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1.
J Oral Pathol Med ; 2024 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-39192690

RESUMO

BACKGROUND: Ameloblastoma is a locally destructive benign odontogenic tumor. While the neoplastic cells of conventional ameloblastoma can infiltrate the connective tissue and bone, in unicystic ameloblastoma the epithelium is encapsulated. The mechanisms driving ameloblastoma's bone resorption remains unclear. METHODS: RNA sequencing (RNA-seq) was performed in a discovery cohort of conventional ameloblastoma, and pathway enrichment analysis was carried out. mRNA levels of MMP13, a gene associated with bone resorption, were assessed using RT-qPCR in a larger cohort of conventional ameloblastoma and in unicystic ameloblastoma. Zymogram gels and the immunoexpression profile of collagenase 3 (encoded by MMP13 gene) were evaluated as well. RESULTS: Enriched pathways related to bone mineralization and upregulation of MMP13 were observed in ameloblastomas. Collagenolytic activity of collagenase 3 was detected in the tumor lysates. Collagenase 3 immunopositivity was observed in ameloblastomatous epithelium infiltrating the fibrous capsule of unicystic ameloblastoma. At the tumor-bone interface, collagenase 3 expression was detected in stromal cells, osteoblasts, and osteocytes. CONCLUSION: The results indicate a potential involvement of MMP13 in ameloblastoma-related bone resorption and progression.

2.
Nature ; 563(7730): 230-234, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30374193

RESUMO

In recent years, artificial neural networks have become the flagship algorithm of artificial intelligence1. In these systems, neuron activation functions are static, and computing is achieved through standard arithmetic operations. By contrast, a prominent branch of neuroinspired computing embraces the dynamical nature of the brain and proposes to endow each component of a neural network with dynamical functionality, such as oscillations, and to rely on emergent physical phenomena, such as synchronization2-6, for solving complex problems with small networks7-11. This approach is especially interesting for hardware implementations, because emerging nanoelectronic devices can provide compact and energy-efficient nonlinear auto-oscillators that mimic the periodic spiking activity of biological neurons12-16. The dynamical couplings between oscillators can then be used to mediate the synaptic communication between the artificial neurons. One challenge for using nanodevices in this way is to achieve learning, which requires fine control and tuning of their coupled oscillations17; the dynamical features of nanodevices can be difficult to control and prone to noise and variability18. Here we show that the outstanding tunability of spintronic nano-oscillators-that is, the possibility of accurately controlling their frequency across a wide range, through electrical current and magnetic field-can be used to address this challenge. We successfully train a hardware network of four spin-torque nano-oscillators to recognize spoken vowels by tuning their frequencies according to an automatic real-time learning rule. We show that the high experimental recognition rates stem from the ability of these oscillators to synchronize. Our results demonstrate that non-trivial pattern classification tasks can be achieved with small hardware neural networks by endowing them with nonlinear dynamical features such as oscillations and synchronization.

3.
Chem Res Toxicol ; 36(1): 66-82, 2023 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-36548215

RESUMO

Cancer incidence is increasing, and the drugs are not very selective. These drugs cause adverse effects, and the cells become resistant. Therefore, new drugs are needed. Here, we evaluated the effects of ZIM, a candidate for chemotherapy, and 4-AA alone and in association with commercial chemotherapeutic agents. Subsequently, the results of ZIM and 4-AA were compared. Male Swiss mice were treated with doses of 12, 24, or 48 mg/kg ZIM or 4-AA alone or in association with cisplatin (6 mg/kg), doxorubicin (16 mg/kg), and cyclophosphamide (100 mg/kg). Biometric parameters, DNA damage (comet and micronuclei), cell death, and splenic phagocytosis were evaluated. DNA docking was also performed to confirm the possible interactions of ZIM and 4-AA with DNA. 4-AA has been shown to have low genotoxic potential, increase the frequency of cell death, and activate phagocytosis. ZIM causes genomic and chromosomal damage in addition to causing cell death and activating phagocytosis. In association with chemotherapeutical agents, both 4-AA and ZIM have a chemopreventive effect and, therefore, reduce the frequency of DNA damage, cell death, and splenic phagocytosis. The association of 4-AA and ZIM with commercial chemotherapeutic agents increased the frequency of lymphocytes compared to chemotherapeutic agents alone. Molecular docking demonstrated that ZIM has more affinity for DNA than 4-AA and its precursors (1 and 2). This was confirmed by the lower interaction energy of the complex (-119.83 kcal/mol). ZIM can break the DNA molecule and, therefore, its chemotherapeutic effect can be related to DNA damage. It is considered that ZIM has chemotherapeutic potential. However, it should not be used in combination with cisplatin, doxorubicin, and cyclophosphamide as it reduces the effects of these drugs.


Assuntos
Antineoplásicos , Cisplatino , Camundongos , Animais , Masculino , Cisplatino/toxicidade , Ampirona/farmacologia , Simulação de Acoplamento Molecular , Morte Celular , Ciclofosfamida/farmacologia , Doxorrubicina/farmacologia , Dano ao DNA , DNA , Norbornanos/farmacologia , Antineoplásicos/toxicidade
4.
Nature ; 547(7664): 428-431, 2017 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-28748930

RESUMO

Neurons in the brain behave as nonlinear oscillators, which develop rhythmic activity and interact to process information. Taking inspiration from this behaviour to realize high-density, low-power neuromorphic computing will require very large numbers of nanoscale nonlinear oscillators. A simple estimation indicates that to fit 108 oscillators organized in a two-dimensional array inside a chip the size of a thumb, the lateral dimension of each oscillator must be smaller than one micrometre. However, nanoscale devices tend to be noisy and to lack the stability that is required to process data in a reliable way. For this reason, despite multiple theoretical proposals and several candidates, including memristive and superconducting oscillators, a proof of concept of neuromorphic computing using nanoscale oscillators has yet to be demonstrated. Here we show experimentally that a nanoscale spintronic oscillator (a magnetic tunnel junction) can be used to achieve spoken-digit recognition with an accuracy similar to that of state-of-the-art neural networks. We also determine the regime of magnetization dynamics that leads to the greatest performance. These results, combined with the ability of the spintronic oscillators to interact with each other, and their long lifetime and low energy consumption, open up a path to fast, parallel, on-chip computation based on networks of oscillators.

5.
Molecules ; 28(3)2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36770711

RESUMO

3-heptylidene-4,6-dimethoxy-3H-isobenzofuran-1-one (Phthalide 1) is the precursor of three resorcinol lipids that have been described as potential chemotherapeutic agents and capable of potentiating the effects of cyclophosphamide. In this study, we evaluated the genotoxic potential, cell-killing potential, and interactions with cyclophosphamide and cisplatin of phthalide 1. Twelve groups were created from 120 mice: Negative Control, cyclophosphamide (100 mg/kg), cisplatin (6 mg/kg), Phthalide 1 (5, 10 and 20 mg/kg), and associations of 1 with cyclophosphamide and 1 with cisplatin. The results demonstrate that 1 increases (p < 0.05) the frequency of chromosomal damage, liver and kidney cell death, and splenic phagocytosis. The association of 1 with cyclophosphamide and cisplatin demonstrated a chemopreventive effect and, therefore, a reduction (p < 0.05) in the frequency of chromosomal damage. However, cell death and splenic phagocytosis did not suffer significant variations. As a result of the above, 1 has potential chemotherapeutic application and may be a candidate for developing a new generation of chemotherapeutics. In addition, it has characteristics to be used as a chemotherapy adjuvant in association with cyclophosphamide and cisplatin since it increases the frequency of cell death induced by chemotherapy. We also reported that the chemopreventive effect of 1, in association with cyclophosphamide and cisplatin, can prevent adverse effects (induction of DNA damage in non-tumor cells) without interfering with the mode of action of chemotherapy drugs and, therefore, without reducing the induction of cell death.


Assuntos
Anticarcinógenos , Antineoplásicos , Camundongos , Animais , Cisplatino/efeitos adversos , Antineoplásicos/toxicidade , Ciclofosfamida/toxicidade , Apoptose , Dano ao DNA , Anticarcinógenos/farmacologia
6.
Drug Chem Toxicol ; 45(4): 1504-1521, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33252270

RESUMO

Pachira aquatica is a species used for medicinal and food purposes and has numerous phytochemicals that may have systemic toxic effects and damage to genetic material. This study aimed to evaluate acute and short-term oral toxicity, as well as genotoxic and clastogenic effects of oil extracted from P. aquatica (PASO) seeds in rats and Drosophila melanogaster. The results obtained with biochemical and hematological analyses did not show significant changes in any evaluated parameters when compared with reference values for the species used in the study. Data from the histopathological analysis corroborated results found in this study. These findings indicate low acute and short-term toxicity following oral PASO exposure in rats under the experimental conditions tested. Tests performed in rats showed that PASO did not present significant genotoxic or clastogenic effects on the cells analyzed with the three doses tested. Treatment with PASO in the offspring of HB crossing, which showed high cytochrome P450 levels, did not exhibit genotoxic activity, as demonstrated by the SMART test. These results suggest that products from the hepatic oil metabolism did not show genotoxicity under the conditions tested. Together, the results indicate that, under the experimental conditions tested, PASO is safe for repeated intake. As PASO exhibited low potential to cause harmful effects on living organisms, our study encourages further research aimed at assessing its pharmacological activity, since it is a widely consumed plant.


Assuntos
Bombacaceae , Malvaceae , Animais , Drosophila melanogaster , Mutagênicos/química , Extratos Vegetais/farmacologia , Ratos , Sementes , Testes de Toxicidade Aguda
7.
Sensors (Basel) ; 21(9)2021 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-33923209

RESUMO

Leukaemia is a dysfunction that affects the production of white blood cells in the bone marrow. Young cells are abnormally produced, replacing normal blood cells. Consequently, the person suffers problems in transporting oxygen and in fighting infections. This article proposes a convolutional neural network (CNN) named LeukNet that was inspired on convolutional blocks of VGG-16, but with smaller dense layers. To define the LeukNet parameters, we evaluated different CNNs models and fine-tuning methods using 18 image datasets, with different resolution, contrast, colour and texture characteristics. We applied data augmentation operations to expand the training dataset, and the 5-fold cross-validation led to an accuracy of 98.61%. To evaluate the CNNs generalisation ability, we applied a cross-dataset validation technique. The obtained accuracies using cross-dataset experiments on three datasets were 97.04, 82.46 and 70.24%, which overcome the accuracies obtained by current state-of-the-art methods. We conclude that using the most common and deepest CNNs may not be the best choice for applications where the images to be classified differ from those used in pre-training. Additionally, the adopted cross-dataset validation approach proved to be an excellent choice to evaluate the generalisation capability of a model, as it considers the model performance on unseen data, which is paramount for CAD systems.


Assuntos
Aprendizado Profundo , Leucemia , Humanos , Leucemia/diagnóstico , Redes Neurais de Computação
8.
Trop Anim Health Prod ; 53(6): 524, 2021 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-34705124

RESUMO

Whole genome sequencing of bovine breeds has allowed identification of genetic variants in milk protein genes. However, functional repercussion of such variants at a molecular level has seldom been investigated. Here, the results of a multistep Bioinformatic analysis for functional characterization of recently identified genetic variants in Brazilian Gyr and Guzerat breeds is described, including predicted effects on the following: (i) evolutionary conserved nucleotide positions/regions; (ii) protein function, stability, and interactions; (iii) splicing, branching, and miRNA binding sites; (iv) promoters and transcription factor binding sites; and (v) collocation with QTL. Seventy-one genetic variants were identified in the caseins (CSN1S1, CSN2, CSN1S2, and CSN3), LALBA, LGB, and LTF genes. Eleven potentially regulatory variants and two missense mutations were identified. LALBA Ile60Val was predicted to affect protein stability and flexibility, by reducing the number the disulfide bonds established. LTF Thr546Asn is predicted to generate steric clashes, which could mildly affect iron coordination. In addition, LALBA Ile60Val and LTF Thr546Asn affect exonic splicing enhancers and silencers. Consequently, both mutations have the potential of affecting immune response at individual level, not only in the mammary gland. Although laborious, this multistep procedure for classifying variants allowed the identification of potentially functional variants for milk protein genes.


Assuntos
Caseínas , Proteínas do Leite , Animais , Bovinos/genética , Simulação por Computador , Mutação , Regiões Promotoras Genéticas
9.
Drug Chem Toxicol ; 43(2): 200-207, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30044655

RESUMO

Tea leaves of Alibertia edulis is popularly used in folk medicine. However, studies on the genotoxicity of this plant are not available. We aimed to investigate the in vivo and in vitro cytotoxic, genotoxic and mutagenic potentials of the aqueous extract of A. edulis leaves (AEAE). Antioxidant assays, the Artemia salina test, MTT in human platelets, micronucleus in bone marrow and comet in peripheral blood were performed. Animals received four different doses of the AEAE by oral gavage for 30 days. Saline and cyclophosphamide were used as controls. The AEAE exhibited a maximal inhibition at 100 and 250 µg/mL, according to the ABTS and DPPH methods, respectively. The A. salina assay showed that the AEAE presented some toxicity at doses of 100, 250 and 500 µg/mL. Through the MTT assay, the AEAE showed no toxic effects on human platelets during the incubation period. The alkaline comet assay showed that all doses of the AEAE were statistically similar to the negative control group since they did not induce any significant increase of the overall number of damaged cells nor the severity of the cell damage. In the micronucleous assay, results demonstrate that the AEAE did not increase the production of micronucleated polychromatic erythrocytes and was statistically similar to the negative control. The four doses of the plant extract did not affect the production of new erythrocytes and were statistically similar to the negative control groups. Furthermore, the AEAE demonstrated no cytotoxicity, genotoxicity and mutagenicity at the doses tested in rats.


Assuntos
Eritrócitos/efeitos dos fármacos , Extratos Vegetais/toxicidade , Rubiaceae/química , Animais , Brasil , Ensaio Cometa , Relação Dose-Resposta a Droga , Eritrócitos/metabolismo , Feminino , Humanos , Masculino , Testes para Micronúcleos , Testes de Mutagenicidade , Extratos Vegetais/administração & dosagem , Folhas de Planta , Ratos , Ratos Wistar
10.
J Strength Cond Res ; 34(4): 1001-1007, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29985228

RESUMO

Melo, KCB, Araújo, FdS, Cordeiro Júnior, CCM, de Andrade, KTP, and Moreira, SR. Pilates method training: Functional and blood glucose responses of older women with type 2 diabetes. J Strength Cond Res 34(4): 1001-1007, 2020-The objective of this study was to investigate the effect of 12 weeks of the Pilates method on the functional capacity (FC) and glycemic control of older women with type 2 diabetes (T2D). Twenty-two women with T2D were randomized into control (CONTROL: 67.5 ± 6.3 years; 154.7 ± 6.1 cm; 73.5 ± 6.1 kg) and Pilates (PILATES: 65.5 ± 5.5 years; 155.0 ± 4.5 cm; 66.2 ± 5.4 kg) groups, which held sessions of 60 minutes at a frequency of 3 times per week during 12 weeks. Blood glucose was measured before and after sessions in PILATES, as well as in moments of pre, rest, 4, 8, and 12 weeks of the PILATES and CONTROL interventions. The glycated hemoglobin (HbA1c) level before and after 12 weeks of the intervention was evaluated. The general index of the FC (GIFC) was obtained through a battery of tests for older patients with T2D. Analysis of variance detected differences in the GIFC for PILATES vs. CONTROL, respectively, in 4 weeks (30.3 ± 4.6 vs. 34.8 ± 4.9 seconds; p < 0.05), 8 weeks (29.2 ± 4.5 vs. 34.6 ± 4.9 seconds; p < 0.05), and 12 weeks (27.2 ± 4.0 vs. 35.3 ± 4.6 seconds; p < 0.05). PILATES presented a difference in postprandial glycemia pre- vs. 4 and 12 weeks (246.1 ± 58.5 vs. 219.9 ± 59.9 and 207.6 ± 49.1 mg·dl, respectively; p < 0.05), as well as in HbA1c pre- vs. 12 weeks (7.8 ± 1.0 vs. 6.7 ± 0.6%, respectively; p < 0.05). Differences in postprandial glycemia (p < 0.05) were found in PILATES before vs. after sessions, respectively, of 1st-12th (217.1 ± 49.1 vs. 157.9 ± 55.7 mg·dl), 13th-24th (204.5 ± 44.7 vs. 146.3 ± 44.5 mg·dl), and 25th-36th (214.3 ± 40.4 vs. 152.7 ± 52.0 mg·dl). A correlation between postprandial glycemia and GIFC after 12 weeks was detected (r = 0.37; p = 0.04). It is concluded that 12 weeks of the Pilates method induces improvement and relationship in the FC and glycemic control in older women with T2D.


Assuntos
Glicemia/fisiologia , Diabetes Mellitus Tipo 2/terapia , Técnicas de Exercício e de Movimento/métodos , Idoso , Feminino , Hemoglobinas Glicadas/análise , Humanos , Pessoa de Meia-Idade , Desempenho Físico Funcional , Período Pós-Prandial , Precursores de Proteínas/análise
11.
Genet Mol Biol ; 41(1): 154-166, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29473933

RESUMO

The increased incidence of cancer and its high treatment costs have encouraged the search for new compounds to be used in adjuvant therapies for this disease. This study discloses the synthesis of (Z)-4-((1,5-dimethyl-3-oxo-2-phenyl-2,3dihydro-1H-pyrazol-4-yl) amino)-4-oxobut-2-enoic acid (IR-01) and evaluates not only the action of this compound on genetic integrity, increase in splenic phagocytosis and induction of cell death but also its effects in combination with the commercial chemotherapeutic agents doxorubicin, cisplatin and cyclophosphamide. IR-01 was designed and synthesized based on two multifunctionalyzed structural fragments: 4-aminoantipyrine, an active dipyrone metabolite, described as an antioxidant and anti-inflammatory agent; and the pharmacophore fragment 1,4-dioxo-2-butenyl, a cytotoxic agent. The results indicated that IR-01 is an effective chemoprotector because it can prevent clastogenic and/or aneugenic damage, has good potential to prevent genomic damage, can increase splenic phagocytosis and lymphocyte frequency and induces cell death. However, its use as an adjuvant in combination with chemotherapy is discouraged since IR-01 interferes in the effectiveness of the tested chemotherapeutic agents. This is a pioneer study as it demonstrates the chemopreventive effects of IR-01, which may be associated with the higher antioxidant activity of the precursor structure of 4-aminoantipyrine over the effects of the 1,4-dioxo-2-butenyl fragment.

12.
BMC Genomics ; 18(1): 204, 2017 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-28241794

RESUMO

BACKGROUND: The parasite Echinococcus canadensis (G7) (phylum Platyhelminthes, class Cestoda) is one of the causative agents of echinococcosis. Echinococcosis is a worldwide chronic zoonosis affecting humans as well as domestic and wild mammals, which has been reported as a prioritized neglected disease by the World Health Organisation. No genomic data, comparative genomic analyses or efficient therapeutic and diagnostic tools are available for this severe disease. The information presented in this study will help to understand the peculiar biological characters and to design species-specific control tools. RESULTS: We sequenced, assembled and annotated the 115-Mb genome of E. canadensis (G7). Comparative genomic analyses using whole genome data of three Echinococcus species not only confirmed the status of E. canadensis (G7) as a separate species but also demonstrated a high nucleotide sequences divergence in relation to E. granulosus (G1). The E. canadensis (G7) genome contains 11,449 genes with a core set of 881 orthologs shared among five cestode species. Comparative genomics revealed that there are more single nucleotide polymorphisms (SNPs) between E. canadensis (G7) and E. granulosus (G1) than between E. canadensis (G7) and E. multilocularis. This result was unexpected since E. canadensis (G7) and E. granulosus (G1) were considered to belong to the species complex E. granulosus sensu lato. We described SNPs in known drug targets and metabolism genes in the E. canadensis (G7) genome. Regarding gene regulation, we analysed three particular features: CpG island distribution along the three Echinococcus genomes, DNA methylation system and small RNA pathway. The results suggest the occurrence of yet unknown gene regulation mechanisms in Echinococcus. CONCLUSIONS: This is the first work that addresses Echinococcus comparative genomics. The resources presented here will promote the study of mechanisms of parasite development as well as new tools for drug discovery. The availability of a high-quality genome assembly is critical for fully exploring the biology of a pathogenic organism. The E. canadensis (G7) genome presented in this study provides a unique opportunity to address the genetic diversity among the genus Echinococcus and its particular developmental features. At present, there is no unequivocal taxonomic classification of Echinococcus species; however, the genome-wide SNPs analysis performed here revealed the phylogenetic distance among these three Echinococcus species. Additional cestode genomes need to be sequenced to be able to resolve their phylogeny.


Assuntos
Equinococose/genética , Echinococcus/genética , Genoma de Protozoário , Animais , Proteínas Argonautas/antagonistas & inibidores , Proteínas Argonautas/genética , Proteínas Argonautas/metabolismo , Hibridização Genômica Comparativa , Mapeamento de Sequências Contíguas , Ilhas de CpG , Metilação de DNA , Equinococose/parasitologia , Equinococose/patologia , Echinococcus/classificação , Echinococcus/metabolismo , Humanos , Sequências Repetitivas Dispersas/genética , Filogenia , Polimorfismo de Nucleotídeo Único , Proteínas de Protozoários/antagonistas & inibidores , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo
13.
Mamm Genome ; 28(1-2): 66-80, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27853861

RESUMO

In bovines, artificial selection has produced a large number of breeds which differ in production, environmental adaptation, and health characteristics. To investigate the genetic basis of these phenotypical differences, several bovine breeds have been sequenced. Millions of new SNVs were described at every new breed sequenced, suggesting that every breed should be sequenced. Guzerat or Guzerá is an indicine breed resistant to drought and parasites that has been the base for some important breeds such as Brahman. Here, we describe the sequence of the Guzerá genome and the in silico functional analyses of intragenic breed-specific variations. Mate-paired libraries were generated using the ABI SOLiD system. Sequences were mapped to the Bos taurus reference genome (UMD 3.1) and 87% of the reference genome was covered at a 26X. Among the variants identified, 2,676,067 SNVs and 463,158 INDELs were homozygous, not found in any database searched, and may represent true differences between Guzerá and B. taurus. Functional analyses investigated with the NGS-SNP package focused on 1069 new, non-synonymous SNVs, splice-site variants (including acceptor and donor sites, and the conserved regions at both intron borders, referred to here as splice regions) and coding INDELs (NS/SS/I). These NS/SS/I map to 935 genes belonging to cell communication, environmental adaptation, signal transduction, sensory, and immune systems pathways. These pathways have been involved in phenotypes related to health, adaptation to the environment and behavior, and particularly, disease resistance and heat tolerance. Indeed, 105 of these genes are known QTLs for milk, meat and carcass, production, reproduction, and health traits. Therefore, in addition to describing new genetic variants, our approach provided groundwork for unraveling key candidate genes and mutations.


Assuntos
Resistência à Doença/genética , Variação Genética , Termotolerância/genética , Sequenciamento Completo do Genoma/métodos , Animais , Cruzamento , Bovinos , Genótipo , Mutação INDEL/genética , Anotação de Sequência Molecular , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas/genética
14.
Int J Med Microbiol ; 307(6): 287-290, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28587735

RESUMO

Penicillin is the antibiotic of choice for the treatment of meningococcal infections, and mutations in penA gene are involved with reduced susceptibility (penI) emergence to this antibiotic. This study aimed to characterize the penA allelic diversity, their association with penI phenotype and distribution among prevalent meningococci serogroups in Brazil. The entire penA from 49 invasive strains of distinct serogroups circulating in Brazil for more than two decades were obtained by PCR and sequencing. Additionally, the penA from 22 publicly available complete Neisseria meningitidis genomes from Brazil were included in the study. The allelic diversity was determined and a genetic tree was built using the penA sequence alignment. The penicillin MIC was obtained by the E-Test method. In general, the identified penA alleles correlated with the observed penI phenotype. The canonical penA1 was the most prevalent allele, however, several altered penA were also identified in strains presenting increased penicillin MICs. It was identified a new penA amino acid position (residue 480) that possibly influence the penicillin MIC in some strains. Interestingly, the altered penA14 was found in penI invasive MenC cc103 strains spread in Brazil and persisting since 2011, indicating that the biological cost imposed by penI phenotype can be ameliorated by particular features present in this lineage, which represents an additional public health threat.


Assuntos
Antibacterianos/farmacologia , Infecções Meningocócicas/microbiologia , Neisseria meningitidis Sorogrupo C/genética , Resistência às Penicilinas/genética , Proteínas de Ligação às Penicilinas/genética , Penicilinas/farmacologia , Alelos , Brasil , Genes Bacterianos , Variação Genética , Humanos , Testes de Sensibilidade Microbiana , Alinhamento de Sequência , Sorogrupo
15.
Phys Rev Lett ; 118(24): 247202, 2017 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-28665656

RESUMO

Phase coupling between auto-oscillators is central for achieving coherent responses such as synchronization. Here we present an experimental approach to probe it in the case of two dipolarly coupled spin-torque vortex nano-oscillators using an external microwave field. By phase locking one oscillator to the external source, we observe frequency pulling on the second oscillator. From coupled phase equations we show analytically that this frequency pulling results from concerted actions of oscillator-oscillator and source-oscillator couplings. The analysis allows us to determine the strength and phase shift of coupling between two oscillators, yielding important information for the implementation of large interacting oscillator networks.

16.
Exp Parasitol ; 177: 98-103, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28457995

RESUMO

RNA interference is a well established and widely used reverse genetic tool available for gene functional studies in trematodes. This technique requires the use of nonrelevant double-stranded RNA as control. However, several authors have reported inconsistencies associated with RNAi. We used RNASeq to analyze genes affected by nonspecific dsRNA exposure. We found only few genes presenting altered expression in schistosomula exposed to GFP or mCherry nonspecific-dsRNAs, most of them encoding uncharacterized proteins. Correlation analysis revealed that there are more differences among biological replicates, than due to treatment with nonspecific controls. These observations are of key relevance to other RNAi gene function assessment in other organisms.


Assuntos
Genes de Helmintos/fisiologia , Interferência de RNA , RNA de Cadeia Dupla/genética , RNA de Helmintos/genética , Schistosoma mansoni/genética , Animais , Biomphalaria/parasitologia , Expressão Gênica , Proteínas de Helminto/genética , Análise de Componente Principal , Esquistossomose mansoni/parasitologia , Esquistossomose mansoni/transmissão , Análise de Sequência de RNA
17.
Genet Mol Biol ; 40(3): 665-675, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28898353

RESUMO

Chemotherapy is one of the major approaches for the treatment of cancer. Therefore, the development of new chemotherapy drugs is an important aspect of medicinal chemistry. Chemotherapeutic agents include isocoumarins, which are privileged structures with potential antitumoral activity. Herein, a new 3-substituted isocoumarin was synthesized from 2-iodo-3,5-dimethoxy-benzoic acid and oct-1-yne in a cross-coupling Sonogashira reaction followed by a copper iodide-catalyzed intramolecular cyclization as key step using MeOH/Et3N as the solvent system. The present study also evaluated the leukometry, phagocytic activity, genotoxic potential and cell death induction of three different doses (5 mg/kg, 10 mg/kg and 20 mg/kg) of this newly synthesized isocoumarin, alone and in combination with the commercial chemotherapeutic agents cyclophosphamide (100 mg/kg) and cisplatin (6 mg/kg) in male Swiss mice. The results suggest that the isocoumarin has genotoxicity and causes cell death. Noteworthy, this new compound can increase splenic phagocytosis and lymphocyte frequency, which are related to immunomodulatory activity. When combined with either cyclophosphamide or cisplatin, chemopreventive activity led to a reduction in the effects of both chemotherapeutic drugs. Thus, the new isocoumarin is not a candidate for chemotherapeutic adjuvant in treatments using cyclophosphamide or cisplatin. Nevertheless, the compound itself is an important prototype for the development of new antitumor drugs.

18.
Regul Toxicol Pharmacol ; 82: 32-38, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27793745

RESUMO

This study evaluates the toxicological, genotoxic, mutagenic and apoptotic potential of an in vivo assay from Echinodorus macrophyllus extract (EEM). The acute toxicity test used 02 groups (n = 5) of female Wistar rats: negative control group (saline) and experimental group (2000 mg/kg b.w. EEM), both orally administered (gavage) at single doses and monitored for 14 days. To assess the genotoxic, mutagenic and apoptotic potential, 50 male Swiss mice were divided into 5 groups (n = 10): Group I: negative control (saline solution 0.1 ml/10 g b.w.); Group II: positive control (cyclophosphamide 100 mg/kg b.w.) intraperitoneally administered; groups III-V received EEM at 500, 1000 and 2000 mg/kg b.w., respectively. Groups I, III-V received oral administrations (gavage). The results showed that there was no acute lethality or any signs of acute toxicity, indicating that LD50 is greater than 2000 mg/kg b.w. The groups treated with EEM showed no genotoxic or mutagenic activity and did not induce apoptosis in the liver and kidney. Therefore, EEM showed no acute toxicity and at doses of 500, 1000 and 2000 mg/kg b.w. absence of genotoxicity, mutagenicity and no apoptotic events were observed.


Assuntos
Alismataceae/toxicidade , Apoptose/efeitos dos fármacos , Etanol/química , Rim/efeitos dos fármacos , Fígado/efeitos dos fármacos , Extratos Vegetais/toxicidade , Folhas de Planta/toxicidade , Solventes/química , Toxicocinética , Administração Oral , Alismataceae/química , Animais , Cromatografia Líquida de Alta Pressão , Ensaio Cometa , Feminino , Injeções Intraperitoneais , Rim/patologia , Dose Letal Mediana , Fígado/patologia , Masculino , Camundongos , Testes para Micronúcleos , Fitoterapia , Extratos Vegetais/administração & dosagem , Extratos Vegetais/isolamento & purificação , Folhas de Planta/química , Plantas Medicinais , Ratos Wistar , Medição de Risco , Fatores de Tempo , Testes de Toxicidade Aguda
19.
Genet Mol Biol ; 39(4): 589-599, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27801482

RESUMO

This study used qRT-PCR to examine variation in the expression of 13 myogenes during muscle development in four prenatal periods (21, 40, 70 and 90 days post-insemination) in commercial (the three-way Duroc, Landrace and Large-White cross) and local Piau pig breeds that differ in muscle mass. There was no variation in the expression of the CHD8, EID2B, HIF1AN, IKBKB, RSPO3, SOX7 and SUFU genes at the various prenatal ages or between breeds. The MAP2K1 and RBM24 genes showed similar expression between commercial and Piau pigs but greater expression (p < 0.05) in at least one prenatal period. Pair-wise comparisons of prenatal periods in each breed showed that only the CSRP3, LEF1, MRAS and MYOG genes had higher expression (p < 0.05) in at least one prenatal period in commercial and Piau pigs. Overall, these results identified the LEF1 gene as a primary candidate to account for differences in muscle mass between the pig breeds since activation of this gene may lead to greater myoblast fusion in the commercial breed compared to Piau pigs. Such fusion could explain the different muscularity between breeds in the postnatal periods.

20.
Regul Toxicol Pharmacol ; 73(3): 699-705, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26545326

RESUMO

This study assessed the anti-inflammatory effects of the essential oil from Piper vicosanum leaves (OPV) and evaluated the toxicological potential of this oil through acute toxicity, genotoxicity and mutagenicity tests. The acute toxicity of OPV was evaluated following oral administration to female rats at a single dose of 2 g/kg b.w. To evaluate the genotoxic and mutagenic potential, male mice were divided into five groups: I: negative control; II: positive control; III: 500 mg/kg of OPV; IV: 1000 mg/kg of OPV; V: 2000 mg/kg of OPV. The anti-inflammatory activity of OPV was evaluated in carrageenan-induced pleurisy and paw edema models in rats. No signs of acute toxicity were observed, indicating that the LD50 of this oil is greater than 2000 mg/kg. In the comet assay, OPV did not increase the frequency or rate of DNA damage in groups treated with any of the doses assessed compared to that in the negative control group. In the micronucleus test, the animals treated did not exhibit any cytotoxic or genotoxic changes in peripheral blood erythrocytes. OPV (100 and 300 mg/kg) significantly reduced edema formation and inhibited leukocyte migration analyzed in the carrageenan-induced edema and pleurisy models. These results show that OPV has anti-inflammatory potential without causing acute toxicity or genotoxicity.


Assuntos
Anti-Inflamatórios/farmacologia , Edema/prevenção & controle , Óleos Voláteis/farmacologia , Piper , Extratos Vegetais/farmacologia , Óleos de Plantas/farmacologia , Pleurisia/prevenção & controle , Administração Oral , Animais , Anti-Inflamatórios/administração & dosagem , Anti-Inflamatórios/isolamento & purificação , Anti-Inflamatórios/toxicidade , Carragenina , Quimiotaxia de Leucócito/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Edema/imunologia , Eritrócitos/efeitos dos fármacos , Eritrócitos/patologia , Feminino , Dose Letal Mediana , Masculino , Camundongos , Testes para Micronúcleos , Óleos Voláteis/administração & dosagem , Óleos Voláteis/isolamento & purificação , Óleos Voláteis/toxicidade , Fitoterapia , Piper/química , Piper/toxicidade , Extratos Vegetais/administração & dosagem , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/toxicidade , Folhas de Planta , Óleos de Plantas/administração & dosagem , Óleos de Plantas/isolamento & purificação , Óleos de Plantas/toxicidade , Plantas Medicinais , Pleurisia/induzido quimicamente , Pleurisia/imunologia , Ratos , Ratos Wistar , Medição de Risco , Fatores de Tempo
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