Search

La alergia es una reacción de hipersensibilidad activada por mecanismos inmunitarios específicos mediados por células o anticuerpos. Las alergias han aumentado en los países industrializados durante las últimas décadas. El aumento de las enfermedades respiratorias alérgicas, como la rinitis alérgica (RA) y el asma alérgica (AA), es una amenaza potencial para la salud pública. Se realizaron búsquedas en PubMed, Google Scholar y Medline utilizando los siguientes términos clave: allergic rhinitis OR asthma AND probiotics, allergic airway inflammation AND immune disorders, probiotics OR gut microbiota AND allergic disease, probiotics AND inflammatory. Se incluyeron estudios de todos los años, específicamente aquellos publicados en los últimos diez años. Se buscó en algunos artículos de revisión y en su lista de referencias para identificar artículos relacionados. El papel de la microbiota en las enfermedades alérgicas respiratorias ha atraído cada vez más atención. Algunas pruebas sugieren que el desarrollo de las enfermedades alérgicas provoca un desequilibrio en la composición de la microbiota intestinal. En comparación con ratones colonizados, los ratones sin gérmenes presentan respuestas alérgicas exageradas en las vías respiratorias, lo que indica que las interacciones microbianas con el huésped tienen un papel importante en el desarrollo de las enfermedades alérgicas. Los probióticos modulan tanto la respuesta inmune innata como la adaptativa, y a menudo se emplean como suplementos dietéticos que aportan beneficios a la salud en los trastornos gastrointestinales. Los probióticos pueden actuar como inmunomoduladores y activadores de las vías de defensa del huésped. Asimismo, los probióticos orales pueden modular la respuesta inmune en el sistema respiratorio. Estudios recientes en humanos y animales han demostrado el papel de los probióticos en la RA y la AA. Para entender la caracterización de la microbiota y el efecto potencial de los probióticos en la AA/AR, esta revisión ofrece un panorama de las características clínicas de la AA y la RA y del uso de probióticos para la prevención y el tratamiento de la RA, los cambios en la microbiota intestinal y sus mecanismos de acción.

This study investigated the protective effects of sodium alginate (SA) on the gut microbiota, immunity, and intestinal mucosal barrier function in cyclophosphamide-induced immunosuppressed BALB/c mice. SA alleviated spleen tissue damage and restored impaired immune functions, such as increasing the immune organ index, decreasing splenic T lymphocytes, and markedly increasing the secretion of serum immunoglobulins and cytokines in immunosuppressed mice. In addition, SA reversed the intestinal mucosal injury and increased the intestinal permeability by upregulating the expression of tight junction proteins. Moreover, SA decreased gut inflammation by reducing serum d-lactic acid (D-LA) and lipopolysaccharide (LPS) concentrations and downregulating toll-like receptor 4 (Tlr4) and mitogen-activated protein kinase (Mapk) pathway expression. Furthermore, SA significantly increased the abundance of beneficial bacteria (Lactobacillus, Roseburia, and Lachnospiraceae NK4A136) and decreased pathogenic bacteria (Helicobacter, Peptococcus, and Tyzzerella) in the intestine as determined by 16S rRNA gene high-throughput sequencing. In conclusion, our study provides a scientific basis for SA as a functional food in modulating gut microbiota and protecting against intestinal mucosal injury and indicates that SA has potential application for enhancing immunity.

We present 10‐year continuous seismic velocity changes from 2007 to 2017 around the Longmenshan fault zone, where the 2008 Mw7.9 Wenchuan earthquake and the 2013 Mw6.6 Lushan earthquake occurred. We collected continuous waveforms recorded by 20 broadband stations covering the entire Longmenshan fault zone and used three‐component ambient noise correlation techniques to measure the velocity changes in four different period bands. Our results show that a significant drop, 0.04–0.06%, occurred in the coseismic velocity at the time of the Wenchuan earthquake, near the rupture zone for the period bands of 1–3 and 3–8 s. In addition, only one fourth of the coseismic velocity drop has been recovered 9 years after the earthquake. We also observed a subtle velocity drop, 0.0066%, delayed by ~100 days relative to the time of the mainshock in the period bands of 6–15 s. In the source region of the Lushan earthquake, we detected a weak but reliable coseismic velocity change of ~0.01% in the period band of 1–3 s. The physical mechanism of the seismic velocity change could involve the damage in the shallow subsurface layer (<3 km), the damage in the fault zone at depth (~10 km), and the postseismic slip along the deep rupture zone up to ~20 km. The uncommonly slow postseismic velocity recovery indicates the slow healing of the Longmenshan fault zone after the Wenchuan earthquake, which may be associated with the low rate of stress loading onto the fault zone. The 2008 Wenchuan earthquake caused velocity changes in the fault zone at depth (~20 km)An uncommonly slow postseismic velocity recovery was observed, probably implying a slow healing of the Longmenshan fault zoneA weak but reliable coseismic velocity change of ~0.01% was detected related to the 2013 Lushan earthquake

Passive image interferometry (PII) is becoming a powerful tool for detecting the temporal variations in the Earth’s structure, which applies coda wave interferometry to the waveforms from the cross-correlation of seismic ambient noise. There are four techniques for estimating temporal change of seismic velocity with PII: moving-window cross-correlation technique (MWCCT), moving-window cross-spectrum technique (MWCST), stretching technique (ST) and moving-window stretching technique (MWST). In this paper, we use the continuous seismic records from a typical station pair near the Wenchuan MS8.0 earthquake fault zone and generate three sets of waveforms by stacking cross-correlation function of ambient noise with different numbers of days, and then apply four techniques to processing the three sets of waveforms and compare their results. Our results indicate that the techniques based on moving-window (MWCCT, MWCST and MWST) are superior in detecting the change of seismic velocity, and the MWCST can give a better estimate of velocity change than the other moving-window techniques due to measurement error. We also investigate the clock errors and their influences on measuring velocity change. We find that when the clock errors are not very large, they have limited impact on the estimate of the velocity change with the moving-window techniques.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.