BACKGROUND:Poly-D,L-lactic-co-glycolic acid (PLGA) that was characterized as absorbable,weak cytotoxicity,and adjustable hardness was ideal to be synthetized artificial spinal dura mater.Because of lacking of functional group at the surface of PLGA,it should be modified to fit the demand of satisfied biocompatibility.OBJECTIVE:To study the biocompatibility of PLGA membrane modified by type-Ⅰ collagen and chitosan.DESIGN,TIME AND SETTING:Contrast observation study,which was carded out in the Biochemistry and Molecular Biology Laboratory Shanghai University of Traditional Chinese Medicine from May to December 2007.MATERIALS:Porous PLGA membrane was provided by Jinan Banzheng Biology-Technology Co.,Ltd.,type-Ⅰ collagen by Sigma Company,USA,chitosan by Shanghai Qisheng Biological Agent Medical Apparatus and Instrument Company,and L929 L cell by Cellular Institute of Shanghai Academy of Life Science,Chinese Academy of Science.METHODS:PLGA membrane (P membrane),PLGA/type-Ⅰ collagen composite membrane (PG membrane),PLGA/type-Ⅰ collagen/chitosan (9:1) composite membrane (PGC 9:1 membrane) and PLGA/type-Ⅰ collagen/chitosan (5:5) composite membrane (PGC 5:5 membrane) were produced through a certain process.MAIN OUTCOME MEASURES:Contact angle,absorption rate and cytotoxicity were tested.Morphological changes of L929 L cell cultured for 1,3,and 7 days were observed under fiberscope.RESULTS:Contact angle was shown as PG membrane＜PGC 9:1 membrane＜PGC 5:5 membrane＜P membrane (P＜0.01 );absorption rate was shown as P membrane＜PGC 5:5 membrane＜PGC 9:1 membrane＜PG membrane (P＜0.01).L929 L cell was characterized as well distribution,expansion and appearance after inoculation of PG membrane,PGC 9:1 membrane and PGC 5:5 membrane.Cytotoxic experiment (MTT methods) showed that,on the 1st day,there was no significant difference in absorbency among groups (P＞0.05).On the 3rd and 7th days,there were significant differences between P membrane and PG membrane or PGC 9:1 membrane,and between PGC 9:1 membrane and PCK2 5:5 membrane (P＜0.05).PGC 9:1 membrane could further improve cell adhesion and proliferation,and PGC 5:5 membrane could inhibit cell proliferation and differentiation.CONCLUSION:Type-Ⅰ collagen and chitosan appended to the exterior of PLGA can enhance the biocompatibility of membrane.In terms of biocompatibility,PLGA/type-Ⅰ collagen/chitosan (9:1) composite membrane can be fit to the qualification as a type of material of artificial spinal dura mater.

Objective To study the effects of gamma-aminobutyric acid (GABA) on the induction of long-term potentiation (LTP) in developing rat visual cortical slices. Methods Field potentials recorded from layer Ⅱ/Ⅲ induced by layer Ⅳ stimulation in rat visual cortical slices were examined. LTP was induced by tetanus in the slices on the postnatal 2, 3 and 5-week rats. The LTP incidences and the effects of GABA on them in different developmental stages were compared. Results LTP incidence at postnatal week 5 was significantly lower than that in other two groups. GABA A receptor antagonist picrotoxin could reverse this tendency, but had no effects on the LTP induction at the early postnatal age. Conclusion In visual cortex, GABA has inhibitory effects on the LTP induction only after the end of critical period and has no any facilitatory effects on the LTP induction before the developmental critical period.

AIM: To investigate whether the expression of integrin ?_3 and the activation of focal adhesion kinase(FAK) are involved in neointima formation after de-endothelium.METHODS: The model of intima hyperplasia was prepared by balloon injury.The levels of osteopontin(OPN),integrin ?_3 and FAK in vascular tissue were detected by Western blotting and immunohistochemistry.RESULTS: There were similar expression patterns in OPN,integrin ?_3 and FAK following balloon injury.The levels of three proteins were markedly increased 3 days after operation and reached the peak at 7th day.The increased FAK was mainly the phosphorylated form.The migration and proliferation of vascular smooth muscle cells was associated with the increase in the expression of integrin ?_3 and FAK,and was parallel with rapid turnover of extracellular matrix(ECM).CONCLUSION: The interaction of cells with ECM mediated by OPN and integrin ?_3 is essential for migration.The integrin ?_3-FAK pathway is involved in neointima formation.

Objective To investigate the time and implant selection in conversion from external fixation to internal fixation of tibial shaft fracture.Methods Data of 57 cases of tibial shaft fracture fixed externally followed by internal fixation from February 2003 to February 2012 were analyzed.Internal fixation (intramedullary nails or plates) initiated within 2 weeks (Group A,n =.35) and over 2 weeks (Group B,n =22) were compared in outcomes.Results One infection (3％) and four poor bone healing (11％) were observed in Group A.Five infections (23％) and three poor bone healing (14％) occurred in Group B.For intramedullary nail fixation,no infection was observed in Group A but infection rate of44％ was found in Group B.For plate internal fixation,infection rate was 8％ for both groups.Conclusions The conversion from internal fixation to internal fixation had better start within 2 weeks,with better resuhs,lower rate of infection and safer in comparison with that over 2 weeks.In addition,pin-tract infection is the high risk factor for infection after the conversion of the fixation.

Objective To observe the changes of CD+8CD+28,CD+8CD-28 and CD+4CDhigh25CDlow127 regulate T (Treg)cellsin peripheral blood of lung cancer patients,and to analyze the correlation between CD+8CD-28 and CD+4CDhigh25CDlow127 Treg cells to reveal the role and clinical significance of them in lung cancer patients.Methods Flow cytometry was applied to evaluate the level of CD+8CD+28,CD+8CD-28 and CD+4CDhigh25CDlow127 Treg cells in peripheral blood of 60 untreated lung cancer patients and 60 healthy controls group.The association of each term with clinical features was analyzed.Results The percentage of CD+8CD-28 and CD+4CDhigh25CDlow127 Treg cells in lung cancer group[(58.430:15.749) ％,(7.365±2.025) ％]was significantly higher than those in healthy group [(41.057±15.436)％,(6.648±1.669)％,(t=6.102,P＜0.05;t=2.115,P＜0.05)],while the percentage of CD+8CD+28cells is lower(41.570±15.739)％ than that in healthy group[(58.700±15.298)％,(t=-6.043,P＜0.05)].No close associations were found between three index and gender,age,and biological characteristics.With the increase of TNM stage,The percentage of CD+4CDhigh25 CDlow127 Treg cells increased gradually,which was remarkably higher in patients rith stage Ⅳ than that with stage ⅢA(t=-3.898,P＜0.05).The percentage of CD+4CDhigh25 CDlow127 Tregcells was uncorrelated with CD+8CD-28 cells(r=-0.169,P＞0.05).Conclusion The higher percentage of CD+8CD-28 and CD+4CDhigh25 CDlow127 Treg cells,the lower percentage of CD+8CD+28 cells may be the important reasons of immune suppression in lung cancer patients.Though there is no correlation between CD+8CD-28 and CD+4CDhigh25 CDlow127 Treg cells,it is may be helpful to understand immunologic function and it may look for more specific therapy and provide a new reference in the prognosis of lung cancer.

Objective To study the changes of field potentials (FPs) during development and after long-term potentiation (LTP) induction in rat visual cortical slices. Methods Field potentials recorded from layer Ⅱ/Ⅲ induced by layer Ⅳ in the rat visual cortical slices were examined. The developing changes of FPs from postnatal days 8-13,15-21 and 29-35 were observed. Amplitudes, peak latencies and slopes of FPs before and after LTP induction were compared. Results Field potentials changed with the development, and the stimulating threshold at p15-21 was lower than that of the other two groups. The increase of FP amplitude was positively correlated with increase of its slope. The shortening of FP latency was positively correlated with the difference between changes of slope and amplitude. Conclusion Developing changes of field potentials reflect the development of visual cortex. The changes of FP slope follow the changes of its amplitude and latency, and thereby the slope is a proper parameter used as an index to evaluate LTP in visual cortex.

? AIM: To investigate the influence of phacoemulsification on corneal endothelial cells and its injury risk factors in diabetic cataract patients.?METHODS: From January 2013 to October 2015, 186 diabetic cataract patients ( 224 eyes ) as diabetes group and 190 patients with simple cataract ( 227 eyes ) as control group in our hospital were enrolled. All patients received phacoemulsification combined with intraocular lens implantation. Observation of corneal endothelial cell density, coefficient of variation and percentage of hexagonal cells preoperatively, 1d, 1wk, 1 and 3mo postoperatively were carried out, and multiple Logistic regression analysis for risk factors of corneal endothelial cell injury was taken.?RESULTS: There were no significant difference in the density of corneal endothelial cells, the coefficient of variation and the percentage of hexagonal cells between the two groups before surgery (P>0. 05). Each time point after operation corneal endothelial cell density and the percentage of hexagonal endothelial cells of diabetes group were significantly lower than the preoperative and those of control group ( P < 0. 05 ). Each time after operation endothelial cell coefficient of variation of diabetes group were significantly higher than the preoperative(P<0. 05). The endothelial cell coefficient of variation in diabetes group of the 1wk, 1 and 3mo after operation were significantly higher than those of the control group ( P<0. 05 ) . Corneal endothelial cell density and percentage of hexagonal cells of the control group at 1wk, 1 and 3mo after operation were significantly lower than the preoperative ( P<0. 05 ). The endothelial cell coefficient of variation of control group at 1wk, 1 and 3mo after operation were significantly higher than the preoperative(P<0. 05). Single factor analysis showed that age, shallow anterior chamber, long ultrasonic time, short eye axis, high energy ultrasonic, high cumulative released energy, a lot of perfusate and nuclear hardness ≥ grade Ⅲ associated with corneal endothelial cell injury ( P< 0. 05 ) . Multivariate Logistic regression analysis showed that age, long ultrasonic time, high ultrasonic energy, high cumulative released energy and nuclear hardness ≥ grade Ⅲ were the risk factors of corneal endothelial cell injury, the OR value and 95%CI were 1. 742 (1. 056-2. 682), 1. 958 (1. 227-3. 135), 2. 064(1. 274-3. 256), 2. 585(1. 493-3. 682), 2. 193 (1. 348-3. 316).?CONCLUSION: The injury of corneal endothelial cells after phacoemulsification in diabetic cataract patients is more serious than in patients with simple cataract. Age, long ultrasonic time, high ultrasonic energy, high cumulative released energy and nuclear hardness ≥grade Ⅲ are the risk factors of corneal endothelial cell injury.

Objective To study the possibility of establishment of an animal model of hydronephrosis by ureteropelvic junction obstruction,and to evaluate the value of CT perfusion imaging in assessment of the renal function in the animal models. Method Fifty 10-week-old male New Zealand rabbits were randomly assigned to two groups:sham-operated group with separation of the left ureter (20 rabbits),and model group (30 rabbits) with the left ureter embedded at the ureteropelvic junction under the psoas major muscle. The left kidney function in the two groups was confirmed to be normal by SPECT before operation. CT perfusion and SPECT imagings were performed to assess the left kidney function in the two groups at three months after surgery,and the results were compared with that of pathological examination. Statistical analysis was performed on the parameters of SPECT and CT perfusion imaging and glomerular filtration rate (GFR). Results The success rate of model establishment was 70%,showing pathological changes of chronic hydronephrosis. CT perfusion demonstrated that BF,BV,PS of the left renal cortex and medulla were decreased,and had a good positive correlation with the changes of GFR. Conclusions It is feasible to establish a rabbit model of chronic hydronephrosis by embedding the left ureter at ureteropelvic junction under the psoas major muscle,and CT perfusion imaging parameters can be used to evaluate the renal function in the animal models.

A BBB co-culture cell model consisting of rat brain microvascular endothelial cells (BMEC) and astrocytes (AS) was established to study the effect of Angelica dahurica coumarins on the transport behavior of puerarin across blood-brain barrier (BBB) in vitro and in vivo. The barrier function of this model was evaluated by measuring the transendothelial resistance, phenol red permeability and BBB related protein expression. The permeability assay and western blot methods were performed to study the effects of Angelica dahurica coumarins on the BBB permeability and the expression of BBB related protein. The animal experiment protocols in this study were approved by the Animal Ethics Committee of Xi'an Jiaotong University (Animal Ethics No.: 2021-1329). The results showed that the established BMEC/AS co-culture model could be used to evaluate drug transport across BBB in vitro. After combined with Angelica dahurica coumarins, the transport capacity of puerarin was significantly increased in vitro and in vivo. Additionally, Angelica dahurica coumarins enhanced BBB permeability and inhibited the protein expression of P-glycoprotein (P-gp), zonula occludens-1 (ZO-1) and occludin. Angelica dahurica coumarins might increase BBB permeability by inhibiting the expression of P-gp and tight junction protein, thereby increasing the content of puerarin in brain tissue.