Background-Open-label oral immunotherapy (OIT) protocols have been used to treat small numbers of patients with peanut allergy. Peanut OIT has not been evaluated in double-blind, placebo-controlled trials.
BackgroundProlonged exposure to hyperoxia in neonates can cause hyperoxic acute lung injury (HALI), which is characterized by increased pulmonary permeability and diffuse infiltration of various inflammatory cells. Disruption of the epithelial barrier may lead to altered pulmonary permeability and maintenance of barrier properties requires intact epithelial tight junctions (TJs). However, in neonatal animals, relatively little is known about how the TJ proteins are expressed in the pulmonary epithelium, including whether expression of TJ proteins is regulated in response to hyperoxia exposure. This study determines whether changes in tight junctions play an important role in disruption of the pulmonary epithelial barrier during hyperoxic acute lung injury.MethodsNewborn rats, randomly divided into two groups, were exposed to hyperoxia (95% oxygen) or normoxia for 1–7 days, and the severity of lung injury was assessed; location and expression of key tight junction protein occludin and ZO-1 were examined by immunofluorescence staining and immunobloting; messenger RNA in lung tissue was studied by RT-PCR; transmission electron microscopy study was performed for the detection of tight junction morphology.ResultsWe found that different durations of hyperoxia exposure caused different degrees of lung injury in newborn rats. Treatment with hyperoxia for prolonged duration contributed to more serious lung injury, which was characterized by increased wet-to-dry ratio, extravascular lung water content, and bronchoalveolar lavage fluid (BALF):serum FD4 ratio. Transmission electron microscopy study demonstrated that hyperoxia destroyed the structure of tight junctions and prolonged hyperoxia exposure, enhancing the structure destruction. The results were compatible with pathohistologic findings. We found that hyperoxia markedly disrupted the membrane localization and downregulated the cytoplasm expression of the key tight junction proteins occludin and ZO-1 in the alveolar epithelium by immunofluorescence. The changes of messenger RNA and protein expression of occludin and ZO-1 in lung tissue detected by RT-PCR and immunoblotting were consistent with the degree of lung injury.ConclusionsThese data suggest that the disruption of the pulmonary epithelial barrier induced by hyperoxia is, at least in part, due to massive deterioration in the expression and localization of key TJ proteins.
Peanut OIT leads to decreases in pro-allergic cytokines, including IL-5, IL-13, and IL-9 and decreased basophil activation. No differences in T cell or basophil responses were found between subjects on low or high-dose maintenance OIT, which has implications for clinical dosing strategies.
[1] The focus of this paper is to study the relationship between sporadic Fe (Fe s ) and Na (Na s ) layers through simultaneous and common volume Fe and Na lidar observations. A total of 37 sporadic layering events were identified from one year (195 hours) of observations at Wuhan (30.5°N, 114.4°E), China. Out of the 37 events, 23 (62%) are characterized by the simultaneous formation of Fe s and Na s layers. The most prominent feature for each of the 23 events is that the Fe s and Na s layers occurred in overlapping altitude ranges and moved following almost the same track. On occasion the Fe s and Na s layers exactly simultaneously reached their maximum peak densities at nearly the same altitude. These observational results strongly suggest that Fe s and Na s layers are formed via the same or very similar mechanisms. This conclusion contradicts the previous suggestion based on those independent observations of Fe s and Na s layers, that the Fe s and Na s layers may be formed via different mechanisms. Out of the 37 events, 14 (38%) belong to single-species sporadic layering events. It is noticed that the formation of each single-species sporadic atom layer was usually accompanied by a weak density enhancement in the other metal atom. This supports the suggestion that Fe s and Na s layers are formed via the same or very similar mechanisms. Both the Fe s and Na s layers over Wuhan showed a tendency to strengthen with decreasing occurrence altitude. This tendency is consistent with the earlier Na s layer observations at high and low latitudes. Moreover, it is noticed by comparing the currently available Fe s and Na s layer characteristics, which came from the observations at five different locations (including Wuhan) during different periods, that a lower average altitude could link to a higher average peak density and vice versa. The statistics-based link might perhaps represent a universal feature of sporadic layers. From our simultaneous Fe and Na density data we have found that the undersides of the normal Fe and Na layers follow nearly the exact movements and occur at nearly the same altitude. The normal Fe layer tended to be narrower than the corresponding Na layer nearly at all times, and this difference was generally reflected in the extent of the upper edge of the layer. The nearly persistent underside overlap strongly suggests that on the undersides of these meteoric metal layers there exist some sink mechanisms leading to the concurrent removal of different sorts of free neutral metal atoms.
[1] The complete seasonal variation patterns of the nocturnal mesospheric Na and Fe layers over Wuhan, China (30°N), have been established on the basis of several years of Na and Fe lidar measurements. Both the Na and Fe layer column abundances show strong annual variations as well as moderate semiannual variations with maxima in winter and double minima from late spring to midautumn (note that only one night of Fe data is presently available between mid-May and mid-July). The seasonal variation in the Fe abundance is evidently stronger than that of Na. The Na layer abundance has an annual mean of $2.5 Â 10 9 cm À2 , while this value for Fe is $7.5 Â 10 9 cm À2 . The Na and Fe centroid heights are dominated by semiannual oscillations with similar phases. The mean centroid heights are $91.4 km for Na and $88.7 km for Fe. The Na RMS width exhibits a strong semiannual oscillation with the layer slightly broader in winter, whereas the Fe width varies principally annually with a maximum in winter. The mean RMS widths of the Na and Fe layers are 4.5 and 4.1 km, respectively. The seasonal characteristics of the Na and Fe layers observed at 30°N have been compared with those currently available at other latitudes. The seasonal ratios of their abundances are smaller compared with 40°N and the South Pole. Their centroid heights and RMS widths also show less seasonal variations than the counterparts at all other latitudes. The annual mean Na and Fe abundances are about 60-77% of the counterparts at 40°N, 18°N, and the South Pole. This suggests that both the nocturnal Na and Fe layers have a low-abundance region around 30°N. On the basis of the results observed at the three latitudes in the Northern Hemisphere, the annual mean Fe layer width decreases with increasing latitude.
[1] High-accuracy atom density profiles, obtained by the simultaneous and commonvolume Fe and Na lidar measurements at Wuhan, China (30.5°N, 114.4°E), reveal some ubiquitous features of the Fe and Na layers on their borders. The Fe and Na lower boundaries show consistently a delicate stratification in which the lower boundary of the Fe layer is in general slightly higher than or coincident with that of the Na layer, with an overall mean altitude difference being about 0.2 km. Despite the existence of considerable vertical displacements, the two lower boundaries vary always following almost the same track. The overall correlation coefficient between them is as high as 0.96. This ubiquitous delicate stratification of the measured lower boundaries (nearly coincident density cutoff ) suggests strongly that the undersides of Fe and Na layers are controlled by the same or very similar processes. The upper boundary of the Na layer is always several kilometers higher than that of the Fe layer. A relatively weak positive correlation is also persistently observed between the two upper boundaries. Weak sporadic layering events frequently occur on the upper extent of the metal layers. They may impair the correct determination of the upper boundaries of the normal metal layers and consequently weaken the correlation. Both the Fe and Na layers often show an evidently steeper density gradient on the underside than on the upper extent, and the borders of the Fe layer are clearly steeper than those of the Na layer. The explanation to these ubiquitous features needs further experimental and modeling efforts.
[1] Based on lidar measurements between March and September 2001, the characteristics of sporadic Na layers (Na s layers) over Wuhan (30.5°N, 114.4°E) are presented. Na s layers were observed on 29 occasions from 275 h observational data. They tended to show a seasonal variation with a maximum occurrence rate in July. The maximum Na density was 24080 cm À3 which was comparable with those observed at low and high latitudes. Different from the observations at all other sites over the world, most Na s layers over Wuhan tended to occur around the peak altitudes of the normal Na layers ($92 km). However, a Na s layer was observed at 112.9 km altitude. The formation of the Na s layers over Wuhan generally needed a longer time than those at low and high latitudes. The formation processes usually consisted of consecutive density enhancement bursts. The Na s layers often exhibited broader layer widths than those at low and high latitudes.
We compare the mesospheric Na and Fe layers by using simultaneous and common‐volume lidar measurements made at the Arecibo Observatory (18.3°N, 66.75°W), Puerto Rico, in 2003. The temporal variations of the two species are highly correlated at practically all heights, although not always positively. Positive correlations occur in the bottom and top sides while negative correlation is observed in a relatively narrow region in the middle part. Chemical and dynamical effects are discussed to interpret this particular relationship between Na and Fe layers. It is shown that gas phase chemistry determines the structure of the Na and Fe layers after the metals are ablated from meteoroids entering the atmosphere. The observed region of negative correlation appears to be slightly lower than that of the expected region of negative correlation based on inert response to dynamics. It appears that such a difference may be due to temperature‐dependent chemistry. Overall, the observed correlations between Na and Fe layers can be well explained by their responses to wave dynamics.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.