PubMed Health⌕ Search

Biomedical subjects

C Stoner

Publications and source records attributed to C Stoner.

6 recordsLinked to original sources
PubMed1990

Characterization of the Escherichia coli araFGH and araJ promoters.

The identities of two cloned, arabinose-inducible promoters were tested by hybridizing promoter DNA fragments with restriction digests of chromosomal DNA containing Mudlac phage inserted in either araFGH or in araE transport operons. One promoter, thought to be araE, is within 10(3) base-pairs of a Mudlac insertion in the araE gene. The second promoter was not found within several thousand base-pairs of either of the known transport genes. This promoter is now named araPJ (araJ). The DNA sequence of the fragment containing the araFGH promoter was determined. The start site of transcription in vivo was located to within +/- 1 base-pair (bp) by S1 nuclease mapping. DNase 1 footprinting revealed that, in comparison with the araBAD and araE promoters, the locations of the AraC and cyclic AMP receptor protein (CRP) binding sites are reversed with CRP lying between AraC and RNA polymerase. The central location of the CRP binding site may explain why the araFGH promoter is more catabolite sensitive than the other ara promoters. AraC and CRP were both required for maximal transcription in vitro, although a low level of transcription was detected with CRP alone. S1 nuclease mapping of mRNA-DNA hybrids from the araJ promoter located the transcription start point to within #/- 3 bp, and demonstrates that the promoter is dependent upon AraC protein and CRP in vivo. DNase footprinting showed that the location of the AraC protein binding site on araJ is adjacent to the RNA polymerase site, as seen at the araBAD and araE promoters. Two CRP sites were observed; one is upstream from the AraC site and one is downstream from the transcription start site.

Amino Acid Sequence↗
PubMed1984

Kwashiorkor in Baltimore.

Advanced cases of malnutrition are rare in the United States. Since it is rarely suspected, a correct diagnosis of malnutrition, even in extreme form, may easily be missed. We present a recent case of the kwashiorkor form of the syndrome of protein-energy malnutrition to emphasize its diagnostic features and to enhance early recognition and initiation of proper therapy. The misunderstanding of a physician's recommendations by a teen-aged mother may have initiated this illness.

Adolescent↗
PubMed1983

The araE low affinity L-arabinose transport promoter. Cloning, sequence, transcription start site and DNA binding sites of regulatory proteins.

The promoter for the gene encoding the low affinity L-arabinose uptake protein in Escherichia coli was studied. The promoter was cloned, sequenced, its transcription start site determined by S1 nuclease mapping, the proteins required for in vitro transcription were determined, and the regulatory protein binding sites located by DNase footprinting. The araE promoter shows no evidence of an operator site upstream from the CRP binding site, but otherwise it is similar to the araBAD promoter.

Arabinose↗
PubMed1982

Risk of complications during intravenous heparin therapy.

The records of all patients to whom heparin was dispensed by the pharmacy of the University of California Medical Center, San Diego, during the year 1979 were reviewed. A total of 131 patients above age 15 met the inclusion criteria-they had received more than 10,000 units of heparin per 24 hours for at least 24 hours. All 131 patients were administered heparin by continuous intravenous infusion by peristaltic pump. All heparin was porcine heparin from a single commercial source. The daily mean minimum dose averaged 19,700 units, the maximum, 25,600 units. The activated partial thromboplastin time, usually measured once a day, was the only test used to monitor the dose. Major complicating events occurred in 13 patients (10 percent), and minor complicating events occurred in 10 patients (7.6 percent). All major complicating events occurred in patients with serious concurrent diseases. In subpopulations of 58 patients without concurrent disease, and of 24 in whom heparin was initiated for suspicion of thromboembolism that was not confirmed, no major complicating events occurred. These data indicate that continuous, intravenous administration of heparin is associated with minimal risk, and that risk is concentrated among older patients with serious concurrent disease.

Adult↗