Regulatory T (Treg) cells exert significant influence on the control of autoimmunity and maintenance of homeostasis,while the progressive roles of Treg cells in solid tumor and hematological malignance have also attracted much attention recently.Except for the specific expression of transcription factor forkhead box protein 3 (Foxp3),natural Treg (nTreg) cells have Treg-specific hypomethylation pattern in a limited number of key genes,which is indispensable for stable Treg cells and functional nTreg cells to define the T-cell subpopulation possessing Treg-type epigenome more accurately.The expression of Foxp3 and Treg-specific hypomethylation phenotype have close relationship with the epigenetic regulation,which involves DNA methylation,histone methylation,acetylation,microRNA,etc.This review summarizes the different mechanisms of epigenetic regulation according to the two important features of Treg cells.

Post-transcriptional regulation of prokaryotes is of pivotal importance to the quality control and stability main -tenance of multiple proteins .The ubiquitin and ubiquitin-like proteins-mediated modifications have widely participated in the manipulation of cell cycle control , subcellular localization and cellular metabolisms .Typical ubiquitin like proteins (UBLs) are ubiquitin,SUMO,Nedd8 and FAT10.Recently, the dynamic regulation mechanisms between sumoylation and de-sumoylation have become the cutting edge in the era of ubiquitin-like modifications.In this review, we briefly summa-rized the entire SUMO-mediated modification systems and the intricate balance regulation .We also discussed the counter acting star molecule SENP1 and its relationship with tumor initiation and progression ,immunological regulation and develop-mental homeostasis .

Acute megakaryoblastic leukemia(AML-M7)is a rare neoplastic hematologic disorder,the pathogenesis is not clearly.Recent research has found many eytogenetic changes in this disease;and also some genes mutation,such as GATAI,p53,RUNXI play very important roles in AMKL.The aim of this article is to review the cytogenetic and molecule mechanism of acute megakaryoblastic leukemia.

Bone marrow-derived stem cells, mainly including hematopoietic stem cells, mesenchymal stem cells, multipotent adult progenitor cells, etc., are the most densely studied adult stem cells up to now. Recent findings indicate that adult stem cells have the potential to differentiate across lineage barriers and to adopt the expression profiles and functional phenotypes of cells unique to other tissues. This flexibility is termed "plasticity",which has posed challenges to conventional concepts. Meanwhile, it brings new hopes for the therapeutic application of cell engineering and tissue engineering. This review focuses on the biological features, the plasticity and its possible mechanisms, research method and potential clinical application of bone marrow-derived adult stem cells

Objective:To observe the effect of ischemic preconditioning(IP)on hepatocellular apoptosis caused by ischemia-reperfus ion(IR)injury and expression of apoptosis regulatory genes(Survivin,HIF-1?)protein,to explore the protective mechanisms of IP on IR injury in rat liver.Methods:Ninty SD rats were randomly divided into sham operation(SO)group,ischemia-reperfusion(IR)group,ischemic preconditioning(IP)group.In SO group,the hepatoduodenal ligament of rat was only pulled and separated,and then closed the abdomen;IR group subjected to 30 minutes of ischemia;IP group was achieved by ischemia for 5 minutes,followed by reperfusion for 5 minutes before continuous to ischemia for 30 minutes.Ten rats of each group were killed after reperfusion for 2,6,12,24 hours respectively,then liver tissues were taken out.The rats in SO group were killed after operation for 2 hours.To detect the Apotosis index(A)Iand Survivin,HIF-1? protein levels.Results:AI of hepotocytes significantly increased in IR group and IP group than that in SO group(P

Ventilator-associated pneumonia (VAP) is a common hospital acquired infection in neonatal intensive care unit with high incidence in China. There is no diagnostic gold standard of VAP. The risk factors include premature birth, low birth weight, dura-tion of mechanical ventilation, episodes of intubation, blood stream infections. The recommended precautions include rising head of bed, closed tracheal suction, sucralfate, selective decontamination in digestive tract, improvement of mechanical ventilation, oral and skin care, hand hygiene. However, it is controversial that sucralfate, selective decontamination in digestive tract, passive humidifiers, oral and skin care can reduce the incidence of VAP.

The root canal system of mandibular second molar is complex.This article presents one case with type 1-2 mesial root canal of mandibular second molar.The canal was treated by warm gutta percha,and conformed by X-ray examination and dental operating microscopy.

Objective To establish an in-vitro root canal-apical complex model for studying the mechanisms of the infected root canal to apical periodontitis and periapical biofilm .Methods Single rooted premolar extracted for orthodontic ,was sealed in sterile vial containing LB solid medium ,and the culture medium covered apical thirds .Totally 25 root canal-apical complex models were prepared .Five models were randomly selected for the bacteria detection in periapical by PCR at 1st day .The remained 20 models were randomly subjected to a control group(n=10) and experimental group(n=10) .Extracted teeth were opened in experimental group and control group with no treatment .All models were exposed in air .At 21st day ,bacteria were detected through PCR in root canal and apical;endotoxin content in apical was assayed by chromogenic end-point limulus test .Results In apical ,bacteria was not found in all groups ,but not for the experimental group .The mean endotoxin content was (8 .913 ± 0 .614)EU/mL in control group and (10 .525 ± 0 .981)EU/mL in experimental group .The endotoxin content was increased significantly in experimental group ,when compared with control group(P<0 .01) .Conclusion Root canal-apical complex was established in vitro through this method .Bac-teria was not easy to reach the apical when the infected root canal was not disturbed .Bacteria in the infected root canal caused apical periodontitis through the secretion of virulence factors such as endotoxin .

Cognitive function has become a hot spot in the field of epilepsy. However,the relationship between cognitive function and epilepsy has not been clearly demonstrated. Clinical trials have showed that epi-lepsy and epileptic relevant factors are both associated with cognitive function in children. Children with cogni-tive impairment are often caused by those two factors. This article focuses on cognitive function in children with epilepsy age below 6 years,and mainly reviews the characteristics of cognitive function in these children with epilepsy.