Search PubMed⌕ Search

Biomedical subjects

J N Miller

Publications and source records attributed to J N Miller.

At least 109 records · Page 6Linked to original sources
PubMed1984

Humoral immunity in experimental syphilis: the demonstration of IgG as a treponemicidal factor in immune rabbit serum.

The neutralizing activity present in immune rabbit serum (IRS) against virulent Treponema pallidum was shown to be mediated by IgG and complement. IgG was isolated and purified from both IRS and nonimmune rabbit serum (NRS) by the use of an affinity system in which staphylococcal protein A was conjugated to Sepharose 4B. The purity of the isolated IgG fractions was demonstrated by both immunoelectrophoresis and SDS-polyacrylamide gel electrophoresis. Fractions of IgG were tested for specific neutralizing activity as measured by an in vitro-in vivo neutralization test. Lesions failed to develop at 80% of the sites inoculated with treponemal suspensions containing IgG from IRS in the presence of unheated NRS as a source of complement; delayed atypical lesions were observed at the remaining sites. In contrast, typical lesions developed at all sites inoculated with suspensions containing IgG from IRS in the presence of heated NRS. They were significantly delayed, however, as compared with lesion development at control sites inoculated with suspensions containing IgG from NRS. These results provide the first direct evidence for an IgG complement-mediated treponemicidal mechanism operative in immune serum from rabbits with latent syphilis.

Animals↗
PubMed1983

Editorial.

Explore the source record for details and available documents.

Editorial↗
PubMed1983

Photoluminescence and chemiluminescence methods of drug analysis.

The analysis of drugs in biological fluids requires sensitive, selective and convenient methods. Luminescence techniques provide extreme sensitivity and, alone or in conjunction with other methods, excellent selectivity. This paper assesses several recent developments in luminescence analysis, including the use of derivative and synchronous spectroscopy, luminescence immunoassays, room temperature phosphorimetry, and fluorescence excited by chemiluminescence energy transfer.

Journal Article↗
PubMed1983

Molecular characterization of common treponemal antigens.

A molecular characterization of cross-reactive antigens of Treponema pallidum Nichols and Treponema phagedenis biotype Reiter that are reactive with normal and syphilitic human sera is described. At least 8 common polypeptides, 14 T. pallidum-specific antigens, and 2 T. phagedenis biotype Reiter-specific antigens were identified.

Antigens, Bacterial↗
PubMed1983

Cloning and expression of Treponema pallidum (Nichols) antigen genes in Escherichia coli.

Hybrid pBR322 plasmid clone banks comprised of more than 125,000 recombinant DNA clones and representing the entire Treponema pallidum Nichols genome were constructed in Escherichia coli K-12 RR1. The two clone banks individually contain over 53,000 and 72,000 recombinant clones. The number average and mass average sizes of the cloned DNA inserts were found to be approximately 12 and 13 kilobase pairs, respectively, indicating the presence of large treponemal DNA inserts in a majority of recombinant clones. To detect E. coli clones synthesizing T. pallidum antigens as hybrid plasmid gene translation products in the clone bank, a simplified, direct, solid-phase radioimmuno-colony blot (RICB) assay was developed employing immunoglobulin G antibody isolated from anti-T. pallidum immune rabbit serum. Clones with positive reactivities in the RICB assay were isolated at frequencies of 0.1 to 0.2%. One isolated RICB-positive clone, designated RICB2-1, produced a very strong signal in the RICB assay and was subsequently found through E. coli cell-free in vitro transcription/translation analysis to encode the synthesis of two gene translation products with apparent molecular weights of 77,000 and 44,000. The 44,000-dalton protein was effectively immunoprecipitated from [35S]methionine-labeled E. coli clone cells by using either immune rabbit serum (preabsorbed with Treponema phagedenis biotype Reiter antigens) or selected human syphilitic serum, whereas the 77,000-dalton protein was never immunoprecipitable by similar methods. Purified plasmid DNA from clone RICB2-1 contained a treponemal DNA insert of 3.70 kilobase pairs, which was of suitable size to code for the 121-dalton (44 + 77) protein. The insert was also flanked on each end by PstI sites and possessed three internal PstI sites with fragment sizes of 2.15, 1.18, 0.20, and 0.17 kilobase pairs. Purified clone RICB2-1 plasmid DNA was capable of transforming recipient E. coli cells to virtually 100% RICB reactivity, thus substantiating the plasmid-encoded characteristic. Further experiments employing various antisera in radioimmunoprecipitation systems utilizing cell-free in vitro synthesized gene translation products from clone RICB2-1 also provided the first evidence that E. coli may be capable of using endogenous T. pallidum DNA promotors for genetic expression. These studies, amplified by the isolation of a potentially significant immunoprecipitable 44,000-dalton recombinant protein antigen, point to the importance of the "cloned antigen gene" approach for the eventual eludication of specific antigens or immunogens operative in the pathogenesis, immunology, and serodiagnosis of T. pallidum infection.

Antigens, Bacterial↗
PubMed1983

Humoral immune response in experimental syphilis to polypeptides of Treponema pallidum.

The ontogeny of the IgG response in rabbits with experimental syphilis to individual polypeptides of Treponema pallidum, Nichols strain, was examined. The polypeptides of motile, virulent T. pallidum, purified from host tissue by Percoll density gradient centrifugation, were separated on SDS-polyacrylamide gels and were electrophoretically transferred to a solid-phase matrix of nitrocellulose for antigen analysis. Serum from rabbits early in infection at day 3 post-infection showed a weak but detectable IgG response to two polypeptides of 60,000 and 46,000 m.w. This was followed on days 11, 17, and 19 by an apparent quantitative increase in antibody to other treponemal protein antigens. By day 19, 21 of the 22 detectable polypeptides could be identified. A similar set of antigens was detected by serum from patients with human secondary and early latent syphilis. A close correlation was found between the presence of IgG antibody to T. pallidum polypeptides at day 9 and 1, 4.5, 13.5, and 17 mo post-infection and the immune status of the rabbit to symptomatic reinfection. Serum from rabbits that were partially immune to challenge at day 9 detected three polypeptides of 60,000, 46,000, and 36,000 daltons. By 1 mo post-infection, at a time when a more complete immunity had developed, the number of detectable antigens increased to 21 polypeptides ranging in m.w. from 94,000 to 14,400 daltons. IgG antibody to 22 treponemal antigens persisted in animals that were solidly immune to symptomatic reinfection at 3, 4.5, 13.5, and 17 mo post-infection. Serum neutralizing activity was not demonstrable at day 9 or 1 mo post-infection, however, but was present at 3, 4.5, 13.5, and 17 mo. The results suggest that after intratesticular challenge a vigorous IgG response to T. pallidum polypeptides can be detected. The potential role of humoral immune mechanisms in the development and maintenance of immunity is discussed.

Animals↗
PubMed1982

Comparative pharmacokinetics of frusemide in female rhesus monkeys, cynomolgus monkeys and baboons.

1. The pharmacokinetics of frusemide have been compared in 3 non-human primate species after single intravenous dose of 3 mg/kg of the drug. 2. Peak mean plasma concentrations of frusemide were 31.6, 33.6, 43.6 micrograms/ml in the rhesus monkey, cynomolgus monkey and baboon respectively, and concentrations declined with a half-life of about 20 min. 3. There were no notable differences in the pharmacokinetic parameters estimated from either a one-compartment or two-compartment open model. 4. There were statistically significant species-related differences in clearance, half-lives and volumes of distribution adjusted for bodyweight. 5. The pharmacokinetics of frusemide in the cynomolgus monkey are closer to those in man than are those in the rhesus monkey, the baboon or other commonly used laboratory animal species.

Animals↗
PubMed1982

Murine monoclonal antibodies specific for virulent Treponema pallidum (Nichols).

Murine anti-Treponema pallidum (Nichols) lymphocyte hybridoma cell lines secreting monoclonal antibodies against a variety of treponemal antigens have been generated. Hybridomas isolated were of three major types: those that were directed specifically against T. pallidum antigens, those that were directed against treponemal group antigens (as evidenced by their cross-reactivity with T. phagedenis biotype Reiter antigens), and those that cross-reacted with both treponemal as well as rabbit host testicular tissue antigens. The majority (31 of 39 clones) of these anti-T. pallidum hybridomas, which produced monoclonal antibodies of mouse isotypes immunoglobulin G1 (IgG1), IgG2a, IgG2b, IgG3 or IgM, were directed specifically against T. pallidum and not other treponemal or rabbit antigens tested by radioimmunoassay. Four of these T. pallidum-specific hybridomas secreted monoclonal antibodies with greater binding affinity for "aged" rather than freshly isolated intact T. pallidum cells, suggesting a possible specificity for "unmasked" surface antigens of T. pallidum. Six anti-T. pallidum hybridomas produced complement-fixing monoclonal antibodies (IgG2a, IgG2b, or IgM) that were capable of immobilizing virulent treponemes in the T. pallidum immobilization (TPI) test; these may represent biologically active monoclonal antibodies against treponemal surface antigens. Three other hybridomas secreted monoclonal antibodies which bound to both T. pallidum and T. phagedenis biotype Reiter antigens, thus demonstrating a possible specificity for treponemal group antigens. Five hybridoma cell lines were also isolated which produced IgM monoclonal antibodies that cross-reacted with all treponemal and rabbit host testicular tissue antigens employed in the radioimmunoassays. This report describes the construction and characteristics of these hybridoma cell lines. The potential applications of the anti-T. pallidum monoclonal antibodies are discussed.

Aging↗
PubMed1982

Humoral immune response in human syphilis to polypeptides of Treponema pallidum.

A molecular characterization of the polypeptide antigens of Treponema pallidum reactive with sera from patients with different stages of syphilis is described. Polypeptides of motile, virulent T. pallidum, purified from rabbit testes, were separated on SDS polyacrylamide gels and electrophoretically transferred to nitrocellulose for antigenic analysis ("Western blotting"). Serum IgG from uninfected individuals reacts weakly with three polypeptides of 45,000, 33,000, and 30,000 m.w. In this study patients with primary syphilis have IgM antibody, and all patients with syphilis have IgG antibody to at least four polypeptides of 45,000, 33,000, 30,000, and 15,500 m.w. Antibody to polypeptides of 42,000 and 16,500 m.w. appear to be markers for nonprimary syphilis. These six polypeptides have been termed the major antigenic proteins (MAP) of T. pallidum. Those patients studied with secondary and early latent syphilis acquire antibody to a set of 16 additional polypeptide antigens. Those patients studied with late latent or late syphilis have antibody to a much smaller set of five or four antigens, respectively, in addition to MAP. The results suggest that a correlation exists between acquisition of antibody and the development of "chancre immunity." Additionally, the loss of antibody that characterizes late latent and late syphilis may be associated with the potential development of destructive late syphilis.

Animals↗
PubMed1981

Plasmid DNA in Treponema pallidum (Nichols): potential for antibiotic resistance by syphilis bacteria.

A plasmid DNA structure (approximate molecular weight = 7.5 X 10(6)) was identified in the human pathogen Treponema pallidum (Nichols). The inability to isolate this plasmid from rabbit host tissue and the total lack of DNA homology of the plasmid with rabbit DNA has confirmed its Treponema pallidum origin. The observation documents a newly recognized and potentially significant genetic capability for Treponema pallidum.

Animals↗
PubMed1981

Clinical manifestations of pulmonary oxygen toxicity.

Despite the seriousness of pulmonary O2 toxicity, patients can generally withstand 1 atm. of PO2 for at least 24 hours. Also, there is no evidence that clinically relevant pulmonary O2 toxicity occurs in humans at inspired partial pressures below 0.4 to 0.5 ATA, even with prolonged exposures. Neither is there clinical or experimental evidence to indicate that patients with preexisting pulmonary disease are more sensitive to O2 toxicity than are normal volunteers. Although the florid manifestations of pulmonary O2 toxicity may have dire consequences, a lower dosage of O2, though still potentially toxic, may well be acceptable. The lung itself can generate some level of self-protection with prolonged O2 exposure, ultimately healing itself to a significant degree. Therefore, no patient should be exposed to dangerous levels of hypoxia out of fear of causing pulmonary O2 toxicity. Pulmonary hyperoxia and systemic hypoxia can usually be avoided with skillful, titrated management of respiratory insufficiency.

Animals↗