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Biomedical subjects

R J Lesher

Publications and source records attributed to R J Lesher.

8 recordsLinked to original sources
PubMed1988

Outbreak of hypersensitivity pneumonitis in an industrial setting.

Symptoms consistent with hypersensitivity pneumonitis developed in several workers in two multistory buildings in an industrial complex. A health questionnaire survey was conducted to determine the extent of the problem. Eighty-seven percent of the population of 1050 employees completed the health questionnaire. Serological testing identified 152 positive precipitin reactors to the fungus Aureobasidium pullulans; 115 reactors were symptomatic. The clinical and laboratory features at the time of the acute illness and during four years of follow-up are described. The agent, A pullulans, was identified as a contaminant of the heating-cooling ventilation units containing open waterspray chambers. Control was accomplished by replacement of the ventilation systems. A secondary source of antigen was found to be corrugated cardboard. Some sensitized employees required removal from work exposure to corrugated cardboard to prevent recurrent symptoms.

Adult↗
PubMed1985

Enteritis caused by Pasteurella pneumotropica infection in hamsters.

Pasteurella pneumotropica was isolated in essentially pure cultures from the bowels of hamsters with enteritis 7 days after parturition. Newly received hamsters showed presence of P. pneumotropica in their nasal cavities but not in their uteri, lungs, spleens, or bowels.

Animals↗
PubMed1985

Comparison of fluorescent antibody, bacitracin susceptibility, latex agglutination, coagglutination, and API 20S for identifying group A streptococci.

A total of 200 beta-hemolytic streptococci, isolated from clinical specimens submitted to our laboratory, were identified as group A versus non-A using the fluorescent antibody technique (FA), bacitracin susceptibility (BBL, Difco, and Raven disks), SeroSTAT, Streptex, Phadebact, and the API 20S system. Of the 122 group A isolates, all methods except SeroSTAT and Phadebact yielded 92-99% agreement when compared with the Lancefield precipitin test. Phadebact yielded an 84% agreement and SeroSTAT changed from 83 to 98% after trypsinization. Numerous false positives were obtained and only FA (91%) and API 20S (96%) yielded better than 90% agreement on non-A identification when compared with the Lancefield test. The most false positives were obtained (45%) using the SeroSTAT reagents. Considering accuracy, our data suggests the FA technique to be the method of choice for identifying group A streptococci.

Agglutination Tests↗
PubMed1977

Bacteriolytic action of fluoride ions.

Bacillus subtilis, Neisseria subflava, and LYT coccus were found to undergo massive lysis after growth in media containing 0.01 to 10 mM NaF. When cells of these organisms were transferred from late-exponential-phase cultures to 0.02 M sodium phosphate buffer plus 0.1 M KCl, they underwent spontaneous autolysis. Cells grown in media with fluoride were more liable to autolysis, and walls isolated from them also showed enhanced autolytic sensitivity, even though added fluoride did not directly stimulate autolysins. Sporadic or partial lysis occurred in populations of Streptococcus sanguis and Streptococcus mutans BHT or LM-7 after growth in fluoridated media. Most bacteria that were tested did not undergo fluoride-induced lysis. However, cells of all test bacteria were found to have reduced amounts of peptidoglycan per unit of cell weight when grown in the presence of fluoride. Incorporation of labeled lysine or glucosamine into peptidoglycan (Park-Hancock residue) was stimulated, instead of inhibited, by fluoride. However, fluoride also stimulated the loss of radioactivity from Park-Hancock residues of cells that had previously incorporated labeled lysine or glucosamine. Thus, fluoride appeared to enhance peptidoglycan turnover, and this turnover reduced the peptidoglycan contents of all bacteria tested, but induced lysis in only those bacteria that normally have highly active autolytic systems.

Bacteria↗
PubMed1977

Chemically defined medium for Rothia dentocariosa.

A chemically defined medium for Rothia dentocariosa has been established. All strains tested, including the type strain, grew well in this medium. Rothia strains had a generation time of 3.5 to 4.0 h, with a yield of 62 mg (dry weight) per 100 ml after 72 h of growth in the chemically defined medium.

Actinomycetaceae↗