Removal of ochratoxin A from contaminated white and red wines using oenological fining agents

Mycotoxins are toxic secondary metabolites produced by certain moulds, being ochratoxin A (OTA) one of the most relevant. Its chemical structure is a dihydro-isocoumarin connected at the 7-carboxy group to a molecule of L--phenylalanine via an amide bond. OTA contamination of wines might be a risk to consumer health, thus requiring treatments to achieve acceptable standards for human consumption [1]. According to the Regulation No. 1881/2006 of the European Commission, the maximum limit for OTA in wine is 2 ��g/kg [2]. Therefore, the aim of this work was to know the effect of different fining agents on OTA removal, as well as their impact on white and red wine physicochemical characteristics. To evaluate their efficiency, 11 commercial fining agents (mineral, synthetic, animal and vegetable proteins) were used to get new approaches on OTA removal from white and red wines. Trials were performed in wines artificially supplemented (at a final concentration of 10 ��g/L) with OTA. The most effective fining agent in removing OTA (80%) from white wine was a commercial formulation that contains gelatine, bentonite and activated carbon. Removals between 10-30% were obtained with potassium caseinate, yeast cell walls and pea protein. With bentonites, carboxymethylcellulose, polyvinylpolypyrrolidone and chitosan no considerable OTA removal was verified. In red wine, removals between 6-19% were obtained with egg albumin, yeast cell walls, pea protein, isinglass, gelatine, polyvinylpolypyrrolidone and chitosan. The most effective fining agents in removing OTA from red wine were an activated carbon (66%) followed again by the commercial formulation (55%), being activated carbon a well-known adsorbent of mycotoxins. These results may provide useful information for winemakers, namely for the selection of the most appropriate oenological product for OTA removal, reducing wine toxicity and simultaneously enhancing food safety and wine quality.

Food safety in wine: removal of ochratoxin A in contaminated white wine using commercial fining agents

The presence of mycotoxins in foodstuff is a matter of concern for food safety. Mycotoxins are toxic secondary metabolites produced by certain molds, being ochratoxin A (OTA) one of the most relevant. Wines can also be contaminated with these toxicants. Several authors have demonstrated the presence of mycotoxins in wine, especially ochratoxin A (OTA) [1]. Its chemical structure is a dihydro-isocoumarin connected at the 7-carboxy group to a molecule of L--phenylalanine via an amide bond. As these toxicants can never be completely removed from the food chain, many countries have defined levels in food in order to attend health concerns. OTA contamination of wines might be a risk to consumer health, thus requiring treatments to achieve acceptable standards for human consumption [2]. The maximum acceptable level of OTA in wines is 2.0 g/kg according to the Commission regulation No. 1881/2006 [3]. Therefore, the aim of this work was to reduce OTA to safer levels using different fining agents, as well as their impact on white wine physicochemical characteristics. To evaluate their efficiency, 11 commercial fining agents (mineral, synthetic, animal and vegetable proteins) were used to get new approaches on OTA removal from white wine. Trials (including a control without addition of a fining agent) were performed in white wine artificially supplemented with OTA (10 ��g/L). OTA analysis were performed after wine fining. Wine was centrifuged at 4000 rpm for 10 min and 1 mL of the supernatant was collected and added of an equal volume of acetonitrile/methanol/acetic acid (78:20:2 v/v/v). Also, the solid fractions obtained after fining, were centrifuged (4000 rpm, 15 min), the resulting supernatant discarded, and the pellet extracted with 1 mL of the above solution and 1 mL of H2O. OTA analysis was performed by HPLC with fluorescence detection according to Abrunhosa and Ven��ncio [4]. The most effective fining agent in removing OTA (80%) from white wine was a commercial formulation that contains gelatine, bentonite and activated carbon. Removals between 10-30% were obtained with potassium caseinate, yeast cell walls and pea protein. With bentonites, carboxymethylcellulose, polyvinylpolypyrrolidone and chitosan no considerable OTA removal was verified. Following, the effectiveness of seven commercial activated carbons was also evaluated and compared with the commercial formulation that contains gelatine, bentonite and activated carbon. The different activated carbons were applied at the concentration recommended by the manufacturer in order to evaluate their efficiency in reducing OTA levels. Trial and OTA analysis were performed as explained previously. The results showed that in white wine all activated carbons except one reduced 100% of OTA. The commercial formulation that contains gelatine, bentonite and activated carbon (C8) reduced only 73% of OTA concentration. These results may provide useful information for winemakers, namely for the selection of the most appropriate oenological product for OTA removal, reducing wine toxicity and simultaneously enhancing food safety and wine quality.

Beta-adrenergic blocking agents in heart failure

Cardiac dysfunction in heart failure is widely recognized as a progressive process, regardless of the clinical signs and symptoms. An increase in cardiac sympathetic drive is one of the earliest neurohormonal responses occurring in patients with heart failure and may be one of the major causes of the progressive remodeling leading to the decline in myocardial function, and responsible for the poor prognosis of patients with heart failure. Therefore, recent data provided by several appropriately designed clinical trials clearly indicate the benefits of beta-adrenoceptor blocking agents, combined with diuretics, ACE inhibitors, and digoxin in chronic heart failure class II to IV due to systolic ventricular dysfunction. The benefits are related to symptoms, functional capacity, remodeling, and improvement in left ventricular function, reduction in cardiovascular hospitalization, a decrease in the overall and sudden cardiac death rate, and are similar in patients with ischemic or nonischemic cardiomyopathy, independent of age, gender, or functional class. In this review we describe the cardiovascular effects of the increase in sympathetic drive, the pharmacological properties of the beta-blockers most evaluated in heart failure therapy (metoprolol, bisoprolol, and carvedilol), the major clinical trials related to these agents in heart failure, the recommendations for their appropriate use in clinical practice, the precautions to be adopted, and how to handle the more common adverse reactions.

Agentes delet��reos para Trypanosoma cruzi: Patogenia de la infecci��n de placenta humana en la enfermedad cong��nita de Chagas, in vitro. Deleterious agents to Trypanosoma cruzi: Pathogenia of the human placenta infection in the congenital Chagas disease.

Trypanosoma cruzi, agente causal del Chagas, atraviesa la barrera placentaria y produce la enfermedad cong��nita. Objetivo general: Analizar si el T. cruzi, agente causal del Chagas, produce alteraciones trofobl��sticas de las vellosidades cori��nicas mediadas por ��xido n��trico (principal agente delet��reo contra T. cruzi) y estr��s oxidativo con variaciones que pudieran depender de la disponibiidad de L-arginine, sobre placentas en modelos in vitro de co-cultivos de explantos de vellosidades cori��nicas, de sinciciotrofoblasto aislado y de c��lulas derivadas del trofoblasto de placentas humanas en interacci��n con distintas cepas del Trypanosoma cruzi, que pudieran dar alguna luz en la explicaci��n de mecanismos involucrados en la infecci��n placentaria y en algunos s��ndromes cl��nicos de la transmisi��n cong��nita del Chagas. Objetivos Espec��ficos: a) Describir alteraciones estructurales y presencia de T. cruzi en vellosidades cori��nicas de placentas humanas procedentes de co-cultivos con Trypanosoma cruzi in vitro (y sus respectivos controles), mediante t��cnicas histol��gicas y PCR analizando secuencias de ADN espec��ficas del par��sito.b) Establecer la localizaci��n y expresi��n proteica y la expresi��n transcripcional de las isoformas II y III de la ��xido N��trico Sintasa sobre la misma poblaci��n muestral de (a) mediante t��cnicas inmunohistoqu��mica, RT-PCR y semicuantificaci��n con software adecuado. c) Analizar la susceptibilidad a la infecci��n por el T. cruzi del citotrofoblasto (CTB) y sinciciotrofoblasto (STB) placentario aislado in vitro. d) Determinar concentraciones de ��xido n��trico y estr��s oxidativo del sinciciotrofoblasto (STB) aislado ante la infecci��n por T. cruzi. e) Relacionar concentraciones de L-arginina con infecci��n del trofoblasto aislado. f) Relacionar inhibiciones de la eNOS y de la arginasa con infecci��n trofobl��stica y ��xido n��trico producido.Se emplear��n m��todos y t��cnicas de Biolog��a celular y molecular, mediciones hormonales, enzim��ticas, proteicas, parasitarias y bioqu��micas en medios sobrenadantes de cultivo, de inmuno-detecci��n de epitopes proteicos en tejidos, expresi��n de ARN por RT-PCR, Western blot, detecci��n de DNA en tejidos por PCR, Cuantificaciones morfom��tricas. En general, el presente proyecto podr��a redundar en beneficios para un sector de la poblaci��n de las ��reas end��micas para esta enfermedad de bajos recursos econ��micos, sociales y culturales, mediante la obtenci��n de datos que pudieran explicar algunos mecanismos de s��ndromes cl��nicos descriptos en esta patolog��a y que pudieran participar en la transmisi��n cong��nita de la enfermedad de Chagas.

Estudios in vitro e in vivo de agentes fotosensibilizadores y su aplicaci��n en terapia fotodin��mica. In vitro and in vivo studies of photosensitizer agents and its application in photodynamic therapy.

Muchos esfuerzos se est��n realizando en el dise��o de nuevos m��todos para la eliminaci��n de las c��lulas tumorales y as�� inhibir el crecimiento neopl��sico. Entre los m��todos no convencionales se encuentran la Terapia Fotodin��mica.La Terapia Fotodin��mica (TFD) es un tratamiento experimental de algunos tipos de c��ncer, basado en el efecto citot��xico inducido en el tejido tumoral, por la acci��n combinada de una droga (fotosensibilizador) y la luz visible. El fotosensibilizador posee la propiedad de absorber la luz y reaccionar con el ox��geno molecular, produciendo una forma activa del ox��geno: el ox��geno singlete (1O2) que oxida diversas mol��culas biol��gicas, induciendo un efecto citot��xico que se traduce en la regresi��n tumoral. Los nuevos avances en la dosimetr��a de la luz, as�� como la b��squeda de una segunda generaci��n de nuevos fotosensibilizadores m��s eficaces que los actualmente utilizados, han permitido incluir protocolos de Terapia Fotodin��mica en numerosos centros hospitalarios principalmente para el tratamiento de c��nceres de pulm��n, vejiga, es��fago y piel. Plantas fotot��xicas, sus metabolitos fotosensibilizantes y sus posibles usos; En general, dentro de las especies vegetales t��xicas existen aquellas denominadas plantas alerg��nicas, que son las que pueden producir sus efectos indeseables por v��a d��rmica. Tambi��n existen aquellas que pueden producir efectos t��xicos por v��a sist��mica. Sin embargo, coexiste en la naturaleza otro grupo de plantas t��xicas que desencadenan sus efectos nocivos bajo la acci��n de la luz, por lo que son llamadas plantas fotot��xicas, cuyos principios activos son com��nmente denominados agentes fotosensibilizantes La apoptosis como blanco terap��utico contra el c��ncer: Los conocimientos moleculares sobre la apoptosis adquiridos en los ��ltimos a��os est��n siendo aplicados al desarrollo de nuevos f��rmacos que puedan modular selectivamente las se��ales involucradas en la muerte de las c��lulas. Una de las razones que justifica el inter��s en el estudio de este tipo de mol��culas, es que una de las caracter��sticas m��s tempranas en la transformaci��n de la c��lulas neopl��sicas esta relacionada con la incapacidad de responder a los est��mulos de muerte. Esto lleva a una desregulaci��n del proceso de apoptosis desencadenando una proliferaci��n descontrolada. Los otros eventos que desencadenan el c��ncer son, la invasi��n vascular y la met��stasis a distanciaLa adquisici��n de resistencia a los efectos citot��xicos de los tratamientos anticancer��genos ha emergido como un significante impedimento para el efectivo tratamiento de la enfermedad. Por ello, en el presente proyecto se investigar�� si la adquisici��n de resistencia a TFD inducida en la l��nea celular estudiada es conferida por el aumento de la prote��na MDRP1 a trav��s de la v��a de se��alizaci��n PI3K/Akt. Adem��s, se estudiar�� la correlaci��n entre la posible resistencia a drogas y la inducci��n de apoptosis, analizando los mecanismos involucrados. Los resultados obtenidos contribuir��n a dilucidar y entender los mecanismos moleculares implicados en la resistencia y sensibilidad tumoral a la TFD, y de esta manera mejorar la eficacia de dicha terapia antitumoral para sensibilizar a las c��lulas a la apoptosis. OBJETIVOS Estudiar el efecto de agentes fotosensibilizadores de origen sint��tico (ftalocianinas), comercialmente ya aprobadas por la FDA (Me-ALA), de origen natural (antraquinonas), y obtenidas en procesos nanotecnologicos (nanofibras) respecto a su capacidad de inducir la muerte celular en sistemas experimentales in vivo, para el desarrollo de nuevas drogas de aplicaci��n en Terapia Fotodin��mica (PDT). Estudiar las se��ales de apoptosis que se desencadenan, combinando la PDT con iRNA (antisurvivina) con la finalidad de aumentar la eficiencia de la muerte tumoral. Estudiar los mecanismos de resistencia a la Terapia Fotodin��mica en carcinoma de c��lulas escamosas con fotosensibilizadores permitidos (Me-ALA).

A rapid method for testing in vivo the susceptibility of different strains of Trypanosoma cruzi to active chemotherapeutic agents

A method is described which permits to determine in vivo an in a short period of time (4-6 hours) the sensitivity of T. cruzo strains to known active chemotherapeutic agents. By using resistant- and sensitive T. cruzi stains a fairly good correlation was observed between the results obtained with this rapid method (which detects activity against the circulating blood forms) and those obtained with long-term schedules which involve drug adminstration for at least 20 consecutive days and a prolonged period of assessment. This method may be used to characterize susceptibility to active drugs used clinically, provide infomation on the specific action against circulating trypomastigotes and screen active compounds. Differences in the natural susceptibility of Trypanosoma cruzi strains to active drugs have been already reported using different criteria, mostly demanding long-term study of the animal (Hauschka, 1949; Bock, Gonnert & Haberkorn, 1969; Brener, Costa & Chiari, 1976; Andrade & Figueira, 1977; Schlemper, 1982). In this paper we report a method which detects in 4-6 hours the effect of drugs on bloodstream forms in mice with established T. cruzi infections. The results obtained with this method show a fairly good correlation with those obtained by prolonged treatment schedules used to assess the action of drugs in experimental Chagas' disease and may be used to study the sensitivity of T. cruzi strains to active drugs.

Mobilitat inter-plataforma d'agents software: protocol de migraci�� fragmentada

En aquest projecte s'ha realitzat l'an��lisi, disseny i implementaci�� d'un protocol de migraci�� d'agents software basat en l'enviament del codi dels agents fragmentat en m��ltiples missatges. Aquest protocol es troba dins d'una arquitectura de migraci�� multi-protocol per a la mobilitat d'agents entre plataformes JADE. Finalment, s'ha realitzat un estudi que compara el rendiment assolit pel protocol i les prestacions que aporta.

MedIGS, un sistema segur basat en agents per al descobriment i obtenci�� de dades m��diques distribu��des: estudi i desenvolupament

En aquest projecte es desenvolupa en totes les seves fases(estudi, an��lisi, disseny, implementaci�� i proves) l'aplicaci�� MedIGS. MedIGS ��s una aplicaci�� destinada a satisfer algunes de les necesitats actuals del sistema sanitari, la compartici�� d���informaci�� i la m��xima coordinaci�� possible, utilitzant una tecnologia novedosa: els agents, i m��s concretament, els agents m��bils. Gr��cies a aquesta tecnologia aconseguirem una integraci�� segura de dades m��diques distribu��des. Est�� previst fer una prova pilot a Portugal, a partir dels resultats d���aquest projecte.

Construcci�� modular d'agents basats en components: estudi i desenvolupament

La complexitat de disseny d���agents m��bils creix a mesura que s���incrementen les seves funcionalitats. Aquest projecte proposa enfocar el problema des d���un punt de vista modular. S���ha realitzat un estudi tant dels propis agents com de les parts que ho integren. De la mateixa forma, s���han establert i s'han implementat els mecanismes necessaris per habilitar les comunicacions segures entre agents. Finalment, s���han desenvolupat dos components que ofereixen les funcionalitats de seguiment de l���agent m��bil i la recuperaci�� dels resultats generats. El desenvolupament d���agents basats en components tracta d���aplicar la vella estrat��gia "divideix i vencer��s" a la fase de disseny, reduint, aix��,la seva gran complexitat.

Proposta de migraci�� segura d'agents amb sol��licitud de classes sota demanda per a la plataforma JADE

Aquest projecte consisteix en la implementaci�� d'una migraci�� d'agents m��bils amb sol��licitud de classes sota demanda de manera segura per a la plataforma JADE. En aquest projecte hem desenvolupat dos protocols de control d'acc��s i autentificaci�� sobre agents i/o plataformes. Per�� la l��nia central de desenvolupament d'aquest projecte radica en la creaci�� d'un protocol de migraci�� sota demanda d'agents. Hem implementat dues versions d'aquest protocol. La primera versi�� del protocol de migraci�� es centra en la sol��licitud de classes sota demanda i la segona versi��, per tal de millorar-ne el rendiment de la primera, emmagatzema les classes que ha demanat sota demanada en una cache de la plataforma.

Ultra high performance supercritical fluid chromatography coupled with tandem mass spectrometry for screening of doping agents. II: Analysis of biological samples.

The potential and applicability of UHPSFC-MS/MS for anti-doping screening in urine samples were tested for the first time. For this purpose, a group of 110 doping agents with diverse physicochemical properties was analyzed using two separation techniques, namely UHPLC-MS/MS and UHPSFC-MS/MS in both ESI+ and ESI- modes. The two approaches were compared in terms of selectivity, sensitivity, linearity and matrix effects. As expected, very diverse retentions and selectivities were obtained in UHPLC and UHPSFC, proving a good complementarity of these analytical strategies. In both conditions, acceptable peak shapes and MS detection capabilities were obtained within 7min analysis time, enabling the application of these two methods for screening purposes. Method sensitivity was found comparable for 46% of tested compounds, while higher sensitivity was observed for 21% of tested compounds in UHPLC-MS/MS and for 32% in UHPSFC-MS/MS. The latter demonstrated a lower susceptibility to matrix effects, which were mostly observed as signal suppression. In the case of UHPLC-MS/MS, more serious matrix effects were observed, leading typically to signal enhancement and the matrix effect was also concentration dependent, i.e., more significant matrix effects occurred at the lowest concentrations.

A class of stochastic games with infinitely many interacting agents related to Glauber dynamics on random graphs

We introduce and study a class of infinite-horizon nonzero-sum non-cooperative stochastic games with infinitely many interacting agents using ideas of statistical mechanics. First we show, in the general case of asymmetric interactions, the existence of a strategy that allows any player to eliminate losses after a finite random time. In the special case of symmetric interactions, we also prove that, as time goes to infinity, the game converges to a Nash equilibrium. Moreover, assuming that all agents adopt the same strategy, using arguments related to those leading to perfect simulation algorithms, spatial mixing and ergodicity are proved. In turn, ergodicity allows us to prove ���fixation���, i.e. that players will adopt a constant strategy after a finite time. The resulting dynamics is related to zerotemperature Glauber dynamics on random graphs of possibly infinite volume.