| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
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| 3. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Ademuyiwa, Adesoji O., et al.
(författare)
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Determinants of morbidity and mortality following emergency abdominal surgery in children in low-income and middle-income countries
- 2016
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Ingår i: BMJ Global Health. - : BMJ Publishing Group Ltd. - 2059-7908. ; 1:4
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Tidskriftsartikel (refereegranskat)abstract
- Background: Child health is a key priority on the global health agenda, yet the provision of essential and emergency surgery in children is patchy in resource-poor regions. This study was aimed to determine the mortality risk for emergency abdominal paediatric surgery in low-income countries globally.Methods: Multicentre, international, prospective, cohort study. Self-selected surgical units performing emergency abdominal surgery submitted prespecified data for consecutive children aged <16 years during a 2-week period between July and December 2014. The United Nation's Human Development Index (HDI) was used to stratify countries. The main outcome measure was 30-day postoperative mortality, analysed by multilevel logistic regression.Results: This study included 1409 patients from 253 centres in 43 countries; 282 children were under 2 years of age. Among them, 265 (18.8%) were from low-HDI, 450 (31.9%) from middle-HDI and 694 (49.3%) from high-HDI countries. The most common operations performed were appendectomy, small bowel resection, pyloromyotomy and correction of intussusception. After adjustment for patient and hospital risk factors, child mortality at 30 days was significantly higher in low-HDI (adjusted OR 7.14 (95% CI 2.52 to 20.23), p<0.001) and middle-HDI (4.42 (1.44 to 13.56), p=0.009) countries compared with high-HDI countries, translating to 40 excess deaths per 1000 procedures performed.Conclusions: Adjusted mortality in children following emergency abdominal surgery may be as high as 7 times greater in low-HDI and middle-HDI countries compared with high-HDI countries. Effective provision of emergency essential surgery should be a key priority for global child health agendas.
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| 5. |
- Aleksyniene, Ramune, et al.
(författare)
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The Role of Nuclear Medicine Imaging with F-18-FDG PET/CT, Combined In-111-WBC/(99)mTc-Nanocoll, and Tc-99m-HDP SPECT/CT in the Evaluation of Patients with Chronic Problems after TKA or THA in a Prospective Study
- 2022
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Ingår i: Diagnostics. - : MDPI AG. - 2075-4418. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Background: The aim of this prospective study was to assess the diagnostic value of nuclear imaging with F-18-FDG PET/CT (FDG PET/CT), combined In-111-WBC/(99)mTc-Nanocoll, and Tc-99m-HDP SPECT/CT (dual-isotope WBC/bone marrow scan) for patients with chronic problems related to knee or hip prostheses (TKA or THA) scheduled by a structured multidisciplinary algorithm.Materials and Methods: Fifty-five patients underwent imaging with Tc-99m-HDP SPECT/CT (bone scan), dual-isotope WBC/bone marrow scan, and FDG PET/CT. The final diagnosis of prosthetic joint infection (PJI) and/or loosening was based on the intraoperative findings and microbiological culture results and the clinical follow-up.Results: The diagnostic performance of dual-isotope WBC/bone marrow SPECT/CT for PJI showed a sensitivity of 100% (CI 0.74-1.00), a specificity of 97% (CI 0.82-1.00), and an accuracy of 98% (CI 0.88-1.00); for PET/CT, the sensitivity, specificity, and accuracy were 100% (CI 0.74-1.00), 71% (CI 0.56-0.90), and 79% (CI 0.68-0.93), respectively.Conclusions: In a standardized prospectively scheduled patient group, the results showed highly specific performance of combined dual-isotope WBC/bone marrow SPECT/CT in confirming chronic PJI. FDG PET/CT has an appropriate accuracy, but the utility of its use in the clinical diagnostic algorithm of suspected PJI needs further evidence.
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| 6. |
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| 7. |
- Alhuseinalkhudhur, Ali, et al.
(författare)
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Human Epidermal Growth Factor Receptor 2-Targeting [68Ga]Ga-ABY-025 PET/CT Predicts Early Metabolic Response in Metastatic Breast Cancer.
- 2023
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Ingår i: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 1535-5667. ; 64:9, s. 1364-1370
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Tidskriftsartikel (refereegranskat)abstract
- Imaging using the human epidermal growth factor receptor 2 (HER2)-binding tracer 68Ga-labeled ZHER2:2891-Cys-MMA-DOTA ([68Ga]Ga-ABY-025) was shown to reflect HER2 status determined by immunohistochemistry and in situ hybridization in metastatic breast cancer (MBC). This single-center open-label phase II study investigated how [68Ga]Ga-ABY-025 uptake corresponds to biopsy results and early treatment response in both primary breast cancer (PBC) planned for neoadjuvant chemotherapy and MBC. Methods: Forty patients with known positive HER2 status were included: 19 with PBC and 21 with MBC (median, 3 previous treatments). [68Ga]Ga-ABY-025 PET/CT, [18F]F-FDG PET/CT, and core-needle biopsies from targeted lesions were performed at baseline. [18F]F-FDG PET/CT was repeated after 2 cycles of therapy to calculate the directional change in tumor lesion glycolysis (Δ-TLG). The largest lesions (up to 5) were evaluated in all 3 scans per patient. SUVs from [68Ga]Ga-ABY-025 PET/CT were compared with the biopsied HER2 status and Δ-TLG by receiver operating characteristic analyses. Results: Trial biopsies were HER2-positive in 31 patients, HER2-negative in 6 patients, and borderline HER2-positive in 3 patients. The [68Ga]Ga-ABY-025 PET/CT cutoff SUVmax of 6.0 predicted a Δ-TLG lower than -25% with 86% sensitivity and 67% specificity in soft-tissue lesions (area under the curve, 0.74 [95% CI, 0.67-0.82]; P = 0.01). Compared with the HER2 status, this cutoff resulted in clinically relevant discordant findings in 12 of 40 patients. Metabolic response (Δ-TLG) was more pronounced in PBC (-71% [95% CI, -58% to -83%]; P < 0.0001) than in MBC (-27% [95% CI, -16% to -38%]; P < 0.0001), but [68Ga]Ga-ABY-025 SUVmax was similar in both with a mean SUVmax of 9.8 (95% CI, 6.3-13.3) and 13.9 (95% CI, 10.5-17.2), respectively (P = 0.10). In multivariate analysis, global Δ-TLG was positively associated with the number of previous treatments (P = 0.0004) and negatively associated with [68Ga]Ga-ABY-025 PET/CT SUVmax (P = 0.018) but not with HER2 status (P = 0.09). Conclusion: [68Ga]Ga-ABY-025 PET/CT predicted early metabolic response to HER2-targeted therapy in HER2-positive breast cancer. Metabolic response was attenuated in recurrent disease. [68Ga]Ga-ABY-025 PET/CT appears to provide an estimate of the HER2 expression required to induce tumor metabolic remission by targeted therapies and might be useful as an adjunct diagnostic tool.
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| 8. |
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| 9. |
- Fällmar, David, et al.
(författare)
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Z-score maps from low-dose 18F-FDG PET of the brain in neurodegenerative dementia.
- 2018
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Ingår i: American Journal of Nuclear Medicine and Molecular Imaging. - 2160-8407. ; 8:4, s. 239-246
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Tidskriftsartikel (refereegranskat)abstract
- Neuroimaging is a central part of diagnostic work-up of patients with suspected neurodegenerative disease. FDG-PET can reveal pathological changes earlier and more reliably than morphological imaging. Diagnostic accuracy can be improved by constructing 3D SSP Z-score maps, showing patterns of significant deficits. During FDG-PET, the subject receives a moderate but not insignificant dose of ionizing radiation, and a dose reduction with retained image quality is desirable. With lower dose, repeated examinations can become a useful tool for monitoring disease progress and potential effects of disease-modifying interventions. The aim of this study was to evaluate Z-maps created from low-dose and normal-dose FDG-PET of the brain, with quantitative and qualitative methods. Nine patients with neurodegenerative disorders were prospectively enrolled and nine age-matched controls were recruited through advertising. All subjects (n=18) underwent two FDG-PET scans on separate occasions; a routine and a low-dose scan. The routine dosage of FDG was 3 MBq/kg, and low dosage was 0.75 MBq/kg. 3D-SSP images showing Z-scores of < -1.96 were created from 10-minute summations. The study was comprised of a quantitative part comparing the Z-scores, and a qualitative part where experienced nuclear medicine specialists visually assessed the images. Regarding the quantitative part, Bland-Altman analysis showed a slight constant bias (0.206). Regarding qualitative discrimination between patients and controls, the performance between normal- and low-dose were equal, both showing 72% sensitivity, 83% specificity and 78% accuracy. In this study, visual assessment of 3D-SSP Z-score maps from low-dose FDG-PET provided diagnostic information highly comparable to normal-dose, with minor quantitative discrepancies.
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| 10. |
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| 11. |
- Mylam, Karen Juul, et al.
(författare)
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F-18-fluorodeoxyglucose-positron emission tomography/computed tomography after one cycle of chemotherapy in patients with diffuse large B-cell lymphoma: results of a Nordic/US intergroup study
- 2015
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Ingår i: Leukemia & Lymphoma. - : Informa UK Limited. - 1042-8194 .- 1029-2403. ; 56:7, s. 2005-2012
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Tidskriftsartikel (refereegranskat)abstract
- We evaluated the predictive value of interim positon emission tomography (I-PET) after one course of chemoimmunotherapy in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL). One hundred and twelve patients with DLBCL were enrolled. All patients had PET/computed tomography (CT) scans performed after one course of chemotherapy (PET-1). I-PET scans were categorized according to International Harmonization Project criteria (IHP), Deauville 5-point scale (D 5PS) with scores 1-3 considered negative (D 5PS>3) and D 5PS with scores 1-4 considered negative (D 5PS = 5). Ratios of tumor maximum standardized uptake value (SUVmax) to liver SUVmax were also analyzed. We found no difference in progression-free survival (PFS) between PET-negative and PET-positive patients according to IHP and D 5PS>3. The 2-year PFS using D 5PS = 5 was 50.9% in the PET-positive group and 84.8% in the PET-negative group (p = 0.002). A tumor/liver SUVmax cut-off of 3.1 to distinguish D 5PS scores of 4 and 5 provided the best prognostic value. PET after one course of chemotherapy was not able to safely discriminate PET-positive and PET-negative patients in different prognostic groups.
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| 12. |
- Pearce, Mark, 1970-, et al.
(författare)
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Science prospects for SPHiNX - A small satellite GRB polarimetry mission
- 2019
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Ingår i: Astroparticle physics. - : ELSEVIER SCIENCE BV. - 0927-6505 .- 1873-2852. ; 104, s. 54-63
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Tidskriftsartikel (refereegranskat)abstract
- Gamma-ray bursts (GRBs) are exceptionally bright electromagnetic events occurring daily on the sky. The prompt emission is dominated by X-/gamma-rays. Since their discovery over 50 years ago, GRBs are primarily studied through spectral and temporal measurements. The properties of the emission jets and underlying processes are not well understood. A promising way forward is the development of missions capable of characterising the linear polarisation of the high-energy emission. For this reason, the SPHiNX mission has been developed for a small-satellite platform. The polarisation properties of incident high-energy radiation (50-600 keV) are determined by reconstructing Compton scattering interactions in a segmented array of plastic and Gd3Al2Ga3O12(Ce) (GAGG(Ce)) scintillators. During a two-year mission, similar to 200 GRBs will be observed, with similar to 50 yielding measurements where the polarisation fraction is determined with a relative error <= 10%. This is a significant improvement compared to contemporary missions. This performance, combined with the ability to reconstruct GRB localisation and spectral properties, will allow discrimination between leading classes of emission models.
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| 13. |
- Regula, Naresh, 1985-, et al.
(författare)
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Comparison of 68Ga-PSMA-11 PET/CT with 18F-fluoride PET/CT for detection of bone metastatic disease in prostate cancer
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- 18F-fluoride positron emission tomography/computed tomography (PET/CT) is considered the most sensitive technique to detect bone metastasis in prostate cancer (PCa). 68Ga-PSMA-11 PET/CT is increasingly used for staging of PCa. This study primarily aimed to compare the diagnostic performance of 18F-fluoride PET/CT and 68Ga-PSMA-11 PET/CT in identifying bone metastasis followed by a comparison of 68Ga-PSMA-11 PET/CT with diagnostic CT in identifying soft tissue lesions as a secondary objective.Methods: Twenty-eight PCa patients with high suspicion of widespread disease following curative treatment were prospectively evaluated. PET/CT examinations using 18F-fluoride and 68Ga-PSMA-11 were performed. All suspicious bone lesions were counted, and the tracer uptake was measured as standardized uptake values (SUV) for both tracers. In patients with multiple findings, ten bone lesions with highest SUVmax were selected from which identical lesions from both scans were considered for direct comparison of SUVmax. PSA at scan was correlated with findings of both scans.Results: Both scans were negative for bone lesions in 7 patients (25%). Of 699 lesions consistent with skeletal metastasis in 21 patients on 18F-fluoride PET/CT, 68Ga-PSMA-11 PET/CT identified 579 lesions (83%). In 69 identical bone lesions 18F-fluoride PET/CT showed significantly higher uptake (mean SUVmax:73.1±36.8) compared to 68Ga-PSMA-11 PET/CT (34.5±31.4; p<0.001). PSA at scan was correlated with SUVmax of PSMA-PET (r=58; p=0.01). No correlation was seen between PSA and 18F-fluoride PET/CT measurements. Compared to diagnostic CT, 68Ga-PSMA-11 PET/CT showed better diagnostic performance in locating local (96% vs 61%, p=0.004) and lymph node (94% vs 46%, p<0.001) metastasis.Conclusion: 68Ga-PSMA-11 PET/CT was able to detect majority of bone lesions that were positive on 18F-fluoride PET/CT and was better correlated with PSA at time of scan. Further, this study indicates better diagnostic performance of 68Ga-PSMA-11 PET/CT to locate soft tissue lesions compared to diagnostic CT.
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| 14. |
- Regula, Naresh Kumar, et al.
(författare)
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Comparison of Ga-68-PSMA PET/CT with fluoride PET/CT for detection of bone metastatic disease in prostate cancer
- 2022
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Ingår i: European Journal of Hybrid Imaging. - : Springer Nature. - 2510-3636. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- Background F-18-NaF positron emission tomography/computed tomography (fluoride PET/CT) is considered the most sensitive technique to detect bone metastasis in prostate cancer (PCa). Ga-68-PSMA-11 (PSMA) PET/CT is increasingly used for staging of PCa. This study primarily aimed to compare the diagnostic performance of fluoride PET/CT and gallium-based PSMA PET/CT in identifying bone metastasis followed by a comparison of PSMA PET/CT with contrast-enhanced CT (CE-CT) in identifying soft tissue lesions as a secondary objective. Methods Twenty-eight PCa patients with high suspicion of disseminated disease following curative treatment were prospectively evaluated. PET/CT examinations using fluoride and PSMA were performed. All suspicious bone lesions were counted, and the tracer uptake was measured as standardized uptake values (SUV) for both tracers. In patients with multiple findings, ten bone lesions with highest SUVmax were selected from which identical lesions from both scans were considered for direct comparison of SUVmax. Soft tissue findings of local and lymph node lesions from CE-CT were compared with PSMA PET/CT. Results Both scans were negative for bone lesions in 7 patients (25%). Of 699 lesions consistent with skeletal metastasis in 21 patients on fluoride PET/CT, PSMA PET/CT identified 579 lesions (83%). In 69 identical bone lesions fluoride PET/CT showed significantly higher uptake (mean SUVmax: 73.1 +/- 36.8) compared to PSMA PET/CT (34.5 +/- 31.4; p < 0.001). Compared to CE-CT, PSMA PET/CT showed better diagnostic performance in locating local (96% vs 61%, p = 0.004) and lymph node (94% vs 46%, p < 0.001) metastasis. Conclusion In this prospective comparative study, PSMA PET/CT detected the majority of bone lesions that were positive on fluoride PET/CT. Further, this study indicates better diagnostic performance of PSMA PET/CT to locate soft tissue lesions compared to CE-CT.
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| 15. |
- Sigfridsson, Jonathan, et al.
(författare)
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Prospective data-driven respiratory gating of [Ga-68]Ga-DOTATOC PET/CT
- 2021
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Ingår i: EJNMMI Research. - : Springer Nature. - 2191-219X. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The aim of this prospective study was to evaluate a data-driven gating software's performance, in terms of identifying the respiratory signal, comparing [Ga-68]Ga-DOTATOC and [F-18]FDG examinations. In addition, for the [Ga-68]Ga-DOTATOC examinations, tracer uptake quantitation and liver lesion detectability were assessed.Methods: Twenty-four patients with confirmed or suspected neuroendocrine tumours underwent whole-body [Ga-68]Ga-DOTATOC PET/CT examinations. Prospective DDG was applied on all bed positions and respiratory motion correction was triggered automatically when the detected respiratory signal exceeded a certain threshold (R value >= 15), at which point the scan time for that bed position was doubled. These bed positions were reconstructed with quiescent period gating (QPG), retaining 50% of the total coincidences. A respiratory signal evaluation regarding the software's efficacy in detecting respiratory motion for [Ga-68]Ga-DOTATOC was conducted and compared to [F-18]FDG data. Measurements of SUVmax, SUVmean, and tumour volume were performed on [Ga-68]Ga-DOTATOC PET and compared between gated and non-gated images.Results: The threshold of R >= 15 was exceeded and gating triggered on mean 2.1 bed positions per examination for [Ga-68]Ga-DOTATOC as compared to 1.4 for [F-18]FDG. In total, 34 tumours were evaluated in a quantitative analysis. An increase of 25.3% and 28.1%, respectively, for SUVmax (P < 0.0001) and SUVmean (P < 0.0001), and decrease of 21.1% in tumour volume (P < 0.0001) was found when DDG was applied.Conclusions: High respiratory signal was exclusively detected in bed positions where respiratory motion was expected, indicating reliable performance of the DDG software on [Ga-68]Ga-DOTATOC PET/CT. DDG yielded significantly higher SUVmax and SUVmean values and smaller tumour volumes, as compared to non-gated images.
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