Connective Tissue CellsConnective TissueConnective Tissue DiseasesFibroblastsConnective Tissue Growth FactorMicroscopy, ElectronPlatelet-Derived Growth FactorCollagenSkinCells, CulturedAntigensMixed Connective Tissue DiseaseImmunohistochemistryRNA, MessengerAntigens, BacterialAntigens, NeoplasmAntigens, SurfaceAntigens, ViralGranulation TissueImmediate-Early ProteinsIntercellular Signaling Peptides and ProteinsAntigens, Protozoan