Biomedical subjects

D J Magliano

Publications and source records attributed to D J Magliano.

3 recordsLinked to original sources

PubMed1992

Computer-assisted morphometry: point, intersection, and profile counting and three-dimensional reconstruction.

The use of computers in morphometry can involve 1) automated image analysis, semiautomated image analysis and point, intersection, intercept and profile counts of two-dimensional images on tissue sections with mathematical extrapolation to the third dimension, 2) direct measurement of volumes, surfaces, lengths, and curvature using x,y,z coordinates of serial sectioned images, or 3) stereologic techniques and serial sections which is a combination of 1 and 2 above. Automated and semiautomated image analysis are generally restricted to specimens that are characterized by differential contrast such as interalveolar septa in the lung or histochemically stained mucous granules in pulmonary epithelium. Point, intersection, and profile counts using hand-held, notebook PCs, portable PCs, or standard PCs and MS-DOS-based application programs are extremely efficient, precise, affordable, and convenient methods of quantitating average values of a population. When morphometric measurements of individual structures are required, computer-assisted three-dimensional reconstruction using x,y,z coordinates of the surface outline from serial sections is a tedious yet precise method. We describe a computer program that efficiently estimates mean caliper diameter, volume, and surface area with less than five percent error with five sections per structure. We also describe a program that does digital image subtraction on serial sections, superimposes digitally generated test systems on biological images, and accumulates point, intersection, and profile counts using a Macintosh II series computer.

Animals↗

PubMed1991

Morphometric assessment of pulmonary toxicity in the rodent lung.

An overview of the epithelial and interstitial composition of rat respiratory airways shows complexity and variability. Airway epithelium varies in 1) different airway levels; 2) the types and ultrastructure of cells present; and 3) the abundance, type, and composition of stored secretory product. Unbiased sampling of airways is done using airway microdissection with a specific binary numbering system for airway generation. Vertical sections of selected airways are used to sample epithelium and interstitium. We determine the ratios of the volume of epithelial or interstitial cells to the total epithelial or interstitial volume (Vv). The surface of the epithelial basal lamina to the total epithelial or interstitial volume (Sv) is determined using point and intersection counting with a cycloid grid. Using the selector method on serial plastic sections, we determine the number of epithelial or interstitial cells per volume (Nv) of total epithelium or interstitium. We calculate the number of epithelial or interstitial cells per surface of epithelial basal lamina (Ns) by dividing Nv by Sv where the volumes are the same compartment. We calculate average cell volumes (v) for specific epithelial and interstitial cells by dividing the absolute nuclear volume by the ratio of the nucleus to cell volume (Vv). By multiplying the average cell volume (v) by the ratio of organellar volume to cell volume (Vv), we calculate the average organellar volume per cell. These unbiased stereological approaches are critical in a quantitative evaluation of toxicological injury of rat tracheobronchial airways.

Administration, Inhalation↗

PubMed1987

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.

Animals↗