[Selective U-shaped osteotomy of lateral tibial condyle for the treatment of collapse and comminuted fracture of lateral tibial plateau].

Objective: To explore methods and clinical effects of selective U-shaped osteotomy of lateral tibial condyle in treating collapse and comminuted fracture of lateral tibial plateau.

Methods: From January 2014 to October 2019, 15 patients with collapse and comminuted fracture of lateral tibial plateau were treated by selective U-shaped osteotomy of lateral tibial condyle, including 9 males and 6 females. The age of patients ranged from 25 to 70 years old, with an average age of (38.

Fates of donor and recipient mitochondrial DNA during generation of interspecies SCNT-derived human ES-like cells.

To investigate nuclear donor and cytoplast recipient mitochondria fate and their effects on generation of interspecies somatic cell nuclear transfer (iSCNT)-derived human embryonic stem (ES)-like cells, iSCNT embryos were reconstructed between enucleated goat oocytes and human neural stem cells (hNSCs). A total of 10.74% cleaved embryos (13/121) developed to blastocyst stage.

Isolation and characterization of human anti-VEGF165 monoclonal antibody with anti-tumor efficacy from transgenic mice expressing human immunoglobulin loci.

The purpose of this study was to prepare a fully human anti-VEGF (vascular endothelial growth factor) monoclonal antibody with anti-tumor activity from five-feature mice which express human immunoglobin loci. Four hybridomas secreting mAb stably were isolated successfully. Some characters such as isotypes, cross-reactivity, inhibition on the binding of hVEGF to VEGFR-2, dissociation constants and the idiotypic characteristic were determined.

Different intervals of ovum pick-up affect the competence of oocytes to support the preimplantation development of cloned bovine embryos.

The objective of this study was to determine the effect of different frequencies of transvaginal ovum pick-up (OPU) on the quantity of recovered cumulus oocyte complexes (COCs) and subsequently the competence of matured oocytes to support the preimplantation development of cloned bovine embryos. The COCs were aspirated from the ovaries of 6 Chinese Holstein cows by transvaginal follicle aspiration twice a week (every 3 or 4 days) (Group I), every 5 days (Group II), once a week (every 7 days) (Group III), every 10 days (Group IV), and once every 2 weeks (every 14 days) (Group V). The developmental stages of the follicles were confirmed by the diameter of the dominant follicle (DF) and harvested COCs, and the dynamics of the follicular wave were clarified.

Secondary SCNT doubles the pre-implantation development rate of reconstructed interspecies embryos by using cytoplasts of Sannen dairy goat ova.

The aim of this study was to investigate whether ova of Sannen goat could support the pre-implantation development of interspecies embryos constructed through somatic cell nucleus transfer (SCNT) embryos and whether secondary SCNT (SSCNT) could improve the pre-implantation development of those embryos. The primary SCNT (PSCNT) embryos were produced by using Sannen goat ovum cytoplasts as recipients and fibroblast cells, derived from human, rabbit and Boer goat skins, as nucleus donors. The blastomeres of 8 to 16 cells stage of PSCNT embryos were subsequently used as nucleus donor cells and Sannen goat ovum cytoplasts as recipients to evaluate the effect of SSCNT on the pre-implantation development rate of these reconstructed interspecies embryos.

[Knockout serum replacement improves establishment efficiency of C57BL/6J mouse embryonic stem cell line].

Aim: To eliminate the influence of serum on self-renewal of embryonic stem cells (ESCs), knockout serum replacement (KSR), a defined formulation, was used to replace serum for the establishment of C57BL/6J mouse ESC line.

Methods: C57BL/6J mouse blastocysts collected at 3.5 days post coitum (d.

Effect of cytoplast on the development of inter-subspecies nuclear transfer reconstructed goat embryo.

The aim of this study was to investigate effect of cytoplast on the development competence of reconstructed embryos derived from inter-subspecies somatic cell nucleus transfer (SCNT). First, the development potency of reconstructed embryos produced by transferring Boer goat fibroblast cell nucleus of different ages into enucleated Sannen goat ova was evaluated in order to determine which age of nuclear donor is favorable for the reconstructed embryos development. Secondly, the another component of reconstructed embryos, "cytoplast," was evaluated by comparing the effect of ovum cytoplast derived from Sannen male symbol x Boer female symbol descendant on the reconstructed embryos development to that of Sannen goat ovum cytoplast.

Factors derived from mouse embryonic stem cells promote self-renewal of goat embryonic stem-like cells.

Goat embryonic stem (ES)-like cells could be isolated from primary materials-inner cell masses (ICMs) and remain undifferentiated for eight passages in a new culture system containing mouse ES cell conditioned medium (ESCCM) and on a feeder layer of mouse embryo fibroblasts (MEFs). However, when cultured in medium without mouse ESCCM, goat ES-like cells could not survive for more than three passages. In addition, no ES-like cells could be obtained when ICMs were cultured on goat embryo fibroblasts or the primary materials-whole goat blastocysts were cultured on MEFs.

[Expression of goat beta-casein gene targeting vector in mammary gland cell].

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.

[Effect on development in NT embryos after transplantation of nuclei derived from transfected goat fetal fibroblasts suffering different treatments into enucleate eggs].

In order to improve the development rate of preimplantation nuclear transfer embryos (NT embryos) after transplanting nuclei derived from transgenic goat fetal cells, the donor fetal fibroblasts starved for 5 days in DMEM containing 0.5% FCS were divided into three groups and treated with different methods respectively before using as donor cell. Group 1 was frozen at -80 degrees C or in liquid nitrogen for several days or months.

Efficient differentiation of embryonic stem cells into neurons in glial cell-conditioned medium under attaching conditions.

Embryonic stem (ES) cells can differentiate into neurons in vitro, which provides hope for the treatment of some neurodegenerative diseases through cell transplantation. However, it remains a challenge to efficiently induce ES cells to differentiate into neurons. Here, we show that murine ES cells can efficiently differentiate into neurons when cultured in glial cell-conditioned medium (GCM) under attaching conditions without the formation of embryoid bodies.

Transfer of an expression YAC into goat fetal fibroblasts by cell fusion for mammary gland bioreactor.

Yeast artificial chromosomes (YACs) as transgenes in transgenic animals are likely to ensure optimal expression levels. Microinjection of YACs is the exclusive technique used to produce YACs transgenic livestock so far. However, low efficiency and high cost are its critical restrictive factors.

[Preparation and preliminary application of monoclonal antibody against recombinant human erythropoietin].

Aim: To prepare monoclonal antibody (mAb) against erythropoietin(EPO), characterize its biological properties and use it to purify the rhEPO from transgenic goat milk.

Methods: A crude rhEPO product was used as the antigen to immunize BALB/c mice for preparing mAbs against rhEPO. The mAbs were characterized by Western blot and indirect ELISA.

[Preparation methods of nanocavity biomaterials with recognition specificity via template imprinting of proteins].

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.

[Comparison of vitrification cryopreservation among different stages of mouse embryos].

The cryopreservation of different embryo stages collected from ICR, C57BL/6 and F1 of DBA*C57BL/6 was carried out by using vitrification method. The morphology, in vitro development and birth rates of these embryos were compared after frozen-thawed. The results showed that more than 75% of the morphology from 2-cell embryos to morula stages from different strains was normal, the normal morphology rates of 8-cell embryos being the highest, while those of blastulas being the lowest.

Generation and characterization of transgenic mice expressing tamoxifen-inducible cre-fusion protein specifically in mouse liver.

Aim: To establish transgenic mice expressing tamoxifen-inducible Cre-ERt recombinase specifically in the liver and to provide an efficient animal model for studying gene function in the liver and creating various mouse models mimicking human diseases.

Methods: Alb-Cre-ERt transgenic mice were produced by microinjecting the construct with Cre-ERt fusion gene of DNA fragments into fertilized eggs derived from inbred C57BL/6 strain. Transgenic mice were identified by using PCR and Southern blotting.

[Nano-structured scaffold materials used in tissue engineering].

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.

Conditional gene activation in cultured hepatocytes using a ligand-dependent chimeric Cre recombinase.

By combining liver-specific promoter and a chimeric Cre recombinase, conditional gene activation could be finely achieved in hepatocytes at selected time points. To this end, the expression vector of Cre-ERt under the control of the mouse albumin gene promoter/enhancer, alb-Cre-ERt, was constructed, and transfected into engineering BRL (Rat hepatocytes) and BRK (Rat kidney) reporter cells which carries a chromosomally integrated 'floxed' beta geo gene, which is inserted between the promoter and the human alkaline phosphatase( hAP) reporter gene, thereby preventing hAP reporter gene transcription, respectively. After treatment with 1 micromol/L 4-hydroxytamoxifen(4-OHT), a proportion of hAP staining positive cells were detected by hAP staining.

[Molecularly imprinted polymeric microspheres prepared by seed swelling and suspension polymerization].

A series of molecularly imprinted polymeric microspheres(MIPMs) were prepared by seed swelling and suspension polymerization method in aqueous system using tyrosine as printing molecules, methacrylic acid as functional monomers and trimethylolpropane trimethacrylate (TRIM) as cross-linkers. The morphology including the size, size distribution, pore and pore distribution of the polymer beads was analyzed by scanning electron microscope(SEM). The major factors that influence these properties of the beads are discussed.

Preliminary study on the production of transgenic mice harboring hepatitis B virus X gene.

AIM:To establish transgenic mice lineage harboring hepatitis B virus X gene and to provide an efficient animal model for studying the exact role of the HBx gene in the process of hepatocarcinogenesis.METHODS:The HBx transgenic mice were produced by microinjecting the construct with X gene of HBV (subtype adr) DNA fragment into fertilzed eggs derived from inbred C57BL/6 strain; transgenic mice were identified by using Nested PCR; expression and phenotype of HBx gene were analyzed in liver from transgenic mic at the age of 8 weeks by RT-PCR, pathologic examination and periodic acid-schiff staining (PAS), respectively.RESULTS:Five hundred and fourteen fertilized eggs of C57 BL/6 mice were microinjected with recombinant retroviral DNA fragment, and 368 survival eggs injected were transferred to the oviducts of 18 pseudopregnant recipient mice, 8 of them became pregnant and gave birth to 20 F1 offspring.