Correlation between ribonucleoside-diphosphate reductase and three replication proteins in Escherichia coli

<p>Abstract</p> <p>Background</p> <p>There has long been evidence supporting the idea that RNR and the dNTP-synthesizing complex must be closely linked to the replication complex or replisome. We contributed to this body of evidence in proposing the hypothesis of the replication hyperstructure. A recently published work called this postulate into question, reporting that NrdB is evenly distributed throughout the cytoplasm. Consequently we were interested in the localization of RNR protein and its relationship with other replication proteins.</p> <p>Results</p> <p>We tagged NrdB protein with 3×FLAG epitope and detected its subcellular location by immunofluorescence microscopy. We found that this protein is located in nucleoid-associated clusters, that the number of foci correlates with the number of replication forks at any cell age, and that after the replication process ends the number of cells containing NrdB foci decreases.</p> <p>We show that the number of NrdB foci is very similar to the number of SeqA, DnaB, and DnaX foci, both in the whole culture and in different cell cycle periods. In addition, interfoci distances between NrdB and three replication proteins are similar to the distances between two replication protein foci.</p> <p>Conclusions</p> <p>NrdB is present in nucleoid-associated clusters during the replication period. These clusters disappear after replication ends. The number of these clusters is closely related to the number of replication forks and the number of three replication protein clusters in any cell cycle period. Therefore we conclude that NrdB protein, and most likely RNR protein, is closely linked to the replication proteins or replisome at the replication fork. These results clearly support the replication hyperstructure model.</p

Estudio antigenotoxicológico y de citotoxicidad de plantas medicinales de uso cotidiano y de sus fenoles más caracterísiticos

Para dar respuesta al creciente interés de los consumidores sobre los efectos beneficiosos en su salud de preparados herbales que se suelen tomar sin prescripción médica, hemos seleccionado un grupo de plantas medicinales de uso cotidiano y fenoles contenidos en ellas para estudiar ciertos indicadores de su posible bioactividad. Las plantas seleccionadas ha sido de tres tipos: antiinflamatorias (Matricaria chamomilla y Uncaria tomentosa), digestivas (Mentha piperita y Mentha pulegium) y sedantes (Tilia cordata y Valeriana officinalis); y los fenoles contenidos en ellas: Bisabolol, Apigenina, Ácido Protocatecuico, Mentol, Pulegona, Quercitina, Limoneno y Ácido Valerénico. Los marcadores de bioactividad seleccionados han sido: (i) toxicidad (ensayada en el modelo eucariota Drosophila melanogaster), (ii) genotoxicidad o seguridad genómica (ensayada en el modelo in vivo de Mutaciones y Recombinaciones Somáticas de D. melanogaster, S.M.A.R.T.), (iii) antigenotoxicidad o protección frente al daño genético causado por agentes oxidantes (ensayada en el modelo in vivo de Mutaciones y Recombinaciones Somáticas de D. melanogaster) y (iv) citotoxicidad o potencial quimiopreventivo (ensayada en el modelo de inhibición del crecimiento tumoral in vitro de células HL60 de leucemia humana). Todas las plantas y moléculas ensayadas han resultado tóxicas para D. melanogaster, aunque a distintas intensidades, que son en orden creciente: V. officinalis, Ác. Valerénico, Bisabolol, Limoneno, Quercitina, DHBA, Mentol, T. cordata, Pulegona, M. chamomilla, Apigenina, U. tomentosa, M. pulegium, y M. piperita. Destacamos en general, las plantas sedantes Tila y Valeriana así como sus componentes estudiados, los menos tóxicos y las digestivas Mentas, las más tóxicas. Ninguna planta ni molécula ha resultado genotóxica en el ensayo de Mutaciones y Recombinaciones Somáticas de D. melanogaster, por lo que todas son seguras. Aunque algunas sustancias muestran tasas de inducción de clones altas, como U. tomentosa y M. chamomilla; las de otras están incluso por debajo del control negativo, como el Bisabolol y la Apigenina. Todas las plantas y moléculas, excepto la Pulegona, han mostrado actividad protectora del genoma frente al daño oxidativo provocado por el Peróxido de Hidrógeno. Las más potentes son las infusiones de las plantas, ejerciendo las moléculas individuales inhibiciones medias o bajas. Este fenómeno sugiere la existencia de interacciones epigenéticas que pueden darse entre elementos endógenos altamente oxidantes (Peróxido de Hidrógeno) y elementos altamente antioxidantes (fenoles) actuando conjuntamente en la planta...To give an answer to the growing interest of consumers about the beneficial effects on their health of herbal preparations that are usually taken without medical prescription, we have selected a group of medicinal plants of daily use and phenols contained in them to study certain indicators of its possible bioactivity. Three types of plants have been selected: anti-inflammatory (Matricaria chamomilla and Uncaria tomentosa), digestives (Mentha piperita and Mentha pulegium) and sedatives (Tilia cordata and Valeriana officinalis); and the phenols contained in them: Bisabolol, Apigenin, Protocatecuic Acid, Menthol, Pulegone, Quercetin, Limonene and Valerenic Acid. The selected markers of bioactivity have been: (i) toxicity (being tested in the eukaryotic model Drosophila melanogaster), (ii) genotoxicity or genomic safety (tested in the in vivo model of somatic mutations and recombinations of D. melanogaster, S.M.A.R.T.), (iii) antigenotoxicity or protection against the genetic damage caused by oxidants agents (tested in the in vivo somatic mutations and recombinations of D. melanogaster model) and (iv) cytotoxicity or chemopreventive potential (tested in the tumor growth inhibition in vitro model of HL60 human leukemia cells). All plants and tested molecules have proved to be toxic to D. melanogaster, although in different extent, in increasing order: V. officinalis, Valerenic Ac., Bisabolol, Limonene, Quercetin, DHBA, Menthol, T. cordata, Pulegone, M. chamomilla, Apigenin, U. tomentosa, M. pulegium, and M. piperita. In general, Tila and Valerian sedative plants as well as their components studied molecules were the less toxic; and the digestive mints, the more toxic. No plant or molecule has been genotoxic in the Somatic Mutation and Recombination Test of D. melanogaster, so they all are safe. Although some substances show high rates of clone induction, like U. tomentosa and M. chamomilla; being others even below the negative control, like the Bisabolol and Apigenin. All plants and molecules, with the exception the Pulegone, have shown protective activity of the genome against hydrogen peroxide-induced oxidative damage. The most powerful are the infusions of plants, exerting the individual molecules medium or low inhibition rates. This phenomenon suggests the existence of epigenetic interactions that can occur between highly oxidants endogenous elements (hydrogen peroxide) and highly antioxidants elements (phenols) acting together on the plant

El implante coclear en población infantil

El implante coclear (IC) ha revolucionado el tratamiento de las pérdidas graves de audición, especialmente de aquellas que dificultan o impiden la adquisición de la lengua oral. Desde que en 1990 se determinase que podía ser utilizado en niños muy pequeños, el IC ha llegado a ser considerado un procedimiento seguro y exento de riesgo antes del año de vida. España es uno de los países europeos donde un mayor número de niños sordos reciben un implante coclear cada año, dato que no se corresponde con la dedicación investigadora al respecto. El objetivo del presente trabajo de investigación fue, por un lado, analizar, a través de una muestra de 116 niños sordos españoles que utilizan un IC desde los primeros años de su vida, como había sido su desarrollo auditivo, del habla y del lenguaje, posterior al uso del dispositivo, así como los factores predictores de este desarrollo, y por otro, comparar un grupo de 104 niños sordos (procedente de la muestra inicial de 116 sujetos) con otro grupo de pares oyentes en los hitos más importantes del desarrollo, la conducta adaptativa, los problemas de conducta y los resultados educativos. Algunas de las conclusiones extraídas del estudio son: 1-La variabilidad de los resultados obtenidos por los niños y niñas que componían la muestra, en ocasiones han conseguido cotas similares a sus pares oyentes y en otras no han logrado emitir las primeras palabras. 2- La edad a la que los niños recibieron su dispositivo ha resultado uno de los factores que predicen en mayor medida los resultados, a menor edad, mejores resultados. 3- La opción comunicativa que incluye la lengua de signos además de la lengua oral, parece mejorar aspectos del lenguaje de estos niños. 4- Respecto a los pares oyentes, los niños sordos desarrollan más tarde determinados hitos como la marcha y la emisión de las primeras palabras y frases. 5- Los niños sordos del estudio muestran un mayor porcentaje de problemas de conducta

Application of a Neural Network classifier for the generation of clean Small Magellanic Cloud stellar samples

Context. Previous attempts to separate Small Magellanic Cloud (SMC) stars from the Milky Way (MW) foreground stars are based only on the proper motions of the stars. Aims. In this paper we develop a statistical classification technique to effectively separate the SMC stars from the MW stars using a wider set of Gaia data. We aim to reduce the possible contamination from MW stars compared to previous strategies. Methods. The new strategy is based on neural network classifier, applied to the bulk of the Gaia DR3 data. We produce three samples of stars flagged as SMC members, with varying levels of completeness and purity, obtained by application of this classifier. Using different test samples we validate these classification results and we compare them with the results of the selection technique employed in the Gaia Collaboration papers, which was based solely on the proper motions. Results. The contamination of MW in each of the three SMC samples is estimated to be in the 10-40%; the "best case" in this range is obtained for bright stars (G > 16), which belong to the Vlos sub-samples, and the "worst case" for the full SMC sample determined by using very stringent criteria based on StarHorse distances. A further check based on the comparison with a nearby area with uniform sky density indicates that the global contamination in our samples is probably close to the low end of the range, around 10%. Conclusions. We provide three selections of SMC star samples with different degrees of purity and completeness, for which we estimate a low contamination level and have successfully validated using SMC RR Lyrae, SMC Cepheids and SMC/MW StarHorse samples.Comment: arXiv admin note: substantial text overlap with arXiv:2210.0172

Distribution of melanopsin positive neurons in pigmented and albino mice: evidence for melanopsin interneurons in the mouse retina.

Here we have studied the population of intrinsically photosensitive retinal ganglion cells (ipRGCs) in adult pigmented and albino mice. Our data show that although pigmented (C57Bl/6) and albino (Swiss) mice have a similar total number of ipRGCs, their distribution is slightly different: while in pigmented mice ipRGCs are more abundant in the temporal retina, in albinos the ipRGCs are more abundant in superior retina. In both strains, ipRGCs are located in the retinal periphery, in the areas of lower Brn3a(+)RGC density. Both strains also contain displaced ipRGCs (d-ipRGCs) in the inner nuclear layer (INL) that account for 14% of total ipRGCs in pigmented mice and 5% in albinos. Tracing from both superior colliculli shows that 98% (pigmented) and 97% (albino) of the total ipRGCs, become retrogradely labeled, while double immunodetection of melanopsin and Brn3a confirms that few ipRGCs express this transcription factor in mice. Rather surprisingly, application of a retrograde tracer to the optic nerve (ON) labels all ipRGCs, except for a sub-population of the d-ipRGCs (14% in pigmented and 28% in albino, respectively) and melanopsin positive cells residing in the ciliary marginal zone (CMZ) of the retina. In the CMZ, between 20% (pigmented) and 24% (albino) of the melanopsin positive cells are unlabeled by the tracer and we suggest that this may be because they fail to send an axon into the ON. As such, this study provides the first evidence for a population of melanopsin interneurons in the mammalian retina

Additive Manufacturing with RepRap Methodology: Current Situation and Future Prospects

In February 2004, Adrian Bowyer, from the University of Bath, began an open initiative called RepRap, with the purpose of creating an open source rapid prototyping machine which, moreover, could replicate itself. This article analyzes the current status of the RepRap initiative, commenting the basic components of RepRap machines, the differences between the different 3D printers developed by the RepRap community so far, and the technical possibilities that opens this technology from the engineering point of view. In addition we propose some improvements that could be perfectly feasible in the short term. For this purpose, the assembly of a RepRap Mendel Prusa was performed, but with some modifications.Mechanical Engineerin

Interacción de los antineoplásicos orales con los alimentos: revisión sistemática

[email protected]ón: Los estudios de biodisponibilidad son parte integrante del desarrollo clínico de medicamentos para administración oral con el fin de identificar potenciales interacciones fármaco-alimento (iFA). Actualmente, para los antineoplásicos orales se empieza a reconocer su importancia clínica, aun cuando lamentablemente, la información disponible presenta variabilidad en su evidencia científica. Objetivos: Revisar la evidencia científica disponible sobre las interacciones de los alimentos con medicamentos antineoplásicos orales y establecer recomendaciones para su administración. Métodos: Se realizó una búsqueda bibliográfica en Medline y The Cochrane Library para el periodo comprendido entre enero de 1966 a marzo de 2008, enfocada a identificar las publicaciones sobre interacciones fármaco alimento con antineoplásicos orales. El análisis bibliográfico consta de dos fases. En la primera fase se excluyeron los artículos que por título y contenido del resumen no se correspondían con el objetivo planteado; en la segunda fase se eliminaron las referencias duplicadas en ambas bases de datos. Los criterios de inclusión para seleccionar los artículos fueron: diseño (revisiones sistemáticas, metaanálisis, ensayos clínicos randomizados Fase I y II), población (pacientes adultos; >19 años de edad), intervención evaluada (administración de antineoplásicos orales bajo condiciones de ayuno o con alimentos) y medida del resultado de la iFA (cálculo del IC90% de la razón entre la media geométrica de valores del área bajo la curva de concentraciones plasmáticas (ABC) o la concentración plasmática máxima (Cmax) con y sin alimentos). Se excluyeron las publicaciones que como medida de resultado no hacían referencia al dictamen de bioequivalencia establecido por la Food and Drugs Administration (FDA). La valoración crítica de los artículos seleccionados se realizó según las recomendaciones que de acuerdo con la FDA deben cumplir estos estudios. Resultados: En la búsqueda inicial se obtuvieron 850 referencias (98,5% Medline + y 1,4% Cochrane). En la primera fase se excluyeron el 87,7% (746) de los artículos, correspondiendo el 100% a la búsqueda en Medline. En la segunda fase, quedaron 40 artículos (5,2% de los iniciales) para su lectura crítica a texto completo, a los que se añadieron cuatro más no indexados en Medline. De la lectura crítica de los 44 artículos finales, se excluyeron 25 artículos (20 artículos originales, 4 comunicaciones cortas y 1 metanálisis) por no incluir como medida de resultado el dictamen de bioequivalencia. Los 19 (2,2%) artículos restantes proporcionaron información sobre 19 fármacos antineoplásicos orales, en 210 pacientes y 146 voluntarios sanos. De estos 19 fármacos, el 63% no presentan iFA o interacciones fármaco-alimento, pudiéndose administrar indistintamente con/sin alimentos; el 21% se deben administrar con alimentos y sólo el 16% presentan interacción fármaco alimento, por lo que se deben administrar sin alimentos. Discusión: Actualmente, la importancia clínica de las interacciones fármaco alimento con antineoplásicos orales se identifica más directamente con la seguridad del paciente que con la efectividad del tratamiento. Ante el desarrollo de estos agentes orales, su irrupción en la terapia oncológica desplazando a la terapia parenteral, con costes mensuales de miles de euros, hay necesidad de realizar estudios farmacocinéticos y farmacodinámicos bien diseñados. Su objetivo debe de ser comparar su biodisponibilidad en presencia o ausencia de alimentos con la respuesta clínica. Mientras tanto, establecer recomendaciones para su administración en relación con los alimentos, es inconsistente para algunos de estos fármacos y su resultado incierto por la falta de estudios fundamentados en el dictamen de bioequivalencia establecido por la FDA.Introduction: studies on bioavailability are part of the clinical development of drugs for oral use in order to identify potential drug-food interactions. For oral antitumor drugs, their clinical importance is currently recognized although regrettably the information available presents variability concerning the scientific evidence. Objectives: To review the available scientific evidence about oral anti-tumor medications and establish the recommendations for their administration with foods. Methods: We carried out a bibliographic search in Medline and The Cochrane Library for the period January of 1966 to March of 2008, focused on identifying those publications about drug-food interactions with oral antitumor medications. The bibliographical analysis was made in two steps. During the first phase, we excluded those articles in which the title or their content did not correspond with the objective settled; during the second phase, we deleted all the references duplicated in both databases. The inclusion criteria to select the articles were: design (systematic reviews, meta-analysis, Phase I and Phase II randomized clinical trials), population (adult patients; >19 years of age), intervention evaluated (administration of oral anti-tumor drugs under fasting conditions or with food) and measurement of the iFA results (calculation of the 90% CI of the odds ratio between the geometric mean of the values under the curve of the plasma concentrations (ABC) or the maximal plasma concentration (Cmax) with and without foods). We excluded those publications that did not make reference to the bioequivalence dictamen established by the Food and Drugs Administration (FDA) in their outcomes measurement. A critical appraisal of the selected articles was done according to the recommendations that the FDA established to be met by these studies. Results: At the initial search we obtained 850 references (98.5% Medline + and 1.4% Cochrane). During the first phase, we excluded 87.7% (746) of the articles, 100% of them corresponding to the search in Medline. During the second phase, 40 studies remained (5.2% of the initial ones) for full-text critical appraisal, to which four studies were added not indexed in Medline. From the critical appraisal of the 44 final articles, 25 were excluded (20 original articles, 4 short communications, and 1 meta-analysis) because they did not include as an outcome measure the bioequivalence dictamen. The 19 (2.2%) remaining articles provided information on 19 oral anti-tumor drugs in 210 patients and 146 healthy volunteers. Of these 19 drugs, 63% did not present drugfood interactions, with the possibility of administering them either with or without food; 21% have to be administered with foods and only 16% present drug-food interactions, so they have to be administered without foods. Discussion: Currently, the clinical importance of drugfood interactions with oral anti-tumor drugs is identified more directly with the patient's safety than with the efficacy of the therapy. Given the development of these oral agents, their incorporation into the oncologic strategy displacing parenteral therapy, with monthly costs of thousands of Euros, it is necessary to perform well-designed studies on pharmacokinetics and pharmacodynamics. Their goal has to be comparing their bioavailability in the presence or absence of foods with the clinical response. In the meanwhile, to establish recommendations for their administration in relation to foods is inconsistent for some of these drugs and their results is uncertain given the lack of studies based on the FDAbioequivalence dictamen

Effects of the inclusion of oat hulls or sugar beet pulp in the diet on gizzard characteristics, apparent ileal digestibility of nutrients, and microbial count in the ceca in 36 day old broilers reared on floor

The effects of the inclusion of oat hulls (OH) and sugar beet pulp (SBP) in the diet on gizzard characteristics, apparent ileal nutrient digestibility (AID), and Clostridium perfringens, Enterobacteriaceae, and Lactobacillus proliferation in the ceca were studied in 36 d?old broilers. There were a control diet with a low CF content (1.61%) and 2 additional diets that resulted from the dilution of this feed with 5% of either OH or SBP

The Role of Nrf2 Signaling in PPARβ/δ-Mediated Vascular Protection against Hyperglycemia-Induced Oxidative Stress

Hyperglycemia induces oxidative stress and plays a substantial role in the progression of vascular diseases. Here, we demonstrated the potentiality of peroxisome proliferator-activated receptor (PPAR)β/δ activation in attenuating high glucose-induced oxidative stress in endothelial cells and diabetic rats, pointing to the involvement of nuclear factor erythroid 2-related factor 2 (Nrf2). HUVECs exposed to high glucose showed increased levels of reactive oxygen species (ROS) and upregulated NOX-2, NOX-4, Nrf2, and NQO-1 effects that were significantly reversed by the PPARβ/δ agonists GW0742 and L165041. Both PPARβ/δ agonists, in a concentration-dependent manner, induced transcriptional and protein upregulation of heme oxygenase-1 (HO-1) under low- and high-glucose conditions. All effects of PPARβ/δ agonists were reversed by either pharmacological inhibition or siRNA-based downregulation of PPARβ/δ. These in vitro findings were confirmed in diabetic rats treated with GW0742. In conclusion, PPARβ/δ activation confers vascular protection against hyperglycemia-induced oxidative stress by suppressing NOX-2 and NOX-4 expression plus a direct induction of HO-1; with the subsequent downregulation of the Nrf2 pathway. Thus, PPARβ/δ activation could be of interest to prevent the progression of diabetic vascular complications.This work was supported by Grants from Ministerio de Economía y Competitividad and Fondo Europeo de Desar- rollo Regional (FEDER) (SAF2010-22066-C02-01, SAF2010-22066-C02-02, SAF2011-28150, SAF2014-55523- R), Junta de Andalucía (Proyecto de excelencia, P12-CTS- 2722), and Instituto de Salud Carlos III (RIC RD12/0042/ 0011), Spain