Acute exercise in elite rugby players increases the circulating level of the cardiovascular biomarker GDF-15.

BACKGROUND: Intense training can lead to a pathophysiological change in serum concentration of a variety of biomarkers. Traditional biomarkers of cardiac injury are very useful in monitoring CVD patients, but in healthy subjects or athletes they cannot be informative enough about the cardiovascular risk, because in these cases their serum levels do not increase over the pathological limit. Therefore novel cardiovascular biomarkers are required in order to allow a better monitoring of sport performance, prediction of overtraining and diagnosis of sport-related cardiac injuries. Growth differentiation factor-15 (GDF-15) is emerging as a powerful cardiovascular injury risk indicator. In this study we investigate the effect of intense physical training of on the circulating levels of GDF-15 in rugby professional players. METHODS: Serum GDF-15, Erythropoietin, IL-6, the cardiovascular parameter ST-2, NT-proBNP and routine hematological parameters were measured in a group of 30 rugby players before and after a session of intense training. RESULTS: While ST-2, IL-6 and hsCRP displayed no significant changes after intense training, NT-proBNP and GDF-15 showed a significant increase, even without reaching the pathological level. DISCUSSION: The measure of GDF-15 in professional rugby players could be a useful tool to monitoring their cardiovascular status during training and competition session in order to prevent the onset of collateral cardiovascular adverse event due to the intense training and, in the case of cardiac injury, it could possibly allow a very early diagnosis at the beginning of the pathogenic process.

Stability of osteopontin in plasma and serum.

BACKGROUND: Osteopontin is a glycoprotein widely expressed in many tissues and in different physiological conditions. Osteopontin concentrations are usually measured through immunological methods; however, little is known about the pre-analytical management of the sample. We evaluated the effects of different times and temperatures storage conditions on serum and plasma concentrations of osteopontin. METHODS: Serum and plasma aliquots were frozen at ­ 80° C, following storage at 4° C or room temperature for 0, 2, 4, 8, 12, 24 and 48 h. Osteopontin concentrations were determined by enzymoimmunometric assay. Serum samples obtained from tubes with or without gel separator were compared to verify the effect of gel. Western blotting analysis was performed to characterize the antibody. RESULTS: Osteopontin concentrations were stable over time in all conditions in both serum and plasma. Plasma showed 3.8 ­ 4.8-fold higher concentrations than serum. Comparable levels were found between serum tubes with or without gel separator and always lower than those in plasma, demonstrating no effect of gel in serum tubes. Western blotting analysis showed various osteopontin bands, indicating that the antibody recognizes the entire panel of different osteopontin forms. CONCLUSIONS: We demonstrated the stability across 48 h of osteopontin in serum and plasma at either room temperature or 4° C, when the evaluation is carried out by an immune-based method. The minimal variations observed over time were always lower than the calculated intra- and inter-assay coefficients of variation. Plasma specimens should be preferred when osteopontin concentration are assayed by immunological methods.

Hematological profile and martial status in rugby players during whole body cryostimulation.

Cold-based therapies are commonly applied to alleviate pain symptoms secondary to inflammatory diseases, but also to treat injuries or overuse, as done in sports rehabilitation. Whole body cryotherapy, a relatively new form of cold therapy, consists of short whole-body exposure to extremely cold air (-110°C to -140°C). Cryostimulation is gaining wider acceptance as an effective part of physical therapy to accelerate muscle recovery in rugby players. The aim of this study was to evaluate the effect of repeated cryostimulation sessions on the hematological profile and martial status markers in professional rugby players. Twenty-seven professional rugby players received 2 daily cryostimulation treatments for 7 consecutive days. Blood samples were collected before and after administration of the cryotherapic protocol and hematological profiles were obtained. No changes in the leukocyte count or composition were seen. There was a decrease in the values for erythrocytes, hematocrit, hemoglobin and mean corpuscular hemoglobin content, and an increase in mean corpuscular volume and red cell distribution width. Platelet count and mean volume remained unchanged. Serum transferrin and ferritin decreased, while soluble transferrin receptor increased. Serum iron and transferrin saturation were unchanged, as was reticulocyte count, whereas the immature reticulocyte fraction decreased substantially. In conclusion, in this sample of professional rugby players, cryostimulation modified the hematological profile, with a reduction in erythrocyte count and hemoglobinization paralleled by a change in martial status markers.

Metabolic effects of vitamin D active metabolites in monolayer and micromass cultures of nucleus pulposus and annulus fibrosus cells isolated from human intervertebral disc.

Intragenic polymorphisms in the vitamin D receptor gene are linked to disc degeneration features, suggesting that alterations in the vitamer-mediated signalling could be involved in the pathophysiology of the disc and that interaction of disc cells with vitamin D metabolites may be critical for disc health. The vitamer-mediated modulation of disc cells proliferation, metabolic activity, extracellular matrix (ECM) genes expression and proteins production was investigated. It was stated that disc cells express vitamin D receptor and are very sensitive to metabolic stimuli. In monolayer cultures, 1,25(OH)(2)D(3), but not 24,25(OH)(2)D(3), determined an inhibition of the proliferation and regulated also the ECM genes expression in nucleus pulposus and annulus fibrosus cells. Micromass cultures induced a more physiologic expression pattern of extracellular matrix genes. Cells Treatment with vitamin D metabolites did not result in relevant modifications of glycosaminoglycans production, except for annulus cells, whose production was reduced after 1,25(OH)(2)D(3) treatment. Moreover, a reduced glycosaminoglycans staining in both cell types and a significant reduced aggrecan gene expression in annulus cells treated with 1,25(OH)(2)D(3) were observed. A reduction of collagen I and II staining in annulus cells 1,25(OH)(2)D(3) treated, in accordance with a downregulation of collagen genes expression, was also registered. Finally, the vitamin D receptor gene expression did not show significant metabolite-mediated modification in monolayer or micromass cultures. These findings could enhance new insights on the biochemical mechanisms regulated by vitamin D in disc cartilage and possibly involved in the development of physiological/pathological modifications of the disc.