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1.
BMC Med Genomics ; 16(1): 207, 2023 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-37658350

RESUMO

BACKGROUND: Statin-induced myopathy is reported to be associated with the solute carrier organic anion transporter family member 1B1 gene single nucleotide polymorphism, c.521 T > C. There is no epidemiologic data on this gene polymorphism in several countries. Therefore, this study aimed at assessing the genotype and allele frequencies of the gene variant in three countries. METHODS: This study involved healthy individuals from Colombia, Mozambique, and Portugal. Genomic DNA was isolated from blood samples using the Qiamp DNA Extraction Kit (Qiagen). The isolated DNA was genotyped using novel Polymerase Chain Reaction-Restriction Fragment Length Polymorphism. Microstat and GraphPad QuickCal software were used for the Chi-square test and the evaluation of Hardy-Weinberg equilibrium respectively. RESULTS: A total of 181 individuals' blood samples were analyzed. Overall, the TT (74.0%) genotype was the highest and the CC (7.8%) was the lowest. Country wise genotypic frequencies were Colombia 47(70.2%) TT, 12(17.9%) TC and 8(11.9%) CC; Mozambique 47(88.7%) TT, 5(9.4%) TC, and 1(1.9%) CC; and Portugal 40(65.6%) TT, 16(26.2%) TC, and 5(8.2%) CC. The reference (T) allele was highest among Mozambicans (93.4%) compared to Colombians (79.1%) and Portuguese (78.7%). Mozambicans showed statistically significant genotypic and allelic frequency differences compared to Colombians (p < 0.01) and Portuguese (p < 0.01). CONCLUSIONS: Overall and country-wise, CC genotype was less frequent and it is relatively high for Colombians and Portuguese populations. This finding may imply statins risk-benefit variability associated with CC genotype among these populations that needs further understanding.


Assuntos
Inibidores de Hidroximetilglutaril-CoA Redutases , Testes Farmacogenômicos , Humanos , Colômbia , Moçambique , Portugal , Proteínas de Membrana Transportadoras , Transportador 1 de Ânion Orgânico Específico do Fígado/genética
2.
J Pers Med ; 13(5)2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37240898

RESUMO

PURPOSE: To assess the ability of apparent diffusion coefficient (ADC) measurements in predicting the histological grade of endometrial cancer. A secondary goal was to assess the agreement between MRI and surgical staging as an accurate measurement. METHODS: Patients with endometrial cancers diagnosed between 2018-2020 and having received both MRI and surgical staging were retrospectively enrolled. Patients were characterized according to histology, tumor size, FIGO stage (MRI and surgical stage), and functional MRI parameters (DCE and DWI/ADC). Statistical analysis was performed to determine if an association could be identified between ADC variables and histology grade. Secondarily, we assessed the degree of agreement between the MRI and surgical stages according to the FIGO classification. RESULTS: The cohort included 45 women with endometrial cancer. Quantitative analysis of ADC variables did not find a statistically significant association with histological tumor grades. DCE showed higher sensitivity than DWI/ADC in the assessment of myometrial invasion (85.00% versus 65.00%) with the same specificity (80.00%). A good agreement between MRI and histopathology for the FIGO stage was found (kappa of 0.72, p < 0.01). Differences in staging between MRI and surgery were detected in eight cases, which could not be justified by the interval between MRI and surgery. CONCLUSIONS: ADC values were not useful for predicting endometrial cancer grade, despite the good agreement between MRI interpretation and histopathology of endometrial cancer staging at our center.

3.
Life (Basel) ; 13(2)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36836763

RESUMO

The present work aimed to detail the mechanisms elicited by Allophylus africanus P. Beauv. stem bark extract in human stomach cancer cells and to identify the bioactives underlying the cytotoxicity. MTT reduction and LDH leakage assays allowed characterizing the cytotoxic effects in AGS cells, which were further detailed by morphological analysis using phalloidin and Hoechst 33258. Proapoptotic mechanisms were elucidated through a mitochondrial membrane potential assay and by assessing the impact upon the activity of caspase-9 and -3. The extract displayed selective cytotoxicity against AGS cells. The absence of plasma membrane permeabilization, along with apoptotic body formation, suggested that pro-apoptotic effects triggered cell death. Intrinsic apoptosis pathway activation was verified, as mitochondrial membrane potential decrease and activation of caspase-9 and -3 were observed. HPLC-DAD profiling enabled the identification of two apigenin-di-C-glycosides, vicenin-2 (1) and apigenin-6-C-hexoside-8-C-pentoside (3), as well as three mono-C-glycosides-O-glycosylated derivatives, apigenin-7-O-hexoside-8-C-hexoside (2), apigenin-8-C-(2-rhamnosyl)hexoside (4) and apigenin-6-C-(2-rhamnosyl)hexoside (5). Isovitexin-2″-O-rhamnoside (5) is the main constituent, accounting for nearly 40% of the total quantifiable flavonoid content. Our results allowed us to establish the relationship between the presence of vicenin-2 and other apigenin derivatives with the contribution to the cytotoxic effects on the presented AGS cells. Our findings attest the anticancer potential of A. africanus stem bark against gastric adenocarcinoma, calling for studies to develop herbal-based products and/or the use of apigenin derivatives in chemotherapeutic drug development.

4.
Sci Total Environ ; 869: 161705, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36682566

RESUMO

The effective management of species with small and fragmented populations requires an in-depth understanding of how the effects of human-induced habitat disturbance shape the structure and gene flow at fine spatial scales. Identification of putative environmental barriers that affect individual exchange among subpopulations is imperative to prevent extinction risks. Here, we investigated how landscape affects the gene flow and relatedness structure of a population of the endangered lesser horseshoe bat (Rhinolophus hipposideros). We also assessed the effects of sexbiased dispersal on genetic relatedness. We genotyped 287 bat samples collected across southern Portugal and developed resistance surfaces for landscape variables hypothesized to affect gene flow. Then, we used spatially explicit models to fit relatedness distance through the resistance surfaces. We found genetic evidence of sex-biased dispersal and identified a significant fine scale structuring in the relatedness regarding females, the philopatric sex. Males displayed uniform levels of relatedness throughout the landscape. The results indicated less relatedness between the female´ from roosts located on proximity of roads than in roosts away from roads. Also, when analysing the sexes together the relatedness on roosts separated by highway were subtly less related in comparison to those occurring on the same side. Roads seem to be major shapers of the contemporary population structure of females, regardless of being relatively recent structures in the landscape. Furthermore, the relatedness patterns detected suggested that high tree density among roosts and continuity of forest patches in broader surrounding areas, promotes the relatedness among individuals. Landscape heterogeneity among roosts slightly decreases genetic relatedness. Nevertheless, those relationships are still weak, suggesting that population structuring driven by those factors is slowly ongoing. Thus, effective management measures should focus on issues for promoting safe road passages and suitable habitat corridors, allowing for the exchange of individuals and gene flow among lesser horseshoe bat roosts.


Assuntos
Quirópteros , Humanos , Masculino , Animais , Feminino , Quirópteros/genética , Florestas , Ecossistema , Árvores , Fluxo Gênico , Genética Populacional
5.
Food Res Int ; 155: 111082, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35400458

RESUMO

Among several extracts from species from Guinea-Bissauan flora, the hydroethanol extract obtained from the leaves of gingerbread plum (Neocarya macrophylla (Sabine) Prance ex F. White.) revealed to be one of the most cytotoxic towards human gastric AGS carcinoma cells. Considering the increasing use of N. macrophylla in the food industry and the abundant biomass of agricultural wastes being generated, the identification of phenolic bioactives has been attained by HPLC-DAD-ESI/MSn and UHPLC-ESI/QTOF/MSn. Twenty-seven phenolic constituents were identified for the first time in the monotypic genus Neosartorya, 5-O-caffeoylquinic acid being detected as the major constituent (4.90 ± 0.20 mg g-1 dry extract). While 15 flavan-3-ols derivatives were determined, the extract is predominantly characterized by the occurrence of quercetin, kaempferol, apigenin and chrysoeriol glycosides. Typical apoptotic changes in gastric adenocarcinoma AGS cells upon exposure to N. macrophylla leaf extract were observed. The apoptotic cell death is mediated by the activation of the mitochondrial pathway, as loss of mitochondrial membrane potential was detected, as well as increased caspase-9 and -3 activities. The industrial relevance of this plant material, along with the data presented here on the potential anticancer effects of N. macrophylla and the efficient extraction of phenolic bioactives using water and ethanol (GRAS substance), calls for further research on the leaves as a potential functional food and/or ingredient.


Assuntos
Carcinoma , Chrysobalanaceae , Cromatografia Líquida de Alta Pressão , Humanos , Fenóis/análise , Fenóis/farmacologia , Extratos Vegetais/farmacologia , Polifenóis/farmacologia , Espectrometria de Massas por Ionização por Electrospray
6.
Int J Sex Health ; 34(4): 567-576, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-38596387

RESUMO

Objective: Repetitive negative thinking (RNT) is a transdiagnostic process involved in the development and maintenance of emotional disorders that negatively affect sexual functioning. However, empirical evidence for the role of RNT on sexual functioning is still lacking. The current study aimed to investigate the role of RNT on sexual functioning in men and women by examining differences in RNT between men and women and between individuals with and without subclinical sexual difficulties. It also aimed to investigate the predictive role of RNT on sexual function indices in men and women. Methods: A total of 424 participants (270 women) completed online a sociodemographic questionnaire and Portuguese versions of the Persistent and Intrusive Negative Thoughts Scale, the Female Sexual Functioning Index, and the International Index of Erectile Function. Results: The main findings showed that women scored significantly higher than men on the RNT. Similarly, individuals with subclinical sexual difficulties scored significantly higher on the RNT compared with individuals without sexual difficulties. RNT was a statistically significant and negative predictor of sexual functioning in women and men. The role of RNT on sexual functioning in women and men was found, with men and women with subclinical sexual difficulties more likely to express persistent and intrusive negative thoughts compared with men and women without sexual difficulties. Conclusions: In summary, RNT appears to be a negative predictor of sexual functioning in both women and men, suggesting that individuals with more intrusive and negative persistent thoughts also have more difficulty in their sexual response.

7.
Food Res Int ; 141: 110121, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33641988

RESUMO

While the fruits of Xylopia aethiopica (Dunal) A. Rich. are important in African countries as a local trade product, their composition remains scarcely investigated. Phenolic fingerprint is herein delivered through HPLC-DAD-ESI(Ion Trap)-MSn and UPLC-ESI-QTOF-MS2 analysis, six cinnamoylquinic acid derivatives and twenty-four flavonoid glycosides being determined, chrysoeriol-7-O-glycosides being the main constituents. A cytotoxicity screening of twenty-eight hydroethanol extracts, obtained from a collection of Guinea-Bissauan plants, against A549 and AGS carcinoma cells, revealed the selective and potent effect towards AGS cells (IC50 = 151 × 10-3 g L-1), upon exposure to the extract from X. aethiopica fruits. Additional experiments demonstrated insignificant effect on LDH release at 151 × 10-3 g L-1, morphological analysis further suggesting induction of apoptosis. Pro-apoptotic effects were confirmed, as the extract enabled the activation of the effector caspase-3, broadening the knowledge on the anticancer mechanisms elicited by the fruits of X. aethiopica. Phenolic constituents might contribute to the cytotoxic effects, particularly via caspase-3 activation. Considering that X. aethiopica fruit is very often referred as an anticancer ingredient in Africa, but mainly the potent cytotoxicity herein recorded, our results call for additional research aiming to identify non-phenolic constituents contributing to the effects and also to further detail the anticancer mechanisms.


Assuntos
Adenocarcinoma , Xylopia , África , Caspase 3 , Cromatografia Líquida de Alta Pressão , Frutas , Extratos Vegetais/farmacologia , Neoplasias Gástricas
8.
J Ethnopharmacol ; 248: 112312, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31629028

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Ethnopharmacological surveys on Guinea-Bissauan flora reveal that several species are used to treat or ameliorate the symptomatology of conditions with an inflammatory background. As such, extracts obtained from a series of plants recorded in those surveys were screened for their anti-inflammatory properties, a hydroethanolic extract obtained from the leaves of Xylopia aethiopica (Dunal) A. Rich, (Annonaceae), used on the treatment of headache, muscular pain and rheumatic pain, scoring positively and being further investigated. AIM OF THE STUDY: In order to identify species with anti-inflammatory properties, extracts were screened for their ability to interfere with LPS-induced TNF-α levels. Since significant effects were recorded upon treatment with the extract of the leaves obtained from X. aethiopica, further assays were conducted to elucidate additional mechanisms underlying its anti-inflammatory potential. Since little is known on the chemical composition of the plant, we also aimed to characterise its phenolic profile. MATERIALS AND METHODS: Interference with cytokines was evaluated by ELISA assay, through the quantification of TNF-α and IL-6 levels in the culture medium collected from LPS-activated THP-1-derived-macrophages. Inhibition of 5-lipoxygenase was assessed based on the oxidation of linoleic acid to 13-hydroperoxylinoleic acid. Characterization of the phenolic profile was attained by HPLC-DAD. RESULTS: Evaluation of TNF-α levels in LPS-challenged THP-1 macrophages evidenced a significant inhibition (>90%) upon treatment with the hydroethanolic extract obtained from X. aethiopica leaves at a concentration of 500 µg/mL. Additional anti-inflammatory effects were recorded, including a significant decrease on IL-6 levels at 250 and 500 µg/mL. The extract proved to be active towards 5-LOX, leading to significant inhibition at concentrations ranging from 16 to 250 µg/mL (IC50 = 85 µg/mL). Phenolic profiling allowed the identification and quantitation of eight constituents, including caffeoylquinic acids (1-3), mono-O-glycosylated flavonols (5-8), and the mono-O-glycosyl flavone luteolin-7-O-glucoside (4). The main phenolic constituent, kaempferol-3-O-rutinoside (8), was found to significantly contribute to the anti-inflammatory effects, namely through the inhibition of 5-LOX. However, no effects on the decrease of TNF-α and IL-6 levels caused by this phenolic compound were found. CONCLUSION: The anti-inflammatory effects of X. aethiopica leaves are demonstrated experimentally, thus substantiating its use in folk Medicine. Relevantly, the observed anti-inflammatory properties can stimulate further studies in order to fully unveil the therapeutic potential of the plant, namely as a source of phenolic compounds with a significant ability to interfere with conventional inflammatory targets.


Assuntos
Anti-Inflamatórios/farmacologia , Flavonoides/farmacologia , Mediadores da Inflamação/metabolismo , Interleucina-6/metabolismo , Macrófagos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Folhas de Planta , Fator de Necrose Tumoral alfa/metabolismo , Xylopia , Anti-Inflamatórios/isolamento & purificação , Araquidonato 5-Lipoxigenase/metabolismo , Flavonoides/isolamento & purificação , Humanos , Lipopolissacarídeos/toxicidade , Macrófagos/metabolismo , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Células THP-1 , Xylopia/química
10.
Clin. biomed. res ; 40(3): 154-160, 2020. tab, graf
Artigo em Português | LILACS | ID: biblio-1247796

RESUMO

Introdução: embora, no Brasil, muito tenha sido feito para estimular a criação e manutenção de programas de pós-graduação ainda há carência de meios para avaliar e para mensurar a evolução profissional dos egressos. O objetivo é compreender a trajetória dos Doutores formados pelo Programa de Pós-Graduação em Medicina Ciências Médicas (PPGCM), Faculdade de Medicina, Universidade Federal do Rio Grande do Sul (UFRGS) e propor um índice de desempenho acadêmico e de inserção profissional. Métodos: foi realizado um estudo transversal. Foram coletados dados dos Currículos Lattes dos egressos de doutorado do Programa de Pós-Graduação em Medicina: Ciências Médicas (PPGCM), no período de 1987 a 2014. Foram extraídos apenas os dados pertinentes a sua origem, curso de graduação e de mestrado, produção intelectual, inserção acadêmica e a posição profissional. Resultados: foram analisados 324 doutores egressos, 221 eram graduados em Medicina. Foram utilizadas as variáveis: graduação em medicina, vínculo laboral em universidade pública, exerce atividade como orientador em nível de doutorado, exerce atividade como orientador em nível de mestrado, bolsista de produtividade em pesquisa do CNPq e possui registro do índice H no currículo Lattes. O coeficiente de determinação (R2) demonstrou que as variáveis incluídas no modelo explicam 99% do modelo hierárquico. Conclusão: os resultados demonstram que os egressos têm contribuído para a construção de conhecimento qualificado disseminado em jornais de circulação internacional, formação de recursos humanos, interagir e criar parcerias em seu ambiente de trabalho, gerenciar e repassar o conhecimento, bem como para fomentar o conhecimento na área das ciências médicas com relevância regional, nacional e internacional. (AU)


Introduction: Although, in Brazil, much has been done to encourage the creation and maintenance of graduate programs, there remains a lack of means to assess and measure the professional outcomes of graduates. The objective is to understand the trajectory of doctoral graduates from the Graduate Program in Medicine: Medical Sciences (PPGCM), School of Medicine, Universidade Federal do Rio Grande do Sul (UFRGS), and propose an index for academic performance and professional placement. Methods: A cross-sectional study was conducted. Data available at CV Lattes database of the National Council for Scientific and Technological Development (CNPq) were collected on doctoral graduates from the PPGCM, from 1987 to 2014. Only data pertaining to their origin, undergraduate and master's degrees, intellectual output, academic performance, and professional placement were retrieved. Results: Data on 324 doctoral graduates were analyzed, 221 had graduated in medicine. Undergraduate degree, employment at a public university, working as a doctoral-level advisor, working as a master's-level advisor, CNPq research productivity grantee, and having a recorded h-index in the Lattes curriculum were collected. The coefficient of determination (R 2 ) demonstrated that the variables included in the model explain 99% of the hierarchical model. Conclusion: The results show that the graduates have contributed to developing qualified knowledge disseminated in international newspapers, training human resources, interacting and creating partnerships in the workplace, managing and passing on knowledge, as well as fostering knowledge in the area of medical sciences with regional, national, and international relevance. (AU)


Assuntos
Universidades , Desempenho Acadêmico , Médicos/estatística & dados numéricos , Educação Médica , Avaliação Educacional , Atividades Científicas e Tecnológicas
11.
Phytomedicine ; 63: 153017, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31325684

RESUMO

BACKGROUND: The roots and tubers of several species of the Cyperus genus are used in several parts of the world as foodstuffs and beverages. The genus is rich in several classes of quinones, however their biological properties have not been studied before. PURPOSE: We evaluated the anticancer effect of several benzoquinones isolated from the genus and described their mechanism of action towards cancer cells. METHODS: The most potent molecules were selected according to their effect upon cell viability. The mechanism of cell death was studied by using pharmacological inhibitors of caspases, caspase-3/4/9 activity assays, annexin-V/7-AAD by flow cytometry and intracellular reactive oxygen species and calcium levels through fluorescence spectroscopy. Elucidation of the involvement of distinct branches of the ER stress pathway was pursued by RT-PCR and WB for mRNA and protein expression levels, respectively, as well as pharmacological inhibitors. Proteasome inhibitory activity was assessed by using purified 20S catalytic subunit with the fluorogenic substrate Suc-Leu-Leu-Val-Tyr-AMC. RESULTS: Cytotoxicity studies against cancer cell lines showed that the human gastric cancer cell line AGS was the most susceptible, the most potent molecule, hydroxycyperaquinone, exhibiting an IC50 close to 1 µM. Morphological and biochemical traits suggested that a process of regulated cell death was taking place, which was shown to be intrinsic pathway-independent. Results indicated that benzoquinones exert their toxicity by triggering ER stress, as shown by increased expression of CHOP (mRNA and protein levels), intracellular reactive oxygen species, changes in calcium dynamics and caspase-4 activation. Proteasome inhibition by these molecules is described for the first time. CONCLUSION: Hydroxycyperaquinone is a novel sub-micromolar inhibitor of the 20S catalytic core of the 26S proteasome, causing cell death via IRE1α-independent/PERK-dependent pathways in stomach cancer cells. Its presence in products consumed orally may be of relevance for gastric tumors.


Assuntos
Benzoquinonas/farmacologia , Cyperus/química , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Inibidores de Proteassoma/farmacologia , Neoplasias Gástricas/tratamento farmacológico , Células A549 , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Endorribonucleases/metabolismo , Humanos , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Sesquiterpenos/farmacologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , eIF-2 Quinase/metabolismo
12.
Sci Total Environ ; 660: 340-347, 2019 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-30640102

RESUMO

The effects of roads on bats are still a poorly documented issue. Most of the available research focuses on large and high-traffic highways, while low-medium-traffic roads are often assumed to have negligible impacts. However, small roads are ubiquitous in landscapes around the world. We examined the effects of these roads, as well as habitat types, on the activity of three bat guilds (short-, mid- and long-range echolocators) and the most common bat species Pipistrellus kuhlii. We performed three bat acoustic surveys between May and October 2015, with these surveys being performed along twenty transects that were each 1000 m long and perpendicular to three roads with different traffic volumes. The surveys were performed in dense Mediterranean woodland ("montado") and open agricultural field habitats, which were the two dominant land uses. At each transect, bat activity was simultaneously registered at 0, 50, 100, 200, 500 and 1000 m from the road with the use of an ultrasound recorder. According to the generalized linear mixed effects models, the overall activity of bats and of the short- and mid-range echolocators increased with increased distance from the roads and was dependent on the surrounding habitats. In contrast, the long-range echolocators and P. kuhlii were more tolerant to road. Our results also show that the activity was higher in woodland areas, however road verges seem to be a significant habitat in an open agricultural landscape. The major negative effects extended to approximately 300 m from the roads in woodlands and penetrate further into the open field (>500 m). The management of roadside vegetation, combined with the bat habitat improvement in areas that are further from the roads, may mitigate the negative effects. To make road-dominated landscapes safer for bats, the transport agencies need to balance the trade-offs between habitat management and road kill risk.


Assuntos
Quirópteros/fisiologia , Ecossistema , Comportamento Alimentar , Animais , Portugal
13.
Artigo em Inglês | MEDLINE | ID: mdl-27881056

RESUMO

BACKGROUND: The proteasome is the major proteolytic site on the eukaryotic cell, degrading most of its short-lived or misfolded polypeptides. The ubiquitin-proteasome pathway has been found to play a fundamental role in the development of several pathologies, from cancer to neurodegenerative diseases, or even retroviral infections. Nature remains a powerful source for the discovery of bioactive compounds. Recently, a number of molecules of natural origin, as well as natural product derivatives, have been described as proteasome inhibitors. Most of these molecules directly block one or more catalytic sites of the 20S proteasome, but some of them act upstream of proteolytic degradation, for instance, inhibiting the ubiquitin tagging process. OBJECTIVES: The present review focuses on recent patents on proteasome inhibitors of natural origin, their derivatives and synthetic routes to obtain such molecules, as well as their application as a tool in chemotherapy. CONCLUSION: With several of these modulators of the ubiquitin-proteasome system under clinical trials, we hope that the next few years lead to the development of new pharmaceutical drugs and characterization of new proteasome inhibitors of natural origin or inspiration.


Assuntos
Produtos Biológicos/uso terapêutico , Patentes como Assunto , Inibidores de Proteassoma/uso terapêutico , Ubiquitina/antagonistas & inibidores , Animais , Produtos Biológicos/metabolismo , Produtos Biológicos/farmacologia , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Inibidores de Proteassoma/metabolismo , Inibidores de Proteassoma/farmacologia , Ubiquitina/metabolismo
14.
J Inorg Biochem ; 147: 165-76, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25958839

RESUMO

The nuclease activity of VO(acac)2 (1, acac = acetylacetone) and its derivatives VO(hd)2 (2, hd = 3,5-heptanedione), VO(Cl-acac)2 (3, Cl-acac = 3-chloro-2,4-pentanedione), VO(Et-acac)2 (4, Et-acac = 3-ethyl-2,4-pentanedione) and VO(Me-acac)2 (5, Me-acac = 3-methyl-2,4-pentanedione), is studied by agarose gel electrophoresis, UV-visible spectroscopy, cyclic and square wave voltammetry and (51)V NMR. The mechanism is shown to be oxidative and associated with the formation of reactive oxygen species (ROS). Hydrolytic cleavage of the phosphodiester bond is also promoted by 1, but at much slower rate which cannot compete with the oxidative mechanism. The generation of ROS is much higher in the presence of phosphate buffer when compared with organic buffers and this was attributed to the formation of a mixed-ligand complex containing phosphate, (V(IV)O)(V(V)O)(acac)2(HnPO4(n-3)), presenting a quasi-reversible voltammetric behavior. The formation of this species was further observed by Electrospray Ionization Mass Spectrometry (ESI-MS). Phosphate being an essential species in most biological media, the importance of the formation of mixed-ligand species in other vanadium systems is emphasized.


Assuntos
DNA/química , Fosfatos/química , Compostos de Vanádio/química , Hidrólise , Oxirredução , Espécies Reativas de Oxigênio/química
15.
Org Biomol Chem ; 13(10): 2866-9, 2015 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-25581012

RESUMO

Cucurbiturils (CB6 and CB7) were shown to inhibit the enzymatically catalyzed restriction of plasmids and linear DNA. This effect can be inverted by supramolecular masking of the macrocycles through competitive complexation with polyamines. These experiments provide supramolecular control of biocatalytic processes.


Assuntos
DNA/antagonistas & inibidores , DNA/química , Endonucleases/química , Inibidores Enzimáticos/farmacologia , Compostos Macrocíclicos/química , Animais , Ligação Competitiva , Catálise , Bovinos , DNA Super-Helicoidal/química , Inibidores Enzimáticos/química , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Peptídeos/química , Plasmídeos/metabolismo , Poliaminas/química
16.
Mol Metab ; 4(12): 891-902, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26909306

RESUMO

OBJECTIVE: Farnesoid X receptor (FXR) plays a prominent role in hepatic lipid metabolism. The FXR gene encodes four proteins with structural differences suggestive of discrete biological functions about which little is known. METHODS: We expressed each FXR variant in primary hepatocytes and evaluated global gene expression, lipid profile, and metabolic fluxes. Gene delivery of FXR variants to Fxr(-/-) mouse liver was performed to evaluate their role in vivo. The effects of fasting and physical exercise on hepatic Fxr splicing were determined. RESULTS: We show that FXR splice isoforms regulate largely different gene sets and have specific effects on hepatic metabolism. FXRα2 (but not α1) activates a broad transcriptional program in hepatocytes conducive to lipolysis, fatty acid oxidation, and ketogenesis. Consequently, FXRα2 decreases cellular lipid accumulation and improves cellular insulin signaling to AKT. FXRα2 expression in Fxr(-/-) mouse liver activates a similar gene program and robustly decreases hepatic triglyceride levels. On the other hand, FXRα1 reduces hepatic triglyceride content to a lesser extent and does so through regulation of lipogenic gene expression. Bioenergetic cues, such as fasting and exercise, dynamically regulate Fxr splicing in mouse liver to increase Fxrα2 expression. CONCLUSIONS: Our results show that the main FXR variants in human liver (α1 and α2) reduce hepatic lipid accumulation through distinct mechanisms and to different degrees. Taking this novel mechanism into account could greatly improve the pharmacological targeting and therapeutic efficacy of FXR agonists.

17.
Rev. nutr ; 26(4): 397-406, July-Aug. 2013. graf, tab
Artigo em Inglês | LILACS-Express | LILACS | ID: lil-687378

RESUMO

OBJECTIVE: This study determined the sodium content of processed foods aimed at children and adolescents and the adequacy of its content in relation to the dietary reference intakes, and verified label compliance. METHODS: The sodium content of 17 food samples (instant noodles, breaded items, hamburger patties, hot dogs and bologna sausages) was determined by flame photometry and chloride titration, and the results were compared with nutritional data. The labels were checked for compliance with the pertinent laws. RESULTS: According to flame photometry and chloride titration, 13 and 5 products, respectively, had sodium contents that exceeded those reported on the nutrition facts label by more than 20%. All samples had more than 480mg of sodium per serving. The tolerable upper intake level for sodium for children aged 4-8 years was exceeded in 8 instant noodles and 3 breaded items according to flame photometry, and in 9 items according to chloride titration. Regarding the legislation, 5 products used a daily reference intake other than that provided by the legislation to report their percent sodium content per serving. Moreover, the serving sizes of 3 instant noodles, the terminology used in 1 instant noodles and the protein content of 1 breaded item were also not compliant with the legislation. CONCLUSION: The sodium contents in the study samples were high and there was no regard for the legislation.


OBJETIVO: Determinar o teor de sódio em alimentos processados voltados para crianças e adolescentes, averiguar a adequação do teor encontrado em relação aos níveis de ingestão dietética de referência e verificar a conformidade das informações veiculadas na rotulagem. MÉTODOS: Análise experimental do teor de sódio em 17 amostras (massa instantânea, empanado, hambúrguer, salsicha e mortadela) pela fotometria de chama e determinação de cloretos por volumetria. Os resultados foram comparados aos dados das informações nutricionais. A conformidade da rotulagem foi verificada a partir das legislações pertinentes. RESULTADOS: Houve variação maior que 20% entre o teor de sódio analisado e o declarado em 13 produtos pela fotometria de chama, e em 5, pela volumetria. Todas as amostras apresentaram mais de 480mg de sódio/porção e o limite de ingestão adequada para crianças de 4 a 8 anos foi ultrapassado, pela fotometria, nas 8 massas instantâneas e em 3 empanados. Pela volumetria, a oferta de sódio ultrapassa os níveis de ingestão recomendados para crianças entre 4 e 8 anos em 9 amostras analisadas. Em relação à legislação: 5 amostras apresentaram desacordos nos percentuais de referência estabelecidos; a regulamentação das porções dos alimentos foi descumprida por 3 massas instantâneas; 1 produto dessa categoria utilizou-se de denominação incorreta; e 1 empanado apresenta teor proteico menor que o estabelecido. CONCLUSÃO: Verificou-se elevado teor de sódio nos alimentos e desrespeito às legislações vigentes.

18.
Anticancer Res ; 33(6): 2549-55, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23749907

RESUMO

We aimed to study the prevalence of Hypoxia inducible factor-1α (HIF-1α) P582S and A588T polymorphisms in a Portuguese breast cancer population and its effect on the transcriptional activity of HIF-1α in MCF7 breast adenocarcinoma cells. We performed a polymerase chain Reaction--restriction fragment length polymorphism (PCR-RFLP)-based genotyping of a Portuguese breast cancer population for two HIF-1α polymorphisms. Furthermore, by site-directed mutagenesis, we generated a variant form of HIF-1α and compared its transcriptional activity with the wild-type HIF-1α in MCF7 cells. There were no significant differences in genotypic frequencies for P582S and A588T between breast cancer patients and controls, nor between the transcriptional activity of the 582S mutant and the wild-type HIF-1α. In conclusion, there is no association between HIF-1α polymorphisms and incidence of breast cancer in the Portuguese examined population. Furthermore, the P582S mutation does not affect transcriptional activity of HIF-1α in breast cancer cells, contrary to previous findings in other cell lines, suggesting that the impact of this mutation is cell-type specific.


Assuntos
Neoplasias da Mama/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Transcrição Gênica , Ativação Transcricional , Linhagem Celular Tumoral , Feminino , Frequência do Gene , Genótipo , Humanos , Pessoa de Meia-Idade , Mutagênese Sítio-Dirigida , Polimorfismo de Nucleotídeo Único , Portugal
20.
Braz. arch. biol. technol ; 55(4): 613-621, July-Aug. 2012. ilus, tab
Artigo em Inglês | LILACS | ID: lil-645415

RESUMO

The aim of this work was to study the influence of essential oil fractionation on acaricidal activity against the cattle tick Rhipicephalus (Boophilus) microplus. The citronella (Cymbopogon winterianus J.) and pepper tree (Schinus molle L.) essential oils were fractionated by vacuum distillation yielding fractions that were analyzed by the GC/MS. Laboratory tests were carried out to determine the effect of the total essential oil and fractions on larvae of the cattle tick R. (B.) microplus. The fractions 04 and 05 of the C. winterianus essential oil were the most active showing LC50 values of 1.20 and 1.34 μL/mL, respectively. The LC50 of the total oil was 3.30 μL/mL while the effect of the fractions 01, 02 and 03 was less pronounced, with LC50 values of 4.37, 4.24 and 3.49 μL/mL, respectively. The fraction 03 of the S. molle essential oil was the most active showing LC50 value of 8.80 μL/mL while the fractions 01 and 02 did not show toxic effects on the larvae.

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