简介:TheundecapeptidesubstanceP(SP)wasshowntobeintimatelyinvolvedinboththestructuralandfunctionalaspectsoftheanteriorpituitary.Yet,inadditiontoitsinfluencesonhormonalsecretion,SPmaywellpossessmoreactionsinthismastergland.ThepresentstudywasfthereforeaimedtoinvestigatetheeffectofSPontheproliferationofratanteriorpituitarycellsinprimaryculture,ItwasfoundthatSPcoulddose-dependentlyincreasetheincorporationoftritiatedthymidine(3H-TdR)intoculturedanteriorpituitarycells.OthermammaliantachykininssuchasneurokininAandneurokininBhadsimilareffectbuttovaryingdegrees.TheequipotentanalogueofSP,Norleucine^11-SP(Nle^11-SP),alsoactedlikewise.withitsactionantagonizablebyspantide,aSPreceptorblocker.TofurthercharacterizethenatureofcellsresponsivetothechallengeofSP,immunocytochemicalstainingagainstS-100proteinandsomeadenohypophysealhormoneswasperformedaloneorplusautoradiography.TheresultsshowedthatthepercentageofS-100proteinimmunorectivecellswasapparentlyelevatedbytheaddtionofNle^11-Spfor48h,whichindicatesapreferentialproliferationoffolliculo-stellatecellsundertheregime.ThiswasconfirmedbyincreasesinimmunocytochemicalorautoradiographicallabellingindicesofanteriorpituitarySubstancePandanteriorpituitarycellproliferation.Cellstreatedsimilarly.Takentogether,TheseresultsrevealthatthetrophicactionofSPobservedpreviouslyinothertissuesisalsopresentatleastinculturedratanteriorpituitarycells.withrespondingcellsbeingpredominantlyfolliculo-stellatecellsastypifiedbyS-100proteinimmunoreactivity.Therefore,anintra-pituitarytrophicactionofSPinvivocouldbeanticipated.
简介:本文综述了在杀虫剂抗性中起重要作用的P450酶系研究的最新进展,内容包括:细胞色素P450酶系基因及其基因的表达与调控,P450介导抗性的分子基础。细胞色素P450表达表现出发育期,组织,品系特异性及可诱导性。P450表达的调控机制复杂,可能受顺式调控元件(如CYP6B1)或反式作用因子(如CYP6A1)或顺式,反式因子的共同调控(如CYP6D1),调控可能涉及转录增强的转录机制或mRNA稳定性增加的转录后机制。P450的超量表达是P450酶系介导抗性的主要机制,P450的氨基酸替换也可能在杀虫剂抗性中起作用。
简介:目的探讨P53家族新成员P73及P63在脑星形细胞瘤中的表达和在不同恶性程度中的表达变化.方法采用免疫组化方法检测61例不同恶性程度的星形细胞瘤P73及P63基因的表达情况,与置换一抗的空白对照组比较,并同时进行组间对照.结果P73与P63总的阳性表达率为31.15%和40.98%.组间对照:P73组3~4级与1~2级比较P<0.05,2~3级与1~2级比较P>0.05;P63组3~4级与1~2级比较P<0.01.,2~3级与1~2级比较P<0.05.结论P73及P6.3作为P53家族的新成员可能是候选的抑癌基因,且随着恶性程度的增加其表达越明显.
简介:cAMPmediatedsignalingmayplayasuppressiveroleinimmuneresponse.WepreviouslyfoundthatthecAMP-elevators(CTxand8-Br-cAMP)inhibitedIL-12,IL-la,IL-6geneexpression,butincreasedthetranscriptionallevelsofIL-10andIL-1RainLPS-treatedmurineperitonealmacrophages.ThepresentstudyexaminedapossiblemolecularmechanisminvolvedincAMPelevators-inducedinhibitionofIL-12p40expressioninresponsetoLPS.OurdatademonstratedthatcAMPelevatorsdownregulatedIL-12p40mRNAexpressionandIL-12pT0productioninmurineperitonealmacrophages.SubsequentstudiesrevealedthatcAMP-elevatorsblockedphosphorylationofp38MAPK,butdidnotaffecttheactivityofNF-κBbindingtoIL-12promoter(-136/-112).ThisisthefirstreportthatcAMPelevatorsinhibitLPS-inducedIL-12productionbyamechanismthatisassociated,atleastinpart,withp38-dependentinhibitionbycAMPsignalingpathways.
简介:Basedonwaveformdata,severalmethodstodeterminefocalmechanismsofsmallearthquakesweredevelopedsince1980.Kisslinger(1980)andJulian,Foulger(1996)proposedanapproachtodeterminesolutionbyusingamplituderatioofPandSwave.Schwartz(1995)devisedamethodtodeterminesolutionsbytheuseofpolaritydataandamplitudesofseismogramenvelopes.Amplitudesofshortperiodseismicwavespropagatinginaninhomogene-ousmediumaresensitivetothevariationinvelocityandQstructure.Nakamura,etal(1999)tookmediuminhomo-geneityintoaccountindeterminingfocalmechanismsofsmallearthquakesusingwaveformdata.Ifthelocationsofsmallearthquakesareconcentratedinasmallregion,wecanassumethattheraypathsfromtheeventstoagivenstationarealmostthesame.SoPandSwaveattenuationsareindependentofeventlocations.Inthiscaseitiscon-venienttodeterminefocalmechanismsoftheseeventsbyusingshortperiodPandSwavedataj.Focalmechanismsolutionsofsmallearthquakesin5regions,i.e.,Rongchang,Mabian-Muchuan,Ya¢an,BaoxingandMianzhu,whicharecoveredbytheChengduTelemeteredNetwork,areobtainedbyanalyzingthePpolarityandshortbodywaveamplitudedatarecordedinthenetworksince1992.AccordingtothemethodproposedbyGephartandForsyth(1984),basedonwelldeterminedfocalmechanismsolutionsin15sub-zonesofSichuanandYunnanarea,threeprincipalstresstensorss1,s2,ands3,insteadofaveragesofP,B,andTaxisofthesolutions,aredeterminedtorepresenttheregionalstressfielddistribution.
简介:Inthispaper,weshallestablishthateachweaksolutionofp-harmonictypesystemswiththegradientsbelowthecontrollablegrowthbelongsto,HldercontinuityspaceswithanyHlderexponenta∈[0,1).Furthermore,wecanobtainthatthegradientsofthecorrespondingweaksolutionsalsobelongtolocallyHldercontinuityspaceswithsomeHlderexponent.