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Biomedical subjects

Peter Cowan

Publications and source records attributed to Peter Cowan.

7 recordsLinked to original sources
PubMed2006

Treatment of third molar teeth--surgery.

The indications for removal of third molar teeth along with the pre-operative assessment of the patient have been outlined. This article reviews the surgical options and identifies the possible post-operative sequelae and potential complications of treatment.

Humans↗
PubMed2005

Treatment of third molar teeth assessment.

This first article will discuss the indications for removal of third molars and the initial assessment of the patient. The importance of good communication will be highlighted.

Adolescent↗
PubMed2004

Allogeneic sensitization is more effective than xenogeneic sensitization in eliciting Gal-mediated skin graft rejection.

The generation of Gal knockout (KO) pigs is likely to be an important advance in xenotransplantation. However, recent reports suggesting that expression of Gal may not be completely eliminated raise the possibility of a continuing anti-Gal immune response. The authors used a Gal-mismatched skin graft model to study cell-mediated anti-Gal rejection. Gal KO mice on a BALB/c or C57BL/6 background were sensitized with allogeneic or xenogeneic (rat) Gal-positive skin grafts and underwent transplantation with a secondary skin graft solely mismatched for Gal 21 days later. Most allograft-sensitized recipients rejected the secondary graft (n=26 [96%]) compared with less than half of xenograft-sensitized recipients (n=25 [44%]). An immunoglobulin (Ig) M response was detected in some xenograft-sensitized but not allograft-sensitized recipients. No recipients developed detectable anti-Gal IgG. The authors' findings contrast with previous reports that xenografts are more potent than allografts in eliciting an anti-Gal response and suggest that a predominantly cell-mediated response can mediate rejection.

Animals↗
PubMed2004

An efficient method for producing alpha(1,3)-galactosyltransferase gene knockout pigs.

We have reported relatively efficient methods for somatic cell nuclear transfer and for knocking out the alpha(1,3)-galactosyltransferase (alpha1,3-GT) gene in porcine fetal fibroblasts using a nonisogenic promoterless construct approach. Here we report the production of alpha1,3-GT gene knockout pigs using these procedures. Seven alpha1,3-GT gene knockout cell clones were identified by long-range PCR from 108 neomycin resistant (neo(R)) colonies, giving a 6.5% targeting efficiency. Three cell clones were used for nuclear transfer. Nuclear transfer was performed using a fusion before activation protocol using in vitro-matured adult oocytes. Between 51 and 110 fused couplets were transferred to 10 recipients synchronized 1 day behind the embryos. Parturition was induced on day 115, and piglets were delivered by caesarean section. Four recipients gave birth to a total of 18 live piglets. All pigs were female, and all three clones resulted in the birth of live pigs. alpha1,3-GT gene knockout pigs were identified by long-range PCR and confirmed by Southern blot analysis. The efficiency (embryos transferred/piglets born) of our cloning protocol was 1.9% for all transfers and 4.6% for animals that gave birth.

Animals↗