Search PubMed⌕ Search

Biomedical subjects

G A Schultz

Publications and source records attributed to G A Schultz.

At least 91 records · Page 5Linked to original sources

Polyadenylic acid sequences in the RNA of Hyphomicrobium.

Heterogeneous RNA containing polyadenylic acid [poly(A)] sequence has been isolated from Hyphomicrobium by affinity chromatography on oligothymidylic acid cellulose and polyuridylic acid Sepharose columns. About 0.1 to 0.3% of [3H]adenine-labeled RNA over a 60-min period is associated with poly(A) sequences. This percentage decreases to about 0.03 in a 20-h labeling period. The poly(A) tracts recovered after digestion with ribonuclease A and T1 are composed of greater than 95% adenine residues and are up to 200 nucleotides in length with a predominant range of 15 to 40 nucleotides. Adenosine and AMP are present in the ratio of 1:36 in alkaline digests of Hyphomicrobium poly(A) tracts. This is compatible with nucleotide lengths determined on acrylamide gels and location at the 3'-OH terminus of the RNA molecule.

Bacteria↗

Lactate dehydrogenase in rabbit oocytes and eggs.

It has recently been reported that the rabbit oocyte lactate dehydrogenase (LDH) isozyme pattern shifts dramatically at ovulation. We have determined that both ovarian oocytes and ovulated eggs have predominantly LDH-5 with minor amounts of LDH-4. Therefore, no change occurs at ovulation. When oocytes or eggs are not treated to remove follicle cells, all five LDH isozymes are observed. Isolated follicle cells also have five isozymes. We suggest that failure to remove follicle cells can cause altered LDH isozyme patterns and may account for conflicting results in the literature.

Animals↗

Effect of the hepatocarcinogen ethionine on hepatic messenger RNA synthesis.

An experiment was conducted to determine if any changes resulted in the proportion of hepatic messenger RNA following treatment with ethionine, a hepatocarcinogen. The relative specific activity of the total RNA isolated from nontumor-like tissues was increased in Sprague-Dawley rats fed ethionine. However, the percentage of total RNA that was message was found to be decreased in the ethionine-treated rats.

Animals↗

Lactate dehydrogenase in preimplantation rabbit embryos.

Unfertilized eggs and early embryos up to the 2-day (16-cell) cleavage stage of development in the rabbit contain predominantly the most cathodal lactate dehydrogenase isoenzyme made up of A-type subunits. Following early cleavage there is a progressing increase in total LDH activity in the embryo as development proceeds through 4- and 6-day blastocyst stages. This is accompanied by an increase in the amount of B-type subunits and a concomitant shift in the lactate dehydrogenase isoenzyme electrophoretic pattern toward the anodal isoenzyme types.

Animals↗