Osteoblasts are the most important mechanoreceptive and osteogenic cells.The loss of bone in microgravity is mainly due to the dysfunction of osteoblasts.Research on osteoblast cytology under simulated weightlessness has made great progress in recent years.Current experiments are focusing on the changes in the cellular proliferation,differentiation,apoptosis, function and signal transduction in osteoblasts.This paper reviews the progress of the studies in this field.

Objective To evaluate the dynamic contrast-enhanced magnetic resonance angiography(DCE MRA)value of definitive diagnosis and typing as well as its roles to clinical management with aortic dissection(AD).Methods 20 patients with different types aortic dissection were examined using DCE MRA and proved by operation.Results The reliable MRA image was obtained in all the 20 cases.The MRA typical appearences were the true and false lumen of AD.The entrance and exit site,true and false channel,and intimal flap can be demonstrated on DCE MRA image.Conclusion DCE MRA is an accurate,quick,non-invasive medical imaging technique and can serve as an initial imaging modality for AD diagnosis.

[Objective]To explore the effect of hip joint center on the stability of hip joint,the radiographic measurements were compared between preoperation and postoperation.[Method]A total of 155 hips from 120 patients with primary total hip replacement from resent years were studied,the hip joint center difference through radiographic measurements between preoperation and postoperation were compared.[Result]The coincident rate and the incoincident rate were 63.23%(group A,98 hips) and 36.77%(group B,57 hips) respectively.For loose,dislocation or low back pain,the rate of revision in group A and group B were 6.12% and 29.82% respectively.[Conclusion]The comeback of hip joint center was essential for stability of hip joint.

Objective:To construct Interleukin 21 (IL 21) expression plasimd pCDNA3.1 IL21 and express it in Hela cell and analysis its acitivity of costimilating T cell proliferation with anti CD3 monoclonal antibody in vitro.Methods:The CDs of IL 21 was amplified by PCR using the pMD IL21 as templet.The expression plasimd pCDNA3.1 IL21 was constructed by inserting the sequence of coding region of the IL 21 into pCDNA3.1/Hismyc B containing CMV promoter and transfected into Hela cells.The stability expression stain was screened by the condition media containing 400 mg/L G418 and cloned through the limited dilution method.The target protein was purified through Ni 2+ chelating Sepharose Fast Flow.The bioactivity was confirmed by MTT method on costimulating the T cell proliferation with anti CD3.SDS PAGE and Western blot analysis the rhIL 21 expressed.Results:hIL 21 was expressed in Hela cell successfully.SDS PAGE analysis showed the IL 21 fusion protein with Mr 18 000 or so was expressed in supernatant of the cells.The rhIL 21 has significant proliferation effect on mature human T cells in the presence of anti CD3 monoantibody.Conclusion:The rhIL 21 with bioactivity has been obtained,which may help researcher study its new function and effects. [

Objective: To clone cDNA of human interleukin-29(IL-29) and express it in cos-7 cells, and to study its anti-HBV activity in vitro. Methods: Total RNA was extracted from PBMCs which had been infected with vesicular stomatitis virus(VSV) in vitro.IL-29 cDNA was amplified using one-step RT-PCR technique. The recombinant expressing plasimd of psectagB/His-myc-IL29 was constructed by inserting IL-29 cDNA into the vector and was then transfected into cos-7 cells. Stable expression stains were screened by Hygromycin B and limited dilution method. The target protein was purified through Ni2+-chelating Sepharose Fast Flow. Anti-viral bioactivity of the recombinant IL-29 fusion protein was analyzed through an in vitro model of production of HBV by the HepG2.2.2.15 cell line.ELISA was used for detection of the viral titers in the cell cultural supernants. Results: IL-29 was cloned and stably expressed in cos-7 cells successfully. SDS-PAGE and Western blot analysis showed multiple bands of the target protein with the molecular weights between 20 000 and 33 000, and the major band was located at about 33 000, indicating the fused IL-29 modified by additional glycosylation. The rhIL-29 was shown to dose-dependently inhibit secretion of HBsAg and HBeAg accompanied by the reduction of HBV genomic DNA in the cells tested. The inhibition ratio of HBsAg and HBeAg production was attained 85% at a concentration of 160 ?g/L of rhIL-29. Conclusion: The rhIL-29 with anti-HBV activity has been obtained.

Objective To investigate the effect of ketamine on hippocampal uncoupling protein 2 (UCP 2) expression after forebrain ischemia-reperfusion (I/R) in rats and the mechanism of protective effect of ketamine on brain. Method Forty-five male Wistar rats weighing 250～300 g were randomly divided into 3 groups, with 15 animals in each group. Forebrain I/R was estabhshed by occlusion of bilaleral carotid artery combined with hy-potemion,EFG in a sustained low rate of 7 Hz, 30～40 μVθ rhythm was the success signs of forebrain I/R. Con-trol group (C) :sham operation was performed; I/R group (Ⅰ): bilateral common carotid arteries were clamped for lOmin combined with hypotension [MAP:(40±5) mmHg] induced by exsanguinations, then saline (1 mg/kg) was injected into the lateral cerebral ventricle using microsyringe; ketamine group (K):ketamine (1 mg/kg) was injected into the lateral cerebral ventricle using microsyringe after I/R. The animals were decapitated, the brain was immediately removed,and the hippocampal tissues were dissociated at 6 h after reperfusion. The cerebral I/R injury was observed with light microscope, the levels of UCP 2 mRNA expression in hippocampus were detected by using semi-quantitative RT-PCR technique (n=7), coronal sections including hippocampal tissue were obtained for detection of UCP 2 protein expression by immuno-histochemistry (IH) method (n=8). The RT-PCRR and IH data were expressed as the mean±SD, the statistical signiticance was determined by one-way ANOVA. Results The UCP 2 mRNA expression was (1.06±0.02) in group Ⅰ and (1.18±0.06)in group K increased significantly compared with that in group C(0.91±0.02) (P<0.05), there were more UCP2 mRNA expression in group K increased than that in group Ⅰ(P<0.05). The expression of UCP 2 protein was (31.56±4.01) in group Ⅰ and (44.61±4.96) in group K, increased significantly compared with that in group C (17.91±5.49) (P<0.05),there were more UCP 2 protein expression in group K than that in group Ⅰ (P<0.05). Conclusions Ketamine can attenuate the cerebral I/R injury in rats, the underlying mechanism may be related to the up-regulartion of the expression of hippocampal UCP 2 mRNA and UCP 2 protein.

ObjectiveTo investigate glutathione S-transferase GSTO 1 Glu155△Glu genetic polymorphism and risks of arsenic poisoning caused by coal-burning in Guizhou.Methods GSTO1 Glu155 △Glu gene polymorphism was analyzed by polymerase chain reaction-with confronting two-pair primers among one hundred and thirty arsenic poisoning patients and one hundred and thirty healthy controls.The results were verified by DNA sequencing.The association between different genotypes and arsenic poisoning was analyzed by unconditional Logistic regression model.ResultsThe results of Glu/Glu and Glu/△Glu genotype detected by this method were consistent with those of DNA sequencing.The frequencies of GSTO1 Glu/Glu genotype and Glu/△Glu genotype were 94.85％(92/97) and 5.15％(5/97) in the patients,99.15％(117/118) and 0.85％(1/118) in the controls,respectively.The difference was statistically significant(x2 =3.896,P ＜ 0.05).△Glu/△Glu genotype was not found in both patients and controls.After age and sex adjusting,GSTO1 Glu155 △Glu polymorphism was found to be a risk factor of arsenic poisoning [odds ratio (OR) =1.85,95％ confidence interval (CI):1.39 - 17.48].ConclusionsThe study finds that GSTO1 Glu 155 △ Glu polymorphism is associated with risk of arsenic poisoning.The relationship between them should be further studied through increasing sample size.

Objective To investigate the effects of external fixator with dynamic device under low frequency and controlled micromovement on the callus calcification and mechanical property of healing bone.MethodsForty-five sheep were performed transverse osteotomy with a gap of 2 mm on the mid-shafts of both tibias,and the hind limbs were fixed with unilateral external fixators connected to a controlled micromovement device.Ten days after osteotomy,one hind limb of each sheep was randomly selected for micromovement(30 min/d).According to different micromovement frequencies,the sheep were randomly divided into 3 groups: 0.5 Hz group,1 Hz group and 5 Hz group(n=15).The amplitude of micromovement was 0.25 mm and the micromovement stopped by the end of the fourth week postoperation.The other hind limb of each sheep was served as control group without micromovement.Morphometry of callus was done at the end of 4,6 and 9 weeks after osteotomy.Bone formation velocity,bone mineral density and biomechanical properties were compared at the end of 9 weeks.Results The areas of mineralized bone and osteoid in different miromovement groups were larger than that of control group at the end of 4,6 weeks postoperation(P

Objective To establish human choriocarcinoma JeG-3 cell line resistant to floxuridine (FUDR)and describe the characteristics of this FUDR-resistant subline.The thymidylate synthase (TS) expression level in FUDR-resistant subline was also discussed.Methods The FUDR-resistant sub-line JeG-3/FUDRA was established by intermitted exposure to grads increased FUDR.Reversed microscope was used to observe the morphological changes in FUDR-resistant sub-line.Population doubling time was calculated and compared based on the growth curve of these two cell lines,cell cycles and chromosomal ploidy were assayed with flow cytometry methods.The chemo-luminescence assay was used to detect the hormone secretion by two kinds of cell lines.The resistant index (RI) was measured by cell counting kit-8 (CCK-8)assay.Quantitative RT-PCR was used to detect the mRNA expression level of TS and we also detected the TS mRNA expression level in different doses exposed subline.Results The RI of JeG-3/FUDRA was 31.62.Compared with the JeG-3 cell,the FUDR-resistant cell line had gross changes in morphological,cell growth,cell cycles and chromosomal numbers.The ability of human chorionic gonadotrop(hCG) and progesterone secretion was lower in JeG-3/FUDRA subline.The trend of TS mRNA expression was:while exposed to low concentration of FUDR,the TS mRNA expression level was downregulated,then followed the increasing dose of the drug,the expression level of TS mRNA ascended gradually.When the terminal concentration was reached,the expression level of TS mRNA in JeG-3/FUDRA subline was higher than that of JeG-3 cell line (P＜0.05).Conclusions We established the FUDR-resistant subline of JeG-3 successfully.The TS mRNA expression level is stage-related to the different concentration and different phase in FUDR exposure.Our data suggested that TS mRNA expression level may not be used as a biomarker to predict the chemosensitivity in FUDR-based chemotherapy.

Hepatic tumor-specific magnetic resonance (MR) enhancement with Gd-EOB-DTPA can detect and distinguish small hepatocellular carcinoma (HCC) with greater sensitivity than conventional magnetic resonance imaging and computed tomography.Hepatic tumor-specific MR enhancement with Gd-EOB-DTPA is more sensitive in detecting focal HCC,and more reliable in detecting lesions with a diameter smaller than 2cm.Gd-EOB-DTPA is excreted through the kidneys and biliary tract,and thus may provide more information about anatomic structures,demonstrate non-obstruction of the intra- and extrahepatic bile duct system,and provide information about hepatic function.