MicroRNAs as regulators in plant metal toxicity response

Metal toxicity is a major stress affecting crop production. This includes metals that are essential for plants (copper, iron, zinc, manganese), and non-essential metals (cadmium, aluminum, cobalt, mercury). A primary common effect of high concentrations of metal such as aluminum, copper, cadmium, or mercury is root growth inhibition. Metal toxicity triggers the accumulation of reactive oxygen species leading to damage of lipids, proteins, and DNA. The plants response to metal toxicity involves several biological processes that require fine and precise regulation at transcriptional and post-transcriptional levels. MicroRNAs (miRNAs) are 21 nucleotide non-coding RNAs that regulate gene expression at the post-transcriptional level. A miRNA, incorporated into a RNA-induced silencing complex, promotes cleavage of its target mRNA that is recognized by an almost perfect base complementarity. In plants, miRNA regulation is involved in development and also in biotic and abiotic stress responses. We review novel advances in identifying miRNAs related to metal toxicity responses and their potential role according to their targets. Most of the targets for plant metal-responsive miRNAs are transcription factors. Information about metal-responsive miRNAs in different plants points to important regulatory roles of miR319, miR390, miR393, and miR398. The target of miR319 is the TCP transcription factor, implicated in growth control. miR390 exerts its action through the biogenesis of trans-acting small interference RNAs that, in turn, regulate auxin responsive factors. miR393 targets the auxin receptors TIR1/AFBs and a bHLH transcription factor. Increasing evidence points to the crucial role of miR398 and its targets Cu/Zn superoxide dismutases in the control of the oxidative stress generated after high copper or iron exposure

Quinolone Resistance: Much More than Predicted

Since quinolones are synthetic antibiotics, it was predicted that mutations in target genes would be the only mechanism through which resistance could be acquired, because there will not be quinolone-resistance genes in nature. Contrary to this prediction, a variety of elements ranging from efflux pumps, target-protecting proteins, and even quinolone-modifying enzymes have been shown to contribute to quinolone resistance. The finding of some of these elements in plasmids indicates that quinolone resistance can be transferable. As a result, there has been a developing interest on the reservoirs for quinolone-resistance genes and on the potential risks associated with the use of these antibiotics in non-clinical environments. As a matter of fact, plasmid-encoded, quinolone-resistance qnr genes originated in the chromosome of aquatic bacteria. Thus the use of quinolones in fish-farming might constitute a risk for the emergence of resistance. Failure to predict the development of quinolone resistance reinforces the need of taking into consideration the wide plasticity of biological systems for future predictions. This plasticity allows pathogens to deal with toxic compounds, including those with a synthetic origin as quinolones

Cavernous hemangioma of the parotid gland in adults

Hemangiomas account for 0.4-0.6% of all tumors of the parotid gland and most of them occur in children, never - theless in adults hemangiomas are very rare. We report the case of a 62 year old woman with a mass in the parotid right tail associated with fluctuating swelling episodes unrelated to meals and with a slowly progressive growth. The provisional diagnosis was a pleomorphic adenoma, so a right superficial parotidectomy was performed. During surgery, the macroscopic appearance makes suspect a vascular lesion. The histopathological result was a cavernous hemangioma. The classic clinical presentation of a parotid hemangioma is an intraglandular mass associated or not with skin lesions characterized by reddish macules and/or papules, and a vibration or pulsation when palpating the parotid region. In imaging tests, phleboliths could be observed which are very suggestive of a hemangioma or a vascular malformation. In the absence of these signs, the diagnosis could be difficult, particularly in an adult due to its low prevalence, with about 50 cases reported worldwide. However a hemangioma should be considered in the differential diagnosis of parotid tumors in adults

A Real-Time Time-Dependent Density Functional Tight-Binding Implementation for Semiclassical Excited State Electron–Nuclear Dynamics and Pump–Probe Spectroscopy Simulations

The increasing need to simulate the dynamics of photoexcited molecular systems and nanosystems in the subpicosecond regime demands new efficient tools able to describe the quantum nature of matter at a low computational cost. By combining the power of the approximate DFTB method with the semiclassical Ehrenfest method for nuclear–electron dynamics, we have achieved a real-time time-dependent DFTB (TD-DFTB) implementation that fits such requirements. In addition to enabling the study of nuclear motion effects in photoinduced charge transfer processes, our code adds novel features to the realm of static and time-resolved computational spectroscopies. In particular, the optical properties of periodic materials such as graphene nanoribbons or the use of corrections such as the “LDA+U” and “pseudo SIC” methods to improve the optical properties in some systems can now be handled at the TD-DFTB level. Moreover, the simulation of fully atomistic time-resolved transient absorption spectra and impulsive vibrational spectra can now be achieved within reasonable computing time, owing to the good performance of the implementation and a parallel simulation protocol. Its application to the study of UV/visible light-induced vibrational coherences in molecules is demonstrated and opens a new door into the mechanisms of nonequilibrium ultrafast phenomena in countless materials with relevant applications

¿Cuál es la actitud de los médicos hacia el actual modelo de atención primaria?

ObjetivoDeterminar cómo es la actitud de los médicos hacia el actual modelo de atención primaria de salud y estimar su relación con variables de tipo sociodemográfico y/o laboral.DiseñoEstudio multicéntrico, transversal.EmplazamientoCentros de salud del Área II de la Región de Murcia.ParticipantesTotalidad de médicos generales, de familia y pediatras de los centros de salud mencionados (54 en total).Mediciones principalesComo instrumento de evaluación se utiliza la «Escala de actitudes hacia los contenidos de atención primaria de salud», de Ballesteros et al. Esta escala proporciona una puntuación total, así como una puntuación específica para cada una de las 7 dimensiones que la componen.ResultadosEn general, la actitud de los médicos es favorable (4,1 puntos de media sobre 5). En la dimensión «Inclusión de los profesionales del segundo nivel en atención primaria» es donde hemos encontrado una actitud menos favorable, siendo los médicos de familia los que se muestran más de acuerdo. En cuanto a las demás variables asociadas, los profesionales que trabajan en centros periféricos y en situación de interinidad muestran una actitud más positiva hacia el actual modelo.ConclusionesEl conocimiento de las actitudes de los profesionales, así como de las variables relacionadas, puede servir de base para diseñar posibles estrategias de intervención dirigidas a la mejora de la calidad asistencial en atención primaria y para una evolución positiva de los profesionales que prestan sus servicios.ObjectivesTo determine the attitude of doctors towards the current model of primary care and to calculate its relationship with social and demographic and/or work variables.DesignMulti-centre cross-sectional study.SettingHealth centres in Area II of the Murcia region.ParticipantsAll general practitioners, family doctors and paediatricians in the health centres mentioned (54 in all).Main measurementsThe «Scale of attitudes towards the contents of primary health care» by Ballesteros et al. was used as the tool of evaluation. This scale provides both a total score and a specific score for each of its 7 dimensions.ResultsIn general, doctors´ attitudes were favourable (4.1 points average out of 5). We found a less favourable attitude in the dimension «Inclusion of second-level professionals in primary care», with family doctors most in agreement. The professionals working in centres on the periphery and those without tenure had a more positive attitude towards the current model, for the remaining variables.ConclusionsUnderstanding professionals´ attitudes and the variables related to them may serve as a basis for designing intervention strategies aimed at improving the quality of primary care and for the positive evolution of professionals working in PC

Predictive analysis of transmissible quinolone resistance indicates Stenotrophomonas maltophilia as a potential source of a novel family of Qnr determinants

Additional files: Microsoft excel document containing the descriptions of the genes shown in Figure 2.Background Predicting antibiotic resistance before it emerges at clinical settings constitutes a novel approach for preventing and fighting resistance of bacterial pathogens. To analyse the possibility that novel plasmid-encoded quinolone resistance determinants (Qnr) can emerge and disseminate among bacterial pathogens, we searched the presence of those elements in nearly 1000 bacterial genomes and metagenomes. Results We have found a number of novel potential qnr genes in the chromosomes of aquatic bacteria and in metagenomes from marine organisms. Functional studies of the Stenotrophomonas maltophilia Smqnr gene show that plasmid-encoded SmQnr confers quinolone resistance upon its expression in a heterologous host. Conclusion Altogether, the data presented in our work support the notion that predictive studies on antibiotic resistance are feasible, using currently available information on bacterial genomes and with the aid of bioinformatic and functional tools. Our results confirm that aquatic bacteria can be the origin of plasmid-encoded Qnr, and highlight the potential role of S. maltophilia as a source of novel Qnr determinants.This work has been supported by grants BIO2005-04278, LSHM-CT-2005-518152 and LSHM-CT-2005-018705. L. M-M and J.M. R.-M. are supported by REIPI, RD06/0008 from ISCIII, Ministerio de Sanidad y Consumo, Spain.Peer reviewe

Physicochemical characterization and antimicrobial activity against Erwinia amylovora, Erwinia vitivora, and Diplodia seriata of a light purple Hibiscus syriacus L. Cultivar

Phytochemicals are essential raw materials for the production of formulations that can be helpful in crop protection. In particular, Hibiscus spp., which are often used in traditional medicine, are rich in potential bioactive molecules. This study presents an analysis of the thermal, vibrational, and phytochemical characteristics of a light purple variety of Hibiscus syriacus, using thermal gravimetric and differential scanning calorimetry, Fourier-transform infrared spectroscopy, and gas chromatography-mass spectroscopy techniques. Further, with a view to its valorization, the antimicrobial activity of its extracts has been investigated in vitro against Erwinia amylovora (the phytopathogen responsible for fire blight in apples, pears, and some other members of the family Rosaceae), Erwinia vitivora (the causal agent of the “maladie d’Oléron” in grapevines), and Diplodia seriata (responsible for “Bot canker”). Higher heating values and thermal features showed similarities with kenaf biomass. The main compounds identified in the hydro-methanolic extracts were: in flowers, 1-heptacosanol, heptacosane, 1-tetracosanol, hexadecenoic acid, 9,12,15-octadecatrienoic acid, and 9,12-octadecadienoic acid; and in leaves, the coumarin derivative 4,4,6,8-tetramethyl-2-chromanone, vitamin E, phytol, and sitosterol. MIC values of 500 and 375 μg·mL−1 were obtained against E. amylovora for flower and leaf extracts, respectively, upon conjugation with chitosan oligomers (to improve solubility and bioavailability). In the case of E. vitivora, MIC values of 250 and 500 μg·mL−1, respectively, were registered. Regarding the antifungal activity, EC90 values of 975.8 and 603.5 μg·mL−1, respectively, were found. These findings suggest that H. syriacus (cv. ‘Mathilde’) may be a promising source of antimicrobials for agriculture