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Biomedical subjects

R B Knox

Publications and source records attributed to R B Knox.

7 recordsLinked to original sources
PubMed1992

Mechanism of grass-pollen-induced asthma.

Many asthmatics are sensitive to rye-grass pollen, but pollen grains are too large to penetrate the lower airways. Our aim was to investigate the mechanism by which rye-grass pollen causes asthma. A major allergen of rye-grass pollen, Lol pIX, is located in intracellular starch granules within pollen grains. In-vitro tests showed that pollen grains are ruptured in rainwater by osmotic shock, each grain releasing about 700 starch granules into the environment. These granules are small enough to enter the airways (less than 3 microns in diameter). The starch granules were present in atmospheric samples taken during the pollen season, and showed a 50-fold increase in atmospheric concentration on days following rainfall. Isolated granules elicited IgE-mediated responses in asthmatic patients, and 4 patients with rainfall-associated asthma who underwent an inhalation challenge test had striking bronchial constriction after exposure to starch granules. Starch granules released from rye-grass pollen seem to be capable of causing asthma.

Allergens↗
PubMed1979

Childhood asthma and grass pollen aerobiology in Melbourne.

Children from the Melbourne metropolitan area with laboratory proven bronchial sensitivity to ryegrass pollen were selected for a clinical trial which was run concurrently with an aerobiological survey during the grass pollen season of 1975 to 1976. During periods of high pollen counts, significant deterioration in the children's asthma occurred. The grass pollen season was of 10 weeks' duration with the highest daily counts during November and December. Highest diurnal pollen concentrations occurred at night and were associated with winds from the north, north-west, and south-east and with other meteorological factors.

Adolescent↗
PubMed1977

Immunofluorescent localization of urease in the cotyledons of jack bean, Canavalia ensiformis.

Urease has been localized in sections of cotyledons from germinating seeds of jack bean, using FITC-labelled immunoglobulin prepared from urease antiserum raised in rabbits. The complication of lectin binding to the immunoglobulins was resolved by treatment of the sections with specific glycosides. Urease is localized in 2 sites: within the cytoplasm of storage parenchyma cells in spherical granules up to 3 micrometer in diameter, and within the intercellular spaces in spherical granules. Although similar in size, the latter are distinguished from the cytoplasmic granules by the presence of beta-lectin and appear to function as an extracellular lytic compartment or lysosome.

Antibody Specificity↗
PubMed1976

Pollen-wall proteins: quantitative cytochemistry of the origins of intine and exine enzymes in Brassica oleracea.

Simultaneous coupling methods for detection of acid phosphatase and non-specific esterase produce a coloured reaction product that is quantitatively related to enzyme content in freeze-sectioned Brassica pollen and tapetal cells. The intine-located acid phosphatase has 2 periods of synthesis: the first in late vacuolate period, associated with the completion of deposition of the intine polysaccharides; the second during pollen maturation, apparently reflecting cytoplasmic synthesis, Esterase activity accumulates in the tapetal cells until dissolution at early maturation period, when there is a dramatic rise in pollen-wall esterase activity, reflecting the transfer from tapetum to exine cavities. These quantitative studies confirm the gametophytic and sporophytic origins of the intine and exine proteins.

Acid Phosphatase↗
PubMed1975

Localization of lectins in legume cotyledons.

High-resolution techniques for the localization of lectins are described. Concanavalin A (Con A) and phytohaemagglutinin (PHA) are localized using a fluorescent method with (FITC)-labelled immunoglobulins which bind to the lectins in sections of jack and red kidney bean cotyledons. Specificity is defined by the use of specific sugar inhibitors. Both Con A and PHA are found in cytoplasmic sites. Lectins with beta-glycoside specificity are detected with red-coloured artificial carbohydrate antigens. The beta-galactosyl and beta-glucosyl antigens bind specifically to clusters of spherical bodies in the intercellular spaces, to cell wall sites, and to the periphery of the cytoplasm associated with the cell membrane.

Cell Wall↗