Effect of benzothiadiazole on the metabolome of Arabidopsis thaliana.

Benzothiadiazole (BTH) is a functional analog of the plant endogenous hormone-like compound, salicylic acid (SA), which is required for the induction of plant defense genes leading to systemic acquired resistance (SAR). Previous molecular and genetic studies have suggested that BTH itself might potentiate SAR resulting in the induction of several pathogenesis-related (PR) genes. However, the changes in the metabolome, which occur as a result of BTH-treatment, remain unclear. In this study, metabolic alterations in BTH-treated Arabidopsis thaliana were investigated using nuclear magnetic resonance (NMR) spectroscopy followed by multivariate data analyses such as principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA). Both PCA and PLS-DA show that increase of glucose, glutamine, inositol, malic acid, sucrose, and threonine as well as BTH and its degraded metabolites contribute to the clear discrimination of the metabolome of BTH-treated Arabidopsis from control plants. However, the levels of phenolic metabolites, which have generally been observed to be induced by other signaling molecules were significantly reduced in BTH-treated Arabidopsis. In addition to these changes due to BTH-treatment, it was also found that the EtOH used as a solvent in this treatment may per se act as an inducer of the accumulation of a flavonoid.

Polymerization of coniferyl alcohol by Mn3+ -mediated (enzymatic) oxidation: Effects of H2 O2 concentration, aqueous organic solvents, and pH.

The objective of this study was to evaluate the ability of one versatile peroxidase and the biocatalytically generated complex Mn(III)-malonate to polymerize coniferyl alcohol (CA) to obtain dehydrogenation polymers (DHPs) and to characterize how closely the structures of the formed DHPs resemble native lignin. Hydrogen peroxide was used as oxidant and Mn2+ as mediator. Based on the yields of the polymerized product, it was concluded that the enzymatic reaction should be performed in aqueous solution without organic solvents at 4.5 ≤ pH ≤ 6.0 and with 0.75 ≤ H2 O2 :CA ratio ≤ 1. The results obtained from the Mn3+ -malonate-mediated polymerization showed that the yield was almost 100%. Reaction conditions had, however, effect on the structures of the formed DHPs, as detected by size exclusion chromatography and pyrolysis-GC/MS. It can be concluded that from the structural point of view, the optimal pH for DHP formation using the presently studied system was 3 or 4.5. Low H2 O2 /CA ratio was beneficial to avoid oxidative side reactions. However, the high frequency of ß-ß linkages in all cases points to dimer formation between monomeric CA rather than endwise polymerization. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:81-90, 2018.

Continuous removal of endocrine disruptors by versatile peroxidase using a two-stage system.

The oxidant Mn(3+) -malonate, generated by the ligninolytic enzyme versatile peroxidase in a two-stage system, was used for the continuous removal of endocrine disrupting compounds (EDCs) from synthetic and real wastewaters. One plasticizer (bisphenol-A), one bactericide (triclosan) and three estrogenic compounds (estrone, 17ß-estradiol, and 17α-ethinylestradiol) were removed from wastewater at degradation rates in the range of 28-58 µg/L·min, with low enzyme inactivation. First, the optimization of three main parameters affecting the generation of Mn(3+) -malonate (hydraulic retention time as well as Na-malonate and H2 O2 feeding rates) was conducted following a response surface methodology (RSM). Under optimal conditions, the degradation of the EDCs was proven at high (1.3-8.8 mg/L) and environmental (1.2-6.1 µg/L) concentrations. Finally, when the two-stage system was compared with a conventional enzymatic membrane reactor (EMR) using the same enzyme, a 14-fold increase of the removal efficiency was observed. At the same time, operational problems found during EDCs removal in the EMR system (e.g., clogging of the membrane and enzyme inactivation) were avoided by physically separating the stages of complex formation and pollutant oxidation, allowing the system to be operated for a longer period (∼8 h). This study demonstrates the feasibility of the two-stage enzymatic system for removing EDCs both at high and environmental concentrations.

Biocatalytic generation of Mn(III)-chelate as a chemical oxidant of different environmental contaminants.

The objective of this study was to investigate the enzymatic generation of the Mn(3+) -malonate complex and its application to the process of oxidizing several organic compounds. The experimental set-up consisted of an enzymatic reactor coupled to an ultrafiltration membrane, providing continuous generation of Mn(3+) -malonate from a reaction medium containing versatile peroxidase (an enzyme produced by Bjerkandera adusta strain BOS55), H(2) O(2) , MnSO(4,) and malonate. The effluent of the enzymatic reactor was introduced into a batch-stirred reactor to oxidize three different classes of compounds: an azo dye (Orange II), three natural and synthetic estrogens, and a polycyclic aromatic hydrocarbon (anthracene). The enzymatic reactor provided the Mn(3+) complex under steady-state conditions, and this oxidative species was able to transform the three classes of xenobiotics considerably (90-99%) with negligible loss of activity.

Papilotomía quirúrgica transduodenal: aspectos técnicos en 20 años de experiencia con aporte al diseño instrumental / Transduodenal surgical papillotomy: technical aspects in 20 years experience with an instrumental design contribution

En contraste con la aparente proscripción del procedimiento en nuestro medio, los autores, sin entrar a discutir las indicaciones exponen su aporte instrumental y los detalles de técnica que en 20 años de experiencia le permiten afirmar que la papilotomía quirúrgica no aumenta la morbimortalidad de la simple colecistetomía en ausencia de las terribles complicaciones y de la mortalidad que amenaza la bibliografía. En la discusión de los resultados y de la consulta bibliográfica resulta la prodigalidad actual del procedimiento endoscópico y la validez del procedimiento quirúrgico en la seguridad del apoyo instrumental y la perfección técnica

Traumatismos toracoabdomonales / Thoracic abdominal injuries

Se revisan 26 historias de TTA. Se comprueba la alta mortalidad y la gravedad inicial, exigiendo el desarrollo de recursos de atención primaria. Se propone una mayor utilización de la laparoscopía de urgencia. Se considera favorable la colocación de drenajes torácicos preventivos. Se comcienza la exploración abordaje transverso subcostal, agregando las ampliaciones necesarias. La toracofrenolaparotomía es la vía de elección para los sectores posteriores de las regiones toracoabdominales. Es necesario protocolizar los modelos lesionales viscerales y los procedimientos operatorios para ajustar la conservación de parénquimas

Ulceras de causa tumoral e insuficiencia venosa: análisis de un posible vínculo patogénico / Ulcers due to tumor and venous failure: analysis of a possible pathogenic link

Si bien las úlceras de las piernas responden sobre todo a insuficiencia venosa, patología arterial o diabetes, existen multiplicidad de otras causas menos frecuentes a las que el médico puede enfrentarse y cuyo conocimiento es imprescindible. Dentro de este grupo minoritario cobran especial importancia los tumores malignos cutáneos, cuyo diagnóstico no debe dilatarse para iniciar el tratamiento adecuado en forma oportuna. Este trabajo describe una serie de 15 pacientes con tumores ulcerados en piernas que fueron diagnosticados inicialmente como úlceras de etiología vascular, de los cuales el 60 por ciento presentaba insuficiencia venosa confirmada por estudio eco Doppler venoso. Este hecho nos lleva a plantear la existencia de una relación patogénica entre la hipertensión venosa y el desarrollo del tumor. Centramos la discusión en esta posible relación, a la vez que insistimos en la necesidad de tener presente la etiología tumoral en las úlceras de las piernas y realizar el estudio anatomopatológico a fin de iniciar el diagnóstico oportuno