Biomedical subjects

C Gatewood

Publications and source records attributed to C Gatewood.

6 recordsLinked to original sources

PubMed1996

Differential effects of total and upper airway influenza viral infection on sleep in mice.

Sleepiness is a common perception during most infectious diseases, including viral infections. Previously, we observed that a lethal strain of influenza virus (H1N1) causes a greater increase in non-rapid eye movement sleep (NREMS) than a nonlethal strain of influenza virus (H3N2), suggesting that the magnitude of sleep responses after viral inoculation depends on the severity of the infection. The aim of the present experiment was to further test this possibility. The effects of total airway infection versus upper airway infection on sleep were tested in two groups of mice using the same strain of virus (H1N1). After 2-3 days of baseline sleep recordings. Swiss-Webster mice were infected intranasally with H1N1 influenza virus. Sleep was determined again for an additional 3 days and 6 hours. Total airway infection significantly increased NREMS beginning about 24 hours after the viral inoculation and significantly suppressed rapid eye movement sleep (REMS) with a longer latency. Both the increase in NREMS and the decrease in REMS lasted until the end of the experiment. Total airway infection also significantly decreased the body weight of the mice. In contrast, upper airway infection did not induce clear changes in sleep and body weight.

Animals↗

PubMed1983

Cytotoxicity of the bacterium Actinobacillus actinomycetemcomitans extracts in human gingival fibroblasts.

Filter-sterilized sonic extracts (SE) of strains of Actinobacillus actinomycetemcomitans were shown to inhibit the proliferation of human gingival fibroblasts in vitro. The inhibition was dose-dependent: a 50 per cent inhibitory dose of 2 micrograms protein/ml was found for A. actinomycetemcomitans strain Y4. The inhibitory activity could be neutralized by homologous antiserum and was heat inactivated by temperatures of 80 degrees C or greater. The fibroblast-inhibitory activity was present in SEs of both leukotoxic-producing and non-leukotoxic strains of A. actinomycetemcomitans, suggesting that a separate agent is responsible for leukotoxicity and fibroblast inhibition. A short (10 min) exposure of the fibroblasts to the A. actinomycetemcomitans SE was sufficient to inhibit irreversibly cell proliferation, provided that serum was present at the time that the cells were exposed to the SE. SE-challenged fibroblasts exhibited a marked decrease in the rate of DNA synthesis, but no inhibition of RNA or protein synthesis. Although the SE-treated cells did not proliferate, they appeared to remain intact and viable; and displayed no gross morphological alterations.

Actinobacillus↗

PubMed1979

Effect of medium temperature on recovery of gonococci.

The temperature of the isolation medium exerted no significant effect on the rate of positive cultures for Neisseria gonorrhoeae. However, significantly more colonies were obtained on ambient-temperature medium than on cold (4C) medium. A small number of specimens (six) failed to grow on cold medium but grew on ambient-temperature medium. Viable counts showed essentially no effect of medium temperature on the nondiscriminating strain, a 90% reduction on the cold medium for the cold-intolerant strain, and for the strains with warm medium preference, about twice as many colonies on warm as on cold or ambient-temperature medium.

Cold Temperature↗

PubMed1979

Simultaneous scabies and gonococcal infection.

A case is presented of an unusual complication arising in a man with scabies and gonococcal urethritis: the secondary infection of excoriated genital lesions by Neisseria gonorrhoeae. This occurred after he had occluded his genitals with a plastic wrap.

Adult↗

PubMed1977

Neisseria meningitidis in the anal canal of homosexual men.

Cultures were obtained from the oropharynx, urethra, and anal canal of 157 homosexual men. Neisseria gonorrhoeae was identified in 30 men (19.1%), Neisseria meningitidis in 32 men (20.4%), and Neisseria lactamicus and Branhamella catarrhalis in one man each. N. gonorrhoeae was isolated from the anal canal of three men (1.9%), and N. meninititidis was identified in the anal canal of seven men (4.5%). These findings suggest that confirmatory tests are indicated for homosexual males with rectal isolates presumptively identified as N. gonorrhoeae.

Anal Canal↗

PubMed1976

Combining cervical and rectal cultures for gonorrhea on a single modified Thayer-Martin plate.

Cultures of the cervix and rectum are recommended for the routine diagnosis of gonorrhea in women. Specimens are usually inoculated on separate plates of selective medium. The present study compares to the recovery rates of N. gonorrhoeae for cervical and rectal specimens plated separately to specimens combined on a single plate of modified Thayer-Martin medium (MTM). No statistically significant difference was detected between the two methods. It is concluded that the practice of combining cervical and rectal specimens on a single MTM plate provides the sensitivity of separately plated specimens at half the cost. Combining specimens could provide a significant cost benefit to gonorrhea control programs.

Bacteriological Techniques↗