Manifestaciones gastrointestinales en el sindrome post covid agudo: Revisión de la literatura y su impacto en la actualidad

El síndrome post COVID-19 (o post COVID agudo) se caracteriza por la persistencia o prolongación de síntomas durante más de 4 semanas después de la infección inicial por SARS-CoV-2. La prevalencia del síndrome post COVID-19, va del 10% al 87% en los pacientes que tuvieron COVID-19. Este síndrome fue descartado inicialmente por muchos, pero ahora se la reconoce como una enfermedad multiorgánica, la cual refleja un desafío constante en la atención médica. Existen factores neuropsiquiátricos que, asociados a la inflamación del tubo digestivo y la activación del sistema nervioso entérico, son los mecanismos potenciales para el desarrollo del Trastorno de la Interacción Intestino Cerebro (DGBI) Post COVID agudo.Post-COVID-19 (or acute post-COVID) syndrome is characterized by the persistence or prolongation of symptoms for more than 4 weeks after the initial SARS-CoV-2 infection. The prevalence of post- COVID-19 syndrome ranges from 10% to 87% in patients who had COVID-19. This syndrome was initially dismissed by many, but is now recognized as a multiorgan disease, reflecting a constant challenge in medical care. There are neuropsychiatric factors that, associated with the inflammation of the digestive tract and the activation of the enteric nervous system, are the potential mechanisms for the development of acute Post-COVID Gut-Brain Interaction Disorder (GBID)

Thevenon positivo sin anemia, caso inusual en un paciente adulto mayor: tumor neuroendrocrino ILEAL

Los tumores neuroendocrinos (TNE) representan menos del 5% de las neoplasias del tracto gastrointestinal, con origen en células del sistema endocrino difuso. Clínicamente pueden pasar desapercibidas por muchos años, siendo diagnosticadas cuando la enfermedad ya está en un grado avanzado. Se presenta el caso de un paciente varón de 66 años asintomático quien, por un examen de sangre oculta en heces positivo sin anemia, es sometido a estudios endoscópicos, con hallazgo de una tumoración que prolapsa a través de la válvula ileocecal y que impide la intubación de íleon terminal. El paciente es transferido al servicio de cirugía oncológica, donde fue programado para cirugía curativa y actualmente está en controles hasta definir actitud terapéutica

Esofagitis herpética en un paciente inmunocompetente

Herpetic esophagitis usually occurs more frequently in immunosuppressed patients, however, it has also been documented in immunocompetent patients, although infrequently. In immunocompetent patients, it is usually due to primary infection by the herpes simplex virus, usually type 1. The clinical picture is usually acute in onset and is characterized by the triad of sore throat, retrosternal pain, and fever. Diagnosis is based on the findings of the upper gastrointestinal endoscopy and the taking of biopsies for the study of pathological anatomy and immunohistochemistry. The course is usually benign and early initiation of antiviral treatment allows rapid disappearance of symptoms and limits the severity of the infection.La esofagitis herpética usualmente ocurre con mayor frecuencia en pacientes inmunodeprimidos, sin embargo, también ha sido documentada en pacientes inmunocompetentes, aunque de manera infrecuente. En pacientes inmunocompetentes suele deberse a la primoinfección por el virus del herpes simple, usualmente el tipo 1. El cuadro clínico suele ser de inicio agudo y estar caracterizado por la tríada de odinofagia, dolor retroesternal y fiebre. El diagnóstico se basa en los hallazgos de la videoendoscopia digestiva alta y en la toma de biopsias para el estudio de anatomía patológica e inmunohistoquímica. El curso usualmente es benigno y el inicio del tratamiento antiviral de manera precoz permite lograr la rápida desaparición de los síntomas y limitar la severidad de la infección

Effects of Ascent to High Altitude on Human Antimycobacterial Immunity

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Lasers, stem cells, and COPD

The medical use of low level laser (LLL) irradiation has been occurring for decades, primarily in the area of tissue healing and inflammatory conditions. Despite little mechanistic knowledge, the concept of a non-invasive, non-thermal intervention that has the potential to modulate regenerative processes is worthy of attention when searching for novel methods of augmenting stem cell-based therapies. Here we discuss the use of LLL irradiation as a "photoceutical" for enhancing production of stem cell growth/chemoattractant factors, stimulation of angiogenesis, and directly augmenting proliferation of stem cells. The combination of LLL together with allogeneic and autologous stem cells, as well as post-mobilization directing of stem cells will be discussed

Senda Darwin Biological Station: Long-term ecological research at the interface between science and society

Indexación: Web of Science; Scielo.La Estación Biológica Senda Darwin (EBSD) constituye un centro de investigación inmerso en el paisaje rural del norte de la Isla de Chiloé (42º S), donde fragmentos del bosque siempreverde original coexisten con praderas de uso ganadero, turberas de Sphagnum, matorrales sucesionales, plantaciones de Eucalyptus y otras formaciones de origen antropogénico. Desde 1994 hemos realizado estudios de largo plazo centrados en algunas especies de plantas (e.g., Pilgerodendron uviferum D. Don) y animales (e.g., Aphrastura spinicauda Gmelin, Dromiciops gliroides [Thomas]) catalogados como amenazados o escasamente conocidos y en ecosistemas nativos de importancia regional y global (e.g., turberas de Sphagnum, bosque Valdiviano y Nordpatagónico). Las investigaciones han considerado las respuestas de las especies y de los ecosistemas frente al cambio antropogénico del paisaje y cambio climático, así como los efectos de diferentes formas de manejo. Este escenario es semejante al de otras regiones de Chile y Latinoamérica lo que da generalidad a nuestros resultados y modelos. En este período, investigadores asociados a la EBSD han producido más de un centenar de publicaciones en revistas nacionales e internacionales y 30 tesis de pre y postgrado. Entendiendo el papel clave de los seres humanos en los procesos ecológicos de la zona rural, la EBSD ha desarrollado un programa de educación ecológica y vinculación del avance científico con la sociedad local y nacional. La integración de la EBSD a la naciente red de Sitios de Estudios Socio-Ecológicos de Largo Plazo en Chile consolidará y fortalecerá la investigación básica y aplicada que realizamos para proyectarla hacia la siguiente década.Senda Darwin Biological Station (SDBS) is a field research center immersed in the rural landscape of northern Chiloé island (42º S), where remnant patches of the original evergreen forests coexist with open pastures, secondary successional shrublands, Sphagnum bogs, Eucalyptus plantations and other anthropogenic cover types, constituting an agricultural frontier similar to other regions in Chile and Latin America. Since 1994, we have conducted long-term research on selected species of plants (e.g., Pilgerodendron uviferum) and animals (e.g., Aphrastura spinicauda, Dromiciops glirioides) that are considered threatened, poorly known or important for their ecological functions in local ecosystems, and on ecosystems of regional and global relevance (e.g., Sphagnum bogs, North Patagonian and Valdivian rain forests). Research has assessed the responses of species and ecosystems to anthropogenic land-use change, climate change, and the impact of management. During this period, more than 100 scientific publications in national and international journals, and 30 theses (graduate and undergraduate) have been produced by scientists and students associated with SDBS. Because of our understanding of the key role that humans play in ecological processes at this agricultural frontier, since the establishment of SDBS we have been committed to creative research on the communication of science to society and ecological education. The integration of SDBS to the nascent Chilean network of long-term socio-ecological research will consolidate and strengthen basic and applied research to project our work into the next decade.http://ref.scielo.org/vbm4r

Stability mechanisms of a thermophilic laccase probed by molecular dynamics.

Laccases are highly stable, industrially important enzymes capable of oxidizing a large range of substrates. Causes for their stability are, as for other proteins, poorly understood. In this work, multiple-seed molecular dynamics (MD) was applied to a Trametes versicolor laccase in response to variable ionic strengths, temperatures, and glycosylation status. Near-physiological conditions provided excellent agreement with the crystal structure (average RMSD ∼0.92 Å) and residual agreement with experimental B-factors. The persistence of backbone hydrogen bonds was identified as a key descriptor of structural response to environment, whereas solvent-accessibility, radius of gyration, and fluctuations were only locally relevant. Backbone hydrogen bonds decreased systematically with temperature in all simulations (∼9 per 50 K), probing structural changes associated with enthalpy-entropy compensation. Approaching T opt (∼350 K) from 300 K, this change correlated with a beginning "unzipping" of critical β-sheets. 0 M ionic strength triggered partial denucleation of the C-terminal (known experimentally to be sensitive) at 400 K, suggesting a general salt stabilization effect. In contrast, F(-) (but not Cl(-)) specifically impaired secondary structure by formation of strong hydrogen bonds with backbone NH, providing a mechanism for experimentally observed small anion destabilization, potentially remedied by site-directed mutagenesis at critical intrusion sites. N-glycosylation was found to support structural integrity by increasing persistent backbone hydrogen bonds by ∼4 across simulations, mainly via prevention of F(-) intrusion. Hydrogen-bond loss in distinct loop regions and ends of critical β-sheets suggest potential strategies for laboratory optimization of these industrially important enzymes

A Cell Cycle Role for the Epigenetic Factor CTCF-L/BORIS

CTCF is a ubiquitous epigenetic regulator that has been proposed as a master keeper of chromatin organisation. CTCF-like, or BORIS, is thought to antagonise CTCF and has been found in normal testis, ovary and a large variety of tumour cells. The cellular function of BORIS remains intriguing although it might be involved in developmental reprogramming of gene expression patterns. We here unravel the expression of CTCF and BORIS proteins throughout human epidermis. While CTCF is widely distributed within the nucleus, BORIS is confined to the nucleolus and other euchromatin domains. Nascent RNA experiments in primary keratinocytes revealed that endogenous BORIS is present in active transcription sites. Interestingly, BORIS also localises to interphase centrosomes suggesting a role in the cell cycle. Blocking the cell cycle at S phase or mitosis, or causing DNA damage, produced a striking accumulation of BORIS. Consistently, ectopic expression of wild type or GFP- BORIS provoked a higher rate of S phase cells as well as genomic instability by mitosis failure. Furthermore, downregulation of endogenous BORIS by specific shRNAs inhibited both RNA transcription and cell cycle progression. The results altogether suggest a role for BORIS in coordinating S phase events with mitosis