| 1. |
- Axelsson, Emelie, et al.
(författare)
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Rutile R632-A New Natural Reference Material for U-Pb and Zr Determination
- 2018
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Ingår i: Geostandards and Geoanalytical Research. - : Wiley. - 1639-4488 .- 1751-908X. ; 42:3, s. 319-338
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Tidskriftsartikel (refereegranskat)abstract
- A new natural rutile reference material is presented, suitable for U-Pb dating and Zr-in-rutile thermometry by microbeam methods. U-Pb dating of rutile R632 using laser ablation ICP-MS with both magnetic sector field and quadrupole instruments as well as isotope dilution-thermal ionisation mass spectrometry yielded a concordia age of 496 +/- 2Ma. The high U content (>300gg(-1)) enabled measurement of high-precision U-Pb ages despite its young age. The sample was found to have a Zr content of 4294 +/- 196gg(-1), which makes it an excellent complementary reference material for Zr-in-rutile thermometry. Individual rutile grains have homogeneous compositions of a number of other trace elements including V, Cr, Fe, Nb, Mo, Sn, Sb, Hf, Ta and W. This newly characterised material significantly expands the range of available rutile reference materials relevant for age and temperature determinations.
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| 2. |
- Axelsson, Emelie, et al.
(författare)
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The Kuunga Orogeny in the Eastern Ghats Belt : Evidence from geochronology of biotite, amphibole and rutile, and implications for the assembly of Gondwana
- 2020
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Ingår i: Precambrian Research. - : Elsevier BV. - 0301-9268 .- 1872-7433. ; 347
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Tidskriftsartikel (refereegranskat)abstract
- The Eastern Ghats Belt, India, is a high grade polymetamorphic terrane; most of it was metamorphosed under high temperature to ultra-high temperature (UHT) conditions at 1000-900 Ma. This study presents new Rb-Sr biotite, Ar-40-Ar-39 amphibole and U-Pb rutile ages for 32 samples of HT and UHT lithologies from across the Eastern Ghats, Jaypore and Rengali Provinces. This dataset provides the first comprehensive evidence for a pervasive, region-wide amphibolite facies metamorphism at ca. 500 Ma throughout the Eastern Ghats Belt that overprinted the earlier (U)HT mineral assemblages. The lower-grade Cambrian overprint did not lead to retrogression of the high grade mineral assemblages but is recorded by different geochronometers. Rb-Sr biotite, Ar-40-Ar-39 amphibole and U-Pb rutile ages from the entire Eastern Ghats Belt cluster around ca. 500 Ma. U-Pb ages for zircon from six of the samples dated by Rb-Sr biotite and/or U-Pb rutile do not record this young event but yield ages that correspond to the earlier high-grade metamorphism. Combined with previously published geochronological information, the new ages show that a medium grade tectonothermal event during the Cambrian affected the whole Eastern Ghats Belt on a regional scale. This last regional metamorphism was essentially fluid-absent, as the parageneses originating from high-grade metamorphism at 1000-900 Ma are still pristine and do not show pervasive retrograde mineral reactions. This Cambrian metamorphic episode is also recorded as a high-T overprint in the high-grade gneisses of Sri Lanka, southern India and Madagascar and is the result of the assembly of Gondwana that led to the collision of Antarctica with India, which formed part of the Kuunga orogeny. The new data provide evidence for the extension of the Kuunga orogeny into eastern India and support it representing a major orogenic event in the assembly of Gondwana.
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| 3. |
- Lundgren, Anna, 1974, et al.
(författare)
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Plasmablasts in previously immunologically naive COVID-19 patients express markers indicating mucosal homing and secrete antibodies cross-reacting with SARS-CoV-2 variants and other beta-coronaviruses
- 2023
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Ingår i: Clinical and Experimental Immunology. - 0009-9104 .- 1365-2249. ; 213:2, s. 173-89
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Tidskriftsartikel (refereegranskat)abstract
- Antigen-specific class-switched antibodies are detected at the same time or even before IgM in serum of non-vaccinated individuals infected with SARS-CoV-2. These derive from the first wave of plasmablasts formed. Hence, the phenotype and specificity of plasmablasts can reveal information about early B-cell activation. Here we have analyzed B cells and plasmablasts circulating in blood of COVID-19 patients not previously exposed to SARS-CoV-2 during and after disease. We find that during infection with the original Wuhan strain, plasmablasts in blood produce IgA1, IgG1, and IgM, and that most express CCR10 and integrin beta 1, only some integrin beta 7, while the majority lack CCR9. Plasmablast-secreted antibodies are reactive to the spike (S) and nucleocapsid (N) proteins of the Wuhan strain as well as later variants of concern, but also bind S proteins from endemic and non-circulating betacoronaviruses. In contrast, after recovery, antibodies produced from memory B cells target variants of SARS-CoV-2 and SARS-CoV-1 but compared to previously non-infected individuals do not show increased binding to endemic coronaviruses. This suggests that the early antibody response to a large extent stems from pre-existing cross-reactive class-switched memory B cells, and that although newly formed memory cells target the novel SARS-CoV-2 virus the numbers of broadly cross-reactive memory B cells do not increase extensively. The observations give insight into the role of pre-existing memory B cells in early antibody responses to novel pathogens and may explain why class-switched antibodies are detected early in the serum of COVID-19 patients. During an infection, plasmablasts circulating in blood represent ongoing formation of antibody-producing cells from activated B cells. Here we study the early plasmablasts in previously naive COVID-19 patients arriving at hospital. We find extensive cross-reactivity to circulating and non-circulating beta-coronaviruses, that IgA1 responses dominate, and that the cells express markers suggesting mucosal homing.
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| 4. |
- Marklund, Emelie, et al.
(författare)
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Serum-IgG responses to SARS-CoV-2 after mild and severe COVID-19 infection and analysis of IgG non-responders.
- 2020
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Ingår i: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 15:10
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Tidskriftsartikel (refereegranskat)abstract
- To accurately interpret COVID-19 seroprevalence surveys, knowledge of serum-IgG responses to SARS-CoV-2 with a better understanding of patients who do not seroconvert, is imperative. This study aimed to describe serum-IgG responses to SARS-CoV-2 in a cohort of patients with both severe and mild COVID-19, including extended studies of patients who remained seronegative more than 90 days post symptom onset.SARS-CoV-2-specific IgG antibody levels were quantified using two clinically validated and widely used commercial serological assays (Architect, Abbott Laboratories and iFlash 1800, YHLO), detecting antibodies against the spike and nucleocapsid proteins.Forty-seven patients (mean age 49 years, 38% female) were included. All (15/15) patients with severe symptoms and 29/32 (90.6%) patients with mild symptoms of COVID-19 developed SARS-CoV-2-specific IgG antibodies in serum. Time to seroconversion was significantly shorter (median 11 vs. 22 days, P = 0.04) in patients with severe compared to mild symptoms. Of the three patients without detectable IgG-responses after >90 days, all had detectable virus-neutralizing antibodies and in two, spike-protein receptor binding domain-specific IgG was detected with an in-house assay. Antibody titers were preserved during follow-up and all patients who seroconverted, irrespective of the severity of symptoms, still had detectable IgG levels >75 days post symptom onset.Patients with severe COVID-19 both seroconvert earlier and develop higher concentrations of SARS-CoV-2-specific IgG than patients with mild symptoms. Of those patients who not develop detectable IgG antibodies, all have detectable virus-neutralizing antibodies, suggesting immunity. Our results showing that not all COVID-19 patients develop detectable IgG using two validated commercial clinical methods, even over time, are vital for the interpretation of COVID-19 seroprevalence surveys.
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| 5. |
- Scharf, Lydia, et al.
(författare)
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Longitudinal single-cell analysis of SARS-CoV-2-reactive B cells uncovers persistence of early-formed, antigen specific clones.
- 2023
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Ingår i: JCI insight. - : American Society for Clinical Investigation. - 2379-3708. ; 8:1
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Tidskriftsartikel (refereegranskat)abstract
- Understanding persistence and evolution of B cell clones after COVID-19 infection and vaccination is crucial for predicting responses against emerging viral variants and optimizing vaccines. Here, we collected longitudinal samples from severe COVID-19 patients every third to seventh day during hospitalization and every third month after recovery. We profiled the antigen-specific immune cell dynamics by combining single cell RNA-Seq, Cellular Indexing of Transcriptomes and Epitopes by Sequencing (CITE)-Seq, B cell receptor (BCR)-Seq with oligo-tagged antigen baits. While the proportion of Spike Receptor Binding Domain-specific memory B cells (MBC) increased from 3 months after infection, the other Spike- and Nucleocapsid-specific B cells remained constant. All patients showed ongoing class switching and sustained affinity maturation of antigen specific cells, which was not significantly increased early after vaccine. B cell analysis revealed a polyclonal response with limited clonal expansion; nevertheless, some clones detected during hospitalization, as plasmablasts, persisted for up to one year, as MBC. Monoclonal antibodies derived from persistent B cell families increased their binding and neutralization breadth and started recognizing viral variants by 3 months after infection. Overall, our findings provide important insights into the clonal evolution and dynamics of antigen specific B cell responses in longitudinally sampled COVID-19 infected patients.
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| 6. |
- Svensson, Emelie, et al.
(författare)
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Success rate of external cephalic version in relation to the womans body mass index and other factors-a population-based cohort study
- 2021
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Ingår i: Acta Obstetricia et Gynecologica Scandinavica. - : Wiley. - 0001-6349 .- 1600-0412. ; 100:12, s. 2260-2267
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Tidskriftsartikel (refereegranskat)abstract
- Introduction The aim of this study was to evaluate the impact of womens body mass index (BMI) on the probability of a successful external cephalic version (ECV). Material and methods A retrospective population-based observational study including all women that underwent an ECV in the southeast region of Sweden from January 2014 to December 2019. Data were collected from electronic medical records, Obstetrix, Cerner. The women were divided into BMI categories according to the World Health Organization classification. Women with a BMI below 25 kg/m(2) formed the reference group. Crude and adjusted odds ratios for unsuccessful ECV in each BMI group were calculated using binary logistic regression. Furthermore, the association between maternal characteristics and clinical and ultrasound variables at the time of the ECV and unsuccessful ECV was evaluated. Results A total of 2331 women were included. The overall success rate of ECV was 53.4%. Women with a BMI below 25 kg/m(2) had a success rate of 51.3% whereas obese women had a success rate of 58.6%. The risk of an unsuccessful ECV among obese women (BMI >= 30 kg/m(2)) had an OR of 0.74 (95% CI 0.59-0.94) compared with women with a BMI below 25 kg/m(2). After adjusting for suitable confounding factors, the association was no longer significant. Higher maternal age, multiparity, higher gestational age, posterior placenta position, polyhydramnios and higher estimated weight of the fetus at the ECV significantly decreased the risk of an unsuccessful ECV. Conclusions Maternal obesity does not seem to negatively influence the success rate of ECV. This is a finding that may encourage both caregivers and obese pregnant women to consider an ECV and so avoid a planned cesarean section for breech presentation in this group.
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| 7. |
- Svensson, Emelie, et al.
(författare)
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Success Rate of External Cephalic Version in Relation to the Womans Body Mass Index and Other Factors-A Population-Based Cohort Study
- 2022
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Ingår i: Obstetrical and Gynecological Survey. - Philadelphia, PA, United States : Lippincott Williams & Wilkins. - 0029-7828 .- 1533-9866. ; 77:6, s. 330-331
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- (Abstracted from Acta Obstet Gynecol Scand 2021;100:2260–2267)For pregnancies with fetuses in the breech position, external cephalic version (ECV) is used to turn the fetus into a cephalic presentation. The procedure is associated with low complication rates, with the most common being transient fetal heart rate abnormalities, and a success rate up to 65% in various studies.
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