Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 137
Filtrar
1.
Front Toxicol ; 4: 933300, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36071823

RESUMO

The herbicide atrazine (ATR; 2-chloro-4-ethylamino-6-isopropylamino-s-triazine) is widely used to destroy grasses and broadleaf weeds in crops and some fruits. Studies in rodents have shown that acute, repeated or chronic exposure to ATR is associated with alterations in the nigrostriatal dopaminergic pathway, whereas its effects on GABAergic and glutamatergic pathways have only recently been reported. Sprague-Dawley male rats were exposed daily to 1 or 10 mg ATR/kg of BW for 13 months to evaluate the ATR effects on GABAergic and glutamatergic systems. At the end of the ATR treatment, the levels of mRNA of several genes involved in the production, vesiculation, reuptake, and receptors of GABA and Glu in the striatum (STR), nucleus accumbens (NAcc), prefrontal cortex (PFC), ventral midbrain (vMID) and hippocampus (HIPP) were evaluated by absolute qPCR. For the GABAergic genes, increased expression of GAD67 and Slc32a1 in STR and/or vMID in rats exposed to 1 and/or 10 mg ATR were detected. With regard to the expression of genes involved in the glutamatergic system, Slc17a6 and Grin1 in HIPP of rats exposed to 1 and/or 10 mg ATR, increased as was Gria1 in STR and PFC in the group exposed to 1 mg ATR. In the same fashion, Slc1a3 expression and MGLUR1 increased in STR of rats exposed to 1 and 10 mg ATR groups. The expression of the glutaminases gls (variants 1 and 2) was greater in STR, NAcc, HIPP, and PFC of rats exposed to 1 and/or 10 mg ATR. These findings show that the GABAergic and, especially glutamatergic systems are targets of ATR exposure.

2.
Arch Microbiol ; 204(10): 652, 2022 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-36173466

RESUMO

We aimed to evaluate whether two commonly used PCR primers are effective to identify P. endodontalis and discriminate from other prevalent black-pigmented bacteria in apical periodontitis (AP). Endodontic canal samples from patients with asymptomatic AP (n = 20) were collected and cultured in anaerobiosis. Two primer sets to detect P. endodontalis were selected from the literature and first analyzed for their specificity in silico; and then tested on clinical isolates in vitro and finally, in apical exudates ex vivo. The identity of P. endodontalis was verified by PCR and Sanger sequencing with universal primers for bacterial V3-V6 regions 16S rDNA. Only one primer set showed specificity only for P. endodontalis clones in silico and also was specific for P. endodontalis in vitro and ex vivo.


Assuntos
Periodontite Periapical , Porphyromonas endodontalis , DNA Bacteriano/genética , DNA Ribossômico , Humanos , Periodontite Periapical/microbiologia , Reação em Cadeia da Polimerase
3.
Phys Rev Lett ; 128(9): 091803, 2022 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-35302807

RESUMO

We report the measurement of sub-MeV solar neutrinos through the use of their associated Cherenkov radiation, performed with the Borexino detector at the Laboratori Nazionali del Gran Sasso. The measurement is achieved using a novel technique that correlates individual photon hits of events to the known position of the Sun. In an energy window between 0.54 to 0.74 MeV, selected using the dominant scintillation light, we have measured 10 887_{-2103}^{+2386}(stat)±947(syst) (68% confidence interval) solar neutrinos out of 19 904 total events. This corresponds to a ^{7}Be neutrino interaction rate of 51.6_{-12.5}^{+13.9} counts/(day·100 ton), which is in agreement with the standard solar model predictions and the previous spectroscopic results of Borexino. The no-neutrino hypothesis can be excluded with >5σ confidence level. For the first time, we have demonstrated the possibility of utilizing the directional Cherenkov information for sub-MeV solar neutrinos, in a large-scale, high light yield liquid scintillator detector. This measurement provides an experimental proof of principle for future hybrid event reconstruction using both Cherenkov and scintillation signatures simultaneously.

4.
Biol Res ; 55(1): 12, 2022 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-35296351

RESUMO

BACKGROUND: The Atacama salt flat is located in northern Chile, at 2300 m above sea level, and has a high concentration of lithium, being one of the main extraction sites in the world. The effect of lithium on microorganism communities inhabiting environments with high concentrations of this metal has been scarcely studied. A few works have studied the microorganisms present in lithium-rich salt flats (Uyuni and Hombre Muerto in Bolivia and Argentina, respectively). Nanocrystals formation through biological mineralization has been described as an alternative for microorganisms living in metal-rich environments to cope with metal ions. However, bacterial lithium biomineralization of lithium nanostructures has not been published to date. In the present work, we studied lithium-rich soils of the Atacama salt flat and reported for the first time the biological synthesis of Li nanoparticles. RESULTS:  Bacterial communities were evaluated and a high abundance of Cellulomonas, Arcticibacter, Mucilaginibacter, and Pseudomonas were determined. Three lithium resistant strains corresponding to Pseudomonas rodhesiae, Planomicrobium koreense, and Pseudomonas sp. were isolated (MIC > 700 mM). High levels of S2- were detected in the headspace of P. rodhesiae and Pseudomonas sp. cultures exposed to cysteine. Accordingly, biomineralization of lithium sulfide-containing nanomaterials was determined in P. rodhesiae exposed to lithium salts and cysteine. Transmission electron microscopy (TEM) analysis of ultrathin sections of P. rodhesiae cells biomineralizing lithium revealed the presence of nanometric materials. Lithium sulfide-containing nanomaterials were purified, and their size and shape determined by dynamic light scattering and TEM. Spherical nanoparticles with an average size < 40 nm and a hydrodynamic size ~ 44.62 nm were determined. CONCLUSIONS: We characterized the bacterial communities inhabiting Li-rich extreme environments and reported for the first time the biomineralization of Li-containing nanomaterials by Li-resistant bacteria. The biosynthesis method described in this report could be used to recover lithium from waste batteries and thus provide a solution to the accumulation of batteries.


Assuntos
Lítio , Nanopartículas , Bactérias , Biomineralização , Lítio/farmacologia , Nanopartículas/química , Pseudomonas
5.
Osteoarthritis Cartilage ; 30(2): 329-340, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34774790

RESUMO

OBJECTIVE: One driving factor in the progression to posttraumatic osteoarthritis (PTOA) is the perpetuation of the inflammatory response to injury into chronic inflammation. Molecular imaging offers many opportunities to complement the sensitivity of current imaging modalities with molecular specificity. The goal of this study was to develop and characterize agents to image hyaluronan (HA)-mediated inflammatory signaling. DESIGN: We developed optical (Cy5.5-P15-1) and magnetic resonance contrast agents (Gd-DOTA-P15-1) based in a hyaluronan-binding peptide (P15-1) that has shown anti-inflammatory effects on human chondrocytes, and validated them in vitro and in vivo in two animal models of PTOA. RESULTS: In vitro studies with a near infrared (NIR) Cy5.5-P15-1 imaging agent showed a fast and stable localization of Cy5.5-P15-1 on chondrocytes, but not in synovial cells. In vivo NIR showed significantly higher retention of imaging agent in PTOA knees between 12 and 72 h (n = 8, Cohen's d > 2 after 24 h). NIR fluorescence accumulation correlated with histologic severity in cartilage and meniscus (ρ between 0.37 and 0.57, P < 0.001). By using in vivo magnetic resonance imaging with a Gd-DOTA-P15-1 contrast agent in 12 rats, we detected a significant decrease of T1 on injured knees in all cartilage plates at 48 h (-15%, 95%-confidence interval (CI) = [-18%,-11%]) while no change was observed in the controls (-2%, 95%-CI = [-5%,+1%]). CONCLUSIONS: This study provides the first in vivo evidence that hyaluronan-related inflammatory response in cartilage after injury is a common finding. Beyond P15-1, we have demonstrated that molecular imaging can provide a versatile technology to investigate and phenotype PTOA pathogenesis, as well as study therapeutic interventions.


Assuntos
Cartilagem Articular/diagnóstico por imagem , Imagem Multimodal , Osteoartrite do Joelho/diagnóstico por imagem , Animais , Humanos , Receptores de Hialuronatos/fisiologia , Imageamento por Ressonância Magnética , Ratos
6.
Antonie Van Leeuwenhoek ; 115(1): 89-102, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34797466

RESUMO

Bacillus thuringiensis is the major bioinsecticide worldwide produced due to the Cry protein activity. Several studies have been done to improve the cost-productivity relation. The neutral protease A (NprA) is the major extracellular protein massively produced during the stationary phase by this bacterium, contributing to the Cry proteins' degradation. Also, the deletion of aprA and nprA genes enhanced the yield of Cry protein, stabilizing it. Therefore, to increase Cry production, one possibility is to degrade the NprA protease in the culture media. In the present study, proteinase K was used to hydrolyze the NprA to increase Cry production. Proteinase K was added during the exponential growth of B. thuringiensis culture. The bacilli and endospores were measured along all culture, while the Cry protein was measured at the end of the culture. The addition of PK affects the bacilli and spore kinetics positively but negatively to the Cry protein (there is no Cry protein detection). Therefore, the gene expression of the cry1Ac, nprX, nprA, and spo0A was measured. The expression of each gene was followed along all culture. Results demonstrated that PK alters both the transcriptional levels and the expression order of the genes.


Assuntos
Bacillus thuringiensis , Bacillus thuringiensis/genética , Proteínas de Bactérias/genética , Endopeptidase K , Endotoxinas/genética , Proteínas Hemolisinas/genética , Transcrição Gênica
7.
Lett Appl Microbiol ; 74(3): 311-333, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34714944

RESUMO

Cadmium (Cd) is considered a toxic heavy metal; nevertheless, its toxicity fluctuates for different organisms. Cadmium-tolerant bacteria (CdtB) are diverse and non-phylogenetically related. Because of their ecological importance these bacteria become particularly relevant when pollution occurs and where human health is impacted. The aim of this review is to show the significance, culturable diversity, metabolic detoxification mechanisms of CdtB and their current uses in several bioremediation processes applied to agricultural soils. Further discussion addressed the technological devices and the possible advantages of genetically modified CdtB for diagnostic purposes in the future.


Assuntos
Metais Pesados , Poluentes do Solo , Agricultura , Bactérias/genética , Biodegradação Ambiental , Cádmio/toxicidade , Humanos , Metais Pesados/análise , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
8.
Biol. Res ; 55: 12-12, 2022. ilus, tab
Artigo em Inglês | LILACS | ID: biblio-1383915

RESUMO

BACKGROUND: The Atacama salt flat is located in northern Chile, at 2300 m above sea level, and has a high concentration of lithium, being one of the main extraction sites in the world. The effect of lithium on microorganism communities inhabiting environments with high concentrations of this metal has been scarcely studied. A few works have studied the microorganisms present in lithium-rich salt flats (Uyuni and Hombre Muerto in Bolivia and Argentina, respectively). Nanocrystals formation through biological mineralization has been described as an alternative for microorganisms living in metal-rich environments to cope with metal ions. However, bacterial lithium biomineralization of lithium nanostructures has not been published to date. In the present work, we studied lithium-rich soils of the Atacama salt flat and reported for the first time the biological synthesis of Li nanoparticles. RESULTS: Bacterial communities were evaluated and a high abundance of Cellulomonas, Arcticibacter, Mucilaginibacter, and Pseudomonas were determined. Three lithium resistant strains corresponding to Pseudomonas rodhesiae, Planomicrobium koreense, and Pseudomonas sp. were isolated (MIC > 700 mM). High levels of S2− were detected in the headspace of P. rodhesiae and Pseudomonas sp. cultures exposed to cysteine. Accordingly, biomineralization of lithium sulfide-containing nanomaterials was determined in P. rodhesiae exposed to lithium salts and cysteine. Transmission electron microscopy (TEM) analysis of ultrathin sections of P. rodhesiae cells biomineralizing lithium revealed the presence of nanometric materials. Lithium sulfide-containing nanomaterials were purified, and their size and shape determined by dynamic light scattering and TEM. Spherical nanoparticles with an average size < 40 nm and a hydro-dynamic size ~ 44.62 nm were determined. CONCLUSIONS: We characterized the bacterial communities inhabiting Li-rich extreme environments and reported for the first time the biomineralization of Li-containing nanomaterials by Li-resistant bacteria. The biosynthesis method described in this report could be used to recover lithium from waste batteries and thus provide a solution to the accumulation of batteries.


Assuntos
Nanopartículas/química , Lítio/farmacologia , Pseudomonas , Bactérias , Biomineralização
9.
J Appl Microbiol ; 131(1): 155-168, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33274558

RESUMO

AIM: Fluorescent semiconductor nanoparticles or quantum dots (QDs) have excellent properties as photosensitizers in photodynamic therapy. This is mainly a consequence of their nanometric size and the generation of light-activated redox species. In previous works, we have reported the low-cost biomimetic synthesis of glutathione (GSH) capped QDs (CdTe-GSH QDs) with high biocompatibility. However, no studies have been performed to determine their phototoxic effect. The aim of this work was to characterize the light-induced toxicity of green (QDs500 ) and red (QDs600 ) QDs in Escherichia coli, and to study the molecular mechanism involved. METHODS AND RESULTS: Photodegradation and reduction power of biomimetic QDs was determined to analyse their potential for radical generation. Escherichia coli cells were exposed to photoactivated QDs and viability was evaluated at different times. High toxicity was determined in E. coli cells exposed to photoactivated QDs, particularly QDs500 . The molecular mechanism involved in QDs phototoxicity was studied by determining Cd2+ -release and intracellular reactive oxygen species (ROS). Cells exposed to photoactivated QDs500 presented high levels of ROS. Cells exposed to photoactivated QDs500 presented high levels of ROS. Finally, to understand this phenomenon and the importance of oxidative and cadmium-stress in QDs-mediated phototoxicity, experiments were performed in E. coli mutants in ROS and Cd2+ response genes. As expected, E. coli mutants in ROS response genes were more sensitive than the wt strain to photoactivated QDs, with a higher effect in green-QDs500 . No increase in phototoxicity was observed in cadmium-related mutants. CONCLUSION: Obtained results indicate that light exposure increases the toxicity of biomimetic QDs on E. coli cells. The mechanism of bacterial phototoxicity of biomimetic CdTe-GSH QDs is mostly associated with ROS generation. SIGNIFICANCE AND IMPACT OF THE STUDY: The results presented establish biomimetic CdTe-GSH QDs as a promising cost-effective alternative against microbial infections, particularly QDs500 .


Assuntos
Compostos de Cádmio/farmacologia , Cádmio/metabolismo , Escherichia coli/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Pontos Quânticos/toxicidade , Telúrio/farmacologia , Antibacterianos/farmacologia , Materiais Biomiméticos/farmacologia , Biomimética , Viabilidade Microbiana , Mutação , Oxirredução/efeitos da radiação , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
10.
Rev. chil. obstet. ginecol. (En línea) ; 85(supl.1): S28-S34, set. 2020. tab
Artigo em Espanhol | LILACS | ID: biblio-1138646

RESUMO

INTRODUCCIÖN Y OBJETIVOS: Describir la experiencia de los partos en gestantes con diagnóstico confirmado de COVID 19 mediante RT-PCR asintomáticas o con sintomatología leve y aquellas sin la enfermedad, y determinar la tasa de éxito de parto vaginal en inducción de trabajo de parto. MÉTODOS: Análisis retrospectivo de pacientes que tuvieron su parto entre 15 de Abril y 03 de Julio del 2020 en el Hospital San Juan de Dios. Se incluyeron las pacientes inducidas con Dinoprostona, Oxitocina o ambas de manera secuencial y se dividieron según estatus COVID 19 mediante RT-PCR al ingreso. Se caracterizó demográficamente el grupo de pacientes positivas y se determinaron los datos de ambos grupos en relación a la necesidad de inducción de trabajo de parto y su éxito para parto vaginal. RESULTADOS: De un total de 657 nacimientos, hubo un 9.7% (n=64) de pacientes con COVID 19, de las cuales un 23.4% (n=15) requirió inducción de trabajo de parto, con una tasa de éxito para parto vaginal de un 66.7% (n=10). De estas pacientes, un 50% recibió Oxitocina, un 40% Dinosprostona y un 10% ambos medicamentos de forma secuencial. En las pacientes negativas, hubo un total de 568 nacimientos, con un 29.8% (n=169) de usuarias que requirieron inducción. La tasa de éxito para parto vaginal en este grupo fue de 72.2% (n=122), utilizando un 50% Oxitocina; un 27% Dinoprostona; un 14.8% ambas; y un 8.2% Balón de Cook. CONCLUSIONES: Sabemos que los resultados de este estudio están limitados por el bajo número de pacientes incluidas, sin embargo, podemos observar que, en nuestra experiencia con las pacientes que arrojaron PCR SARS-CoV-2 positivas, asintomáticas o con enfermedad leve, se logró realizar la inducción de trabajo de parto según protocolos habituales, obteniendo porcentajes de éxito para partos vaginales, similares a las pacientes sin la enfermedad.


INTRODUCTION AND OBJECTIVES: Describe the experience of deliveries in pregnant women with a confirmed diagnosis of COVID 19 by asymptomatic RT-PCR or with mild symptoms and those without the disease, and determine the success rate of vaginal delivery in the induction of labor. METHODS: Retrospective study of patients who had their delivery between 15th April and 03rd of July, 2020 in the San Juan de Dios Hospital. Patients induced with Dinoprostone, Oxytocin or both sequentially were included, and were divided according to COVID 19 status by RT-PCR on their admission process. The group of positive patients was demographically characterized and the data of both groups was determined in relation to the need for labor induction and its success for vaginal delivery. RESULTS: Of a total of 657 births, there were 9.7% (n = 64) of patients with COVID 19, of which 23.4% (n = 15) required labor induction, with a success rate for vaginal delivery of 66.7% (n = 10). Of these patients, 50% received Oxytocin, 40% Dinosprostone and 10% both drugs sequentially. In the negative patients, there were a total of 568 births, with 29.8% (n = 169) of users requiring labor induction. The success rate for vaginal delivery in this group was 72.2% (n = 122); 50% using Oxytocin; 27% Dinoprostone; 14.8% using both; and 8.2% using Cook's Catheter. CONCLUSIONS: We know that the results of this study are limited by the low number of patients included, however, in our experience, we can observe that, in patients with SARS-CoV-2 PCR positive, asymptomatic or with mild disease, it was possible to perform induction of labor according to standard protocols, achieving success rates for vaginal deliveries, similar to patients without the disease.


Assuntos
Humanos , Feminino , Gravidez , Recém-Nascido , Adolescente , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Pneumonia Viral/complicações , Complicações Infecciosas na Gravidez/terapia , Complicações Infecciosas na Gravidez/virologia , Infecções por Coronavirus/complicações , Trabalho de Parto Induzido/métodos , Ocitocina/administração & dosagem , Resultado da Gravidez , Dinoprostona/administração & dosagem , Cesárea , Estudos Retrospectivos , Parto Obstétrico , Pandemias , Betacoronavirus
11.
Arch Toxicol ; 94(9): 3217-3230, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32561961

RESUMO

Atrazine (ATR; 2-chloro-4-ethylamino-6-isopropylamino-s-triazine) is an herbicide widely used to kill annual grasses and broadleaf weeds in crops such as corn, sorghum, and sugarcane. Studies in rodents have shown that chronic ATR exposure is associated with alterations in the nigrostriatal dopaminergic pathway such as hyperactivity, decreased striatal dopamine levels, and diminished numbers of tyrosine hydroxylase positive cells in substantia nigra pars compacta. However, the effects of ATR on neurotransmitters such as GABA and glutamate have been scarcely studied. To evaluate the impact of ATR on motor and anxiety tasks, tissue levels of GABA, glutamate, glutamine, and extracellular and potassium-evoked release of glutamate in the striatum, we daily exposed Sprague-Dawley male rats to 1 or 10 mg ATR/kg of body weight for 12-14 months. As previously reported, chronic ATR exposure causes hyperactivity in the group exposed to 10 mg ATR/kg and increased anxiety in both groups exposed to ATR. GABA, glutamate, and glutamine levels were differentially altered in brain regions related to nigrostriatal and mesolimbic systems, the amygdala, and the prefrontal cortex. The groups exposed to 10 mg ATR/kg showed increased extracellular levels and release of glutamate in the striatum. These neurochemical alterations could underlie the behavioral changes observed in rats. These results indicate that chronic exposure to the herbicide ATR disrupts the neurochemistry of several brain structures and could be a risk factor for the development of neurodegenerative diseases.


Assuntos
Atrazina/toxicidade , Encéfalo/efeitos dos fármacos , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Herbicidas/toxicidade , Ácido gama-Aminobutírico/metabolismo , Animais , Encéfalo/fisiologia , Corpo Estriado , Dopamina/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Tirosina 3-Mono-Oxigenase
12.
Br Poult Sci ; 61(3): 274-280, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31951478

RESUMO

1. This study was conducted to determine the effect of different sources of selenium (Se) on breast and liver tissue deposition, apparent metabolisable energy (AME), growth performance and antioxidant status of broilers, measured as Se content in liver and breast tissues and glutathione peroxidase (GSH-Px) in blood, when used in 0-35 d broiler chicken diets. 2. A total of 200 male Ross 308 broilers were used in the feeding trial, which comprised two dietary phases, a starter from 0 to 21 d and finisher from 21 to 35 d of age. Four treatments with 10 replications each were used. A control diet (C) was formulated that was sufficient in protein and energy (230 and 215 g/kg of crude protein and 12.67 and 13.11 MJ/kg of metabolisable energy, respectively), for both phases, but contained background Se only from the feed ingredients. Diet 2 (IS) was supplemented with 10.35 g/t inorganic, elemental source of Se. Diet 3 (SY) was supplemented with 136.36 g/t selenised yeast, an organic source derived from Saccharomyces cerevisiae. Diet 4 (SS) was supplemented with 0.666 g/t sodium selenite, an inorganic source. 3. Birds fed the SY diet consumed less and weighed less than those fed IS or C (P < 0.05; 0-35 d of age), but there was no difference compared to birds fed SS diets. There were no differences in FCR or dietary AME between broilers fed different Se sources. All diets containing supplementary Se increased concentrations in the liver and breast muscle, and for GSH-Px levels in blood compared to birds fed the C diet (P < 0.001). Birds fed SY diets had greater Se levels in liver and breast tissues compared to birds fed any of the other diets (P < 0.001). 4. Diets supplemented with Se had variable effects on broiler growth performances and antioxidant status. Feeding Se from a yeast source has higher transfer into breast tissues. Feeding different sources and levels of Se to birds in a more challenging situation to induce oxidative stress may bring more conclusive results.


Assuntos
Ração Animal , Suplementos Nutricionais , Selênio , Ração Animal/análise , Animais , Antioxidantes , Galinhas , Dieta , Masculino , Selenito de Sódio
13.
Sci Rep ; 9(1): 1953, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30760793

RESUMO

Here we report the biological synthesis of CdS fluorescent nanoparticles (Quantum Dots, QDs) by polyextremophile halophilic bacteria isolated from Atacama Salt Flat (Chile), Uyuni Salt Flat (Bolivia) and the Dead Sea (Israel). In particular, a Halobacillus sp. DS2, a strain presenting high resistance to NaCl (3-22%), acidic pH (1-4) and cadmium (CdCl2 MIC: 1,375 mM) was used for QDs biosynthesis studies. Halobacillus sp. synthesize CdS QDs in presence of high NaCl concentrations in a process related with their capacity to generate S2- in these conditions. Biosynthesized QDs were purified, characterized and their stability at different NaCl concentrations determined. Hexagonal nanoparticles with highly defined structures (hexagonal phase), monodisperse size distribution (2-5 nm) and composed by CdS, NaCl and cysteine were determined by TEM, EDX, HRXPS and FTIR. In addition, QDs biosynthesized by Halobacillus sp. DS2 displayed increased tolerance to NaCl when compared to QDs produced chemically or biosynthesized by non-halophilic bacteria. This is the first report of biological synthesis of salt-stable QDs and confirms the potential of using extremophile microorganisms to produce novel nanoparticles. Obtained results constitute a new alternative to improve QDs properties, and as consequence, to increase their industrial and biomedical applications.


Assuntos
Nanopartículas/química , Pontos Quânticos/química , Pontos Quânticos/metabolismo , Compostos de Cádmio/química , Extremófilos/metabolismo , Halobacillus/metabolismo , Cloreto de Sódio , Espectrometria de Fluorescência/métodos , Sulfetos/química
14.
Poult Sci ; 98(9): 3443-3449, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30325468

RESUMO

This study aimed to assess the effect of a commercial blend of phytogenic feed additives (PA), comprising 5% carvacrol, 3% cinnamaldehyde, and 2% capsicum oleoresin on the modulation of immune biomarkers of broiler chickens, their growth performance, dietary energy, and nutrient retention. Four-hundred day-old birds were assigned to one of four dietary treatments. Two control diets based on either wheat (WC) or maize (MC) were each given with and without PA at 100 g/t. Growth performance variables including feed intake (FI), weight gain (WG), and feed conversion ratio (FCR) were recorded. Dietary N-corrected apparent metabolizable energy (MEn), dry matter (DMR), nitrogen (NR), and fat retention (FR) coefficients were also determined. Gene expression of immune biomarkers (cytokines) were determined in caecal tonsil tissue from 21 d old birds. Expression of IL2, IL18, IL10, and IL17C in the caecal tonsils were upregulated (P < 0.05) in the birds fed MC-based diets compared to the WC fed birds. Feeding PA supplemented diets downregulated the expression of CD40LG (P < 0.001), IFNG, and IL6 (P < 0.05). There was a cereal type × PA interaction (P < 0.05), as expression of IFNB was downregulated in the birds fed PA supplemented MC but not WC. However, expression of IL12B was downregulated in birds fed PA supplemented WC but there was no significant (P > 0.05) change in expression levels in birds fed MC diets. Feeding MC diets gave greater FI (P < 0.001) and ME (P < 0.05), but lower FCR (P < 0.05) compared to birds fed WC diets. The WG and nutrient retention coefficients were not affected (P > 0.05) by cereal type. Supplementary PA improved FI (P < 0.05), WG (P < 0.001), FCR (P < 0.05), MEn (P < 0.05), MEn: GE ratio (P < 0.05), and FR (P < 0.05). In conclusion, dietary inclusion of PA improved overall growth performance variables, energy, and nutrient retention and intestinal cytokine expression.


Assuntos
Acroleína/análogos & derivados , Galinhas/imunologia , Dieta/veterinária , Imunomodulação , Monoterpenos/metabolismo , Extratos Vegetais/metabolismo , Acroleína/administração & dosagem , Acroleína/metabolismo , Ração Animal/análise , Animais , Capsicum/química , Galinhas/crescimento & desenvolvimento , Galinhas/fisiologia , Cimenos , Masculino , Monoterpenos/administração & dosagem , Extratos Vegetais/administração & dosagem , Distribuição Aleatória
15.
Animal ; 13(3): 502-508, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29983137

RESUMO

The aim of this study was to test the hypothesis of an improved growth, dietary nutrient availability and overall health of broiler chickens reared on recycled litter when fed a standardised combination of essential oils (EO; carvacrol, cinnamaldehyde and capsicum oleoresin). To assess the effect of dietary treatments, feed intake, weight gain, feed efficiency, availability of dietary nutrients and energy, villus morphometry, excreta sialic acid concentration, hepatic antioxidants and serum amyloid A (SAA) when fed to broiler chickens were evaluated. Counts of Eimeria spp. oocysts were also determined in excreta samples. Four experimental diets were offered, including two basal control diets based on either wheat or maize that contained 215 g CP/kg and 12.13 MJ/kg metabolisable energy and another two diets using the basal control diets supplemented with the EO combination at 100 mg/kg diet. Each diet was fed to eight floor pens, containing two birds each, following randomisation. Birds fed the EO-supplemented diets had an improved (P0.05) were observed in villus morphometry, sialic acid secretion, number of oocysts and SAA. Feeding the EO improved (P<0.05) the retention of dietary Ca and Na. Compared with maize, feeding wheat-based diets improved the retention coefficients for Ca, P and Na (P<0.05). Feeding dietary EO improved (P<0.05) the concentrations of the hepatic antioxidants, including carotene, coenzyme Q10 and total vitamin E. The hepatic concentration of carotene of the maize-fed birds was 55.6% greater (P<0.05) compared with the wheat-fed birds. These results demonstrated that the addition of a standardised combination of EO in wheat- and maize-based diets provided benefits in terms of feed efficiency, mineral retention and antioxidant status of the birds when reared on recycled litter.


Assuntos
Antioxidantes/metabolismo , Galinhas/crescimento & desenvolvimento , Gorduras Insaturadas na Dieta/administração & dosagem , Fígado/efeitos dos fármacos , Óleos Voláteis/administração & dosagem , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Dieta/veterinária , Suplementos Nutricionais , Metabolismo Energético/efeitos dos fármacos , Fígado/metabolismo , Masculino , Minerais , Triticum , Aumento de Peso , Zea mays
16.
Bone ; 112: 97-106, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29680264

RESUMO

INTRODUCTION: Aminocaproic acid is approved as an anti-fibrinolytic for use in joint replacement and spinal fusion surgeries to limit perioperative blood loss. Previous animal studies have demonstrated a pro-osteogenic effect of aminocaproic acid in spine fusion models. Here, we tested if aminocaproic acid enhances appendicular bone healing and we sought to uncover the effect of aminocaproic acid on osteoprogenitor cells (OPCs) during bone regeneration. METHODS: We employed a well-established murine femur fracture model in adult C57BL/6J mice after receiving two peri-operative injections of aminocaproic acid. Routine histological assays, biomechanical testing and micro-CT analyses were utilized to assess callus volume, and strength, progenitor cell proliferation, differentiation, and remodeling in vivo. Two disparate ectopic transplantation models were used to study the effect of the growth factor milieu within the early fracture hematoma on osteoprogenitor cell fate decisions. RESULTS: Aminocaproic acid treated femur fractures healed with a significantly smaller cartilaginous callus, and this effect was also observed in the ectopic transplantation assays. We hypothesized that aminocaproic acid treatment resulted in a stabilization of the early fracture hematoma, leading to a change in the growth factor milieu created by the early hematoma. Gene and protein expression analysis confirmed that aminocaproic acid treatment resulted in an increase in Wnt and BMP signaling and a decrease in TGF-ß-signaling, resulting in a shift from chondrogenic to osteogenic differentiation in this model of endochondral bone formation. CONCLUSION: These experiments demonstrate for the first time that inhibition of the plasminogen activator during fracture healing using aminocaproic acid leads to a change in cell fate decision of periosteal osteoprogenitor cells, with a predominance of osteogenic differentiation, resulting in a larger and stronger bony callus. These findings may offer a promising new use of aminocaproic acid, which is already FDA-approved and offers a very safe risk profile.


Assuntos
Condrogênese , Fraturas do Fêmur/patologia , Consolidação da Fratura , Osteogênese , Periósteo/patologia , Ativadores de Plasminogênio/antagonistas & inibidores , Ácido Aminocaproico/farmacologia , Animais , Fenômenos Biomecânicos/efeitos dos fármacos , Coagulação Sanguínea/efeitos dos fármacos , Calo Ósseo/patologia , Microambiente Celular/efeitos dos fármacos , Condrogênese/efeitos dos fármacos , Fraturas do Fêmur/sangue , Fraturas do Fêmur/diagnóstico por imagem , Consolidação da Fratura/efeitos dos fármacos , Hematoma/patologia , Masculino , Camundongos Endogâmicos C57BL , Osteogênese/efeitos dos fármacos , Periósteo/diagnóstico por imagem , Periósteo/efeitos dos fármacos , Periósteo/fisiopatologia , Ativadores de Plasminogênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Microtomografia por Raio-X
17.
J Environ Manage ; 213: 530-540, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29477352

RESUMO

A process-simulation model for a novel process consisted of an anaerobic bioscrubber was developed in Aspen Plus®. A novel approach was performed to implement the anaerobic reactor in the simulation, enabling it to be connected to the scrubber. The model was calibrated and validated using data from an industrial prototype that converted air emissions polluted with volatile organic compounds with an average daily concentration of 1129 mgC Nm-3 into bioenergy for more than one year. The scrubber, which showed a removal efficiency within 83-93%, was successfully predicted with an average absolute relative error of 5.2 ±â€¯0.08% using an average height-to-theoretical-plate value of 1.05 ±â€¯0.08 m and 1.37 ±â€¯0.11 m for each of the two commercial packing materials used, respectively. The anaerobic reactor, which treated up to 24 kg of chemical oxygen demand m-3 d-1 with efficiencies of about 93%, was accurately simulated, both in effluent-stream characteristics and in the biogas stream. For example, the average absolute error between the experimental biogas production and the model values was 19.6 ±â€¯18.9%. The model proved its capability as a predictive tool and an aid in design, resulting in savings of time and money for practitioners. In addition, the approach proposed can be expanded to other bioprocesses that include unit operations.


Assuntos
Biocombustíveis , Compostos Orgânicos Voláteis , Anaerobiose , Reatores Biológicos , Metano
18.
J Appl Microbiol ; 124(5): 1175-1194, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29345852

RESUMO

AIMS: This research aims to assess total-cadmium soil content and microbiological aspects to understand the dynamics of culturable cadmium-tolerant bacteria (CdtB) in cacao soils from northeastern Colombia. METHODS AND RESULTS: An integration of inverted dish plating, Cd determination and a microcalorimetry assay (IMC) was carried out. A farm in Boyacá showed the highest level of total soil Cd (3·74 mg kg-1 ) followed by farms in Santander and Arauca (2·76 and 1·16 mg kg-1 , respectively). Coefficient of determination between total soil Cd and CFU of CdtB was high (R2  = 0·83) for the farm in Boyacá. Moreover, a pool of 129 CdtB was isolated, and phylogeny of 21 CdtB was discussed. Among CdtB strains isolated, Enterobacter sp. CdDB41 showed major Cd immobilization capacity (Qmax of 2·21 and 2·32 J at 6 and 24 mg l-1 of CdCl2 ), with an immobilization rate of 0·220 mg kg-1  h-1 . CONCLUSIONS: Among CdtB strains isolated, Enterobacter sp. CdDB41 showed major Cd immobilization capacity (Qmax of 2·21 and 2·32 J at 6 and 24 mg l-1 of CdCl2 ), with an immobilization rate of 0·220 mg kg-1  h-1 . SIGNIFICANCE AND IMPACT OF THE STUDY: Nothing is known about soil CdtB in cacao. Our data showed that CdtB such as Enterobacter sp. has high immobilization capacity. Furthermore, the otavite found in situ might be mineralized due to the bacterial metabolic activity of CdtB.


Assuntos
Bactérias/isolamento & purificação , Bactérias/metabolismo , Cacau/química , Cacau/microbiologia , Cádmio/análise , Cádmio/metabolismo , Produtos Agrícolas/microbiologia , Microbiologia do Solo , Colômbia , Produtos Agrícolas/química , Poluentes do Solo/análise , Poluentes do Solo/metabolismo
19.
Eur J Neurol ; 25(4): 644-650, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29266602

RESUMO

BACKGROUND AND PURPOSE: Zika virus (ZIKV) infection has been associated with an increased incidence of Guillain-Barré syndrome (GBS) but the relative frequency of acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and axonal GBS subtypes is controversial. METHODS: Twenty GBS patients diagnosed according to the Brighton criteria during the ZIKV outbreak in Cúcuta, Colombia, were evaluated clinically and electrophysiologically. The electrodiagnosis of GBS subtypes was made according to a recently described criteria set that demonstrated a high diagnostic accuracy on the basis of a single test. The electrophysiological features of 34 Italian AIDP patients were used as control. RESULTS: All patients had symptoms compatible with ZIKV infection before the onset of GBS and ZIKV infection was laboratory confirmed through a plaque reduction neutralization test (PRNT90 ) in 100% of patients. The median time from onset of ZIKV infection symptoms to GBS was 5 days (interquartile range 1-6 days). Cranial nerve palsy was present in 85% of patients (facial palsy in 75%, bulbar nerve involvement in 60%), autonomic dysfunction in 85%, and 50% of patients required invasive mechanical ventilation. AIDP was diagnosed in 70% of patients. 40% of nerves of AIDP patients showed a prevalent distal demyelinating involvement but this pattern was not different from the Italian AIDP patients without ZIKV infection. CONCLUSIONS: Guillain-Barré syndrome associated with ZIKV infection in Cúcuta is characterized by a high frequency of cranial nerve involvement, autonomic dysfunction and requirement of mechanical ventilation indicating an aggressive and severe course. AIDP is the most frequent electrophysiological subtype. Demyelination is prevalent distally but this pattern is not specific for ZIKV infection.


Assuntos
Síndrome de Guillain-Barré/etiologia , Síndrome de Guillain-Barré/fisiopatologia , Condução Nervosa , Infecção por Zika virus/complicações , Adulto , Doenças do Sistema Nervoso Autônomo/etiologia , Colômbia , Doenças dos Nervos Cranianos/etiologia , Eletrodiagnóstico , Feminino , Síndrome de Guillain-Barré/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Paralisia/etiologia , Respiração Artificial , Ensaio de Placa Viral , Zika virus
20.
J Dairy Sci ; 100(7): 5974-5983, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28390713

RESUMO

Plants produce an extensive array of organic compounds derived from secondary metabolism that may be useful in animal nutrition because of their chemical makeup. These plant-derived bioactive compounds, also referred to as phytonutrients (PN) or phytobiotics, have been shown to express antimicrobial activities against a wide range of bacteria, yeast, and fungi and have been investigated as rumen modifiers in ruminant nutrition. Studies have reported that PN may inhibit deamination of AA and methanogenesis in the rumen and shift fermentation toward propionate and butyrate. Most of the experiments, however, have been conducted in vitro, and responses have been highly variable and inconsistent in animal experiments. In addition, some studies have reported that PN had positive effects on productivity, although rumen fermentation was not affected. Other than antimicrobial effects in the gut, PN are known to bind specific receptors expressed in neurons, intestines, and other cells and exhibit related physiological effects in nonruminants. The receptor-mediated effects include immune responses, oxidative stress, and insulin secretion and activity. Some PN, due to their phenolic nature, are likely less susceptible to microbial degradation in the rumen and may exhibit activities postruminally, similar to their mode of action in nonruminant species. This opens a new area of research in ruminants, including effects of PN on the animal's immune system, postruminal nutrient use, and animal physiology. Although limited, studies with ruminants provide first evidence of PN's regulatory effects on the host responses. For example, PN were reported to regulate immune cells related to adaptive and innate immunity in challenged or nonchallenged dairy cows. Supplementation of PN reduced oxidative stress by decreasing lipid peroxidation and increasing endogenous antioxidants in ruminants. Additionally, insulin secretion and sensitivity were reportedly regulated by PN in dairy cows. The regulatory effects of PN on immunity may be beneficial for immune suppression and inflammation in dairy cows. In addition, PN could positively affect energy partitioning for milk production through their effects on insulin secretion and sensitivity. Further research is needed to elucidate the effect and mode of action of PN on immune function and animal energetics.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal/fisiologia , Compostos Fitoquímicos/metabolismo , Rúmen/metabolismo , Ruminantes/metabolismo , Animais , Bovinos , Dieta , Feminino , Fermentação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...