AIM:To investigate the effects of estrogen on the expression of matrix metalloproteinases-2(MMP-2), tissue inhibitor of metalloproteinases-2(TIMP-2) and transforming growth factor-β1(TGF-β1) in cultured human corneal stromal cells.METHODS: Inflammatory environments of human corneal stromal cells were simulated by using 1.5ng/mL IL-1β.The cells were then treated with or without different concentrations of estrogen(0, 1×10-4, 1×10-6, 1×10-8, 1×10-10mol/L estradiol)in vitro.Cell viability was evaluated by MTT.Expression levels of MMP-2, TIMP-2 and TGF-β1 proteins were measured by enzyme-linked immunosorbent assay(ELISA).RESULTS:Estrogen did not affect the viability of human corneal stromal cells.Compared with the control group, expression levels of MMP-2 and TGF-β1 proteins in E2 treatment group significantly decreased after being treated with estrogen, while the expression level of TIMP-2 significantly increased.CONCLUSION: Estrogen could, to some extent, down-regulate the expression of MMP-2 and TGF-β1 and up-regulate the expression of TIMP-2, which might contribute to protecting human cornea.

Aim To discuss whether specific mitochon-drial ATP-sensitive potassium channel opener diazoxide ( DZ ) postconditioning activates RISK signaling path-way to protect isolated rat hearts against ischemica reperfusion injury ( IRI ) . Methods Langendorff de-vice was used to establish rat in vitro model of myocar-dial ischemia reperfusion. SD rats were randomly di-vided into normal group ( NOR ) , control group ( CON ) , diazoxide after treatment group ( DZ ) , and LY294002 antagonistic nitrogen Triazine group ( DZ +LY) , with 8 cases in each. The following was com-pared:①whether heart function of each group changed at the end of equilibration and reperfusion; ② at the end of myocardial perfusion and separation, protein was extracted, and protein kinase B ( PKB / Akt ) , P70S6 kinase (P70S6K), endothelial nitric oxide syn-thase ( eNOS) phosphorylation level of expression were analysed by Western blot. Results ① Indicators of changes in heart function: for DZ group at the end of reperfusion , HR , CF , LVDP , LVEDP , +d p/d tmax and -dp/dtmax were significantly better than those in CON group and DZ + LY group ( P <0.01 ) , but worse than those in NOR group ( P <0.01 ); there was no statistical difference in cardioac function at the end of equilibration. ② For DZ group at the end of reperfu-sion Akt, P70S6K, eNOS phosphorylation level of ex-pression were significantly higher than those in NOR group, CON group, and DZ + LY group (P<0.01). There was no difference in expression level of ERK1/2 phosphorylation ( P >0.05 ) . Conclusion Diazoxide postconditioning through the activation of RISK signa-ling pathway can protect isolated rat hearts against is-chemia reperfusion injury.

Objective To evaluate the role of phosphoinositide 3 kinase/protein kinase B/glycogen synthase kinase 3β (PI3K/Akt/GSK-3β) signaling pathway in mitigation of ischemia-reperfusion (I/R) injury by diazoxide postconditioning in isolated rat hearts.Methods Pathogen-free Sprague-Dawley rats were used in the study.Thirty hearts were excised and passively perfused in a Langendorff apparatus with oxygenated K-H solution at 37 ℃.The hearts were randomly divided into 5 groups (n =6 each) using a random number table:control group (group C),I/R group,diazoxide postconditioning group (group DZ),PI3K inhibitor LY294002 group (group LY),and diazoxide postconditioning + LY294002 group (group DZ + LY).In group C,the hearts were continuously perfused with K-H solution for 70 min.In group I/R,the hearts were perfused with cardioplegic solution 4 ℃ ST-Thomas 10 ml/kg,the perfusion pump was then stopped to induce global ischemia,and 40 min later the hearts were perfused with K-H solution for 30 min.In DZ group,5 min of retrograde perfusion with diazoxide 50μmol/L was performed through the aorta starting from the onset of reperfusion.In LY group,5 min of retrograde perfusion with LY294002 15 μnol/L was performed through the aorta starting from the onset of reperfusion.In LY + DZ group,5 min of retrograde perfusion with LY294002 15 μmol/L was performed through the aorta starting from the onset of reperfusion,followed by 5 min of retrograde perfusion with diazoxide 50 μmol/L.At 20 min of stabilization (T1) and 30 min of reperfusion (T2),heart rate (HR),coronary flow (CF),left ventricular developed pressure (LVDP),left ventricular developed pressure (LVEDP) and ± dp/dtmax were measured.The expression of total Akt (t-Akt) and total GSK-3β (t-GSK-3β) and phosphorylation of Akt and GSK-3β in myocardial tissues were determined by Western blot.Results Compared with C group,HR,LVDP and ± dp/dtmax were significantly decreased,and LVEDP was increased at T2 in the other four groups,CF was decreased in I/R,LY and DZ + LY groups,and the phosphorylation of Akt and GSK-3β in myocardial tissues was increased in DZ group.Compared with I/R group,HR,CF,LVDP and ± dp/dtmax were significantly increased,and LVEDP was decreased at T2,and the phosphorylation of Akt and GSK-3β in myocardial tissues was increased in DZ group,and no significant changes were found in the phosphorylation of Akt and GSK-3 β in LY and DZ + LY groups.Compared with DZ group,HR,CF,LVDP and ± dp/dtmax were significantly decreased,LVEDP was increased,and the phosphorylation of Akt and GSK-3β in myocardial tissues was decreased in LY and DZ + LY groups.Conclusion PI3K/Akt/GSK-3β signaling pathway is involved in the mechanism by which diazoxide postconditioning mitigates I/R injury in isolated rat hearts.

OBJECTIVETo determine the interaction between miR-21 and DNA methylation in different breast cancer cells.

METHODSFluorescence tagged miR-21 inhibitor and its negative control (NC) were transient transfected into MCF-7 and MDA-MB-231 cell, the transfection efficiency was observed using fluorescence microscopy, and the miR-21 expression level and genome DNA methylation status before and after transfection were assessed by real-time PCR and bisulfite-qMSP respectively. To investigate the regulation effect of DNA methylation on miR-21, cells were treated with 5-AZA (2.5 µmol/L) for 72 h, with dimethyl sulfoxide (DMSO) treatment as its negative control (NC), and the expression level of phosphatase and tensin homolog deleted on chromosome ten (PTEN) and AKT(also known as Protein Kinase B), two downstream genes of miR-21 were detected by Western blot.

RESULTSThe expression of miR-21 in MCF-7 cell was significantly knocked down (P < 0.01) by miR-21 inhibitor, with the genome DNA methylation level (P < 0.05) and all the three Dnmts: Dnmt1, Dnmt3a, and Dnmt3b unregulated. In contrast, the miR-21 expression in MDA-MB-231 cell was elevated ( P < 0.01) by miR-21 inhibitor, meanwhile, down- regulated of genome DNA methylation (P < 0.05) and Dnmt3b expression, upregulation of Dnmt3a were also observed. In addition, treated with 5-AZA resulted in significant increases of miR-21 expression in both MCF-7 and MDA-MB-231 cells (P < 0.01), with the protein level of PTEN increased in MCF-7 cell, which was further involved in the downregulation of AKT.

CONCLUSIONThe regulation effects of DNA methylation by transient transfection of miR-21 in MCF-7 and MDA-MB-231 cells are almost opposite, whilst the expression of miR-21 in two cell lines were all upregulated by decreased DNA methylation level and our results may provide some experimental evidences for the future development of rational therapy for different breast cancer.

Azacitidine ; Breast Neoplasms ; genetics ; Cell Line, Tumor ; DNA (Cytosine-5-)-Methyltransferase 1 ; DNA (Cytosine-5-)-Methyltransferases ; metabolism ; DNA Methylation ; Down-Regulation ; Gene Expression Regulation, Neoplastic ; Humans ; MCF-7 Cells ; MicroRNAs ; genetics ; PTEN Phosphohydrolase ; metabolism ; Promoter Regions, Genetic ; Proto-Oncogene Proteins c-akt ; metabolism ; Real-Time Polymerase Chain Reaction ; Up-Regulation

Adolescent ; Adult ; Cyclophosphamide ; adverse effects ; Female ; Femur Head Necrosis ; etiology ; Humans ; Immunosuppressive Agents ; adverse effects ; Male ; Middle Aged ; Paraquat ; poisoning ; Young Adult

Objective To explore the simplified method by examining the levels of luteinizing hormone(LH),follicle-stimulating hormone(FSH),estradid(E2) and stosterone(T) at different times in the stimutation test of luteinizing hormone-releasing hormone(LHRH).Methods Sixty patients with precocious puberty accepted LHRH stimutation test.The levels of E2,T,FSH,LH before injection and after 30,60,90 minutes were compaired.The levels of stimutation test of LHRH examined with ACS:180 chemiluminesence.Results There were 39 patients in the group of central precocious puberty(CPP).The levels of FSH and LH in CPP group significantly increased after LHRH 30 minutes injection.The ratio of LH/FSH was higher than 1.The peak level of LH was higher than 12 IU/L.There were 21 patients in group of peripheral precocious puberty(PPP).Compared with the results before injection,the levels of LH were similar to the results of 30,60 and 90 minutes after LHRH injection.Compared with the result before injection,the levels of E2 and T were similar to the result of 60 minutes after LHRH injection.The peak levels of LH and FSH in two groups all focused in 30,60 minutes.Conclusions LHRH stimutation test is mainly based on the peak level of LH and the ratio of LH/FSH,the test can be simplified to examine the levels the of LH and FSH before the test and 30,60 minutes after injection as a basis for the clinical diagnosis.

ObjectiveTo investigate the electrocardiogram (ECG) characteristics of patients with early repolarization variant (ERV).Methods One hundred and six patients diagnosed of ERV based on clinical and ECG and the healthy control group of 100 patients were analyzed and ECG features and ERV site were compared between these two groups.Results The mean heart rate( [ 68.6 ± 8.4 ] beats/min vs [ 74.8 ± 12.6 ]beats/min),QRS time( [95 ± 10] ms,[96 ± 11] ms vs[ 388 ± 12 ] ms,[379 ± 14]ms),QT dispersion and Tp-Te ( [ 80.4 ± 7.6 ] ms vs [ 78.5 ± 8.3 ] ms) were compared respectively between ERV group and control group and there was no significant difference (P ＞ 0.05).The occurrence of J wave in inferior leads was 67.9％,15.1％for the side wall leads,and 17.0％ for the chest leads,thus inferior wall leads had higher incidence than other hads relativelv in ERV ( P ＜ 0.01 ).Conclusion ERV exhibits more occurrence in inferior wall leads.

Objective: To evaluate the diagnostic performance of conventional ultrasound, compression elastography (CE) and acoustic radiation force impulse imaging (ARFI) in diff erential diagnosis of benign and malignant breast tumors. Methods: A total of 98 patients with liver lesions were included in the study. The images of conventional ultrasound, CE and the values of virtual touch tissue quantiifcation (VTQ) of breast lesions were obtained. hTe diagnostic performance of conventional ultrasound, CE and ARFI were assessed by using pathology as the gold standard, and then evaluate the diagnosis effciency of these three approaches in differential diagnosing benign and malignant breast tumors. Results: The specificity, sensitivity and accuracy in the diagnosis of malignant breast tumors for conventional ultrasound were 80.0%, 81.1% and 81.7%, respectively, whereas for CE elastic score were 85.7%, 86.7% and 86.3%, respectively. With a cutoff value of 3.71 for the SR, the sensitivity, speciifcity, accuracy in diagnosis of malignant breast tumors were 97.1%, 83.3% and 88.4%, respectively. With a cutoff value of 3.78 m/s for VTQ, the sensitivity, speciifcity, accuracy in diagnosis of malignant breast tumors were 94.3%, 91.7% and 92.6%, respectively. The difference in diagnosis efficiency among ARFI, CE and conventional ultrasound in differential diagnosis of benign and malignant breast tumors was signiifcant (P<0.05). Conclusion: Conventional ultrasound, CE and ARFI are all useful for the differential diagnosis of benign and malignant breast tumors. But the diagnosis effciency of ARFI is superior to CE and conventional ultrasound. The three approaches can help each other in differential diagnosis of benign and malignant breast tumors.

Objective:To explore the value of reading report in upbringing the integrated faculties of medical students.Methods:To give the training of reading report to the Seven-year and the five-year program medical students in their last year.Results:Such a training stirred the students' learning interests,improved their abilities in independent study,promoted their ability in collecting and dealing with information and widened their knowledge.Medical students grasped of the essential methods in writing reading report,which settled the groundwork for research abilities in the future.Conclusions:Reading report writing is instrumental in de- veloping students' integrated faculties and worthy advocating in medical teaching.

Objective To evaluate the effect of hypoxic-ischemic time on reduction of hypoxic-ischemic brain injury by sevoflurane postconditioning in neonatal rats.Methods Two hundred and ten 7-day-old Sprague-Dawley rats (105 male,105 female),weighing 13-17 g,were randomly divided into 7groups (n=30 each) using a random number table:sham operation group (group Sham),hypoxia-ischemia group (group HI),and sevoflurane postconditioning at different hypoxic-ischemic time point groups (P0,P3,P6,P 12 and P24 groups).Immediately after ligation of the left common carotid artery,and at 3,6,12 and 24 h after ligation,the rats inhaled the mixed gas containing 2％ sevoflurane for 30 min in P0,P3,P6,P13 and P24 groups,respectively.The fatality was recorded within 7 days after establishment of the model.At 7 days after establishment of the model,the rats were sacrificed,the brains were removed,and the right and left cerebral hemispheres were weighed separately,and the left/right cerebral hemisphere weight ratio was calculated.The hippocampal CA1 region and posterior cingulate gyrus were isolated,and the ratio of density of normal neurons in the left to the right was calculated.Results Compared with group Sham,the left cerebral hemisphere weight,left/right cerebral hemisphere weight ratio,and ratio of density of normal neurons were significantly decreased,and the fatality rate was increased in the other six groups (P＜0.05).Compared with group HI,the left cerebral hemisphere weight,left/right cerebral hemisphere weight ratio,and ratio of density of normal ncurons were significantly increased in P0,P3 and P6 groups (P＜0.05),and no significant change was found in the parameters mentioned above in P12 and P24 groups (P＞0.05).Compared with group P6,the left cerebral hemisphere weight,left/right cerebral hemisphere weight ratio,and ratio of density of normal neurons were significantly increased in P0 and P3 groups (P＜ 0.05).There was no significant difference in the parameters mentioned above between group P0 and group P3 (P＞0.05).Conclusion Sevoflurane postconditioning performed within 6 h of hypoxia-ischemia can reduce hypoxic-ischemic brain injury,and it provides no cerebral protection if exceeding 12 h.