ABSTRACT The objective of this study was to evaluate the effect of either a limited forage intake or concentrate supplementation prior to the adaptation to high-concentrate diets on dry matter intake, ruminal pH, bacteria, and protozoa of Nellore cattle. The experiment was designed as a two 3×3 Latin square, and six cannulated Nellore steers were used. Each experimental period was composed by three feeding phases: pre-adaptation (14 days), adaptation (12 days), and finishing (seven days) diet, in a total of 33 days per period. The steers were assigned to one of three pre-adaptation dietary treatments: control (Tifton hay fed ad libitum + mineral supplement), restriction (Tifton hay fed at 1.4% of BW + mineral supplement), and concentrate (Tifton hay fed ad libitum + 0.5% of BW of a mix of concentrate feedstuffs and mineral supplement). The adaptation period consisted of two adaptation diets, which contained 72 and 79% concentrate for six days each. The finishing diet contained 86% concentrate. During the pre-adaptation phase, restricted cattle had higher pH than concentrate-fed cattle. There was a reduction in M. elsdenii relative population in cattle from either restriction or concentrate groups. During adaptation and finishing phases, cattle from concentrate group had smaller F. succinogenes populations compared with the control group. The previous nutritional backgrounds impact ruminal microbiota during adaptation and finishing phases without causing any negative effect on ruminal pH. Feeding concentrate prior to the adaptation positively impacted the transition to high-concentrate diets and promoted increased dry matter intake.

Abstract Cell cycle alterations are among the principle hallmarks of cancer. Consequently, the study of cell cycle regulators has emerged as an important topic in cancer research, particularly in relation to environmental exposure. Particulate matter and coal dust around coal mines have the potential to induce cell cycle alterations. Therefore, in the present study, we performed chemical analyses to identify the main compounds present in two mineral coal samples from Colombian mines and performed systems chemo-biology analysis to elucidate the interactions between these chemical compounds and proteins associated with the cell cycle. Our results highlight the role of oxidative stress generated by the exposure to the residues of coal extraction, such as major inorganic oxides (MIOs), inorganic elements (IEs) and polycyclic aromatic hydrocarbons (PAH) on DNA damage and alterations in the progression of the cell cycle (blockage and/or delay), as well as structural dysfunction in several proteins. In particular, IEs such as Cr, Ni, and S and PAHs such as benzo[a]pyrene may have influential roles in the regulation of the cell cycle through DNA damage and oxidative stress. In this process, cyclins, cyclin-dependent kinases, zinc finger proteins such as TP53, and protein kinases may play a central role.

ABSTRACT We assessed elemental composition of the liver in mice subjected to one-time or chronic consumption of the juice of vegetables cultivated in a vegetable garden built over deposits of coal waste. Lactuca sativa L. (lettuce), Beta vulgaris L. (beet), Brassica oleracea L. var. italica (broccoli) and Brassica oleracea L. var. acephala (kale) were collected from the coal-mining area and from a certified organic farm (control). Elemental composition was analyzed by particle-induced X-ray emission (PIXE) method. Concentrations of Mg, S, and Ca of mice subjected to one-time consumption of broccoli and concentrations of these same elements plus Si of mice receiving kale were higher in the coal-mining area. Concentrations of P, K, and Cu were increase after chronic consumption of lettuce from the coal-mining area, whereas the levels of Si, P, K, Fe, and Zn were higher in the group consuming kale from the coal-mining area. Our data suggests that people consuming vegetables grown over coal wastes may ingest significant amounts of chemical elements that pose a risk to health, since these plants contain both essential and toxic metals in a wide range of concentrations, which can do more harm than good.

RESUMO Os agricultores envolvidos na colheita do tabaco estão regularmente expostos a grande quantidade de agroquímicos. Para determinar como esta exposição a pesticidas induz alterações genéticas nestes agricultores, amostras de sangue foram obtidas de 77 indivíduos expostos e de 60 indivíduos não expostos. O dano ao DNA foi analisado pelo Ensaio Cometa e pelo Teste de Micronúcleos (MN). A capacidade antioxidante foi avaliada pela atividade da enzima superóxido dismutase (SOD), e a influência do polimorfismo do gene PON1 foi usada como um biomarcador de susceptibilidade. O teor de elementos inorgânicos foi determinado nas amostras de sangue pela análise PIXE. Nossos resultados mostraram que a freqüência de danos, índice de danos, freqüência de MN e a atividade da SOD foram significativamente mais elevados no grupo exposto em relação ao não exposto. O gene PON1 demonstrou influenciar a frequência de MN observada no grupo exposto. As concentrações de elementos inorgânicos foram maiores no grupo exposto em relação ao não exposto. Neste estudo observamos que danos genéticos e alterações no balanço oxidativo foram induzidos pela exposição dos agricultores a misturas complexas de pesticidas na presença de componentes inorgânicos, e pelas quais a influência do genótipo foi evidente.

ABSTRACT Agricultural workers involved in the harvest of tobacco crops are regularly exposed to large quantities of pesticides. In order to determine how this exposure to pesticides induces genetic alterations in these workers, blood samples were obtained from 77 exposed individuals, as well as from 60 unexposed subjects. DNA damage was analyzed by the Comet assay and by the micronucleus (MN) test. The antioxidant profile was evaluated by activity of superoxide dismutase (SOD), and the polymorphism of gene PON1 was used as a susceptibility biomarker. The content of inorganic elements in the blood samples was determined by PIXE analysis. Our results demonstrated that the damage frequency, damage index, the MN frequency, and the SOD activity were significantly elevated in the exposed relative to the unexposed group. A modulation of the MN results for the PON1 gene was observed in the exposed group. The concentrations of inorganic elements in the exposed group were higher compared to those of the unexposed group. In this study, we observed that genetic damage, and change in oxidative balance were induced by the exposure of workers to complex mixtures of pesticides in the presence of inorganic compounds, whereby an influence of the genotype was evident.

As frutas são ricas em minerais, sendo estes essenciais para uma grande variedade de processos metabólicos e fisiológicos no corpo humano. A utilização de frutas congeladas tem se ampliado nos últimos anos, não só na preparação de sucos, mas também como matéria-prima para iogurtes, doces, biscoitos, bolos, sorvetes e alimentos infantis. No entanto, até o momento não há dados sobre o perfil mineral de frutas congeladas. Este trabalho é o primeiro banco de dados para quantificar os níveis de minerais em 23 amostras de frutas congeladas, bastante consumidas em todo o mundo e de algumas frutas nativas da floresta amazônica, Brasil. Considerando-se as Referências de Ingestão Diárias, 100g de frutas congeladas podem fornecer 0,2-2,8% de macro e de 2,5 a 100% dos mi-crominerais para adultos (31-50 anos). Embora as diferenças geográficas devam ser consideradas, estes dados ajudam para o plano de dietas e desenvolvimento de intervenções junto à população co o objetivo de prevenir doenças crônicas.

Fruits are rich in minerals, which are essential for a wide variety of metabolic and physiologic processes in the human body. The use of frozen fruits has greatly spread in the last years not only in the preparation of juices, but also as raw material for yogurts, candies, cookies, cakes, ice creams, and children's food. However, up to now there is no data about the mineral profile of frozen fruits. This is the first database to quantify the levels of minerals in 23 samples of frozen fruits, including the most used around the world and some native fruits from the Amazon rainforest in Brazil. Considering the Dietary Reference Intakes, 100g of frozen fruits can provide 0.2 to 2.8% of macro and 2.5 to 100% of microminerals for adults (31-50 years old). Although geographical differences should be considered, these data can help to plan diets and to develop population interventions aiming to prevent chronic diseases.

O ferro é um nutriente essencial para as plantas. Em condições aeróbicas, é altamente indisponível para absorção pelas plantas, e sua deficiência pode ser severa em plantas cultivadas em solos calcáreos. Em solos alagados, no entanto, a disponibilidade de Fe aumenta e pode atingir concentrações tóxicas. O arroz é uma cultura básica mundialmente importante e enfrenta deficiência ou excesso de Fe, dependendo das condições de cultivo. Para contribuir com o estudo dos mecanismos envolvidos nas respostas a deficiência de Fe e resistência ao excesso de Fe, foram realizados experimentos com as cultivares de arroz BR-IRGA 409 (I409 - sensível à toxidez por Fe) e EPAGRI 108 (E108 - resistente à toxidez por Fe) submetidas a excesso de ferro, concentração-controle ou deficiência (500, 6.5 ou zero mg L-1 Fe, respectivamente). A avaliação do peso seco das partes aéreas confirmou a resistência da cultivar E108 ao excesso de Fe. A espectroscopia Mössbauer indicou a presença de quatro diferentes compostos de Fe3+. Os parâmetros obtidos coincidem com os esperados para ferrihidrita, lepidocrocito (e/ou citrato) e Fenicotianamina. As concentrações de minerais foram determinadas pela técnica PIXE (Particle Induced X-Ray Emission). A concentração de Fe em plantas da cultivar E108 foi menor do que em plantas da cultivar I409, quando expostas a excesso de Fe. Exceto por concentrações de Mn menores em raízes e partes aéreas, o excesso de Fe não resultou em concentrações de nutrientes mais baixas na cultivar sensível do que na cultivar resistente. Plantas da cultivar I409 parecem ser afetadas diretamente pela toxidez de Fe, e não por efeitos secundários na nutrição mineral, enquanto plantas da cultivar E108 parecem valer-se de mecanismos de exclusão na resistência ao excesso de Fe. Ambas cultivares responderam à deficiência de Fe com alocação de P, das raízes para as partes aéreas. Além de ser mais resistente ao excesso de Fe, a cultivar E108 parece ser mais eficiente na indução de respostas à deficiência de Fe.

Iron is an essential nutrient for plants. In aerobic conditions, Fe is highly unavailable for plant uptake, and Fe deficiency can be severe in plants grown in calcareous soils. In waterlogged soils, however, Fe availability increases and can reach toxic concentrations. Rice is an important staple crop worldwide and faces iron deficiency or excess, depending on the growth conditions. To contribute to the study of mechanisms involved in response to Fe deficiency and resistance to Fe excess, experiments were carried out with rice cultivars BR-IRGA 409 (I409, susceptible to Fe toxicity) and EPAGRI 108 (E108, resistant to Fe toxicity) grown in culture solutions and submitted to Fe excess, control concentration or deficiency (500, 6.5 or zero mg L-1 Fe, respectively). Analysis of shoot dry weight confirmed the resistance of E108 plants to Fe excess. Mössbauer spectroscopy analysis indicated the presence of four different Fe3+compounds. The parameters obtained match those expected for ferrihydrite, lepidocrocite (and/or citrate) and Fe-nicotianamine. Mineral concentrations were determined using the PIXE (Particle Induced X-Ray Emission) technique. E108 plants had lower Fe concentrations than I409 plants when exposed to excess Fe. Except for lower Mn levels in roots and shoots, the excess of Fe did not result in lower nutrient concentrations in the susceptible cultivar compared to the resistant one. I409 plants seem to be affected directly by Fe toxicity rather than by secondary effects on mineral nutrition, whereas E108 plants seem to make use of the avoidance mechanism in the resistance to Fe overload. Both cultivars responded to Fe deficiency with allocation of P from roots to shoots. In addition to being more resistant to iron overload, E108 plants seem to be more efficient in inducing Fe deficiency responses.