Publications by authors named "Sergio Di Meo"

While a low level of ROS plays a role in cellular regulatory processes, a high level can lead to oxidative stress and cellular dysfunction. Insulin resistance (IR) is one of the dysfunctions in which oxidative stress occurs and, until now, the factors underlying the correlation between oxidative stress and IR were unclear and incomplete. This study aims to explore this correlation in skeletal muscle, a tissue relevant to insulin-mediated glucose disposal, using the hyperthyroid rat as a model of oxidative stress.

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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.

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Free radicals are chemical species (atoms, molecules, or ions) containing one or more unpaired electrons in their external orbitals and generally display a remarkable reactivity. The evidence of their existence was obtained only at the beginning of the 20th century. Chemists gradually ascertained the involvement of free radicals in organic reactions and, in the middle of the 20th century, their production in biological systems.

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Background: Bladder cancer is the eleventh most commonly diagnosed cancer worldwide. The recurrence rate of this cancer can be very high, up to 45%. Photodynamic diagnosis (PDD) is more sensitive than standard procedures for the detection of malignant tumours.

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Currently, it is known 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. It is also known that mitochondria, because of their capacity to produce free radicals, play a major role in tissue oxidative damage and dysfunction and provide protection against excessive tissue dysfunction through several mechanisms, including the stimulation of permeability transition pore opening. This process leads to mitoptosis and mitophagy, two sequential processes that are a universal route of elimination of dysfunctional mitochondria and is essential to protect cells from the harm due to mitochondrial disordered metabolism.

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Mitochondria are both the main sites of production and the main target of reactive oxygen species (ROS). This can lead to mitochondrial dysfunction with harmful consequences for the cells and the whole organism, resulting in metabolic and neurodegenerative disorders such as type 2 diabetes, obesity, dementia, and aging. To protect themselves from ROS, mitochondria are equipped with an efficient antioxidant system, which includes low-molecular-mass molecules and enzymes able to scavenge ROS or repair the oxidative damage.

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From their discovery in biological systems, reactive oxygen species (ROS) have been considered key players in tissue injury for their capacity to oxidize biological macromolecules [...

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Unaccustomed and/or exhaustive exercise generates excessive free radicals and reactive oxygen and nitrogen species leading to muscle oxidative stress-related damage and impaired contractility. Conversely, a moderate level of free radicals induces the body's adaptive responses. Thus, a low oxidant level in resting muscle is essential for normal force production, and the production of oxidants during each session of physical training increases the body's antioxidant defenses.

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In addition to insulin, glycemic control involves thyroid hormones. However, an excess of thyroid hormone can disturb the blood glucose equilibrium, leading to alterations of carbohydrate metabolism and, eventually, diabetes. Indeed, experimental and clinical hyperthyroidism is often accompanied by abnormal glucose tolerance.

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We investigated the effects of thyroid state on the mechanisms underlying rat heart mitochondrial capacity to remove HO produced by an exogenous source. The removal rates were higher in the presence of respiratory substrates independently from thyroid state and were higher in hyperthyroid than in hypothyroid preparations. The thyroid state-linked changes in HO removal rates, mirrored those in HO release rates, showing that endogenous and exogenous HO do not compete for the removing system.

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Objective: We investigated the efficacy of intravesical instillations of combined hyaluronic acid (HA) and chondroitin sulphate (CS) in patients with bacillus Calmette-Guérin (BCG)-induced chemical cystitis unresponsive to first-line therapies.

Patients And Methods: We retrospectively reviewed the clinical records of patients with grade 2 BCG-induced chemical cystitis unresponsive to first line therapeutic options performed according to the International Bladder Cancer Group guidelines who underwent intravesical instillations of HA/CS. Bladder pain, urinary urgency, voiding volume and number of voids/24 hours recorded prior to treatment, at the end of the treatment, at six months and at one-year follow-up were recorded and analyzed.

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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.

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Paragangliomas (PGL) are rare neuroendocrine tumors of the autonomic nervous system originating from paraganglia. Although PGL may arise at any site where physiologic paraganglionic tissue exists, the localization in the small pelvis is extremely rare. PGL may be hormonally active and release surplus catecholamines into the blood or inactive.

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We studied the effects of adrenaline administration and depletion (induced by reserpine) on rat liver oxidative metabolism. We showed that adrenaline increases, and reserpine decreases aerobic capacity (inferred by cytochrome oxidase activity) in tissue modifying the hepatic content of mitochondrial proteins without changing mitochondrial aerobic capacity. The changes in tissue cytochrome oxidase activity, which agreed with the expression levels of factors involved in mitochondrial biogenesis, such as PGC-1, NRF-1, and NRF-2, were associated with similar changes in tissue and mitochondrial State 3 respiration.

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Lipomas are benign mesenchymal tumours that are rarely seen in the scrotum. Few cases of primary scrotal lipomas originating from the scrotal wall have been reported in the literature. We describe the case of a giant primary intrascrotal lipoma presenting as scrotal swelling and discomfort.

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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.

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Anaplastic seminoma (AS) is an uncommon histological variant of classical seminoma of the testis and account for 5%-15% of cases. It is poorly described in the scientific literature. We present the case of a 50-years-old homeless man presenting with fever, marked left scrotal hardness and a fungating left scrotal lesion.

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Carcinomas of unknown primary origin (CUP) represent a diagnostic and therapeutic challenge. Squamous cell CUP located in the male pelvis are very rare. We describe a case of a locally advanced squamous cell CUP occurring in the male pelvis presenting as perineal abscess and urethral stenosis and diagnosed by means of transperineal needle biopsy.

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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.

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At present, obesity is one of the most important public health problems in the world because it causes several diseases and reduces life expectancy. Although it is well known that insulin resistance plays a pivotal role in the development of type 2 diabetes mellitus (the more frequent disease in obese people) the link between obesity and insulin resistance is yet a matter of debate. One of the most deleterious effects of obesity is the deposition of lipids in non-adipose tissues when the capacity of adipose tissue is overwhelmed.

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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.

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