Search

Duchenne muscular dystrophy (DMD) is a severe muscle wasting disease caused by mutations or deletions in the dystrophin gene, for which there remains no cure. As DMD patients also develop bone fragility because of muscle weakness and immobilization, better understanding of the pathophysiological mechanisms of dystrophin deficiency will help develop therapies to improve musculoskeletal health. Since alterations in muscle phenotype can influence bone structure, we investigated whether modifying muscle contractile activity through low-frequency stimulation (LFS) could alter bone architecture in mouse models of DMD. We tested the hypothesis that increasing muscle contractile activity could influence bone mass and structure in dystrophin-deficient (mdx) and dystrophin- and utrophin-deficient (dko) dystrophic mice. Tibial bone structure in dko mice was significantly different from that in mdx and wild-type (C57BL/10) control mice. Effects of LFS on bone architecture differed between dystrophic and healthy mice, with LFS thinning cortical bone in both dystrophic models. Bone mass was maintained in LFStreated healthy mice, with a reduced proportion of high-density bone and concomitant increase in low-density bone. LFS-treated dko mice exhibited a net deficit in cortical thickness and reduced high-density bone but no equivalent increase in low-density bone. These alterations in bone structure and mineral density reduced mechanical strength in mdx and dko mice. The findings reveal that muscle activity can regulate bone mass, structure, mineral accrual, and strength, especially in the context of dystrophin and/or utrophin deficiency. The results provide unique insights into the development of bone fragility in DMD and for devising interventions to improve musculoskeletal health. [ABSTRACT FROM AUTHOR]

Objective: β2-agonist medications are thought to have adverse effects on bone density. Surgical denervation and intramuscular β2-agonist injections appear to have opposing effects on skeletal muscles. The present study has been designed to assess the effects of denervation of the masseter, intramuscular injection of a β2-agonist and the combination of both procedures, on bone density in the craniofacial skeleton in rats.

This article presents findings from an empirical study exploring student and teacher perspectives on positive learning experiences in practical theological education. Forty-five students and twenty teachers were interviewed in focus groups in four educational institutions delivering programs in practical theology. The findings indicated that students valued practical theological education when it enabled them to think critically in relation to their personal or professional experience, and that students valued tutors, their peers and a flexible curriculum design in promoting this kind of learning. There was a high correlation between students' views of positive learning experiences and what tutors perceived as important qualities that they hoped their students would develop. Difficulties associated with the students' lack of clarity about the learning process and the tensions between academic and professional contexts are also discussed.

Objectives: To develop guidelines, informed by health‐care consumer values and preferences, for sarcopenia prevention, assessment and management for use by clinicians and researchers in Australia and New Zealand. Methods: A three‐phase Consumer Expert Delphi process was undertaken between July 2020 and August 2021. Consumer experts included adults with lived experience of sarcopenia or health‐care utilisation. Phase 1 involved a structured meeting of the Australian and New Zealand Society for Sarcopenia and Frailty Research (ANZSSFR) Sarcopenia Diagnosis and Management Task Force and consumer representatives from which the Phase 2 survey was developed. In Phase 2, consumers from Australia and New Zealand were surveyed online with opinions sought on sarcopenia outcome priorities, consultation preferences and interventions. Findings were confirmed and disseminated in Phase 3. Descriptive statistical analyses were performed. Results: Twenty‐four consumers (mean ± standard deviation age 67.5 ± 12.8 years, 18 women) participated in Phase 2. Ten (42%) identified as being interested in sarcopenia, 7 (29%) were health‐care consumers and 6 (25%) self‐reported having/believing they have sarcopenia. Consumers identified physical performance, living circumstances, morale, quality of life and social connectedness as the most important outcomes related to sarcopenia. Consumers either had no preference (46%) or preferred their doctor (40%) to diagnose sarcopenia and preferred to undergo assessments at least yearly (54%). For prevention and treatment, 46% of consumers preferred resistance exercise, 2–3 times per week (54%). Conclusions: Consumer preferences reported in this study can inform the implementation of sarcopenia guidelines into clinical practice at local, state and national levels across Australia and New Zealand. [ABSTRACT FROM AUTHOR]

Cancer cachexia is common in many cancers and the loss of skeletal muscle mass compromises the response to therapies and quality of life. A contributing mechanism is oxidative stress and compounds able to attenuate it may be protective. Sulforaphane (SFN), a natural antioxidant in cruciferous vegetables, activates nuclear factor erythroid 2-related factor 2 (Nrf2) signaling to decrease oxidative stress. Although SFN has potential as a cancer therapeutic, whether it can attenuate muscle wasting in the absence or presence of chemotherapy is unknown. In healthy C2C12 myotubes, SFN administration for 48 h induced hypertrophy through increased myoblast fusion via Nrf2 and ERK signaling. To determine whether SFN could attenuate wasting induced by cancer cells, myotubes were cocultured with or without Colon-26 (C-26) cancer cells for 48 h and treated with 5-fluorouracil (5-FU, 5 μM) or vehicle (DMSO). SFN (10 μM) or DMSO was added for the final 24 h. Coculture with cancer cells in the absence and presence of 5-FU reduced myotube width by ~30% (P < 0.001) and ~20% (P < 0.01), respectively, which was attenuated by SFN (P < 0.05). Exposure to C-26 conditioned media reduced myotube width by 15% (P < 0.001), which was attenuated by SFN. Western immunoblotting and qRT-PCR confirmed activation of Nrf2 signaling and antioxidant genes. Coadministration of Nrf2 inhibitors (ML-385) or MEK inhibitors (PD184352) revealed that SFN's attenuation of atrophy was blocked by ERK inhibition. These data support the chemoprotective and antioxidative function of SFN in myotubes, highlighting its therapeutic potential for cancer-related muscle wasting. [ABSTRACT FROM AUTHOR]

Sarcopenia is an age-related condition of slow, progressive loss of muscle mass and strength, which contributes to frailty, increased risk of hospitalization and mortality, and increased health care costs. The incidence of sarcopenia is predicted to increase to >200 million affected older adults worldwide over the next 40 years, highlighting the urgency for understanding biological mechanisms and developing effective interventions. An understanding of the mechanisms underlying sarcopenia remains incomplete. Iron in the muscle is important for various metabolic functions, including oxygen supply and electron transfer during energy production, yet these same chemical properties of iron may be deleterious to the muscle when either in excess or when biochemically unshackled (eg, in ferroptosis), it can promote oxidative stress and induce inflammation. This review outlines the mechanisms leading to iron overload in muscle with aging and evaluates the evidence for the iron overload hypothesis of sarcopenia. Based on current evidence, studies are needed to (a) determine the mechanisms leading to iron overload in skeletal muscle during aging; and (b) investigate whether skeletal muscles are functionally deficient in iron during aging leading to impairments in oxidative metabolism. [ABSTRACT FROM AUTHOR]

Presents findings from a qualitative study exploring young people's perceptions about the provision of a youth-counseling service. Study reveals factors that hinder willingness to seek counseling and factors that encourage young people to make use of counseling. (Author/GCP)

Explores the foundation of therapeutic theory from the perspective of social constructionism. Proposes a theoretical description of the interaction between an individual and the social context in the formation of therapeutic theory. Then explores this description in relation to the early life and subsequent therapeutic theory of Carl Rogers. (RJM)