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Search Results: 1 - 10 of 1043 matches for " SJ Semple "
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C-reactive protein - biological functions, cardiovascular disease and physical exercise
SJ Semple
South African Journal of Sports Medicine , 2006,
Abstract: C-reactive protein (CRP) is an acute-phase reactant that increases in response to noxious stimuli that inevitably induce cellular and/or tissue injury. The increased synthesis of CRP occurs predominantly in the liver and peaks 24 - 48 hours after the inciting stimulus. CRP forms an integral component of innate immunity and serves primarily to recognise potential pathogens and damaged cells. It facilitates the removal of these cells through opsonisation and activates the complement system. With increasing evidence supporting the classification of artherosclerosis as inflammatory in nature, CRP has received considerable attention as a marker, and in some cases a contributor towards this cardiovascular disease. Traditionally, CRP has been measured within exercise studies to provide evidence that an acute-phase inflammatory response can or has been initiated. Although the elevation in CRP following exercise has largely been attributed to muscle damage, evidence is mounting to contest this premise. Participation in chronic exercise has been associated with a reduced risk of cardiovascular disease. Numerous studies have now shown an inverse relationship between physical activity levels and resting concentrations of CRP. Thus, exercise may prove beneficial in lowering systemic inflammatory markers such as CRP, and consequently contribute towards preventing the progression of inflammatory disorders. South African Journal of Sports Medicine Vol. 18 (1) 2006: pp. 24-28
Non-allergic activation of eosinophils after strenuous endurance exercise
AJ McKune, LL Smith, SJ Semple, AA Wadee
South African Journal of Sports Medicine , 2004,
Abstract: Objective. To determine the effect of prolonged endurance exercise on the serum concentrations of eosinophil cationic protein (ECP), immunoglobulin E (IgE) and upper respiratory tract symptoms (URTS). Design. In 11 healthy, experienced volunteers (6 males, 5 females, age 43 ± 9.8 years) the serum concentrations of ECP and IgE were measured, 24 hours prior to projected finishing time, immediately post exercise (IPE), and 3 h, 24 h, and 72 h after an ultramarathon (90 km). Self-reported URTS were also recorded for 14 days after the race. ECP was measured using radioimmunoassay and IgE using the Alastat Microplate Total IgE kit. The after-exercise values were corrected for plasma volume changes, which were calculated from haematocrit and haemoglobin values. Serum concentrations of ECP and IgE were analysed using an analysis of variance (ANOVA) comparing values with before-exercise levels. Level of significance was set at p ≤ 0.05. Results. ECP was significantly elevated at 72 hours (+52%), whilst IgE was not significantly altered after the ultramarathon. There were no reported URTS for the 14 days after the race. Conclusion. The eosinophil is a pro-inflammatory leukocyte involved in bronchial hyperreactivity and allergic inflammation of the airways. IgE is associated with allergic diseases such as asthma and rhinitis. Serum ECP is a sensitive marker of eosinophil activation. The result provides evidence for the non-allergic activation of blood eosinophils during prolonged endurance exercise. Whether this indicates exercise or environmentally induced airway inflammation, or a role for ECP in muscle /tissue repair, are hypotheses that require additional research. SA Sports Medicine Vol.16(2) 2004: 12-16
Alterations in mood state following an ultra-marathon
SJ Semple, LL Smith, N Neveling, A McKune
South African Journal of Sports Medicine , 2003,
Abstract: SA Sports Medicine Vol.15(3) 2003: 29-31
Complement, immunoglobulin and creatine kinase response in black and white males after muscle-damaging exercise
AJ McKune, SJ Semple, LL Smith, AA Wadee
South African Journal of Sports Medicine , 2009,
Abstract:
Comparison of clinic-based versus home-based balance and agility training for the symptoms of knee osteo-arthritis
MW Rogers, N Tamulevicius, SJ Semple, MF Coetsee, BF Curry
South African Journal of Sports Medicine , 2011,
Abstract: Objective. To compare clinic-based (CB) and home-based (HB) deliveries of a knee osteoarthritis (OA) exercise programme. Methods. Outcomes from a CB exercise study (N=6) utilising kinesthesia, balance and agility (KBA) exercises were compared with those from a HB KBA study (N=6). Both conditions trained 30 minutes, 3 days per week for 8 weeks. CB sessions were conducted in a group led by an exercise physiologist (EP); HB participants received an initial 3 sessions of one-to-one training from an EP, written/pictorial instructions, telephone and e-mail follow-up, and in-person refresher sessions during weeks 4 and 6. The primary outcome was an OA-specific physical function survey. Community activity level, self-report knee stability, 15-m get up and go walk, and stair climb and descent were also measured. Results. Adherence was 94% in both conditions. KBA improved PF in both CB (59%; 18±12.5 pts; p=0.008) and HB (33%; 7.3±7.5 pts; p=0.03), with no difference between conditions. All outcome improvements were somewhat larger for CB, but these differences did not reach statistical significance. Conclusion. We found no difference in outcomes between CB and HB exercise in this preliminary comparison. Our results support that KBA is an effective intervention for symptomatic knee OA that may be delivered in CB or HB settings.
Alterations in acute-phase reactants (CRP, rheumatoid factor, complement, Factor B, and immune complexes) following an ultramarathon
SJ Semple, LL Smith, AJ McKune, N Neveling, A Wadee
South African Journal of Sports Medicine , 2004,
Abstract: Objectives. The human body initiates an acute phase response (APR) in response to a wide range of homeostatic disturbances. This complex series of reactions serves to activate repair processes and prevent ongoing tissue damage. An important aspect of the APR is the de novo synthesis of acute phase proteins (APP), many of which have not been thoroughly investigated. Main outcome measures. Alterations in CRP (C-reactive protein), C1est, C3, C4, C6, rheumatoid factor (RF) and Factor B were determined before and after an ultramarathon. Data were analysed using a one-way analysis of variance comparing values to pre-exercise levels. Significance was set at p < 0.05. Design. Venepunctures were performed on athletes participating in an ultramarathon (90 km) 24 hours before, immediately post-exercise (IPE), and 3h, 24h and 72h after the race. Serum was stored at –80°C until analysed. CRP levels in serum were assessed using the N Latex CRP kit. The levels of circulating immune complexes (CIC) were determined using particle-enhanced nephelometry. Complement proteins C1est, C3, C4 and RF were measured using laser nephelometry. C6 and Factor B were determined by radial immunodiffusion. Results. CRP was significantly elevated IPE (58%), 3h post (77%), 24h post (87%) and 72h post (69%). Pre-race CRP levels were above the normative range (5.10 ± 3.08 mg/l), C6 was significantly elevated (p < 0.05) at 24h post (7.8%) and 72h post (8.8%) exercise. Factor B was significantly elevated (p < 0.05) at 72h post exercise (12.8%). RF was significantly elevated at 72h post exercise (6.7%). Conclusion. Significant increases in selected acutephase reactants occur several days after the exercise event. In addition, as indicated by elevated resting levels of CRP, the athletes began the race with some degree of inflammation, presumably as a result of the cumulative training and racing mileage in preparation for the ultramarathon. SA Sports Medicine Vol.16(2) 2004: 17-21
The effects of an L-methionine combination supplement on symptoms of upper respiratory tract infections and performance in ultramarathon runners before, during and after ultra-endurance exercise
LM Harden, N Neveling, F Rossouw, SJ Semple, FE Marx, J Rossouw, G Rogers
South African Journal of Sports Medicine , 2004,
Abstract: Objective. To evaluate whether supplementation with an L-methionine combination would reduce the incidence of upper respiratory tract symptoms (URTS) and improve performance in ultramarathon runners. Design. A double-blind placebo-controlled study. Setting. Twenty-one ultramarathon runners (17 males, 4 females) preparing for participation in an 87.3 km ultramarathon. Interventions. L-methionine combination supplement (L-methionine, vitamin B6, vitamin B12, folic acid and magnesium) or placebo containing potato starch. Main outcome measures. Incidence of URTS was recorded during the runner's preparation for an ultramarathon race (75 days) and recovery from the same (75 days). CD4+, CD8+ cell counts and ratios were measured pre race, immediately post race and 75 days post race. VO2max and endurance fitness (percentage VO2max at 4 mmol-1 lactate concentration) were measured during the preparation for the race. Results. During the preparation period the incidence of URTS was 36% in the supplement group and 80% in the placebo group (p = 0.08). The incidence of URTS during the 3 weeks post race was 27% in the supplement group and 40% in the placebo group (p = 0.65). The CD4+/CD8+ cell ratios were not significantly different between groups. Endurance fitness prior to the race and race times were not significantly different. Conclusions. Although the findings of the current study show that an L-methionine combination supplement did not reduce the incidence of URTS or improve performance in ultramarathon runners, benefits may be found with a more detailed investigation using larger sample sizes and immunosuppressed athletes. South African Journal of Sports Medicine Vol.16(1) 2004: 10-16
Changes in neutrophil count, creatine kinases and muscle soreness after repeated bouts of downhill running
LL Smith, SJ Semple, AJ McKune, N Neveling, M Caldeira, J-M Swanepoel, L Tsomele, M Naidoo, E Sibanda
South African Journal of Sports Medicine , 2007,
Abstract: Objective. A primary objective was to examine circulating neutrophil count after repeated bouts of downhill running. An additional aim was to determine creatine kinase (CK) levels during the initial 12 hours, after repeated DHRs. Design. Eleven healthy, untrained Caucasian males performed 2 x 60 min bouts of DHR (-13.5%), spaced 14 days apart, at a speed equal to 75% VO2max on a level grade. Blood was collected before, after, and every hour for 12 hours, and every 24 hours for 6 days. Absolute neutrophil count, CK, and delayed-onset muscle soreness (DOMS) were assessed. Results were analysed using repeated measures ANOVA (p<0.05) with appropriate post hoc tests. Results. There were no significant differences in neutrophil count (p=0.24) during the 12-h period following run 1 (mean±se, 6.45±0.29 10-9.l-1) versus run 2 (5.96±0.09 10-9.l-1), or during the 24-h periods for run 1 (3.48±0.09 10-9.l-1) or run 2 (3.47±0.09 10-9.l-1). During the initial 12-h period, there was a significant interaction effect (p=0.0001) for CK with differences between bouts seen between 3 - 12 h; differences remained evident at 24 h and at 96 - 144 h. In all muscle groups, DOMS was significantly lower after run 2 compared with run 1. Conclusion. The lack of significance in neutrophils, as well as the early onset of difference in CK between run 1 and run 2 were attributed to the type of eccentric protocol used. It was proposed that future studies be more cognisant of whether the eccentric mode is predominantly low-intensity long-duration or high-intensity short-duration. South African Journal of Sports Medicine Vol. 19 (3) 2007: pp. 86-93
The desktop genome
Colin Semple
Genome Biology , 2001, DOI: 10.1186/gb-2000-2-1-reports2001
Abstract: And now the caveats. Genscan can detect most (perhaps between 70 and 90%), but not all, of the genes present in human genomic sequences, and by no means all novel genes show significant similarity to previously known sequences. This means that the set of confirmed genes in Ensembl is necessarily a conservative one. This problem may be further exacerbated by the quality of the sequence submitted. Ensembl uses the Human genome project working draft sequence assemblies (or 'golden path') produced at the University of California at Santa Cruz, which are known to contain many gaps and misassemblies. The golden path appears to be particularly unreliable in regions where it is composed of many small genomic sequence fragments from recently sequenced bacterial artificial chromosomes (BAC) clones. Many of these fragments are assembled in the wrong order and/or orientation. Such misassemblies will be a further source of errors and omissions in Ensembl. Although Genscan can detect the presence of most genes, it is substantially less successful in predicting their correct exonic structures (as with other ab initio gene predictions). This means that many, if not most, of the gene structures in Ensembl will be incorrect, or 'partial' predictions in Ensembl parlance.In spite of these difficulties Ensembl remains a useful tool for the cautious biologist. It should detect the presence of most genes in a given fragment of genomic sequence and indicate their location in the genome on the basis of the best mapping data available. In addition it has a stab at predicting gene structures that should be accurate if the gene in question has a close homolog which is already known. Most aspects of the analysis Ensembl carries out are the subject of active research, so improvements in performance, as a result of the inclusion of new sequence data and algorithms, will be ongoing. Having secured major funding earlier this year, the database promises to become the most important source of annotat
The family way
Colin Semple
Genome Biology , 2000, DOI: 10.1186/gb-2000-1-2-reports2044
Abstract: Since its inception in 1996, Pfam has aimed to be a comprehensive database of protein families defined by the presence of shared domains. The database is partitioned into two sections: Pfam-A contains accurate multiple alignments that are curated manually, whereas Pfam-B is generated automatically by clustering and aligning protein sequences not already covered by Pfam-A. Pfam-A families have permanent accession numbers and contain functional annotation and cross-references to other protein domain and motif databases, whereas Pfam-B families are regenerated at each release and are less well annotated. Each domain in Pfam is represented by a position-specific scoring model or profile; the particular type of statistical model used to derive such profiles in Pfam is the hidden Markov model (HMM). Pfam consists of a library of HMMs that can be used as sensitive tools to find new members of the domains represented. It is reported that Pfam HMMs match around two thirds of proteins in SWISSPROT and TrEMBL, and that for complete genomes Pfam currently matches up to half of the proteins discovered. It is possible to browse Pfam online or to perform a search with a protein or DNA sequence of interest. Once a Pfam domain has been identified, information relating to its physical structure, typical position (for example, carboxy-terminal), functional annotation and species distribution can be retrieved.The site is well documented with links to related literature and software as well as other profile search sites. It is possible to bookmark individual Pfam domain pages.Pfam is updated erratically every few months from the protein sequences deposited in SWISSPROT and TrEMBL.A single Pfam search can often be as sensitive as a detailed trawl through the databases with BLAST or FASTA, and can therefore save a lot of time in characterizing proteins with no strong similarities to known sequences. In addition, the HMM software on which Pfam is based is licensed under the Gnu Public Lice
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