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1.
Brain ; 147(5): 1644-1652, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38428032

RESUMO

The pathological misfolding and aggregation of soluble α-synuclein into toxic oligomers and insoluble amyloid fibrils causes Parkinson's disease, a progressive age-related neurodegenerative disease for which there is no cure. HET-s is a soluble fungal protein that can form assembled amyloid fibrils in its prion state. We engineered HET-s(218-298) to form four different fibrillar vaccine candidates, each displaying a specific conformational epitope present on the surface of α-synuclein fibrils. Vaccination with these four vaccine candidates prolonged the survival of immunized TgM83+/- mice challenged with α-synuclein fibrils by 8% when injected into the brain to model brain-first Parkinson's disease or by 21% and 22% when injected into the peritoneum or gut wall, respectively, to model body-first Parkinson's disease. Antibodies from fully immunized mice recognized α-synuclein fibrils and brain homogenates from patients with Parkinson's disease, dementia with Lewy bodies and multiple system atrophy. Conformation-specific vaccines that mimic epitopes present only on the surface of pathological fibrils but not on soluble monomers, hold great promise for protection against Parkinson's disease, related synucleinopathies and other amyloidogenic protein misfolding disorders.


Assuntos
Camundongos Transgênicos , Doença de Parkinson , alfa-Sinucleína , Animais , Doença de Parkinson/imunologia , Doença de Parkinson/patologia , Camundongos , alfa-Sinucleína/imunologia , alfa-Sinucleína/metabolismo , Humanos , Amiloide/imunologia , Amiloide/metabolismo , Vacinação , Proteínas Fúngicas/imunologia , Encéfalo/patologia , Encéfalo/metabolismo , Encéfalo/imunologia , Feminino , Camundongos Endogâmicos C57BL
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 309: 123817, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38211445

RESUMO

Advances in precision medical diagnostics require accurate and sensitive characterization of pathogens. In particular, health conditions associated with protein misfolding require an identification of proteinaceous amyloid fibrils or their precursors. These pathogenic entities express specific molecular structures, which require ultra-sensitive, molecular-level detection methods. A potentially transformative technique termed nanoplasmonics employs electro-optical phenomena in the vicinity of specially engineered metal nanostructures. A signature application of nanoplasmonics exploits enhancement of inelastic scattering of light in specific locations near metallic nanostructures, known as surface-enhanced Raman scattering (SERS). We applied SERS complemented with confocal microscopy imaging for ultra-sensitive, non-invasive, and label-free characterization of the fungal prion HET-s (218-289) as a model for ß-sheet rich amyloid structures. This characterization employed Au-coated dielectric supports as plasmonic substrates. After confirming the formation of HET-s fibrils at both pH 7.5 and 2.8 using negative staining transmission electron microscopy, we subjected the fibril-containing solutions to multimodal analysis using confocal microscopy and SERS. The SERS spectral fingerprints from all HET-s samples expressed vibrational markers for ß-structure, unstructured backbone, and aromatic side-chains. However, relative intensities of major SERS bands were pronouncedly different for the two pH levels. We have analyzed potential origins of the most pronounced SERS bands and proposed hypothetical mechanistic models that could explain the observed SERS fingerprints from HET-s fibrils grown at pH 7.5 and 2.8.


Assuntos
Príons , Príons/química , Amiloide/química , Concentração de Íons de Hidrogênio , Proteínas Fúngicas/química
3.
Antibiotics (Basel) ; 12(7)2023 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-37508180

RESUMO

Bacterial biofilms are a significant problem in the food industry, as they are difficult to eradicate and represent a threat to consumer health. Currently, nanoparticles as an alternative to traditional chemical disinfectants have garnered much attention due to their broad-spectrum antibacterial activity and low toxicity. In this study, silver nanoparticles (AgNPs) were synthesized by a biological method using a Jacaranda mimosifolia flower aqueous extract and by a chemical method, and the factors affecting both syntheses were optimized. The nanoparticles were characterized by Ultraviolet-visible (UV-Vis) spectrophotometry, Fourier-transform infrared spectroscopy (FTIR), Dynamic light scattering (DLS), X-ray diffraction (XRD), and Transmission electron microscopy (TEM) with a spherical and uniform shape. The antibacterial and antibiofilm formation activity was carried out on bacterial species of Pseudomonas aeruginosa and Staphylococcus aureus with the capacity to form biofilm. The minimum inhibitory concentration was 117.5 µg/mL for the chemical and 5.3 µg/mL for the biological nanoparticles. Both types of nanoparticles showed antibiofilm activity in the qualitative Congo red test and in the quantitative microplate test. Antibiofilm activity tests on fresh lettuce showed that biological nanoparticles decreased the population of S. aureus and P. aeruginosa by 0.63 and 2.38 logarithms, respectively, while chemical nanoparticles had little microbial reduction. In conclusion, the biologically synthesized nanoparticles showed greater antibiofilm activity. Therefore, these results suggest their potential application in the formulation of sanitizing products for the food and healthcare industries.

4.
Front Cell Dev Biol ; 10: 947769, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36120556

RESUMO

Glial cells are non-neuronal elements of the nervous system (NS) and play a central role in its development, maturation, and homeostasis. Glial cell interest has increased, leading to the discovery of novel study fields. The CRISPR/Cas system has been widely employed for NS understanding. Its use to study glial cells gives crucial information about their mechanisms and role in the central nervous system (CNS) and neurodegenerative disorders. Furthermore, the increasingly accelerated discovery of genes associated with the multiple implications of glial cells could be studied and complemented with the novel screening methods of high-content and single-cell screens at the genome-scale as Perturb-Seq, CRISP-seq, and CROPseq. Besides, the emerging methods, GESTALT, and LINNAEUS, employed to generate large-scale cell lineage maps have yielded invaluable information about processes involved in neurogenesis. These advances offer new therapeutic approaches to finding critical unanswered questions about glial cells and their fundamental role in the nervous system. Furthermore, they help to better understanding the significance of glial cells and their role in developmental biology.

5.
Materials (Basel) ; 15(16)2022 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-36013835

RESUMO

Silver nanoparticles (AgNPs) synthesized with plants are widely used in different industries, such as the medical, industrial, and food industries; however, their hazards and risks remain unclear. Here, we aimed to evaluate the toxicological effects of AgNPs in both in vitro and in vivo models. Previously, we developed and characterized green synthesized AgNPs based on Stenocereus queretaroensis (S. queretaroensis). The present study evaluates the toxicity of these AgNPs through cytotoxicity and mutagenicity tests in vitro, as well as genotoxicity tests, including the evaluation of acute oral, dermal, and inhalation toxicity, along with dermal and ocular irritation, in vivo, according to guidelines of The Organization for Economic Co-operation and Development (OECD). We evaluated cell cytotoxicity in L929 cells, and the half-maximal inhibitory concentration was 134.76 µg/mL. AgNPs did not cause genotoxic or mutagenic effects. Furthermore, in vivo oral, dermal, and acute inhalation toxicity results did not show any adverse effects or mortality in the test animals, and after the dermal and ocular irritation assessments, the in vivo models did not exhibit irritation or corrosion. Therefore, the results show that these previously synthesized S. queretaroensis AgNPs do not represent a risk at the tested concentrations; however, little is known about the effects that AgNPs induce on physiological systems or the possible risk following long-term exposure.

6.
Saudi J Biol Sci ; 29(5): 3830-3837, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35844370

RESUMO

An inflammation response occurs when the body reacts to exogenous and endo enous noxious stimuli, and it helps the body respond to infection and repair tissues, adapt to stress, and remove dead or damaged cells. Anti-inflammatory drugs such as non-steroidal anti-inflammatory drugs are traditionally used to treat inflammation; however, these drugs often cause negative side effects. For this reason, developing and establishing effective alternative medicines for treating many chronic diseases with underlying inflammation is critically dependent on the identification of new organic molecules and bioactive substances. Aromatic and volatile compounds found in essential oils isolated from Pimenta dioica (allspice), Cuminum cyminum (cumin), and Citrus sinensis (sweet orange) are a source of bioactive compounds. Allspice essential oil reduces ear inflammation more than 65% and the anti-inflammatory activity of allspice essential oil is enhanced when combined with sweet orange peel and cumin essential oils, resulting in the reduction of edema inflammation by more than 85%, similar to indomethacin. As an alternative to anti-inflammatory treatment, essential oil mix is pharmacologically safe as it is neither toxic nor mutagenic.

7.
Artigo em Inglês | MEDLINE | ID: mdl-34769555

RESUMO

Landfill leachate is a complex mixture of organic and inorganic molecules, as well as environmental pollutants that can cause harm to ecosystems and living beings. The micronucleus test in peripheral blood erythrocytes was used to evaluate the genotoxic and cytotoxic effects of exposure to a landfill leachate from an outdoor solid waste storage system on Wistar strain rats at different developmental stages, pre-adolescents and young adults, and the heavy metal content of the leachate was determined by atomic absorption spectrometry. Contents of arsenic, cadmium, chromium, mercury, and lead in the landfill leachate were outside the allowable international standards, and the exposure to the landfill leachate caused genotoxic and cytotoxic effects on Wistar rats, where the pre-adolescent animals were more susceptible to the toxics contained in the landfill leachate than young adults. Heavy metals contained in landfill leachate, individually or synergically with other molecules can be responsible for clastogenic and cytotoxic effects that can be harmful to humans and ecosystems.


Assuntos
Eliminação de Resíduos , Poluentes Químicos da Água , Animais , Dano ao DNA , Ecossistema , Ratos , Ratos Wistar , Resíduos Sólidos/análise , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
8.
Parasite ; 28: 65, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34533454

RESUMO

Rhipicephalus (Boophilus) microplus ticks are obligatory hematophagous ectoparasites of cattle and act as vectors for disease-causing microorganisms. Conventional tick control is based on the application of chemical acaricides; however, their uncontrolled use has increased resistant tick populations, as well as food and environmental contamination. Alternative immunological tick control has shown to be partially effective. Therefore, there is a need to characterize novel antigens in order to improve immunological protection. The aim of this work was to evaluate Cys-loop receptors as vaccine candidates. N-terminal domains of a glutamate receptor and of a glycine-like receptor were recombinantly produced in Escherichia coli. Groups of BALB/c mice were independently immunized with four doses of each recombinant protein emulsified with Freund's adjuvant. Both vaccine candidates were immunogenic in mice as demonstrated by western blot analysis. Next, recombinant proteins were independently formulated with the adjuvant Montanide ISA 50 V2 and evaluated in cattle infested with Rhipicephalus microplus tick larvae. Groups of three European crossbred calves were immunized with three doses of each adjuvanted protein. ELISA test was used to evaluate the IgG immune response elicited against the recombinant proteins. Results showed that vaccine candidates generated a moderate humoral response on vaccinated cattle. Vaccination significantly affected the number of engorged adult female ticks, having no significant effects on tick weight, egg weight and egg fertility values. Vaccine efficacies of 33% and 25% were calculated for the glutamate receptor and the glycine-like receptor, respectively.


TITLE: Évaluation de l'immunoprotection du domaine N-terminal recombinant des récepteurs Cys-loop contre l'infestation par les tiques Rhipicephalus (Boophilus) microplus. ABSTRACT: Les tiques Rhipicephalus (Boophilus) microplus sont des ectoparasites hématophages obligatoires des bovins et agissent comme vecteurs de micro-organismes pathogènes. Le contrôle conventionnel des tiques est basé sur l'application d'acaricides chimiques, mais leur utilisation incontrôlée a augmenté les populations de tiques résistantes ainsi que la contamination des aliments et de l'environnement. Le contrôle immunologique alternatif des tiques s'est avéré partiellement efficace. Par conséquent, il est nécessaire de caractériser de nouveaux antigènes afin d'améliorer la protection immunologique. Le but de ce travail était d'évaluer les récepteurs Cys-loop comme candidats vaccins. Les domaines N-terminaux d'un récepteur du glutamate et d'un récepteur de type glycine ont été produits par recombinaison chez Escherichia coli. Des groupes de souris BALB/c ont été immunisés indépendamment avec quatre doses de chaque protéine recombinante émulsionnée avec l'adjuvant de Freund. Les deux vaccins candidats étaient immunogènes chez la souris, comme l'a démontré l'analyse par transfert Western. Ensuite, des protéines recombinantes ont été formulées indépendamment avec l'adjuvant Montanide ISA 50 V2 et évaluées chez des bovins infestés de larves de tiques Rhipicephalus microplus. Des groupes de trois veaux croisés européens ont été immunisés avec trois doses de chaque protéine avec adjuvant. Le test ELISA a été utilisé pour évaluer la réponse immunitaire IgG induite contre les protéines recombinantes. Les résultats ont montré que les candidats vaccins généraient une réponse humorale modérée sur les bovins vaccinés. La vaccination a affecté de manière significative le nombre de tiques femelles adultes engorgées mais n'a eu aucun effet significatif sur le poids des tiques, le poids des œufs et les valeurs de fertilité des œufs. Des efficacités vaccinales de 33 % et 25 % ont été calculées pour le récepteur du glutamate et le récepteur de type glycine, respectivement.


Assuntos
Doenças dos Bovinos , Receptores de Canais Iônicos de Abertura Ativada por Ligante com Alça de Cisteína , Rhipicephalus , Infestações por Carrapato , Animais , Bovinos , Doenças dos Bovinos/prevenção & controle , Feminino , Camundongos , Camundongos Endogâmicos BALB C , Infestações por Carrapato/prevenção & controle , Infestações por Carrapato/veterinária
9.
Materials (Basel) ; 14(16)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34443066

RESUMO

The synthesis and application of nanomaterials as antioxidants and cytotoxic agents has increased in recent years. Biological methods go beyond the chemical and physical synthesis that is expensive and not friendly to the environment. Foodborne pathogens and microorganisms causing candidiasis are responsible of 5-10% hospitalized patients. The nutritional properties of the fruit called pitaya, from the Stenocereus queretaroensis species, have been little explored. Therefore, in this study the phytochemical composition of S. queretaroensis peel was evaluated and silver nanoparticles (AgNPs) were synthesized biologically in an environmentally friendly way by S. queretaroensis peel aqueous extract that contains phytochemicals capable of reducing silver nitrate. The antimicrobial activity of the AgNPs was tested by determining the minimum inhibitory concentration (MIC), minimal bactericidal concentration (MBC) and time-kill kinetics. AgNPs were characterized visually, by UV-visible spectroscopy and TEM. FTIR spectroscopy identified metabolites responsible for the AgNPs formation. AgNPs showed potent antimicrobial activity against gram-negative and gram-positive bacteria, against fungi, and a methicillin-resistant strain of S. aureus. MIC and MBC values were as low as 0.078 and 0.156 µg/mL using AgNPs biosynthesized by S. queretaroensis fruit peel and the time kill assay started a log reduction in CFU/mL at 1 × MIC and 2 × MIC. S. queretaroensis-mediated AgNPs could be the basis for the formulation of biofilms for packaging products or as disinfectants for use on different surfaces.

10.
Exp Ther Med ; 18(6): 4467-4472, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31777549

RESUMO

Eupatorium aschenbornianum has been widely used in traditional Mexican and folk medicine for the treatment of wounds, skin lesions, hemorrhages and gastric ulcers in humans. Phytochemical studies have indicated that hexane extracts of E. aschenbornianum have anti-microbial and anti-fungal activities. In the present study, an accurate and reliable approach using a murine model was pursued to evaluate the anti-ulcer activity, lipid peroxidation properties and acute toxicity of powdered dried stem of E. aschenbornianum. The results indicated that administration of E. aschenbornianum exerted an anti-ulcerative effect and decreased lipid peroxidation in gastric ulcers induced by acetylsalicylic acid. An acute toxicity assay indicated normal behavior and no significant variations in the weight and food consumption of animals. In addition, quantitative analysis of biochemical parameters did not indicate any liver or kidney damage. The results indicated that E. aschenbornianum may be a safe therapeutic agent for the prevention of gastric ulcers.

11.
Pathogens ; 7(2)2018 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-29734684

RESUMO

Pathogenic amyloids are the main feature of several neurodegenerative disorders, such as Creutzfeldt⁻Jakob disease, Alzheimer’s disease, and Parkinson’s disease. High resolution structures of tau paired helical filaments (PHFs), amyloid-β(1-42) (Aβ(1-42)) fibrils, and α-synuclein fibrils were recently reported using cryo-electron microscopy. A high-resolution structure for the infectious prion protein, PrPSc, is not yet available due to its insolubility and its propensity to aggregate, but cryo-electron microscopy, X-ray fiber diffraction, and other approaches have defined the overall architecture of PrPSc as a 4-rung β-solenoid. Thus, the structure of PrPSc must have a high similarity to that of the fungal prion HET-s, which is part of the fungal heterokaryon incompatibility system and contains a 2-rung β-solenoid. This review compares the structures of tau PHFs, Aβ(1-42), and α-synuclein fibrils, where the β-strands of each molecule stack on top of each other in a parallel in-register arrangement, with the β-solenoid folds of HET-s and PrPSc.

12.
Plant Foods Hum Nutr ; 73(1): 34-39, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29417384

RESUMO

Obesity affects millions of people worldwide, constituting a public health problem associated with premature mortality. Agave fructans decrease fat mass, body and liver weight, and generate satiety in rodents. In the present study the effects of agave fructans on weight control, lipid profile, and physical tolerability were evaluated in obese people. Twenty-eight obese volunteers were randomly divided into two groups. In the first group, 96 mg/bw of agave fructans was administered for 12 weeks; in the second group, maltodextrin as a placebo was administered for 12 weeks. All participants consumed a low-calorie diet of 1500 kcal/day. Anthropometric and biochemical measurements were taken at baseline and at the end of the study. The body mass index (BMI) of the agave fructans treated group was reduced significantly from the baseline to the final measurements. Hip and waist circumferences decreased statistically in both groups. A decrease of 10% in total body fat was observed in the agave fructans treated group, resulting in a statistically significant difference in the final versus baseline measurements between the Agave fructans treated group and the placebo treated group. Triglycerides were reduced significantly in the agave fructans treated group. Glucose values did not change in either group. Agave fructans intake was safe and well tolerated throughout the study. The results showed that the ingestion of agave fructans enhanced the decrease in BMI, the decrease in total body fat, and the decrease in triglycerides in obese individuals who consume a low-calorie diet.


Assuntos
Agave/química , Fármacos Antiobesidade/farmacologia , Frutanos/farmacologia , Lipídeos/sangue , Obesidade/tratamento farmacológico , Tecido Adiposo/efeitos dos fármacos , Adolescente , Adulto , Índice de Massa Corporal , Restrição Calórica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Triglicerídeos/sangue
13.
Pharmacogn Mag ; 13(52): 613-616, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29200722

RESUMO

BACKGROUND: Previous studies of Citrus spp. peel have shown hypoglycemic and antioxidant activities. Citrus limetta has been studied for its therapeutic properties. Diabetes mellitus (DM) is a health problem in Mexico and worldwide, that takes a vital importance due to its high incidence. Recently, scientists have searched natural sources to control the disease. MATERIALS AND METHODS: In this study, we evaluated the in vitro hypoglycemic activity and in vivo postprandial glycemic effect of C. limetta peel flour by glucose adsorption and retardation assays as well as postprandial serum glucose levels using a group of female Balb-c mice, respectively. RESULTS: C. limetta peel flour showed a glucose adsorption capacity of 16.58 mM, having a similar effect regarding the positive control. The glucose diffusion in the dialysate was elevated, with a glucose dialysis retardation index of 33.79% in a period of 3 h, showing similar results to positive control. Postprandial serum glucose levels in the animal group treated with C. limetta peel flour showed a glucose level of 41.4 mg/dL, being this value significantly lower than negative control group and similar to positive control. Toxicity tests showed good tolerance to the dose of 2000 mg/kg. CONCLUSION: C. limetta peel flour could act as a source of functional compounds for the control of DM. SUMMARY: Citrus limetta peel flour showed a glucose adsorption capacity similar to the positive controlThe glucose diffusion in the dialysate was elevated, showing similar results to positive controlPostprandial serum glucose levels in the animal group treated with C. limetta peel flour showed a glucose level significantly lower than negative control group and similar to positive controlToxicity tests showed good toleranceC. limetta peel flour could act as a source of functional compounds for the control of diabetes mellitus. Abbreviations used: CIATEJ: Center for Research and Assistance in Technology and Design of Jalisco; DM: Diabetes mellitus; FGC: Final glucose concentration; GDRI: Glucose dialysis retardation index; IGC: Initial glucose concentration; OECD: Organization for Economic Cooperation and Development.

14.
Parasitology ; 143(13): 1802-1809, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27609093

RESUMO

The cattle tick Rhipicephalus (Boophilus) microplus is a hematophagous ectoparasite of major importance for the livestock industry. It shows a remarkable ability to survive over long periods without feeding. However, the mechanisms used to endure long-term starvation are poorly understood. It is believed that autophagy, a process of intracellular protein degradation, may play a significant role to confront adverse environmental conditions. To advance our understanding of autophagy in R. microplus, in the present study we report the molecular characterization of three autophagy-related (ATG) genes, namely, RmATG3, RmATG4 and RmATG6, as well as their expression profiles in different developmental stages and organs of the parasite. The deduced amino acid sequences derived from the characterized gene sequences were subjected to Basic Local Alignment Search Tool analysis. The testing produced significant alignments with respective ATG proteins from Haemaphysalis longicornis and Ixodes scapularis ticks. Real-time polymerase chain reaction assays revealed that RmATG4 and RmATG6 transcripts were elevated in egg and ovary tissue, when compared with larva and midgut samples, while RmATG3 expression in midgut was 2-fold higher than in egg, larva and ovary samples.


Assuntos
Proteínas Relacionadas à Autofagia/genética , Perfilação da Expressão Gênica , Rhipicephalus/embriologia , Rhipicephalus/genética , Animais , Larva/genética , Larva/crescimento & desenvolvimento , Reação em Cadeia da Polimerase em Tempo Real , Zigoto/crescimento & desenvolvimento
15.
Biomed Res Int ; 2015: 837452, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26078966

RESUMO

Cholesterol control is fundamental for prevention of cardiovascular disorders. In this work, the hypocholesterolemic activity of an aqueous Opuntia ficus-indica extract (AOE) was tested in triton-induced mice. The inhibitory activity on pancreatic lipase enzyme was evaluated in vitro by the same extract. Furthermore, polyphenol content of the extract was evaluated. Hypercholesterolemia was induced in three groups of mice by intraperitoneal administration of Triton WR-1339. After induction of hypercholesterolemia, the groups were treated with an AOE (500 mg/kg) and saline solution and the positive control group with orlistat, respectively. Cholesterol levels were measured 24 h later in peripheral blood. The levels of blood cholesterol after administration of AOE significantly decreased compared to negative control. The inhibitory activity of AOE on pancreatic lipase enzyme was evaluated at concentrations from 60 to 1000 µg/mL. The AOE inhibited the pancreatic lipase with an IC50 = 588.5 µg/mL. The AOE had a high content of polyphenolic compounds. These results show that AOE is able to prevent hypercholesterolemia by pancreatic lipase inhibition, in part due to its polyphenolic compounds.


Assuntos
Hipercolesterolemia/tratamento farmacológico , Lipase/sangue , Opuntia/química , Extratos Vegetais/administração & dosagem , Animais , Colesterol/sangue , Humanos , Hipercolesterolemia/sangue , Hipercolesterolemia/induzido quimicamente , Lipase/antagonistas & inibidores , Camundongos , Pâncreas/efeitos dos fármacos , Pâncreas/enzimologia , Extratos Vegetais/química , Polietilenoglicóis/toxicidade , Triglicerídeos/sangue
16.
Parasite ; 21: 43, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25174962

RESUMO

The cattle tick Rhipicephalus (Boophilus) microplus is the most economically important ectoparasite affecting the cattle industry in tropical and subtropical areas around the world. The principal method of tick control has relied mainly on the use of chemical acaricides, including ivermectin; however, cattle tick populations resistant to ivermectin have recently been reported in Brazil, Mexico, and Uruguay. Currently, the molecular basis for ivermectin susceptibility and resistance are not well understood in R. microplus. This prompted us to search for potential molecular targets for ivermectin. Here, we report the cloning and molecular characterization of a R. microplus glycine-like receptor (RmGlyR) gene. The characterized mRNA encodes for a 464-amino acid polypeptide, which contains features common to ligand-gated ion channels, such as a large N-terminal extracellular domain, four transmembrane domains, a large intracellular loop and a short C-terminal extracellular domain. The deduced amino acid sequence showed around 30% identity to GlyRs from some invertebrate and vertebrate organisms. The polypeptide also contains the PAR motif, which is important for forming anion channels, and a conserved glycine residue at the third transmembrane domain, which is essential for high ivermectin sensitivity. PCR analyses showed that RmGlyR is expressed at egg, larval and adult developmental stages. Our findings suggest that the deduced receptor is an additional molecular target to ivermectin and it might be involved in ivermectin resistance in R. microplus.


Assuntos
Proteínas de Artrópodes/genética , Receptores de Glicina/genética , Rhipicephalus/genética , Acaricidas/farmacologia , Sequência de Aminoácidos , Animais , Proteínas de Artrópodes/metabolismo , Sequência de Bases , Sítios de Ligação , Clonagem Molecular , DNA Complementar/genética , Resistência a Medicamentos/genética , Escherichia coli , Regulação da Expressão Gênica no Desenvolvimento , Canais Iônicos/genética , Canais Iônicos/metabolismo , Ivermectina/farmacologia , Larva , Dados de Sequência Molecular , Óvulo , RNA Mensageiro/genética , Receptores de Glicina/metabolismo , Rhipicephalus/crescimento & desenvolvimento , Rhipicephalus/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos
17.
ScientificWorldJournal ; 2014: 784613, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25143991

RESUMO

Insecticidal activity of essential oil extracted from Morinda lucida was tested on pulse beetle Callosobruchus maculatus, which is a pest that causes serious damage to several pulses. The insecticidal activity was compared with two pesticides, Phostoxin and Primo-ban-20. 120 mixed sex adult C. maculatus were introduced, along with 30 g of cowpeas. Four concentrations (0.40, 0.20, 0.10, and 0.05 µg/mL) of the M. lucida essential oil, Phostoxin, and Primo-ban-20 were tested. Essential oil chemical composition was analyzed by GC-MS. M. lucida essential oil showed a high toxicological effect, producing 100% mortality after 72 hours at a dose of 0.20 µg/mL. M. lucida essential oil had a potent insecticidal activity (LC90 = 0.629 µg/mL) compared to both pesticides, Phostoxin (LC90 = 0.652 µg/mL) and Primo-ban-20 (LC90 = 0.726 µg/mL), at 24 h. The main compounds of the essential oil were the oxygenated monoterpenoids, 1,8-cineole (43.4%), and α-terpinyl acetate (14.5%), and the monoterpene hydrocarbons, mostly sabinene (8.2%) and ß-pinene (4.0%). Results clearly indicate that M. lucida essential oil can be used as an effective alternative for pulse beetle C. maculatus control, and it could be tested against other pulse beetles affecting Asia and Africa and throughout the world, thereby reducing use of synthetic pesticides.


Assuntos
Besouros/efeitos dos fármacos , Inseticidas/química , Inseticidas/farmacologia , Morinda/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Animais , Monoterpenos Bicíclicos , Compostos Bicíclicos com Pontes/química , Cicloexanóis/química , Eucaliptol , Cromatografia Gasosa-Espectrometria de Massas , Monoterpenos/química
18.
Future Oncol ; 10(8): 1501-13, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25052758

RESUMO

Considerable efforts have been undertaken to produce an effective screening method to reduce lung cancer mortality. Imaging tools such as low-dose computed tomography has shown an increase in the detection of early disease and a reduction in the rate of death. This screening modality has, however, several limitations, such as overdiagnosis and a high rate of false positives. Therefore, new screening methods, such as the use of circulating protein biomarkers, have emerged as an option that could complement imaging studies. In this review, current imaging techniques applied to lung cancer screening protocols are presented, as well as up-to-date status of circulating protein biomarker panels that may improve lung cancer diagnosis. Additionally, diverse statistical and artificial intelligence tools applied to the design and optimization of these panels are discussed along with the presentation of two commercially available blood tests recently developed to help detect lung cancer early.


Assuntos
Biomarcadores/sangue , Proteínas Sanguíneas , Detecção Precoce de Câncer , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/diagnóstico , Diagnóstico por Imagem/métodos , Detecção Precoce de Câncer/métodos , Humanos , Kit de Reagentes para Diagnóstico , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
19.
Exp Appl Acarol ; 64(4): 533-42, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25039003

RESUMO

Rhipicephalus (Boophilus) microplus is an obligate haematophagous arthropod and the major problem for cattle industry due to economic losses it causes. The parasite shows a remarkable adaptability to changing environmental conditions as well as an exceptional ability to survive long-term starvation. This ability has been related to a process of intracellular protein degradation called autophagy. This process in ticks is still poorly understood and only few autophagy-related (ATG) genes have been characterized. The aim of the present study was to examine the ESTs database, BmiGI, of R. microplus searching for ATG homologues. We predicted five putative ATG genes, ATG3, ATG4, ATG6 and two ATG8s. Further characterization led to the identification of RmATG8a and RmATG8b, homologues of GABARAP and MAP1LC3, respectively, and both of them belonging to the ATG8 family. PCR analyses showed that the expression level of RmATG8a and RmATG8b was higher in egg and larval stages when compared to ovary and midgut from adult ticks. This up-regulation coincides with the period in which ticks are in a starvation state, suggesting that autophagy is active in R. microplus.


Assuntos
Bovinos/parasitologia , Rhipicephalus/genética , Sequência de Aminoácidos , Animais , Autofagia/genética , Sequência de Bases , Clonagem Molecular , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase , RNA/química , RNA/genética , Alinhamento de Sequência , Análise de Sequência de DNA
20.
ScientificWorldJournal ; 2014: 121760, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25587557

RESUMO

Type 2 diabetes mellitus is one of the most frequent causes of death in Mexico, characterized by chronic hyperglycemia. One alternative strategy for this metabolic abnormality is inhibiting the enzymes responsible for the metabolism of carbohydrates. We evaluated whether the aqueous Citrus limetta peel extract could inhibit the metabolism of carbohydrates. We found that this extract inhibited primarily the enzyme α-amylase by 49.6% at a concentration of 20 mg/mL and to a lesser extent the enzyme α-glucosidase with an inhibition of 28.2% at the same concentration. This inhibition is likely due to the high polyphenol content in the Citrus limetta peel (19.1 mg GAE/g). Antioxidant activity of the Citrus limetta peel demonstrated dose-dependent antioxidant activity, varying from 6.5% at 1.125 mg/mL to 42.5% at 20 mg/mL. The study of these polyphenolic compounds having both antihyperglycemic and antioxidant activities may provide a new approach to the management of type 2 diabetes mellitus.


Assuntos
Citrus/química , Diabetes Mellitus Tipo 2/tratamento farmacológico , Extratos Vegetais/administração & dosagem , alfa-Amilases/antagonistas & inibidores , Antioxidantes/administração & dosagem , Antioxidantes/química , Metabolismo dos Carboidratos/efeitos dos fármacos , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Hiperglicemia/tratamento farmacológico , Hiperglicemia/patologia , México , Extratos Vegetais/química , Polifenóis/administração & dosagem , Polifenóis/química
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