Objective To observe the cell apoptosis, oxidative stress reaction and expressions of Bcl-2 and Bax in kid?ney of dietary zinc deficiency mice during growth period, and discuss the mechanism of renal cell apoptosis induced by zinc deficiency. Methods Thirty weaning male mice were randomly divided into zinc-deficient group and zinc-adequate group, and 15 mice for each group. Zinc-deficient group was fed with zinc deficiency diet (0.85 mg/kg), while zinc-adequate group was fed with enough zinc diet (30 mg/kg). The TUNEL method was applied to observe the cell apoptosis, and the apoptotic in?dex was measured. The content of SOD and MDA were detected to observe the oxidative stress reaction in kidney. The ex?pression levels of Bcl-2 and Bax protein were detected by Western blot assay. Results Compared with zinc-adequate group, the cell apoptosis and oxidative stress reaction were increased in zinc-deficient group. The expression of Bcl-2 de?creased, and the expression of Bax increased. The ratio of Bcl-2 and Bax declined in kidney of zinc deficiency mice. Conclu?sion Diet zinc deficiency in growth period may result in the decreased antioxidase, the increased oxidative stress reaction, and the changed Bcl-2 and Bax expression, which promote the occurrence of cell apoptosis in kidney.

Objective To discuss the selection of short- or long-segment posterior fixation for treatment of unstable thoracolumbar fractures. Methods A total 134 patients with thoracolumbar fractures treated with pedicle instrument fixation from January 2005 to December 2008 were studied retrospectively. According to AO fracture classification, there were 70 patients with type A fractures, 37 with type B and 27 with type C. The patients were divided into two groups according to the number of instrumented levels; short-segment posterior fixation (SSPF) group (four screws; one vertebral body above or below the fractured vertebrae) and long-segment posterior fixation (LSPF) group (eight screws; two vertebral bodies above or below the fractured vertebrae). Clinical outcomes and radiological parameters (superior-inferior endplate angle, vertebral body angle, displacement of vertebral body) were compared according to AO fracture classification. Results All type A fractures were treated with SSPF, mean superior-inferior endplate angle changed from preoperative 21.3° to postoperative 8.5° and 11.1° at final follow up. There was no statistical difference in the correction of Cobb angle for type B fractures in SSPF group (26 patients) and LSPF group (11 patients), while the correction loss of vertebral body angle was 3. 64° in SSPF group and 1.09° in LSPF group, with statistical difference (P < 0. 05). There was no statistical difference in the correction of Cobb angle for type C fractures in SSPF group (7 patients) and in LSPF group (20 patients), but the correction loss of vertebral body angle was 3.6° in SSPF group and 0. 8° in LSPF group, with statistical difference (P < 0. 05). There was no statistical difference in vertebral displacement correction. Conclusions Most types A and Bl fractures should be treated with SSPF; most types B2, B3 and C fractures should be treated with LSPF.

Objective To discuss the selections of surgical treatment for lower cervical spine fracture and dislocation and the treatment outcome.Methods Clinical data of 50 cases of lower cervical spine fracture and dislocation were analyzed retrospectively.There were 37 males and 13 females at mean age of 41 years (range,20-80 years).Forty-four cases underwent anterior fusion,but 4 with ankylosing spondylitis and 2 with extremely unstable cervical spine were treated with combined posterior fusion.Two cases sustaining ankylosing spondylitis and being unable to be operated via the anterior approach due to the maximum neck flexion limits were treated with posterior decompression and fusion.Two cases developed delayed fracture and underwent posterior release prior to the anterior fixation and fusion.Two cases underwent a second surgery with the posterior release,anterior fusion and posterior fusion performed successively.Neurological performance was evaluated using the American Spinal Injury Association (ASIA)scale.Results All the patients were followed up for mean 28 months (range,12-48 months).Implant loosening and redislocation occurred in one ankylosing spondylitis case 2 months after anterior fusion.Other 49 cases achieved bony fusion in 6 months.Neurological function showed no recovery in complete spinal cord injury cases,but improved for average ASIA 1-2 grades for incomplete spinal cord injury cases.Conclusions Anterior surgery provides good reduction and neurological improvement in treatment of lower cervical spine fracture and dislocation.For extremely unstable cases or difficult anterior reduction cases,posterior surgery or combined anterior/posterior surgery should be considered.

Objective To investigate the expressions of GDNF and GFRα1 in childhood nephroblastoma, and therefore its clinical significance. Methods The expression levels of GDNF and GFRα1 were examined by immunohistochemistry of 30 parrafin samples from nephroblastoma section as well as 16 parrafin samples of peritumor renal tissue. Results The pos?itive expression rate of GDNF and GFRα1 in nephroblastoma were higher than those in normal renal tissue(66.7%vs 6.3%;63.3%vs 6.3%). GDNF and GFRα1 were strongly expressed in epithelium and embryo bud, but weakly expressed in lobus intermedius of nephroblastoma. There was no correlation between the expressions of GDNF and GFRα1 with histological types, clinical stage and metastasis of nephroblastoma of patients. Conclusion High expression of GDNF and GFRα1 in childhood nephroblastoma might indicate its role in tumor development.

Aim To investigate the effect of artesunate on the invasion of human colon cancer Lovo cells and the possible mechanisms. Methods After Lovo cells were treated with different doses of artesunate(20,80, 160 μmol·L - 1 ), the soft agar colony formation test was adopted to observe the anchorage-independent pro-liferation of Lovo cells. Transwell assay was used to determine the effect of artesunate on the invasion abili-ty of Lovo cells. And the protein expressions of HMGB1 and MMP-2 were investigated by western blot. Results Artesunate could significantly inhibit both proliferation and invasion ability of Lovo cells in a dose-dependent manner(P < 0. 01). The experimental group treated with artesunate significantly down-regula-ted the protein expressions of HMGB1 and MMP-2 compared with control group(P < 0. 05). Conclusion Artesunate could inhibit the invasion of human colon cancer Lovo cells by down-regulating HMGB1 and MMP-2 expressions.

BACKGROUND:The homing ability of mesenchymal stem cells after transplantation can decrease along with culture and passage in vitro. And the decline of homing abilities can further influence the implantation of mesenchymal stem cells in the target tissue, thus seriously affecting the repair effect.
OBJECTIVE:To investigate the effect and its related mechanisms by which in vitro culture and passage affect the homing ability of mesenchymal stem cells.
METHODS:Mesenchymal stem cells were isolated from the bone marrow using Ficol density gradient centrifugation, and then purified using adhesion method. The mesenchymal stem cells were cultured into the seventh generations with the normal cultural condition, and the morphological features of the 3rd, 5th and 7th generations of mesenchymal stem cells were observed. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide chromatometry was used to detect the growth feature of the 3rd, 5th and 7th generations of mesenchymal stem cells, and the growth curve was drawn. Real-time PCR was used to detect the expression of CXCR4, CXCR6, CXCL12, CD44 in the 3rd, 5th and 7th generations of mesenchymal stem cells, 2-△△Ct was calculated to get the relative value of each target gene, and the differences in expression of CXCR4, CXCR6, CXCL12, CD44 between different generations were compared.
RESULTS AND CONCLUSION:Mononuclear cells could be obtained from the bone marrow by using Ficol density gradient centrifugation. High-purity mesenchymal stem cells could be obtained using adherent method. The ability of in vitro growing was strong, but fol owing the passage, the cellmorphology became wider and shorter. And the proliferation rate, the overal proliferated multiple and the expression of homing related factors decreased fol owing the passage. The expression of CXCR4, CXCR6, CXCL12 and CD44 of mesenchymal stem cells decreased fol owing the passage. The homing ability of mesenchymal stem cells was decreased fol owing the passage, and may be relevant with the lower expression of CXCR4, CXCR6, CXCL12 and CD44 in cultured mesenchymal stem cells.

Objective To explore the association between Doppler echocardiography parameters and pulmonary capillary wedge pressure (PCWP) obtained by right heart catheterization (RHC) in patients with pulmonary hypertension (PH).Methods RHC and a simultaneous echocardiography were performed in 86 PH patients.The correlation between the echocardiographic parameters and PCWP was analyzed.Results The early diastolic velocity(E) of mitral valve blood flow was significantly correlated with PCWP ( γ =0.36,P ＜0.01 ).Tissue Doppler imaging measured the diastolic velocity of mitral annulus on the lateral(E'L)and the septal (E'S) wall.Then the average E'M was calculated.The ratio of E to E'L,E'S and E'M showed a strong correlation with PCWP ( γ =0.62,0.34 and 0.47 respectively,P ＜ 0.01 ).E/E'L ＜ 6 accurately predicted 100％ PCWP≤ 15 mm Hg (1 mm Hg =0.133 kPa),and E/E'L ＞ 15 could predict PCWP ＞ 15 nun Hg with specificity of 98.5％.Conclusion There are positive correlation between E/E' and PCWP obtained by RHC in PH patients.

AIM:To explore relationship between the normal strehl ratio ( SR ) values of total aberrations/SR values of total higher-order aberrations and modulation transfer function ( MTF ) at total corneal at different pupil diameters in normal population.
METHODS: To exam the SR values of total aberrations and SR values of total higher-order aberrations of total corneals in 200 people ( 400 eyes ) using SIRIUS 3D topography system and analysis the corresponding root-mean-square ( RMS) .
RESULTS: The subjects with different pupil diameters (3. 0, 5. 0, 6. 0, 7. 0mm)'s exam results of total corneal were as following:SR value of total aberrations 100’(0. 45±0. 12), (0. 25±0. 06), (0. 17±0. 05), (0. 13±0. 04); SR value of total higher order ab cerrations 100’(0. 69±0. 14), (0. 34±0. 07), (0. 24±0. 05), (0. 16±0. 04);SR value of total aberrations 200’(0. 45±0. 12), (0. 24±0. 06), (0. 20±0. 04), (0. 16±0. 03); SR value of total higher order aberrations 200’(0.70±0. 13), (0. 35±0. 07), (0. 27±0. 06), (0. 20±0.04 ) . The SR values of each group decreases with the increases of pupil diameters. The SR values of total aberrations and SR values of total higher - order aberrations at total corneals are negatively correlated with corresponding RMS value. When the pupil diameter is small, the SR value of total aberrations is more related to higher frequency region of MTF. When the pupil diameter is big, the SR value of total aberrations is more related to lower frequency region of MTF.
CONCLUSION: The visual performance of normal people can be well reflected by SR values of total aberrations and SR values of total higher - order aberrations at total corneal.

Objective To identify seven species of Gynostemma BI.,including G.pentaphyllum,G. pentagynum,G.cardiospermum,G.longipes,G.yixingense,G.laxiflorum,and G.guangxiense,by in- ter-simple sequence repeat(ISSR)markers.Methods General DNA was isolated from leaves of the seven species in Gynostemma B1.by CTAB,57 primers constituted by ISSR were tested for PCR and sepharose electrophoresis.Results Fourteen primers amplified polymorphic bands,the amplification patterns of primers UBC-873 and UBC-895 were higher in terms of polymorphic and amplified band ratio.They are used to distinguish all the examined seven species.Conclusion ISSR-PCR Method provides a quick,reli- able molecular marker technique for the identification of different species of Gynostemma B1.

Objective To explore the safety, efficacy and 1-year follow-up outcome of radiofrequency ablation combined with magnetic navigation assistance system in elderly patients with atrioventricular node reentrant tachycardia (AVNRT). Methods Forty cases of patients with AVNRT identified by the electrophysiological test were enrolled in the study. Twenty cases were ablated with magnetic navigation system. The other 20 cases underwent the conventional catheters operation. With the cardiodrive, the 8 Frablation magnetic Helios I (Stereotaxis Inc, USA) was advanced to the Koch triangle area from the inferior caval vein (IVC). With the assistance of magnetic navigation (AXIOM Artis, Siemens, Germany), the direction of tip and the advancement or retraction of the catheters were regulated. The success rate, the time of procedure, the fluoroscopy time and the 1-year follow-up outcome were analyzed, and the complications of procedure were recorded. Results Forty cases with AVNRT underwent radiofrequency ablation successfully. In magnetic navigation group, 19/20 cases underwent magnetic catheter operation. The cases who failed to finish magnetic catheter operation underwent successfully conventional catheter operation. There was no perforation complication and no significant statistic difference in the success rate between two groups. No recurring case was found in the two groups 1 year later. The total of fluoroscopy time in magnetic navigation group was more than that in standard ablation group [(16.4±2.7) min vs. (11.1±1.0)rain, P<0.01], but the decreasing trend of fluoroscopy time in magnetic navigation group was showed. The operator's fluoroscopy time in magnetic navigation group was obviously less than that in standard ablation group [(4.5±0.6) min vs. (11.1±1.0) min, P<0.01]. Conclusions The radiofrequeney ablation combining with magnetic navigation system has the similar safety and efficacy to the conventional ablation in elderly patients with AVNRT, but the operator's fluoroscopy time was significantly decreased.