Eduardo Oliveira

Biochemical impact of a soccer match — analysis of oxidative stress and muscle damage markers throughout recovery

BACKGROUND Exercise is a prone condition to enhanced oxidative stress and damage and the specific activity pattern of a soccer match may favour additional pro-oxidant redox alterations. To date, no studies have reported the impact of a soccer match on oxidative stress and muscle damage markers. AIM To analyse the effect of a competitive soccer match on plasma levels of oxidative stress and muscle damage markers, and to relate these findings with lower limb functional data. METHODS Blood samples, leg muscle strength, sprint ability and delayed-onset muscle soreness (DOMS) were obtained in 16 soccer players before, at 30 min, 24, 48 and 72 h after a soccer match. Plasma creatine kinase (CK), myoglobin (Mb), malondialdehyde (MDA), sulfhydryl (-SH) groups, total antioxidant status (TAS), uric acid (UA) and blood leukocyte counts were determined. RESULTS A soccer match elevated plasma Mb following 30 min and CK levels throughout the 72 h-recovery period. MDA increased throughout the recovery period and -SH decreased until 48 h post-match. TAS increased at 30 min and UA increased throughout the 72 h recovery. Blood neutrophils increased at 30 min whereas lymphocytes decreased and returned to baseline from 24 to 72 h. DOMS was higher than baseline until 72 h. Lower limb strength and sprint ability were lower than baseline until 72 h recovery. CONCLUSION The present data suggest that a soccer match increases the levels of oxidative stress and muscle damage throughout the 72 h-recovery period. The extent to which the redox alterations are associated with the recovery of muscle function should be further analysed.

TwitterEcho: a distributed focused crawler to support open research with twitter data

Modern social network analysis relies on vast quantities of data to infer new knowledge about human relations and communication. In this paper we describe TwitterEcho, an open source Twitter crawler for supporting this kind of research, which is characterized by a modular distributed architecture. Our crawler enables researchers to continuously collect data from particular user communities, while respecting Twitters imposed limits. We present the core modules of the crawling server, some of which were specifically designed to focus the crawl on the Portuguese Twittosphere. Additional modules can be easily implemented, thus changing the focus to a different community. Our evaluation of the system shows high crawling performance and coverage.

Effect of off-road competitive motocross race on plasma oxidative stress and damage markers

Aim: To analyse the effect of an off-road motocross heat on plasma levels of oxidative stress and damage, blood leucocyte counts and urine catecholamine concentration. Methods: Plasma contents of total, reduced and oxidised (GSSG) glutathione, %GSSG, malondialdehyde (MDA), protein carbonyl and sulphydryl groups, total antioxidant status (TAS), uric acid, and blood neutrophil and lymphocyte counts were evaluated in 10 male top-level riders before, immediately after (0 h) and 1 h after a simulated competitive motocross race. 24-h urine adrenaline, noradrenaline and dopamine concentrations were also measured. Results: The motocross heat resulted in an increase in plasma oxidative stress and damage (p<0.05). This was shown by a significant increase in %GSSG, TAS, MDA and carbonyls, and by a decrease in sulphydryl groups after the race. There was a significant increase in both plasma uric acid and urine catecholamine concentration after the race (p<0.05). Blood neutrophil counts increased at 0 and 1 h after exercise (p<0.05). Lymphocyte count increased from baseline to 0 h, although it decreased from baseline and 0 to 1 h after exercise (p<0.05). Conclusion: The data reinforce the marked metabolic and hormonal demands imposed by motocross, resulting in a condition of enhanced plasma oxidative stress and damage.