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.

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.

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

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 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 study the mechanism of tubular epithelial hypertrophy induced by high glucose.[Methods]Human tubular epithelium line HK-2 cells were cultured in DMEM/F12 medium containing 1 g/L glucose(normal control group),4.5 g/L glacose(high slucose group),and 1 g/L glucose+3.5 g/L mannitol(iso-osmia control group),respectively.The cells of every group after cultured for 24 h,48 h.and 96 h were collected.The mRNA levels of CTGF and p27~(kip) were detected by real-time PCR.The protein levels of CTGF and p27~(kip) were detected by Western blot.The cellular proliferative activities were observed by MTT.The total cellular protein contents were detected by Bradford method.The cell cycle process was analyzed by flow cytometry.The cells of every group after being cultured for 30 win,1 h,24 h,and 48 h were collected.The levels of phospho-ERK1/2 were detected by Western blot.Every step was repeated for 3 times.[Results]High slucose could significantly up-regulate the mRNA and protein levels of CTGF and p27~(kip),activate ERK1/2 signal conductive pathway in HK-2 cells,make more cells arrest in G1 phase,decrease cellular proliferative activities,increase total cellular protein content reflecting cellular hypertrophy.[Conclusion]CTGF is an important mediator of tubular epithelial hypertrophy induced by high slucose.The mechanism is that CTGF up-regulates the p27~(kip) expression through activating ERK1/2 pathway.Up-regulated p27~(kip) lead proliferative cell to be arrested in G1 phase and cause cellular hypertrophy.

Objective To explore the significance and correlation between MCP-1 and cardiovascular complication of diabetes. Methods 65 patients with diabetes and 64 patents with IGT and 60 healthy persons as control group are chosen from a population of 1231residents at Jiangnan community in Guangzhou city. Ultrasonic inspection of carotid artery was applied to the intimae media thickness (IMT),and the levels of-MCP-1 were detected by Elisa. Result There was significant difference in the levels of MCP-1 among the normal control group, IGT group and DM group (P=0.000).The levels of MCP-1 in IGT complicated with AS patients were significantly higher than that in IGT alone patients. The levels of MCP-1 in DM complicated with AS patients were significantly higher than that in DM alone patients. The levels of MCP-1 were positively correlated with IMT in these patients. A forward LR Logistic regression analysis showed that IMT was a dependent variable, gender, MCP-1 and age are independently correlated with IMT. Conclusion MCP-1 is correlated with diabetes and its cardiovascular complication and it may be served as the target of therapy.

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 investigate the effect of cilazapril on reactivit y of blood vessels in diabetic rats. 　Methods The mesenteric vessels of streptozotocin induced diabetic rats wer e perfused with Kreb-Ringer's solution in vitro,the mesenteric vessels reactivi ty of diabetic rats was measured by physiological recorder. 　Results The responsive continual time to norepinephrine was delay ed signific antly(9.4±3.1 vs 5.2±2.1,P<0.01) and the highest perfusion pressu re decrease significantly in diabetic rats(5.12±0.87 vs 7.81±0.92 kPa, P<0.01); When taken cilazapril showed no difference in these indexes in diabetic animal s.