Lipoteichoic acids in lactobacillus strains that colonize the mouse gastric epithelium

[This corrects the article on p. 302 in vol. 52.].     

Lipoteichoic acids in Lactobacillus strains that colonize the mouse gastric epithelium

Extracts of cells of 22 strains of Lactobacillus species, and of fluids from cultures in a defined medium of two of the strains, were assayed by hemagglutination inhibition for lipoteichoic acids. A total of 10 of the preparations gave positive tests for the acids, including those from eight strains known to adhere to the keratinized squamous epithelium of the mouse stomach. These findings are consistent with an hypothesis that lactobacilli colonize the epithelial surface via adhesive interaction with the keratinized cells mediated by macromolecular complexes containing lipoteichoic acids.     

Lipoteichoic acids in Lactobacillus strains that colonize the mouse gastric epithelium.

Extracts of cells of 22 strains of Lactobacillus species, and of fluids from cultures in a defined medium of two of the strains, were assayed by hemagglutination inhibition for lipoteichoic acids. A total of 10 of the preparations gave positive tests for the acids, including those from eight strains known to adhere to the keratinized squamous epithelium of the mouse stomach. These findings are consistent with an hypothesis that lactobacilli colonize the epithelial surface via adhesive interaction with the keratinized cells mediated by macromolecular complexes containing lipoteichoic acids.     

The effect of estrogen on the tubal epithelium of immature ovariectomized rhesus monkey (Macaca mulatta).

The effect of 3 doses of estradiol dipropionate (EDP) on tubal epithelium of immature ovariectomized rhesus monkey (Macaca mulatta) was studied under both light and electron microscopy. EDP at a dose of 5 microgram/kg/day for 6 consecutive days changed differentiation of the epithelial cells into clear and dark cell-types; ciliogenesis, formation of some ciliary buds and even a few cilia were also induced in some clear cells throughout the tubal epithelium. Development of ciliated cells with fully formed ciliary apparatus was accelerated at 10 microgram/kg dosage. The secretory granules (SG) appeared at this dose in some nonciliated cells of the infundibular and ampullary but not the isthmic segments of the tube; some of the infundibular secretory cells, so formed, exhibited even a tendency to secrete. Nearly complete maturation of the tubal epithelium occurred at 20 microgram/kg dose; further signs of secretory activity appeared in all tubal segments. The results indicated that--(i) Nearly complete transformation of tubal epithelium of the immature animal into one of the adult type could be achieved by EDP at a dose not less than 20 microgram/kg under the present conditions. (ii) The response of undifferentiated cells to EDP differed depending upon the location of the epithelial cell within the tube and nature of the cell-type to be formed. (iii) The mode of tubal secretion in this infra-human species was probably apocrine.     

Retinal pigment epithelium pigment granules stimulate the photo-oxidation of unsaturated fatty acids

The cellular pigments of the retinal pigment epithelium (RPE) have been shown to catalyze free radical activity, especially when illuminated with visible or ultraviolet light. This activity is sufficient to cause photooxidation of several major cellular components. The present investigation determined the relative ability of melanin, lipofuscin, and melanolipofuscin granules isolated from human and bovine eyes to oxidize polyunsaturated fatty acids, specifically linoleic and docosahexaenoic acids. The dark reactivity as well as the light-stimulated reactions were determined. The production of hydroperoxide derivatives of the linoleic and docosahexaenoic acids were determined by NADPH oxidation coupled to the activity of glutathione peroxidase, and also by production of thiobarbituric acid reactive substances. All RPE pigment granules stimulated fatty acid oxidation when irradiated with short wavelength (< 550 nm) visible light, with the melanosomes exhibiting the greatest light-induced activity. Only lipofuscin granules, however, caused peroxidation of fatty acids in the dark. These findings provide additional support for the role of RPE pigments in "blue light toxicity" as well as indicating that accumulation of lipofuscin may contribute to increased photooxidation in the aging RPE.