The effects of low and high glycemic index foods on exercise performance and beta-endorphin responses

Τhe aim of this study was to examine the effects of the consumption of foods of various glycemic index values on performance, β-endorphin levels and substrate (fat and carbohydrate) utilization during prolonged exercise. Eight untrained healthy males underwent, in a randomized counterbalanced design, three experimental conditions under which they received carbohydrates (1.5 gr. kg-1 of body weight) of low glycemic index (LGI), high glycemic index (HGI) or placebo. Food was administered 30 min prior to exercise. Subjects cycled for 60 min at an intensity corresponding to 65% of VO2max, which was increased to 90% of VO2max, then they cycled until exhaustion and the time to exhaustion was recorded. Blood was collected prior to food consumption, 15 min prior to exercise, 0, 20, 40, and 60 min into exercise as well as at exhaustion. Blood was analyzed for β-endorphin, glucose, insulin, and lactate. The mean time to exhaustion did not differ between the three conditions (LGI = 3.2 ± 0.9 min; HGI = 2.9 ± 0.9 min; placebo = 2.7 ± 0.7 min). There was a significant interaction in glucose and insulin response (P < 0.05) with HGI exhibiting higher values before exercise. β-endorphin increased significantly (P < 0.05) at the end of exercise without, however, a significant interaction between the three conditions. Rate of perceived exertion, heart rate, ventilation, lactate, respiratory quotient and substrate oxidation rate did not differ between the three conditions. The present study indicates that ingestion of foods of different glycemic index 30 min prior to one hour cycling exercise does not result in significant changes in exercise performance, β-endorphin levels as well as carbohydrate and fat oxidation during exercise

Undifferentiated carcinoma of the head of pancreas with osteoclast-like giant cells presenting as a symptomatic cystic mass, following acute pancreatitis: Case report and review of the literature

AbstractIntroductionUndifferentiated head of pancreas carcinoma with osteoclast-like giant cells (UC-OGC) is a rare neoplasm, with less than a hundred cases reported. We present such a case, in which the UC-OGC presented atypically as a cystic lesion following acute pancreatitis and led to late diagnosis.Presentation of caseA 75-year-old female patient, who had suffered acute pancreatitis three years ago, was referred with a diagnosis of osteoclast-like giant cell (OGC) tumor of the head of pancreas. She had suffered acute pancreatitis three years ago. Two years ago she developed abdominal pain, steatorrhea and weight loss. Abdominal computed tomography imaging showed a cystic mass in the head of the pancreas (maximum diameter 4cm). The initial diagnosis was pancreatic pseudocyst; however as the mass gradually increased in size and the patient continued to be symptomatic, a CT-guided biopsy was performed. Histological examination revealed an OGC pancreatic tumor. In laparotomy a large (9cm) encapsulated heterogeneous mass was found with partial involvement of the common hepatic artery. Pancreaticoduodenectomy was performed and the involved part of the common hepatic artery was replaced with a homologous graft from the major saphenous vein. Post-operative course was uneventful. Histology revealed an undifferentiated pancreatic adenocarcinoma with OGCs. She survived 10 months after the operation.DiscussionPancreatic undifferentiated carcinomas with OGCs are very rare neoplasms and can present with an atypical clinical picture.ConclusionsA symptomatic cystic lesion of the pancreas, which is growing in size, should be investigated promptly in order to exclude the presence of malignancy

Uniform and prolonged changes in blood oxidative stress after muscle-damaging exercise

Background: The effect of eccentic exercise on the time-course changes in several indices of muscle damage and blood oxidative stress as examined. Materials and methods: Isometric rorque, delayed-onset muscle soreness, creatine kinase, reduced glutathione (GSH), oxidized glutathione (GSSG), thiobarbituric-acid reactive substances (TBARS), protein carbonyls, catalase, uric acid, bilirubin and total antioxidant capacity (TAC) in blood were measured pre-, 24 h, 48 h and 72 h post-exercise of knee extensors in ten females. Results: The concentration of all oxidative stress indices changed significantly in a way indicating increased oxidative stress in the blood (GSH and GSH/GSSG, decreased, whereas GSSG, TBARS, protein carbonyls, catalase, uric acid, bilirubin and TAC increased) peaking, in all but TBARS, at 48 h and returning towards baseline afterwards. Conclusion: We believe that muscle-damaging exercise should be viewedd as a different challenge compared to non-muscle-damaging exercise with regard to its effects on blood oxidative stress

Beneficial changes in energy expenditure and lipid profile after eccentric exercise in overweight and lean women

The aim was to compare lean and overweight females in regard to the effects of eccentric exercise on muscle damage indices, resting energy expenditure (REE) and respiratory quotient (RQ) as well as blood lipid and lipoprotein profile. Lean and overweight females (deviated by their body mass index) performed an eccentric exercise session. Muscle damage, energy cost and lipid profile were assessed pre-exercise and up to 72 h post-exercise. After eccentric exercise (i) muscle damage indices were affected more in the overweight subjects compared with the lean subjects; (ii) the elevation of absolute and relative REE was larger and more prolonged in the overweight group compared with the lean group; (iii) after 24 h, RQ had significantly declined, with the overweight subjects exhibiting a larger reduction compared with the lean group; and (iv) the blood lipid profile was favorably modified, with the overweight group exhibiting more favorable responses compared with the lean group. The differences between the lean and the overweight subjects may be partly due to the fact that overweight individuals experienced greater muscle damage than lean individuals. Eccentric exercise may be a promising lifestyle factor to combat obesity and dyslipidemias

Oxidative stress biomarkers responses to physical overtraining: Implications for diagnosis

Overtraining syndrome is characterized by declining performance and transient inflammation following periods of severe training with major health implications for the athletes. Currently, there is no single diagnostic marker for overtraining. The present investigation examined the responses of oxidative stress biomarkers to a resistance training protocol of progressively increased and decreased volume/intensity. Twelve males (21.3 +/- 2.3 years) participated in a 12-week resistance training consisting of five 3-week periods (T1, 2 tones/week; T2, 8 tones/week; T3, 14 tonesAveek: T4, 2 tonesAveek), followed by a 3-week period of complete rest. Blood/urine samples were collected at baseline and 96 h following the last training session of each period. Performance (strength, power, jumping ability) increased after T2 and declined thereafter, indicating an overtraining response. Overtraining (T3) induced sustained leukocytosis, an increase of urinary isoprostanes (7-fold), TBARS (56%), protein carbonyls (73%), catalase (96%), glutathione peroxidase, and oxidized glutathione (GSSG) (25%) and a decline of reduced glutathione (GSH) (31%), GSH/GSSG (56%), and total antioxidant capacity. lsoprostanes and GSH/GSSG were highly (r=0.764-0.911) correlated with performance drop and training Volume increase. In conclusion, overtraining induces a marked response of oxidative stress biomarkers, which, in some cases, was proportional to training load, Suggesting that they may serve as a tool for overtraining diagnosis. (c) 2007 Elsevier Inc. All rights reserved

Time of sampling is crucial for measurement of cell-free plasma DNA following acute aseptic inflammation induced by exercise

Objectives: To determine the time-course changes of cell-free plasma DNA (cfDNA) following heavy exercise. Methods: cfDNA concentration, C-reactive protein levels (hs-CRP), uric acid concentration (UA), creatine kinase activity (CK) were measured before and post-exercise (immediately post, 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 8 h, 10 h, 24 h). Results: cfDNA increased (15-fold) 30-min post-exercise and normalized thereafter. hs-CRP increased (56%, p&lt;0.001) 1 h post-exercise, remained elevated throughout recovery (52-142%, p&lt;0.0001), and peaked (200% rise, p&lt;0.0001) at 24 h post-exercise. UA and CK increased (p&lt;0.05), immediately post-exercise, remained elevated throughout recovery (p&lt;0.0001), and peaked (p&lt;0.0001) at 24 h of post-exercise recovery. Conclusions: cfDNA sampling timing is crucial and a potential source of error following aseptic inflammation. (C) 2010 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved