ObjectiveTo analyze the autophagy of mouse melanoma B16 cells induced by TNF-ct.MethodsMouse melanoma B 16 cells treated with TNF-α were used in this study.The expression levels of LC3- Ⅱand Beclinl were measured by western blot and mRNA levels of autophagy related gene atg5,atg7 and atgl2 were measured by reverse transcription polymerase chain reaction (RT-PCR) after TNF-α treatment.ResultsThe viability of B16 cells were obviously inhibited after incubation with TNF-α.The expression levels of autophagy related protein LC3- Ⅱ and Beclinl were elevated in TNF-α treated B16 cells compared with in control B16 cells.The mRNA expression levels of autophagy related gene Atg5,atg7 and atg12 showed consistent up regulation in TNF-a treated B16 cells compared with in control B16 cells.ConclusionTNF-α can induce autophagic cell death in B16 cells.

Objective To morphologically observe the changes of cornea tissue a long period after myopic LASIK with confocal microscopy. Methods 34 patients (68 eyes) from April 1999 to July 2004, who had undertook LASIK in our Hospital, were involved in present study. The confocal microscopy was employed to examine the changes of cornea tissue. The average spherical equivalence was -6.81?2.88D (ranged from -3.0 to -16D). The average age of the patients was 24.17?5.93 (ranged from 18 to 42). The average follow-up time was 39?3 months (ranged from 6 to 73 months). Results The Micro-folds at the Bowman's layer were found in 68 eyes (100%), as well as variously reflectivity particles located at the interface in all eyes examined after operation. The density of high reflective particles did not decrease significantly with time. In the middle stroma, the mean depth of acellular area was 44.01?10.67?m in all 68 eyes (100%). The appearance of morphology of subbasel corneal nerve fiber bundles after operation recovered. Conclusions Morphologic changes were found in central cornea. Acellular area, micro-folds as well as variously reflectivity particles located at the interface in all eyes existed in the central cornea for long time.

Medical science is the science which closely combines scientific knowledge with humanistic spirit. Becausemodern science and technology have been more and more applied in medical research and practice, the medical sciencehas been developed rapidly. But medical science calls us to concern more about medical humanistic spirit, so how wecombine medical scientific knowledge with humanistic spirit is a very important topic in our medical university education.[

Objective To investigate the infectious complications after nonmyeloablative allogeneic peripheral blood stem cell transplantation (NASCT). Methods Ten patients with leukemia received NASCT from HLA-identical or 1-3 antigen mismatched sibling donors with conditioning regimens of Flu/Cy+BU+ALG. Five patients were acute leukemia (AL) and all of them is in complete remission (CR1). Cyclosporine in combination with methotrexate was administered for GVHD prophylaxis. Results WBC recovered to more than 0.5 ?10 9/L during postoperative 10 day to 38 day and platelet recovered to more than 20?10 9/L during postoperative 8 day to 16 day. Bacterial infections occurred in 3 patients (30 %) and cytomegalovirus (CMV) infections in 2 patients (20 %). Varicella zoster virus (VZV) infections occurred in one patient (10 %). No fungal infections were documented. No patients died as a result of infection . Conclusion NASCT is a safe and effective therapeutic method for leukemia. It reduces acute GVHD,regimen-related toxicity and early neutropenia associated with traditional allo-HSCT.

Objectives To optimize the curriculum for better education quality. Methods By literature review, the curriculum of the bio-medical English program of Peking University was summa-rized. Interviews were conducted on 8 sophomores of the program based on convenience sampling for their concerns over the curriculum and a questionnalre was designed based on such concerns. Ques-tionnalre survey was used for the remarks and suggestions of the 129 graduates of year 2002, 2003 and 2004 on the curriculum, with 79 valid questionnalres collected and the data analyzed by Microsoft Excel. Results Respectively 64 (81.02%), 52 (65.82%), 53 (67.09%) respondents believe the se-quence, duration and connection of the English courses are appropriate and 65 (82.27%), 46 (58.22%), 50 (63.29%) respondents believe the sequence, duration and connection of the medical courses are appropriate. 63 (81.77%) respondents hoped that they could do experiments in the medical courses, but 18 of them (23.08%) worried that the experiments would make the curriculum more tense. 71 (89.97%) respondents thought that the internship at hospital in the curriculum was conducive to better understanding of medical course contents . Suggestions on the improvement of the curriculum were also made by respondents. Conclusions The curriculum could be further optimized, especially on the connection between different courses, although most of the respondents by and large believe that the curriculum of the program is rational and hold positive attitude towards the internship in hospital and experiments in the curriculum.

Objective To investigate the mechanism of xCT on tumor metastasis in breast cancer cell MDA-MB-231. Methods Wound scratch assay and Transwell assay were performed to evaluate the effect of disruption and knockdown of xCT on cell migration and cell invasion in breast cancer cell MDA-MB-231 .Western Blot and RT-PCR were used to detect the expression levels of autophagy and EMT related markers in breast cancer cell MDA-MB-231 after treatment with sulfasalazine (SASP), an inhibitor of xCT activity and SLC7A11-RNAi.Results Both the scratch assay and the transwell migration assay showed that inhibition of xCT reduced the motility of MDA-MB-231 .The expression level of autophagy related protein LC3-Ⅱ/LC3-Ⅰwas elevated, the protein level of transcription factor Snail was down-regulated, while the mRNA level of Snail did not change in xCT inhibited MDA-MB-231 cells compared with MDA-MB-231 cells.Epithelial marker E-cadherin was up-regulated but mesenchymal marker Vimentin was down-regulated when xCT was deficient.Con-clusion Our current studies show that xCT is an endogenous regulator of tumor growth and metastasis in MDA -MB-231 and the expression level of xCT determines the phenotypes of MDA-MB-231 cells in invasion and migration in vitro.Inhibition of xCT can activate autophagy , induce the degradation of Snail ,and attenuate the EMT process in highly metastatic MDA-MB-231 cells.

Objective To explore the expression and significance of matrix metalloproteinases-9(MMP-9) and tissue inhibitors of matrix metalloproteinase-1(TIMP-1) in serum at acute phase of severe pneumonia in infants.Methods A total of 45 infants of pneumonia were selected and divided into 20 cases of severe pneumonia group and 25 cases of mild pneumonia group according to the severity of the disease,and all 45 infants were also divided into virus group of 24 cases and non-virus group of 21 cases on the basis of etiology.Additionally,20 cases of healthy children who accepted the physical examination at the same time were selected as the control group.Serum levels of MMP-9 and TIMP-1 were detected by using ELISA.Tidal breathing lung function was measured in all selected infants.Results Compared with the control group,the serum levels of MMP-9,TIMP-1 and MMP-9/TIMP-1 ratio of the infants with acute pneumonia were significantly higher,the severe pneumonia group were higher than the mild pneumonia group,and the virus group were higher than the non-virus group(P＜0.05).The ratio of the time to reach peak tidal expiratory flow to total expiratory time (TPTEF/TE) and the volume to reach peak tidal expiratory flow to total expiratory volume(VPTEF/VE) of pneumonia group in recovery period were significantly lower than those in the control group,severe pneumonia group were lower than those in the mild pneumonia group,and the virus group were lower than those in the non-virus group (all P＜0.05).There were no statistically significant about VT/kg among three groups.The serum MMP-9 levels and the MMP-9/TIMP-1 ratio were negatively correlated with TPTEF/TE and VPTEF/VE (r1=-0.459,-0.376; r2=-0.413,-0.327; all P＜0.05).Conclusion The serum levels of MMP-9 and the MMP-9/TIMP-1 ratio in the acute phase of infantile pneumonia are correlated with pneumonia severity and pulmonary function injury in recovery period,and the performance is particularly prominent in the viral pneumonia,and can be used as a prognosis monitoring indicator.

Objective To identify the mechanisms underlying xCT deficiency by high-resolution proteomic analysis of differential protein expression in Sut and wild melanocytes .Methods The proteins,extracted from Sut and wild melano-cytes,were analyzed by two dimensional electrophoresis and PDQuest software .Subsequent MALDI-TOF mass spectrometry analysis was carried out .The protein identification was based on peptide mass fingerprint combined with the pI and the rela -tive molecular mass ( Mr) .Sequence coverage was performed with the Peptldent software on the NCBnlm website .Also,the autophagy marker protein LC3-Ⅱ, and the autophagic cell death marker protein Beclin 1 were detected by Western blotting . Results and Conclusion Twenty apparently upregulated or downregulated proteins were identified .Strikingly, important modifications in regulators of trafficking and organization of vesicles and autophagy ( Anxa3; Hist 1h2bk, NDRG1, and CaM) and in regulators of invasion and metastasis of carcinoma (S100A-4;S100A-6 and vimentin)are likely to account for dysfunctions in cell viability and cell-extracellular adhesion .These results indicate that the proteins regulating autophagy , vesicles trafficking and MAP kinase related pathways are activated and play a role in xCT-deficiency .

Objective To investigate the mechanism of Sut melanocytes growth inhibition in response to xCT -deficiency. Methods TTotal proteins were extracted from xCT-deficient Sut melanocytes and wild melanocytes, respectively, and were separated by 2-dimensional electrophoresis. Altered expression profile of proteins of Sut melanocytes was analyzed by PDQuest software and compared with that of wild melanocytes.Proteins with significant change were chosen to be identified by mass spectrometry and database query.Results Twenty proteins in Sut melanocytes altered significantly compared with wild melanocytes. Ten of the proteins were up-regulated, while the other tens were down-regulated. Four proteins from both up-regulated and down-regulated were identified respectively: up-regulated proteins were Tubulin alpha-1b, S100-A6,Nucleoside, S-formylglutathione, and down-regulated proteins were Calumenin,NDRG1 ,DPYSL2, 14kDa unknown protein. Conclusion The identification of the xCT-deficiency related proteins may provide supporting evidence for the mechanism research of Sut melanocytes' growth inhibition caused by xCT-deficiency.

Background Corneal confocal microscopy can denamically offer the morphological image of corneal cells at cellular level.To find out the dynamic change of corneal thickness and morphology of corneal cells with aging is very important for the design of corneal refractive surgery.ObjectivePresent study is to find out the important relevance of dynamic change of corneal thickness and morphology of corneal cells with aging and the design of corneal refractive surgery and investigate the influence of age on central corneal tissue and characterize precisely the anatomy of cornea by in vivo confocal microscopy.Methods122 eyes of 122 normal subjects were enrolled in this study with the age from 18 through 80 years old.The subjects were diagnosed as emmetropia in the Center of Tianjin Medical University from August 2003 to December 2007.All eyes were examined in vivo by confocal microscopy.The cell morphology,cell density and corneal thickness were measured by confocal microscopy.The relationship of central corneal tissue change and age was evaluated.ResultsThe density of corneal superficial basement epithelial cells showed a significantly negative correlation with age (r=-0.355,P=0.017).The keratocyte density in the anterior and posterior stroma indicated a significantly negative correlation with age (r_1=-0.462,P=0.001;r_2=-0.403,P=0.016).The thickness of corneal epithelium cells had a significantly negative correlation with age (P=0.02).The mean value of total corneal thickness and stromal thickness in high myopic eyes was (523.2±26.20)μm and (468.4±20.72)μm respectively,presenting a significantly negative correlation with age (r_1=-0.552,P=0.014;r_2=-0.545,P=0.035).A significantly negative correlation was also found in endothelial cell areas and density with age (r_1=0.417,P=0.004;r_2=-0.598,P=0.002).The percentage of polymorphological corneal endothelial cells was considerably increased(r=0.417,P=0.004)but that of pleomorphism cells was significantly decreased in >60-year-old population compared with younger subjects (r=-0.598,P=0.002).The morphology of corneal basement cell,anterior stroma cytocyte and endothelial cell were normal in younger subjects,and enlargement of the cells in size,decreases of number and density of the cells were found in >60-year-old subject.ConclusionThe anatomy and histology of the central cornea in young subjects exist discrepancy from older ones.The corneal hisological changes with aging include thinner thickness of epithelium,thinner thickness of cornea,decreased density of keratocyte and endothelial cells and increased size of endothelial cells.Corneal thickness is asymmetric and seems to undergo age-related anatomic changes.