PubMed Health⌕ Search

Biomedical subjects

L A Lindsey

Publications and source records attributed to L A Lindsey.

9 recordsLinked to original sources
PubMed2000

Information access for the new millennium: publishers and portals.

The rise in Internet access has a number of implications for surgeons, both in terms of their personal use of information and in the accessibility of surgical information to their hospitals and patients. This article outlines some of the opportunities offered by the development of new ways to access information, and suggests that the ability to use the new technologies is now becoming an essential clinical skill.

General Surgery↗
PubMed1999

Surgery and the information age.

Surgeons' basic competency relies upon their ability to combine their existing knowledge and practical skills in the care of their patients, and also upon keeping up to date and encompassing change. We now live in a society which has become accustomed to receive a constant flow of up-to-date information about the world around it. With recent developments, including the Internet, the World Wide Web, and advances in personal computer systems, the pace of change of information technology (IT) has been increasing. These changes have had a significant impact upon surgery, and it is now becoming necessary to be able to make use of these new resources to function effectively in modern practice. This article will outline some of the more important topics relating to IT in surgical practice as an introduction to a series on this subject which will be appearing in forthcoming issues of the Journal.

Education, Medical, Continuing↗
PubMed1998

Functional conservation of the human homolog of the yeast pre-mRNA splicing factor Prp17p.

Splicing of pre-mRNAs involves two sequential transesterification reactions commonly referred to as the first and second steps. In Saccharomyces cerevisiae, four proteins, Prp16p, Prp17p, Prp18p, and Slu7p are exclusively required for the second step of splicing. The human homologs of Prp16p, Prp17p, and Prp18p have been identified, and the human proteins hPrp16 and hPrp18 have been shown to be required for the second step of splicing in vitro. Here we provide further evidence for the functional conservation of the second step factors between yeast and humans. Human hPrp17, which is 35% identical to the S. cerevisiae protein, is able to partially rescue the temperature-sensitive phenotype in a yeast strain where PRP17 has been knocked out, suggesting that the human and yeast proteins are functionally conserved. Overexpression of hPrp17 in the knockout yeast strain partially rescues the splicing defect seen in vitro and in vivo. In HeLa cells, hPrp17 is highly concentrated in the nuclear speckles, as is SC35 and many other splicing factors, thus providing further support that this protein also functions as a splicing factor in humans.

Amino Acid Sequence↗
PubMed1995

A mammalian activity required for the second step of pre-messenger RNA splicing.

Splicing of precursors to messenger RNAs occurs via a two-step mechanism. In the first step, the 5'-exon is released concomitant with the production of a lariat intermediate, and in the second step, the exons are joined, releasing the intron in the form of a lariat product. Several gene products of the yeast Saccharomyces cerevisiae have been shown to be required exclusively for the second step. Although mammalian proteins have been implicated in the second step of splicing, none have been shown to act only at this step. We identify here the first mammalian activity shown to be exclusively required for the second step. The activity was shown to increase by 5-fold the rate for this splicing step, whereas it had no effect on the rate of the first step. The activity was not affected by treatment with micrococcal nuclease, whereas it is sensitive to heating to 55 degrees C, suggesting that it is not dependent on an RNA, but more likely is a protein. The second step activity was separated from other factors required for the first step and from PSF, a splicing factor thought to have a second step activity. The activity does not require ATP hydrolysis, suggesting that it acts at a late stage of the second step of splicing.

Adenosine Triphosphate↗
PubMed1994

Low hprt mRNA levels and multiple hprt mRNA species in 6-thioguanine-resistant Chinese hamster cell mutants possessing nonsense mutations.

Previous studies suggested that many Chinese hamster ovary (CHO) cell hprt mutants having point mutations in the protein coding region also have low steady-state hprt mRNA concentrations. In addition, polymerase-chain reaction (PCR) amplification of hprt cDNA synthesized from some of these mutants results in multiple products containing deleted exons indicating that these mutants possess multiple species of hprt mRNA. In this study, we have used northern blot analysis to quantify the concentrations of hprt mRNA in 86 mutants known to possess point mutations leading to either missense or nonsense mutations. 28 of 35 nonsense mutants (80%), but only 7 of 51 missense mutants (14%), had < 50% of the hprt mRNA concentration found in parental CHO cells. Furthermore, all the nonsense mutants with premature termination codons in the internal exons of the gene (i.e., exons 3, 4, 5, 6 and 7) showed a significant reduction (averages < 16% of parental) in the steady-state levels of hprt mRNA, while nonsense mutants with termination codons situated in the extreme 5' and 3' regions of the gene had near parental hprt mRNA levels. In the same collection of mutants, the proportion of mutants producing multiple cDNA PCR products was much greater (18/35) for mutants having nonsense mutations than for mutants with missense mutations (2/51). All nonsense mutants with mutations in exons 3, 4 and 5 produced multiple species, while all those with mutations in exons 7, 8 and 9 produced a single PCR product. These results suggest that sequence changes in mammalian genes that affect protein chain length can also affect mRNA concentration and the splicing of pre-mRNA molecules.

Animals↗
PubMed1993

Temporal bone dissection using a low cost miniature electric drill.

The performance of various specialized and general purpose drills was assessed for use in temporal bone dissection. The Minicraft MB 120 and MB 130 were found to be as effective as specialized drills but with greater convenience and much reduced cost. The use of these drills allows high quality temporal bone dissection to be performed on a limited budget.

Evaluation Studies as Topic↗
PubMed1991

Pulse oximetry in postoperative monitoring of free muscle flaps.

The use of a pulse oximeter for monitoring free muscle transfers is described. Three cases are presented, two of which were uncomplicated and one in which the need for revision of anastomosis was identified by the oximeter. Observations on a pedicled muscle flap are also reported. Pulse oximeters provide an improved photoplethysmographic monitoring technique which is easily performed using completely standard operating theatre equipment.

Adolescent↗
PubMed1991

In vivo loss of telomeric repeats with age in humans.

Telomeric DNA in the skin cells of 21 human subjects aged between 0 and 92 years was quantified by determining the length of the telomeric smear and the relative amount of TTAGGG repeat sequences. Both telomere length and quantity of telomeric repeat sequences were found to decrease significantly with age. Telomere loss has previously been postulated to be a caused of cell senescence.

Adolescent↗