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Biomedical subjects

J A Boyle

Publications and source records attributed to J A Boyle.

At least 37 records · Page 2Linked to original sources
PubMed1983

Melting order of successively longer yeast phenylalanine-accepting transfer ribonucleic acid fragments with a common 5' end.

Temperature-jump methods were used to study the kinetics of the helix to coil transition in three fragments of yeast tRNAPhe that share a common 5' terminus (the 5' end of the mature tRNA). Correlation of the extrapolated helix dissociation time constants with NMR exchange broadening results allows assignment of the structural basis of the optical melting transition in the fragments. The results confirm nuclear magnetic resonance findings on these fragments: the 5' 1/4 fragment has no helical structure; the 5' 1/2 fragment contains the D stem; and the 5' 3/5 fragment contains the D stem and the anticodon stem. These are the structures expected if sequential folding of the tRNA during biosynthesis were to occur. The D stem is the last helix to melt in the 5' 3/5 fragment. We suggest that structural elements in addition to the four Watson-Crick base pairs of the D-stem helix are responsible for the anomalously high Tm of that hairpin.

Kinetics↗
PubMed1983

Clinical characteristics of patients with rheumatic disorders who possess antibodies against ribonucleoprotein particles.

IgG was purified from 91 serum samples obtained from patients with systemic rheumatic diseases and examined for the presence of antinuclear antibodies reactive with small ribonucleoprotein (RNP) complexes. Antibody specificity was determined by autoradiographic detection of 32P labeled RNA which had been separated by polyacrylamide gel electrophoresis. This RNA was extracted from immune complexes formed by adding purified IgG to a homogenate of 32P labeled HeLa cells. Anti-RNP antibodies were detected in 70% of these samples. Specific antibodies detected were anti-(U1)-RNP (35%), anti-Sm (30%), anti-Ro (24%), and anti-La (10%). Other antibodies (9%) were reactive with structures containing 5S and 5.8S RNA or 4S RNA. There was a significant relationship between the presence of anti-RNP antibodies in patients with systemic lupus erythematosus (SLE) (78%) as opposed to their presence in patients with non-SLE rheumatic disorders (45%). However, taken individually, anti-Ro was the only antibody whose presence in SLE patients (30%) was significantly greater than its presence in non-SLE patients (5%). Vasculitis was the only clinical manifestation found to correlate with the presence of a particular antibody, anti(U1)RNP. There is some suggestion of a racial distribution of antibody types.

Antibody Specificity↗
PubMed1981

Two novel classes of small ribonucleoproteins detected by antibodies associated with lupus erythematosus.

The RNP and Sm antigens recognized by lupus erythematosus antibodies are located on discrete particles containing single small nuclear RNA's complexed with proteins. The antigens Ro and La are also on ribonucleoproteins. The small RNA's in ribonucleoproteins with Ro are discrete, like those associated with RNP and Sm; in contrast, ribonucleoproteins with La contain a striking highly banded spectrum of small RNA's from uninfected cells as well as virus-associated RNA from adenovirus-infected cells.

Animals↗
PubMed1977

Effects of furosemide on glomerular filtration rate and clearance of practolol, digoxin, cephaloridine, and gentamicin.

Furosemide was shown to decrease inulin clearance in 20 of 27 normal subjects. The depression in inulin clearance occurred in both water-loaded and non-water-loaded subjects. The renal clearance of practolol, but not digoxin, was reduced when furosemide was given. The average total plasma clearances of gentamicin and of cephaloridine over a 6-hr period were decreased after furosemide. The reduced clearances of the antibiotics were associated with higher plasma levels, the increase in antibiotic concentration being as much as 100% at 1 hr after an intravenous bolus injection.

Adult↗
PubMed1970

Lesch-Nyhan syndrome: preventive control by prenatal diagnosis.

The Lesch-Nyhan syndrome was detected in a fetus at a time sufficiently early to allow termination of the pregnancy. The feasibility of a preventive program for control of a severe sex-linked neurological disease through prenatal diagnosis is thus demonstrated.

Adenine↗
PubMed1970

Substrate stabilization: genetically controlled reciprocal relationship of two human enzymes.

5-Phosphoribosyl-l-pyrophosphate, a substrate shared by adenine phosphoribosyltransferase and hypoxanthine-guanine phosphoribosyltransferase, accumulates in human erythrocytes lacking hypoxanthine-guanine phosphoribosyltransferase. 5-Phosphoribosyl-l-pyrophosphate added to purified adenine phosphoribosyltransferase stabilizes it against heat inactivation. The increased activity of adenine phosphoribosyltransferase seen in erythrocytes deficient in hypoxanthine-guanine phosphoribosyltransferase may result from substrate stabilization of this enzyme in vivo.

Erythrocyte Aging↗