Biomedical subjects

E Burgi

Publications and source records attributed to E Burgi.

8 recordsLinked to original sources

PubMed1978

Auditory changes associated with moderate blood salicylate levels.

Thirty patients with rheumatoid arthritis were randomly assigned to two groups: aspirin and placebo. Aspirin group subjects received five grain ASA capsules and placebo group subjects received lactose placebo for seven days. Blood salicylate level (BSL) and audiological evaluations were performed on Days 0, 3 and 7. BSLs never exceeded 21 mg/100 ml. BSLs during the seven days varied only slightly among aspirin group subjects but dropped consistently in the placebo group. Intra-subject comparison of scores on low versus high BSL days indicated significant differences between mean speech reception thresholds (SRT) scores and pure-tone air-conduction thresholds at all test frequencies for both groups, except at 2000 Hz for the aspirin group. Inter-group differences occurred on SRT and high-frequency pure-tone thresholds. The results indicate that moderate BSLs adversely affect hearing ability. These adverse effects appear to be temporary.

Adult↗

PubMed1978

Association of the folded chromosome with the cell envelope of Escherichia coli: nature of the membrane-associated DNA.

Membrane-associated folded chromosomes isolated from Escherichia coli in the presence of spermidine sedimented at about 5,800S. The folded chromosome and the membrane fragment were each stable in the absence of the other; a 1,700S folded chromosome was obtained after removal of the membrane by a Sarkosyl treatment, and a 4,000S membrane fragment remained after digestion of the chromosomal DNA with deoxyribonuclease I. The interaction between the folded chromosome and the membrane fragment was stable, and, even when the DNA was unfolded, both components remained associated and cosedimented. The large frictional effect of the unfolded DNA reduced the sedimentation rate of the complex to about 2,000S. Partial removal of this unfolded DNA with restriction endonucleases caused the membrane fragments and the remaining associated DNA to sediment faster, at about 3,500S. The DNA remaining associated with the membrane fragments after restriction endonuclease treatment, about 4.5% of the total DNA when EcoRI was used, was indistinguishable from the DNA released from the membranes by three criteria: (i) DNA size distribution in agarose gels after electrophoresis, (ii) reassociation kinetics, and (iii) thermal elution from hydroxylapatite. This finding, that random DNA sequences rather than specific ones were responsible for the majority of the DNA-membrane interactions, argues against the folded chromosome's being a static structure with specific DNA sequences interacting with the cell envelope.

Cell Wall↗

PubMed1974