biological function of RDEC-1 lifA were analysed with gene cloning,gene knock-out and in vivo virulence examination. The result showed that the entire coding sequence of the lifA of RDEC-1 shares nearly absolute homology with the lifA of human isolates. RDEC-1 lifA inhibited IL-2 expression in stimulated rabbit peripheral blood mononuclear cells. We further demonstrated significant reduction in fecal bacterial shedding by RDEC-1 derivative lifA mutant when compared with its parent strain. In a competitive study when rabbits were inoculated with a combination of the WT and the mutant, the WT was the predominant bacteria recovered from fecal samples, while fewer mutant bacteria were recovered. However,the lifA mutant is able to induce A/E type of lesions as efficient as the parent strain. The data provide direct evidence that lifA of rEPEC plays a role in immunomodulation and in in vivo colonization in the intestinal tract.

[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.

Five cases of carcinoma located in the middle portion of the esophagus were resected with end-to-end anastomosis in the left neck. The lower portion (about 2.5-4.0cm in length) of the esophaguswas reserved to preserve the physiological function of the lower esophageal sphincter. The operationwas satisfactory, especially in the prevention of regurgitant esophagitis. No tension was observed at the site "of the anastomosis, and blood supply to the esophagus was not disturbed. Adequate mobilization of the lesser curvature of the stomach was the most important step. Such complications as leakage of the esophageal anastomosis and stricture were not seen in these five cases. Regurgitation was not observed in short-term follow-up. A normal esophageal peristalsis and cardiac opening were observed by barium meal radiography after the operation.

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 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 evaluate diagnostic value and analyze the complications of the lung nodules by 64 slice CT guided percutaneous thoracic biopsy(PTB)with coaxial technique.Methods The clinical data of 63 patients with lung placeholder in coaxial line casing biopsy under CT guidance were retrospectively analyzed.After CT positioning,16G coaxial trocar rapidly passed through the pleura,the tip to the edge of the tumor or pathological lesions,pulled out the needle core,the coaxial sleeve in 18G semi automatic biopsy needle,the materials were multi-angle cuted and sent to the pathology examination,the positive rate and the incidence of complications were analyzed.Results In 63 cases of lesions under CT guidance,the success rate of drawing materials was 100.0%,the pathological diagnosis rate was 88.9%.Intraoperative and postoperative complications occurred in 18 cases,the incidence rate was 28.6%,among them 9 cases of pneumothorax(14.3%),pulmonary hemorrhage in 8 cases(12.7%),hemoptysis in 1 case(1.6%),no severe adverse reaction was observed.Conclusion Multi slice CT guided percutaneous coaxial biopsy has the advantages of simple operation,high diagnosis rate,less complications,low risk,it can be promoted in hospitals.

OBJECTIVE:To measure and analysis the related costs of drug-induced liver injury (D1LI) from different decision makers,and to provide reference for reducing related costs of DILI,improving medical insurance system and realizing effective health resource distribution.METHODS:In retrospective study,60 cured or recovered DILI inpatieuts were randomly selected as subjects from medical record management system of 4 hospitals in Henan province during Jun.2014-Jun.2015.Demographic character istic,clinical characteristic and related cost of DILI were analyzed retrospectively and the cost structure was also analyzed from different decison makers (patient,society,medical insurance payer).RESULTS:The total direct medical cost of 60 cases was 584 113.05 yuan,and total direct non-medical cost was 31 093.15 yuan and total indirect cost was 169 379.95 yuan.The total cost of DILI of fered by patients was 616 296.38 yuan;the total cost of DILI offered by society was 784 586.15 yuan;the total cost of DILI offered by medical insurance was 168 289.77 yuan.CONCLUSIONS:DILI results in serious economic damage for patients and society,deserving attracting extensive attention worldwide.The study provide reference for reducing patient's medical burden and improving medical insurance system,and contribute to optimize medical resource distribution.

Objective To investigate the effects of transplantation of oligodendrocyte precursor cells(OPCs) on the recovery of neural function in rats with spinal cord injury.Methods The spinal cord injury(T10) rat model was established by Allen's method of weight-drop injury.Ninety six SD rats were randomly divided into 4 groups(24 each): transplantation group,control group,injury-only group and sham-operation group.Seven days after spinal cord injury,the rats of transplantation group received OPCs transplantation,of control group were injected with equivalent saline,and of injury-only group were untreated.The effects of OPCs transplantation on neural functional recovery in spinal cord injured rats were measured by the behavioral test and assessments of motor evoked potentials(MEP) and somatosensory evoked potentials(SEP).Results Immediately after spinal cord injuries,the neural function of spinal cord of rats was markedly impaired.The results of behavioral test,MEP and SEP in injured rats were much worse than those in sham-operation group.Although the neural function in spinal cord injured rats improved in different degrees with the time,the results of behavioral test,MEP and SEP showed it was significantly better in transplantation group than that in control group.Conclusion The transplantation of OPCs may enhance the recovery of neural function of rats with spinal cord injuries.

Objective To prepare the acellular scaffold of spinal cord and analyze its component.Methods The acellular scaffold was prepared with the freeze thawing and chemical extraction,its structure was observed by HE and SEM,its component was analyzed by immunohistochemistry.Results The cells,myelin sheath and axon of nerve fibers in the rat spinal cord were eliminated,but three-dimensional supports of extracellular matrix were reserved.The analytical results showed the component of the acellular spinal cord contain laminin,fibronectin and type Ⅳ collagen—the necessary components to facilitate and induce the regeneration of the injured nerves and enhance the adhesion and proliferation of cells.Conclusion The acellular spinal cord has three dimensional structure and contains several proteins related to the regeneration of the injured nerves and promotion of the survival and proliferation of cells.