Objective To investigate and analyze the epidemiological characteristics of epidemic hemorrhagic fever (EHF),and explore the causes and possible routes of transmission in Yingkou City for proposing prevention and control measures.Methods A case restropective investigation was done to all outbreak cases of EHF in Yingkou City,relevant epidemiological investigation,clinical examination and laboratory test were done.Search of case and new case were carried out in the population.Density of rats (night clip) and rate of rat infection (Hanta virus antigenemia) in the region of the epidemic area of EHF were investigated.Blood samples were collected,antibody of EHF was detected with enzyme linked immunosorbent assay (ELISA).The rat lung was detected virus antigen using immunofluorescence.EHF diagnosis was based on Diagnostic Criteria for Epidemic Hemorrhagic Fever (WS 278-2008).Results The results of the case study showed that a family of three was infected with the same disease in one month.It was a family cluster of EHF.Of the three cases,one case was Seoul virus (SEO) positive and showed infection for rattus type.Totally 54 human serum samples from the case search in key groups were tested.Two cases were seropositive with IgG,through epidemiological investigation,all people were healthy.On physical examination they had no symptoms such as viral infection with fever,fatigue,symptoms of three red and pains of EHF.Two cases were determined latent infection.The patient's living and health conditions were very poor.The floor of indoor was soil,all of the things were placed in chaos in this family,there were many signs of rats and rat holes in the yard,and there were several rat holes around the wellhead.Rat density surveillance showed that cloth clip 108 times,effective clamp 105 times,4 rats were captured,and the density of rats was 3.81％.The density of rats exceeded the national standard of no more than 1％ of the residential area.All the rats were Rattus norvegicus.Detection of lung antigen was negative in rats by immunofluorescence.Conclusions This event is a family cluster of EHF caused by Rattus norvegicus.Rodent prevention and control,improving family conditions and environmental management are essential measures for blocking of the disease transmission and infection controlling.

AIM:To determine the biological feature of circulating endothelial cells (CECs) in acute promye-locytic leukemia ( APL) patients before and after treatment , and to analyze the relationship between CECs and the clinical characteristics .METHODS: The CECs were sorted from peripheral blood by magnetic-activated cell sorting and then counted by 3-color flow cytometry.The cells were identified by immunofluorescence staining for the expression of CD 146, CD31, CD144, VEGFR-2, CD45 and CD133.The CECs were cultured in vitro, and the tube formation and colony-forming rate were determined .RESULTS:Increased quantity of CECs was observed in CD 34 positive group and group with WBC >10 ×109/L (P<0.05).The quantity of CECs had a significant difference among low risk , medium risk and high risk groups (P<0.05).The positive rate of CD133 and quantity of CECs significantly reduced in 32 APL patients when they gain complete remission after treatment (P<0.05).The amount of tube formation and colony-forming rate were significant-ly reduced after treatment (P<0.05).The ratio of CECs quantity from APL patients after treatment to that before treatment had a negative correlation with arsenic concentration in urine on day 7 during As2O3 treatment (P<0.05).CONCLU-SION:Accurately counting CECs may be helpful for evaluating prognosis and designing treatment strategy .