Sobre Lamium hybridum L. en Andalucía

Las primeras noticias sobre la presencia de Lamium hybridum en Andalucía son relativamente recientes, Molero Mesa & Martínez Parras (1983; 1987) lo citaron en un área históricamente muy visitada por los botánicos: Peñón de San Francisco, en la Sierra Nevada granadina, a 2400 m, al pie de rocas cuarcíticas nitrificadas, considerándola como muy escasa. Posteriormente esta referencia se recogió en el catálogo andaluz por Carazo Montijano & Fernández López (1994). La ausencia, en su momento, de pliegos testigos de la localidad mencionada motivó seguramente que esta cita no fuera tomada en consideración en el listado de labiadas andaluzas (Navarro et al., 2002) ni tampoco en la Flora Vascular de Andalucía oriental (Navarro, 2009). Por otra parte es una especie de la que no existen referencias en la Flora Vascular de Andalucía Occidental (Ubera, 1987), y además parece que, finalmente, no alcanza el norte de África, donde es sustituido por L. mauritanicum Gand. ex Batt. (cf. Rejdali & Montserrat, 2000), por lo que las sierras andaluzas marcan su limite meridional de distribución. Aportamos las siguientes localidades (con los pliegos testigos del herbario GDA, recientemente localizados, además de los que se han incorporado al herbario COA) que confirman su presencia en Sierra Nevada y amplían su distribución en Andalucía [después de revisar los herbarios COA, COI, GDA, MA, MGC, SALA/SALAF, SANT, SEV para la revisión realizada por uno de los autores para Flora iberica]

Corrigendum to Relationship between structural damage with loss of strength and functional disability in psoriatic arthritis patients [Clin. Biomech. volume 68 (2019) Pages 169–174/Article Number JCLB 4795]

Erratu

Xenopus Oocytes as a Powerful Cellular Model to Study Foreign Fully-Processed Membrane Proteins

The use of Xenopus oocytes in electrophysiological and biophysical research constitutes a long and successful story, providing major advances to the knowledge of the function and modulation of membrane proteins, mostly receptors, ion channels, and transporters. Earlier reports showed that these cells are capable of correctly expressing heterologous proteins after injecting the corresponding mRNA or cDNA. More recently, the Xenopus oocyte has become an outstanding host–cell model to carry out detailed studies on the function of fully-processed foreign membrane proteins after their microtransplantation to the oocyte. This review focused on the latter overall process of transplanting foreign membrane proteins to the oocyte after injecting plasma membranes or purified and reconstituted proteins. This experimental approach allows for the study of both the function of mature proteins, with their native stoichiometry and post-translational modifications, and their putative modulation by surrounding lipids, mostly when the protein is purified and reconstituted in lipid matrices of defined composition. Remarkably, this methodology enables functional microtransplantation to the oocyte of membrane receptors, ion channels, and transporters from different sources including human post-mortem tissue banks. Despite the large progress achieved over the last decades on the structure, function, and modulation of neuroreceptors and ion channels in healthy and pathological tissues, many unanswered questions remain and, most likely, Xenopus oocytes will continue to help provide valuable responses.The work in the authors’ laboratories has been supported by grants SAF2017-82977-P (AEI/FEDER, UE) and PGC2018-093505-B-I00 from MINECO and GRE17-01 from Universidad de Alicante (Spain)

Muscle-Type Nicotinic Receptor Blockade by Diethylamine, the Hydrophilic Moiety of Lidocaine

Lidocaine bears in its structure both an aromatic ring and a terminal amine, which can be protonated at physiological pH, linked by an amide group. Since lidocaine causes multiple inhibitory actions on nicotinic acetylcholine receptors (nAChRs), this work was aimed to determine the inhibitory effects of diethylamine (DEA), a small molecule resembling the hydrophilic moiety of lidocaine, on Torpedo marmorata nAChRs microtransplanted to Xenopus oocytes. Similarly to lidocaine, DEA reversibly blocked acetylcholine-elicited currents (IACh) in a dose-dependent manner (IC50 close to 70 μM), but unlike lidocaine, DEA did not affect IACh desensitization. IACh inhibition by DEA was more pronounced at negative potentials, suggesting an open-channel blockade of nAChRs, although roughly 30% inhibition persisted at positive potentials, indicating additional binding sites outside the pore. DEA block of nAChRs in the resting state (closed channel) was confirmed by the enhanced IACh inhibition when pre-applying DEA before its co-application with ACh, as compared with solely DEA and ACh co-application. Virtual docking assays provide a plausible explanation to the experimental observations in terms of the involvement of different sets of drug binding sites. So, at the nAChR transmembrane (TM) domain, DEA and lidocaine shared binding sites within the channel pore, giving support to their open-channel blockade; besides, lidocaine, but not DEA, interacted with residues at cavities among the M1, M2, M3, and M4 segments of each subunit and also at intersubunit crevices. At the extracellular (EC) domain, DEA and lidocaine binding sites were broadly distributed, which aids to explain the closed channel blockade observed. Interestingly, some DEA clusters were located at the α-γ interphase of the EC domain, in a cavity near the orthosteric binding site pocket; by contrast, lidocaine contacted with all α-subunit loops conforming the ACh binding site, both in α-γ and α-δ and interphases, likely because of its larger size. Together, these results indicate that DEA mimics some, but not all, inhibitory actions of lidocaine on nAChRs and that even this small polar molecule acts by different mechanisms on this receptor. The presented results contribute to a better understanding of the structural determinants of nAChR modulation.This work was supported by grants BFU2012-31359, BFU2012-39092-C02-01, BFU2011-25920, and CSD2008-00005 from the MINECO and PROMETEO/2014/11 from GVA (Spain)

In Situ Study of Road Marking Durability Using Glass Microbeads and Antiskid Aggregates as Drop-On Materials

Road markings play an important role in road safety because they provide significant information to drivers about the road. For that reason, they must be replaced when they are not correctly perceived by road users. To analyse which are the main factors that affect road marking perception over time, a test section was designed in a two-lane rural highway, running actual traffic over 18 different types of markings fabricated with different combinations of drop-on materials. Chromatic coordinates, luminance, and retroreflectivity of each sample were measured during 18 months in order to study their evolution over time. The results obtained show different behaviours depending on the aggregates and application method used. An increment of the durability has been observed with the use of different layers and mixtures of glass microbeads with different sizes

Mechanisms of Blockade of the Muscle-Type Nicotinic Receptor by Benzocaine, a Permanently Uncharged Local Anesthetic

Most local anesthetics (LAs) are amine compounds bearing one or several phenolic rings. Many of them are protonated at physiological pH, but benzocaine (Bzc) is permanently uncharged, which is relevant because the effects of LAs on nicotinic acetylcholine (ACh) receptors (nAChRs) depend on their presence as uncharged or protonated species. The aims of this study were to assess the effects of Bzc on nAChRs and to correlate them with its binding to putative interacting sites on this receptor. nAChRs from Torpedo electroplaques were microtransplanted to Xenopus oocytes and currents elicited by ACh (IAChs), either alone or together with Bzc, were recorded at different potentials. Co-application of ACh with increasing concentrations of Bzc showed that Bzc reversibly blocked nAChRs. IACh inhibition by Bzc was voltage-independent, but the IACh rebound elicited when rinsing Bzc suggests an open-channel blockade. Besides, ACh and Bzc co-application enhanced nAChR desensitization. When Bzc was just pre-applied it also inhibited IACh, by blocking closed (resting) nAChRs. This blockade slowed down the kinetics of both the IACh activation and the recovery from blockade. The electrophysiological results indicate that Bzc effects on nAChRs are similar to those of 2,6-dimethylaniline, an analogue of the hydrophobic moiety of lidocaine. Furthermore, docking assays on models of the nAChR revealed that Bzc and DMA binding sites on nAChRs overlap fairly well. These results demonstrate that Bzc inhibits nAChRs by multiple mechanisms and contribute to better understanding both the modulation of nAChRs and how LAs elicit some of their clinical side effects.This work was supported by grants BFU2012-31359, BFU2015-66612-P, SAF2015-66275-C2-1-R and SAF2017-82977-P (AEI/FEDER, UE) from MINECO, PROMETEO/2014/11 from Generalitat Valenciana (Spain) and GRE17-01 from Universidad de Alicante. R.C. held a predoctoral fellowship from Universidad de Alicante (FPUUA36) and M.N. a predoctoral industrial fellowship from Ministerio de Economía, Industria y Competitividad (DI-16-08303)

Inverse problems in high pressure processes and food engineering

Depto. de Análisis Matemático y Matemática AplicadaInstituto de Matemática Interdisciplinar (IMI)Fac. de Ciencias MatemáticasTRUEpu

Muscle-Type Nicotinic Receptor Modulation by 2,6-Dimethylaniline, a Molecule Resembling the Hydrophobic Moiety of Lidocaine

To identify the molecular determinants responsible for lidocaine blockade of muscle-type nAChRs, we have studied the effects on this receptor of 2,6-dimethylaniline (DMA), which resembles lidocaine’s hydrophobic moiety. Torpedo marmorata nAChRs were microtransplanted to Xenopus oocytes and currents elicited by ACh (IACh), either alone or co-applied with DMA, were recorded. DMA reversibly blocked IACh and, similarly to lidocaine, exerted a closed-channel blockade, as evidenced by the enhancement of IACh blockade when DMA was pre-applied before its co-application with ACh, and hastened IACh decay. However, there were marked differences among its mechanisms of nAChR inhibition and those mediated by either the entire lidocaine molecule or diethylamine (DEA), a small amine resembling lidocaine’s hydrophilic moiety. Thereby, the IC50 for DMA, estimated from the dose-inhibition curve, was in the millimolar range, which is one order of magnitude higher than that for either DEA or lidocaine. Besides, nAChR blockade by DMA was voltage-independent in contrast to the increase of IACh inhibition at negative potentials caused by the more polar lidocaine or DEA molecules. Accordingly, virtual docking assays of DMA on nAChRs showed that this molecule binds predominantly at intersubunit crevices of the transmembrane-spanning domain, but also at the extracellular domain. Furthermore, DMA interacted with residues inside the channel pore, although only in the open-channel conformation. Interestingly, co-application of ACh with DEA and DMA, at their IC50s, had additive inhibitory effects on IACh and the extent of blockade was similar to that predicted by the allotopic model of interaction, suggesting that DEA and DMA bind to nAChRs at different loci. These results indicate that DMA mainly mimics the low potency and non-competitive actions of lidocaine on nAChRs, as opposed to the high potency and voltage-dependent block by lidocaine, which is emulated by the hydrophilic DEA. Furthermore, it is pointed out that the hydrophobic (DMA) and hydrophilic (DEA) moieties of the lidocaine molecule act differently on nAChRs and that their separate actions taken together account for most of the inhibitory effects of the whole lidocaine molecule on nAChRs.This work was supported by grants BFU2012-31359, SAF2015-66275-C2-1-R, BFU2011-25920, BFU2015-66612-P, and CSD2008-00005 from the MINECO and PROMETEO/2014/11 from GVA (Spain)

Recomendaciones de experto sobre el bloqueo de la interleucina 6 en pacientes con artritis reumatoide

[Abstract] Objective: To draft recommendations on interleukin 6 (IL-6) blockade in rheumatoid arthritis (RA), based on best evidence and experience. Methods: A group of 10 experts on IL-6 blockade in RA was selected. The 2 coordinators formulated 23 questions about IL-6 blockade (indications, efficacy, safety, etc.). A systematic review was conducted to answer the questions. Using this information, inclusion and exclusion criteria were established, as were the search strategies (Medline, EMBASE and the Cochrane Library were searched). Two different reviewers selected the articles. Evidence tables were created. At the same time, European League Against Rheumatism and American College of Rheumatology abstracts were evaluated. Based on this evidence, the coordinators proposed preliminary recommendations that the experts discussed and voted on in a nominal group meeting. The level of evidence and grade of recommendation were established using the Oxford Centre for Evidence Based Medicine and the level of agreement with the Delphi technique (2 rounds). Agreement was established if at least 80% of the experts voted yes (yes/no). Results: The 8 preliminary recommendations were accepted after the Delphi process. They covered aspects such as the use of these therapies in monotherapy, in combination, in patients with refractory disease or intolerant patients, response evaluation, optimization and risk management. Conclusions: The manuscript aims to solve frequently asked questions and aid in decision making strategies when treating RA patients with IL-6 blockade.[Resumen] Objetivo. Generar recomendaciones sobre el bloqueo de la interleucina 6 (IL-6) en pacientes con artritis reumatoide (AR), basadas en la mejor evidencia y experiencia. Métodos. Se seleccionó a 10 expertos reumatólogos en el manejo de los inhibidores de la IL-6. Los 2 coordinadores generaron 23 preguntas sobre el bloqueo de la IL-6 en la AR (perfiles de indicación, eficacia, seguridad, etc.) para ser contestadas mediante una revisión sistemática de la literatura. Con base en las preguntas se definieron los criterios de inclusión y exclusión, y las estrategias de búsqueda (para interrogar Medline, Embase y la Cochrane Library). Dos revisores seleccionaron los artículos resultantes de la búsqueda. Se generaron tablas de evidencia. Paralelamente, se evaluaron abstracts de congresos de EULAR y ACR. Con toda esta evidencia los coordinadores propusieron 8 recomendaciones preliminares que se evaluaron, discutieron y votaron en una reunión de grupo nominal con el resto de los expertos. Para cada recomendación se estableció el nivel de evidencia y grado de recomendación, y el grado de acuerdo mediante un Delphi. Se definió acuerdo si al menos el 80% de los participantes contestaban sí a la recomendación (sí o no). Resultados. Las 8 recomendaciones preliminares se aceptaron tras el Delphi. Abarcan aspectos como su uso en monoterapia, en combinación, en pacientes refractarios o intolerantes, la evaluación de su respuesta, la optimización o la gestión del riesgo. Conclusiones. Este documento pretende resolver algunos interrogantes clínicos habituales y facilitar la toma de decisiones con el bloqueo de la IL-6 en el manejo de la AR