Irwin Walter Scopp

Subcellular Distribution of NADH Cytochrome c Reductase in Rat Gingiva

NADH cytochrome c reductase has been reported in liver nuclei inner and outer mitochondrical membranes, microsomes, and in the soluble fraction (BEREZNEY, Biochem Biophys Res Commun 38:93, 1970; ERNSTER, FEBS (Symposium 17): 5, 1969; MACLENNAN, Biochem Biophys Acta 131:59, 1967). NADH cytochrome c reductase activity in gingival homogenates was found to be insensitive to rotenone, amobarbital, and antimycin A at concentrations that completely inhibited heart mitochondria (FINE, unpublished results). This suggested that the enzyme might be associated with the outer mitochondrial or other subcellular gingival components. Rat gingival specimens from three young (150 gm) and three adult (300 gm) groups (ten rats per group) were homogenized in 0.25 M sucrose-i X 10-3 M ethylenediaminetetraacetic acid (EDTA), pH 7.4. The homogenates (fraction A) were fractionated by a modification of the method of Schneider (J Biol Chem 183:123, 1950). Fractions were centrifuged at the following average gravity (g)time forces: 600 g-10 minutes,* 19.5 x 103 g-25 minutes, and 102 X 103 g-60 minutes.t NADH cytochrome c reductase, cytochrome oxidase (mitochondrial), and NADPH cytochrome c reductase (microsomal) were analyzed in each fraction. Activity was expressed as percentage of the total homogenate or as specific activity (nanomoles) of cytochrome c reduced or oxidized per milligram protein per minute). Cytochrome oxidase (WAINTO, J Biochem 216:349, 1951), NADH cytochrome c,

Germ-Tube Formation by Candida albicans

Germ-tube formation by Candida albicans has been reported as a significant factor in pathogenicity. Wide variation has been seen in the formation of germ tubes in saliva specimens obtained from both healthy and systemically ill individuals. However, germ tubes were found more frequently and in higher numbers in the saliva of diseased individuals.