443 research outputs found
Meta-analysis of genome-wide association studies of asthma in ethnically diverse North American populations.
Asthma is a common disease with a complex risk architecture including both genetic and environmental factors. We performed a meta-analysis of North American genome-wide association studies of asthma in 5,416 individuals with asthma (cases) including individuals of European American, African American or African Caribbean, and Latino ancestry, with replication in an additional 12,649 individuals from the same ethnic groups. We identified five susceptibility loci. Four were at previously reported loci on 17q21, near IL1RL1, TSLP and IL33, but we report for the first time, to our knowledge, that these loci are associated with asthma risk in three ethnic groups. In addition, we identified a new asthma susceptibility locus at PYHIN1, with the association being specific to individuals of African descent (P = 3.9 × 10(-9)). These results suggest that some asthma susceptibility loci are robust to differences in ancestry when sufficiently large samples sizes are investigated, and that ancestry-specific associations also contribute to the complex genetic architecture of asthma
Layer-Dependent Charge State Lifetime of Single Se Vacancies in WSe
Defect engineering in two-dimensional semiconductors has been exploited to
tune the optoelectronic properties and introduce new quantum states in the band
gap. Chalcogen vacancies in transition metal dichalcogenides in particular have
been found to strongly impact charge carrier concentration and mobility in 2D
transistors as well as feature sub-gap emission and single-photon response. In
this letter, we investigate the layer-dependent charge state lifetime of Se
vacancies in WSe. In one monolayer WSe, we observe ultrafast charge
transfer from the lowest unoccupied orbital of the top Se vacancy to the
graphene substrate within (1.0 0.2) ps measured via the current
saturation in scanning tunneling approach curves. For Se vacancies decoupled by
TMD multilayers, we find a sub-exponential increase of the charge lifetime from
(62 14) ps in bilayer to few nanoseconds in four-layer WSe, alongside
a reduction of the defect state binding energy. Additionally, we attribute the
continuous suppression and energy shift of the dI/dV in-gap defect state
resonances at very close tip--sample distances to a current saturation effect.
Our results provide a key measure of the layer-dependent charge transfer rate
of chalcogen vacancies in TMDs
Yellow sea mine hunting using the Navy's CASS/GRAB model
The purpose of this work is to determine the necessity of a near real time ocean modeling capability such as the Naval Oceanographic Office's (NAVOCENANO) Modular Ocean Data Assimilation System (MODAS) model in shallow water (such as the Yellow Sea) mine hunting applications using the Navy's Comprehensive Acoustic Simulation System/Gaussian Ray Bundle (CASS/GRAB) Mode. Sound speed profiles inputted into CASS/GRAB were calculated from observational (MOODS) and climatological (GDEM) data sets for different seasons and regions of four different bottom types (sand, gravel, mud and rock). The CASS/GRAB model outputs were compared to the outputs from corresponding MODAS data sets. The results of the comparisons domonstrated in many cases a significant acoustic difference between the alternate profiles. These results demonstrated that there is a need for a predictive modeling capability such as MODAS to address the mine warfare (MIW) needs in the Yellow Sea region. There were some weaknesses detected in the profiles the MODAS model produces in the Yellow Sea, which must be resolved before it can reliably address the MIW needs in the regionNAVOCEANO, Stennis Space Center, MS 39522-5001Approved for public release; distribution is unlimited
cGMP-independent nitric oxide signaling and regulation of the cell cycle
BACKGROUND: Regulatory functions of nitric oxide (NO(•)) that bypass the second messenger cGMP are incompletely understood. Here, cGMP-independent effects of NO(• )on gene expression were globally examined in U937 cells, a human monoblastoid line that constitutively lacks soluble guanylate cyclase. Differentiated U937 cells (>80% in G0/G1) were exposed to S-nitrosoglutathione, a NO(• )donor, or glutathione alone (control) for 6 h without or with dibutyryl-cAMP (Bt(2)cAMP), and then harvested to extract total RNA for microarray analysis. Bt(2)cAMP was used to block signaling attributable to NO(•)-induced decreases in cAMP. RESULTS: NO(• )regulated 110 transcripts that annotated disproportionately to the cell cycle and cell proliferation (47/110, 43%) and more frequently than expected contained AU-rich, post-transcriptional regulatory elements (ARE). Bt(2)cAMP regulated 106 genes; cell cycle gene enrichment did not reach significance. Like NO(•), Bt(2)cAMP was associated with ARE-containing transcripts. A comparison of NO(• )and Bt(2)cAMP effects showed that NO(• )regulation of cell cycle genes was independent of its ability to interfere with cAMP signaling. Cell cycle genes induced by NO(• )annotated to G1/S (7/8) and included E2F1 and p21/Waf1/Cip1; 6 of these 7 were E2F target genes involved in G1/S transition. Repressed genes were G2/M associated (24/27); 8 of 27 were known targets of p21. E2F1 mRNA and protein were increased by NO(•), as was E2F1 binding to E2F promoter elements. NO(• )activated p38 MAPK, stabilizing p21 mRNA (an ARE-containing transcript) and increasing p21 protein; this increased protein binding to CDE/CHR promoter sites of p21 target genes, repressing key G2/M phase genes, and increasing the proportion of cells in G2/M. CONCLUSION: NO(• )coordinates a highly integrated program of cell cycle arrest that regulates a large number of genes, but does not require signaling through cGMP. In humans, antiproliferative effects of NO(• )may rely substantially on cGMP-independent mechanisms. Stress kinase signaling and alterations in mRNA stability appear to be major pathways by which NO(• )regulates the transcriptome
Protocadherin-18 Is a Novel Differentiation Marker and an Inhibitory Signaling Receptor for CD8+ Effector Memory T Cells
CD8+ tumor infiltrating T cells (TIL) lack effector-phase functions due to defective proximal TCR-mediated signaling previously shown to result from inactivation of p56lck kinase. We identify a novel interacting partner for p56lck in nonlytic TIL, Protocadherin-18 (‘pcdh18’), and show that pcdh18 is transcribed upon in vitro or in vivo activation of all CD8+ central memory T cells (CD44+CD62LhiCD127+) coincident with conversion into effector memory cells (CD44+CD62LloCD127+). Expression of pcdh18 in primary CD8+ effector cells induces the phenotype of nonlytic TIL: defective proximal TCR signaling, cytokine secretion, and cytolysis, and enhanced AICD. pcdh18 contains a motif (centered at Y842) shared with src kinases (QGQYQP) that is required for the inhibitory phenotype. Thus, pcdh18 is a novel activation marker of CD8+ memory T cells that can function as an inhibitory signaling receptor and restrict the effector phase
Food insecurity in South Indian households with TB during COVID-19 lockdowns and the impact of nutritional interventions: A qualitative study
Tuberculosis (TB) mortality rose during the COVID-19 pandemic, as did food insecurity worldwide. Undernourished individuals are at increased risk for incident TB disease and TB mortality. This study examines the impact of COVID lockdowns on the food security of households with TB in Southern India. In-depth interviews and focus group discussions were conducted with household contacts enrolled in a nutritional intervention study, conducted in Puducherry and Tamil Nadu (2018–2024), which provided household contacts of persons with TB with a six-month nutritional intervention. During the COVID-19 lockdowns, 78% of households in our study had no income; 67% resorted to distress financing, such as loans, to afford food; and 44% changed their eating habits, such as buying less food or different items. Respondents reported that the provided nutritional intervention improved their food security. Crises such as the COVID-19 pandemic can reduce both food access and diversity, leading to macronutrient and micronutrient deficiencies that increase the risk of TB incidence and mortality. Undernutrition due to food insecurity may have been a driver for hastened disease progression or disease-related morbidity and increased mortality during the pandemic. Nutritional support interventions should be implemented as a part of pandemic response
Riboflavin/UVA Collagen Cross-Linking-Induced Changes in Normal and Keratoconus Corneal Stroma
Purpose To determine the effect of Ultraviolet-A collagen cross-linking with hypo-osmolar and iso-osmolar riboflavin solutions on stromal collagen ultrastructure in normal and keratoconus ex vivo human corneas. Methods Using small-angle X-ray scattering, measurements of collagen D-periodicity, fibril diameter and interfibrillar spacing were made at 1 mm intervals across six normal post-mortem corneas (two above physiological hydration (swollen) and four below (unswollen)) and two post-transplant keratoconus corneal buttons (one swollen; one unswollen), before and after hypo-osmolar cross-linking. The same parameters were measured in three other unswollen normal corneas before and after iso-osmolar cross-linking and in three pairs of swollen normal corneas, in which only the left was cross-linked (with iso-osmolar riboflavin). Results Hypo-osmolar cross-linking resulted in an increase in corneal hydration in all corneas. In the keratoconus corneas and unswollen normal corneas, this was accompanied by an increase in collagen interfibrillar spacing (p<0.001); an increase in fibril diameter was also seen in two out of four unswollen normal corneas and one unswollen keratoconus cornea (p<0.001). Iso-osmolar cross-linking resulted in a decrease in tissue hydration in the swollen normal corneas only. Although there was no consistent treatment-induced change in hydration in the unswollen normal samples, iso-osmolar cross-linking of these corneas did result in a compaction of collagen fibrils and a reduced fibril diameter (p<0.001); these changes were not seen in the swollen normal corneas. Collagen D-periodicity was not affected by either treatment. Conclusion The observed structural changes following Ultraviolet-A cross-linking with hypo-osmolar or iso-osmolar riboflavin solutions are more likely a consequence of treatment-induced changes in tissue hydration rather than cross-linking
Modern management of pyogenic hepatic abscess: a case series and review of the literature
<p>Abstract</p> <p>Background</p> <p>Pyogenic hepatic abscesses are relatively rare, though untreated are uniformly fatal. A recent paradigm shift in the management of liver abscesses, facilitated by advances in diagnostic and interventional radiology, has decreased mortality rates. The aim of this study was to review our experience in managing pyogenic liver abscess, review the literature in this field, and propose guidelines to aid in the current management of this complex disease.</p> <p>Methods</p> <p>Demographic and clinical details of all patients admitted to a single institution with liver abscess over a 5 year period were reviewed. Clinical presentation, aetiology, diagnostic work-up, treatment, morbidity and mortality data were collated.</p> <p>Results</p> <p>Over a 5 year period 11 patients presented to a single institution with pyogenic hepatic abscess (55% males, mean age 60.3 years). Common clinical features at presentation were non-specific constitutional symptoms and signs. Aetiology was predominantly gallstones (45%) or diverticular disease (27%). In addition to empiric antimicrobial therapy, all patients underwent radiologically guided percutaneous drainage of the liver abscess at diagnosis and only 2 patients required surgical intervention, including one 16-year old female who underwent hemi-hepatectomy for a complex and rare Actinomycotic abscess. There were no mortalities after minimum follow-up of one year.</p> <p>Conclusions</p> <p>Pyogenic liver abscesses are uncommon, and mortality has decreased over the last two decades. Antimicrobial therapy and radiological intervention form the mainstay of modern treatment. Surgical intervention should be considered for patients with large, complex, septated or multiple abscesses, underlying disease or in whom percutaneous drainage has failed.</p
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