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T F DeMaria

Publications and source records attributed to T F DeMaria.

At least 37 records · Page 2Linked to original sources
PubMed1994

Peptidoglycan isolated from nontypeable Haemophilus influenzae induces experimental otitis media in the chinchilla.

Bacterial cell wall components induce a number of biologic effects and promote inflammatory changes in a variety of hosts. Peptidoglycan isolated from Streptococcus pneumoniae can induce inflammation in the middle ear; however, an analogous role for peptidoglycan derived from gram-negative otitis media pathogens has not been described. Peptidoglycan isolated from nontypeable Haemophilus influenzae (NTHi), a major cause of otitis media, was evaluated in a chinchilla model. The direct injection of the middle ear with 3-300 micrograms of peptidoglycan resulted in tympanic membrane inflammation, abnormal pressure in the middle ear, leukocytosis, and histopathologic changes in the middle ear mucosa that included marked edema, osteoneogenesis, focal hemorrhage, and a mononuclear infiltration into the subepithelial space. These data indicate that NTHi peptidoglycan induced inflammation and histopathologic changes in the tympanic membrane and middle ear mucosal epithelium and may contribute to the pathogenesis of otitis media.

Animals↗
PubMed1994

Effect of endotoxin on cultured rat middle ear epithelium, rat meatal epidermis, and human keratinocytes.

Several factors seem to contribute to the series of events in the pathogenesis of otitis media and cholesteatoma. Endotoxin is likely to be one of these factors, since it has been found in human middle ear effusions and since injection of this substance into the middle ear, in animal experiments, gave rise to prominent reactions. Provoking of epithelial cells in vitro with endotoxin led to distinct cell responses that might be associated with cholesteatoma formation. In this study the effect of endotoxin on serially cultured rat middle ear epithelium, rat meatal epidermis, and human keratinocytes was investigated. Endotoxin strongly stimulated the proliferation of middle ear epithelium and human keratinocytes and inhibited that of meatal epidermis. Furthermore, endotoxin affected the morphology of the three types of tissue. Rat middle ear epithelium revealed epithelial cell tracks with interconnecting bridge-like structures protruding above the culture plane, whereas rat meatal epidermis showed increased terminal differentiation expressing large areas of blister-like structures detaching from the culture dish. Cross-linked envelope analysis of human keratinocytes showed an increased terminal differentiation that was morphologically confirmed but was not confirmed by cytokeratin analysis. The results of this study support the hypothesis that endotoxin may play an important role in the pathogenesis of otitis media and cholesteatoma.

Animals↗
PubMed1993

Cytological and histological changes in the middle ear after inoculation of influenza A virus.

Experimental otitis media induced in the chinchilla by inoculation of influenza A virus into the middle ear resulted in capillary engorgement, subepithelial hemorrhage, tissue edema and acute inflammatory cell infiltration. Quantitative morphometric measurements were made for 28 days. Ciliated cells appeared to be the primary target of this strain of influenza virus and demonstrated the greatest degree of damage. Three weeks were required to restore the ciliated epithelium in the tubotympanum to normal levels.

Animals↗
PubMed1992

Changes in the structure of the cell surface carbohydrates of the chinchilla tubotympanum following Streptococcus pneumoniae-induced otitis media.

Streptococcus pneumoniae (Spn) are among the most frequently isolated pathogens in acute otitis media (AOM) and in otitis media with effusion (OME). Recently, the specific receptor for Spn has been identified as the trisaccharide unit Gal beta 1-4 GlcNAc beta 1-3 Gal beta with GlcNAc beta 1-3 Gal beta as the principal binding site. During the colonization of mucosal surfaces, pneumococci produce a variety of enzymes. This study was conducted to identify any resulting changes in the cell surface carbohydrate structure due to the action of these enzymes during pneumococcal otitis media (OM) in chinchillas. Using a lectin histochemical method with seven different lectins (SNA, LFA, WGA, Succ WGA, BSL II, PNA, ECL), the labeling pattern revealed not only the removal of the terminal sialic acid, but also the exposure of N-acetyl-glucosamine. These results suggested that Spn-produced enzymes uncover part of their own receptor structure and thus may facilitate adherence and subsequent infection.

Acute Disease↗
PubMed1992

Effect of endotoxin on cultured chinchilla middle ear epithelium.

The effect of endotoxin on the growth and morphology of cultured chinchilla middle ear epithelium was examined. Within 24 hours of culture, cells maintained in medium containing endotoxin exhibited dose-dependent morphological changes. The highest concentration of endotoxin (100 mg) resulted in cell death. The growth curve of the cells in culture demonstrated a dose-dependent, significant increase in cell number when endotoxin was added to the medium.

Animals↗
PubMed1991

Primary culture of chinchilla middle ear epithelium.

Chinchilla middle ear epithelium was successfully cultured in medium containing Dulbecco's modified Eagle's medium, Ham's F12 mixture, and fetal bovine serum. After 3 to 5 days, the explants produced outgrowths of primarily flat polygonal and ciliated cells that persisted for up to 10 days in culture. These cells in the outgrowth often formed a "dome" indicating the presence of functional polarization and fluid transportation capability. The ciliated cells were more frequently found near the explant, and were fewer in number in the area distant from the explant. This finding suggests that the ciliated cells in the outgrowth are migrated ciliated cells deriving from the explant. That secretory cells were not identified in the outgrowth indicated that the present culture technique did not support secretory activity. Using the present culture technique, we were able to maintain the explants and primary cultured cells for up to 14 days in a majority of cases; hence, these techniques appear to be applicable to a number of in vitro studies.

Animals↗
PubMed1991

Serial culture and characterization of the chinchilla middle ear epithelium.

We have successfully cultured a fibroblast-free chinchilla middle ear epithelium up to the 10th passage by using conditioned medium or using irradiated 3T3 cells as feeder cells. The cultured epithelial cells assumed a polygonal shape with a cobblestone appearance, indicating tight junction formation. A small number of the cells began to show abnormal morphology, such as indistinct cell boundaries, fibroid appearance, or giant cell formation, as the passage increased, particularly after the 5th passage. These morphologically transformed cells showed positive labeling with an anticytokeratin antibody, which indicated the epithelial origin of these cells. Neither ciliated nor secretory cells were observed in the serially cultured cells. The rate of cell growth slowed after the 7th passage, and after the 11th passage the cells no longer proliferated. Even with the above limitations, these cultured cells can be used for a number of in vitro experiments.

Animals↗
PubMed1991

Surface active substances in the chinchilla tubotympanum. A biochemical study.

It has been demonstrated that the eustachian tube and middle ear epithelium produce Tubal Surface Active Substances (TSAS), which facilitate the opening of the eustachian tube. In order to characterize the biochemical contents of chinchilla TSAS, the tubal washings were analyzed using 2-D thin layer chromatography. The results indicate that phosphatidylcholine was the predominant phospholipid, followed by sphingomyelin, phosphatidylinositol phosphatidylethanolamine, and phosphatidylserine. In comparison, pulmonary lavage showed phosphatidylcholine to be highest allowed by phosphatidylethanolamine and sphingomyelin. Phosphatidylcholine/phosphatidylethanolanim ratios were 5:1 in the tubal lavage, and 8:1 in the pulmonary lavage. Phosphatidylcholine/sphingomyelin ratios were 2:1 in the tubal lavage, and 67:1 in the pulmonary lavage. It is concluded that the biochemical content of TSAS is similar but not identical to that of pulmonary surfactants.

Animals↗
PubMed1990

Role of middle ear endotoxin in inner ear inflammatory response and hydrops: long-term study.

The permeability of the round window membrane for Salmonella typhimurium-derived endotoxin was examined with use of a total of 33 chinchillas. One milligram of each endotoxin was instilled into the tympanic cavities via the superior bullae. The endotoxin activities in middle ear effusions (MEEs), perilymph, and sera were determined by limulus amebocyte lysate assay. Endotoxin was detected in perilymph on the inoculated side by 12 hours after endotoxin instillation and persisted for up to 3 weeks. Endotoxin level peaked at 24 to 48 hours postinstillation, and it steadily declined afterward. This result suggests that the maximum penetration occurred during the active inflammatory stage. Histologic evidence demonstrated remarkable pathologic changes in the inner ear, including bleeding and inflammatory cell recruitment, mostly in the perilymphatic spaces (eg, scalae tympani, scalae vestibuli, spiral ligament), strial swelling, and sensory cell degeneration. This result suggests that endotoxin present in the middle ear can permeate the round window membrane, causing inner ear tissue damage in this animal model.

Animals↗
PubMed1989

Immunological responsiveness of chinchillas to outer membrane and isolated fimbrial proteins of nontypeable Haemophilus influenzae.

Thin, nonhemagglutinating fimbriae have been demonstrated on 100% of the clinical isolates of nontypeable Haemophilus influenzae recovered from children with chronic otitis media tested in this laboratory (L. O. Bakaletz, B.M. Tallan, T.M. Hoepf, T.F. DeMaria, H.G. Birck, and D.J. Lim, Infect. Immun. 56:331-335, 1988). Chinchillas with induced otitis media responded to this surface-located antigen of both the infecting and a heterologous strain. Antibodies were found in both serum and middle ear fluids.

Animals↗
PubMed1989

Endotoxin permeability through the round window.

The permeability of the round window membrane to Salmonella typhimurium derived endotoxin was examined using a total of 17 chinchillas. One mg of endotoxin was instilled into the tympanic cavity via the superior bulla. Endotoxin activity in middle ear effusions (MEEs), perilymph (both inoculated and non-inoculated side), and sera was determined by Limulus lysate assay after 12, 24, 48, 72, and 120 h following endotoxin instillation. Endotoxin was detected in perilymph on the inoculated side by 12 h after endotoxin instillation and persisted for 5 days during the present measurement period. Endotoxin level peaked at 24-48 h post-instillation, and steadily declined afterwards. This result suggests that the maximum penetration occurred during the active inflammatory stage. Histologic investigation revealed marked pathological changes in the inner ear, including bleeding and inflammatory cell recruitment, mostly in the perilymphatic spaces (e.g. scalae tympani and vestibuli, spiral ligament), strial swelling, and sensory cell degeneration. These results suggest that endotoxin, when introduced into the middle ear, can permeate through the round window membrane and can cause inner ear tissue damage in this animal model.

Animals↗
PubMed1988

Beta 2-microglobulin in otitis media with effusion.

beta 2-Microglobulin (beta 2M) is a low-molecular-weight protein present in serum and other fluids during various autoimmune or chronic inflammatory diseases. beta 2-Microglobulin was measured in middle ear effusion (MEE) and serum samples obtained from 36 patients with chronic otitis media with effusion. Using a quantitative competitive enzyme immunoassay, we were able to demonstrate beta 2M in 98% of the MEE samples. The mean concentration of beta 2M was higher in the MEE samples than in the serum samples. There was considerable variability between ears in those patients with bilateral MEE. There was no correlation between beta 2M concentration and the patients' age, sex, MEE type, and culture results, or cytologic profiles of the MEEs. This increased beta 2M may reflect earlier lymphocyte activity during the inflammatory process.

Child↗
PubMed1988

Frequency of fimbriation of nontypable Haemophilus influenzae and its ability to adhere to chinchilla and human respiratory epithelium.

To date, we have examined nearly 60 clinical isolates of nontypable Haemophilus influenzae (26 nasopharyngeal, 33 from middle ear effusions) and have found that 100% were fimbriated. The percentage of cells bearing fimbriae within each isolate varied from less than 10 to 100%, with fimbriae being either peritrichous or bipolar in distribution. Fimbriae were approximately 2.4 to 3.6 nm in width; however, there was a high degree of variability in both length and number of fimbriae per individual bacterial cell among these isolates. All isolates tested adhered to both human oropharyngeal cells and chinchilla tracheal epithelium regardless of the degree to which the particular isolate was fimbriate. The level or degree of fimbriation did not correlate with either site of isolation, biotype, strength of hemagglutination reaction, or type of effusion present in the ear. These appendages appear to be quite different from those described for type b H. influenzae in which the ability to adhere and strength of ability to hemagglutinate correlated strongly with degree of fimbriation.

Animals↗