| 261. |
- Swartling, Johannes, et al.
(författare)
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Estimation of depth of fluorescing lesions in tissue from changes in fluorescence spectra
- 2005
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Ingår i: Proceedings of the SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 5693:1, s. 225-231
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Konferensbidrag (refereegranskat)abstract
- We present a novel method for estimating the depth of a fluorescent lesion in tissue based on measurements of the fluorescence signal in different wavelength bands. The measured fluorescence spectrum following irradiation by excitation light at the surface is a function of several parameters, because the fluorescence light has to pass through tissue with characteristic scattering and absorption properties. Thus, the intrinsic fluorescence spectrum will be altered, in a way determined by the tissue optical properties, the depth of the fluorophore, and also by the geometry of the light irradiation and the detection system. By analyzing the ratio between the signals at two wavelengths we show that it is possible to estimate the depth of the lesion. We have performed Monte Carlo simulations and measurements on an Intralipid phantom in the wavelength range 850 - 1000 nm. By taking the ratio between the signals at the wavelengths 875 and 930 nm the depth of a fluorescing layer could be determined with 0.8 mm accuracy down at least a depth of 10 mm. Monte Carlo simulations were also performed for different tissue types with various composition. The results indicate that depth estimation of a lesion is possible with no assumptions made about the optical properties for a wide range of tissues
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| 262. |
- Swartling, Johannes, et al.
(författare)
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Fluorescence spectra provide information on the depth of fluorescent lesions in tissue
- 2005
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Ingår i: Applied Optics. - 2155-3165. ; 44:10, s. 1934-1941
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Tidskriftsartikel (refereegranskat)abstract
- The fluorescence spectrum measured from a fluorophore in tissue is affected by the absorption and scattering properties of the tissue, as well as by the measurement geometry. We analyze this effect with Monte Carlo simulations and by measurements on phantoms. The spectral changes can be used to estimate the depth of a fluorescent lesion embedded in the tissue by measurement of the fluorescence signal in different wavelength bands. By taking the ratio between the signals at two wavelengths, we show that it is possible to determine the depth of the lesion. Simulations were performed and validated by measurements on a phantom in the wavelength range 815-930 nm. The depth of a fluorescing layer could be determined with 0.6-mm accuracy down to at least a depth of 10 mm. Monte Carlo simulations were also performed for different tissue types of various composition. The results indicate that depth estimation of a lesion should be possible with 2-3-mm accuracy, with no assumptions made about the optical properties, for a wide range of tissues.
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| 263. |
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| 264. |
- Thimansson, Erick, et al.
(författare)
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Deep learning algorithm performs similarly to radiologists in the assessment of prostate volume on MRI
- 2023
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Ingår i: European Radiology. - : Springer Science and Business Media LLC. - 0938-7994 .- 1432-1084. ; 33, s. 2519-2528
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Tidskriftsartikel (refereegranskat)abstract
- ObjectivesProstate volume (PV) in combination with prostate specific antigen (PSA) yields PSA density which is an increasingly important biomarker. Calculating PV from MRI is a time-consuming, radiologist-dependent task. The aim of this study was to assess whether a deep learning algorithm can replace PI-RADS 2.1 based ellipsoid formula (EF) for calculating PV.MethodsEight different measures of PV were retrospectively collected for each of 124 patients who underwent radical prostatectomy and preoperative MRI of the prostate (multicenter and multi-scanner MRI’s 1.5 and 3 T). Agreement between volumes obtained from the deep learning algorithm (PVDL) and ellipsoid formula by two radiologists (PVEF1 and PVEF2) was evaluated against the reference standard PV obtained by manual planimetry by an expert radiologist (PVMPE). A sensitivity analysis was performed using a prostatectomy specimen as the reference standard. Inter-reader agreement was evaluated between the radiologists using the ellipsoid formula and between the expert and inexperienced radiologists performing manual planimetry.ResultsPVDL showed better agreement and precision than PVEF1 and PVEF2 using the reference standard PVMPE (mean difference [95% limits of agreement] PVDL: −0.33 [−10.80; 10.14], PVEF1: −3.83 [−19.55; 11.89], PVEF2: −3.05 [−18.55; 12.45]) or the PV determined based on specimen weight (PVDL: −4.22 [−22.52; 14.07], PVEF1: −7.89 [−30.50; 14.73], PVEF2: −6.97 [−30.13; 16.18]). Inter-reader agreement was excellent between the two experienced radiologists using the ellipsoid formula and was good between expert and inexperienced radiologists performing manual planimetry.ConclusionDeep learning algorithm performs similarly to radiologists in the assessment of prostate volume on MRI.Key Points• A commercially available deep learning algorithm performs similarly to radiologists in the assessment of prostate volume on MRI.• The deep-learning algorithm was previously untrained on this heterogenous multicenter day-to-day practice MRI data set.
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| 265. |
- Thorell, Kaisa, 1983, et al.
(författare)
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In vivo analysis of the viable microbiota and Helicobacter pylori transcriptome in gastric infection and early stages of carcinogenesis
- 2017
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Ingår i: Infection and Immunity. - 1098-5522 .- 0019-9567. ; 85:10
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Tidskriftsartikel (refereegranskat)abstract
- Emerging evidence shows that the human microbiota plays a larger role in disease progression and health than previously anticipated. Helicobacter pylori, the causative agent of gastric cancer and duodenal and gastric ulcers, was early associated with gastric disease, but it has also been proposed that the accompanying microbiota in Helicobacter pylori-infected individuals might affect disease progression and gastric cancer development. In this study, the composition of the transcriptionally active microbial community and H. pylori gene expression were determined using metatranscriptomic RNA sequencing of stomach biopsy specimens from individuals with different H. pylori infection statuses and premalignant tissue changes. The results show that H. pylori completely dominates the microbiota not only in infected individuals but also in most individuals classified as H. pylori uninfected using conventional methods. Furthermore, H. pylori abundance is positively correlated with the presence of Campylobacter, Deinococcus, and Sulfurospirillum. Finally, we quantified the expression of a large number of Helicobacter pylori genes and found high expression of genes involved in pH regulation and nickel transport. Our study is the first to dissect the viable microbiota of the human stomach by metatranscriptomic analysis, and it shows that metatranscriptomic analysis of the gastric microbiota is feasible and can provide new insights into how bacteria respond in vivo to variations in the stomach microenvironment and at different stages of disease progression.
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| 266. |
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| 267. |
- Tops, Dolf, et al.
(författare)
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Staff experience and understanding of working with abused women suffering from mental illness
- 2009
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Ingår i: Health & Social Care in the Community. - : Hindawi Limited. - 0966-0410 .- 1365-2524. ; 17:5, s. 459-465
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Tidskriftsartikel (refereegranskat)abstract
- The phenomenon of abused women with mental illness is often unrecognised by staff working within welfare services. This may be explained by staff members' attitudes, insecurity or lack of awareness. Today, there are shortcomings in the knowledge of staff members' experiences and interpretations of abuse against women suffering from mental illness. The aim of this qualitative study was to describe how staff members experience and understand their work with abused women suffering from mental illness. Thematic interviews were conducted with 13 staff members from various welfare services. Data were subject to content analysis. The findings showed that working with abused women was experienced as ambiguous and painful and made the staff act pragmatically. Feelings of ambiguity were mainly related to the lack of theoretical frameworks for interpreting why women with mental illness are exposed to abuse. Painful experiences involved intertwined feelings of distress, frustration, worthlessness, ambivalence and powerlessness. These were all feelings that emerged in the direct encounters with the abused women. In response to the abused women's comprehensive needs, staff members acted pragmatically, implying networking without any sanction from the leaders of the organisation, compliance with routines and taking action in here-and-now situations. By acting pragmatically, staff members could achieve concrete results through their interventions. It is concluded that staff members, working with abused women with mental illness, are in a vulnerable situation and in need of formally accepted and implemented support and legitimacy as well as theoretical knowledge regarding causes and consequences of abuse in this particular group of women.
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| 268. |
- Vallejo, J., et al.
(författare)
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Activation of immune responses against the basement membrane component collagen type IV does not affect the development of atherosclerosis in ApoE-deficient mice
- 2019
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 9:1
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Tidskriftsartikel (refereegranskat)abstract
- Oxidation of low-density lipoprotein (LDL) in the arterial extracellular matrix results in malondialdehyde (MDA)-modifications of surrounding matrix proteins. We have recently demonstrated an association between high levels of autoantibodies against MDA-modified collagen type IV and risk for development of myocardial infarction. Collagen type IV is an important component of the endothelial basement membrane and influences smooth muscle cell function. We hypothesized that immune responses against collagen type IV could contribute to vascular injury affecting the development of atherosclerosis. To investigate this possibility, we induced an antibody-response against collagen type IV in apolipoprotein E (Apo E)-deficient mice. Female ApoE −/− mice on C57BL/6 background were immunized with α1α2 type IV collagen chain peptides linked to the immune-enhancer PADRE, PADRE alone or PBS at 12 weeks of age with three subsequent booster injections before the mice were killed at 23 weeks of age. Immunization of PADRE alone induced autoantibodies against PADRE, increased IL-4 secretion from splenocytes and reduced SMC content in the subvalvular plaques. Immunization with peptides of α1α2 type IV collagen chains induced a strong IgG1antibody response against collagen type IV peptides without affecting the distribution of T cell populations, plasma cytokine or lipid levels. There were no differences in atherosclerotic plaque development between collagen α1α2(IV)-PADRE immunized mice and control mice. Our findings demonstrate that the presence of antibodies against the basement membrane component collagen type IV does not affect atherosclerosis development in ApoE −/− mice. This suggests that the association between autoantibodies against collagen type IV and risk for myocardial infarction found in humans does not reflect a pathogenic role of these autoantibodies.
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| 269. |
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| 270. |
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