Application of intermittent flap opening in L-shaped surgical incision of calcaneal fracture / 中国骨伤

OBJECTIVE@#To explore clinical effect of intermittent flap opening technique in L-shaped incision of calcaneal fracture.@*METHODS@#From January 2017 to January 2019, 48 patients with Sanders typeⅡ to Ⅳ calcaneal fractures were treated by open reduction and internal fixation. According to different flap opening techniques, the patients were divided into control group and observation group, 24 patients in each group. In observation group, there were 17 males and 7 females, aged from 20 to 60 years old with an average of(45.12±9.56) years old;7 patients were typeⅡ, 10 patients were type Ⅲ and 7 patients were type Ⅳ according to Sanders classification;3 patients were C0, 16 patients were C1 and 5 patients were C2 according to Tscherne-Gotzen soft-tissue assessment;treated with intermittent flap technique. In control group, there were 19 males and 5 females aged from 20 to 60 years old with an average of (47.32±10.67) years old;7 patients were typeⅡ, 11 patients were type Ⅲ and 6 patients were type Ⅳ according to Sanders classification;2 patients were C0, 18 patients were C1 and 4 patients were C2 according to Tschemc-Gotzen soft-tissue assessment;treated with static flap opening technique. Operation time, flap retraction time, changes of Böhler angle and Gissane angle before and after operation at 3 days, and occurrence of incision complications were observed and compared between two groups.@*RESULTS@#All patients were followed up from 3 to 6 months with an average of(4.52±1.01) months. There were no significant differences in operation time, changes of Böhler angle and Gissane angle before and after operation at 3 days between the two groups(P>0.05);there was statistical difference in flap retraction time between two groups(P<0.05). Occurrence of incision complications in observation group was significantly lower than that in control group (P<0.05).@*CONCLUSION@#Intermittent flap opening technique is superior to static opening technique in reducing incision complications of lateral "L" approach of calcaneus. Single Kirschner wire opening does not affect the exposure, reduction and fixation of fracture during operation.

Establish a transgenic mice model harboring structural genes of hepatitis C virus / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To establish an animal model of HCV transgenic mice to elucidate the pathogenesis of hepatitis C virus infection and function of the viral structural proteins.</p><p><b>METHODS</b>Structural gene of HCV were amplified and recombined into eukaryotic expression vectors, pcDNA4HisMax and pMT/BiP/V5-His A, after their expressive activity was confirmed to detect the structural protein in the transfected COS7 and S2 cells by Western blot. The fertilized expression element, which contained CMV or pMT promoter, structural gene of HCV and polyadenylation signal sequence, was microinjected into 1736 C57BL/6 mouse fertilized ova. The ova were then replanted into the oviducts of 69 pseudopregnant recipient mice.</p><p><b>RESULTS</b>Twenty-five recipient mice were impregnated and later produced 105 newborns; 49 of them died from unknown causes and 57 survived. After the specific HCV structural genes were identified by PCR and Southern blot hybridization, 26 founders were obtained; among them 10 were stable expression mice and 16 were the inducible ones. The rate of founders developed from implanted embryos was only 1.50%. Through hybridization with normal mice, 58 hybrid mice have been obtained at present.</p><p><b>CONCLUSION</b>Two kinds of different transgenic mice of HCV were developed; one is of stable expression, and the other is inducible. This transgenic mice model may create an opportunity for studying the function of the structural gene of HCV and elucidate its pathogenicity.</p>

Expression of goat beta-casein gene targeting vector in mammary gland cell / 生物工程学报

The study of mammary gland bioreactor is in the ascendant. In order to generate transgenic goats of well-controlled expression of exogenic genes, we constructed a human lactoferrin (hLF) gene targeting vector containing promoter, exon 1, intron1 and some of exon 2 (about 6.1 kb fragment) and exon 6 approximately 9 (about 3.3 kb fragment) of the goat beta-casein gene as well as hLF minigene, neo gene inserted into them and tk gene ligated to the 3' end of the construct. The 9.4 kb goat genomic sequences as homologous arms were initially amplified by PCR with local goat tissue DNA. The expression vector was named pBC-tk-neo-hlf. Then the recombinant plasmid pBC-tk-neo-hlf containing hLF minigene was transfected into mice mammary tumor cell line C127 by liposome, cell clones were selected with G418. After proliferating, the transfected cells were induced with insulin, luteotropic hormone and hydrocortisone. The result of Western-blotting analysis showed that the transfected cells can secrete hLF protein, and the recombinant protein expressed in cultured cell supernatant has the similar molecular weight as the native protein. The expression level detected by ELISA was 0.21 microg/mL. This result indicated that the targeting vector could efficiently direct the expression of hLF in mammary cells,and it confirmed the validity of the constructed vector. At the same time, C127 cell line proved to be useful for evaluating the regulation of a foreign gene expression in mammary gland specific expression vector.

Preparation methods of nanocavity biomaterials with recognition specificity via template imprinting of proteins / 中国医学科学院学报

Nanocavity biomaterials with recognition specificity imprinted by using proteins as templates may successful serve as substitutes for antibodies, enzymes, and other native biological structures as well as cell bracket materials. It has numerous applications in biotechnology, medicine and so on. In this paper, the principle of template imprinting is introduced briefly, the specialty of template imprinting of proteins is analyzed, and the methods of template imprinting of proteins including protein entrapment, microbead surface imprinting, flat surface imprinting as well as the epitope are reviewed in details.

Nano-structured scaffold materials used in tissue engineering / 中国医学科学院学报

Micro- and nano-structured surfaces of scaffold materials have important effects on cells' adhesion and proliferation. Nano-structured surfaces can improve cells' adhesion and biocompatibility of materials. The effects of nano-biomaterials on the development of tissue engineering and the methods of preparation of nano-biomaterials such as molecular self-assemble and template technology are discussed.