Muscle Oxidative Stress Plays a Role in Hyperthyroidism-Linked Insulin Resistance.

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. The development of IR in the liver from hyperthyroid animals has been widely reported, whereas data concerning the muscle are quite controversial. Thus, we investigated whether hyperthyroidism induces IR in skeletal muscle and the role of oxidative stress in this process. Particularly, we compared the effects of hyperthyroidism on IR both in the absence and presence of vitamin E (Vit E), acting as an antioxidant. Putative correlations between ROS production, oxidative stress markers, antioxidant capacity and changes in intracellular signalling pathways related to insulin action (AKT) and cellular stress response (EIF2α; JNK; PGC1α; BIP; and NRF1) were investigated. Moreover, we assessed the effects of hyperthyroidism and Vit E on the expression levels of genes encoding for glucose transporters (Slc2a1; Slc2a4), factors involved in lipid homeostasis and insulin signalling (Pparg; Ppara, Cd36), as well as for one of the IR-related inflammatory factors, i.e., interleukin 1b (Il1b). Our results suggest that hyperthyroidism-linked oxidative stress plays a role in IR development in muscle and that an adequate antioxidant status, obtained by vitamin E supplementation, that mitigates oxidative stress, may prevent IR development.

Physiological and Pathological Role of ROS: Benefits and Limitations of Antioxidant Treatment 2.0.

Following the discovery of superoxide dismutase enzymes [...].

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

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.

Evolution of the Knowledge of Free Radicals and Other Oxidants.

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. For several decades, free radicals were thought to cause exclusively damaging effects . This idea was mainly supported by the finding that oxygen free radicals readily react with all biological macromolecules inducing their oxidative modification and loss of function. Moreover, evidence was obtained that when, in the living organism, free radicals are not neutralized by systems of biochemical defences, many pathological conditions develop. However, after some time, it became clear that the living systems not only had adapted to the coexistence with free radicals but also developed methods to turn these toxic substances to their advantage by using them in critical physiological processes. Therefore, free radicals play a dual role in living systems: they are toxic by-products of aerobic metabolism, causing oxidative damage and tissue dysfunction, and serve as molecular signals activating beneficial stress responses. This discovery also changed the way we consider antioxidants. Their use is usually regarded as helpful to counteract the damaging effects of free radicals but sometimes is harmful as it can block adaptive responses induced by low levels of radicals.

The Role of Reactive Oxygen Species in the Life Cycle of the Mitochondrion.

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. To date, there is significant evidence not only that the above processes are induced by enhanced reactive oxygen species (ROS) production, but also that such production is involved in the other phases of the mitochondrial life cycle. Accumulating evidence also suggests that these effects are mediated through the regulation of the expression and the activity of proteins that are engaged in processes such as genesis, fission, fusion, and removal of mitochondria. This review provides an account of the developments of the knowledge on the dynamics of the mitochondrial population, examining the mechanisms governing their genesis, life, and death, and elucidating the role played by free radicals in such processes.

Hexaminolevulinate blue light cystoscopy (Hal) assisted transurethral resection of the bladder tumour vs white light transurethral resection of the bladder tumour in non-muscle invasive bladder cancer (NMIBC) : a retrospective analysis.

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. The aim of the study was to evaluate oncological outcomes in white light TURB (WL-TURB) and hexaminolevuninate blue light TURB (Hal-TURB). PATIENTS AND METHODS: This was a retrospective longitudinal single-center study. In the period between January 2016 and October 2016 WL-TURB was the only therapeutic option available. From November 2016 until April 2017 all TURBs were fluorescence-guided (Hal-TURB). Kaplan-Meier curves have been used to estimate recurrence free survival rates. RESULTS: One hundred and eleven patients underwent Hal- TURB and 137 underwent WL-TURB. Recurrence rate after 12 months was 19.8% (22 out of 111 patients) and 37.2% (51 out of 137 patients) in HAL-group and WL-group respectively (p < 0.01). The recurrence-free period was longer in HAL-group rather than WL-group (8.9 months vs 7.3 months, p < 0.05). Moreover, the recurrence rate during the first 6 months was 3.7% in patients who underwent HAL-TURB and 16% in those who received WL-TURB (p < 0.01). CONCLUSION: The results of the study show that recurrence-free survival was longer in patients undergoing HAL-TURB compared to the patients who received standard WL-TURB.

Vitamin E Supplementation and Mitochondria in Experimental and Functional Hyperthyroidism: A Mini-Review.

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. In the mitochondrial membranes, a major role is played by the lipid-soluble antioxidant vitamin E, which reacts with the peroxyl radicals faster than the molecules of polyunsaturated fatty acids, and in doing so, protects membranes from excessive oxidative damage. In the present review, we summarize the available data concerning the capacity of vitamin E supplementation to protect mitochondria from oxidative damage in hyperthyroidism, a condition that leads to increased mitochondrial ROS production and oxidative damage. Vitamin E supplementation to hyperthyroid animals limits the thyroid hormone-induced increases in mitochondrial ROS and oxidative damage. Moreover, it prevents the reduction of the high functionality components of the mitochondrial population induced by hyperthyroidism, thus preserving cell function.

Physiological and Pathological Role of ROS: Benefits and Limitations of Antioxidant Treatment.

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 [...].

Mediators of Physical Activity Protection against ROS-Linked Skeletal Muscle Damage.

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. Mitochondria, NADPH oxidases and xanthine oxidases have been identified as sources of free radicals during muscle contraction, but the exact mechanisms underlying exercise-induced harmful or beneficial effects yet remain elusive. However, it is clear that redox signaling influences numerous transcriptional activators, which regulate the expression of genes involved in changes in muscle phenotype. The mitogen-activated protein kinase family is one of the main links between cellular oxidant levels and skeletal muscle adaptation. The family components phosphorylate and modulate the activities of hundreds of substrates, including transcription factors involved in cell response to oxidative stress elicited by exercise in skeletal muscle. To elucidate the complex role of ROS in exercise, here we reviewed the literature dealing on sources of ROS production and concerning the most important redox signaling pathways, including MAPKs that are involved in the responses to acute and chronic exercise in the muscle, particularly those involved in the induction of antioxidant enzymes.

Insulin resistance and diabetes in hyperthyroidism: a possible role for oxygen and nitrogen reactive species.

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. A common characteristic of hyperthyroidism and type 2 diabetes is the altered mitochondrial efficiency caused by the enhanced production of reactive oxygen and nitrogen species. It is known that an excess of thyroid hormone leads to increased oxidant production and mitochondrial oxidative damage. It can be hypothesised that these species represent the link between hyperthyroidism and development of insulin resistance and diabetes, even though direct evidence of this relationship is lacking. In this review, we examine the literature concerning the effects of insulin and thyroid hormones on glucose metabolism and discuss alterations of glucose metabolism in hyperthyroid conditions and the cellular and molecular mechanisms that may underline them.

Thyroid state affects H2O2 removal by rat heart mitochondria.

We investigated the effects of thyroid state on the mechanisms underlying rat heart mitochondrial capacity to remove H2O2 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 H2O2 removal rates, mirrored those in H2O2 release rates, showing that endogenous and exogenous H2O2 do not compete for the removing system. Mitochondrial content of coenzyme Q9 and Q10 was lower in hypothyroidism and higher in hyperthyroidism suggesting that the thyroid state-linked changes in the rates of H2O2 production are due to changes in the ubiquinone mitochondrial content. The rates of H2O2 removal in the presence of antioxidant enzyme inhibitors indicated that the contribution of each antioxidant is dependent on the thyroid state. This was supported by enzymatic activity measurements. Pharmacological inhibition also showed that the overall percentage contribution of the enzymatic processes, as well as that of non-enzymatic processes, is not affected by thyroid state. Cytochrome levels, inferred by light emission measurements, and western blot determination of cytochrome c, were lower in hypothyroid and higher in hyperthyroid preparations supporting the idea that the levels of reducing compounds were modified in opposite way by the changes in thyroid state. Further support was obtained showing that the whole antioxidant capacity, which provides an evaluation of capacity of the systems, different from cytochromes, assigned to H2O2 scavenging, was lower in hyperthyroid than in hypothyroid state.

Intravesical administration of combined hyaluronic acid and chondroitin sulfate can improve symptoms in patients with refractory bacillus Calmette-Guerin-induced chemical cystitis: Preliminary experience with one-year follow-up.

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. RESULTS: The records of 20 patients were identified. All patients underwent eight weekly instillations of HA/CS. Mean baseline visual analogue scale (VAS) scores ± Standard Deviation (SD) for urinary urgency and bladder pain were 7.8 ± 0.5 and 7.2 ± 1.0, respectively. Mean number of voids/24 hours ± SD was 15.4 ± 2.3 and mean urine volume per void ± SD was 85.8 ± 21.0 mL. At the end of the treatment, mean VAS scores ± SD for urgency and pain significantly decreased to 4.7 ± 1.1 and 4.2 ± 0.9, respectively (p < 0.05 in both cases). Mean number of voids/24 hours ± SD decreased to 9.6 ± 1.4 (p < 0.05) and mean urine volume per void ± SD significantly increased to 194.1 ± 59.5 mL (p < 0.05). At six months and one-year followup, all outcome measures remained stable. CONCLUSIONS: Bladder instillations of HA/CS provide significant and durable improvement of bladder pain, urinary urgency, urinary volume per void and urinary frequency in patients with refractory BCG-induced chemical cystitis.

Adrenaline induces mitochondrial biogenesis in rat liver.

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. Adrenaline and reserpine induced extensive lipid and protein oxidative damage in tissue and mitochondria. The increase in H2O2 release by respiring mitochondria and the decrease in the activities of the antioxidant enzymes glutathione peroxidase and reductase contributed to the reserpine effect on oxidative damage. The adrenaline effect is more difficult to explain, since the hormone increased the antioxidant enzyme activities but, in respiring mitochondria, increased ROS release rate in the presence of succinate and decreased it in the presence of pyruvate/malate. These opposite changes were due to the increased content of the autoxidizable electron carrier located at complex III and decreased content of that located at complex I. Our data suggest that adrenaline can be involved in the mitochondrial population adaptation which verify in conditions in which an increased body energy expenditure verify such as cold exposure.

Giant primary scrotal lipoma: A case report.

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. Findings from scrotal magnetic resonance imaging were highly suspicious for lipoma. The mass was completely excised and histological examination confirmed the diagnosis of lipoma.

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

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.

A case of highly aggressive anaplastic seminoma of the testis presenting as fungating scrotal lesion.

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. He underwent left orchiopexy 40 years before. A computed tomography with contrast media showed a suspect testis cancer with scrotal involvment, extensive intralesional necrosis and multiple systemic metastases. A wide excision of the left hemiscrotum including the testis was performed in order to prevent severe local and systemic infectious complications. Histological examination revealed an AS. General conditions showed a rapid deterioration and the patient died on post operative day 10.

A rare case of male pelvic squamous cell carcinoma of unknown primary origin presenting as perineal abscess and urethral stenosis.

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.

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

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.