Objective This study aimed to investigate the effects of angiotensin Ⅱ and Losartan pretreatment on regulating insulin secretion in human islet ? cells.Methods We measured changes in intracellular calcium by confocal laser scanning microscopy using Flou3-AM-loaded human islet cells.RT-PCR was used to measure changes in intracellular CaM.Dynamic insulin secretory responses were determined by chemiluminescence following perfusion of human islets.Results Exposure of the isolated islets to angiotensin Ⅱ induced glucose-stimulated insulin release coupled with intracellular calcium ascending in first phase and descending in second phase.Intracellular CaM concentration could not be affected by angiotensin Ⅱ.Conclusion The change of free Ca2+is induced by the combination of AngⅡ with ATI receptors of islet B cells,which results in the damage to islet B cells.Losartan pretreatment protects the islet B-cell function by inhibiting calcium overload.

Objective To examine the effects of mixed infusion of mesenchymal stem cells(MSCs) and bone marrow cells(BMCs) in the induction of chimerism and islet allograft tolerance.Methods BALB/C mouse was used as the recipient and C57BL/6 mouse was as the donor.BALB/C mice were rendered diabetic via injection of streptozotocin.The islet cells of donor mice were transplanted into the recipient mice under the capsule of kidney.Rat anti-mouse CD154 mAb was intraperitoneally injected to the recipient mice.All of recipient mice(n=25) were then randomly divided into five groups: A group(received nothing),B group(donor MSCs),C group(donor BMCs),D group(donor BMCs and MSCs) and E group(donor BMCs and the third strain-derived MSCs).The chimerism level of donor cells and the survival time of islet grafts were compared among these five groups on 7,30d and 60d after transplantation.Results On 30d and 60d after islet transplantation,the chimerism levels of donor cells in D and E groups,in which the recipient mice received the mixed infusion of MSCs and BMCs,were significantly higher than that in C group,in which the recipient mice received BMCs infusion only,and the survival time of islet graft prolonged from 53.0?16.4d to 77.0?7.7d and 61.0?2.2d,respectively(P

To study the abnormality of the plasma concentration of ATRA in T1DM patients.T1DM patients(n=26),T2DM patients(n=33) and healthy people(n=30) were enrolled.The plasma concentration of ATRA was determined by HPLC.Compared with T2DM patients and healthy people,the concentration of ATRA increased significantly in T1DM patients.

Almost all multicellular organisms have a symbiotic relationship with prokaryotes in nature.In humans,the interaction between host and microbial flora is particularly important in the gastrointestinal tract.Technical and conceptual advances have enabled us to establish its role in human health and disease.Studies have shown that disorder of gut microbiota may participate in the development of metabolic diseases,such as obesity and type 2 diabetes.This review opens up new ideas to find strategies for modifying gut microbiota to impact on the occurrence of metabolic diseases.

Objective:To investigate whether superantigen SEB,with the assistance of APCs,could induce apoptosis of thymocytes in vitro,and to study the mechanism involved.Methods:SEB was given to thymocytes which were cultured together with APCs.Apoptosis was detected by DNA electrophoresis and DNA fragmentation assay.Expressions of Fas and FasL were detected by flow cytometry.Results:The thymocytes treated with SEB had the characters of apoptosis,and the apoptotic rate and expressions of Fas and FasL was significantly increased compared with control.Conclusion:SEB,together with APCs,can induce apoptosis of thymocytes in vitro,high expressions of Fas and FasL on thymocyte may participate in the mediation of apoptosis.This may provide a method to study the negative selection of thymocytes.

Objective To study the histopathological characteristics and the correlations between the cortical tissues from ictal discharge (ID) area and interictal epileptiform discharge (IED) area in epilepsy patients due to focal cortical dysplasia (FCD), in order to further discuss the mechanism of epileptogenicity. Methods Twenty-two subjects who underwent epilepsy surgeries consecutively in our institute since April 2005 to August 2006. All patients underwent intracranial electrode implantations and long-term video-EEG monitoring before the resective surgeries and the postoperative pathologies proved to be FCD. According the long-term EEG monitoring results, the cortex with intense IED and the cortex with ID onset were resected separatively in the operation for further histopathologic studies. Twenty cases were collected. Based on the Palimini' s pathologic subtype classification for FCD as well as quantificational scoring for immunocytochemistry for the calcium-binding protein parvalbumin (PV) which we designed by ourself, the specimens of IED and ID were studied and compared. Results The resected specimens from 20 cases were examed. ID specimens showed more severe abnormalities in the laminar cortical architecture, alterations in the morphology of neurons and in the appearance of abnormal balloon cells. With the PV quantificational scoring, we found significant difference between IED (6.4±2.1) and ID (4.4±1.8) from FCD Ⅱ specimens (P=0.042). No difference was found between ID subtypes (F=2.734, P=0.093 ). Conclusions ID cortical area showed more severe abnormalities in histopathologic changes than lED area. Our results suggested that the ID area of FCD had more severe damage in inhibitory synaptic circuits and neural networks, which meant it was more epileptogenic than IED. No difference was identified between each ID subtype in term of epileptogenicity, which meant all of them should be resected during the surgery.

Objective To explore the changes in angiotensin Ⅱ(AngⅡ)produced by Langerhan islets of Syrian hamsters after blockage of renin-angiotensin system(RAS)by different inhibitors.Methods Islet cells from Syrian golden hamster were isolated and purified,and angiotensin Ⅰ was added.The experiment was then divided into six groups:control group(PBS was added),captopril group,chymostatin group,aprotinin group,?-antitrypsin group,and captopril+chymostatin group(according to inhibitors added).The content of AngⅡ in supernatant was detected by enzyme-linked immunosorbent assay(ELISA).Results Compared with control group,the AngⅡ content decreased by 42.50% and 50.94% in captopril group and chymostatin group,respectively(P

Objective To investigate the effect of angiotensin Ⅱ(AngⅡ) and losartan on ? cells,and its related molecular mechanisms.Methods Normally cultured RIN-m cells were divided into three groups:control group(cultured with RPMI 1640 medium),AngⅡ group(treated with 100 nmol/L AngⅡ),losartan group(treated with 1 ?mol/L losartan 15min before addition of 100nmol/L AngⅡ).After incubation for another 48h,the apoptosis rate of RIN-m cells was quantified by flow cytometry(FCM) with Annexin-V FITC/PI dual staining.The expressions of Bcl-2 and Bax mRNA and protein were determined by RT-PCR and Western blotting,and the activities of Caspase 3 and Caspase 9 were detected by spectrophotometry.Results The apoptosis rate of RIN-m cells was significantly higher in AngⅡgroup than in both control and losartan group(P0.05).In comparison to the control group,the expressions of Bcl-2 mRNA and protein significantly declined,while of Bax mRNA and protein increased obviously in AngⅡ group(P0.05),but the expressions of Bcl-2 mRNA and protein were significantly higher(P0.05).Conclusion AngⅡ may induce the apoptosis of ? cells through mitochondrial pathway,and pre-intervention with losartan,which partly reverses the effect of AngⅡ,may play a protective effect on ? cells.

Objective To investigate the effects of injecting allogeneic mesenchymal stem cells(MSCs) on the cellular immunity in rat in vivo.Methods Bone marrow-derived MSCs were isolated from Wistar rats.The purity of MSCs was identified by morphological examination with microphotography,and the phenotypes were identified with flow cytometry.Twenty SD rats were randomly divided into 4 groups.Different concentrations of MSCs(5?106/ml for group A,5?105/ml for group B,and 5?104/ml for group C,respectively) and PBS(for group D) were given to allogeneic SD rats via intravenous infusions.The suppressive effect of MSCs on lymphocytes proliferation in recipient rat was analyzed using mixed lymphocyte cultures(MLR) 10 days after cultivation.At the same time,proportions of CD4+,CD8+ and CD4+CD25+/CD4+ T-lymphocytes in peripheral blood and spleen were analyzed with flow cytometry.Results Proliferation rate of splenic lymphocytes in group A(5?106/ml MSCs,8.58%?0.27%) was markedly lowered compared with that in group D(PBS,24.40%?5.21%,P

The teacher training of medical colleges has become a pressing task force.Young doctors should systematically study the educational theory,make positive observation,conduct teaching rounds and share experience,use the Internet,read the literature and pay attention to academic practice to improve clinical teaching ability.