Tumor microenvironment plays a crucial role in neoplastic evolution process as it may provide functional interactions between neoplastic and non-neoplastic cells involved in tumor invasion,metastasis and angiogenesis,which implies that it can be regarded as a novel target for the antitumor therapy of polysaccharides.This review focuses on the protumor variations existing in tumor microenvironment,such as growth factors,immunosuppressive factors,proteases,glycoproteins,etc.,which may offer possible mechanisms of polysaccharides on the regulation of their corresponding functions.

Objective To investigate the status quo and characteristics of medical students'job choosing view,to analyze the reasons and to propose countermeasures.Methods Questionnaires on job choosing view concerning job choosing cognition,ideals,method,motivation and values were conducted among 1700 medical students in Shandong University.Data entry and statistics were done by SPSS 17.0.Difference was analyzed by t-test and ANOVA.Results Significant differences were showed in sex,whether being the only-child in the family,father's education and family's economic status(P＜0.05).Conclusions Medical students'job choosing views are characterized by professional,highly expected,diversified and utilitarian,which is caused by society,school and family.Therefore,much importance should be attached to improving educational environment,making educational objective clear and constructing educational content system.

Objective To evaluate the cranioplasty with Titanium mesh.Methods Clinical studies of 110 cases who accepted cranioplasty with Titanium mesh (2000-2001) were reviewed retrospectively.Results A satisfactory moulding with no complication occurred in 91%(100/110). The most common recent complication of cranioplasty with Titanium was subcutaneous hematoma(19/110); the next was epidural hematoma(3/110), intracerebral hematoma(3/110) and brain contusion(1/110). 69 cases more than 1 year after cranioplasty were followed, no one appeared long term complications such as infection, exposure or mobilization of the mending material.Conclusion The results of cranioplasty with Titanium mesh are satisfactory, the recent complications of the operation are mainly related to incompletely hemostasis, the long term complication occurred rarely.

In recent years, much attention has been paid to arterial stiffness detection,but the relation between arterial stiffness and cerebrovascular disease has not been fully elucidated.This article reviews the detective methods of arterial stiffness and its relationship between the risk factors for cerebrovascular disease, ischemic stroke (including asymptomatic cerebral infarction) and cerebral hemorrhage.

? AlM: To observe the differences of central cornea thickness, anterior chamber depth, corneal anterior curvature and corneal posterior curvature between the Kazak and the Han nationality college emmetropia students, and analyze the relationship of corneal thickness and corneal curvature.?METHODS: More than 500 students in grade one in Xinjiang Medical University for screening, selected 55 emmetropia eyes in Han nationality students and 51 in Kazak students. Sirius corneal topography was applied to the measurement.? RESULTS: Kazak and the Han nationality college emmetropia students' central cornea thickness ( Kazak:0. 52± 0. 03mm, Han:0. 54 ± 0. 03mm), anterior chamber depth (Kazak:2. 97 ± 0. 31mm, Han: 3. 14 ± 0. 25mm) had significant difference (P<0. 05). Corneal anterior curvature and corneal posterior curvature were no significant difference (P>0. 05). Han had no significant relationship in corneal thickness and corneal anterior curvature (r<0), or in corneal posterior curvature ( r < 0. 1 ) . Kazak had no significant relationship in corneal thickness and corneal anterior curvature (r<0), or in corneal posterior curvature(r<0. 1).? CONCLUSlON: There are significant differences between the Kazak and the Han nationality college emmetropia students in cornea thickness, anterior chamber depth. There is no significant relationship between corneal thickness and corneal curvature (K1, K2) in Kazak and the Han nationality college emmetropia students.

Objective:To study the changes of PTEN gene expression in radiation-induced bystander cells.Methods:The irradiated cells and non-irradiated cells were co-cultured in a ratio of 11.The culture medium of irradiated cells was used to culture non-irradiated cells to create two bystander cell models. The expression of PTEN mRNA and protein in the bystander cells,irradiated cells,non-irradiated cells was compared.Results:The protein expression of PTEN in the irradiated cells was negatively associated with the irradiation dose.The down-regulation degree of PTEN protein was related to the different treatments of cells.The most prominent down-regulation was found in the bystander cells cultured with medium of irradiated cells.The down-regulation of PTEN protein in the two kinds of bystander cells was more severe than that in the irradiated cells(P

Objective:To investigate the in vivo absorption kinetics of caffeine at different intestine segments in rats.Methods: The rat intestine was cannulated for in situ recirculation.The absorption kinetics of caffeine,including the absorption segments of intestine,drug concentration and pH value,were investigated in all the rats under light anesthesia.Ultraviolet light spectrometry and high-performance liquid chromatography were used to determine the concentrations of phenol red and caffeine,respectively.Results: The absorption rate constants(Ka) of caffeine in the small intestine at the concentrations of 2.5,5,10 and 25 mg?L-1 were 0.252,0.247,0.304 and 0.232 h-1,respectively.The Ka values at pH of 7.8,6.8,and 5.4 were 0.267,0.274 and 0.247 h-1,respectively.The Ka values in the duodenum,jejunum,ileum,and colon were 0.112,0.099,0.095 and 0.069 5 h-1,respectively.Conclusion: Concentration and pH value have no obvious effect on the absorption kinetics of caffeine.Caffeine can be better absorbed in the duodenum,jejunum and ileum than in the colon.The absorption of caffeine in the intestine is a first-order process through passive diffusion mechanism.

Background Vitretomy and lenstomy with silicone oil tamponade is an effective method for complicated vitreous retinopathy.The severe anisometropia after silicone retention is usually treated by two-point transscleral suture fixation for posterior chamber intraocular lens(IOL)implantation.In order to reduce the number and difficulty and complication of the operation,the surgical method should be improved.Objective The goal of this study was to observe the resuh of silicone oil removal combined with four-point trans-scleral suture fixation of posterior chamber IOL after vitrectomy.Methods A retrospective case-observational study design was adopted.Twenty eyes with silicone oil tamponade from 20 patients without lens and posterior capsule after vitrectomy were included in this study.Silicone oil removal with four-point trans-scleral suture fixation of posterior chamber IOL was performed.The anterior ocular inflammatory response,intraocular pressure,uncorrected and corrected acuities before and after operation,corneal endothelial cell counting and postoperative complications were observed and analyzed.Written informed consent was obtained from all patients prior to the operation.Results All of the operative eyes in this study showed improvement of visual acuity after operation.Of the 20 eyes,a visual acuity of ≥0.8 was seen in 2 eyes,0.6-0.7 in 6 eyes,0.3-0.5 in 8 eyes and 0.05-0.2 in 4 eyes 3 months after the removal of silicone oil.The uncorrected acuity postoperation was significantly improved in comparison with preoperation(H=10.147,P＜0.01),but no significant difference was found in the corrected acuity between preoperation and postoperation(X =2.089,P＜ 0.01).The number of the corneal endothelial cells was(2064±329)cells/mm2 before operation,and that after operation was(1987±269)cells/mm2,showing an insignificant change between them(t =1.660,P ＞ 0.05).No abnormality of IOL position was found in all 20 operated eyes.There was not serious postoperative complication in all 20 patients.Conclusions The combination of silicon oil extraction with four-point transscleral suture fixation IOL is effective in eyes without posterior capsule or lens after vitrectomy.It can reduce the operation time and improve the postoperative acuity and the quality of life of patients.

ObjectiveTo investigate the protein expression of ERK1/2,p-ERK1/2,HIF-1α and α-enolase in hypertrophic cardiomyocytes induced by ET-1 and explore the regulation mechanism of overexpression of α-enolase in hypertrophic cardiomyocytes.MethodsET-1-induced abnormal cardiomyocytes were used as model of cardiac hypertrophy.Cellsurface area, [<'3>H]-leucine incorporation and the actin staining were measured to determine the extent of hypertrophy. Cultured cardiomyocytes were divided into 4 groups at random, control group, PD98059 treated group, ET-1 treated group and PD980594- ET-1 treated group. The protein expressions of ERK1/2, p-ERK1/2,HIF-1α and α-enolase were detected by immunoblotting analysis.ResultsCompared with the control group , cell surface area and [<'3>H] leucine incorporation were increased in ET-1 treated group ((1350.7±107.5)μtm<'2> vs. (896.1±70. 2)μtm<'2> , P<0.05; (1387.9±14.8) dpm vs. (787.7±10.2)dpm,P<0.013. Actin staining showed that ET-1-treated cardiomyoeytes had more intense actin staining and clear cross-striations than did control group, which suggested that myocardial cell hypertrophy could be induced by ET-1 in WKY neonatal cardiomyocytes. After MEK 1/2 inhibitor PD98059 was used, the cell surface area and [<'3>H] leucine incorporation were decreased in PD980594-ET-1 treated group compared with ET-1 treated group[(907.0±92.5)μm<'2> vs. (1350.7±107.5)μm<'2>;(841.5±10. 5)dpm vs. (1387.9±14.8)dpm, both P<0.05], which suggested that myocardial cell hypertrophy could be regulated by ERK1/2 signal pathway. Immunoblotting analysis showed that the protein expressions of p-ERK1/2, HIF-1α and α-enolase increased after ET-1 treatment,while PD98059 as an inhibitor of the upstream kinase of ERK1/2 was used, the protein expressions of HIF-1α and α-enolase were partially inhibited.ConclusionsET-1 induces hypertrophic cardiomyocytes through ERK1/2 phosphorylation in cultured neonatal rat cardiac myocytes.ERK1/2 and HIF-1α signal pathway may play an important role in the overexpression of α-enolase in the hypertrophic cardiomyocytes.

BACKGROUND: There is few studies addressing the long-playing dynamic observation of cysteinyl aspartate specific protease 3 (Caspase-3) expression following cerebral ischemia/reperfusion.OBJECTIVE: To investigate the effect of transplantation of the neural stem cells (NSCs) modified with gene of glial cell line-derived neurotrophic factor (GDNF) on expression of Caspase-3 in adult Sprague Dawley rats with transient cerebral ischemia.DESING: Randomized controlled animal study.MATERIALS: Sixty Sprague Dawley rats were divided randomly into normal control group (N, n =5), ischemia/reperfusion group (IR, n=5), neural stem cell group (NSCs, n=25) and NSCs modified with gene of GDNF group (GDNF/NSCs, n =25). Several clean neonatal Sprague-Dawley rats were selected to harvest NSCs.METHODS: With the exception of normal control group, models of transient cerebral ischemia were created by modified suture method in other groups. At day 3 following reperfusion, 20 μL NSC suspension containing (4.0-5.0)×10~5 NSCs was infused into rats of the NSC group via right lateral ventricle. An equal volume of GDNF-modified NSC suspension was injected into rats of the GDNF/NSC group. 20 μL saline was infused into the rats of the ischemia/reperfusion group. Animals were anesthetized and sacrificed at week 1 following ischemia/reperfusion in the normal control and ischemia/reperfusion groups. Animals were anesthetized and sacrificed at weeks 1, 2, 3, 5, 7 following ischemia/reperfusion in the NSC and GDNF/NSC groups, 5 rats in each time point.MAIN OUTCOME MEASURES: The strept avidin-biotin immunostaining method was used to observe the distributive characteristics of Caspase-3 in the hippocampus and frontal parietal cortex.RESULTS: Immunohistochemical method (SP) showed that positive capase-3 products expressed in nucleus, cytoplasm and partial neurite. In hippocampus, number of Caspase-3-positive cells was decreased in NSC and GDNF/NSC groups. With the exception of at 1-week reperfusion, number of Caspase-3-positive cells was significantly lessened in the GDNF/NSC group compared with the NSC group at other time points (P < 0.05). In frontoparietal cortex, number of Caspase-3-positive cells was reduced in the NSC and GDNF/NSC groups over time. Except 1 and 2 weeks following ischemia/reperfusion, number of Caspase-3-positive cells was significantly lessened in the GDNF/NSC group compared with the NSC group (P < 0.05).CONCLUSION: Transplanting NSCs modified with gene of GDNF can improve remarkably neural function by deceasing Caspase-3 expression and reducing the nervous cell apoptosis. The transplantation of NSCs modified with gene of GDNF obtained better outcomes compared with NSC transplantation.