852 results on '"Wikström, Johan"'
Search Results
202. Pregnancy hypertensive disease and risk of dementia and cardiovascular disease in women aged 65 years or older : a cohort study
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Nelander, Maria, Cnattingius, S, Åkerud, Helena, Wikström, Johan, Pedersen, N L, Wikström, Anna-Karin, Nelander, Maria, Cnattingius, S, Åkerud, Helena, Wikström, Johan, Pedersen, N L, and Wikström, Anna-Karin
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OBJECTIVE: The primary aim was to study pregnancy hypertensive disease and subsequent risk of dementia. The second aim was to study if the increased risks of cardiovascular disease (CVD) and stroke after pregnancy hypertensive disease persist in an elderly population. DESIGN: Cohort study. SETTING: Sweden. POPULATION OR SAMPLE: 3232 women 65 years or older (mean 71 years) at inclusion. METHODS: Cox proportional hazards regression analyses were used to calculate risks of dementia, CVD and/or stroke for women exposed to pregnancy hypertensive disease. Exposure data were collected from an interview at inclusion during the years 1998-2002. Outcome data were collected from the National Patient Register and Cause of Death Register from the year of inclusion until the end of 2010. Age at inclusion was set as a time-dependent variable, and adjustments were made for body mass index, education and smoking. MAIN OUTCOME MEASURES: Dementia, CVD, stroke. RESULTS: During the years of follow-up, 7.6% of the women exposed to pregnancy hypertensive disease received a diagnosis of dementia, compared with 7.4% among unexposed women (HR 1.19; 95% CI 0.79 to 1.73). The corresponding rates for CVD were 22.9% for exposed women and 19.0% for unexposed women (HR 1.29; 95% CI 1.02 to 1.61), and for stroke 13.4% for exposed women and 10.7% for unexposed women (HR 1.36; 95% CI 1.00 to 1.81). CONCLUSIONS: There was no increased risk of dementia after self-reported pregnancy hypertensive disease in our cohort. We found that the previously reported increased risk of CVD and stroke after pregnancy hypertensive disease persists in an older population.
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- 2016
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203. Human fertilizer and the productivity of farming households
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Pettersson, Jan, Wikström, Johan, Pettersson, Jan, and Wikström, Johan
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Ecological sanitation offers both sanitation and fertilizer through recycling of nutrients. Human fertilizer provides a close to free addition of nutrients in household farming and may, therefore, decrease the downward risk of fertilizer adoption. We study an ecological sanitation investment program in southern Mali, where just over 150 beneficiaries got a urine diverting dry toilet installed. Our results suggest that the average household in our study is able to produce amounts of N, P, and K equivalent to around a fourth of its yearly expenditures on artificial fertilizers, corresponding to a yearly addition of nutrients or a yearly reduction in fertilizer expenditures to a value of about 50 Euro. However, the quantity and quality of N, P, and K actually retained is found to be only a fraction of this potential amount. Using propensity score matching methods, we find an increase in maize yields among beneficiary households, but no effect on the yields of other crops. Moreover, households substitute artificial fertilizer with human fertilizer at 10-15% of the average household use of artificial fertilizers. Thus, the substitution may worsen an already bad soil nutrient balance. Higher retention levels are needed for solutions to prove financially viable.
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- 2016
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204. The effect of combined hormonal contraceptives use on brain reactivity during response inhibition
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Gingnell, Malin, Bannbers, Elin, Engman, Jonas, Frick, Andreas, Moby, Lena, Wikström, Johan, Sundström-Poromaa, Inger, Gingnell, Malin, Bannbers, Elin, Engman, Jonas, Frick, Andreas, Moby, Lena, Wikström, Johan, and Sundström-Poromaa, Inger
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Objectives Cognitive control, which can be described as the ability to moderate impulses, has not previously been investigated in users of combined hormonal contraception (CHC). Given the suggested modulatory role of ovarian steroids in prefrontal dopaminergic function, which in turn taps into cognitive control, this randomised, double-blinded, placebo-controlled oral contraceptive trial set out to investigate the brain activity pattern during response inhibition in CHC users. Methods Thirty-four women were randomised to one treatment cycle with a levonorgestrel-containing CHC or placebo. The women performed a Go/NoGo task to measure brain activity during response inhibition by use of event-related functional magnetic resonance imaging (fMRI) prior to and during the CHC/placebo treatment cycle. Results No differences between CHC and placebo users in number of correct inhibitions were found during treatment, but only women on CHC significantly improved their performance between the baseline and treatment assessments. During the treatment cycle CHC users displayed decreased activity in the right middle frontal gyrus in comparison with placebo users. No other significant activations were evident between treatment groups or within groups. Conclusion Overall, CHC use had marginal effects on brain activity during response inhibition. If anything, the findings of the study may suggest reduced effort or increased efficiency in maintaining orbitofrontal cortex inhibitory cognitive control when using a combined oral contraceptive.
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- 2016
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205. Re : Placental magnetic resonance imaging T2*measurements in normal pregnancies and in those complicated by fetal growth restriction. M. Sinding, D. A. Peters, J. B. Frokjaer, O. B. Christiansen, A. Petersen, N. Uldbjerg and A. Sorensen. Ultrasound Obstet Gynecol 2016; 47: 748-754.
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Wikström, Johan and Wikström, Johan
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- 2016
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206. MRI analysis of diffuse axonal injury - Hemorrhagic lesions in the mesencephalon idicate poor long-term outcome
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Abu Hamdeh, Sami, Marklund, Niklas, Lannsjö, Marianne, Howells, Tim, Raininko, Raili, Wikström, Johan, Enblad, Per, Abu Hamdeh, Sami, Marklund, Niklas, Lannsjö, Marianne, Howells, Tim, Raininko, Raili, Wikström, Johan, and Enblad, Per
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Purpose: Clinical outcome after traumatic diffuse axonal injury (DAI) is difficult to predict. Three MRI techniques were compared in demonstrating acute brain lesions. Relationship of the anatomical distribution of the lesions in combination with clinical prognostic factors to outcome after 6 months was evaluated. Methods and Materials: Thirty patients, aged 16-60 years (mean 31.2 years) with severe DAI (Glasgow Motor Score = GMS < 6) were examined with MRI at 1.5T within one week after the injury. A diffusion-weighted (DW) sequence (SE-EPI, b value 1000 s/mm2), a T2*-weighted gradient echo (T2*GRE) sequence and a susceptibility-weighted (SWI) sequence were evaluated by two independent reviewers with short and long neuroradiological experiences. Clinical outcome was assessed with Extended Glasgow Outcome Score (GOSE) after ≥ 6 months. Results: Interreviewer agreement for DAI classification was very good (ҡ 0.82 – 0.91) with all three sequences. SWI visualized more lesions than the T2*GRE or DW sequence. In univariate analysis, number of DW lesions in the deep gray matter area including the internal capsules, number of SWI lesions in the mesencephalon, age, and GMS at admission and discharge correlated significantly with poor outcome. Multivariate analysis only revealed an independent relation with poor outcome for age (p = 0.011) and lesions in the mesencephalic region including crura cerebri, substantia nigra and tegmentum on SWI (p = 0.032). Conclusion: SWI is the most sensitive technique to visualize lesions in DAI. Age over 30 years and hemorrhagic mesencephalic lesions anterior to the tectum are indicators of poor long-term outcome in DAI.
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- 2016
207. Parahippocampal involvement in source encoding: does sex make a difference?
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Stening, Eva, Persson, Jonas, Nordin, Kristin, Wikström, Johan, and Söderlund, Hedvig
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- 2014
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208. Evaluation of INTERPRET Decision Support System (DSS) in clinical MRS of intracranial lesions and comparison to conventional MRS analysis and MRI.
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Hellström, Jussi, Romanos Zapata, Romina, Ortiz-Nieto, Francisco, Libard, Sylwia, Alafuzoff, Irina, Wikström, Johan, Raininko, Raili, Hellström, Jussi, Romanos Zapata, Romina, Ortiz-Nieto, Francisco, Libard, Sylwia, Alafuzoff, Irina, Wikström, Johan, and Raininko, Raili
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- 2015
209. Relation between Cardiovascular Disease Risk Markers and Brain Infarcts Detected by Magnetic Resonance Imaging in an Elderly Population
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Nylander, Ruta, Lind, Lars, Wikström, Johan, Lindahl, Bertil, Venge, Per, Larsson, Anders, Arnlöv, Johan, Berglund, Lars, Ahlström, Håkan, Johansson, Lars, Larsson, Elna-Marie, Nylander, Ruta, Lind, Lars, Wikström, Johan, Lindahl, Bertil, Venge, Per, Larsson, Anders, Arnlöv, Johan, Berglund, Lars, Ahlström, Håkan, Johansson, Lars, and Larsson, Elna-Marie
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BACKGROUND: Established cardiovascular risk markers, such as hypertension, are associated with increased risk of brain infarcts. The newer markers N-terminal pro-brain natriuretic peptide, troponin I, C-reactive protein, and cystatin C may affect the risk of cardiovascular events and potentially, thereby, also stroke. We investigated the association between established and new risk markers for cardiovascular disease and brain infarcts detected by magnetic resonance imaging (MRI) at age 75. METHODS: Four hundred six randomly selected subjects from the Prospective Investigation of the Vasculature in Uppsala Seniors study were examined with MRI of the brain at age 75. Blood samples, measurements, and dedicated questionnaires at age 70 were used for analysis of risk markers. A history of diseases had been obtained at age 70 and 75. MRI was evaluated regarding lacunar and cortical infarcts. Univariate associations between outcomes and risk markers were assessed with logistic regression models. RESULTS: One or more infarcts were seen in 23% of the subjects (20% had only lacunar infarcts, 1% had only cortical infarcts, and 2% had both). Hypertension (odds ratio [OR] 2.6, 95% confidence interval [CI] 1.4, 4.7) and obesity (OR 1.3; CI 1.0, 1.8) were significantly associated with increased risk of brain infarction. The newer risk markers were not significantly associated with the brain infarcts. CONCLUSIONS: The new markers were not associated with the predominantly lacunar infarcts in our 75-year-old population, why troponin I and NT-proBNP may be associated mainly with cardioembolic infarcts as shown recently.
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- 2015
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210. Clinical value of MR spectroscopy: How often does MRS yield more information than MRI?
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Hellström, Jussi, Romanos Zapata, Romina, Libard, Sylwia, Alafuzoff, Irina, Wikström, Johan, Ortiz-Nieto, Francisco, Raininko, Raili, Hellström, Jussi, Romanos Zapata, Romina, Libard, Sylwia, Alafuzoff, Irina, Wikström, Johan, Ortiz-Nieto, Francisco, and Raininko, Raili
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- 2015
211. Evaluating supervised machine learning algorithms to predict recreational fishing success : A multiple species, multiple algorithms approach
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Wikström, Johan and Wikström, Johan
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This report examines three different machine learning algorithms and their effectiveness for predicting recreational fishing success. Recreational fishing is a huge pastime but reliable methods of predicting fishing success have largely been missing. This report compares random forest, linear regression and multilayer perceptron to a reasonable baseline model for predicting fishing success. Fishing success is defined as the expected weight of the fish caught. Previous reports have mainly focused on commercial fishing or limited the research to examining the impact of a single variable. In this exploratory study, multiple attributes and multiple algorithms are examined to determine if supervised machine learning is a viable tool to predict recreational fishing success. Recreational fishing success can potentially be predicted by a large number of attributes, which may be different for different species. In this report, data is fetched from multiple sources and combined into a unified data format. The primary source of data is a database from the fishing app FishBrain, containing data of over 250000 logged catches. Another is the World Weather Online API which supplies weather data. The report focuses on the four most common species in the database, largemouth bass, Micropterus salmoides, northern pike, Esox lucius, rainbow trout, Oncorhynchus mykiss and European perch, Perca fluviatilis with a focus on largemouth bass since it has the most data available. Algorithms are evaluated using the Weka data mining software. Hyperparameters are found using cross-validation and some data is used as a test set to validate the results after cross-validation. Results are measured as the error compared to a baseline algorithm. Random forest is the most effective algorithm in the experiments, reducing error compared to the baseline for all the examined fish species. It is also found that no single variable affects the chosen metric of fishing success much, but rather a combination, I denna rapport evalueras tre olika maskininlärningsalgoritmer och deras effektivitet för att förutsäga framgång inom sportfiske. Sport- fiske är en mycket populär hobby, men pålitliga metoder att förutsäga framgångsrikt sportfiske saknas. Denna rapport jämför random forest, linjär regression och flerlagers neurala nätverk mot en rimlig baselinealgorithm för att förutsäga framgång inom sportfiske. Framgång defineras som fiskens förväntade vikt i kg. Tidigare undersökningar har huvudsakligen fokuserat på kommersiellt fiske eller begränsat undersökningen till påverkan av en enskild variabel. I denna studie undersöks flera attribut och algoritmer för att avgöra om övervakad maskininlärning är ett användbart verktyg för att förutsäga framgång inom sportfiske. Framgång inom sportfiske kan potentiellt påverkas av ett stort antal attribut som kan vara olika för olika arter. I denna studie hämtas data från ett flertal källor som kombineras i ett unifierat dataformat. Den primära datakällan är en databas tillhörande sportfiskeappen FishBrain som innehåller över 250000 loggade fångster. En annan källa är World Weather Online:s API som bidrar med väderdata. Rapporten fokuserar på de fyra vanligaste arterna i databasen, largemouth bass, Micropterus salmoides, gädda, Esox lucius, regnbågsöring, Oncorhynchus mykiss och europeisk abborre, Perca fluviatilis med ett särskilt fokus på largemouth bass eftersom den har mest data tillgängligt. Algoritmerna evalueras med hjälp av data mining-verktyget Weka. Hyperparametrar bestäms med hjälp av korsvalidering och en delmängd av datan separeras och används för att validera resultaten efter korsvalidering. Resultaten mäts relativt en baseline-algoritm. Random forest är den mest effektiva algoritmen i experimenten och reducerar felet jämfört med baseline-algoritmen för alla undersökta fiskarter. Inget enskilt attribut påverkar slutresultatet mycket utan det behövs en kombination av flera attribut för att ge optimala prediktioner. Slutsatsen
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- 2015
212. Emotion Reactivity Is Increased 4-6 Weeks Postpartum in Healthy Women: A Longitudinal fMRI Study
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Gingnell, Malin, Bannbers, Elin, Moes, Harmen, Engman, Jonas, Sylvén, Sara, Skalkidou, Alkistis, Kask, Kristiina, Wikström, Johan, Sundström-Poromaa, Inger, Gingnell, Malin, Bannbers, Elin, Moes, Harmen, Engman, Jonas, Sylvén, Sara, Skalkidou, Alkistis, Kask, Kristiina, Wikström, Johan, and Sundström-Poromaa, Inger
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- 2015
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213. Peeing out of poverty? Human fertilizer and the productivity of farming households
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Pettersson, Jan and Wikström, Johan
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Household Productivity ,Ecological Sanitation ,UDDT ,Mali ,Fertilizer ,Matching ,jel:O13 ,jel:O12 ,jel:Q12 ,jel:D13 - Abstract
In many parts of the world, soils poor in nutrients are farmed with little addition of fertilizer, further depleting the farmland. The very same farmers often face poor sanitary solutions. So-called ecological sanitation aims at providing sanitation and at recycling nutrients as fertilizer. This human fertilizer may act as a substitute for artificial fertilizers (improving the household budget) or as a complement (improving soil quality, increasing agricultural yields). We collected demographic, economic and farming data from 618 households in southern Mali, of which 155 benefitted from an ecological sanitation investment program. We do not find any support for human fertilizer being used complementary, although the effect on yields varies over crops. Instead, we find that beneficiary households substitute artificial fertilizer with human fertilizer at 10 to 15 per cent of the average household use of artificial fertilizers. While our results imply small economic incentives at the household level for investing in ecological sanitation, we do not account for health effects at the household or community level.
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- 2013
214. Peeing out of poverty? Human fertilizer andthe productivity of farming households
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Pettersson, Jan and Wikström, Johan
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Household Productivity ,Ecological Sanitation ,UDDT ,Mali ,Fertilizer ,Matching - Abstract
In many parts of the world, soils poor in nutrients are farmed with little addition of fertilizer, further depleting the farmland. The very same farmers often face poor sanitary solutions. So-called ecological sanitation aims at providing sanitation and at recycling nutrients as fertilizer. This human fertilizer may act as a substitute for artificial fertilizers (improving the household budget) or as a complement (improving soil quality, increasing agricultural yields). We collected demographic, economic and farming data from 618 households in southern Mali, of which 155 benefitted from an ecological sanitation investment program. We do not find any support for human fertilizer being used complementary, although the effect on yields varies over crops. Instead, we find that beneficiary households substitute artificial fertilizer with human fertilizer at 10 to 15 per cent of the average household use of artificial fertilizers. While our results imply small economic incentives at the household level for investing in ecological sanitation, we do not account for health effects at the household or community level.
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- 2013
215. Evolution of Artificial Brains in Simulated AnimalBehaviour
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TEGELUND, BJÖRN and WIKSTRÖM, JOHAN
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Datavetenskap (datalogi) ,Computer Sciences - Abstract
In this report we simulate artificial intelligence in animals using genetic algorithms. In similar models, advanced artificial neural networks have been used for decision making. We present two simpler decision-making models. Using two models based on linear and radial basis functions we find similar behaviours as those found in other studies, including food seeking, obstacle avoidance and predator-versus-prey dynamics. The results show that both decision-making models are equally efficient at gathering food and avoiding obstacles. The models differed in survival strategies when faced with dangerous obstacles and in a predator-versus-prey situation the predators based on radial basis functions performed better. Some evolutionary phenomena were observed during the evolution of the animals, including an evolutionary armsrace between predator and prey. We hoped to find signs of mimicry as well, but classic mimicry was not found in the results. med hjälp av genetiska algoritmer. I liknande modeller har man tidigare använd avancerade artificiella neuronnät som beslutsmodeller. I denna rapport presenterar vi två enklare beslutsmodeller. Med två modeller baserade på linjära och radiella basfunktioner hittas liknande beteenden som i tidigare rapporter, inklusive födoletande, hinderundvikande och predator-bytesdjursdynamik. Resultaten visar att båda beslutsmodeller är lika effektiva vid födoletande och hinderundvikande. Modellernas överlevnadsstrategier skiljer sig när farliga hinder införs och i predator-bytesdjurssitationer är predatorn baserad på radiella basfunktioner effektivare. Vissa evolutionära fenomen observerades under evolutionen av djuren, inklusive en evolutionär kapplöpning mellan bytesdjur och predator. Vi hoppades även finna tecken på mimikry, men klassisk mimikry observerades inte i resultaten
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- 2013
216. Den sökande är en man : Hur språket påverkar bedömningen i en rekryteringsprocess
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Wikström, Johan and Strömbäck, Ellen
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agentic ,diskriminering ,könsstereotypiskt språk ,rekrytering ,communal ,sexism ,lack of fit ,genus ,hen - Abstract
Svensk arbetsmarknad är snedfördeladmellan män och kvinnor. Tidigare forskning har visat att könsstereotypiskt språk (agentic/communal) kan bidra till att upprätthålla denna snedfördelning, skapa statusskillnader mellan kvinnor och män samt leda till diskriminering av kvinnor redan i en rekryteringsprocess. Med ett flerfaktoriellt experiment (N=194) av dubbel-blind-design med randomiserade deltagare undersöktes, huruvida bedömningen av en arbetssökande påverkas av könsstereotypiskt språk, samt vilken attityd deltagarna hade till pronomenHen. Deltagare betingades med agentic eller communal platsannons samt en av fyra personbeskrivningar.Sedan skattades den sökandes agentic och communal egenskaper. Deltagarna svarade på frågor gällande sexism samt uttryckte sin åsikt om Hen. Två av studiens fyra hypoteser kunde styrkas, de övriga två förkastades. Studien visar att könsstereotypiskt språk har betydelse för hur en sökande bedöms, att Den sökande uppfattas som en man och att sexism predicerar negativa åsikter om Hen.
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- 2013
217. Human fertilizer and the productivity of farming households
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Pettersson, Jan, primary and Wikström*, Johan, additional
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- 2015
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218. The effect of combined hormonal contraceptives use on brain reactivity during response inhibition
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Gingnell, Malin, primary, Bannbers, Elin, additional, Engman, Jonas, additional, Frick, Andreas, additional, Moby, Lena, additional, Wikström, Johan, additional, and Sundström-Poromaa, Inger, additional
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- 2015
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219. Emotion Reactivity Is Increased 4-6 Weeks Postpartum in Healthy Women: A Longitudinal fMRI Study
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Gingnell, Malin, primary, Bannbers, Elin, additional, Moes, Harmen, additional, Engman, Jonas, additional, Sylvén, Sara, additional, Skalkidou, Alkistis, additional, Kask, Kristiina, additional, Wikström, Johan, additional, and Sundström-Poromaa, Inger, additional
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- 2015
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220. Relation between Cardiovascular Disease Risk Markers and Brain Infarcts Detected by Magnetic Resonance Imaging in an Elderly Population
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Nylander, Ruta, primary, Lind, Lars, additional, Wikström, Johan, additional, Lindahl, Bertil, additional, Venge, Per, additional, Larsson, Anders, additional, Ärnlöv, Johan, additional, Berglund, Lars, additional, Ahlström, Håkan, additional, Johansson, Lars, additional, and Larsson, Elna-Marie, additional
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- 2015
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221. Social stimulation and corticolimbic reactivity in premenstrual dysphoric disorder : a preliminary study
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Gingnell, Malin, Ahlstedt, Victoria, Bannbers, Elin, Wikström, Johan, Sundström-Poromaa, Inger, Fredrikson, Mats, Gingnell, Malin, Ahlstedt, Victoria, Bannbers, Elin, Wikström, Johan, Sundström-Poromaa, Inger, and Fredrikson, Mats
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BACKGROUND: Premenstrual dysphoric disorder (PMDD), characterized by luteal phase-induced negative affect and loss of impulse control, often results in compromised social interactions. Although amygdala activation is generally linked to negative affect, increased amygdala reactivity to aversive stimuli in the luteal phase has not been consistently reported in PMDD. We tested the hypothesis that amygdala hyper-reactivity in PMDD is symptom specific, rather than generalized, and linked to socially relevant stimuli. Blood oxygenation level dependent signal changes during exposure to negative images with social and non-social content were evaluated in the mid-follicular and late luteal phase of the menstrual cycle. Fourteen women with PMDD and 13 healthy controls participated. RESULTS: When compared with healthy controls, women with PMDD in the luteal phase had enhanced reactivity to social stimuli compared to non-social stimuli in the amygdala and insula, but attenuated reactivity in the anterior cingulate cortex. Functional couplings between emotion processing and controlling areas were significantly different, being positive in women with PMDD and negative in healthy controls. Changes in progesterone levels in women with PMDD correlated positively with altered amygdala reactivity. CONCLUSIONS: Socially relevant aversive stimulation elicited enhanced activity in affective processing brain regions that were functionally coupled to compromised activity in cognitive control areas. Because increased reactivity correlated positively with alterations in ovarian steroid levels, data preliminary support the hypothesis that enhanced progesterone sensitivity in PMDD affects corticolimbic processing of social emotions., De två sista författarna delar sistaförfattarskapet.
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- 2014
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222. Plasma Levels of S100B in Preeclampsia and Association With Possible Central Nervous System Effects
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Bergman, Lina, Akhter, Tansim, Wikström, Anna-Karin, Wikström, Johan, Naessén, Tord, Åkerud, Helena, Bergman, Lina, Akhter, Tansim, Wikström, Anna-Karin, Wikström, Johan, Naessén, Tord, and Åkerud, Helena
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BACKGROUND: S100B is supposed to be a peripheral biomarker of central nervous system (CNS) injury. The purpose of this study was to compare levels of S100B in women with preeclampsia with levels in healthy pregnant control subjects and furthermore to analyze levels of S100B in relation to possible CNS effects. METHODS: A cross-sectional case-control study in antenatal care centers in Uppsala, Sweden, was performed. Fifty-three women with preeclampsia and 58 healthy pregnant women were recruited at similar gestational length; women with preeclampsia were recruited at time of diagnosis, and control subjects were recruited during their routine visit to an antenatal clinic. Plasma samples were collected, and levels of S100B were analyzed with an enzyme-linked immunosorbent assay. Information about demographic and clinical characteristics, including symptoms related to CNS affection, was collected from the medical records. The main outcome measures were plasma levels of S100B and possible CNS effects. RESULTS: Levels of S100B were significantly higher among women with preeclampsia than among control subjects (0.12 µg/L vs. 0.07 µg/L; P < 0.001). In preeclampsia, there was a significant association between high levels of S100B and visual disturbances (P < 0.05). CONCLUSIONS: S100B is increased among women with preeclampsia, and high levels of S100B associate with visual disturbances, which might reflect CNS affection in women with preeclampsia.
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- 2014
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223. In vivo(31)P-MR spectroscopy in normal pregnancy, early and late preeclampsia : A study of placental metabolism
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Sohlberg, Sara, Wikström, Anna-Karin, Olovsson, Matts, Lindgren, Peter, Axelsson, Ove, Mulic-Lutvica, Ajlana, Weis, Jan, Wikström, Johan, Sohlberg, Sara, Wikström, Anna-Karin, Olovsson, Matts, Lindgren, Peter, Axelsson, Ove, Mulic-Lutvica, Ajlana, Weis, Jan, and Wikström, Johan
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INTRODUCTION: Preeclampsia affects about 3% of pregnancies and the placenta is believed to play a major role in its pathophysiology. Lately, the role of the placenta has been hypothesised to be more pronounced in preeclampsia of early (<34 weeks) rather than late (≥34 weeks) onset. (31)P Magnetic Resonance Spectroscopy (MRS) enables non-invasive, in vivo studies of placental metabolism. Our aim was to study placental energy and membrane metabolism in women with normal pregnancies and those with early and late onset preeclampsia. METHODS: The study population included fourteen women with preeclampsia (five with early onset and nine with late onset preeclampsia) and sixteen women with normal pregnancy (seven with early and nine with late pregnancy). All women underwent a (31)P-MRS examination of the placenta. RESULTS: The phosphodiester (PDE) spectral intensity fraction of the total (31)P signal and the phosphodiester/phosphomonoester (PDE/PME) spectral intensity ratio was higher in early onset preeclampsia than in early normal pregnancy (p = 0.03 and p = 0.02). In normal pregnancy the PDE spectral intensity fraction and the PDE/PME spectral intensity ratio increased with increasing gestational age (p = 0.006 and p = 0.001). DISCUSSION: Since PDE and PME are related to cell membrane degradation and formation, respectively, our findings indicate increased cell degradation and maybe also decreased cell proliferation in early onset preeclampsia compared to early normal pregnancy, and with increasing gestational age in normal pregnancy. CONCLUSIONS: Our findings could be explained by increased apoptosis due to ischaemia in early onset preeclampsia and also increased apoptosis with increasing gestational age in normal pregnancy.
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- 2014
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224. The relationship between carotid intima-media thickness and global atherosclerosis
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Lundberg, Christina, Hansen, Tomas, Ahlström, Håkan, Lind, Lars, Wikström, Johan, Johansson, Lars, Lundberg, Christina, Hansen, Tomas, Ahlström, Håkan, Lind, Lars, Wikström, Johan, and Johansson, Lars
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BACKGROUND: The aim of this study was to investigate the relationship between (i) carotid intima-media thickness (CIMT) at baseline as well as (ii) change in CIMT over 5 years (ΔCIMT) and atherosclerotically induced luminal narrowing in non-coronary arterial territories assessed by whole-body magnetic resonance angiography (WBMRA). METHODS AND RESULTS: In subgroups of the Prospective Investigation of Vasculature in Uppsala Seniors (PIVUS) study, US measurements of CIMT in the common carotid arteries were analysed at 70 and 75 years and ΔCIMT was calculated (n = 272). WBMRA, assessing arterial stenosis in five different territories by which also a total atherosclerotic score (TAS) was calculated, was performed at 70 years (n = 306). RESULTS: Carotid intima-media thickness in the carotid artery at baseline was correlated with TAS (P = 0·0001) when adjusted to a set of traditional risk factors for atherosclerosis, as well as to stenosis in two of the different investigated territories (aorta and lower leg, P = 0·013 and P = 0·004), but there was no significant correlation between ΔCIMT and TAS (P = 0·41). CONCLUSIONS: In the present study, CIMT, but not ΔCIMT over 5 years, in the carotid artery was related to overall stenoses in the body, as assessed by WBMRA. These findings support CIMT as a general marker for atherosclerosis.
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- 2014
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225. Placental perfusion in normal pregnancy and early and late preeclampsia : A magnetic resonance imaging study.
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Sohlberg, Sara, Mulic-Lutvica, Ajlana, Lindgren, Peter, Ortiz-Nieto, Fransisco, Wikström, Anna-Karin, Wikström, Johan, Sohlberg, Sara, Mulic-Lutvica, Ajlana, Lindgren, Peter, Ortiz-Nieto, Fransisco, Wikström, Anna-Karin, and Wikström, Johan
- Abstract
OBJECTIVE: Our primary aim was to investigate if women with early or late preeclampsia have different placental perfusion compared with normal pregnancies. A secondary aim was to investigate if placental perfusion changes with increasing gestational age in normal pregnancy. METHODS: The study population included thirteen women with preeclampsia (five with early and eight with late preeclampsia) and nineteen women with normal pregnancy (ten with early and nine with late pregnancy). Early was defined as <34 weeks and late as ≥34 weeks gestation. All women underwent a magnetic resonance imaging (MRI) examination including a diffusion weighted sequence at 1.5 T. The perfusion fraction was calculated. RESULTS: Women with early preeclampsia had a smaller placental perfusion fraction (p = 0.001) and women with late preeclampsia had a larger placental perfusion fraction (p = 0.011), compared to women with normal pregnancies at the corresponding gestational age. The placental perfusion fraction decreased with increasing gestational age in normal pregnancies (p = 0.001). CONCLUSION: Both early and late preeclampsia differ in placental perfusion from normal pregnant women. Observed differences are however in the opposite direction, suggesting differences in pathophysiology. Placental perfusion decreases with increasing gestational age in normal pregnancy.
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- 2014
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226. Differential diagnosis of therapy-related changes and recurrent intracranial tumours using perfusion MRI and methionine PET
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Romanos Zapata, Romina, Danfors, Torsten, Wikström, Johan, Raininko, Raili, Romanos Zapata, Romina, Danfors, Torsten, Wikström, Johan, and Raininko, Raili
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- 2014
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227. 3D-avatarskaparen
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Wikström, Johan and Martín, Per
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Teknik ,Technology ,reconstruction ,body and face geometry ,body and face texturing ,virtual characters ,Three-dimensional avatars ,face scanning ,stereo image ,stereo vision - Abstract
Validerat; 20101217 (root)
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- 2009
228. The effect of employer incentives in social insurance on individual wages
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Wikström, Johan
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employer incentives ,Ökonomischer Anreiz ,I18 ,J39 ,Lohn ,social insurance ,Gesetzliche Krankenversicherung ,work absence ,Wage ,sickness absence ,co-insurance ,Sozialversicherung ,ddc:330 ,Fehlzeit ,H55 ,C23 ,Schweden - Abstract
Several studies have documented that employer incentives, in form of experience rating, co-insurance or deductibles, could decrease the social insurance usage. Such employer incentives may though have unintended side effects, as it gives employers incentives to transfer the costs to their workers, affecting individual wages and inducing cream skimming. Side effects which have been given limited attention. This paper aims to fill one part of this gap in the literature. The effect off employer incentives on individual wages is estimated using a reform in January 1992, which introduced an employer co-insurance system into the Swedish sickness absence insurance. The analysis based on a long population panel database, including survey information on hourly wages, gives no support of any important individual wage effects from the co-insurance reform. This is not a result of lack of variation in individual wage increases, nor is it a result of large standard errors.
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- 2009
229. Utländska studenter : Vilka samhällsekonomiska effekter kan motivera att deras utbildning i Sverige subventioneras?
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Wikström, Johan
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Economics ,Nationalekonomi - Abstract
De senaste åren har det förts en debatt i Sverige om utländska studenter vid svenska universitet och högskolor och om studieavgifter ska införas för denna grupp studenter. Genom att försöka koppla de ofta förekommande argumenten i den diskussionen till den ekonomiska teorin om externa effekter syftar denna uppsats till att svara på vilka effekter av utländska studenter som, ur ett samhällsekonomiskt perspektiv, skulle kunna berättiga att det svenska samhället subventionerar deras utbildning. Det finns flera effekter, varav de flesta är externa, som gynnar svenska samhället och därmed skulle kunna berättiga subventioner. Den viktigaste är att kvalificerad arbetskraft lockas till Sverige.
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- 2008
230. Human resource managment på den svenska hotellmarknaden : Vilka stategier används av aktörerna på den svenska hotellmarknaden
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Saeedi, Nima and Wikström, Johan
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Human resource Managment ,Business studies ,Företagsekonomi - Abstract
Sammanfattning Den svenska hotellmarknaden domineras till stor del av utländska aktörer. Stora hotellkedjor som Hilton, som representerar Storbritannien, Accor, som representerar Frankrike är bland de dominerande aktörerna. Bland de nordiska representanterna så är First/Tribe Hotels en organisation som ”sticker ut”. Alla dessa organisationer präglas av den organisationskultur som de uppstod i. De har alla arbetat fram framgångsrika strategier i sina respektive hemland. På den svenska marknaden så är konkurrensen bland dessa hotell är väldigt hög. Företagen försöker att åstadkomma fördelar gentemot sina konkurrenter genom olika strategier och koncept. En viktig del av arbetet är vilka Human resource strategier som används. För oss var det intressant att förstå hur dessa strategier var uppbyggda. Tar de olika hotellen med sig de strategier som de utvecklat i sitt ”hemland” eller anpassar man sig till de strategier som karakteriserar den svenska företagskulturen? Med bakgrund av detta kommit fram till följande problem: Vilka HR modeller använder de tre stora aktörerna när de agerar på den svenska hotellmarknaden? Vi har tittat på detta problem genom arbetstagarnas perspektiv och använt oss av en kvalitativ metod. Vi ville först förstå hur organisationskulturen så ut i varje hotells hemland och har därför använt oss av en deduktiv ansats. Vårt syfte var att kartlägga vilka HRM-strategier som används inom den svenska hotellmarknaden. Sedan ska vi undersöka om de aktuella aktörerna har anpassat sina HRM-strategier till den svenska organisationskulturen eller om de använder sig av HRM-strategier som används i deras respektive ”hemländer”. Vi ansåg att Hofstede arbete om olika organisationskulturer och hans fyra dimensioner (maktdistans, individualism gentemot kollektivism, mannlighet gentemot kvinnlighet och osäkerhetsundvikande) var en bra ”grund” för att kunna upptäcka skillnader i de olika hotellens strategier. Vår förförståelse bygger på att vi är Hotell & Restaurang studenter och har en viss erfarenhet av branschen. Denna erfarenhet har präglat arbetet på det sätt att vi har haft vissa förutfattade meningar om vilka human resource som används på marknaden. Vi har genomfört semistrukturerade intervjuer med sex stycken respondenter. Vi valde att först transkribera all data som vi samlat in för att sedan sortera ut det data som vi tolkade var relevant för uppsatsen. Genom att vi har tolkat respondenternas svar djupgående för att förstå hur deras arbetssituation såg ut så har vi använt oss av en hermeneutikisk kunskapssyn. Genom att jämföra våra teoretiska antaganden med det empiriska materialet så har vi kommit fram till att aktörerna på den svenska hotellmarknaden anpassar sig till en stor grad till de svenska human resource strategier som präglas av den svenska organisationskulturen. Den enda avvikelse som vi upptäckte var att under variabeln osäkerhetsundvikande så ansåg vi att Accor präglades av den franska organisationskulturen och hade alltså inte fullt ut anpassat sig till de strategier som präglar det svenska human resource arbetet. Vi anser att vi har uppnått vårt syfte med denna uppsats och idag så har vi en större förståelse om vilka human resource strategier som är framgångsrika på den svenska hotellmarknaden.
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- 2007
231. Extended Anatomical Grading in Diffuse Axonal Injury Using MRI: Hemorrhagic Lesions in the Substantia Nigra and Mesencephalic Tegmentum Indicate Poor Long-Term Outcome.
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Hamdeh, Sami Abu, Marklund, Niklas, Lannsjö, Marianne, Howells, Tim, Raininko, Raili, Wikström, Johan, and Enblad, Per
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- 2017
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232. Hur fysiklärare gör fysik intressant för både pojkar och flickor från skolår sex till nio
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Leimer, Kicki and Wikström, Johan
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SOCIAL SCIENCES ,SAMHÄLLSVETENSKAP - Abstract
Hur arbetar lärare, från skolår sex till nio, för att få elever mer intresserade av fysik? Syftet med arbetet är att ge fysiklärare med elever i alla årskurser bakgrund och exempel på hur läraren kan göra fysiken mer ”elevvänlig”. Författarna undersöker genom enkäter samt därefter intervjuer vilka arbetssätt lärare, med elever i skolår sex till nio, väljer för att få elever mer intresserade av fysik. Undersökningen omfattar även ifall lärarna ser skillnader, under fysiklektionerna, mellan flickors och pojkars attityder, intresse och arbetssätt. Resultaten från undersökningen visar att lärarna uppfattar skillnader i pojkars och flickors arbetssätt. Respondenterna visar även att andra faktorer inverkar på elevers inlärning i fysik såsom trygghet i gruppen och laborationer. De slutsatser författarna dragit är att laborationen har ett mångfacetterat användningsområde samt att de fysiklärare som enbart har traditionella metoder på fysiklektionerna kan hämma elevers intresse för fysik.
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- 2005
233. Plasma Levels of S100B in Preeclampsia and Association With Possible Central Nervous System Effects
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Bergman, Lina, primary, Akhter, Tansim, additional, Wikström, Anna-Karin, additional, Wikström, Johan, additional, Naessen, Tord, additional, and Åkerud, Helena, additional
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- 2014
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234. Social stimulation and corticolimbic reactivity in premenstrual dysphoric disorder: a preliminary study
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Gingnell, Malin, primary, Ahlstedt, Victoria, additional, Bannbers, Elin, additional, Wikström, Johan, additional, Sundström-Poromaa, Inger, additional, and Fredrikson, Mats, additional
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- 2014
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235. Visualisation of the fetal lip and palate : is brain-targeted MRI reliable?
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Canto Moreira, Nuno, Ribeiro, Valentina, Teixeira, João, Raininko, Raili, Wikström, Johan, Canto Moreira, Nuno, Ribeiro, Valentina, Teixeira, João, Raininko, Raili, and Wikström, Johan
- Abstract
Introduction: The purpose of the study was to evaluate the ability of brain-targeted MRI to assess the anatomy of the fetal upper lip and palate. Methods: Two independent readers made a blind retrospective review of 60 MRI of fetuses of 20 to 38 gestational weeks (GW). Fifty-five fetuses had normal post-natal follow-up. Five fetuses had oro-facial anomalies at post-natal follow-up, including five cleft lips (two bilateral, three unilateral), four cleft primary palates (two bilateral, two unilateral) and two cleft secondary palates. The upper lip, primary palate, secondary palate and nasal septum were scored into four levels, from evidently normal to evidently abnormal. In case of a suspected pathology, the readers attempted a diagnosis. Results: Interobserver agreement (weighted kappa) was 0.79 for the upper lip, 0.70 for the primary palate, 0.86 for the secondary palate, and 0.90 for the nasal septum. The scoring levels of the readers did not change significantly across gestational age. The readers identified 100% of all pathological cases. The normality was correctly scored in 96-100% of the normal lips and primary palates and in 93-97% of the normal secondary palates depending on the reader. A deviated septum was only scored in two fetuses with unilateral cleft palates. Conclusion: MRI in experienced hands seems reliable for assessment of the fetal lip and palate, even in brain-targeted examinations. Attention should therefore be paid to the lip and palate in all fetal MRI examinations, since unsuspected clefts may be revealed., MRI Studies of the Fetal Brain and Cranium
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- 2013
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236. Oral contraceptive use changes brain activity and mood in women with previous negative affect on the pill : A double-blinded, placebo-controlled randomized trial of a levonorgestrel-containing combined oral contraceptive
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Gingnell, Malin, Engman, Jonas, Frick, Andreas, Moby, Lena, Wikström, Johan, Fredrikson, Mats, Sundström Poromaa, Inger, Gingnell, Malin, Engman, Jonas, Frick, Andreas, Moby, Lena, Wikström, Johan, Fredrikson, Mats, and Sundström Poromaa, Inger
- Abstract
OBJECTIVE: Most women on combined oral contraceptives (COC) report high levels of satisfaction, but 4-10% complain of adverse mood effects. The aim of this randomized, double-blinded, placebo-controlled trial was to investigate if COC use would induce more pronounced mood symptoms than placebo in women with previous history of COC-induced adverse mood. A second aim was to determine if COC use is associated with changes in brain reactivity in regions previously associated with emotion processing. METHODS: Thirty-four women with previous experience of mood deterioration during COC use were randomized to one treatment cycle with a levonorgestrel-containing COC or placebo. An emotional face matching task (vs. geometrical shapes) was administered during functional magnetic resonance imaging (fMRI) prior to and during the COC treatment cycle. Throughout the trial, women recorded daily symptom ratings on the Cyclicity Diagnoser (CD) scale. RESULTS: During the last week of the treatment cycle COC users had higher scores of depressed mood, mood swings, and fatigue than placebo users. COC users also had lower emotion-induced reactivity in the left insula, left middle frontal gyrus, and bilateral inferior frontal gyri as compared to placebo users. In comparison with their pretreatment cycle, the COC group had decreased emotion-induced reactivity in the bilateral inferior frontal gyri, whereas placebo users had decreased reactivity in the right amygdala. CONCLUSION: COC use in women who previously had experienced emotional side effects resulted in mood deterioration, and COC use was also accompanied by changes in emotional brain reactivity. These findings are of relevance for the understanding of how combined oral contraceptives may influence mood. Placebo-controlled fMRI studies in COC sensitive women could be of relevance for future testing of adverse mood effects in new oral contraceptives.
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- 2013
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237. Premenstrual dysphoric disorder and prefrontal reactivity during anticipation of emotional stimuli
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Gingnell, Malin, Bannbers, Elin, Wikström, Johan, Fredrikson, Mats, Sundström Poromaa, Inger, Gingnell, Malin, Bannbers, Elin, Wikström, Johan, Fredrikson, Mats, and Sundström Poromaa, Inger
- Abstract
Premenstrual disorder (PMDD) affects around 5% of women in childbearing ages. An increased sensitivity in emotion processing areas of the brain to variations in ovarian steroid levels has been suggested as part of the pathophysiology in PMDD, but prior neuroimaging studies of emotion processing are yet inconclusive. Previous behavioral studies of women with PMDD have, however, reported enhanced luteal phase startle responsivity during emotional anticipation. Here we used functional magnetic resonance imaging (fMRI) to investigate central neural circuitry activity during anticipation of, and exposure to, emotional stimuli across the menstrual cycle in women with and without PMDD. As compared to healthy controls, women with PMDD displayed significantly enhanced reactivity in the prefrontal cortex during anticipation of, but not exposure to, negative emotional stimuli during the luteal phase. In PMDD patients, BOLD reactivity during anticipation or viewing of negative emotional stimuli was not dependent on absolute levels of estradiol or progesterone. However, progesterone levels were positively correlated with emotion-induced reactivity in the dorsolateral prefrontal cortex to positive emotional stimuli. These findings suggest that cortical emotional circuitry reactivity during anticipation is altered in PMDD during the luteal phase, which might be part of the pathophysiology behind the emotional symptoms or lack of emotional control reported by women with PMDD.
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- 2013
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238. The Precuneus Makes The Difference : Precuneal Activity During Recollection Of Concrete Compared To Abstract Nouns Is Linked To Retrieval Success
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Stening, Eva, Persson, Jonas, Wikström, Johan, Söderlund, Hedvig, Stening, Eva, Persson, Jonas, Wikström, Johan, and Söderlund, Hedvig
- Published
- 2013
239. A Network For Navigation : Cross-Hemispheric Hippocampal Connectivity Predicts Water Maze Performance
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Persson, Jonas, Stening, Eva, Wikström, Johan, Söderlund, Hedvig, Persson, Jonas, Stening, Eva, Wikström, Johan, and Söderlund, Hedvig
- Published
- 2013
240. Non-echo planar diffusion-weighted MRI increases follow-up accuracy after one-step step canal wall-down obliteration surgery for cholesteatoma
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Edfeldt, Lennart, Strömbäck, Karin, Danckwardt-Lillieström, Niklas, Rask-Andersen, Helge, Abdasaleh, Shahin, Wikström, Johan, Edfeldt, Lennart, Strömbäck, Karin, Danckwardt-Lillieström, Niklas, Rask-Andersen, Helge, Abdasaleh, Shahin, and Wikström, Johan
- Abstract
Conclusion: Non-echo planar (non-EPI) diffusion-weighted (DW) magnetic resonance imaging (MRI) increases the number of detected cholesteatoma after one-step canal-wall down (CWD) obliteration surgery for cholesteatoma compared with clinical evaluation alone. Objective: To evaluate the use of DW-MRI for detection of cholesteatoma after surgical treatment using CWD obliteration technique. Methods: Thirty-eight adult patients (41 ears) treated with identical one-step canal-wall down obliteration surgical technique were included in a prospective and blinded study. All patients were investigated with non-EPI and EPI DW-MRI 1-9 months after the clinical examination. Follow-up time after primary surgery varied between 10 and 234 months. DW-MRI were assessed by two neuroradiologists and compared with clinical results. Inter-rater agreement was calculated. Positive non-EPI DW-MRI cases underwent revision surgery within 18-159 days after imaging. Results: Out of 41 cases seven were evaluated as positive for cholesteatoma on non-EPI DW-MRI. Since one patient refused surgery six of these seven cases underwent surgical revision and all were verified. There was agreement between clinical and non-EPI findings in five of eight cases. EPI findings correlated poorly with non-EPI and clinical findings. Inter-rater agreement (Cohen´s kappa) was 0.91 for non-EPIDW-MRI (p<0.001) and -0.062 for EPI DW-MRI (p=0.43)
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- 2013
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241. Influence of reproductive hormones on mood and anxiety in women: premenstrual dysphoric disorders
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Sundström-Poromaa, Inger, Gingnell, Malin, Bannbers, Elin, Wikström, Johan, Engman, Jonas, Fredrikson, Mats, Sundström-Poromaa, Inger, Gingnell, Malin, Bannbers, Elin, Wikström, Johan, Engman, Jonas, and Fredrikson, Mats
- Published
- 2013
242. Asymmetric Development of the Hippocampal Region Is Common : A Fetal MR Imaging Study
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Bajic, Dragan, Canto Moreira, Nuno, Wikström, Johan, Raininko, Raili, Bajic, Dragan, Canto Moreira, Nuno, Wikström, Johan, and Raininko, Raili
- Abstract
BACKGROUND AND PURPOSE: Hippocampal development is poorly understood. This study evaluated the normal development of the hippocampal region during the fetal period by using MR imaging. MATERIALS AND METHODS: MR images of 63 fetuses without intracranial pathology were reviewed independently by 2 radiologists with no knowledge of the fetal GA. Three MR images were performed postmortem and 60 in vivo. The progress of hippocampal inversion was analyzed in coronal sections, and the left and right sides of the hippocampal region were compared in every case. RESULTS: The fetuses in the postmortem examinations were at GWs 17-18 and in the in vivo examinations, at GWs 19-36. The hippocampal sulcus was open, bi- or unilaterally, in 39 fetuses. The oldest was at GW 32. The sulcus was closed at GW 21 at the earliest, unilaterally. In 26/63 fetuses (41%), the deepening or closure of the hippocampal sulcus or hippocampal inversion was asymmetric; in 23 fetuses, the right side developed faster. A shallow collateral sulcus was found earliest at GW 17. A deep collateral sulcus was visible earliest at GW 26 unilaterally, but in all fetuses from GW 31 onward, it was seen bilaterally. The orientation of the collateral sulcus was not related to the GA. CONCLUSIONS: There are wide individual temporal variations in the development and the inversion process of the hippocampal sulcus as well as in the formation of the collateral sulcus. Asymmetric development is common, and in most of the asymmetric cases, the right hippocampus develops faster.
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- 2012
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243. Plasma levels of S100B during pregnancy in women developing pre-eclampsia
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Wikström, Anna-Karin, Ekegren, Lina, Karlsson, Mathias, Wikström, Johan, Bergenheim, Mikael, Åkerud, Helena, Wikström, Anna-Karin, Ekegren, Lina, Karlsson, Mathias, Wikström, Johan, Bergenheim, Mikael, and Åkerud, Helena
- Abstract
Objective S100B is suggested to be a peripheral biomarker of central nervous system injury with increased blood–brain barrier permeability. The aim of this study was to investigate if there is a difference in plasma levels of S100B throughout pregnancy between women developing pre-eclampsia and those who did not. Study design A nested case-control study within a longitudinal study cohort was performed. Healthy pregnant women were enrolled and plasma samples were collected at gestational weeks 10, 25, 28, 33 and 37. Levels of S100B throughout pregnancy were analyzed with an ELISA assay. Results The levels of S100B did not change between gestational weeks 10 and 37 (0.047 vs. 0.052; p = 0.71) in the healthy controls, but the S100B levels increased between corresponding weeks in women who developed pre-eclampsia (0.052 vs. 0.075; p < 0.05). In gestational weeks 33 and 37 women who developed pre-eclampsia had higher levels of S100B than the controls (p = 0.047 and p = 0.010, respectively). Conclusion S100B levels increase during pregnancy in women who develop pre-eclampsia and there is an increased S100B level in women who develop pre-eclampsia compared with healthy pregnancies several weeks before clinical symptoms of the disease. The increased amount of plasma S100B in women developing pre-eclampsia might be secondary to cerebral vascular damage and S100B is a potential peripheral biomarker reflecting cerebral involvement in pre-eclampsia.
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- 2012
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244. The effect of premenstrual dysphoric disorder and menstrual cycle phase on brain activity during response inhibition
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Bannbers, Elin, Gingnell, Malin, Engman, Jonas, Morell, Arvid, Comasco, Erika, Kask, Kristiina, Garavan, Hugh, Wikström, Johan, Sundström Poromaa, Inger, Bannbers, Elin, Gingnell, Malin, Engman, Jonas, Morell, Arvid, Comasco, Erika, Kask, Kristiina, Garavan, Hugh, Wikström, Johan, and Sundström Poromaa, Inger
- Abstract
BACKGROUND: Premenstrual dysphoric disorder (PMDD) has generally not been associated with impulsive behavior. However, some studies suggest that women with PMDD have higher impulsivity scores than healthy controls and that brain activity during response inhibition may vary across the menstrual cycle. Therefore, our aim was to unravel potentially important cognitive aspects of PMDD by investigating brain activity during response inhibition in women with PMDD and healthy controls in relation to menstrual cycle phase. METHODS: Fourteen PMDD patients and 13 healthy controls performed a Go/NoGo task to measure brain activity during response inhibition by use of event-related functional magnetic resonance imaging. RESULTS: Women with PMDD displayed decreased activity during both menstrual cycle phases compared to healthy controls in several task-related parietal areas. A significant group by phase interactions was found in the left insula, driven by enhanced activity among healthy controls in the follicular phase and by enhanced insula activity during the luteal phase among PMDD patients. LIMITATIONS: The limitations of the present study are the relatively limited sample size, the relatively small number of NoGo trials and the lack of a baseline contrast for the NoGo trials. CONCLUSIONS: During response inhibition women with PMDD have reduced activity in areas associated with attention and motor function which is unrelated to menstrual cycle phase. Insular cortex activity, involved in both affective and cognitive processing, was significantly activated during the luteal phase among PMDD women. These findings are relevant for the understanding of how ovarian steroids influence mood symptoms in women.
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- 2012
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245. Measurements of the normal fetal brain at gestation weeks 17 to 23 : a MRI study
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Canto Moreira, Nuno, Teixeira, João, Themudo, Raquel, Amini, Hashem, Axelsson, Ove, Raininko, Raili, Wikström, Johan, Canto Moreira, Nuno, Teixeira, João, Themudo, Raquel, Amini, Hashem, Axelsson, Ove, Raininko, Raili, and Wikström, Johan
- Abstract
INTRODUCTION: To obtain measurements of the normal fetal brain before 24 weeks of gestation (GW), a deadline for medical decisions on fetal viability in a large number of countries. METHODS: We retrospectively reviewed 70 normal MR examinations of fetuses aged GW 17 to 23. The fronto-occipital diameter, the cerebral bi-parietal diameter, the transverse cerebellar diameter, the vermian height, and antero-posterior diameter were measured. RESULTS: The median, maximum, and minimum values for each parameter were displayed for each individual GW. CONCLUSION: The recorded data might contribute to a better assessment of fetal health by providing normal boundaries for the brain growth.
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- 2011
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246. Patients with premenstrual dysphoric disorder have increased startle modulation during anticipation in the late luteal phase period in comparison to control subjects
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Bannbers, Elin, Kask, Kristiina, Wikström, Johan, Risbrough, Victoria, Sundström Poromaa, Inger, Bannbers, Elin, Kask, Kristiina, Wikström, Johan, Risbrough, Victoria, and Sundström Poromaa, Inger
- Abstract
The acoustic startle response (ASR) is a withdrawal reflex to sudden or noxious auditory stimuli and, most importantly, an unbiased measure of emotional processing of appetitive and aversive stimuli. By exposing subjects to fearful situations, such as aversive pictures, the ASR may be enhanced, suggesting that amygdala modulates the startle circuit during threat situations. As one previous study, investigating affective modulation of the ASR in women with premenstrual dysphoric disorder (PMDD), discovered no difference during picture viewing it is possible that the mood changes observed in PMDD relate to anxious anticipation rather than to direct stimulus responding. Hence we sought to examine the effects of PMDD on picture anticipation and picture response. Sixteen PMDD patients and 16 controls watched slide shows containing pleasant and unpleasant pictures and positive and negative anticipation stimuli during the follicular and luteal phase of the menstrual cycle. Simultaneously, semi-randomized startle probes (105dB) were delivered and the ASR was assessed with electromyography. Compared with control subjects, PMDD patients displayed an enhanced startle modulation by positive and negative anticipation stimuli in the luteal phase of the menstrual cycle. This finding was mainly driven by increased modulation in the luteal phase in comparison to the follicular phase among PMDD patients but also by an increased modulation in patients compared to controls during luteal phase. This suggests that the neural circuits underlying response to emotional anticipation are more sensitive during this period and emphasize the need of examining the neural correlates of anticipatory processes in women with PMDD.
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- 2011
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247. The ear in fetal MRI : what can we really see?
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Canto Moreira, Nuno, Teixeira, João, Raininko, Raili, Wikström, Johan, Canto Moreira, Nuno, Teixeira, João, Raininko, Raili, and Wikström, Johan
- Abstract
INTRODUCTION: The aim of this study was to investigate the ability to depict the components of the ear on brain-oriented fetal MRI studies. METHODS: Retrospective evaluation of the ear in MRI studies was performed post-mortem in 16 fetuses ranging from 15 to 22 gestation weeks (GW), and in 122 examinations in vivo of fetuses ranging from 20 to 38 GW. The cochlea, vestibular apparatus, middle ear, and external auditory canal were separately graded according to the components that were delineated. RESULTS: The components of the inner and middle ear were fully delineated in 100% of the post-mortem examinations, but the external auditory canals were only seen in only 25%. In the in vivo group, the imaging detail was much lower. Cochlear turns could be identified in 75% of the fetuses, the vestibule and the lateral semicircular canals in 72% andossicles in 70%. Before 25 GW, the ability to identify these individual parts was 50%, 30%, and 33%, respectively, and above it was 89%, 93%, and 90% . In most cases, the external auditory canals could only be seen after 29 GW. CONCLUSION: In fetal MRI studies in vivo, it is possible to depict the components of the ear in the majority of the fetuses, in such a manner as to exclude major malformations. However, MRI might not provide enough detail to rule out pathology of the ear before 25 GW, this being a critical age for pregnancy management in many countries.
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- 2011
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248. Development of the hippocampal region demonstrated on fetal MRI : A preliminary report
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Bajic, Dragan, Canto Moreira, Nuno, Wikström, Johan, Raininko, Raili, Bajic, Dragan, Canto Moreira, Nuno, Wikström, Johan, and Raininko, Raili
- Abstract
Coronal slices of three fetal MRIs performed post mortem and 37 performed in utero, all without intracranial pathology, was assessed. Progress of the hippocampal inversion was analyzed, the left and right sides were compared and occurrence of the collateral sulcus was revealed. The fetuses in the post mortem examinations were at gestation weeks (GW) 17-18 and in the in utero examinations at GW 19-35. The symmetric development of the hippocampal sulcus was revealed in 26 subjects and asymmetric in 14. The non-ovoid hippocampal formation could be evaluated at GW 24 at earliest and an ovoid hippocampus at GW 29. The collateral sulcus could be recognized at GW 17 in post mortem and at GW 22 in in utero examinations. From GW 29 onwards it was seen in all fetuses and it was symmetric in all but one case. Evaluation of the hippocampi is difficult on fetal MRI, especially in in utero examinations. The hippocampal development is not fulfilled at GW 21 as presumed. There is a wide temporal variation in the development of the hippocampal region, and the developmental process does not progress simultaneously in the right and left side of the same individual.
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- 2011
249. Hippocampal development demonstrated by fetal MRI. Asymmetric development is common.
- Author
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Bajic, Dragan, Canto Moreira, Nuno, Wikström, Johan, Raininko, Raili, Bajic, Dragan, Canto Moreira, Nuno, Wikström, Johan, and Raininko, Raili
- Published
- 2011
250. Lower levels of prepulse inhibition in luteal phase cycling women in comparison with postmenopausal women
- Author
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Bannbers, Elin, Kask, Kristiina, Wikström, Johan, Sundström Poromaa, Inger, Bannbers, Elin, Kask, Kristiina, Wikström, Johan, and Sundström Poromaa, Inger
- Abstract
Menopause denotes the end of the reproductive period in a woman's life and is characterized by gradually declining plasma levels of ovarian hormones. Mounting evidence suggests that prepulse inhibition (PPI) is sensitive to fluctuations in estradiol and progesterone. Deficits in PPI are associated with conditions characterized by increased levels of ovarian steroids, such as the mid-luteal phase of the menstrual cycle and the third trimester of pregnancy. The aim of the current study was to further elucidate ovarian steroid-related effects on PPI by examining 43 women with regular menstrual cycles, 20 healthy postmenopausal women without hormone replacement treatment (HRT) and 21 healthy postmenopausal women with ongoing estradiol-only or estradiol and progesterone therapy (EPT). Cycling women were tested during the late luteal phase of the menstrual cycle while postmenopausal women were tested on any arbitrary day. The PPI was measured by electromyography. Cycling women exhibited lower levels of PPI than postmenopausal women (p<0.05). There were no differences in PPI between postmenopausal HRT users and non-users. However, postmenopausal women with estradiol serum concentrations in the cycling range had lower PPI than postmenopausal women with low estradiol concentrations (groupxPPI interaction, p<0.05). In conclusion, the results further suggest a role for the ovarian steroids in PPI regulation as PPI is increased in postmenopausal women in comparison to regularly menstruating women examined during the late luteal phase. Furthermore, postmenopausal women with estradiol levels in the cycling range had lower PPI than postmenopausal women with low estradiol levels.
- Published
- 2010
- Full Text
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