title: Surface fractal computation and its application to immunofluorescent histochemical studies of calpain and calpastatin in PC12 cells.
abstract: The purpose of this report is to present a method which can be used to parameterize patterns of immunofluorescent staining in cultured neural cells. The algorithm is based on the observation that the variance in pixel intensity of the image is a power function of the magnitude of the area in immunofluorescently stained PC12 cells. This property is used to derive the fractal dimension (D) of the region of interest (ROI), and corresponds to the complexity of the pixel intensity associated with the ROI, which is analogous to a fractal surface. We show that the measure is useful in characterizing immunofluorescent staining patterns, and apply this measure to study the effects of ethanol exposure on mu-calpain and calpastatin-associated immunoreactivity. Exposure of PC12 cells to ethanol (80 mM)x48 h resulted in alterations in immunofluorescent signal (Control vs ethanol) associated with actin, calpastatin and mu-calpain: 2289+/-166 vs 1709+/-69, P<0.01; 1681+/-38 vs 2224+/-95, P<0.001; 1823+/-39 vs 2841+/-68, P<0.0001 respectively, magnitudes being pixel intensity units on a scale of 0-4095. D-values for the three proteins in the same order were: 2.32+/-0.01 vs 2.31+/-0.03, NS; 2.31+/-0.01 vs 2.32+/-0.01, NS; 2.16+/-0.03 vs 2. 24+/-0.02, P<0.01, with a possible D-value range of 2-3.
authors.affiliation: Unit of Clinical and Biochemical Pharmacology, Laboratory of Clinical Studies, Division of Intramural Clinical and Biochemical Research, National Institute on Alcohol Abuse and Alcoholism, NIH, Bethesda, MD 20892-1256, USA. pbdp@helix.nih.gov
authors.forename: P B
authors.initials: PB
authors.lastname: DePetrillo
authors.forename: Q
authors.initials: Q
authors.lastname: Yang
authors.forename: J
authors.initials: J
authors.lastname: Rackoff
authors.forename: A
authors.initials: A
authors.lastname: SanMiguel
authors.forename: K
authors.initials: K
authors.lastname: Karimullah
mesh_terms: D000199:Actins / Q000378:metabolism / Q000648:ultrastructure; D000465:Algorithms; D000818:Animals; D002135:Calcium-Binding Proteins / Q000378:metabolism / Q000648:ultrastructure*; D002154:Calpain / Q000378:metabolism / Q000648:ultrastructure*; D000431:Ethanol / Q000494:pharmacology; D005455:Fluorescent Antibody Technique / Q000295:instrumentation / Q000379:methods*; D017709:Fractals; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D016014:Linear Models; D008856:Microscopy, Fluorescence / Q000295:instrumentation* / Q000379:methods*; D008954:Models, Biological; D016716:PC12 Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D051381:Rats
chemical_list: D000199:Actins; D002135:Calcium-Binding Proteins; D000431:Ethanol; C033668:calpastatin; D002154:Calpain