After a genomewide screen in the Hutterites was completed, the IL4RA gene was examined as the 16p-linked susceptibility locus for asthma and atopy. Seven known variants and one novel variant, representing all nonsynonymous substitutions in the mature protein, were examined in the Hutterites; on the basis of studies in the Hutterites, outbred white, black, and Hispanic families were genotyped for selected markers. All population samples showed evidence of association to atopy or to asthma (P values.039-.0044 for atopy and. 029-.0000061 for asthma), but the alleles or haplotypes showing the strongest evidence differed between the groups. Overall, these data suggest that the IL4RA gene is an atopy- and asthma-susceptibility locus but that variation outside the coding region of the gene influences susceptibility.
Background-The natriuretic peptide system contributes to blood pressure regulation. Atrial and brain natriuretic peptides are cleaved into smaller biologically active molecules by corin, a transmembrane serine protease expressed in cardiomyocytes. Method and Results-This genotype-phenotype genetic association study included replication samples and genomic control to correct for population stratification. Sequencing of the human corin gene identified 2 nonsynonymous, nonconservative single nucleotide polymorphisms (Q568P and T555I) in near-complete linkage disequilibrium, thus describing a single minor I555 (P568) corin gene allele. This allele was present in the heterozygote state in Ϸ12% of blacks but was extremely rare in whites (Ͻ0.5% were homozygous for the minor allele). In our primary population sample, the Dallas Heart Study, after adjustment for potential confounders, including population stratification, the corin I555 (P568) allele remained independently associated with increased risk for prevalent hypertension (odds ratio, 1.63; 95% CI, 1.11 to 2.38; Pϭ0.013). The corin I555 (P568) allele also was associated with higher systolic blood pressure in subjects not using antihypertensive medication in unadjusted (133.7Ϯ20.7 versus 129.4Ϯ17.4 mm Hg; Pϭ0.029) and adjusted (132.5Ϯ1.6 versus 128.9Ϯ0.6 mm Hg; Pϭ0.029) analyses. The independent association of the minor corin allele with increased risk for prevalent hypertension was confirmed in the Multi-Ethnic Study of Atherosclerosis (odds ratio, 1.50; 95% CI, 1.09 to 2.06; Pϭ0.014). In addition, the association of the minor corin I555 (P568) allele with higher systolic blood pressure was confirmed in adjusted analysis in the Chicago Genetics of Hypertension Study (125.8Ϯ1.9 versus 121.4Ϯ0.7 mm Hg; Pϭ0.03). Conclusions-The corin I555 (P568) allele is common in blacks and is associated with higher blood pressure and an increased risk for prevalent hypertension.
e Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease characterized by high fever, thrombocytopenia, multiorgan dysfunction, and a high fatality rate between 12 and 30%. It is caused by SFTS virus (SFTSV), a novel Phlebovirus in family Bunyaviridae. Although the viral pathogenesis remains largely unknown, hemopoietic cells appear to be targeted by the virus. In this study we report that human monocytes were susceptible to SFTSV, which replicated efficiently, as shown by an immunofluorescence assay and real-time reverse transcription-PCR. We examined host responses in the infected cells and found that antiviral interferon (IFN) and IFN-inducible proteins were induced upon infection. However, our data also indicated that downregulation of key molecules such as mitochondrial antiviral signaling protein (MAVS) or weakened activation of interferon regulatory factor (IRF) and NF-B responses may contribute to a restricted innate immunity against the infection. NSs, the nonstructural protein encoded by the S segment, suppressed the beta interferon (IFN-) and NF-B promoter activities, although NF-B activation appears to facilitate SFTSV replication in human monocytes. NSs was found to be associated with TBK1 and may inhibit the activation of downstream IRF and NF-B signaling through this interaction. Interestingly, we demonstrated that the nucleoprotein (N), also encoded by the S segment, exhibited a suppressive effect on the activation of IFN- and NF-B signaling as well. Infected monocytes, mainly intact and free of apoptosis, may likely be implicated in persistent viral infection, spreading the virus to the circulation and causing primary viremia. Our findings provide the first evidence in dissecting the host responses in monocytes and understanding viral pathogenesis in humans infected with a novel deadly Bunyavirus.
A combined analysis of genome scans for obesity was undertaken using the interim results from the National Heart, Lung, and Blood Institute Family Blood Pressure Program. In this research project, four multicenter networks of investigators conducted eight individual studies. Data were available on 6,849 individuals from four ethnic groups (white, black, Mexican American, and Asian). The sample represents the largest single collection of genomewide scan data that has been analyzed for obesity and provides a test of the reproducibility of linkage analysis for a complex phenotype. Body mass index (BMI) was used as the measure of adiposity. Genomewide linkage analyses were first performed separately in each of the eight ethnic groups in the four networks, through use of the variance-component method. Only one region in the analyses of the individual studies showed significant linkage with BMI: 3q22.1 (LOD 3.45, for the GENOA network black sample). Six additional regions were found with an associated LOD >2, including 3p24.1, 7p15.2, 7q22.3, 14q24.3, 16q12.2, and 17p11.2. Among these findings, the linkage at 7p15.2, 7q22.3, and 17p11.2 has been reported elsewhere. A modified Fisher's omnibus procedure was then used to combine the P values from each of the eight genome scans. A complimentary approach to the meta-analysis was undertaken, combining the average allele-sharing identity by descent (pi) for whites, blacks, and Mexican Americans. Using this approach, we found strong linkage evidence for a quantitative-trait locus at 3q27 (marker D3S2427; LOD 3.40, P=.03). The same location has been shown to be linked with obesity-related traits and diabetes in at least two other studies. These results (1) confirm the previously reported obesity-susceptibility locus on chromosomes 3, 7, and 17 and (2) demonstrate that combining samples from different studies can increase the power to detect common genes with a small-to-moderate effect, so long as the same gene has an effect in all samples considered.
Viruses have adopted various mechanisms to evade or subvert host antiviral responses initiated by viral RNA or DNA through Toll-like receptor (TLR) (1, 2) and RIG-I-like receptor (RLR) (3-5) signaling pathways. Viral double-stranded RNA (dsRNA) can be sequestered by VP35 of Ebola virus (6) to avoid the activation of TLRs or RLRs. Viral proteins that contain the TIR domain can be interferon (IFN) antagonists such as A46R of vaccinia virus, which blocks upstream IFN signaling by directly targeting MyD88, MAL, TRIF, and TRAM, the TIR domain-containing adaptors (2). RLR sensors such as RIG-I and MDA5 and adaptor IPS1 are targeted by NS1 of influenza virus (7), V protein of paramyxoviruses (3), and the protease precursor protein 3ABC of hepatitis A virus (5). The adaptor protein TRIF of the TLR signaling pathway can be targeted for degradation by viral proteins containing protease activities, such as NS3/4A of flavivirus hepatitis C virus (HCV) (8) and 3C of picornavirus EV71 (9), which can also cleave transcription factor (TF) IRF7, compromising IFN induction. In addition, the N-terminal fragment of cleaved IRF7 interacts with and inhibits IRF3, another TF essential for IFN induction, thereby enhancing viral infection (10). Downstream TFs are also targeted by viral proteins, such as NS1 of West Nile virus, which inhibits TLR3 signaling by preventing IRF3 translocation into the nucleus (11). Between TLR/RLR sensors and downstream TFs, IKK complexes are also targeted by proteins encoded by HCV, vaccinia virus, and rabies virus (12-14), among others.Severe fever with thrombocytopenia syndrome (SFTS) is an emerging febrile illness caused by a novel phlebovirus, SFTS bunyavirus (SFTSV), in the family Bunyaviridae (15). SFTSV is a vector-borne zoonotic arbovirus transmitted to humans by tick bites, causing high fever, loss of white blood cells and platelets, and, in severe cases, multiorgan failure. It is a single-stranded negativesense RNA virus with three genomic segments, L, M, and S (15). The L segment encodes viral RNA polymerase, while the M segment encodes the two viral envelope glycoproteins, Gc and Gn. The S segment is an ambisense RNA of 1,744 bases encoding a nucleoprotein (NP) and a nonstructural protein (NSs). Our recent study demonstrated that NSs inhibits host IFN- and NF-B responses, although the mechanism remains unclear (16). Here we report that NSs forms unique cytoplasmic inclusion bodies (IBs) in infected or transfected cells that appear to play a role in immune evasion through the interaction of NSs and the IKK complex. Our data indicate that SFTSV has adopted a novel host immune evasion strategy involving the sequestration of IKK complex components TBK1, IKKε, and IRF, which are critical for the activation of the IFN signaling pathway, into IBs. MATERIALS AND METHODSCells, viruses, and reagents. African green monkey kidney Vero, HeLa, human embryonic kidney 293T, and MDCK cells were grown in Dulbecco's modified Eagle's medium (DMEM; Gibco, Invitrogen, Carlsbad, CA) supplemented with 10% fetal bovin...
Summary. Many types of genetic analyses depend on estimates of allele frequencies. We consider the problem of allele-frequency estimation based on data from related individuals. The motivation for this work is data collected on the Hutterites, an isolated founder population, so we focus particularly on the case in which the relationships among the sampled individuals are specified by a large, complex pedigree for which maximum likelihood estimation is impractical. For this case, we propose to use the best linear unbiased estimator (BLUE) of allele frequency. We derive this estimator, which is equivalent to the quasilikelihood estimator for this problem, and we describe an efficient algorithm for computing the estimate and its variance. We show that our estimator has certain desirable small-sample properties in common with the maximum likelihood estimator (MLE) for this problem. We treat both the case when parental origin of each allele is known and when it is unknown. The results are extended to prediction of allele frequency in some set of individuals S based on genotype data collected on a set of individuals R. We compare the mean-squared error of the BLUE, the commonly used naive estimator (sample frequency) and the MLE when the latter is feasible to calculate. The results indicate that although the MLE performs the best of the three, the BLUE is close in performance to the MLE and is substantially easier to calculate, making it particularly useful for large complex pedigrees in which MLE calculation is impractical or infeasible. We apply our method to allele-frequency estimation in a Hutterite data set.
Background The National Early Warning Score (NEWS2) is currently recommended in the UK for the risk stratification of COVID-19 patients, but little is known about its ability to detect severe cases. We aimed to evaluate NEWS2 for the prediction of severe COVID-19 outcome and identify and validate a set of blood and physiological parameters routinely collected at hospital admission to improve upon the use of NEWS2 alone for medium-term risk stratification. Methods Training cohorts comprised 1276 patients admitted to King’s College Hospital National Health Service (NHS) Foundation Trust with COVID-19 disease from 1 March to 30 April 2020. External validation cohorts included 6237 patients from five UK NHS Trusts (Guy’s and St Thomas’ Hospitals, University Hospitals Southampton, University Hospitals Bristol and Weston NHS Foundation Trust, University College London Hospitals, University Hospitals Birmingham), one hospital in Norway (Oslo University Hospital), and two hospitals in Wuhan, China (Wuhan Sixth Hospital and Taikang Tongji Hospital). The outcome was severe COVID-19 disease (transfer to intensive care unit (ICU) or death) at 14 days after hospital admission. Age, physiological measures, blood biomarkers, sex, ethnicity, and comorbidities (hypertension, diabetes, cardiovascular, respiratory and kidney diseases) measured at hospital admission were considered in the models. Results A baseline model of ‘NEWS2 + age’ had poor-to-moderate discrimination for severe COVID-19 infection at 14 days (area under receiver operating characteristic curve (AUC) in training cohort = 0.700, 95% confidence interval (CI) 0.680, 0.722; Brier score = 0.192, 95% CI 0.186, 0.197). A supplemented model adding eight routinely collected blood and physiological parameters (supplemental oxygen flow rate, urea, age, oxygen saturation, C-reactive protein, estimated glomerular filtration rate, neutrophil count, neutrophil/lymphocyte ratio) improved discrimination (AUC = 0.735; 95% CI 0.715, 0.757), and these improvements were replicated across seven UK and non-UK sites. However, there was evidence of miscalibration with the model tending to underestimate risks in most sites. Conclusions NEWS2 score had poor-to-moderate discrimination for medium-term COVID-19 outcome which raises questions about its use as a screening tool at hospital admission. Risk stratification was improved by including readily available blood and physiological parameters measured at hospital admission, but there was evidence of miscalibration in external sites. This highlights the need for a better understanding of the use of early warning scores for COVID.
BACKGROUND: The viral shedding duration of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has not been fully defined. Consecutive detection of SARS-CoV-2 RNA from respiratory tract specimens is essential for determining duration of virus shedding and providing evidence to optimize the clinical management of coronavirus disease 2019 (COVID-19). RESEARCH QUESTION: What are the shedding durations of SARS-CoV-2 RNA in the upper and lower respiratory tract specimens? What are their associated risk factors? STUDY DESIGN AND METHODS: A total of 68 patients with COVID-19 admitted to Wuhan Taikang Tongji Hospital and Huoshenshan Hospital from February 10, 2020, to March 20, 2020, were recruited. Consecutive SARS-CoV-2 RNA detection from paired specimens of nasopharyngeal swab (NPS) and sputum were carried out. The clinical characteristics of patients were recorded for further analysis. RESULTS: SARS-CoV-2 RNA was detected from NPSs in 48 patients (70.6%), and from sputum specimens in 30 patients (44.1%). The median duration of viral shedding from sputum specimens (34 days; interquartile range [IQR], 24-40) was significantly longer than from NPSs (19 days; IQR, 14-25; P < .001). Elderly age was an independent factor associated with prolonged virus shedding time of SARS-CoV-2 (hazard ratio, 1.71; 95% CI, 1.01-2.93). It was noteworthy that in 9 patients, the viral RNA was detected in sputum after NPS turned negative. Chronic lung disease and steroids were associated with virus detection in sputum, and diabetes mellitus was associated with virus detection in both NPS and sputum. INTERPRETATION: These findings may impact a test based clearance discharge criteria given patients with COVID-19 may shed virus longer in their lower respiratory tracts, with potential implication for prolonged transmission risk. In addition, more attention should be given to elderly patients who might have prolonged viral shedding duration.
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