Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 37
Filtrar
1.
Poult Sci ; 103(3): 103401, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38183881

RESUMO

This study investigated the effects of xylanase and stimbiotic (fiber fermentation enhancer) on the response of broiler chickens fed different corn varieties and determine correlations between variables of interest. Four corn genetic varieties were selected based on their range in nutrient composition. Diets containing 600 g/kg of each corn were supplemented with 0 or 100 g/ton of xylanase or stimbiotic. A total of 1,152 one-day-old male broiler chicks (Ross 308) were divided into 12 treatments, each with 8 pens and 12 birds per pen, for a 21-day study. On d 21, performance parameters were measured, and the ileal energy and organic matter (OM) digestibility and cecal xylanase activity determined. Stimbiotic supplementation improved mFCR compared with all other treatments. There was a treatment by corn variety interaction for body weight (BW), BW gain and coefficient of variation (CV) of BW (P ≤ 0.05). Birds fed corn Variety 1 (highest neutral dietary fiber, protein and soluble arabinoxylan content) supplemented with stimbiotic had the highest BW, while Variety 2 control diet had the lowest. The BW CV in corn Variety 2 was the highest, which improved with stimbiotic supplementation. The BW CV in corn Variety 1 responded better to stimbiotic than xylanase. There were no treatment differences on BW CV in corn Varieties 3 and 4. The lowest OM digestibility was observed in birds fed corn Variety 1 with xylanase, and the highest value was associated with corn Variety 3 with xylanase (highest total arabinoxylan). Xylanase and stimbiotic supplementation increased the endogenous xylanase activity regardless of the corn variety (P ≤ 0.05). Positive correlations between corn fiber contents and phytic acid and the arabinose:xylose ratio were seen, while nonstarch polysaccharide content was negatively correlated with apparent metabolizable energy. In conclusion, corn variety influenced nutrient digestibility and broiler chicken growth. The response to supplementation with xylanase or stimbiotic varied based on the nutritional profile of corn with regards to improvements in digestibility and performance in broiler chickens.


Assuntos
Galinhas , Zea mays , Animais , Masculino , Galinhas/fisiologia , Digestão , Dieta/veterinária , Valor Nutritivo
2.
J Anim Sci ; 1022024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38035764

RESUMO

Three trials were undertaken to provide an answer to different questions: 1) Are suckling pigs able to maintain physiological serum Zn levels throughout lactation and do these levels vary between high and low body weight (BW) pigs?, 2) Are serum Zn levels in pigs soon after weaning a predisposing factor for diarrhea?, and 3) Is it possible to increase serum Zn levels at weaning by supplementing Zn during lactation. In trial 1, blood samples were taken from pigs during lactation. Eight pigs (one piglet per litter) had blood drawn on days 0 (farrowing), 7, 14, 21, and 28 (weaning), and 60 pigs (selected from the whole farrowing batch with 35 sows), categorized as either heavy (8.63 kg) or light (5.50 kg) had blood drawn on day 28. Serum Zn levels at birth were 1.2 mg/L and decreased (P < 0.01) to 0.67 mg/L on day 28. Heavier pigs showed greater (P < 0.01) serum Zn levels (0.98 mg/L) than light BW pigs (0.79 mg/L). In trial 2, blood samples were obtained from 240 pigs at weaning (26.2 ±â€…2.5 d) with an average initial BW of 6.94 ±â€…1.87 kg and were distributed into 24 pens (10 pigs/pen) by BW. Diarrhea incidence was recorded daily from days 0 to 35 post-weaning. From the 240 pigs, a group of 110 pigs with uniform BW (6.5 ±â€…1.9 kg) was selected and separated into two groups based on serum Zn levels at weaning with 55 pigs with low serum Zn (LZn: <0.71 mg/L) and 55 pigs with high serum Zn (HZn: >0.9 mg/L). Pigs with LZn were 2.49 times as likely to have diarrhea as pigs with HZn (P < 0.02). In trial 3, a total of 96 suckling pigs were allotted four treatments that consisted of the daily administration of 0, 6, 18, or 30 mg of Zn as Zn citrate in capsule form during the last 7 d of lactation. Pigs were individually weighed, and blood samples were obtained on days 14, 21 (weaning), and 7 after weaning. Serum Zn levels linearly increased by day as Zn citrate supplementation increased (interaction, P < 0.001). However, only light pigs supplemented with 18 and 30 mg/L of Zn experienced an increase in serum Zn levels during lactation. In conclusion, a decrease in serum Zn levels occurs during lactation and is more severe in low BW pigs. Low Zn status (< 0.7 mg/L) at weaning may be a predisposing factor for diarrhea. However, Zn supplementation during lactation can mitigate this decrease in light pigs.


At weaning, young pigs may experience a decrease in serum Zn levels which can predispose them to diarrhea, particularly when fed diets with nutritional Zn levels. For several decades, this gap has been covered by using therapeutic levels of Zn. However, due to the negative collateral effects of these supra doses, from June 2022 in the EU the maximum level of Zn allowed in piglet diets is 150 mg/kg. In this scenario, it is imperative to investigate the Zn status evolution in pigs even before weaning, to anticipate the appearance of Zn deficiencies. This study had three main objectives: to investigate the Zn serum levels of light and heavy body weight pigs during lactation, to study these Zn levels as a predisposing factor to developing diarrhea during weaning and to study the effects of extra Zn supplementation during lactation to prevent Zn deficiency while weaning. Overall, the results indicate a decrease in pig serum Zn levels during lactation which is more severe in low body weight pigs. Low Zn status at weaning may be a predisposing factor for diarrhea. Nevertheless, external pig supplementation with Zn during lactation can mitigate this issue.


Assuntos
Desnutrição , Doenças dos Suínos , Animais , Suínos , Feminino , Suplementos Nutricionais , Lactação/fisiologia , Minerais , Desnutrição/veterinária , Zinco , Diarreia/veterinária , Citratos , Dieta/veterinária , Ração Animal/análise
3.
Bol Med Hosp Infant Mex ; 80(Supl 1): 53-57, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37490692

RESUMO

BACKGROUND: As retinoblastoma (RB) is the most frequent primary intraocular malignant tumor in childhood, it should be the main pathology to rule out in pediatric patients with leukocoria. Persistence of fetal vasculature (PFV) is within the differential diagnosis of leukocoria, a vitreous disorder arising from a defect in the involution of the hyaloid vasculature in the embryonic stage, which affects normal ocular development and commonly produces associated microophthalmia. An early diagnosis and timely treatment are crucial for a better prognosis and life expectancy of the child. CASE REPORT: We present a case of retinoblastoma and coexisting with PFV: a 2-years-and 11-months-old male with no red reflex, and vasculature and yellowish-white membrane behind the lens of the right eye. B-mode ultrasound with disorganization of the vitreous cavity with high reflectivity echoes suggestive of calcification. On examination we found an enlarged eyeball, rubeosis iridis, posterior vasculature, intraocular pressure 28 mmHg. Computed tomography with heterogeneous intraocular mass with hyperdense regions. With a diagnosis of probable retinoblastoma, enucleation was performed. Histopathology reported moderately differentiated retinoblastoma coexisting with PFV. CONCLUSIONS: The finding of these two diagnoses in the same eye is very rare due to the different pathophysiology.


INTRODUCCIÓN: El retinoblastoma (RB) es el tumor maligno primario intraocular más frecuente en la infancia y debe ser la principal patología a descartar en los pacientes pediátricos con leucocoria. La persistencia de la vasculatura fetal (PVF) está dentro del diagnóstico diferencial de la leucocoria, un trastorno del vítreo que surge de un defecto en la involución de la vasculatura hialoidea en la etapa embrionaria que afecta al desarrollo ocular normal y comúnmente produce microoftalmia asociada. El diagnóstico temprano y tratamiento oportuno son cruciales para un buen pronóstico y mejor esperanza de vida del infante. CASO CLÍNICO: Presentamos un caso de coexistencia de retinoblastoma y PVF: paciente de sexo masculino de 2 años y 11 meses sin reflejo rojo y vasculatura y membrana blanco-amarillenta detrás del cristalino en el ojo derecho. La ecografía en modo B con desorganización de la cavidad vítrea con ecos de alta reflectividad sugestivos de calcificación. A la exploración se observó globo ocular agrandado, rubeosis iridis, vasculatura posterior, presión intraocular 28 mmHg. Tomografía computarizada con masa intraocular heterogénea con regiones hiperdensas. Con diagnóstico de probable retinoblastoma, se realizó la enucleación. La histopatología informó el hallazgo de retinoblastoma moderadamente diferenciado coexistente con PVF. CONCLUSIONES: El hallazgo de estos dos diagnósticos en un mismo ojo es muy poco frecuente debido a la diferente fisiopatología.


Assuntos
Calcinose , Vítreo Primário Hiperplásico Persistente , Neoplasias da Retina , Retinoblastoma , Humanos , Masculino , Criança , Lactente , Retinoblastoma/diagnóstico , Vítreo Primário Hiperplásico Persistente/diagnóstico , Vítreo Primário Hiperplásico Persistente/complicações , Vítreo Primário Hiperplásico Persistente/patologia , Calcinose/complicações , Tomografia Computadorizada por Raios X , Neoplasias da Retina/diagnóstico
4.
Bol. méd. Hosp. Infant. Méx ; 80(supl.1): 53-57, 2023. graf
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1513766

RESUMO

Resumen Introducción: El retinoblastoma (RB) es el tumor maligno primario intraocular más frecuente en la infancia y debe ser la principal patología a descartar en los pacientes pediátricos con leucocoria. La persistencia de la vasculatura fetal (PVF) está dentro del diagnóstico diferencial de la leucocoria, un trastorno del vítreo que surge de un defecto en la involución de la vasculatura hialoidea en la etapa embrionaria que afecta al desarrollo ocular normal y comúnmente produce microoftalmia asociada. El diagnóstico temprano y tratamiento oportuno son cruciales para un buen pronóstico y mejor esperanza de vida del infante. Caso clínico: Presentamos un caso de coexistencia de retinoblastoma y PVF: paciente de sexo masculino de 2 años y 11 meses sin reflejo rojo y vasculatura y membrana blanco-amarillenta detrás del cristalino en el ojo derecho. La ecografía en modo B con desorganización de la cavidad vítrea con ecos de alta reflectividad sugestivos de calcificación. A la exploración se observó globo ocular agrandado, rubeosis iridis, vasculatura posterior, presión intraocular 28 mmHg. Tomografía computarizada con masa intraocular heterogénea con regiones hiperdensas. Con diagnóstico de probable retinoblastoma, se realizó la enucleación. La histopatología informó el hallazgo de retinoblastoma moderadamente diferenciado coexistente con PVF. Conclusiones: El hallazgo de estos dos diagnósticos en un mismo ojo es muy poco frecuente debido a la diferente fisiopatología.


Abstract Background: As retinoblastoma (RB) is the most frequent primary intraocular malignant tumor in childhood, it should be the main pathology to rule out in pediatric patients with leukocoria. Persistence of fetal vasculature (PFV) is within the differential diagnosis of leukocoria, a vitreous disorder arising from a defect in the involution of the hyaloid vasculature in the embryonic stage, which affects normal ocular development and commonly produces associated microophthalmia. An early diagnosis and timely treatment are crucial for a better prognosis and life expectancy of the child. Case report: We present a case of retinoblastoma and coexisting with PFV: a 2-years-and 11-months-old male with no red reflex, and vasculature and yellowish-white membrane behind the lens of the right eye. B-mode ultrasound with disorganization of the vitreous cavity with high reflectivity echoes suggestive of calcification. On examination we found an enlarged eyeball, rubeosis iridis, posterior vasculature, intraocular pressure 28 mmHg. Computed tomography with heterogeneous intraocular mass with hyperdense regions. With a diagnosis of probable retinoblastoma, enucleation was performed. Histopathology reported moderately differentiated retinoblastoma coexisting with PFV. Conclusions: The finding of these two diagnoses in the same eye is very rare due to the different pathophysiology.

5.
J Anim Sci ; 100(6)2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35511683

RESUMO

Modern hyperprolific sows must deal with large litters (16-20 piglets) which reduce piglet birthweight with a concomitant increase in the proportion of small and intrauterine growth retarded piglets. However, larger litters do not only have a greater variation of piglet weights, but also a greater variation in colostrum and milk consumption within the litter. To further understand the impact that body weight has on piglets, the present study aimed to evaluate the degree of physiological weakness of the smallest piglets at birth and during the suckling period (20 d) compared to their middle-weight littermates through their jejunal gene expression. At birth, light piglets showed a downregulation of genes related to immune response (FAXDC2, HSPB1, PPARGC1α), antioxidant enzymes (SOD2m), digestive enzymes (ANPEP, IDO1, SI), and nutrient transporter (SLC39A4) (P < 0.05) but also a tendency for a higher mRNA expression of GBP1 (inflammatory regulator) and HSD11ß1 (stress hormone) genes compared to their heavier littermates (P < 0.10). Excluding HSD11ß1 gene, all these intestinal gene expression differences initially observed at birth between light and middle-weight piglets were stabilized at the end of the suckling period, when others appeared. Genes involved in barrier function (CLDN1), pro-inflammatory response (CXCL2, IL6, IDO1), and stress hormone signaling (HSD11ß1) over-expressed compared to their middle-weight littermates (P < 0.05). In conclusion, at birth and at the end of suckling period, light body weight piglets seem to have a compromised gene expression and therefore impaired nutrient absorption, immune and stress responses compared to their heavier littermates.


Under hyperprolific situations, piglets must deal with a reduced birthweight and a severe sibling competition for nutrients. Therefore, light body weight newborn and suckling piglets may also have physiological disadvantages compared to their middle-weight littermates. To further understand the impact that body weight has on piglets, the present study aimed to evaluate the degree of physiological weakness of the smallest piglets at birth and during the suckling period (20 d) compared to their middle-weight littermates through their jejunal gene expression. Newborn light piglets downregulated genes related to immunity, antioxidant, and digestive activities, but also a tendency to upregulate other genes related to inflammation and stress responses. At the end of the suckling period, those genes expression differences vanished while others appear. Light weight piglets showed lower expression of genes involved in barrier function, inflammation, and stress responses compared to their middle-weight littermates. At birth and at the end of lactation, light piglets seem to have a compromised intestinal gene expression for nutrient absorption, immune and stress responses compared to their heavier littermates.


Assuntos
Colostro , Hormônios , Animais , Animais Recém-Nascidos , Animais Lactentes , Peso ao Nascer , Peso Corporal , Feminino , Expressão Gênica , Lactação , Gravidez , Suínos/genética
6.
Animals (Basel) ; 11(7)2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34359190

RESUMO

In the present research, two studies were performed to determine the effects of specific botanical compounds (BCs) on the innate feed preference and feed intake of piglets, as follows: Exp. 1 studied the innate feed preferences of post-weaning piglets using a double-choice feeding test. A total of 828 weaned piglets were distributed into 36 pens (23 pigs/pen) and assigned to three dietary pair choice feeding options (n = 12): unsupplemented prestarter diets (reference) versus reference plus D-limonene, trans-anethole, or eucalyptol. Piglets showed a preference for diets with D-limonene (53.8%) and trans-anethole (54.5%), and an aversion to eucalyptol (41.6%) (p < 0.05). Exp. 2 studied whether the prenatal and perinatal exposure to D-limonene, trans-anethole, and eucalyptol influences the feed intake and growth of newly-weaned piglets. Twenty-eight gestating and lactating sows were distributed into two dietary treatments (n = 14): unsupplemented Control diets or Control plus a blend of BCs (BBC; containing D-limonene, trans-anethole, and eucalyptol). D-limonene, trans-anethole, and eucalyptol were transferred into the placental fluid, and D-limonene and trans-anethole into the milk (p < 0.05). Furthermore, weanling piglets (n = 200; Control) and (n = 203; BBC) received the same treatment as their mothers in prestarter diets. The early response after weaning showed that piglets' post-weaning BW gain was higher in the Control (p < 0.05) group than in those exposed to BBC. In conclusion, prenatal exposure to preferred D-limonene and trans-anethole, or familiarity to eucalyptol did not help to overcome the innate aversion to eucalyptol and its negative effect on weanling piglets' BW.

7.
J Anim Sci ; 99(7)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34057466

RESUMO

The aim of the present study was to evaluate the effect of trace mineral nutrition on sow performance, mineral content, and intestinal gene expression of neonate piglets when inorganic mineral sources (ITM) were partially replaced by their organic mineral (OTM) counterparts. At 35 d postmating, under commercial conditions, a total of 240 hyperprolific multiparous sows were allocated into three experimental diets: 1) ITM: with Zn, Cu, and Mn at 80, 15, and 60 mg/kg, respectively; 2) partial replacement trace mineral source (Replace): with a 30 % replacement of ITM by OTM, resulting in ITM + OTM supplementation of Zn (56 + 24 mg/kg), Cu (10.5 + 4.5 mg/kg), and Mn (42 + 18 mg/kg); and 3) Reduce and replace mineral source (R&R): reducing a 50% of the ITM source of Zn (40 + 24 mg/kg), Cu (7.5 + 4.5 mg/kg), and Mn (30 + 18 mg/kg). At farrowing, 40 piglets were selected, based on birth weight (light: <800 g, and average: >1,200 g), for sampling. Since the present study aimed to reflect results under commercial conditions, it was difficult to get an equal parity number between the experimental diets. Overall, no differences between experimental diets on sow reproductive performance were observed. Light piglets had a lower mineral content (P < 0.05) and a downregulation of several genes (P < 0.10) involved in physiological functions compared with their average littermates. Neonate piglets born from Replace sows had an upregulation of genes involved in functions like immunity and gut barrier, compared with those born from ITM sows (P < 0.10), particularly in light piglets. In conclusion, the partial replacement of ITM by their OTM counterparts represents an alternative to the totally inorganic supplementation with improvements on neonate piglet gene expression, particularly in the smallest piglets of the litter. The lower trace mineral storage together with the greater downregulation of gut health genes exposed the immaturity and vulnerability of small piglets.


Assuntos
Oligoelementos , Ração Animal/análise , Animais , Dieta/veterinária , Suplementos Nutricionais , Feminino , Desenvolvimento Fetal , Gravidez , Suínos
8.
Animals (Basel) ; 10(12)2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33321976

RESUMO

This study was conducted to investigate the effects of dietary supplementation of porcine digestible peptides (PDP), spray-dried plasma (SDP), or a combination of both, on growth performance and the expression of genes related to intestinal function of weaned pigs. A total of 180 piglets (trial 1) and 198 piglets (trial 2) were used to evaluate the partial substitution of soybean ingredients with 2% SDP or 2% PDP (trial 1), and with 3% SDP or the combination of 1% SDP and 2% PDP (SDP-PDP; trial 2) during the pre-starter period (0-14 days). The gene expression of 56 genes was quantified in a qPCR platform in jejunum and ileum samples obtained from piglets 14 d after weaning (trial 2). Piglets fed SDP, PDP and SDP-PDP had a higher body weight (BW), average daily gain (ADG) and feed efficiency (G:F) than the soybean control on day 14 (p < 0.05). In addition, the combination of SDP and PDP upregulated ten genes in jejunum samples (p < 0.05) related to intestinal function. More research is needed to confirm that gene expression upregulation by PDP in combination with SDP has an impact on intestinal function and to elucidate its underlying mechanisms.

9.
J Anim Sci ; 98(5)2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32277238

RESUMO

A 42-d experiment was conducted to evaluate the effect of Cu and Zn source and Cu level on pig performance, mineral status, bacterial modulation, and the presence of antimicrobial-resistant genes in isolates of Enterococcus spp. At weaning, 528 pigs (5.9 ± 0.50 kg) were allotted to 48 pens of a randomized complete block design in a 2 × 2 factorial arrangement with two Cu and Zn sources (SF: sulfate and HCl: hydroxychloride) and two Cu levels (15 and 160 mg/kg). As a challenge, the pigs were reared in dirty pens used by a previous commercial batch. Two-phase diets were offered: the pre-starter (PS) phase from day 1 to 14 and the starter phase (ST) from day 14 to 42. At days 14 and 42, pigs were individually weighed and blood samples from one pig per pen were taken. At the end of the experiment, one pig per pen was euthanized to collect the samples. Feeding high levels of Cu increased body weight (BW) from 16.6 to 17.7 kg (P < 0.001). Furthermore, average daily gain, gain to feed (G:F) ratio, average daily feed intake (ADFI), and mineral status were enhanced with Cu at 160 mg/kg (P < 0.05) compared with Cu at 15 mg/kg. There was no effect of the interaction between source × level on any of the growth performance responses except for ADFI (P = 0.004) and G:F (P = 0.029) at the end of the ST period and for G:F (P = 0.006) for entire nursery period (day 0 to 42). At the end of the ST period, pigs fed Cu at 160 mg/kg as HCl had not only higher ADFI but also lower G:F than those fed Cu as SF at 160 mg/kg. Meanwhile, for the entire nursery period, G:F did not differ between pigs fed Cu at 160 mg/kg as HCl or SF. In colonic digesta, the relative abundance of Streptococcus, Enterobacter, Escherichia, among others, decreased (P-adjust < 0.05), while Lachnospira and Roseburia tended (P-adjust < 0.10) to increase in pigs fed Cu at 160 mg/kg as HCl compared with those fed Cu SF at 160 mg/kg. An increase (P-adjust < 0.05) in Methanosphaera and Roseburia was observed in pigs fed Cu at 160 mg/kg. From colon digesta, Enterococcus spp. was isolated in 40 samples, being E. faecalis the most dominating (65%) regardless of the experimental diet. Genes of ermB (7.5%) and tetM (5%) were identified. No genes for Cu (tcrB) or vancomycin (vanA, vanB, vanC1, and vanC2) were detected. In conclusion, European Union permissible levels of Cu (160 mg/kg), of both sources, were able to increase performance, mineral status, and bacterial modulation compared with nutritional level. Different effects on growth performance, mineral tissue content, and microbial modulation were observed between Cu and Zn sources.


Assuntos
Cobre/farmacologia , Farmacorresistência Bacteriana/genética , Enterococcus/efeitos dos fármacos , Microbioma Gastrointestinal/efeitos dos fármacos , Suínos/fisiologia , Zinco/farmacologia , Ração Animal/análise , Animais , Antioxidantes/metabolismo , Peso Corporal/efeitos dos fármacos , Dieta/veterinária , Enterococcus/isolamento & purificação , Feminino , Microbioma Gastrointestinal/genética , Masculino , Distribuição Aleatória , Suínos/genética , Suínos/crescimento & desenvolvimento , Suínos/microbiologia , Desmame
10.
Food Chem ; 303: 125406, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31472386

RESUMO

This study reports the heat-induced formation of furan by decarboxylation of 2-furoic acid, and 2-methylfuran by dehydration of furfuryl alcohol under dry conditions. Model systems were incubated at temperatures up to 190 °C, followed by quantitative determination of furan and 2-methylfuran performed by isotope dilution headspace gas chromatography-mass spectrometry. Results show that 2-furoic acid decarboxylation and furfuryl alcohol dehydration are activated as from about 140-160 °C. Furfuryl alcohol and 2-furoic acids were measured in a selection of roasted coffee products by isotope dilution liquid chromatography-high resolution mass spectrometry, and the data evidenced a strong correlation between the two compounds, suggesting an intimate mechanistic relationship between them. The possible oxidation of furfuryl alcohol to furfural and 2-furoic acid in heated food is raised with particular emphasis on coffee roasting. These findings are relevant for better understanding the formation of furan and alkylfurans in food, and ultimately opening avenues for mitigation.


Assuntos
Furanos/análise , Furanos/química , Coffea/química , Culinária , Contaminação de Alimentos/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Temperatura Alta , Sementes/química
11.
Chemosphere ; 238: 124575, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31446274

RESUMO

Significance of surface and ground water contamination by synthetic organic compounds has been pointed out in a very high number of papers worldwide, as well as the need of application of treatment technologies capable to assure their complete removal. Among these processes, the electrochemical advanced oxidation is an interesting option, especially when irradiated with UVC light (photo-electrochemical, P-EC) to promote homolysis of electrogenerated oxidants. In this work, the herbicide glyphosate (GLP) was used as model compound and it was electrochemically treated under UVC irradiation in the presence of NaCl and using a DSA® and BDD anodes. Total organic carbon concentration was measured throughout the electrolysis, as well as the concentration of short chain carboxylic acids and inorganic ions (NO3-, PO43-,ClO-, ClO3- and ClO4-). The synergism of the P-EC was more pronounced when using a DSA® electrode, which led to complete GLP mineralization in 1 h (0.52 A h L-1), as also confirmed by the stoichiometric formation of NO3- and PO43- ions, with an energy consumption as low as 1.25 kW h g-1. Unexpectedly, the concentration evolution of oxyhalides for the P-EC process using both anodes, especially for DSA® at 10 mA cm-2, showed the production of ClO3-, whereas detection of ClO4- species was only found when using BDD at 100 mA cm-2 for the electrochemical process. Finally, small amounts of carboxylic acids were detected, including dichloroacetic acid, especially when using a BDD electrode.


Assuntos
Técnicas Eletroquímicas/métodos , Glicina/análogos & derivados , Água Subterrânea/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Purificação da Água/métodos , Ácidos Carboxílicos/análise , Diamante/química , Eletrodos , Glicina/análise , Oxidantes/química , Oxirredução , Raios Ultravioleta , Glifosato
12.
Folia Microbiol (Praha) ; 63(4): 517-523, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29488180

RESUMO

Candida bracarensis is an emerging cryptic species within the Candida glabrata clade. To date, little is known about its epidemiology, virulence, and antifungal susceptibility. This study documents the occurrence of C. bracarensis for the first time in Mexico and focuses on its in vitro production of hydrolytic enzymes, as well as antifungal susceptibility to echinocandins. This strain was isolated from a vaginal swab of a female with vulvovaginal candidosis; exhibited a very strong activity of aspartyl proteinase, phospholipase, and hemolysin; and was susceptible to caspofungin, anidulafungin, and micafungin (MIC = 0.031 µg/mL). Data obtained could contribute to the knowledge of the epidemiology and virulence attributes of this yeast as a fungal opportunistic human pathogen.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candida/enzimologia , Candidíase Vulvovaginal/microbiologia , Hidrolases/metabolismo , Viabilidade Microbiana/efeitos dos fármacos , Candida/classificação , Candida/fisiologia , DNA Fúngico/genética , DNA Espaçador Ribossômico/genética , Feminino , Genoma Fúngico , Humanos , México , Testes de Sensibilidade Microbiana
13.
BMC Microbiol ; 18(1): 20, 2018 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-29523074

RESUMO

BACKGROUND: The cyclic-di-GMP (c-di-GMP) second messenger exemplifies a signaling system that regulates many bacterial behaviors of key importance; among them, c-di-GMP controls the transition between motile and sessile life-styles in bacteria. Cellular c-di-GMP levels in bacteria are regulated by the opposite enzymatic activities of diguanylate cyclases and phosphodiesterases, which are proteins that have GGDEF and EAL domains, respectively. Azospirillum is a genus of plant-growth-promoting bacteria, and members of this genus have beneficial effects in many agronomically and ecologically essential plants. These bacteria also inhabit aquatic ecosystems, and have been isolated from humus-reducing habitats. Bioinformatic and structural approaches were used to identify genes predicted to encode GG[D/E]EF, EAL and GG[D/E]EF-EAL domain proteins from nine genome sequences. RESULTS: The analyzed sequences revealed that the genomes of A. humicireducens SgZ-5T, A. lipoferum 4B, Azospirillum sp. B510, A. thiophilum BV-ST, A. halopraeferens DSM3675, A. oryzae A2P, and A. brasilense Sp7, Sp245 and Az39 encode for 29 to 41 of these predicted proteins. Notably, only 15 proteins were conserved in all nine genomes: eight GGDEF, three EAL and four GGDEF-EAL hybrid domain proteins, all of which corresponded to core genes in the genomes. The predicted proteins exhibited variable lengths, architectures and sensor domains. In addition, the predicted cellular localizations showed that some of the proteins to contain transmembrane domains, suggesting that these proteins are anchored to the membrane. Therefore, as reported in other soil bacteria, the Azospirillum genomes encode a large number of proteins that are likely involved in c-di-GMP metabolism. In addition, the data obtained here strongly suggest host specificity and environment specific adaptation. CONCLUSIONS: Bacteria of the Azospirillum genus cope with diverse environmental conditions to survive in soil and aquatic habitats and, in certain cases, to colonize and benefit their host plant. Gaining information on the structures of proteins involved in c-di-GMP metabolism in Azospirillum appears to be an important step in determining the c-di-GMP signaling pathways, involved in the transition of a motile cell towards a biofilm life-style, as an example of microbial genome plasticity under diverse in situ environments.


Assuntos
Azospirillum/genética , Azospirillum/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , GMP Cíclico/análogos & derivados , Domínios Proteicos , Transdução de Sinais , Adaptação Biológica , Azospirillum/enzimologia , Biofilmes/crescimento & desenvolvimento , Biologia Computacional , GMP Cíclico/metabolismo , Proteínas de Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Modelos Moleculares , Diester Fosfórico Hidrolases/metabolismo , Fósforo-Oxigênio Liases/metabolismo , Conformação Proteica , Sistemas do Segundo Mensageiro/genética
14.
Anal Chim Acta ; 913: 22-40, 2016 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-26944987

RESUMO

This paper reviews the latest developments and analytical applications of chemiluminescence detection coupled to capillary electrophoresis (CE-CL). Different sections considering the most common CL systems have been included, such as the tris(2,2'-bipyridine)ruthenium(II) system, the luminol and acridinium derivative reactions, the peroxyoxalate CL or direct oxidations. Improvements in instrumental designs, new strategies for improving both resolution and sensitivity, and applications in different fields such as clinical, pharmaceutical, environmental and food analysis have been included. This review covers the literature from 2010 to 2015.


Assuntos
Eletroforese Capilar/métodos , Poluentes Ambientais/análise , Análise de Alimentos , Luminescência
15.
Anal Bioanal Chem ; 408(11): 3033-42, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26873195

RESUMO

In this work, we report the synthesis of novel magnetic molecularly imprinted polymers (m-MIPs) and their application to the selective extraction of the mycotoxin citrinin (CIT) from food samples. The polymers were prepared by surface imprinting of Fe3O4 nanoparticles, using 2-naphtholic acid (2-NA) as template molecule, N-3,5-bis(trifluoromethyl)phenyl-N'-4-vinylphenyl urea and methacrylamide as functional monomers and ethyleneglycol dimethacrylate as cross-linker. The resulting material was characterized by transmission electron microscopy (TEM), and X-ray diffraction (XRD) and Fourier transform infrared spectroscopies (FT-IR). The polymers were used to develop a solid-phase extraction method (m-MISPE) for the selective recovery of CIT from rice extracts prior to its determination by HPLC with UV diode array detection. The method involves ultrasound-assisted extraction of the mycotoxin from rice samples with (7:3, v/v) methanol/water, followed by sample cleanup and preconcentration with m-MIP. The extraction (washing and elution) conditions were optimized and their optimal values found to provide CIT recoveries of 94-98 % with relative standard deviations (RSD) less than 3.4 % (n = 3) for preconcentrated sample extracts (5 mL) fortified with the analyte at concentrations over the range 25-100 µg kg(-1). Based on the results, the application of the m-MIPs facilitates the accurate and efficient determination of CIT in rice extracts.


Assuntos
Cromatografia Líquida/métodos , Citrinina/análise , Magnetismo , Impressão Molecular , Oryza/química , Polímeros/química , Espectrofotometria Ultravioleta/métodos
16.
Artigo em Inglês | MEDLINE | ID: mdl-26125614

RESUMO

A rapid, simple and effective method for the determination of citrinin in rice by UHPLC coupled to fluorescence detection has been developed and validated. Extraction of citrinin from rice samples was achieved by applying a QuEChERS-based extraction/partitioning process with water and acetonitrile, without the need of further extract clean-up. The method was fully validated for white rice, and its applicability in other rice matrices, such as brown and red rice, was confirmed by recovery experiments. Under optimum conditions, recoveries ranged from 72.5% to 92.8%, with relative standard deviations (RSDs) lower than 7.1%. Detection and quantification limits were estimated to be 1.5 and 5.0 µg kg(-1), respectively. Finally, 21 organic rice samples were analysed, but none was contaminated with citrinin above the detection limit of the method. The method proved to be fast and non-laborious.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Citrinina/análise , Contaminação de Alimentos/análise , Oryza/química , Fluorescência , Limite de Detecção , Reprodutibilidade dos Testes
17.
Chemosphere ; 136: 281-8, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26048815

RESUMO

In this work, the usefulness of Conductive Diamond Electrochemical Oxidation (CDEO) to degrade caffeine in real urban wastewater matrixes was assessed. The oxidation of actual wastewater intensified with caffeine (from 1 to 100 mg L(-1)) was studied, paying particular attention to the influence of the initial load of caffeine and the differences observed during the treatment of caffeine in synthetic wastewater. The results showed that CDEO is a technology that is capable of efficiently degrading this compound even at very low concentrations and that it can even be completely depleted. Profiles of the ionic species of S (SO4(2-)), N (NH4(+), NO3(-)) and Cl (ClO(-), ClO3(-) and ClO4(-)) were monitored and explained for plausible oxidation mechanisms. It was observed that the efficiency achieved is higher in the treatment of real wastewater than in the oxidation of synthetic wastewater because of the contribution of electrogenerated oxidant species such as hypochlorite. The formation of chlorate and perchlorate during electrochemical processes was observed, and a combined strategy to prevent this important drawback was successfully tested based on the application of low current densities with the simultaneous dosing of hydrogen peroxide.


Assuntos
Cafeína/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Biodegradação Ambiental , Diamante/química , Peróxido de Hidrogênio/química , Oxidantes , Oxirredução , Águas Residuárias/microbiologia
18.
Talanta ; 139: 174-80, 2015 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-25882424

RESUMO

A new method based on vortex-assisted surfactant-enhanced-emulsification liquid-liquid microextraction has been developed for the extraction of carbamate pesticides in juice samples prior to their determination by micellar electrokinetic chromatography coupled to tandem mass spectrometry. This sample treatment allowed the satisfactory extraction and the extract clean-up of 25 carbamates from different fruit and vegetal juices (banana, tomato, and peach). In this study, the addition of ammonium perfluorooctanoate in the aqueous sample in combination with vortex agitation, provided very clean extracts with short extraction times. Under optimized conditions, recoveries of the proposed method for these pesticides from fortified juice samples ranged from 81% to 104%, with relative standard deviations lower than 15%. Limits of quantification were between 2.3µgkg(-)(1) and 4.7µgkg(-)(1), showing the high sensitivity of this fast and simple method.


Assuntos
Bebidas/análise , Carbamatos/análise , Cromatografia Capilar Eletrocinética Micelar/métodos , Frutas/química , Microextração em Fase Líquida/métodos , Praguicidas/análise , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Limite de Detecção , Micelas , Praguicidas/isolamento & purificação , Tensoativos/química
19.
Food Chem Toxicol ; 78: 60-3, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25660482

RESUMO

The objective of this study is to evaluate the efficacy of a new mycotoxin inactivator (AdiDetox™) in reducing the toxic effects of fumonisin B1 (FB1) in the diet of rats. Sixty-four male Sprague-Dawley growing rats (125 g ± 1 g BW) were assigned to eight dietary treatments for seven days. The experiment had a 2 × 4 factorial arrangement with two levels of FB1 (0 mg and 15 mg of FB1/kg feed) and four levels of AdiDetox™ (0 g, 1 g, 2 g and 5 g /kg feed) in the diet. No significant differences were observed in the growth performance among treatments (P > 0.05), though low levels of sphingosine (So) and sphinganine (Sa) were detected in the liver. However, So and Sa and the Sa/So ratio in kidneys were higher in rats receiving the FB1 diets (P < 0.0001) than in those fed the Control diet. Supplementation of AdiDetox™ to the diet significantly reduced the toxic effects of FB1, leading to a significant decrease in the Sa content and in the Sa/So ratio in kidneys. In conclusion, the results suggest that AdiDetox™ can effectively reduce toxicity of FB1 in growing rats.


Assuntos
Fumonisinas/toxicidade , Sequestrantes/farmacologia , Fosfatase Alcalina/sangue , Animais , Aspartato Aminotransferases/sangue , Rim/efeitos dos fármacos , Rim/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Triglicerídeos/sangue , Ácido Úrico/sangue
20.
Food Chem ; 177: 274-9, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25660886

RESUMO

Consumption of cereal syrups is increasing nowadays. Mycotoxins may be found in syrups resulting from the use of contaminated raw material or invading microorganisms in the final manufactured product. However, these matrices have been scarcely explored regarding their mycotoxin content. A sensitive, simple and rapid method for the determination of ten mycotoxins (ochratoxin A, fumonisin B1, fumonisin B2, deoxynivalenol, fusarenon-X, T-2 and HT-2 toxin, citrinin, sterigmatocystin and zearalenone) in cereal syrups (rice, wheat and barley) has been developed and characterised using ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) and a sample treatment based on QuEChERS procedure. Matrix-matched calibration curves were established and limits of quantification were below the limits usually established by current legislation in different foodstuff. The relative standard deviation of the whole analytical method was lower than 12% in all cases, while recoveries ranged from 70.2% to 100.6%, therefore fulfilling the current requirements for mycotoxins analysis.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Grão Comestível/química , Micotoxinas/química , Espectrometria de Massas em Tandem/métodos , Análise de Alimentos , Micotoxinas/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA