| 1. |
- Antonoglou, Georgios N., et al.
(author)
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Clinical Performance of Dental Implants Following Sinus Floor Augmentation : A Systematic Review and Meta-Analysis of Clinical Trials with at Least 3 Years of Follow-up
- 2018
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In: International Journal of Oral & Maxillofacial Implants. - : Quintessence. - 0882-2786 .- 1942-4434. ; 33:3, s. E45-E65
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Research review (peer-reviewed)abstract
- Purpose: The purpose of this systematic review was to assess the survival of implants placed in augmented sinuses on a medium-to long-term basis, and identify factors affecting implant survival such as surgical technique, bone grafts, and timing of implant placement. Materials and Methods: A literature search up to July 2016 was performed to identify prospective clinical studies on sinus floor augmentation in conjunction with implant placement with a minimum follow-up of 3 years. Meta-analytic methods were implemented to calculate implant survival rates and relative risks (RR) for failure and the effect of surgical technique, use of bone graft, graft type, use of membrane, mean residual bone height, and timing of implant insertion. Results: A total of 17 clinical trials (1 randomized and 16 prospective nonrandomized) were included, which pertained to 637 patients (at least 48% male) and 1,610 implants placed after sinus floor augmentation with the osteotome (transalveolar) or lateral window approach. The pooled implant survival rate at 3 to 6 years of follow-up was 97.7% (17 studies; 95% CI = 94.4% to 99.7%) with high heterogeneity. Smoking was associated with significantly worse implant survival (2 studies; RR = 4.8; 95% CI = 1.2 to 19.4; P < .05). However, evidence of influencing factors varied from very low to moderate after adopting the GRADE approach, due to risk of bias, imprecision, inconsistency, and small-study effects. Conclusion: Current evidence suggests that implants in augmented sinuses have high survival rates, with smoking playing a potentially important negative role in their prognosis. Both indirect and direct maxillary sinus floor augmentation seem to have a low frequency of manageable complications.
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| 2. |
- Argyropoulou, Eftychia, et al.
(author)
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The eigenvalue problem for a bianisotropic cavity
- 2013
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In: PIERS proceedings 2013. - : Electromagnetics Acad. - 9781934142264 ; , s. 858-862
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Conference paper (peer-reviewed)abstract
- We discuss the eigenvalue problem for a perfectly conducting bianisotropic cavity. We formulate the corresponding mathematical problem and we give a characterization of the eigenelements (non-zero eigenfrequencies and modes) via a perturbation argument involving the eigenelements of the hollow cavity.
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| 3. |
- Axfors, Cathrine, et al.
(author)
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Association between convalescent plasma treatment and mortality in COVID-19 : a collaborative systematic review and meta-analysis of randomized clinical trials
- 2021
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In: BMC Infectious Diseases. - : BioMed Central (BMC). - 1471-2334. ; 21:1
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Research review (peer-reviewed)abstract
- Background: Convalescent plasma has been widely used to treat COVID-19 and is under investigation in numerous randomized clinical trials, but results are publicly available only for a small number of trials. The objective of this study was to assess the benefits of convalescent plasma treatment compared to placebo or no treatment and all-cause mortality in patients with COVID-19, using data from all available randomized clinical trials, including unpublished and ongoing trials (Open Science Framework, ). Methods: In this collaborative systematic review and meta-analysis, clinical trial registries (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform), the Cochrane COVID-19 register, the LOVE database, and PubMed were searched until April 8, 2021. Investigators of trials registered by March 1, 2021, without published results were contacted via email. Eligible were ongoing, discontinued and completed randomized clinical trials that compared convalescent plasma with placebo or no treatment in COVID-19 patients, regardless of setting or treatment schedule. Aggregated mortality data were extracted from publications or provided by investigators of unpublished trials and combined using the Hartung-Knapp-Sidik-Jonkman random effects model. We investigated the contribution of unpublished trials to the overall evidence. Results: A total of 16,477 patients were included in 33 trials (20 unpublished with 3190 patients, 13 published with 13,287 patients). 32 trials enrolled only hospitalized patients (including 3 with only intensive care unit patients). Risk of bias was low for 29/33 trials. Of 8495 patients who received convalescent plasma, 1997 died (23%), and of 7982 control patients, 1952 died (24%). The combined risk ratio for all-cause mortality was 0.97 (95% confidence interval: 0.92; 1.02) with between-study heterogeneity not beyond chance (I-2 = 0%). The RECOVERY trial had 69.8% and the unpublished evidence 25.3% of the weight in the meta-analysis. Conclusions: Convalescent plasma treatment of patients with COVID-19 did not reduce all-cause mortality. These results provide strong evidence that convalescent plasma treatment for patients with COVID-19 should not be used outside of randomized trials. Evidence synthesis from collaborations among trial investigators can inform both evidence generation and evidence application in patient care.
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| 4. |
- Axfors, Cathrine, et al.
(author)
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Mortality outcomes with hydroxychloroquine and chloroquine in COVID-19 from an international collaborative meta-analysis of randomized trials
- 2021
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In: Nature Communications. - : Springer Nature. - 2041-1723. ; 12:1
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Journal article (peer-reviewed)abstract
- Substantial COVID-19 research investment has been allocated to randomized clinical trials (RCTs) on hydroxychloroquine/chloroquine, which currently face recruitment challenges or early discontinuation. We aim to estimate the effects of hydroxychloroquine and chloroquine on survival in COVID-19 from all currently available RCT evidence, published and unpublished. We present a rapid meta-analysis of ongoing, completed, or discontinued RCTs on hydroxychloroquine or chloroquine treatment for any COVID-19 patients (protocol: https://osf.io/QESV4/). We systematically identified unpublished RCTs (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, Cochrane COVID-registry up to June 11, 2020), and published RCTs (PubMed, medRxiv and bioRxiv up to October 16, 2020). All-cause mortality has been extracted (publications/preprints) or requested from investigators and combined in random-effects meta-analyses, calculating odds ratios (ORs) with 95% confidence intervals (CIs), separately for hydroxychloroquine and chloroquine. Prespecified subgroup analyses include patient setting, diagnostic confirmation, control type, and publication status. Sixty-three trials were potentially eligible. We included 14 unpublished trials (1308 patients) and 14 publications/preprints (9011 patients). Results for hydroxychloroquine are dominated by RECOVERY and WHO SOLIDARITY, two highly pragmatic trials, which employed relatively high doses and included 4716 and 1853 patients, respectively (67% of the total sample size). The combined OR on all-cause mortality for hydroxychloroquine is 1.11 (95% CI: 1.02, 1.20; I-2=0%; 26 trials; 10,012 patients) and for chloroquine 1.77 (95%CI: 0.15, 21.13, I-2=0%; 4 trials; 307 patients). We identified no subgroup effects. We found that treatment with hydroxychloroquine is associated with increased mortality in COVID-19 patients, and there is no benefit of chloroquine. Findings have unclear generalizability to outpatients, children, pregnant women, and people with comorbidities. Hydroxychloroquine and chloroquine have been investigated as a potential treatment for Covid-19 in several clinical trials. Here the authors report a meta-analysis of published and unpublished trials, and show that treatment with hydroxychloroquine for patients with Covid-19 was associated with increased mortality, and there was no benefit from chloroquine.
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| 5. |
- Costanza, Gabriele, et al.
(author)
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Remarks on the mathematical solution of the hollow cavity eigenvalue problem
- 2013
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In: Progress in Electromagnetics Research Symposium. - : Electromagnetics Acad.. - 9781934142264 ; , s. 79-83
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Conference paper (peer-reviewed)abstract
- We discuss the eigenvalue problem for a perfectly conducting hollow cavity under a strict functional analytic point of view. We make use of a variant of the classical spectral theorem for compact selfadjoint operators and we pay extra attention on the null space of the Maxwell operator. We also discuss the corresponding inhomogeneous problem, where currents are present, even when they may depend on the fields.
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| 6. |
- Delfin, Carl, et al.
(author)
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A Federated Database for Obesity Research : An IMI-SOPHIA Study
- 2024
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In: Life. - 0024-3019. ; 14:2
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Journal article (peer-reviewed)abstract
- Obesity is considered by many as a lifestyle choice rather than a chronic progressive disease. The Innovative Medicines Initiative (IMI) SOPHIA (Stratification of Obesity Phenotypes to Optimize Future Obesity Therapy) project is part of a momentum shift aiming to provide better tools for the stratification of people with obesity according to disease risk and treatment response. One of the challenges to achieving these goals is that many clinical cohorts are siloed, limiting the potential of combined data for biomarker discovery. In SOPHIA, we have addressed this challenge by setting up a federated database building on open-source DataSHIELD technology. The database currently federates 16 cohorts that are accessible via a central gateway. The database is multi-modal, including research studies, clinical trials, and routine health data, and is accessed using the R statistical programming environment where statistical and machine learning analyses can be performed at a distance without any disclosure of patient-level data. We demonstrate the use of the database by providing a proof-of-concept analysis, performing a federated linear model of BMI and systolic blood pressure, pooling all data from 16 studies virtually without any analyst seeing individual patient-level data. This analysis provided similar point estimates compared to a meta-analysis of the 16 individual studies. Our approach provides a benchmark for reproducible, safe federated analyses across multiple study types provided by multiple stakeholders.
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| 7. |
- Elbaz, Alexis, et al.
(author)
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Independent and Joint Effects of the MAPT and SNCA Genes in Parkinson Disease
- 2011
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In: Annals of Neurology. - : Wiley. - 1531-8249 .- 0364-5134. ; 69:5, s. 778-792
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Journal article (peer-reviewed)abstract
- Objective: We studied the independent and joint effects of the genes encoding alpha-synuclein (SNCA) and microtubule-associated protein tau (MAPT) in Parkinson disease (PD) as part of a large meta-analysis of individual data from case-control studies participating in the Genetic Epidemiology of Parkinson's Disease (GEO-PD) consortium. Methods: Participants of Caucasian ancestry were genotyped for a total of 4 SNCA (rs2583988, rs181489, rs356219, rs11931074) and 2 MAPT (rs1052553, rs242557) single nucleotide polymorphism (SNPs). Individual and joint effects of SNCA and MAPT SNPs were investigated using fixed- and random-effects logistic regression models. Interactions were studied on both a multiplicative and an additive scale, and using a case-control and case-only approach. Results: Fifteen GEO-PD sites contributed a total of 5,302 cases and 4,161 controls. All 4 SNCA SNPs and the MAPT H1-haplotype-defining SNP (rs1052553) displayed a highly significant marginal association with PD at the significance level adjusted for multiple comparisons. For SNCA, the strongest associations were observed for SNPs located at the 30 end of the gene. There was no evidence of statistical interaction between any of the 4 SNCA SNPs and rs1052553 or rs242557, neither on the multiplicative nor on the additive scale. Interpretation: This study confirms the association between PD and both SNCA SNPs and the H1 MAPT haplotype. It shows, based on a variety of approaches, that the joint action of variants in these 2 loci is consistent with independent effects of the genes without additional interacting effects. ANN NEUROL 2011; 69: 778-792
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| 8. |
- Evangelou, Evangelos, et al.
(author)
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Non-replication of association for six polymorphisms from meta-analysis of genome-wide association studies of Parkinson's disease : large-scale collaborative study
- 2010
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In: American Journal of Medical Genetics, Part B: Neuropsychiatric Genetics. - : Wiley. - 1552-4841 .- 1552-485X. ; 153B:1, s. 8-220
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Journal article (peer-reviewed)abstract
- Early genome-wide association (GWA) studies on Parkinson's disease (PD) have not been able to yield conclusive, replicable signals of association, perhaps due to limited sample size. We aimed to investigate whether association signals derived from the meta-analysis of the first two GWA investigations might be replicable in different populations. We examined six single-nucleotide polymorphisms (SNPs) (rs1000291, rs1865997, rs2241743, rs2282048, rs2313982, and rs3018626) that had reached nominal significance with at least two of three different strategies proposed in a previous analysis of the original GWA studies. Investigators from the "Genetic Epidemiology of Parkinson's Disease" (GEOPD) consortium were invited to join in this study. Ten teams contributed replication data from 3,458 PD cases and 3,719 controls. The data from the two previously published GWAs (599 PD cases, 592 controls and 443 sibling pairs) were considered as well. All data were synthesized using both fixed and random effects models. The summary allelic odds ratios were ranging from 0.97 to 1.09 by random effects, when all data were included. The summary estimates of the replication data sets (excluding the original GWA data) were very close to 1.00 (range 0.98-1.09) and none of the effects were nominally statistically significant. The replication data sets had significantly different results than the GWA data. Our data do not support evidence that any of these six SNPs reflect susceptibility markers for PD. Much stronger signals of statistical significance in GWA platforms are needed to have substantial chances of replication. Specifically in PD genetics, this would require much larger GWA studies and perhaps novel analytical techniques.
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| 9. |
- Heckman, Michael G., et al.
(author)
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Population-specific Frequencies for LRRK2 Susceptibility Variants in the Genetic Epidemiology of Parkinson's Disease (GEO-PD) Consortium
- 2013
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In: Movement Disorders. - : Wiley. - 0885-3185. ; 28:12, s. 1740-1744
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Journal article (peer-reviewed)abstract
- BackgroundVariants within the leucine-rich repeat kinase 2 gene are recognized as the most frequent genetic cause of Parkinson's disease. Leucine-rich repeat kinase 2 variation related to disease susceptibility displays many features that reflect the nature of complex, late-onset sporadic disorders like Parkinson's disease. MethodsThe Genetic Epidemiology of Parkinson's Disease Consortium recently performed the largest genetic association study for variants in the leucine-rich repeat kinase 2 gene across 23 different sites in 15 countries. ResultsHerein, we detail the allele frequencies for the novel risk factors (p.A419V and p.M1646T) and the protective haplotype (p.N551K-R1398H-K1423K) nominated in the original publication. Simple population allele frequencies not only can provide insight into the clinical relevance of specific variants but also can help genetically define patient groups. ConclusionsEstablishing individual patient-based genomic susceptibility profiles that incorporate both risk factors and protective factors will determine future diagnostic and treatment strategies. (c) 2013 International Parkinson and Movement Disorder Society
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| 10. |
- Ioannidis, Andreas, et al.
(author)
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A mathematical framework for propagation in an open cavity
- 2013
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In: Proceeding of 2013 URSI International Symposium on Electromagnetic Theory (EMTS). - : IEEE Press. - 9781467349390 ; , s. 1043-1046
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Conference paper (peer-reviewed)abstract
- The purpose of this paper is to establish a formal mathematical framework for the electromagnetic wave propagation in an arbitrary cavity. The walls of the cavity are not assumed perfectly conducting and we use the transmission boundary conditions for the tangential fields. Our main tool is the Laplace transform. The focus here is on the modeling and detailed proofs or calculations are not provided.
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