Synergistic use of siderophores and weak organic ligands during zinc transport in the rhizosphere controlled by pH and ion strength gradients.

Citrate (Cit) and Deferoxamine B (DFOB) are two important organic ligands coexisting in soils with distinct different affinities for metal ions. It has been theorized that siderophores and weak organic ligands play a synergistic role during the transport of micronutrients in the rhizosphere, but the geochemical controls of this process remain unknown. Here we test the hypothesis that gradients in pH and ion strength regulate and enable the cooperation. To this end, first we use potentiometric titrations to identify the dominant Zn(II)-Cit and Zn(II)-DFOB complexes and to determine their ionic strength dependent stability constants between 0 and 1 mol dm-3. We parametrise the Extended Debye-Hückel (EDH) equation and determine accurate intrinsic association constants (logß0) for the formation of the complexes present. The speciation model developed confirms the presence of [Zn(Cit)]-, [Zn(HCit)], [Zn2(Cit)2(OH)2]4-, and [Zn(Cit)2]4-, with [Zn(Cit)]- and [Zn2(Cit)2(OH)2]4- the dominant species in the pH range relevant to rhizosphere. We propose the existence of a new [Zn(Cit)(OH)3]4- complex above pH 10. We also verify the existence of two hexadentate Zn(II)-DFOB species, i.e., [Zn(DFOB)]- and [Zn(HDFOB)], and of one tetradentate species [Zn(H2DFOB)]+. Second, we identify the pH and ionic strength dependent ligand exchange points (LEP) of Zn with citrate and DFOB and the stability windows for Zn(II)-Cit and Zn(II)-DFOB complexes in NaCl and rice soil solutions. We find that the LEPs fall within the pH and ionic strength gradients expected in rhizospheres and that the stability windows for Zn(II)-citrate and Zn(II)-DFOB, i.e., low and high affinity ligands, can be distinctly set off. This suggests that pH and ion strength gradients allow for Zn(II) complexes with citrate and DFOB to dominate in different parts of the rhizosphere and this explains why mixtures of low and high affinity ligands increase leaching of micronutrients in soils. Speciation models of soil solutions using newly determined association constants demonstrate that the presence of dissolved organic matter and inorganic ligands (i.e., bicarbonate, phosphate, sulphate, or chlorides) do neither affect the position of the LEP nor the width of the stability windows significantly. In conclusion, we demonstrate that cooperative and synergistic ligand interaction between low and high affinity ligands is a valid mechanism for controlling zinc transport in the rhizosphere and possibly in other environmental reservoirs such as in the phycosphere. Multiple production of weak and strong ligands is therefore a valid strategy of plants and other soil organisms to improve access to micronutrients.

Copper accumulation in agricultural soils: Risks for the food chain and soil microbial populations.

The long-term use of Cu-based fungicides at doses of several kilograms per hectare stimulated a wide debate about the human health and environmental risks of the progressive accumulation of Cu in agricultural soils. Here, the health risks due to copper accumulation in agricultural soils were evaluated with a survey in intensive agricultural land of the Campania region (Italy), aiming to evaluate Cu accumulation in food crops. The health risk due to dietary exposure was estimated by using the Hazard Quotient (HQ), calculated as the ratio between the average daily dose and the reference dose of copper, suggesting that when HQ > 1 there is a potential risk for consumers. According to a survey of soils with a Cu content up to 217 mg kg-1, no foodstuffs showed dietary risks. Nevertheless, the contribution of Cu contained in these foodstuffs to the overall intake of Cu by consumers could increase health risks since such risks must be evaluated on the basis of the whole standard diet by quantifying the Cu content not only in vegetables and fruits but also in other sources, such as cereals, not cultivated in the study area and thus not considered in this paper. The environmental risks due to copper accumulation in agricultural soils were then evaluated with a field experiment in a soil characterized by a very high Cu concentration (up to 1700 mg kg-1), aiming to study the impacts of Cu on native soil microorganisms. The study of the microbiota highlighted that the presence of Cu in soil did not reduce the total richness and diversity of microorganisms, which were not related to increasing concentrations of Cu in the soil. Nevertheless, Cu contamination was found to exert significant selection pressure on the soil microbiota, as shown by beta diversity and correlation analysis between taxa and Cu content.

Contribution of ultra-processed foods consumption in sodium ingestion of atherosclerotic disease patients, residents in the southern region of Brazil.

BACKGROUND AND OBJECTIVE: Recent studies have related the consumption of ultra-processed foods with the development of cardiovascular diseases and have considered this relation with excessive sodium intake. While Brazilian studies have analysed that this consumption may have no direct relationship with the processing, but rather with the addition of salt. The purpose of this study is to investigate the contribution of the consumption of processed products in the daily intake of sodium ingestion by atherosclerotic disease patients. METHODS: A sub study, conducted with data from 630 cardiopathic patients who take part in "Effect of Brazilian Cardioprotective Food Program study on the reduction of events and risk factors in secondary prevention of cardiovascular disease part". Food was classified as: unprocessed or minimally processed foods, processed culinary ingredients, processed foods, ultra-processed food and beverages. Twenty-four-hour food recall (R24h) was collected from patients, and the estimation of total calories and sodium intake were calculated, as well as the percentage of sodium contribution according to the categories already mentioned. For the adequacy ratio analysis, the daily values of sodium intake were used to compared to the recommendations of the World Health Organization (<2000 mg / day). RESULTS: The average sodium intake was 1970.87 mg for women and 2642.86 mg for men, being higher for males' patients aged 60-79. It was observed that 64% of the studied population demonstrated sodium intake > 2000 mg. When considered levels > 3001 mg, a higher incidence of consumption was observed in the male group. Only 21.1% were intaking sodium within the recommended amount. Industrialized foods contributed to 33% of the mineral intake. CONCLUSION: These findings have demonstrated that the majority of the studied patients exceeded the dietary sodium recommendation. It has also indicated that patient's male, have presented increased consumption of the mineral. Consequently, warning for the necessity of greater investments in the nutritional re-education of these patients.

Comparative assessment of autochthonous bacterial and fungal communities and microbial biomarkers of polluted agricultural soils of the Terra dei Fuochi.

Organic and inorganic xenobiotic compounds can affect the potential ecological function of the soil, altering its biodiversity. Therefore, the response of microbial communities to environmental pollution is a critical issue in soil ecology. Here, a high-throughput sequencing approach was used to investigate the indigenous bacterial and fungal community structure as well as the impact of pollutants on their diversity and richness in contaminated and noncontaminated soils of a National Interest Priority Site of Campania Region (Italy) called "Terra dei Fuochi". The microbial populations shifted in the polluted soils via their mechanism of adaptation to contamination, establishing a new balance among prokaryotic and eukaryotic populations. Statistical analyses showed that the indigenous microbial communities were most strongly affected by contamination rather than by site of origin. Overabundant taxa and Actinobacteria were identified as sensitive biomarkers for assessing soil pollution and could provide general information on the health of the environment. This study has important implications for microbial ecology in contaminated environments, increasing our knowledge of the capacity of natural ecosystems to develop microbiota adapted to polluted soil in sites with high agricultural potential and providing a possible approach for modeling pollution indicators for bioremediation purposes.

Impact of waste-derived organic and inorganic amendments on the mobility and bioavailability of arsenic and cadmium in alkaline and acid soils.

In agriculture, more and more frequently waste-derived amendments are applied to soil to improve physical and chemical properties. Nevertheless, in soils polluted by potentially toxic metal(loid)s, this agricultural practice may significantly affect the mobility and bioavailability of pollutants modifying the risks for biota and human health. This work was aimed to assess the influence of poultry manure, biochar and coal fly ash on the mobility and bioavailability of As and Cd spiked in two Australian soils with different pH and texture: Mount Gambier (MGB)-alkaline sandy clay loam and Kapuda (KPD)-acid loamy sand. After 4 weeks of incubation from spiking and another 4 weeks from amendment addition, the soils were analysed for pH and amounts of As and Cd in pore-water and following 1 M NH4NO3 extraction. Bioavailable amounts were assessed by plant uptake, using Zea mays L. as test crop. In the alkaline MGB soil, the availability of Cd was reduced, while that of As increased. An opposite behaviour was observed in the acid KPD soil. All amendments, when added to KPD soil, increased pH and consequently reduced the mobility of Cd and increased the mobility of As. In MGB, the amendment addition had an effect only on As mobility and bioavailability, which increased likely as a result of the increased competition for adsorption with DOC released by organic compounds. These trends were confirmed by the amounts of Cd and As uptaken by maize plants.

Relação entre estado nutricional e atividade inflamatória em pacientes com doença inflamatória intestinal / Relationship between nutritional status and inflammatory activity in patients with inflammatory bowel disease

RACIONAL: As doenças inflamatórias intestinais caracterizam-se por diversos sintomas que afetam o aparelho digestório e, consequentemente, podem interferir sobre o estado nutricional. OBJETIVO: Avaliar o estado nutricional de pacientes com doença inflamatória intestinal em diferentes estágios de atividade inflamatória. MÉTODOS: Foram avaliados 55 pacientes com doença inflamatória intestinal, por meio de dados antropométricos, com aferição de peso, altura, circunferência do braço e prega cutânea do tríceps e tiveram sua composição corporal determinada por impedância bioelétrica. Para determinação de atividade inflamatória da doença foram utilizados os níveis séricos de proteína C reativa e o índice de Harvey e Bradshaw. Para comparação de médias foi usado o teste t não pareado, e para as médias não paramétricas, o teste de Mann-Whitney, considerando nível de significância valor de p<0,05. RESULTADOS: Entre os pacientes avaliados, 28 apresentavam doença de Crohn e 27 retocolite ulcerativa inespecífica, com idade entre 19 e 63 anos e tempo de diagnóstico de 1 a 22 anos. Não houve diferença nas medidas antropométricas e na composição corporal dos pacientes cuja doença inflamatória estava em atividade ou em remissão. Os que usaram glicocorticóides nos seis meses anteriores à avaliação apresentaram percentual de gordura corporal de 23,4±8,2 por cento, enquanto para os que não usaram o percentual foi de 30,7±11,3 (p<0,0199). Os sintomas gastrintestinais mais comuns foram distensão abdominal (41 por cento), diarréia (18 por cento), náusea (13 por cento), obstipação (12 por cento), inapetência (11 por cento) e vômito (5 por cento). Todos os sintomas foram mais frequentes nos pacientes com maior índice de massa corporal e de gordura corporal. CONCLUSÃO: Houve maior número de pacientes com excesso de peso e de gordura corporal, sendo que esses pacientes foram mais sintomáticos e apresentaram maiores valores de proteína C reativa.

BACKGROUND: The inflammatory bowel diseases are characterized by multiple digestive tract symptoms and therefore may interfere with nutritional status. AIM: To assess the nutritional status of patients with inflammatory bowel disease in different stages of inflammatory activity. METHODS: Fifty five patients with inflammatory bowel disease were demographically evaluated with weight measurement, height, arm circumference and triceps skinfold and had their body composition determined by bioelectrical impedance. For determination of inflammatory activity of the disease were used serum C-reactive protein and the index of Harvey and Bradshaw. To compare means it was used the unpaired t test, and the average non-parametric, the Mann-Whitney test, level of significance p <0.05. RESULTS: Among the patients, 28 had Crohn's disease and 27 ulcerative colitis, aged between 19 and 63 years and time since diagnosis 1-22 years. There was no difference in anthropometric measurements and body composition of patients whose disease was inflammatory activity or in remission. Patients who used glucocorticoids in the six months preceding the assessment showed body fat percentage of 23.4 ± 8.2 percent whilst those who did not use the percentage was 30.7 ± 11.3 (p <0.0199). The most common gastrointestinal symptoms were abdominal distension (41 percent), diarrhea (18 percent), nausea (13 percent), constipation (12 percent), anorexia (11 percent) and vomiting (5 percent). All symptoms were more common in patients with higher body mass index and body fat. CONCLUSION: There were more patients with excess weight and body fat, and these patients were more symptomatic and had higher values of C-reactive protein.

Antioxidant screening of medicinal herbal teas.

Herbal tea consumption is deeply and widely rooted amongst South-American populations. In view of the involvement of oxygen- and nitrogen-reactive species in the ethiogenesis of several diseases, the antioxidant properties of some of the herbal teas most commonly consumed in the southern regions was assessed in vitro. Around one-third of the 13 examined herbs, displayed a substantially higher ability to scavenge ABTS(+.) radicals (TEAC assay), and to quench the pro-oxidant species, hypochlorite (HClO) and peroxynitrite (ONOO(-)). Amongst the tested herbs, teas prepared from Haplopappus baylahuen, Rosa moschata and Peumus boldus showed the highest TEAC and HClO-quenching activities. These herbs were around 5- to 7-fold more potent than the least active herbs. Based on the TEAC assay, 150 mL of tea prepared from H. baylahuen, R. moschata and P. boldus would be equivalent to around 200 mg of Trolox). Teas from H. baylahuen and P. boldus were also found to be particularly potent in quenching HClO. In the ONOO(-) assay, H. baylahuen and Buddleia globosa showed the highest activities. The results obtained suggest that the regular consumption of teas prepared from some of these herbs may be useful potentially to provide the organism with molecules capable of protecting the gastrointestinal tract against certain pathologically relevant oxidant species.

Reaction of 5-aminosalicylic acid with peroxyl radicals: protection and recovery by ascorbic acid and amino acids.

PURPOSE: The aims of the study are to analyze the interaction between 5-aminosalicylic acid (5-ASA) and peroxyl radicals and to evaluate the effect of some endogenous compounds such as ascorbic acid and amino acids on the oxidation of 5-ASA induced by 2,2'-azo-bis(2-amidinopropane) dihydrochloride. METHODS: The consumption and/or the recovery of 5-ASA (7.6 microM) exposed to a peroxyl radical source [2,2'-azo-bis(2-amidinopropane)] was followed by techniques such as spectrofluorescence, high-performance liquid chromatography, and differential pulse voltammetry. RESULTS: 5-Aminosalicylic acid was found to readily react with peroxyl radicals at micromolar concentrations and to protect c-Phycocyanin in a very similar fashion to that shown by Trolox. Exposure of 5-ASA to peroxyl radicals led to its oxidation into the corresponding quinone-imine. Disappearance of 5-ASA was prevented by tryptophan, cysteine, glutathione, and ascorbic acid. Furthermore, some of these compounds induced the partial (cysteine and glutathione) or total (ascorbic acid) recovery of 5-ASA when added after its almost total consumption. CONCLUSIONS: 5-Aminosalicylic acid is a very efficient peroxyl radical scavenger. The 5-ASA oxidation by peroxyl radicals was prevented by ascorbic acid, cysteine, and glutathione. In addition, 5-ASA can be regenerated by these endogenous compounds, which would be a valuable mechanism to preserve 5-ASA in tissues undergoing oxidative stress conditions.

Peroxidaçäo lipídica e antioxidantes no lúpus eritematoso sistêmico / Lipid peroxidation and antioxidants in Systemic Lupus Erythematosus

O estresse oxidativo está relacionado ao Lúpus Eritematoso Sistêmico (LES) e é provável que o desequilíbrio entre a geraçäo de radicais livres e antioxidantes esteja envolvido com o agravamento do estado de saúde. Objetivo: Estudar a peroxidaçäo lipídica e componentes de defesa antioxidante no LES. Casuística e métodos: Foram estudados 54 pacientes com LES. separados em dois grupos: Grupo Doença Ativa (n=25) e Grupo Doença Inativa (n=29) e 12 controles. Para o Grupo Doença Ativa, dois subgrupos foram constituídos considerando o status do processo inflamatório: Agudo e Crônico. Foi analisada a oxidaçäo de lipídios [malondialdeído (MDA)]; de proteínas (grupo carbonila) e de DNA (Teste de SOD)...

Peroxidação lipídica e antioxidantes no Lúpus Eritematoso Sistêmico / Lipid peroxidation and antioxidants in Systemic Lupus Erythematosus

O estresse oxidativo está relacionado ao Lúpus Eritematoso Sistêmico (LES) e é provável que o desequilíbrio entre a geração de radicais livres e antioxidantes esteja envolvido com o agravamento do estado de saúde. Objetivo: Estudar a peroxidação lipídica e componentes de defesa antioxidante no LES. Casuística e métodos: Foram estudados 54 pacientes com LES, separados em dois grupos: Grupo Doença Ativa (n=25) e Grupo Doença Inativa (n=29) e 12 Controles. Para o Grupo Doença Ativa, dois subgrupos foram constituídos considerando o status do processo inflamatório: agudo e crônico. Foi analisada a oxidação de lipídios [malondialdeído (MDA)]; de proteínas (grupo carbonila) e de DNA (Teste do Cometa)...

Elaboraçäo de pós para bebida utilizando milho pipoca / Elaboration of powder for drink useful popcorn

Visa a elaboraçäo de pós para bebida a partir de milho pipoca, observando-se aspectos de preparo de matéria-prima e condiçöes operacionais de processamento. Conclui que as bebidas servidas com açúcar e leite obtiveram melhor aceitaçäo na análise sensorial

Merenda escolar: consideraçoes / School snack: considerations

Discorre sobre alguns aspectos da merenda escolar como distribuiçao e preparo, objetivando principalmente abordar alguns dos fatores determinantes do consumo de alimentos servidos em programa desta natureza, bem como, características a serem observadas para avaliaçao de aceitabilidade