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1.
Braz J Biol ; 83: e274499, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38055576

RESUMO

Salinity is harmful to crops when the concentration of soluble salts overcomes the salinity threshold of the crop, causing osmotic stress and limitations in plant growth. In this scenario, adopting tolerant cultivars is the most adequate strategy to minimize agricultural losses. However, the inheritance of tolerance depends on the genotype. From this perspective, this study assessed the tolerance to severe salt stress in 11 cotton cultivars based on gas exchange parameters and the free proline content. The cultivars were grown in a greenhouse and subjected to 34 days of saline irrigation (10 dS m-1), starting 45 days after seedling emergence (B1 phase). Plant growth was monitored weekly until the end of the salt stress period. The treatments consisted of a combination of two factors: eleven cultivars associated with two electrical conductivity levels of irrigation water (ECw: 0.3 and 10.0 dS m-1). The experimental design was in randomized blocks in a 11 × 2 factorial arrangement with three replications (66 plots), with the experimental unit consisting of one plant per plot. Salinity impacted plant growth, being reflected on the gas exchange and free proline data of most cultivars. However, BRS 286, FMT 705, BRS 416, and BRS Acácia, and CNPA 7MH withstood the effects of stress and osmotically adjusted to the salt stress conditions, thus minimizing the damage to growth. Those cultivars are the most indicated for improvement programs aiming at tolerance to salt stress based on the results found in this research.


Assuntos
Estresse Salino , Tolerância ao Sal , Plântula , Salinidade , Prolina
2.
Braz J Biol ; 83: e272003, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37162072

RESUMO

The lack of water during crop growth causes damage to any production system, especially when it occurs during the initial establishment or beginning of the reproductive stage. Although cotton can be properly managed in regions with water limitation, its yield is affected at different levels according to the genetics of the cultivar adopted. Exogenous application of some organic components has shown a stress-mitigating effect and can be a valuable procedure to enhance the yield of water stress-sensitive cultivars. The objective of this work was to evaluate the benefits of exogenous application of pyruvic acid (100 µM) in cotton plants under water deficit varying the phenological stage of the crop. The experiment was conducted in a greenhouse, where the plants were grown in pots and subjected to seven days of water suspension, initiated individually in stages V2 and B1. Each pot contained two plants. The treatments adopted were: T1 - control, T2 - water suppression; and T3 - water suppression + pyruvate application. The design was randomized blocks in a factorial scheme (3 × 3) with three replicates. The reductions in gas exchange and growth of the cultivars BRS Seridó, CNPA 7MH and FM 966 were more significant in the reproductive stage, especially for FM 966, which was more sensitive. Pyruvate application reduced the effects of water suppression on boll production by 31% in BRS Seridó and 34% in CNPA 7MH and FM 966.


Assuntos
Gossypium , Ácido Pirúvico , Ácido Pirúvico/farmacologia , Gossypium/genética , Reprodução
3.
Braz J Med Biol Res ; 55: e11635, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35137852

RESUMO

Hypovolemia induced by hemorrhage is a common clinical complication, which stimulates vasopressin (AVP) secretion by the neurohypophysis in order to retain body water and maintain blood pressure. To evaluate the role of brain L-glutamate and angiotensin II on AVP secretion induced by hypovolemia we induced hemorrhage (∼25% of blood volume) after intracerebroventricular (icv) administration of AP5, NBQX, or losartan, which are NMDA, AMPA, and AT1 receptor antagonists, respectively. Hemorrhage significantly increased plasma AVP levels in all groups. The icv injection of AP5 did not change AVP secretion in response to hemorrhage. Conversely, icv administration of both NBQX and losartan significantly decreased plasma AVP levels after hemorrhage. Therefore, the blockade of AMPA and AT1 receptors impaired AVP secretion in response to hemorrhage, suggesting that L-glutamate and angiotensin II acted in these receptors to increase AVP secretion in response to hemorrhage-induced hypovolemia.


Assuntos
Arginina Vasopressina , Hemorragia , Receptor Tipo 1 de Angiotensina , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico , Angiotensina II , Animais , Arginina Vasopressina/metabolismo , Pressão Sanguínea , Injeções Intraventriculares , Masculino , Ratos Wistar , Receptor Tipo 1 de Angiotensina/metabolismo
4.
Braz. j. med. biol. res ; 55: e11635, 2022. graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1360232

RESUMO

Hypovolemia induced by hemorrhage is a common clinical complication, which stimulates vasopressin (AVP) secretion by the neurohypophysis in order to retain body water and maintain blood pressure. To evaluate the role of brain L-glutamate and angiotensin II on AVP secretion induced by hypovolemia we induced hemorrhage (∼25% of blood volume) after intracerebroventricular (icv) administration of AP5, NBQX, or losartan, which are NMDA, AMPA, and AT1 receptor antagonists, respectively. Hemorrhage significantly increased plasma AVP levels in all groups. The icv injection of AP5 did not change AVP secretion in response to hemorrhage. Conversely, icv administration of both NBQX and losartan significantly decreased plasma AVP levels after hemorrhage. Therefore, the blockade of AMPA and AT1 receptors impaired AVP secretion in response to hemorrhage, suggesting that L-glutamate and angiotensin II acted in these receptors to increase AVP secretion in response to hemorrhage-induced hypovolemia.

5.
Food Chem ; 330: 127187, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32531636

RESUMO

The objective of this study was to evaluate the chemical composition and fatty acid profile of broilers fed diets containing glycerol monolaurate (GML) in place of antimicrobials. Groups: T0 group used as control; T100, T200, and T300 groups received diets supplemented with 100, 200, and 300 mg/kg of GML, respectively. The feed mixture used in the poultry feed during the four phases of the production cycle (days 1 to 7; 8 to 21; 22 to 35; and 36 to 42 of birds age) showed similar levels of protein, lipid and ash, as well as fatty acid profiles. Samples of frozen breasts from chickens slaughtered at 42 days of age were used for chemical gross composition and fatty acid analysis. We observed lower lipid levels in the meat of broilers in the T200 and T300 groups than in the T0 group. Lower lipid peroxidation occurred in the meat of animals that consumed GML in respect to control. Total saturated fatty acid percentage was lower, while total polyunsaturated fatty acid percentage was higher in the meat of broilers fed GML than in the control group. We conclude that the increase in GML concentrations alters the lipid profile of broiler meat.


Assuntos
Ácidos Graxos/química , Lauratos/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Carne/análise , Monoglicerídeos/farmacologia , Ração Animal , Animais , Galinhas , Ácidos Graxos/análise
6.
Exp Physiol ; 104(12): 1754-1761, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31553087

RESUMO

NEW FINDINGS: What is the central question of this study? Can Na+ depletion mobilize Na+ from the skin reservoir in ovariectomized rats? Does oestrogen replacement change the amount and the dynamics of skin Na+ storage? Is the reduced salt appetite after Na+ depletion in ovariectomized rats with oestrogen replacement related to changes in the skin Na+ ? What is the main finding and its importance? This work demonstrated that acute body Na+ depletion induced by frusemide mobilized the osmotically inactive skin Na+ reservoir to become osmotically active. Oestrogen treatment decreased the induced Na+ intake in ovariectomized rats but did not modulate the inactive Na+ reservoir in control conditions or its mobilization induced by Na+ depletion. ABSTRACT: Oestradiol, which is an important hormone for water and electrolyte balance, also has a role in the inhibition of induced Na+ appetite. Sodium can be stored in the skin in osmotically active or inactive forms, and this skin Na+ reservoir may be involved in the control of body Na+ levels during physiopathological challenges. In this study, we investigated whether the effect of sodium depletion by frusemide can mobilize Na+ from the skin reservoir and whether oestradiol replacement changes or mobilizes the Na+ reserves in the skin. Ovariectomized Wistar rats were treated with vehicle or oestradiol for 7 days to evaluate the effects of oestrogen on the hydroelectrolyte balance, intake responses and skin Na+ and water content in basal conditions. Furthermore, the effects of oestrogen were evaluated after 24 h frusemide-induced whole-body Na+ depletion. Oestradiol-replaced rats exhibited reduced water intake without any significant changes in salt intake, Na+ excretion or water and Na+ skin content in basal conditions. After sodium depletion, both vehicle- and oestradiol-treated rats exhibited an increase in the osmotically active skin Na+ , which was associated with a decrease of the inactive skin Na+ reservoir. Oestrogen decreased the hypertonic saline intake induced by Na+ depletion, but it was not associated with any significant changes in the skin Na+ reservoir. Thus, sodium depletion is able to change the inactive-active skin Na+ reservoir balance. However, the oestrogenic modulation of sodium appetite after Na+ depletion is probably not related to the action of this hormone in the skin Na+ reservoir balance.


Assuntos
Estradiol/farmacologia , Hiponatremia/induzido quimicamente , Hiponatremia/metabolismo , Pele/metabolismo , Inibidores de Simportadores de Cloreto de Sódio e Potássio/toxicidade , Sódio/deficiência , Animais , Estradiol/uso terapêutico , Feminino , Furosemida/toxicidade , Hiponatremia/tratamento farmacológico , Ovariectomia/efeitos adversos , Ovariectomia/tendências , Ratos , Ratos Wistar , Pele/efeitos dos fármacos , Cloreto de Sódio na Dieta/administração & dosagem
7.
Rev Neurol (Paris) ; 175(10): 604-613, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31519304

RESUMO

A growing number of studies have shown that exposure to air pollutants such as particulate matter and gases can cause cardiovascular, neurodegenerative and psychiatric diseases. The severity of the changes depends on several factors such as exposure time, age and gender. Inflammation has been considered as one of the main factors associated with the generation of these diseases. Here we present some cellular mechanisms activated by air pollution that may represent risk factors for epilepsy and drug resistance associated to epilepsy.


Assuntos
Poluição do Ar , Epilepsia/etiologia , Gases , Exposição por Inalação , Fatores Etários , Poluição do Ar/efeitos adversos , Poluição do Ar/estatística & dados numéricos , Epilepsia Resistente a Medicamentos/epidemiologia , Epilepsia Resistente a Medicamentos/etiologia , Doença Ambiental/epidemiologia , Doença Ambiental/etiologia , Epilepsia/epidemiologia , Epilepsia/patologia , Feminino , Gases/administração & dosagem , Gases/efeitos adversos , Humanos , Exposição por Inalação/efeitos adversos , Exposição por Inalação/estatística & dados numéricos , Masculino , Material Particulado/toxicidade , Fatores de Risco , Fatores Sexuais
8.
J Comp Pathol ; 170: 34-45, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31375157

RESUMO

The lowland tapir (Tapirus terrestris) is the largest land mammal in South America. The species faces steady population decline due to poaching, habitat loss and fragmentation, road-kill, pesticide pollution, competition with domestic livestock and fires, among other threats. The lowland tapir is currently listed as vulnerable to extinction. Little information is available about natural disease processes for the species. This study aimed to report the pathological findings recorded in a cohort of 35 lowland tapirs killed by motor vehicle collision (MVC) on highways of Mato Grosso do Sul State, Brazil, between 2015 and 2018. The main gross pathological findings were those associated with MVC, primarily involving skeletal fractures and internal multiorgan damage with extensive bleeding and/or severe central nervous system injury. The most prevalent concurrent histopathological findings, unrelated to the cause of death, were: adrenal gland degeneration, necrosis and loss of fascicular and reticular cells with replacement fibrosis and cortical atrophy (9/15; 60%); interstitial pneumonia (20/34; 59%); glossitis (9/24; 38%); pulmonary anthracosis (12/34; 35%); colitis (9/28; 32%); and cholangitis/pericholangitis (9/35; 26%). The aetiopathogeneses and clinicopathological significance of some of these findings are unclear; however, parasitic infections appear to be common. Our results highlight the importance of wildlife health information obtained through the study of carcasses of roadkills.


Assuntos
Animais Selvagens , Perissodáctilos , Acidentes de Trânsito , Animais , Brasil
9.
Oper Dent ; 44(3): 273-280, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30517067

RESUMO

OBJECTIVES: To investigate the survival and failure mode of fiber-post resin restorations over preparations with different ferrule designs when submitted to a fatigue load test. METHODS AND MATERIALS: Fifty bovine incisors were selected and divided into five groups (n=10) according to ferrule design: a no-ferrule group, a 2-mm circumferential ferrule group, a 2-mm buccal ferrule group, a 2-mm lingual ferrule group, and a 2-mm buccal and lingual ferrule group. The fiberglass post was cemented and the composite core was built up and prepared, followed by cementation of a full composite crown. The samples were subjected to a cyclic fatigue test with loading applicator at 135°; a staircase approach was used until fracture. Survival (cycles to fracture) and failure modes were recorded. Survival data were analyzed with the log-rank test, while Kruskal-Wallis and Fisher exact tests were used to analyze failure mode data (α=0.05). RESULTS: The median number of cycles to fracture ranged from 215,000 to 236,153. The log-rank test showed no statistically significant difference in survival rates among the groups (p=0.82). Regarding failure mode, three types were observed: I, post and/or core fracture; II, root fracture in the cervical third; and III, root fracture in the middle third. No statistical difference was observed among the groups (Kruskal-Wallis test, p=0.147). CONCLUSION: The ferrule design had no effect on fatigue resistance or failure mode of endodontically treated incisor teeth restored with a fiber post, composite core buildup, and composite crown.


Assuntos
Técnica para Retentor Intrarradicular , Fraturas dos Dentes , Dente não Vital , Animais , Bovinos , Resinas Compostas , Coroas , Análise do Estresse Dentário
10.
J Phys Chem A ; 122(38): 7628-7645, 2018 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-30226385

RESUMO

A combined study of vibrational and thermodynamic properties of metaboric acid (BOH)3O3 crystal polymorphs α, ß, and γ were obtained through density functional theory (DFT) calculations in an attempt to resolve the conflicting assignments that currently exist in the literature for them. A complete correlation between the normal-mode assignment and vibrational signatures to distinguish particular features of each metaboric acid polymorph, in particular, those related to motions of the planar layers in α-(BOH)3O3, with a level of detail surpassing essays based on previous published experimental works has been achieved. Besides, no DFT-based research work was published early on the (BOH)3O3 polymorph vibrational properties, and our DFT-simulated infrared and Raman spectra for all metaboric acid polymorphs agree very well with experiment. Comparison of the previously published experimental IR and Raman spectroscopic results with predictions from higher levels DFT calculations allows identification of the in-plane and out-of-plane B-O bending modes. For example, the strongest measured (DFT-calculated) Raman modes of α-(BOH)3O3 at 591 and 797 cm-1 (599 and 810 cm-1) are identified as vibrational signatures of breathing B3O3/Ag in-plane modes, while the shoulder in the lattice modes region at 135 (143) cm-1 is the vibrational signature of the bending B3O3/B1g out-of-plane mode. Phonon-dispersion bands and their respective phonon densities of states were also evaluated for each system, as well as temperature-dependent curves for entropy, enthalpy, free energy, heat capacity, and Debye temperature. Phonon dispersion curves are singular for each (BOH)3O3 species, and a consistent gap decrease between the lowest and highest frequency vibrational bands was observed. The DFT-based calculations also revealed that the noncovalent interactions prevalent in the α and ß crystals lead to significant differences with respect to the thermodynamic properties in comparison with the γ phase.

11.
J Neuroendocrinol ; : e12604, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29717520

RESUMO

The impairment in arginine vasopressin (AVP) secretion during sepsis is described in clinical and experimental studies and has been associated with oxidative stress, apoptosis, and diminished activation of hypothalamic neurons. Few studies have, however, assessed these abnormalities in sepsis survivors. Here we performed two sets of experiments on Wistar rats that had been subjected to sepsis by cecal ligation and puncture (CLP) or nonmanipulated (naive) as control. In the first set, tissues and blood were collected from survivor rats 10 days after CLP to quantify hypothalamic Bcl-2, cleaved caspase- 3 and synaptophysin content, and bacterial load. In the second set, survivor rats were submitted to an acute osmotic stimulus (hypertonic saline), and after 30 minutes the water intake and AVP secretion were analyzed. The sepsis-surviving rats did not show bacterial load in tissues, but their hypothalamic synaptophysin and Bcl-2 levels were decreased, and the cleaved caspase- 3 level was increased when compared with the control group. However, AVP secretion was significantly attenuated in the CLP survivor animals submitted to an acute osmotic stimulus. These results suggest that the persistent AVP impairment in sepsis survivor animals may be due to a hypothalamic dysfunction associated with a synaptic deficit and decreased anti-apoptotic protein expression. This article is protected by copyright. All rights reserved.

12.
J Phys Chem A ; 122(5): 1312-1325, 2018 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-29328646

RESUMO

Boric acid (H3BO3) is being used effectively nowadays in traps/baits for the management of Aedes aegypti L. and Aedes albopictus Skuse species of mosquitoes, which are the main spreading vectors worldwide for diseases such as malaria, dengue, and zika. Previously, we published results on the structural, electronic, and optical properties of its molecular triclinic H3BO3-2A and trigonal H3BO3-3T polymorphs within the framework of density functional theory (DFT). Because of the renewed importance of these materials, the focus of this work is on the vibrational properties of the bulk boric acid 2A and 3T polymorphs. We measured the infrared and Raman spectra of the former, which was accompanied and interpreted through state-of-the-art DFT calculations, supplemented by computations regarding the H3BO3 molecule and two-dimensional layers based on the bulk structures. We identify/assign their normal modes and find vibrational signatures for each polymorph as well as in- and out-of-plane motions and molecular vibrations, unveiling a nice agreement between the DFT level of theory employed and our improved spectroscopic measurements in the wavenumber ranges of 400-2000 cm-1 (infrared) and 0-1500 cm-1 (Raman). We show that a dispersion-corrected DFT functional within the generalized gradient approximation (GGA) can be very accurate in describing the vibrational properties of the boric acid polymorphs. Besides, several issues left open/not clearly resolved in previously published works on the vibrational mode assignments of the bulk and 2D sheets of boric acid are explained satisfactorily. Finally, phonon dispersions and associated densities of states were also evaluated for each polymorph along with their temperature-dependent DFT-calculated entropy, enthalpy, free energy, heat capacity, and Debye temperature. In particular, our DFT calculations suggest a possible way to differentiate the 2A and 3T boric acid polymorphs through Raman spectroscopy and heat capacity measurements.

13.
J Fish Dis ; 41(5): 791-796, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29350421

RESUMO

Nanoencapsulated Melaleuca alternifolia essential oil (tea tree oil, TTO) is a natural alternative treatment, with 100% therapeutic efficacy in fish experimentally infected with Pseudomonas aeruginosa, and has also potent protective effects linked with antioxidant properties. However, the pathways responsible for the antioxidant capacity remain unknown. Thus, this study evaluated whether the inhibition of seric xanthine oxidase (XO) activity can be considered a pathway involved in the antioxidant capacity of nanoencapsulated TTO in fish experimentally infected with P. aeruginosa. Seric samples from fish infected with P. aeruginosa showed increased XO activity, as well as increased uric acid and reactive oxygen species (ROS) levels. In contrast, the prophylactic treatment with nanoencapsulated TTO prevented these infection-induced alterations. Based on the evidence obtained, the upregulation of seric XO activity induced pro-oxidative effects in the serum of fish experimentally infected with P. aeruginosa, due to excessive formation of uric acid, which stimulates the release of ROS. This treatment was able to prevent the upregulated seric XO activity and, consequently, the excessive formation of uric acid and ROS. In summary, inhibition of seric XO activity can be considered a pathway involved in the antioxidant capacity of nanoencapsulated TTO in fish experimentally infected with P. aeruginosa.


Assuntos
Antibacterianos/farmacologia , Peixes-Gato , Doenças dos Peixes/tratamento farmacológico , Infecções por Pseudomonas/veterinária , Pseudomonas aeruginosa/efeitos dos fármacos , Óleo de Melaleuca/farmacologia , Animais , Antioxidantes/metabolismo , Doenças dos Peixes/microbiologia , Proteínas de Peixes/antagonistas & inibidores , Proteínas de Peixes/sangue , Nanocápsulas , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Xantina Oxidase/antagonistas & inibidores , Xantina Oxidase/sangue
14.
J Fish Dis ; 41(2): 209-213, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28836668

RESUMO

Central nervous system (CNS) infections continue to be an important cause of morbidity and mortality, and microbial invasion of the blood-brain barrier (BBB) is considered a prerequisite for CNS infections, which contribute to behavioural abnormalities and disease pathogenesis. Based on this information, the aim of this study was to evaluate whether Pseudomonas aeruginosa causes disruption of the BBB, and to investigate the involvement of cerebral myeloperoxidase (MPO) activity in this process in experimentally infected silver catfish. The permeability of the BBB to Evans blue dye increased in the infected animals on days three and six post-infection (PI) compared to the control group. Moreover, cerebral MPO activity and reactive oxygen species (ROS) levels also increased in the infected animals on days three and six PI compared to the control group. Based on this evidence, we concluded that P. aaeruginosa causes a disruption of the BBB, which may contribute to disease pathogenesis in the CNS. Moreover, the increase in cerebral MPO activity and ROS levels may be considered a pathway involved in BBB breakdown, allowing the passage of bacteria to the CNS.


Assuntos
Barreira Hematoencefálica/fisiopatologia , Peixes-Gato , Doenças dos Peixes/fisiopatologia , Proteínas de Peixes/genética , Peroxidase/genética , Infecções por Pseudomonas/veterinária , Pseudomonas aeruginosa/fisiologia , Animais , Modelos Animais de Doenças , Doenças dos Peixes/microbiologia , Proteínas de Peixes/metabolismo , Permeabilidade , Peroxidase/metabolismo , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/fisiopatologia , Regulação para Cima
15.
J Fish Dis ; 41(1): 27-32, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28699699

RESUMO

It has been recognized that the cholinergic and adenosinergic systems have an essential role in immune and inflammatory responses during bacterial fish pathogens, such as the enzymes acetylcholinesterase (AChE) and adenosine deaminase (ADA), which are responsible for catalysis of the anti-inflammatory molecules acetylcholine (ACh) and adenosine (Ado) respectively. Thus, the aim of this study was to investigate the involvement of the cholinergic and adenosinergic systems on the immune response and inflammatory process in gills of experimentally infected Rhamdia quelen with Streptococcus agalactiae. Acetylcholinesterase activity decreased, while ACh levels increased in gills of infected animals compared to uninfected animals. On the other hand, a significant increase in ADA activity with a concomitant decrease in Ado levels was observed in infected animals compared to uninfected animals. Based on this evidence, we concluded that infection by S. agalactiae in silver catfish alters the cholinergic and adenosinergic systems, suggesting the involvement of AChE and ADA activities on immune and inflammatory responses, regulating the ACh and Ado levels. In summary, the downregulation of AChE activity exerts an anti-inflammatory profile in an attempt to reduce or prevent the tissue damage, while the upregulation of ADA activity exerts a pro-inflammatory profile, contributing to disease pathophysiology.


Assuntos
Doenças dos Peixes/microbiologia , Brânquias/imunologia , Infecções Estreptocócicas/veterinária , Streptococcus agalactiae/imunologia , Acetilcolinesterase/análise , Adenosina Desaminase/análise , Animais , Peixes-Gato , Doenças dos Peixes/imunologia , Brânquias/enzimologia , Brânquias/microbiologia , Inflamação/imunologia , Inflamação/microbiologia , Infecções Estreptocócicas/imunologia
16.
J Fish Dis ; 41(3): 469-474, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29193157

RESUMO

Several studies have been demonstrated that phosphotransfer network, through the adenylate kinase (AK) and pyruvate kinase (PK) activities, allows for new perspectives leading to understanding of disease conditions associated with disturbances in energy metabolism, metabolic monitoring and signalling. In this sense, the aim of this study was to evaluate whether experimental infection by Aeromonas caviae alters hepatic AK and PK activities of silver catfish Rhamdia quelen. Hepatic AK and PK activities decreased in infected animals compared to uninfected animals, as well as the hepatic adenosine triphosphate (ATP) levels. Also, a severe hepatic damage was observed in the infected animals due to the presence of dilation and congestion of vessels, degeneration of hepatocytes and loss of liver parenchyma architecture and sinusoidal structure. Therefore, we have demonstrated, for the first time, that experimental infection by A. caviae inhibits key enzymes linked to the communication between sites of ATP generation and ATP utilization. Moreover, the absence of a reciprocal compensatory mechanism between these enzymes contributes directly to hepatic damage and for a severe energetic imbalance, which may contribute to disease pathophysiology.


Assuntos
Aeromonas caviae/fisiologia , Peixes-Gato , Doenças dos Peixes/enzimologia , Proteínas de Peixes/genética , Infecções por Bactérias Gram-Negativas/veterinária , Fígado/enzimologia , Adenilato Quinase/genética , Adenilato Quinase/metabolismo , Animais , Metabolismo Energético , Doenças dos Peixes/virologia , Proteínas de Peixes/metabolismo , Infecções por Bactérias Gram-Negativas/enzimologia , Infecções por Bactérias Gram-Negativas/virologia , Fígado/virologia , Piruvato Quinase/genética , Piruvato Quinase/metabolismo
17.
J Fish Dis ; 41(4): 683-687, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29265378

RESUMO

Extracellular adenosine triphosphate (ATP) and its metabolite adenosine (Ado) are recognized as key mediators of immune and inflammatory responses. Depending on its concentration, ATP may act as an immunostimulant or immunodepressant, while Ado levels display an anti-inflammatory profile. The aim of this study was to evaluate whether splenic purinergic signalling is capable of modulating immune and inflammatory responses in fish experimentally infected with Aeromonas caviae. Triphosphate diphosphohydrolase (NTPDase) and 5'-nucleotidase activities increased in the spleen of silver catfish (Rhamdia quelen) experimentally infected with A. caviae compared with the uninfected control group. Moreover, splenic Ado levels increased in the infected animals relative to the uninfected control group. Based on these lines of evidence, our findings revealed that adenine nucleotide hydrolysis is modified in the spleen of fish infected with A. caviae attempting to restrict the inflammatory process through the upregulation of NTPDase and 5'-nucleotidase activities, which occurs in an attempt to hydrolyse the excessive ATP in the extracellular environment and rapidly hydrolyse AMP to form Ado. In summary, purinergic signalling can modulate immune and inflammatory responses during A. caviae infection.


Assuntos
Aeromonas caviae/fisiologia , Peixes-Gato , Doenças dos Peixes/imunologia , Infecções por Bactérias Gram-Negativas/veterinária , Baço/imunologia , Animais , Doenças dos Peixes/microbiologia , Proteínas de Peixes/imunologia , Infecções por Bactérias Gram-Negativas/imunologia , Infecções por Bactérias Gram-Negativas/microbiologia , Baço/microbiologia
18.
Colloids Surf B Biointerfaces ; 156: 282-291, 2017 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-28544960

RESUMO

Nosocomial infections associated with biofilm formation on urinary catheters are among the leading causes of complications due to biofilm characteristics and high antimicrobial resistance. An interesting alternative are natural products, such as Dihydromyricetin (DMY), a flavonoid which presents several pharmacological properties, including strong antimicrobial activity against various microorganisms. However, DMY, has low aqueous solubility and consequently low bioavailability. Nanoencapsulation can contribute to the improvement of characteristics of some drugs, by increasing the apparent solubility and sustained release has been reported among other advantages. The aim of this study was to evaluate, for the first time, the feasibility of DMY nanoencapsulation, and to look at its influence on nanoencapsulation of DMY as well as verify its influence on antimicrobial and antibiofilm activity on urinary catheters infected by Pseudomonas aeruginosa. The physicochemical characterization showed an average diameter less than 170nm, low polydispersity index, positive zeta potential (between +11 and +14mV), slightly acidic pH. The values of the stability study results showed that the best condition for suspension storage without losing physical and chemical characteristics was under refrigeration (4±2°C). The antibiofilm activity of the formulations resulted in the eradication of biofilms both in free DMY formulations and in nanocapsules of DMY during those periods. However, within 96h the results of the inhibition of biofilm by DMY nanocapsules were more effective compared with free DMY. Thus, the nanocapsule formulation containing DMY can potentially be used as an innovative approach to urinary catheter biofilm treatment or prevention.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Flavonóis/farmacologia , Nanocápsulas/química , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Antibacterianos/síntese química , Antibacterianos/química , Flavonóis/síntese química , Flavonóis/química , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Cateteres Urinários/microbiologia
19.
Microb Pathog ; 104: 125-132, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28089949

RESUMO

Candida infection is an important cause of morbidity and mortality on immunosuppressed patients. This growing trend has been associated with resistance to the antimicrobial therapy and the ability of microorganism to form biofilms. TTO oil is used as antimicrobial which shows antibiofilm activity against Candida species. However, it presents problems due to its poor solubility and high volatility. The present study aimed to evaluate in vitro antibiofilm activity of TTO nanoparticles against many Candida species. It was performed the characterization of the oil and nanoparticles. The levels of exopolysaccharides, proteins, and the biomass of biofilms were measured. The chromatographic profile demonstrated that the TTO oil is in accordance with ISO 4730 with major constituents of 41.9% Terpinen-4-ol, 20.1% of γ-Terpinene, 9,8% of α-Terpinene, and 6,0% of 1,8-Cineole. The TTO nanoparticles showed pH of 6.3, mean diameter of 158.2 ± 2 nm, polydispersion index of 0.213 ± 0.017, and zeta potential of -8.69 ± 0.80 mV. The addition of TTO and its nanoparticles represented a significant reduction of biofilm formed by all Candida species, as well as a reduction of proteins and exopolysaccharides levels. It was possible to visualize the reduction of biofilm in presence of TTO nanoparticles by Calcofluor White method.


Assuntos
Antifúngicos/administração & dosagem , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Candida/fisiologia , Melaleuca/química , Nanopartículas/administração & dosagem , Extratos Vegetais/administração & dosagem , Antifúngicos/química , Proteínas de Bactérias/metabolismo , Biomassa , Candida/ultraestrutura , Testes de Sensibilidade Microbiana , Nanopartículas/química , Extratos Vegetais/química , Óleos de Plantas/administração & dosagem , Óleos de Plantas/química
20.
Clin Exp Pharmacol Physiol ; 43(4): 476-83, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26748814

RESUMO

Premenopausal women are known to show lower incidence of cardiovascular disease than men. During myocardial infarction (MI), homeostatic responses are activated, including the sympathetic autonomic nervous system and the rennin-angiotensin-aldosterone system, which is related to the fluid and electrolyte balance, both aiming to maintain cardiac output. This study sought to perform a serial evaluation of sexual dimorphism in cardiac autonomic control and fluid and electrolyte balance during the development of MI-induced heart failure in rats. Experimental MI was induced in male (M) and female (F) adult (7-9 weeks of age) Wistar rats. The animals were placed in metabolic cages to assess fluid intake and urine volume 1 and 4 weeks after inducing MI (male myocardial infarction (MMI) and female myocardial infarction (FMI) groups). They subsequently underwent echocardiographic evaluation and spectral analysis of heart rate variability. After completing each protocol, the animals were killed for postmortem evaluation and histology. The MMI group showed earlier and more intense cardiac morphological and functional changes than the FMI group, although the extent of MI did not differ between groups (P > 0.05). The MMI group showed higher sympathetic modulation and sodium and water retention than the FMI group (P < 0.05), which may partly explain both the echocardiographic and pathological findings. Females subjected to infarction seem to show attenuation of sympathetic modulation, more favourable fluid and electrolyte balances, and better preserved cardiac function compared to males subjected to the same infarction model.


Assuntos
Sistema Nervoso Autônomo/fisiopatologia , Líquidos Corporais/metabolismo , Eletrólitos/metabolismo , Coração/fisiopatologia , Infarto do Miocárdio/fisiopatologia , Caracteres Sexuais , Animais , Progressão da Doença , Feminino , Masculino , Infarto do Miocárdio/metabolismo , Ratos , Ratos Wistar
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