The purpose of the study was to investigate whether severe fatigue, possibly leading to overreaching, could be diagnosed at an early stage by a combination of parameters. Seven well-trained male subjects (age [mean +/- SD]: 25.3 +/- 4.7 yr; body mass: 76 +/- 6.6 kg; VO2max: 61.1 +/- 7 ml.kg(-1).min(-1)) increased their training load by doubling their training volume and increasing the intensity by 15 % over a period of two weeks. Before and after this intensified training period subjects underwent a series of tests including a maximal incremental cycle ergometer test (Wmax) with continuous ventilatory measurements and blood lactate values, time trial, basal blood parameter tests (red and white blood profile), hormones [growth hormone (GH), insulin-like growth factor 1(IGF-1), adreno-corticotropic hormone (ACTH), cortisol], neuro-endocrine stress test [short insulin tolerance test (SITT), combined anterior pituitary test (CAPT) and exercise], a shortened Profile of Mood State (POMS), the estimated rate of perceived exertion (RPE) and a cognitive reaction time test. The intensified training period resulted in a significant increase of the training load (p <0.01), training monotony (p <0.01) and training strain (p <0.01). The RPE during training increased significantly (p <0.01) during the intensified training period. Total mood score obtained from the POMS tended to increase (p=0.06), reflecting an increase in worse mood state. A novel finding was that reaction times increased significantly, indicating that overreaching might adversely affect speed of information processing by the brain, especially for the most difficult conditions. After the intensified training period, neither changes in exercise-induced plasma hormone values, nor SITT values were observed. During the CAPT only cortisol showed a significant decrease after the intensified training period. Hemoglobin showed a significant decrease after the intensified training period whereas hematocrit, red blood cell count (RBC) and MCV tended to decrease. The intensified training had no effect on physical performance (Wmax or time trial), maximal blood lactate, maximal heart rate and white blood cell profile. The most sensitive parameters for detecting overreaching are reaction time performance (indicative for cognitive brain functioning), RPE and to a lesser extend the shortened POMS. This strongly suggests, that central fatigue precedes peripheral fatigue. All other systems,including the neuro-endocrine, are more robust and react most likely at a later stage in exhaustive training periods.
Background: Body temperature is a strong predictor of outcome in acute stroke. In a previous randomized trial we observed that treatment with high-dose acetaminophen (paracetamol) led to a reduction of body temperature in patients with acute ischemic stroke, even when they had no fever. The purpose of the present trial was to study whether this effect of acetaminophen could be reproduced, and whether ibuprofen would have a similar, or even stronger effect.
BackgroundIn patients with frequent migraine, prophylactic treatments are used. Patients often request non-pharmacological alternatives. One treatment option can be aerobic exercise. The value of aerobic exercise as prophylactic treatment however needs to be determined.MethodsA systematic review and meta-analysis was performed to investigate the result of aerobic exercise on the number of migraine days, duration and pain intensity in patients with migraine. After screening three online databases, PubMed, Cochrane library and Web of Science, using predefined in- and exclusion criteria, six studies were retained. Pooling of data was performed when possible.ResultsSignificant reductions in the number of migraine days after aerobic exercise treatment were found with a mean reduction of 0.6 ± 0.3 migraine days/month. Other outcomes were too variable to pool due to heterogeneity of outcome measurements. Unpooled data revealed small to moderate reductions in attack duration (20–27%) and pain intensity (20–54%) after aerobic exercise intervention. Various exercise intensities are applied.ConclusionThere is moderate quality evidence that in patients with migraine aerobic exercise therapy can decrease the number of migraine days. No conclusion for pain intensity or duration of attacks can be drawn. Effect sizes are small due to a lack of uniformity. For future studies, we recommend standardized outcome measures and sufficiently intense training programs.Trial registrationCRD42018091178.Electronic supplementary materialThe online version of this article (10.1186/s10194-019-0961-8) contains supplementary material, which is available to authorized users.
Phosphatidylinositol 3-kinase, which is composed of a 110-kDa catalytic subunit and a regulatory subunit, plays important roles in various cellular signaling mechanisms. We screened a rat brain cDNA expression library with 32 P-labeled human IRS-1 protein and cloned cDNAs that were very likely to be generated by alternative splicing of p85␣ gene products. These cDNAs were demonstrated to encode a 55-kDa protein (p55␣) containing two SH2 domains and an inter-SH2 domain of p85␣ but neither a bcr domain nor a SH3 homology domain. Interestingly, p55␣ contains a unique 34-amino acid sequence at its NH 2 terminus, which is not included in the p85␣ amino acid sequence. This 34-amino acid portion was revealed to be comparable with p55PIK (p55␥) in length, with a high homology between the two, suggesting that these NH 2 -terminal domains of p55␣ and p55␥ may have a specific role that p85 does not. The expression of p55␣ mRNA is most abundant in the brain, but expression is ubiquitous in most rat tissues. Furthermore, it should be noted that the expression of p85␣ mRNA in muscle is almost undetectably low by Northern blotting with a cDNA probe coding for the p85␣ SH3 domain, while the expression of p55␣ can be readily detected. These results suggest that p55␣ may play an unique regulatory role for phosphatidylinositol 3-kinase in brain and muscle.Phosphatidylinositol 3-kinase (PI 3-kinase) 1 (1, 2) has been implicated in the regulation of various cellular activities, including proliferation (3, 4), differentiation (5), membrane ruffling (6), and prevention of apoptosis (7). In addition, PI 3-kinase activation is required for insulin-stimulated glucose transport and insulin-dependent p70S6K activation (3). PI 3-kinase is a heterodimeric enzyme consisting of a regulatory subunit (1, 2, 8, 9) and a 110-kDa catalytic subunit (p110␣, ). Recently, a novel 110-kDa catalytic subunit (p110␥), which is stimulated via G␣ and G␥, was cloned (10). For the former type of PI 3-kinase, three regulatory subunit isoforms for PI 3-kinase have been identified. Among them, p55PIK is a unique protein since the SH3 domain and bcr homology domains found in p85␣ are replaced in p55PIK by a unique 34-residue NH 2 terminus (11).In this study, we isolated a novel alternatively spliced cDNA from the p85␣ gene by expression screening from a rat brain cDNA library using a 32 P-labeled human IRS-1 protein. This cDNA was demonstrated to encode a 55-kDa protein, which was designated p55␣, because it is partly identical to p85␣. In addition, we suggest changing the name of p55PIK to p55␥ to avoid confusion between p55PIK (p55␥) and p55␣. Herein, we compare the amino acid sequences of four isoforms of the regulatory subunit of rat PI 3-kinase and show their tissue distributions. These isoforms may be activated by different stimuli and/or at different intercellular locations. MATERIALS AND METHODSPreparation of Recombinant Human IRS-1-Human IRS-1 cDNA was obtained by screening the human genomic library using a 32 Plabeled DNA fragment. According to the seq...
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