Acute consequences of a unilateral VIIIth nerve transection on vestibulo-ocular and optokinetic reflexes in Xenopus laevis tadpoles

Loss of peripheral vestibular function provokes severe impairments of gaze and posture stabilization in humans and animals. However, relatively little is known about the extent of the instantaneous deficits. This is mostly due to the fact that in humans a spontaneous loss often goes unnoticed initially and targeted lesions in animals are performed under deep anesthesia, which prevents immediate evaluation of behavioral deficits. Here, we use isolated preparations of Xenopus laevis tadpoles with functionally intact vestibulo-ocular (VOR) and optokinetic reflexes (OKR) to evaluate the acute consequences of unilateral VIIIth nerve sections. Such in vitro preparations allow lesions to be performed in the absence of anesthetics with the advantage to instantly evaluate behavioral deficits. Eye movements, evoked by horizontal sinusoidal head/table rotation in darkness and in light, became reduced by 30% immediately after the lesion and were diminished by 50% at 1.5 h postlesion. In contrast, the sinusoidal horizontal OKR, evoked by large-field visual scene motion, remained unaltered instantaneously but was reduced by more than 50% from 1.5 h postlesion onwards. The further impairment of the VOR beyond the instantaneous effect, along with the delayed decrease of OKR performance, suggests that the immediate impact of the sensory loss is superseded by secondary consequences. These potentially involve homeostatic neuronal plasticity among shared VOR-OKR neuronal elements that are triggered by the ongoing asymmetric activity. Provided that this assumption is correct, a rehabilitative reduction of the vestibular asymmetry might restrict the extent of the secondary detrimental effect evoked by the principal peripheral impairment

Transcardial injection and vascular distribution of microalgae in Xenopus laevis as means to supply the brain with photosynthetic oxygen

Oxygen in vertebrates is generally provided through respiratory organs and blood vessels. This protocol describes transcardial injection, vascular distribution, and accumulation of phototrophic microalgae in the brain of Xenopus laevis tadpoles. Following tissue isolation, oxygen dynamics and neuronal activity are recorded in semi-intact whole-head preparations. Illumination of such microalgae-filled preparations triggers the photosynthetic production of oxygen in the brain that, under hypoxic conditions, rescues neuronal activity. This technology is potentially able to ameliorate consequences of hypoxia under pathological conditions. For complete details on the use and execution of this protocol, please refer to Özugur et al. (2021)

Formación universitaria humanismo y conocimiento

El libro está integrado por seis capítulos, los cuales representan el fruto de la investigación que desarrolla el Cuerpo Académico: “Estudios de la Universidad”, adscrito al Instituto de Estudios sobre la Universidad (IESU), de la Universidad Autónoma del Estado de México. El propósito de los siguientes trabajos es abrir una serie de caminos que permitan pensar el ser y quehacer de la universidad en el siglo XXI. Los temas resaltan la necesidad e importancia de pensar la educación universitaria en pos de una formación que le dé sentido a la existencia humana.La función social de las universidades se ancla en la base de una formación del ser humano tanto en su ser como en la ciencia y el conocimiento. Formar significa construir desde sí mismo y para los otros la condición de la humanidad. La universidad en ese sentido tiene la tarea de promover en el universitario las condiciones para la formación de la persona, desde todo tipo de conocimientos y saberes. El propósito de los siguientes trabajos es abrir una serie de caminos que permitan pensar el ser y quehacer de la universidad en el siglo XXI. Los temas resaltan la necesidad e importancia de pensar la educación universitaria en pos de una formación que le dé sentido a la existencia humana.UAE

Metallofluorescent Nanoparticles for Multimodal Applications

Herein, we describe the synthesis and application of cross-linked polystyrene-based dual-function nano- and microparticles containing both fluorescent tags and metals. Despite containing a single dye, these particles exhibit a characteristic dual-band fluorescence emission. Moreover, these particles can be combined with different metal ions to obtain hybrid metallofluorescent particles. We demonstrate that these particles are easily nanofected into living cells, allowing them to be used for effective fingerprinting in multimodal fluorescence-based and mass spectrometry-based flow cytometry experiments. Likewise, the in situ reductions of the metal ions enable other potential uses of the particles as heterogeneous catalysts

Informe sobre la producción científica de Costa Rica en revistas iberoamericanas de acceso abierto en redalyc.org, 2005-2011

Objetivo: Proporcionar información sobre el Perfil de Producción Científica de Costa Rica en revistas del acervo redalyc.org para el periodo 2005-2011, a fin de conocer cuáles son tanto las tendencias como el comportamiento de las estrategias de comunicación y de colaboración que registran los artículos producidos por los investigadores nacionales.Método: Se estudia la producción científica de 800 revistas iberoamericanas de acceso abierto durante 2005-2011, a partir de un modelo de análisis centrado en entidades de producción y comunicación, las cuales permiten generar un Perfil de Producción Científica según los indicadores de: Producción (P), Producción en Colaboración (PC) y Colaboración (C), aplicados a un núcleo de 145,515 artículos científicos que forman parte del acervo redalyc.org.Resultados: La producción de Costa Rica asciende a 2,201 artículos que corresponden a una aportación de 1.5% sobre el total analizado, de los cuales 16% fueron publicados en revistas del extranjero, Cabe destacar que poco más de la mitad de la Producción corresponde al área de ciencias sociales (53.5%), seguida de ciencias con 41.6%, así como de las artes y humanidades y del área multidisciplinaria con 4.7 y 0.2 por ciento respectivamente. En dicho contexto, las instituciones costarricenses con mayor aporte a la producción científica son la Universidad de Costa Rica, la Universidad Nacional y la Caja Costarricense del Seguro Social; mientras que 46.8% de los trabajos firmados por autores nacionales se han realizado en colaboración, principalmente interna de tipo institucional (58.7%), y donde la participación de autores extranjeros se vincula prioritariamente con Estados Unidos, México, España y Colombia, que en conjunto representan 62.3% de la producción de Costa Rica en colaboración con otros países

Development of Potent Cellular and Humoral Immune Responses in Long-Term Hemodialysis Patients After 1273-mRNA SARS-CoV-2 Vaccination

Long-term hemodialysis (HD) patients are considered vulnerable and at high-risk of developing severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) infection due to their immunocompromised condition. Since COVID-19 associated mortality rates are higher in HD patients, vaccination is critical to protect them. The response towards vaccination against COVID-19 in HD patients is still uncertain and, in particular the cellular immune response is not fully understood. We monitored the humoral and cellular immune responses by analysis of the serological responses and Spike-specific cellular immunity in COVID-19-recovered and naïve HD patients in a longitudinal study shortly after vaccination to determine the protective effects of 1273-mRNA vaccination against SARS-CoV-2 in these high-risk patients. In naïve HD patients, the cellular immune response measured by IL-2 and IFN-ɣ secretion needed a second vaccine dose to significantly increase, with a similar pattern for the humoral response. In contrast, COVID-19 recovered HD patients developed a potent and rapid cellular and humoral immune response after the first vaccine dose. Interestingly, when comparing COVID-19 recovered healthy volunteers (HV), previously vaccinated with BNT162b2 vaccine to HD patients vaccinated with 1273-mRNA, these exhibited a more robust immune response that is maintained longitudinally. Our results indicate that HD patients develop strong cellular and humoral immune responses to 1273-mRNA vaccination and argue in favor of personalized immune monitoring studies in HD patients, especially if COVID-19 pre-exposed, to adapt COVID-19 vaccination protocols for this immunocompromised population.Funding was obtained from Instituto de Salud Carlos III (ISCIII) RICORS program to RICORS2040 (RD21/0005/0001), FEDER funds; Acción Estratégica en Salud Intramural (AESI), Instituto de Salud Carlos III, grant number AESI PI21CIII_00022 to PP and Healthstar-plus -REACT-UE Grant through Segovia Arana Research Institute Puerta de Hierro Majadahonda-IDIPHIM. JO is a member of VACCELERATE (European Corona Vaccine Trial Accelerator Platform) Network, which aims to facilitate and accelerate the design and implementation of COVID-19 phase 2 and 3 vaccine trials. JO is a member of the INsTRuCT under the MSC grant agreement Nº860003 (Innovative Training in Myeloid Regulatory Cell Therapy) Consortium, a network of European scientists from academia and industry focused on developing innovative immunotherapies.S

Cancer stem cells from human glioblastoma resemble but do not mimic original tumors after in vitro passaging in serum-free media

Human gliomas harbour cancer stem cells (CSCs) that evolve along the course of the disease, forming highly heterogeneous subpopulations within the tumour mass. These cells possess self-renewal properties and appear to contribute to tumour initiation, metastasis and resistance to therapy. CSC cultures isolated from surgical samples are considered the best preclinical in vitro model for primary human gliomas. However, it is not yet well characterized to which extent their biological and functional properties change during in vitro passaging in the serum-free culture conditions. Here, we demonstrate that our CSC-enriched cultures harboured from one to several CSC clones from the human glioma sample. When xenotransplanted into mouse brain, these cells generated tumours that reproduced at least three different dissemination patterns found in original tumours. Along the passages in culture, CSCs displayed increased expression of stem cell markers, different ratios of chromosomal instability events, and a varied response to drug treatment. Our findings highlight the need for better characterization of CSC-enriched cultures in the context of their evolution in vitro, in order to uncover their full potential as preclinical models in the studies aimed at identifying molecular biomarkers and developing new therapeutic approaches of human gliomas.Peer reviewe

Detection of EGFR mutations with mutation-specific antibodies in stage IV non-small-cell lung cancer

<p>Abstract</p> <p>Background</p> <p>Immunohistochemistry (IHC) with mutation-specific antibodies may be an ancillary method of detecting EGFR mutations in lung cancer patients.</p> <p>Methods</p> <p>EGFR mutation status was analyzed by DNA assays, and compared with IHC results in five non-small-cell lung cancer (NSCLC) cell lines and tumor samples from 78 stage IV NSCLC patients.</p> <p>Results</p> <p>IHC correctly identified del 19 in the H1650 and PC9 cell lines, L858R in H1975, and wild-type EGFR in H460 and A549, as well as wild-type EGFR in tumor samples from 22 patients. IHC with the mAb against EGFR with del 19 was highly positive for the protein in all 17 patients with a 15-bp (ELREA) deletion in exon 19, whereas in patients with other deletions, IHC was weakly positive in 3 cases and negative in 9 cases. IHC with the mAb against the L858R mutation showed high positivity for the protein in 25/27 (93%) patients with exon 21 EGFR mutations (all with L858R) but did not identify the L861Q mutation in the remaining two patients.</p> <p>Conclusions</p> <p>IHC with mutation-specific mAbs against EGFR is a promising method for detecting EGFR mutations in NSCLC patients. However these mAbs should be validated with additional studies to clarify their possible role in routine clinical practice for screening EGFR mutations in NSCLC patients.</p