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Biomedical subjects

J A Boyle

Publications and source records attributed to J A Boyle.

At least 19 recordsLinked to original sources
PubMed1992

Amplification and characterization of an inverted repeat from the Chlamydomonas reinhardtii mitochondrial genome.

Based on the nucleotide (nt) sequences of cob and L2a, two oligodeoxyribonucleotides (oligos) were synthesized and used in the polymerase chain reaction (PCR) to amplify the termini of the Chlamydomonas reinhardtii mitochondrial (mt) genome. A 0.8-kb PCR product was detected by agarose-gel electrophoresis when using unligated mt DNA as the template for PCR. This may have indicated the presence of a naturally occurring circular mt DNA molecule that acted as the PCR template. The 0.8-kb DNA could also be amplified from the linear mt DNA via an intramolecular jump during PCR. The sequence data from the 0.8-kb PCR product, and the right 0.6-kb and left 1-kb terminal fragments of the linear mt DNA, along with Southern hybridization analysis, indicated that a 0.49-kb inverted repeat (IR) sequence is present at the right and left termini of the linear mt DNA. The IR contains A+T-rich clusters, as well as numerous short direct repeats (DR) and IR, and might be involved in the recombination, replication and expression of the C. reinhardtii mt genome.

Animals↗
PubMed1991

Halobacterium halobium Mn-SOD gene: archaebacterial and eubacterial features.

A 1.8 kb PstI fragment from Halobacterium halobium DNA was found to hybridize to synthetic oligonucleotide probes constructed by using the sequence of the N-terminus of a Mn-containing superoxide dismutase purified from H. halobium. The entire insert containing a 600-bp coding sequence for Mn-SOD and its 5' and 3' flanking regions was sequenced. The derived amino acid sequence of the structural gene showed a similarity to other manganic and iron-containing superoxide dismutases in normally conserved regions. Primer extension analysis of the H. halobium Mn-SOD mRNA showed that gene transcription begins 14 bases upstream of the translational start. A Shine-Dalgarno sequence and archaebacterial consensus promoter sequences were observed. Several other promoter and terminator nucleotide sequences homologous to prokaryotic and eukaryotic organisms were found.

Amino Acid Sequence↗
PubMed1990

Adapting the polymerase chain reaction to a double-stranded RNA genome.

We have adapted the polymerase chain reaction (PCR) to a double-stranded RNA (dsRNA) target without possessing unambiguous sequence information. Infectious bursal disease virus of chickens, a member of the binavirus group, has a dsRNA genome which is resistant to denaturation and subsequent enzyme modification. The only published sequence information was for a strain of virus unavailable to us. We have used a quick primer binding assay to select appropriate primers and have combined a simple denaturation method with reverse transcription and subsequent polymerization using the cDNA template to yield amplified product easily detectable by ethidium bromide staining. By varying the times of denaturation, annealing, and polymerization and by reducing the total number of amplification cycles, artifacts have been eliminated when using purified genome as the template. This allowed us to obtain partial sequence information for one viral strain. We have enhanced the utility of our method by optimizing a rapid cell lysis and capsid digestion protocol such that no purification steps are required from initial tissue handling through final PCR product. Total time for all procedures involved no more than 6 h. This technique should be applicable to all other members of the Birnaviradae family and to any other species of dsRNA.

Animals↗
PubMed1989

Sea urchin oocytes possess elaborate cortical arrays of microfilaments, microtubules, and intermediate filaments.

Extensive arrays of microfilaments, microtubules and cytokeratin-type intermediate filaments were detected in the cortex of Strongylocentrotus droebachiensis oocytes using fluorescently labeled antibodies on both cortex and whole mount preparations. All three filament systems undergo dramatic structural reorganization during meiotic maturation of the egg. Microfilaments form a dense meshwork within the cortex of the oocyte. After meiosis, the filaments rearrange and shorten, resulting in a more loosely organized network. Both cortical microtubules and microtubules associated with a microtubule-organizing center are observed within the oocyte. After meiosis, the number and length of the cortical microtubules gradually diminish. A microtubule organizing center is found situated between the germinal vesicle and the plasma membrane in many oocytes. A network of filaments extends from the microtubule organizing center and radiates peripherally toward the germinal vesicle, presumably marking the animal pole. Cytokeratin-like intermediate filaments form a reticular network within the oocyte cortex, then solubilize during meiosis. In whole mounts of oocytes there is a single focal center of cytokeratin staining from which filaments radiate. Indirect immunofluorescence experiments, using anti-tubulin and anti-cytokeratin antibodies simultaneously, reveal the intermediate filament focal center to be localized within the microtubule organizing center. These results demonstrate the presence of a complex cortical cytoskeleton in premeiotic eggs of the sea urchin, Strongylocentrotus droebachiensis.

Actin Cytoskeleton↗
PubMed1989

Plasmid homologies in Edwardsiella ictaluri.

Plasmids from all available non-channel catfish isolates of Edwardsiella ictaluri were classified by gel electrophoresis and hybridization methods. All isolates, regardless of source, contained classes of homologous plasmids with similar but not identical sizes.

Animals↗
PubMed1988

Vertical transmission of channel catfish virus.

Channel catfish broodfish were examined nondestructively for the presence of channel catfish virus (CCV), using a nucleic acid-probing technique. A dot blot assay was tested and shown to be accurate and rapid in the diagnosis of CCV. Two CCV-positive fish were successfully mated, and fertilized eggs were collected. Offspring that hatched were tested and were shown to have CCV. This result indicated vertical transmission of CCV, a herpesvirus.

Animals↗
PubMed1986

Channel catfish virus: use of nucleic acids in studying viral relationships.

Restriction digestion patterns were used to determine differences in the DNA of various isolates of channel catfish virus (CCV). All viruses were different from each other and from the type strain of CCV. The differences in the digestion patterns were used to relate the viruses quantitatively as to sequence divergence between all pairs of viruses. A range of values from 104 nucleotide changes to 1,690 nucleotide changes/total DNA of CCV was found for the various pairs. A cladistic analysis produced a phylogenetic network relating the viruses by possible ancestory. This network indicated that some viruses were relatively more separated from other viruses that were clustered in the network. A phenetic analysis indicated that the viruses that were clustered in the network were also reasonably similar to one another.

Animals↗
PubMed1984

Antigenic relatedness of small ribonucleoprotein particles.

We have examined the relationships among small ribonucleoprotein particles found in eucaryotic cells by an antigen depletion technique using autoimmune antibodies. We have confirmed that the (U1) ribonucleoprotein particle antigen is found on the same complex as the Sm antigen. We have also shown that the Ro antigen is found on the same complexes as the La antigen. However, both Sm and La antigens are also found on complexes that are never associated with (U1) ribonucleoprotein particle and Ro, respectively. Further, U1 containing complexes can exist that contain the Sm antigen but not the (U1) ribonucleoprotein particle antigen. In a similar manner, we find several La-Ro RNA containing complexes that carry the La antigen but do not always carry the Ro antigen. Sm and La antigen are quantitatively associated with their specific ribonucleoprotein complexes.

Antigen-Antibody Complex↗
PubMed1984

Isoxicam.

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Adult↗
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↗