Síntesis y caracterización de dos nuevas oximas derivadas del 4-dimetilamino benzilo

El presente artículo describe la síntesis de dos nuevos ligantes: la 4— Dimetilamino benzilmonoxima y la 4—Dimetilamino benzildioxima derivadas del 4—Dimetilamino benzilo; y su caracterización por métodos instrumentales. De acuerdo a nuestros resultados, la síntesis de la 4—Dimetilamino benzildioximapropuesta por Rense et al (9) no corresponde a este compuesto

Oncogenic transformation of mesenchymal stem cells decreases Nrf2 expression favoring in vivo tumor growth and poorer survival

BACKGROUND: The transcription factor Nrf2 is a key regulator of the cellular antioxidant response, and its activation by chemoprotective agents has been proposed as a potential strategy to prevent cancer. However, activating mutations in the Nrf2 pathway have been found to promote tumorigenesis in certain models. Therefore, the role of Nrf2 in cancer remains contentious. METHODS: We employed a well-characterized model of stepwise human mesenchymal stem cell (MSC) transformation and breast cancer cell lines to investigate oxidative stress and the role of Nrf2 during tumorigenesis. The Nrf2 pathway was studied by microarray analyses, qRT-PCR, and western-blotting. To assess the contribution of Nrf2 to transformation, we established tumor xenografts with transformed MSC expressing Nrf2 (n = 6 mice per group). Expression and survival data for Nrf2 in different cancers were obtained from GEO and TCGA databases. All statistical tests were two-sided. RESULTS: We found an accumulation of reactive oxygen species during MSC transformation that correlated with the transcriptional down-regulation of antioxidants and Nrf2-downstream genes. Nrf2 was repressed in transformed MSC and in breast cancer cells via oncogene-induced activation of the RAS/RAF/ERK pathway. Furthermore, restoration of Nrf2 function in transformed cells decreased reactive oxygen species and impaired in vivo tumor growth (P = 0.001) by mechanisms that included sensitization to apoptosis, and a decreased hypoxic/angiogenic response through HIF-1α destabilization and VEGFA repression. Microarray analyses showed down-regulation of Nrf2 in a panel of human tumors and, strikingly, low Nrf2 expression correlated with poorer survival in patients with melanoma (P = 0.0341), kidney (P = 0.0203) and prostate (P = 0.00279) cancers. CONCLUSIONS: Our data indicate that oncogene-induced Nrf2 repression is an adaptive response for certain cancers to acquire a pro-oxidant state that favors cell survival and in vivo tumor growth

Cyrhetrenylaniline and new organometallic phenylimines derived from 4- and 5-nitrothiophene: Synthesis, characterization, X-Ray structures, electrochemistry and in vitro anti-T. brucei activity

A novel series of cyrhetrenyl (3a-4a) and ferrocenyl (3b-4b) Schiff bases were synthesized through a condensation reaction, between the known 4-ferrocenylaniline (2b) or the unreported 4-cyhretrenylaniline (2a) with 4- or 5-nitrothiophenecarboxaldehyde. The structure of 2a and the new Schiff bases have been elucidated using conventional spectroscopic techniques (FT-IR, 1H and 13C NMR), mass spectrometry, and single-crystal X-ray diffraction analysis of compounds 2a, 4a and 3b. Cyclic voltammetry of organometallic phenylimines derived from 5-nitrothiophene showed NO2 group reduction potentials (E1/2z 0.575 V) that were more anodic than those registered for their 4-nitro analogues (E1/2z 0.981 V). All organometallic imines were tested against the bloodstream form of Trypanosoma brucei. Evaluation indicated that the most active complexes are the 5-nitrothiophene derivatives, 4a, which were remarkably more active than nifurtimox. In addition, complex 4b resulted in less toxicity to host L6 cells than nifurtimox. The results revealed that the electronic effects of cyrhetrene and ferrocene are not an influential factor in E1/2 and anti-Trypanosoma brucei activity for these new imines, which is probably due to the non-coplanarity of the [(h5-C5H4)-C6H4-N=CH-(C4H2S)] system

Human colon cancer cell lines show a diverse pattern of nitric oxide synthase gene expression and nitric oxide generation.

A panel of human colonic adenocarcinoma cell lines was examined both for expression of mRNAs of the nitric oxide synthase (NOS) gene family and for evidence of enzymic activity based on citrulline and nitrite (NO2-) formation. Reverse transcription-polymerase chain reaction (RT-PCR), revealed that all lines (SW480, SW620, DLD-1 and WiDr) expressed mRNA for the Ca(2+)-dependent endothelial (e)NOS, while SW480 cells also expressed the Ca(2+)-dependent neuronal (n)NOS. The mRNA for the Ca(2+)-independent inducible (i)NOS was expressed both by cytokine-stimulated and by unstimulated SW480, SW620 and DLD-1 cells, but none was seen at any time in the WiDr cells. There was, however, little correlation between mRNA expression and enzymic activity based on citrulline and NO2- formation. Thus none of the cell lines exhibited measurable Ca(2+)-dependent NOS activity, while Ca(2+)-independent NOS activity was seen in all but the WiDr cells. Furthermore, DLD-1 cells generated citrulline with resultant NO2- formation only after stimulation with lipopolysaccharide (LPS) and/or cytokines, while SW480 and SW620 did so constitutively. Thus RT-PCR studies indicate that tumour cells of similar epithelial origin display a diverse pattern of NOS gene family expression, and parallel biochemical studies clearly indicate that such expression does not always result in measurable enzymic activity leading to the generation of NO

Exploring working conditions as determinants of job satisfaction: an empirical test among Catalonia service workers

Job satisfaction is particularly important in the service industry since it involves direct contact with customers and thus has a direct influence on company performance. We analyzed the impact of ten working conditions on job satisfaction by means of structural equation modelling in a representative stratified random sample of 1553 service sector employees in Catalonia (Spain). We found significant effects in social aspects (recognition of a job well done and social support), followed by psychological loads (emotional demands and job insecurity) and by task contents (development & meaning and predictability). These variables explained 50% of the variance in job satisfaction

Diseño e implementación de medios de laboratorio para contribuir al proceso de enseñanza aprendizaje en el área de Instrumentación Industrial

This paper presents a pilot plant for academic purpose. FESTO methodology was used as a reference for its design and implementation. It simulates an industrial process described as: water tank filling, water heating, tank pressurization and depressurization and finally water discharged, all of them automatically. A SCADA system implemented using LabVIEWTM was designed to interact with the user. In addition it counts with a security system in order to avoid person and equipment damage during the experiments. As a lab tool this plant illustrates an industrial facility, while providing the opportunity to practice subjects as: G programming for industrial applications, use of industrial instruments and process modeling.  It had been installed in a lab facility, and its performance was successfully tested.   Keywords: learning, instrumentation, G programmingEste artículo presenta el diseño e implementación de una planta piloto para propósitos académicos. La planta se diseñó siguiendo la metodología expuesta por FESTO Didactic e implementa el proceso de llenado, calentado, presurización, descompresión y descarga de un tanque con agua, de forma automática. Cuenta con un sistema de seguridad (sistema centinela) que lleva a cabo funciones de control sobre las variables críticas del proceso y un sistema SCADA implementado bajo la plataforma LabVIEWTM. La planta piloto facilita la adquisición de conocimientos en: programación gráfica para aplicaciones industriales, instrumentación industrial y modelaje de procesos. Familiariza a los estudiantes con las normas, metodologías y terminologías utilizadas en el ambiente industrial. Finalmente, se instaló en un local de laboratorio y sus métricas de desempeño fueron probadas satisfactoriamente.   Palabras claves: aprendizaje, instrumentación, programación grafic

Forage Production is Not Changed in Dwarf Elephantgrass Swards Managed in a Wide Range of Pre-Grazing Canopy Heights

Height corresponding to the critical leaf area index (LAI) has been successfully used to define pre-grazing management targets in pastures subjected to intermittent stocking. However, studies on short/stoloniferous grasses have demonstrated that it is possible to manage pastures at heights below those corresponding to the critical LAI (with a threshold grazing height of approximately 65% of those corresponding to the critical LAI) and achieve a similar forage yield, provided that the severity of defoliation does not exceed 50 percent of the pre-grazing height. In this study, we hypothesized that in tall tussock grasses (such as elephant grass), the amplitude of grazing height required to maintain the same forage yield is lower than that generally observed in small/stoloniferous grasses. Pennisetum purpureum Schum. BRS Kurumi\u27s elephant grass pastures were grazed at three different heights (50, 65, and 80 cm), leaving residual heights of 25, 32, and 40 cm. Our preliminary results suggest that under moderate defoliation and no nutrient limitations, tall tussock-forming grasses exhibit forage accumulation flexibility in the same range of management heights as grasses of smaller size and growth habits. In the present study, elephant grass cv. Kurumi these heights corresponded to a pre-grazing height range of 50 to 80 cm

Lipopolysaccharides of brucella abortus and brucella melitensis induce nitric oxide synthesis in rat peritoneal macrophages

Producción CientíficaSmooth lipopolysaccharide (S-LPS) and lipid A of Brucella abortus and Brucella melitensis induced the production of nitric oxide (NO) by rat adherent peritoneal cells, but they induced lower levels of production of NO than Escherichia coli LPS. The participation of the inducible isoform of NO synthase (iNOS) was confirmed by the finding of an increased expression of both iNOS mRNA and iNOS protein. These observations might help to explain (i) the acute outcome of Brucella infection in rodents, (ii) the low frequency of septic shock in human brucellosis, and (iii) the prolonged intracellular survival of Brucella in humans.This work was supported by (grants FIS 96/1017, SAF96-0144, and SAF98-0176