skeletal muscle

Human cachexia induces changes in mitochondria, autophagy and apoptosis in the skeletal muscle

Cachexia is a wasting syndrome characterized by the continuous loss of skeletal muscle mass due to imbalance between protein synthesis and degradation, which is related with poor prognosis and compromised quality of life. Dysfunctional mitochondria are associated with lower muscle strength and muscle atrophy in cancer patients, yet poorly described in human cachexia. We herein investigated mitochondrial morphology, autophagy and apoptosis in the skeletal muscle of patients with gastrointestinal cancer-associated cachexia (CC), as compared with a weight-stable cancer group (WSC).

Association between growth differentiation factor-15 (GDF-15) serum levels, anorexia and low muscle mass among cancer patients

The pathophysiology of cancer anorexia is complex and serum biomarkers, including growth and differentiation factor(s) (GDF), may be modulated. We explored the association(s) between GDF-15 serum levels and anorexia and, secondarily, with low muscle mass and body weight loss in cancer patients. We considered gastrointestinal and lung cancer patients (CP) and healthy BMI-matched controls. The FAACT-questionnaire was administered to diagnose anorexia and we calculated the L3-SMI by CT scan to assess low muscularity, setting their cutoff values at the lowest tertile.

Atrophy, oxidative switching and ultrastructural defects in skeletal muscle of the ataxia telangiectasia mouse model

Ataxia telangiectasia is a rare, multi system disease caused by ATM kinase deficiency. Atm-knockout mice recapitulate premature aging, immunodeficiency, cancer predisposition, growth retardation and motor defects, but not cerebellar neurodegeneration and ataxia. We explored whether Atm loss is responsible for skeletal muscle defects by investigating myofiber morphology, oxidative/glycolytic activity, myocyte ultrastructural architecture and neuromuscular junctions. Atm-knockout mice showed reduced muscle and fiber size.

Inhibition of phosphoinositide 3-kinase/protein kinase B signaling hampers the vasopressin-dependent stimulation of myogenic differentiation

Arginine-vasopressin (AVP) promotes muscle differentiation, hypertrophy, and regeneration through the combined activation of the calcineurin and Calcium/Calmodulin-dependent Protein Kinase (CaMK) pathways. The AVP system is impaired in several neuromuscular diseases, suggesting that AVP may act as a physiological factor in skeletal muscle. Since the Phosphoinositide 3-kinases/Protein Kinase B/mammalian Target Of Rapamycin (PI3K/Akt/mTOR) signaling plays a significant role in regulating muscle mass, we evaluated its role in the AVP myogenic effect.

Downstream of IL-6 cytokine signaling: the JAK/STAT pathway in skeletal muscle pathophysiology

The Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway is a key intracellular mediator of a variety of metabolically relevant hormones and cytokines, including the interleukin-6 (IL-6) family of cytokines. The JAK/STAT pathway transmits extracellular signals to the nucleus, leading to the transcription of genes involved in multiple pleiotropic biological activities. The JAK/STAT pathway has been reported to be required for the homeostasis of different tissues and organs, where it is required for normal homeostasis.

Bedside Assessment of the Microvascular Venous Compartment in Cardiac Surgery Patients With Valvular Diseases Undergoing Cardiopulmonary Bypass

OBJECTIVE: Blood volume reserve for venous return and the effects of cardiopulmonary bypass (CPB) on microvascular bed partitioning and blood flow were examined in patients with valvular diseases.
DESIGN: Prospective, consecutive, case-control study.
SETTING: Single university hospital.
PARTICIPANTS: The study comprised 20 adult cardiac surgery patients and 20 healthy volunteers.

Sarcopenia predicts reduced survival in patients with hepatocellular carcinoma at first diagnosis

Background. Sarcopenia is a complication and independent risk factor for mortality in patients with liver cirrhosis.
AIM:
To assess the prevalence and influence of sarcopenia on overall survival in a cohort of cirrhotic patients with hepatocellular carcinoma managed in a tertiary center.
MATERIAL AND METHODS:

Biomarkers for sarcopenia: reductionism vs. complexity

Sarcopenia, the progressive and generalized loss of muscle mass and strength/function, is a major health issue in older adults, given its high prevalence and burdensome clinical ramifications. The absence of a unified operational definition for sarcopenia has hampered its full appreciation by healthcare providers, researchers and policy-makers. At the same time, this unresolved debate and the complexity of musculoskeletal aging pose major challenges to the identification of clinically meaningful biomarkers.

Biomarkers for physical frailty and sarcopenia

Physical frailty (PF) and sarcopenia are major health issues in geriatric populations, given their high prevalence and association with several adverse outcomes. Nevertheless, the lack of an univocal operational definition for the two conditions has so far hampered their clinical implementation. Existing definitional ambiguities of PF and sarcopenia, together with their complex underlying pathophysiology, also account for the absence of robust biomarkers that can be used for screening, diagnostic and/or prognostication purposes.

Engineering muscle networks in 3D gelatin methacryloyl hydrogels: influence of mechanical stiffness and geometrical confinement

In this work, the influence of mechanical stiffness and geometrical confinement on the 3D culture of myoblast-laden gelatin methacryloyl (GelMA) photo-crosslinkable hydrogels was evaluated in terms of in vitro myogenesis. We formulated a set of cell-laden GelMA hydrogels with a compressive modulus in the range 1÷17 kPa, obtained by varying GelMA concentration and degree of cross-linking. C2C12 myoblasts were chosen as the cell model, to investigate the supportiveness of different GelMA hydrogels on myotube formation up to 2 weeks.

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