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Biomedical subjects

Chris Wilson

Publications and source records attributed to Chris Wilson.

7 recordsLinked to original sources
PubMed2004

Advances in measuring lifespan in the yeast Saccharomyces cerevisiae.

Much research aimed at discovering the genetic bases of longevity focuses on the budding yeast Saccharomyces cerevisiae. Unfortunately, yeast researchers use a definition of longevity not applied to other species. We propose here a method that makes it possible to estimate for yeast the same measures of longevity calculated for other species. We also show that the conventional method (equating longevity with the number of offspring) is only an approximate measure of true chronological lifespan. Our method will allow results for yeast to be compared more correctly with those for other species.

Genotype↗
PubMed2004

The relationship between plasma and red cell concentrations of vitamins thiamine diphosphate, flavin adenine dinucleotide and pyridoxal 5-phosphate following elective knee arthroplasty.

BACKGROUND & AIMS: Water soluble vitamins B1, B2 and B6 are essential precursors for a wide variety of coenzymes involved in intermediary metabolism and their status is usually assessed from blood samples. The aim of the study was to examine the relationship between plasma and intra-cellular B-vitamins following the systemic inflammatory response of surgery. METHODS: Patients (n = 10) who underwent an elective knee arthroplasty, had venous blood samples withdrawn pre-operatively and at 12, 24, 48, 72 and 168 h after the start of surgery for the analysis of circulating concentrations of C-reactive protein and albumin and also plasma and/ or red cell thiamine diphosphate (TDP), flavin adenine dinucleotide (FAD), pyridoxal 5-phosphate (PLP) as indicators of vitamins B1, B2, and B6 status respectively. RESULTS: Pre-operative, baseline vitamin assessments were all within population reference ranges. Over the study period of 0-168 h there was a significant increase in circulating C-reactive protein concentrations (peak 48 h, P < 0.001) and a significant fall in albumin concentrations (trough 48 h, P < 0.001). Plasma FAD and PLP concentrations fell transiently (P < 0.001) by approximately 40% reaching their nadir at approximately 48 h. CONCLUSIONS: The results of the present study indicate that plasma concentrations of FAD and PLP are transiently reduced following an inflammatory insult and therefore unlikely to be a reliable measure of status in the presence of a systemic inflammatory response. It may be that during such a response red cell concentrations provide a more reliable measure.

Aged↗
PubMed2002

Pathologic indicators of degradation and inflammation in human osteoarthritic cartilage are abrogated by exposure to n-3 fatty acids.

OBJECTIVE: To determine if n-3 polyunsaturated fatty acid (PUFA) supplementation (versus treatment with n-6 polyunsaturated or other fatty acid supplements) affects the metabolism of osteoarthritic (OA) cartilage. METHODS: The metabolic profile of human OA cartilage was determined at the time of harvest and after 24-hour exposure to n-3 PUFAs or other classes of fatty acids, followed by explant culture for 4 days in the presence or absence of interleukin-1 (IL-1). Parameters measured were glycosaminoglycan release, aggrecanase and matrix metalloproteinase (MMP) activity, and the levels of expression of messenger RNA (mRNA) for mediators of inflammation, aggrecanases, MMPs, and their natural tissue inhibitors (tissue inhibitors of metalloproteinases [TIMPs]). RESULTS: Supplementation with n-3 PUFA (but not other fatty acids) reduced, in a dose-dependent manner, the endogenous and IL-1-induced release of proteoglycan metabolites from articular cartilage explants and specifically abolished endogenous aggrecanase and collagenase proteolytic activity. Similarly, expression of mRNA for ADAMTS-4, MMP-13, and MMP-3 (but not TIMP-1, -2, or -3) was also specifically abolished with n-3 PUFA supplementation. In addition, n-3 PUFA supplementation abolished the expression of mRNA for mediators of inflammation (cyclooxygenase 2, 5-lipoxygenase, 5-lipoxygenase-activating protein, tumor necrosis factor alpha, IL-1alpha, and IL-1beta) without affecting the expression of message for several other proteins involved in normal tissue homeostasis. CONCLUSION: These studies show that the pathologic indicators manifested in human OA cartilage can be significantly altered by exposure of the cartilage to n-3 PUFA, but not to other classes of fatty acids.

Adult↗
PubMed2002

Effects of n-3 fatty acids on cartilage metabolism.

Although the clinical benefits of dietary supplementation with n-3 polyunsaturated fatty acids (PUFA) has been recognised for a number of years, the molecular mechanisms by which particular PUFA affect metabolism of cells within the synovial joint tissues are not understood. This study set out to investigate how n-3 PUFA and other classes of fatty acids affect both degradative and inflammatory aspects of metabolism of articular cartilage chondrocytes using an in vitro model of cartilage degradation. Using well-established culture models, cartilage explants from normal bovine and human osteoarthritic cartilage were supplemented with either n-3 or n-6 PUFA, and cultures were subsequently treated with interleukin 1 to initiate catabolic processes that mimic cartilage degradation in arthritis. Results show that supplementation specifically with n-3 PUFA, but not n-6 PUFA, causes a decrease in both degradative and inflammatory aspects of chondrocyte metabolism, whilst having no effect on the normal tissue homeostasis. Collectively, our data provide evidence supporting dietary supplementation of n-3 PUFA, which in turn may have a beneficial effect of slowing and reducing inflammation in the pathogenesis of degenerative joint diseases in man.

Adult↗