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  • 1.
    Andersson, Jonas
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Mellberg, Caroline
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Otten, Julia
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Ryberg, Mats
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Rinnström, Daniel
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Kardiologi.
    Larsson, Christel
    Lindahl, Bernt
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. d Department of Radiography and Biomedical Science, Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
    Johansson, Bengt
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Kardiologi.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Left ventricular remodelling changes without concomitant loss of myocardial fat after long-term dietary intervention2016Ingår i: International Journal of Cardiology, ISSN 0167-5273, E-ISSN 1874-1754, Vol. 216, s. 92-96Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Accumulation of myocardial triglycerides (MTG) is associated with impaired left ventricular (LV) remodelling and function in obese and diabetic subjects. The role of MTG accumulation in development of heart failure in this group of patients is unknown. Short-term studies suggest that diets that lead to weight loss could mobilize MTG, with a favourable effect on cardiac remodelling. In a 24-month, randomized, investigator-blinded study, we assessed the effect of two different diets and subsequent weight loss on cardiac function and MTG in postmenopausal women. Methods: Sixty-eight healthy postmenopausal women with body mass index [BMI] >= 27 kg/m(2) were randomized to an ad libitum Palaeolithic diet (PD) or a Nordic Nutrition Recommendation (NNR) diet for 24 months. Morphology, cardiac function, and MTG levels were measured using magnetic resonance (MR) scanning, including proton spectroscopy at baseline and 6 and 24 months. Results: Despite mean weight losses of 4.9 (1.0) kg (NNR) and 7.8 (1.1) kg (PD), the MTG content did not change over time (p = 0.98 in the NNR and p = 0.11 in the PD group at 24 months). Reduced left ventricular mass was observed in both diet groups over 24 months. Blood pressure was reduced at 6 months, but returned to baseline levels at 24 months. End diastolic volume, stroke volume, and cardiac output decreased over time. No differences between diet groups were observed. Conclusions: Diet intervention and moderate weight loss over 24 months improved LV remodelling but did not alter MTG levels in overweight/obese postmenopausal women.

  • 2.
    Asklund, Thomas
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Onkologi.
    Nyholm, Tufve
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Garpebring, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Brynolfsson, Patrik
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Karlsson, Mikael
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Henriksson, Roger
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Onkologi.
    Evaluation of advanced MR techniques for development of early biomarkers for treatment efficacy in malignant brain tumors2010Konferensbidrag (Refereegranskat)
  • 3.
    Brynolfsson, Patrik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Nilsson, David
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Henriksson, Roger
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Karlsson, Mikael
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Garpebring, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Birgander, Richard
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Trygg, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Nyholm, Tufve
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Asklund, Thomas
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    ADC texture-An imaging biomarker for high-grade glioma?2014Ingår i: Medical physics (Lancaster), ISSN 0094-2405, Vol. 41, nr 10, s. 101903-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose:

    Survival for high-grade gliomas is poor, at least partly explained by intratumoral heterogeneity contributing to treatment resistance. Radiological evaluation of treatment response is in most cases limited to assessment of tumor size months after the initiation of therapy. Diffusion-weighted magnetic resonance imaging (MRI) and its estimate of the apparent diffusion coefficient (ADC) has been widely investigated, as it reflects tumor cellularity and proliferation. The aim of this study was to investigate texture analysis of ADC images in conjunction with multivariate image analysis as a means for identification of pretreatment imaging biomarkers.

    Methods:

    Twenty-three consecutive high-grade glioma patients were treated with radiotherapy (2 Gy/60 Gy) with concomitant and adjuvant temozolomide. ADC maps and T1-weighted anatomical images with and without contrast enhancement were collected prior to treatment, and (residual) tumor contrast enhancement was delineated. A gray-level co-occurrence matrix analysis was performed on the ADC maps in a cuboid encapsulating the tumor in coronal, sagittal, and transversal planes, giving a total of 60 textural descriptors for each tumor. In addition, similar examinations and analyses were performed at day 1, week 2, and week 6 into treatment. Principal component analysis (PCA) was applied to reduce dimensionality of the data, and the five largest components (scores) were used in subsequent analyses. MRI assessment three months after completion of radiochemotherapy was used for classifying tumor progression or regression.

    Results:

    The score scatter plots revealed that the first, third, and fifth components of the pretreatment examinations exhibited a pattern that strongly correlated to survival. Two groups could be identified: one with a median survival after diagnosis of 1099 days and one with 345 days, p = 0.0001.

    Conclusions:

    By combining PCA and texture analysis, ADC texture characteristics were identified, which seems to hold pretreatment prognostic information, independent of known prognostic factors such as age, stage, and surgical procedure. These findings encourage further studies with a larger patient cohort. (C) 2014 Author(s).

  • 4.
    Chorell, Elin
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Otten, Julia
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Stomby, Andreas
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Ryberg, Mats
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Waling, Maria
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för kost- och måltidsvetenskap.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Svensson, Michael B.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Avdelningen för idrottsmedicin.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Improved peripheral and hepatic insulin sensitivity after lifestyle interventions in type 2 diabetes is associated with specific metabolomic and lipidomic signatures in skeletal muscle and plasma2021Ingår i: Metabolites, ISSN 2218-1989, E-ISSN 2218-1989, Vol. 11, nr 12, artikel-id 834Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lifestyle interventions with weight loss can improve insulin sensitivity in type 2 diabetes (T2D), but mechanisms are unclear. We explored circulating and skeletal muscle metabolite signatures of altered peripheral (pIS) and hepatic insulin sensitivity (hIS) in overweight and obese T2D individuals that were randomly assigned a 12-week Paleolithic-type diet with (diet-ex, n = 13) or without (diet, n = 13) supervised exercise. Baseline and post-intervention measures included: mass spectrometry-based metabolomics and lipidomics of skeletal muscle and plasma; pIS and hIS; ectopic lipid deposits in the liver and skeletal muscle; and skeletal muscle fat oxidation rate. Both groups lowered BMI and total % fat mass and increased their pIS. Only the diet-group improved hIS and reduced ectopic lipids in the liver and muscle. The combined improvement in pIS and hIS in the diet-group were associated with decreases in muscle and circulating branched-chain amino acid (BCAA) metabolites, specifically valine. Improved pIS with diet-ex was instead linked to increased diacylglycerol (34:2) and triacylglycerol (56:0) and decreased phosphatidylcholine (34:3) in muscle coupled with improved muscle fat oxidation rate. This suggests a tissue crosstalk involving BCAA-metabolites after diet intervention with improved pIS and hIS, reflecting reduced lipid influx. Increased skeletal muscle lipid utilization with exercise may prevent specific lipid accumulation at sites that perturb insulin signaling.

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  • 5.
    Elg Christoffersson, Kristina
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Hauksson, Jón
    Edlund, Ulf
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Sjöström, Michael
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Dolk, Matti
    Characterisation of dissolving pulp using designed process variables, NIR and NMR spec-troscopy, and multivariate analysis1999Ingår i: Cellulose, Vol. 6, s. 233-249Artikel i tidskrift (Refereegranskat)
  • 6.
    Fortuin-De Smidt, Melony C.
    et al.
    Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa; Non-Communicable Diseases Research Unit, South African Medical Council, Tygerberg, South Africa.
    Mendham, Amy E.
    Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa; Non-Communicable Diseases Research Unit, South African Medical Council, Tygerberg, South Africa.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Alhamud, Ali
    Department of Human Biology, MRC/UCT Medical Imaging Research Unit, University of Cape Town, Cape Town, South Africa; The Modern Pioneer Center and ArSMRM for MRI Training and Development, Tripoli, Libyan Arab Jamahiriya.
    Stefanovski, Darko
    Department of Clinical Studies, New Bolton Centre, University of Pennsylvania, School of Veterinary Medicine, PA, Kennett Square, United States.
    Hakim, Olah
    Department of Diabetes, Faculty of Life Sciences and Medicine, School of Life Course Sciences, King’s College London, London, United Kingdom.
    Swart, Jeroen
    Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa.
    Goff, Louise M.
    Department of Diabetes, Faculty of Life Sciences and Medicine, School of Life Course Sciences, King’s College London, London, United Kingdom.
    Kahn, Steven E.
    Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, Veterans Affairs Puget Sound Health Care System, University of Washington, WA, Seattle, United States.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Goedecke, Julia H.
    Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa; Non-Communicable Diseases Research Unit, South African Medical Council, Tygerberg, South Africa.
    β-cell function in black South African women: Exploratory associations with insulin clearance, visceral and ectopic fat2021Ingår i: Endocrine Connections, E-ISSN 2049-3614, Vol. 10, nr 5, s. 550-560Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The role of ectopic fat, insulin secretion and clearance in the preservation of β-cell function in black African women with obesity who typically present with hyperinsulinaemia is not clear. We aim to examine the associations between disposition index (DI, an estimate of β-cell function), insulin secretion and clearance and ectopic fat deposition. This is a cross-sectional study of 43 black South African women (age 20–35 years) with obesity (BMI 30–40 kg/m2) and without type 2 diabetes that measured the following: DI, insulin sensitivity (SI), acute insulin response (AIRg), insulin secretion rate (ISR), hepatic insulin extraction and peripheral insulin clearance (frequently sampled i.v. glucose tolerance test); pancreatic and hepatic fat, visceral adipose tissue (VAT) and abdominal s.c. adipose tissue (aSAT) volume (MRI), intra-myocellular (IMCL) and extra-myocellular fat content (EMCL) (magnetic resonance spectroscopy). DI correlated positively with peripheral insulin clearance (β 55.80, P = 0.002). Higher DI was associated with lower VAT, pancreatic fat and soleus fat, but VAT explained most of the variance in DI (32%). Additionally, higher first phase ISR (P = 0.033) and lower hepatic insulin extraction (P = 0.022) were associated with lower VAT, independent from SI, rather than with ectopic fat. In conclusion, peripheral insulin clearance emerged as an important correlate of DI. However, VAT was the main determinant of a lower DI above ectopic fat depots. Importantly, VAT, but not ectopic fat, is associated with both lower insulin secretion and higher hepatic insulin extraction. Prevention of VAT accumulation in young black African women should, therefore, be an important target for beta cell preservation.

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  • 7. Fortuin-de Smidt, Melony C.
    et al.
    Mendham, Amy E.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Hakim, Olah
    Stefanovski, Darko
    Clamp, Louise
    Phiri, Lindokuhle
    Swart, Jeroen
    Goff, Louise M.
    Micklesfield, Lisa K.
    Kahn, Steven E.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Goedecke, Julia H.
    Effect of exercise training on insulin sensitivity, hyperinsulinemia and ectopic fat in black South African women: a randomized controlled trial2020Ingår i: European Journal of Endocrinology, ISSN 0804-4643, E-ISSN 1479-683X, Vol. 183, nr 1, s. 51-61Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objective: We investigated the effects of a 12-week exercise intervention on insulin sensitivity (SI) and hyperinsulinemia and associated changes in regional and ectopic fat.

    Research design and methods: Healthy, black South African women with obesity (mean age 23 ± 3.5 years) and of isiXhosa ancestry were randomised into a 12-week aerobic and resistance exercise training group (n = 23) and a no exercise group (control, n = 22). Pre and post-intervention testing included assessment of SI, insulin response to glucose (AIRg), insulin secretion rate (ISR), hepatic insulin extraction (FEL) and disposition index (DI) (AIRg × SI) (frequently sampled i.v. glucose tolerance test); fat mass and regional adiposity (dual-energy X-ray absorptiometry); hepatic, pancreatic and skeletal muscle fat content and abdominal s.c. and visceral adipose tissue volumes (MRI).

    Results: Exercise training increased VO2peak (mean ± s.d.: 24.9 ± 2.42 to 27.6 ± 3.39 mL/kg/min, P < 0.001), SI (2.0 (1.2–2.8) to 2.2 (1.5–3.7) (mU/l)−1 min−1, P = 0.005) and DI (median (interquartile range): 6.1 (3.6–7.1) to 6.5 (5.6–9.2) × 103 arbitrary units, P = 0.028), and decreased gynoid fat mass (18.5 ± 1.7 to 18.2 ± 1.6%, P < 0.001) and body weight (84.1 ± 8.7 to 83.3 ± .9.7 kg, P = 0.038). None of these changes were observed in the control group, but body weight increased (P = 0.030). AIRg, ISR and FEL, VAT, SAT and ectopic fat were unaltered after exercise training. The increase in SI and DI were not associated with changes in regional or ectopic fat.

    Conclusion: Exercise training increased SI independent from changes in hyperinsulinemia and ectopic fat, suggesting that ectopic fat might not be a principal determinant of insulin resistance in this cohort.

  • 8. Goedecke, Julia H.
    et al.
    Mendham, Amy E.
    Clamp, Louise
    Nankam, Pamela A. Nono
    Fortuin-de Smidt, Melony C.
    Phiri, Lindokuhle
    Micklesfield, Lisa K.
    Keswel, Dheshnie
    Woudberg, Nicholas J.
    Lecour, Sandrine
    Alhamud, Ali
    Kaba, Mamadou
    Lutomia, Faith M.
    van Jaarsveld, Paul J.
    de Villiers, Anniza
    Kahn, Steven E.
    Chorell, Elin
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    An Exercise Intervention to Unravel the Mechanisms Underlying Insulin Resistance in a Cohort of Black South African Women: Protocol for a Randomized Controlled Trial and Baseline Characteristics of Participants2018Ingår i: JMIR Research Protocols, E-ISSN 1929-0748, Vol. 7, nr 4, artikel-id e75Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: The pathogenesis of type 2 diabetes (T2D) in black African women is complex and differs from that in their white counterparts. However, earlier studies have been cross-sectional and provide little insight into the causal pathways. Exercise training is consistently used as a model to examine the mechanisms underlying insulin resistance and risk for T2D.

    Objective: The objective of the study was to examine the mechanisms underlying the changes in insulin sensitivity and secretion in response to a 12-week exercise intervention in obese black South African (SA) women.

    Methods: A total of 45 obese (body mass index, BMI: 30-40 kg/m2) black SA women were randomized into a control (n=22) or experimental (exercise; n=23) group. The exercise group completed 12 weeks of supervised combined aerobic and resistance training (40-60 min, 4 days/week), while the control group maintained their typical physical activity patterns, and both groups were requested not to change their dietary patterns. Before and following the 12-week intervention period, insulin sensitivity and secretion (frequently sampled intravenous glucose tolerance test) and its primary and secondary determinants were measured. Dietary intake, sleep quality and quantity, physical activity, and sedentary behaviors were measured every 4 weeks.

    Results: The final sample included 20 exercise and 15 control participants. Baseline sociodemographics, cardiorespiratory fitness, anthropometry, cardiometabolic risk factors, physical activity, and diet did not differ between the groups (P>.05).

    Conclusions: The study describes a research protocol for an exercise intervention to understand the mechanisms underlying insulin sensitivity and secretion in obese black SA women and aims to identify causal pathways underlying the high prevalence of insulin resistance and risk for T2D in black SA women, targeting specific areas for therapeutic intervention.

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  • 9.
    Hauksson, Jón B
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Bergqvist, Göran
    Bergsten, Urban
    Sjöström, Michael
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Edlund, Ulf
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Prediction of basic wood properties for Norway spruce. Interpretation of Near Infrared Spectroscopy data using partial least squares regression2001Ingår i: Wood Science and Technology, ISSN 0043-7719 (Print) 1432-5225 (Online), Vol. 35, nr 6, s. 475-85Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This work was undertaken to investigate the feasibility of using near infrared spectroscopy (NIR) and partial least squares regression (PLS) as a tool to characterize the basic wood properties of Norway Spruce (Picea abies (L.) Karst.). The wood samples originated from a trial located in the province of Västerbotten in Sweden. In this trial, the effects of birch shelterwoods (Betula pendula Roth) of different densities on growth and yield in Norway spruce understorey were examined. All Norway spruce trees in each shelterwood treatment were divided into three growth rate classes based on diameter at breast height (1.3 m) over bark. Five discs were cut from each tree (i.e. from the root stem, and at 20%, 40%, 60%, and 80% of the total height). The discs from 40% tree height were used (i.e., where the largest variations in annual ring widths and wood density were found). A total of 27 discs were selected. The discs were used for measuring annual ring widths, wood density, average fiber length and the fiber length distributions. Milled wood samples prepared from the discs were used for recording NIR spectra. PLS regression was used to generate prediction models for the wood properties (Y-matrix) and NIR spectra (X-matrix) as well as between the wood properties (Y-matrix) and the fiber length distributions (X-matrix). One set of models was generated using untreated spectra and fiber length distributions. For a second set of models the structure in the X-matrix, which was orthogonal to the matrix described by the wood properties, was eliminated using a soft target rotation technique called orthogonal signal correction (OSC). The PLS model obtained using "raw" untreated NIR spectra and fiber length distributions had a poor modeling power as evidenced by the cumulative Q2 values. For the PLS models based on untreated NIR spectra the cumulative Q2 values ranged from a minimum of 16% (wood density) to a maximum of 46% (no. of annual rings). Orthogonal signal correction of the X-matrix (NIR spectra or fiber length distributions) gave PLS models with a modeling power corresponding to cumulative Q2 values well in excess of 70%. The improvement in predictive ability accomplished by the OSC procedure was verified by placing four of the 27 observations in an external test set and comparing RMSEP values for the test set observations without OSC and with OSC.

  • 10.
    Hauksson, Jón B
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Edlund, Ulf
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Trygg, Johan
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    NMR processing techniques based on multivariate data analysis and orthogonal signal correction. 13C CP/MAS NMR spectroscopic characterization of softwood kraft pulp2001Ingår i: Magnetic Resonance in Chemistry, Vol. 39, nr 5, s. 267-75Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a novel way of extracting information from a series of severely overlapped NMR spectra using multivariate data analysis techniques. A number of softwood pulps were prepared from wood chips that were subjected to kraft cooking conditions in laboratory digesters. In addition to measurements of traditional physical parameters, the pulps were characterized using standard 13C CP/MAS NMR spectroscopy. The relationship between the kappa number and both the NMR time domain and frequency domain data was modeled using multivariate data analysis techniques. The variation in the NMR spectra that was not correlated with the kappa number was removed using a new preprocessing tool, orthogonal signal correction (OSC). The resulting OSC-treated NMR spectra were used as descriptors to generate partial least-squares projections to latent structures (PLS) models for the variation of the kappa number. PLS weights were used to generate NMR sub-spectra which correspond to changes in the pulps that occur as the pulping process proceeds from high to low values of the kappa number. The sub-spectra were used to gain insight into the changes in the pulps occurring at the molecular level. Concomitant changes in cellulose crystallinity and the amounts of hemicellulose and lignin were observed in these sub-spectra. Copyright © 2001 John Wiley & Sons, Ltd.

  • 11.
    Lenfeldt, Niklas
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Birgander, Richard
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Eklund, Anders
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Malm, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Improvement after cerebrospinal fluid drainage is related to levels of N-acetyl-aspartate in idiopathic normal pressure hydrocephalus2008Ingår i: Neurosurgery, ISSN 0148-396X, E-ISSN 1524-4040, Vol. 62, nr 1, s. 135-142Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVE: This study uses proton magnetic resonance spectroscopy to investigate whether or not idiopathic normal pressure hydrocephalus is associated with neuronal dysfunction or ischemia in the brain. We evaluate whether or not proton magnetic resonance spectroscopy is useful for predicting improvement after long-term external lumbar drainage (ELD) of cerebrospinal fluid.

    METHODS: Eighteen patients (mean age, 73 yr; six women) and 10 matching controls participated. Participants were characterized by clinical features, cognitive and motor function tests, and cerebrospinal fluid hydrodynamics (patients only). Signals from N-acetyl-aspartate (NAA), choline, lactate, and creatine (Cr) (reference) were sampled once in controls and twice in patients (before and after a 3-day ELD of approximately 135 mL/24 h) by proton magnetic resonance spectroscopy (1.5 T) from a 7.2-mL volume in the frontal white matter. Improvement was defined by video recordings of the patients' gait.

    RESULTS: Sixteen patients finished the ELD (one patient had meningitis, and one patient had catheter insertion failure) with a mean drain volume of 395 mL. NAA/Cr ratios were lower in patients than in controls (1.60 versus 1.84, P = 0.02), but no difference was found for choline/Cr ratios. No lactate signals were detected. Fifty percent of patients improved after ELD. They had higher NAA/Cr ratios than nonimproved patients (1.70 versus 1.51, P = 0.01), but no differences were found in choline/Cr ratios or drain volume.

    CONCLUSION: NAA/Cr ratios were decreased in patients with idiopathic normal pressure hydrocephalus, which is consistent with neuronal dysfunction in the frontal white matter. Improved patients had NAA/Cr ratios close to normal, indicating that enough functional neurons are a prerequisite for the cerebrospinal fluid drainage to have an effect.

  • 12.
    Mellberg, Caroline
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Otten, Julia
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Ryberg, Mats
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Sandberg, Susanne
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Lindahl, Bernt
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Larsson, C
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Decreased liver fat during a two-year diet intervention was not associated with improvement in hepatic insulin sensitivityManuskript (preprint) (Övrigt vetenskapligt)
  • 13.
    Mendham, Amy E.
    et al.
    MRC/Wits Developmental Pathways for Health Research Unit, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa.
    Goedecke, Julia H.
    Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa; Non-communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa.
    Zeng, Yingxu
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för hållbar hälsa. Hainan Tropical Ocean University, Sanya, Hainan, China.
    Larsen, Steen
    Center for Healthy Aging, Department of Biomedical Sciences, Copenhagen University, Copenhagen, Denmark; Clinical Research Centre, Medical University of Bialystok, Bialystok, Poland.
    George, Cindy
    Non-communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Fortuin-de Smidt, Melony C.
    Division of Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Cape Town, South Africa; Non-communicable Diseases Research Unit, South African Medical Research Council, Cape Town, South Africa.
    Chibalin, Alexander V.
    Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Chorell, Elin
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Exercise training improves mitochondrial respiration and is associated with an altered intramuscular phospholipid signature in women with obesity2021Ingår i: Diabetologia, ISSN 0012-186X, E-ISSN 1432-0428, Vol. 64, nr 7, s. 1642-1659Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aims/hypothesis: We sought to determine putative relationships among improved mitochondrial respiration, insulin sensitivity and altered skeletal muscle lipids and metabolite signature in response to combined aerobic and resistance training in women with obesity.

    Methods: This study reports a secondary analysis of a randomised controlled trial including additional measures of mitochondrial respiration, skeletal muscle lipidomics, metabolomics and protein content. Women with obesity were randomised into 12 weeks of combined aerobic and resistance exercise training (n = 20) or control (n = 15) groups. Pre- and post-intervention testing included peak oxygen consumption, whole-body insulin sensitivity (intravenous glucose tolerance test), skeletal muscle mitochondrial respiration (high-resolution respirometry), lipidomics and metabolomics (mass spectrometry) and lipid content (magnetic resonance imaging and spectroscopy). Proteins involved in glucose transport (i.e. GLUT4) and lipid turnover (i.e. sphingomyelin synthase 1 and 2) were assessed by western blotting.

    Results: The original randomised controlled trial showed that exercise training increased insulin sensitivity (median [IQR]; 3.4 [2.0–4.6] to 3.6 [2.4–6.2] x10−5 pmol l−1 min−1), peak oxygen consumption (mean ± SD; 24.9 ± 2.4 to 27.6 ± 3.4 ml kg−1 min−1), and decreased body weight (84.1 ± 8.7 to 83.3 ± 9.7 kg), with an increase in weight (pre intervention, 87.8± 10.9 to post intervention 88.8 ± 11.0 kg) in the control group (interaction p < 0.05). The current study shows an increase in mitochondrial respiration and content in response to exercise training (interaction p < 0.05). The metabolite and lipid signature at baseline were significantly associated with mitochondrial respiratory capacity (p < 0.05) but were not associated with whole-body insulin sensitivity or GLUT4 protein content. Exercise training significantly altered the skeletal muscle lipid profile, increasing specific diacylglycerol(32:2) and ceramide(d18:1/24:0) levels, without changes in other intermediates or total content of diacylglycerol and ceramide. The total content of cardiolipin, phosphatidylcholine (PC) and phosphatidylethanolamine (PE) increased with exercise training with a decrease in the PC:PE ratios containing 22:5 and 20:4 fatty acids. These changes were associated with content-driven increases in mitochondrial respiration (p < 0.05), but not with the increase in whole-body insulin sensitivity or GLUT4 protein content. Exercise training increased sphingomyelin synthase 1 (p < 0.05), with no change in plasma-membrane-located sphingomyelin synthase 2.

    Conclusions/interpretation: The major findings of our study were that exercise training altered specific intramuscular lipid intermediates, associated with content-driven increases in mitochondrial respiration but not whole-body insulin sensitivity. This highlights the benefits of exercise training and presents putative target pathways for preventing lipotoxicity in skeletal muscle, which is typically associated with the development of type 2 diabetes.

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  • 14. Mendham, Amy E.
    et al.
    Larsen, Steen
    George, Cindy
    Adams, Kevin
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Fortuin-de Smidt, Melony C.
    Nankam, Pamela A. Nono
    Hakim, Olah
    Goff, Louise M.
    Pheiffer, Carmen
    Goedecke, Julia H.
    Exercise training results in depot-specific adaptations to adipose tissue mitochondrial function2020Ingår i: Scientific Reports, E-ISSN 2045-2322, Vol. 10, nr 1, artikel-id 3785Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We assessed differences in mitochondrial function in gluteal (gSAT) and abdominal subcutaneous adipose tissue (aSAT) at baseline and in response to 12-weeks of exercise training; and examined depot-specific associations with body fat distribution and insulin sensitivity (S-I). Obese, black South African women (n = 45) were randomized into exercise (n = 23) or control (n = 22) groups. Exercise group completed 12-weeks of aerobic and resistance training (n = 20), while the control group (n = 15) continued usual behaviours. Mitochondrial function (high-resolution respirometry and fluorometry) in gSAT and aSAT, SI (frequently sampled intravenous glucose tolerance test), body composition (dual-energy X-ray absorptiometry), and ectopic fat (MRI) were assessed pre- and post-intervention. At baseline, gSAT had higher mitochondrial respiratory capacity and hydrogen peroxide (H2O2) production than aSAT (p < 0.05). Higher gSAT respiration was associated with higher gynoid fat (p < 0.05). Higher gSAT H2O2 production and lower aSAT mitochondrial respiration were independently associated with lower SI (p < 0.05). In response to training, S-I improved and gynoid fat decreased (p < 0.05), while H2O2 production reduced in both depots, and mtDNA decreased in gSAT (p < 0.05). Mitochondrial respiration increased in aSAT and correlated with a decrease in body fat and an increase in soleus and hepatic fat content (p < 0.05). This study highlights the importance of understanding the differences in mitochondrial function in multiple SAT depots when investigating the pathophysiology of insulin resistance and associated risk factors such as body fat distribution and ectopic lipid deposition. Furthermore, we highlight the benefits of exercise training in stimulating positive adaptations in mitochondrial function in gluteal and abdominal SAT depots.

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  • 15.
    Otten, Julia
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Andersson, Jonas
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Ståhl, Jens
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Stomby, Andreas
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Saleh, Ahmed
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Waling, Maria
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för kostvetenskap.
    Ryberg, Mats
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Department of Radiography and Biomedical Science, Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
    Svensson, Michael B.
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Avdelningen för idrottsmedicin.
    Johansson, Bengt
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Kardiologi.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Avdelningen för medicin.
    Exercise Training Adds Cardiometabolic Benefits of a Paleolithic Diet in Type 2 Diabetes Mellitus2019Ingår i: Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease, ISSN 2047-9980, E-ISSN 2047-9980, Vol. 8, nr 2, artikel-id e010634Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: The accumulation of myocardial triglycerides and remodeling of the left ventricle are common features in type 2 diabetes mellitus and represent potential risk factors for the development of diastolic and systolic dysfunction. A few studies have investigated the separate effects of diet and exercise training on cardiac function, but none have investigated myocardial changes in response to a combined diet and exercise intervention. This 12-week randomized study assessed the effects of a Paleolithic diet, with and without additional supervised exercise training, on cardiac fat, structure, and function.

    Methods and Results: Twenty-two overweight and obese subjects with type 2 diabetes mellitus were randomized to either a Paleolithic diet and standard-care exercise recommendations ( PD ) or to a Paleolithic diet plus supervised exercise training 3 hours per week ( PD - EX ). This study includes secondary end points related to cardiac structure and function, ie, myocardial triglycerides levels, cardiac morphology, and strain were measured using cardiovascular magnetic resonance, including proton spectroscopy, at baseline and after 12 weeks. Both groups showed major favorable metabolic changes. The PD - EX group showed significant decreases in myocardial triglycerides levels (-45%, P=0.038) and left ventricle mass to end-diastolic volume ratio (-13%, P=0.008) while the left ventricle end-diastolic volume and stroke volume increased significantly (+14%, P=0.004 and +17%, P=0.008, respectively). These variables were unchanged in the PD group.

    Conclusions: Exercise training plus a Paleolithic diet reduced myocardial triglycerides levels and improved left ventricle remodeling in overweight/obese subjects with type 2 diabetes mellitus.

    Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 01513798.

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  • 16.
    Otten, Julia
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Stomby, Andreas
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Ryberg, Mats
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Svensson, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Effects of a paleolithic diet with and without supervised exercise on liver fat and insulin sensitivity: a randomised controlled trial in individuals with type 2 diabetes2016Ingår i: Diabetologia, ISSN 0012-186X, E-ISSN 1432-0428, Vol. 59, s. S10-S10Artikel i tidskrift (Refereegranskat)
  • 17.
    Otten, Julia
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Stomby, Andreas
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Waling, Maria
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för kostvetenskap.
    Isaksson, Andreas
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Idrottsmedicin.
    Söderström, Ingegerd
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Ryberg, Mats
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Svensson, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Idrottsmedicin.
    Hauksson, Jón
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    A heterogeneous response of liver and skeletal muscle fat to the combination of a Paleolithic diet and exercise in obese individuals with type 2 diabetes: a randomised controlled trial2018Ingår i: Diabetologia, ISSN 0012-186X, E-ISSN 1432-0428, Vol. 61, nr 7, s. 1548-1559Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aims/hypothesis: The aim of the study was to investigate ectopic fat deposition and insulin sensitivity, in a parallel single-blinded randomised controlled trial, comparing Paleolithic diet alone with the combination of Paleolithic diet and exercise in individuals with type 2 diabetes. Methods: Thirty-two individuals with type 2 diabetes with BMI 25-40 kg/m(2) and 30-70 years of age followed a Paleolithic diet ad libitum for 12 weeks. In addition, study participants were randomised by computer program to either supervised combined exercise training (PD-EX group) or standard care exercise recommendations (PD group). Staff performing examinations and assessing outcomes were blinded to group assignment. Thirteen participants were analysed in each group: hepatic and peripheral insulin sensitivity were measured using the hyperinsulinaemic-euglycaemic clamp technique combined with [6,6-H-2(2)]glucose infusion, and liver fat was assessed by proton magnetic resonance spectroscopy; both analyses were secondary endpoints. Intramyocellular lipid (IMCL) content was measured by magnetic resonance spectroscopy as a secondary analysis. All examinations were performed at Umca University Hospital, Umca, Sweden. Results: Both study groups showed a median body weight loss of 7 kg. Fat mass decreased by 5.7 kg in the PD group and by 6.5 kg in the PD-EX group. Maximum oxygen uptake increased in the PD-EX group only. Liver fat showed a consistent reduction (74% decrease) in the PD group, while the response in the PD-EX group was heterogeneous (p < 0.05 for the difference between groups). IMCL content of the soleus muscle decreased by 40% in the PD group and by 22% in the PD-EX group (p < 0.05 for the difference between groups). Both groups improved their peripheral and adipose tissue insulin sensitivity, but not their hepatic insulin sensitivity. Plasma fetuin-A decreased by 11% in the PD group (p < 0.05) and remained unchanged in the PD-EX group. Liver fat changes during the intervention were correlated with changes in fetuin-A (r(S) = 0.63, p < 0.01). Participants did not report any important adverse events caused by the intervention. Conclusions/interpretation: A Paleolithic diet reduced liver fat and IMCL content, while there was a tissue-specific heterogeneous response to added exercise training.

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  • 18.
    Otten, Julia
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Stomby, Andreas
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Waling, Maria
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för kostvetenskap.
    Isaksson, Andreas
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Idrottsmedicin.
    Söderström, Ingegerd
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Ryberg, Mats
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Svensson, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Idrottsmedicin.
    Hauksson, Jón
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Exercise training reverses the effect of a Paleolithic diet on liver fat and intramyocellular lipid content in patients with type 2 diabetes2017Konferensbidrag (Refereegranskat)
  • 19.
    Otten, Julia
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Stomby, Andreas
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Waling, Maria
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för kostvetenskap.
    Isaksson, Andreas
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Idrottsmedicin.
    Söderström, Ingegerd
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Ryberg, Mats
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Svensson, Michael
    Umeå universitet, Medicinska fakulteten, Institutionen för samhällsmedicin och rehabilitering, Idrottsmedicin.
    Hauksson, Jón
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Exercise training reverses the effect of a Paleolithic diet on liver fat and intramyocellular lipid content in patients with type 2 diabetes2017Konferensbidrag (Refereegranskat)
  • 20.
    Ryberg, Mats
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Sandberg, Susanne
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Mellberg, Caroline
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Stegle, O
    Lindahl, Bernt
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Larsson, Christel
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för kostvetenskap.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    A Palaeolithic-type diet causes strong tissue-specific effects on ectopic fat deposition in obese postmenopausal women2013Ingår i: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 274, nr 1, s. 67-76Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECTIVES: Ectopic fat accumulation in liver and skeletal muscle may be an essential link between abdominal obesity, insulin resistance and increased risk of cardiovascular disease after menopause. We hypothesized that a diet containing a relatively high content of protein and unsaturated fat [mainly monounsaturated fatty acids (MUFAs)] but limited carbohydrates and saturated fat would reduce lipid content in liver and muscle and increase insulin sensitivity in postmenopausal women.

    SUBJECTS: Ten healthy, nonsmoking postmenopausal women with a body mass index (BMI) >27 (28-35) kg m-2 were included in the study.

    INTERVENTIONS: Participants were instructed to consume an ad libitum Palaeolithic-type diet intended to provide approximately 30 energy percentage (E%) protein, 40 E% fat (mainly MUFAs) and 30 E% carbohydrate. Intramyocellular lipid (IMCL) levels in calf muscles and liver triglyceride levels were quantified using proton magnetic resonance spectroscopy (1 H-MRS) before and 5 weeks after dietary intervention. Insulin sensitivity was estimated by homoeostasis model assessment (HOMA) indices and the euglycaemic hyperinsulinaemic clamp technique.

    RESULTS: Mean energy intake decreased by 25% with a weight loss of 4.5 kg. BMI, waist and hip circumference, waist/hip ratio and abdominal sagittal diameter also decreased significantly, as did diastolic blood pressure (mean -7 mmHg), levels of fasting serum glucose, cholesterol, triglycerides, LDL/HDL cholesterol, apolipoprotein B (ApoB) and apolipoprotein A1 (ApoA1), urinary C-peptide and HOMA indices. Whole-body insulin sensitivity did not change. Liver triglyceride levels decreased by 49%, whereas IMCL levels in skeletal muscle were not significantly altered.

    CONCLUSIONS: A modified Palaeolithic-type diet has strong and tissue-specific effects on ectopic lipid deposition in postmenopausal women.

  • 21.
    Ryberg, Mats
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Sandberg, Susanne
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Mellberg, Caroline
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Stegle, O
    Lindahl, Bernt
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Yrkes- och miljömedicin.
    Larsson, Christel
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för kostvetenskap. Department of Food and Nutrition and Sport Science, University of Gothenburg, Gothenburg, Sweden.
    Hauksson, Jon
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper. Department of Radiography and Biomedical Science, Faculty of Medicine, University of Iceland, Reykjavik, Iceland.
    Olsson, Tommy
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Tissue-specific effects on ectopic lipid deposition by a Palaeolithic-type diet in obese postmenopausal women2013Ingår i: Journal of Internal Medicine, ISSN 0954-6820, E-ISSN 1365-2796, Vol. 274, nr 1, s. 67-76Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Objectives Ectopic fat accumulation in liver and skeletal muscle may be an essential link between abdominal obesity, insulin resistance and increased risk of cardiovascular disease after menopause. We hypothesized that a diet containing a relatively high content of protein and unsaturated fat [mainly monounsaturated fatty acids (MUFAs)] but limited carbohydrates and saturated fat would reduce lipid content in liver and muscle and increase insulin sensitivity in postmenopausal women.

    Subjects Ten healthy, nonsmoking postmenopausal women with a body mass index (BMI) >27 (28–35) kg m−2 were included in the study.

    Interventions Participants were instructed to consume an ad libitum Palaeolithic-type diet intended to provide approximately 30 energy percentage (E%) protein, 40 E% fat (mainly MUFAs) and 30 E% carbohydrate. Intramyocellular lipid (IMCL) levels in calf muscles and liver triglyceride levels were quantified using proton magnetic resonance spectroscopy (1H-MRS) before and 5 weeks after dietary intervention. Insulin sensitivity was estimated by homoeostasis model assessment (HOMA) indices and the euglycaemic hyperinsulinaemic clamp technique.

    Results Mean energy intake decreased by 25% with a weight loss of 4.5 kg. BMI, waist and hip circumference, waist/hip ratio and abdominal sagittal diameter also decreased significantly, as did diastolic blood pressure (mean −7 mmHg), levels of fasting serum glucose, cholesterol, triglycerides, LDL/HDL cholesterol, apolipoprotein B (ApoB) and apolipoprotein A1 (ApoA1), urinary C-peptide and HOMA indices. Whole-body insulin sensitivity did not change. Liver triglyceride levels decreased by 49%, whereas IMCL levels in skeletal muscle were not significantly altered.

    Conclusions A modified Palaeolithic-type diet has strong and tissue-specific effects on ectopic lipid deposition in postmenopausal women.

  • 22.
    Stenman, Katarina
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Hauksson, Jón
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Gröbner, Gerhard
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Stattin, Pär
    Umeå universitet, Medicinska fakulteten, Institutionen för kirurgisk och perioperativ vetenskap, Urologi och andrologi.
    Bergh, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för medicinsk biovetenskap, Patologi.
    Riklund, Katrine
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Detection of polyunsaturated omega-6 fatty acid in human malignant prostate tissue by 1D and 2D high-resolution magic angle spinning NMR spectroscopy2009Ingår i: Magnetic Resonance Materials in Physics, Biology and Medicine, ISSN 0968-5243, E-ISSN 1352-8661, Vol. 22, nr 6, s. 327-331Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    OBJECT: Polyunsaturated omega-6 fatty acids (PUFAs) have been shown to promote prostate cancer. Here, we describe the use of HRMAS NMR spectroscopy to detect omega-6 PUFA species in prostate tissues. MATERIALS AND METHODS: Samples originating from non-malignant (n = 54) and malignant (n = 27) prostate tissues (from 27 prostatectomized men) were studied by 1D (1)H, 2D (1)H-(1)H and (1)H-(13)C HRMAS NMR spectroscopy followed by histopathological characterization. RESULTS: HRMAS NMR proved to be a powerful, non-destructive method to identify and characterize PUFAs. The omega-6 PUFA was found in 15% of examined human prostate tumors. CONCLUSION: It is possible to detect PUFAs in prostate tissues using our NMR-based spectroscopic approach.

  • 23.
    Wilén, Jonna
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Hauksson, Jón
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Hansson Mild, Kjell
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Modification of pulse sequences reduces occupational exposure from MRI switched gradient fields: Preliminary results.2010Ingår i: Bioelectromagnetics, ISSN 0197-8462, E-ISSN 1521-186X, Vol. 31, nr 1, s. 85-87Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The gradient fields in magnetic resonance imaging (MRI) will in some circumstances exceed the ICNIRP guidelines of occupational electromagnetic field exposure when personnel are near the scanner during MRI scanning. In this work we have shown that using commercially available modified sequences for noise reduction purposes, exposure will decrease by a factor of 1.5 with preserved image quality. This is a first step toward optimizing occupational exposure within the scanner room without affecting image quality. Bioelectromagnetics 31:85-87, 2010. (c) 2009 Wiley-Liss, Inc.

  • 24.
    Wåhlin, Anders
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Ambarki, Khalid
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Hauksson, Jón
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik.
    Birgander, Richard
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Diagnostisk radiologi.
    Malm, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för farmakologi och klinisk neurovetenskap, Klinisk neurovetenskap.
    Eklund, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för strålningsvetenskaper, Radiofysik. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Centrum för medicinsk teknik och fysik (CMTF).
    Phase contrast MRI quantification of pulsatile volumes of brain arteries, veins, and cerebrospinal fluids compartments: repeatability and physiological interactions2012Ingår i: Journal of Magnetic Resonance Imaging, ISSN 1053-1807, E-ISSN 1522-2586, Vol. 35, nr 5, s. 1055-1062Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To study measurement repeatability and physiological determinants on measurement stability for phase contrast MRI (PC-MRI) measurements of cyclic volume changes (ΔV) of brain arteries, veins, and cerebrospinal fluid (CSF) compartments.

    MATERIALS AND METHODS: Total cerebral blood flow (tCBF), total internal jugular flow (tJBF) and spinal CSF flow at C2-C3 level and CSF in the aqueduct was measured using five repetitions in 20 healthy subjects. After subtracting net flow, waveforms were integrated to calculate ΔV of arterial, venous, and cerebrospinal fluid compartments. The intraclass correlation coefficient (ICC) was used to measure repeatability. Systematic errors were investigated by a series of phantom measurements.

    RESULTS: For ΔV calculated from tCBF, tJBF and both CSF waveforms, the ICC was ≥0.85. ΔV from the tCBF waveform decreased linearly between repetitions (P = 0.012). Summed CSF and venous volume being shifted out from the cranium was correlated with ΔV calculated from the tCBF waveform (r = 0.75; P < 0.001). Systematic errors increased at resolutions <4 pixels per diameter.

    CONCLUSION: Repeatability of ΔV calculated from tCBF, tJBF, and CSF waveforms allows useful interpretations. The subject's time in the MR system and imaging resolution should be considered when interpreting volume changes. Summed CSF and venous volume changes was associated with arterial volume changes.

    J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.

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