Background Refractive regression is a common complication of high myopia after laser in situ keratomileusis (LASIK),and it affects the stability of surgery.Objective This study was to observe the preventive effect of timolol on refractive regression in high myopia after LASIK.Methods A perspective randomized controlled trial was performed under the approval of Affiliated Hospital of Zunyi Medical College and the informed consent of the patients.Sixty eyes of 60 patients with high myopia (-7.16±0.95) D for LASIK were randomized into experimental group and control group.Regular eye drops were topically administered in the patients after LASIK in both groups,and timolol 0.5 ％ was added topically from 1 day after LASIK.The uncorrected visual acuity (UCVA),best corrected visual acuity (BCVA),spherical equivalent (SE),corneal anterior surface curvature,intraocular pressure (IOP),central corneal thickness (CCT) were measured before LASIK,1 week,1 month,3 months and 6 months after LASIK,respectively.Residual stromal bed thickness was calculated before LASIK.The differences of above-mentioned indexes were analyzed and compared between the two groups and among the various time points using repetitive measurements analysis of variance,independent simple t test and Bonferroni test.Results No significant differences were found in the demography between the experimental group and the control group,including age,UCVA,BCVA,SE,IOP,corneal anterior surface curvature,CCT and residual stromal bed thickness (all at P＞0.05).UCVA was significantly different between the two groups among various time points (Fgroup =3.91,P＜0.05 ; Ftime =3.80,P＜0.05),and the UCVA was significantly higher in the experimental group than the control group 6 months after LASIK (t=2.97,P＜0.05),and UCVA was gradually increased as the lapse of postoperative time with the significant difference between 7 days and 6 months after LASIK in the experimental group (P＜0.05).No significant difference was seen in the BCVA between the two groups at various postoperative time points (Fgroup =2.44,P＞0.05;Ftime =2.31,P＞0.05).SE refraction in both groups were significantly reduced from 7 days through 6 months after LASIK,showing significant difference between the groups at various time points after LASIK(Fgroup =11.52,P＜0.05;Ftime =22.06,P＜0.05).The SE refraction was higher in the experimental group than that in the control group 6 months after LASIK (t =2.47,P＜0.05).Corrected IOP in the experimental group was lower than that of the control group at 7 days,1 month and 3 months after LASIK,respectively (Fgroup =14.83,P＜0.05).The change of CCT was not statistically different between the control group and the experimental group (Fgroup =0.04,P＞0.05).The anterior corneal surface curvature was steady in the experimental group during the following-up duration after LASIK,while the control group was growing gradually (Ftime =18.73,P＜0.05).Conclusions The study data show that topical administration of 0.5％ timolol early in high myopia following LASIK is effective for the reduction of the refractive regression.It is suggested that 0.5％ timolol can prevent cornea ectasia by lowering IOP.Reduction of the IOP may contribute to improving the regression after keratorefractive surgery in high myopic eyes.

Objective To evaluate the association between cytomegalovirus (HCMV) infection and atherosclerosis (AS) and explore the possible role of endothelin (ET) and serum tumor necrosis factor(TNF ?) in the pathogenesis of AS in diabetic patients and the relationship between HCMV infection and concentrations of ET and TNF ?. Methods Blood samples were collected from 21 patients with AS of type 2 DM, 47 patients with non AS of type 2 DM and 20 controls. Special antibodies to HCMV (IgM,IgG) were measured by enzyme linked immunosorbent assay (ELISA) . The concentrations of serum TNF ? and plasma ET were determined by RIA. Results (1) Type 2 diabetic patients, especially those with established AS, had a higher prevalence of active infection of HCMV. (2) The levels of plasma ET and serum TNF ? in type 2 diabetic patients were higher than those in normal people. In the pathogenesis of AS in diabetic patients, the ET played more important role than the TNF ?.(3) There was a significantly positive correlation between anti IgM to HCMV and the level of plasma ET in type 2 DM patients. It suggested that the injury of endothelium cell was related to the active infection of HCMV. Conclusion The study suggests that HCMV infection may be important in the pathogenesis of AS in type 2 diabetic patients and ET possibly plays an important role on the pathological course of AS.

Objective To investigate the effects of antisense oligodeoxynucleotide c-myc (c-myc ASODN) on the growth of rabbit lens epithelial cells (LECs) induced by galactose. Methods Based on the translation initiation region of the second extron of c-myc gene, oligonucleotides were synthesized and modified with phosphorothioate. Lens epithelial cells were treated with galactose and c-myc ASODN. The effects of c-myc ASODN on the growth of LECs, cultured in high concentration of galactose, were observed by cytometry and MTT. Results The results demonstrated that c-myc ASODN at the doses of 2.5-10.0 ?mol/L inhibited the growth of LECs induced by galactose in a dose-dependent manner. Conclusion These results indicate that c-myc ASODN can inhibit the growth of LEC induced by galactose.

Objective To evaluate of the clinical efficacy of two kinds of methods extracorporeal shock wave lithotripsy in treatment of ureteral calculi. Methods A retrospective analysis was conducted on the data of 108 patients with acute renal colic and ureteral stones (calculi diameter<2 cm) from March 2011 to April 2013. The patients were divided into two groups. 69 cases in A group underwent emergency positioning urography ureteral catheterization combined extracorporeal shock wave lithotripsy, 39 cases in B group underwent emergency extracorporeal shock wave lithotripsy. Results A group:lithotripsy was successful in 63 cases among 69 cases at the first time,the first success rate was 91.33% (63/69), the second success rate was 94.2%(65/69),2 cases of retrograde ureteroscopy failed, 2 cases of self-discharge after intubation stones, the recurrent renal colic rate was 14.3%(9/63),the use of analgesic drugs rate was 11.1%(7/63) . B group:the first success rate of stone clearance rate was 74.4%(25/39),the second success rate of stone clearance rate was 87.2%(34/39),5 cases underwent ureteroscopy lithotripsy, the renal colic recurrence rate was 20.5% (8/39), the use rate of analgesic drugs was 15.4% (6/39) . Conclusion Extracorporeal shock wave lithotripsy assisted by urography through retrograde ureteral catheterization has satisfying therapeutic effect in treatment of patients with ureteral calculi.

Objective To explore the safety and feasibility of single-incision laparoscopic cholecystectomy without using titanium-clips. Methods Data of 1016 patients(group A) undergoing single-incision laparoscopic cholecystectomy without using titanium-clips were compared to that of 874 patients(group B)undergoing two-port laparoscopic cholecystectomy without using titanium-clips by t test and chi square test for operating time,operative hemorrhage,the length of postoperative hospital stay and postoperative pain.Results In group A,1001 cases were successfully operated on with single-incision laparoscopic cholecystectomy,with conversion to classic four-port laparoscopic cholecystectomy in 15 cases,while 874 cases in group B were operated on with two-port laparoscopic cholecystectomy.There were no bile leakage,biliary tract injury or death in both groups.There were no difference in operating time[(34.5 ±5.2) min vs (32.0±7.4)min,t=0.063,P=0.526],the length of postoperative hospital stay[(3.1±0.8)d vs(3.2±0.7)d,t=1.073,P=0.326]and operative hemorrhage[(56.5±17.8)ml vs (55.2±15.9)ml,t=0.812,P=0.425](P>0.05) between the two groups,but the postoperative pain was less severe in Group A than that in group B (P=0.000<0.05). Conclusions The single-incision laparoscopic cholecystectomy is feasible,safe,less traumatic and more cosmetic.

Purpose To evaluate the application value of ERCC2 gene polymorphism ( rs3916840 C/T, rs1799793 G/A and rs238416 G/A) detection in molecular pathological diagnosis of breast cancer. Methods The polymorphisms of ERCC2 ( rs3916840, rs1799793 and rs238416) were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay in 101 patients with breast cancer and in 101 cancer-free controls. Results Analysis of the data showed a 0. 287-fold increased risk of breast cancer due to the deletion of genotype GA at rs238416 (P<0. 001, 95%CI: 0. 153 ~0. 537). However, polymorphisms of rs3916840 and rs1799793 were not associated with breast cancer risk (P>0. 05). Furthermore, Heterozygous genotype of rs3916840 was significantly associated with tumor size (P=0. 049), heterozygous genotype of rs1799793 was significantly associated with PR sta-tus and triple negative breast cancer (P=0. 037). Remarkably, the genotype frequency of GA in p53-positive patients was lower than that in p53-negiative patients (P=0. 026). Conclusions These results indicate that the polymorphism of rs238416 of ERCC2 is sig-nificantly associated with breast cancer risk. Tumor size, PR status, triple negative breast cancer, and p53 protein expression are asso-ciated with polymorphisms of ERCC2 (rs3916840, rs1799793 and rs238416) respectively. ERCC2 gene polymorphism detection is useful for the early diagnosis and prognosis evaluation of breast cancer.

BACKGROUND:Scaffolds made of chitosan and its derivatives play an important role in cellmigration and axonal regeneration. Chitosan and its derivatives have good histocompatibility, which is easy to make stem cells grow on the surface, thereby having a more broad application prospect in the nerve tissue engineering.
OBJECTIVE:To fabricate a thermosensitive hydrogel scaffold using chitosan/hydroxypropyltrimethyl ammonium chloride chitosan/sodium glycerophosphate (CS/HACC/GP), which is suitable for cellgrowth, and then, to observe the growth and proliferation of bone marrow mesenchymal stem cells on the scaffold.
METHODS:Chitosan was modified using quaternary ammonium salt and confirmed by Fourier transform infrared spectroscopy. The chitosan and quaternary ammonium salt of chitosan was mixed at a ratio of 8:1 to successful y prepare stable CS/HACC/GP thermosensitive hydrogel scaffold. Then, the gel ing was observed, and biosafety test was conducted.
RESULTS AND CONCLUSION:Fourier transform infrared spectroscopy showed the characteristic peak of quaternary ammonium groups. Cytotoxicity test showed that rat bone marrow mesenchymal stem cells cultured in hydrogel extracts had no toxicity. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide test showed that hydrogel extracts exerted no significant effect on the increase in body weight, and the biological safety of the scaffold was good. Under the scanning electron microscopy, bone marrow-derived mesenchymal stem cells grew and proliferated normal y in the scaffold. The results confirmed that the CS/HACC/GP thermosensitive hydrogel scaffold was successful y prepared in the experiment, which is suitable for the growth and proliferation of bone marrow mesenchymal stem cells.

BACKGROUND:In recent years, chitosan-based thermosensitive hydrogel, as scaffold materials, have received more and more attentions in the field of tissue repair because of good biocompatibility, biodegradability and drug-sustained release.
OBJECTIVE:To explore the directed differentiation and growth of rat bone marrow mesenchymal stem cells on the quaternary chitosan thermosensitive hydrogel scaffold and to look for more ideal tissue engineering materials for the treatment of nervous system damage.
METHODS:The thermosensitive hygrogel scaffold was prepared using hydroxypropyltrimethyl ammonium chloride chitosan (HACC) andβ-glycerophosphate (β-GP). The spatial structure of scaffold was observed by scanning electronic microscope. Effect of leaching liquor from the HACC/β-GP scaffold on the viability of bone marrow mesenchymal stem cells was detected by (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The albumin from bovine serum was combined with the scaffold, and the slow-release effect of the scaffold was detected by ultraviolet absorption spectrometry. Bone marrow mesenchymal stem cells were incubated onto the compound scaffold at 3 passages. The adhesion, growth and differentiation of bone marrow mesenchymal stem cells on the compound scaffold were observed by the scanning electron microscope. Neuron-specific enolase was detected by immunofluorescence.
RESULTS AND CONCLUSION:The porosity and thermal sensitivity of HACC/β-GP scaffold and slow-release effect of glial cellline-derived neurotrophic factor were apparent. The results of MTT showed that the compound scaffold cannot take apparent negative effects to the proliferation of bone marrow mesenchymal stem cells. After inoculation, bone marrow mesenchymal stem cells permeated the porous structure of the scaffold and adhered to the scaffold. Under the role of glial cellline-derived neurotrophic factor, bone marrow mesenchymal stem cells showed neuron-like cellmorphology and cells co-cultured with the compound scaffold expressed the marker of neurons, neuron-specific enolase. Under the role of slow-release glial cellline-derived neurotrophic factor, bone marrow mesenchymal stem cells can grow wel in vitro and differentiate into neuron-like cells on the HACC/β-GP scaffold.

Objective In this article Response Surface Analysis(RSA)was applied to optimize the formulation of doxycycline hydrochloride sustained release tablet.Methods Single factor exploration was used to determine the three factors which have the greatest impact on the release rate.The three factors were the dosage of the HPMC in the total weight of the tablet,the concentration of PVP-K30,and the ratio of lactose to microcrystalline cellulose,respectively.The composite score of the release behaviour was taken as the response value.The dosage of the ingredients were determined by Box-Benhnke design principles and 3 factors and 3 levels.Results The optimized formulation and process are as follows:the dosage of the HPMC in the total weight of the tablet was 30%;the concentration of PVP-K30 was 10%,and the ratio of lactose to microcrystalline cellulose was 13.The release behavior in vitro is ideal.Conclusion The optimized preparation process of doxycycline hydrochloride sustained release tablet is stable,highly efficient and suitable for industrial production.

BACKGROUND:Exogenous neurotrophic factors or chemical induction can induce rat bone marrow mesenchymal stem cells to differentiate into neuron-like cells. However, exogenous inductors exert a short inducible action, and their chemical substances inevitably have a negative impact on cellviability to limit the application prospects of bone marrow mesenchymal stem cells to a certain extent.
OBJECTIVE:To investigate the effect of glial cellline-derived neurotrophic factor, green fluorescent protein gene transfection by adenovirus vector on biological characteristics of rat bone marrow mesenchymal stem cells, to observe the expression of glial cellline-derived neurotrophic factor and green fluorescent protein and the role of nutrition on bone marrow mesenchymal stem cells, and to explore the ability to differentiate into neuron-like cells induced by glial cellline-derived neurotrophic factor.
METHODS:The bone marrow mesenchymal stem cells at passage 3 were transfected by recombinant adenovirus (Multiplicity of infection=10, 50, 80, 100, 150, 200). The experiment had two groups according to target genes:bone marrow mesenchymal stem cells were transfected by Ad-GDNF-GFP in transfection group, and bone marrow mesenchymal stem cells were not transfected in control group. The expression of green fluorescent protein was detected by inverted fluorescence microscope. Transfection efficiency was calculated by flow cytometry. cells viability and the morphological changes of cells were compared respectively by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and inverted fluorescence microscope between the two groups. On days 5 and 10 after transfection, the expression of glial cel-derived neurotrophic factor mRNA was detected by PCR. On day 5, the expression of neuron-specific enolase was determined by immunofluorescence examination. On day 10, the expression of microtubule-associated protein 2 was identified.
RESULTS AND CONCLUSION:By the end of 12 hours after transfection, the green fluorescent protein expressed in cells, and the fluorescence intensity gradual y increased with time. When the multiplicity of infection was 100, the fluorescence intensity was strong and stable, and the transfection rate was nealy 90%on day 3 after transfection. cellviability in the transfection group was strengthened after transfection. On day 5 after transfection, bone marrow mesenchymal stem cells expressed neuron-specific enolase, and neuron-like protrusions gradual y extended. On day 10 after transfection, bone marrow mesenchymal stem cells expressed microtubule-associated protein 2 and glial cellline-derived neurotrophic factor mRNA, and exhibited neuron-like morphology and interconnected synpases. The recombinant adenovirus, Ad-GDNF-GFP, can highly transfect bone marrow mesenchymal stem cells when the multiplicity of infection is 100, and glial cellline-derived neurotrophic factor can promote the proliferation of bone marrow mesenchymal stem cells and induce bone marrow mesenchymal stem cells to differentiate into neuron-like cells.