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D K Jasper

Publications and source records attributed to D K Jasper.

7 recordsLinked to original sources
PubMed1985

Sodium hypochlorite as a tissue solubilizing agent compatible with liquid scintillation counting.

The use of hypochlorite to prepare biological samples, containing incorporated radiolabeled molecules, for liquid scintillation counting was investigated. Hypochlorite both solubilized and decolorized a variety of animal tissues, but fat aggregates, cartilagenous tissue, and plant material resisted digestion. Although hypochlorite induced chemiluminescence, addition of acidified stannous chloride to the counting cocktail alleviated the spurious counts. The reported procedure, modified to suit particular experiments, may be applicable in a variety of situations where quantitation of biologically incorporated radiolabeled molecules is desired.

Animals↗
PubMed1976

ER-annulate lamellar associations of mucosal epithelial cells of the rat jejunum.

Mucosal cells of the rat jejunum vary greatly in the relative abundance and kind of endoplasmic reticulum (ER). Many cells have few rough surfaced cisternal ER elements; these cells frequently are located in basal villous regions and generally are less differentiated than those near apices. Profiles of rough ER cisternae were often encountered in stacks of 3-4 parallel units in apical cells. A number of differentiating basal cells were found to contain ER-annulate lamellar associations arranged similarly to the ER stacks of apical cells. The annulate lamellae of this complex resemble those described for other rapidly differentiating or embryonic cells and may be derived from the nuclear envelope. They could be involved in the formation of the ER.

Animals↗
PubMed1968

Studies on the physiological and structural characteristics of rat intestinal mucosa. Mitochondrial structural changes during amino acid absorption.

Sections from mucosal strips and rings of rat jejunum were studied with the light microscope and the electron microscope before and after incubation in a modified Krebs bicarbonate Ringer. Various additions were made to the incubation medium, and their effects on both the structure and the respiratory activity of the mucosal tissue were noted. In those cases in which an amino acid mixture was added, there was a pronounced increase in the rate of respiration. When strips of intestine were used, the presence of the amino acid mixture more than doubled the rate of oxygen consumption. Along with the increased levels of respiration there was a sharp rise in the percentage of mitochondria assuming a condensed ultrastructural conformation. The amino acid mixture did not cause the condensation of jejunal mitochondria if glucose was included in the incubation medium or if 2,4-dinitrophenol was present. The evidence suggests that a high proportion of the jejunal mitochondria assumes a condensed conformation in response to an increased energy demand. Apparently glucose can prevent the amino acid mixture from increasing the energy drain on the oxidative processes in these cells. Although a high rate of respiration was obtained in the presence of dinitrophenol, the studies indicated that mitochondrial condensation was only associated with a high rate of coupled oxidative phosphorylation.

Amino Acids↗