Resumen Presentamos un modelo de equilibrio parcial de comercio entre dos países, doméstico y foráneo, con una empresa en cada país, que producen un bien homogéneo en un mercado segmentado con dumping recíproco. Ambos países establecen un subsidio cooperativo y no cooperativo para sus empresas. El surgimiento de un shock de miedo en el país doméstico, dado por la pandemia de Covid-19, cambia el equilibrio de mercado. Los resultados muestran que con políticas no cooperativas, los gobiernos establecen un subsidio a sus empresas. Sin embargo, el país con mayor participación de mercado establece un mayor subsidio. Con un shock de miedo, el bienestar se reduce en ambos países y el gobierno domestico responde disminuyendo el subsidio. Con la política cooperativa se establece un subsidio uniforme. Cuando el shock de miedo reduce el bienestar de ambos países, la respuesta óptima es aumentar el subsidio, de otra forma se rompe el acuerdo.

Abstract We present a partial equilibrium model of trade between two countries, domestic and foreign, with one firm in each country, producing a homogeneous good in a segmented market with reciprocal dumping. Both countries establish a cooperative and non-cooperative subsidy for their firms. The emergence of a fear shock in the home country, given by the Covid-19 pandemic, changes the market equilibrium. The results show that with non-cooperative policies, governments establish a subsidy to their firms. However, the country with higher market share sets a higher subsidy. With a fear shock, welfare is reduced in both countries and the domestic government responds by reducing the subsidy. With the cooperative policy, a uniform subsidy is set. When the fear shock reduces welfare in both countries, the optimal response is to increase the subsidy, otherwise the agreement breaks down.

Resumen: En el presente texto se explora cómo se debaten y consensan los diversos significados del patrimonio cultural en el caso de los vestigios arqueológicos de Teotihuacan, México. Con un enfoque cualitativo, a partir de observación y entrevistas se encontró evidencia empírica de que, a pesar de haber sido excluidos de su patrimonialización, los pobladores de San Martín de las Pirámides y San Juan Teotihuacan han resignificado los valores sobre la zona arqueológica y han incorporado algunos de esos aspectos como elementos de su identidad social y cultural. La zona arqueológica de Teotihuacan no significa ni representa lo mismo para todos, es decir, para los agentes externos y para las comunidades residentes en su alrededor. Se concluye que la construcción de la identidad comunitaria echa mano de ciertos elementos que se integran a la narrativa y la legitiman. Uno de los usos del patrimonio cultural es la afirmación y legitimación de la identidad.

Abstract: This text explores how the various meanings of cultural heritage are debated and agreed upon, based on reviewing the archaeological remains of Teotihuacan, México. With a qualitative approach, based on observation and interviews, we found empirical evidence that, despite their exclusion from being named cultural heritage sites, the inhabitants of San Martín de las Pirámides and San Juan Teotihuacan have resignified the values of the archaeological zone and incorporated some of those aspects as an element of their social and cultural identity. The Archaeological Zone of Teotihuacan does not mean or represent the same thing for everyone, that is, for external agents or for the communities around it. We concluded that the construction of community identity makes use of certain elements that are integrated into the narrative that legitimize it. One of the uses of cultural heritage is the affirmation and legitimation of identity.

Resumen Introducción La pandemia por COVID-19 ha generado transformaciones importantes en la sociedad. Para la educación superior, especialmente las instituciones y centros de atención médica con programas de formación de médicos especialistas, las medidas de confinamiento generaron retos importantes para la continuidad de los procesos de enseñanza-aprendizaje, a partir del diseño e implementación de nuevas estrategias para preservar la formación médica. Objetivo Analizar la percepción de los estudiantes de posgrado de un hospital de tercer nivel de atención, sobre las transformaciones de los procesos de enseñanza-aprendizaje en modalidad virtual, a partir de los cambios organizacionales que se implementaron durante la pandemia por la COVID-19. Método Estudio con diseño mixto, cuantitativo y cualitativo, que incluyó a 100 médicos especialistas en formación del Instituto Nacional de Cardiología “Ignacio Chávez” (INCICh). Se diseñó una encuesta con 151 reactivos, que fue aplicada a la muestra total. Además, se realizaron 10 entrevistas semiestructuradas a profundidad con 13 preguntas. Los datos cualitativos se analizaron con el programa MAXQDA versión 18 y los datos cuantitativos con el programa R versión 3.6.0. Resultados Se muestra un tipo de cambio radical-adaptativo, que se materializó con la emergencia de nuevas prácticas y formas de organización ligadas a las Tecnologías de la Información y Comunicación (TIC) en los procesos de enseñanza-aprendizaje. Conclusiones Derivado de la pandemia, la implementación de estrategias ligadas al uso de TIC permitió parcialmente la continuidad de los procesos formativos en los especialistas. Se generaron estrategias innovadoras de enseñanza-aprendizaje que permiten enriquecer los procesos educativos y organizacionales actuales y futuros.

Abstract Introduction The COVID-19 pandemic has generated important transformations in society. In higher education, especially in those institutions and tertiary care centers with training programs for medical specialists, the confinement measures generated significant challenges for the continuity of their internal processes and, particularly, in the teaching-teaching processes, and new strategies to preserve medical education were created. Objective To analyze the perception of graduate students about educational transformations based on the organizational changes that were implemented for virtual education during the COVID-19 pandemic in a tertiary care hospital. Method Study with a mixed, quantitative and qualitative design, which included 100 medical specialists in training from the National Institute of Cardiology "Ignacio Chávez". A survey with 151 items was developed, which was applied to the total sample. In addition, 10 in-depth semi-structured interviews with 13 questions were conducted. Qualitative data was analyzed through the MAXQDA version 18 program and quantitative data was analyzed using the R version 3.6.0 program. Results A type of radical-adaptive change is shown, which materialized with the emergence of new practices and forms of organization linked to Information and Communication Technologies (ICT) in the teaching-learning processes. Conclusions Due to the pandemic, the implementation of strategies linked to the use of ICT allowed the continuity of the training processes in the specialists. In addition, a type of learning will be presented that allows enriching educational processes, both pedagogical and organizational.

ABSTRACT Soil salinity is a factor affecting crop production and yield. An estimated 74% of agricultural soils are saline, a problem that could be aggravated due to climate change. Our goal was to determine the lethal dose 50 (LD50) of NaCl and ethyl methanesulfonate (EMS) in jalapeño pepper (Capsicum annuum L. cv. Jalapeño M.) for selecting putative salt-tolerant mutants. Root length was used as an indicator of the LD50 of NaCl in seedlings cultured for 35 days in MS medium containing 0 (without NaCl), 50, 100, 150, 200, or 250 mM NaCl and germination rate as an indicator of the LD50 of EMS in seeds exposed to 0% (without EMS), 0.01%, 0.1%, 0.25%, or 0.5% EMS for 3 and 6 h. We selected salt-tolerant seedlings after 35 days in medium with the determined LD50 of NaCl. Canonical and probit analyses to the LD50 of NaCl and EMS results and multinomial linear regression for germination and survival were applied. LD50 of NaCl (150 mM) and EMS (0.3%) were determined. Seed exposure to 0.5% EMS for 6 h reduced germination (67%) and seedling survival (18%). We obtained four putative salt-tolerant mutants by culturing in medium containing the LD50 of NaCl, two from seeds exposed for 6 h to 0.01 EMS, and one each from of the seeds treated with 0.1% or 0.5% EMS. The results show that it is possible to select putative salt-tolerant mutants of jalapeño pepper through mutagenesis with EMS and in vitro culture in media containing the LD50 of NaCl.

RESUMO A salinidade do solo é um factor que afeta a produção e o rendimento das culturas. Estima-se que 74% dos solos agrícolas são salinos, um problema que pode ser agravado devido às alterações climáticas. O objetivo deste trabalho foi determinar a dose letal 50 (LD50) de NaCl e metanossulfonato de etila (EMS) em pimenta jalapeño (Capsicum annuum L. cv. Jalapeño M.) para a seleção de mutantes putativos tolerantes ao sal. Foi utilizado o comprimento da raiz como indicador do LD50 de NaCl em plântulas cultivadas durante 35 dias em meio MS contendo 0 (sem NaCl), 50, 100, 150, 200, ou 250 mM de NaCl e a taxa de germinação como indicador do LD50 de EMS em sementes expostas a 0% (sem EMS), 0.01%, 0.1%, 0.25%, ou 0.5% EMS durante 3 e 6 h. Plântulas tolerantes ao sal após 35 dias em meio com o LD50 para NaCl foram selecionadas. Foram usadas análises canônicas e probit nos resultados de LD50 de NaCl e de EMS e regressão linear multinomial para germinação e sobrevivência. Foram determinados o LD50 de NaCl (150 mM) e EMS (0.3%). A exposição de sementes a 0.5% EMS por 6 h reduziu a germinação (67%) e sobrevivência das plântulas (18%). Quatro mutantes putativos tolerantes ao sal através de cultivos em meio contendo o LD50 de NaCl, dois de sementes expostas durante 6 h a 0.01 EMS, e um de cada uma das sementes tratadas com 0.1% ou 0.5% de EMS foram obtidos. Os resultados mostram que é possível selecionar mutantes putativos tolerantes de pimenta jalapeño ao sal por meio de mutagênese com EMS e cultura in vitro em meios contendo o LD50 de NaCl.

RESUMO Introdução: A urticária crônica é uma doença heterogênea delimitada da pele caracterizada pelo desenvolvimento de urticária ou urticária. Objetivo: Determinar as características clínicas e o tratamento farmacológico indicado em pacientes com diagnóstico de urticária crônica. Método: Estudo quantitativo, prospectivo, observacional e descritivo realizado em um universo de 48 pacientes com diagnóstico de urticária crônica, Hospital Militar Principal, Guiné-Bissau, 2018-2020. As variáveis foram mensuradas: idade, sexo, tipo de urticária, tempo de evolução, comorbidade e tratamento utilizado na primeira e última consulta registrada, bem como a atividade da doença. Resultados: A média de idade foi de 38,52 anos com predomínio do sexo feminino. O tempo médio de evolução da doença foi de 4,67 anos e 70,83% não apresentavam angioedema. A urticária crônica espontânea foi o tipo predominante. A ciproeptadina foi o tratamento mais indicado no início do tratamento e ao final do seguimento seu uso aumentou. O montelucaste foi a outra droga que aumentou seu uso ao final do seguimento. A atividade da doença foi reduzida com o tratamento para taxas reconhecidas como urticária crônica espontânea controlada. Conclusões: A urticária crônica na Guiné-Bissau tem prevalência e manifestações clínicas compatíveis com a relatada mundialmente, com esquemas de tratamento que podem ser modificados dependendo do início do uso de medicamentos recomendados como ciclosporina ou omalizumabe.

ABSTRACT Introduction: Chronic urticaria is a heterogeneous demarcated skin disease characterized by the development of wheals or hives. Objective: Determination of the clinical characteristics and the pharmacological treatment indicated in patients diagnosed with chronic urticaria. Method: A quantitative, prospective, observational and descriptive study was conducted in a total of 48 patients (the universe) diagnosed with chronic urticaria, Main Military Hospital, Guinea-Bissau, 2018-2020. The following variables were used: age, sex, type of urticaria, time of evolution, comorbidity and treatment used in the first and last recorded consultation, as well as disease activity. Results: The mean age was 38.52 years with a female predominance. The mean time of evolution of the disease was 4.67 years and 70.83% did not present angioedema. Chronic spontaneous urticaria was the predominant type. cyproheptadine was the treatment most indicated to be used at baseline and at the end of treatment follow-up its use increased. montelukast was the other drug that increased its use at the end of follow-up. With the treatment used disease activity was reduced up to rates recognized as controlled chronic spontaneous urticaria. Conclusions: Chronic urticaria in Guinea-Bissau has prevalence and clinical manifestations in line with those reported worldwide, with treatment regimens susceptible to modifications depending on the early use of recommended drugs such as cyclosporine or omalizumab.

RESUMEN Introducción: La urticaria crónica es una enfermedad heterogénea delimitada de la piel caracterizada por el desarrollo de ronchas o habones. Objetivo: Determinar las características clínicas y el tratamiento farmacológico indicado en pacientes con diagnóstico de urticaria crónica. Método: Se realizó un estudio cuantitativo, prospectivo, observacional y descriptivo en un universo de 48 pacientes con diagnóstico de urticaria crónica, Hospital Militar Principal, Guinea-Bisáu, 2018-2020. Se midieron las variables: edad, sexo, tipo de urticaria, tiempo de evolución, comorbilidad y tratamiento utilizado en la primera y última consulta registrada, así como la actividad de la enfermedad. Resultados: La edad media fue de 38,52 años con predomino del sexo femenino. El tiempo medio de evolución de la enfermedad fue de 4,67 años y el 70,83 % no presentó angioedema. La urticaria crónica espontánea fue el tipo predominante. La ciproheptadina fue el tratamiento más indicado al inicio del tratamiento y al término del seguimiento su uso se incrementó. El montelukast fue el otro medicamento que incremento su uso al término del seguimiento. La actividad de la enfermedad se redujo con el tratamiento a índices reconocidos como urticaria crónica espontánea controlada. Conclusiones: La urticaria crónica en Guinea-Bisáu tiene una prevalencia y manifestaciones clínicas acorde a lo reportado a nivel mundial con esquemas de tratamiento susceptibles de modificaciones según el inicio del uso de medicamentos recomendados como ciclosporina u omalizumab.

RESUMEN Este proyecto evalúa el riesgo de falla del suministro de agua para el sector agrícola en condiciones de cambio climático mediante la implementación de modelos hidrológicos que apoyan la toma de decisiones para satisfacer las demandas de consumo en tiempos de escasez. Este proyecto se desarrolló a través de una metodología que utiliza herramientas de modelado hidrológico como el software HydroBID y los modelos de gestión de recursos hídricos SIMGES y SIMRISK de AQUATOOL DSS. Las series de caudales para un escenario futuro se obtuvieron para diferentes escenarios de cambio climático a partir de un Modelo Climático Global (GCM) y el Experimento Regional Coordinado de Reducción del Clima (CORDEX) reduciendo la escala de los resultados de la escala global a la escala de cuenca utilizando un método estadístico basado en la teoría del caos. Estas proyecciones muestran que, en condiciones de cambio climático, el sector agrícola de la cuenca del Balsillas no sufrirá impactos significativos ya que podrá satisfacer la mayoría de los puntos de demanda.

ABSTRACT This project assesses the risk of water supply failure for the agricultural sector under climate change conditions by implementing hydrological models that support decision-making for satisfying consumptive demands in times of scarcity. This project was developed using hydrological modeling tools such as the HydroBID software and the SIMGES and SIMRISK water resource management models of AQUATOOL DSS. The flow series for a future scenario were obtained for different climate change scenarios from a Global Climate Model (GCM) and the Coordinated Regional Experiment on Climate Reduction (CORDEX) by downscaling the results from the global scale to basin-scale using a statistical method based on chaos theory. These projections show that under conditions of climate change, the agricultural sector of the Balsillas basin will not suffer significant impacts since they will be able to satisfy most demand points.

Resumen Objetivo: identificar el grado de integración de características de calidad inherentes a las revistas digitales para valorar la forma en cómo están aprovechando las actuales herramientas que facilitan el acceso y uso de información científica. Metodología: se seleccionan las ocho características digitales de la metodología del Catálogo 2.0 de Latindex y se comprueba su presencia en los sitios web institucionales de 195 revistas académicas editadas en México. Resultados: Las características que presentan menor ocurrencia son los servicios de interactividad con las personas lectoras, el uso de más de un formato de edición para la consulta de los textos completos, así como el establecimiento de políticas de preservación digital, todas ellas con menos del 50% de cumplimiento. Del grupo estudiado, 127 revistas (65%) integraron entre cinco y ocho características en sus sitios web. Conclusiones: Se percibe que las revistas del estudio cumplen de manera diferente en la integración de los criterios de calidad digital; asimismo, se hace evidente que la mayoría no aprovechan a cabalidad las herramientas y servicios digitales disponibles en el gestor OJS, el cual es utilizado por casi la totalidad de las revistas analizadas. Se evidencia que aún hay trabajo por realizar para fomentar la integración de un mayor número de herramientas digitales, particularmente en las revistas que integran un mínimo de ellas y que sin embargo son denominadas digitales a la par de aquellas que presentan una mayor adaptación digital.

Abstract Objective: to identify the degree of integration of quality characteristics inherent to digital journals in order to assess how they are taking advantage of the current tools that facilitate the access and use of scientific information. Methodology: Eight digital characteristics of the Latindex Catalog 2.0 methodology were selected and their presence was verified in the institutional websites of 195 journals edited in Mexico. Results: Characteristics with a lesser degree of presence are: interactivity services with readers, use of more than one editing format for full text consultation, as well as the establishing of digital preservation policies, all of them with a compliance of less than 50%. Of the studied group, 127 journals (65%) integrated between five and eight characteristics on their websites. Conclusions: The integration of the eight quality criteria inherent to digital journals is differentially met by the studied publications. Likewise, it became clear that the digital tools and services available in the OJS manager are not being fully exploited by most of the analyzed journals. One of the most important findings is that there is necessary to promote the integration of a greater number of the characteristics specific to digital journals, particularly in those that remain in a very basic level and that nevertheless are referred as digital on par with other journals that have a higher digital adaptation.

ABSTRACT Introduction: allergic rhinitis is a chronic, allergen-specific, inflammatory disease of the nasal mucosa, involving various cells. Objective: to determine the prevalence of allergic rhinitis and its risk factors in students in two regions of Guinea Bissau. Materials and methods: a quantitative, cross-sectional and analytic study was carried out in a universe of 2,008 students from 7th to 12th class, in the regions of Gabú y Bafatá, in Guinea Bissau, between 2019 and 2020. The Diagnostic Questionnaire of Allergic Rhinitis for Epidemiologic Studies and the Questionnaire to Identify the Risk Factors in Allergic Rhinitis were used. The study data proposed to be measured were drawn from the surveys. It was asked authorization from the authorities of the institutions. Results: the prevalence of allergic rhinitis was 17.77 %. The mean age was higher in Bafatá region (17.34 years), with female predominance in both regions (51.71 % vs. 51.97 %). Risk factors found in both regions-with a high level of statistical significance-were female sex (OR: 1.92 / 1.64), family history of disease (OR: 9.68 / 10.82), and history of recurrent upper respiratory disease (OR: 6.43 / 5.33). Factors like humidity were not found risky (OR: 0.71 / 0.93). Conclusions: allergic rhinitis is a common condition among the young population in Guinea Bissau. The family history of atopy and the personal history of recurrent upper respiratory disease resulted in a very high level of statistical significance.

RESUMEN Introducción: la rinitis alérgica es una enfermedad inflamatoria crónica de la mucosa nasal, alérgeno-específica, con participación de diversas células. Objetivo: determinar la prevalencia de rinitis alérgica y sus factores de riesgo en estudiantes en dos regiones de Guinea Bissau. Materiales y Métodos: se realizó un estudio cuantitativo, transversal y analítico en un universo de 2 008 estudiantes de 7ª a 12ª clase, en las regiones de Gabú y Bafatá, en Guinea Bissau, entre 2019 y 2020. Se utilizó el Cuestionario diagnóstico de rinitis alérgica para estudios epidemiológicos y el Cuestionario para identificar los factores de riesgo en rinitis alérgica. Los datos del estudio propuestos a medir fueron extraídos de las encuestas. Se solicitó autorización de las autoridades de las instituciones. Resultados: la prevalencia de rinitis alérgica fue del 17,77 %. La media de edad fue mayor en la región de Bafatá (17,34 años), con predominio del sexo femenino en ambas regiones (51,71 % vs. 51,97 %). Resultaron factores de riesgo en ambas regiones -con alto nivel de significación estadística- el sexo femenino (OR: 1,92 / 1,64), el antecedente familiar de la enfermedad (OR: 9,68 / 10,82) y el antecedente de enfermedad recurrente de vías respiratorias superiores (OR: 6,43 / 5,33). Factores como la humedad no resultaron de riesgo (OR: 0,71 / 0,93). Conclusiones: la rinitis alérgica es una condición frecuente en población joven en Guinea Bissau. El antecedente familiar de atopia y el antecedente personal de enfermedad recurrente de vías respiratorias superiores resultaron de un nivel de significación estadística muy alto.

ABSTRACT Introduction: safety during medical or surgical procedures is threatened by anaphylaxis. Objective: to evaluate the clinical characteristics, study method and eventual outcome of re-exposure in patients with anaphylactic and allergic reactions during medical or surgical procedures. Materials and methods: a quantitative, observational and descriptive study was carried out in 11 patients with a diagnosis of anaphylaxis in the course of a surgical intervention or medical procedure, in the Main Military Hospital and the National Hospital Simão Méndes, of Guinea Bissau between 2018 and 2020. The evaluated variables were: age, sex, procedure, anesthetic method, allergic history, severity of anaphylaxis and causal agent. Results: of the 11 patients studied, 10 had reactions in surgical procedures. The mean age was 46.09 years with a sex ratio of 0.57 male cases for each female case. Five patients (45.45 %) developed the maximum degree of anaphylaxis severity. Anesthetic agents were the cause of anaphylaxis in two of the four patients who underwent the general anesthesia method, and in two of the five who underwent the regional anesthesia method. Latex was found to be the causal agent in 45.45 % of the patients. Conclusions: the proper identification of anaphylactic reactions during their appearance is the cornerstone of medical action. In any case, subsequent allergo-anesthetic studies would be needed to define the causative agent.

RESUMEN Introducción: la seguridad durante los procedimientos médicos o quirúrgicos se ve amenazada por la anafilaxia. Objetivo: evaluar el cuadro clínico, método de estudio y eventual resultado de la reexposición en pacientes con reacciones anafilácticas y alérgicas durante procedimientos médicos o quirúrgicos. Materiales y métodos: se realizó un estudio cuantitativo, observacional y descriptivo en 11 pacientes con diagnóstico de anafilaxia en el curso de una intervención quirúrgica o proceder médico, en los hospitales Militar Principal y Nacional Simão Méndes, de Guinea Bissau, entre 2018 y 2020. Se evaluaron las variables: edad, sexo, procedimiento, método anestésico, antecedentes alérgicos, gravedad de la anafilaxia y agente causal. Resultados: de los 11 pacientes estudiados, 10 tuvieron reacciones en procedimientos quirúrgicos. La media de edad fue de 46,09 años, con una relación por sexo de 0,57 casos masculinos por cada caso femenino. Cinco pacientes (45,45 %) desarrollaron el grado máximo de severidad de la anafilaxia. Los agentes anestésicos fueron la causa de la anafilaxia en dos de los cuatro pacientes sometidos al método de anestesia general y en dos de los cinco sometidos al método de anestesia regional. Por su parte, el látex resultó ser el agente causal en el 45,45 % de los pacientes. Conclusiones: la apropiada identificación de las reacciones anafilácticas durante su aparición, constituye la piedra angular de la actuación médica. En cualquier caso, conllevará estudios alergoanestésicos posteriores que definan el agente causal.

Abstract INTRODUCTIONSARS-CoV-2 infection can produce endothelial injury and microvascular damage, one cause of the multiorgan failure associated with COVID-19. Cerebrovascular endothelial damage increases the risk of stroke in COVID-19 patients, which makes prompt diagnosis important. Endothelial dysfunction can be evaluated by using transcranial Doppler ultrasound to study cerebral hemodynamic reserve, but there are few of these studies in patients with COVID-19, and the technique is not included in COVID-19 action and follow-up guidelines nationally or internationally. OBJECTIVEEstimate baseline cerebral hemodynamic patterns, cerebral hemodynamic reserve, and breath-holding index in recovered COVID-19 patients. METHODWe conducted an exploratory study in 51 people; 27 men and 24 women 20–78 years of age, divided into two groups. One group comprised 25 recovered COVID-19 patients, following clinical and epidemiological discharge, who suffered differing degrees of disease severity, and who had no neurological symptoms or disease at the time they were incorporated into the study. The second group comprised 26 people who had not been diagnosed with COVID-19 and who tested negative by RT-PCR at the time of study enrollment. Recovered patients were further divided into two groups: those who had been asymptomatic or had mild disease, and those who had severe or critical disease. We performed transcranial Doppler ultrasounds to obtain baseline and post-apnea tests of cerebral hemodynamic patterns to evaluate cerebral hemodynamic reserve and breath-holding indices. We characterized the recovered patient group and the control group through simple descriptive statistics (means and standard deviations). RESULTSThere were no measurable differences in baseline cerebral hemodynamics between the groups. However, cerebral hemodynamic reserve and breath-holding index were lower in those who had COVID-19 than among control participants (19.9% vs. 36.8% and 0.7 vs. 1.2 respectively). These variables were similar for patients who had asymptomatic or mild disease (19.9% vs.19.8%) and for those who had severe or critical disease (0.7 vs. 0.7). CONCLUSIONSPatients recovered from SARS-CoV-2 infection showed decreased cerebral hemodynamic reserve and breath-holding index regardless of the disease’s clinical severity or presence of neurological symptoms. These abnormalities may be associated with endothelial damage caused by COVID-19. It would be useful to include transcranial Doppler ultrasound in evaluation and follow-up protocols for patients with COVID-19.

Abstract BACKGROUND: The clinical manifestations of ectopic pregnancies are variable and may be related to congenital factors, the age of the patient, previous ectopic pregnancies, among others. OBJECTIVE: To report the case of a cervical ectopic pregnancy that received successful conservative medical treatment. CLINICAL CASE: A 32-year-old patient, nulliparous, who came to the clinic due to vaginal bleeding and pain in the hypogastrium, of three hours of evolution. Physical examination reported: blood pressure 80-40 mmHg, heart rate 100 beats per minute, respiratory rate 22 breaths per minute, Glasgow 15-15; generalized mucocutaneous pallor and cryodiaphoresis. The blood count reported: hemoglobin 7.3 mg/dL; hematocrit of 22.6; leukocytes: 15,000; neutrophils: 90%; platelets: 255,000; blood classification: AB+, positive pregnancy test, and transvaginal ultrasound with a diagnostic impression of a mass in the cervical region, compatible with cervical pregnancy vs uterine myomatosis. With the ultrasound suspicion of ectopic pregnancy, the determination of the beta subunit of human chorionic gonadotropin (β-hCG) was requested, titrating it at 18,273 mUl/mL, which required a transfusion of two units of blood products, due to the hemoglobin concentration , optimizing her figures at 9.6 mg/dL, with stable vital signs and decreased vaginal bleeding. The diagnosis of cervical ectopic pregnancy was established. Treatment with tranexamic acid was started. Hemoglobin was within reference limits. The patient had a satisfactory evolution, with decreased bleeding, so conservative treatment was maintained. CONCLUSION: Conservative treatment is an effective protocol in the follow-up and control of patients with ectopic pregnancy, since it reduces the risk of mortality and hysterectomy, after establishing the timely diagnosis, with anamnesis, ultrasound and β-hCG concentrations for diagnostic suspicion.

Resumen ANTECEDENTES: Las manifestaciones clínicas del embarazo ectópico son variables y pueden relacionarse con factores congénitos, edad de la paciente, embarazos ectópicos previos, entre otros. OBJETIVO: Reportar el caso de una paciente con embarazo ectópico cervical que recibió tratamiento médico conservador. CASO CLÍNICO: Paciente de 32 años, nulípara, que acudió a consulta por sangrado vaginal y dolor en el hipogastrio, de tres horas de evolución. El examen físico reportó: presión arterial de 80-40 mmHg, frecuencia cardiaca de 100 latidos por minuto, frecuencia respiratoria de 22 respiraciones por minuto, Glasgow 15-15; palidez mucocutánea generalizada y criodiaforesis. El hemograma informó: hemoglobina de 7.3 mg/dL; hematocrito de 22.6; leucocitos: 15,000 neutrófilos: 90%; plaquetas: 255,000; hemoclasificación: AB+, prueba de embarazo positiva, y ecografía transvaginal con impresión diagnóstica de masa en la región cervical, compatible con embarazo cervical vs miomatosis uterina. Con la sospecha ecográfica de embarazo ectópico, se solicitó la determinación de la subunidad beta de gonadotropina coriónica humana (β-hCG), titulando en 18.273 mUl/mL, por lo que requirió trasfusión de dos unidades de hemoderivados, debido a la concentración de hemoglobina, optimizando sus cifras en 9.6 mg/dL, con signos vitales estables y disminución del sangrado vaginal. Se estableció el diagnóstico de embarazo ectópico cervical. Se inició tratamiento con ácido tranexámico. La hemoglobina estuvo en los límites de referencia. La paciente tuvo evolución satisfactoria, con disminución del sangrado, por lo que se mantuvo el tratamiento conservador. CONCLUSIÓN: El tratamiento conservador es un protocolo efectivo en el seguimiento y control de pacientes con embarazo ectópico, pues reduce el riesgo de mortalidad e histerectomía, después de establecer el diagnóstico oportuno, con anamnesis, ecografías y concentraciones de β-hCG por sospecha diagnóstica.

Resumen Se presenta un listado de especies acuáticas de 6 phyla (Platyhelminthes, Acanthocephala, Nematoda, Arthropoda, Mollusca, Chordata) muestreadas en la cuenca del río Lacantún, en la región conocida como “Selva Lacandona”, Chiapas, México. El listado representa 10 años de monitoreo (2010-2020) realizado en 13 estaciones permanentes ubicadas en una sección de 74 km del río Lacantún. Se registraron 236 especies, 220 (93.2%) nativas, 25 (10.6%) endémicas de la región y 16 (6.8%) introducidas. El número de especies por estación varió de 41 en el río Lacanjá a 112 en el río Tzendales. Se presentan 23 nuevos registros distribucionales y 123 nuevos registros de hospederos para platelmintos, acantocéfalos y nemátodos. El análisis del estatus de conservación muestra que la gran mayoría de las especies registradas carece de una evaluación. El incremento de especies registradas a través del tiempo muestra la importancia de los estudios de largo plazo. A pesar del deterioro de los ecosistemas acuáticos debido a altas tasas de deforestación en la región de Marqués de Comillas, la contaminación provocada por sistemas de producción agropecuarios no sustentables y la introducción de especies acuáticas invasoras, la mayor parte de las especies acuáticas estudiadas se ha mantenido en una condición saludable.

Abstract A list of aquatic species belonging to 6 phyla (Platyhelminthes, Acanthocephala, Nematoda, Arthropoda, Mollusca, Chordata) sampled in the basin of the Lacantún River, in the region known as “Selva Lacandona”, Chiapas, Mexico, is presented. The list represents a 10-year sampling program (2010-2020) conducted over a network of 13 permanent stations which covered a 74 km river section in the Lacantún River. A total of 236 species was registered, 220 (93.2%) are native, 25 (10.6%) endemic to the region and 16 (6.8%) introduced. The number of species per sampling station ranged from 41 in the Lacanjá River to 112 in the Lacantún River. Twenty-three new distribution records and 123 new host records for platyhelminths, acanthocephalans and nematodes are presented. The conservation status analysis shows that most of the recorded species lack a first assessment. The increment in the number of species recorded through time shows the importance of long-term studies. Despite the degradation of the aquatic ecosystems due to high deforestation rates in the Marqués de Comillas region, the pollution produced by the non-sustainable agricultural systems, and the introduction of invasive aquatic species, most of the studied aquatic species have maintained a healthy condition.

Abstract Antimicrobial resistance is a global public health problem. Root canal microbiota associated with apical periodontitis represents a well-known reservoir of antimicrobial resistance genes (ARGs). However, the effect of type 2 diabetes mellitus (T2DM) in this reservoir is unknown. This study aimed to establish if root canal microbiota associated with apical periodontitis in T2DM patients is an augmented reservoir by identifying the prevalence of nine common ARGs and comparing it with the prevalence in nondiabetic patients. Methodology This cross-sectional study included two groups: A T2DM group conformed of 20 patients with at least ten years of living with T2DM and a control group of 30 nondiabetic participants. Premolar or molar teeth with pulp necrosis and apical periodontitis were included. A sample was collected from each root canal before endodontic treatment. DNA was extracted, and ARGs were identified by polymerase chain reaction. Results tetW and tetM genes were the most frequent (93.3 and 91.6%, respectively), while ermA was the least frequent (8.3%) in the total population. The distribution of the ARGs was similar in both groups, but a significant difference (p<0.005) was present in ermB, ermC, cfxA, and tetQ genes, being more frequent in the T2DM group. A total of eighty percent of the T2DM patients presented a minimum of four ARGs, while 76.6% of the control group presented a maximum of three. Conclusions Root canal microbiota associated with apical periodontitis in T2DM patients carries more ARGs. Therefore, this pathological niche could be considered an augmented reservoir.

ABSTRACT Introduction: Hepatocellular carcinoma is a hypervascular tumor made up of abnormal blood vessels. It is the most frequent form of primary liver cancer. About 90 % of these tumors develop over a previous liver disease. An increase in vascular load due to portal hypertension leads to bleeding. Objective: To present a patient who underwent emergency exploratory laparotomy due to large hemoperitoneum secondary to an intratumoral rupture of a cirrhotic liver. Clinical case: A 66-year-old male patient with a pathological history of type 2 diabetes mellitus, benign prostatic hyperplasia, chronic alcoholism and liver cirrhosis. He came to emergency due to diffuse abdominal pain, as well as signs of acute hypovolemia. An emergency laparotomy was performed, confirming a large hemoperitoneum secondary to an intratumoral rupture. Blood content aspiration, electrocoagulation and compression by packing were performed, managing to control bleeding. He had a torpid evolution, dying 24 hours after the laparotomy. Conclusions: Hemoperitoneum secondary to rupture of a hepatocellular carcinoma is a rare, but fatal complication; therefore, its study is necessary to achieve a timely diagnosis and treatment.

RESUMEN Introducción: El carcinoma hepatocelular es un tumor hipervascular compuesto por vasos sanguíneos anormales, constituye la forma más frecuente de cáncer primario del hígado. Alrededor del 90 % de estos tumores se desarrollan sobre una enfermedad hepática previa. Un aumento en la carga vascular debido a la hipertensión portal conlleva a sangrado. Objetivo: Presentar un paciente a quien se le practicó laparotomía exploradora de urgencia por hemoperitoneo de gran cuantía secundario a una rotura intratumoral sobre un hígado cirrótico. Caso clínico: Paciente de 66 años de edad, con antecedentes patológicos de diabetes mellitus tipo 2, hiperplasia benigna de próstata, alcoholismo crónico y cirrosis hepática. Acudió al cuerpo de guardia por dolor abdominal difuso y signos de hipovolemia aguda. Se realizó laparotomía de urgencia y se constata hemoperitoneo de gran cuantía, secundario a una rotura intratumoral. Se le realizó aspiración de contenido hemático, electrocoagulación y compresión por empaquetamiento. Se controló el sangrado. El paciente tuvo una evolución tórpida y falleció 24 horas posteriores a la laparotomía. Conclusiones: El hemoperitoneo secundario a rotura de un carcinoma hepatocelular, es una complicación poco frecuente, pero fatal; por lo que se hace necesario su estudio para lograr un diagnóstico y tratamiento oportuno.

Resumen La miocarditis es una entidad causada principalmente por agentes virales. Etiologías menos frecuentes incluyen otros agentes infecciosos, enfermedades autoinmunes y tóxicos. La miocarditis fulminante es una complicación inusual con un curso rápidamente progresivo que resulta en insuficiencia cardiaca grave y shock cardiogénico. A continuación, se presenta el caso de un paciente joven, previamente sano, que debutó con un síndrome de Stokes-Adams al ingreso al servicio de urgencias y, posteriormente, su evolución clínica, que progresó a falla cardiaca aguda y shock cardiogénico. La confirmación diagnóstica de miocarditis fulminante se realizó por biopsia endomiocárdica. Fue necesario un monitoreo hemodinámico avanzado, asociado a manejo vasopresor e inotrópico, medidas de soporte ventilatorio mecánico e implante de un marcapasos definitivo con una evolución clínica satisfactoria.

Abstract Myocarditis is an entity caused mainly by viral agents. Less frequent etiologies include other infectious agents, autoimmune diseases and toxins. Fulminant myocarditis is an unusual complication with a rapid progressive course resulting in severe heart failure and cardiogenic shock. Continuing, we present the case of a previously healthy young patient who presented with Stokes Adams' syndrome upon admissions to the emergency department and whose clinical course subsequently progressed to acute heart failure and cardiogenic shock. Diagnostic confirmation of fulminant myocarditis was made by myocardial biopsy. Advanced hemodynamic monitoring, vasopressor and inotropic management and mechanical ventilatory support measures were needed with a satisfactory clinical outcome, though, requiring definitive bicameral pacing.