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Biomedical subjects

P H Hardy

Publications and source records attributed to P H Hardy.

At least 19 recordsLinked to original sources
PubMed1984

Prevalence of six sexually transmitted disease agents among pregnant inner-city adolescents and pregnancy outcome.

115 pregnant girls aged 13-17 years were investigated during the third trimester for endocervical infection with six sexually transmissible microorganisms. Specimens from 21 patients destroyed the tissue cell monolayers for propagation of Chlamydia trachomatis, but 11 were no longer toxic when recultured after freezing or with additional antimicrobial agents; Trichomonas vaginalis was present in 76% of the toxic specimens. C trachomatis was recovered from 37% of 105 specimens. T vaginalis was recovered from 34% of the 115 subjects, candida from 38%, Mycoplasma hominis from 70%, and Ureaplasma urealyticum from 90%. Neisseria gonorrhoeae was cultured from 1 of 12 girls infected earlier in pregnancy. T vaginalis infection, alone or with C trachomatis or candida, was associated with low gestational age and low birthweight. C trachomatis and candida infections alone had no effect on pregnancy outcome.

Adolescent↗
PubMed1983

Lack of endotoxin in Borrelia hispanica and Treponema pallidum.

Borrelia hispanica from infected guinea pigs and Treponema pallidum from testicular syphilomas of rabbits were assayed for the presence of endotoxin with the Limulus lysate test. A suspension of Borrelia, containing 1.3 X 10(8) spirochetes/ml, was nonreactive both when it was tested as intact organisms, and when tested after disruption of the spirochetes by sonication. Eight different suspensions of treponemes, ranging from 0.6 X 10(9) to 3 X 10(9) treponemes/ml, were negative at a 1:10 dilution and were no more active than control suspensions of normal rabbit testes. Therefore, it was concluded that T. pallidum, as well as the Borrelia, possessed no endotoxin.

Animals↗
PubMed1980

Abrogation of genetically controlled resistance of mice to Treponema pallidum by irradiation.

Infection with Treponema pallidum, the causative agent of human syphilis, gives rise to a complex immune response involving both humoral and cellular components. The exact nature of this response and how it relates to the disease process is a matter of considerable speculation. In recent years, studies have been directed towards defining the role of cell-mediated immunity (CMI) in syphilis. These have been conducted mainly in vitro because the general unavailability of inbred rabbits, the principal animals for experimental syphilis research, has limited the application of in vivo procedures. A prime deterrent to using mice for the study of syphilis has been their failure to exhibit pathology, even in the face of a persistent infection. We report here that on intradermal (i.d.) infection, transient primary lesions, characteristic of those seen in naturally acquired human syphilis, can be produced regularly in some strains of mice but not others, indicating a genetic basis for host susceptibility. Strains of mice which normally fail to develop lesions, do so after exposure to ionising radiation. Evidence is presented for a multiple role of the immune response during local infection.

Animals↗
PubMed1979

Macrophages in immunity to syphilis: suppressive effect of concurrent infection with Mycobacterium bovis BCG on the development of syphilitic lesions and growth of Treponema pallidum in tuberculin-positive rabbits.

Paired groups of male rabbits were challenged with Treponema pallidum and Mycobacterium bovis BCG. One group had been sensitized to BCG by inoculation 3 weeks before challenge. All animals were challenged intradermally at multiple sites with T. pallidum alone, BCG alone, and both organisms into the same sites. The resulting lesions were followed clinically and histologically. BCG lesions enlarged more rapidly in sensitized rabbits, but they were otherwise no different from those in the controls. T. pallidum lesions enlarged and regressed simultaneously in both groups, but in the BCG-sensitized animals they became twice as large as those in the unsensitized rabbits. Mixed BCG-T. pallidum lesions showed the greatest differences in the two groups of animals. Like the pure BCG lesions, they enlarged more rapidly in the sensitized rabbits but began to recede after 1 week. The corresponding lesions in the controls enlarged more slowly and reached their maximum size after 3 weeks when the receding lesions in the sensitized animals were much smaller. The most marked histological-histochemical difference between the two groups of animals was in the number and activation of macrophages. These cells were more numerous in the mixed lesions of BCG-sensitized animals than in similar lesions of the controls and more activated as determined by beta-galactosidase staining. Although sparsely distributed, activated macrophages were more numerous in the pur T. pallidum lesions of sensitized animals than in those of control animals. Silver-stained sections revealed fewer treponemes in mixed lesions of sensitized animals than in the mixed lesions of control animals. Quantitation of treponemes in pure T. pallidum versus mixed lesions was determined in two groups of rabbits challenged intratesticularly. The total number of treponemes per testis in the mixed lesions of BCG-sensitized rabbits was significantly less than the number in the mixed lesions of control animals, and also less than the number in pure T. pallidum lesions of both groups of animals.

Animals↗
PubMed1978

Counterimmunoelectrophoresis of Reiter Treponeme Axial filaments as a diagnostic test for syphilis.

Purified axial filaments from the cultivable Reiter treponeme, previously shown to share an antigenic component with pathogenic Treponemia pallidum, were evaluated as antigen in a diagnostic test for syphilis. Antibody to the filaments was revealed by counterimmunoelectrophoresis. Conditions that produced optimal results in the test were established. A total of 343 sera from normal individuals, biological false-positive reactors, and from patients in the different stages of syphilis were subjected to the test. The results indicate the test to be sensitive and highly specific for detecting treponemal antibodies in human syphilis.

Antigens, Bacterial↗
PubMed1975

Isolation and antigenic characteristics of axial filaments from the Reiter Treponeme.

Axial filaments were isolated and purified from Reiter treponemes after detergent solubilization of the cells" outer envelope. The axial filaments were separated from the spirochetal cells by shearing, purified by density gradient centrifugation, and fragmented by ultrasonication. Acrylamide gel electrophoresis of dissociated filaments revealed two major protein bands. Gel diffusion precipitin tests and immunoelectrophoresis between a purified axial filament suspension and anti-Reiter treponeme serum gave a single precipitin line. Checkerboard complement fixation tests also gave results consistent with a single antigen-antibody system. Tests with immune sera to other cultivable spirochetes were positive with some and negative with others. In addition, strongly positive reactions were obtained in complement fixation and precipitin tests with sera from rabbits and humans with syphilis and other treponematoses. However, both serological tests gave reactions of partial identity between the antigen(s) of Reiter treponeme axial filaments and those of the pathogenic treponemes. It was concluded from these studies that the axial filaments were probably the cellular locus of the so-called "Reiter protein" antigen of syphilis serology.

Animals↗
PubMed1975

Isolation and purification of Treponema pallidum from syphilitic lesions in rabbits.

Treponema pallidum were extracted from testicular syphilomas of corticosteroid-treated rabbits and purified by differential centrifugation. The steroid therapy allowed a longer holding time for infected rabbits, which produced greater treponeme yields, averaging 1.58 x 10(10) treponemes per rabbit. The treatment, which also diminished cellular infiltration and increased the extracellular mucoid material in lesions, produced much cleaner suspensions than preparations from nontreated animals. Most of the treponemes in the purified suspensions were still motile, and none carried demonstrable host immunoglobulin. The preparations were free of recognizable host tissue debris and they contained, on the average, 1.9 x 10(-7) mug of protein per treponeme.

Adrenal Cortex Hormones↗