PubMed Health⌕ Search

Biomedical subjects

F Ostroy

Publications and source records attributed to F Ostroy.

6 recordsLinked to original sources
PubMed1979

Ferrocyanide staining of transferrin and ferritin-conjugated antibody to transferrin.

To evaluate the ultrastructural distribution of transferrin on the surface of L1210 ascites tumor cells, we used ferrocyanide to stain ferric iron (Prussian blue reaction) in transferrin, as well as in ferritin conjugated to antibody that was immunologically attached to the transferrin. Small deposits averaging 5 nm in diameter identified transferrin iron, whereas large cuboidal deposits averaging 50 nm in diameter stained ferritin conjugated-antibody that was bound to both transferrin and apotransferrin on the cell surface. The ability of transferrin to deliver iron to ascites tumor cells was confirmed by kinetic studies of transferrin labeled with 59Fe and 125I. These preliminary results are consistent with release of transferrin iron at the cell surface and demonstrate additional uses for ferrocyanide in ultrastructural cytochemical techniques.

Animals↗
PubMed1979

Effect of hypoxia on 67Ga incorporation into human granulocytes.

Human granulocytes accumulate 67Ga when incubated under anoxic conditions and exclude the isotope when oxygenated. When incorporated, 67Ga is associated with the lysosomal fraction of the granulocytes. The ability of granulocytes to exclude the isotope except under hypoxic conditions may explain 67Ga localization in abscesses and some tumor masses.

Adult↗
PubMed1978

Inhibition of lysozyme by polyvalent metal ions.

The rate of hen egg-white lysozyme (mucopeptide N-acetylmuramoylhydrolase, EC 3.2.1.17), catalysis was determined in the presence of various metal ions (Co2+, Zn2+ and eight of the trivalent lanthanide ions). In the assay system employed, the lanthanides were found to inhibit more strongly than either Zn2+ or Co2+. The inhibition data was fitted to several models of the interactions of the metal ion with the enzyme. These models ranged in complexity from a single inhibitory metal binding site on the enzyme (two-parameter fit) to the presence of two non-independent and non-equivalent inhibitory metal binding sites (five-parameter fit). The more complicated models did not fit the data more precisely than the simplest one-site model, suggesting that the adoption of the simpler model is warranted. The fact that the association constants obtained from the simplest analysis for Co2+ (1.3 +/- 1.9 . 10(2) M-1) and Gd3+ (7.0 +/- 2.6 . 10(3) M-1) are consistent with literature values determined from spectroscopic measurements further supports the validity of the simplest model.

Cobalt↗
PubMed1976

Protein-mediated uptake of vitamin B12 by isolated mitochondria.

Protein-mediated B12 uptake by isolated rat liver mitochondria has been shown to be enhanced by plasma transcobalamin (TC-II) but not by salivary R binder in vitro. The process is enhanced by calcium and depends on active mitochondrial respiration. Following uptake, cyanocobalamin is converted to adenosyl and methylcobalamins and released from the mitochondria. TC-II appears to be required for both cellular and mitochondrial uptake of vitamin B12.

Animals↗
PubMed1975

Antigenic properties of subcellular fractions from canine pancreas: development of a zymogen membrane specific antibody.

Immunization of rabbits with a membrane preparation from dog pancreas produced precipitating antibody against an antigen present in the pancreas of several mammals. This antigen appears to be organ-specific but not species-specific and is localized in the pancreatic zymogen granule membrane fraction. It is thought to represent glycoproteins of mol wt 70,000-90,000 as well as a smaller species of mol wt less than 10,000.

Animals↗