Ependimoma de fosa posterior en una embarazada: diagnóstico diferencial de una hiperémesis. Reporte de caso / Posterior fossa ependymoma in a pregnant woman: differential diagnosis of hyperemesis. Case report

Resumen ANTECEDENTES: Los tumores intracraneales se diagnostican con una frecuencia muy baja durante el embarazo. Entre los síntomas iniciales destacan: cefalea, náuseas y vómitos frecuentes que, a su vez, son característicos del embarazo, de ahí la necesidad de establecer un diagnóstico diferencial correcto. CASO CLÍNICO: Paciente primigesta, de 25 años, 11+4 semanas de embarazo, con un cuadro de vómitos, cefalea, vértigo e inestabilidad, de inicio subagudo en los últimos dos meses. Antecedentes de interés: cefalea de características tensionales en comparación con migraña crónica no estudiada previamente. Durante la exploración se advirtió enlentecimiento en el lenguaje, nistagmo evocado por la mirada de manera bilateral y dolor periocular izquierdo, junto con vómitos incoercibles que no cedían, pese a la dieta absoluta y administración pautada de metoclopramida y pantoprazol. La resonancia magnética nuclear cerebral con contraste mostró una masa tumoral centrada en el cuarto ventrículo. Con base en lo anterior se procedió a la craniectomía suboccipital con exéresis subtotal del tumor y diagnóstico anatomopatológico de ependimoma de fosa posterior grupo A. Se propuso, y la paciente aceptó, la interrupción del embarazo con el propósito de completar el tratamiento coadyuvante con radioterapia. La intervención quirúrgica le dejó importantes secuelas neurológicas que ameritaron un proceso de rehabilitación. CONCLUSIONES: El momento del diagnóstico es decisivo para indicar el tratamiento de las tumoraciones intracraneales, sobre todo si son de naturaleza maligna, puesto que habrá que establecer un equilibrio entre la salud de la madre y la viabilidad de la gestación. En tanto se trata de pacientes con una afección compleja, su atención médica debe ser multidisciplinaria para disminuir los riesgos para la madre y el feto.

Abstract BACKGROUND: Intracranial tumours are diagnosed very rarely during pregnancy. The initial symptoms include headache, nausea and frequent vomiting, which are characteristic of pregnancy, so a correct differential diagnosis is necessary. CLINICAL CASE: Primigravida patient, 25 years old, 11+4 weeks pregnant, with a history of vomiting, headache, dizziness and instability of subacute onset in the last two months. History of interest: tension-type headache compared with chronic migraine, not previously studied. On examination, slowed speech, bilateral gaze-evoked nystagmus and left periocular pain were noted, together with incoercive vomiting that did not resolve despite a strict diet and prescribed metoclopramide and pantoprazole. A contrast-enhanced MRI of the brain showed a tumour mass centred in the fourth ventricle. Based on the above, a suboccipital craniectomy was performed with subtotal excision of the tumour and anatomopathological diagnosis of group A posterior fossa ependymoma. The interruption of pregnancy was proposed and accepted by the patient to complete the adjuvant treatment with radiotherapy. The surgical intervention left her with significant neurological sequelae that merited rehabilitation. CONCLUSIONS: The time of diagnosis is crucial in the management of intracranial tumours, especially if they are malignant, as a balance must be struck between the health of the mother and the viability of the pregnancy. As these are patients with a complex condition, their medical care must be multidisciplinary in order to reduce the risks to the mother and foetus.

Towards the development of an epitope-focused vaccine for SARS-CoV-2.

The rapid spread of COVID-19 on all continents and the mortality induced by SARS-CoV-2 virus, the cause of the pandemic coronavirus disease 2019 (COVID-19) has motivated an unprecedented effort for vaccine development. Inactivated viruses as well as vaccines focused on the partial or total sequence of the Spike protein using different novel platforms such us RNA, DNA, proteins, and non-replicating viral vectors have been developed. The high global need for vaccines, now and in the future, and the emergence of new variants of concern still requires development of accessible vaccines that can be adapted according to the most prevalent variants in the respective regions. Here, we describe the immunogenic properties of a group of theoretically predicted RBD peptides to be used as the first step towards the development of an effective, safe and low-cost epitope-focused vaccine. One of the tested peptides named P5, proved to be safe and immunogenic. Subcutaneous administration of the peptide, formulated with alumina, induced high levels of specific IgG antibodies in mice and hamsters, as well as an increase of IFN-γ expression by CD8+ T cells in C57 and BALB/c mice upon in vitro stimulation with P5. Neutralizing titers of anti-P5 antibodies, however, were disappointingly low, a deficiency that we will attempt to resolve by the inclusion of additional immunogenic epitopes to P5. The safety and immunogenicity data reported in this study support the use of this peptide as a starting point for the design of an epitope restricted vaccine.

Gas Sensors Based on Porous Ceramic Bodies of MSnO3 Perovskites (M = Ba, Ca, Zn): Formation and Sensing Properties towards Ethanol, Acetone, and Toluene Vapours.

In this work, the gas-sensing functionality of porous ceramic bodies formed by the slip casting technique was studied using perovskite nanoparticles of an MSnO3 system (M = Ba, Ca, Zn) synthesized by a chemical route. The performance and reliability of the sensitive materials in the presence of different volatile organic compounds (acetone, ethanol, and toluene), and other gases (CO, H2 and NO2) were analysed. The ZnSnO3, BaSnO3, and CaSnO3 sensors showed sensitivities of 40, 16, and 8% ppm-1 towards acetone, ethanol, and toluene vapours, respectively. Good repeatability and selectivity were also observed for these gaseous analytes, as well as excellent stability for a period of 120 days. The shortest response times were recorded for the ZnSnO3 sensors (e.g., 4 s for 80 ppm acetone) with marked responses to low concentrations of acetone (1000 ppb). These results are attributed to the porosity of the sensitive materials, which favours the diffusion of gases, induces surface defects, and provides greater surface area and good sensitivity to acetone, as is seen in the case of ZnSnO3.

Association between preoperative serum lactate concentrate with tumor cell proliferative index in primary brain tumor.

BACKGROUND: Elevated preoperative lactate levels have been reported in patients admitted for resection of brain tumors. As histologic type and tumor grade have also been linked to lactate concentration, we hypothesized that preoperative lactate concentration in patients with brain tumors may be associated with tumor proliferation. We describe the relationship between preoperative plasma lactate levels, and the cell proliferation marker Ki-67 in brain tumor surgery. METHODS: In this cross-sectional study, records of patients who underwent craniotomy between June 2017 and February 2018 at our Hospital were reviewed to select glioma and meningioma cases in which lactate concentrations in plasma and degree of cell proliferation were registered. Bivariable and linear regression analyses were used to assess the association between lactate concentrations and the Ki-67 Index. RESULTS: Lactate concentrations in plasma and Ki-67 Index were available in 55 patients. Meningioma cases had a mean concentration of 1.2 (0.1) mmol/L compared to diffuse astrocytic and oligodendroglial tumors cases with 1.7 (0.1) mmol/L (P<0.01). Both variables had a low positive correlation in meningiomas (Spearman's r, 0.29; 95% CI, -0.10-0.61; P=0.13) and a high correlation in gliomas (Spearman's r, 0.64; 95% CI, 0.33-0.82; P<0.01). The pooled analysis showed a high correlation index (Spearman's r, 0.61; 95% CI, 0.40-0.76; P<0.01). A linear regression model showed that the Ki-67 Index explained 43% of the variation in lactate (P<0.01). CONCLUSIONS: Brain tumors with higher rates of cell proliferation have higher plasma lactate levels. In this scenario, lactate concentrations may not only reflect systemic perfusion.

Vacunas terapéuticas del virus del papiloma humano: revisión de la evidencia actual / Therapeutic vaccines of the human papilloma virus: current evidence review

Resumen: OBJETIVO: Evaluar la inmunogenicidad de los distintos tipos de vacunas terapéuticas y de su efecto en las lesiones causadas por el virus del papiloma humano (VPH) después de su aplicación. Además, analizar los estudios de seguridad y las perspectivas de las vacunas terapéuticas contra el VPH. METODOLOGÍA: Estudio retrospectivo efectuado mediante la búsqueda bibliográfica sistemática en la base de datos PubMed, sin restricción de fecha de publicación. Criterio de inclusión: ensayos clínicos aleatorizados (metanálisis y revisiones sistemáticas). Criterios de exclusión: ensayos clínicos en fase preclínica del desarrollo y publicaciones en idiomas distintos al inglés o español. RESULTADOS: Se seleccionaron 30 artículos publicados entre 2000 y 2020. Entre ellos, 5 ensayos clínicos aleatorizados con vacunas terapéuticas que ya han finalizado o aún están en estudio. Las 25 publicaciones restantes incluyen: metanálisis y revisiones sistemáticas de aspectos seleccionados con objetivos primarios y secundarios. CONCLUSIONES: Las vacunas terapéuticas contra VPH se encuentran en fase experimental; hasta ahora se han conseguido resultados prometedores con algunas de ellas. Si bien existen distintos tipos de vacunas terapéuticas, los mejores resultados se han conseguido con las basadas en ADN. Las vacunas VGX-3100 y TS, en fase III, han demostrado diferencias significativas en el aclaramiento viral y la regresión de las lesiones de alto grado en pacientes vacunadas. Una vacuna terapéutica efectiva tendría una repercusión inmediata en la morbilidad y mortalidad por lesiones asociadas al virus.

Abstract: OBJECTIVE: To assess the immunogenicity of different types of therapeutic vaccines and their effect on human papillomavirus (HPV) lesions after application. In addition, to analyze the safety studies and prospects of therapeutic HPV vaccines. METHODOLOGY: Retrospective study based on a systematic literature search of the PubMed database, with no publication date restrictions. Inclusion criteria: randomized clinical trials (meta-analyses and systematic reviews). Exclusion criteria: clinical trials in the pre-clinical phase of development and publications in languages other than English or Spanish. RESULTS: 30 articles published between 2000 and 2020 were selected. Among them, 5 randomized clinical trials with therapeutic vaccines that have already been completed or are still under study. The remaining 25 publications include: meta-analyses and systematic reviews of selected aspects with primary and secondary objectives. CONCLUSIONS: Therapeutic HPV vaccines are in the experimental phase; so far promising results have been achieved with some of them. Although different types of therapeutic vaccines exist, the best results have been achieved with DNA-based vaccines. The VGX-3100 and TS vaccines, in phase III, have demonstrated significant differences in viral clearance and regression of high-grade lesions in vaccinated patients. An effective therapeutic vaccine would have an immediate impact on morbidity and mortality from virus-associated lesions.

ZIF Nanocrystal-Based Surface Acoustic Wave (SAW) Electronic Nose to Detect Diabetes in Human Breath.

In the present work, a novel, portable and innovative eNose composed of a surface acoustic wave (SAW) sensor array based on zeolitic imidazolate frameworks, ZIF-8 and ZIF-67 nanocrystals (pure and combined with gold nanoparticles), as sensitive layers has been tested as a non-invasive system to detect different disease markers, such as acetone, ethanol and ammonia, related to the diagnosis and control of diabetes mellitus through exhaled breath. The sensors have been prepared by spin coating, achieving continuous sensitive layers at the surface of the SAW device. Low concentrations (5 ppm, 10 ppm and 25 ppm) of the marker analytes were measured, obtaining high sensitivities, good reproducibility, short time response and fast signal recovery.

Acoustic Sensors Based on Amino-Functionalized Nanoparticles to Detect Volatile Organic Solvents.

Love-wave gas sensors based on surface functionalized iron oxide nanoparticles has been developed in this research. Amino-terminated iron oxide nanoparticles were deposited, by a spin coating technique, onto the surface of Love-wave sensors, as a very reproducible gas-sensing layer. The gases tested were organic solvents, such as butanol, isopropanol, toluene and xylene, for a wide and low concentration range, obtaining great responses, fast response times of a few minutes (the time at which the device produced a signal change equal to 90%), good reproducibilities, and different responses for each detected solvent. The estimated limits of detection obtained have been very low for each detected compound, about 1 ppm for butanol, 12 ppm for isopropanol, 3 ppm for toluene and 0.5 ppm for xylene. Therefore, it is demonstrated that this type of acoustic wave sensor, with surface amino-functionalized nanoparticles, is a good alternative to those ones functionalized with metal nanoparticles, which result very expensive sensors to achieve worse results.

Anestesia para Neurocirugía Mínimamente Invasiva / Anesthesia for minimally invasive neurosurgery

Introduction: Advances in imaging, computing and optics have encouraged the application of minimally invasive surgical approach to a variety of neurosurgical procedures. The advantages include accurate localization of lesions usually inaccessible to conventional surgery, less trauma to healthy brain, blood vessels and nerves, shorter operating time, reduced blood loss, and early recovery and discharge. Nevertheless minimally invasive neurosurgical (MIN) procedures still have potential intra-and post-operative complications that can cause morbidity and mortality. Objectives: The aim of this study was to review and analyze published literature describing experiences in the anesthetic management of the most commonly performed MIN procedures. Materials and methods: Neurosurgical and neuroanesthesia literature (1990-2013) was reviewed and description of anesthetic technique/management and perioperative morbidity/mortality was reported. We also compared the different authors' experience with MIN procedures. Results: The neurosurgical literature dealing with MIN has expanded, but there are few references in relation to anesthetic management. Anesthesia goals remain the same: careful pre-operative assessment and planning, and meticulous cerebral hemodynamic control to ensure adequate cerebral perfusion pressure. The degree of postoperative care depends on local practice, patient factors and postoperative brain imaging.

Introducción: Los avances en la formación de imágenes, la computación y la óptica han alentado la aplicación del enfoque quirúrgico mínimamente invasivo a una variedad de procedimientos neuroquirúrgicos. Las ventajas incluyen la localización exacta de las lesiones generalmente inaccesibles a la cirugía convencional, menos trauma al cerebro sano, vasos sanguíneos y nervios, más corto el tiempo de funcionamiento, la reducción de la pérdida de sangre, la recuperación temprana y el alta. Sin embargo los procedimientos neuroquirúrgicos mínimamente invasivos (NMI) todavía tienen potencial complicaciones intra y post-operatorias que pueden causar morbilidad y mortalidad. Objetivos: El objetivo de este estudio fue revisar y analizar la literatura publicada que describe las experiencias en el manejo anestésico de los procedimientos más comúnmente realizados en NMI. Materiales y métodos: Literatura sobre neurocirugía y neuroanestesia (1990-2013). Revisión y descripción de la técnica anestésica/gestión y morbilidad perioperatoria/mortalidad notificada. Comparación de la experiencia de los diferentes autores en procedimientos de NMI. Resultados: La literatura sobre NMI se ha expandido, pero hay pocas referencias en relación con el manejo anestésico. Las metas anestésicas siguen siendo las mismas: la evaluación preoperatoria cuidadosa y la planificación, el meticuloso control de hemodinámica cerebral para asegurar la presión de perfusión cerebral adecuada. El grado de cuidado postoperatorio depende de la práctica local, factores del paciente y de imagen cerebral postoperatoria.

Food web of a toopical high mountain stream: effects of nutrient addition / Red trófica de un arroyo de montaña tropical: efectos de la adición de nutrientes

In order to define the effect of nutrient enrichment on trophic webs in an Andean mountain stream we performed an experiment using stable isotope ratios (δ15N and δ13C) to analyze different trophic compartments: 1) basal level: CPOM and biofilm; 2) primary consumers - macroinvertebrates: collector-gatherers (Heterelmis sp., Thraulodes sp. and Trichorythodes sp.), and collectorfilterers (Simulium sp.); 3) predators - fish (Oncorhynchus mykiss and Trichomycterus bogotensis). The average fractionation of nitrogen among the primary consumers with respect to CPOM was 4.7 ‰, and 1.7 ‰ with respect to biofilm. Predators incremented their δ15N signal by 5.9 % with respect to primary consumers. A depletion of δ15N was observed in Impact with respect to Control reach after fertilization in different compartments (biofilm, Heterelmis, Simulium andTricorythodes), while depletion was not significant for top predators. In most cases, the δ13C signal of biofilm overlapped with that of primary consumers, but a clear enrichment was observed with respect to CPOM. Macroinvertebrate gut contents showed fine detritus to be their most abundant food, and that in general there were no changes in diet as a consequence of nutrient enrichment. The only exception was Heterelmis, who increased its consumption in the Impact reach.

Con el fin de determinar el efecto del incremento de nutrientes sobre la red trófica de un río de montaña andino, se realizó un experimento en donde se analizaron las proporciones de isotopos estables (δ15N y δ13C) para analizar los siguientes compartimientos tróficos: 1) Nivel basal: CPMO y Biofilm; 2) Consumidores primarios - macroinvertebrados: colectores - recolectores (Heterelmis sp., Thraulodes sp., yTrichorythodes sp.) y colectores - filtradores (Simulium sp.); 3) Depredadores - peces (Oncorhynchus mykiss y Trichomycterus bogotensis). La fracción promedio de nitrógeno entre los consumidores primarios con respecto a CPOM fue de 4.7 ‰, y de 1.7 ‰ con respecto al biofilm. Los depredadores incrementaron en un 5.9 % la señal δ15N con respecto a los consumidores primarios. Después de la fertilización, se observó en diferentes compartimientos (biofilm, Heterelmis, Simulium yTricorythodes) del tramo impacto un agotamiento de δ15N con respecto al control, mientras que el agotamiento no fue significativo para los depredadores superiores. En la mayoría de los casos la señal δ13C del biofilm se sobrepuso con la de los consumidores primarios pero un claro enriquecimiento fue observado con respecto a CPOM. Los macroinvertebrados referidos fueron seleccionados para analizar su contenido estomacal y los resultados nos mostraron que el detritus fino es el alimento más abundante para los invertebrados, y únicamente, Heterelmis mostró, después de la adición de nutrientes, diferencias significativas en el detritus fino y el material vegetal entre el tramo control y el impactado.

Prevalencia del asma: encuesta en una población escolar de Coatzacoalcos, Veracruz, México / Asthma prevalence: investigation in students poblation in Coatzacoalcos, Veracruz, Mexico

En algunas áreas de la República Mexicana se han efectuado pocos estudios sobre prevalencia de asma, razón por la que el presente complementará los existentes y contribuirá al conocimiento de la prevalencia de esta enfermedad en la ciudad de Coatzacoalcos, Veracruz. La encuesta se realizó en 583 escolares de 6 a 12 años de edad (309 del sexo masculino y 274 del femenino). La encuesta abarcó al 5.8 por ciento de la población escolar de la localidad. El 34 por ciento reportó asma en algún momento de su vida; 44 por ciento bronquitis asmática y 20 por ciento tos crónica