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Biomedical subjects

R C Gordon

Publications and source records attributed to R C Gordon.

At least 37 records · Page 2Linked to original sources
PubMed1979

Evaluation of gentamicin and penicillin as a synergistic combination in experimental murine listeriosis.

The administration of a combination of penicillin and gentamicin to mice given an intraperitoneal challenge of a highly pathogenic strain of Listeria monocytogenes resulted in increased survival as compared with groups receiving penicillin alone or gentamicin alone or a control group that received no antibiotic. The median survival of animals that eventually died was no longer than in groups receiving single antibiotics and suggests that additional studies should be carried out to further investigate the possibility of synergism in animal models.

Animals↗
PubMed1976

Common childhood bacterial infections.

Acute bacterial infections are a common cause of pediatric visits to the emergency department. The diagnosis and treatment of pharyngitis, otitis media, pneumonia, urinary tract infection, acute bacterial lymphadenitis and gastroenteritis are reviewed. The authors propose the use of a limited number of antibiotic agents including penicillin, ampicillin, erythromycin, lincomycin, cephalexin, a sulfonamide and tetracycline to improve efficiency and quality of care and to allow physicians to become familar with the drugs' characteristics, indications, dosage and side effects.

Anti-Bacterial Agents↗
PubMed1976

Comparative in vitro studies of cinoxacin, nalidixic acid, and oxolinic acid.

Cinoxacin and nalidixic acid were found to be similar in in vitro activity against 138 Shigella isolates and somewhat less active than oxolinic acid on a weight basis. Cross-resistance developed when 10 shigellae were transferred on increasing amounts of the respective agent contained in Mueller-Hinton agar. Plate dilution studies of the effect of changes in agar pH on the minimum inhibitory concentration revealed that the antibacterial activity increased with decreasing pH. Protein binding investigations revealed a high degree of binding, with nalidixic acid > oxolinic acid > cinoxacin.

Culture Media↗
PubMed1976

Fecal indicator bacteria persistence under natural conditions in an ice-covered river.

Total coliform (TC), fecal coliform (FC), and fecal streptococcus (FS) survival characteristics, under natural conditions at 0 degrees C in an ice-covered river, were examined during February and March 1975. The membrane filter (MF) technique was used throughout the study, and the multiple-tube (MPN) method was used in parallel on three preselected days for comparative recovery of these bacteria. Survival was studied at seven sample stations downstream from all domestic pollution sources in a 317-km reach of the river having 7.1 days mean flow time (range of 6.0 to 9.1 days). The mean indicator bacteria densities decreased continuously at successive stations in this reach and, after adjustment for dilution, the most rapid die-off was found to occur during the first 1.9 days, followed by a slower decrease. After 7.1 days, the relative survival was TC less than FC less than FS, with 8.4%, 15.7%, and 32.8% of the initial populations remaining viable, respectively. These rates are higher than previously reported and suggest that the highest survival rates for these bacteria in receiving streams can be expected at 0 degree C under ice cover. Additionally, the FC-FS ratio was greater than 5 at all stations, indicating that this ratio may be useable for determining the source of fecal pollution in receiving streams for greater than 7 days flow time at low water temperatures. The MPN and MF methods gave comparable results for the TC and FS at all seven sample stations, with both the direct and verified MF counts within the 95% confidence limits of the respective MPNs in most samples, but generally lower than the MPN index. Although FC recovery on membrane filters was comparable results at stations near the pollution source. However, the results became more comparable with increasing flow time. The results of this study indicate that heat shock is a major factor in suppression of the FC counts on the membrane filters at 44.5 degree C. Heat shock may be minimized by extended incubation at 35 degrees C before exposure to the higher temperature.

Alaska↗
PubMed1975

Antimicrobial resistance of Shigellae isolated in Michigan.

Patterns of antimicrobial resistance were studied for 213 strains of shigellae isolated in rural and urban areas of Michigan by quantitative techniques: 66% of these organisms were resistant to ampicillin, tetracycline, cephalexin, or chloramphenicol or had multiple resistance to various combinations of these antibiotics. The incidence of resistant organisms was higher in the Detroit-Wayne County area, which is the most urban part of the state. Nalidixic acid and oxolinic acid were noted to be quite effective in vitro against shigellae and perhaps warrant further clinical study as potential agents for therapy of shigellosis, especially in view of the appearance of isolates with multiple resistance. Sulfamethoxazole alone was effective against only 62% of the Shigella isolates tested, but mixture with trimethoprim in a 20:1 ratio yielded a highly active in vitro combination.

Anti-Bacterial Agents↗
PubMed1972

Serum protein binding of the aminoglycoside antibiotics.

The binding of four aminoglycoside antibiotics by human serum was investigated under controlled conditions of physiological pH and temperature, by means of an ultrafiltration technique. No serum binding was demonstrable for gentamicin, tobramycin, or kanamycin, whereas streptomycin was 35% bound. Previous conflicting studies are discussed, and some of the pharmacological implications are considered.

Aminoglycosides↗