RESUMO
Maize (Zea mays L.) is of socioeconomic importance as an essential food for human and animal nutrition. However, cereals are susceptible to attack by mycotoxin-producing fungi, which can damage health. The methods most commonly used to detect and quantify mycotoxins are expensive and time-consuming. Therefore, alternative non-destructive methods are required urgently. The present study aimed to use near-infrared spectroscopy with hyperspectral imaging (NIR-HSI) and multivariate image analysis to develop a rapid and accurate method for quantifying fumonisins in whole grains of six naturally contaminated maize cultivars. Fifty-eight samples, each containing 40 grains, were subjected to NIR-HSI. These were subsequently divided into calibration (38 samples) and prediction sets (20 samples) based on the multispectral data obtained. The averaged spectra were subjected to various pre-processing techniques (standard normal variate (SNV), first derivative, or second derivative). The most effective pre-treatment performed on the spectra was SNV. Partial least squares (PLS) models were developed to quantify the fumonisin content. The final model presented a correlation coefficient (R2) of 0.98 and root mean square error of calibration (RMSEC) of 508 µg.kg-1 for the calibration set, an R2 of 0.95 and root mean square error of prediction (RMSEP) of 508 µg.kg-1 for the test validation set and a ratio of performance to deviation of 4.7. It was concluded that NIR-HSI with partial least square regression is a rapid, effective, and non-destructive method to determine the fumonisin content in whole maize grains.
Assuntos
Fumonisinas , Imageamento Hiperespectral , Espectroscopia de Luz Próxima ao Infravermelho , Zea mays , Zea mays/química , Fumonisinas/análise , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Imageamento Hiperespectral/métodos , Reprodutibilidade dos Testes , Quimiometria/métodosRESUMO
The maize yield, nutritional status, and grain fumonisins concentration were evaluated in different genotypes, doses, and nitrogen sources (N) in two years and three locations. Two experiments were carried out in each area and year in an experimental design of a subdivided plot with four replications. One experiment involved a 4x2 factorial treatment: four nitrogen (N) doses (0, 80, 160, and 240 kg ha-1) in coverage and having urea as a source of N and two genotypes. Another experiment involved a 4x2 factorial treatment: four N sources: urea, urea covered with polymer, ammonium nitrate, and ammonium nitrate + urea (UAN), at a dose of 160 kg ha-1, in two genotypes. The genotype generally influenced maize yield more than N doses and sources, mainly due to the bushy stunt/corn stunt tolerance of AG7098 PRO2 and AG8677 PRO2. The N doses linearly increased the N leaf content. However, the N sources did not affect the N leaf content. The N doses and sources had no significant effect on the content of fumonisins, which was affected only by the genotypes in Sete Lagoas in 2016 (N doses experiment) and 2017 (N sources experiment). The hybrids, P3630H and AG8677PRO2 (Sete Lagoas, 2016, N doses experiment and 2017, N sources experiment, respectively) exceeded the Brazilian legislation for Maximum Tolerance Limit for fumonisins in corn grains, which is 5,000 µg kg-1. The best result was obtained with AG7098 PRO2, with yields (above 10,000 kg ha-1) and fumonisins consistently below 5,000 µg kg-1. Therefore, the selection of corn hybrids is a strategy to reduce the occurrence of fumonisins in the grains.
Assuntos
Fumonisinas , Zea mays , Zea mays/genética , Nitrogênio , Estado Nutricional , Incidência , Genótipo , UreiaRESUMO
Previous studies proposed that myosin-Va regulates apoptosis by sequestering pro-apoptotic Bmf to the actin cytoskeleton through dynein light chain-2 (DLC2). Adhesion loss or other cytoskeletal perturbations would unleash Bmf, allowing it to bind and inhibit pro-survival Bcl2 proteins. Here, we demonstrated that overexpression of a myosin-Va medial tail fragment (MVaf) harboring the binding site for DLC2 dramatically decreased melanoma cell viability. Morphological and molecular changes, including surface blebbing, mitochondrial outer membrane permeabilization, cytochrome-c and Smac release, as well as caspase-9/-3 activation and DNA fragmentation indicated that melanoma cells died of apoptosis. Immobilized MVaf interacted directly with DLCs, but complexed MVaf/DLCs did not interact with Bmf. Overexpression of DLC2 attenuated MVaf-induced apoptosis. Thus, we suggest that, MVaf induces apoptosis by sequestering DLC2 and DLC1, thereby unleashing the pair of sensitizer and activator BH3-only proteins Bmf and Bim. Murine embryonic fibroblasts (MEFs) lacking Bim and Bmf or Bax and Bak were less sensitive to apoptosis caused by MVaf expression than wild-type MEFs, strengthening the putative role of the intrinsic apoptotic pathway in this response. Finally, MVaf expression attenuated B16-F10 solid tumor growth in mice, suggesting that this peptide may be useful as an apoptosis-inducing tool for basic and translational studies.
Assuntos
Dineínas do Citoplasma/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Melanoma/genética , Cadeias Pesadas de Miosina/genética , Miosina Tipo V/genética , Fragmentos de Peptídeos/genética , Neoplasias Cutâneas/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/genética , Proteína 11 Semelhante a Bcl-2 , Linhagem Celular Tumoral , Dineínas do Citoplasma/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Melanoma/metabolismo , Melanoma/patologia , Proteínas de Membrana/deficiência , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Cadeias Pesadas de Miosina/metabolismo , Miosina Tipo V/metabolismo , Transplante de Neoplasias , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/farmacologia , Ligação Proteica , Proteínas Proto-Oncogênicas/deficiência , Proteínas Proto-Oncogênicas/genética , Transdução de Sinais/efeitos dos fármacos , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Proteína Killer-Antagonista Homóloga a bcl-2/deficiência , Proteína Killer-Antagonista Homóloga a bcl-2/genéticaRESUMO
Considerando-se a expansão crescente do uso e comercialização de produtos naturais nos últimos anos e a preocupação com a qualidade e segurança dos produtos anunciados na mídia, buscou-se avaliar a adequação de sua publicidade em relação à legislação vigente. Com este objetivo, foi feita a coleta de 135 peças publicitárias, anunciando 690 diferentes produtos, obtidas em cinco diferentes veículos de comunicação: impressos, revistas, jornais regionais, emissoras de TV e de rádio veiculadas no município de João Pessoa/PB, no período de outubro de 2002 a outubro de 2003. O conteúdo das peças publicitárias foi analisado, considerando-se a sua adequação a Resolução de Diretoria Colegiada (RDC) número 102/2000/ANVISA, que regula a publicidade de medicamentos. Foi observado que 97,04% das peças publicitárias anunciadas na Paraíba não se encontram coerentes com a legislação brasileira, podendo promover diversos danos aos seus usuários, como o uso indiscriminado de medicamentos, a automedicação e reações adversas
