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Biomedical subjects

D Taylor-Robinson

Publications and source records attributed to D Taylor-Robinson.

At least 343 records · Page 19Linked to original sources
PubMed1981

Observations on the occurrence of mycoplasmas in the central nervous system of some laboratory animals.

Mycoplasma pulmonis was isolated from the brains of 6 (23%) of 26 mice which had a naturally-occurring respiratory infection with this mycoplasma, and from the brains of 6 (8%) of 71 mice which had been inoculated intranasally or intravenously. The incidence of natural infection was greater in older mice, but there was no obvious mouse strain difference except for higher incidence in athymic nudes. There was no evidence that the organisms passed the blood-brain barrier. Some isolations, especially from nudes, may have been extraneous contaminants, as these were fewer when the mouse skulls were sterilized with ignited methanol. M. pneumoniae was not isolated from the brains of 14 hamsters which had a respiratory infection after intranasal inoculation nor were ureaplasmas isolated from the cerebrospinal fluids of 12 marmosets with a natural oropharyngeal infection. The aetiology of M. pneumoniae encephalitis in man is discussed.

Age Factors↗
PubMed1981

Immunity to reinfection of the genital tract of marmosets with Chlamydia trachomatis.

Eleven marmosets inoculated intra-vaginally with either of 2 serotypes (D/E and H) of Chlamydia trachomatis developed a self-limited infection which persisted usually for 10-42 days. Animals re-inoculated on one or more occasions were, however, infected generally for a shorter duration, usually 3-7 days. Curtailed infections were observed after re-inoculation with either the same or a different serotype, indicating that immunity was not serotype specific but cross-protective. IgM and/or IgG chlamydial antibody, measured by micro-immunofluorescence, developed in most of the marmosets on primary infection and was not serotype specific. The antibody titres were boosted on re-infection and there was a correlation between pre-existing high antibody titres and infections of short duration. Chlamydial infection of the genital tract was accompanied by acute inflammation which persisted in about half of the immune animals for up to several weeks despite rapid clearance of the organisms. These features of the experimental infection should help to provide a greater understanding of the immunobiology and pathogenesis of chlamydial genital-tract infections of humans.

Animals↗
PubMed1981

Mycoplasmal adherence with particular reference to the pathogenicity of Mycoplasma pulmonis.

Various eucaryotic cells adhere to colonies of some mycoplasmas (adsorption). The chemical nature of the receptors on the cells is not the same for all mycoplasma species, nor are the binding sites on different mycoplasmas the same. Some receptors comprise sialic acid, but in the case of Mycoplasma pulmonis, for example, attachment to cells is not mediated in this way. Nevertheless, adherence seems to be an important factor in the pathogenicity of this mycoplasma. Strain JB caused pneumonia in mice when inoculated intranasally, and colonies of this strain on agar absorbed erythrocytes (hemadsorption) strongly. After multiple passes in mycoplasma liquid medium, the strain lost its hemadsorbing capacity and also its mouse virulence, suggesting that the ability to attach to cells is virulence factor. Examination by electron microscopy of the virulent mycoplasma and its induced avirulent form after ruthenium-red staining showed that the stain was less thick on the surface of the avirulent form. In addition, the protein pattern of the avirulent mycoplasma, demonstrated by polyacrylamide gel electrophoresis, was deficient in three bands. These observations suggest that a glycosylated protein may form the binding site on M. pulmonis organisms that mediates their attachment to cells.

Adhesiveness↗
PubMed1981

Recovery and identification of human genital tract mycoplasmas.

Implicit in the optimal isolation of mycoplasmas from the genitourinary tract is the taking of 1) appropriate specimens, along with 2) an understanding and avoidance of the toxicity of certain swabs and antiseptics. Specimens should be 3) transported without undue delay, particularly if quantitative estimations are to be made, and 4) diluted serially in 5) supportive medium or media. The mere fulfillment of a particular medium formulation, however useful the medium is reported to be, is unlikely to lead to success without constant trial and error. The color-change technique, based in the case of ureaplasmas on the metabolism of urea, revolutionized the isolation of these organisms, and is used for other mycoplasmas too. Specific identification may be accomplished by one or more of several techniques, but usually growth inhibition on agar for large-colony-forming mycoplasmas, and metabolism inhibition for ureaplasmas.

Bacteriological Techniques↗
PubMed1981

Urogenital mycoplasma infections of man: a review with observations on a recently discovered mycoplasma.

Ureaplasma urealyticum organisms (ureaplasmas), Mycoplasma hominis, M. fermentans, M. primatum, M. Salivarium and M. pneumoniae have been isolated from the genitourinary tract. The first two of these microorganisms are found most frequently. M. hominis is a cause of some cases of postpartum and postabortal fever, acute pyelonephritis and pelvic inflammatory disease. Ureaplasmas have been associated with chorioamnionitis, habitual spontaneous abortion, low birthweight, the urethral syndrome in women, and nongonococcal urethritis (NGU) in men; but the difficulty of proving an etiological relationship is emphasized. However, in NGU there is accumulating evidence to indicate that ureaplasmas cause some cases. Some patients suffering from NGU, from whom ureaplasmas, mycoplasmas and chlamydiae cannot be isolated, respond to tetracycline therapy. This has suggested that a tetracycline-sensitive microorganism might be responsible. In this context, the isolation of a glucose-metabolizing mycoplasma from the genitourinary tracts of 2 of 13 men with NGU is of interest. This mycoplasma, serologically different from all other tested, has the structural and biological features of a pathogenic organism.

Abortion, Habitual↗
PubMed1981

Mycoplasmal arthritis in man.

Naturally occurring mycoplasmal arthritis in various animals species and the ability to induce mycoplasmal arthritis experimentally have been the main reasons for searching for evidence of mycoplasmal infection in the joints of patients with rheumatoid arthritis. However, reliable reports of the isolation of mycoplasmas from synovial fluids and tissue of such patients do not exist, and measurements of specific antibodies have not proved rewarding. There is some evidence that infection by Mycoplasma pneumoniae occasionally has an arthritic sequela, although the microorganism has not been isolated from the joints of immunocompetent patients. In contrast, this and other mycoplasmas, including ureaplasmas, have been isolated from the arthritic joints of several hypogammaglobulinemic patients, and there is some evidence to indicate that the organisms are responsible for the disease. A relationship between mycoplasmas and sexually acquired Reiter's disease is unproven, but deserves thorough investigation in view of the link between ureaplasmas and nongonococcal urethritis. Furthermore, as new media and techniques become available, the possibility the mycoplasmas may have some role in rheumatoid arthritis should be reappraised.

Agammaglobulinemia↗
PubMed1981

Role of viable mycoplasmas in the pathogenesis of arthritis induced by M. pulmonis.

The role of viable M. pulmonis organism in the pathogenesis of both the acute and chronic phases of M. pulmonis-induced arthritis was examined. In the acute phase of the arthritis most clinically involved joints contained organisms and the degree of clinical arthritis in a given joint correlated with the number of organisms isolated. The more severe the acute arthritis, the more frequently the M. pulmonis organism was isolated from the joints during the chronic phase. In the chronic phase, arthritis defined histologically correlated with the presence of M. pulmonis organisms within a given joint. No correlation was observed between clinical arthritis during the chronic phase and histopathology or the presence of M. pulmonis organisms within the joint. In chronically infected mice, M. pulmonis was isolated from the joints only but not from the blood, liver, spleen, lung or kidney of any mouse examined. The results support the concept that viable organisms play an essential role in the pathogenesis of the acute and chronic phases of M. pulmonis-induced arthritis in mice.

Animals↗
PubMed1981

Enhanced resistance of mice to Mycoplasma pulmonis-induced arthritis by administration of killed Corynebacterium parvum.

Inoculation of mice with Corynebacterium parvum 14 days before intraperitoneal inoculation of Mycoplasma pulmonis resulted in arthritis of significantly lesser magnitude than in control mice as measured both clinically and histologically. Mycoplasmas were isolated from the joints of mice inoculated with C. parvum less frequently than from control mice when the arthritis was maximal. Mycoplasmas were also isolated in smaller numbers from the blood and joints of mice pretreated with C. parvum within 2 hr after M. pulmonis inoculation. Complement-fixing antibody to M. pulmonis did not account for the differences observed. C. parvum given during an established mycoplasmal infection, although capable of enhancing elimination of M. pulmonis from the joints of infected mice, had no effect upon the arthritis as measured clinically or histologically. The results provide evidence that immunomodulators such as C. parvum are capable of enhancing elimination of mycoplasmas from the joints of infected mice prior to or after the induction of arthritis.

Animals↗
PubMed1980

Effect of T-cell deficiency on the chronicity of arthritis induced in mice by Mycoplasma pulmonis.

Mycoplasma pulmonis inoculated parenterally into athymic nude mice congenitally deficient in T cells caused a chronic arthritis of significantly greater magnitude than in immunologically normal mice. During the chronic phase of arthritis, M. pulmonis organisms were isolated from the joints and spleens of athymic nude mice more frequently and in larger numbers than from immunologically normal mice. The results support the concept that impaired T-cell function predisposes the mice to a severe degree of chronic arthritis as a result of their failure to eliminate the causative organisms.

Animals↗
PubMed1980

Evidence of Chlamydia trachomatis infection in sexually acquired reactive arthritis.

Thirty male patients with sexually acquired reactive arthritis (SARA) have been studied at the time of their initial presentation and thereafter. Chlamydia trachomatis was isolated from the urethral exudate of 9 (36.0%) of the 25 patients from whom urethral specimens were taken, and elevated titres of IgM antibody of C. trachomatis were detected in 11 (36.6%) of the 30 initial sera. Thirteen (43.3%) of the patients has a positive urethral culture and/or elevated titre of IgM antibody, and it is therefore suggested that 43.3% of these patients suffered an acute chlamydial infection at or near the time of the onset of their joint disease. The demonstration of 4-fold or greater rises and/or falls in IgM antibody titre (8 patients) and IgG antibody titre (6 patients) in a group of 15 men studied throughout the course of their disease strongly supports this conclusion. A positive urethral culture and/or raised titre of IgM serum antibody was also detected in 25 (50%) of 50 men with uncomplicated nongonococcal urethritis (NGU), suggesting that the prevalence of chlamydial infections in the 2 conditions is similar. Titres of IgG serum antibody to C. trachomatis were, however, significantly higher in patients with SARA than in those with NGU or other rheumatic diseases, and in healthy controls. The geometric mean titres (GMT) of IgG serum antibody in patients with SARA, NGU, rheumatoid arthritis, ankylosing spondylitis, systemic lupus erythematosus, and in healthy controls were 1:47.5, 1:8.6, 1:2.2, 1;2.2, 1:3.5, and 1:1.4, respectively. These findings suggest that an exaggerated antibody response to acute infection by C. trachomatis may be an important factor in the development of SARA in some but not all patients.

Antigens, Bacterial↗
PubMed1980

A comparison of the sensitivity of immunofluorescence and Giemsa for staining Chlamydia trachomatis inclusions in cycloheximide-treated McCoy cells.

In a clinical study of 190 men with non-gonococcal urethritis, Chlamydia trachomatis inclusions were sought in cycloheximide-treated McCoy cells by an indirect immunofluorescent antibody technique. The method was consistently reliable over a period of two years, and the results were obtained within 24 hours of a patient's attendance. The results correlated with those obtained by Giemsa staining in 91.6% of patients, and the new method was at least as sensitive as the established Giemsa-staining method.

Azure Stains↗
PubMed1980

Detection of Chlamydia trachomatis in rapidly produced McCoy cell monolayers.

The 24-hour delay between seeding coverslips with cells and inoculating samples for culture of chlamydiae was reduced to less than 1 hour by using coverslips which had been pre-treated with glutaraldehyde-activated gamma-aminopropyl-triethoxysilane. Treated coverslips were not toxic for McCoy cells and even one year after treatment monolayers formed rapidly on them. Furthermore, all of 13 Chlamydia trachomatis serotypes and one C. psittaci strain tested produced inclusions in such cell monolayers. In comparative tests, when there were large numbers of inclusions, more were always seen in conventionally produced monolayers than in monolayers on treated coverslips. However, when there were few inclusions, more were seen in the latter monolayers, a phenomenon observed with unpassaged chlamydiae in clinical specimens as well as in laboratory-passaged strains. The rapid method is, therefore, as sensitive for isolating chlamydiae as using conventionally produced monolayers.

Bacteriological Techniques↗