Nancy K. Tyler

Cancer-Associated Retinopathy (CAR Syndrome) with Antibodies Reacting with Retinal, Optic-Nerve, and Cancer Cells

A VARIETY of neurologic disorders are associated with different forms of cancer.1 2 3 4 5 6 7 Secondary neurologic effects that become manifest in the absence of metastasis are collectively called ...

Effect of murine gamma interferon on the cellular responses to bleomycin in mice.

Because in vitro studies have shown inhibition of fibroblast proliferation and collagen synthesis by interferon, we tested the hypothesis that murine gamma interferon inhibits bleomycin-induced pulmonary fibrosis in mice. Mice were divided into the following groups: saline plus vehicle (27), saline plus interferon (29), bleomycin plus vehicle (26), and bleomycin plus interferon (26). Bleomycin or saline were given intratracheally once at the beginning of the experiment and vehicle (phosphate-buffered saline) or interferon was given intramuscularly daily. Mice were killed at 14 or 21 days of the experiment. About half of the mice from each group were used for collagen biochemistry and half for bronchoalveolar lung lavage, transmission electron microscopy (TEM), and morphometry. Hydroxyproline content showed a significant reduction in bleomycin plus interferon compared to bleomycin plus vehicle mice at 21 days. The saline plus vehicle and saline plus interferon mice showed no difference in hydroxyproline content. Similarly, bronchoalveolar lavage showed no differences between saline plus vehicle and saline plus interferon mice; however, all mice treated with bleomycin showed significant increases in total cells as compared to saline treated mice. At 14 and 21 days in bronchoalveolar lavage there were significantly more lymphocytes in bleomycin plus interferon compared to bleomycin plus vehicle mice. In bronchoalveolar lavage, there were usually fewer neutrophils, monocytes and macrophages in bleomycin plus interferon compared to bleomycin plus vehicle mice. Morphometric estimates of the volume of lesion within lung showed no significant differences among the bleomycin treated groups. Stainable collagen fibers were less, but not significantly, in the bleomycin plus interferon compared to bleomycin plus vehicle mice. The number of fibroblasts per volume of lesion was significantly decreased at 14 and 21 days in bleomycin plus interferon compared to bleomycin plus vehicle mice. The total volume of lymphocytes in interstitial lesions was significantly greater at 14 and 21 days in bleomycin plus interferon mice compared to bleomycin plus vehicle mice. These results suggest an inhibitory action of gamma interferon on collagen accumulation and fibroblast proliferation associated with lymphocyte accumulation in the lungs of mice following bleomycin administration.

Comparison of daily and seasonal exposures of young monkeys to ozone

Oxidant air pollution tends to occur in both seasonal and daily cycles of polluted and clean air. To compare the effects of these 2 cycles, we exposed 2 groups of 7-month-old male monkeys to 0.25 ppm (0.49 mg/m3) of ozone (UV photometric standard) 8 h/day either daily or, in the seasonal model, days of alternate months during a total exposure period of 18 months. This is a longer ozone exposure period than any previously reported. A control group breathed only filtered air. Young monkeys were studied as their lungs are similar to those of man and their lungs, like those of man, grow over a period of several years. Monkeys from the seasonal exposure model, but not those exposed daily, had significantly increased total lung collagen content, chest wall compliance, and inspiratory capacity. All monkeys exposed to ozone had respiratory bronchiolitis with significant increases in related morphometric parameters. The only significant difference between seasonal and daily groups was in the volume fraction of macrophages. Even though the seasonally exposed monkeys were exposed to the same concentration of ozone for only half as many days, they had larger biochemical and physiological alterations and equivalent morphometric changes as those exposed daily. Lung growth was not completely normal in either exposed group. Long-term effects of oxidant air pollutants which have a seasonal occurrence may be more dependent upon the sequence of polluted and clean air than on the total number of days of pollution. Estimations of the risks of human exposure to seasonal air pollutants from effects observed in animals exposed daily may underestimate long-term pulmonary damage.

Morphometry of the Respiratory Tract: Avoiding the Sampling, Size, Orientation, and Reference Traps

The extrapolation to humans of studies of infectious or toxic agents injurious to the respiratory system using animal models assumes comparability in the structure and function of animal models and humans. Measurement of conducting airways and parenchyma yields quantitative data for parameters like volume, surface area, length, cell number and cell size. Over the past few decades, there has been an evolution of rigorous uniform sampling designs of stereology that ensure unbiased estimates of number, length, surface area, and volume. This approach has been termed ‘design-based’ stereology because of the reliance on sampling design rather than geometric model-based stereology that makes assumptions. The aim of this paper is to define new design-based stereological approaches for the direct estimation of anatomical structures and epithelial, interstitial and endothelial cells of specific regions of the lung independent of the sampling, size, orientation and reference traps. An example is provided using wildtype and transgenic mice expressing transforming growth factor-α to show the importance of the reference trap in stereologic estimates of postnatal lung growth.

Airway generation-specific differences in the spatial distribution of immune cells and cytokines in allergen-challenged rhesus monkeys.

Background Accumulation of immune cell populations and their cytokine products within tracheobronchial airways contributes to the pathogenesis of allergic asthma. It has been postulated that peripheral regions of the lung play a more significant role than proximal airways with regard to inflammatory events and airflow obstruction.

Antibody Indications of Secondary and Superimposed Retinal Hypersensitivity in Retinitis Pigmentosa

Antibody reactions with recognized retinopathy-inducing retinal antigens may be interpreted to reflect ongoing autoimmune events responsible for some forms of vision loss. We sought evidence of secondary and superimposed retinal hypersensitivity indicated by such antibody reactivity in a random group of patients with retinitis pigmentosa. We identified patterns of immunologic reactivity within members of a group of 52 patients with retinitis pigmentosa, which suggests some patients with retinitis pigmentosa may experience consequential superimposed retinal hypersensitivity. Identifying subgroups of patients with retinitis pigmentosa who exhibit indications of retinal hypersensitivity to known uveitopathogenic retinal proteins may permit the reduction of their rate of retinal degradation by immunomodulation.

Structural Evaluation of the Respiratory System

The theoretical and practical bases for morphological evaluation of the respiratory system useful for inhalation toxicology are reviewed. For most studies we recommend a comprehensive gross examination followed by in vitro tracheal infusion of a fixative containing both glutaraldehyde and formaldehyde in cacodylate buffer. Lungs fixed in this manner are suitable for LM, SEM, and TEM and lung volumes can be determined. The airway orientation of many lesions and the potential for gradients of damage are considered in the lung sampling plan. While LM of paraffin sections continues to be the basic method for evaluation, the SEM and TEM, especially when ancillary methods are used, provide valuable additional information. The use of backscattered electrons and energy-dispersive X-ray analysis in the SEM provides information concerning the localization and elemental analyses of particles. Cytochemical procedures characterize biological activities of specific cell types and are becoming more widely used. Morphometry permits correlation of quantified structure with physiological and biochemical data.

Effects of ozone on lung and somatic growth. Pair fed rats after ozone exposure and recovery periods

Minor differences in lung growth and development during childhood have been considered as a potential cause of rapid decline in pulmonary function in adulthood. Inhalation of ozone commonly causes changes in both body weight and lung volumes, which complicates interpretation of any changes in lung growth. The effects of ozone on lung growth were studied in rats which were pair fed. This technique permitted comparison of ozone-exposed and filtered-air control rats of the same body weight and body size as well as age and sex. Exposure was to filtered air or to 0.64 or 0.96 ppm ozone (UV standard) 8 h/night for 42 nights. A second control group was fed ad libitum and exposed to only filtered air. Half the rats were studied at the end of the 42-night exposures, the rest after a 42-day post-exposure period during which all rats were fed ab libitum and breathed filtered air. Rats examined at the end of the exposure period had larger saline and fixed lung volumes. These larger lungs had greater volumes of parenchyma, alveoli and respiratory bronchioles. Some of these changes persisted throughout a 42-day post-exposure period. Ozone inhalation by young rats alters lung growth and development in ways likely to be detrimental and those changes persist after ozone inhalation stops.

Ozone Exposure During thE Early Postnatal Period Alters the Timing and Pattern of Alveolar Growth and Development in Nonhuman Primates

Exposure to oxidant air pollutants in early childhood, with ozone as the key oxidant, has been linked to significant decrements in pulmonary function in young adults and exacerbation of airway remodeling in asthma. Development of lung parenchyma in rhesus monkeys is rapid during the first 2 years of life (comparable to the first 6 years in humans). Our hypothesis is that ozone inhalation during infancy alters alveolar morphogenesis. We exposed infant rhesus monkeys biweekly to 5, 8hr/day, cycles of 0.5 ppm ozone with or without house dust mite allergen from 1 to 3 or 1 to 6 months of age. Monkeys were necropsied at 3 and 6 months of age. A morphometric approach was used to quantify changes in alveolar volume and number, the distribution of alveolar size, and capillary surface density per alveolar septa. Quantitative real time PCR was used to measure the relative difference in gene expression over time. Monkeys exposed to ozone alone or ozone combined with allergen had statistically larger alveoli that were less in number at 3 months of age. Alveolar capillary surface density was also decreased in the ozone exposed groups at 3 months of age. At 6 months of age, the alveolar number was similar between treatment groups and was associated with a significant rise in alveolar number from 3 to 6 months of age in the ozone exposed groups. This increase in alveolar number was not associated with any significant increase in microvascular growth as measured by morphometry or changes in angiogenic gene expression. Inhalation of ozone during infancy alters the appearance and timing of alveolar growth and maturation. Understanding the mechanism involved with this altered alveolar growth may provide insight into the parenchymal injury and repair process that is involved with chronic lung diseases such as severe asthma and COPD. Anat Rec, 2012.

Design-Based Sampling and Quantitation of the Respiratory Airways

Design-based quantitation of the nasal cavity, larynx and tracheobronchial conducting airways after exposure to inhaled toxicants requires complete measurement of all respiratory airways or appropriate sampling followed by morphometric measurements. In vivo imaging (MRI or CT) of the nasal cavity, larynx and conducting airways provides anatomical detail of all the airways down to the distal airways. Since inhaled toxicants show predictable deposition patterns in the airways, identification and sampling of conducting airways becomes essential in a precise toxicological evaluation. Lengths, diameters and luminal surface areas can be directly measured on fixed specimens using a steromicroscope. Estimates of cell numbers, extracellular matrix volumes and vessel/nerve lengths per airway or epithelial basal laminar surface are estimated stereologically. Selected airways are cut into smaller pieces using a “fractionator” for uniform sampling of the airways. Cell numbers are estimated using a “disector.” Volumes are estimated using point probes, while length and surface areas are estimated by isotropically oriented sections with plane and line probes; an approach free of assumptions of shape, size or spatial orientation. True biological variance and the average sampling variance of the stereological measurement define the minimal sampling required to achieve precise estimates of the nasal cavity, larynx and conducting airways.