| 1. |
- Axelsson, Rebecca, et al.
(author)
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Finite element model of mechanical imaging of the breast
- 2022
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In: Journal of Medical Imaging. - 2329-4302. ; 9:3, s. 1-15
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Journal article (peer-reviewed)abstract
- Purpose: Malignant breast lesions can be distinguished from benign lesions by their mechanical properties. This has been utilized for mechanical imaging in which the stress distribution over the breast is measured. Mechanical imaging has shown the ability to identify benign or normal cases and to reduce the number of false positives from mammography screening. Our aim was to develop a model of mechanical imaging acquisition for simulation purposes. To that end, we simulated mammographic compression of a computer model of breast anatomy and lesions. Approach: The breast compression was modeled using the finite element method. Two finite element breast models of different sizes were used and solved using linear elastic material properties in open-source virtual clinical trial (VCT) software. A spherical lesion (15 mm in diameter) was inserted into the breasts, and both the location and stiffness of the lesion were varied extensively. The average stress over the breast and the average stress at the lesion location, as well as the relative mean pressure over lesion area (RMPA), were calculated. Results: The average stress varied 6.2-6.5 kPa over the breast surface and 7.8-11.4 kPa over the lesion, for different lesion locations and stiffnesses. These stresses correspond to an RMPA of 0.80 to 1.46. The average stress was 20% to 50% higher at the lesion location compared with the average stress over the entire breast surface. Conclusions: The average stress over the breast and the lesion location corresponded well to clinical measurements. The proposed model can be used in VCTs for evaluation and optimization of mechanical imaging screening strategies.
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| 2. |
- Allard, Christina, et al.
(author)
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Rasbiologiskt språkbruk i statens rättsprocess mot sameby
- 2015
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In: Dagens Nyheter. - 1101-2447.
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Journal article (pop. science, debate, etc.)abstract
- Statens hantering av forskningsresultat i rättsprocessen med Girjas sameby utgör ett hot mot Sverige som rättsstat och kunskapsnation. Åratal av svensk och internationell forskning underkänns och man använder ett språkbruk som skulle kunna vara hämtat från rasbiologins tid. Nu måste staten ta sitt ansvar och börja agera som en demokratisk rättsstat, skriver 59 forskare.
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| 3. |
- Allard, Christina, et al.
(author)
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Rasbiologiskt språkbruk i statens rättsprocess mot sameby : DN Debatt 2015-06-11
- 2015
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Other publication (pop. science, debate, etc.)abstract
- Statens hantering av forskningsresultat i rättsprocessen med Girjas sameby utgör ett hot mot Sverige som rättsstat och kunskapsnation. Åratal av svensk och internationell forskning underkänns och man använder ett språkbruk som skulle kunna vara hämtat från rasbiologins tid. Nu måste staten ta sitt ansvar och börja agera som en demokratisk rättsstat, skriver 59 forskare.
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| 4. |
- Almqvist, Helena, et al.
(author)
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CETSA screening identifies known and novel thymidylate synthase inhibitors and slow intracellular activation of 5-fluorouracil
- 2016
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 7
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Journal article (peer-reviewed)abstract
- Target engagement is a critical factor for therapeutic efficacy. Assessment of compound binding to native target proteins in live cells is therefore highly desirable in all stages of drug discovery. We report here the first compound library screen based on biophysical measurements of intracellular target binding, exemplified by human thymidylate synthase (TS). The screen selected accurately for all the tested known drugs acting on TS. We also identified TS inhibitors with novel chemistry and marketed drugs that were not previously known to target TS, including the DNA methyltransferase inhibitor decitabine. By following the cellular uptake and enzymatic conversion of known drugs we correlated the appearance of active metabolites over time with intracellular target engagement. These data distinguished a much slower activation of 5-fluorouracil when compared with nucleoside-based drugs. The approach establishes efficient means to associate drug uptake and activation with target binding during drug discovery.
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| 5. |
- Axelsson, Anna, et al.
(author)
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Patient-reported QoL in anal cancer survivors 3 and 6 years after treatment-results from the Swedish national ANCA study
- 2022
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In: Supportive Care in Cancer. - : Springer Science and Business Media LLC. - 0941-4355 .- 1433-7339. ; 30:5, s. 4169-4178
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Journal article (peer-reviewed)abstract
- Purpose The impact of anal cancer treatment for the patients is best evaluated by the patients themselves. The purpose of this study was to investigate quality of life (QoL) in patients with anal cancer at 3 and 6 years after treatment. Methods A Swedish national cross-sectional prospective cohort study with patients diagnosed with anal cancer between 2011 and 2013. Patients were invited to respond to a QoL questionnaire at 3 and 6 years, with focus on bowel, urinary and sexual function, social and mental function, co-morbidity, lifestyle, daily activities, personal characteristics, and perceived QoL. It also contained questions on the severity of the symptoms regarding occurrence, frequency, and duration and the level of "bother" experienced related to functional symptoms. QoL and prevalence of bother with urinary, sexual, bowel dysfunction, and anal pain were described. The prevalence of impaired QoL was compared with a healthy reference population. The association between QoL and experiencing bother was quantified by regression models. Results From an original cohort of 464 patients with anal cancer, 264 (57%) were alive and contacted at 3 years and 230 (50%) at 6 years. One hundred ninety-five (74%) patients responded to the 3-year and 152 (66%) to the 6-year questionnaire. Sixty percent reported low QoL at both 3 and 6 years. Impaired QoL was more prevalent among patients with major bother due to bowel dysfunction (at 3 years RR 1.42, 95% CI (1.06-1.9) p-value 0.020, at 6 years RR 1.52, 95% CI (1.03-2.24) p-value 0.034) and urinary dysfunction (at 6 years RR 1.44, 95% CI (1.08-1.91) p-value 0.013). There was a tendency to a positive relationship between the number of bodily functions causing bother and risk for impaired QoL. Conclusion Patients treated for anal cancer reported bother regarding several bodily functions as well as poor QoL both at 3 and 6 years without much improvement. Bother was also associated with low QoL indicating that function-related bother should be addressed.
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| 6. |
- Axelsson, Ida, et al.
(author)
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Impact of storage time prior to cryopreservation on mechanical properties of aortic homografts
- 2024
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In: Cell and Tissue Banking. - : Springer Science and Business Media LLC. - 1389-9333 .- 1573-6814. ; 25:1, s. 27-37
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Journal article (peer-reviewed)abstract
- Optimal time spans in homograft procurement are still debatable among tissue banks and needs to be further investigated. Cell viability decreases at longer preparation intervals, but the effect on collagen and elastic fibers has not been investigated to the same extent. These fibers are of importance to the homograft elasticity and strength. The objective of this study was to analyze the mechanical properties of homograft tissue at different time spans in the procurement process. Ten aortic homografts were collected at the Tissue Bank in Lund. Twelve samples were obtained from each homograft, cryopreserved in groups of three after 2–4 days, 7–9 days, 28–30 days, and 60–62 days in antibiotic decontamination. Mechanical testing was performed with uniaxial tensile tests, calculating elastic modulus, yield stress and energy at yield stress. Two randomly selected samples were assessed with light microscopy. Procurement generated a total of 120 samples, with 30 samples in each time group. Elastic modulus and yield stress was significantly higher in samples cryopreserved after 2–4 days (2.7 MPa (2.5-5.0) and 0.78 MPa (0.68-1.0)) compared to 7–9 days (2.2 MPa (2.0-2.6) and 0.53 MPa (0.46–0.69)), p = 0.008 and 0.011 respectively. Light microscopy did not show any difference in collagen and elastin at different time spans. There was a significant decrease in elastic modulus and yield stress after 7 days of decontamination at 4 °C compared to 2–4 days. This could indicate some deterioration of elastin and collagen at longer decontamination intervals. Clinical significance of these findings remains to be clarified.
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| 7. |
- Axelsson, Malin, et al.
(author)
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Differences in diagnostic patterns of obstructive airway disease between areas and sex in Sweden and Finland : The Nordic EpiLung Study
- 2021
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In: Journal of Asthma. - : Taylor & Francis. - 0277-0903 .- 1532-4303. ; 58:9, s. 1196-1207
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Journal article (peer-reviewed)abstract
- Objective: To investigate the current prevalence of physician-diagnosed obstructive airway diseases by respiratory symptoms and by sex in Sweden and Finland. Method: In 2016, a postal questionnaire was answered by 34,072 randomly selected adults in four study areas: Västra Götaland and Norrbotten in Sweden, and Seinäjoki-Vaasa and Helsinki in Finland. Results: The prevalence of asthma symptoms was higher in Norrbotten (13.2%), Seinäjoki-Vaasa (14.8%) and Helsinki (14.4%) than in Västra Götaland (10.7%), and physician-diagnosed asthma was highest in Norrbotten (13.0%) and least in Västra Götaland (10.1%). Chronic productive cough was most common in the Finnish areas (7.7-8.2 % versus 6.3-6.7 %) while the prevalence of physician-diagnosed chronic bronchitis (CB) or chronic obstructive pulmonary disease (COPD) varied between 1.7-2.7% in the four areas. Among individuals with respiratory symptoms, the prevalence of asthma was most common in Norrbotten, while a diagnosis of COPD or CB was most common in Västra Götaland and Seinäjoki-Vaasa. More women than men with respiratory symptoms reported a diagnosis of asthma in Sweden and Seinäjoki-Vaasa but there were no sex differences in Helsinki. In Sweden, more women than men with symptoms of cough or phlegm reported a diagnosis of CB or COPD, while in Finland the opposite was found. Conclusion: The prevalence of respiratory symptoms and corresponding diagnoses varied between and within the countries. The proportion reporting a diagnosis of obstructive airway disease among individuals with respiratory symptoms varied, indicating differences in diagnostic patterns both between areas and by sex.
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| 8. |
- Axelsson, Rebecca, et al.
(author)
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Computer model of mechanical imaging acquisition for virtual clinical trials
- 2021
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In: Medical Imaging 2021 : Physics of Medical Imaging - Physics of Medical Imaging. - : SPIE. - 1605-7422. - 9781510640191 ; 11595, s. 1-115950
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Conference paper (peer-reviewed)abstract
- Malignant breast tumours can be distinguished from benign lesions and normal tissue based on their mechanical properties. Our pilot studies have demonstrated the potential of using Mechanical Imaging (MI) combined with mammography to reduce recalls and false positives in breast cancer screening by more accurately identifying benign lesions. To enable further optimization of MI we propose a computer simulation of the MI acquisition, for use in a Virtual Clinical Trial (VCT) framework. VCTs are computer simulated clinical trials used to efficiently evaluate clinical imaging systems. A linear elastic finite element (FE) model of the breast under dynamic compression was implemented using an open-source FE solver. A spherical tumour (15 mm in diameter) was inserted into the simulated predominantly adipose breast. The location and stiffness of the tumour was varied. The average stress on the compressed breast surface was calculated and compared with the local average stress at the tumour location and the Relative Mean Pressure over lesion Area (RMPA) was calculated. Preliminary results were within a realistic range with an average stress on the breast (tumour) of 5.9-16.6 kPa which is in agreement with published values between 1.0 - 22.5 kPa. This corresponds to RMPA values of 0.96-2.15 depending on stiffness and location of the tumour. This can lead to more detailed validation of various MI acquisition schemes through VCTs before their use in clinical studies.
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| 9. |
- Barufaldi, Bruno, et al.
(author)
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Virtual Clinical Trials in Medical Imaging System Evaluation and Optimisation
- 2021
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In: Radiation Protection Dosimetry. - : Oxford University Press (OUP). - 1742-3406 .- 0144-8420. ; 195:3-4, s. 363-371
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Journal article (peer-reviewed)abstract
- Virtual clinical trials (VCTs) can be used to evaluate and optimise medical imaging systems. VCTs are based on computer simulations of human anatomy, imaging modalities and image interpretation. OpenVCT is an open-source framework for conducting VCTs of medical imaging, with a particular focus on breast imaging. The aim of this paper was to evaluate the OpenVCT framework in two tasks involving digital breast tomosynthesis (DBT). First, VCTs were used to perform a detailed comparison of virtual and clinical reading studies for the detection of lesions in digital mammography and DBT. Then, the framework was expanded to include mechanical imaging (MI) and was used to optimise the novel combination of simultaneous DBT and MI. The first experiments showed close agreement between the clinical and the virtual study, confirming that VCTs can predict changes in performance of DBT accurately. Work in simultaneous DBT and MI system has demonstrated that the system can be optimised in terms of the DBT image quality. We are currently working to expand the OpenVCT software to simulate MI acquisition more accurately and to include models of tumour growth. Based on our experience to date, we envision a future in which VCTs have an important role in medical imaging, including support for more imaging modalities, use with rare diseases and a role in training and testing artificial intelligence (AI) systems.
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