210 research outputs found

    Prediction of Signed Protein Kinase Regulatory Circuits.

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    Complex networks of regulatory relationships between protein kinases comprise a major component of intracellular signaling. Although many kinase-kinase regulatory relationships have been described in detail, these tend to be limited to well-studied kinases whereas the majority of possible relationships remains unexplored. Here, we implement a data-driven, supervised machine learning method to predict human kinase-kinase regulatory relationships and whether they have activating or inhibiting effects. We incorporate high-throughput data, kinase specificity profiles, and structural information to produce our predictions. The results successfully recapitulate previously annotated regulatory relationships and can reconstruct known signaling pathways from the ground up. The full network of predictions is relatively sparse, with the vast majority of relationships assigned low probabilities. However, it nevertheless suggests denser modes of inter-kinase regulation than normally considered in intracellular signaling research. A record of this paper's transparent peer review process is included in the Supplemental Information

    Support for involvement of the AHI1 locus in schizophrenia

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    To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldRecently, markers in the Abelson Helper Integration Site 1 (AHI1) region were shown to be associated with schizophrenia in a family sample of Israeli-Arabs. Here, we report a study evaluating the relevance of the AHI1 region to schizophrenia in an Icelandic sample. Seven markers shown to confer risk in the previous report were typed in 608 patients diagnosed with broad schizophrenia and 1,504 controls. Odds ratios for the overtransmitted alleles in the Israeli-Arab families ranged from 1.15 to 1.29 in the Icelandic sample. After Bonferroni correction for the seven markers tested, two markers were significantly associated with schizophrenia. Thus, our results are in general agreement with the previous report, with the strongest association signal observed in a region upstream of the AHI1 gene

    Short-term outcome of 1,465 computer-navigated primary total knee replacements 2005–2008: A report from the Norwegian Arthroplasty Register

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    Background and purpose: Improvement of positioning and alignment by the use of computer-assisted surgery (CAS) might improve longevity and function in total knee replacements, but there is little evidence. In this study, we evaluated the short-term results of computer-navigated knee replacements based on data from the Norwegian Arthroplasty Register. Patients and methods: Primary total knee replacements without patella resurfacing, reported to the Norwegian Arthroplasty Register during the years 2005–2008, were evaluated. The 5 most common implants and the 3 most common navigation systems were selected. Cemented, uncemented, and hybrid knees were included. With the risk of revision for any cause as the primary endpoint and intraoperative complications and operating time as secondary outcomes, 1,465 computer-navigated knee replacements (CAS) and 8,214 conventionally operated knee replacements (CON) were compared. Kaplan-Meier survival analysis and Cox regression analysis with adjustment for age, sex, prosthesis brand, fixation method, previous knee surgery, preoperative diagnosis, and ASA category were used. Results: Kaplan-Meier estimated survival at 2 years was 98% (95% CI: 97.5–98.3) in the CON group and 96% (95% CI: 95.0– 97.8) in the CAS group. The adjusted Cox regression analysis showed a higher risk of revision in the CAS group (RR = 1.7, 95% CI: 1.1–2.5; p = 0.02). The LCS Complete knee had a higher risk of revision with CAS than with CON (RR = 2.1, 95% CI: 1.3–3.4; p = 0.004)). The differences were not statistically significant for the other prosthesis brands. Mean operating time was 15 min longer in the CAS group. Interpretation: With the introduction of computer-navigated knee replacement surgery in Norway, the short-term risk of revision has increased for computer-navigated replacement with the LCS Complete. The mechanisms of failure of these implantations should be explored in greater depth, and in this study we have not been able to draw conclusions regarding causation

    Current European guidelines for management of arterial hypertension: Are they adequate for use in primary care? Modelling study based on the Norwegian HUNT 2 population

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    <p>Abstract</p> <p>Background</p> <p>Previous studies indicate that clinical guidelines using combined risk evaluation for cardiovascular diseases (CVD) may overestimate risk. The aim of this study was to model and discuss implementation of the current (2007) hypertension guidelines in a general Norwegian population.</p> <p>Methods</p> <p>Implementation of the current <it>European Guidelines for the Management of Arterial Hypertension </it>was modelled on data from a cross-sectional, representative Norwegian population study (The Nord-Trøndelag Health Study 1995-97), comprising 65,028 adults, aged 20-89, of whom 51,066 (79%) were eligible for modelling.</p> <p>Results</p> <p>Among individuals with blood pressure ≥120/80 mmHg, 93% (74% of the total, adult population) would need regular clinical attention and/or drug treatment, based on their total CVD risk profile. This translates into 296,624 follow-up visits/100,000 adults/year. In the Norwegian healthcare environment, 99 general practitioner (GP) positions would be required in the study region for this task alone. The number of GPs currently serving the adult population in the study area is 87 per 100,000 adults.</p> <p>Conclusion</p> <p>The potential workload associated with the European hypertension guidelines could destabilise the healthcare system in Norway, one of the world's most long- and healthy-living nations, by international comparison. Large-scale, preventive medical enterprises can hardly be regarded as scientifically sound and ethically justifiable, unless issues of practical feasibility, sustainability and social determinants of health are considered.</p

    Use and feasibility of delayed prescribing for respiratory tract infections: A questionnaire survey

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    <p>Abstract</p> <p>Background</p> <p>Delayed prescribing of antibiotics for respiratory tract infections (RTIs) lowers the amount of antibiotics consumed. Several national treatment guidelines on RTIs recommend the strategy. When advocating treatment innovations, the feasibility and credibility of the innovation must be taken into account. The objective of this study was to explore GPs use and patients uptake of wait-and-see prescriptions for RTIs, and to investigate the feasibility of the strategy from GPs' and patients' perspectives.</p> <p>Methods</p> <p>Questionnaire survey among Norwegian GPs issuing and patients receiving a wait-and-see-prescription for RTIs. Patients reported symptoms, confidence and antibiotics consumption, GPs reported diagnoses, reason for issuing a wait-and-see-prescription and their opinion about the method.</p> <p>Results</p> <p>304 response pairs from consultations with 49 GPs were received. The patient response rate was 80%. The most common diagnosis for the GPs to issue a wait-and-see prescription was sinusitis (33%) and otitis (21%). 46% of the patients reported to consume the antibiotics. When adjusted for other factors, the diagnosis did not predict antibiotic consumption, but both being 16 years or more (p = 0,006) and reporting to have a fever (p = 0,012) doubled the odds of antibiotic consumption, while feeling very ill more than quadrupled the odds (p = 0,002). In 210 cases (69%), the GP found delayed prescribing a very reasonable strategy, and 270 patients (89%) would prefer to receive a wait-and-see prescription in a similar situation in the future. The GPs found delayed prescribing very reasonable most frequently in cases of sinusitis (79%, p = 0,007) and least frequently in cases of lower RTIs (49%, p = 0,002).</p> <p>Conclusion</p> <p>Most patients and GPs are satisfied with the delayed prescribing strategy. The patients' age, symptoms and malaise are more important than the diagnosis in predicting antibiotic consumption. The GP's view of the method as a reasonable approach depends on the patient's diagnosis. In our setting, delayed prescribing seems to be a feasible strategy, especially in cases of sinusitis and otitis. Educational efforts to promote delayed prescribing in similar settings should focus on these diagnoses.</p

    Infectious disease management in primary care: perceptions of GPs

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    <p>Abstract</p> <p>Background</p> <p>It is important to keep the level of antibiotic prescribing low to contain the development of resistant bacteria. This study was conducted to reveal new knowledge about how GPs think in relation to the prescribing of antibiotics - knowledge that could be used in efforts toward rational treatment of infectious diseases in primary care. The aim was to explore and describe the variations in GPs' perceptions of infectious disease management, with special reference to antibiotic prescribing.</p> <p>Methods</p> <p>Twenty GPs working at primary care centres in a county in south-west Sweden were purposively selected based on the strategy of including GPs with different kinds of experience. The GPs were interviewed and perceptions among GPs were analysed by a phenomenographic approach.</p> <p>Results</p> <p>Five qualitatively different perceptions of infectious disease management were identified. They were: (A) the GP must help the patient to achieve health and well-being; (B) the management must meet the GP's perceived personal, professional and organisational demands; (C) restrictive antibiotic prescribing is time-consuming; (D) restrictive antibiotic prescribing can protect the effectiveness of antibiotics; and (E) patients benefit personally from restrictive antibiotic prescribing.</p> <p>Conclusions</p> <p>Restrictive antibiotic prescribing was considered important in two perceptions, was not an issue as such in two others, and was considered in one perception although the actual prescribing was greatly influenced by the interaction between patient and GP. Accordingly, to encourage restrictive antibiotic prescribing several aspects must be addressed. Furthermore, different GPs need various kinds of support. Infectious disease management in primary care is complex and time-consuming, which must be acknowledged in healthcare organisation and planning.</p

    Reduced Lentivirus Susceptibility in Sheep with TMEM154 Mutations

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    Visna/Maedi, or ovine progressive pneumonia (OPP) as it is known in the United States, is an incurable slow-acting disease of sheep caused by persistent lentivirus infection. This disease affects multiple tissues, including those of the respiratory and central nervous systems. Our aim was to identify ovine genetic risk factors for lentivirus infection. Sixty-nine matched pairs of infected cases and uninfected controls were identified among 736 naturally exposed sheep older than five years of age. These pairs were used in a genome-wide association study with 50,614 markers. A single SNP was identified in the ovine transmembrane protein (TMEM154) that exceeded genome-wide significance (unadjusted p-value 3×10−9). Sanger sequencing of the ovine TMEM154 coding region identified six missense and two frameshift deletion mutations in the predicted signal peptide and extracellular domain. Two TMEM154 haplotypes encoding glutamate (E) at position 35 were associated with infection while a third haplotype with lysine (K) at position 35 was not. Haplotypes encoding full-length E35 isoforms were analyzed together as genetic risk factors in a multi-breed, matched case-control design, with 61 pairs of 4-year-old ewes. The odds of infection for ewes with one copy of a full-length TMEM154 E35 allele were 28 times greater than the odds for those without (p-value<0.0001, 95% CI 5–1,100). In a combined analysis of nine cohorts with 2,705 sheep from Nebraska, Idaho, and Iowa, the relative risk of infection was 2.85 times greater for sheep with a full-length TMEM154 E35 allele (p-value<0.0001, 95% CI 2.36–3.43). Although rare, some sheep were homozygous for TMEM154 deletion mutations and remained uninfected despite a lifetime of significant exposure. Together, these findings indicate that TMEM154 may play a central role in ovine lentivirus infection and removing sheep with the most susceptible genotypes may help eradicate OPP and protect flocks from reinfection

    A Two-Stage Meta-Analysis Identifies Several New Loci for Parkinson's Disease

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    A previous genome-wide association (GWA) meta-analysis of 12,386 PD cases and 21,026 controls conducted by the International Parkinson's Disease Genomics Consortium (IPDGC) discovered or confirmed 11 Parkinson's disease (PD) loci. This first analysis of the two-stage IPDGC study focused on the set of loci that passed genome-wide significance in the first stage GWA scan. However, the second stage genotyping array, the ImmunoChip, included a larger set of 1,920 SNPs selected on the basis of the GWA analysis. Here, we analyzed this set of 1,920 SNPs, and we identified five additional PD risk loci (combined p<5x10(-10), PARK16/1q32, STX1B/16p11, FGF20/8p22, STBD1/4q21, and GPNMB/7p15). Two of these five loci have been suggested by previous association studies (PARK16/1q32, FGF20/8p22), and this study provides further support for these findings. Using a dataset of post-mortem brain samples assayed for gene expression (n = 399) and methylation (n = 292), we identified methylation and expression changes associated with PD risk variants in PARK16/1q32, GPNMB/7p15, and STX1B/16p11 loci, hence suggesting potential molecular mechanisms and candidate genes at these risk loci

    The Val158Met COMT polymorphism is a modifier of the age at onset in Parkinson's disease with a sexual dimorphism

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    The catechol-O-methyltranferase (COMT) is one of the main enzymes that metabolise dopamine in the brain. The Val158Met polymorphism in the COMT gene (rs4680) causes a trimodal distribution of high (Val/Val), intermediate (Val/Met) and low (Met/Met) enzyme activity. We tested whether the Val158Met polymorphism is a modifier of the age at onset (AAO) in Parkinson's disease (PD). The rs4680 was genotyped in a total of 16 609 subjects from five independent cohorts of European and North American origin (5886 patients with PD and 10 723 healthy controls). The multivariate analysis for comparing PD and control groups was based on a stepwise logistic regression, with gender, age and cohort origin included in the initial model. The multivariate analysis of the AAO was a mixed linear model, with COMT genotype and gender considered as fixed effects and cohort and cohort-gender interaction as random effects. COMT genotype was coded as a quantitative variable, assuming a codominant genetic effect. The distribution of the COMT polymorphism was not significantly different in patients and controls (p=0.22). The Val allele had a significant effect on the AAO with a younger AAO in patients with the Val/Val (57.1±13.9, p=0.03) than the Val/Met (57.4±13.9) and the Met/Met genotypes (58.3±13.5). The difference was greater in men (1.9 years between Val/Val and Met/Met, p=0.007) than in women (0.2 years, p=0.81). Thus, the Val158Met COMT polymorphism is not associated with PD in the Caucasian population but acts as a modifier of the AAO in PD with a sexual dimorphism: the Val allele is associated with a younger AAO in men with idiopathic PD

    Variability in Working Memory Performance Explained by Epistasis vs Polygenic Scores in the ZNF804A Pathway

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    Importance: We investigated the variation in neuropsychological function explained by risk alleles at the psychosis susceptibility gene ZNF804A and its interacting partners using single nucleotide polymorphisms (SNPs), polygenic scores, and epistatic analyses. Of particular importance was the relative contribution of the polygenic score vs epistasis in variation explained. Objectives To (1) assess the association between SNPs in ZNF804A and the ZNF804A polygenic score with measures of cognition in cases with psychosis and (2) assess whether epistasis within the ZNF804A pathway could explain additional variation above and beyond that explained by the polygenic score. Design, Setting, and Participants: Patients with psychosis (n = 424) were assessed in areas of cognitive ability impaired in schizophrenia including IQ, memory, attention, and social cognition. We used the Psychiatric GWAS Consortium 1 schizophrenia genome-wide association study to calculate a polygenic score based on identified risk variants within this genetic pathway. Cognitive measures significantly associated with the polygenic score were tested for an epistatic component using a training set (n = 170), which was used to develop linear regression models containing the polygenic score and 2-SNP interactions. The best-fitting models were tested for replication in 2 independent test sets of cases: (1) 170 individuals with schizophrenia or schizoaffective disorder and (2) 84 patients with broad psychosis (including bipolar disorder, major depressive disorder, and other psychosis). Main Outcomes and Measures: Participants completed a neuropsychological assessment battery designed to target the cognitive deficits of schizophrenia including general cognitive function, episodic memory, working memory, attentional control, and social cognition. Results: Higher polygenic scores were associated with poorer performance among patients on IQ, memory, and social cognition, explaining 1% to 3% of variation on these scores (range, P = .01 to .03). Using a narrow psychosis training set and independent test sets of narrow phenotype psychosis (schizophrenia and schizoaffective disorder), broad psychosis, and control participants (n = 89), the addition of 2 interaction terms containing 2 SNPs each increased the R2 for spatial working memory strategy in the independent psychosis test sets from 1.2% using the polygenic score only to 4.8% (P = .11 and .001, respectively) but did not explain additional variation in control participants. Conclusions and Relevance: These data support a role for the ZNF804A pathway in IQ, memory, and social cognition in cases. Furthermore, we showed that epistasis increases the variation explained above the contribution of the polygenic score
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