969 research outputs found

    Anti-EGFR therapy: strategies in head and neck squamous cell carcinoma.

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    Epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor that activates downstream signaling pathways, including the Ras-MEK-Erk and PI3K-AKT pathways, leading to cell proliferation, resistance to apoptosis, angiogenesis and the ability to metastasize. EGFR overexpression is a significant finding in cancer, particularly in head and neck cancer, where it is also associated with a poor prognosis. In recent years, several molecules have been designed to inhibit EGFR activation. Among the many available anti-EGFR drugs, only cetuximab was approved for the treatment of head and neck cancers. However, no predictive biomarkers of cetuximab response are currently known. In the present review, we provide an updated assessment of EGFR biology and its clinical impact in head and neck cancers. A special emphasis is placed on novel patents of EGFR-inhibitors that are anticipated to diversify the anti-EGFR therapies available to treat head and neck cancers. In particular, we outline a new class of irreversible multi-target inhibitors (e.g. afatinib, icotinib, CUDC-101), which may significantly contribute to new head and neck cancer therapies.The authors would like to acknowledge Dr. Laura Mussel white for critical revision of the manuscript. André L. Carvalho and Rui M. Reis have a National Counsel of Technological and Scientific Development (CNPq) scholarship. A.C.C, has a FAPESP (2013/13834-7) scholarship.info:eu-repo/semantics/publishedVersio

    (-)-tarchonanthuslactone Exerts A Blood Glucose-increasing Effect In Experimental Type 2 Diabetes Mellitus

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)A number of studies have proposed an anti-diabetic effect for tarchonanthuslactone based on its structural similarity with caffeic acid, a compound known for its blood glucose-reducing properties. However, the actual effect of tarchonanthuslactone on blood glucose level has never been tested. Here, we report that, in opposition to the common sense, tarchonanthuslactone has a glucose-increasing effect in a mouse model of obesity and type 2 diabetes mellitus. The effect is acute and non-cumulative and is present only in diabetic mice. In lean, glucose-tolerant mice, despite a slight increase in blood glucose levels, the effect was not significant.20350385049Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Institute of Chemistry/UNICAMPFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [proc. 13/07607-8]FAPESP [11/50514-5, 12/09254-2, 10/08673-6, 2009/53606-8

    Reduction of Tubulin Expression in Angomonas deanei by RNAi Modifies the Ultrastructure of the Trypanosomatid Protozoan and Impairs Division of Its Endosymbiotic Bacterium

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    In the last two decades, RNA interference pathways have been employed as a useful tool for reverse genetics in trypanosomatids. Angomonas deanei is a non-pathogenic trypanosomatid that maintains an obligatory endosymbiosis with a bacterium related to the Alcaligenaceae family. Studies of this symbiosis can help us to understand the origin of eukaryotic organelles. The recent elucidation of both the A. deanei and the bacterium symbiont genomes revealed that the host protozoan codes for the enzymes necessary for RNAi activity in trypanosomatids. Here we tested the functionality of the RNAi machinery by transfecting cells with dsRNA to a reporter gene (green fluorescent protein), which had been previously expressed in the parasite and to α-tubulin, an endogenous gene. In both cases, protein expression was reduced by the presence of specific dsRNA, inducing, respectively, a decreased GFP fluorescence and the formation of enlarged cells with modified arrangement of subpellicular microtubules. Furthermore, symbiont division was impaired. These results indicate that the RNAi system is active in A. deanei and can be used to further explore gene function in symbiont-containing trypanosoma tids and to clarify important aspects of symbiosis and cell evolution. This article is protected by copyright. All rights reserved

    The association of diabetes, subclinical hypothyroidism and carotid intima-media thickness: results from the Brazilian Longitudinal Study of Adult Health (ELSA-Brazil)

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    Introduction: The association of diabetes with subclinical thyroid diseases may increase the risk of cardiovascular diseases. We analyzed the association of subclinical hypothyroidism, diabetes, and both diseases with carotid Intima-Media Thickness (cIMT) as a surrogate maker for early cardiovascular disease in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Methods: Cross-sectional analysis with data from the 3rd visit (2017‒2019). Linear regression models were used to evaluate the association of subclinical hypothyroidism, diabetes and of both diseases with a cIMT presented as Beta (95% Confidence Interval ‒ 95% CI) without adjustment, with adjustment for sociodemographic variables (Model 1) and multivariable adjustment (Model 1 more cardiovascular risk factors). We also used logistic regression models to analyze the Odds Ratio (OR) and 95% CI for the association of both diseases using cIMT > P75%. Results: After the exclusion of patients with previous cardiovascular disease, 5,077 participants with no diseases, 1578 with diabetes, 662 with subclinical hypothyroidism, and 234 with both diseases were included in the analysis. Linear regression models showed an association of cIMT with only diabetes (β = 0.019; 95% CI 0.012 to 0.027; p < 0.0001) and subclinical hypothyroidism more diabetes (β = 0.03; 95% CI 0.010‒0.047, p < 0.0001). The logistic regression model reported an association between diabetes and CIMT higher than P75% (OR = 1.49, 95% CI 1.30‒1.71). No interaction between diabetes and subclinical hypothyroidism was detected using cIMT respectively as a continuous (p = 0.29) or as a categorical variable (p = 0.92). Discussion: Diabetes was associated with higher cIMT values. However, no additive effect of subclinical hypothyroidism associated with diabetes over cIMT was detected

    Is urinary density an adequate predictor of urinary osmolality?

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    Urinary density (UD) has been routinely used for decades as a surrogate marker for urine osmolality (U-osm). We asked if UD can accurately estimate U-osm both in healthy subjects and in different clinical scenarios of kidney disease. UD was assessed by refractometry. U-osm was measured by freezing point depression in spot urines obtained from healthy volunteers (N = 97) and in 319 inpatients with acute kidney injury (N = 95), primary glomerulophaties (N = 118) or chronic kidney disease (N = 106). UD and U-osm correlated in all groups (p < 0.05). However, a wide range of U-osm values was associated with each UD value. When UD was <= 1.010, 28.4% of samples had U-osm above 350 mOsm/kg. Conversely, in 61.6% of samples with UD above 1.020, U-osm was below 600 mOsm/kg. As expected, U-osm exhibited a strong relationship with serum creatinine (S-creat), whereas a much weaker correlation was found between UD and Screat. We found that UD is not a substitute for U-osm. Although UD was significantly correlated with U-osm, the wide dispersion makes it impossible to use UD as a dependable clinical estimate of U-osm. Evaluation of the renal concentrating ability should be based on direct determination of U-osm1

    Skin picking treatment with the Rothbaum cognitive behavioral therapy protocol : a randomized clinical trial

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    Introduction: Although behavioral therapies can effectively treat skin picking disorder (SPD), there is no standardized treatment for improving SPD and its comorbidities and there is no group intervention option. This trial aimed to adapt the Rothbaum trichotillomania protocol to SPD (Study 1) and test its efficacy for treating SPD and comorbidities in individual and group formats (Study 2). Methods: The adapted protocol was applied to 16 SPD patients, who were allocated to group or individual treatment (Study 1). Afterwards, 54 patients were randomly allocated to treatment in an individual (n=27) or group format (n=27) (Study 2). In both studies, assessments of SPD severity, anxiety, depression, clinical status and skin lesion severity were performed at baseline and the endpoint. Results: The adapted protocol was feasible in both treatment modalities (Study 1) and led to high SPD remission rates (individual 63%; group 52%), with no significant difference between intervention types (p = 0.4) (Study 2). SPD, anxiety, and depression symptoms and objective patient lesion measures improved after treatment. There was large effect size for SPD symptom improvement in both treatment types (Cohen’s d: group = 0.88; individual = 1.15) (Study 2). Conclusion: The adapted Rothbaum protocol was effective for SPD remission, comorbidities, and skin lesions, both in individual and group formats

    Surface Physicochemical Properties At The Micro And Nano Length Scales: Role On Bacterial Adhesion And Xylella Fastidiosa Biofilm Development.

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    The phytopathogen Xylella fastidiosa grows as a biofilm causing vascular occlusion and consequently nutrient and water stress in different plant hosts by adhesion on xylem vessel surfaces composed of cellulose, hemicellulose, pectin and proteins. Understanding the factors which influence bacterial adhesion and biofilm development is a key issue in identifying mechanisms for preventing biofilm formation in infected plants. In this study, we show that X. fastidiosa biofilm development and architecture correlate well with physicochemical surface properties after interaction with the culture medium. Different biotic and abiotic substrates such as silicon (Si) and derivatized cellulose films were studied. Both biofilms and substrates were characterized at the micro- and nanoscale, which corresponds to the actual bacterial cell and membrane/ protein length scales, respectively. Our experimental results clearly indicate that the presence of surfaces with different chemical composition affect X. fastidiosa behavior from the point of view of gene expression and adhesion functionality. Bacterial adhesion is facilitated on more hydrophilic surfaces with higher surface potentials; XadA1 adhesin reveals different strengths of interaction on these surfaces. Nonetheless, despite different architectural biofilm geometries and rates of development, the colonization process occurs on all investigated surfaces. Our results univocally support the hypothesis that different adhesion mechanisms are active along the biofilm life cycle representing an adaptation mechanism for variations on the specific xylem vessel composition, which the bacterium encounters within the infected plant.8e7524

    Biotinidase deficiency: Genotype-biochemical phenotype association in Brazilian patients

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    [EN] The association between the BTD genotype and biochemical phenotype [profound biotinidase deficiency (BD), partial BD or heterozygous activity] is not always consistent. This study aimed to investigate the genotype-biochemical phenotype association in patients with low biotinidase activity. Methods All exons, the 5'UTR and the promoter of the BTD gene were sequenced in 72 Brazilian individuals who exhibited low biotinidase activity. For each patient, the expected biochemical phenotype based on the known genotype was compared with the observed biochemical phenotype. Additional non-genetic factors that could affect the biotinidase activity were also analysed. Most individuals were identified by neonatal screening (n = 66/72). When consecutive results for the same patient were compared, age, prematurity and neonatal jaundice appeared to affect the level of biotinidase activity. The biochemical phenotype at the time of the second blood collection changed in 11/22 patients compared to results from the first sample. Three novel variants were found: c.1337T>C (p.L446P), c.1466A>G (p.N489S) and c.962G>A (p.W321*). Some patients with the same genotype presented different biochemical phenotypes. The expected and observed biochemical phenotypes agreed in 68.5% of cases (concordant patients). The non-coding variants c.-183G>A, c.-315A>G and c.-514C>T were present in heterozygosis in 5/17 discordant patients. In addition, c.- 183G>A and c.-514C>T were also present in 10/37 concordant patients. The variants found in the promoter region do not appear to have a strong impact on biotinidase activity. Since there is a disparity between the BTD genotype and biochemical phenotype, and biotinidase activity may be affected by both genetic and non-genetic factors, we suggest that the diagnosis of BD should be based on more than one measurement of plasma biotinidase activity. DNA analysis can be of additional relevance to differentiate between partial BD and heterozygosity.SIThis study received financial support from Fundo de Incentivo à Pesquisa e Eventos/Hospital de Clínicas de Porto Alegre (FIPE-HCPA) for research materials and publication fee. Post Graduate Program in Genetics and Molecular Biology (Universidade Federal do Rio Grande do Sul) funded the translation. ECN has a commercial affiliation (CTN Diagnósticos) which did not have any role or financial contribution to this research. TB have fellowship from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes). FS had fellowship from the Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS). IVDS, MRSC and PASF have fellowships from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). HB receives a research grant of Orphan Europe. The funders did no provide support in the form of salaries for any author, and did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section

    Acidocalcisomes as Calcium- and Polyphosphate-Storage Compartments during Embryogenesis of the Insect Rhodnius prolixus Stahl

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    BACKGROUND: The yolk of insect eggs is a cellular domain specialized in the storage of reserve components for embryo development. The reserve macromolecules are stored in different organelles and their interactions with the embryo cells are mostly unknown. Acidocalcisomes are lysosome-related organelles characterized by their acidic nature, high electron density and large content of polyphosphate bound to several cations. In this work, we report the presence of acidocalcisome-like organelles in eggs of the insect vector Rhodnius prolixus. METHODOLOGY/PRINCIPAL FINDINGS: Characterization of the elemental composition of electron-dense vesicles by electron probe X-ray microanalysis revealed a composition similar to that previously described for acidocalcisomes. Following subcellular fractionation experiments, fractions enriched in acidocalcisomes were obtained and characterized. Immunofluorescence showed that polyphosphate polymers and the vacuolar proton translocating pyrophosphatase (V-H(+)-PPase, considered as a marker for acidocalcisomes) are found in the same vesicles and that these organelles are mainly localized in the egg cortex. Polyphosphate quantification showed that acidocalcisomes contain a significant amount of polyphosphate detected at day-0 eggs. Elemental analyses of the egg fractions showed that 24.5±0.65% of the egg calcium are also stored in such organelles. During embryogenesis, incubation of acidocalcisomes with acridine orange showed that these organelles are acidified at day-3 (coinciding with the period of yolk mobilization) and polyphosphate quantification showed that the levels of polyphosphate tend to decrease during early embryogenesis, being approximately 30% lower at day-3 compared to day-0 eggs. CONCLUSIONS: We found that acidocalcisomes are present in the eggs and are the main storage compartments of polyphosphate and calcium in the egg yolk. As such components have been shown to be involved in a series of dynamic events that may control embryo growth, results reveal the potential involvement of a novel organelle in the storage and mobilization of inorganic elements to the embryo cells
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