Biomedical subjects

Y C Zee

Publications and source records attributed to Y C Zee.

58 records · Page 4Linked to original sources

PubMedDate not supplied

Immunological alterations in the lungs of mice following ozone exposure: changes in immunoglobulin levels and antibody-containing cells.

Ozone was added to the air of the environmental chambers containing specific pathogen-free mice. At levels of 0.5 and 0.8 ppm the oxidant was seen to have inflammatory effects, as shown by rising serum albumin levels in lung lavage fluid. Fluorescein conjugated anti-heavy chain sera were used to detect cells containing IgM, IgG, and IgA in measured lung areas termed Pulmonary Units. Antigenic stimuli occurred along the airways, with significant increases of IgA-containing cells in the bronchus-associated lymphoid tissue. The numbers of IgM- and IgG-containing cells did not increase. Immunodiffusion analyses for immunoglobulins in lung lavage fluid indicated increases of IgG1, IgG2, and IgA in lung secretions. The calculation of changing Ig/Alb ratios suggested that the IgA present was largely the result of local synthesis, while IgG molecules were mainly of serum origin. Possible sources of antigenic stimuli to ozone-exposed lungs are discussed.

Albumins↗

PubMedDate not supplied

Optimizing the enzyme-linked immunosorbent assay for evaluating immunity of chickens to Newcastle disease.

Experiments employing the various steps and reagents used in the enzyme-linked immunosorbent assay (ELISA) were conducted to produce an ELISA with the highest sensitivity and specificity possible for detecting Newcastle disease antibodies in chicken sera. Of the four types of antigen tested, crude antigen gave inconsistent results. However, an alcohol-precipitated antigen prepared from infectious allantoic-amniotic fluids was as satisfactory as more highly purified virus preparations. Other factors found to be extremely important were a 0.5M concentration of NaCl in the diluent and wash solutions used in the procedure, and a pH of 13 for sensitizing solution for maximum specific binding of the antigen to the microplate plastic wells. A comparison was made between the hemagglutination-inhibition (HI) titers of 550 known chicken sera and the corresponding ELISA values. Although the ELISA is much more sensitive than the HI test, there was a general but not a direct correlation between the two tests. The ELISA did not give more information than the HI test concerning protection against an NDV-induced drop in egg production. Preliminary observations indicated that this ELISA procedure is also applicable for turkey sera.

Animals↗

PubMedDate not supplied

Pulmonary changes induced by low-level ozone: morphological observations.

This study defines the surface and ultrastructural changes which occur in mouse lungs during the early stages of continuous low-level ozone exposure. Swiss-Webster mice were exposed for 35 consecutive days to 0.5 ppm ozone, a level of oxidant gas which simulates levels occurring during an episode of severe smog in urban areas of the California south coast air basin. Groups of mice were killed on day 7, 21, or 35 of exposure and their lungs excised and examined by light microscopy, scanning electron microscopy, and transmission electron microscopy. Lung damage was most severe at the transition zone from terminal bronchiole to alveolar duct. This centriacinar lesion consisted of (1) increased numbers of macrophages within proximal alveoli of alveolar ducts, (2) clusters of type 2 pneumonocytes lining these proximal alveoli, (3) changes in surface characteristics of Clara cells, and (4) hyperplastic nodules of bronchiolar epithelium within terminal bronchioles. Inflammatory cell infiltrates were reduced in numbers at 35 days of exposure as compared to 7 days of exposure, but the hyperplastic bronchiolar epithelium persisted and, in fact, increased in severity as exposure length increased. Although inflammatory cell infiltrates were observed in proximal alveoli of alveolar ducts, the hyperplastic bronchiolar epithelial changes were observed throughout the lengths of terminal bronchioles examined. The variability in response to ozone insult of nonciliated cells in the terminal bronchiole of rats, mice, and monkeys is discussed.

Animals↗

PubMedDate not supplied

Studies on the enhancement of allergic lung sensitization by inhalation of ozone and sulfuric acid aerosol.

Air pollutants were found to enhance the allergic sensitization of mice to an inhaled antigen. Aerosolized ovalbumin was used to mimic the inhalation of an environmental allergen. In three experiments the antigenic contact was repeated at 4 to 7 times over a period of approximately a month. Groups of mice were intermittently exposed to ozone at 0.5 and 0.8 ppm, sulfuric acid aerosol (1 mg/m3), and a combination of the two air pollutants. Antigenically sensitized mice showed some evidence of atopic reactivity to the inhaled antigen, but the interpretation of these responses was difficult to evaluate by observation alone. Clear evidence of allergic sensitization was obtained by injecting the antigen intravenously and recording the instances of systemic anaphylaxis. Allergic mice demonstrated anaphylactic shock within a few minutes of the injection, and fatally shocked animals died within 20 to 40 min. Significant increases in the levels of sensitization were obtained in animals exposed to ozone and the combination of ozone and sulfuric acid aerosol.

Aerosols↗