Biomedical subjects

J E Marion

Publications and source records attributed to J E Marion.

14 recordsLinked to original sources

PubMed2000

Flavopiridol inhibits P-TEFb and blocks HIV-1 replication.

Flavopiridol (L86-8275, HMR1275) is a cyclin-dependent kinase (Cdk) inhibitor that is in clinical trials as a cancer treatment because of its antiproliferative properties. We found that the flavonoid potently inhibited transcription by RNA polymerase II in vitro by blocking the transition into productive elongation, a step controlled by P-TEFb. The ability of P-TEFb to phosphorylate the carboxyl-terminal domain of the large subunit of RNA polymerase II was inhibited by flavopiridol with a K(i) of 3 nm. Interestingly, the drug was not competitive with ATP. P-TEFb composed of Cdk9 and cyclin T1 is a required cellular cofactor for the human immunodeficiency virus (HIV-1) transactivator, Tat. Consistent with its ability to inhibit P-TEFb, flavopiridol blocked Tat transactivation of the viral promoter in vitro. Furthermore, flavopiridol blocked HIV-1 replication in both single-round and viral spread assays with an IC(50) of less than 10 nm.

Adenosine Triphosphate↗

PubMed1991

Ethics and the scientist.

Ethical issues are receiving considerable attention in the scientific community just as in other areas of society. Scientists who have in the past been accorded a select position in society are no longer guaranteed that status just by virtue of their occupation. Science, and scientists, may not yet be subject to the same intense scrutiny as some other professions, but the trend is evident. Scientists do have special obligations due to the nature of their profession, yet incidences of indiscretion are documented. Expectations of scientists in specific areas such as consulting, animal rights, and advocacy are discussed, and some thoughts on the scientist as an administrator are presented. A short summary of actions being taken in the field of ethics is included.

Administrative Personnel↗

PubMed1988

Influence of source and physical form of xanthophyll pigment on broiler pigmentation and performance.

Two experiments were conducted using 21-day-old, commercial-strain broilers to determine the effect of various commercial pigmentation products on pigmentation and bird performance. Birds received finisher/withdrawal diets that included 8% corn gluten meal or either a 2.5 or 5.0% substitution of gluten meal with Liquid OroGlo5, Dry Oroglo10, or Cromophyl-oro. When birds were slaughtered at either 48 or 51 days of age there were no differences in the birds' breast skin hue (dominant wavelength) or brightness (luminosity). Data indicated similar levels of pigmentation among birds in all treatments. Color intensity (excitation purity) values of shank and breast skin samples suggested that the liquid form of OroGlo was more effective than the dry form in pigmenting broiler skin when both forms were fed at equal calculated levels. Data indicated that actual xanthophyll intake was higher when the liquid source was fed. Body weight gain and feed efficiency among the treatments, in general, indicated that commercial pigment sources can be substituted for corn gluten meal without appreciably altering broiler performance.

Animals↗

PubMed1987

Nutritive value of new cultivars of triticale and wheat for broiler chick diets.

Three experiments were conducted with broiler chicks from 1 to 21 days of age to evaluate Florida 301 variety of wheat and Beagle 82 variety of triticale. In Experiment 1, a completely randomized design (CRD) was used for five dietary treatments: yellow corn-soy (control), triticale-soy, yellow corn-triticale-soy, wheat-soy and yellow corn-wheat-soy. Diets were balanced to maintain equal levels of sulfur amino acids and lysine and were kept isocaloric (3,124 kcal/kg) using corn oil. In Experiment 2, a CRD was used for 10 dietary treatments. Each grain was substituted partially and totally for corn on both iso and nonisocaloric basis. Animal fat was the supplemental fat source. In Experiment 3, a CRD was used for 8 dietary treatments. Each grain was substituted for corn isocalorically using corn oil, animal fat, or both as supplemental fat sources. Results from these experiments showed that Florida 301 wheat is an excellent cereal grain for broiler chicks as measured by feed efficiency and growth response, which was numerically but not significantly greater than with a corn-soy control diet. Growth response was inconsistent with Beagle 82 triticale throughout the three experiments. However, feed efficiency was better with triticale diets than corn-based diets.

Animal Feed↗

PubMed1987

Influence of Monoprop in controlling mold growth and improving chick performance when fed high moisture corn.

Two trials were conducted with broiler chicks from hatch to 21 days of age to study the effects of feeding high moisture corn diets with and without a mold inhibitor. Monoprop High moisture corn (HMC) diets supported growth rates and dry matter feed conversion ratios as well as dry corn diets when Monoprop was present in the feed even when the feed was seeded with moldy corn screenings. Without the mold inhibitor, body weight gains were depressed. This was not due to depressed feed intake as feed consumption for chicks on HMC diets without mold inhibitor was as high as other groups.

Animal Feed↗

PubMed1969