90 research outputs found

    Experimental analysis of the station keeping response of a double-barge float-over system with an elastically scaled physical model

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    In this paper, an experimental investigation of the global response to waves relative to a newly developed float-over concept by TechnipFMC Rome Operating Center for transportation, installation and decommissioning of the off-shore platform topside is presented. A flexible scaled model of the float-over system was tested in the wave basin to determine the range of the sea-state conditions for which the response of the catamaran float-over is acceptable for mating operations. The present analysis is part of a more extensive experimental campaign which has involved also the use of a scaled rigid physical model (Dessi et al., 2016) and numerical simulations for which the collected data provide also a validation database

    Histone deacetylase 4 is crucial for proper skeletal muscle development and disease

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    Epigenetics plays a pivotal role in modulating gene response to physiological or pathological stimuli. Histone Deacetylase inhibitors (HDACi) have been used in the treatment of various cancers1, are ef-fective in several animal models of neurodegenerative diseases, including amyotrophic lateral scle-rosis (ALS), and are currently in clinical trial to promote muscle repair in muscular dystrophies2. However, long-term use of pan-HDAC inhibitors is not tolerated3. The assignment of distinct biologi-cal functions to individual HDACs in skeletal muscle is a prerequisite to improve the efficacy of pharmacological treatments based on HDACi. HDAC4 is a member of class II HDACs that mediates many cellular responses. Clinical reports suggest that inhibition of HDAC4 can be beneficial to cancer cachexia, dystrophic or ALS patients. All the above conditions are characterized by progressive mus-cle wasting and up-regulation of HDAC4 expression in skeletal muscle, suggesting a potential role for this protein in regulating these diseases. To study the role of HDAC4 with a genetic approach, we generated several models of muscle disease in mice lacking HDAC4 in skeletal muscle: cancer ca-chexia, by implanting Lewis lung carcinoma (LLC), muscular dystrophy, by using mdx mice, or ALS, by using SODG93A mice. Lack of HDAC4 worsens skeletal muscle atrophy induced by both LLC and ALS, demonstrated by a reduction in muscle mass and myofibers size. Conversely, dystrophic mice lacking HDAC4 in skeletal muscle show an increased number of necrotic myofibers and run less efficiently than mdx mice. The aggravation of the dystrophic phenotype may be partially due to the impairment in skeletal muscle regeneration observed in mice lacking HDAC4 in skeletal muscle. Our results indi-cate that HDAC4 is necessary for maintaining skeletal muscle homeostasis and function. Current studies aim to investigate the molecular mechanisms underlying the role of HDAC4 in skeletal mus-cle maintenance in response to cancer cachexia, ALS or muscular dystrophy

    Histone deacetylase 4 protects from denervation and skeletal muscle atrophy in a murine model of amyotrophic lateral sclerosis

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    Background: Histone deacetylase 4 (HDAC4) has been proposed as a target for Amyotrophic Lateral Sclerosis (ALS) because it mediates nerve-skeletal muscle interaction and since its expression in skeletal muscle correlates with the severity of the disease. However, our recent studies on the skeletal muscle response upon long-term denervation highlighted the importance of HDAC4 in maintaining muscle integrity. Methods: To fully identify the yet uncharacterized HDAC4 functions in ALS, we genetically deleted HDAC4 in skeletal muscles of a mouse model of ALS. Body weight, skeletal muscle, innervation and spinal cord were analyzed over time by morphological and molecular analyses. Transcriptome analysis was also performed to delineate the signaling modulated by HDAC4 in skeletal muscle of a mouse model of ALS. Findings: HDAC4 deletion in skeletal muscle caused earlier ALS onset, characterized by body weight loss, muscle denervation and atrophy, and compromised muscle performance, although the main catabolic pathways were not activated. Transcriptome analysis identified the gene networks modulated by HDAC4 in ALS, revealing UCP1 as a top regulator that may be implicated in worsening ALS features. Interpretation: HDAC4 plays an important role in preserving innervations and skeletal muscle in ALS, likely by modulating the UCP1 gene network. Our study highlights a possible risk in considering HDAC inhibitors for the treatment of ALS. Fund: This work was supported by FIRB grant (RBFR12BUMH) from Ministry of Education, Universities and Research, by Fondazione Veronesi, by Sapienza research project 2017 (RM11715C78539BD8) and Polish National Science Center grant (UMO-2016/21/B/NZ3/03638)

    Aerobic Exercise and Pharmacological Treatments Counteract Cachexia by Modulating Autophagy in Colon Cancer

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    Recent studies have correlated physical activity with a better prognosis in cachectic patients, although the underlying mechanisms are not yet understood. In order to identify the pathways involved in the physical activity-mediated rescue of skeletal muscle mass and function, we investigated the effects of voluntary exercise on cachexia in colon carcinoma (C26)-bearing mice. Voluntary exercise prevented loss of muscle mass and function, ultimately increasing survival of C26-bearing mice. We found that the autophagic flux is overloaded in skeletal muscle of both colon carcinoma murine models and patients, but not in running C26-bearing mice, thus suggesting that exercise may release the autophagic flux and ultimately rescue muscle homeostasis. Treatment of C26-bearing mice with either AICAR or rapamycin, two drugs that trigger the autophagic flux, also rescued muscle mass and prevented atrogene induction. Similar effects were reproduced on myotubes in vitro, which displayed atrophy following exposure to C26-conditioned medium, a phenomenon that was rescued by AICAR or rapamycin treatment and relies on autophagosome-lysosome fusion (inhibited by chloroquine). Since AICAR, rapamycin and exercise equally affect the autophagic system and counteract cachexia, we believe autophagy-triggering drugs may be exploited to treat cachexia in conditions in which exercise cannot be prescribed

    Air Pollution, Aeroallergens, and Emergency Room Visits for Acute Respiratory Diseases and Gastroenteric Disorders among Young Children in Six Italian Cities

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    Past studies reported evidence of associations between air pollution and respiratory symptoms and morbility for children. Few studies examined associations between air pollution and emergency room (ER) visits for wheezing, and even fewer for gastroenteric illness. We conducted a multicity analysis of the relationship between air pollution and ER visits for wheezing and gastroenteric disorders in children 0-2 years of age.BACKGROUND: Past studies reported evidence of associations between air pollution and respiratory symptoms and morbidity for children. Few studies examined associations between air pollution and emergency room (ER) visits for wheezing, and even fewer for gastroenteric illness. We conducted a multicity analysis of the relationship between air pollution and ER visits for wheezing and gastroenteric disorder in children 0-2 years of age. METHODS: We obtained ER visit records for wheezing and gastroenteric disorder from six Italian cities. A cityspecific case-crossover analysis was applied to estimate effects of particulate matter (PM), nitrogen dioxide, sulfur dioxide, ozone, and carbon monoxide, adjusting for immediate and delayed effects of temperature. Lagged effects of air pollutants up to 6 prior days were examined. The cityspecific results were combined using a random-effect meta-analysis. RESULTS: CO and SO2 were most strongly associated with wheezing, with a 2.7% increase [95% confidence interval (CI), 0.5-4.9] for a 1.04 \u3bcg/m3 increase in 7day average CO and a 3.4% (95% CI, 1.5-5.3) increase for an 8.0 \u3bcg/m3 increase in SO2. Positive associations were also found for PM with aerodynamic diameter 64 10 \u3bcg and NO2. We found a significant association between the 3day moving average CO and gastroenteric disorders [3.8% increase (95% CI, 1.0-6.8)]. When data were stratified by season, the associations were stronger in summer for wheezing and in winter for gastroenteric disorders. CONCLUSION: Air pollution is associated with triggering of wheezing and gastroenteric disorders in children 0-2 years of age; more work is needed to understand the mechanisms to help prevent wheezing in children

    Factors affecting the formation, nature and properties of iron precipitation products at the soil-root interface.

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    Factors Affecting the Formation, Nature and Properties of Iron Precipitation Products at the Soil-Root Interface

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