Biomedical subjects

Philipp Steven

Publications and source records attributed to Philipp Steven.

3 recordsLinked to original sources

PubMed2003

Region-specific immunological response of the different laryngeal compartments: significance of larynx-associated lymphoid tissue.

The occurrence of primary extranodal marginal-zone B-cell lymphoma [of the mucosa-associated lymphoid tissue (MALT) type] has only been described in the supraglottic region, implying that preexistent organized lymphoid tissue is present at that site only. To date, studies have not established clearly whether organized MALT shows a site-related distribution in the larynx. The supraglottic region of the false vocal folds and the subglottis from 87 unselected cadavers with no known history of nasal, oral, pharyngeal, laryngeal, tracheal, or esophageal disease were examined for the presence of organized MALT. Organized lymphoid tissue was found with the cytomorphological and immunophenotypic features of MALT in 100% of false vocal folds of children and in more than 90% of adolescents, decreasing to 7.1% in persons in their sixth decade, whereas MALT was completely absent in the subglottis in all age groups. The results explain why primary extranodal marginal-zone B-cell lymphoma has only been described in the supraglottic region but is absent in the subglottis. Moreover, the results suggest a region-specific immunological response of the different laryngeal areas as reflected in clinical observations and animal studies. However, the impact on presence or absence of laryngeal MALT awaits clarification.

Adolescent↗

PubMed2002

Upper airway epithelial structural changes in obstructive sleep-disordered breathing.

The etiology of upper airway collapsibility in patients with snoring and obstructive sleep apnea (OSA) remains unclear. Structural mucosal changes could be contributory factors. The objective of this study was to determine whether pathologic changes in the epithelium or the epithelial-connective tissue interface are present in patients with snoring and/or OSA by means of scanning electron microscopy and immunohistochemistry. Uvulae were obtained by uvulopalatopharyngoplasty from three patients with habitual snoring and nine patients with mild to severe OSA, as well as by dissection from 43 nonsnoring body donors. Scanning electron microscopy revealed structural changes in the epithelial-connective tissue boundary that significantly differed from age-related changes in the control subjects. The immunohistochemical staining with antibodies against epithelial cytokeratins showed differences in the expression pattern of cytokeratin 13 between patients and control subjects. No differences were found in the distribution pattern of laminin. Analysis of defense cells revealed a significant diffuse infiltration of leukocytes, mainly T cells, inside the lamina propria of the patient group, which was not observed in the control group. In conclusion, these results support the hypothesis that progressive structural changes in the mucosa caused by the trauma of snoring are a possible contributory factor to upper airway collapsibility.

Adult↗

PubMed2002

The human false vocal folds -- an analysis of antimicrobial defense mechanisms.

Inflammatory processes often lead to pathologic changes in the area of the larynx. A moistening function of the false vocal folds has been described frequently. Up to now we have little knowledge of the role of the false vocal folds in protection against pathogenic agents. The present study analyzes the structures of the false vocal folds in their relations to antimicrobial defense mechanisms. Investigations were performed on false vocal folds of larynges from 34 cadavers using histologic, histochemical and immunohistochemical methods. Seromucous glands, together with epithelial and goblet cells of the folds, synthesize a complex mucus layer. In all of the investigated samples this layer contains carbohydrates including N-acetyl-glucosamine, N-acetyl-galactosamine, galactose, mannose, fucose, and sialic acids. Furthermore, antimicrobial peptides like lactoferrin, lysozyme, alpha and beta defensins are also found in these structures. IgA, produced by plasma cells in the false vocal folds, is frequently integrated in the secretory product. Synthesized mucins, antimicrobial peptides and immunoglobulins form a specialized protective substance that is secreted mainly at the true vocal folds. Here the layer functions to lubricate the true vocal folds, resulting in positive functional consequences during vocal production. Moreover, together with immunocompetent cells, the protective layer seems to play a major role in antigen defense and prevents invasion of pathogenic agents.

Aged↗