190 research outputs found

    Marcadores tumorales (p53 y Ki67) en la secuencia metaplasia, displasia, adenocarcinoma en el esófago de Barrett

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    La Enfermedad de Reflujo Gastroesofágico (ERGE) constituye en gastroenterología, junto con el síndrome de intestino irritable y la dispepsia, la patología de más alta prevalencia. El reflujo gastroesofágico (RGE) crónico y severo puede conducir a lesiones de la mucosa del esófago distal, objetivables endoscópicamente, como Erosiones, Estenosis, Ulceras y Metaplasia Columnar. La Metaplasia Columnar (reemplazo del epitelio esofágico por epitelio columnar) puede ser del tipo Cardial (transicional), Gástrico Fúndico o Intestinal. La Metaplasia Intestinal (MI) se denomina Esófago de Barrett, y es una condición precancerosa con alta prevalencia (del 5 al 20%). En nuestra casuística de los últimos años gira siempre alrededor del 20%. La historia natural de la Enfermedad por Reflujo Gastroesofágico es la siguiente: RGE – metaplasia cardial del epitelio esofágico – carditis por reflujo - metaplasia intestinal – displasia – adenocarcinoma. ¿Cómo se podría modificar esta historia natural?. A través de la prevención, la detección precoz y el desarrollo de terapéuticas efectivas. La lesión histológica que aparece precediendo, y/o acompañando al adenocarcinoma (ACa) , es la displasia (D), definida como una alteración citoarquitectural de los tejidos y de las células, muchas veces imprecisa y subjetiva, y que puede ser de bajo (DBG) y de alto grado (DAG). Como acercamiento al diagnóstico temprano del ACa, además de la búsqueda de displasia, es posible detectar alteraciones moleculares o genéticas en los tejidos, mediante técnicas inmunohistoquímicas, utilizando ciertos tipos de Marcadores Tumorales (MT). El objetivo principal de este trabajo es la detección precoz (diagnóstico temprano del cáncer) en el esófago de Barrett en nuestro medio, mediante la utilización de los mencionados MT.Fil: Trakal, Juan José. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; ArgentinaFil: Sambuelli, Rubén Horacio. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; Argentin

    Marcadores tumorales (p53 y Ki67) en la secuencia metaplasia, displasia, adenocarcinoma en el esófago de Barrett

    Get PDF
    La Enfermedad de Reflujo Gastroesofágico (ERGE) constituye en gastroenterología, junto con el síndrome de intestino irritable y la dispepsia, la patología de más alta prevalencia. El reflujo gastroesofágico (RGE) crónico y severo puede conducir a lesiones de la mucosa del esófago distal, objetivables endoscópicamente, como Erosiones, Estenosis, Ulceras y Metaplasia Columnar. La Metaplasia Columnar (reemplazo del epitelio esofágico por epitelio columnar) puede ser del tipo Cardial (transicional), Gástrico Fúndico o Intestinal. La Metaplasia Intestinal (MI) se denomina Esófago de Barrett, y es una condición precancerosa con alta prevalencia (del 5 al 20%). En nuestra casuística de los últimos años gira siempre alrededor del 20%. La historia natural de la Enfermedad por Reflujo Gastroesofágico es la siguiente: RGE – metaplasia cardial del epitelio esofágico – carditis por reflujo - metaplasia intestinal – displasia – adenocarcinoma. ¿Cómo se podría modificar esta historia natural?. A través de la prevención, la detección precoz y el desarrollo de terapéuticas efectivas. La lesión histológica que aparece precediendo, y/o acompañando al adenocarcinoma (ACa) , es la displasia (D), definida como una alteración citoarquitectural de los tejidos y de las células, muchas veces imprecisa y subjetiva, y que puede ser de bajo (DBG) y de alto grado (DAG). Como acercamiento al diagnóstico temprano del ACa, además de la búsqueda de displasia, es posible detectar alteraciones moleculares o genéticas en los tejidos, mediante técnicas inmunohistoquímicas, utilizando ciertos tipos de Marcadores Tumorales (MT). El objetivo principal de este trabajo es la detección precoz (diagnóstico temprano del cáncer) en el esófago de Barrett en nuestro medio, mediante la utilización de los mencionados MT.Fil: Trakal, Juan José. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; ArgentinaFil: Sambuelli, Rubén Horacio. Universidad Católica de Córdoba. Facultad de Ciencias de la Salud; Argentin

    Pre-activated biochar by fertilizers mitigates nutrient leaching and stimulates soil microbial activity

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    Background: Previous studies have suggested that the targeted application of biochars in agricultural soils may benefit soil health and crop production. Physico-chemical properties of soils after biochar addition have been explored, but less is known about how microbial parameters respond. Therefore, impact of biochar (NB), mineral fertilizer-activated biochar (AB), or mineral fertilizer (MF) application on selected chemical and microbial parameters of lettuce-planted soil was evaluated in a pot experiment. Results: In comparison to the control, soil enzymes activities, related to carbon (C), nitrogen (N), and phosphorus (P) cycling, and their content in plant biomass, were significantly increased by the addition of mineral fertilizer with or without biochar (MF, NB + MF). Conversely, microbial respiration (basal and substrate induced) was highly responsive to the activated biochar amendment (AB) as compared to other treatments. N, P, and potassium (K) concentrations in soil pore water were stabilized by the mineral fertilizer-activated biochar, indicating reduced leaching and the likelihood of increased longevity of these nutrients in soils. Enhanced carbon acquisition and mitigated nitrogen acquisition in soil of the most experimental treatments were coupled with higher crop (lettuce) biomass. Conclusions: Our study demonstrates that the application of biochar both with and without mineral fertilizer has the potential to enhance microbial activity and fertility in the tested agricultural soil, but that leaching of fertilizer-borne nutrients may be mitigated by the activation proces.O

    Future food contaminants: An assessment of the plant uptake of Technology-critical elements versus traditional metal contaminants

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    Technology-critical elements (TCEs) include most rare earth elements (REEs), the platinum group elements (PGEs), and Ga, Ge, In, Nb, Ta, Te, and Tl. Despite increasing recognition of their prolific release into the environment, their soil to plant transfer remains largely unknown. This paper provides an approximation of the potential for plant uptake by calculating bioconcentration factors (BCFs), defined as the concentration in edible vegetable tissues relative to that in cultivation soil. Here data were obtained from an indoor cultivation experiment growing lettuce, chard, and carrot on 22 different European urban soils. Values of BCFs were determined from concentrations of TCEs in vegetable samples after digestion with concentrated HNO3, and from concentrations in soil determined after 1) Aqua Regia digestion and, 2) diluted (0.1 M) HNO3 leaching. For comparison, BCFs were also determined for 5 traditional metal contaminants (TMCs; As, Cd, Cu, Pb, and Zn). The main conclusions of the study were that: 1) BCF values for the REEs were consistently low in the studied vegetables; 2) the BCFs for Ga and Nb were low as well; 3) the BCFs for Tl were high relative to the other measured TCEs and the traditional metal contaminants; and 4) mean BCF values for the investigated TCEs were generally highest in chard and lowest in carrot. These findings provide initial evidence that there are likely to be real and present soil–plant transfer of TCEs, especially in the case of Tl. Improvements in analytical methods and detection limits will allow this to be further investigated in a wider variety of edible plants so that a risk profile may be developed

    Urban vegetable contamination - The role of adhering particles and their significance for human exposure.

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    While urban-grown vegetables could help combat future food insecurity, the elevated levels of toxic metals in urban soils need to be met with measures that minimise transfer to crops. The study firstly examines soil/dust particle inclusion in leafy vegetables and its contribution to vegetable metals (As, Ba, Cd, Co, Cr, Cu, Ni, Pb, Sb, and Zn), using vegetable, soil and dust data from an open-field urban farm in southeastern Sweden. Titanium concentrations were used to assess soil/dust adherence. Results showed that vegetables contained 0.05-1.3 wt% of adhering particles (AP) even after washing. With 0.5 % AP, an adult with an average intake of vegetables could ingest approximately 100 mg of particles per day, highlighting leafy vegetables as a major route for soil/dust ingestion. The presence of adhering particles also significantly contributed to the vegetable concentrations of As (9-20 %), Co (17-20 %), Pb (25-29 %), and Cr (33-34 %). Secondly, data from an indoor experiment was used to characterise root metal uptake from 20 urban soils from Sweden, Denmark, Spain, the UK, and the Czech Republic. Combining particle adherence and root uptake data, vegetable metal concentrations were calculated for the 20 urban soils to represent hypothetical field scenarios for these. Subsequently, average daily doses were assessed for vegetable consumers (adults and 3-6 year old children), distinguishing between doses from adhering particles and root uptake. Risks were evaluated from hazard quotients (HQs; average daily doses/tolerable intakes). Lead was found to pose the greatest risk, where particle ingestion often resulted in HQs > 1 across all assessed scenarios. In summary, since washing was shown to remove only a portion of adhering metal-laden soil/dust particles from leafy vegetation, farmers and urban planners need to consider that measures to limit particle deposition are equally important as cultivating in uncontaminated soil. [Abstract copyright: Copyright © 2023. Published by Elsevier B.V.

    Lead and copper-induced hormetic effect and toxicity mechanisms in lettuce (Lactuca sativa L.) grown in a contaminated soil

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    Lead (Pb) and copper (Cu) contamination seriously threatens agricultural production and food safety. This study aims to investigate Pb and Cu induced hormetic effect and toxicity mechanisms in lettuce (Lactuca sativa L.) and establish reliable empirical models of potentially toxic elements (PTEs) transfer in the soil–plant system. The content and distribution of Pb and Cu at subcellular levels in lettuce plants were examined using inductively coupled plasma-mass spectrometry, differential centrifugation and micro-X-ray fluorescence spectroscopy. The PTE-loaded capacity of Pb that ensures food safety was lower than that of Cu in the studied soil, but the PTE-loaded capacity of Pb that limits yield was higher than that of Cu. Lead in lettuce roots mainly accumulated in the cell wall (41%), while Cu mainly accumulated in the vacuoles (46%). The Pb and Cu were primarily distributed in the radicle of lettuce seeds under severe PTE stress, resulting in no seed development. Iron plaque formed on the root surface of lettuce seedlings and sequestered Pb and Cu via chelation. At the same concentration, lettuce was less tolerant to Cu in contaminated soil than Pb due to the higher activity of Cu ions in the soil. Lead was more phytotoxic to lettuce than Cu, however, since the radicle emerged from the seed under severe Cu levels, while it did not protrude under severe Pb levels. The potentially damaging effect of Pb in the visually healthy lettuce appeared to be higher than that of Cu under the same soil contamination level

    The relationship between properties of plant-based biochars and sorption of Cd(II), Pb(II) and Zn(II) in soil model systems

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    Plant based biochars are proposed as soil amendments to immobilize potentially toxic trace elements (PTEs), such as Cd(II), Pb(II) and Zn(II) and aid in soil restoration. However, the sorption capacity of biochar for these elements can vary widely depending on biochar nature and metal properties. Currently, there is no clear methodology to pre-screen biochars for their suitability as adsorbents for these elements. Therefore, to facilitate biochar selection for application in soil restoration, this study explored the relationships between the physico-chemical properties of five plant-based biochars and their capacity to immobilize Cd(II), Pb(II) and Zn(II). Batch experiments using synthetic soil pore water were used to assess the sorption of these elements. The sorption isotherms described by the Hill model indicated that PTE sorption capacity followed the order Pb(II) > Cd(II) >Zn(II) regardless of biochar type in mono-element systems. Preferential sorption of Pb(II) limited the immobilization of Cd(II) and Zn(II) in multi-element systems. ATR-FTIR and SEM-EDX spectroscopy studies indicated that Cd(II) and Pb(II) sorption was mediated by complexation with carboxylic groups, cation–π interactions and precipitation with phosphates and silicates, while Zn(II) sorption occurred mainly by complexation with phenolic groups and precipitation with phosphates. A high correlation (>0.8) between Electrical Conductivity, Cation Exchange Capacity, pH and sorption capacity was identified for all metals tested, highlighting the electrostatic nature of the sorption mechanisms involved. Biochars derived from herbaceous feedstock were better candidates for remediation of soil polluted with Cd(II), Pb(II) and Zn(II), rather than wood-derived biochar. Overall, this study provides evidence of the direct relationship between specific properties of plant-based biochars (pH and EC) and their suitability as adsorbents for some PTEs in soil systems
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