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Biomedical subjects

M Listgarten

Publications and source records attributed to M Listgarten.

12 recordsLinked to original sources
PubMed1984

Bacterial invasion of oral tissues of immunosuppressed rats.

The periodontia of immunosuppressed rats were examined by light and electron microscopy. Bacterial invasion was noted in the periodontal tissues of septicemic ligature-treated animals. Invading bacteria consisted of gram-negative rods which were morphologically similar to the Pseudomonas aeruginosa strain isolated from the mouth of one of the septicemic animals.

Alveolar Process↗
PubMed1982

Release of toxic microvesicles by Actinobacillus actinomycetemcomitans.

Oral isolates of Actinobacillus actinomycetemcomitans (strain Y4) release spherical microvesicles in large numbers during normal growth. The biological activities of these products were studied, and it was estimated that approximately 1/10 of their dry weight was made up of heat- and proteolysis-resistant endotoxin. The chicken embryo lethality and bone-resorbing activity of the microvesicles were heat stable but proteolysis sensitive. Other laboratories have reported the presence of a heat- and proteolysis-sensitive leukotoxin in similar preparations. Accordingly, the microvesicles released by strain Y4 may contain, in addition to endotoxin, several potent substances which are highly toxic and active in bone resorption, and these may be significant factors in the pathogenesis of periodontal diseases.

Actinobacillus↗
PubMed1978

Role of bacterial products in periodontitis: immune response in gnotobiotic rats monoinfected with Eikenella corrodens.

The development of humoral and cell-mediated immune responses to Eikenella corrodens (a bacterium that causes periodontal lesions in gnotobiotic rats) was measured and compared with the rate of appearance of macroscopic lesions. A possible inverse relationship was found. A strong cell-mediated immune response, as measured by skin reactivity and lymphocyte mitogenesis, occurred between 4 and 6 weeks after infection and subsided soon thereafter to a low response level. Humoral antibodies to endotoxin from E. corrodens could not be detected at any time. The disease developed only after the cell-mediated immune response diminished, thus suggesting that lack of an efficient immune response may permit the development of the disease. This is seemingly in contradiction to the assumption that tissue destruction in such cases is caused by the immune response and its products. We are inclined to believe, based on our findings reported here, that the lack of immune responsiveness to the bacterium and/or its products is the major causative factor in the development of periodontitis. At the same time, we wish to emphasize that occurrence of both phenomena during the long development of periodontal disease is possible.

Animals↗
PubMed1978

Role of bacterial products in periodontitis: humoral immune response to Eikenella corrodens.

Eikenella corrodens can induce periodontitis-like disease in gnotobiotic rats. Some components of this bacterial cell elicit measurable humoral immune response during the development of the disease, but in this system endotoxin is not among the efficient immunogens. Because no humoral immune response could be seen to the endotoxin of Eikenella corrodens it is assumed that this endotoxin can act uncontrolled in monoinfected rats. Accordingly, the lack of protective humoral immune response to pathogenic components of Eikenella corrodens may be the major factor permitting the development of the disease described here. The possibility that both cell-mediated immunity and uncontrolled endotoxic action are parts of the pathomechanism of the disease is supported by our observations.

Animals↗
PubMed1973

Serology of Streptococcus sanguis: localization of antigens with unlabeled antisera.

A new technique for the electron microscope localization of bacterial surface antigens, using unlabeled antisera, has been developed. This technique, called the "immuno-coating reaction" was applied to serological studies of Streptococcus sanguis, using antisera which had been shown to be specific for this species by gel diffusion analysis. The results of the immuno-coating reaction confirmed the specificity of the antisera for S. sanguis. In addition, the data indicate that some of the antigens responsible for the reaction were proteins which formed filamentous processes on the surface of the cell.

Absorption↗
PubMed1969

Morphological and biochemical differentiation of three types of small oral spirochetes.

THIRTY STRAINS OF HUMAN ORAL ANAEROBIC SPIROCHETES WERE ISOLATED IN THREE DIFFERENT MEDIA: veal heart infusion-ascitic fluid, Spirolate-Brain Heart Infusion-rabbit serum, and supplemented PPLO broth. The morphological and biochemical characteristics of the isolates permitted their differentiation into three distinct species: Treponema denticola, T. macrodentium, and T. oralis (proposed new species). These species could be differentiated as follows. Organisms of the T. denticola type had a "2-4-2" axial fibril relationship as determined by electron microscopy, required serum for growth, did not utilize glucose or lactate, and produced indole, ammonia, acetate, and lactate as end products. T. macrodentium had a "1-2-1" axial fibril relationship, did not require serum, utilized glucose but not lactate, did not produce indole or ammonia, and produced formate, acetate, lactate, and succinate as acid end products. T. oralis had a "1-2-1" axial fibril relationship, required serum for growth, utilized lactate but not glucose, produced indole but not ammonia, and produced propionate and acetate as acid end products.

Culture Media↗