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Biomedical subjects

S Broome

Publications and source records attributed to S Broome.

12 recordsLinked to original sources
PubMed2005

Nitric oxide levels and ciliary beat frequency in indigenous New Zealand children.

New Zealand children's morbidity from respiratory disease is high. This study examines whether subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. A prospective study enrolled a group of healthy children who were screened for respiratory disease by questionnaire and lung function. Skin-prick tests were performed to control for atopy. Exhaled and nasal NO was measured online by a single-breath technique using chemiluminescence. Ciliary specimens were obtained by nasal brushings for assessment of structure and function. The ciliary beat frequency (CBF) (median CBF, 12.5 Hz; range, 10.4-16.8 Hz) and NO values (median exhaled NO, 5.6 ppb; range, 2.3-87.7 ppb; median nasal NO, 403 ppb; range, 34-1,120 ppb) for healthy New Zealand European (n=58), Pacific Island (n=61), and Maori (n=16) children were comparable with levels reported internationally. No ethnic differences in NO, atopy, or CBF were demonstrated. Despite an apparently normal ciliary beat, the percentage of ciliary structural defects was 3 times higher than reported controls (9%; range, 3.6-31.3%), with no difference across ethnic groups. In conclusion, it is unlikely that subclinical ciliary abnormalities underlie the increased prevalence of respiratory disease in indigenous New Zealand children. The high percentage of secondary ciliary defects suggests ongoing environmental or infective damage.

Adolescent↗
PubMed1999

Phase 1 safety and immune response studies of a DNA vaccine encoding hepatitis B surface antigen delivered by a gene delivery device.

This study was designed to determine the safety and immunogenicity in volunteers of a DNA vaccine consisting of a plasmid encoding hepatitis B surface antigen delivered by the PowderJect XR1 gene delivery system into human skin. Seven healthy adult volunteers received two immunizations at one of three forces of delivery on day 0 and 56. The vaccine was well tolerated. One of six seronegative volunteers developed high titers of persistent HBsAb after a single immunization. In retrospect, this volunteer may have had previous exposure to hepatitis B. Our study suggests that the hepatitis B DNA vaccine given by this gene delivery system may induce a booster response, but the vaccine at the extremely low DNA dose used (0.25 microg) did not induce primary immune responses.

Adolescent↗
PubMed1990

Simplified northern blot hybridization using 5% sodium dodecyl sulfate.

We describe a simplified Northern blot hybridization procedure. This procedure eliminates the need for many reagents commonly used in RNA hybridization and replaces them with two buffers containing 5% sodium dodecyl sulfate for pre-hybridization, hybridization and all post-hybridization washes.

Animals↗
PubMed1985

Rous sarcoma virus encodes a transcriptional activator.

Rous sarcoma virus expresses a transcriptional activator that affects the LTR as well as other promoters. We discern this activity as a stimulation of the transient expression of an LTR-promoted hybrid transcriptional unit and also of the rat preproinsulin II gene in transfected NIH 3T3 cells. We map the activity to an alternate reading frame in the p19-p10 region of the gag gene and identify a mRNA whose spliced structure would direct translation of this reading frame from the Pr76gag initiation codon. This mRNA probably differs from genomic RNA only by the 282 nucleotide splice. The predicted translation product is a 124 residue polypeptide; the first six amino acids arise from gag. The target for the action of this transcriptional modulator at the LTR lies between 111 and 620 nucleotides upstream of the cap site.

Animals↗
PubMed1985

Hypothermia-induced supersensitivity to adenosine for responses mediated via A1-receptors but not A2-receptors.

Four isolated tissues were examined in which the responses to adenosine are mediated via either A1- or A2-receptors. The responses examined were the inhibition of cholinergic transmission of field-stimulated guinea-pig ileum (A1), inhibition of noradrenergic transmission of field-stimulated rat vas deferens (A1), inhibition of developed tension of rat paced left atria (A1) and relaxation of carbachol-contracted guinea-pig trachea (A2). Cumulative concentration-response curves for adenosine and 2-chloroadenosine were constructed at 37, 30 or 27 degrees C. When plotted as a percentage of the maximum response, the concentration-response curves were displaced to the left by cooling in the ileum, vas deferens and atria, indicative of supersensitivity. This increase in sensitivity does not arise from inhibition of uptake or deamination by cooling, since it occurs equally for adenosine and 2-chloroadenosine, the latter being immune to these processes. In contrast, the sensitivity of the trachea was not affected (2-chloroadenosine) or reduced (adenosine) by cooling. Thus responses mediated via adenosine receptors of the A1 subtype exhibit hypothermia-induced supersensitivity, whereas those mediated via A2-receptors do not. This suggests a fundamental temperature-dependent difference between the two adenosine receptor subtypes.

2-Chloroadenosine↗
PubMed1978

Immunological screening method to detect specific translation products.

We describe a very sensitive method to detect as antigens the presence of specific proteins within phage plaques or bacterial colonies. We coat plastic sheets with antibody molecules, expose the sheet to lysed bacteria so that a released antigen can bind, and then label the immobilized antigen with radioiodinated antibodies. Thus, the antigen is sandwiched between the antibodies attached to the plastic sheet and those carrying the radioactive label. Autoradiography then shows the positions of antigen-containing colonies or phage plaques. A few molecules of antigen released from each bacterial cell generatean adequate signal.

Antibody Specificity↗
PubMed1978

A bacterial clone synthesizing proinsulin.

We have cloned double-stranded cDNA copies of a rat preproinsulin messenger RNA in Escherichia coli chi1776, using the unique Pst endonuclease site of plasmid pBR322 that lies in the region encoding amino acids 181-182 of penicillinase. This site was reconstructed by inserting the cDNA with an oligo(dG)-oligo(dC) joining procedure. One of the clones expresses a fused protein bearing both insulin and penicillinase antigenic determinants. The DNA sequence of this plasmid shows that the insulin region is read in phase; a stretch of six glycine residues connects the alanine at position 182 of penicillinase to the fourth amino acid, glutamine, of rat proinsulin.

Base Sequence↗
PubMedDate not supplied

Biological activity of rat proinsulin synthesized by Escherichia coli.

Fused proteins possessing insulin antigenic determinants are synthesized and secreted by several strains of Escherichia coli K-12 bearing plasmids containing cDNA copies of rat proinsulin mRNA. Small amounts of the secreted, fused protein from E. coli strains chi 1776 and HB101 bearing plasmid p147 were partially purified and assayed for biological activity by determining stimulation of [1-14C]glucose oxidation to 14CO2 in the rat epididymal fat pad assay. Guinea pig anti-insulin serum (GPAIS) was used to suppress glucose oxidation stimulated by insulin. After mild treatment with trypsin, fused protein stimulated 14CO2 production, and over 90% of this activity was suppressible by GPAIS. Untrypsinized fused protein demonstrated no GPAIS-suppressible 14CO2 production. Larger amounts of fused protein were obtained by transformation of strain PR13 of E. coli in which the yield of eukaryotic proteins is increased approx. 50-fold. A single intravenous injection of trypsinized fused protein from E. coli PR13 containing plasmid p287.47 resulted in a rapid decline in the plasma glucose levels of fasted mice, and the hypoglycemic effect persisted for at least 120 min.

Adipose Tissue↗