PubMed Health⌕ Search

Biomedical subjects

J C Hubbard

Publications and source records attributed to J C Hubbard.

7 recordsLinked to original sources
PubMed1980

Non-specific incorporation of nucleic acid precursors in Blastomyces dermatitidis and Histoplasma capsulatum.

Incorporation of thymidine, thymidine monophosphate (TMP), thymidine triphosphate (TTP), uridine and orotic acid into DNA, RNA and protein in Blastomyces dermatitidis and Histoplasma capsulatum was studied utilizing a specific acid hydrolysis technique developed for these fungi. Thymidine was incorporated to the greatest extent (approximately 0.5% of added label) followed by uridine, orotic acid, TMP and TTP. In Blastomyces, uridine and orotic acid labeled primarily RNA. TMP and TTP labeled RNA, DNA and protein at nearly the same level. In Histoplasma RNA was labeled poorly by any of these precursors. TMP and TTP labeled DNA predominately and protein to a slightly lower level. Deoxyadenosine or uridine media supplements of 250 micrograms/ml did not enhance incorporation. All precursors tested were found to be nonspecific in that RNA, DNA and protein were labeled. All data indicate that neither RNA nor DNA synthesis can be specifically measured in whole cells or acid precipitates by any of these precursors. Specific radiometric monitoring with these isotopes therefore requires the separation of these macromolecules.

Animals↗
PubMed1978

In Vitro and In Vivo Activity of a Synthetic Halogenated Quinoline Against Cryptococcus neoformans.

The minimum inhibitory concentrations of a halogenated quinoline, 3-amino-7-chloro-3,4-dihydro-1-hydroxycarbostyril (CBS), against nine clinical strains of Cryptococcus neoformans were determined by in vitro testing. The CBS was fungistatic at a minimum concentration of 0.2 mug/ml at 48 h for several strains. In vivo toxicity studies were carried out in mice. Mice were also infected with C. neoformans strain Price and injected with various concentrations of CBS. Mean life expectancy of treated groups of animals was increased over infected untreated controls.

Journal Article↗
PubMed1971

Improved microscopy of Mycoplasma in vitro.

Techniques were developed for continuous microscopic observation of mycoplasmata growing in vitro in Rose chambers by using an inverted phase microscope. The methods permitted direct microscopic observation of undisturbed growth of mycoplasmata in liquid medium. Inocula of mycoplasmata were passed through 0.22-mum filters before culture to provide a suspension of discrete particles. The sequential growth of Mycoplasma pneumoniae was followed from points or single straight lines, with development of branching, a net-like confluence of filaments, large bodies occurring in the center of developing colonies, and finally coccoid forms. Other species of Mycoplasma which did not attach as readily to glass could be observed also by inverted phase microscopy. Umbonation of colonies (a "friedegg" appearance) occurred in liquid medium, indicating that this appearance was not due simply to interaction with the agar medium, but may reflect a qualitative difference in growth patterns between center and periphery. For growth on solid medium, direct observation of colonies in uncovered plates of agar medium was made by using inverted phase microscopy. This was found helpful in detecting small colonies and in observing relationships between colonies.

Agar↗