title: RNA-instructed DNA polymerase activity in a cytoplasmic particulate fraction in brains from Guamanian patients.
abstract: Nervous system tissues from a number of patients with idiopathic neurological disorders were examined for biochemical evidence of RNA tumor virus infection.  RNase-sensitive DNA polymerase activity was found in a cytoplasmic particulate fraction from two patients with Guamanian amyotrophic lateral sclerosis (ALS) but not in brains from two normal U.S. individuals.  The buoyant density of the enzyme-containing fraction was 1.16-1.18 g/ml and could be converted to a denser region of the gradient (1.24 g/ml) by treatment with the nonionic surfactant, Sterox.  The cation and detergent requirements for the endogenous RNase-sensitive DNA polymerase reaction were determined.  The early (5 min) endogenous reverse transcriptase product was analyzed by cesium sulfate gradient centrifugation.  RNase- and heat-sensitive RNA-DNA hybrids were detected in the product analysis of two ALS, one Parkinsonism-dementia (PD) brain, and two brains from asymptomatic Chamorros but not in brains from normal U.S. individuals and a number of patients with neuro-psychiatric disorders.  The DNA product was a 4.5S heteropolymer that hybridized more extensively to RNA extracted from the enzyme-containing pellet from PD brain as compared to a similar fraction from normal U.S. brain.  The DNA product appeared to be unrelated to Rausvher or visna virus 70S RNA as determined by RNA-[-3H]DNA hybridization.
mesh_terms: D000690:Amyotrophic Lateral Sclerosis / Q000201:enzymology*; D001344:Autopsy; D001921:Brain / Q000201:enzymology*; D001923:Brain Chemistry; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D003593:Cytoplasm / Q000201:enzymology*; D004247:DNA; D006801:Humans; D009693:Nucleic Acid Hybridization; D010300:Parkinson Disease / Q000201:enzymology*; D012313:RNA; D012194:RNA-Directed DNA Polymerase / Q000032:analysis*; D011925:Rauscher Virus / Q000032:analysis; D014316:Tritium; D014790:Visna-maedi virus / Q000032:analysis
chemical_list: D014316:Tritium; D012313:RNA; D004247:DNA; D012194:RNA-Directed DNA Polymerase