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W de Villiers

Publications and source records attributed to W de Villiers.

5 recordsLinked to original sources
PubMed2006

Temporal gene expression profiles of target-ablated olfactory epithelium in mice with disrupted expression of scavenger receptor A: impact on macrophages.

Target ablation [removal of the olfactory bulb (OBX)] induces apoptotic death of olfactory sensory neurons (OSNs) and an immune response in which activation and recruitment of macrophages (ms) into the olfactory epithelium (OE) occupy a central role. Ms phagocytose apoptotic neurons and secrete cytokines/growth factors that regulate subsequent progenitor cell proliferation and neurogenesis. Scavenger receptor A (SR-A) is a pattern recognition receptor that mediates binding of ms to apoptotic cells and other relevant immune response functions. The aim of this study was to determine the impact of the absence of SR-A on the immune response to OBX. The immune response to OBX was evaluated in mice in which functional expression of the m scavenger receptor (MSR) was eliminated by gene disruption (MSR-/-) and wild-type (wt) mice of the same genetic background. OBX induced significant apoptotic death of mature OSNs in the two strains. However, subsequent m infiltration and activation and progenitor cell proliferation were significantly reduced in MSR-/- vs. wt mice. Gene expression profiling at short intervals after OBX demonstrated significant differences in temporal patterns of expression of several gene categories, including immune response genes. Many immune response genes that showed different temporal patterns of expression are related to m function, including cytokine and chemokine secretion, phagocytosis, and m maturation and activation. These studies suggest that impairment of the immune response to OBX in the OE of MSR-/- mice most likely resulted from decreased m adhesion and subsequent reduced infiltration and activation, with a resultant decrease in neurogenesis.

Animals↗
PubMed1993

Influence of specific mutations at the LDL-receptor gene locus on the response to simvastatin therapy in Afrikaner patients with heterozygous familial hypercholesterolaemia.

Simvastatin, an inhibitor of HMG CoA reductase, lowers the plasma total cholesterol and LDL-cholesterol concentration in familial hypercholesterolemic patients. The efficacy of the drug shows considerable inter-individual variation, however. In this study we have assessed the influence of certain LDL-receptor gene mutations on this variation. A group of 20 male and female heterozygotic familial hypercholesterolemic patients, all Afrikaners and each bearing one of two different LDL receptor gene mutations, FH Afrikaner-1 (FH1) and FH Afrikaner-2 (FH2), was treated with simvastatin (40 mg once daily) for 18 months. The average reduction in total plasma cholesterol was 35.3% in the case of the FH2 men but only 23.2% in that of the FH1 men (P = 0.005); the reduction in LDL cholesterol concentrations was also greater in the FH2 group (39% as opposed to 27.1%, P = 0.02). The better response of the FH2 group was also evident when men and women were considered together. Female FH1 patients responded better to simvastatin treatment, however, than did males with the same gene defect. Mutations at the LDL-receptor locus may thus play a significant role in the variable efficacy of the drug. The particular mutations in the males of this group may have contributed up to 35% of the variance in total cholesterol response and 29% of the variance in LDL-cholesterol response to simvastatin treatment.

Adult↗
PubMed1980

Capsular contracture after breast augmentation--a comparison between gel- and saline-filled prostheses.

Capsular contracture around the breast prostheses remains the major drawback to the otherwise very satisfying operation of breast augmentation. The possible aetiology of this complication is discussed and local aggravating factors are implicated. The two major types of modern breast prostheses are the Silastic gel-filled and the inflatable. A short-term retrospective clinical study was conducted on 79 augmented breasts to compare the contracture rate when using the gel-filled and the inflatable prostheses--90,7% of the gel-filled prostheses developed capsular contracture (the majority grade III), compared with 22,2% of the inflatables (the majority grade II). On the basis of this trial, we now only use inflatable prostheses for breast augmentation.

Breast↗
PubMed1980

Vaginoplasty.

The historical development of vaginal reconstruction in vaginal atresia is reviewed. Two more recent indications for vaginoplasty are (i) total pelvic exenteration for carcinoma; and (ii) sex conversion in trans-sexuals. The operations available for these conditions are discussed, with particular emphasis on sex-conversion techniques. A method of vaginoplasty in inadequately treated transsexuals, using random medial thigh flaps, is presented with illustrative case reports.

Adult↗