Medicine (Western Health) - Research Publications
Permanent URI for this collection
Search Results
1 - 10 of 17
-
ItemNo Preview AvailableDetecting the vitamin D receptor (VDR) protein in mouse and human skeletal muscle: Strain-specific, species-specific and inter-individual variation(ELSEVIER IRELAND LTD, 2023-12-01)Vitamin D, and its receptor (VDR), play roles in muscle development/function, however, VDR detection in muscle has been controversial. Using different sample preparation methods and antibodies, we examined differences in muscle VDR protein abundance between two mouse strains and between mice and humans. The mouse D-6 VDR antibody was not reliable for detecting VDR in mouse muscle, but was suitable for human muscle, while the rabbit D2K6W antibody was valid for mouse and human muscle. VDR protein was generally lower in muscles from C57 B l/6 than FVB/N mice and was higher in human than mouse muscle. Two putative VDR bands were detected in human muscle, possibly representing VDR isoforms/splice variants, with marked inter-individual differences. This study provides new information on detecting VDR in muscle and on inter-mouse strain and inter-human individual differences in VDR expression. These findings may have implications for future pre-clinical and clinical studies and prompt further investigation to confirm possible VDR isoforms in human muscle.
-
ItemConsensus guidelines for sarcopenia prevention, diagnosis and management in Australia and New Zealand(WILEY, 2023-02)BACKGROUND: Sarcopenia is an age-associated skeletal muscle condition characterized by low muscle mass, strength, and physical performance. There is no international consensus on a sarcopenia definition and no contemporaneous clinical and research guidelines specific to Australia and New Zealand. The Australian and New Zealand Society for Sarcopenia and Frailty Research (ANZSSFR) Sarcopenia Diagnosis and Management Task Force aimed to develop consensus guidelines for sarcopenia prevention, assessment, management and research, informed by evidence, consumer opinion, and expert consensus, for use by health professionals and researchers in Australia and New Zealand. METHODS: A four-phase modified Delphi process involving topic experts and informed by consumers, was undertaken between July 2020 and August 2021. Phase 1 involved a structured meeting of 29 Task Force members and a systematic literature search from which the Phase 2 online survey was developed (Qualtrics). Topic experts responded to 18 statements, using 11-point Likert scales with agreement threshold set a priori at >80%, and five multiple-choice questions. Statements with moderate agreement (70%-80%) were revised and re-introduced in Phase 3, and statements with low agreement (<70%) were rejected. In Phase 3, topic experts responded to six revised statements and three additional questions, incorporating results from a parallel Consumer Expert Delphi study. Phase 4 involved finalization of consensus statements. RESULTS: Topic experts from Australia (n = 62, 92.5%) and New Zealand (n = 5, 7.5%) with a mean ± SD age of 45.7 ± 11.8 years participated in Phase 2; 38 (56.7%) were women, 38 (56.7%) were health professionals and 27 (40.3%) were researchers/academics. In Phase 2, 15 of 18 (83.3%) statements on sarcopenia prevention, screening, assessment, management and future research were accepted with strong agreement. The strongest agreement related to encouraging a healthy lifestyle (100%) and offering tailored resistance training to people with sarcopenia (92.5%). Forty-seven experts participated in Phase 3; 5/6 (83.3%) revised statements on prevention, assessment and management were accepted with strong agreement. A majority of experts (87.9%) preferred the revised European Working Group for Sarcopenia in Older Persons (EWGSOP2) definition. Seventeen statements with strong agreement (>80%) were confirmed by the Task Force in Phase 4. CONCLUSIONS: The ANZSSFR Task Force present 17 sarcopenia management and research recommendations for use by health professionals and researchers which includes the recommendation to adopt the EWGSOP2 sarcopenia definition in Australia and New Zealand. This rigorous Delphi process that combined evidence, consumer expert opinion and topic expert consensus can inform similar initiatives in countries/regions lacking consensus on sarcopenia.
-
ItemNo Preview AvailableAssessment of the tocolytic nifedipine in preclinical primary models of preterm birth(NATURE PORTFOLIO, 2023-04-06)Spontaneous preterm birth is the leading cause of perinatal morbidity and mortality. Tocolytics are drugs used in cases of imminent preterm birth to inhibit uterine contractions. Nifedipine is a calcium channel blocking agent used to delay threatened spontaneous preterm birth, however, has limited efficacy and lacks preclinical data regarding mechanisms of action. It is unknown if nifedipine affects the pro-inflammatory environment associated with preterm labour pathophysiology and we hypothesise nifedipine only targets myometrial contraction rather than also mitigating inflammation. We assessed anti-inflammatory and anti-contractile effects of nifedipine on human myometrium using in vitro and ex vivo techniques, and a mouse model of preterm birth. We show that nifedipine treatment inhibited contractions in myometrial in vitro contraction assays (P = 0.004 vs. vehicle control) and potently blocked spontaneous and oxytocin-induced contractions in ex vivo myometrial tissue in muscle myography studies (P = 0.01 vs. baseline). Nifedipine treatment did not reduce gene expression or protein secretion of pro-inflammatory cytokines in either cultured myometrial cells or ex vivo tissues. Although nifedipine could delay preterm birth in some mice, this was not consistent in all dams and was overall not statistically significant. Our data suggests nifedipine does not modulate preterm birth via inflammatory pathways in the myometrium, and this may account for its limited clinical efficacy.
-
ItemNo Preview AvailableA blended learning exercise physiology theory module that supports student autonomy and improves academic performance(AMER PHYSIOLOGICAL SOC, 2022-09)A limited number of studies have explored the impact of blended exercise physiology theory curricula on student learning and experience. This study aimed to investigate the impact of an exercise physiology blended learning theory module on student performance, engagement, and perceptions. The module, which comprised a range of elements (student guide, lecturer-recorded videos, supplementary videos, formative quizzes, workshops, and discussion forum), was implemented in a third-year subject taken by students in nonspecialist undergraduate science, technology, engineering, and mathematics (STEM) degrees. Students chose which elements to engage with to support their learning. Exam performance was assessed by comparing exam marks from fully face-to-face delivery to the blended delivery with an independent t test. Student perceptions were determined via an end-of-module questionnaire comprised of Likert-scale questions and open-ended questions. Descriptive statistical analysis was conducted on the Likert-scale responses, and qualitative content analysis was conducted on the open-ended responses. Student engagement with online resources was determined through analysis of access statistics from the learning management system. Student exam marks in the blended learning student group were significantly higher (P < 0.0001) than in the face-to-face group, even though the questions were of a higher Bloom's level in the blended learning group. Students preferred blended delivery over fully face-to-face delivery. Most students accessed the student guide, lecturer-recorded videos, and quizzes, with supplementary videos, workshops, and discussion forums accessed by fewer students. In conclusion, a blended exercise physiology theory module improved student exam performance and was positively perceived by students, and engagement with the elements of the module was varied.NEW & NOTEWORTHY Few studies have explored the impact of blended delivery of exercise physiology theory curricula on student learning and experience. This study investigated the impact of a novel blended model on student learning and experience. The module comprised a range of elements (student guide, lecturer-recorded videos, supplementary videos, formative quizzes, workshops, and discussion forum), where students were able to choose which elements to engage with to support their learning.
-
ItemNo Preview AvailableBody composition, physical function and quality of life in healthy men and across different stages of prostate cancer(SPRINGERNATURE, 2021-09)BACKGROUND: Androgen deprivation therapy (ADT) for prostate cancer (PC) has detrimental effects on physical function and quality of life (QoL), but the addition of androgen receptor signalling inhibitors (ARSI) on these outcomes is unclear. PURPOSE: To compare body composition, physical function, and QoL across progressive stages of PC and non-cancer controls (CON). METHODS: In men with hormone sensitive PC (HSPC, n = 43) or metastatic castration-resistant PC (mCRPC, n = 22) or CON (n = 37), relative and absolute lean and fat mass, physical function (6 m walk, chair stands, timed up and go [TUG], stair climb), and QoL were determined. RESULTS: Relative body composition differed amongst all groups, along with ~39% greater absolute fat mass in mCRPC vs. CON. TUG and chair stands were ~71% and ~33% slower in mCRPC compared to both CON and HSPC, whereas stair climb was ~29% and 6 m walk was ~18% slower in mCRPC vs. CON. Relative body composition was correlated with physical function (r = 0.259-0.385). Clinically relevant differences for mCRPC were observed for overall QoL and several subscales vs. CON, although body composition and physical function did not influence QoL. CONCLUSIONS: PC progression is associated with deteriorations in body composition and physical function. As ADT length was similar between groups, ARSI use for mCRPC likely contributed in part to these changes. Given the difficulties of improving lean mass during ADT, interventions that reduce adiposity may lessen the side effects of hormone therapy.
-
ItemOsteocalcin and vascular function: is there a cross-talk?(ELSEVIER, 2021-07)BACKGROUND: The bone-derived protein osteocalcin (OC), in its undercarboxylated (ucOC) form, has a beneficial effect on energy metabolism and may be a future therapeutic target for metabolic diseases. Increasing evidence suggests a link between ucOC and cardiovascular disease (CVD) development; however, the exact relationship is conflicting and unclear. SCOPE OF REVIEW: The aim of this review was to summarise the current research examining the interaction between OC and vascular dysfunction, the initiating stage in the development of atherosclerosis and CVD. MAJOR CONCLUSIONS: In humans, the association between OC and vascular function is inconsistent. Several studies report that total OC (tOC) is associated with adverse function or beneficial function, whereas others report that tOC and ucOC has no effect on vascular function. The conflicting data are likely due to several methodological inconsistencies, in particular the lack of studies reporting circulating ucOC levels. In animal models, the direct administration of ucOC to isolated blood vessels ex vivo produced minimal changes in endothelial function, but importantly, no adverse responses. Finally, in human endothelial and vascular smooth muscle cells, ucOC treatment did not influence classical markers of cellular function, including endothelin-1, vascular adhesion molecule-1 and monocyte chemoattractant protein-1 after exposure to high glucose and inflammatory conditions. The lack of adverse effects in ex vivo and in vitro studies suggests that ucOC may be targeted as a future therapeutic for metabolic diseases, without the risk of detrimental effects in the vasculature. However, further studies are needed to confirm these findings and to investigate whether there is a direct beneficial influence of ucOC.
-
ItemMetronomic 5-Fluorouracil Delivery Primes Skeletal Muscle for Myopathy but Does Not Cause Cachexia(MDPI, 2021-05)Skeletal myopathy encompasses both atrophy and dysfunction and is a prominent event in cancer and chemotherapy-induced cachexia. Here, we investigate the effects of a chemotherapeutic agent, 5-fluorouracil (5FU), on skeletal muscle mass and function, and whether small-molecule therapeutic candidate, BGP-15, could be protective against the chemotoxic challenge exerted by 5FU. Additionally, we explore the molecular signature of 5FU treatment. Male Balb/c mice received metronomic tri-weekly intraperitoneal delivery of 5FU (23 mg/kg), with and without BGP-15 (15 mg/kg), 6 times in total over a 15 day treatment period. We demonstrated that neither 5FU, nor 5FU combined with BGP-15, affected body composition indices, skeletal muscle mass or function. Adjuvant BGP-15 treatment did, however, prevent the 5FU-induced phosphorylation of p38 MAPK and p65 NF-B subunit, signalling pathways involved in cell stress and inflammatory signalling, respectively. This as associated with mitoprotection. 5FU reduced the expression of the key cytoskeletal proteins, desmin and dystrophin, which was not prevented by BGP-15. Combined, these data show that metronomic delivery of 5FU does not elicit physiological consequences to skeletal muscle mass and function but is implicit in priming skeletal muscle with a molecular signature for myopathy. BGP-15 has modest protective efficacy against the molecular changes induced by 5FU.
-
ItemAssociations of sarcopenia components with physical activity and nutrition in Australian older adults performing exercise training(BMC, 2021-04-26)BACKGROUND: The risk of progressive declines in skeletal muscle mass and strength, termed sarcopenia, increases with age, physical inactivity and poor diet. The purpose of this study was to explore and compare associations of sarcopenia components with self-reported physical activity and nutrition in older adults participating in resistance training at Helsinki University Research [HUR] and conventional gyms for over a year, once a week, on average. METHODS: The study looked at differences between HUR (n = 3) and conventional (n = 1) gyms. Muscle strength (via handgrip strength and chair stands), appendicular lean mass (ALM; via dual energy X-ray absorptiometry) and physical performance (via gait speed over a 4-m distance, short physical performance battery, timed up and go and 400-m walk tests) were evaluated in 80 community-dwelling older adults (mean ± SD 76.5 ± 6.5 years). Pearson correlations explored associations for sarcopenia components with self-reported physical activity (via Physical Activity Scale for the Elderly [PASE]) and nutrition (via Australian Eating Survey). RESULTS: No differences in PASE and the Australian Recommended Food Score (ARFS) were observed between HUR and conventional gyms, however HUR gym participants had a significantly higher self-reported protein intake (108 ± 39 g vs 88 ± 27 g; p = 0.029) and a trend to have higher energy intake (9698 ± 3006 kJ vs 8266 ± 2904 kJ; p = 0.055). In both gym groups, gait speed was positively associated with self-reported physical activity (r = 0.275; p = 0.039 and r = 0.423; p = 0.044 for HUR and conventional gyms, respectively). ALM was positively associated with protein (p = 0.047, r = 0.418) and energy (p = 0.038, r = 0.435) intake in the conventional gym group. Similar associations were observed for ALM/h2 in the HUR group. None of the sarcopenia components were associated with ARFS in either gym group. CONCLUSION: Older adults attending HUR and conventional gyms had similar self-reported function and nutrition (but not protein intake). Inadequate physical activity was associated with low gait speed and inadequate nutrition and low protein ingestion associated with low lean mas, even in older adults participating in exercise programs. Optimal physical activity and nutrition are important for maintaining muscle mass and function in older adults.
-
ItemFeasibility and adherence to moderate intensity cardiovascular fitness training following stroke: a pilot randomized controlled trial(BMC, 2021-03-22)BACKGROUND: Stroke is a leading cause of disability worldwide and the cardiovascular fitness levels of stroke survivors are diminished to an extent that impairs functioning and activities of daily living performance. While cardiovascular training seems an empirically appropriate intervention, the optimal dosage and intensity of cardiovascular training in stroke survivors remains unclear. The aim was to determine the safety and feasibility of moderate-intensity cardiovascular training following stroke, including measurement of adherence to training. METHODS: A pilot, prospective, patient- and assessor-blinded randomised controlled trial conducted in a tertiary, metropolitan hospital-based community rehabilitation centre. Eligibility criteria included ambulant (> 100 m), 6 weeks-12 months post stroke. Moderate-intensity fitness training or control (low-intensity) exercise was offered biweekly for 12 weeks. Outcome measures included adverse events, peak oxygen uptake (VO2), functional exercise capacity (6-Minute Walk Test, 10-m Walk Test) and health-related quality of life (Short Form-36) and mood (Patient Health Questionnaire, PHQ9). RESULTS: Feasibility: Seventy-one (50%) of 141 screened participants were eligible (29% did not agree to participate). Twenty participants (10 intervention, 10 control) were recruited. The median (%; IQR) supervised sessions was 19.5 (81%; 12, 20); and 20 (83%; 19, 22) in the intervention and control groups, respectively. Progression of duration and intensity was limited; mean of 10 sessions to achieve target duration (30 min). There were no adverse events. Baseline peak oxygen uptake (VO2) levels were low (15.94 ml/kg/min). Significant improvements in VO2 peak in both groups were observed (p < 0.05). Although there were no significant between-group differences, this feasibility trial was not powered to detect change. CONCLUSIONS: Moderate-intensity fitness training was safe but achievement of target duration and intensity was challenging for stroke survivors. A definitive adequately-powered randomised trial is required. Alternative fitness training protocols may need to be explored. TRIAL REGISTRATION: The trial protocol was prospectively registered on the Australian New Zealand Clinical Trials Registry ( ACTRN 12613000822785 ) on 25/07/2013.
-
ItemThe Paradoxical Effect of PARP Inhibitor BGP-15 on Irinotecan-Induced Cachexia and Skeletal Muscle Dysfunction(MDPI, 2020-12)Chemotherapy-induced muscle wasting and dysfunction is a contributing factor to cachexia alongside cancer and increases the risk of morbidity and mortality. Here, we investigate the effects of the chemotherapeutic agent irinotecan (IRI) on skeletal muscle mass and function and whether BGP-15 (a poly-(ADP-ribose) polymerase-1 (PARP-1) inhibitor and heat shock protein co-inducer) adjuvant therapy could protect against IRI-induced skeletal myopathy. Healthy 6-week-old male Balb/C mice (n = 24; 8/group) were treated with six intraperitoneal injections of either vehicle, IRI (30 mg/kg) or BGP-15 adjuvant therapy (IRI+BGP; 15 mg/kg) over two weeks. IRI reduced lean and tibialis anterior mass, which were attenuated by IRI+BGP treatment. Remarkably, IRI reduced muscle protein synthesis, while IRI+BGP reduced protein synthesis further. These changes occurred in the absence of a change in crude markers of mammalian/mechanistic target of rapamycin (mTOR) Complex 1 (mTORC1) signaling and protein degradation. Interestingly, the cytoskeletal protein dystrophin was reduced in both IRI- and IRI+BGP-treated mice, while IRI+BGP treatment also decreased β-dystroglycan, suggesting significant remodeling of the cytoskeleton. IRI reduced absolute force production of the soleus and extensor digitorum longus (EDL) muscles, while IRI+BGP rescued absolute force production of the soleus and strongly trended to rescue force output of the EDL (p = 0.06), which was associated with improvements in mass. During the fatiguing stimulation, IRI+BGP-treated EDL muscles were somewhat susceptible to rupture at the musculotendinous junction, likely due to BGP-15's capacity to maintain the rate of force development within a weakened environment characterized by significant structural remodeling. Our paradoxical data highlight that BGP-15 has some therapeutic advantage by attenuating IRI-induced skeletal myopathy; however, its effects on the remodeling of the cytoskeleton and extracellular matrix, which appear to make fast-twitch muscles more prone to tearing during contraction, could suggest the induction of muscular dystrophy and, thus, require further characterization.