1,955 research outputs found
Environmental Estrogens Induce Mast Cell Degranulation and Enhance IgE-Mediated Release of Allergic Mediators
BACKGROUND: Prevalence and morbidity of allergic diseases have increased over the last decades. Based on the recently recognized differences in asthma prevalence between the sexes, we have examined the effect of endogenous estrogens on a key element of the allergic response. Some lipophilic pollutants have estrogen-like activities and are termed environmental estrogens. These pollutants tend to degrade slowly in the environment and to bioaccumulate and bioconcentrate in the food chain; they also have long biological half-lives. OBJECTIVES: Our goal in this study was to identify possible pathogenic roles for environmental estrogens in the development of allergic diseases. METHODS: We screened a number of environmental estrogens for their ability to modulate the release of allergic mediators from mast cells. We incubated a human mast cell line and primary mast cell cultures derived from bone marrow of wild type and estrogen receptor α (ER-α )–deficient mice with environmental estrogens with and without estradiol or IgE and allergens. We assessed degranulation of mast cells by quantifying the release of β -hexosaminidase. RESULTS: All of the environmental estrogens tested caused rapid, dose-related release of β -hexosaminidase from mast cells and enhanced IgE-mediated release. The combination of physiologic concentrations of 17β -estradiol and several concentrations of environmental estrogens had additive effects on mast cell degranulation. Comparison of bone marrow mast cells from ER-α –sufficient and ER-α –deficient mice indicated that much of the effect of environmental estrogens was mediated by ER-α . CONCLUSIONS: Our findings suggest that estrogenic environmental pollutants might promote allergic diseases by inducing and enhancing mast cell degranulation by physiologic estrogens and exposure to allergens
A Pilot Study of total Personal Exposure to Volatile organic Compounds among Hispanic Female Domestic Cleaners
Cleaners have an elevated risk for the development or exacerbation of asthma and other respiratory conditions, possibly due to exposure to cleaning products containing volatile organic compounds (VOCs) leading to inflammation and oxidative stress. This pilot study aimed to quantify total personal exposure to VOCs and to assess biomarkers of inflammation and pulmonary oxidative stress in 15 predominantly Hispanic women working as domestic cleaners in San Antonio, Texas, between November 2019 and July 2020. In partnership with a community organization, Domésticas Unidas, recruited women were invited to attend a training session where they were provided 3M 3500 passive organic vapor monitors (badges) and began a 72-hr sampling period during which they were instructed to wear one badge during the entire period ( AT, fo
GPU-based Private Information Retrieval for On-Device Machine Learning Inference
On-device machine learning (ML) inference can enable the use of private user
data on user devices without revealing them to remote servers. However, a pure
on-device solution to private ML inference is impractical for many applications
that rely on embedding tables that are too large to be stored on-device. In
particular, recommendation models typically use multiple embedding tables each
on the order of 1-10 GBs of data, making them impractical to store on-device.
To overcome this barrier, we propose the use of private information retrieval
(PIR) to efficiently and privately retrieve embeddings from servers without
sharing any private information. As off-the-shelf PIR algorithms are usually
too computationally intensive to directly use for latency-sensitive inference
tasks, we 1) propose novel GPU-based acceleration of PIR, and 2) co-design PIR
with the downstream ML application to obtain further speedup. Our GPU
acceleration strategy improves system throughput by more than over
an optimized CPU PIR implementation, and our PIR-ML co-design provides an over
additional throughput improvement at fixed model quality. Together,
for various on-device ML applications such as recommendation and language
modeling, our system on a single V100 GPU can serve up to queries per
second -- a throughput improvement over a CPU-based baseline --
while maintaining model accuracy
Influence of Nanoparticle Size and Shape on Oligomer Formation of an Amyloidogenic Peptide
Understanding the influence of macromolecular crowding and nanoparticles on
the formation of in-register -sheets, the primary structural component
of amyloid fibrils, is a first step towards describing \emph{in vivo} protein
aggregation and interactions between synthetic materials and proteins. Using
all atom molecular simulations in implicit solvent we illustrate the effects of
nanoparticle size, shape, and volume fraction on oligomer formation of an
amyloidogenic peptide from the transthyretin protein. Surprisingly, we find
that inert spherical crowding particles destabilize in-register -sheets
formed by dimers while stabilizing -sheets comprised of trimers and
tetramers. As the radius of the nanoparticle increases crowding effects
decrease, implying smaller crowding particles have the largest influence on the
earliest amyloid species. We explain these results using a theory based on the
depletion effect. Finally, we show that spherocylindrical crowders destabilize
the ordered -sheet dimer to a greater extent than spherical crowders,
which underscores the influence of nanoparticle shape on protein aggregation
Design Considerations for Fire Safety
ERAF: 48415Papers presented at the Symposium on Design Considerations for Fire Safety at the Semiannual Meeting of The American Society of Heating, Refrigerating and Air-conditioning Engineer
Rising Powers and Order Contestation: Disaggregating the Normative from the Representational
One of the central themes of the current literature on rising powers is that new aspirants to great power status pose a challenge to the underlying principles and norms that underpin the existing, Western-led order. However, in much of the literature, the nature and significance of rising powers for international order is imprecisely debated, in particular the concept and practice of ‘contestation’. In this article we aim to establish a distinction between normative contestation and what can be thought of as ‘contestation over representation’: that is, contestation over who is setting and overseeing the rules of the game rather than the content of the rules themselves and the kind of order that they underpin. This distinction is important for providing a more nuanced understanding of the nature of the current power transition and therefore for guiding attempts at accommodation on the part of the established powers. Theoretically, the paper engages with debates on international order and international society. Its empirical basis is provided by a thorough analysis of the discourse of rising power summitry, in particular at meetings of the BRICS and Shanghai Cooperation Organization groupings
Molecular Cloning and Expression of Cro s 1: an Occupational Allergen from Saffron Pollen (Crocus sativus)
Background: The cultivation of saffron is expanding through the southeast of Iran, and allergy to
saffron pollen occurs in workers involved in processing this plant. We aimed to clone, sequence and
express a major allergen involved in saffron pollen allergy, and to compare the recombinant with the
natural allergen.
Methods: The N-terminal amino acid sequence of Cro s 1, an allergen from saffron pollen, was
determined after immunoblotting. The cDNA encoding for this allergen was cloned by PCR utilizing a
primer based on the N-terminal amino acid sequence. Recombinant Cro s 1 (rCro s 1) was expressed as
a soluble protein in Pichia pastoris and purified to homogeneity by gel filtration. Inhibition of IgE
binding to rCro s 1 by pollen extract was analyzed by ELISA.
Results: The allergen Cro s 1 was identified from saffron pollen extracts and cloned by PCR. Cro s 1
cDNA defined an acidic polypeptide with homology to pollen proteins from Chenopodium album and
Ligastrum vulgaris. The rCro s 1 was expressed in P. pastoris at 28 mg/l. Saffron pollen extract
inhibited the binding of patient serum IgE to rCro s 1.
Conclusion: We identified and cloned the first Crocus sativus pollen allergen. rCro s 1 cDNA shows a
very high homology with Che a 1, the major allergen of lamb's-quarter, Chenopodium album,
Caryophyllales, pollen (97%). Cro s 1 is a useful tool for specific diagnosis and structural studies of
occupational allergy to saffron
Telomeric expression sites are highly conserved in trypanosoma brucei
Subtelomeric regions are often under-represented in genome sequences of eukaryotes. One of the best known examples of the use of telomere proximity for adaptive purposes are the bloodstream expression sites (BESs) of the African trypanosome Trypanosoma brucei. To enhance our understanding of BES structure and function in host adaptation and immune evasion, the BES repertoire from the Lister 427 strain of T. brucei were independently tagged and sequenced. BESs are polymorphic in size and structure but reveal a surprisingly conserved architecture in the context of extensive recombination. Very small BESs do exist and many functioning BESs do not contain the full complement of expression site associated genes (ESAGs). The consequences of duplicated or missing ESAGs, including ESAG9, a newly named ESAG12, and additional variant surface glycoprotein genes (VSGs) were evaluated by functional assays after BESs were tagged with a drug-resistance gene. Phylogenetic analysis of constituent ESAG families suggests that BESs are sequence mosaics and that extensive recombination has shaped the evolution of the BES repertoire. This work opens important perspectives in understanding the molecular mechanisms of antigenic variation, a widely used strategy for immune evasion in pathogens, and telomere biology
Correlations of behavioral deficits with brain pathology assessed through longitudinal MRI and histopathology in the R6/1 mouse model of huntington's disease
Huntington's disease (HD) is caused by the expansion of a CAG repeat in the huntingtin (HTT) gene. The R6 mouse models of HD express a mutant version of exon 1 HTT and typically develop motor and cognitive impairments, a widespread huntingtin (HTT) aggregate pathology and brain atrophy. Unlike the more commonly used R6/2 mouse line, R6/1 mice have fewer CAG repeats and, subsequently, a less rapid pathological decline. Compared to the R6/2 line, fewer descriptions of the progressive pathologies exhibited by R6/1 mice exist. The association between the molecular and cellular neuropathology with brain atrophy, and with the development of behavioral phenotypes remains poorly understood in many models of HD. In attempt to link these factors in the R6/1 mouse line, we have performed detailed assessments of behavior and of regional brain abnormalities determined through longitudinal, in vivo magnetic resonance imaging (MRI), as well as an end-stage, ex vivo MRI study and histological assessment. We found progressive decline in both motor and non-motor related behavioral tasks in R6/1 mice, first evident at 11 weeks of age. Regional brain volumes were generally unaffected at 9 weeks, but by 17 weeks there was significant grey matter atrophy. This age-related brain volume loss was validated using a more precise, semi-automated Tensor Based morphometry assessment. As well as these clear progressive phenotypes, mutant HTT (mHTT) protein, the hallmark of HD molecular pathology, was widely distributed throughout the R6/1 brain and was accompanied by neuronal loss. Despite these seemingly concomitant, robust pathological phenotypes, there appeared to be little correlation between the three main outcome measures: behavioral performance, MRI-detected brain atrophy and histopathology. In conclusion, R6/1 mice exhibit many features of HD, but the underlying mechanisms driving these clear behavioral disturbances and the brain volume loss, still remain unclear. © 2013 Rattray et al
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