Aorto-bifemoral bypass using a total laparoscopic approach can be performed safely. As all new techniques, a learning curve is observed. This new technique should be evaluated in a larger randomised trial to assess its clinical value in comparison to conventional surgery.
Muscle weakness and atrophy are clinical hallmarks of myotonic dystrophy type 1 (DM1). Muscle stem cells, which contribute to skeletal muscle growth and repair, are also affected in this disease. However, the molecular mechanisms leading to this defective activity and the impact on the disease severity are still elusive. Here, we explored through an unbiased approach the molecular signature leading to myogenic cell defects in DM1. Single cell RNAseq data revealed the presence of a specific subset of DM1 myogenic cells expressing a senescence signature, characterized by the high expression of genes related to senescence-associated secretory phenotype (SASP). This profile was confirmed using different senescence markers in vitro and in situ. The excessive accumulation of intranuclear RNA foci in DM1 senescent cells compared to non-senescent cells suggests that RNA-mediated toxicity contribute to senescence induction. High expression of IL-6, a prominent SASP cytokine, in the serum of DM1 patients was identified as a biomarker correlating with muscle weakness and functional capacity limitations. Drug screening revealed that the BCL-XL inhibitor (A1155463), a senolytic drug, can specifically target senescent DM1 myoblasts to induce their apoptosis and reduce their SASP. Removal of senescent cells re-established the myogenic function of the non-senescent DM1 myoblasts, which displayed improved proliferation and differentiation capacity in vitro; and enhanced engraftment following transplantation in vivo. Altogether this study presents a well-defined senescent molecular signature in DM1 untangling part of the pathological mechanisms observed in the disease; additionally, we demonstrate the therapeutic potential of targeting these defective cells with senolytics to restore myogenesis.
Individuals born preterm show reduced exercise capacity and increased risk for pulmonary and cardiovascular diseases, but the impact of preterm birth on skeletal muscle, an inherently critical part of cardiorespiratory fitness, remains unknown. We evaluated the impacts of preterm birth-related conditions on the development, growth, and function of skeletal muscle using a recognized preclinical rodent model in which newborn rats are exposed to 80% oxygen from day 3 to 10 of life. We analyzed different hindlimb muscles of male and female rats at 10 days (neonatal), 4 weeks (juvenile) and 16 weeks (young adults). Neonatal high oxygen exposure increased the generation of reactive oxygen species and the signs of inflammation in skeletal muscles, which was associated with muscle fiber atrophy, fiber type shifting (reduced proportion of type I slow fibers and increased proportion of type IIb fast-fatigable fibers), and impairment in muscle function. These effects were maintained until adulthood. Fast-twitch muscles were more vulnerable to the effects of hyperoxia than slow-twitch muscles. Male rats, which expressed lower antioxidant defenses, were more susceptible than females to oxygen-induced myopathy. Overall, preterm birth-related conditions have long-lasting effects on the composition, morphology, and function of skeletal muscles; and these effects are sex-specific. Oxygen-induced changes in skeletal muscles could contribute to the reduced exercise capacity and to increased risk of diseases of preterm born individuals.
Skeletal muscle possesses a high plasticity and a remarkable regenerative capacity that relies mainly on muscle stem cells. Molecular and cellular components of the muscle stem cell niche, such as immune cells, play key roles to coordinate muscle stem cell function and to orchestrate muscle regeneration. An abnormal infiltration of immune cells and/or imbalance of pro- and anti-inflammatory cytokines could lead to muscle stem cell dysfunctions that could have long lasting effects on muscle function. Different genetic variants were shown to cause muscular dystrophies that intrinsically compromise muscle stem cell function and disturb their microenvironment leading to impaired muscle regeneration that contributes to disease progression. Alternatively, many acquired myopathies caused by comorbidities (e.g., cardiopulmonary or kidney diseases), chronic inflammation/infection, or side effects of different drugs can also perturb muscle stem cell function and their microenvironment. The goal of this review is to comprehensively summarize the current knowledge on acquired myopathies and their impact on MuSC function. We further describe potential therapeutic strategies to restore muscle stem cell regenerative capacity.
Background: Individuals born preterm present left ventricle changes and increased risk of cardiac diseases and heart failure. The pathophysiology of heart disease after preterm birth is incompletely understood. Mitochondria dysfunction is a hallmark of cardiomyopathy resulting in heart failure. We hypothesized that neonatal hyperoxia in rats, a recognized model simulating preterm birth conditions and resulting in oxygen-induced cardiomyopathy, induce left ventricle mitochondrial changes in juvenile rats. We also hypothesized that humanin, a mitochondrial-derived peptide, would be reduced in young adults born preterm. Methods: Sprague-Dawley pups were exposed to room air (controls) or 80% O 2 at postnatal days 3 to 10 (oxygen-induced cardiomyopathy). We studied left ventricle mitochondrial changes in 4 weeks old males. In a cohort of young adults born preterm (n=55) and age-matched term (n=54), we compared circulating levels of humanin. Results: Compared with controls, oxygen-exposed rats showed smaller left ventricle mitochondria with disrupted integrity on electron microscopy, decreased oxidative phosphorylation, increased glycolysis markers, and reduced mitochondrial biogenesis and abundance. In oxygen-exposed rats, we observed lipid deposits, increased superoxide production (isolated cardiomyocytes), and reduced Nrf2 gene expression. In the cohort, left ventricle ejection fraction and peak global longitudinal strain were similar between groups however humanin levels were lower in preterm and associated with left ventricle ejection fraction and peak global longitudinal strain. Conclusions: In conclusion, neonatal hyperoxia impaired left ventricle mitochondrial structure and function in juvenile animals. Serum humanin level was reduced in preterm adults. This study suggests that preterm birth–related conditions entail left ventricle mitochondrial alterations that may underlie cardiac changes perpetuated into adulthood. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT03261609.
Individuals born preterm are at higher risk of cardiovascular and metabolic diseases in adulthood, through mechanisms not completely understood. White adipose tissue in humans and rodents is a dynamic endocrine organ and a critical player in the regulation of metabolic homeostasis. However, the impact of preterm birth on white adipose tissue remains unknown. Using a well‐established rodent model of preterm birth‐related conditions in which newborn rats are exposed during postnatal days 3–10 to 80% of oxygen, we evaluated the impact of transient neonatal hyperoxia on adult perirenal white adipose tissue (pWAT) and liver. We further assessed the effect of a second hit with a high‐fat high‐fructose hypercaloric diet (HFFD). We evaluated 4‐month‐old adult male rats after 2 months of HFFD. Neonatal hyperoxia led to pWAT fibrosis and macrophage infiltration without modification in body weight, pWAT weight, or adipocyte size. In animals exposed to neonatal hyperoxia vs. room air control, HFFD resulted in adipocyte hypertrophy, lipid accumulation in the liver, and increased circulating triglycerides. Overall, preterm birth‐related conditions had long‐lasting effects on the composition and morphology of pWAT, along with a higher susceptibility to the deleterious impact of a hypercaloric diet. These changes suggest a developmental pathway to long‐term metabolic risk factors observed clinically in adults born preterm through programming of white adipose tissue.
We report two patients with toxic hepatitis due to the solvent dimethylformamide (DMF). Other causes of hepatitis such as viral, drug induced or alcoholic hepatitis, could be excluded or were considered to be unlikely. Hepatotoxicity due to professional exposure to solvents e.g. dimethylformamide should be considered in any patient with unexplained hepatitis. The fast improvement of the clinical symptoms and the progressive normalisation of the liver function tests once the exposure to the product has been stopped, supports the diagnosis. Yet, non-drug induced toxic hepatitis remains an exclusion diagnosis. Therapy consists of avoiding every contact with the causative agent. Table 3 (Addendum) gives an overview of some industrial agents able to cause hepatitis.
Introduction: Preterm (PT) birth is associated with increased risk of cardiovascular diseases (CVD) and heart failure. We previously reported left ventricular (LV) mitochondrial dysfunction in a rat model mimicking the deleterious conditions associated with PT birth. Whether mitochondrial function is altered in humans born PT and associated with LV function changes is unknown. We aimed to determine if serum humanin levels, a mitochondrial-derived peptide with cytoprotective effects, are altered in humans born PT and are associated with impaired myocardial function. Methods: Data were obtained from 55 young adults born PT (<30 weeks of gestational age, GA) compared to 54 full-term (T) controls of the same age. Serum humanin levels were determined by ELISA and LV ejection fraction (LVEF) by echocardiography. Results are shown as median (interquartile range) and comparisons between groups were performed using non-parametric tests. Results: Individuals were evaluated at 23.3 (21.4, 25.3) years, and age and sex distribution were similar between groups. Median GA was 27.5 (26.2, 28.4) weeks in the PT group. Humanin levels (pg/ml) were 132.9 (105.1, 189.3) and 161.1 (123.6, 252) in the PT and the T groups, respectively (p=0.0414). LVEF was within the normal range and similar between groups. Lower LVEF was associated with lower humanin levels (p<0.001), and this association was observed both in the term (p=0.002) and the preterm (p=0.047) groups. Conclusions: Serum humanin levels are lower in adult born PT. Since lower humanin levels are also associated with lower LVEF, our results suggest that mitochondrial alterations could play a role in the long-term adverse cardiovascular consequences of PT birth. Humanin analogs improve LV function in experimental models. Our results pave the way for future studies exploring humanin as a therapeutic avenue for the prevention and treatment of CVD in individuals born PT.
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