Heat shock response and exercise-induced muscle damage: effects of 17-AAG and glutamine as pharmaceutical inducers of HSPs

This thesis comprises four interlinked studies investigating the effects of 17-AAG and glutamine (GLN) on the heat shock response, and the mechanisms underlying its cross-protective effect in limiting muscle damage and functional impairment following eccentric exercise. Study 1 aimed to replicate a previous mouse study using 17-AAG but with a different species, muscle group and exercise protocol. It was showed that downhill running increased the post-exercise red vastus HSP72 response of both 17-AAG and vehicle-treated rats but the rise in HSP72 content was attenuated by 17-AAG at 24 h after exercise. Histological analysis showed signs of ultrastructural abnormalities only in vehicle-treated animals. Study 2 examined the effect of GLN treatment on the heat shock response in intact animals. We observed multiple oral GLN treatments, regardless of dose, increased plasma GLN availability. Surprisingly, the treatment had no effect on plasma, red vastus or heart HSP72 response in the sedentary unstressed animals. However, it was associated with a reduction in heart HSP25 as well as red vastus HSF1 content. In Study 3a, we investigated the effect of GLN treatment on plasma and red vastus HSP72 response following downhill running. The muscle HSP72 content increased at 4 and 24 h after exercise. However, there was no treatment effect on plasma or muscle HSP72 response in healthy animals following the exercise. Lastly, in Study 3b, we tested the hypothesis that GLN treatment is required to enhance plasma and red vastus HSP72 response in heat-stressed animals. The study also investigated whether there is an additive effect of GLN and heat preconditioning on exercise-induced muscle damage. We found that only plasma HSP72 in the heat-preconditioned rats increased with GLN treatment, but the effect was diminished following downhill running. The treatment, respectively, reduced the HSP25 content and enhanced HSF1 response in muscle at 4 h and 24 h after exercise. (1982/2000 maximum characters with spaces

Heat shock response and exercise-induced muscle damage: effects of 17-AAG and glutamine as pharmaceutical inducers of HSPs

This thesis comprises four interlinked studies investigating the effects of 17-AAG and glutamine (GLN) on the heat shock response, and the mechanisms underlying its cross-protective effect in limiting muscle damage and functional impairment following eccentric exercise. Study 1 aimed to replicate a previous mouse study using 17-AAG but with a different species, muscle group and exercise protocol. It was showed that downhill running increased the post-exercise red vastus HSP72 response of both 17-AAG and vehicle-treated rats but the rise in HSP72 content was attenuated by 17-AAG at 24 h after exercise. Histological analysis showed signs of ultrastructural abnormalities only in vehicle-treated animals. Study 2 examined the effect of GLN treatment on the heat shock response in intact animals. We observed multiple oral GLN treatments, regardless of dose, increased plasma GLN availability. Surprisingly, the treatment had no effect on plasma, red vastus or heart HSP72 response in the sedentary unstressed animals. However, it was associated with a reduction in heart HSP25 as well as red vastus HSF1 content. In Study 3a, we investigated the effect of GLN treatment on plasma and red vastus HSP72 response following downhill running. The muscle HSP72 content increased at 4 and 24 h after exercise. However, there was no treatment effect on plasma or muscle HSP72 response in healthy animals following the exercise. Lastly, in Study 3b, we tested the hypothesis that GLN treatment is required to enhance plasma and red vastus HSP72 response in heat-stressed animals. The study also investigated whether there is an additive effect of GLN and heat preconditioning on exercise-induced muscle damage. We found that only plasma HSP72 in the heat-preconditioned rats increased with GLN treatment, but the effect was diminished following downhill running. The treatment, respectively, reduced the HSP25 content and enhanced HSF1 response in muscle at 4 h and 24 h after exercise. (1982/2000 maximum characters with spaces

Composition and Physicochemical Properties of Fresh and Freeze-Concentrated Coconut (Cocos nucifera) Water

The aim of this study was to produce a double-strength freeze-concentrated coconut water. Coconut water obtained from green (GC) and mature coconuts (MC) with initial total soluble solids (TSS) of approximately 6 and 4 °Brix, respectively, were used for the production of a double strength coconut water (12 and 8 °Brix, respectively) using a simplified freeze-concentration process. The freeze-concentrated samples were significantly (P<0.05) higher in sugars, acidity, minerals, protein, crude fat, and total phenolic compounds as compared to the fresh coconut water. Sensory evaluation indicated no significant difference (P>0.05) in consumers’ acceptability score of the freeze-concentrated coconut water when compared with fresh coconut water. Upon reconstitution (to initial TSS), reconstituted freeze-concentrated samples retained the same acceptability as of fresh coconut water. This suggest that both the freeze-concentration and reconstitution processes had no significant (P>0.05) changes to consumers’ acceptability score. Hence, freeze-concentrated coconut water could be a better rehydration drink than fresh coconut water; providing more nutrients without affecting its acceptability

Ramadan fasting and sports performance: A Malaysian perspective

The purpose of this study was to identify factors that would affect Muslim athletes in their training or competition during the Ramadan fast. This would lead to a better understanding of the changes in lifestyle, behavioural and training practices of Muslim athletes when they participate in Ramadan fasting and exercise at the same time. A total of 172 Malaysian Muslim national elite athletes participated in a questionnaire survey assessing personal perception on sport performance, sleep pattern, food and fluid intake during Ramadan fasting. The results showed that a quarter of these athletes perceived that there was an adverse effect from the Ramadan fast on their sport performance. A majority of them (58.1%) said that Ramadan fasting did not affect their sleep pattern but 52.3% of them did take an extra nap during the daytime. Most of the athletes (45.9%) ate the same amount of calories as they normally would however 86.0 % believed that they drank more fluids than usual. The changes in lifestyle during the Ramadan fast did not adversely affect the perceived sport performance in this cohort of Muslim elite athletes. However, there is an equivocal opinion on the impact of Ramadan fasting on the quality of training

Relationships between High-Resolution Computed Tomography, Lung Function and Bacteriology in Stable Bronchiectasis

To determine the relationship between high-resolution computed tomography (HRCT) findings, lung function, and bacteriology in bronchiectasis, we conducted a retrospective study of 49 Korean patients with stable bronchiectasis. To quantify the extent and severity of bronchiectasis, we used a CT scoring system consisting of bronchial dilatation, bronchial wall thickening, the number of bronchiectatic segments, the number of bulla, and the number of emphysema segments. The presence of air-fluid levels and lung consolidation were also evaluated. The results of CT scoring, spirometry and sputum culture were analyzed. Patients with cystic bronchiectasis had higher CT score, more dilated lumen and lower forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), and FEV1/FVC than patients with cylindrical bronchiectasis. Patients with mixed ventilatory impairment had larger number of bronchiectatic segments than patients with obstructive ventilatory impairment. CT score and the number of bronchiectatic segments were significantly associated with FVC and FEV1, while CT score and the number of emphysema segments were significantly associated with FEV1/FVC. Twenty-one patients of 49 patients showed a positive sputum culture including 15 cases of Pseudomonas aeruginosa. The CT score was the most important predictor of lung function. The presence of air-fluid levels predicted bacterial colonization

Acute ingestion of hydrogen-rich water does not improve incremental treadmill running performance in endurance-trained athletes

There is emerging evidence that hydrogen-rich water (H2-water) has beneficial effects on the physiological responses to exercise. However, few studies investigate its ergogenic potential. This randomized controlled trial examined the effects of H2-water ingestion on physiological responses and exercise performance during incremental treadmill running. In a double-blind crossover design, 14 endurance-trained male runners (age, 34 ± 4 years; body mass, 63.1 ± 7.2 kg; height, 1.72 ± 0.05 m) were randomly assigned to ingest 2 doses of 290-mL H2-water or placebo on each occasion. The first bolus was given before six 4-min submaximal running bouts, and the second bolus was consumed before the maximal incremental running test. Expired gas, heart rate (HR), and ratings of perceived exertion (RPE) were recorded; blood samples were collected at the end of each submaximal stage and post maximal running test. Cardiorespiratory responses, RPE, and blood gas indices were not significantly different at each submaximal running intensity (range: 34%–91% maximal oxygen uptake) between H2-water and placebo trials. No statistical difference was observed in running time to exhaustion (618 ± 126 vs. 619 ± 113 s), maximal oxygen uptake (56.9 ± 4.4 vs. 57.1 ± 4.7 mL·kg−1·min−1), maximal HR (184 ± 7 vs. 184 ± 7 beat·min−1), and RPE (19 ± 1 vs. 19 ± 1) in the runners between the trials. The results suggest that the ingestion of 290 mL of H2-water before submaximal treadmill running and an additional dose before the subsequent incremental running to exhaustion were not sufficiently ergogenic in endurance-trained athletes. Novelty Acute ingestion of H2-water does not seem to be ergogenic for endurance performance. A small dose of H2-water does not modulate buffering capacity during intense endurance exercise in athletes.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

SELF-GENERATED COPING STRATEGIES AMONG MUSLIM ATHLETES DURING RAMADAN FASTING

The study explored the self-generated coping strategies employed by Muslim athletes from South East Asian region during the Ramadan fasting month. Sixty-five National elite Muslim athletes responded to an open-ended question on coping strategies employed during Ramadan fasting. Inductive content analysis identified five general dimensions from 54 meaning units which were abstracted into 14 first-order themes and 10 second order themes. The general dimension included four problem-focused coping: training modifications, dietary habits, psychological, rest and recovery, and one emotion-focused coping i.e., self- control. The coping strategies employed were diverse and dynamic in nature and no specific pattern was evident. The most frequently employed strategies were associated with training and dietary habits. Emotion focused coping was the least frequently used by the athlete