807 research outputs found

    Exercise as medicine : reversing treatment toxicities in prostate cancer patients

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    A common treatment for prostate cancer, which is the most common form of cancer after skin cancer in Australian males, is androgen deprivation therapy (ADT). However, ADT is associated with an array of adverse effects including reduced bone and lean mass, loss of muscle strength, negative change in lipid profile, and increased risk of cardiovascular disease (CVD) as well as diabetes, all of which can compromise physical function and quality of life. Physical exercise has been suggested as a key lifestyle intervention for this group of cancer patients as it has enormous potential to limit and even reverse the effects of such treatment toxicities. This thesis is comprised of a review of the literature and three experimental chapters examining the effects of androgen deprivation therapy (ADT) and the role of exercise in ADT treated prostate cancer patients. The review of literature provides a background to cancer, in particular prostate cancer and the commonly reported side effects of treatment. The review identified gaps in the literature that highlighted the need for well controlled and longer term experimental studies to: 1) investigate the impact of androgen deprivation therapy duration on cardiovascular and metabolic outcomes, and 2) investigate the effects of a long term exercise intervention in reversing cardiovascular risk factors and unfavourable alterations in the metabolic profile. Study 1 examined the feasibility and safety of a maximal treadmill exercise test in ADT treated prostate cancer patients as this was a key assessment of physiological response to the exercise intervention. One hundred and twelve prostate cancer patients undergoing ADT took part in a physician supervised multistage maximal stress test (Bruce protocol). Of these men, 85% were able to meet the criteria for the attainment of VO2max whilst three positive tests (3.2%) were observed. The three participants who recorded a positive stress test were sent for further examination and subsequently cleared of any serious issues. Apart from the relatively low VO2max (10-15th percentile), compared to healthy age matched controls, the cardiovascular response to exercise is similar in this cancer population. Maximal exercise testing in this population was demonstrated to be feasible and safe providing a direct assessment of VO2max whilst treatment duration did not appear to influence the cardiovascular responses to exercise. Study 2 was a cross-sectional design comparing chronic versus acute ADT treated patients to examine if therapy time exposure leads to additional risk factors for CVD and metabolic toxicities in prostate cancer patients. One hundred and seven men undergoing ADT for treatment of prostate cancer were stratified into two groups, either acute (months) or chronic (\u3e3 months) exposure. Chronic ADT exposure was associated with a 17% reduction maximal aerobic capacity (-0.4 L.min-1) and an 8% reduction in resting metabolic rate (-147 kcal/24hr). The chronically exposed group also exhibited 8-22% lower maximal strength values (chest press -5.9kg, seated row -3.9kg, leg press -27.5kg and leg extension -12.2 kg) and a corresponding decrement in physical function variables ranging from 9-16% (400m walk +24.9s, chair rise +2.0s, and stair climb +0.7s). Whilst not significant, there was also a trend towards a decrease in lean mass of 3.5% (-2.1kg) and an increase in fat mass of 6.5% (1.5kg) in the chronically suppressed group. ADT exposure did in fact have a negative effect on CVD risk factors as well as physical function outcomes. Whilst the exact mechanisms remain unclear as to why these cardiovascular alterations and physical function variables are further declining as treatment time progresses, it is possible that factors other than those assessed in this study, such as reduced physical activity levels, may have influenced the results. Study 3 utilised a randomized controlled trial (RCT) study design to examine the long-term effects (6 months) of a combined aerobic and resistance training intervention in reducing or stabilizing CVD and diabetes risk factors in men receiving ADT. Participants were randomly allocated to either an exercise (EX) group (n= 50) or a control (CON) group (n= 48). The combined aerobic and resistance training program consisted of twice weekly clinic based sessions at which the participants completed 20mins of aerobic activity (70- 90% maximal intensity) and 6 resistance based exercises targeting the major upper and lower body muscle groups. In addition, participants were prescribed a home based training program consisting of 110 minutes of aerobic activity. The control group were instructed to adhere to their usual lifestyle and care routine. Body composition [lean mass 1.1% (+0.8kg), fat mass -4.2% (-1.1kg) & body fat -3.8% (-1.1kg], muscular strength [chest press 9.6% (+3.6kg), seated row 7% (+6.0kg), leg press 14.8% (+20kg) & leg extension 19.4% (+10.2kg)], muscular endurance [chest press 49.4% (+5.0 reps) & leg 49.9% (+7.7 reps)] and 400m walk [-4.8% (-13s)] significantly improved (p This research has demonstrated that: 1) maximal cardiorespiratory exercise testing is safe and feasible in this population, 2) prolonged exposure to androgen deprivation therapy (\u3e3 months) has a negative impact on a number of cardiovascular, metabolic and physical function outcomes, and 3) a combined aerobic and resistance training program can be safely undertaken in men undergoing ADT and results in an array of benefits for cardiovascular and metabolic outcomes as well physical function. As a result of these findings, patients prescribed ADT for the treatment of prostate cancer should be appropriately counselled as to the negative side effects commonly associated with this form of treatment and be made aware of the safety and beneficial effects an appropriately administered exercise intervention can have on reversing these adverse alterations occurring throughout the course of treatment. Further, these specifically designed exercise interventions should be commenced as soon as practically possible post prostate cancer diagnosis and continue for the course of treatment and ideally beyond

    Household Food Insecurity and Student Behavior: The Impact of One School\u27s Second Breakfast Program

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    Household Food Insecurity (HFI) is a frequent challenge for children living in poverty that impacts social, emotional, and behavioral development. Federally assisted meal programs, such as the National School Breakfast Program, address HFI for students living in poverty through free or reduced-price breakfast. However, there are challenges for students to take advantage of this opportunity, and it is underutilized. In this research, all middle school students at a high poverty school were offered a free of charge meal alternative called Second Chance Breakfast. Since this program was started, student participation in school breakfast increased and behavior incidences in school dropped significantly. Along with improved behavior outcomes, teachers reported improved student academic behavior

    Hyperthermic Fatigue Precedes a Rapid Reduction in Serum Sodium in an Ironman Triathlete: A Case Report

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    Purpose: To monitor the hydration, core temperature, and speed (pace) of a triathlete performing an Ironman triathlon. Methods: A 35-year-old experienced male triathlete participated in the Western Australian Ironman triathlon on December 1, 2006. The participant was monitored for blood Na+ concentration before the race (PRE), at the transitions (T1 and T2), halfway through the run (R21), and after the race (POST; 2hPOST). Core body temperature (Tc; pill telemetry) was recorded continuously, and running speed (s3 stride sensor) was measured during the run. Results: The participant completed the race in 11 h 38 min, in hot conditions (26.6 ± 5.8°C; 42 ± 19% rel. humidity). His Tc increased from 37.0 to 38.6°C during the 57-min swim, and averaged 38.4°C during the 335-min bike (33.5 km·h−1). After running at 12.4 km·h−1 for 50 min in the heat (33.1°C), Tc increased to 39.4°C, before slowing to 10.0 km·h−1 for 20 min. Tc decreased to 38.9°C until he experienced severe leg cramps, after which speed diminished to 6 km·h−1 and Tc fell to 38.0°C. The athlete’s blood Na+ was constant from PRE to T2 (139–140 mEq·L−1, but fell to 131 mEq·L−1 at R21, 133 mEq·L−1 at POST, and 128 mEq·L−1 at 2hPOST. The athlete consumed 9.25 L of fluid from PRE to T2, 6.25 L from T2 to POST, and lost 2% of his body mass, indicating sweat losses greater than 15.5 L. Conclusion: This athlete slowed during the run phase following attainment of a critically high Tc and experienced an unusually rapid reduction in blood Na+ that preceded cramping, despite presenting with signs of dehydration

    Effect of a 5 min cold water immersion recovery on exercise performance in the heat

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    Background This study examined the effect of a 5-min cold-water immersion (14°C) recovery intervention on repeated cycling performance in the heat. Methods 10 male cyclists performed two bouts of a 25-min constant-paced (254 (22) W) cycling session followed by a 4-km time trial in hot conditions (35°C, 40% relative humidity). The two bouts were separated by either 15 min of seated recovery in the heat (control) or the same condition with 5-min cold-water immersion (5th—10th minute), using a counterbalanced cross-over design (CP1TT1 → CWI or CON → CP2TT2). Rectal temperature was measured immediately before and after both the constant-paced sessions and 4-km timed trials. Cycling economy and Vo2 were measured during the constant-paced sessions, and the average power output and completion times were recorded for each time trial. Results Compared with control, rectal temperature was significantly lower (0.5 (0.4)°C) in cold-water immersion before CP2 until the end of the second 4-km timed trial. However, the increase in rectal temperature (0.5 (0.2)°C) during CP2 was not significantly different between conditions. During the second 4-km timed trial, power output was significantly greater in cold-water immersion (327.9 (55.7) W) compared with control (288.0 (58.8) W), leading to a faster completion time in cold-water immersion (6.1 (0.3) min) compared with control (6.4 (0.5) min). Economy and Vo2 were not influenced by the cold-water immersion recovery intervention. Conclusion 5-min cold-water immersion recovery significantly lowered rectal temperature and maintained endurance performance during subsequent high-intensity exercise. These data indicate that repeated exercise performance in heat may be improved when a short period of cold-water immersion is applied during the recovery period

    Facilitating Cross-Cultural Online Discussion Groups: Issues and Challenges

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    This action research identifies the issues and challenges experienced by facilitators who moderated cross-cultural group discussion activities in an online environment. This study found that in a cross-cultural online environment, the challenges of the facilitator expand beyond the currently identified range of problems for online discussion

    Success of organ donation after out-of-hospital cardiac death and the barriers to its acceptance

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    It is well documented that transplants save lives and improve quality of life for patients suffering from kidney, liver, and heart failure. Uncontrolled donation after cardiac death (UDCD) is an effective and ethical alternative to existing efforts towards increasing the available pool of organs. However, people who die from an out-of-hospital cardiac arrest are currently being denied the opportunity to be organ donors except in those few locations where out-of-hospital UDCD programs are active, such as in Paris, Madrid, and Barcelona. Societies have the medical and moral obligation to develop UDCD programs

    Nuclear Magnetic Resonance and Hyperfine Structure

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    Contains reports on five research projects

    Nuclear Magnetic Resonance and Hyperfine Structure

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    Contains research objectives and reports on six research objectives

    Reduced Cardiovascular Capacity and Resting Metabolic Rate in Men with Prostate Cancer Undergoing Androgen Deprivation: A Comprehensive Cross-Sectional Investigation

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    Objectives. To investigate if androgen deprivation therapy exposure is associated with additional risk factors for cardiovascular disease and metabolic treatment-related toxicities. Methods. One hundred and seven men (42-89 years) with prostate cancer undergoing androgen deprivation therapy completed a maximal graded objective exercise test to determine maximal oxygen uptake, assessments for resting metabolic rate, body composition, blood pressure and arterial stiffness, and blood biomarker analysis. A cross-sectional analysis was undertaken to investigate the potential impact of therapy exposure with participants stratified into two groups according to duration of androgen deprivation therapy (<3 months and ≥3 months). Results. Maximal oxygen uptake (26.1 ± 6.0 mL/kg/min versus 23.2 ± 5.8 mL/kg/min, = 0.020) and resting metabolic rate (1795 ± 256 kcal/d versus 1647 ± 236 kcal/d, = 0.005) were significantly higher in those with shorter exposure to androgen deprivation. There were no differences between groups for peripheral and central blood pressure, arterial stiffness, or metabolic profile. Conclusion. Three months or longer exposure to androgen deprivation therapy was associated with reduced cardiorespiratory capacity and resting metabolic rate, but not in a range of blood biomarkers. These findings suggest that prolonged exposure to androgen deprivation therapy is associated with negative alterations in cardiovascular outcomes. Trial registry is: ACTRN12609000200280
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