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Biomedical subjects

J N Miller

Publications and source records attributed to J N Miller.

At least 91 records · Page 5Linked to original sources
PubMed1986

The surface of virulent Treponema pallidum: resistance to antibody binding in the absence of complement and surface association of recombinant antigen 4D.

The binding of immunoglobulin G present in syphilitic immune rabbit serum, syphilitic human serum, and rabbit antiserum to purified recombinant Treponema pallidum antigen 4D by T. pallidum, Nichols strain, was studied by immunoelectron microscopy. Treponemes were incubated with antiserum under the conditions of the T. pallidum immobilization test, in which T. pallidum-specific antibody renders the organism nonmotile and avirulent only in the presence of complement after a 16-h incubation period in an anaerobic environment. Antibody was not demonstrable on the surface of T. pallidum incubated with nonimmune rabbit serum or normal human serum in the presence of complement. Similarly, in the absence of complement, little or no antibody was found on the treponemal surface after incubation with syphilitic immune rabbit serum, syphilitic human serum, or rabbit antiserum directed against the recombinant 4D antigen. The addition of complement to syphilitic immune rabbit serum, syphilitic human serum, and anti-4D antibody resulted in immobilization and the deposition of antibody on the entire surface of the immobilized organisms. These results corroborate earlier work by other investigators demonstrating the resistance of freshly isolated T. pallidum to antibody binding in a variety of serological tests. Detection of 4D antigen on the surface of immobilized T. pallidum strongly implies that the use of T. pallidum immobilization test conditions provides a means to demonstrate the association of individual surface antigens on virulent T. pallidum. The resistance of T. pallidum to antibody binding may be relevant to the pathogenesis of syphilis.

Animals↗
PubMed1986

Native surface association of a recombinant 38-kilodalton Treponema pallidum antigen isolated from the Escherichia coli outer membrane.

A recombinant plasmid designated pAW305, containing a 6-kilobase insert of Treponema pallidum DNA, directed the expression of a 38-kilodalton (kDa) treponemal antigen in Escherichia coli. The 38-kDa antigen copurified with the outer membrane fraction of the E. coli cell envelope after treatment with nonionic detergents or sucrose density gradient centrifugation. Rabbits immunized with the recombinant 38-kDa antigen developed antibodies which reacted specifically with a 38-kDa T. pallidum antigen on immunoblots, and 38-kDa antisera specifically immobilized T. pallidum in a complement-dependent manner in the T. pallidum immobilization test. Antisera to the 38-kDa recombinant antigen were also used to demonstrate its native surface association on T. pallidum by immunoelectron microscopy.

Animals↗
PubMed1986

Antigenic interrelationship between endoflagella of Treponema phagedenis biotype Reiter and Treponema pallidum (Nichols): molecular characterization of endoflagellar proteins.

Purified endoflagella from nonpathogenic Treponema phagedenis biotype Reiter were characterized biochemically and compared antigenically with the endoflagellar proteins of Treponema pallidum. T. phagedenis biotype Reiter endoflagella were dissociated into constituent polypeptides by incubation under conditions which disrupt noncovalent bonds. Chymotrypsin peptide maps of T. phagedenis biotype Reiter endoflagellar proteins revealed that the 37- and 33-kilodalton (kDa) major components shared significant homology with the 27- and 30-kDa minor components, respectively. The peptide maps also suggested that the major components shared a lesser degree of structural similarity with each other. These relationships were confirmed by Western blots of T. phagedenis biotype Reiter endoflagellar proteins employing antibodies that were purified against the individual endoflagellar polypeptides. Western blots of T. pallidum with the purified antibodies also demonstrated strong cross-reactivity between the T. phagedenis biotype Reiter endoflagellar proteins and T. pallidum proteins of identical or similar molecular weights. A unique Western blotting technique that we called epitope bridging was used to determine that the 37-kDa subunit contains most of the external epitopes on T. phagedenis biotype Reiter endoflagella. Immunoelectron microscopy with human syphilitic serum and rabbit T. phagedenis biotype Reiter endoflagellar antiserum confirmed the presence of cross-reactive epitopes on the surface of intact T. phagedenis and T. pallidum endoflagella.

Animals↗
PubMed1986

Microbiological and biochemical characterization of spirochetes isolated from the feces of homosexual males.

Spirochetes were isolated from the feces of 11 homosexual males who had diarrhea. The anaerobic organisms were isolated from a selective medium that consisted of Trypticase soy agar supplemented with either 5% horse or human blood, 400 micrograms of spectinomycin per ml, and 5 micrograms of polymyxin B per ml. Nonselective media that permitted good growth of these fastidious organisms were developed, and selected biochemical tests were performed. The tests included carbohydrate utilization, detection of certain enzymes, and determination of volatile fatty-acid end products of metabolism. Two growth patterns were noted on solid media, a haze of growth and production of small colonies. Based on the results of biochemical tests, patterns of preformed enzymes, and volatile fatty-acid production, we believe that the 11 isolates represent a heterogeneous group of spirochetes. The data suggest that the human colon may harbor unique strains of cultivable spirochetes; additional study of the taxonomy of the organisms and assessment of their virulence for humans are needed.

Culture Media↗
PubMed1986

Monaghan 225 ventilator use under hyperbaric conditions.

The Monaghan 225 ventilator was tested to ambient pressures of 6 atmospheres absolute (ATA) in a hyperbaric chamber. The ventilator would function with delivered tidal volume which was independent of ambient pressure. Ventilatory rate declined in an exponential fashion. At 6 ATA, the ventilatory rate was 45 percent of the preset rate at 1 ATA. By decreasing the circuit resistance and increasing the inspiratory flow rate, the 6 ATA rate could be increased to 72 percent of the 1 ATA value. The maximum minute ventilation of the ventilator at 1 ATA was approximately 48 L/min; at 6 ATA, its maximum was 18 L/min. Synchronized intermittent mandatory ventilation, assist/control, and PEEP functions were satisfactory at 6 ATA. While using 100 percent O2 to power the ventilator at 2.82 ATA, the oxygen leakage was 57.7 L/min (converted to 1 ATA pressure, 20 degrees C), of which 33.7 L/min was successfully scavenged using simple techniques. A minor modification was made to the ventilator, allowing it to be driven by compressed air while maintaining complete flexibility in setting the FIo2. The ventilator has proven stable and reliable in clinical use at ambient pressures up to 6 ATA.

Equipment Design↗
PubMed1986

Public hospitals: the legal obstacles of entering into joint ventures.

Public hospitals, as public entities, are limited in many of their activities by state constitutions and statutes. One area where activity can be particularly limited is the joint venture. Constitutional and statutory limitations can influence several aspects of the joint venture: scope of activities, geographic boundaries, authority to enter into joint ventures, gift of public funds prohibition, and stock ownership. Therefore, public hospitals must be aware of possible legal obstacles and carefully consider their options.

Financial Management↗
PubMed1985

Anesthesiology.

Explore the source record for details and available documents.

Anesthesia, General↗
PubMed1985

Binding of glycosaminoglycans to the surface of Treponema pallidum and subsequent effects on complement interactions between antigen and antibody.

Acidified bovine serum albumin (acid BSA) reacts with glycosaminoglycans to form a precipitate. This reaction was adapted to Treponema pallidum to show glycosaminoglycans associated with the surface of the micro-organism. As testicular infection progressed from days 4 to 18, treponemes showed increasing amounts of these surface components. High speed centrifuging effectively removed the glycosaminoglycans, thus indicating that they were loosely bound. The subsequent addition of commercial preparations of hyaluronic acid or chondroitin sulphate resulted in their immediate adherence to the surface of the pathogens T pallidum and T pertenue, but not to the non-pathogens T vincenti, T denticola, or T phagedenis. The amount adhering to the treponemal surface varied depending on the concentration added. Intradermal inoculation showed that the virulence of T pallidum was not altered by the glycosaminoglycans associated with its surface. The coating of treponemes with hyaluronic acid or chondroitin sulphate did not interfere with neutralising antibodies or antibodies found by radioimmunoassay using whole organisms. In contrast, hyaluronic acid or chondroitin sulphate on the treponemal surface did interfere with immobilising antibodies. Results are discussed in terms of the potential role of the treponemal glycosaminoglycans in the infectious process.

Animals↗
PubMed1984

Monoclonal antibody with hemagglutination, immobilization, and neutralization activities defines an immunodominant, 47,000 mol wt, surface-exposed immunogen of Treponema pallidum (Nichols).

Radioimmunoprecipitation (RIP) analyses performed on 125I-surface-labeled Treponema pallidum cells using various immune sera revealed the presence of six major surface antigens (immunogens) with apparent molecular weights of 47 K, 36 K, 34 K, 32 K, 29 K, and 13 K. Among these, the 47 K surface antigen was most abundant. Radioimmunoprecipitation assays using 125I-labeled T. phagedenis biotype Reiter or immunoblot analyses using the same strain, failed to reveal the presence of the 47 K mol wt antigen in the representative nonpathogenic treponeme. Preabsorption of anti-T. pallidum immune rabbit serum (IRS) with the Reiter organism did not remove anti-T. pallidum antibodies from immune serum that reacted with the 47 K mol wt immunogen or other immunogens of T. pallidum present in the characteristic antigenic profile. Monoclonal antibodies (mAb) directed specifically against the 47 K mol wt immunogen of T. pallidum also failed to react with an analogous 47 K mol wt component in Treponema phagedenis biotype Reiter, further suggesting the unique presence of this antigen in pathogenic treponemes. The presence of the 47 K mol wt surface immunogen in pathogenic treponemes other than T. pallidum subspecies pallidum was also observed (43). Anti-47 K immunogen mAb was nonreactive against rabbit IgG or IgM. mAb directed specifically against the 47 K mol wt immunogen of T. pallidum was examined for strategic functional activities. It was found to be reactive in the microhemagglutination assay for T. pallidum antibodies, the T. pallidum immobilization test, and was found to be capable of significant blockage of attachment of virulent T. pallidum to host cells in tissue culture. Additional significant biological activity for the anti-47 K mol wt immunogen mAb was revealed through results of the in vitro-in vivo neutralization test of Bishop and Miller, in which a 99% or 100% neutralizing activity was demonstrated. The combined data of this study suggest that the 47 K mol wt immunogen of T. pallidum represents an abundant, immunodominant, surface-exposed immunogen possessing potential biological importance in the pathogenesis and immunology of T. pallidum infection. These studies serve to establish the first functionally defined immunogen for T. pallidum, which may represent the major immunogen of the organism.

Animals↗
PubMed1984

Purification and characterization of a cloned protease-resistant Treponema pallidum-specific antigen.

A cloned Treponema pallidum antigen, designated 4D, was purified from Escherichia coli predominantly as a 190-kilodalton (kd) polypeptide, although higher oligomeric forms exist. Extensive proteolysis of 4D created a limit digestion product of 90 kd which retained antigenicity with sera from patients with primary, secondary, early latent, late latent, and tertiary syphilis. A molecule indistinguishable from 90-kd 4D in size, isoelectric point, and antigenicity was isolated from T. pallidum after proteolysis. The 190- and 90-kd forms of 4D were stable at 68 degrees C but converted to 19- and 14-kd species, respectively, after boiling in sodium dodecyl sulfate. The low-molecular-weight species did not react with syphilitic sera. Rabbits immunized with the purified 4D antigen developed antibodies which immobilized virulent T. pallidum in a complement-dependent assay system, suggesting that the antigen has a native surface location.

Animals↗
PubMed1984

Sensitivity and specificity of monoclonal antibodies directed against antigenic determinants of Treponema pallidum Nichols in the diagnosis of syphilis.

Murine anti-Treponema pallidum monoclonal antibodies were employed in studies on sensitivity and specificity of binding to examine their potential for use in the detection of low numbers of pathogenic treponemes present in various body fluids. Monoclonal antibodies were used as a primary antibody source in a solid-phase immunoblot assay system. All monoclonal antibodies assayed were capable of detecting ca. 1.0 X 10(3) to 2.5 X 10(3) treponemes. Of 13 monoclonal antibodies examined, 3 were able to detect 10(3) virulent treponemes, and 1 of these antibodies was able to reveal the presence of as few as 500 organisms. Western blot analyses showed that all anti-T. pallidum monoclonal antibodies exhibiting high sensitivities for the detection of T. pallidum cells were directed against an abundant, 47,000-dalton surface-exposed antigen of the organism (S. A. Jones, K. S. Marchitto, J. N. Miller, and M. V. Norgard, Abstr. Annu. Meet. Am. Soc. Microbiol. 1984, B173, p. 46; K. S. Marchitto, S. A. Jones, and M. V. Norgard, Abstr. Annu. Meet. Am. Soc. Microbiol. 1984, B182, p. 48). Differences in binding properties of the various monoclonal antibodies were most likely a reflection of differential binding affinities or their specificities for different epitopes on the 47,000-dalton surface antigen. With two possible exceptions, the monoclonal antibodies tested reacted specifically with T. pallidum, either purified or found within a high-contaminating tissue background, and not with Treponema phagedenis biotype Reiter, Haemophilus ducreyi, Neisseria gonorrhoeae, herpes simplex virus type 2, or normal rabbit testicular tissue. The high sensitivity and specificity exhibited by these anti-T. pallidum monoclonal antibodies make them excellent candidates for employment in new syphilis or other treponemal diagnostic tests designed to detect very low numbers of pathogenic treponemes in lesion exudates or other body fluids.

Animals↗
PubMed1984

Attachment of Treponema pallidum to fibronectin, laminin, collagen IV, and collagen I, and blockage of attachment by immune rabbit IgG.

As shown by scanning electron and phase contrast microscopy, Treponema pallidum attached in vitro to basement membranes purified from kidney cortex tissues or from retinal vessels. This organism also attached to the extracellular matrix remaining after cultured cells had been solubilised with Triton X. Fibronectin, laminin, collagen, IV, collagen I, and hyaluronic acid are structural components of basement membranes and extracellular matrices. Experiments were performed to investigate the in vitro attachment of T pallidum to each of these components. Viable or heat inactivated treponemes were added to glass coverslips precoated with different concentrations of each component. After various times of incubation, coverslips were washed and the attached organisms were counted. Large numbers of viable organisms attached to each of these five components. In contrast, heat inactivation sharply reduced numbers of attached organisms. The IgG fractions of immune and non-immune rabbit serum samples were affinity purified using protein A. T pallidum was preincubated with both fractions, then incubated with either intact cultured cells or with coverslips coated with the five tissue components. The IgG from immune serum blocked treponemal attachment to the cultured cells and to fibronectin, laminin, collagen IV, and collagen I, but not to hyaluronic acid. These results are discussed in terms of attachment mechanisms of T pallidum and potential applications to in vivo infection.

Adhesiveness↗
PubMed1984

Experimental neonatal syphilis. I. Evidence of resistance to symptomatic infection in neonatal rabbits following intradermal inoculation with Treponema pallidum (Nichols strain).

Resistance of 5- to 8-day-old neonatal rabbits to dermal lesion development after intradermal inoculation of Treponema pallidum was demonstrated. Clinical evidence of infection following inoculation of 1 X 10(6) Treponema pallidum at each of two sites was either minimal or absent. Atypical, nonprogressive, nonulcerative lesions occurred in 59% of the inoculated neonates and at 45% of inoculated sites. Differences in incubation periods, duration, and maximum diameters of lesions among adult controls versus neonatal rabbits were significant. The age of waning resistance was determined by inoculating groups of neonates ranging from 1 to 7 weeks of age. Five-week-old (31-36 days) neonates demonstrated waning resistance by the appearance of typically ulcerative, progressive lesions, though their parameters (duration, size) were not yet those of adult control lesions. The resistance demonstrated by neonates may be due in part to group housing (nesting) which could create unfavorable temperatures for T. pallidum survival; comparison of lesion development between nesting and individually housed neonates, 31 to 46 days of age, revealed a greater percentage of typical lesions developing among those individually housed (95 versus 52%). However, these differences may reflect the variability of typical lesion development found among animals of this age when resistance begins to wane. In both groups, the duration of typical lesions was significantly shorter than for adult controls. A heat-stable serum factor(s) was demonstrated in 19 of 20 basal sera from neonates 4 to 6 days of age; this presented another possible mechanism of resistance. The neutralizing serum factor(s) was not demonstrable in the sera of does either before mating, during gestation, or shortly after kindling.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1984

Experimental neonatal syphilis. II. Immunological responses of neonatal rabbits to intradermal inoculation with Treponema pallidum (Nichols strain).

The immunological competence of neonatal rabbits inoculated intradermally with Treponema pallidum was examined. Both cellular responses and the production of humoral antibody to specific T. pallidum antigens and to nonspecific antigens or mitogens were investigated. In blast transformation assays, splenic and popliteal lymph node lymphocytes from neonates inoculated with virulent T. pallidum responded to T. pallidum antigens in a manner similar to or greater than inoculated adult rabbits. Splenic and popliteal lymph node lymphocytes from both uninoculated and T. pallidum-inoculated neonate and adult animals showed consistent and similar responses to concanavalin A. Both neonate and adult animals inoculated with heat-killed T. pallidum also responded but to a significantly lesser degree. Immunofluorescent examination of skin sections from the site of inoculation of adult and neonatal animals revealed 1) that the early infiltrate was composed predominantly of T cells, 2) diffuse antibody staining with rare B cells, and 3) fewer treponemes with significant fragmentation in neonates as compared to adult controls. Antibody production by neonates inoculated with virulent T. pallidum was delayed 4 to 6 weeks postinoculation as measured by the fluorescent Treponemal antibody absorption and Venereal Disease Research Laboratory (VDRL) test procedures, respectively. Antibody was not detected among neonates inoculated with heat-killed treponemes during a 6-week observation period and only low levels of VDRL antibody were detected in a few adult control animals. Evidence for incomplete resistance of neonatal rabbits to the intradermal inoculation of Treponema pallidum was provided.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Using a corporate structure 'check-up' to spot potential problems.

Hundreds of hospitals across the country have now completed a corporate restructuring. As a result, many hospital boards and administrators are now dealing with a multiple-entity corporate structure for the first time. Moreover, the legal, accounting, management, and other specialists who helped to plan and form the new structure probably will not be involved in its day-to-day operation and maintenance. This combination of factors creates a risk that the various entities will not be run as required in order to maintain their separate corporate status. This article explains why it is important to preserve the separate corporate status of these entities, it identifies common problems in this area, and it shows how an audit of the corporate restructuring can help prevent those problems.

Financial Audit↗