Publications by authors named "Fernando C Silva"

Non-standard diesel blends can be harmful to the environment and human health. In this context, a simple analytical method to estimate the biodiesel mixture ratio in diesel was developed based on impedance spectroscopy (IS) associated with interdigitated sensors. In this article, four different interdigitated sensors with varied comb spacing (G) were simulated using the COMSOL Multiphysics software.

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The search for new compounds with antimalarial activity is urgent, as resistance to ones in the classical drug, has already been described in more than one continent. Compounds derived from 1,2,3-triazoles are effective against parasites and bacteria. Here, we evaluated the potential antimalarial activity against the human malaria parasite in a culture of fifty-four triazole compounds derived from 1-and 2-1,2,3-triazole.

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The tumor suppressor protein p53 is often called "the genome guardian" and controls the cell cycle and the integrity of DNA, as well as other important cellular functions. Its main function is to trigger the process of apoptosis in tumor cells, and approximately 50% of all cancers are related to the inactivation of the p53 protein through mutations in the gene. Due to the association of mutant p53 with cancer therapy resistance, different forms of restoration of p53 have been subject of intense research in recent years.

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In recent years, the development of new pharmaceutical formulations for the treatment of sporotrichosis has become a relevant research field. In this work, we aimed to develop an emulgel containing itraconazole and clotrimazole to ensure therapeutic effectiveness against Sporothrix brasiliensis. The topical use of a formulation that combines both drugs represents an interesting option for the complementary treatment of sporotrichosis.

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The aim of this study was to develop a microemulsion (ME) formulation containing an association of itraconazole (ITC) and clotrimazole (CLT) as a transdermal delivery system for the treatment of sporotrichosis. Pseudoternary phase diagrams were constructed to optimize the ME formulation. The ME formulation selected contained 1% (w/w) ITC and 1% (w/w) CLT and was composed of 23.

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Four new heterospin compounds with molecular formula {[Cu(hfac)(TlTrzNIT)][Ln(hfac)]} ·CH (Ln = Gd (1), Tb (2), or Dy (3)) and [Co(hfac)(TlTrzNIT)][Dy(hfac)] (4), where hfac is hexafluoroacetylacetonato and TlTrzNIT is the nitronylnitroxide radical 1-( m-tolyl)-1 H-1,2,3-triazole-4-(4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide), were obtained. All structures were determined by single-crystal X-ray diffraction. In compounds 1-3, the TlTrzNIT radical is bridge-coordinated to copper(II) ions, leading to positively charged copper(II)-radical chains containing [Ln(hfac)] as counterions.

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Background: Chagas disease, also known as American trypanosomiasis, is classified as one of the 17 most important neglected diseases by the World Health Organization. The only drugs with proven efficacy against Chagas disease are benznidazole and nifurtimox, however both show adverse effects, poor clinical efficacy, and development of resistance. For these reasons, the search for new effective chemical entities is a challenge to research groups and the pharmaceutical industry.

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Background: Breast cancer is a major cause of death among women worldwide. Treatment for breast cancer involves the surgical removal of cancer tissue, followed by chemotherapy. Although the treatment is efficient, especially when the cancer is detected early, recurrence is common and is often resistant to the previous treatment.

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Background: Stauffer's syndrome corresponds to a set of clinical and analytical changes of paraneoplastic nature firstly recognized more than 50 years ago, in association to renal cell carcinoma. A definitive review including universal diagnostic criteria and updated knowledge since the original description is lacking.

Basic Procedures: The authors conducted a comprehensive bibliographical review and propose updated diagnostic criteria to standardize diagnosis for clinical practice purposes and avoid misclassification.

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This study aimed to assess the benefits of dithiothreitol (DTT)-based sample treatment for protein equalization to assess potential biomarkers for bladder cancer. The proteome of plasma samples of patients with bladder carcinoma, patients with lower urinary tract symptoms (LUTS) and healthy volunteers, was equalized with dithiothreitol (DTT) and compared. The equalized proteomes were interrogated using two-dimensional gel electrophoresis and matrix assisted laser desorption ionization time of flight mass spectrometry.

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Diarrhea is an infectious disease caused by bacterial, virus, or protozoan, and dengue is caused by virus, included among the neglected diseases in several underdeveloped and developing countries, with an urgent demand for new drugs. Considering the antidiarrheal potential of species of Maytenus genus, a phytochemical investigation followed by antibacterial activity test with extracts of branches and heartwood and bark of roots from Maytenus gonoclada were conducted. Moreover, due the frequency of isolation of lupeol from Maytenus genus the antiviral activity against Dengue virus and cytotoxicity of lupeol and its complex with β-cyclodextrins were also tested.

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The phytochemical study of hexane, chloroform and methanol extracts from leaves of Psychotria viridis resulted in the identification of: the pentacyclic triterpenes, ursolic and oleanolic acid; the steroids, 24-methylene-cycloartanol, stigmasterol and β-sitosterol; the glycosylated steroids 3-O-β-D-glucosyl-β-sitosterol and 3-O-β-D-glucosyl-stigmasterol; a polyunsaturated triterpene, squalene; the esters of glycerol, 1-palmitoylglycerol and triacylglycerol; a mixture of long chain hydrocarbons; the aldehyde nonacosanal; the long chain fat acids hentriacontanoic, hexadecanoic and heptadenoic acid; the ester methyl heptadecanoate; the 4-methyl-epi-quinate and two indole alkaloids, N,N-dimethyltryptamine (DMT) and N-methyltryptamine. The chemical structures were determined by means of spectroscopic (IR, 1H and 13C NMR, HSQC, HMBC and NOESY) and spectrometric (CG-MS and LCMS-ESI-ITTOF) methods. The study of biologic properties of P.

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A new and efficient method for the synthesis of hexahydropyrimidine-fused 1,4-naphthoquinones in one step with high yields from the reaction of lawsone with 1,3,5-triazinanes was developed.

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Background: There are no prognostic factor publications on stage Ta-T1 non-muscle-invasive bladder cancer (NMIBC) treated with 1-3 yr of maintenance bacillus Calmette-Guérin (BCG).

Objective: To determine prognostic factors in NMIBC patients treated with 1-3 yr of BCG after transurethral resection of the bladder (TURB), to derive nomograms and risk groups, and to identify high-risk patients who should be considered for early cystectomy.

Design, Setting, And Participants: Data for 1812 patients were merged from two European Organization for Research and Treatment of Cancer randomized phase 3 trials in intermediate- and high-risk NMIBC.

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Purpose: To evaluate the clinical outcome of a cohort of localized prostate cancer patients treated with 125-I permanent brachytherapy at the São José Hospital--CHLC, Lisbon.

Materials And Methods: A retrospective analysis was carried out on 429 patients with low and intermediate-risk of prostate adenocarcinoma, according to the recommendations of the EORTC, who underwent 125I brachytherapies in intraoperative dosimetry "real-time" system between September 2003 and September 2013.

Results: The mean follow-up was 71.

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Background: A growing number of treatment options exist to treat metastatic castrate-resistant prostate cancer (mCRPC), and with these newer options, many questions about optimising treatment remain unanswered. One recommendation that may potentially be overlooked by practitioners is that androgen deprivation therapy (ADT) should be maintained when CRPC develops and when treatment with any of the newer agents is initiated.

Aim: However, to emphasise this recommendation, it is valuable to interrogate the evidence for maintaining ADT in different clinical situations.

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Use of intermittent androgen-deprivation therapy (IADT) in patients with prostate cancer has been evaluated in several studies, in an attempt to delay the development of castration resistance and reduce side-effects associated with ADT. However it is still not clear whether survival is adversely affected in patients treated with IADT. In this review, we explore the available data in an attempt to identify the most suitable candidate patients for IADT, and discuss factors that may inform appropriate patient stratification.

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Dengue virus infection is a serious public health problem in endemic areas of the world where 2.5 billion people live. Clinical manifestations of the Dengue infection range from a mild fever to fatal cases of hemorrhagic fever.

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Introduction: The triazoles represent a class of five-membered heterocyclic compounds of great importance for the preparation of new drugs with diverse biological activities because they may present several structural variations with the same numbers of carbon and nitrogen atoms. Due to the success of various triazoles that entered the pharmaceutical market and are still being used in medicines, many companies and research groups have shown interest in developing new methods of synthesis and biological evaluation of potential uses for these compounds. In this review, the authors explored aspects of patents for the 1H-1,2,3-, 2H-1,2,3-, 1H-1,2,4- and 4H-1,2,4-triazole families, including prototypes being considered in clinical studies between 2008 and 2011.

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Purpose Of Review: Intermittent hormonal therapy (IHT) for prostate cancer aims to minimize treatment-related side-effects, to improve overall quality of life, to reduce the cost of care, and possibly to delay progression to castration-resistant prostate cancer.

Recent Findings: With preclinical evidence suggesting a potential benefit for IHT in terms of time to androgen independence, with phase II and phase III studies producing optimistic results, and with the potential for reductions in cost and complications, IHT has become a popular modality of therapy around the globe.

Summary: In the near future intermittent therapy will have place in the treatment strategy in the management of prostate cancer, particularly on men with locally advanced disease.

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Background: Bacillus Calmette-Guérin (BCG) is the intravesical treatment of choice for carcinoma in situ (CIS).

Objective: Our aim was to assess if sequential mitomycin C (MMC) plus BCG after transurethral resection (TUR) is worthy of further study in non-muscle-invasive bladder cancer patients with CIS.

Design, Setting, And Participants: In a noncomparative phase 2 study, 96 patients with primary/secondary/concurrent CIS of the urinary bladder were randomized to sequential MMC plus BCG or to BCG alone after TUR.

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Article Synopsis
  • The study assessed the effects of different naphthoquinones on the growth of Trypanosoma cruzi epimastigotes and the viability of VERO cells, finding that β-lapachone and Epoxy-α-lap exhibited high trypanocidal activity.
  • Results showed that these compounds target different types of proteinases in T. cruzi; β-lapachone inhibits cysteine-proteinases, while Epoxy-α-lap inhibits serine-proteinases, indicating distinct mechanisms of action.
  • The findings suggest the potential for developing new treatments for Chagas disease by utilizing β-lapachone and Epoxy-α-lap as models for designing protease inhibitors.
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Exercise training is known to induce an increase in free radical production potentially leading to enhanced muscle injury. Vitamins C and E are well known antioxidants that may prevent muscle cell damage. The purpose of this study was to determine the effects of these supplemental antioxidant vitamins on markers of oxidative stress, muscle damage and performance of elite soccer players.

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