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G C Burke

Publications and source records attributed to G C Burke.

24 records · Page 2Linked to original sources
PubMed1975

Alteratons in RNA synthesis in lymphotoxin-treated target cells.

Lymphotoxin, a cellular mediator produced in vitro by antigen- or mitogen-stimulated lymphocytes, is capable of lysing various types of cells. We have shown that highly purified lymphotoxin preparations both mediate cytolysis and stimulate RNA synthesis in target cells. When RNA extracts from lymphotoxin-treated cells were examined by means of sucrose density gradient centrifugation, we observed a general increase in RNA synthesis, accentuated in species larger than 28S. Analysis on oligo(dT)-cellulose columns revealed a relatively larger increase in adenine-rich m-RNA. In concordance with this finding, we observed a moderate increase in RNA polymerase I (nucleolar) activity and a striking increase in RNA polymerase II (nucleoplasmic) activity in isolated nuclei of lymphotoxin-treated target cells.

Animals↗
PubMed1969

Fractionation of phytohemagglutinin. I. Purification of the RNA and DNA synthesis-stimulating substances and evidence that they are not proteins.

We have separated the RNA synthesis-stimulating activity and the DNA synthesis-stimulating activity of extracts of Phaseolus vulgaris (phytohemagglutinin) from the erythroagglutinins, leukoagglutinins, and cytotoxic factors. We have shown that the substances stimulating the synthesis of nucleic acids are probably not proteins, since they are not significantly affected by rigorous deproteinization or treatment by trypsin and pronase. Likewise, they do not appear to be nucleic acids, since they are not precipitated by perchloric acid and resist RNase, DNase, and phosphodiesterases. They are probably not carbohydrates, since 98 per cent of the carbohydrate can be removed from a preparation with only a moderate loss in activity. The RNA and DNA synthesis-stimulating activities are probably associated with separate molecules, since they are destroyed by periodate at different rates.

Animals↗
PubMedDate not supplied

Renewal and change for clinical laboratory managers.

This article examines barriers to change in the clinical laboratory and discusses suggestions for maintaining vitality, renewal, and professional growth. The major barriers to change and renewal include institutional pressures that underlie the personnel shortage and financial implications of laboratory service, time pressures associated with the normal operation of a laboratory, work habits that develop early in the career of a laboratory manager, and managerial policies that limit or discourage change. Some solutions to overcome these barriers include goal setting, job or career change, lifelong learning, good staff members, mentors, and outside interests.

Career Mobility↗