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Biomedical subjects

J D May

Publications and source records attributed to J D May.

At least 55 records · Page 3Linked to original sources
PubMed1980

Effects of dietary ascorbic acid, aspirin, lysine, and thiouracil on thyroid activity.

Broiler chickens were reared in batteries and fed diets designed to determine the effects of either ascorbic acid, aspirin (acetylsalicylic acid), lysine, or thiouracil on thyroid weight and serum thyroid hormone concentrations. Thyroxine (T4) and 3,5,5'-triiodothyronine (T3) concentrations in serum were determined by radioimmunoassay. Neither ascorbic acid nor lysine affected T3 or T4 concentration, but thiouracil significantly reduced T3 concentration after 1 day and reduced T4 concentration after 3 days. After 3 days or more of thiouracil feeding, relative reduction was greater for T4 than T3. Dietary aspirin significantly reduced T3 concentration at 7 of 16 sampling times but significantly reduced T4 concentration at only 1 of 16 sampling times. After 11 days of the dietary treatment, chickens fed thiouracil had significantly heavier thyroids than the controls but ascorbic acid, aspirin, and lysine had no effect on thyroid weight.

Animals↗
PubMed1979

Changes in the virus-host cell relationship in a stable non-virogenic cell line persistently infected with measles virus (BGM/MV).

A non-virogenic African green monkey kidney cell line BGM/MV persistently infected with a neurotropic mouse brain-adapted strain of measles virus, was found to have undergone significant changes in the virus-host cell relationship between passages 35 and 119. Rather than the stable non-cytopathic relationship previously reported in which approximately 100% of the cells contained measles antigens and less than 1% of the cells expressed cell surface measles antigen, we observed cyclic manifestations of c.p.e. together with changes in the percentage of cells expressing intracellular and cell surface measles antigens. Treatment of BGM/MV cells with actinomycin D effected an increase in the percentage of cells expressing cell surface virus haemagglutinin (HA) at times when the percentage of cells with surface HA was less than the percentage of cells with intracellular measles antigens. Superinfection studies employing measles virus and vesicular stomatitis virus revealed a consonant cyclic refractivity and essentially no refractivity, respectively. Endogenous, infectious measles virus was not detected nor was interferon. It was concluded that a host cell factor other than interferon was modulating the cyclic expression of the measles virus infection.

Animals↗
PubMed1978

Lysine requirement of broilers as influenced by environmental temperatures.

Two experiments were conducted to determine the influence of 15.6 and 29.4 degrees C. environmental temperatures on 2- to 4-week broiler lysine requirements. Weights for 4-week-old cockerels were maximum when either 1.10% dietary lysine in the 15.6 degrees C. environment or 1.00% dietary lysine in the 29.4 degrees C. environment were fed. Feed was used more efficiently by 4-week old cockerels fed either 1.10% dietary lysine in the 15.6 degrees C. environment or 0.95% dietary lysine in the 29.4 degrees C. environment. Plasma free lysine concentrations from 4-week-old cockerels increased as dietary lysine increased. Total plasma free amino acid concentrations from chicks grown in a 15.6 degrees C. environment were approximately 25% greater than from chicks grown at 29.4 degrees C. Total plasma free amino acids for 4-week-old cockerels peaked when 1.05% dietary lysine in the cool environment and 0.95% dietary lysine in the warm environment were fed.

Amino Acids↗
PubMed1978

Studies on the effect of butylated hydroxytoluene on Mycoplasma synoviae.

Butylated hydroxytoluene (BHT) is one of the antioxidants added to human and animal feed products in concentrations ranging from 50 to 200 ppm to delay degradation of the labile lipid components. BHT is known to be an inactivator of mammalian and bacterial viruses that contain lipid. Results of in vitro studies showed that 10 ppm of BHT in Mycoplasma medium prevented growth of each of the six Mycoplasma synoviae (Ms) isolates. BHT added at 100, 200, and 400 ppm in the feed did not have any significant in vivo effect on the Ms serological responses or show any chemoprophylactic effect on birds infected with Ms.

Animals↗
PubMed1978

A radioimmunoassay for 3,5,3'-triiodothyronine in chicken serum.

A double-antibody radioimmunoassay is described for 3,5,3'-triiodothyronine (T3) in chicken serum. Primary antibody produced in a rabbit had negligible crossreactivity with 3,3,5'-triiodothyronine and thyroxine. The primary antibody diluted 1:1000 bound 50% of a tracer dose of 125I-T3, and a standard curve of 0 to 800 pg/tube was used. Percent binding ranged from 14.1 to 54.1 for a standard curve. Serum volume ranging from 50 to 150 microliter tube did not affect assay results. Coefficient of variation was 2.8% within the assay and 5.5% between assays. The inhibitor 8-anilino-1-naphthalene sulfonic acid was necessary for recovery of T3 from spiked samples. Young chickens had reduced serum T3 concentrations when fed diets containing .1% thiouracil for 14 days when compared with serum T3 concentrations of chickens fed the diet without thiouracil. Feeding .2% thiouracil for 3 days did not affect serum T3 concentration.

Animals↗