BACKGROUND: Growth differentiation factor-5 (GDF-5) plays an important role in the development and formation of cartilage, extremities, and joints, which is a widely used joint development marker.OBJECTIVE: To express mature peptide of human GDF-5 in E. coil by the way of genetic engineering, and to explore the inductive activity of recombinant protein in vivo.DESIGN, TIME AND SETTING: The observation experiment based on gene was performed at the Analysis and Testing Center of Southern Medical University from January to June 2006.MATERIALS: Human fetus cartilage tissue was harvested from Department of Gynaecology and Obstetrics, and the consent was obtained from the family. Ten KM mice were purchased from experimental animal center of Southern Medical University, half male and half female, weighing 18-22 g, aged 6-8 weeks.METHODS: The hGDF-5 gene encoding mature peptide was gained by RT-PCR from the total RNA which was extracted from fetus cartilage tissues, and was inserted into the pET22b(+) vector to construct recombinant prokaryotic expression plasmid pET22b(+)-GDF5, which was transformed into E. coil BL-21 to be expressed after IPTG induction. Proteins of interest were purified with sepharose chelated with nickel ions (Ni2+) and then implanted in mouse hindlimb muscle to evaluate the biological activities by routine hematoxylin-eosin staining.MAIN OUTCOME MEASURES: The expression, sequencing of target gene was observed by agarose gel electrophoresis, and the protein expression was detected by SDS-PAGE electrophoresis, meanwhile, the GDF5-inducing activity was evaluate by histological observation.RESULTS: RT-PCR product was about 350 bp in length, which was confirmed by double enzyme digestion of the recombinant plasmid, sequencing result was in agreement with the reported hGDF-5 sequence in Genbank. SDS-PAGE analysis showed a conspicuous band representing a new foreign protein with relative molecular mass of approximately 14 KD after induced expressioin. Cartilage tissues were formed in the mouse muscle where the purified proteins were implanted. CONCLUSION: The integral human GDF-5 mature peptide gene was cloned successfully from human fetus cartilage tissue and a high-yield expression was achieved in E. coli, the pudfied protein has chondrogenic activities in vivo.

Objective To improve the diagnostic accuracy by analyzing the CT manifestations of ovarian cystadenoma .Methods The CT images of 57 patients with 62 ovarian cystadenomas proved by surgery and pathology were studied retrospectively . Results Of 62 ovarian cystadenomas, 26 cases with 31 tumors were serous,another 31 cases were mucinous . Unilocular and multilocular forms were seen respectively in 19(61.3%)and 12(38.7% ) of 31 serous cystadenomas, and in 3(9.7%)and 28(90.3%) of 31 mucinous cystadenomas.22 (71.0%) tumors were benign, and 9(29.0%)were of borderline and/or malignant transformation in 31 serous cystadenomas.23 (74.2%) tumors were benign, and 8 (25.8%) were of borderline and/or malignant transformation in 31 cases of mucinous cystadenomas.Benign cystadenomas were frequently round or oval cysts with thin regular wall and septa.Borderline or malignant transformation cystadenomas demonstrated predominately thick irregular wall or septa with projections.The overall preoperative accuracy of characterization was 48.4% in serous and 77.4% in mucinous cystadenomas.Conclusion Multilocular cystadenomas have the typical CT manifestations and CT is a high valuable procedure for imaging them, whereas unilocular cystadenomas, having similar CT findings with some other benign cystic lesions, are lack of enough characteristic features for CT correct characterization.

Objective To investigate the effects of gene transfection with human growth/differentiation factor 5(GDF5)on the growth and difierentiation of bone nlarrow stromal stem cells (BMSCs).Methods GDF5 gene was trans fected into BMSCs by liposome method. Then cell proliferation and cycles were examined by MTT and flow cytometry respectively. Cell morphology was observed under light microscope and electron microscope (EM).GDF5 and Collagen Ⅱ were detected at the level of mRNA and protein by RT-PCR and immunocytochemistry. Alkaline phosphate activity was examined by lead citrate method. Osteocalcin mRNA expression was determined bv RT-PCR. ResulIs GDF5 gene was transfected into BMSCs successfully and the transfected cells still maintained their natural growth and proliferation features. Stable expression of GDF5 gene in BMSCs was obtained. The trans fected ceils had basically the same proliferation ability and cell cycles as the untransfccted ones. After transfection comparatively more polygonal cells could be seen in light microscope, showing irregular arrangement mode. Plenty organells were observed and cell nucleus showed irregular shape under EM. The expressions of Collagen Ⅱ mRNA and protein were positive. But osteocalcin mRNA expression was negative. Conclusion Since BMSCs can be induced by GDF5 to differentiate into chondrogenic cells. GDF5 gene-modified BMSCs may be used as candidate seed cells of cartilage tissue engineering.

Objective To correlate CT findings of secondary hepatic lymphoma with pathology and to evaluate it's clinical value.Methods Nine patients with secondary hepatic lymphoma confirmed by pathology underwent spiral CT scanning and dual-phase dynamic contrast-enhancement scanning before operation, the CT data were reviewed and analysed retrospectively in comparison with surgical and pathological results.Results Twenty-three lesions of secondary hepatic lymphoma in 9 patients were located in the left lobe (9 lesions), the fight lobe (6 lesions),the porta of the liver (5 lesions) and the caudate lobe (3 lesions), respectively.Sixteen of these 23 lesions were distributed over an area near the portal vein, 7 were seattered in the exterior of liver.17 lesions had an ellipsoid contour and 6 showed irregular contour.The diameter of the lesions ranged from 2.7 to 16.5 cm, with a mean diameter of 5.9cm.The tumor demonstrated mild homogeneous dynamic delayed contrasted-enhancement and the CT value of the non-contrast scans, AP phases and PVP phases were 20.7 to 31.5 HU(with a mean value of 25.3 HU), 23.8 to 48.5 HU(with a mean value of 31.9 HU) and 35.3 to 60.2 HU(with a mean value of 47.8 HU) respectively.Intrinsic hepatic vessels could be discerned in 6 lesions.The lesions situated in the perta of the liver encased the portal vessels, but there was no vessel compression or occlusion.Conclusion Recognition of the dynamic CT features of hepatic lymphoma could enhance its diagnostic accuracy.

Objective To integrate existing data and analyze the optogenetic application in the study of the cocaine addiction mechanism.Methods The key words optogenetics,addiction, cocaine and so on were selected.Relevant research information was collected from various authentic databases such as China Journal Full-text Database,Chinese Biomedical Databases,Wanfang Digital Journals,VIP Full-text Database and PubMed,SCIENCEDIRECT,SPRINGERLINK databases by literature study,assess the quality of the studies and the qualitative systematic review was conducted in this study.Results Findings from present data showed that:with great spatial and temporal specificity,the optogenetic application not only proved the important role of traditional theories of mesolimbic dopamine system,but also dissected the neural circuits and molecular mechanisms of dopaminergic and glutamatergic neurotransmission underlying cocaine addiction.Conclusion The use of optogenetic tools has given researchers the potential to dissect the neuronal circuits and molecular changes,leading us to a better understanding of the mechanisms of cocaine addiction and to the development of novel treatment.

Objective To explore the imaging features and dynamic CT findings of primary adrenocortical carcinoma and evaluating its clinical value.Methods All 11 cases patients with primary adrenocortical carcinoma confirmed by surgical pathology underwent spiral CT plain scanning and two phases dynamic enhancement scanning before operation.Contrast injection was done by using nonionic Omnipaque at a flow rate of 3 ml/s with a power injector.The CT images were reviewed and analysed retrospectively in comparison with surgical and pathological results.Results Five of 11 lesions were located in the right adrenal gland,6 in the left.The diameter of the tumors was 4.1—16.0cm with 2 cases10.0cm.The attenuation of the plain scans,two phases contrast scans was 21.9—46.7 HU(with a mean value of 35.3 HU),30.5—65.8 HU(mean value 47.1 HU),and 52.6— 97.0 HU(mean value 74.2 HU),respectively.Four were in the shape of capsule,6 reticular,1 slightly inhomogeneous masses.The irregular tumor vessels of 6 reticular masses were seen in the artery phase. Conclusion The dynamic CT features of primary adrenocortical carcinoma were obvious,dynamic SCT scans could suggest the diagnose.