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Plant-microbiota interactions have significant effects on plant growth, health, and productivity. Rhizosphere microorganisms are involved in processes that promote physiological responses to biotic and abiotic stresses in plants. In recent years, the interest in microorganisms to improve plant productivity has increased, mainly aiming to find promising strains to overcome the impact of climate change on crops. In this work, we hypothesize that given the desertic environment of the Antarctic and the Atacama Desert, different plant species inhabiting these areas might share microbial taxa with functions associated with desiccation and drought stress tolerance. Therefore, in this study, we described and compared the composition of the rhizobacterial community associated with Deschampsia antarctica (Da), Colobanthus quitensis (Cq) from Antarctic territories, and Croton chilensis (Cc), Eulychnia iquiquensis (Ei) and Nicotiana solanifolia (Ns) from coastal Atacama Desert environments by using 16S rRNA amplicon sequencing. In addition, we evaluated the putative functions of that rhizobacterial community that are likely involved in nutrient acquisition and stress tolerance of these plants. Even though each plant microbial rhizosphere presents a unique taxonomic pattern of 3,019 different sequences, the distribution at the genus level showed a core microbiome with a higher abundance of Haliangium, Bryobacter, Bacillus, MND1 from the Nitrosomonadaceae family, and unclassified taxa from Gemmatiamonadaceae and Chitinophagaceae families in the rhizosphere of all samples analyzed (781 unique sequences). In addition, species Gemmatirosa kalamazoonesis and Solibacter usitatus were shared by the core microbiome of both Antarctic and Desert plants. All the taxa mentioned above had been previously associated with beneficial effects in plants. Also, this microbial core composition converged with the functional prediction related to survival under harsh conditions, including chemoheterotrophy, ureolysis, phototrophy, nitrogen fixation, and chitinolysis. Therefore, this study provides relevant information for the exploration of rhizospheric microorganisms from plants in extreme conditions of the Atacama Desert and Antarctic as promising plant growth-promoting rhizobacteria.

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In this work, copper (II) ions were saturated and copper oxide nanoparticles (CuO NPs) were supported in natural zeolite from Chile; this was achieved by making the adsorbent material come into contact with a copper ion precursor solution and using mechanical agitation, respectively. The kinetic and physicochemical process of the adsorption of copper ions in the zeolite was studied, as well as the effect of the addition of CuO NPs on the antibacterial properties. The results showed that the saturation of copper (II) ions in the zeolite is an efficient process, obtaining a 27 g L-1 concentration of copper ions in a time of 30 min. The TEM images showed that a good dispersion of the CuO NPs was obtained via mechanical stirring. The material effectively inhibited the growth of Gram-negative and Gram-positive bacteria that have shown resistance to methicillin and carbapenem. Furthermore, the zeolite saturated with copper at the same concentration had a better bactericidal effect than the zeolite supported with CuO NPs. The results suggested that the ease of processing and low cost of copper (II) ion-saturated zeolitic material could potentially be used for dental biomedical applications, either directly or as a bactericidal additive for 3D printing filaments.

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Cells of vertebrate and invertebrate organisms express proteins specialized in membrane channel-based cell-cell communication that are absent in unicellular organisms. We recently described the prediction of some members of the large-pore channel family in kinetoplastids, consisting of proteins called unnexins, which share several structural features with innexin and pannexin proteins. Here, we demonstrated that the unnexin1 protein (Unx1) is delivered to the cell membrane, displaying a topology consisting of four transmembrane domains with C and N termini on the cytoplasmic side and form large-pore channels that are permeable to small molecules. Low extracellular Ca2+/Mg2+ levels or extracellular alkalinization, but not mechanical stretching, increases channel activity. The Unx1 channel mediates the influx of Ca2+ and does not form intercellular dye coupling between HeLa Unx1 transfected cells. Unx1 channel function was further evidenced by its ability to mediate ionic currents when expressed in Xenopus oocytes. Downregulation of Unx1 mRNA with morpholine contains Trypanosoma cruzi invasion. Phylogenetic analysis revealed the presence of Unx1 homologs in other protozoan parasites, suggesting a conserved function for these channel parasites in other protists. Our data demonstrate that Unx1 forms large-pore membrane channels, which may serve as a diffusional pathway for ions and small molecules that are likely to be metabolic substrates or waste products, and signaling autocrine and paracrine molecules that could be involved in cell invasion. As morpholinos-induced downregulation of Unx1 reduces the infectivity of trypomastigotes, the Unx1 channels might be an attractive target for developing trypanocide drugs.

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Resumen La fibrosis epidural es un hallazgo clínico y radiológico el cual se encuentra relacionado directamente en su génesis con los procedimientos quirúrgicos realizados en la columna vertebral. Esta patología es la causa más frecuente del síndrome de cirugía fallida de columna, manifestada clínicamente como un dolor equiparable en severidad al presentado previo a la intervención quirúrgica realizada. La fibrosis epidural es parte del proceso de cicatrización usual de los tejidos circundantes de la columna vertebral, en otras palabras, es esperable que esta suceda, sin embargo, solo una mínima cantidad de las personas intervenidas desarrollan clínicamente la sintomatología. La importancia del análisis de esta patología radica en que estas valoraciones son ingresadas al Departamento de Medicina Legal por asunto de reagravación de alguna secuela ocasionada por algún evento traumático. Es imprescindible conocer a profundidad los diferentes aspectos etiológicos, fisiopatológicos, clínicos, radiológicos y terapéuticos que involucran esta patología vertebral, así como, el respectivo análisis médico legal en este tipo de casos, tomando en consideración todos los elementos de juicio que permitan relacionar este hallazgo con algún hecho denunciado. En el presente artículo se realizará un análisis médico legal de un caso de reagravación por fibrosis epidural valorado en el Departamento de Medicina Legal de Costa Rica, donde el peritado interpone una denuncia contra el ente asegurador al ser rechazada la posibilidad de reapertura del riesgo laboral presentado.

Abstract The epidural fibrosis is a clinical and radiological finding that is related with the surgical procedures performed on the spine. This pathology is the most frequent cause of failed back syndrome or post laminectomy syndrome, that is clinically manifested by an acute pain comparable in severity with the surgical intervention. Epidural fibrosis is part of the usual healing process of the surrounding tissues of the spine, in other words, it's to be expected as a result of this procedures, nevertheless, only a small number of people who have been intervened, actually develop the symptoms clinically. The importance of this pathology lies in the fact that these assessments are attended in the Legal Medicine Department due to the aggravation issues of any sequel caused by a traumatic event. It is essential to know such things as the etiology, pathophysiology, clinical manifestations, radiological findings, and the therapeutic aspects that involve this vertebral disease, as well as, the respective forensic analysis, in order to use all the elements of judgment that allows to relate what is documented with the denounced findings.

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In this work we propose a bone metastasis model using power law growth functions in order to describe the biochemical interactions between bone cells and cancer cells. Experimental studies indicate that bone remodeling cycles are different for human life stages: childhood, young adulthood, and adulthood. In order to include such differences in our study, we estimate the model parameter values for each human life stage via bifurcation analysis. Results reveal an intrinsic relationship between the active period of remodeling cycles and the proliferation of cancer cells. Subsequently, using optimal control theory we analyze a possible antigen receptor therapy as a new treatment for bone metastasis. Theoretical results such as existence of optimal solutions are proved. Numerical simulations for late stages of bone metastasis are presented and a discussion of our results is carried out.

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A phylogenomic and functional analysis of the first two Crenarchaeota MAGs belonging to El Tatio geysers fields in Chile is reported. A soil sample contiguous to a geothermal activity exposed lagoon of El Tatio was used for shotgun sequencing. Afterwards, contigs were binned into individual population-specific genomes data. A phylogenetic placement was carried out for both MAG 9-5TAT and MAG 47-5TAT. Then functional comparisons and metabolic reconstruction were carried out. Results showed that both MAG 9-5TAT and MAG 47-5TAT likely represent new species in the genus Thermoproteus and the genus Sulfolobus, respectively. These findings provide new insights into the phylogenetic and genomic diversity for archaea species that inhabit the El Tatio geysers field and expand the understanding of the Crenarchaeota phylum diversity.

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Recently, a family of nonlinear mathematical discrete systems to describe biological interactions was considered. Such interactions are modeled by power-law functions where the exponents involve regulation processes. Considering exponent values giving rise to hyperbolic equilibria, we show that the systems exhibit irregular behavior characterized by strange attractors. The systems are numerically analyzed for different parameter values. Depending on the initial conditions, the orbits of each system either diverge to infinity or approach a periodic orbit or a strange attractor. Such dynamical behavior is identified by their Lyapunov exponents and local dimension. Finally, an application to the biochemical process of bone remodeling is presented. The existence of deterministic chaos in this process reveals a possible explanation of reproducibility failure and variation of effects in clinical experiments.

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Resumen La valoración médico legal implica establecer un nexo de causalidad entre lo denunciado por los usuarios y los hallazgos encontrados clínica y radiológicamente, esto implica tener un conocimiento amplio de la biomecánica que permita interrelacionar de manera objetiva un mecanismo de trauma que se relacione en su génesis con el movimiento denunciado. En este artículo se realizará una revisión bibliográfica de la epicondilitis, tomando en consideración todos los aspectos de importancia médico legal.

Abstract The forensic evaluation implies establishing the causality between the story and the clinical and radiologic findings, this implies having a broad knowledge of biomechanics that allows an objective interrelation of a trauma mechanism. This article consists in a bibliographical revision about the etiopathogenesis of the epicondylitis and the interpretation of this patology in relation to medico legal analysis.

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The El Tatio Geyser Field (ETGF), located in Northern Chile, is the main geyser field in the southern hemisphere. Despite this, details of its microbial ecology are still unknown. Here, we briefly report on  the composition and predicted functions of the bacterial community in spouting pool sediments from the ETGF as revealed by high-throughput sequencing of 16S rRNA genes. Results of this analysis showed that while there were differences in richness and diversity between samples, bacterial communities were primarily dominated by the phyla Proteobacteria, followed Firmicutes, Bacteroidetes, Acidobacteria, and Chloroflexi. Analyses of predicted functional activity indicated that the functions were mostly attributed to chemoheterotrophy and aerobic chemoheterotrophy, followed by sulfur (respiration of sulfur compounds and sulfate) and nitrogen (nitrate reduction, respiration of nitrogen and nitrate) cycling. Taken together, our results suggest a high diversity in taxonomy and predictive functions of bacterial communities in sediments from spouting pools. This study provides fundamentally important  information on the structure and function  predictive functions of microbiota  communities in spouting pools. Moreover, since the ETGF is intensively visited and impacted by tens of thousands of tourists every year, our results can be used to help guide the design of sustainable conservation strategies.

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The Holostei group occupies a critical phylogenetic position as the sister group of the Teleostei. However, little is known about holostean pituitary anatomy or brain distribution of important reproductive neuropeptides, such as the gonadotropin-inhibitory hormone (GnIH). Thus, the present study set out to characterize the structure of the pituitary and to localize GnIH-immunoreactive cells in the brain of Atractosteus tropicus from the viewpoint of comparative neuroanatomy. Juveniles of both sexes were processed for general histology and immunohistochemistry. Based on the differences in cell organization, morphology, and staining properties, the neurohypophysis and three regions in the adenohypophysis were identified: the rostral and proximal pars distalis (PPD) and the pars intermedia. This last region was found to be innervated by the neurohypophysis. This organization, together with the presence of a saccus vasculosus, resembles the general teleost pituitary organization. A vast number of blood vessels were also recognized between the infundibulum floor of the hypothalamus and the PPD, evidencing the characteristic presence of a median eminence and a portal system. However, this well-developed pituitary portal system resembles that of tetrapods. As regards the immunohistochemical localization of GnIH, we found four GnIH-immunoreactive (GnIH-ir) populations in three hypothalamic nuclei (suprachiasmatic, retrotuberal, and tuberal nuclei) and one in the diencephalon (prethalamic nucleus), as well as a few scattered neurons throughout the olfactory bulbs, the telencephalon, and the intersection between them. GnIH-ir fibers showed a widespread distribution over almost all brain regions, suggesting that GnIH function is not restricted to reproduction only. In conclusion, the present study describes, for the first time, the pituitary of A. tropicus and the neuroanatomical localization of GnIH in a holostean fish that exhibits a similar distribution pattern to that of teleosts and other vertebrates, suggesting a high degree of phylogenetic conservation of this system.

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Resumen Las muertes súbitas se encuentran dentro de las indicaciones de autopsia médico legal de Costa Rica, según el Reglamento de Autopsias Hospitalarias y Médico Legales publicada el 12 de Marzo de 1987. Para establecer el criterio de muerte súbita debemos conocer inicialmente la definición médico legal, su importancia y la finalidad por la cual se realiza, ésta se define como toda muerte de origen no violento, la cual se desarrolla de manera rápida e inesperada, en una persona que no presentaba ninguna patología médica y por la cual era improbable su muerte; ahora bien estas muertes podrían presentar cierta posibilidad de haber sido provocadas por algún tipo de crimen, por esta razón, se debe descartar toda aquella causa de muerte de origen violento. Existen múltiples causas de muertes súbitas, sin embargo las cardíacas en definitiva son las más frecuentes, en este artículo se abordará las muertes súbitas cardiacas de causa no ateroesclerótica durante el ejercicio ya que ante el advenimiento de las nuevas políticas de prevención y promoción de la salud, al realizar deporte se han logrado identificar ciertas patologías cardíacas que en algunos de los casos se evidencian por medio de una muerte súbita, el médico legal es el encargado de esclarecer y brindarle a los familiares de la persona fallecida la causa precisa de su muerte y de esta manera determinar la manera de muerte desde un punto de vista médico legal.

Abstract The indications of forensic autopsy in relation to sudden deaths in Costa Rica, are according to the Regulation of Autopsies in Hospital or in Forensic Department, published on March 12, 1987. To establish the criteria of sudden death we must know mainly its forensic definition, the importance and the purpose for which it is carried out, it is defined as any non-violent, rapid and unexpected death, in a person who did not present any medical pathology and for which his death was unlikely; these deaths could be caused by some type of crime, the forensic is in relation to determinate all those causes of violent death. There are multiple causes of sudden deaths, however, the cardiac are the most frequent, in this article will be discussed cardiac pathologies that could cause a sudden death during the exercise. The forensic pathologist is the responsible for clarifying the precise cause of his death and determine the manner of death.

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RFamide peptides are expressed in the early stages of development in most vertebrates. Gonadotropin-inhibitory hormone (GnIH) belongs to the RFamide family, and its role in reproduction has been widely studied in adult vertebrates, ranging from fish to mammals. As only three reports evaluated GnIH during development, the aim of this study was to characterise the ontogeny of GnIH in a fish model, Cichlasoma dimerus. We detected the presence of two GnIH-immunoreactive (GnIH-ir) cell clusters with spatial and temporal differences. One cluster was observed by 3 days post-hatching (dph) in the nucleus olfacto-retinalis (NOR) and the other in the nucleus posterioris periventricularis by 14 dph. The number of GnIH-ir neurons increased in both nuclei, whereas their size increased only in the NOR from hatchling to juvenile stages. These changes occurred from the moment larvae started feeding exogenously and during development and differentiation of gonadal primordia. We showed by double-label immunofluorescence that only GnIH-ir neurons in the NOR co-expressed GnRH3 associated peptide. In addition, GnIH-ir fibre density increased in all brain regions from 5 dph. GnIH-ir fibres were also detected in the retina, optic tract and optic tectum, suggesting that GnIH acts as a neuromodulator of photoreception and the integration of different sensory modalities. Also, there were GnIH-ir fibres in the pituitary from 14 dph, which were in close association with somatotropes. Moreover, GnIH-ir fibres were observed in the saccus vasculosus from 30 dph, suggesting a potential role of GnIH in the modulation of its function. Finally, we found that gnih was expressed from 1 dph, and that the pattern of variation of its transcript levels was in accordance with that of cell number. Present results are the starting point for the study of new GnIH roles during development. This article is protected by copyright. All rights reserved.

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The current rectification displayed by solid-state p-n semiconductor diodes relies on the abundance of electrons and holes near the interface between the p-n junction. In analogy to this electronic device, we propose here the construction of a purely ionic liquid-state electric rectifying heterojunction displaying an excess of monovalent cations and anions near the interface between two immiscible solvents with different dielectric properties. This system does not need any physical membrane or material barrier to show preferential ion transfer but relies on the ionic solvation energy between the two immiscible solvents. We construct a simple device, based on an oil/water interface, displaying an asymmetric behavior of the electric current as a function of the polarity of an applied electric field. This device also exhibits a region of negative differential conductivity, analogous to that observed in brain and heart cells via voltage clamp techniques. Computer simulations and mean field theory calculations for a model of this system show that the application of an external electric field is able to control the bulk concentrations of the ionic species in the immiscible liquids in a manner that is asymmetric with respect to the polarity or direction of the applied electric field. These properties make possible to enhance or suppress selective ion transport at liquid-liquid interfaces with the application of an external electric field or electrostatic potential, mimicking the function of biological ion channels, thus creating opportunities for varied applications.

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BACKGROUND: Mexico is in the malaria pre-elimination phase; therefore, continuous assessment and understanding of the social and behavioural risk factors related to exposure to malaria are necessary to achieve the overall goal. The aim of this research was to investigate socio-economic backgrounds, attitudes and practices related with malaria in rural locations from the coastal plain of Chiapas. METHODS: In January 2012, 542 interviews were conducted to householders from 20 villages across the coastal plain of Chiapas. Questions were about housing conditions, protection from mosquito bites and general information of householders. Chi2 analyses were performed to see whether there was a dependence of those reported having malaria with their house conditions and their malaria preventive practices. Results were discussed and also compared statistically against those obtained 17 years ago from the same area. RESULTS: Most households had 2-5 people (73.6%), 91.6% of houses had 1-3 bedrooms. The physical structure of the houses consisted of walls mainly made of block or brick 72.3%, the floor made of cement 90.0%, while the roof made of zinc sheet 43.9%, and straw or palm 42.2%. A 23.1% of the interviewed completed elementary school and 16.6% was illiterate. A 9.9% of the residents reported at least one family member having had malaria. A 98.1% of families used some method to prevent mosquito bites; those using bed nets were 94.3%. Almost 72% of families bought products for mosquito protection. A total of 537 out of 542 families agreed with the indoor residual spraying (IRS) of insecticide and a frequency of application as often as every two months was preferred. CONCLUSION: Housing conditions and malaria preventive practices have improved in these rural areas in 17 years, which could be in favor of malaria elimination in this area. Information generated by this study could help in the decision making about whether to use insecticide as indoor residual spraying or to implement massive distribution of long-lasting impregnated bed nets, considering the number of bedrooms and the structure of houses in the region, which may lead to a more efficient vector control for the coastal plain of Chiapas.

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Commercial preparations of the Mexican herbal drug known as "miracle tea" (Packera candidissima and P. bellidifolia) have been profiled qualitatively by HPLC and GC-MS. Eremophilanes (3-7) were the major components found in the hexane-soluble fraction, while pyrrolizidine alkaloids (PAs) were identified in the alkaloid extracts. The content of free PAs and their N-oxides was determined for a total of 22 samples, and the results showed that the amount of these hepatotoxic compounds (0.0005-0.94% free PAs; 0.0004-0.55% N-oxides), through the presence of retrorsine (1) and senesionine (2) as the main constituents, may reach toxic levels. Hexane-soluble extracts from commercial presentations (dried whole plants) of both species afforded neoadenostylone (3), 6-(2-methylbutanoyloxy)-9-oxo-1-(10)-furanoeremophilene (4), and epineoadenostylone (5), in addition to methyl-4-hydroxyphenylacetate (8) and methyl-2-(1-hydroxy-4-oxocyclohexyl)acetate (9). Also, epicacalone (6) and the new compound 2ß-hydroxyneoadenostylone (7) were isolated from P. bellidifolia.

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Se seleccionaron 28 diferentes patologías del archivo de enseñanza y de la práctica diaria del Hospital Nacional de Niños de San José, Costa Rica, que estuvieran relacionados con procesos infecciosos, tumorales, diferentes síndromes, desordenes metabólicos y displasias óseas. Se agruparon por periodos de edad que van desde el recién nacido al adolescente para facilitar al radiólogo y al pediatra la orientación hacia las diferentes patologías óseas en relación directa con el desarrollo del niño. Se tabuló solo un padecimiento por periodo de edad, pues algunos por su evolución natural como la osteopetrosis, osteogénesis imperfecta, acondroplasia, etc., se repiten a diferentes edades.

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Synovial tissue is a highly specialized tissue that keeps the articular joint well lubricated, and at the same time provides nutrients to the articular surface. A joint needs a small amount of synovial fluid to work. Although the tissue structure is simple, its function is highly sophisticated. Because synovial tissue is the target of most autoimmune diseases, joints need to be understood in their entirety to create new treatments for such immunological disorders.

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We report a study on the DNA organization in Entamoeba histolytica using a ribosomal DNA probe. The rDNA genes were found forming mers which were separated in a typical ladder pattern by pulse field electrophoresis. DNA rosette structures were visualized through electron microscopy in DNA eluted from bands recognized by the ribosomal probe. The in situ hybridization experiments using a DNA probe suggested that the rDNA genes are portioned between the nucleus and a cytoplasmic structure. These findings provide new data on DNA organization in E. histolytica and open the question concerning the presence of a novel organelle in this eukaryotic parasite

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