AIM:To investigate the effect of lipopolysaccharides(LPS)preconditioning on CCl4-induced liver injury and the change of LPS signal transduction.METHODS:The male Wistar rats were divided randomly into liver-injury group,which were injected with CCl4 5 mL/kg first,three days later were injected 0.3 mL 40% CCl4 and 60% olive oil. Animals in LPS preconditioning group were injected with LPS 0.5 mg/kg before the day CCl4 was given. Rats received high fat diet were as liver injury group,and normal control group received normal diet. The lymphocytes infiltrated in the liver tissue were counted. The endotoxin and ALT level in rat plasma,TNF-? content and expressions of TLR4,p38,p-p38,I??,NF-?? in the rat livers were also determined.RESULTS:The lymphocytes in liver slice and ALT level of the plasma in LPS preconditioning group were lower significantly than those in the liver injury group,and the expressions of TLR4,p-p38,NF-?? in the liver were the same. In contrast,the expression of I?? was higher.CONCLUSION:LPS preconditioning relieves obviously CCl4-induced chronic liver injury. The mechanism may be associated with change of signal transduction of LPS,which results in decrease of pre-inflammatory cytokines.

Objective To study the generating algorithm of personalized external fixation model based on STL file, so as to realize the fabrication of personalized external fixation through 3D scanning, model generation and 3D printing. Compared with the traditional plaster fixation, the external fixation obtained by the proposed method has the advantages of good adhesion to the external surface of the limb, good gas permeability and light weight. Methods In order to generate a personalized external fixation model, the key generating algorithms of the model were studied. The point cloud file of the residual limb was obtained by a 3D scanner, and then was converted into an STL format file. The triangular patches were processed by cutting, offsetting, triangulating and hollowing to create an external fixation model with good gas permeability and conformable surface that is fully fitted with the body surface. Finally, the external fixation was fabricated by 3D printing. Results Using the improved point offset algorithm, the problem of severe distortion of the point offset at the plane and sharp corners was solved. Using the tangent sort method, the points on the contour ring were sorted clockwise to obtain a triangular profile. The hollowing of the model was achieved by using the typical three-dimensional "cutting tool" mathematical model and the STL file space intersection method. Conclusions The improved model generating algorithm was validated based on a wrist case, and the personalized external fixed fixation model with conformable surface was obtained. It is proved that the proposed model generating algorithm is effective and practical.

3D printing technology has unique advantages and broad application prospect in biomedicine field. In recent years, cell printing, tissue printing, and organ printing technologies h have appeared successively, and drug printing and medical device printing have been realized. For complex surgical cases, surgeons and researchers have explored a surgical program that involves 3D printing technology, and completed many clinical applications including case discussions, surgical simulations and implantation surgeries. These efforts promoted the application and development of 3D printing technology in medical field. The purpose of this paper is to describe the application and research status of 3D printing technology in medical field from the aspects of medical teaching, orthopedic surgery, stomatology, bioprinting, drug printing, medical device manufacturing, etc., and put forward the prospects for future development.

Objective: To detect pathogenic gene variants in two Chinese families with cone-rod dystrophy(CORD). Methods: After the informed consent and comprehensive ophthalmic examinations for the patients, 3 mL peripheral blood was taken from the patients’ blood vessel and DNA was extracted. The DNA was sequenced by whole-exome sequencing technology and variants were analyzed. Results: Two novel compound heterozygous AIPL1 variants were detected in two patients, which were c. 923T>C(p.L308P) and c. 421C>T(p.Q141X) variants in Family 1, c. 572T>C(p.L191P) and c. 421C>T(p.Q141X) in Family 2 . Conclusion The results supported that AIPL1 gene variants are the main cause of the two CORD families. Whole-exome sequencing technology is a useful tool in the clinical differentiated diagnosis and genetic counseling for CORD patients.