| 1. |
- Dewan, Ramita, et al.
(författare)
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Pathogenic Huntingtin Repeat Expansions in Patients with Frontotemporal Dementia and Amyotrophic Lateral Sclerosis.
- 2021
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Ingår i: Neuron. - : Elsevier BV. - 1097-4199 .- 0896-6273. ; 109:3
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Tidskriftsartikel (refereegranskat)abstract
- We examined the role of repeat expansions in the pathogenesis of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) by analyzing whole-genome sequence data from 2,442 FTD/ALS patients, 2,599 Lewy body dementia (LBD) patients, and 3,158 neurologically healthy subjects. Pathogenic expansions (range, 40-64 CAG repeats) in the huntingtin (HTT) gene were found in three (0.12%) patients diagnosed with pure FTD/ALS syndromes but were not present in the LBD or healthy cohorts. We replicated our findings in an independent collection of 3,674 FTD/ALS patients. Postmortem evaluations of two patients revealed the classical TDP-43 pathology of FTD/ALS, as well as huntingtin-positive, ubiquitin-positive aggregates in the frontal cortex. The neostriatal atrophy that pathologically defines Huntington's disease was absent in both cases. Our findings reveal an etiological relationship between HTT repeat expansions and FTD/ALS syndromes and indicate that genetic screening of FTD/ALS patients for HTT repeat expansions should be considered.
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| 2. |
- Hansson, Oskar, et al.
(författare)
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CSF placental growth factor – a novel candidate biomarker of frontotemporal dementia
- 2019
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Ingår i: Annals of Clinical and Translational Neurology. - : Wiley. - 2328-9503. ; 6:5, s. 863-872
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Diagnosis of frontotemporal dementia (FTD) is complicated by the overlap of clinical symptoms with other dementia disorders. Development of robust fluid biomarkers is critical to improve the diagnostic work-up of FTD. Methods: CSF concentrations of placental growth factor (PlGF) were measured in the discovery cohort including patients with FTD (n = 27), Alzheimer disease (AD) dementia (n = 75), DLB or PDD (n = 47), subcortical vascular dementia (VaD, n = 33), mild cognitive impairment that later converted to AD (MCI-AD, n = 34), stable MCI (sMCI, n = 62), and 50 cognitively healthy controls from the Swedish BioFINDER study. For validation, CSF PlGF was measured in additional independent cohort of FTD patients (n = 22) and controls (n = 18) from the Netherlands. Results: In the discovery cohort, MCI, MCI-AD, AD dementia, DLB-PDD, VaD, and FTD patients all showed increased CSF levels of PlGF compared with controls (sMCI P = 0.019; MCI-AD P = 0.005; AD dementia, DLB-PDD, VaD, and FTD all P < 0.001). PlGF levels were 1.8–2.1-fold higher in FTD than in AD, DLB-PDD and VaD (all P < 0.001). PlGF distinguished with high accuracy FTD from controls and sMCI performing better than tau/Aβ42 (AUC 0.954–0.996 versus 0.564–0.754, P < 0.001). A combination of PlGF, tau, and Aβ42 (tau/Aβ42/PlGF) was more accurate than tau/Aβ42 when differentiating FTD from a group of other dementias (AUC 0.972 vs. 0.932, P < 0.01). Increased CSF levels of PlGF in FTD compared with controls were corroborated in the validation cohort. Interpretation: CSF PlGF is increased in FTD compared with other dementia disorders, MCI, and healthy controls and might be useful as a diagnostic biomarker of FTD.
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| 3. |
- Sepehri, Sobhan, 1986, et al.
(författare)
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Characterization of Binding of Magnetic Nanoparticles to Rolling Circle Amplification Products by Turn-On Magnetic Assay
- 2019
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Ingår i: Biosensors-Basel. - : MDPI AG. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- The specific binding of oligonucleotide-tagged 100 nm magnetic nanoparticles (MNPs) to rolling circle products (RCPs) is investigated using our newly developed differential homogenous magnetic assay (DHMA). The DHMA measures ac magnetic susceptibility from a test and a control samples simultaneously and eliminates magnetic background signal. Therefore, the DHMA can reveal details of binding kinetics of magnetic nanoparticles at very low concentrations of RCPs. From the analysis of the imaginary part of the DHMA signal, we find that smaller MNPs in the particle ensemble bind first to the RCPs. When the RCP concentration increases, we observe the formation of agglomerates, which leads to lower number of MNPs per RCP at higher concentrations of RCPs. The results thus indicate that a full frequency range of ac susceptibility observation is necessary to detect low concentrations of target RCPs and a long amplification time is not required as it does not significantly increase the number of MNPs per RCP. The findings are critical for understanding the underlying microscopic binding process for improving the assay performance. They furthermore suggest DHMA is a powerful technique for dynamically characterizing the binding interactions between MNPs and biomolecules in fluid volumes.
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| 4. |
- Sepehri, Sobhan, 1986, et al.
(författare)
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Homogeneous Differential Magnetic Assay
- 2019
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Ingår i: Acs Sensors. - : American Chemical Society (ACS). - 2379-3694. ; 4:9, s. 2381-2388
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Tidskriftsartikel (refereegranskat)abstract
- Assays are widely used for detection of various targets, including pathogens, drugs, and toxins. Homogeneous assays are promising for the realization of point-of-care diagnostics as they do not require separation, immobilization, or washing steps. For low concentrations of target molecules, the speed and sensitivity of homogeneous assays have hitherto been limited by slow binding kinetics, time-consuming amplification steps, and the presence of a high background signal. Here, we present a homogeneous differential magnetic assay that utilizes a differential magnetic readout that eliminates previous limitations of homogeneous assays. The assay uses a gradiometer sensor configuration combined with precise microfluidic sample handling. This enables simultaneous differential measurement sample containing a synthesized Vibrio cholerae target and a negative control sample, which reduces the background signal and increases the readout speed. Very low concentrations of targets down to femtomolar levels are thus detectable without any additional amplification of the number of targets. Our homogeneous differential magnetic assay method opens new possibilities for rapid and highly sensitive diagnostics at the point of care.
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| 5. |
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| 6. |
- Sundström, Johan, Professor, 1971-, et al.
(författare)
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Rationale for a Swedish cohort consortium
- 2019
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Ingår i: Upsala Journal of Medical Sciences. - : Taylor & Francis Group. - 0300-9734 .- 2000-1967. ; 124:1, s. 21-28
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Tidskriftsartikel (refereegranskat)abstract
- We herein outline the rationale for a Swedish cohort consortium, aiming to facilitate greater use of Swedish cohorts for world-class research. Coordination of all Swedish prospective population-based cohorts in a common infrastructure would enable more precise research findings and facilitate research on rare exposures and outcomes, leading to better utilization of study participants' data, better return of funders' investments, and higher benefit to patients and populations. We motivate the proposed infrastructure partly by lessons learned from a pilot study encompassing data from 21 cohorts. We envisage a standing Swedish cohort consortium that would drive development of epidemiological research methods and strengthen the Swedish as well as international epidemiological competence, community, and competitiveness.
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| 7. |
- Zuberbier, T., et al.
(författare)
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Proposal of 0.5 mg of protein/100 g of processed food as threshold for voluntary declaration of food allergen traces in processed food-A first step in an initiative to better inform patients and avoid fatal allergic reactions: A GA(2)LEN position paper
- 2022
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Ingår i: Allergy. - : Wiley. - 0105-4538 .- 1398-9995. ; 77:6, s. 1736-1750
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Tidskriftsartikel (refereegranskat)abstract
- Background Food anaphylaxis is commonly elicited by unintentional ingestion of foods containing the allergen above the tolerance threshold level of the individual. While labeling the 14 main allergens used as ingredients in food products is mandatory in the EU, there is no legal definition of declaring potential contaminants. Precautionary allergen labeling such as "may contain traces of" is often used. However, this is unsatisfactory for consumers as they get no information if the contamination is below their personal threshold. In discussions with the food industry and technologists, it was suggested to use a voluntary declaration indicating that all declared contaminants are below a threshold of 0.5 mg protein per 100 g of food. This concentration is known to be below the threshold of most patients, and it can be technically guaranteed in most food production. However, it was also important to assess that in case of accidental ingestion of contaminants below this threshold by highly allergic patients, no fatal anaphylactic reaction could occur. Therefore, we performed a systematic review to assess whether a fatal reaction to 5mg of protein or less has been reported, assuming that a maximum portion size of 1kg of a processed food exceeds any meal and thus gives a sufficient safety margin. Methods MEDLINE and EMBASE were searched until 24 January 2021 for provocation studies and case reports in which one of the 14 major food allergens was reported to elicit fatal or life-threatening anaphylactic reactions and assessed if these occurred below the ingestion of 5mg of protein. A Delphi process was performed to obtain an expert consensus on the results. Results In the 210 studies included, in our search, no reports of fatal anaphylactic reactions reported below 5 mg protein ingested were identified. However, in provocation studies and case reports, severe reactions below 5 mg were reported for the following allergens: eggs, fish, lupin, milk, nuts, peanuts, soy, and sesame seeds. Conclusion Based on the literature studied for this review, it can be stated that cross-contamination of the 14 major food allergens below 0.5 mg/100 g is likely not to endanger most food allergic patients when a standard portion of food is consumed. We propose to use the statement "this product contains the named allergens in the list of ingredients, it may contain traces of other contaminations (to be named, e.g. nut) at concentrations less than 0.5 mg per 100 g of this product" for a voluntary declaration on processed food packages. This level of avoidance of cross-contaminations can be achieved technically for most processed foods, and the statement would be a clear and helpful message to the consumers. However, it is clearly acknowledged that a voluntary declaration is only a first step to a legally binding solution. For this, further research on threshold levels is encouraged.
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