1,383 research outputs found

    Improvement of obesity-linked skeletal muscle insulin resistance by strength and endurance training.

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    Obesity-linked insulin resistance is mainly due to fatty acid overload in non-adipose tissues, particularly skeletal muscle and liver, where it results in high production of reactive oxygen species and mitochondrial dysfunction. Accumulating evidence indicates that resistance and endurance training alone and in combination can counteract the harmful effects of obesity increasing insulin sensitivity, thus preventing diabetes. This review focuses the mechanisms underlying the exercise role in opposing skeletal muscle insulin resistance-linked metabolic dysfunction. It is apparent that exercise acts through two mechanisms: (1) it stimulates glucose transport by activating an insulin-independent pathway and (2) it protects against mitochondrial dysfunction-induced insulin resistance by increasing muscle antioxidant defenses and mitochondrial biogenesis. However, antioxidant supplementation combined with endurance training increases glucose transport in insulin-resistant skeletal muscle in an additive fashion only when antioxidants that are able to increase the expression of antioxidant enzymes and/or the activity of components of the insulin signaling pathway are used

    "Cold training" affects rat liver responses to continuous cold exposure.

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    Continuous exposure of homeothermic animals to low environmental temperatures elicits physiological adaptations necessary for animal survival, which are associated to higher generation of pro-oxidants in thermogenic tissues. It is not known whether intermittent cold exposure (cold training) is able to affect tissue responses to continuous cold exposure. Therefore, we investigated whether rat liver responses to continuous cold exposure of 2 days are modified by cold training (1h daily for 5 days per week for 3 consecutive weeks). Continuous cold increased liver oxidative metabolism by increasing tissue content of mitochondrial proteins and mitochondrial aerobic capacity. Cold training did not affect such parameters, but attenuated or prevented the changes elicited by continuous cold exposure. Two-day cold exposure increased lipid hydroperoxide and protein-bound carbonyl levels in homogenates and mitochondria, whereas cold training decreased such effects although it decreased only homogenate protein damage in control rats. The activities of the antioxidant enzymes GPX and GR and H2O2 production were increased by continuous cold exposure. Despite the increase in GPX and GR activities, livers from cold-exposed rats showed increased susceptibility to in vitro oxidative challenge. Such cold effects were decreased by cold training, which in control rats reduced only H2O2 production and susceptibility to stress. The changes of PGC-1, NRF-1, and NRF-2 expression levels were consistent with those induced by cold exposure and cold training in mitochondrial protein content and antioxidant enzyme activities. However, the mechanisms by which cold training attenuates the effects of the continuous cold exposure remain to be elucidated

    Role of ROS and RNS Sources in Physiological and Pathological Conditions

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    There is significant evidence that, in living systems, free radicals and other reactive oxygen and nitrogen species play a double role, because they can cause oxidative damage and tissue dysfunction and serve as molecular signals activating stress responses that are beneficial to the organism. Mitochondria have been thought to both play a major role in tissue oxidative damage and dysfunction and provide protection against excessive tissue dysfunction through several mechanisms, including stimulation of opening of permeability transition pores. Until recently, the functional significance of ROS sources different from mitochondria has received lesser attention. However, the most recent data, besides confirming the mitochondrial role in tissue oxidative stress and protection, show interplay between mitochondria and other ROS cellular sources, so that activation of one can lead to activation of other sources. Thus, it is currently accepted that in various conditions all cellular sources of ROS provide significant contribution to processes that oxidatively damage tissues and assure their survival, through mechanisms such as autophagy and apoptosis

    Autonomous take-off and landing for unmanned aircraft system: Risk and safety analysis

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    The aim of this paper is to conceive the possibility of applying the Required Navigation Performance (RNP) requirements where Global Navigation Satellite System (GNSS) augmentations are considered for the Automatic Take-Off and Landing (ATOL). An aircraft, belonging to the Medium Altitude Long Endurance (MALE) category of Unmanned Aerial System (UAS) has been considered as case-study. Once the avionic architecture has been designed, the Safety and risk analysis was carried out with a particular focus on Functional Hazard Analysis and Fault Tree Analysis techniques. The proposed methodology allows the researchers to evaluate the reliability of each avionic equipment and the safety level of the whole avionic system. Furthermore, the results pointed out the main criticalities of the architecture and some future in-depth studies are proposed

    Sporotrichoid Mycobacterium marinum infection in an elderly woman

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    We describe the case of an elderly woman who acquired a Mycobacterium marinum infection following skin exposure to the bacteria through a small wound on her right ring finger, obtained while preparing fish. The resultant sporotrichoid nodules of the right hand and the distal forearm, refractory to the initial therapy with doxycycline and rifampicin, were successfully treated with oral regimen of clarithromycin

    Hepatic Insulin Resistance in Hyperthyroid Rat Liver: Vitamin E Supplementation Highlights a Possible Role of ROS

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    Thyroid hormones are normally involved in glycaemic control, but their excess can lead to altered glucose metabolism and insulin resistance (IR). Since hyperthyroidism-linked increase in ROS results in tissue oxidative stress that is considered a hallmark of conditions leading to IR, it is conceivable a role of ROS in the onset of IR in hyperthyroidism. To verify this hypothesis, we evaluated the effects of vitamin E on thyroid hormone-induced oxidative damage, insulin resistance, and on gene expression of key molecules involved in IR in the rat liver. The factors involved in oxidative damage, namely the total content of ROS, the mitochondrial production of ROS, the activity of antioxidant enzymes, the in vitro susceptibility to oxidative stress, have been correlated to insulin resistance indices, such as insulin activation of hepatic Akt and plasma level of glucose, insulin and HOMA index. Our results indicate that increased levels of oxidative damage ROS content and production and susceptibility to oxidative damage, parallel increased fasting plasma level of glucose and insulin, reduced activation of Akt and increased activation of JNK. This last result suggests a role for JNK in the insulin resistance induced by hyperthyroidism. Furthermore, the variation of the genes Pparg, Ppara, Cd36 and Slc2a2 could explain, at least in part, the observed metabolic phenotypes. © 2022 by the authors. Licensee MDPI, Basel, Switzerland

    Nonabsorbable polymer clip as a cause of chronic perineal pain after radical prostatectomy: Description of a case treated by transperineal approach

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    The occurrence of persistent perineal pain caused by surgical clips has rarely been described after radical prostatectomy (RP). We describe the case of a patient complaining of chronic perineal pain occurred soon after robotic RP, refractory to conventional medical therapy and exacerbated by the sitting position. Pain was related to a nonabsorbable polymer clip used to secure lateral pedicles. A transpeerineal approach was used to perform an hydrodissection of the rectovesical space at the level of the surgical clip combined with local injection of mepivacaine and betametasone. The patient experienced a clinically significant reduction of pain that remained stable at three months' follow-up

    Seminal vesicle abscess causing unilateral hydroureteronephrosis: A case report

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    Seminal vesicle abscess (SVA) is a rare urologic entity. It mainly occurs in subjects with predisposing factors and may be associated with other urogenital infections. We describe the case of a diabetic subject with SVA associated with funiculitis, epididymitis and obstructive pyelonephritis. Treatment consisted of laparotomic surgical drainage of the abscess and ureteral stent placement

    Clinical Study The Influence of the Coexpression of CD4 and CD8 in Cutaneous Lesions on Prognosis of Mycosis Fungoides: A Preliminary Study

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    Background. Although techniques of immunophenotyping have been successful in characterizing the cells in the cutaneous infiltrates of mycosis fungoides little evidence suggests that variations in the phenotypic characterization correlate with prognosis. Objectives. In a preliminary prospective, single-centre, study we correlated the T-cell phenotype in cutaneous biopsies with the progression of the disease to determine whether the coexpression of CD4 and CD8 has an impact on prognosis. Methods. Skin biopsy specimens from 30 newly diagnosed patients were stained with immunoperoxidase techniques to determine their phenotypic characteristics. After a median followup of 42 months patients were divided into two groups with stable and progressive disease. Results. Eighteen patients had the conventional CD4+CD8− T-cell phenotype. Ten patients showed the coexpression of CD4 and CD8 and had a slightly lower rate of progressive disease. Conclusions. The coexpression of CD4 and CD8 in cutaneous lesions is not rare and is associated with a slightly lower rate of progressive disease. Since double positive CD4/CD8 phenotype is rarely reported in mycosis fungoides the presence on conventional immunophenotyping of both CD may be due to a "mixture" of neoplastic cells and inflammatory CD8+ tumor infiltrating lymphocytes. Immunohistochemical study combined with confocal microscopy could clarify this issue
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