For implanted electronic prostheses to function successfully in the deaf, residual spiral ganglion neurons are presumed to be necessary. Several studies have tried to determine the effects cochlear electrode implantation and electrical stimulation have on the neurons of the spiral ganglion. Little work has been published, however, on the trophic effects of electrical stimulation on cell survival after cochlear damage by ototoxicity. This report presents the results of an investigation to determine the effects of early intrncochlear electrical stimulation on spiral ganglion neuron survival after chemically induced deafness in young guinea pigs. A significantly larger number of spiral ganglion cells remained in stimulated ears 6 weeks after deafening than were seen in the unstimulated ears of the same animals. These results suggest that early implantation after acquired deafness may affect the success obtainable with electronic hearing prostheses.
A modified American Optical (Model 100) CO2 laser was used to produce lesions in the tympanic membranes, ossicles, and cochlear capsules of guinea pigs. Even with the lowest available intensities and durations (0.4 watts, 50 msec), there was damage to the inner ear. Although laser surgery of the ear can avoid mechanical trauma and bleeding as well as increase accuracy, the use of commercial lasers in ear surgery should be avoided until a proven unit is available.
The lipid from an anaerobic organism provisionally designated Bacteroides symbiosus was found to contain D-galactose. Alkaline hydrolysis of the lipid yielded a new glycerol galactoside, specific rotation -73°, with a crystalline hexabenzoate, mp 133-134°, specific rotation -6°. The properties of the new galactoside indicate it to be a 1-glycerol ß-D-galactofuranoside. This appears to be the first recorded recognition of a naturally occurring galactofuranoside.An anaerobic organism provisionally designated Bacteroides symbiosus is consumed in quantity by Entamoeba histolytica during amebal growth in the Shaffer-Frye culture systems (Shaffer, 1952;Reeves et al., 1957). Our interest in determining the lipid requirements for amebal growth led to a study of the composition of the bacterial lipid. This report deals with the finding of a new glycerol galactoside in the lipid.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.