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Biomedical subjects

G M Wright

Publications and source records attributed to G M Wright.

65 records · Page 4Linked to original sources
PubMed1981

Immunohistochemical localization of procollagens. III. Type I procollagen antigenicity in osteoblasts and prebone (osteoid).

Frozen sections of unfixed tibia and mandibles from day-old rats were immunostained by the peroxidase-antiperoxidase technique after exposure to antisera against procollagen I or other collagenous materials. Light microscopic study of bone growth areas showed that procollagen I antigenicity was present in osteoblasts and prebone (osteoid), but not bone tissue; neither procollagen III nor collagen IV antigenicity were detected. The localization of procollagen I antigenicity within osteoblasts was then attempted in the electron microscope. Chopper slices of formaldehyde-fixed tibia from day-old rats were incubated with affinity-purified anti-procollagen I antibodies linked to peroxidase and were treated with hydrogen peroxide in the presence of 3,3'-diaminobenzidine. The dot-like reaction indicative of procollagen I antigenicity was found to be moderate in rough endoplasmic reticulum (rER) cisternae, strong in spherical and cylindrical Golgi distensions, and intense in prosecretory and secretory granules. Reactivity was also observed within the matrix of multivesicular bodies Thus an increasing gradient of procollagen I antigenicity occurs from rER cisternae through Golgi distensions to secretory granules, that is, along the presumed pathway of procollagen synthesis. The antigenicity present within rER cisternae is attributed to the precursor pro alpha (I) chains, while that in the cylindrical Golgi distensions, secretory granules, and prebone is attributed to procollagen itself. The antigenicity of multivesicular bodies suggests some degradation of pro alpha chains or procollagen.

Animals↗
PubMed1980

An attempt at quantitation of procollagens I and III and of collagen IV in tooth sections by exposure to the corresponding antibodies followed by 125I-protein A and radioautography.

The immunoreactivity of procollagen types I and III and of collagen type IV was detected in frozen sections of the growing apical end of rat incisor teeth by an indirect method making use of protein A. The sections were exposed to affinity-purified antibodies against these substances. The bound antibodies were then detected by incubation with radioiodinated protein A, followed by radioautography. This immunoradioautographic approach yielded preparations with low background, in which the reactions could be quantitated by counts of silver grains. The distribution of the radioautographic reactions was essentially the same as that previously observed with direct and indirect peroxidase methods, that is, procollagen I antigenicity predominated in odontoblasts and predentin, with minor amounts in periodontal tissue and pulp; procollagen III antigenicity was present in periodontal tissue and, to a lesser extent, in the pulp; and collagen IV antigenicity was restricted to basement membranes. Moreover, grain counts provided quantitative support for the conclusions on the distribution of procollagen I and III antigenicity.

Animals↗
PubMed1978

Light and electron microscopic immunocytochemical localization of thyroglobulin in the thyroid gland of the anadromous sea lamprey, Petromyzon marinus L., during its upstream migration.

Antibodies made against thyroglobulin (TG) were used in an immunocytochemical study for the light and electron microscopic localization of TG in the thyroid gland of the anadromous sea lamprey, Petromyzon marinus, during its upstream migration. TG was found in the follicular lumen and in some colloid droplets within the follicular cells. Except for an immunoreactive product observed in a small portion of the interstitial connective tissue, the location of TG in the lamprey was similar to that in the thyroid of the rat.

Animals↗
PubMed1978

Immunocytochemical localization of thyroglobulin in the endostyle of the anadromous sea lamprey, Petromyzon marinus L.

Thyroglobulin (TG) was localized in the endostyle of the anadromous sea lamprey, Petromyzon marinus L. by means of the unlabeled antibody peroxidase-antiperoxidase immunocytochemical method. TG was found localized on the apical surface and within the cytoplasm of type 2c and 3 cells and in some type 5 cells. By identifying the cells of the endostyle immunocytochemically it may be possible to study more readily the events of endostylar transformation during metamorphosis.

Animals↗
PubMed1977

Serum thyroxine concentrations in larval and metamorphosing anadromous sea lamprey, Petromyzon marinus L.

Thyroxine (T4) concentrations in samples of fresh sera taken from fed and unfed larval (ammocoetes) and metamorphosing anadromous sea lamprey (Petromyzon marinus) were measured by means of radioimmunoassay. T4 levels in unfed ammocoetes after a 1-month period were not significantly different from those of the fed ammocoetes. Nutritional state of ammocoetes therefore does not seem to affect their serum T4 levels. Serum T4 concentrations decreased abruptly at the onset of metamorphosis and declined to levels observed in spawing adults (Leloup and Hardy, '76; Packard et al., '76) by the middle (stage 3) of metamorphosis. No significant change in serum T4 levels occurred between stage 3 to the end of metamorphosis. The possible significance of decline in serum T4 levels to the metamorphic event in lamprey is discussed.

Animals↗