Objective To explore the risk factors for infantile hemangiomas with the emphasis on perinatal factors and socioeconomic and environmental status.Methods A questionnaire survey was carried out targeting mothers and their babies who admitted to the Department of Prevention and Health Care of China-Japan Friendship Hospital for registration from Jan.1st,2009 to Dec.31st,2011.Information gathered included maternal basic information,perinatal factors before and during pregnancy,and socioeconomic and environmental status.Photos and record of the position and size of the pathological change were taken once infantile hemangiomas were diagnosed.Univariate analysis and multivariate Logistic regression analysis were carried out to investigate the risk factors.Results One thousand nine hundred and ninety-eight questionnaires with detail information were collected,among which 94 infants were diagnosed with infantile hemangiomas (4.7 ％).It showed that maternal age≥ 30 (OR =2.687,95％ CI:1.615-4.472,P =0.000),multiple pregnancies (OR =1.730,95 ％CI:1.032-2.901,P=0.038),female infants (OR =1.855,95 ％ CI:1.187-2.899,P =0.007 ),threatened abortion ( OR =3.135,95％ CI:1.487-6.609,P =0.003),amniocentesis (OR =2.754,95 ％CI:1.278-5.938,P =0.010),family history of hemangiomas (OR =2.978,95 ％ CI:1.127-4.049,P=0.032) and video display terminals exposure ＞45 h/week (OR=3.166,95％CI:2.027-4.944,P=0.000) were closely associated with infantile hemangiomas development.Conclusions The elderly maternal age,multiple pregnancies,female infants,threatened abortion,amniocentesis and family history of infantile hemangiomas and long-time exposure of video display terminals might be the risk factors for infantile hemangiomas.

Exosomes are 40–100 nm nano-sized vesicles that are released from many cell types into the extracellular space. Such vesicles are widely distributed in various body fluids. Recently, mRNAs and microRNAs (miRNAs) have been identified in exosomes, which can be taken up by neighboring or distant cells and subsequently modulate recipient cells. This suggests an active sort-ing mechanism of exosomal miRNAs, since the miRNA profiles of exosomes may differ from those of the parent cells. Exosomal miRNAs play an important role in disease progression, and can stimu-late angiogenesis and facilitate metastasis in cancers. In this review, we will introduce the origin and the trafficking of exosomes between cells, display current research on the sorting mechanism of exo-somal miRNAs, and briefly describe how exosomes and their miRNAs function in recipient cells. Finally, we will discuss the potential applications of these miRNA-containing vesicles in clinical settings.