Landspítali University Hospital Research Archive
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Alzheimer's disease neuropathology in the hippocampus and brainstem of people with obstructive sleep apnea.
No full textTo access publisher's full text version of this article click on the hyperlink belowObstructive sleep apnea (OSA) involves intermittent cessations of breathing during sleep. People with OSA can experience memory deficits and have reduced hippocampal volume; these features are also characteristic of Alzheimer's disease (AD), where they are accompanied by neurofibrillary tangles (NFTs) and amyloid beta (Aβ) plaques in the hippocampus and brainstem. We have recently shown reduced hippocampal volume to be related to OSA severity, and although OSA may be a risk factor for AD, the hippocampus and brainstems of clinically verified OSA cases have not yet been examined for NFTs and Aβ plaques. The present study used quantitative immunohistochemistry to investigate postmortem hippocampi of 34 people with OSA (18 females, 16 males; mean age 67 years) and brainstems of 24 people with OSA for the presence of NFTs and Aβ plaques. OSA severity was a significant predictor of Aβ plaque burden in the hippocampus after controlling for age, sex, body mass index (BMI), and continuous positive airway pressure (CPAP) use. OSA severity also predicted NFT burden in the hippocampus, but not after controlling for age. Although 71% of brainstems contained NFTs and 21% contained Aβ plaques, their burdens were not correlated with OSA severity. These results indicate that OSA accounts for some of the "cognitively normal" individuals who have been found to have substantial Aβ burdens, and are currently considered to be at a prodromal stage of AD.
Keywords: Alzheimer’s disease; amyloid beta; continuous positive airway pressure; neurofibrillary tangles; tau.RMIT University Higher Degree by Research Publication Gran
The impact and cost-effectiveness of introducing the 10-valent pneumococcal conjugate vaccine into the paediatric immunisation programme in Iceland-A population-based time series analysis.
Get PDFTo access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadIntroduction: Streptococcus pneumoniae is a cause of infections that range in severity from acute otitis media (AOM) to pneumonia and invasive pneumococcal disease (IPD). The 10-valent pneumococcal conjugate vaccine (PHiD-CV10) was introduced into the Icelandic paediatric immunisation programme in 2011. The aim was to estimate the population impact and cost-effectiveness of PHiD-CV10 introduction.
Methods: Data on primary care visits from 2005-2015 and hospitalisations from 2005-2017 were obtained from population-based registries. A Bayesian time series analysis with synthetic controls was employed to estimate the number of cases of AOM, pneumonia and IPD that would have occurred between 2013-2017, had PHiD-CV10 not been introduced. Prevented cases were calculated by subtracting the observed number of cases from this estimate. The cost of the programme was calculated accounting for cost-savings due to prevented cases.
Results: The introduction of PHiD-CV10 prevented 13,767 (95% credible interval [CI] 2,511-29,410) visits for AOM from 2013-2015, and prevented 1,814 (95%CI -523-4,512) hospitalisations for pneumonia and 53 (95%CI -17-177) admissions for IPD from 2013-2017. Visits for AOM decreased both among young children and among children 4-19 years of age, with rate ratios between 0.72-0.89. Decreases were observed in both pneumonia hospitalisations (rate ratios between 0.67-0.92) and IPD (rate ratios between 0.27-0.94). The total cost of implementing PHiD-CV10 in Iceland was -7,463,176 United States Dollars (USD) (95%CI -16,159,551-582,135) with 2.1 USD (95%CI 0.2-4.7) saved for every 1 USD spent.
Conclusions: The introduction of PHiD-CV10 was associated with large decreases in visits and hospitalisations for infections commonly caused by pneumococcus and was cost-saving during the first five years of the immunisation programme.GlaxoSmithKline
Landspitali University Hospital Research Fun
Factor D Inhibition Blocks Complement Activation Induced by Mutant Factor B Associated With Atypical Hemolytic Uremic Syndrome and Membranoproliferative Glomerulonephritis.
Get PDFTo access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadComplement factor B (FB) mutant variants are associated with excessive complement activation in kidney diseases such as atypical hemolytic uremic syndrome (aHUS), C3 glomerulopathy and membranoproliferative glomerulonephritis (MPGN). Patients with aHUS are currently treated with eculizumab while there is no specific treatment for other complement-mediated renal diseases. In this study the phenotype of three FB missense variants, detected in patients with aHUS (D371G and E601K) and MPGN (I242L), was investigated. Patient sera with the D371G and I242L mutations induced hemolysis of sheep erythrocytes. Mutagenesis was performed to study the effect of factor D (FD) inhibition on C3 convertase-induced FB cleavage, complement-mediated hemolysis, and the release of soluble C5b-9 from glomerular endothelial cells. The FD inhibitor danicopan abrogated C3 convertase-associated FB cleavage to the Bb fragment in patient serum, and of the FB constructs, D371G, E601K, I242L, the gain-of-function mutation D279G, and the wild-type construct, in FB-depleted serum. Furthermore, the FD-inhibitor blocked hemolysis induced by the D371G and D279G gain-of-function mutants. In FB-depleted serum the D371G and D279G mutants induced release of C5b-9 from glomerular endothelial cells that was reduced by the FD-inhibitor. These results suggest that FD inhibition can effectively block complement overactivation induced by FB gain-of-function mutations.
Keywords: C3 glomerulopathy; atypical hemolytic uremic syndrome; complement; danicopan; factor B; factor D.Swedish Research Council
European Commission
Knut & Alice Wallenberg Foundation
Skane Centre of Excellence in Health
IngaBritt and Arne Lundberg's Research Foundation
Olle Engkvist Byggmastare Foundatio
Changes in obstetric interventions and preterm birth during COVID-19: A nationwide study from Iceland.
No full textTo access publisher's full text version of this article click on the hyperlink belowIntroduction: Previous evidence has been conflicting regarding the effect of coronavirus disease 2019 (COVID-19) pandemic lockdowns on obstetric intervention and preterm birth rates. The literature to date suggests potentially differential underlying mechanisms based on country economic setting. We aimed to study these outcomes in an Icelandic population where uniform lockdown measures were implemented across the country.
Material and methods: The study included all singleton births (n = 20 680) during 2016-2020 identified from the population-based Icelandic Medical Birth Register. We defined two lockdown periods during March-May and October-December in 2020 according to government implemented nationwide lockdown. We compared monthly rates of cesarean section, induction of labor and preterm birth during lockdown with the same time periods in the 4 previous years (2016-2019) using logit binomial regression adjusted for confounders.
Results: Our results indicated a reduction in the overall cesarean section rate, which was mainly evident for elective cesarean section, both during the first (adjusted odd ratio [aOR] 0.71, 95% CI 0.51-0.99) and second (aOR 0.72, 95% CI 0.52-0.99) lockdown periods, and not for emergency cesarean section. No change during lockdown was observed in induction of labor. Our results also suggested a reduction in the overall preterm birth rate during the first lockdown (aOR 0.69, 95% CI 0.49-0.97) and in the months immediately following the lockdown (June-September) (aOR 0.67, 95% CI 0.49-0.89). The reduction during the first lockdown was mainly evident for medically indicated preterm birth (although not statistically significant) and the reduction during June-September was mainly evident for spontaneous preterm birth.
Conclusions: This study suggested a reduction in elective cesarean section during COVID-19 lockdown, possibly reflecting changes in prioritization of non-urgent health care during lockdown. We also found a reduction in overall preterm birth during the first lockdown and spontaneous preterm birth following the first lockdown, but further research is needed to shed light on the underlying mechanisms for these findings.
Keywords: COVID-19; cesarean section; induction of labor; lockdown; preterm birth.University of New South Wales Scientia Fellowshi
Effectiveness of a couple-based intervention on sexuality and intimacy among women in active cancer treatment: A quasi-experimental study.
No full textTo access publisher's full text version of this article click on the hyperlink belowPurpose: To evaluate the effectiveness of a strenghts-oriented therapeutic conversation intervention on confidence about how illness beliefs affect sexuality and intimacy and on perceived relationship quality among women in active cancer treatment and their partners.
Methods: A quasi-experimental single-group pre-post-follow-up design was used. Women in active cancer treatment and their intimate partners were randomly assigned to a nurse-managed couple-based intervention (experimental group, n = 30 couples) or wait-list (delayed intervention) control group (n = 27 couples) plus 4 additional couples who pilot tested feasibility of the intervention, prior to the RCT. However, baseline differences in demographic and clinical variables prevented comparisons between groups. Therefore, a repeated-one-group pre-post test setup was used, comparing women with cancer and their partners over three time points. The intervention consisted of three Couple-Strengths-Oriented Therapeutic Conversations (CO-SOTC) sessions. The participants also had access to web-based evidence-based educational information. Data were collected before intervention (T1, baseline), one to two weeks post-intervention (T2), and after a follow-up session at three months (T3). Data from 60 couples (N = 120) were analyzed.
Results: Significant differences were observed, for both women and intimate partners, over time in more confidence about how illness beliefs affected sexuality and intimacy (T1 versus T2, and T1 versus T3), and increased overall quality of the relationship (T1 versus T2, and T1 versus T3). No differences were found between dyad members' scores on illness beliefs or relationship quality at any time point.
Conclusions: The CO-SOTC intervention was effective in supporting sexual adjustment among women in cancer treatment and their intimate partners.
Trial registration number: NCT03936400 at clinicaltrials.gov.
Keywords: Advanced practice nursing; Couples therapy; Neoplasms; Psychosocial support systems; Sexual health; Sexuality; Spouses; Women.Research Fund of Ingibjorg R. Magnusdottir
Icelandic Nurses' Association Scientific Fund
Landspitali University Hospital Scientific Fund
Scientific Fund of the Icelandic Cancer Societ
Metformin is associated with decreased risk of basal cell carcinoma: A whole-population case-control study from Iceland.
No full textTo access publisher's full text version of this article click on the hyperlink belowBackground: Metformin has anticarcinogenic properties and is also known to inhibit the sonic hedgehog pathway, but population-based studies analyzing the potential protective effect for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are needed.
Objectives: To delineate the association between metformin use and invasive SCC, SCC in situ (SCCis), and BCC.
Methods: A population-based case-control study design was employed using all 6880 patients diagnosed in Iceland between 2003-2017 with first-time BCC, SCCis, or invasive SCC, and 69,620 population controls. Multivariate odds ratios (ORs) were calculated using conditional logistic regression.
Results: Metformin was associated with a lower risk of developing BCC (OR, 0.71; 95% confidence interval [CI], 0.61-0.83), even at low doses. No increased risk of developing SCC was observed. SCCis risk was mildly elevated in the 501-1500 daily dose unit category (OR, 1.40; 95% CI, 1.00-1.96).
Limitations: This study was retrospective in nature with the inability to adjust for ultraviolet exposure, Fitzpatrick skin type, and comorbidities.
Conclusion: Metformin is associated with decreased risk of BCC development, even at low doses. Metformin might have potential as a chemoprotective agent for patients at high risk of BCC, although this will need confirmation in future studies.
Keywords: basal cell carcinoma; keratinocyte carcinoma; metformin; squamous cell carcinoma; squamous cell carcinoma in situ
The predictive ability of the 313 variant-based polygenic risk score for contralateral breast cancer risk prediction in women of European ancestry with a heterozygous BRCA1 or BRCA2 pathogenic variant.
Get PDFTo access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadPurpose: To evaluate the association between a previously published 313 variant-based breast cancer (BC) polygenic risk score (PRS313) and contralateral breast cancer (CBC) risk, in BRCA1 and BRCA2 pathogenic variant heterozygotes.
Methods: We included women of European ancestry with a prevalent first primary invasive BC (BRCA1 = 6,591 with 1,402 prevalent CBC cases; BRCA2 = 4,208 with 647 prevalent CBC cases) from the Consortium of Investigators of Modifiers of BRCA1/2 (CIMBA), a large international retrospective series. Cox regression analysis was performed to assess the association between overall and ER-specific PRS313 and CBC risk.
Results: For BRCA1 heterozygotes the estrogen receptor (ER)-negative PRS313 showed the largest association with CBC risk, hazard ratio (HR) per SD = 1.12, 95% confidence interval (CI) (1.06-1.18), C-index = 0.53; for BRCA2 heterozygotes, this was the ER-positive PRS313, HR = 1.15, 95% CI (1.07-1.25), C-index = 0.57. Adjusting for family history, age at diagnosis, treatment, or pathological characteristics for the first BC did not change association effect sizes. For women developing first BC < age 40 years, the cumulative PRS313 5th and 95th percentile 10-year CBC risks were 22% and 32% for BRCA1 and 13% and 23% for BRCA2 heterozygotes, respectively.
Conclusion: The PRS313 can be used to refine individual CBC risks for BRCA1/2 heterozygotes of European ancestry, however the PRS313 needs to be considered in the context of a multifactorial risk model to evaluate whether it might influence clinical decision-making.Alpe d'HuZes/Dutch Cancer Society (KWF Kankerbestrijding) project
Dutch Cancer Society (KWF Kankerbestrijding) project
Cancer Research UK
iCOGS: the European Community's Seventh Framework Programm
Low Risk of Central Line-associated Bloodstream Infections in Pediatric Hematology/Oncology Patients.
No full textIcelandic Cancer Society, Reykjavik, IcelandBackground: Central venous lines (CVLs) are essential for standard care of pediatric hematology/oncology patients providing safe administration of cytotoxic drugs and pain-free blood sampling. Central line-associated bloodstream infections (CLABSIs) cause significant morbidity. This study describes the epidemiology, microbiology, and risk factors for CLABSI in all children with malignancies in Iceland.
Methods: All children that were diagnosed with malignancy in Iceland and received a CVL during 2008-2017 were included in the study. Characteristics of CVLs and patients were registered, information on risk factors, and microbiology was collected. International standards were used for CLABSI definition.
Results: One hundred forty-three CVLs were placed in 94 children. Acute lymphoblastic leukemia was the most common underlying disease (31/94). Median age was 7 years. Implantable ports were the most commonly placed CVLs (82/143, 57%), tunneled lines were 39 (27%). Overall CLABSI rate was 0.24 infections/1000 line-days (14 episodes in 58,830 line-days), with little fluctuations. No CLABSI episodes occurred for 4 consecutive years (2012-2015). Staphylococci (of which 7 Staphylococcus aureus) were the cause of 10/14 episodes. Nine CLABSI episodes led to line removal, but no deaths were linked to CLABSIs.
Conclusion: We report very low CLABSI rates over a 9-year period at our hospital, with 4 consecutive CLABSI-free years. Even with the addition of episodes of possible CLABSI, rates were still very low and lower than most published reports
Sjúklingatilfelli við Tannlæknadeild Háskóla Íslands - Partagerð
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Reduction of antimicrobial resistant pneumococci seven years after introduction of pneumococcal vaccine in Iceland.
Get PDFTo access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked DownloadBackground: Penicillin non-susceptible (PNSP) and multi-resistant pneumococci have been prevalent in Iceland since early nineties, mainly causing problems in treatment of acute otitis media. The 10-valent protein conjugated pneumococcal vaccine (PHiD-CV) was introduced into the childhood vaccination program in 2011. The aim of the study was to investigate the changes in antimicrobial susceptibility and serotype distribution of penicillin non-susceptible pneumococci (PNSP) in Iceland 2011-2017.
Methods and findings: All pneumococcal isolates identified at the Landspítali University Hospital in 2011-2017, excluding isolates from the nasopharynx and throat were studied. Susceptibility testing was done according to the EUCAST guidelines using disk diffusion with chloramphenicol, erythromycin, clindamycin, tetracycline, trimethoprim/sulfamethoxazole and oxacillin for PNSP screening. Penicillin and ceftriaxone minimum inhibitory concentrations (MIC) were measured for oxacillin resistant isolates using the E-test. Serotyping was done using latex agglutination and/or multiplex PCR. The total number of pneumococcal isolates that met the study criteria was 1,706, of which 516 (30.2%) were PNSP, and declining with time. PNSP isolates of PHiD-CV vaccine serotypes (VT) were 362/516 (70.2%) declining with time, 132/143 (92.3%) in 2011 and 17/54 (31.5%) in 2017. PNSP were most commonly of serotype 19F, 317/516 isolates declining with time, 124/143 in 2011 and 15/54 in 2017. Their number decreased in all age groups, but mainly in the youngest children. PNSP isolates of non PHiD-CV vaccine serotypes (NVT) were 154/516, increasing with time, 11/14, in 2011 and 37/54 in 2017. The most common emerging NVTs in 2011 and 2017 were 6C, 1/143 and 10/54 respectively.
Conclusions: PNSP of VTs have virtually disappeared from children with pneumococcal diseases after the initiation of pneumococcal vaccination in Iceland and a clear herd effect was observed. This was mainly driven by a decrease of PNSP isolates belonging to a serotype 19F multi-resistant lineage. However, emerging multi-resistant NVT isolates are of concern.Landspitali University Hospital Research Fun