379 research outputs found
Autoinflammatory Disease Reloaded: A Clinical Perspective
Our understanding of the etiology of autoinflammatory disease is growing rapidly. Recent advances offer new opportunities for therapeutic intervention and suggest that the definition of what constitutes an autoinflammatory disease should be reassessed
Effective Sample Size: Quick Estimation of the Effect of Related Samples in Genetic Case-Control Association Analyses
Correlated samples have been frequently avoided in case-control
genetic association
 studies in part because the methods for handling them are either not
easily implemented or not widely known. We
advocate one method for case-control association analysis of correlated
samples -- the effective sample size method -- as a simple and
accessible approach that does not require specialized computer programs.
The effective sample size method captures the variance inflation
of allele frequency estimation exactly, and can be used to modify the
chi-square test statistic, p-value, and 95% confidence interval of
odds-ratio simply by replacing the apparent number of allele counts with the
effective ones. For genotype frequency estimation, although a single
effective sample size is unable to completely characterize the variance inflation,
an averaged one can satisfactorily approximate the simulated result.
The effective sample size method is applied to the rheumatoid arthritis
siblings data collected from the North American Rheumatoid Arthritis Consortium (NARAC)
to establish a significant association with the interferon-induced
helicasel gene (IFIH1) previously being identified as a type 1 diabetes
susceptibility locus. Connections between the effective sample size
method and other methods, such as generalized estimation equation,
variance of eigenvalues for correlation matrices, and genomic controls,
are also discussed.

Insect reproductive behaviors are important mediators of carrion nutrient release into soil
Current declines in terrestrial insect biomass and abundance have raised global concern for the fate of insects and the ecosystem services they provide. However, the ecological and economic contributions of many insects have yet to be quantified. Carrion-specializing invertebrates are important mediators of carrion decomposition; however, the role of their reproductive activities in facilitating this nutrient pulse into ecosystems is poorly understood. Here, we investigate whether insects that sequester carrion belowground for reproduction alter soil biotic and abiotic properties in North American temperate forests. We conducted a field experiment that measured soil conditions in control, surface carrion alone, and beetle-utilized carrion treatments. Our data demonstrate that Nicrophorus beetle reproduction and development results in changes in soil characteristics which are consistent with those observed in surface carrion decomposition alone. Carrion addition treatments increase soil labile C, DON and DOC, while soil pH and microbial C:N ratios decrease. This study demonstrates that the decomposition of carrion drives soil changes but suggests that the behaviors of insect scavengers play an important role in the release of carrion nutrients directly into the soil by sequestering carrion resources in the ecosystem where they were deposited
Use of Oxyrase® enzyme to enhance recovery of Escherichia coli O157:H7 from culture media and ground beef
Escherichia coli O157:H7 is a bacterium
that has caused great concern in the meat and
food industry during the last few years
because of several, well-publicized, disease
outbreaks, including the incident at the Jackin-
the-Box fast food chain in Seattle, Washington.
The organism can cause severe
sickness and even death in certain population
groups. To better assure meat safety, federal
meat inspection is focusing on developing
rapid methods to detect this disease agent
and others. Oxyrase is a commercially available
enzyme that can accelerate the growth of
some bacteria. Current techniques for
isolation and culturing of E. coli O157:H7
from foods require an enrichment period of
18 to 24 hours, thus limiting their usefulness
for perishable foods that are marketed quickly.
Our investigation found that Oxyrase
shortened required enrichment periods in
broth culture only. The enzyme was less
effective in sterilized ground beef
Microbial flora of commercially produced vacuum packaged, cooked beef roast
Commercially produced vacuum
packaged, fully cooked, microwaveable beef
roasts from four producers were purchased
from local retail markets. Salt concentration,
pH, water activity (aw), and percent moisture,
fat and protein were determined. Samples of
both package juice and homogenized beef
plus juice were analyzed for the presence of
aerobic, anaerobic and lactic acid bacteria
and clostridia-type organisms. The cooked
beef products had pH values from 5.82 to
6.19, water activity of 0.992 to 0.997, and
contained 0.34 to 1.07% salt, 61.89 to
72.39% moisture, 4.29 to 18.21% fat and
15.92 to 20.62% protein. No growth was
detected in juice for aerobic, anaerobic or
lactic acid bacteria or clostridia-type
organisms. Combined beef and juice had
less than 2 CFU/g for aerobic, anaerobic or
lactic acid bacteria or clostridia-type
organisms. Cooking and chilling schedules
used in the manufacture of the four products
we evaluated in this study limited survival
and outgrowth of microorganisms
MF2293
Fadi Aramouni et al, Food safety, Kansas State University, October 1997
Pyrin Modulates the Intracellular Distribution of PSTPIP1
PSTPIP1 is a cytoskeleton-associated adaptor protein that links PEST-type phosphatases to their substrates. Mutations in PSTPIP1 cause PAPA syndrome (Pyogenic sterile Arthritis, Pyoderma gangrenosum, and Acne), an autoinflammatory disease. PSTPIP1 binds to pyrin and mutations in pyrin result in familial Mediterranean fever (FMF), a related autoinflammatory disorder. Since disease-associated mutations in PSTPIP1 enhance pyrin binding, PAPA syndrome and FMF are thought to share a common pathoetiology. The studies outlined here describe several new aspects of PSTPIP1 and pyrin biology. We document that PSTPIP1, which has homology to membrane-deforming BAR proteins, forms homodimers and generates membrane-associated filaments in native and transfected cells. An extended FCH (Fes-Cip4 homology) domain in PSTPIP1 is necessary and sufficient for its self-aggregation. We further show that the PSTPIP1 filament network is dependent upon an intact tubulin cytoskeleton and that the distribution of this network can be modulated by pyrin, indicating that this is a dynamic structure. Finally, we demonstrate that pyrin can recruit PSTPIP1 into aggregations (specks) of ASC, another pyrin binding protein. ASC specks are associated with inflammasome activity. PSTPIP1 molecules with PAPA-associated mutations are recruited by pyrin to ASC specks with particularly high efficiency, suggesting a unique mechanism underlying the robust inflammatory phenotype of PAPA syndrome
Critical Signaling Events in the Mechanoactivation of Human Mast Cells through p.C492Y-ADGRE2
A role for the adhesion G-protein coupled receptor ADGRE2 or EMR2 in mechanosensing was revealed by the
finding of a missense substitution (p.C492Y) associated with familial vibratory urticaria. In these patients,
friction of the skin induces mast cell hyper-degranulation through p.C492Y-ADGRE2, causing localized hives,
flushing, and hypotension. We have now characterized the responses and intracellular signals elicited by
mechanical activation in human mast cells expressing p.C492Y-ADGRE2 and attached to dermatan sulfate, a
ligand for ADGRE2. The presence of p.C492Y-ADGRE2 reduced the threshold to activation and increased the
extent of degranulation along with the percentage of mast cells responding. Vibration caused phospholipase C
activation, transient increases in cytosolic calcium, and downstream activation of phosphoinositide 3-kinase
and extracellular signaleregulated kinases 1 and 2 by Gbg, Gaq/11, and Gai/o-independent mechanisms.
Degranulation induced by vibration was dependent on phospholipase C pathways, including calcium, protein
kinase C, and phosphoinositide 3-kinase but not extracellular signaleregulated kinases 1/2 pathways, along
with pertussis toxin-sensitive signals. In addition, mechanoactivation of mast cells stimulated the synthesis and
release of prostaglandin D2, to our knowledge a previously unreported mediator in vibratory urticaria, and
extracellular signaleregulated kinases 1/2 activation was required for this response together with calcium,
protein kinase C, and to some extent, phosphoinositide 3-kinase. Our studies thus identified critical molecular
events initiated by mechanical forces and potential therapeutic targets for patients with vibratory urticaria.This work was supported by the Division of Intramural Research within the National Institute of Allergy and Infectious Diseases and the National Human Genome Research Institute at the National Institutes of Health.S
From second to first order transitions in a disordered quantum magnet
We study the spin-glass transition in a disordered quantum model. There is a
region in the phase diagram where quantum effects are small and the phase
transition is second order, as in the classical case. In another region,
quantum fluctuations drive the transition first order. Across the first order
line the susceptibility is discontinuous and shows hysteresis. Our findings
reproduce qualitatively observations on LiHoYF. We also discuss
a marginally stable spin-glass state and derive some results previously
obtained from the real-time dynamics of the model coupled to a bath.Comment: 4 pages, 3 figures, RevTe
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