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1.
Opt Lett ; 46(10): 2360-2363, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33988583

RESUMO

The optical properties of ZnO nanorod (NR) arrays were investigated by optical total transmittance (TT) and diffuse reflectance (DR) spectroscopy in the visible region. The NRs were grown electrochemically in a three-electrode cell over a glass/fluorine-doped tin oxide (FTO) substrate. The mean length, radius, and density of NR samples were characterized by scanning electron microscopy. The results were correlated with the observed optical properties. Since light scattering for these NR arrays is highly dependent on their morphology, therefore, a model for light scattering based in the Mie theory for cylinders was implemented to understand the observed spectra. The mean scattering and extinction cross sections were calculated from the morphology of the samples. They were used to fit the DR spectra. From the fittings, the TT spectra of the samples could be calculated. A good agreement with the experimental results was obtained. This indicates that the implemented model represents well the observed scattering phenomena.

2.
Arq. bras. med. vet. zootec. (Online) ; 72(3): 862-870, May-June, 2020. ilus, tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1129541

RESUMO

The aim of this study was to evaluate in vitro the probiotic potential and absorption of Saccharomyces cerevisiae for the aflatoxin B1 in simulated fish intestinal tract conditions. Three yeast strains were used, two from brewery: S. cerevisiae RC1 and S. cerevisiae RC3 and one from a fish farming environment: S. cerevisiae A8L2. The selected yeasts were subjected to the following in vitro tests: homologous inhibition, self-aggregation, co-aggregation, antibacterial activity, gastrointestinal conditions tolerance and adsorption of AFB1. All S. cerevisiae strains showed good capability of self-aggregation and co-aggregation with pathogenic bacteria. All yeast strains were able to survive the gastrointestinal conditions. In acidic conditions, the factors (strain vs. time) had interaction (P=0.0317), resulting in significant variation among the strains tested in the time periods analyzed. It was observed that there was also interaction (P=0.0062) in intestinal conditions, with an increased number of cells in the 12-hour period for all strains tested. In the adsorption test, the A8L2 strain was statistically more effective (P<0.005) for both AFB1 concentrations evaluated in this study (10 and 25ng/mL). Thus, it was observed that the strains of S. cerevisiae have potential probiotic and adsorbent of AFB1.(AU)


Objetivou-se, com esta pesquisa, avaliar in vitro o potencial probiótico e adsorvente de Saccharomyces cerevisiae para aflatoxina B1 em condições simuladas do trato intestinal de peixes. Foram utilizadas três cepas de leveduras, sendo duas provenientes de cervejaria: S. cerevisiae RC1 e S. cerevisiae RC3, e uma de ambiente de piscicultura: S. cerevisiae A8L2. As leveduras selecionadas foram submetidas aos seguintes testes in vitro: inibição homóloga, autoagregação, coagregação, atividade antibacteriana, viabilidade às condições gastrointestinais e adsorção de AFB1. Todas as estirpes de S. cerevisiae mostraram boa capacidade de autoagregação e coagregação com bactérias patogênicas. Todas as estirpes de levedura foram capazes de sobreviver às condições gastrointestinais. Em condições ácidas, os fatores (cepa x tempo) tiveram interação (P=0,0317), resultando em variações significativas entre as cepas testadas nos períodos de tempo analisados. Observou-se que também houve interação (P=0,0062) em condições intestinais, havendo um aumento do número de células no período de 12h para todas as cepas avaliadas. No ensaio de adsorção, a estirpe A8L2 foi a mais eficaz estatisticamente (P<0,005), para as duas concentrações de AFB1 avaliadas neste estudo (10 e 25ng. mL-1). Dessa forma, conclui-se que as cepas de Saccharomyces cerevisiae possuem potencial probiótico e adsorvente de AFB1.(AU)


Assuntos
Animais , Saccharomyces cerevisiae , Aflatoxina B1/antagonistas & inibidores , Probióticos/uso terapêutico , Peixes/fisiologia , Intestinos/microbiologia , Técnicas In Vitro , Adsorção
3.
Zootaxa ; 4728(1): zootaxa.4728.1.8, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-32230589

RESUMO

Hippomonavella charrua n. sp. is introduced based on material from the continental shelf off Uruguay. Bilaminar fragments of this species were also found in mid-Holocene deposits of Destacamento Río Salado Member, Canal de las Escobas Formation (Buenos Aires Province, Argentina), ca. 6,000 yr BP. Hippomonavella charrua n. sp. resembles H. brasiliensis Ramalho, Muricy Taylor, 2008, but differs from this species in its more triangular and protruding avicularia occurring in just a small proportion of zooids. Hippomonavella charrua n. sp. is the third species of the genus with both fossil and Recent representatives. The tatiform ancestrula and the early astogeny are described for the first time in a species of Hippomonavella.


Assuntos
Briozoários , Animais , Argentina , Fósseis , Uruguai
4.
Food Res Int ; 111: 306-313, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30007690

RESUMO

The objectives of this study were: to evaluate the use of dry distillery grain soluble extract - DDGse to produce yeast biomass and to obtain cell wall (CW), to use the CW as an aflatoxin B1 (AFB1) adsorbent, to study the variation in the composition and thickness of the CW under the influence of DDGse to evaluate their implication on the adsorption process using transmission electron microscopy (TEM) and fourier-transform infrared spectroscopy (FITR). The production of biomass and CW were variable. The CW thickness values showed that S. boulardii strain grown in yeast extract peptone dextrose (YPD) or DDGse medium, with no significant differences observed. The thickness of the CW for S. cerevisiae (RC012 and VM014) were increased when the cells were grown in DDGse medium, the thickness was almost double compared to the values obtained in YPD medium. The spectra IR of each CW in the two culture media shown regions corresponding to polysaccharides, proteins and lipids. Cells grown in DDGse medium adsorbed more AFB1 than those grown in YPD. The CW adsorbed more AFB1 than the same amount of whole cell. Future studies should be done to determine the type of carbohydrates and the relationship between chitin - beta glucans responsible for mycotoxin adsorption.


Assuntos
Aflatoxina B1/análise , Agricultura , Parede Celular/química , Resíduos Industriais , Saccharomyces boulardii/metabolismo , Saccharomyces cerevisiae/metabolismo , Adsorção , Biomassa , Parede Celular/metabolismo , Microscopia Eletrônica de Transmissão , Espectroscopia de Infravermelho com Transformada de Fourier
5.
Eur J Pharm Sci ; 100: 79-86, 2017 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-28087355

RESUMO

Supercritical antisolvent process (SAS) has been used to precipitate microparticles of quercetin, a plant pigment found in many foods and used for medical treatments, pharmaceutical and cosmetic industries, together with nanoparticles of cellulose acetate phthalate (CAP), a polymer quite frequently used in drug delivery. Previously, precipitation of nanoparticles of CAP by the same process was studied at different conditions of pressure, temperature, CO2 and solution flow rates, nozzle diameter and initial concentration of the solution. Morphologies of the precipitates were analyzed by scanning electron microscopy (SEM). A range between 84 and 145nm of diameter in spherical particle were achievement in CAP precipitation. A same range of semi-spherical particles of CAP around 145nm and needle-like particle of quercetin was obtained in the coprecipitation experiments. X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) were carried out to find out the possible loss of crystallinity of the coprecipitates and the possible interactions between the polymer and quercetin, respectively. Release profiles of quercetin were carried out in simulated gastric and intestinal fluids. Higher quercetin:polymer ratios in the coprecipitates are recommended to achieve faster release and higher solubilities of quercetin in the assayed time. This fact would allow its use in pharmaceutical, cosmetic or nutraceutical applications.


Assuntos
Celulose/análogos & derivados , Sistemas de Liberação de Medicamentos , Quercetina/química , Celulose/química , Precipitação Química , Química Farmacêutica , Liberação Controlada de Fármacos , Suco Gástrico/química , Secreções Intestinais/química , Solubilidade
6.
Lett Appl Microbiol ; 62(2): 160-8, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26551056

RESUMO

UNLABELLED: The aim of this manuscript was to study the influence of water activity (aW ) and pH in the ecophysiological behaviour of Aspergillus fumigatus strains at human body temperature. In addition, gliotoxin production and enzymatic ability among environmental (n = 2) and clinical (n = 5) strains were compared. Ecophysiological study of environmental strains was performed on agar silage incubated at 37°C, studying the interaction at eight aW levels (0·8, 0·85, 0·9, 0·92, 0·94, 0·96, 0·98 and 0·99) and eight pH levels (3·5, 4, 4·5, 5, 6, 7, 7·5 and 8). Considering the influence of the assumed lung conditions on growth of A. fumigatus (aW 0·98/0·99 and pH of 7/7·5), the optimal condition for the development of A. fumigatus RC031 was at aW 0·99 at pH 7. At aW 0·98/0·99 and pH of 7/7·5, the highest growth rate and the lowest lag phase was reported, whereas there were no significant differences at aW 0·98/0·99 and pH 7/7·5 interactions on growth of A. fumigatus RC032. Gliotoxin production of A. fumigatus strains was evaluated. The gliotoxin production was similar in clinical and environmental strains. Elastin activity was studied in solid medium, highest elastase activity index was found for clinical strain A. fumigatus RC0676, followed by the environmental strain A. fumigatus RC031. Opportunistic environmental strains can be considered as pathogenic in some cases when rural workers are exposed constantly to handling silage. SIGNIFICANCE AND IMPACT OF THE STUDY: Aspergillus fumigatus is one of the main opportunist pathogen agents causing invasive aspergillosis. Rural workers present a constant exposition to A. fumigatus spores caused by feed-borne manipulation. In this study, environmental A. fumigatus strains were able to grow and produce gliotoxin onto the studied conditions including the lung ones. Environmental and clinical strains were physiologically similar and could be an important putative infection source in rural workers.


Assuntos
Aspergillus fumigatus/enzimologia , Aspergillus fumigatus/metabolismo , Elastina/metabolismo , Gliotoxina/biossíntese , Silagem/microbiologia , Aspergilose/microbiologia , Aspergilose/patologia , Aspergillus fumigatus/fisiologia , Humanos
7.
Artigo em Inglês | MEDLINE | ID: mdl-25599419

RESUMO

Environmental conditions play a key role in fungal development. During the silage production process, humidity, oxygen availability and pH vary among lactic-fermentation phases and among different silage sections. The aim of this work was to study the physiological behaviour of gliotoxicogenic Aspergillus fumigatus strains isolated from maize silage under simulated natural physicochemical conditions - different water activities (a(W)), temperatures (Tº), pH and oxygen pressure - on the growth parameters (growth rate and lag phase) and gliotoxin production. The silage was made with the harvested whole maize plant that was chopped and used for trench-type silo fabrication. Water activity and pH of the silage samples were determined. Total fungal counts were performed on Dichloran Rose Bengal Chloramphenicol agar and Dichloran 18% Glycerol agar. The morphological identification of A. fumigatus was performed with different culture media and at different growth temperature to observe microscopic and macroscopic characteristics. Gliotoxin production by A. fumigatus was determined by HPLC. All strains isolated were morphologically identified as A. fumigatus. Two A. fumigatus strains isolated from the silage samples were selected for the ecophysiological study (A. fumigatus sensu stricto RC031 and RC032). The results of this investigation showed that the fungus grows in the simulated natural physicochemical conditions of corn silage and produces gliotoxin. The study of the physiological behaviour of gliotoxigenic A. fumigatus under simulated environmental conditions allowed its behaviour to be predicted in silage and this will in future enable appropriate control strategies to be developed to prevent the spread of this fungus and toxin production that leads to impairment and reduced quality of silage.


Assuntos
Aspergillus fumigatus/química , Aspergillus fumigatus/isolamento & purificação , Gliotoxina/análise , Silagem/microbiologia , Zea mays/microbiologia , Aspergillus fumigatus/metabolismo , Físico-Química , Gliotoxina/biossíntese , Zea mays/metabolismo
8.
J Microencapsul ; 31(1): 16-22, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23701219

RESUMO

Encapsulation of amoxicillin (AMC) with ethyl cellulose (EC) by a supercritical antisolvent process (SAS) was investigated. AMC microparticles obtained previously by an SAS process were used as host particles and EC, a biodegradable polymer used for the controlled release of drugs, was chosen as the coating material. In this work, a suspension of AMC microparticles in a solution of ethyl cellulose in dichloromethane (DCM) was sprayed through a nozzle into supercritical CO2. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and HPLC analyses were carried out. The effects of AMC:EC ratio, the initial polymer concentration of the solution, temperature and pressure on the encapsulation process were investigated. Although all the experiments led to powder precipitation, the AMC encapsulation was achieved in only half of the cases, particularly when the lower drug:polymer ratios were assayed. In general, it was observed that the percentages of AMC present in the precipitates were higher on increasing the AMC:EC ratio. In these cases composites rather than encapsulates were obtained. The in vitro release profiles of the resulting materials were evaluated in order to ascertain whether composites can be used as encapsulated systems for drug delivery systems.


Assuntos
Amoxicilina/química , Celulose/análogos & derivados , Sistemas de Liberação de Medicamentos/métodos , Celulose/química , Sistemas de Liberação de Medicamentos/instrumentação , Tamanho da Partícula
9.
Lett Appl Microbiol ; 57(5): 405-11, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23815153

RESUMO

The purposes of this study were to determine the distribution of total mycobiota, to determine the occurrence of Aspergillus spp., Penicillium spp. and Fusarium spp. and to detect and quantify fumonisin B1 and aflatoxin B1 in birds' feedstuffs. Sixty samples from different commercial feeds were collected. Analysis of the total mycobiota was performed and total fungal counts were expressed as CFU g(-1). The isolation frequency (%) and relative density (%) of fungal genera and species were determined. Mycotoxins determination was carried out using commercial ELISA kits. The 48% of standard, 31% of premium and only 9% of super premium feed samples were found above of recommended limit (1 × 10(4) CFU g(-1)). Aspergillus (82%), Cladosporium (50%) and Penicillium (42%) were the most frequently isolated genera. Aspergillus niger aggregate (35%), Aspergillus fumigatus (28%) and Aspergillus flavus (18%) had the highest relative densities. Contamination with fumonisins was detected in 95% of total samples with levels from 0·92 to 6·68 µg g(-1), and the aflatoxins contamination was found in 40% of total samples with levels between 1·2 and 9·02 µg kg(-1). Feed samples contaminated with fumonisins and aflatoxins are potentially toxic to birds.


Assuntos
Aflatoxinas/análise , Ração Animal/microbiologia , Aves , Fumonisinas/análise , Fungos/isolamento & purificação , Ração Animal/análise , Animais , Brasil , Contagem de Colônia Microbiana , Contaminação de Alimentos , Fungos/classificação , Animais de Estimação
10.
J Appl Microbiol ; 115(3): 637-43, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23445404

RESUMO

The present revision shows the early and current knowledge in the field of silage fungi and mycotoxins explaining the relevance of fungi and mycotoxins in silage. The problem does not end in animal disease or production losses as mycotoxins in feed can lead to the presence of their metabolic products in dairy products, which will be eventually affecting human health, mainly infants. Silage is green forage preserved by lactic fermentation under anaerobic conditions. This ecosystem maintains its quality and nutritional value depending on interactions among physical, chemical and biological agents. Forages used for ensilage are naturally in contact with yeasts and filamentous fungi, and the contamination often occurs in the field and can also occur during harvesting, transport, storage. Moreover, postharvest poor management can lead to a rapid spoilage. Studies on fungal contamination of dairy cattle feed have shown how corn silage influences the contamination degree of feed supplied to livestock. Increasing knowledge in this area will help elucidate the influence that this microbiota exerts on production and/or degradation of mycotoxins present in silage. Some of these fungi, although opportunist pathogens, are relevant epidemiologically and represent a high risk of contamination to farm workers who handle them improperly.


Assuntos
Fungos/isolamento & purificação , Micotoxinas/isolamento & purificação , Silagem/microbiologia , Animais , Bovinos , Fungos/metabolismo , Micotoxicose/veterinária , Micotoxinas/metabolismo
11.
J Appl Microbiol ; 114(3): 655-62, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23176728

RESUMO

AIMS: To in vitro evaluate the influence of the corn on the adsorption levels of aflatoxin B1 (AFB1) and zearalenone (ZEA) by yeast cell walls (YCWs). METHODS AND RESULTS: Two commercial YCWs were studied. The YCWs contain different percentages of polysaccharides. YCW1 and 2 contain 5.9 and 21% of mannans and 17.4 and 23% of ß-glucans, respectively. Each YCW was resuspended in pH 2 and pH 6 buffer solutions. Corn was used to study the matrix influence. An aliquot of 500 µl YCW suspension was added to each microtube containing 500 µl of 0.1, 0.25, 0.5, 1, 2.5 and 5 µg ml(-1) AFB(1) or 0.5, 5, 10, 20 and 50 µg ml(-1) ZEA. Microtubes were kept with mechanical agitation at 37 °C for 30 min and then centrifuged for 10 min at 16,873 g and; the supernatants were quantified by high-pressure liquid chromatography. The amount of bound toxin was plotted as a function of the amount of added toxin according to mathematical expressions proposed by three theoretical models. Both YCWs were capable of adsorbing AFB(1) and ZEA in amounts from 0.061 to 0.40 and from 0.10 and 0.26 g g(-1), respectively. In the presence of the matrix, both adsorbents were not able to adsorb AFB(1) . However, they could adsorb ZEA at levels from 0.03 to 0.23 g g(-1). CONCLUSIONS: Both YCWs adsorbed ZEA in the presence of corn and also under simulated gastrointestinal pH conditions. These results suggest that the studied YCWs are potential candidates for ZEA adsorption. SIGNIFICANCE AND IMPACT OF THE STUDY: Several in vitro assays have informed the ability of different substrates including yeast walls to adsorb AFB(1) and ZEA; none of them have evaluated their ability to adsorb AFB(1) and ZEA in the presence of the corn. The corn matrix can influence the adsorption phenomena of these mycotoxins.


Assuntos
Aflatoxina B1/metabolismo , Parede Celular/metabolismo , Saccharomyces cerevisiae/citologia , Zea mays , Zearalenona/metabolismo , Adsorção , Parede Celular/química , Cromatografia Líquida de Alta Pressão , Mananas/química , Modelos Teóricos , Saccharomyces cerevisiae/metabolismo , beta-Glucanas/química
12.
Transplant Proc ; 44(7): 2181-4, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22974950

RESUMO

Decompressive craniectomy (DC) is a surgical practice that has been used since the late 19th century. The cerebral blood flow increase after the performance of a DC can delay and even prevent the development of cerebral circulatory arrest and brain death (BD). We aimed to determine the prevalence of BD, the use of DC, and the evolution to BD with versus without DC. This retrospective, observational, cross-sectional study was performed in a single high-intensity center in Argentina from January 2003 to December 2010. Inclusion criteria were all patients with Glasgow Coma Score of at most 7 on admission or during their stay in the intensive care units. Exclusion criteria were patients with incomplete data. In cases of death, we assessed whether they fulfilled BD criteria or if the cause of death was a cardiac arrest (CA). The 698 patients considered for analysis showed a 60% (n = 418) global mortality rate. The causes were: CA (n = 270); BD (n = 108) and others considered to be "undefined," namely not assessed completely for the diagnosis of BD (n = 40). According to diagnosis category, traumatic brain injury (TBI) was largest (nearly 50%). The DC group (n = 206) showed significant differences regarding sex and diagnosis category versus no DC group. Mortality was significantly lower in this group (48% versus 65%, P < .001). No significant differences were observed comparing causes of death (CA, BD, or undefined). The use of DC did not influence the frequency of BD development (24% versus 26%, P = .72). The average DC rate was 30% and of BD 16%. The prevalence of DC and better survival were recorded compared with subjects without DC. The prevalence of BD was lower than expected in accordance with national registries; however, among our group, DC did not seem to modify the evolution to BD.


Assuntos
Morte Encefálica , Craniotomia , Feminino , Humanos , Masculino , Prevalência , Estudos Retrospectivos
13.
J Appl Microbiol ; 112(5): 865-73, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22372472

RESUMO

AIMS: The aim of this study was to determine total fungal counts and the relative density of Aspergillus fumigatus and related species in silage samples intended for bovines before and after fermentation as well as to monitor the natural occurrence of gliotoxin in silage samples (pre- and postfermentation). METHODS AND METHODS: The survey was performed in farms located in São Paulo and Rio de Janeiro States in Brazil. In addition, the ability of A. fumigatus strains and related species strains to produce gliotoxin was also evaluated. A total of 300 samples were taken, immediately after opening of the silo (3-5 months) and during the ensiling period. Fungal counts were done by the surface-spread method. Gliotoxin production ability of isolates and natural contamination were determined by HPLC. RESULTS: All postfermented samples had a total number of moulds exceeding 1 × 10(4) CFU g(-1), with Aspergillus sp. as the most prevalent genus. Frequency of strains, among A. fumigatus and related species, was able to produce gliotoxin was similar in pre- and postfermented samples, except for sorghum, which showed differences between both kinds of samples. The highest toxin levels were produced by strains isolated from postfermented samples. More than 50% of the samples showed gliotoxin contamination levels that exceeded concentrations known to induce immunosuppressive and apoptotic effects in cells. CONCLUSIONS: The present data suggest that care should be taken because gliotoxin contamination in feedstuffs could affect productivity and also present a health risk for herds. SIGNIFICANCE AND IMPACT OF THE STUDY: Gliotoxin was found at quite important concentrations levels in pre- and postfermented substrates and its presence could therefore probably affect the productivity and health of herds. Current conservation and management practices do not avoid contamination with A. fumigatus on silage. Therefore, farm workers should be adequately protected during its handling.


Assuntos
Ração Animal/microbiologia , Aspergillus fumigatus/isolamento & purificação , Gliotoxina/isolamento & purificação , Silagem/microbiologia , Sorghum/microbiologia , Zea mays/microbiologia , Animais , Aspergillus fumigatus/patogenicidade , Brasil , Bovinos , Contagem de Colônia Microbiana , Grão Comestível/efeitos dos fármacos , Fermentação , Contaminação de Alimentos/análise
14.
ISRN Vet Sci ; 2012: 396590, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23762582

RESUMO

The aim of the study was to determine the mycobiota and natural levels of mycotoxins such as aflatoxin B1 (AFB1), ochratoxin A (OTA), fumonisin B1 (FB1), and deoxynivalenol (DON) present in brewers grains pre- and poststored intended for bovine intensive rearing. Poststored (80%) samples had counts higher than 1 × 10(4) colony-forming units (CFU/g). Cladosporium spp. and Aspergillus spp. were isolated at high frequencies. Aspergillus flavus was the prevalent isolated species. Prestored (70%) and poststored (100%) samples showed AFB1 levels over the recommended limits (20 µ g/Kg), and OTA levels were below the recommended limits (50 µ g/Kg) while pre- and poststored samples did not show FB1 and DON natural contamination levels. The presence of mycotoxins in this substrate indicates the existence of contamination. Regular monitoring of feeds is required in order to prevent chronic and acute toxic syndromes related to this kind of contamination.

16.
Lett Appl Microbiol ; 50(1): 77-81, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19889107

RESUMO

AIMS: To evaluate gliotoxin production by Aspergillus fumigatus strains isolated from feedstuff intended for domestic animals and pets, and to determine the amount of gliotoxin in these substrates. METHODS AND RESULTS: A total of 150 feedstuff samples were collected. They were composed of 30 samples each of five different feed types (pigs, poultry, cattle, horse and pets). Aspergillus fumigatus gliotoxin production ability and gliotoxin presence in feedstuff was determined by HPLC. Aspergillus fumigatus strains were isolated from all of the tested samples. Strains from cattle, horses and pet food were able to produce gliotoxin. Corn silage samples intended for cattle did not show gliotoxin contamination. All the other tested samples had gliotoxin levels ranging from 29 to 209 microg g(-1). Horse and poultry feed samples had the greatest contamination frequency. CONCLUSIONS: Feed samples contaminated with gliotoxin are potentially toxic to animals. SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of gliotoxin could affect animal productivity and health. Moreover, there are risks of contamination to farm workers handling improperly stored animal feed. Aspergillus fumigatus strains isolated from different sources should be investigated to determine prevention and control strategies.


Assuntos
Ração Animal , Animais Domésticos , Aspergillus fumigatus/isolamento & purificação , Contaminação de Alimentos , Gliotoxina/análise , Ração Animal/análise , Ração Animal/microbiologia , Animais , Argentina , Aspergillus fumigatus/metabolismo , Bovinos , Cromatografia Líquida de Alta Pressão , Contagem de Colônia Microbiana , Microbiologia de Alimentos , Gliotoxina/biossíntese , Cavalos , Aves Domésticas , Silagem/análise , Suínos , Zea mays
17.
Toxicon ; 53(2): 283-8, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19073207

RESUMO

Mycotoxin contamination of animal feeds represents a hazard to human and animal health due to potential transmission to meat and milk. Barley by-products are alternative feeding supplies for animal production. The aims of this assay were to study the mycobiota of feedstuffs and finished swine feed, to determine the ability of Aspergillus and Penicillium isolates to produce ochratoxin A (OTA) and to evaluate OTA occurrence in these substrates. Corn, brewers' grains and finished swine feed samples were collected from different factories. Fungal counts were higher than 2.8x10(4)CFU g(-1). Fusarium, Aspergillus and Penicillium genera were isolated at high levels. A 23.7% of the isolates produced 9-116 microg kg(-1) of OTA in vitro. Corn samples (44%) were contaminated with 42-224 microg kg(-1) of OTA. Finished feed (31%) and brewers' grains samples (13%) were contaminated with 36-120 microg kg(-1) and 28-139 microg kg(-1) of OTA, respectively. This is the first scientific report on contamination by OTA-producer molds and OTA in swine feedstuffs from Brazil. The presence of OTA in raw materials and finished feed requires periodic monitoring to prevent mycotoxicoses in animal production, reduce economic losses and minimize hazards to human health.


Assuntos
Ração Animal/análise , Ração Animal/microbiologia , Ocratoxinas/química , Suínos , Animais , Aspergillus/metabolismo , Brasil , Ocratoxinas/metabolismo , Penicillium/metabolismo , Água/química
18.
Lett Appl Microbiol ; 46(5): 555-61, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18363655

RESUMO

AIMS: To evaluate the mycobiota and natural levels of aflatoxins, fumonisins and zearalenone present in compound feed and home-corn grains intended for fattening pigs. METHODS AND RESULTS: Total fungi, Fusarium and Aspergillus species occurrence were examined. Aflatoxins and zearalenone were detected by thin-layer chromatography and fumonisins by high-pressure liquid chromatography. Fungal counts were generally higher than 1 x 10(5) colony forming units (CFU) ml(-1). Aspergillus flavus, Aspergillus parasiticus and Fusarium verticillioides were the most prevalent species. FB(1) and FB(2) were detected in all feed and corn samples. Aflatoxin B(1) was detected in 33.33% of initial and growing feed and in 44.44% of final feed samples. It was not detected in corn samples. All feed and corn samples were negative for AFB(2), AFG(1), AFG(2) and ZEA presence during all growing stages tested. CONCLUSIONS: Fungal counts at all growing periods exceeded the levels proposed as feed hygienic quality limits. Aflatoxin levels in all feeds and fumonisin levels in many samples were higher than the established regulations. SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of mycotoxins indicates the existence of contamination. This fact requires periodic monitoring to prevent the occurrence of mycotoxicosis in animal production, to reduce the economic losses and to minimize hazards to human health.


Assuntos
Ração Animal/microbiologia , Aspergillus/isolamento & purificação , Fusarium/isolamento & purificação , Micotoxinas/análise , Aflatoxinas/análise , Ração Animal/análise , Animais , Argentina , Aspergillus/classificação , Cromatografia Líquida de Alta Pressão , Cromatografia em Camada Fina , Grão Comestível/microbiologia , Contaminação de Alimentos/análise , Fumonisinas/análise , Fusarium/classificação , Técnicas de Tipagem Micológica , Células-Tronco , Suínos , Zearalenona/análise
19.
Transplant Proc ; 37(2): 973-6, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15848595

RESUMO

INTRODUCTION: Hyperparathyroidism (HPT) is a highly prevalent pathology in the chronic renal disease population, which is associated with considerable morbidity, and mortality. The histopathological findings most often reported are solitary adenoma, diffuse hyperplasia, and autonomous hyperplasia. Carcinoma is an unusual cause of primary parathyroid hyperfunction (0.5% to 4% according to data); in renal transplanted patients it is exceptional. We sought to analyze parathyroid gland histology from renal transplant patients in comparison with nontransplanted patients and to report a parathyroid carcinoma case in a renal transplant patient. METHODS: We retrospectively analyzed parathyroidectomies (PTX) and histopathological reports between March 1989 and December 2003. RESULTS: Among 72 PTXs 41 were performed because of primary HPT; 26, secondary HPT; and five, tertiary HPT. Among the 41 primary HPT cases there were two carcinomas (4.88% primary HPT operated patients), one of whom was in a kidney transplant recipient. Among the total number of surgeries, seven were performed in six renal transplant patients, including five diffuse hyperplasia cases; one, nodular hyperplasia with an adenoma focus; and one, parathyroid carcinoma. CONCLUSIONS: Parathyroidectomy indications in the renal transplant population are usually associated with the clinical picture of tertiary HPT, which does not resolve after a functional renal transplant. In spite of this, diffuse hyperplasia, which is associated with secondary HPT, was the most frequent hystological finding. Two carcinomas were observed: one in a renal transplant patient (16.6% parathyroidectomies) and the other in a patient who did not show renal failure. These data coincide with international records.


Assuntos
Hiperparatireoidismo/patologia , Transplante de Rim , Neoplasias das Paratireoides/cirurgia , Complicações Pós-Operatórias/cirurgia , Feminino , Humanos , Hiperparatireoidismo/complicações , Pessoa de Meia-Idade , Neoplasias das Paratireoides/patologia , Paratireoidectomia , Complicações Pós-Operatórias/patologia , Estudos Retrospectivos
20.
Acta bioquím. clín. latinoam ; 25(2): 171-6, jun. 1991. ilus
Artigo em Espanhol | BINACIS | ID: bin-26414

RESUMO

La benzoilmercaptoacetiltriglicina (MAG,) se sintetizó de acuerdo con el método de A.R.Fritzberg y colaboradores. Se comprobó su pureza por punto de fusión, composición centesimal, cromatografía líquida de alta presión y resonancia magnética nuclear. Se realizaron estudios farmacológicos, esterilidad, apirogenicidad, toxicidad aguda y distribución biológica en animales. El producto (MAG,) marcado con tecnecio 99m, según la técnica de J.R.Coveney y M.S.Roblins, se controló por cromatografía en papel. Posteriormente, se inyectó en seres humanos (2,5-3 ,Ci) en normales y con patología renal (39 casos totales) realizándose el estudio comparativo con hipurán


Assuntos
Agregado de Albumina Marcado com Tecnécio Tc 99m/diagnóstico , Renografia por Radioisótopo/métodos , Glicina/análogos & derivados , Ácido Iodoipúrico/diagnóstico , Rim/diagnóstico por imagem , Glicina/metabolismo , Glicina/diagnóstico
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