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Biomedical subjects

J T McMahan

Publications and source records attributed to J T McMahan.

4 recordsLinked to original sources

Bacterial allergy in nasal polyposis. A new method for quantifying specific IgE.

OBJECTIVES: To determine (1) if bacteria-specific serum IgE levels can be more effectively measured by first absorbing competing IgG antibodies from serum and (2) if patients with chronic paranasal sinus disease exhibit a high positive prevalence of bacteria-specific serum IgE. DESIGN: A modified radioallergosorbent test method was employed wherein each serum sample was absorbed with recProtein A to remove competing non-IgE antibodies, and purified proteins extracted from 16 individual bacteria were used as potential allergens. PARTICIPANTS: Twenty-four patients with nasal polyposis and 14 with chronic sinusitis, all refractory to conventional medical therapy and requiring endoscopic sinusotomies, were tested. Tested as controls were 10 subjects with chronic allergic rhinitis, without a history of chronic sinus disease, and possessing total serum IgE and inhalant-specific IgE levels equal to or higher than the patient group. RESULTS: (1) Pretreatment of serum samples with recProtein A resulted in an increase of bacteria-specific radioallergosorbent test sensitivity. (2) Seventeen of 24 patients with polyps, eight of 14 with chronic sinusitis, and one of 10 with chronic allergic rhinitis were determined to be IgE positive when tested with this assay. CONCLUSIONS: (1) Bacteria-specific serum IgE can be quantified; (2) most patients with nasal polyposis and/or chronic sinusitis possess bacteria-specific IgE in their serum, while subjects with only allergic rhinitis do not; and (3) multiple bacterial species isolated from chronically infected sinuses are capable of inducing IgE-mediated sensitization.

Antibodies, Bacterial↗

Paranasal sinusitis. Geriatric considerations.

Heightened awareness of associated symptoms and related diseases has resulted in earlier and more accurate diagnosis of sinusitis. With early recognition, aggressive medical management and appropriate surgical intervention prevent the morbidity and mortality associated with paranasal sinusitis in the geriatric population.

Aged↗

Osteocartilaginous tumors in the parapharyngeal space arising from bone exostoses.

Three osteocartilaginous tumors that arose from bone stalks were diagnosed by the demonstration, on multiplanar cross-sectional CT and MR images, of the site of stalk attachment to the adjacent mandible (one), skull base (one), and cervical vertebra (one). All three patients presented with signs and symptoms related to mass effect in the parapharyngeal region. Mass effect was more pronounced in the two cases of malignant degeneration (osteosarcoma, chondrosarcoma) than in the single case of benign osteocartilaginous exostosis. Differentiation of benign from malignant osteocartilaginous tumor may be accomplished by appreciating characteristic CT and MR features of the cartilage cap. The differential diagnosis of mass lesions of the parapharyngeal space should include tumors of osteocartilaginous origin.

Adolescent↗