Pressure necrosis secondary to negative pressure dressing.

Wound complications in patients with significant co-morbidities is common; however, in our patient the problem was compounded by the inappropriate placement of negative pressure dressing.

Regulation of adhesion molecule expression in human endothelial and smooth muscle cells by omega-3 fatty acids and conjugated linoleic acids: involvement of the transcription factor NF-kappaB?

We previously showed conjugated linoleic acids (CLA) inhibited TNF-alpha-induced monocyte (THP-1) adhesion to human umbilical vein endothelial cells (HUVEC) in vitro which involved an increase in platelet activating factor (PAF). Here we show adhesion molecule (ADM) regulation by fatty acids and the differing role of nuclear factor kappa B (NF-kappaB) activation in HUVEC and vascular smooth muscle cells (vSMC). CLA and omega-3 long-chain polyunsaturated fatty acids (PUFA) (FA) reduced TNF-alpha-induced expression of ADMs (intercellular adhesion molecule-1 (ICAM-1); vascular cell adhesion molecule-1 (VCAM-1) but not E-selectin) on HUVEC and vSMC to different extents depending on FA type and concentration, cell type and method of analysis. IkappaBalpha phosphorylation in HUVEC and vSMC and transient transfection with NF-kappaB-luciferase reporter plasmid (HUVEC only) indicated differential NF-kappaB involvement during FA modulation (cis-9, trans-11; trans-10, cis-12 and a 50:50 mix of both CLA isomers; eicosapentaenoic acid (EPA); docosahexaenoic acid (DHA)). TNF-alpha-induced ADM expression in both cell types by 2-10-fold. In HUVEC, CLA t10, c12 and CLA mix (50:50 mixture of CLA c9, t11 and t10, c12) and EPA and DHA reduced ICAM-1 expression (15-35%) at 12.5, 25 and/or 50 microM. VCAM-1 expression was reduced by 25 microM t10, c12 isomer and mix; omega-3 PUFA and other concentrations of CLA and TNF-alpha-induced E-selectin expression were unaffected. TNFalpha-induced inhibitor kappa B (IkappaB) phosphorylation was biphasic peaking at 5 min in both cell types and 60 and 120 min in HUVEC and SMC, respectively. IkappaBalpha phosphorylation and NF-kappaB activity was reduced (29% and 30%, respectively) by 25 microM CLA mix. n-3 PUFA did not reduce IkappaBalpha phosphorylation or NF-kappaB activity but reduced ADM expression. We show that n-3 PUFA and CLA reduce expression of ADM on HUVEC and vSMC. This reflected reduced adherence of monocytes to HUVEC previously reported by our group. Reduction of ICAM-1 and VCAM-1 protein expression by n-3 PUFA was less dependent on the NF-kappaB pathway than reduction by CLA which reflected the parallel attenuation of NF-kappaB activity. This indicated involvement of other transcription factors (i.e. AP-1) in the FA regulation of ADM expression and has, to our knowledge, not been previously reported.

Effect of activity levels on polyethylene wear in Charnley low-friction arthroplasty.

Polyethylene wear debri has been implicated as a major cause of aseptic loosening following total hip replacement. The purpose of this study is to classify patient activity levels following total hip replacement and determine if it has an effect on radiographic wear of the socket. 97 patients (115 hips) with osteoarthritis who underwent Charnley low-friction arthroplasty with a minimum of 10 year follow-up were selected. Nine patients had died. Eighty-eight questionnaires were sent of which 59 replied. However, only 40 patients (45 hips) with a complete set of x-rays were finally studied. Activity levels were classified according to post-operative occupation and activities into 'active' and 'less active' groups. Radiographic wear was measured by studying the post-operative and the 10-year review radiograph. There was a significant difference in acetabular wear between the active and the less active group (p = 0.024). No correlation was found between weight and acetabular wear (p = 0.475) or between age and acetabular wear (p = 0.278). It was concluded, therefore, that surgeons who advise their patients to avoid heavy or high intensity activities for prolonged periods, after Charnley low-friction arthroplasty, are justified in this approach.

Effect of megadoses of ascorbic acid on serum and urinary oxalate.

Serum and urinary oxalate was determined in 9 normal subjects, ingesting 8 g of ascorbic acid daily. Serum oxalate levels increased to 310% of control values during supplementation. Plasma ascrobate levels reached a mean value of 3.6 mg% far exceeding the previously reported plateau level of 1.8 mg%. Urinary oxalate gradually increased during ascorbate intake and 7 days post cessation of ascorbate, rose unexpectedly for all subjects into the hyperoxaluric range.

A radioprotective effect of vitamin C observed in Chinese hamster ovary cells.

Vitamin C at high concentrations was found to inhibit the growth of CHO clone A cells in culture. It had a radioprotective effect, giving a maximum increase in cell survival of a factor of seven under the experimental conditions used. The protective effect was mainly but not exclusively attributable to an increase in the Do, the maximum increase observed being the order of 1.4.