Objective To observe the in vivo degradation of poly-DL-lactic acid ureteral stent in canine and the pathological change in canine ureter.Methods Poly-DL-lactic acid ureteral stent was inserted into 19 canine ureters,respectively.The stents were taken out every two weeks with their degradation observed with electronic microscopy and their molecular weight change detected by gel permeation chromatography.Pathological change in ureteral tissue specimens stained with hematoxylin and eosin was observed by light microscopy.Results The molecular weight of poly-DL-lactic acid ureteral stent was decreased to 8 033 seven weeks after degradation from 68 900 before degradation,with a degradation rate of 88.3%.Electronic microscopy showed that the number of pores in stent was gradually increased and their diameter became larger.The stent was degraded.The main pathological change observed in canine ureter tissue was non-specific inflammation.Conclusion Poly-DL-lactic acid ureteral stent is good in degradation property and tissue compatibility in vivo.

Objective To study the safety and efficacy of transpedicular osteotomy en bloc lamina resection to treat thoracic spinal stenosis.Methods A retrospective study of 23 consecutive patients underwent transpedicular osteotomy en bloc lamina resection from June 2004 to December 2008,including 12 males and 11 females,with a mean age of 46 years(range,38-62 years)was conducted.The courses of diseases were 1.5 to 20 months with an average of 6.5 months.There were 18 cases caused by thoracic ossification of ligamentum flavum(OLF),4 cases caused by ossification of posterior longitudinal ligament(OPLL)and 1 case caused chondroma.Preoperative CT and MRI examinations showed that all patients got spinal cord compression.Preoperative ASIA Grade was A for 1 case,B for 3 cases,C for 7 cases and D for 13 cases.Postoperative neurological status was evaluated by ASIA grade system.Results The postoperative follow-up duration ranged from 16 to 58 months(mean 30 months).The operation time varied from 90 to 210 min,with the average of 163 min.Blood loss varied from 600 to 3200 ml,with the average of 2150 ml.Pedicle screws were used in 10 cases with T9-T12 stenosis,and dura excisions were repaired by lumbodorsal fascia in 5 cases.Cerebrospinal fluid leakage occurred in 2 cases.Postoperative ASIA grade showed that there was A for 1 case,B for 2 cases,C for 2 cases,D for 5 cases and E for 13 cases.Conclusion Transpedicular osteotomy is a good approach,which avoid sclerotic cortex and ossified ligamentum flavum,to resect en bloc lamina with with shorter operative time and less blood loss.

Objective:To evaluate the clinical effect of combination of autologous tissue reconstruction of tarsal plate with temporal flap on repair of full-thickness lower eyelid defect.Methods:Eleven patients (11 eyes) underwent hard palate mucosa or ear cartilage combined the emporal flap with the orbicularis oculi muscle to repair full-thickness defect ofpalpebra inferior.Of the 11 patients,6 had more than 75％ eyelid defect area,and 5 had more than 50％ eyelid defect area.Results:All 11 eyes closed completely,with no entropion or ectropion,and returned to normal basically.Postoperative follow-up was performed for 6 months to 5 years,3 years and 4 months on average.The function and form of eyelid remained stable.Infection,leakage or contracture was not found on reconstruction tarsus.Conclusion:Reconstruction of eyelid with autogenous hard palate mucosa or ear cartilage combined the emporal flap with the orbicularis oculi muscle is a simple,convenient and effective method.

Objective To study the radiosensitizing effect of 2'-hydroxyflavanone (2'-HF) on prostate cancer cells,and to preliminarily investigate its mechanism.Methods Colony formation assay,tert-butylhydroperoxide (TBHP) oxidative stress assay,Hoechst staining,and apoptosis flow cytometry using Annexin V-FITC and propidium iodide (PI) were performed to measure the impact of 2'-HF on the radiosensitivity of VCaP prostate cancer cells.Western blot was used to determine the effects of 2'-HF on expression of AKT,phosphorylated AKT (p-AKT),and aldo-keto reductase 1 C3 (AKR1 C3) in VCaP cells and preliminarily investigate the mechanism.Data were analyzed by t test and factorial analysis of variance.Results The results of colony formation assay indicated that after exposure to radiation,VCaP cells treated with 2'-HF had a significantly lower proliferation level than cells in the control group (P=0.010),yielding a sensitization enhancement ratio of 1.19.The resuhs of TBHP oxidative stress assay suggested that VCaP cells treated with 2'-HF had significantly weaker anti-oxidative capacity than cells in the control group (P=0.015).Hoechst staining and apoptosis flow cytometry with Annexin V-FITC and PI indicated that 2'-HF treatment plus irradiation significantly enhanced apoptosis in VCaP cells (P=0.001.The results of Western blot suggested that 2'-HF treatment significantly inhibited the protein expression of p-AKT and AKR1C3 in VCaP cells (P=0.013 and P=0.016).Conclusions 2'-HF can enhance the radiosensitivity of prostate cancer cells,which is probably associated with its inhibitory effects on AKT pathway and AKR1C3 expression in prostate cancer cells.

Objective To investigate the androgen-like effects of Cordyceps sinensis (CS) and its impact on the radiosensitivity of VCaP prostate cancer cells.Methods The hormone levels and weight index of reproductive organs in mice were determined after gavage with CS.Clonogenic assay was performed to determine the impact of CS on the radiosensitivity of VCaP cells.The 3-(4,5-dimethylthiazol-2-yl)-5 (3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium assay,flow cytometry,and tumor xenografts in nude mice were performed to determine the effects of CS on the proliferation of VCaP cells (androgen receptor-positive) and PC-3 cells (androgen receptor-negative) in vitro and in vivo.Serum prostate-specific antigen (PSA) levels in nude mice were evaluated.Data were analyzed by one-way analysis of variance or ttest.Results The testosterone level and weight of prostate in mice were significantly higher in the CS group than in the control group ((8.28± 1.94) vs.(2.08± 1.24) ng/ml,P=0.023;(0.53±0.04) vs.(0.31 ± 0.04) mg/g,P =0.006).The radiosensitivity enhancement ratio (ratio of D0 values) was 0.80.The viability of VCaP cells was significantly higher in the CS group than in the control group (1.32 ± 0.07 vs.0.66 ±0.02,P=0.000),and colony forming efficiency was significantly enhanced in the CS group than in the control group (57.0％ ± 1.9％ vs.47.0％ ± 0.6％,P =0.005).VCaP tumor xenografts in nude mice were inclined to grow faster in the CS group than in the control group,and the serum PSA level in the CS group was significantly higher than that in the control group ((0.66 ± 0.04) vs.(0.26 ±0.06) ng/ml,P =0.000).However,CS had no effect on PC-3 cells at the working concentration.Conclusions CS has the androgen-like effects.It may also promote the proliferation and reduce the radiosensitivity of androgen receptor-positive VCaP cells.

Objective To investigate the methods, feasibility, outcome and indications of atlantoaxial pedicle screw system in the treatment of upper cervical injury. Methods Thirteen patients with upper cervical injury were treated by atlantoaxial pedicle screw system. There were four patients with old odontoid fractures, two with new odontoid fractures (Aderson ⅡC), three with rapture of the transverse ligament of C1 and four with C1 fracture. Results A total of 26 pedicle screws and 26 pedicle screws were implanted. The mean operation time and perioperative blood loss were 2.6 hours and 470 ml, respectively. No injury to the vertebral artery and spinal cord was observed. All patients were followed up for 4-25 months (mean 13 months). The clinical symptoms were improved to some extent according to Japanese Orthopedic Association scoring system, with improvement rate of 72%-91% (mean 81%). The screws were verified to be fixed in a proper position, and no hardware broken or loosening was observed except for one C1 screw penetrating the medial superior cortex of lateral mass for 3 mm without affecting occipito-aflantal motions. All patients had a solid bony fusion 3-6 months later. Conclusion The atlantoaxial pedicle screw system is feasible in the treatment of upper cervical injury with the advantages of better outcomes and wider indications.

Objective To discuss the complication risk factors for early death after cervical injuries and explore the indication for treatment. Methods A retrospective study was carried out on early death and complications in 419 patients with cervical injuries admitted into our hospital. We observed the relationship of all kinds of complications with cervical cord injury severity and the incidence rate of complications in all patients. Results The respiratory complication was the main cause of early death, accounting for 79.11%. There found complications including hypoalbuminemia ( 85.29% ), hypotension(50%) and hyponatremia ( 35.29% ) in the death patients. Conclusions The existence of complications, especially hypoalbuminemia, can aggravate the original dysfunction and is the risk factor for early death. The early treatment of the dangerous complications could prevent multiple organ failure and early death and provide sound condition for functional recovery.

Objective:To explore effects of trehalose as a cryopreserve agent on survival rate of fatty tissue after cryopreservation.Methods:The liposuction was used on the abdomen of adult female.After centrifugation and purification,adipose was randomized into the following three groups,the trehalose group,the fetal bovine serum (FBS)+ 10％DMSO group and the physiological saline group.The specimens were cryopreserved at-196 ℃ for 3 months and then the HE staining,glucose transfer method and CK method were used to detect the cell survival rate in each group.Results:The activity of adipose in the trehalose group and FBS+10％DMSO group adipose was higher than that in the physiological saline group (P＜0.05);while there was no significant difference between the trehalose group and FBS+10％DMSO group (P＞0.05).Conclusion:As cryoprotectant,trehalose could keep fat cell viability,and adipose tissue can be used for clinical transplantation after 3 months' freezing.

ObjectiveTo identify the anatomical feasibility of cross screw fixation in the atlas via posterior arch,provide a reference for clinical applications.MethodsA total of 10 dry atlas specimens were used to measure anatomic data and three dimension(3D) CT data.The data included height of the posterior tubercle,width of the posterior arch,distance from the ideal point to the interior of the vertebral artery sulcus,from nail point to central line,and the ideal direction of the screws.Statistical analysis was done to compare the two methods.Then 100 3D CT data were measured.The parameters included height of the posterior tubercle (mid-sagittal plane),width of the posterior arch (the inner side where arch transformed to the vertebral artery sulcus),distance from the ideal point to the interior of the vertebral artery sulcus (where screws completely located in the medullary cavity),distance between the nail point to central line,and angle of the ideal screws (between screws and horizontal line).The anatomy of the atlas was analyzed for whether height of the posterior tubercle is more than 7 mm,width of the posterior arch is more than 3.5 mm,and whether or not cross screws can be planted.ResultsThere was no statistical difference between anatomic and 3D-CT measures.Thickness of the C1 laminar was (4.7±0.9) mm in the left side,(4.6±0.8) mm in the right side,and 93.5％ of specimens were thicker than 3.5 mm.Distance of the ideal screw was(15.9±3.0) mm in the left side,(15.9±3.0) mm in the right side.Height of the C1 posterior tuber was (7.8±1.2) mm,with 91％ of the data higher than 7.0 mm.Angle between the axial of C1 laminar and frontal plane was 26.8°±6.8° (8°-44°) in the left side,26.8°±6.3°(13°-44°) in the right side,and about 11％ of them can not cross plant.ConclusionIt is feasible and safe to place cross screws in the posterior arch of the C1 in anatomy.

Objective:To investigate the relationship between bedtime procrastination and daytime sleepiness in college students,and to explore the mediating effect of sleep quality and the moderating effect of gender in the a-bove-mentioned relationship.Methods:A total of 2 823 college students(808 males,2 015 females)from two uni-versities were selected.They were assessed with the Bedtime Procrastination Scale(BPS),Epworth Sleeping Scale(ESS,ESS score≥11 indicated daytime sleepiness)and Pittsburgh Sleep Quality Index(PSQI).Process model 4 was used to test the mediating effect of sleep quality and model 14 was used to test the moderating effect of gender.Results:There were 1 214(43.0％)college students suffering from daytime sleepiness.The scores of ESS in college students were positively associated with the BPS scores(β=0.16).The total scores of PSQI partially mediated the effect of BPS scores on college students'ESS scores,and the value of mediating effect was 39.9％.The association between PSQI scores and ESS scores was moderated by gender(β=-0.13).Conclusion:Daytime sleepiness is associated with bedtime procrastination and sleep quality in college students,and the association be-tween sleep quality and daytime sleepiness is moderated by gender.