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Biomedical subjects

D L Gard

Publications and source records attributed to D L Gard.

41 records · Page 3Linked to original sources
PubMed1979

Coexistence of desmin and the fibroblastic intermediate filament subunit in muscle and nonmuscle cells: identification and comparative peptide analysis.

Extraction of chicken embryo fibroblasts (CEF) or baby hamster kidney (BHK) cells with 1% Triton X-100 and 0.6 M KCl leaves an insoluble cytoskeletal residue composed primarily of the 52,000 Mr subunit of intermediate filaments (F-IFP). In addition, CEF cytoskeletons exhibit a minor component with Mr of 50,000, identified as alpha-desmin, one of the two major isoelectric variants of the intermediate filament subunit from smooth muscle. BHK cytoskeletons contain the 50,000 Mr mammalian desmin variant. Cytoskeletons prepared from chicken embryonic myotubes contain F-IFP and both alpha- and beta-desmin. These data suggest that two distinct 10-nm filament subunits coexist in a single cell. One-dimensional peptide analysis of F-IFP and desmin from avian and mammalian cells reveals significant interspecies homology, as well as homology between F-IFP and desmin from the same species. Peptide analyses of 32P-labeled intermediate filament subunits suggest that there is considerable similarity in the phosphorylation sites of these proteins. These results indicate that F-IFP and desmin might be evolutionally related.

Amino Acid Sequence↗
PubMed1979

Specific fluorescent labeling of chicken myofibril Z-line proteins catalyzed by guinea pig liver transglutaminase.

Guinea pig liver transglutaminase has been found to catalyze the covalent incorporation of dansylcadaverine into chicken skeletal muscle myofibril proteins. Epifluorescence microscopy reveals that the incorporated dansylcadaverine is specifically localized at or near the myofibril Z line. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) indicates that actin constitutes a major fraction of the labeled material; the Z-line proteins alpha-actinin and desmin also show significant labeling, as well as tropomyosin, several additional unidentified proteins, and material with an extremely high molecular weight. The Z-line-specific fluorescence can be removed by brief trypsinization, which releases fluorescent alpha-actinin into the supernate. The majority of the fluorescent protein species are resistant to extraction by either 0.6 M KCl or KI. These results, in conjunction with the microscopic localization, suggest that the dansyl-labeled proteins are constituents of the myofibril Z line. A significant amount of fluorescently labeled transglutaminase is also present in labeled myofibrils, which is resistant to extraction with either 0.6 M KCl or KI. This result indicates a strong, noncovalent interaction between the transglutaminase molecule and the myofibril Z line.

Animals↗
PubMed1977

Mitosis of type B alveolar cells in the early hyperplastic response to Freund's adjuvant.

Numerous areas of granulomatous inflammation develop in the lungs of rabbits following the intravenous injection of Freund's complete adjuvant (FCA). Within a few days after FCA injection, hyperplasia of type B (type I) alveolar cells is present on the surface of the septa in which an inflammatory reaction is developing. Mitosis of type B cells is detected 12 h after FCA injection and is common over the next 120 h. In addition, there are morphologic changes that are consistent with migration of these cells. The type B cells in mitosis extend across alveolar septa as well as along the alveolar surface. The extension of type B cells through alveolar septa is not limited to cells in mitosis, but is also observed in non-mitotic type B cells. Stimulation of mitosis and hyperplasia of type B cells is discussed in relation to the focal tissue injury and inflammatory response.

Animals↗