Catalogue Search | MBRL
Search Results Heading
Explore the vast range of titles available.
MBRLSearchResults
-
DisciplineDiscipline
-
Is Peer ReviewedIs Peer Reviewed
-
Item TypeItem Type
-
SubjectSubject
-
YearFrom:-To:
-
More FiltersMore FiltersSourceLanguage
Done
Filters
Reset
21
result(s) for
"Karlsson, Olof Magnus"
Sort by:
Predicting Ecosystem Response from Pollution in Baltic Archipelago Areas Using Mass-Balance Modelling
2011
Baltic archipelago areas have high nature values despite being polluted from various antrophogenic activities within the Baltic Sea catchment area and from long-range transport of airborne substances. The discovery of environmental problems in the Baltic Sea in the 1960s led to countermeasures that gradually gave results in reducing the toxic pollution, e.g. from PCBs. Today, much of the environmental management is focused on reducing the effects of eutrophication. There is a demand from society on science to develop strategies that can direct remedial actions so that the cost-effectiveness is maximised. This work focuses on how mass-balance models can be used to understand how coastal ecosystems are controlled by abiotic processes and to predict the response to changes in loading of different substances. Advection, sedimentation and burial are examples of general transport processes that are regulated by morphometrical characteristics, e.g. size, form, effective fetch and topographical openness. This is why different coastal areas have different sensitivity to loading of pollutants.A comparison of six phosphorus and chlorophyll models of different complexity showed that the model performance was not improved with more state variables of total phosphorus (TP) than two water and two sediment compartments. Modelling chlorophyll as a separate state variable did not improve the results for individual values compared to a simple regression against total phosphorus in surface water. Field investigations of the phosphorus content in accumulation sediments along the coast of Svealand showed a distribution pattern that probably is related to differences in the redox status. The average content of mobile phosphorus was much higher than previously found in offshore Baltic sediments indicating that sediments may play an important role for the phosphorus turnover in Baltic archipelago areas.A one-year field study to measure the levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in water, sediments and fish during different seasons was carried out in Kallrigafjärden Bay. The collected data set was used to test a mass-balance model for PCCD/F-turnover. It was possible to reproduce the concentrations of different PCDD/F-congeners with high accuracy using a general model approach, including one water compartment and two sediment compartments, indicating that the applied model has the necessary qualifications for successful predictions of PCDD/F-turnover in Baltic coastal areas.
Dissertation
Precision of MRI-based body composition measurements of postmenopausal women
by
Holm, Anna-Clara Spetz
,
Borga, Magnus
,
Karlsson, Anette
in
Adipose tissue
,
Biology and Life Sciences
,
Body Composition
2018
To determine precision of magnetic resonance imaging (MRI) based fat and muscle quantification in a group of postmenopausal women. Furthermore, to extend the method to individual muscles relevant to upper-body exercise.
This was a sub-study to a randomized control trial investigating effects of resistance training to decrease hot flushes in postmenopausal women. Thirty-six women were included, mean age 56 ± 6 years. Each subject was scanned twice with a 3.0T MR-scanner using a whole-body Dixon protocol. Water and fat images were calculated using a 6-peak lipid model including R2*-correction. Body composition analyses were performed to measure visceral and subcutaneous fat volumes, lean volumes and muscle fat infiltration (MFI) of the muscle groups' thigh muscles, lower leg muscles, and abdominal muscles, as well as the three individual muscles pectoralis, latissimus, and rhomboideus. Analysis was performed using a multi-atlas, calibrated water-fat separated quantification method. Liver-fat was measured as average proton density fat-fraction (PDFF) of three regions-of-interest. Precision was determined with Bland-Altman analysis, repeatability, and coefficient of variation.
All of the 36 included women were successfully scanned and analysed. The coefficient of variation was 1.1% to 1.5% for abdominal fat compartments (visceral and subcutaneous), 0.8% to 1.9% for volumes of muscle groups (thigh, lower leg, and abdomen), and 2.3% to 7.0% for individual muscle volumes (pectoralis, latissimus, and rhomboideus). Limits of agreement for MFI was within ± 2.06% for muscle groups and within ± 5.13% for individual muscles. The limits of agreement for liver PDFF was within ± 1.9%.
Whole-body Dixon MRI could characterize a range of different fat and muscle compartments with high precision, including individual muscles, in the study-group of postmenopausal women. The inclusion of individual muscles, calculated from the same scan, enables analysis for specific intervention programs and studies.
Journal Article
Clinical decision support for familial hypercholesterolemia (CDS-FH): Rationale and design of a cluster randomized trial in primary care
by
Nilsson, Staffan
,
Henriksson, Martin
,
Karlsson, Lars O
in
Arteriosclerosis
,
Atherosclerosis
,
Cardiology
2022
: Familial hypercholesterolemia (FH) is an underdiagnosed and undertreated genetic disorder with high risk of premature atherosclerotic cardiovascular disease and death. Clinical decision support (CDS) systems have the potential to aid in the identification and management of patients with FH. Prior studies using computer-based systems to screen patients for FH have shown promising results, but there has been no randomized controlled trial conducted. The aim of the current cluster randomized study is to evaluate if a CDS can increase the identification of FH.
: We have developed a CDS integrated in the electronic health records that will be activated in patients with elevated cholesterol levels (total cholesterol >8 mmol/L or low-density lipoprotein-cholesterol >5.5 mmol/L, adjusted for age, ongoing lipid lowering therapy and presence of premature coronary artery disease) at increased risk for FH. When activated, the CDS will urge the physician to send an automatically generated referral to the local lipid clinic for further evaluation. To evaluate the effects of the CDS, all primary care clinics will be cluster randomized 1:1 to either CDS intervention or standard care in a Swedish region with almost 500,000 inhabitants. The primary endpoint will be the number of patients diagnosed with FH at 30 months. Resource use and long-term health consequences will be estimated to assess the cost-effectiveness of the intervention.
: Despite increasing awareness of FH, the condition remains underdiagnosed and undertreated. The present study will investigate whether a CDS can increase the number of patients being diagnosed with FH.
Journal Article
Fatty infiltrate and neck muscle volume in individuals with chronic whiplash associated disorders compared to healthy controls – a cross sectional case–control study
2023
Background
The underlying pathophysiological mechanisms of chronic Whiplash Associated Disorders (WAD) are not fully understood. More knowledge of morphology is needed to better understand the disorder, improve diagnostics and treatments. The aim was to investigate dorsal neck muscle volume (MV) and muscle fat infiltration (MFI) in relation to self-reported neck disability among 30 participants with chronic WAD grade II-III compared to 30 matched healthy controls.
Methods
MV and MFI at spinal segments C4 through C7 in both sexes with mild- to moderate chronic WAD (
n
= 20), severe chronic WAD (
n
= 10), and age- and sex matched healthy controls (
n
= 30) was compared. Muscles: trapezius, splenius, semispinalis capitis and semispinalis cervicis were segmented by a blinded assessor and analyzed.
Results
Higher MFI was found in right trapezius (
p
= 0.007, Cohen’s d = 0.9) among participants with severe chronic WAD compared to healthy controls. No other significant difference was found for MFI (
p
= 0.22–0.95) or MV (
p
= 0.20–0.76).
Conclusions
There are quantifiable changes in muscle composition of right trapezius on the side of dominant pain and/or symptoms, among participants with severe chronic WAD. No other statistically significant differences were shown for MFI or MV. These findings add knowledge of the association between MFI, muscle size and self-reported neck disability in chronic WAD.
Trial registration
NA. This is a cross-sectional case–control embedded in a cohort study.
Journal Article
The relation between local and distal muscle fat infiltration in chronic whiplash using magnetic resonance imaging
by
Borga, Magnus
,
Karlsson, Anette
,
Elliott, James
in
Adipose Tissue - diagnostic imaging
,
Adipose Tissue - pathology
,
Adult
2019
The objective of this study was to investigate the relationship between fat infiltration in the cervical multifidi and fat infiltration measured in the lower extremities to move further into understanding the complex signs and symptoms arising from a whiplash trauma. Thirty-one individuals with chronic whiplash associated disorders, stratified into a mild/moderate group and a severe group, together with 31 age- and gender matched controls were enrolled in this study. Magnetic resonance imaging was used to acquire a 3D volume of the neck and of the whole-body. Cervical multifidi was used to represent muscles local to the whiplash trauma and all muscles below the hip joint, the lower extremities, were representing widespread muscles distal to the site of the trauma. The fat infiltration was determined by fat fraction in the segmented images. There was a linear correlation between local and distal muscle fat infiltration (p<0.001, r2 = 0.28). The correlation remained significant when adjusting for age and WAD group (p = 0.009) as well as when correcting for age, WAD group and BMI (p = 0.002). There was a correlation between local and distal muscle fat infiltration within the severe WAD group (p = 0.0016, r2 = 0.69) and in the healthy group (p = 0.022, r2 = 0.17) but not in the mild/moderate group (p = 0.29, r2 = 0.06). No significant differences (p = 0.11) in the lower extremities' MFI between the different groups were found. The absence of differences between the groups in terms of lower extremities' muscle fat infiltration indicates that, in this particular population, the whiplash trauma has a local effect on muscle fat infiltration rather than a generalized.
Journal Article
Bone Loss and Bone Size after Menopause
by
Johnell, Olof
,
Turner, Charles H
,
Rannevik, Gunnar
in
Biological and medical sciences
,
Biomechanical Phenomena
,
Bone and Bones - anatomy & histology
2003
Bone loss increases after menopause, yet bone strength depends on structural characteristics such as bone size. In this study, the bone mass and skeletal structure of the distal radius were evaluated by single-photon absorptiometry in 108 women, all of whom were followed from menopause for a mean of 15 years. During follow-up, the mean bone mineral density decreased and the medullary bone diameter and periosteal diameter increased annually. The bone-strength index decreased.
Some changes partially preserve bone strength.
Bone strength depends on material properties, such as tissue mineral content. Certain structural characteristics of the skeleton — for example, size, shape, and the three-dimensional architecture — also affect bone strength. The observed increase in the fragility of bone with age is regarded as predominantly the result of the loss of bone density, but changes in bone structure may also influence skeletal strength. Estrogen deficiency after menopause accelerates the age-related loss of bone.
1
,
2
Cortical bone loss occurs mainly at the inner (endosteal) surface and partly in the Haversian canals.
3
,
4
Cross-sectional studies also indicate that bone size increases with . . .
Journal Article
Discovery of mineralization in the caudal vertebrae of perch (Perca fluviatilis L.): A potential new tool for environmental impact assessment
by
Delling, Bo
,
Waldetoft, Hannes
,
Viktor, Tomas
in
Biomarkers
,
Conflicts of interest
,
Deformation
2024
The frequency of skeletal deformations in fish is a common biomarker when investigating the environmental response to effluents of various origins. This study discovered a new biomarker: elevated mineralization levels of the vertebrae in the caudal region of perch Perca fluviatilis. The study was conducted in northern Sweden in lakes receiving discharges from an iron ore mine and adjacent reference lakes. The field observation was followed up with an egg‐hatching experiment showing a similar lake‐specific pattern in hatching and deformation frequencies in larvae.
Journal Article
Endoplasmic reticulum stress in human chronic wound healing: Rescue by 4‐phenylbutyrate
2021
During wound healing, cells have a high rate of protein synthesis and many proteins need to be folded post‐translationally to function, which occurs in the endoplasmic reticulum (ER). In addition to proliferation, several cellular stress conditions, such as hypoxia, in the wound micro‐environment lead to the accumulation of unfolded or misfolded proteins in the ER, causing ER stress. Eukaryotic cells have a signalling system to manage ER stress called the unfolded protein response (UPR). Mild UPR activation has a beneficial homeostatic effect; however, excessive UPR induces cell death. Herein, we examined venous leg ulcer biopsies versus normal acute incisional wounds in age‐matched elderly subjects and found a large increase in ER stress markers. To study the underlying mechanism, we established several cell cultures from amputated legs from the elderly that showed inherent ER stress. While both keratinocytes and fibroblasts migration was impaired by ER stress, migration of elderly leg skin keratinocytes was markedly improved after treatment with the chemical chaperone and clinically established drug 4‐phenylbutyrate (4‐PBA) and demonstrated a reduction in ER stress markers. In a full‐thickness human skin wound healing model, 4‐PBA improved the reepithelialisation rate, which suggests it as a promising drug repurposing candidate for wound healing.
Journal Article
Imaging single DNA molecules for high precision NIPT
2018
Cell-free DNA analysis is becoming adopted for first line aneuploidy screening, however for most healthcare programs, cost and workflow complexity is limiting adoption of the test. We report a novel cost effective method, the Vanadis NIPT assay, designed for high precision digitally-enabled measurement of chromosomal aneuploidies in maternal plasma. Reducing NIPT assay complexity is achieved by using novel molecular probe technology that specifically label target chromosomes combined with a new readout format using a nanofilter to enrich single molecules for imaging and counting without DNA amplification, microarrays or sequencing. The primary objective of this study was to assess the Vanadis NIPT assay with respect to analytical precision and clinical feasibility. Analysis of reference DNA samples indicate that samples which are challenging to analyze with low fetal-fraction can be readily detected with a limit of detection determined at <2% fetal-fraction. In total of 286 clinical samples were analysed and 30 out of 30 pregnancies affected by trisomy 21 were classified correctly. This method has the potential to make cost effective NIPT more widely available with more women benefiting from superior detection and false positive rates.
Journal Article