MicroRNAs(miRNAs),small noncoding RNAs,are essential for posttranscriptional gene regulation and have important roles in a wide range of biological processes,including development,growth and differentiation. Thousands of miRNAs have been identified in animals,plants and microoaganisms. miRNAs regulate their target genes by mRNA degradation or translation suppression. About 30 % of genes in an organism are subject to miRNA regulation. miRNA expression and function are regulated by transcriptional factors,epigenetics,single nucleotide polymorphisms,RNA editing and so on. Additionally,the success in knocking out a specific mouse miRNA gene has provided a valuable model for studying miRNA function.

Implantation window is the transient period when the embryos develop into blastocysts and the uterus differentiates into the receptive state synchronically. Estrogen and progesterone are the comprehensive regulating molecules during this process. They influence the proliferation and differentiation of multiple cell types in the uterus through the modulation of various local-signaling molecules.Uterus and blastocyst interact by the paracrine effects of prostaglandin, histamine, calcitonin, cytokines and growth factors at implantation window. This molecular cross-talk modulates the interaction between trophectoderm and uterine luminal epithelium. Once the implantation window is open, it then switches into unreceptive state spontaneously.

Light and electron microscopic observations revealed that most of the embryos collected 15-16 hours after fertilization were at the pronuclear stage. Many supernumerary spermatozoa were found on the surface and in the outer zone of the zona pellucida, but none of them got into the inner zone of the zona or the perivitelline space. Some spermatozoa on the zona surface were observed in acrosome reaction stage, and those penetrated into the zona always left some acrosome reaction vesicles behind on the surface of the zona. The fertilized ovum eliminated almost all of its cortical granules and where there were some granules left, in the area that the plasma membrane had fewer microvilli. The cortical cytoplasm of the pronuclear zygote was populated with clustered hooded mitochondria, SER vesicles, yolk vacuoles and lipid droplets. Directly surrounding the pronucleus were a variety of organelles including welldeveloped Golgi complex, SER, mitochondria and annulate lamellae. The significance of these morphological changes of the fertilized ovum was discussed.

Objectives: To verify the feasibility and safety of the anterior transpedicular screw(ATPS) fixation of the upper thoracic spine (T1-T4) through the radiological anatomy study on the cadaveric specimens. Methods: The upper thoracic spine thin-section CT data of 40 cases were collected from the radiology de-partment′s database(20 males and 20 females, aged from 18 to 68 years, the mean age was 39.7 years). The data of OPW(outer pedicle width), OPH(outer pedicle height), PAL(pedicle axis length), TPA(transverse section angle), SPA(sagittal section angle), DTIP(distance of transverse intersection point) and DSIP(distance of sagittal intersection point) of each pedicle were measured on the transverse and sagittal sections through the axis of each pedicle. The data were recorded and statistically analyzed. 10 upper thoracic spine(C7-T6) specimens of adults(5 males and 5 females, with unknown ages), with no damage to their appearance, the costovertebral joints and paravertebral soft tissue were completely retained. Then simulate surgical operations were done on the cadaveric specimens based on the obtained data. Screws were implanted anteriorly by free hand. After that, the specimens accepted X-ray fluoroscopy and CT scan. At last, the screws were removed, the speci-mens were sawed along the transaction and sagittal section of the screw channel. Then the success rate of the screw placement was evaluated according to Rao′s worn out classification standard of pedicle screws. Results: From T1 to T4, the OPW decreased from 8.14mm to 3.47mm; the OPH increased from 6.89mm to 10.29mm; the TPA decreased from 32.96° to 11.64°; the DTIP increased from 1.80mm to 5.50mm; the SPA increased from 104.95° to 115.74°; the DSIP increased from 5.95 to 8.76mm; the PAL changed irregularly, from 32.95 to 35.96mm. The pedicle diameters of T3 and T4 were too small to implant ATPS, but the ARTPS can be implanted successfully. The diameter of ATPS was about 4.0mm; the length of ATPS was about 35mm. The diameter of ARTPS was about 5.0mm; the length of ARTPS was about 35mm. 80 pedicle screws were implanted anteriorly, according to Rao′s worn out classification standard of pedicle screws, the fine rate was 90%. The internal walls of 7 pedicles were broken by screws of less than 2mm and no compression to the spinal cord. The internal walls of 5 pedicles were broken of 2 to 4mm, 1 at T1, 1 at T3 and 3 at T4, with varying degrees of spinal cord compression. The internal walls of 2 pedicles were broken of greater than 4mm, 1 at T2 and 1 at T4, with serious spinal cord compression. The external wall of 1 pedicle was broken at T2. Conclusions: The ATPS techniques at T1, T2 and the ARTPS techniques at T3, T4 are feasible, but the safety and clinical practice and further research is needed.

BACKGROUND:Research about the repair of articular cartilage with heterograft chondrocytes is frequently reported, but the method may cause immune rejection. Since the embryonic cells possess lower antigenicity and stronger proliferation capability, it is hoped that they can be used as a novel carrier substitute in tissue engineering research.DESIGN: A randomized grouping observation and comparative experiment.SETTING: Histological Embryonic Laboratory in Guangxi Medical University.MATERIALS: A big white adult New Zealand rabbit pregnant for 4 weeks was adopted; and another 24 big white adult New Zealand rabbits were selected, with no limitationin whether they were female or male and with a body mass of 2 to 2.5 kg.METHODS: This experiment was carried out at the Histological Embryonic Laboratory in Guangxi Medical University between December 2000and June 2002. The models of defects in articular cartilage were made artificially in femur medial malleolus of the mature rabbits. In the experimental group, defects were repaired by the implantation of Fibrin Sealant and embryonic chondrocytes mixture, but for the control group, only Fibrin Sealant was implanted or nothing was done about the defect. The restoration of articular cartilage defect was then observed 4,8 and 12 weeks after the operation, and was scored according to modified Pineda's method. The standard consists of 5 items, I.e., cellular morphology, matrix staining, surfacing smoothness, cartilage thickness and host union. 0 refers to normal and the higher the score is, the more serious the pathological changes are.MAIN OUTCOME MEASURES: ①The general observation of rabbit knee joint; ② Histological observation of rabbit knee joints; ③ Histological semi-quantitative score of articular cartilage; ④ Appraisal of the curative effect of articular cartilage defects.RESULTS: Totally 24 rabbits were enrolled in this experiment and all entered the stage of result analysis. ① The general observation of rabbit knee joint: In embryonic chondrocytes plus fibrin sealant group, the color in defect area was basically the same as that of the normal cartilage, showing a strong quality and better elasticity with the boundaries from the surrounding cartilage approximately vanishing. In Fibrin sealant group and the control group, the defect did not heal completely, but the defect area became small and filled with white fibrous tissues. ② Histological observation of rabbit knee joints: In embryonic chondrocytes plus fibrin sealant group,tissues were predominated by hyaline cartilage, with bone tissues appearing in deeper position, and the surface was slightly raised or smooth, and the matrix showed normal staining, and were completely united with the surrounding cartilage and the division line was not clear. There was no lymphocyte infiltration in the tissues. In Fibrin sealant group and the control group, tissues were predominantly fibrous tissues, and part of them showed obvious residual hollow scar, connecting or partly connecting with the surrounding tissues. ③ Histological semi-quantitative score of articular cartilage: According to modified Pineda's method, the scores of embryonic chondrocytes plus fibrin sealant group after 12 weeks were obviously lower than those of the fibrin sealant group and the control group [(0.50±0.76) vs (7.88±1.13), (8.13±1.36), P ＜ 0.05]; moreover, the difference between pure fibrin sealant group and the control group was of statistical significance 4weeks after the operation (P ＜ 0.05), but there was no obvious difference 8and 12 weeks after the operation. ④Appraisal of the curative effect of articular cartilage defects: 12 weeks after the operation, in the embryonic chondrocytes plus fibrin sealant group, the defect of 8 cases healed completely. In fibrin sealant group 1 case healed but not completely, and 7cases did not get repaired for their defect. In the control group, 8 cases failed to get their defect repaired.CONCLUSION: The repaired tissues in embryonic chondrocytes trans plantation group were basically the same as normal cartilage, obviously superior to the fibrin sealant group and the control group, suggesting that such method is feasible in the repair of articular cartilage defects.

The cytoplasmic and nuclear changes during the development of goat oocytes were studied with light and electron microscopy. The oocyte development may be divided into 8 stages in accordance with the number and distribution of follicle cells and the size of the follicle. The results indicated that the Golgi complex, mitochondria, smooth endoplasmic reticulum and cortical granules became well developed and they moved into the cortical region as the oocyte development proceeded. In the oocytes in the follicle of 1.5-3mm in diameter, all the mitochondria became hooded and the number and size of fibrillar centers in the nucleolus reached maximum, but the nucleolar compaction still not occured at this stage. By the time when the follicle reached 3.5-5mm in diameter, the follicular cell processes began to degenerate, the microvilli of the oocyte withdrew from the zona pellueida and the oocytes might be cultured to mature in vitro. In the mature oocytes, Golgi complex and rough endoplasmic reticulum disappeared, the cortical granules arranged themselves in one layer beneath the oolemma, the mitochondria dispersed in the central region of cytoplasm and the eggs were ready for fertilization.

Objective To investigate the relationship between single nucleotide polymorphisms (SNPs) of PRKCG gene (rs2547362,rs3745406) and osteosarcoma susceptibility in the osteosarcoma patients and the normal population.Methods Sixtyone patients with osteosarcoma who had been admitted in our hospital from January 2011 to December 2012 and 63 healthy adults were enrolled in this study.A 2-ml peripheral blood sample was taken from each participant.The RT-qPCR method was used to detect the genotype and allele frequency distribution of PRKCG gene at rs2547362 and rs3745406 in osteosarcoma patients and normal population.Osteosarcoma patients were divided into several groups according to the clinical parameters such as age,gender,histology,tumor location,Enneking classification,tumor metastasis and therapy,and then we analyzed the relations between the genetic polymorphism and clinical parameters.Results 1) The genotype of PRKCG gene at rs3745406 included CC,CT and TT.The differences of genotypes (CC,CT,TF) and alleles (C,T) frequency distribution at rs3745406 were not statistically significant between osteosarcoma patients and the normal population (P=0.490,P=0.554).2) The genotype of PRKCG gene at rs2547362 included CC,CT and TT.The differences of genotypes (CC,CT,TT) and the alleles(C,T) frequency distribution at rs2547362 were statistically significant between the osteosarcoma patients and the normal population (P=0.006,P=0.007).3) The differences of genotypes (CC,CT,TT) and alleles (C,T) frequency distribution at rs3745406 were statistically significant between patients with metastasis and patients without metastasis (P=0.000,P=0.000).The CT and TT genotypes and the T allele carrier frequency at rs3745406 were higher in patients with metastasis than in patients without metastasis.SNPs at rs2547362 were not associated with clinical parameters.Conclusion The genetic polymorphism of PRKCG gene at rs2547362 is associated with osteosarcoma susceptibility.The TT genotype and T allele at rs3745406 are associated with metastasis of osteosarcoma,which may be a risk factor for metastasis in the osteosarcoma patients.

OBJECTIVE ToexplorethepossiblemechanismoractiontargetsofT-2toxinembryo toxicity by observing the effect of T-2 toxin on mitochondrial function of differentiated murine e mbryonic stemcells(mESCs).METHODS Duringdifferentiationat24,72and120h,ESCswereexposedto T-2 toxin 0.5 μg·L-1 .Meanwhile,mESCs were pre-treated with antioxidant Trolox (200 μmol·L-1 )for 30 min and exposed to T-2 toxin (0.5 μg·L-1 )for 72 h.The mitochondrial ultrasture of differentiated mESCs was observed under a transi mission electrical microscope (TEM).The differentiated ESC mito-chondrial function,including respiratory control ratio (RCR),ATP synthase activity and mitochondrial membranepotential(MMP),wasmeasuredat144hafterdifferentiation.RESULTS Significant decrease of the mitochondrial number,deformation of mitochondrial structure,and lack of complete mito-chodrial crest were observed through TEM in the groups of T-2 toxin exposed for 72 and 1 20 h,respec-tively.Compared with the normal control group,RCR declined by 49.5% and 55.1%,ATP synthase activity decreased by 84.9% and 89.3%,and MMP decreased by 23.2% and 35.2% in T-2 toxin 0.5 μg·L-1 exposure 72 and 1 20 h group,respectively.However,the inhibition of mitochondrial function by T-2 toxin in differentiated mESCs recovered significantly in the presence of the antioxidant Trolox. CONCLUSION T-2toxininducesoxidativestressandinhibitsmESCsmitochondrialfunctionindifferenti-ated mESCs,and ROS-induced mitochondrial malfunction plays an i mportant role in T-2 toxin e mbryonic toxicity mechanis m.

OBJECTIVE To investigate the role of gonadotropin-releasing hormone (GnRH) in es-tradiol(E2 ) induced advance of puberty onset in rats. METHODS Postnatal day 18 SD rats were given a daily intragastric administration of corn oil or E2(50 μg.kg-1 ) for consecutive 5 d. The day of vaginal opening (VO), pathological changes in ovary and protein expression levels of GnRH, G protein-coupled receptor 54 ( GPR54) and phospholipase C ( PLC) in hypothalamus were observed. RESULTS As compared to corn oil controll group, VO was advanced by about 12.2 d, corpus luteum was observed in the ovary section, and the protein expression levels of GnRH,GPR54 and PLC in hypothalamus were significantly increased by 47%, 55% and 56% in E2 group, respectively. CONCLUSION E2 induced onset of puberty advance may be closely related to regulation of the expression of GnRH, GPR54 and PLC in hypothalamus.

Objective To compare the rigidity at upper thoracic spine among the anterior transpedicular screw-plate system (ATPSPS),posterior transpedicle screw-rod system (PTPSRS) and anterior vertebral body screw-plate system (AVBSPS).Methods Twelve embalmed cadaver specimens were divided into three groups.The specimens in each group were randomly allocated to use the above 3 different internal fixation devices for conducting fixation.The stiffness of each specimen on the directions of axial compression,flexion and extension,and left and right lateral bending was detected under original status.All specimens conducted the simulated corpectomy of T2 (damage status).Then the rigidity on various directions was re-detected on the damage status.The corresponding internal fixation system was selected for conducting the install and fixation according to the grouping results.The intra-group and inter-group rigiditieson different directions were compared amongoriginal status,damage status and after internal fixation.Results The rigidities on different directions under original and damage statushad no statistical difference among various groups (P＜0.05).After conducting fixation in each group,the rigidity after fixation on different directions had statistically significant difference among groups(P＜0.05).The stiffness of anterior flexion in the ATPSPS group was greater than that in the other two groups (P＜0.05).The rigidity of axial compression and extension in the PTPSRS group was greater than that in the other two groups,the difference among groups was statistically significant (P＜0.05).The stiffness of lateral bending in the AVBSPS group was smaller than that in the other two groups,the difference was significant (P＜0.05),but the difference between the other two groups had no statistical significance (P＞0.05).Conclusion The rigidity of ATPSPS in all directions is higher than that of AVBSPS.The anterior flexion rigidity is greater than PTPSRS,and the axial compression and extension rigidity are less than PTPSRS,but the lateral bending rigidity is equivalent to PTPSRS.