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Biomedical subjects

D K Ford

Publications and source records attributed to D K Ford.

At least 73 records · Page 4Linked to original sources
PubMed1967

Influence of urea on the growth of T-strain mycoplasmas.

T-strain mycoplasmas require urea for propagation, but urea metabolism also occurs in nonpropagating viable cultures. Ammonia results from this metabolism and alkalinizes the medium. Ammonium ions and an alkaline pH both inhibit the multiplication of T strains and reduce the viability of T strains in broth. These toxic effects of urea metabolism currently limit the growth of T strains in broth. Stock T-strain cultures are optimally maintained in continuous culture if the routine medium at pH 6.0 is supplemented with 0.05% urea and 0.002% phenol red, but an incubation temperature of 30 C is preferable to 37 C for subculture at 24-hr intervals.

Ammonia↗
PubMed1962

CULTURE OF HUMAN GENITAL "T-STRAIN" PLEUROPNEUMONIA-LIKE ORGANISMS.

Ford, Denys K. (University of British Columbia, Vancouver, Canada). Culture of human genital "T-strain" pleuropneumonia-like organisms. J. Bacteriol. 84:1028-1034. 1962.-The conditions under which "T-strain" pleuropneumonia-like organisms, as described by Shepard, are best cultured were investigated. The organisms were found to grow on several types of nutrient agar and broth, of which PPLO medium supplemented with yeast extract and horse serum was the simplest. Subculture was possible through broth cultures, provided the broths were not incubated longer than 16 hr. The organisms on agar required either Fortner's anaerobic atmosphere or 10% CO(2), but broth cultures grew aerobically. "T-strains" grew over a pH range of 6.8 to 7.8, and a temperature range of 30 to 36 C. They were viable after storage for 16 days at 4 C and for 90 days at -20 C, and they resisted lyophilization. They were sensitive to 1.5 mug per ml of tetracycline and streptomycin, but were resistant to ampicillin and penicillin. Quantitative studies showed maximal concentration in broth of 10(6) to 10(7) organisms per ml, and logarithmic multiplication for the first 12 hr of broth culture, with a subsequent rapid decline in number. Colonial morphology was maintained after numerous subcultures.

Journal Article↗
PubMedDate not supplied

Serum antibody levels against T mycoplasmas in two North American Indian populations predisposed to spondylitis.

Serum antibody levels against T mycoplasmas (Ureaplasma urealyticum) were determined by the metabolic inhibition method in several populations. A higher prevalence of antibody was found in Haida Indians and Bella Coola Indians than in blood donors, patients with rheumatoid arthritis, and patients attending a VD clinic. Antibody levels did not correlate with the presence of spodylitis or the histocompatibility antigen HLA-B27, although both these Indian populations have a high prevalence of spondylitis and HLA-B27.

Antibodies, Bacterial↗
PubMedDate not supplied

Yersinia-related arthritis in the Pacific Northwest.

Serologic evidence of Yersinia enterocolitica infection was sought by agglutination testing in serum samples from several populations, including Haida Indians, Red Cross blood donors, and Caucasian patients with rheumatoid arthritis, ankylosing spondylitis, and Reiter's syndrome. No evidence was found to indicate that yersinial infection was etiologically related to Haida spondylitis or Reiter's syndrome. Four of 28 patients with acute arthritis were diagnosed from serologic evidence as having Yersinia-related arthritis.

Adult↗
PubMedDate not supplied

Cell-mediated immune responses of synovial mononuclear cells in Reiter's syndrome against ureaplasmal and chlamydial antigens.

Cell-mediated immune responses of cultured synovial mononuclear cells against ureaplasmal, chlamydial, Mycoplasma hominis and mumps antigens were measured by the 3H-thymidine uptake method. Specific responses against ureaplasmal or chlamydial antigens were found in 3 of 4 patients with venereally-acquired Reiter's syndrome, but not in 3 patients with arthritis after episodes of diarrhea and 4 patients with rheumatoid arthritis.

Adult↗
PubMedDate not supplied

The specificity of synovial mononuclear cell responses to microbiological antigens in Reiter's syndrome.

Statistical assessment has been made of synovial mononuclear cell responses to ureaplasma, chlamydial, enterobacteriaceae and mumps antigens in 16 cases of sexually transmitted Reiter's syndrome, 8 cases of enteric Reiter's syndrome and 12 cases of rheumatoid arthritis. These 3 groups of patients can be differentiated by synovial mononuclear cell responses to these microbial antigens and the microbiological origin of the arthritis in Reiter's syndrome can probably be suggested by this investigative approach.

Adult↗
PubMedDate not supplied

Cell-mediated immune responses of synovial mononuclear cells to sexually transmitted, enteric and mumps antigens in patients with Reiter's syndrome, rheumatoid arthritis and ankylosing spondylitis.

3H-thymidine uptake responses by synovial mononuclear cells to stimulation with sexually transmitted, enteric and mumps antigens were studied in 12 patients with "sexually transmitted Reiter's syndrome", 5 with "enteric Reiter's syndrome", 5 with rheumatoid arthritis, 4 with ankylosing spondylitis and 10 with "indolent arthritis of one knee." The "sexually transmitted" and salmonella cases were distinguishable by the responses. Synovial responses were sometimes marked when peripheral blood responses were negligible.

Adolescent↗