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T J Fitzgerald

Publications and source records attributed to T J Fitzgerald.

At least 73 records · Page 4Linked to original sources
PubMed1983

Interaction of Treponema pallidum with isolated rabbit capillary tissues.

Within infected tissue Treponema pallidum shows a characteristic predilection for perivascular areas. After intact capillaries had been prepared from rabbit brain tissue treponemes were incubated with isolated capillaries and visualised by darkfield, phase contrast, and scanning electron microscopy. The organisms rapidly attached to the surface of the capillaries at the tip of the treponeme; attached organisms retained motility for longer periods than unattached organisms. Treponema pertenue also attached to capillaries. Heat-inactivated T pallidum and three non-pathogenic treponemes did not, however, attach to the capillaries. Immune rabbit serum contains a factor that blocks the attachment of T pallidum to capillaries. Compared with cultured mammalian cells capillaries should provide a better tool for investigating host-parasite relationships in syphilis.

Animals↗
PubMed1983

Further evidence for hyaluronidase activity of Treponema pallidum.

The presence of hyaluronidase in preparations of Treponema pallidum was previously shown using acidified bovine serum albumin reactions and Ouchterlony immunodiffusion. To expand on these preliminary findings more sensitive techniques of viscometry, additional immunologic reactions, and altered capillary permeability were used to characterize treponemal-associated hyaluronidase. The pathogens T. pallidum and T. pertenue degraded hyaluronic acid, whereas the nonpathogens T. denticola and T. vincentii did not. As syphilitic infection progressed, hyaluronidase activity decreased; organisms harvested from 14-day testicular infections degraded hyaluronic acid less rapidly than organisms from 4-day infections. Uninfected rabbit testicular extract also exhibited significant enzyme activity. The neutralizing activity of immune sera was decreased by prior adsorption with bovine hyaluronidase, suggesting that some of the neutralizing factors are associated with this enzyme. Radioimmunoassay was used to quantitate antibodies to hyaluronidase in immune sera. Antihyaluronidase sera were isolated from rabbits immunized with bovine hyaluronidase. Treponema pallidum, as well as uninfected rabbit testicular extract, cross-reacted with these antisera. Immunofluorescence indicated that the hyaluronidase was uniformly distributed along the treponemal surface. As a final indicator of hyaluronidase activity, alterations in capillary permeability were detected 1 h after intradermal injection of T. pallidum.

Animals↗
PubMed1982

Changes in the distribution of fibronectin during limb regeneration in newts using immunocytochemistry.

The distribution of fibronectin in regenerating newt limbs was studied using immunocytochemistry. At appropriate intervals after the initial amputation at the elbow (10-30 days), animals were reamputated at the shoulder and processed for light microscopy. The peroxidase-antiperoxidase technique was used to localize affinity-purified antibodies to fibronectin in limb tissues. At the amputation site, fibronectin was associated with basal laminae and connective tissues adjacent to dedifferentiating limb tissues destined to form the regeneration blastema. Accumulation and growth of the blastema was accompanied by the apparent de novo synthesis of fibronectin, where it appeared randomly in the interstitium between blastemal cells. The onset of chondrogenesis was characterized by a central condensation of prechondroblasts that formed the cartilage anlagen. Fibronectin formed an amorphous network between presumptive chondroblasts. As the mature cartilage phenotype was expressed and chondrocytes became isolated in lacunae, fibronectin was greatly reduced and then disappeared. The extracellular matrix surrounding undifferentiated blastemal cells still contained fibronectin. Fibronectin was also found in high concentrations between differentiating myoblasts. A condensation of fibronectin was also observed beneath the epidermis at the distal limb tip at the onset of digit formation. These observations are consistent with the hypothesis that fibronectin may play a key role in the morphogenetic events that result in the spatial organization and subsequent differentiation of cells during pattern formation in the regenerating limb.

Amputation, Surgical↗
PubMed1982

Morphological destruction of cultured cells by the attachment of Treponema pallidum.

The incubation of Treponema pallidum with rabbit testicular cells, HEP-2 cells, human foreskin cells, rat cardiac cells, and rat skeletal muscle cells caused morphological disruption of these cultured cells. Control preparations of heat-inactivated treponemes, a high-speed supernatant in which treponemes had been pelleted, and culture medium failed to damage the tissue cells, as did viable treponemes when the cells were incubated in inverted Sykes-Moore chambers. Thus, cellular disruption is not associated with soluble treponemal, soluble inflammatory, or soluble testicular constituents but is mediated by the specific attachment of T pallidum. This organism apparently elaborates some type of toxic activity that lyses membranes: this may explain some of the histopathology of syphilitic disease.

Animals↗
PubMed1982

Scanning electron microscopy of the attachment of Treponema pallidum to nerve cells in vitro.

Treponema pallidum (Nichols strain) was incubated with cultured nerve cells derived from rat embryos. Primary cultures were established from dorsal root ganglia, superior cervical ganglia, and spinal cord. Using phase contrast microscopy treponemes were seen to interact with the nerve cells in a similar manner to other cultured mammalian cells. Organisms began to attach within minutes after inoculation, actively motile organisms attached at the tip of one end, higher numbers of organisms attached with continued incubation, and attached organisms survived longer than unattached organisms. T pallidum attached both to nerve cell bodies and to neuronal processes of each of the three nerve cell cultures. As shown by scanning electron microscopy the mechanism of attachment was identical to that of cultured cells derived from rabbits testis, rat skeletal muscle, and human cervical carcinoma. There was no indentation or swelling of the cultured cell surface at the point of attachment, just a close physical proximity of organisms and cells. These techniques provide a biological means of studying the in-vitro detrimental influences of micro-organisms on nerve tissue.

Animals↗
PubMed1982

Electrophysiological dysfunction and cellular disruption of sensory neurones during incubation with Treponema pallidum.

Treponema pallidum (Nichols strain) was incubated with cultured nerve cells derived from dorsal root ganglia of rat embryos. The electrophysiological response of these neuronal cells was then investigated. Cells exposed to 2 X 10(8) treponemes/ml responded abnormally after 13 hours and failed to respond after 18 hours. In contrast, control preparations exposed to heat-inactivated treponemes or to culture medium responded normally after 72 hours. Extended incubation with viable treponemes resulted in various degrees of nerve cell disruption as shown by scanning electron microscopy. With some cells holes in the cytoplasmic membrane were detected; with others a coagulated matrix of apparent nuclear material and remnants of cytoskeletal elements indicated more severe destruction. These findings may explain the painless nature of many of the clinical manifestations of syphilis as well as the severe damage to central nervous system tissue in tertiary and congenital syphilis.

Action Potentials↗
PubMed1982

Fibronectin involvement in granulation tissue and wound healing in rabbits.

This study describes the distribution of fibronectin and its association with reticulin fibers (type III collagen) and hyaluronic acid in shallow rabbit wounds. Linear incisions were made dorsally with a surgical blade. Animals were sacrificed and 1,2,3,4,5, and 8 day wounds were examined using peroxidase-antiperoxidase to localize affinity-purified antibodies to fibronectin. Tissue samples were also stained with hematoxylin and eosin in addition to silver stains for reticulin, and Alcian blue for hyaluronic acid. After wounding, the incision filled with a fibrin clot that stained positively for fibronectin. The underlying dermis and adjacent, unwounded dermis also contained fibronectin. Epidermal cells that migrate from the wound margin between the clot and the dermis were in direct association with fibronectin in these wound components. By 72 hr, epidermal continuity was reestablished. Early granulation tissue formation was apparent just below the epidermis 5 day wounds. Fibronectin was observed in the matrix surrounding individual fibroblasts and codistributed with reticulin fibers and hyaluronic acid in both 5 and 8 day wounds. Granulation tissue of 8 day wounds stained intensely for fibronectin and extended to a greater depth in the reticular dermis. Dense fibrillar networks of fibronectin and fibroblasts were aligned parallel to the epidermis, giving the granulation tissue a highly structured and organized appearance. Fibroblasts contained fibronectin and were surrounded by less fibronectin at the wound periphery than within the granulation tissue. These findings suggest that fibronectin may be important in the reconstruction of tissues during repair by functioning as an extracellular scaffold for migrating cells.

Animals↗
PubMed1981

Accelerated lesion development in experimental syphilis.

In experimental syphilis, lesion development changes when different numbers of treponemes are injected. Lesions at sites inoculated with lower concentrations frequently exhibit delayed incubation periods, less tissue degradation, and more rapid healing. In this report I describe an unusual finding, namely, that accelerated rather than delayed incubation period occurred after intradermal inoculation of different dosages of Treponema pallidum. When rabbits were injected with only one inoculum containing 10(6), 10(5), 10(4), or 10(3) treponemes per rabbit, the corresponding incubation periods were 4.2, 7.5, 11.0 and 15.3 days, respectively. When each rabbit was injected with all four inocula on the back, the incubation periods were shortened to 3.9, 6.0, 7.0 and 8.9 days, respectively. More pronounced differences were observed with more divergent ranges of treponemal inocula. I discuss these findings in terms of the histopathology of syphilitic lesions.

Animals↗
PubMed1980

Influence of testicular fluid infected with Treponema pallidum on intradermal lesions.

A viscous mucoid fluid occasionally accumulates after intratesticular inoculation of rabbits with Treponema pallidum. Experiments were performed to assess the effects of this testicular fluid on the development of syphilitic lesions. Intramuscular injections of this fluid altered host defences as indicated by shorter incubation periods, by reactivation of healing lesions, and by the presence of lesions at a time when solid immunity should have developed.

Animals↗
PubMed1980

Sulfhydryl oxidation using procedures and experimental conditions commonly used for Treponema pallidum.

Certain reducing agents containing sulfhydryl groups are important to the in-vitro survival of Treponema pallidum. Discrepancies occur, however, concerning the agents and the concentrations that are optimal. To clarify some of this confusion, sulfhydryl oxidation was determined using procedures and experimental conditions commonly used for T pallidum. Sulfhydryl oxidation varied according to the type of culture medium, the size of the culture vessels, the volume of the culture medium, and the gaseous environment within the culture vessels, as well as the method of extracting treponmes from infected testicular tissue. Dithiothreotol maintained highly reduced conditions by reducing disulfide groups to sulfhydryl groups. Lastly, the organisms influenced the sulfhydryl concentration by either direct oxidation or specific uptake. The sulfhydryl content was sharply decreased in the presence of viable preparations of T pallidum compared with heated preparations or membrane filtrates of viable preparations.

Animals↗
PubMed1979

Surface mucopolysaccharides of Treponema pallidum.

The viscous mucoid fluid that accumulates within syphilitic lesions may be due to breakdown of host tissue during infection, or may be synthesized by Treponema pallidum. Experiments were performed to investigate the acidic mucopolysaccharides that occur at the surface of T. pallidum (Nichols strain). These mucopolysaccharides were demonstrated by reaction with acidified bovine serum albumin and by agglutination with wheat germ agglutinin and soybean agglutinin. The polycations ruthenium red and toluidine blue influenced treponemal survival. Concentrations of both compounds at 200 mug/ml inhibited survival, whereas concentrations at 0.1mug/ml enhanced survival. The mucopolysaccharide concentration within the mucoid fluid that accumulates during intratesticular infection was determined by reaction with acidified bovine serum albumin; it ranged from 10,000 mug/ml to less than 8 mug/ml. The addition of this mucoid fluid to treponemal suspensions resulted in differing effects on T. pallidum survival. Some preparations were inhibitory, and others were stimulatory. Commercial preparations of hyaluronic acid and chondroitin sulfate at 400, 200, 100, and 50 mug/ml were detrimental to treponemal survival. The organisms exhibited pronounced clumping in the presence of the higher concentrations of hyaluronic acid. These clumps of treponemes were comprised of mucopolysaccharides as shown by acidified bovine serum albumin and toluidine blue reactions and by hyaluronidase degradation. Results are discussed in terms of the derivation and potential role of acidic mucopolysaccharides at the surface of T. pallidum.

Animals↗
PubMed1979

Relationship of Treponema pallidum to acidic mucopolysaccharides.

Attempts were made to relate Treponema pallidum to the acidic mucopolysaccharides that occur in vivo within host ground substance and in vitro on the surface of cultured testicular cells. Infected testicular tissue was fixed and processed for transmission electron microscopy in the presence of ruthenium red. The use of this inorganic dye demonstrated the large quantity of mucopolysaccharide within testicular tissue and the intimate association of treponemes with this material. Wheat germ agglutinin and soybean agglutinin agglutinated freshly harvested trypsinized testicular cells and trypsinized cultured cells derived from normal rabbit testes (NRT). When stained with toluidine blue, both cell preparations were metachromatic. Prior treatment of cultured NRT cells with hyaluronidase slightly decreased their sensitivity to agglutination by wheat germ agglutinin and soybean agglutinin. Lectin agglutination, metachromasia, and hyaluronidase susceptibility indicated that freshly harvested testicular cells and NRT cells have surface-associated acidic mucopolysaccharides that are probably hyaluronic acid and chondroitin sulfate. A rabbit erythrocyte "sandwich" technique was devised to show that hyaluronidase removed wheat germ agglutinin receptors from the cultured NRT cells. Prior incubation of NRT cells with hyaluronidase, followed by the addition of T. pallidum, resulted in a reduction in numbers of treponemes attached to the NRT cells. The attachment of T. pallidum appears to be mediated through the acidic mucopolysaccharides on the surface of NRT cells. The findings are discussed in terms of the importance of host ground substance mucopolysaccharide to the syphilitic infective process.

Animals↗
PubMed1979

Mucopolysaccharidase of Treponema pallidum.

Treponema pallidum (Nichols strain) exhibited mucopolysaccharidase activity. Acidic mucopolysaccharides were broken down more rapidly by viable treponemes than by heat-inactivated treponemes or membrane filtrates of treponemal suspensions. Ouchterlony immunodiffusion demonstrated the occurrence of antibodies to the hyaluronidase-like enzyme within syphilitic sera. After intratesticular inoculation of 2 x 10(7) to 6 x 10(7) treponemes, these anti-mucopolysaccharidase antibodies were detected between 9 and 35 days postinoculation. In addition, acidic mucopolysaccharides were present in the serum of infected animals 9 and 16 days postinoculation. Immune serum that contained antibodies to the mucopolysaccharidase restricted treponemal breakdown of acidic mucopolysaccharides. It has been previously demonstrated that immune rabbit serum contains a factor that blocks attachment of T. pallidum (Nichols strain) to cultured mammalian cells. This factor was effectively absorbed by prior incubation with bovine hyaluronidase. It is postulated that T. pallidum attaches to acidic mucopolysaccharides on the surface of cultured cells through the mucopolysaccharidase enzyme at the surface of the organisms. These findings are discussed in terms of the histopathogenesis of T. pallidum with applications to the healing immune response.

Glycosaminoglycans↗
PubMed1979

Suppression of lymphocyte response to concanavalin A by mucopolysaccharide material from Treponema pallidum-infected rabbits.

The testicular fluid and serum from rabbits infected intratesticularly with Treponema pallidum inhibited the mitogenic response of normal rabbit peripheral blood lymphocytes to concanavalin A. Mucopolysaccharide material present in the testicular fluid and serum was associated with the lymphocyte-inhibitory activity. Degradation of the mucopolysaccharide material with hyaluronidase resulted in the loss of the inhibitory activity of testicular fluid and serum of T. pallidu-infected rabbits.

Animals↗
PubMed1978

Mucopolysaccharide material resulting from the interaction of Treponema pallidum (Nichols strain) with cultured mammalian cells.

During incubation of Treponema pallidum (Nichols strain) with cultured mammlian cells derived from normal rabbit testes (NRT), an amorphous material accumulated at the surface of the cultured cells. This material was randomly distributed on all tissue cells within the culture chambers. The amount of amorphous material was dependent on the treponemal inocula. With 3 x 10(8) organisms per ml, this material was readily apparent within 2 days; with 4 x 10(7) organisms per ml, this material was detectable within 4 to 5 days; with lower inocula, the accumulation of amorphous material was far less apparent. Deposition of this surface-associated material required attachment of treponemes to the cultured cells, and the amount deposited was related to the number of treponemes attached per cell. This amorphous material was not detected when NRT cells were incubated with preparations of T. pallidum that were heat or air inactivated. In addition, the accumulaton of amorphous material was not due to a soluble component from host testicular tissue or to a soluble component developing during treponemal infection. This was demonstrated by the inability of membrane filtered preparations of T. pallidum to induce the deposition of amorphous material at the surface of the cultured cells. The nature of this material appeared to be acidic mucopolysaccharide as indicated by its metachromatic staining properties, its stainability with ruthenium red, and its partial degradation by bovine and streptomyces hyaluronidase. This amorphous material that accumulated in vitro at the surface of cultured cells may be similar to the mucoid material that accumulates in vivo during syphilitic infection.

Animals↗
PubMed1978

Influence of oxygen tension, sulfhydryl compounds, and serum on the motility and virulence of Treponema pallidum (Nichols strain) in a cell-free system.

The motility and virulence of Treponema pallidum (Nichols strain) were monitored during incubation in a modified tissue culture medium to study the effects of oxygen tension and medium composition on survival of the organism. A basal medium of Eagle minimal essential medium with 50% fresh, heat-inactivated normal rabbit serum was used inasmuch as better survival occurred with 50% normal rabbit serum than with lower concentrations. Addition of 0.5 to 2.0 mM dithiothreitol or 2.0 mM dithioerythritol to the basal medium led to significantly longer retention of T. pallidum viability in the presence of 3% oxygen than under aerobic or anaerobic conditions. The results of this investigation lend support to the classification of T. pallidum as a microaerophilic organism and provide direction for the design of potentially successful culture systems, with or without tissue culture cells.

Blood↗
PubMed1977

Interaction of Treponema pallidum (Nichols strain) with cultured mammalian cells: effects of oxygen, reducing agents, serum supplements, and different cell types.

Cultured mammalian cells extend the time of survival of Treponema pallidum (Nichols strain). Various parameters that have been previously shown to enhance treponemal survival in vitro were examined for influences on the interaction of T. pallidum with cultured cells. With cells derived from normal rabbit testes, the time of retention of treponemal virulence was extended in an atmosphere containing reduced concentrations of oxygen. Glutathione and cysteine, when added to the basal tissue culture medium, prolonged treponemal survival. In an assessment of various tissue culture medium supplements, normal rabbit serum was equivalent to fetal bovine serum and superior to bovine serum albumin fraction V (BSA), fatty acid-poor BSA, and lipid-pooed for TRK-2, HSE, NRK, and C6 cells. Dithiotreitol, as an additional reducing agent, sharply enhanced treponemal survival. With SF1Ep NBL-11 cells and basal tissue culture medium containing glutathione, cysteine, and dithiothreitol, in an atmosphere of approximately 3% oxygen, T. pallidum was maintained without detectable decreases in the number of virulent organisms for 6 days.

Blood↗