Search PubMed⌕ Search

Biomedical subjects

R Hess

Publications and source records attributed to R Hess.

At least 163 records · Page 9Linked to original sources
PubMed1969

[Epilepsias].

Explore the source record for details and available documents.

Age Factors↗
PubMed1969

Correlated morphometric and biochemical studies on the liver cell. II. Effects of phenobarbital on rat hepatocytes.

The changes occurring in rat hepatocytes during a 5 day period of treatment with phenobarbital were determined by morphometric and biochemical methods, particular attention being paid to the endoplasmic reticulum. The hepatocytic cytoplasm played an overwhelming part in the liver hypertrophy, while the hepatocytic nuclei contributed to only a moderate extent. The endoplasmic reticulum accounted for more than half of the increase in cytoplasmic volume. The increase in the volume and number of hepatocytic nuclei in the course of phenobarbital treatment was associated with changes in the ploidy pattern. Until the 2nd day of treatment both the rough-surfaced endoplasmic reticulum (RER) and the smooth-surfaced endoplasmic reticulum (SER) participated in the increase in volume and surface of the whole endoplasmic reticulum (ER). Subsequently, the values for RER fell again to control levels, whereas those for SER continued to increase, with the result that by the 5th day of treatment the SER constituted the dominant cytoplasmic element. The specific volume of mitochondria and microbodies (peroxisomes) remained constant throughout the duration of the experiment, while that of the dense bodies increased. The specific number of mitochondria and microbodies displayed a significant increase, associated with a decrease in their mean volume. The phenobarbital-induced increase in the phospholipid and cytochrome P-450 content of the microsomes, as well as in the activities of microsomal reduced nicotinamide-adenine dinucleotide phosphate-cytochrome c reductase and N-demethylase, was correlated with the morphometric data on the endoplasmic reticulum.

Animals↗
PubMed1968

Identification of a precursor pool of ribosome protein in Escherichia coli.

Antibodies prepared against proteins from 50S ribosomes of Escherichia coli also reacted with the supernatant proteins of a cell-free extract of E. coli which was ribosome-free. A reaction of immunological identity (Ouchterlony tests) was demonstrated for one of these supernatant proteins and one protein found in 50S ribosomes. Isotope experiments involving a shift from (14)C-leucine medium to (12)C-leucine medium showed that these proteins are not formed by breakdown of ribosomes during the preparation of cell-free extracts, but instead represent a pool of ribosome protein which is utilized during growth. In shift experiments from (14)C-leucine to (12)C-leucine medium, the kinetics of disappearance of labeled supernatant ribosome proteins (as measured by reaction with antibody) indicated that half the pool is depleted in 0.1 generation time at 37 C in glucose-salts medium. The pool was also depleted under conditions of amino acid starvation of a "relaxed" strain which accumulated "relaxed" particles. Most, if not all, of the protein present in "relaxed" particles was derived from the pool. The pool represented about 3 to 4% of the total soluble proteins in the ribosome-free supernatant fluid of an E. coli extract.

Bacterial Proteins↗