Publications by authors named "Fabio H Silva"

Priapism, a prevalent complication in sickle cell disease (SCD) patients, manifests as prolonged and painful erections unrelated to sexual arousal. The detailed mechanisms contributing to this condition, especially regarding sympathetic function in the corpus cavernosum that maintains penile flaccidity, remain to be elucidated. In this study, it was hypothesized that the pathways of the sympathetic nervous system would be down-regulated, thereby contributing to the development of ischemic priapism in sickle cell disease.

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This study focused on investigating the water quality in the Pirajibú River, a relevant water body that flows through the industrial zone of Sorocaba (São Paulo/Brazil). Due to the limitations of assessing water quality based solely on standard physicochemical tests, an ecotoxicological approach was used to assess biomarker changes in the liver of bullfrog tadpoles (Aquarana catesbeiana). The animals were divided into groups and exposed to water samples collected upstream and downstream of the industrial zone.

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Diabetic bladder dysfunction (DBD) is the most prevalent complication of diabetes mellitus (DM), affecting >50% of all patients. Currently, no specific treatment is available for this condition. In the early stages of DBD, patients typically complain of frequent urination and often have difficulty sensing when their bladders are full.

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Patients with sickle cell disease (SCD) display an overactive bladder (OAB). Intravascular hemolysis in SCD is associated with various severe SCD complications. However, no experimental studies have evaluated the effect of intravascular hemolysis on bladder function.

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Article Synopsis
  • * Current understanding shows that problems in the nitric oxide (NO) and cGMP pathways, along with excess heme from intravascular hemolysis, contribute to the development of priapism in SCD.
  • * The review discusses potential treatments aimed at reducing excess free heme in the plasma as a way to manage priapism in men with SCD.
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Background: Different tasks and proxy measurements have been employed to evaluate dynamic balance in older individuals. However, due to inherent limitations, results from most evaluations could hardly be taken as valid measurements of dynamic balance.

Research Question: Is the Equidyn smartphone application-based protocol valid and sensitive for assessment of dynamic balance in older adults?

Methods: Dynamic balance was evaluated in 52 physically active individuals, age range 60-80 years (M = 69.

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Priapism, defined as a prolonged and often painful penile erection occurring without sexual stimulation or desire, is a common complication in sickle cell disease (SCD), affecting up to 48% of male patients. This condition presents significant clinical challenges and can lead to erectile dysfunction if not properly managed. Current pharmacological treatments for SCD-related priapism are primarily reactive rather than preventative, highlighting a gap in effective medical intervention strategies.

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Background: Autophagy is a well-conserved catabolic process that plays a key role in cell homeostasis. In the prostate, defective autophagy has been implicated in the genesis and progression of several pathological conditions.

Aim: The present review explored the autophagy pathway in prostate-related dysfunctions, focusing on prostate cancer (PCa), benign prostatic hyperplasia (BPH) and prostatitis.

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Patients with sickle cell disease (SCD) display priapism, a prolonged penile erection in the absence of sexual arousal. The current pharmacological treatments for SCD-associated priapism are limited and focused on acute interventions rather than prevention. Thus, there is an urgent need for new drug targets and preventive pharmacological therapies for this condition.

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Article Synopsis
  • Patients with sickle cell disease (SCD) have high levels of a substance called heme, which may cause painful erections known as priapism.
  • The study looked at how heme affects smooth muscle relaxation in mouse penis tissue, discovering that heme helps these muscles relax.
  • Blocking certain pathways stopped this relaxing effect, suggesting that targeting heme could lead to new treatments to prevent priapism in men with SCD.
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Sickle cell disease (SCD) is a genetic disorder that has been associated with priapism. The role of hydroxyurea, a common SCD therapy, in influencing the nitric oxide (NO)-cGMP pathway and its effect on priapism is unclear. To investigate the effect of hydroxyurea treatment on smooth muscle relaxation of corpus cavernosum induced by stimulation of the NO-cGMP pathway in SCD transgenic mice and endothelial NO synthase gene-deficient (eNOS-/-) mice, which are used as model of priapism associated with the low bioavailability of endothelial NO.

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In sickle cell disease (SCD), reduced bioavailability of endothelial NO and cGMP results in reduced expression of phosphodiesterase type 5 (PDE5), thus impairing the penile erection control mechanism and resulting in prolonged penile erection (priapism). In SCD, reduced NO bioavailability is associated with excess plasma hemoglobin due to intravascular hemolysis and increased oxidative stress. Haptoglobin is the plasma protein responsible for reducing plasma hemoglobin levels, but in SCD, haptoglobin levels are reduced, which favors the accumulation of hemoglobin in plasma.

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Patients with sickle cell disease (SCD) display priapism. Clinical studies have shown a strong positive correlation between priapism and high levels of intravascular hemolysis in men with SCD. However, there are no experimental studies that show that intravascular hemolysis promotes alterations in erectile function.

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Background: Children and adult with sickle cell disease (SCD) display priapism associated with low nitric oxide (NO) bioavailability and oxidative stress in penis.

Aim: This study aimed to evaluate the effects of hybrid compound RVT-FxMe, derived from resveratrol bearing a NO-donor subunit, on two murine model that display priapism phenotype, SCD transgenic mice and endothelial NO synthase gene-deficient (eNOS-/-) mice.

Methods: Wild-type, SCD, and eNOS-/- mice were treated with RVT-FxMe (25 mg/kg/d, 2 weeks).

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Lipopolysaccharide (LPS) is a component of gram-negative bacteria wall that elicits inflammatory response in the host through the toll-like receptor 4 (TLR4) activation. In the lower urinary tract (LUT), bacteria-derived LPS has been associated with lower urinary tract symptoms (LUTS); however, little is known about the effects of LPS in the urethral smooth muscle (USM). In the present study, we evaluated the functional and molecular effects of LPS in mouse USM in vitro, focusing on the LPS-induced TLR4-signaling pathway.

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Priapism, a prolonged penile erection in the absence of sexual arousal, is common among patients with sickle cell disease (SCD). Hypogonadism is also common in patients with SCD. While the administration of exogenous testosterone reverses hypogonadism, it is contraceptive.

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Aims: Nitric oxide (NO) has a critical, but not well understood, influence in the physiology of the lower urinary tract. We evaluated the effect of NO/phosphodiesterase (PDE)5 signaling in voiding dysfunction in the sickle cell disease (SCD) mouse, characterized by low NO bioavailability.

Main Methods: Adult SCD (Sickle) and wild-type (WT) male mice were treated daily with sodium nitrate (10 mM) or vehicle.

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Voiding abnormalities are common among the sickle cell disease (SCD) population, among which overactive bladder (OAB) syndrome is observed at rates as high as 39%. Although detrusor overactivity is the most common cause of OAB, its molecular pathophysiology is not well elucidated. The nitric oxide (NO) signaling pathway has been implicated in the regulation of lower genitourinary tract function.

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Obese mice display overactive bladder (OAB) associated with impaired urethra smooth muscle (USM) function. In this study, we evaluated the role of the adipose tissue surrounding the urethra and prostate in obese mice (here referred as periprostatic adipose tissue; PPAT) to the USM dysfunction. Male C57BL6/JUnib mice fed with either a standard-chow or high-fat diet to induce obesity were used.

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Article Synopsis
  • Fetal hemoglobin (HbF) induction through hydroxyurea (HU) therapy improves outcomes for sickle cell anemia (SCA) patients, but not everyone benefits or can tolerate HU, prompting the search for new treatments.
  • Thalidomide analogs have shown potential in inducing HbF while also reducing tumor necrosis factor-alpha, leading to the hybridization of HU and thalidomide to create a new compound called 4C.
  • Compound 4C has been found to enhance HbF production in a SCA mouse model and lower pro-inflammatory cytokine levels in SCA mouse monocytes, positioning it as a promising new therapy with dual HbF-inducing and anti-inflammatory effects for SCA.
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Background: Patients with heart failure (HF) display erectile dysfunction (ED). However, the pathophysiology of ED during HF remains poorly investigated.

Objective: This study aimed to characterize the aortocaval fistula (ACF) rat model associated with HF as a novel experimental model of ED.

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Urethral smooth muscle (USM) contributes to urinary continence by contracting during the urine storage phase, which is mainly mediated by activation of postjunctional α-adrenoceptors. Males and females show differences in the functioning of the lower urinary tract and the most common urinary tract symptoms (LUTS). LUTS in men typically occur in association with bladder outlet obstruction, whereas in women urinary urge-incontinence symptoms are more common.

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Background: The aim of the present study was to evaluate different signaling pathways by which exercise training would interfere in endothelial function in obesity. Therefore, we examined adipocytokine levels and their receptors in the corpus cavernosum and femoral artery from trained rats on a high-fat diet.

Methods: Functional experiments were performed in control sedentary and trained rats, and sedentary (h-SD) and trained male Wistar rats on a high-fat diet (h-TR).

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Background: Sickle cell disease patients display priapism that may progress to erectile dysfunction. However, little is known about the pathophysiological alterations of corpus cavernosum in sickle cell disease.

Objective: Thus, this study aimed to evaluate the functional and molecular alterations of sympathetic machinery and nitric oxide-cyclic guanosine monophosphate signaling pathway in Townes transgenic sickle cell disease mice.

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