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1.
Trop Anim Health Prod ; 51(3): 589-598, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30382497

RESUMO

The purpose of this study was to evaluate the quantitative and qualitative characteristics of the carcass and meat of goats fed diets containing cactus meal (pectin source) replacing corn (starch source). Twenty-eight goats with an average initial weight of 16 ± 2.02 kg were confined in a completely randomized design with four treatments (the replacement levels of 0, 330, 660, and 1000 g kg-1 of dry matter) and seven replicates. The productive performance of the animals was not affected by the replacement of corn by cactus meal. The carcass commercial yield and the dressing percentage decreased with the addition of cactus meal levels in the diets. The commercial cuts, however, especially prime cuts like hind limbs and loin, were not changed by the use of cactus meal. Muscle:bone and fat:bone ratios and muscularity index of hind limbs were influenced by the substitution. The protein and ash contents of the longissimus lumborum muscle decreased while cholesterol levels increased with the presence of cactus meal. Sensory traits of goats' meat fed cactus meal in the diets were not affected. The substitution of corn for cactus meal reduced carcass yield but did not change the yield of commercial cuts or the qualitative characteristics of the meat.


Assuntos
Dieta/veterinária , Cabras/fisiologia , Carne/análise , Opuntia/química , Ração Animal/análise , Animais , Composição Corporal , Relação Dose-Resposta a Droga , Músculo Esquelético/fisiologia , Distribuição Aleatória , Zea mays/química
2.
Bull Entomol Res ; 107(4): 419-430, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27974065

RESUMO

Vector-borne diseases are exceptionally sensitive to climate change. Predicting vector occurrence in specific regions is a challenge that disease control programs must meet in order to plan and execute control interventions and climate change adaptation measures. Recently, an increasing number of scientific articles have applied ecological niche modelling (ENM) to study medically important insects and ticks. With a myriad of available methods, it is challenging to interpret their results. Here we review the future projections of disease vectors produced by ENM, and assess their trends and limitations. Tropical regions are currently occupied by many vector species; but future projections indicate poleward expansions of suitable climates for their occurrence and, therefore, entomological surveillance must be continuously done in areas projected to become suitable. The most commonly applied methods were the maximum entropy algorithm, generalized linear models, the genetic algorithm for rule set prediction, and discriminant analysis. Lack of consideration of the full-known current distribution of the target species on models with future projections has led to questionable predictions. We conclude that there is no ideal 'gold standard' method to model vector distributions; researchers are encouraged to test different methods for the same data. Such practice is becoming common in the field of ENM, but still lags behind in studies of disease vectors.


Assuntos
Vetores Artrópodes , Mudança Climática , Dípteros , Ecossistema , Modelos Teóricos , Animais , Ixodes , Triatoma
3.
Genet Mol Res ; 16(2)2017 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-28437560

RESUMO

Lasiodiplodia theobromae is a plant pathogen with a worldwide distribution, with low host specificity, causing stem cankers, dieback diseases, and fruit rot in several species of plants. In coconut, this pathogen is reported as the etiological agent of "coconut leaf blight" (CLB) disease, causing several losses in fruit production. The CLB is an important disease for this crop in Brazil. In our study, we used a phylogeographic approach through the molecular characterization of the translation elongation factor 1-α (TEF1-α) to elucidate the pathogen distribution in Brazil and other countries, besides, search information about diversity sources of this pathogen in coconut palm tree at Brazilian northern, northeast, and southeast. We found that L. theobromae diversity is within populations (locations), and populations that are located closest to the center of the tropical zone have more variability as Central Africa, Brazilian Southeast, and Northeast. The widespread distribution could be in part related with long-distance dispersal via global trade of plants and plant products. The entrance route of L. theobromae in Brazil probably occurred from Africa route and not occurred once. In Brazil, the diversity of this pathogen in coconut tree could be linked to two agents of selection: high host diversity (in Northeast) and distinct management measures adopted in Southeast. These different sources of selection, mainly the mutations, could be one of the reasons that we found distinct reactions to "coconut leaf blight" chemical control in these regions.


Assuntos
Ascomicetos/genética , Mutação , Polimorfismo Genético , Seleção Genética , Ascomicetos/classificação , Brasil , Ecossistema , Evolução Molecular , Proteínas Fúngicas/genética , Fator 1 de Elongação de Peptídeos/genética , Filogeografia
4.
Genet Mol Res ; 15(4)2016 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-28002615

RESUMO

Northern leaf blight (NLB), caused by Exserohilum turcicum, is one of the main foliar diseases that affect popcorn culture. Farmers use many control measures to minimize damage caused by this disease, among which, the use of cultivars with genetic resistance is the most effective and economical. The aim of this study was to investigate genetic variability influencing resistance to NLB in 25 popcorn maize lines grown under high and low phosphorus conditions in relation to foliar fungal disease caused by E. turcicum. We evaluated the disease incidence and severity, by analysis of variance and cluster test (Scott-Knott). There was sufficient genetic variability between strains for resistance traits. Genotypic variance was higher than environmental variance, and had more discriminatory power. We conclude that new progenies could be selected for the establishment of future populations. P-7, P-9, L-59, L-71, and L-76 progenies possess promising characteristics that simultaneously reduce the severity and the incidence of NLB in popcorn plants.


Assuntos
Fósforo/farmacologia , Doenças das Plantas/estatística & dados numéricos , Zea mays/genética , Ascomicetos/fisiologia , Produtos Agrícolas/genética , Produtos Agrícolas/microbiologia , Resistência à Doença , Variação Genética , Incidência , Doenças das Plantas/microbiologia , Seleção Genética , Zea mays/microbiologia
5.
Plant Biol (Stuttg) ; 25(5): 740-749, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37158679

RESUMO

Aluminium (Al) is toxic to most plants. Nevertheless, some species accumulate Al without showing toxicity symptoms. Previous studies have evidenced Al in chloroplasts of Al-accumulating species from the Cerrado vegetation in South America. We ask whether Al increases carbon assimilation through enhanced apparent efficiency of Rubisco. Seedlings of the Al-accumulator Qualea grandiflora (Vochysiaceae) were grown in nutrient solution with 0, 740, and 1480 µm Al. Growth parameters, relative leaf water content, Al concentration in organs, gas exchange and apparent carboxylation efficiency (measured from A/Ci curves) were evaluated for 60 days. Plants without Al showed no root growth, necrotic roots, low gas exchange rates, and decreased apparent carboxylation efficiency. Al-treated plants, however, showed new white roots and increased root biomass leading to higher leaf hydration, and apparent carboxylation efficiency was higher in these plants. Increased Al available in the nutrient solution increased Al accumulation in plant organs. Absence of Al compromised root integrity in Q. grandiflora, thus limiting leaf hydration. No positive direct effect of Al on Rubisco was evidenced in Al-treated plants.


Assuntos
Alumínio , Myrtales , Alumínio/toxicidade , Ribulose-Bifosfato Carboxilase , Plantas , Plântula , Folhas de Planta , Raízes de Plantas
6.
Diabetologia ; 55(10): 2823-2834, 2012 10.
Artigo em Inglês | MEDLINE | ID: mdl-22828956

RESUMO

AIMS/HYPOTHESIS: A high-fat dietary intake induces obesity and subclinical inflammation, which play important roles in insulin resistance. Recent studies have suggested that increased concentrations of circulating lipopolysaccharide (LPS), promoted by changes in intestinal permeability, may have a pivotal role in insulin resistance. Thus, we investigated the effect of gut microbiota modulation on insulin resistance and macrophage infiltration. METHODS: Swiss mice were submitted to a high-fat diet with antibiotics or pair-feeding for 8 weeks. Metagenome analyses were performed on DNA samples from mouse faeces. Blood was collected to determine levels of glucose, insulin, LPS, cytokines and acetate. Liver, muscle and adipose tissue proteins were analysed by western blotting. In addition, liver and adipose tissue were analysed, blinded, using histology and immunohistochemistry. RESULTS: Antibiotic treatment greatly modified the gut microbiota, reducing levels of Bacteroidetes and Firmicutes, overall bacterial count and circulating LPS levels. This modulation reduced levels of fasting glucose, insulin, TNF-α and IL-6; reduced activation of toll-like receptor 4 (TLR4), c-Jun N-terminal kinase (JNK), inhibitor of κ light polypeptide gene enhancer in B cells, kinase ß (IKKß) and phosphorylated IRS-1 Ser307; and consequently improved glucose tolerance and insulin tolerance and action in metabolically active tissues. In addition, there was an increase in portal levels of circulating acetate, which probably contributed to an increase in 5'-AMP-activated protein kinase (AMPK) phosphorylation in mice. We observed a striking reduction in crown-like structures (CLS) and F4/80(+) macrophage cells in the adipose tissue of antibiotic-treated mice. CONCLUSIONS/INTERPRETATION: These results suggest that modulation of gut microbiota in obesity can improve insulin signalling and glucose tolerance by reducing circulating LPS levels and inflammatory signalling. Modulation also appears to increase levels of circulating acetate, which activates AMPK and finally leads to reduced macrophage infiltration.


Assuntos
Antibacterianos/farmacologia , Dieta Hiperlipídica/efeitos adversos , Trato Gastrointestinal/microbiologia , Insulina/fisiologia , Metagenoma/efeitos dos fármacos , Obesidade/fisiopatologia , Transdução de Sinais/fisiologia , Quinases Proteína-Quinases Ativadas por AMP , Acetatos/sangue , Animais , Bacteroides/isolamento & purificação , Movimento Celular/fisiologia , Citocinas/sangue , Modelos Animais de Doenças , Trato Gastrointestinal/efeitos dos fármacos , Trato Gastrointestinal/patologia , Resistência à Insulina/fisiologia , Lipopolissacarídeos/sangue , Macrófagos/patologia , Masculino , Camundongos , Obesidade/etiologia , Obesidade/patologia , Proteínas Quinases/fisiologia
8.
J Inflamm (Lond) ; 15: 8, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29760586

RESUMO

BACKGROUND: Sepsis is one of the leading causes of death among hospitalized patients. At the onset of this condition, there is an over-production of pro-inflammatory mediators that contribute to organ failure and death. The excess production of pro-inflammatory mediators also impairs insulin signaling, which may be a pathophysiological tissue marker of proinflammatory cytokine action before organ failure. Statins and diacerein have pleiotropic effects, such as the blockage of inflammatory signaling pathways, suggesting that these drugs may be an attractive therapeutic or prophylactic strategy against sepsis. The aim of the present study was to investigate whether a statin or diacerein can improve insulin signaling, disease tolerance and survival in sepsis by inhibiting inflammatory pathways. METHODS: We investigated the effect of these drugs on survival, tissue insulin signaling and inflammatory pathways in the liver and muscle of rats with sepsis induced by cecal ligation and puncture (CLP). RESULTS: The results showed that administration of medications, with anti-inflammatory ability, to septic animals increased survival and improved disease tolerance and insulin resistance in the liver and muscle. The treatment also attenuated ER stress, NF-κB, JNK activation and restored glucose-6-phosphatase (G6Pase) levels in the liver. CONCLUSIONS: Our results indicate that atorvastatin and diacerein treatment can modulate inflammatory pathways and, in parallel, attenuate insulin resistance in sepsis. Since these two drugs have safety profiles and minimal side effects, we suggest that these drugs may be alternative therapies for the prevention or therapies for the treatment of insulin resistance in sepsis, which could potentially reduce mortality in patients with sepsis.

9.
J Ethnopharmacol ; 111(3): 547-52, 2007 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-17276638

RESUMO

The antidiabetic effect of Parkinsonia aculeata water soluble fraction (WSF) made of aerial parts of the plant (leaves and flowers) was investigated in alloxan diabetic rats. Its effect was compared with that of insulin (positive control). The physico-metabolic parameters measured were: body weight, food and liquid intake, urinary volume, hepatic glycogen, serum glucose, total cholesterol, HDL-cholesterol, triglycerides, urinary glucose and urea, and the weight of epididymal adipose tissue, liver, kidneys and the skeletal muscles (soleus and extensor digitorum longus). Oral administration of WSF (125 or 250 mg/kg) for 16 days exhibited a significant reduction in serum and urinary glucose, urinary urea, total cholesterol, HDL-cholesterol and triglycerides in alloxan diabetic rats. An improvement of hepatic glycogen, a decrease of liquid and food intake, and a significantly positive actions in the weight of skeletal muscles (soleus and extensor digitorum longus) and kidneys were also observed, but just diabetic group treated with WSF at a dose of 125 mg/kg showed significant reduction in urinary volume, body weight, an improvement of epididymal adipose tissue and a positive action in liver weight. The effects of WSF on the physico-metabolic parameters was comparable to those observed in diabetic insulin treated group. The results of this work suggest that P. aculeate may have new clinical significant choice in diabetes mellitus illness, and could explain the basis for its traditional use to manage diabetes-related complications by rural community of northeast of Brazil.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Fabaceae/química , Hipoglicemiantes/farmacologia , Extratos Vegetais/farmacologia , Administração Oral , Animais , Peso Corporal/efeitos dos fármacos , Brasil , Relação Dose-Resposta a Droga , Ingestão de Alimentos/efeitos dos fármacos , Glucose/metabolismo , Hipoglicemiantes/administração & dosagem , Insulina/farmacologia , Lipídeos/sangue , Glicogênio Hepático/metabolismo , Masculino , Medicina Tradicional , Músculo Esquelético/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos , Componentes Aéreos da Planta , Extratos Vegetais/administração & dosagem , Ratos , Ratos Wistar , Ureia/urina
10.
Meat Sci ; 124: 61-68, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27838573

RESUMO

Quality and sensory attributes of meat from 32 mixed-breed Santa Inês lambs fed diets composed of four silages with old man saltbush (Atriplex nummularia Lind), buffelgrass (Cenchrus ciliaris), Gliricidia (Gliricidia sepium), and Pornunça (Manihot sp.) were evaluated. Meat from lambs fed diet containing old man saltbush silage (P<0.05) showed greater values for cooking loss. Of the sensory attributes evaluated in the Longissimus lumborum muscle of the lambs, color and juiciness did not differ (P>0.05). However, the silages led to differences (P<0.05) in aroma, tenderness, and flavor values. The meat from animals fed the pornunça and Gliricidia silages was tenderer. Flavor scores were higher in meat from lambs that consumed old man saltbush silage and lower in the meat from those fed buffelgrass silage. Diets formulated with buffelgrass silage for sheep reduce meat production. Based on the results for carcass weight and meat quality, old man saltbush and pornunça are better silages for finishing sheep.


Assuntos
Dieta/veterinária , Carne Vermelha/análise , Silagem/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Cruzamento , Fenômenos Químicos , Comportamento do Consumidor , Proteínas Alimentares/análise , Estudos de Avaliação como Assunto , Fabaceae , Qualidade dos Alimentos , Humanos , Masculino , Músculo Esquelético/química , Carneiro Doméstico , Paladar
11.
Meat Sci ; 121: 88-95, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27288901

RESUMO

Replacement of soybean meal by peanut cake was evaluated on the meat quality of 45 Dorper × Santa Inês crossbred lambs. Animals were distributed in a completely randomized design, with five treatments and nine repetitions, and fed Tifton-85 hay and a concentrate mixed with 0.0%, 25.0%, 50.0%, 75.0% or 100.0% peanut cake based on the dry mass of the complete diet. The longissimus lumborum muscle was used to determine the proximate composition, physical-chemical characteristics and fatty acid profile. Significant differences (P<0.05) were found for the crude protein and ether extract levels, with average values of 23.38% and 2.15% in the sheep meat, respectively. The physical-chemical characteristics of the loin were not affected (P>0.05) by the diets. The fatty acid profile was affected by peanut cake supplementation for myristic, myristoleic, palmitoleic, linolenic and arachidonic fatty acids. Peanut cake can be added in the diet of lambs no effect on physical-chemical characteristics. However, the total replacement of the soybean meal altered the proximate composition and fatty acid profile of the meat.


Assuntos
Ração Animal/análise , Dieta/veterinária , Carne Vermelha/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Ácido Araquidônico/administração & dosagem , Arachis/química , Fenômenos Químicos , Ácidos Graxos/análise , Ácidos Graxos Monoinsaturados/administração & dosagem , Ácidos Linolênicos/administração & dosagem , Masculino , Ácido Mirístico/administração & dosagem , Carneiro Doméstico
12.
Meat Sci ; 118: 157-63, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27050756

RESUMO

Peanut cake is a biodiesel byproduct that has been tested as an alternative feed additive for use in cattle production. This study aimed to assess the importance of dietary peanut cake inclusion for young bull growth rate, beef production, and beef quality. In total, 32 Nellore young bulls individually housed in stalls with a mean initial body weight of 390±43.5kg were distributed in a completely randomized design for the experiment. The animals were fed Tifton 85 hay and one of four concentrate mixtures with 0, 33, 66 or 100% peanut cake instead of soybean meal. There was a linear reduction (P<0.05) in the slaughter weight and hot carcass weight and a quadratic effect (P<0.05) on the beef texture. No alterations occurred in the physicochemical characteristics of the longissimus thoracis; however, changes were observed (P<0.05) in the longissimus thoracis fatty acid profile. The replacement of soybean meal with peanut cake at levels up to 100% in the diet of feedlot-finished young bulls promotes a beneficial increase in the levels of PUFAs and the following nutraceutical compounds: conjugated linoleic acid (CLA) and Ω3 and Ω6 fatty acids.


Assuntos
Ração Animal/análise , Arachis/química , Dieta/veterinária , Qualidade dos Alimentos , Carne Vermelha/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos , Fenômenos Químicos , Ácidos Graxos Insaturados/análise , Ácidos Linoleicos Conjugados/análise , Masculino , Músculo Esquelético/química , Glycine max/química
13.
Food Chem ; 154: 308-14, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24518347

RESUMO

Lactoferrin is a protein that is present in cheese whey (a waste product from the dairy industry) and has several biological activities. However, its production from whey must have a high yield and low cost for industrial applications. As such, this study reports the use of polyacrylamide cryogel, loaded with Cu(2+) (through the bond with iminodiacetic acid (IDA)), as an adsorbent for the chromatographic process to capture lactoferrin whey. Ultrafiltered cheese whey was passed through the cryogel-IDA-Cu(2+) system. The eluates were subjected to analysis of total protein, SDS-PAGE and size exclusion chromatography. The results showed an axial dispersion coefficients, at different superficial velocities of liquid, in a range of 10(-6)-10(-5)m(2)/s. The cryogel demonstrated good hydraulic permeability (4.7086×10(-13)m(2)) and a porosity of approximately 78.2%. The IDA-Cu(2+) cryogel system was also able to capture lactoferrin in high purity.


Assuntos
Queijo/análise , Cromatografia de Afinidade/métodos , Cobre/química , Criogéis/química , Lactoferrina/isolamento & purificação , Proteínas do Leite/química , Resinas Acrílicas/química , Adsorção , Cromatografia de Afinidade/instrumentação , Lactoferrina/química , Porosidade , Ligação Proteica , Proteínas do Soro do Leite
14.
Biomed Res Int ; 2014: 981923, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24901004

RESUMO

Crude venom of Bothrops jararacussu and isolated phospholipases A2 (PLA2) of this toxin (BthTX-I and BthTX-II) were chemically modified (alkylation) by p-bromophenacyl bromide (BPB) in order to study antibody production capacity in function of the structure-function relationship of these substances (crude venom and PLA2 native and alkylated). BthTX-II showed enzymatic activity, while BthTX-I did not. Alkylation reduced BthTX-II activity by 50% while this process abolished the catalytic and myotoxic activities of BthTX-I, while reducing its edema-inducing activity by about 50%. Antibody production against the native and alkylated forms of BthTX-I and -II and the cross-reactivity of antibodies to native and alkylated toxins did not show any apparent differences and these observations were reinforced by surface plasmon resonance (SPR) data. Histopathological analysis of mouse gastrocnemius muscle sections after injection of PBS, BthTX-I, BthTX-II, or both myotoxins previously incubated with neutralizing antibody showed inhibition of the toxin-induced myotoxicity. These results reveal that the chemical modification of the phospholipases A2 (PLA2) diminished their toxicity but did not alter their antigenicity. This observation indicates that the modified PLA2 may provide a biotechnological tool to attenuate the toxicity of the crude venom, by improving the production of antibodies and decreasing the local toxic effects of this poisonous substance in animals used to produce antivenom.


Assuntos
Alquilação/imunologia , Anticorpos/imunologia , Bothrops/metabolismo , Venenos de Crotalídeos/metabolismo , Histidina/metabolismo , Fosfolipases A2/metabolismo , Animais , Antivenenos/imunologia , Antivenenos/metabolismo , Bothrops/imunologia , Reações Cruzadas/imunologia , Venenos de Crotalídeos/imunologia , Histidina/imunologia , Masculino , Camundongos , Músculo Esquelético/imunologia , Músculo Esquelético/metabolismo , Fosfolipases A2/imunologia
15.
Biomed Res Int ; 2014: 654170, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24707493

RESUMO

Currently, Crotalus viridis was divided into two species: Crotalus viridis and Crotalus oreganus. The current classification divides "the old" Crotalus viridis into two new and independent species: Crotalus viridis (subspecies: viridis and nuntius) and Crotalus oreganus (subspecies: abyssus, lutosus, concolor, oreganus, helleri, cerberus, and caliginis). The analysis of a product from cDNA (E6d), derived from the gland of a specie Crotalus viridis viridis, was found to produce an acid phospholipase A2. In this study we isolated and characterized a PLA2 (D49) from Crotalus oreganus abyssus venom. Our studies show that the PLA2 produced from the cDNA of Crotalus viridis viridis (named E6d) is exactly the same PLA2 primary sequence of amino acids isolated from the venom of Crotalus oreganus abyssus. Thus, the PLA2 from E6d cDNA is actually the same PLA2 presented in the venom of Crotalus oreganus abyssus and does not correspond to the venom from Crotalus viridis viridis. These facts highlight the importance of performing more studies on subspecies of Crotalus oreganus and Crotalus viridis, since the old classification may have led to mixed results or mistaken data.


Assuntos
Aminoácidos/química , Venenos de Crotalídeos/enzimologia , Fosfolipases A2/química , Animais , Crotalus , Fosfolipases A2/isolamento & purificação , Estados Unidos
16.
J Chromatogr A ; 1312: 1-9, 2013 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-24034975

RESUMO

The adsorption affinity of lactoferrin from whey in monolithic supermacroporous cryogel was analyzed using equilibrium data adsorptive isothermal titration microcalorimetry to measure thermodynamic information governing the process. Isotherm data was obtained at temperatures of 20, 30 and 40°C, pH 6, 7 and 8, and ionic strength of 200, 600 and 1000mmolL(-1) NaCl. The Langmuir model was fitted to equilibrium data. The binding was tighter at higher temperatures. The adsorption of protein was observed as spontaneous in all cases analyzed. The microcalorimetric study indicated that, in most cases examined, the adsorption of the protein in the matrix was entropy and enthalpy favored and entropy driven. Results provide data to enable the improvement of technical processes for the affinity separation of proteins.


Assuntos
Calorimetria/métodos , Cobre/química , Criogéis/química , Lactoferrina/química , Adsorção , Cromatografia de Afinidade/métodos , Concentração de Íons de Hidrogênio , Lactoferrina/metabolismo , Cloreto de Sódio/química , Termodinâmica
17.
Biomed Res Int ; 2013: 153045, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24171158

RESUMO

Ophidian envenomation is an important health problem in Brazil and other South American countries. In folk medicine, especially in developing countries, several vegetal species are employed for the treatment of snakebites in communities that lack prompt access to serum therapy. However, the identification and characterization of the effects of several new plants or their isolated compounds, which are able to inhibit the activities of snake venom, are extremely important and such studies are imperative. Snake venom contains several organic and inorganic compounds; phospholipases A2 (PLA2s) are one of the principal toxic components of venom. PLA2s display a wide variety of pharmacological activities, such as neurotoxicity, myotoxicity, cardiotoxicity, anticoagulant, hemorrhagic, and edema-inducing effects. PLA2 inhibition is of pharmacological and therapeutic interests as these enzymes are involved in several inflammatory diseases. This review describes the results of several studies of plant extracts and their isolated active principles, when used against crude snake venoms or their toxic fractions. Isolated inhibitors, such as steroids, terpenoids, and phenolic compounds, are able to inhibit PLA2s from different snake venoms. The design of specific inhibitors of PLA2s might help in the development of new pharmaceutical drugs, more specific antivenom, or even as alternative approaches for treating snakebites.


Assuntos
Produtos Biológicos/isolamento & purificação , Inibidores de Fosfolipase A2/isolamento & purificação , Plantas/química , Venenos de Serpentes/química , Animais , Produtos Biológicos/química , Brasil , Inibidores de Fosfolipase A2/química
18.
Peptides ; 36(2): 206-12, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22617223

RESUMO

Crotalus oreganus abyssus is a rattlesnake that is usually found in the Grand Canyon, United States of America. Knowledge regarding the composition of C. o. abyssus venom is scarce. New natriuretic peptides (NPs) have been isolated and characterized from the venoms of members of the Crotalinae family. The NP family comprises three members, ANP (atrial natriuretic peptide), BNP (b-type natriuretic peptide) and CNP (c-type natriuretic peptide), and has an important role in blood pressure regulation and electrolyte homeostasis. The aim of the present study was to characterize a novel natriuretic-like peptide (Coa_NP2), isolated from C. o. abyssus venom. The Coa_NP2 presents an average molecular mass of 3419.88Da (theoretical average molecular mass 3418.94Da, monoisotopic molecular mass 3416.66Da and theoretical PI 7.78) and its amino acid sequence presents the loop region that is characteristic of natriuretic peptides. The peptide has 32 amino acids and its complete sequence is SYGISSGCFGLKLDRIGTMSGLGCWRLLQDSP. Coa_NP2 is a natriuretic peptide of the ANP/BNP-like family, since the carboxyterminal region of CNP has its own NP domain. We demonstrate, herein, that Coa_NP2 produces a dose-dependent decrease in mean arterial pressure in rats, followed by significant increases in concentrations of markers of nitric oxide formation measured in the plasma and vasorelaxation in a thoracic aortic ring bath. The structural and biological aspects confirm Coa_NP2 as a new natriuretic peptide, isolated from snake venom.


Assuntos
Eletrólitos/metabolismo , Peptídeos Natriuréticos/química , Peptídeos Natriuréticos/farmacologia , Venenos de Serpentes/química , Animais , Pressão Arterial/efeitos dos fármacos , Crotalus , Homeostase/efeitos dos fármacos , Masculino , Óxido Nítrico/sangue , Ratos , Ratos Wistar , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
19.
Endocrinology ; 153(11): 5261-74, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22948222

RESUMO

The molecular integration of nutrient- and pathogen-sensing pathways has become of great interest in understanding the mechanisms of insulin resistance in obesity. The double-stranded RNA-dependent protein kinase (PKR) is one candidate molecule that may provide cross talk between inflammatory and metabolic signaling. The present study was performed to determine, first, the role of PKR in modulating insulin action and glucose metabolism in physiological situations, and second, the role of PKR in insulin resistance in obese mice. We used Pkr(-/-) and Pkr(+/+) mice to investigate the role of PKR in modulating insulin sensitivity, glucose metabolism, and insulin signaling in liver, muscle, and adipose tissue in response to a high-fat diet. Our data show that in lean Pkr(-/-) mice, there is an improvement in insulin sensitivity, and in glucose tolerance, and a reduction in fasting blood glucose, probably related to a decrease in protein phosphatase 2A activity and a parallel increase in insulin-induced thymoma viral oncogene-1 (Akt) phosphorylation. PKR is activated in tissues of obese mice and can induce insulin resistance by directly binding to and inducing insulin receptor substrate (IRS)-1 serine307 phosphorylation or indirectly through modulation of c-Jun N-terminal kinase and inhibitor of κB kinase ß. Pkr(-/-) mice were protected from high-fat diet-induced insulin resistance and glucose intolerance and showed improved insulin signaling associated with a reduction in c-Jun N-terminal kinase and inhibitor of κB kinase ß phosphorylation in insulin-sensitive tissues. PKR may have a role in insulin sensitivity under normal physiological conditions, probably by modulating protein phosphatase 2A activity and serine-threonine kinase phosphorylation, and certainly, this kinase may represent a central mechanism for the integration of pathogen response and innate immunity with insulin action and metabolic pathways that are critical in obesity.


Assuntos
Resistência à Insulina/fisiologia , Obesidade/metabolismo , RNA de Cadeia Dupla/metabolismo , eIF-2 Quinase/metabolismo , Animais , Glicemia/genética , Glicemia/metabolismo , Ingestão de Alimentos/fisiologia , Glucose/metabolismo , Intolerância à Glucose/genética , Intolerância à Glucose/metabolismo , Proteínas Substratos do Receptor de Insulina/genética , Proteínas Substratos do Receptor de Insulina/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Camundongos Knockout , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Obesidade/genética , Consumo de Oxigênio/fisiologia , Ácido Palmítico/farmacologia , Fosforilação , Proteína Fosfatase 2/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA de Cadeia Dupla/genética , Transdução de Sinais/efeitos dos fármacos , eIF-2 Quinase/genética
20.
Clin Microbiol Infect ; 17(5): 719-21, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21521412

RESUMO

Melioidosis, a severe infectious disease caused by Burkholderia pseudomallei that is prevalent in Southeast Asia and Northern Australia, has been sporadically reported in Brazil since 2003. We report a case of aortic aneurysm with blood culture positive for B. pseudomallei. The phylogenetic analysis of 16S ribosomal DNA showed this isolate to be evolutionarily grouped with the MSHR346 strains from Thailand.


Assuntos
Aneurisma Infectado/microbiologia , Burkholderia pseudomallei/genética , Burkholderia pseudomallei/isolamento & purificação , Melioidose/microbiologia , Idoso , Brasil , Humanos , Masculino , Melioidose/mortalidade , Filogenia , RNA Ribossômico 16S/genética , Tailândia
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