The antitumor drug, 1,3-bis(2-chloroethyl)-1-nitroso-urea, inactivates human nicotinamide mononucleotide adenylyltransferase.

Nicotinamide mononucleotide (NMN) adenylyltransferase (EC 2.7.7.1) from human placenta is rapidly inactivated by 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). A similar inactivation is observed with other C- and N-nitroso compounds. The inactivation by BCNU is dependent on incubation time, temperature and BCNU concentration. Protective reagents for -SH groups, dithiothreitol and beta-mercaptoethanol, and the substrate NMN are very effective in protecting NMN adenylyltransferase from BCNU inactivation and in preserving its catalytic properties, while ATP is less efficient. Incubation of BCNU-inactivated and dialysed NMN adenylyltransferase with dithiothreitol results in a partial recovery of the enzymatic activity

Changes in the pyruvic acid content correlates with phenotype traits in onion clones

Consumer demand is oriented toward onion cultivars with lower pungency, and the pyruvic acid content of onions is highly correlated with their pungency. Therefore, breeding programmes might be based on the pyruvic acid content of the parental bulbs. The present study was performed using 97 onion clones with the aim of correlating the pyruvic acid levels with phenotype traits in the different genotypes used in breeding programmes. The onion bulbs were provided from the breeding company with blind labels, and four bulbs were individually analysed for each clone. A comparison between the spectrophotometric and HPLC determination of pyruvic acid was also carried out and showed an excellent linear regression with an R 2 = 0.951. The pyruvic acid was studied in correlation with tunic colours, pungency and precocity, and the highest correlation coefficient was found for red skinned onions. The lowest pyruvate content was found in white onions, with 6.5 \u3bcmol g -1 FW, whereas higher values (8.4-8.5 \u3bcmol g -1 FW) were observed in yellow and red onions. The chemical analyses were compared with panel taste assessments. The results confirmed that the pungency and pyruvic acid content were positively and significantly correlated (P<0.0001),even when the coefficient resulted in a relatively low value (r = 0.515). The precocity trait was associated with pyruvate content: precocious onions, in particular, showed lower pungency

Modélisation du transport de plasmides d'ADN du milieu extracellulaire au noyau par électroporation.

We propose a mathematical model for the DNA plasmids transport from the extracellular matrix up to the cell nucleus. The model couples two phenomena: the electroporation process, describing the cell membrane permeabilization to plasmids and the intracellular transport enhanced by the presence of microtubules. Numerical simulations of cells with arbitrary geometry and a network of microtubules show numerically the importance of the microtubules and the electroporation on the effectiveness of the DNA transfection, as observed by previous biological data.Le but de ce rapport est de présenter un modèle mathématique pour le transport de plasmides d'ADN, du milieu extracellulaire jusqu'au noyau, par application d'un champ électrique électroporant. Le modèle couple deux phénomènes : le processus électrique d'électroperméabilisation de la membrane cellulaire, ainsi que le transport électrophorétique de l'ADN dans le milieu extracellulaire d'une part, et le processus de transport actif de l'ADN le long des microtubules d'autre part. Les simulations numériques démontrent l'importance du transport actif le long des microtubules ainsi que l'avantage de l'électroporation pour la transfection de gènes, ce qui est corroboré par de récentes données expérimentales

Flow Index: a novel, non-invasive, continuous, quantitative method to evaluate patient inspiratory effort during pressure support ventilation

Background: The evaluation of patient effort is pivotal during pressure support ventilation, but a non-invasive, continuous, quantitative method to assess patient inspiratory effort is still lacking. We hypothesized that the concavity of the inspiratory flow-time waveform could be useful to estimate patient’s inspiratory effort. The purpose of this study was to assess whether the shape of the inspiratory flow, as quantified by a numeric indicator, could be associated with inspiratory effort during pressure support ventilation. Methods: Twenty-four patients in pressure support ventilation were enrolled. A mathematical relationship describing the decay pattern of the inspiratory flow profile was developed. The parameter hypothesized to estimate effort was named Flow Index. Esophageal pressure, airway pressure, airflow, and volume waveforms were recorded at three support levels (maximum, minimum and baseline). The association between Flow Index and reference measures of patient effort (pressure time product and pressure generated by respiratory muscles) was evaluated using linear mixed effects models adjusted for tidal volume, respiratory rate and respiratory rate/tidal volume. Results: Flow Index was different at the three pressure support levels and all group comparisons were statistically significant. In all tested models, Flow Index was independently associated with patient effort (p < 0.001). Flow Index prediction of inspiratory effort agreed with esophageal pressure-based methods. Conclusions: Flow Index is associated with patient inspiratory effort during pressure support ventilation, and may provide potentially useful information for setting inspiratory support and monitoring patient-ventilator interactions

miRNA-guided reprogramming of glucose and glutamine metabolism and its impact on cell adhesion/migration during solid tumor progression

MicroRNAs (miRNAs) are small, non-coding RNAs about 22 nucleotides in length that regulate the expression of target genes post-transcriptionally, and are highly involved in cancer progression. They are able to impact a variety of cell processes such as proliferation, apoptosis and differentiation and can consequently control tumor initiation, tumor progression and metastasis formation. miRNAs can regulate, at the same time, metabolic gene expression which, in turn, influences relevant traits of malignancy such as cell adhesion, migration and invasion. Since the interaction between metabolism and adhesion or cell movement has not, to date, been well understood, in this review, we will specifically focus on miRNA alterations that can interfere with some metabolic processes leading to the modulation of cancer cell movement. In addition, we will analyze the signaling pathways connecting metabolism and adhesion/migration, alterations that often affect cancer cell dissemination and metastasis formation

Qué sabemos de los Aguarás: Experiencias de un taller educativo sobre Cánidos Silvestres (Mburucuyá, Corrientes)

Esta actividad de extensión es resultado de proyectos de investigación que forman  parte de la Estación Biológica de Corrientes (EBCo, MACN-CONICET) para difundir información sobre la biología, ecología y comportamiento de tres especies de cánidos silvestres que coexisten en la provincia de Corrientes: el aguará guazú (Chrysocyon brachyurus), y dos especies más pequeñas, conocidas como aguará chaí Cerdocyon thous y Lycalopex gymnocercus. El objetivo principal fue establecer un vínculo que sensibilice a los participantes sobre cuestiones referentes a la conservación de estas especies y su entorno, a partir del papel que cumplen las mismas en su ambiente permitiendo que los participantes puedan respetar, cuidar y valorar sus recursos naturales. El presente trabajo da a conocer una de las primeras experiencias del taller denominado “¿Qué sabemos de los aguarás?... Valorando nuestras especies nativas” realizado en el Colegio N° 613 “Ada Ramona Turconi, extensión áulica de la misma escuela ubicada en la localidad de Mburucuyá (Corrientes), el día 22 de junio 2016, con siete actividades diferentes. Tanto para los participantes como los integrantes del equipo de trabajo el intercambio ha sido positivo, pues mediante el juego, propuesto como herramienta de transferencia de conocimientos científicos, se obtuvo una participación enriquecedora para los responsables del taller, y llena de interés y buena predisposición por parte de la comunidad educativa de dicha institución escolar.

Comparison of the i-gel with the cuffed tracheal tube during pressure-controlled ventilation

Background. The i-gel (Intersurgical Ltd) is a novel device that differs from other supraglottic airway devices in that it has a softer and a non-inflatable cuff. Our study was designed to assess whether the i-gel is suitable to provide pressure-controlled ventilation (PCV) during anaesthesia by measuring the gas leaks and comparing these values with that of the tracheal tube. Methods. Twenty-five patients, ASA I–II, were recruited to the study. Patients received a standard anaesthetic technique followed by an initial placement of the i-gel. The lungs were then ventilated at three different pressures (15, 20, 25 cm H2O) using PCV. The difference between the inspired and expired tidal volumes was used to calculate the leak volume. The leak fraction was defined as the leak volume divided by the inspired tidal volume. Following these observations, the i-gel was removed and replaced with the conventional tracheal tube and the recordings repeated. Results. There was no significant difference between the leak fractions of the i-gel and the tracheal tube at 15 and 20 cm H2O PCV. At 25 cm H2O, the median difference in leak fraction was 0.02 (P¼0.014) and the median difference in leak volume was 26.5 ml (P¼0.006). There was no evidence of gastric insufflations with any of the pressures used during PCV. Conclusions. We suggest that the i-gel can be used as a reasonable alternative to tracheal tube during PCV with moderate airway pressures. Br J Anaesth 2009; 102: 264–8 Keywords: equipment, airway; ventilation, mechanical Accepted for publication: November 4, 200