Modulation of antibiotic effect by Fe2(MoO4)3 microstrutures.

In this study, we report the antibacterial activity and modulation of antibiotic activity by Fe2(MoO4)3 microstructures obtained by the hydrothermal route without use of surfactants or organic additives. This material was characterized by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM) images. The XRD pattern showed that the Fe2(MoO4)3 crystallize in a monoclinic structure without secondary phases. Raman spectroscopy confirms the formation of Fe2(MoO4)3. SEM images show that the Fe2(MoO4)3 obtained have ball-of-yarn shaped morphology. In the antibacterial assays, strains of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus were assayed by microdilution method to evaluate the antibacterial and modulatory-antibiotic activity with antibiotics as gentamicin, norfloxacin and imipenem. Against all bacteria, the Minimum Inhibitory Concentration (MIC) was Fe2(MoO4)3 ≥ 1024 µg/mL. This high MIC result must be associated with the fact of the iron be an essential microelement to the bacterial growth. However, when the Fe2(MoO4)3 was assayed in association with the antibiotics was observed an antagonistic effect demonstrated by an enhance of the MIC. This fact is associated directly with the pro-oxidative properties of metallic oxides. These compounds enhance the production of free radicals, as H2O2 and superoxide ions that can affect the cell structures as cell membrane and cell wall. Other effect is associated with the possible coordination of the metal, performing bonds with the chemical structure of the antibiotics, reducing their activity. Our results indicated that nanocompounds as Fe2(MoO4)3 can not be used as antimicrobial products for clinical usage, neither directly and neither in association with antibiotics.

Dietary determinants of urinary molybdenum levels in Mexican women: a pilot study.

OBJECTIVE: This study determined the main dietary sources of urinary molybdenum (Mo) concentrations in a sample of 124 pregnant women in Mexico. MATERIALS AND METHODS: Dietary data was collected during pregnancy, through a semi-qualitative food frequency questionnaire, with information of 84 foods. Urine Mo levels were determined by atomic absorption spectrometry, for at least two trimesters of pregnancy. The associations with Mo levels were estimated by generalized mixed effect regression models. RESULTS: Between 5.8 to 12.7% of the samples were above the 95th percentile of urinary Mo distribution reported by National Health and Nutrition Examination Survey (NHANES) 2009-2010 for women (151 µg/L and 148 µg/g creatinine). After bootstrap resampling was conducted, women with high-consumption of hot peppers (ß=1.34µg/g; 95% CI: 1.00-1.80; p= 0.05) had marginally higher urinary Mo concentration levels, creatinine adjusted, compared to women with low-consumption. CONCLUSION.: Hot chili pepper consumption may contribute to body burden Mo levels in this population.

Dietary determinants of urinary molybdenum levels in Mexican women: a pilot study / Determinantes dietéticos de molibdeno urinario en mujeres mexicanas: un estudio piloto

Abstract: Objective: This study determined the main dietary sources of urinary molybdenum (Mo) concentrations in a sample of 124 pregnant women in Mexico. Materials and methods: Dietary data was collected during pregnancy, through a semi-qualitative food frequency questionnaire, with information of 84 foods. Urine Mo levels were determined by atomic absorption spectrometry, for at least two trimesters of pregnancy. The associations with Mo levels were estimated by generalized mixed effect regression models. Results: Between 5.8 to 12.7% of the samples were above the 95th percentile of urinary Mo distribution reported by National Health and Nutrition Examination Survey (NHANES) 2009-2010 for women (151 μg/L and 148 μg/g creatinine). After bootstrap resampling was conducted, women with high-consumption of hot peppers (β=1.34μg/g; 95% CI: 1.00-1.80; p= 0.05) had marginally higher urinary Mo concentration levels, creatinine adjusted, compared to women with low-consumption. Conclusion. Hot chili pepper consumption may contribute to body burden Mo levels in this population.

Resumen: Objetivo: Determinar las fuentes dietéticas de molibdeno (Mo) urinario en 124 mujeres embarazadas residentes en el estado de Morelos, México. Material y métodos: Mediante un cuestionario de frecuencia de consumo de 84 alimentos, se obtuvo información dietética durante el embarazo. Las concentraciones urinarias de Mo se determinaron por espectrometría de absorción atómica, en al menos dos trimestres del embarazo. La asociación se estimó mediante modelos de efectos mixtos generalizados. Resultados: Entre 5.8 y 12.7% de las muestras superaron el P95 (151 µg/L y 148 µg/g creatinina) de la distribución de Mo urinario reportado para mujeres por la Encuesta Nacional de Nutrición y Salud de Estados Unidos (NHANES) 2009-2010. El mayor consumo de chile (β=1.34μg/g; IC95%: 1.00-1.80; p=0.05) se asoció con concentraciones marginalmente mayores de Mo. Conclusión: Probablemente debido a los fertilizantes o el sistema de riego utilizado en su cultivo, el consumo de chile es una posible fuente de exposición a Mo, en esta población.

Proline partially overcomes excess molybdenum toxicity in cabbage seedlings grown in vitro.

In vitro grown cabbage (Brassica oleracea var. capitata) seedlings exposed to excess molybdenum (Mo) ions exhibited severely reduced plant growth at the cotyledonary stage. Adding 80 mM proline (Pro) to the Mo-treated medium could help 50% seedlings to overcome the toxicity and grow true leaves. Under excess Mo stress, seedlings accumulated blue/purple anthocyanin in their cotyledons and hypocotyls. The anthocyanin content under Mo with 40 mM Pro was 4-fold higher than the control medium, MS with 40 mM Pro. The presence of Pro in the excess-Mo condition reduced chlorophyll a, whereas the chlorophyll b content was much higher than the control media of MS with and without Pro. Moreover, supplementing various concentrations of Pro into the Mo-stressed condition promoted the seedlings with higher antioxidant enzyme activities of superoxide dismutase, ascorbate peroxidate, and catalase. In addition, genes in the anthocyanin biosynthesis and accumulation pathways, phenylalanine ammonia lyase (PAL), chalcone synthase (CHS), flavonone 3-hydroxylase (F3H), leucoanthocyanidin dioxygenase (LDOX), and glutathione-S-transferase (GST), were all upregulated. Our study indicated that, under excess Mo stress, the antioxidant activity of cabbage seedlings was induced in an attempt to protect plants from the Mo-induced toxicity and exacerbated growth. Pro, on the other hand, functioned in producing higher antioxidant enzyme activity to partially help recover plant growth.

Reaçöes aos metais utilizados em ortodontia / Hypersensibility to orthodontic metals appliance

Estudo clínico e experimental da incidência de hipersensibilidade a metais dos aparelhos ortodônticos e das consequências morfológicas da absorçäo do níquel. Realizaram-se testes de contato, antes e dois meses após a colocaçäo de aparelhos, em 38 pacientes, utilizando-se como antígenos o cloreto e cobalto, sulfato de cobre, bicromato de potássio, sulfato de ferro, cloreto de manganês, sal de molibdênio, sulfato de níquel e óxido de titânio. Concluiu-se que: manganês, cromo e níquel apresentaram positividade, estatisticamente significativa, com prevalência de 21,1 por cento para os dois últimos matais. Näo houve diferença estatisticamente significativa no resultado do teste de contato em relaçäo ao sexo e ao aparelho (antes ou depois). Avaliou-se, através de espectroscopia de absorçäo atômica, a quantidade de níquel na urina de 21 pacientes, nestes dois momentos, constatando-se aumento da mesma após a montagem do aparelho, näo havendo diferença estatística entre os sexos. A avaliaçäo experimental foi realizada em 26 camundongos (Swiss webster), divididos em dois grupos controle (C14 e C45) e dois grupos níquel (N14 e N15), que receberam aplicaçäo subcutânea de sulfato de níquel, sendo sacrificados após 15 e 46 dias. Constatou-se, no grupo experimental, aumento de peso total e de alguns órgäos, lesäo microscópica em órgäos hematopoiéticos, coraçäo, fígado e rins, mais evidente em N45. Nefrotoxicidade foi evidenciada por modificaçäo no padräo de ligaçäo às lectinas. No fígado, a análise estereológica demonstrou aumento do volume dos hepatócitos e de seus núcleos. Näo se dectou quantidades mensuráveis de níquel ao micrscópio eletrônico de varredura com raios X por energia dispersa (EDS)