Objective To explore the relationship between plasma amyloid-β(Aβ)and cognitive impairment.Methods A total of all villagers(aged 40 years and above)from two villages of Xi'an,China,were enrolled.A validated Chinese version of the Mini-Mental State Examination and neuropsychological battery were used to assess cognition.Levels of fasting plasma Aβ1-42 and Aβ1-40 were tested using commercial enzyme-linked immunosorbent assay(ELISA).Relationship between plasma Aβ and cognitive impairment was analyzed using Logistic regression analysis.Results Of the 1 314 enrolled subjects,1 180(89.80％)had normal cognition,85(6.47％)had suspected cognitive impairment,and 49(3.73％)had probable cognitive impairment.Univariate analysis showed that plasma Aβ1-42/Aβ1-40 ratio was higher in the suspected cognitive impairment group than in the probable cognitive impairment group(P＜0.05)and normal cognitive group(P＜0.05);plasma Aβ1-42 level in the suspected cognitive impairment group was higher than that in normal cognitive group(P＜0.05).The level of Aβ1-40 did not differ between the three groups.After correcting for confounding factors(including age,gender,degree of education,cognitive impairment risk factors,habits of living)in the multivariate Logistic regression analysis,the results were consistent with those in the univariate analysis.Conclusion Levels of plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio were elevated in patients with suspected cognitive impairment,indicating that elevated plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio may be more pronounced in early stage of cognitive impairment.They may be early biomarkers for cognitive impairment,which can help identify and intervene the disease earlier.

Objective To explore the relationship between plasma amyloid-β(Aβ)and cognitive impairment.Methods A total of all villagers(aged 40 years and above)from two villages of Xi'an,China,were enrolled.A validated Chinese version of the Mini-Mental State Examination and neuropsychological battery were used to assess cognition.Levels of fasting plasma Aβ1-42 and Aβ1-40 were tested using commercial enzyme-linked immunosorbent assay(ELISA).Relationship between plasma Aβ and cognitive impairment was analyzed using Logistic regression analysis.Results Of the 1 314 enrolled subjects,1 180(89.80％)had normal cognition,85(6.47％)had suspected cognitive impairment,and 49(3.73％)had probable cognitive impairment.Univariate analysis showed that plasma Aβ1-42/Aβ1-40 ratio was higher in the suspected cognitive impairment group than in the probable cognitive impairment group(P＜0.05)and normal cognitive group(P＜0.05);plasma Aβ1-42 level in the suspected cognitive impairment group was higher than that in normal cognitive group(P＜0.05).The level of Aβ1-40 did not differ between the three groups.After correcting for confounding factors(including age,gender,degree of education,cognitive impairment risk factors,habits of living)in the multivariate Logistic regression analysis,the results were consistent with those in the univariate analysis.Conclusion Levels of plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio were elevated in patients with suspected cognitive impairment,indicating that elevated plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio may be more pronounced in early stage of cognitive impairment.They may be early biomarkers for cognitive impairment,which can help identify and intervene the disease earlier.

Defensin is a cysteine-rich, low molecular weight and cationic antimicrobial peptide. Human breast milk con-tains high level of defensin. The defensin in human breast milk can not only inhibit the growth of various pathogenic microorgan-isms, but also promote the development of infant immune system and reduce the incidence of infantile upper respiratory infection. Nowadays, the roles of defensin in breast milk is more recognized. This paper focuses on the molecular characteristics of human defensin, its antibacterial and antiviral roles, and the latest progress in defensin research.

ObjectiveTomonitorthehighriskbehaviorsandotherAIDS/STIrelatedfactorsamongmenwhohavesexwithmen(MSM),especiallymalehomosexualsinmainlandChina.MethodsSelf-administratedanonymousmailsurveyswerecarriedoutin2001,andanalyzedwithSPSS.ResultsOnethousandonehundredandnineeffectivequestionnaireswerecollectedfrom30provincesandcities.MostofMSMlivedinbigormedi-um-sizedcities,havinggoodeducation,andbeingyounger.Thenumbersofsamegendersexpartnersweremorethanone.Theyoftenhadcasualsexpartnersandunprotectedintercourse.Inthelastyear,11.45%reportedhavingbeendiagnosedSTI.AmongMSMwhohavebeentestedforHIVantibody,5.45%oftestswerepositive.ConclusionsWhileSTIratehasbeenreachingahighlevel,MSMwithSTIalsohavebeeninfectedwithHIVintheMSMofmainlandChina.OthergroupshavingsexwithMSMareatgreaterriskofSTI/HIVinfection.ItisinurgentneedtopreventandcontrolSTI/AIDSinMSM.