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Biomedical subjects

A Catanzaro

Publications and source records attributed to A Catanzaro.

95 records · Page 6Linked to original sources
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Secondary immune response in the middle ear: immunological, morphological, and physiological observations.

A model of secondary immune response in the middle ear (ME) was developed in the guinea pig. Animals were immunized intradermally with keyhole limpet hemocyanin (KLH) and challenged with KLH in the ME 8 weeks later. The ME displayed effusion, mucosal hyperplasia, mucosal edema, and leukocytic infiltration. These responses were maximal at 3 days postchallenge, and persisted for 2 to 3 weeks. High levels of antibody were observed in the ME effusions, and serum titers increased significantly. Immunohistochemical localization of antibody indicated that substantial free IgG was present in the submucosa, with much less in the mucosal epithelium. IgA plasma cells were observed in the submucosa at 1 week postchallenge, but no IgM was detected. In contrast to the response observed in sensitized animals, antigen presented to the ME of unimmunized control animals resulted in no effusion, minimal mucosal inflammation, and little or no antibody in either the ME or serum. However, substantial neutrophilic infiltration of the ME cavity was observed. The effusion and inflammation produced by secondary ME immune responses were not affected by tympanostomy tubes. Eustachian tube function as measured by a forced response test was not affected by ME immune response. This suggests that the immunologically induced effusion was not the result of eustachian tube obstruction. We postulate that increased vascular permeability in the ME mucosa, induced by chemical mediators, resulted in the transudation of serum.

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Antigenicity of the guinea pig's tympanic membrane.

The immunogenicity of the middle ear constituents is a matter of prime importance. In this work, the authors were interested in the antigenicity of the guinea pig's tymphanic membrane. They reached the conclusion, after developing an antiserum (IgG), that the tympanic membrane of the guinea pig can be antigenic in the rabbit. After purification and absorption, a cross-reactivity remains between the tympanic membrane and the mucosae of the upper respiratory system.

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PubMedDate not supplied

Passive transfer of immune-mediated middle ear inflammation and effusion.

Antigenic challenge in the middle ear of animals previously sensitized intradermally results in an immunologically mediated inflammatory response, including the generation of serous effusion in the middle ear cavity. The mechanisms which contribute to this immune-mediated otitis media with effusion (OME) were investigated by passive transfer with either purified IgG or with sensitized lymphocytes. A peritoneal exudate was raised in strain 13 guinea pigs by repeated injection of keyhole limpet hemocyanin (KLH) with complete Freund's adjuvant. IgG and lymphocytes were isolated from exudates and used for passive sensitization. Middle ear challenge following passive transfer of IgG specific to KLH produced effusion and inflammation which was equivalent to that observed in actively immunized animals, but resulted in significantly greater numbers of leukocytes infiltrating the middle ear. Unlike in the active response, few of the cells infiltrating the middle ear mucosa and middle ear cavity were eosinophils. Middle ear challenge with KLH following passive transfer with sensitized lymphocytes produced no middle ear effusion, relatively little mucosal inflammation, and sharply reduced exocytosis of leukocytes into the middle ear when compared with the active immune response or even with unimmunized controls. It is concluded that middle ear effusion, inflammation, and leukocytic exocytosis are mediated primarily by the IgG fraction of humoral immunity in our model of immune OME.

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PubMedDate not supplied

Identification of human immunodeficiency virus-infected individuals by delayed type hypersensitivity skin testing.

OBJECTIVE: To determine if more useful information could be derived from delayed type hypersensitivity skin testing of human immunodeficiency virus (HIV)-infected patients by measuring the amount of induration in response to skin testing in contrast to assessing for the presence of anergy. DESIGN: Prospective, double-blind trial. SETTING: Two HIV clinics. PATIENTS: A sample of 60 ambulatory, HIV-infected patients and 18 normal controls. INTERVENTIONS: Delayed type hypersensitivity skin testing with a panel of recall antigens. MAIN OUTCOME MEASURES: Anergy, total induration in response to the panel of antigens, and CD4 lymphocyte count. RESULTS: Anergy was present in only 28 of 60 (46.7 percent) HIV-infected subjects. A low skin test score (under 20 mm of total induration) was present in 43 of 60 (71.7 percent) HIV-infected subjects (p < 0.01 vs anergy). One control patient was anergic, while two had a low skin test score (p = NS). Among HIV-infected subjects, there was poor correlation between CD4 lymphocyte count and skin test score (R2 = 0.12). CONCLUSIONS: Skin testing by this method identifies more HIV-infected patients than does assessing the presence or absence of anergy.

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