| 1. |
- Bjerner, Johan, et al.
(author)
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Baseline Serum Prostate-specific Antigen Value Predicts the Risk of Subsequent Prostate Cancer Death-Results from the Norwegian Prostate Cancer Consortium.
- 2024
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In: European Urology. - 0302-2838. ; 86:1, s. 20-26
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Journal article (peer-reviewed)abstract
- Prostate-specific antigen (PSA) levels in midlife are strongly associated with the long-term risk of lethal prostate cancer in cohorts not subject to screening. This is the first study evaluating the association between PSA levels drawn as part of routine medical care in the Norwegian population and prostate cancer incidence and mortality.To determine the association between midlife PSA levels <4.0 ng/ml, drawn as part of routine medical care, and long-term risk of prostate cancer death.The Norwegian Prostate Cancer Consortium collected >8 million PSA results from >1 million Norwegian males ≥40 yr of age. We studied 176099 men (predefined age strata: 40-54 and 55-69 yr) without a prior prostate cancer diagnosis who had a nonelevated baseline PSA level (<4.0 ng/ml) between January 1, 1995 and December 31, 2005.Baseline PSA.We assessed the 16-yr risk of prostate cancer mortality. We calculated the discrimination (C-index) between predefined PSA strata (<0.5, 0.5-0.9, 1.0-1.9, 2.0-2.9, and 3.0-3.9 ng/ml) and subsequent prostate cancer death. Survival curves were plotted using the Kaplan-Meier method.The median follow-up time of men who did not get prostate cancer was 17.9 yr. Overall, 84% of men had a baseline PSA level of <2.0 ng/ml and 1346 men died from prostate cancer, with 712 deaths (53%) occurring in the 16% of men with the highest baseline PSA of 2.0-3.9 ng/ml. Baseline PSA levels were associated with prostate cancer mortality (C-index 0.72 for both age groups, 40-54 and 55-69 yr). The fact that the reason for any given PSA measurement remains unknown represents a limitation.We replicated prior studies that baseline PSA at age 40-69 yr can be used to stratify a man's risk of dying from prostate cancer within the next 15-20 yr.A prostate-specific antigen level obtained as part of routine medical care is strongly associated with a man's risk of dying from prostate cancer in the next two decades.
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| 2. |
- Bjerner, Johan, et al.
(author)
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Non-parametric estimation of reference intervals in small non-Gaussian sample sets
- 2009
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In: ACCREDITATION AND QUALITY ASSURANCE. - : Springer Science and Business Media LLC. - 0949-1775 .- 1432-0517. ; 14:4, s. 185-192
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Journal article (peer-reviewed)abstract
- This study aimed at validating common bootstrap algorithms for reference interval calculation.We simulated 1500 random sets of 50-120 results originating from eight different statistical distributions. In total, 97.5 percentile reference limits were estimated from bootstrapping 5000 replicates, with confidence limits obtained by: (a) normal, (b) from standard error, (c) bootstrap percentile (as in RefVal) (d) BCa, (e) basic, or (f) student methods. Reference interval estimates obtained with ordinary bootstrapping and confidence intervals by percentile method were accurate for distributions close to normality and devoid of outliers, but not for log-normal distributions with outliers. Outlier removal and transformation to normality improved reference interval estimation, and the basic method was superior in such cases. In conclusions, if the neighborhood of the relevant percentile contains non-normally distributed results, bootstrapping fails. The distribution of bootstrap estimates should be plotted, and a non-normal distribution should warrant transformation or outlier removal.
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| 3. |
- Bjerner, Johan, et al.
(author)
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Reference intervals for serum testosterone, SHBG, LH and FSH in males from the NORIP project
- 2009
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In: Scandinavian Journal of Clinical and Laboratory Investigation. - : Informa UK Limited. - 0036-5513 .- 1502-7686. ; 69:8, s. 873-879
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Journal article (peer-reviewed)abstract
- Reference intervals were calculated for male testosterone, SHBG, FSH and LH in serum from 599 individuals in the NORIP study. At 30 years of age, reference limits were calculated to 10.4-32.6 nmol/L testosterone, 13.5-57.4 nmol/L SHBG, 1.93-9.7 IU/L LH and 1.5-10.3 IU/L FSH, at 50 years, 9.3-31.3 nmol/L (testosterone), 18.4-75.6 nmol/L (SHBG), 2.01-10.4 IU/L (LH) and 2.04-12.4 IU/L (FSH), and at 70 years 8.6 to 30.7 nmol/L (testosterone), 27.8-101 nmol/L (SHBG), 2.22-11.2 IU/L (LH) and 2.71-14.2 IU/L (FSH). All age-+related changes were statistically significant. Reference intervals were also calculated for indices derived from testosterone, SHBG and albumin. Free androgen index, simply the ratio between testosterone and SHBG, returned results differing from the other elaborate indices, and the study thus favors use of a more elaborate index such as calculated free testosterone (CFT).
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| 4. |
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| 5. |
- Hellgren, Laila, et al.
(author)
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Severe mitral regurgitation : relations between magnetic resonance imaging, echocardiography and natriuretic peptides
- 2008
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In: Scandinavian Cardiovascular Journal. - : Informa UK Limited. - 1401-7431 .- 1651-2006. ; 42:1, s. 48-55
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Journal article (peer-reviewed)abstract
- BACKGROUND:Assessment of the severity of mitral regurgitation by echocardiography can be technically demanding in certain patients and supplementary methods are therefore desirable. This study addressed the agreement between magnetic resonance imaging (MRI) and echocardiography, and their relations to natriuretic peptides (NT-proANP and NT-proBNP), in quantifying severe mitral regurgitation.METHODS:Eighteen patients with severe mitral regurgitation scheduled for surgery underwent MRI, echocardiography and assay of natriuretic peptides preoperatively for clinical assessment.RESULTS:MRI and echocardiography were comparable in measuring severity of regurgitation qualitatively but not quantitatively, mitral regurgitant fraction (mean difference 27.5 (11) ml). There was a correlation between increasing regurgitant fraction on MRI and increased levels of plasma NT-proANP and NT-proBNP. In echocardiography, increasing vena contracta width and increasing PISA correlated to increased levels of plasma NT-proANP and NT-proBNP. No other correlation was found between measures on MRI and echocardiography and natriuretic peptides.CONCLUSIONS:MRI and echocardiography were comparable grading the severity of mitral regurgitation with qualitative measures but not with quantitative measures. MRI might be a complement to echocardiography when a more distinct measure of the regurgitant volume is needed, as in paravalvular leakage.
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| 6. |
- Kuklin, Vladimir, et al.
(author)
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Influence of therapeutic plasma exchange treatment on short-term mortality of critically ill adult patients with sepsis-induced organ dysfunction : a systematic review and meta-analysis
- 2024
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In: Critical Care. - : BioMed Central (BMC). - 1364-8535 .- 1466-609X. ; 28:1
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Research review (peer-reviewed)abstract
- Introduction: The impact of therapeutic plasma exchange (TPE) on short-term mortality in adult patients with sepsis-induced organ dysfunction remains uncertain. The objective of the study is to assess the effect of adjunct TPE in this setting through a comprehensive literature review.Methods: The National Library of Medicine’s Medline, Ovid (Embase), the Cochrane Library database and clinicaltrial.gov from January 01, 1966, until October 01, 2022, were searched for terms: therapeutic plasma exchange, plasmapheresis, sepsis, and septic shock. We reviewed, selected and extracted data from relevant randomized clinical trials (RCTs) and matched cohort studies (MCSs) comparing short-term mortality in critically ill adult septic patients treated with standard therapy versus those receiving adjunct TPE. Risk of bias was assessed in the RCTs using Cochrane Collaboration tool and in MCSs using ROBINS-I tool. Summary statistics, risk ratios (RRs), and confidence intervals (CIs) were calculated using random effects model.Results: This systematic review included 937 adult critically ill septic patients from five RCTs (n = 367) and fifteen MCSs (n = 570). Of these total, 543 received treatment with TPE in addition to standard care. The meta-analysis includes all five RCTs and only six MCSs (n = 627). The adjunct TPE treatment (n = 300) showed a significant reduction in short-term mortality (RR 0.59, 95% CI 0.47–0.74, I2 3%) compared to standard therapy alone (n = 327). The systematic review of all 20 trials revealed that adding TPE to the standard therapy of critically ill septic patients resulted in faster clinical and/or laboratory recovery.Conclusions: Our comprehensive and up-to-date review demonstrates that adjunct TPE may provide potential survival benefits when compared to standard care for critically ill adult patients with sepsis-induced organ dysfunction. While results of this meta-analysis are encouraging, large well-designed randomized trials are required to identify the optimal patient population and TPE procedure characteristics prior to widespread adoption into practice.
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| 7. |
- Langner, Taro, et al.
(author)
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Identifying morphological indicators of aging with neural networks on large-scale whole-body MRI
- 2020
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In: IEEE Transactions on Medical Imaging. - 0278-0062 .- 1558-254X. ; 39:5, s. 1430-1437
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Journal article (peer-reviewed)abstract
- A wealth of information is contained in images obtained by whole-body magnetic resonance imaging (MRI). Studying the link between the imaged anatomy and properties known from outside sources has the potential to give new insights into the underlying factors that manifest themselves in individual human morphology. In this work we investigate the expression of age-related changes in the whole-body image. A large dataset of about 32,000 subjects scanned from neck to knee and aged 44–82 years from the UK Biobank study was used for a machine-based analysis. We trained a convolutional neural network based on the VGG16 architecture to predict the age of a given subject based on image data from these scans. In 10-fold cross-validation on 23,000 of these images the network reached a mean absolute error (MAE) of 2.49 years (R 2 = 0.83) and showed consistent performance on a separate test set of another 8,000 images. On a second test set of 100 images the network outperformed the averaged estimates given by three experienced radiologists, which reached an MAE of 5.58 years (R 2 = 0.08), by more than three years on average. In an attempt to explain these findings, we employ saliency analysis that opens up the image-based criteria used by the automated method to human interpretation. We aggregate the saliency into a single anatomical visualization which clearly highlights structures in the aortic arch and knee as primary indicators of age.
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| 8. |
- Torkzad, Michael R., et al.
(author)
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The Clinical Perspective on Value of 3D, Thin Slice T2-Weighted Images in 3T Pelvic MRI for Tumors
- 2012
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In: Current Medical Imaging Reviews. - : Bentham Science Publishers Ltd.. - 1573-4056. ; 8:2, s. 76-81(6)
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Journal article (peer-reviewed)abstract
- Pelvic imaging is undergoing rapid changes due to increased use of 3-Tesla (3T) magnetic resonance imaging (3T MRI). One of the advantages of 3T could be the possibility for thin section 3-dimensional (3D) imaging which could improve accuracy and at the same time reduce the need for multi-planar imaging needed for conventional T2 imaging (TSE). In the following text we review the advantages of 3D thin section imaging for assessment of pelvic tumors.
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