132 research outputs found
The potential and pitfalls of unit asking in reducing scope insensitivity
This article revisits and further investigates the extent to which scope insensitivity in helping contexts can be reduced by the unit asking (UA) method. UA is an intervention that first asks people to help one unit and then asks for willingness to help multiple units. In 3 studies (NÂ =Â 3,442), participants took on the role of policymakers to allocate help (motivation to help and willingness to pay) to local aid projects. They underwent either UA or a control condition (in which they stated their willingness to help only to the multiple units). Against expectations, the first 2 studies found a reversed UA effect for helping motivation, such that help decreased when participants were in the UA condition. However, the third study found a UA effect for helping motivation when participants made the sequential assessments within one project (when the individual unit belonged to the multiple units-group), rather than between projects (when the individual unit belonged to another group). Thus, our results suggest that the 2 assessments critical for the UA method should be done within the same project rather than between 2 projects to successfully reduce scope insensitivity. Further, the age of the unit (child or adult), the number of the unit(s), the composition of the group (homogeneous or heterogeneous), and the size of the group did not substantially reduce scope insensitivity with UA
Decreased urge for palatable food after a two-month dietary intervention with green-plant membranes in overweight women
Polymorphism in killer cell immunoglobulin-like receptors and human leukocyte antigen-c and predisposition to preeclampsia in Ethiopian pregnant women population.
INTRODUCTION: Preeclampsia (PE) is a human specific pregnancy-related syndrome of unknown etiology that affects 2-8 % of pregnancies. Polymorphism in maternal Killer Cell Immunoglobulin-like Receptors (KIRs) and the ligand fetal Human Leukocyte Antigen-C (HLA-C) may predispose pregnant mothers for PE due to defective trophoblast invasion into the maternal decidua. Our study aimed to investigate the association between maternal KIR and fetal HLA-C polymorphism and PE in Ethiopian pregnant women. METHODS: We included a total of 288 (157 controls and 131 PE cases) in a case-controls study at Adama Regional Referral Hospital, Ethiopia. The KIR and HLA-C genotyping was done using traditional polymerase chain reaction on genomic DNA extracted form maternal venous and cord blood followed by 2% agarose gel electrophoresis. RESULTS: The statistical associations between variables were evaluated using Pearson's Chi-square test. P < 0.05, with 95 % confidence interval was considered statistically significant. A significant association was observed between the KIR2DS1 and PE, with a higher frequency (60.5 %) of the gene in the control group. Similarly, a significant association was observed between KIR AA genotype and PE, with a higher frequency (38.2 %) of this genotype in the PE group. Ethiopians share the same risk genotype for PE as seen in previous African and European studies, namely homozygosity of a maternal KIR AA genotype. However, Ethiopians differ from other East African populations by sharing the same protective KIR2DS1 gene as Europeans
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Novel role of PKR in inflammasome activation and HMGB1 release
The inflammasome regulates release of caspase activation-dependent cytokines, including IL-1β, IL-18, and high-mobility group box 1 (HMGB1)1-5. During the course of studying HMGB1 release mechanisms, we discovered an important role of double-stranded RNA dependent protein kinase (PKR) in inflammasome activation. Exposure of macrophages to inflammasome agonists induced PKR autophosphorylation. PKR inactivation by genetic deletion or pharmacological inhibition severely impaired inflammasome activation in response to double-stranded RNA, ATP, monosodium urate, adjuvant aluminum, rotenone, live E. coli, anthrax lethal toxin, DNA transfection, and S. Typhimurium infection. PKR deficiency significantly inhibited the secretion of IL-1beta, IL-18 and HMGB1 in E. coli-induced peritonitis. PKR physically interacts with multiple inflammasome components, including NLR family pyrin domain-containing 3 (NLRP3), NLR family pyrin domain-containing 1 (NLRP1), NLR family CARD domain-containing protein 4 (NLRC4), Absent in melanoma 2 (AIM2), and broadly regulates inflammasome activation. PKR autophosphorylation in a cell free system with recombinant NLRP3, ASC and pro-casapse-1 reconstitutes inflammasome activity. These results reveal a critical role of PKR in inflammasome activation, and indicate that it should be possible to pharmacologically target this molecule to treat inflammation
Operationalizing the centiloid scale for [18F]florbetapir PET studies on PET/MRI
INTRODUCTION: The Centiloid scale aims to harmonize amyloid beta (Aβ) positron emission tomography (PET) measures across different analysis methods. As Centiloids were created using PET/computerized tomography (CT) data and are influenced by scanner differences, we investigated the Centiloid transformation with data from Insight 46 acquired with PET/magnetic resonanceimaging (MRI). METHODS: We transformed standardized uptake value ratios (SUVRs) from 432 florbetapir PET/MRI scans processed using whole cerebellum (WC) and white matter (WM) references, with and without partial volume correction. Gaussian-mixture-modelling-derived cutpoints for Aβ PET positivity were converted. RESULTS: The Centiloid cutpoint was 14.2 for WC SUVRs. The relationship between WM and WC uptake differed between the calibration and testing datasets, producing implausibly low WM-based Centiloids. Linear adjustment produced a WM-based cutpoint of 18.1. DISCUSSION: Transformation of PET/MRI florbetapir data to Centiloids is valid. However, further understanding of the effects of acquisition or biological factors on the transformation using a WM reference is needed
Deletion of the membrane complement inhibitor CD59a drives age and gender-dependent alterations to bone phenotype in mice
Degenerative joint diseases such as osteoarthritis are characterised by aberrant region-specificboneformationand abnormal bone mineral content. A recent study suggested a role for the complement membrane attack com-plex in experimental models of osteoarthritis. Since CD59a is the principal regulator of the membrane attackcomplex in mice, we evaluated the impact of CD59a gene deletion upon maintenance of bone architecture.In vivobone morphology analysis revealed that male CD59a-deficient mice have increased femur length and cor-tical bone volume, albeit with reduced bone mineral density. However, this phenomenon was not observed infemale mice. Histomorphometric analysis of the trabecular bone showed increased rates of bone homeostasis,with both increased bone resorption and mineral apposition rate in CD59a-deficient male mice. When bonecells were studied in isolation,in vitroosteoclastogenesis was significantly increased in male CD59a-deficientmice, although osteoblast formation was not altered.Our data reveal, for thefirst time, that CD59a is a regulator of bone growth and homeostasis. CD59a ablation inmale mice results in longer and wider bones, but with less density, which is likely a major contributing factorfor their susceptibility to osteoarthritis. Thesefindings increase our understanding of the role of complementregulation in degenerative arthritis
TLR activation regulates damage-associated molecular pattern isoforms released during pyroptosis
Mechanisms of Intramolecular Communication in a Hyperthermophilic Acylaminoacyl Peptidase: A Molecular Dynamics Investigation
Protein dynamics and the underlying networks of intramolecular interactions and communicating residues within the three-dimensional (3D) structure are known to influence protein function and stability, as well as to modulate conformational changes and allostery. Acylaminoacyl peptidase (AAP) subfamily of enzymes belongs to a unique class of serine proteases, the prolyl oligopeptidase (POP) family, which has not been thoroughly investigated yet. POPs have a characteristic multidomain three-dimensional architecture with the active site at the interface of the C-terminal catalytic domain and a β-propeller domain, whose N-terminal region acts as a bridge to the hydrolase domain. In the present contribution, protein dynamics signatures of a hyperthermophilic acylaminoacyl peptidase (AAP) of the prolyl oligopeptidase (POP) family, as well as of a deletion variant and alanine mutants (I12A, V13A, V16A, L19A, I20A) are reported. In particular, we aimed at identifying crucial residues for long range communications to the catalytic site or promoting the conformational changes to switch from closed to open ApAAP conformations. Our investigation shows that the N-terminal α1-helix mediates structural intramolecular communication to the catalytic site, concurring to the maintenance of a proper functional architecture of the catalytic triad. Main determinants of the effects induced by α1-helix are a subset of hydrophobic residues (V16, L19 and I20). Moreover, a subset of residues characterized by relevant interaction networks or coupled motions have been identified, which are likely to modulate the conformational properties at the interdomain interface
Novel role of PKR in inflammasome activation and HMGB1 release
The inflammasome regulates release of caspase activation-dependent cytokines, including IL-1β, IL-18, and high-mobility group box 1 (HMGB1)1-5. During the course of studying HMGB1 release mechanisms, we discovered an important role of double-stranded RNA dependent protein kinase (PKR) in inflammasome activation. Exposure of macrophages to inflammasome agonists induced PKR autophosphorylation. PKR inactivation by genetic deletion or pharmacological inhibition severely impaired inflammasome activation in response to double-stranded RNA, ATP, monosodium urate, adjuvant aluminum, rotenone, live E. coli, anthrax lethal toxin, DNA transfection, and S. Typhimurium infection. PKR deficiency significantly inhibited the secretion of IL-1beta, IL-18 and HMGB1 in E. coli-induced peritonitis. PKR physically interacts with multiple inflammasome components, including NLR family pyrin domain-containing 3 (NLRP3), NLR family pyrin domain-containing 1 (NLRP1), NLR family CARD domain-containing protein 4 (NLRC4), Absent in melanoma 2 (AIM2), and broadly regulates inflammasome activation. PKR autophosphorylation in a cell free system with recombinant NLRP3, ASC and pro-casapse-1 reconstitutes inflammasome activity. These results reveal a critical role of PKR in inflammasome activation, and indicate that it should be possible to pharmacologically target this molecule to treat inflammation
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