SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Adrian Gabriel) srt2:(2020-2024)"

Sökning: WFRF:(Adrian Gabriel) > (2020-2024)

  • Resultat 1-50 av 72
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Sartelli, Massimo, et al. (författare)
  • Ten golden rules for optimal antibiotic use in hospital settings: the WARNING call to action
  • 2023
  • Ingår i: WORLD JOURNAL OF EMERGENCY SURGERY. - 1749-7922. ; 18:1
  • Forskningsöversikt (refereegranskat)abstract
    • Antibiotics are recognized widely for their benefits when used appropriately. However, they are often used inappropriately despite the importance of responsible use within good clinical practice. Effective antibiotic treatment is an essential component of universal healthcare, and it is a global responsibility to ensure appropriate use. Currently, pharmaceutical companies have little incentive to develop new antibiotics due to scientific, regulatory, and financial barriers, further emphasizing the importance of appropriate antibiotic use. To address this issue, the Global Alliance for Infections in Surgery established an international multidisciplinary task force of 295 experts from 115 countries with different backgrounds. The task force developed a position statement called WARNING (Worldwide Antimicrobial Resistance National/International Network Group) aimed at raising awareness of antimicrobial resistance and improving antibiotic prescribing practices worldwide. The statement outlined is 10 axioms, or "golden rules," for the appropriate use of antibiotics that all healthcare workers should consistently adhere in clinical practice.
  •  
2.
  • Beal, Jacob, et al. (författare)
  • Robust estimation of bacterial cell count from optical density
  • 2020
  • Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
  • 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.
  •  
3.
  • Mareş, Răzvan Gheorghiţă, et al. (författare)
  • S100A8/A9 is a valuable biomarker and treatment target to detect and modulate neutrophil involvement in myocardial infarction
  • 2023
  • Ingår i: Romanian Journal of Morphology and Embryology. - 1220-0522. ; 64:2, s. 151-158
  • Tidskriftsartikel (refereegranskat)abstract
    • Myocardial infarction (MI) leads to irreversible ischemic damage of the heart muscle and is the leading cause of heart failure. The ischemic cardiac injury triggers a potent local and systemic immune response. In the acute phase post-MI, neutrophils infiltrate the myocardium in large numbers and induce further cardiomyocyte death, expanding the infarcted area. The alarmin S100A8/A9 is a proinflammatory mediator primarily produced by myeloid cells, with an emerging role in MI. We previously demonstrated that short-term inhibition of S100A8/A9 during the inflammatory phase of the immune response to MI improves long-term cardiac function. In the present study, we investigated the effects of S100A8/A9 blockade on myocardial inflammation and post-ischemic myocardial injury in a mouse model of coronary artery ligation. Immunohistochemical (IHC) staining revealed that the presence of S100A9 is strongly correlated with neutrophil infiltration in the myocardium on days 1 and 3 post-MI. A 3-day treatment with the S100A8/A9 blocker ABR-238901 starting immediately after MI decreased the number of neutrophils and S100A9 presence in the myocardium and had a positive impact on cardiac damage, reducing infarction size. These findings promote S100A9 as an IHC biomarker of neutrophil infiltration and a promising immunomodulatory target to regulate neutrophil recruitment, reduce ischemic injury and promote long-term beneficial cardiac recovery after MI.
  •  
4.
  • Adrian, Gabriel, et al. (författare)
  • Altered fractionation diminishes importance of tumor volume in oropharyngeal cancer : Subgroup analysis of ARTSCAN-trial
  • 2020
  • Ingår i: Head and Neck. - : Wiley-Blackwell. - 1043-3074 .- 1097-0347. ; 42:8, s. 2099-2105
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: A large tumor volume negatively impacts the outcome of radiation therapy (RT). Altered fractionation (AF) can improve local control (LC) compared with conventional fractionation (CF). The aim of the present study was to investigate if response to AF differs with tumor volume in oropharyngeal cancer.Methods: Three hundred and twenty four patients with oropharyngeal cancer treated in a randomized, phase III trial comparing CF (2 Gy/d, 5 d/wk, 7 weeks, total dose 68 Gy) to AF (1.1 Gy + 2 Gy/d, 5 d/wk, 4.5 weeks, total dose 68 Gy) were analyzed.Results: Tumor volume had less impact on LC for patients treated with AF. There was an interaction between tumor volume and fractionation schedule (P = .039). This differential response was in favor of CF for small tumors and of AF for large tumors.Conclusion: AF diminishes the importance of tumor volume for local tumor control in oropharyngeal cancer.
  •  
5.
  • Adrian, Gabriel (författare)
  • Altering Radiation Response with Time, Volume and Fractionation
  • 2021
  • Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
    • Radioresistance, the failure to achieve a desired outcome, is an obstacle in clinical radiotherapy. In this thesis we investigate factors affecting radioresistance and strategies to overcome it, both with established clinical approaches and by using novel pre-clinical discoveries. Study I & II concern the impact of tumour volume in patients with oropharyngeal cancer. In a large, pooled cohort of 654 patients from three clinical trials, we show that tumour volume is the predominant factor for local control, progression free survival and overall survival. The negative impact of large tumour volumes could, in exploratory analyses, be mitigated by intensified radiotherapy. The studies also confirm the prognostic role of HPV/p16- associated tumours, haemoglobin level and smoking status. Based on the results, individualized treatment based on tumour volume could be suggested. The second part of the thesis is based on pre-clinical experiments of novel discoveries. FLASH, the use of ultra-high dose rate radiotherapy where the irradiation is delivered in a fraction of a second, has been shown to spare normal tissue without hampering tumour control. Thereby, FLASH could be used to overcome radioresistance by escalating the dose to the tumour without increasing the risk of normal tissue complications. Oxygen has been proposed to play a key role in mediating the FLASH effect. We investigated the role of oxygen concentrations in a prostate cancer cell line and found that the FLASH effect appeared in hypoxic cells, but not in normoxic (study III). To further elucidate if FLASH effects are solely appearing in hypoxia, we investigated six additional cell lines under normoxic conditions and found that a FLASH effect may also appear in normoxia (study IV). We did not find any correlation between the FLASH effect and induction of DNA double strand breaks or cell cycle arrests. In the last two decades the discovery of bystander and rescue effects has broaden the understanding of radiation responses. Not only directly hit cells are affected by the irradiation, and cellular communications contribute to part of the radiation response. We investigated if cellular communications could induce radioresistance. By varying the number of irradiated cells, adding cell conditioned medium and irradiating only half of the cells, we found that cellular communications cause a rescue effect, hence radioresistance. In summary, the thesis underpins that radiation responses can be altered. To overcome radioresistance due to large tumour volumes, intensified radiotherapy for patients with large oropharyngeal cancers should be considered. The clinical exploitations of FLASH and bystander/rescue effects remain to be investigated.
  •  
6.
  • Adrian, Gabriel, et al. (författare)
  • Cancer Cells Can Exhibit a Sparing FLASH Effect at Low Doses Under Normoxic In Vitro-Conditions
  • 2021
  • Ingår i: Frontiers in Oncology. - : Frontiers Media SA. - 2234-943X. ; 11
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Irradiation with ultra-high dose rate (FLASH) has been shown to spare normal tissue without hampering tumor control in several in vivo studies. Few cell lines have been investigated in vitro, and previous results are inconsistent. Assuming that oxygen depletion accounts for the FLASH sparing effect, no sparing should appear for cells irradiated with low doses in normoxia. Methods: Seven cancer cell lines (MDA-MB-231, MCF7, WiDr, LU-HNSCC4, HeLa [early passage and subclone]) and normal lung fibroblasts (MRC-5) were irradiated with doses ranging from 0 to 12 Gy using FLASH (≥800 Gy/s) or conventional dose rates (CONV, 14 Gy/min), with a 10 MeV electron beam from a clinical linear accelerator. Surviving fraction (SF) was determined with clonogenic assays. Three cell lines were further studied for radiation-induced DNA-damage foci using a 53BP1-marker and for cell cycle synchronization after irradiation. Results: A tendency of increased survival following FLASH compared with CONV was suggested for all cell lines, with significant differences for 4/7 cell lines. The magnitude of the FLASH-sparing expressed as a dose-modifying factor at SF=0.1 was around 1.1 for 6/7 cell lines and around 1.3 for the HeLasubclone. Similar cell cycle distributions and 53BP1-foci numbers were found comparing FLASH to CONV. Conclusion: We have found a FLASH effect appearing at low doses under normoxic conditions for several cell lines in vitro. The magnitude of the FLASH effect differed between the cell lines, suggesting inherited biological susceptibilities for FLASH irradiation.
  •  
7.
  • Adrian, Gabriel, et al. (författare)
  • Circulating tumour HPV16 DNA quantification – A prognostic tool for progression-free survival in patients with HPV-related oropharyngeal carcinoma receiving curative chemoradiotherapy
  • 2023
  • Ingår i: Radiotherapy and Oncology. - 0167-8140. ; 186
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and Purpose: Circulating tumour (ct) human papillomavirus (HPV) DNA is detectable in HPV-related oropharyngeal carcinoma (OPSCC) patients and has the potential to become an important clinical tool. This study aimed to evaluate the prognostic significance of ctHPV16-DNA kinetics during treatment with chemoradiotherapy in HPV-related OPSCC. Patients with p16-positive OPSCC recruited to the ARTSCAN III trial, comparing radiotherapy plus cisplatin with radiotherapy plus cetuximab, constituted the study cohort. Materials and methods: Blood samples before start and at the end of treatment of 136 patients were analysed. ctHPV16-DNA was quantified by real-time (q)PCR. The correlation between ctHPV16-DNA levels and tumour burden was investigated with Pearson regression analysis. The prognostic value of ctHPV16-DNA levels at baseline and decline during treatment was evaluated by area-under-the-curve (AUC) calculations and analysed with univariable and multivariable Cox proportional hazards models. Results: ctHPV16-DNA was detectable with qPCR in 108/136 patients before start of treatment and cleared in 74% of these patients at the end of treatment. Disease burden was significantly correlated with baseline ctHPV16-DNA levels (R = 0.39, p=<0.001). Both lower baseline levels and AUC-ctHPV16DNA were associated with improved progression-free survival (p = 0.01 and p < 0.001), overall survival (p = 0.013 and p = 0.002), but not local tumour control (p = 0.12 and p = 0.2, respectively), with a stronger association for AUC-ctHPV16DNA (likelihood ratio test 10.5 vs 6.5 in Cox regression analyses of progression-free survival). In multivariable analysis including tumour volume (GTV-T) and treatment allocation (cisplatin vs cetuximab), AUC-ctHPV16DNA remained a significant prognostic marker of progression-free survival. Conclusion: ctHPV16-DNA is an independent prognostic factor in HPV-related OPSCC.
  •  
8.
  •  
9.
  • Adrian, Gabriel, et al. (författare)
  • Importance of tumor volume, overall treatment time and fractionation sensitivity for p16-positive and p16-negative oropharyngeal tumors
  • 2023
  • Ingår i: Acta oncologica (Stockholm, Sweden). - 1651-226X. ; 62:11, s. 1375-1383
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Analyses of clinical outcomes following radiotherapy (RT) have advanced our understanding of fundamental radiobiological characteristics in head and neck squamous cell carcinoma (HNSCC). Low fractionation sensitivity appears to be a common feature, as well as susceptibility to changes in overall treatment time (OTT). Large tumors should be harder to cure if a successful RT requires the sterilization of all clonogenic cells. Congruently, primary tumor volume has proven to be an important parameter. However, most findings come from an era when p16-negative HNSCC was the dominant tumor type. HPV-associated, p16-positive, oropharyngeal tumors (OPSCC) are more radiosensitive and have better outcome. The current study aims to investigate the role of primary tumor volume, OTT and estimate α/β-ratio for p16-positive OPSCC, and to quantify the differences in radiosensitivity depending on p16-status.METHODS: A cohort of 523 patients treated with RT was studied using a tumor control probability (TCP)-model that incorporates primary tumor volume (V) raised to an exponent c, OTT and α/β-estimation. The significance of V was also investigated in Cox-regression models.RESULTS: In the p16-positive cohort (n = 433), the volume exponent c was 1.44 (95%CI 1.06-1.91), compared to 0.90 (0.54-1.32) for p16-negative tumors (n = 90). Hazard ratios per tumor volume doubling were 2.37 (1.72-3.28) and 1.83 (1.28-2.62) for p16-positive and p16-negative, respectively. The estimated α/β-ratio was 9.7 Gy (-2.3-21.6), and a non-significant daily loss of 0.30 Gy (-0.17-0.92) was found. An additional dose of 6.8 Gy (interquartile range 4.8-9.1) may theoretically counteract the more radioresistant behavior of p16-negative tumors.CONCLUSION: Primary tumor volume plays a crucial role in predicting local tumor response, particularly in p16-positive OPSCC. The estimated α/β-ratio for p16-positive oropharyngeal tumors aligns with previous HNSCC studies, whereas the impact of prolonged OTT was slightly less than previously reported. The differences in radiosensitivity depending on p16-status were quantified. The findings should be validated in independent cohorts.
  •  
10.
  • Adrian, Gabriel, et al. (författare)
  • In vitro assays for investigating the FLASH effect
  • 2022
  • Ingår i: Expert Reviews in Molecular Medicine. - : Cambridge University Press (CUP). - 1462-3994. ; 24
  • Forskningsöversikt (refereegranskat)abstract
    • FLASH radiotherapy is a novel technique that has been shown in numerous preclinical in vivo studies to have the potential to be the next important improvement in cancer treatment. However, the biological mechanisms responsible for the selective FLASH sparing effect of normal tissues are not yet known. An optimal translation of FLASH radiotherapy into the clinic would require a good understanding of the specific beam parameters that induces a FLASH effect, environmental conditions affecting the response, and the radiobiological mechanisms involved. Even though the FLASH effect has generally been considered as an in vivo effect, studies finding these answers would be difficult and ethically challenging to carry out solely in animals. Hence, suitable in vitro studies aimed towards finding these answers are needed. In this review, we describe and summarise several in vitro assays that have been used or could be used to finally elucidate the mechanisms behind the FLASH effect.
  •  
11.
  • Adrian, Gabriel, et al. (författare)
  • Primary tumor volume and prognosis for patients with p16-positive and p16-negative oropharyngeal squamous cell carcinoma treated with radiation therapy
  • 2022
  • Ingår i: Radiation Oncology. - : Springer Nature. - 1748-717X. ; 17:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: The prescribed radiation dose to patients with oropharyngeal squamous cell carcinoma (OPSCC) is standardized, even if the prognosis for individual patients may differ. Easy-at-hand pre-treatment risk stratification methods are valuable to individualize therapy. In the current study we assessed the prognostic impact of primary tumor volume for p16-positive and p16-negative tumors and in relationship to other prognostic factors for outcome in patients with OPSCC treated with primary radiation therapy (RT). Methods: Five hundred twenty-three OPSCC patients with p16-status treated with primary RT (68.0 Gy to 73.1 Gy in 7 weeks, or 68.0 Gy in 4.5 weeks), with or without concurrent chemotherapy, within three prospective trials were included in the study. Local failure (LF), progression free survival (PFS) and overall survival (OS) in relationship to the size of the primary gross tumor volume (GTV-T) and other prognostic factors were investigated. Efficiency of intensified RT (RT with total dose 73.1 Gy or given within 4.5 weeks) was analyzed in relationship to tumor volume. Results: The volume of GTV-T and p16-status were found to be the strongest prognostic markers for LF, PFS and OS. For p16-positive tumors, an increase in tumor volume had a significantly higher negative prognostic impact compared with p16-negative tumors. Within a T-classification, patients with a smaller tumor, compared with a larger tumor, had a better prognosis. The importance of tumor volume remained after adjusting for nodal status, age, performance status, smoking status, sex, and hemoglobin-level. The adjusted hazard ratio for OS per cm3 increase in tumor volume was 2.3% (95% CI 0–4.9) for p16-positive and 1.3% (95% 0.3–2.2) for p16-negative. Exploratory analyses suggested that intensified RT could mitigate the negative impact of a large tumor volume. Conclusions: Outcome for patients with OPSCC treated with RT is largely determined by tumor volume, even when adjusting for other established prognostic factors. Tumor volume is significantly more influential for patients with p16-positive tumors. Patients with large tumor volumes might benefit by intensified RT to improve survival.
  •  
12.
  • Agredo Chavez, Angelica Maria, et al. (författare)
  • Data Validation of Strain-Based Monitoring Systems in Low Temperature Conditions, Case Study : The Kalix Bridge
  • 2023
  • Ingår i: Building for the Future: Durable, Sustainable, Resilient - Proceedings of the fib Symposium 2023 - Volume 2. - : Springer. - 9783031325106 - 9783031325113 ; , s. 986-995
  • Konferensbidrag (refereegranskat)abstract
    • Over the last decades, economic growth and sustained development have enforced the need to ensure reliable and long-lasting infrastructure network to guarantee serviceability and safety. Nevertheless, detrimental effects can lead over time to insufficient structural performance under increasing service loadings and extreme events. Hence, Structural Health Monitoring (SHM) arises as a solution to cope with the need of having timely and continuous data to assess the state of crucial structural assets, such as prestressed concrete bridges. On this matter, the validation of the retrieved data becomes essential for the risk-based decision making in the assessment of bridges, where selecting the most suitable monitoring system could allow to addressed main causes to the right phenomena of deterioration during the service life of the bridge. Consistently with these efforts, this paper deals with a comparative study between the data acquired by different strain-based sensors such as Fiber optic systems (FOS) and strain gauges that were installed to monitor a proof loading test developed on a 65-year-old balanced cantilever prestressed concrete bridge located in Northern Sweden. The monitored data led to establish main differences between emerging types of monitoring systems such as FOS to the well-based strain gauges when exposed to low temperature conditions. Conclusions regarding the influencing parameters between both retrieved data are drawn when evaluating the structural response under serviceability loading conditions is performed, supporting decision makers when different levels of structural assessment are required.
  •  
13.
  • Azevedo, Flavio, et al. (författare)
  • Social and moral psychology of COVID-19 across 69 countries
  • 2023
  • Ingår i: Scientific Data. - : NATURE PORTFOLIO. - 2052-4463. ; 10:1
  • Tidskriftsartikel (refereegranskat)abstract
    • The COVID-19 pandemic has affected all domains of human life, including the economic and social fabric of societies. One of the central strategies for managing public health throughout the pandemic has been through persuasive messaging and collective behaviour change. To help scholars better understand the social and moral psychology behind public health behaviour, we present a dataset comprising of 51,404 individuals from 69 countries. This dataset was collected for the International Collaboration on Social & Moral Psychology of COVID-19 project (ICSMP COVID-19). This social science survey invited participants around the world to complete a series of moral and psychological measures and public health attitudes about COVID-19 during an early phase of the COVID-19 pandemic (between April and June 2020). The survey included seven broad categories of questions: COVID-19 beliefs and compliance behaviours; identity and social attitudes; ideology; health and well-being; moral beliefs and motivation; personality traits; and demographic variables. We report both raw and cleaned data, along with all survey materials, data visualisations, and psychometric evaluations of key variables.
  •  
14.
  •  
15.
  • Bista, Dipen, et al. (författare)
  • Numerical parametric study on the influence of location and inclination of large-scale asperities on the shear strength of concrete-rock interfaces of small buttress dams
  • 2024
  • Ingår i: Journal of Rock Mechanics and Geotechnical Engineering. - : Elsevier. - 1674-7755.
  • Tidskriftsartikel (refereegranskat)abstract
    • When assessing the sliding stability of a concrete dam, the influence of large-scale asperities in the sliding plane is often ignored due to limitations of the analytical rigid body assessment methods provided by current dam assessment guidelines. However, these asperities can potentially improve the load capacity of a concrete dam in terms of sliding stability. Although their influence in a sliding plane has been thoroughly studied for direct shear, their influence under eccentric loading, as in the case of dams, is unknown. This paper presents the results of a parametric study that used finite element analysis (FEA) to investigate the influence of large-scale asperities on the load capacity of small buttress dams. By varying the inclination and location of an asperity located in the concrete-rock interface along with the strength of the rock foundation material, transitions between different failure modes and correlations between the load capacity and the varied parameters were observed. The results indicated that the inclination of the asperity had a significant impact on the failure mode. When the inclination was 30° and greater, interlocking occurred between the dam and foundation and the governing failure modes were either rupture of the dam body or asperity. When the asperity inclination was significant enough to provide interlocking, the load capacity of the dam was impacted by the strength of the rock in the foundation through influencing the load capacity of the asperity. The location of the asperity along the concrete-rock interface did not affect the failure mode, except for when the asperity was located at the toe of the dam, but had an influence on the load capacity when the failure occurred by rupture of the buttress or by sliding. By accounting for a single large-scale asperity in the concrete-rock interface of the analysed dam, a horizontal load capacity increase of 30%–160% was obtained, depending on the inclination and location of the asperity and the strength of the foundation material.
  •  
16.
  • Burstroem, Gustav, et al. (författare)
  • Optical Methods for Brain Tumor Detection : A Systematic Review
  • 2024
  • Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 13:9
  • Forskningsöversikt (refereegranskat)abstract
    • Background: In brain tumor surgery, maximal tumor resection is typically desired. This is complicated by infiltrative tumor cells which cannot be visually distinguished from healthy brain tissue. Optical methods are an emerging field that can potentially revolutionize brain tumor surgery through intraoperative differentiation between healthy and tumor tissues. Methods: This study aimed to systematically explore and summarize the existing literature on the use of Raman Spectroscopy (RS), Hyperspectral Imaging (HSI), Optical Coherence Tomography (OCT), and Diffuse Reflectance Spectroscopy (DRS) for brain tumor detection. MEDLINE, Embase, and Web of Science were searched for studies evaluating the accuracy of these systems for brain tumor detection. Outcome measures included accuracy, sensitivity, and specificity. Results: In total, 44 studies were included, covering a range of tumor types and technologies. Accuracy metrics in the studies ranged between 54 and 100% for RS, 69 and 99% for HSI, 82 and 99% for OCT, and 42 and 100% for DRS. Conclusions: This review provides insightful evidence on the use of optical methods in distinguishing tumor from healthy brain tissue.
  •  
17.
  • Burström, Gustav, et al. (författare)
  • Optical Methods for Brain Tumor Detection : A Systematic Review
  • 2024
  • Ingår i: Journal of Clinical Medicine. - : MDPI. - 2077-0383. ; 13:9
  • Forskningsöversikt (refereegranskat)abstract
    • Background: In brain tumor surgery, maximal tumor resection is typically desired. This is complicated by infiltrative tumor cells which cannot be visually distinguished from healthy brain tissue. Optical methods are an emerging field that can potentially revolutionize brain tumor surgery through intraoperative differentiation between healthy and tumor tissues.Methods: This study aimed to systematically explore and summarize the existing literature on the use of Raman Spectroscopy (RS), Hyperspectral Imaging (HSI), Optical Coherence Tomography (OCT), and Diffuse Reflectance Spectroscopy (DRS) for brain tumor detection. MEDLINE, Embase, and Web of Science were searched for studies evaluating the accuracy of these systems for brain tumor detection. Outcome measures included accuracy, sensitivity, and specificity.Results: In total, 44 studies were included, covering a range of tumor types and technologies. Accuracy metrics in the studies ranged between 54 and 100% for RS, 69 and 99% for HSI, 82 and 99% for OCT, and 42 and 100% for DRS.Conclusions: This review provides insightful evidence on the use of optical methods in distinguishing tumor from healthy brain tissue.
  •  
18.
  • Bussy, Aurélie, et al. (författare)
  • Cerebellar and subcortical atrophy contribute to psychiatric symptoms in frontotemporal dementia
  • 2023
  • Ingår i: Human Brain Mapping. - : Wiley. - 1065-9471 .- 1097-0193. ; 44:7, s. 2684-2700
  • Tidskriftsartikel (refereegranskat)abstract
    • Recent studies have reported early cerebellar and subcortical impact in the disease progression of genetic frontotemporal dementia (FTD) due to microtubule-associated protein tau (MAPT), progranulin (GRN) and chromosome 9 open reading frame 72 (C9orf72). However, the cerebello-subcortical circuitry in FTD has been understudied despite its essential role in cognition and behaviors related to FTD symptomatology. The present study aims to investigate the association between cerebellar and subcortical atrophy, and neuropsychiatric symptoms across genetic mutations. Our study included 983 participants from the Genetic Frontotemporal dementia Initiative including mutation carriers and noncarrier first-degree relatives of known symptomatic carriers. Voxel-wise analysis of the thalamus, striatum, globus pallidus, amygdala, and the cerebellum was performed, and partial least squares analyses (PLS) were used to link morphometry and behavior. In presymptomatic C9orf72 expansion carriers, thalamic atrophy was found compared to noncarriers, suggesting the importance of this structure in FTD prodromes. PLS analyses demonstrated that the cerebello-subcortical circuitry is related to neuropsychiatric symptoms, with significant overlap in brain/behavior patterns, but also specificity for each genetic mutation group. The largest differences were in the cerebellar atrophy (larger extent in C9orf72 expansion group) and more prominent amygdalar volume reduction in the MAPT group. Brain scores in the C9orf72 expansion carriers and MAPT carriers demonstrated covariation patterns concordant with atrophy patterns detectable up to 20 years before expected symptom onset. Overall, these results demonstrated the important role of the subcortical structures in genetic FTD symptom expression, particularly the cerebellum in C9orf72 and the amygdala in MAPT carriers.
  •  
19.
  • Buwaider, Ali, et al. (författare)
  • Extended reality in cranial and spinal neurosurgery : a bibliometric analysis
  • 2024
  • Ingår i: Acta Neurochirurgica. - : Springer. - 0001-6268 .- 0942-0940. ; 166:1
  • Forskningsöversikt (refereegranskat)abstract
    • PURPOSE: This bibliometric analysis of the top 100 cited articles on extended reality (XR) in neurosurgery aimed to reveal trends in this research field. Gender differences in authorship and global distribution of the most-cited articles were also addressed.METHODS: A Web of Science electronic database search was conducted. The top 100 most-cited articles related to the scope of this review were retrieved and analyzed for trends in publications, journal characteristics, authorship, global distribution, study design, and focus areas. After a brief description of the top 100 publications, a comparative analysis between spinal and cranial publications was performed.RESULTS: From 2005, there was a significant increase in spinal neurosurgery publications with a focus on pedicle screw placement. Most articles were original research studies, with an emphasis on augmented reality (AR). In cranial neurosurgery, there was no notable increase in publications. There was an increase in studies assessing both AR and virtual reality (VR) research, with a notable emphasis on VR compared to AR. Education, surgical skills assessment, and surgical planning were more common themes in cranial studies compared to spinal studies. Female authorship was notably low in both groups, with no significant increase over time. The USA and Canada contributed most of the publications in the research field.CONCLUSIONS: Research regarding the use of XR in neurosurgery increased significantly from 2005. Cranial research focused on VR and resident education while spinal research focused on AR and neuronavigation. Female authorship was underrepresented. North America provides most of the high-impact research in this area.
  •  
20.
  • Buwaider, Ali, et al. (författare)
  • Extended reality in cranial and spinal neurosurgery – a bibliometric analysis
  • 2024
  • Ingår i: Acta Neurochirurgica. - : Springer Nature. - 0001-6268 .- 0942-0940. ; 166:1
  • Forskningsöversikt (refereegranskat)abstract
    • Purpose: This bibliometric analysis of the top 100 cited articles on extended reality (XR) in neurosurgery aimed to reveal trends in this research field. Gender differences in authorship and global distribution of the most-cited articles were also addressed. Methods: A Web of Science electronic database search was conducted. The top 100 most-cited articles related to the scope of this review were retrieved and analyzed for trends in publications, journal characteristics, authorship, global distribution, study design, and focus areas. After a brief description of the top 100 publications, a comparative analysis between spinal and cranial publications was performed. Results: From 2005, there was a significant increase in spinal neurosurgery publications with a focus on pedicle screw placement. Most articles were original research studies, with an emphasis on augmented reality (AR). In cranial neurosurgery, there was no notable increase in publications. There was an increase in studies assessing both AR and virtual reality (VR) research, with a notable emphasis on VR compared to AR. Education, surgical skills assessment, and surgical planning were more common themes in cranial studies compared to spinal studies. Female authorship was notably low in both groups, with no significant increase over time. The USA and Canada contributed most of the publications in the research field. Conclusions: Research regarding the use of XR in neurosurgery increased significantly from 2005. Cranial research focused on VR and resident education while spinal research focused on AR and neuronavigation. Female authorship was underrepresented. North America provides most of the high-impact research in this area.
  •  
21.
  • Buwaider, Ali, et al. (författare)
  • Predictors of early mortality following surgical or nonsurgical treatment of subaxial cervical spine fractures : a retrospective nationwide registry study
  • 2024
  • Ingår i: The spine journal. - : Elsevier. - 1529-9430 .- 1878-1632.
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Traumatic subaxial cervical spine fractures are a significant public health concern due to their association with spinal cord injuries (SCI). Despite being mostly caused by low-energy trauma, these fractures significantly contribute to morbidity and mortality. Currently, research regarding early mortality based on the choice of treatment following these fractures is limited. Identifying predictors of early mortality may aid in postoperative patient monitoring and improve outcomes. PURPOSE: This study aimed to identify predictors of 30-days, 90-days, and 1-year mortality in adults treated for subaxial fractures.STUDY DESIGN: A retrospective review of the nationwide Swedish Fracture Register (SFR). PATIENT SAMPLE: All adult patients in the SFR who underwent treatment for a subaxial cervical fracture (n = 1,963).OUTCOME MEASURES: Analyzed variables included age, sex, injury mechanism, neurological function, fracture characteristics, and treatment type. The primary endpoints were 30-days, 90-days, and 1-year mortality.METHODS: About 1,963 patients in the SFR, treated for subaxial cervical fractures between 2013 and 2021, were analyzed. Surgical procedures included anterior, posterior, or anteroposterior approaches. Nonsurgical treatment included collar treatment or medical examinations without intervention. Stepwise regression and Cox regression analysis were used to determine predictors. Model performance was tested using the area under the receiver operating characteristic curve (AUC).RESULTS: 620 patients underwent surgery and 1,343 received nonsurgical treatment. Surgical cases had primarily translation fractures, with 323 (52%) displaying no neurological deficits. Mortality rates at 30 days, 90 days, and 1 year were 22/620 (3.5%), 35/620 (5.6%), and 53/620 (8.5%), respectively. Age and SCI were predictors of mortality. Nonsurgically treated patients mostly had compression fracture, with 1,214 (90%) experiencing no neurological deficits. Mortality rates at 30 days, 90 days, and 1 year were 41/1,343 (3.1%), 71/1,343 (5.3%), and 118/1,343 (8.7%). Age, male sex, SCI and fractures occurring at the C3 or C6 levels were predictors of mortality. An intact neurological function was a positive predictor of survival among nonsurgically treated patients (AUC >0.78).CONCLUSIONS: Age and SCI emerged as significant predictors of early mortality in both surgically and nonsurgically treated patients. An intact neurological function served as a protective factor against early mortality in nonsurgically treated patients. Fractures at C3 or C6 vertebrae may impact mortality.
  •  
22.
  • Böhlen, Till Tobias, et al. (författare)
  • Effect of Conventional and Ultrahigh Dose Rate FLASH Irradiations on Preclinical Tumor Models : A Systematic Analysis
  • 2023
  • Ingår i: International Journal of Radiation Oncology Biology Physics. - 0360-3016. ; 117:4, s. 1007-1017
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: Compared with conventional dose rate irradiation (CONV), ultrahigh dose rate irradiation (UHDR) has shown superior normal tissue sparing. However, a clinically relevant widening of the therapeutic window by UHDR, termed “FLASH effect”, also depends on the tumor toxicity obtained by UHDR. Based on a combined analysis of published literature, the current study examined the hypothesis of tumor isoefficacy for UHDR versus CONV and aimed to identify potential knowledge gaps to inspire future in vivo studies. Methods and Materials: A systematic literature search identified publications assessing in vivo tumor responses comparing UHDR and CONV. Qualitative and quantitative analyses were performed, including combined analyses of tumor growth and survival data. Results: We identified 66 data sets from 15 publications that compared UHDR and CONV for tumor efficacy. The median number of animals per group was 9 (range 3-15) and the median follow-up period was 30.5 days (range 11-230) after the first irradiation. Tumor growth assays were the predominant model used. Combined statistical analyses of tumor growth and survival data are consistent with UHDR isoefficacy compared with CONV. Only 1 study determined tumor-controlling dose (TCD50) and reported statistically nonsignificant differences. Conclusions: The combined quantitative analyses of tumor responses support the assumption of UHDR isoefficacy compared with CONV. However, the comparisons are primarily based on heterogeneous tumor growth assays with limited numbers of animals and short follow-up, and most studies do not assess long-term tumor control probability. Therefore, the assays may be insensitive in resolving smaller response differences, such as responses of radioresistant tumor subclones. Hence, tumor cure experiments, including additional TCD50 experiments, are needed to confirm the assumption of isoeffectiveness in curative settings.
  •  
23.
  • Capodanno, Davide, et al. (författare)
  • Defining Strategies of Modulation of Antiplatelet Therapy in Patients With Coronary Artery Disease : A Consensus Document from the Academic Research Consortium
  • 2023
  • Ingår i: Circulation. - : Ovid Technologies (Wolters Kluwer Health). - 0009-7322 .- 1524-4539. ; 147:25, s. 1933-1944
  • Tidskriftsartikel (refereegranskat)abstract
    • Antiplatelet therapy is the mainstay of pharmacologic treatment to prevent thrombotic or ischemic events in patients with coronary artery disease treated with percutaneous coronary intervention and those treated medically for an acute coronary syndrome. The use of antiplatelet therapy comes at the expense of an increased risk of bleeding complications. Defining the optimal intensity of platelet inhibition according to the clinical presentation of atherosclerotic cardiovascular disease and individual patient factors is a clinical challenge. Modulation of antiplatelet therapy is a medical action that is frequently performed to balance the risk of thrombotic or ischemic events and the risk of bleeding. This aim may be achieved by reducing (ie, de-escalation) or increasing (ie, escalation) the intensity of platelet inhibition by changing the type, dose, or number of antiplatelet drugs. Because de-escalation or escalation can be achieved in different ways, with a number of emerging approaches, confusion arises with terminologies that are often used interchangeably. To address this issue, this Academic Research Consortium collaboration provides an overview and definitions of different strategies of antiplatelet therapy modulation for patients with coronary artery disease, including but not limited to those undergoing percutaneous coronary intervention, and consensus statements on standardized definitions.
  •  
24.
  • El-Hajj, Victor Gabriel, et al. (författare)
  • An unusual cause of chronic neuropathic pain : report of a case of multiple intradural spinal arachnoid cysts and review of the literature
  • 2023
  • Ingår i: Acta Neurochirurgica. - : Springer. - 0001-6268 .- 0942-0940. ; 165, s. 2699-2705
  • Forskningsöversikt (refereegranskat)abstract
    • Spinal arachnoid cysts (SACs) arise either intra- or extradurally and are usually solitary, while cases of multiple SACs have been scarcely reported in the literature. Herein, we report on a rare case of multiple and recurring intradural spinal arachnoid cysts (SACs) causing severe spinal cord compression and neuropathic radicular pain, in a 35-year-old female with a 10-year follow-up. Two separate attempts at surgery were performed but only provided temporary relief since the cysts recurred and new ones formed along the entirety of the spinal cord. Finally, a conservative approach with physiotherapy and a combination of analgesic medications was pursued.
  •  
25.
  • El-Hajj, Victor Gabriel, et al. (författare)
  • Conservative or surgical management of orbital schwannomas : a population-based case series
  • 2024
  • Ingår i: Acta Neurochirurgica. - : Springer. - 0001-6268 .- 0942-0940. ; 166
  • Tidskriftsartikel (refereegranskat)abstract
    • Introduction: Orbital schwannomas (OS) are rare occurrences with no more than 500 cases reported in the literature. The tumor's potential to compromise the delicate neuro-ophthalmic structures within the orbit prompts surgical removal. Tumor removal is performed by ophthalmologists, often requiring a multidisciplinary surgical approach. The literature contains a very limited number of cases managed non-surgically. However, the inherent risks of orbital surgery warrant a comparison of the outcomes of conservative and surgical management strategies.Aims: To review the national Swedish experience with the management of orbital schwannomas.Methods: The study center is the primary Swedish referral center for the multidisciplinary management of orbital tumors, including schwannomas. During the period of 2005 to 2021, 16 patients with an OS diagnosis were managed at the center.Results: Four patients initially underwent surgery where gross total resection (GTR) was achieved in three (75%) and subtotal resection (STR) in one (25%) case. The remaining 12 patients, who had a low risk of neuro-ophthalmic impairment, were managed conservatively with radiological and clinical examinations at regular intervals. After an average follow-up of 17 months, surgery was performed in three of these cases (25%). No recurrences or tumor growths were detected on radiological follow-ups (mean 50 months), and all patients experienced postoperative improvement at clinical follow-up (mean 65 months). The remainder of the conservatively treated patients (n=9) experienced no clinical progression (mean 30 months). A slight radiological tumor progression was detected in one patient after 17 months.Conclusion: There were no differences in long-term outcome between patients who had been managed with early surgery and those operated later after an initially conservative management. Conservatively treated patients had minimal to no symptoms and remained clinically stable throughout the follow-up period. Based on these findings, conservative management may successfully be adopted in cases with mild symptoms, no signs of compressive optic neuropathy and low risk of neuro-ophthalmic impairment. Conversion to surgical management is indicated upon clinical deterioration or tumor growth. Based on the findings of this study a decision tree for the management of orbital schwannomas is suggested.
  •  
26.
  • El-Hajj, Victor Gabriel, et al. (författare)
  • Evolution of patient-reported outcome measures, 1, 2, and 5 years after surgery for subaxial cervical spine fractures, a nation-wide registry study
  • 2023
  • Ingår i: The spine journal. - : Elsevier BV. - 1529-9430 .- 1878-1632. ; 23:8, s. 1182-1188
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND CONTEXT: A longer duration of patient follow up arguably provides more reli-able data on the long-term effects of a treatment. However, the collection of long-term follow up data is resource demanding and often complicated by missing data and patients being lost to follow up. In surgical fixation for cervical spine fractures, data are lacking on the evolution of patient reported out -come measures (PROMs) beyond 1-year of follow up. We hypothesized that the PROMs would remain stable beyond the 1-year postoperative follow up mark, regardless of the surgical approach.PURPOSE: To assess the trends in the evolution of patient-reported outcome measures (PROMs) at 1, 2-, and 5-years following surgery in patients with traumatic cervical spine injuries.STUDY DESIGN: Nation-wide observational study on prospectively collected data.PATIENT SAMPLE: Individuals treated for subaxial cervical spine fractures with anterior, poste-rior, or combined anteroposterior approaches, between 2006 and 2016 were identified in the Swed-ish Spine Registry (Swespine).OUTCOME MEASURES: PROMs consisting of EQ-5D-3Lindex and the Neck Disability Index (NDI) were considered.METHODS: PROMs data were available for 292 patients at 1 and 2 years postoperatively. Five-years PROMs data were available for 142 of these patients. A simultaneous within-group (longitu-dinal) and between group (approach-dependent) analysis was performed using mixed ANOVA. The predictive ability of 1-year PROMs was subsequently assessed using linear regression.RESULTS: Mixed ANOVA revealed that PROMs remained stable from 1-to 2-years as well as from 2-to 5-years postoperatively and were not significantly affected by the surgical approach (p<0.05). A strong correlation was found between 1-year and both 2-and 5-years PROMs (R>0.7; p<0.001). Linear regression confirmed the accuracy of 1-year PROMs in predicting both 2-and 5-years PROMs (p<0.001).CONCLUSION: PROMs remained stable beyond 1-year of follow up in patients treated with ante-rior, posterior, or combined anteroposterior surgeries for subaxial cervical spine fractures. The 1 -year PROMs were strong predictors of PROMs measured at 2, and 5 years. The 1-year PROMs were sufficient to assess the outcomes of subaxial cervical fixation irrespective of the surgical approach.& COPY; 2023 The Author(s). Published by Elsevier Inc.This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
  •  
27.
  •  
28.
  • El-Hajj, Victor Gabriel, et al. (författare)
  • Long-term outcomes following surgical treatment of spinal arachnoid cysts : a population-based consecutive cohort study
  • 2023
  • Ingår i: The spine journal. - : Elsevier. - 1529-9430 .- 1878-1632. ; 23:12, s. 1869-1876
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND CONTEXT: Spinal arachnoid cysts (SACs) are rare, cerebrospinal fluid-filled sacs lined by an arachnoid membrane in the spinal canal. Symptoms can develop due to pressure on the spinal cord or adjacent spinal nerves by the cyst itself or by interrupted flow of cerebrospinal fluid. If noninvasive management fails or neurological deterioration occurs, surgical treatment is recommended. However, data is lacking on long-term outcomes after surgery.PURPOSE: To determine long-term outcomes in patients surgically treated for SACs.STUDY DESIGN: Population-based cohort-study.PATIENT SAMPLE: All consecutive patients treated for either intra-or extradural SACs with surgery between 2005 and 2020 at the author's institution were included.OUTCOME MEASURES: American Spinal Injury Association Impairment Scale (AIS) and modified Japanese Orthopedic Association score (mJOA).METHODS: Data was primarily extracted from electronic patient medical notes. Telephone inter-views were performed to assess long-term postoperative outcomes. All analyses were conducted using the statistical software program R version 4.0.5. Statistical significance was set at p<.05.RESULTS: Thirty-four patients were included. Cyst excision was performed in 11 (32%) cases, and fenestration in the remaining 23 (68%). The median follow-up time was 8.0 years. Surgery resulted in a significant long-term improvement in both AIS (p=.012) and mJOA (p=.005). Sensory deficit was the symptom that most often improved (81%), followed by pain (74%) and motor func-tion (64%). AIS deteriorated in two patients, of which one case was attributed to a surgical compli-cation. Local cyst recurrence requiring reoperation was seen in 4 (12%) cases, all of them following cyst fenestration. One patient (3%) required reoperation for progression of the cyst progression at a different level.CONCLUSION: This study reports outcomes of surgically treated SACs with the longest follow-up time to date. Microsurgical cyst excision or fenestration were safe treatment options, and the neurological improvements seen in the immediate postoperative phase were maintained at long-term follow-up.
  •  
29.
  • El-Hajj, Victor Gabriel, et al. (författare)
  • Safety of anterior cervical corpectomy and fusion (ACCF) for the treatment of subaxial cervical spine injuries, a single center comparative matched analysis
  • 2024
  • Ingår i: Acta Neurochirurgica. - : Springer. - 0001-6268 .- 0942-0940. ; 166:1
  • Tidskriftsartikel (refereegranskat)abstract
    • IntroductionAnterior Cervical Discectomy and Fusion (ACDF) and Anterior Cervical Corpectomy and Fusion (ACCF) are both common surgical procedures in the management of pathologies of the subaxial cervical spine. While recent reviews have demonstrated ACCF to provide better decompression results compared to ACDF, the procedure has been associated with increased surgical risks. Nonetheless, the use of ACCF in a traumatic context has been poorly described. The aim of this study was to assess the safety of ACCF as compared to the more commonly performed ACDF.MethodsAll patients undergoing ACCF or ACDF for subaxial cervical spine injuries spanning over 2 disc-spaces and 3 vertebral-levels, between 2006 and 2018, at the study center, were eligible for inclusion. Patients were matched based on age and preoperative ASIA score.ResultsAfter matching, 60 patients were included in the matched analysis, where 30 underwent ACDF and ACCF, respectively. Vertebral body injury was significantly more common in the ACCF group (p = 0.002), while traumatic disc rupture was more frequent in the ACDF group (p = 0.032). There were no statistically significant differences in the rates of surgical complications, including implant failure, wound infection, dysphagia, CSF leakage between the groups (p >= 0.05). The rates of revision surgeries (p > 0.999), mortality (p = 0.222), and long-term ASIA scores (p = 0.081) were also similar.ConclusionResults of both unmatched and matched analyses indicate that ACCF has comparable outcomes and no additional risks compared to ACDF. It is thus a safe approach and should be considered for patients with extensive anterior column injury.
  •  
30.
  • El-Hajj, Victor Gabriel, et al. (författare)
  • Spontaneous spinal cord infarctions : a systematic review and pooled analysis protocol
  • 2023
  • Ingår i: BMJ Open. - : BMJ Publishing Group Ltd. - 2044-6055. ; 13:6
  • Forskningsöversikt (refereegranskat)abstract
    • IntroductionSpinal cord infarction (SCInf) is a rare ischaemic event that manifests with acute neurological deficits. It is typically classified as either spontaneous, defined as SCInf without any inciting event, or periprocedural, which typically occur in conjunction with vascular surgery with aortic manipulations. While periprocedural SCInf has recently been the subject of intensified research, especially focusing on the primary prevention of this complication, spontaneous SCInf remains less studied. Methods and analysisElectronic databases, including PubMed, Web of Science and Embase, will be searched using the keywords "spinal cord", "infarction", "ischemia" and "spontaneous". The search will be set to provide only English studies published from database inception. Editorials, letters and reviews will also be excluded. Reference lists of relevant records will also be searched. Identified studies will be screened for inclusion, by one reviewer in the first step and then three in the next step to decrease the risk of bias. The synthesis will address several topics of interest including epidemiology, presentation, diagnostics, treatment strategies, outcomes and predictors. The review aims to gather the body of evidence to summarise the current knowledge on SCInf. This will lead to a better understanding of the condition, its risk factors, diagnosis and management. Moreover, the review will also provide an understanding of the prognosis of patients with SCInf with respect to neurological function, quality of life and mortality. Finally, this overview of the literature will allow the identification of knowledge gaps to help guide future research efforts. Ethics and disseminationEthics approval was not required for our review as it is based on existing publications. The final manuscript will be submitted to a peer-reviewed journal.
  •  
31.
  • El-Hajj, Victor Gabriel, et al. (författare)
  • The Effect of Concomitant Spinal Cord Injury on Postoperative Health-related Quality of Life After Traumatic Subaxial Cervical Spine Injuries : A Nationwide Registry Study
  • 2024
  • Ingår i: Archives of Physical Medicine and Rehabilitation. - : Elsevier. - 0003-9993 .- 1532-821X. ; 105:6, s. 1069-1075
  • Tidskriftsartikel (refereegranskat)abstract
    • Objective: To evaluate the effect of spinal cord injury (SCI) on the health-related quality of life (HRQoL) in patients surgically treated for traumatic subaxial cervical spine injuries and investigate the agreement between objective neurologic outcomes and patient reported outcome measures (PROMs) in that context.Study Design: Observational study on prospectively collected multi-institutional registry data. Setting: Sweden. Participants: Patients with traumatic subaxial spine injuries identified in the Swedish Spine Registry (Swespine) between 2006 and 2016.Interventions: Anterior, posterior, or anteroposterior cervical fixation surgery. Main Outcomes: Patient-reported outcome measures (PROMs) consisting of EQ-5D-3L(index) and Neck Disability Index (NDI).Results: Among the 418 identified patients, 93 (22%) had a concomitant SCI. In this group, 30 (32%) had a complete SCI (Frankel A), and the remainder had incomplete SCIs (17%) Frankel B; 25 (27%) Frankel C; 22 (24%) Frankel D. PROMs significantly correlated with the Frankel grade (P<.001). However, post hoc analysis revealed that the differences between adjacent Frankel grades failed to reach both statistical and clinical significance. On univariable linear regression, the Frankel grade was a significant predictor of a specific index derived from the EQ-5D-3L questionnaire (EQ-5D-3L(index)) at 1, 2, and 5 years postoperatively as well as the NDI at 1 and 2 years postoperatively (P<.001). Changes of PROMs over time from 1, to 2, and 5 years postoperatively did not reach statistical significance, regardless of the presence and degree of SCI (P>.05).Conclusion: Overall, the Frankel grade significantly correlated with the EQ-5D-3L(index) and NDI and was a significant predictor of PROMs at 1, 2, and 5 years. PROMs were stable beyond 1 year postoperatively regardless of the severity of the SCI. (c) 2024 by the American Congress of Rehabilitation Medicine. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)
  •  
32.
  • El-Hajj, Victor Gabriel, et al. (författare)
  • The negative impact of treatment delays on the long-term neurological outcomes of spinal dural arteriovenous fistulas : a longitudinal cohort study
  • 2024
  • Ingår i: Neurosurgical Focus. - : American Association of Neurological Surgeons. - 1092-0684. ; 56:3
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVE: Dural arteriovenous fistulas are rare vascular malformations that affect the brain and spinal cord. Spinal dural arteriovenous fistulas (sdAVFs) are the most frequently encountered vascular malformation affecting the spinal cord. The object of this study was to evaluate the impact of treatment delays on the long-term neurological outcomes of either open surgical or interventional treatment of sdAVFs.METHODS: In this retrospective, population-based cohort study, the authors examined consecutive patients with diagnosed sdAVFs at a tertiary care center between 2005 and 2020. Patients were assessed using the Aminoff-Logue disability scale (ALS) at various time points including symptom onset, primary care visit, first specialist outpatient visit, as well as both short and long-term follow-ups. The postoperative long-term ALS gait and bladder grades constituted the primary outcomes of the study.RESULTS: Among the 34 patients included in the study, the median age was 65 years, and there was a male predominance (71%). Most lesions were in the lumbar region (47%). Significant worsening in ALS gait and bladder grades was observed preoperatively, followed by postoperative improvements (p < 0.05). There was no difference in outcomes between surgical and endovascular treatments. Older age (OR 1.10, 95% CI 1.03-1.17, p = 0.007), worse preoperative ALS gait grades (OR 5.12, 95% CI 2.18-12.4, p < 0.001), and longer time from first specialist outpatient visit to first treatment (OR 1.00, 95% CI 1.00-1.01, p = 0.040) were independently associated with worse long-term gait outcomes. Only the preoperative ALS bladder score was a predictor of worse long-term bladder function (OR 92.7, 95% CI 28.0-306.7, p < 0.001).CONCLUSIONS: Both surgical and endovascular treatments for sdAVFs led to significant neurological improvements. However, treatment delays were associated with less favorable long-term outcomes. Prompt diagnosis and early intervention prior to symptom progression may enhance recovery and help to preserve neurological function.
  •  
33.
  • El-Hajj, Victor Gabriel, et al. (författare)
  • The negative impact of treatment delays on the long-term neurological outcomes of spinal dural arteriovenous fistulas : a longitudinal cohort study
  • 2024
  • Ingår i: Neurosurgical Focus. - : American Association of Neurological Surgeons. - 1092-0684. ; 56:3
  • Tidskriftsartikel (refereegranskat)abstract
    • OBJECTIVE Dural arteriovenous fistulas are rare vascular malformations that affect the brain and spinal cord. Spinal dural arteriovenous fistulas (sdAVFs) are the most frequently encountered vascular malformation affecting the spinal cord. The object of this study was to evaluate the impact of treatment delays on the long-term neurological outcomes of either open surgical or interventional treatment of sdAVFs.METHODS In this retrospective, population-based cohort study, the authors examined consecutive patients with diagnosed sdAVFs at a tertiary care center between 2005 and 2020. Patients were assessed using the Aminoff-Logue disability scale (ALS) at various time points including symptom onset, primary care visit, first specialist outpatient visit, as well as both short and long-term follow-ups. The postoperative long-term ALS gait and bladder grades constituted the primary outcomes of the study.RESULTS Among the 34 patients included in the study, the median age was 65 years, and there was a male predominance (71%). Most lesions were in the lumbar region (47%). Significant worsening in ALS gait and bladder grades was observed preoperatively, followed by postoperative improvements (p < 0.05). There was no difference in outcomes between surgical and endovascular treatments. Older age (OR 1.10, 95% CI 1.03-1.17, p = 0.007), worse preoperative ALS gait grades (OR 5.12, 95% CI 2.18-12.4, p < 0.001), and longer time from first specialist outpatient visit to first treatment (OR 1.00, 95% CI 1.00-1.01, p = 0.040) were independently associated with worse long-term gait outcomes. Only the preoperative ALS bladder score was a predictor of worse long-term bladder function (OR 92.7, 95% CI 28.0-306.7, p < 0.001).CONCLUSIONS Both surgical and endovascular treatments for sdAVFs led to significant neurological improvements. However, treatment delays were associated with less favorable long-term outcomes. Prompt diagnosis and early intervention prior to symptom progression may enhance recovery and help to preserve neurological function.
  •  
34.
  • Enzell, Jonas, et al. (författare)
  • Post-peak behavior of concrete dams based on nonlinear finite element analyses
  • 2021
  • Ingår i: Engineering Failure Analysis. - : Elsevier. - 1350-6307 .- 1873-1961. ; 130
  • Tidskriftsartikel (refereegranskat)abstract
    • Dam failures are catastrophic events and in order to improve safety, engineers must have good tools for analysis and an understanding of the failure process. Since there are few cases of real failures in concrete dams, which can work as validation, physical model tests are a good way of improving numerical models and the understanding of the failure process. In this article, a physical model test of the buttress from a concrete Ambursen type dam is used as a benchmark for calibrating a FE-model. The dam failure is thereafter simulated using the concept of safety commonly used in the design codes. The advantages and drawbacks of performing load- and displacement-controlled simulations are compared. A new method for performing displacement-controlled simulations, using nonlinear springs to introduce the hydrostatic pressure and ice load is thereafter suggested and tested. The proposed method gives results which corresponds to the classical methods of analysis but has some advantages. Primarily, the new method is stable and does not suffer from convergence issues as was the case with the other methods. It is also simple to introduce in most commercial software compared to classical displacement-controlled simulations.
  •  
35.
  • Frisk, Henrik, et al. (författare)
  • Intraoperative MRI without an intraoperative MRI suite : a workflow for glial tumor surgery
  • 2024
  • Ingår i: Acta Neurochirurgica. - : Springer. - 0001-6268 .- 0942-0940. ; 166:1
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: Intraoperative MRI (iMRI) has emerged as a useful tool in glioma surgery to safely improve the extent of resection. However, iMRI requires a dedicated operating room (OR) with an integrated MRI scanner solely for this purpose. Due to physical or economical restraints, this may not be feasible in all centers. The aim of this study was to investigate the feasibility of using a non-dedicated MRI scanner at the radiology department for iMRI and to describe the workflow with special focus on time expenditure and surgical implications.METHODS: In total, 24 patients undergoing glioma surgery were included. When the resection was deemed completed, the wound was temporarily closed, and the patient, under general anesthesia, was transferred to the radiology department for iMRI, which was performed using a dedicated protocol on 1.5 or 3 T scanners. After performing iMRI the patient was returned to the OR for additional tumor resection or final wound closure. All procedural times, timestamps, and adverse events were recorded.RESULT: The median time from the decision to initiate iMRI until reopening of the wound after scanning was 68 (52-104) minutes. Residual tumors were found on iMRI in 13 patients (54%). There were no adverse events during the surgeries, transfers, transportations, or iMRI-examinations. There were no wound-related complications or infections in the postoperative period or at follow-up. There were no readmissions within 30 or 90 days due to any complication.CONCLUSION: Performing intraoperative MRI using an MRI located outside the OR department was feasible and safe with no adverse events. It did not require more time than previously reported data for dedicated iMRI scanners. This could be a viable alternative in centers without access to a dedicated iMRI suite.
  •  
36.
  • Ghanem, Marc, et al. (författare)
  • Limitations in Evaluating Machine Learning Models for Imbalanced Binary Outcome Classification in Spine Surgery : A Systematic Review
  • 2023
  • Ingår i: Brain Sciences. - : MDPI. - 2076-3425. ; 13:12
  • Forskningsöversikt (refereegranskat)abstract
    • Clinical prediction models for spine surgery applications are on the rise, with an increasing reliance on machine learning (ML) and deep learning (DL). Many of the predicted outcomes are uncommon; therefore, to ensure the models' effectiveness in clinical practice it is crucial to properly evaluate them. This systematic review aims to identify and evaluate current research-based ML and DL models applied for spine surgery, specifically those predicting binary outcomes with a focus on their evaluation metrics. Overall, 60 papers were included, and the findings were reported according to the PRISMA guidelines. A total of 13 papers focused on lengths of stay (LOS), 12 on readmissions, 12 on non-home discharge, 6 on mortality, and 5 on reoperations. The target outcomes exhibited data imbalances ranging from 0.44% to 42.4%. A total of 59 papers reported the model's area under the receiver operating characteristic (AUROC), 28 mentioned accuracies, 33 provided sensitivity, 29 discussed specificity, 28 addressed positive predictive value (PPV), 24 included the negative predictive value (NPV), 25 indicated the Brier score with 10 providing a null model Brier, and 8 detailed the F1 score. Additionally, data visualization varied among the included papers. This review discusses the use of appropriate evaluation schemes in ML and identifies several common errors and potential bias sources in the literature. Embracing these recommendations as the field advances may facilitate the integration of reliable and effective ML models in clinical settings.
  •  
37.
  • Gharios, Maria, et al. (författare)
  • Spontaneous spinal cord infarction : a systematic review
  • 2024
  • Ingår i: BMJ neurology open. - : BMJ Publishing Group Ltd. - 2632-6140. ; 6:1
  • Forskningsöversikt (refereegranskat)abstract
    • BACKGROUND AND OBJECTIVES: Spontaneous spinal cord infarction (SCInf) is a rare condition resulting in acute neurological impairment. Consensus on diagnostic criteria is lacking, which may present a challenge for the physician. This review aims to analyse the current literature on spontaneous SCInf, focusing on epidemiology, the diagnostic process, treatment strategies and neurological outcomes.METHODS: The study was performed in accordance with a previously published protocol. PubMed, Web of Science and Embase were searched using the keywords 'spontaneous', 'spinal cord', 'infarction' and 'ischaemic'. The eligibility of studies was evaluated in two steps by multiple reviewers. Data from eligible studies were extracted and systematically analysed.RESULTS: 440 patients from 33 studies were included in this systematic review. Analysis of vascular risk factors showed that hypertension was present in 40%, followed by smoking in 30%, dyslipidaemia in 29% and diabetes in 16%. The severity of symptoms at admission according to the American Spinal Injury Association (ASIA) Impairment Scale was score A 19%, score B14%, score C36% and score D32%. The mean follow-up period was 34.8 (±12.2) months. ASIA score at follow-up showed score A 11%, score B 3%, score C 16%, score D 67% and score E 2%. The overall mortality during the follow-up period was 5%. When used, MRI with diffusion-weighted imaging (DWI) supported the diagnosis in 81% of cases. At follow-up, 71% of the patients were able to walk with or without walking aids.CONCLUSION: The findings suggest a significant role for vascular risk factors in the pathophysiology of spontaneous SCInf. In the diagnostic workup, the use of DWI along with an MRI may help in confirming the diagnosis. The findings at follow-up suggest that neurological recovery is to be expected, with the majority of patients regaining ambulation. This systematic review highlights gaps in the literature and underscores the necessity for further research to establish diagnostic criteria and treatment guidelines.
  •  
38.
  • Gharios, Maria, et al. (författare)
  • The use of hybrid operating rooms in neurosurgery, advantages, disadvantages, and future perspectives : a systematic review
  • 2023
  • Ingår i: Acta Neurochirurgica. - : Springer. - 0001-6268 .- 0942-0940. ; 165, s. 2343-2358
  • Forskningsöversikt (refereegranskat)abstract
    • Background: Hybrid operating rooms (hybrid-ORs) combine the functionalities of a conventional surgical theater with the advanced imaging technologies of a radiological suite. Hybrid-ORs are usually equipped with CBCT devices providing both 2D and 3D imaging capability that can be used for both interventional radiology and image guided surgical applications. Across all fields of surgery, the use of hybrid-ORs is gaining in traction, and neurosurgery is no exception. We hence aimed to comprehensively review the use of hybrid-ORs, the associated advantages, and disadvantages specific to the field of neurosurgery.Materials and methods: Electronic databases were searched for all studies on hybrid-ORs from inception to May 2022. Findings of matching studies were pooled to strengthen the current body of evidence.Results: Seventy-four studies were included in this review. Hybrid-ORs were mainly used in endovascular surgery (n = 41) and spine surgery (n = 33). Navigation systems were the most common additional technology employed along with the CBCT systems in the hybrid-ORs. Reported advantages of hybrid-ORs included immediate assessment of outcomes, reduced surgical revision rate, and the ability to perform combined open and endovascular procedures, among others. Concerns about increased radiation exposure and procedural time were some of the limitations mentioned.Conclusion: In the field of neurosurgery, the use of hybrid-ORs for different applications is increasing. Hybrid-ORs provide preprocedure, intraprocedure, and end-of-procedure imaging capabilities, thereby increasing surgical precision, and reducing the need for postoperative imaging and correction surgeries. Despite these advantages, radiation exposure to patient and staff is an important concern.
  •  
39.
  • Graf, Christian, et al. (författare)
  • Learning Dense Visual Descriptors using Image Augmentations for Robot Manipulation Tasks
  • 2023
  • Ingår i: Proceedings of the 6th Conference on Robot Learning, CoRL 2022. - : ML Research Press. ; , s. 871-880
  • Konferensbidrag (refereegranskat)abstract
    • We propose a self-supervised training approach for learning view-invariant dense visual descriptors using image augmentations. Unlike existing works, which often require complex datasets, such as registered RGBD sequences, we train on an unordered set of RGB images. This allows for learning from a single camera view, e.g., in an existing robotic cell with a fix-mounted camera. We create synthetic views and dense pixel correspondences using data augmentations. We find our approach to be competitive compared to existing methods, despite the simpler data recording and setup requirements. We show that training on synthetic correspondences provides descriptor consistency across a broad range of camera views. We compare against training with geometric correspondence from multiple views and provide ablation studies. We also show a robotic bin-picking experiment using descriptors learned from a fix-mounted camera for defining grasp preferences.
  •  
40.
  • Hildingsson, Sofia, et al. (författare)
  • Hypoxia in relationship to tumor volume using hypoxia PET-imaging in head & neck cancer – A scoping review
  • 2022
  • Ingår i: Clinical and Translational Radiation Oncology. - : Elsevier BV. - 2405-6308. ; 36, s. 40-46
  • Forskningsöversikt (refereegranskat)abstract
    • Background: Hypoxia and large tumor volumes are negative prognostic factors for patients with head and neck squamous cell carcinoma (HNSCC) treated with radiation therapy (RT). PET-scanning with specific hypoxia-tracers (hypoxia-PET) can be used to non-invasively assess hypoxic tumor volume. Primary tumor volume is readily available for patients undergoing RT. However, the relationship between hypoxic volume and primary tumor volume is yet an open question. The current study investigates the hypotheses that larger tumors contain both a larger hypoxic volume and a higher hypoxic fraction. Methods: PubMed and Embase were systematically searched to identify articles fulfilling the predefined criteria. Individual tumor data (primary tumor volume and hypoxic volume/fraction) was extracted. Relationship between hypoxic volume and primary tumor volume was investigated by linear regression. The correlation between hypoxic fraction and log2(primary tumor volume) was determined for each cohort and in a pooled analysis individual regression slopes and coefficients of determination (R2) were weighted according to cohort size. Results: 21 relevant articles were identified and individual data from 367 patients was extracted, out of which 323 patients from 17 studies had quantifiable volumes of interest. A correlation between primary tumor volume and PET-determined hypoxic volume was found (P <.001, R2 = 0.46). Larger tumors had a significantly higher fraction of hypoxia compared with smaller tumors (P<.01). The weighted analysis of all studies revealed that for each doubling of the tumor volume, the hypoxic fraction increased by four percentage points. Conclusion: This study shows correlations between primary tumor volume and hypoxic volume as well as primary tumor volume and the hypoxic fraction in patients with HNSCC. The findings suggest that not only do large tumors contain more cancer cells, they also have a higher proportion of potentially radioresistant hypoxic cells. This knowledge can be important when individualizing RT.
  •  
41.
  • Iop, Alessandro, et al. (författare)
  • Extended Reality in Neurosurgical Education : A Systematic Review
  • 2022
  • Ingår i: Sensors. - : MDPI. - 1424-8220. ; 22:16
  • Forskningsöversikt (refereegranskat)abstract
    • Surgical simulation practices have witnessed a rapid expansion as an invaluable approach to resident training in recent years. One emerging way of implementing simulation is the adoption of extended reality (XR) technologies, which enable trainees to hone their skills by allowing interaction with virtual 3D objects placed in either real-world imagery or virtual environments. The goal of the present systematic review is to survey and broach the topic of XR in neurosurgery, with a focus on education. Five databases were investigated, leading to the inclusion of 31 studies after a thorough reviewing process. Focusing on user performance (UP) and user experience (UX), the body of evidence provided by these 31 studies showed that this technology has, in fact, the potential of enhancing neurosurgical education through the use of a wide array of both objective and subjective metrics. Recent research on the topic has so far produced solid results, particularly showing improvements in young residents, compared to other groups and over time. In conclusion, this review not only aids to a better understanding of the use of XR in neurosurgical education, but also highlights the areas where further research is entailed while also providing valuable insight into future applications.
  •  
42.
  • Islar, Mine, et al. (författare)
  • Diverse values of nature for sustainability
  • 2022
  • Ingår i: Nature. - 0028-0836 .- 1476-4687. ; 620, s. 813-823
  • Tidskriftsartikel (refereegranskat)abstract
    • Twenty-five years since foundational publications on valuing ecosystem services for human well-being1,2, addressing the global biodiversity crisis3 still implies confronting barriers to incorporating nature’s diverse values into decision-making. These barriers include powerful interests supported by current norms and legal rules such as property rights, which determine whose values and which values of nature are acted on. A better understanding of how and why nature is (under)valued is more urgent than ever4. Notwithstanding agreements to incorporate nature’s values into actions, including the Kunming-Montreal Global Biodiversity Framework (GBF)5 and the UN Sustainable Development Goals6, predominant environmental and development policies still prioritize a subset of values, particularly those linked to markets, and ignore other ways people relate to and benefit from nature7. Arguably, a ‘values crisis’ underpins the intertwined crises of biodiversity loss and climate change8, pandemic emergence9 and socio-environmental injustices10. On the basis of more than 50,000 scientific publications, policy documents and Indigenous and local knowledge sources, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) assessed knowledge on nature’s diverse values and valuation methods to gain insights into their role in policymaking and fuller integration into decisions7,11. Applying this evidence, combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures.
  •  
43.
  • Jakobsson, Gabriel, et al. (författare)
  • Therapeutic S100A8/A9 blockade inhibits myocardial and systemic inflammation and mitigates sepsis-induced myocardial dysfunction
  • 2023
  • Ingår i: Critical Care. - : BMC. - 1364-8535 .- 1466-609X. ; 27, s. 1-16
  • Tidskriftsartikel (refereegranskat)abstract
    • Background and Aims: The triggering factors of sepsis-induced myocardial dysfunction (SIMD) are poorly understood and are not addressed by current treatments. S100A8/A9 is a pro-inflammatory alarmin abundantly secreted by activated neutrophils during infection and inflammation. We investigated the efficacy of S100A8/A9 blockade as a potential new treatment in SIMD. Methods: The relationship between plasma S100A8/A9 and cardiac dysfunction was assessed in a cohort of 62 patients with severe sepsis admitted to the intensive care unit of Linköping University Hospital, Sweden. We used S100A8/A9 blockade with the small-molecule inhibitor ABR-238901 and S100A9−/− mice for therapeutic and mechanistic studies on endotoxemia-induced cardiac dysfunction in mice. Results: In sepsis patients, elevated plasma S100A8/A9 was associated with left-ventricular (LV) systolic dysfunction and increased SOFA score. In wild-type mice, 5 mg/kg of bacterial lipopolysaccharide (LPS) induced rapid plasma S100A8/A9 increase and acute LV dysfunction. Two ABR-238901 doses (30 mg/kg) administered intraperitoneally with a 6 h interval, starting directly after LPS or at a later time-point when LV dysfunction is fully established, efficiently prevented and reversed the phenotype, respectively. In contrast, dexamethasone did not improve cardiac function compared to PBS-treated endotoxemic controls. S100A8/A9 inhibition potently reduced systemic levels of inflammatory mediators, prevented upregulation of inflammatory genes and restored mitochondrial function in the myocardium. The S100A9−/− mice were protected against LPS-induced LV dysfunction to an extent comparable with pharmacologic S100A8/A9 blockade. The ABR-238901 treatment did not induce an additional improvement of LV function in the S100A9−/− mice, confirming target specificity. Conclusion: Elevated S100A8/A9 is associated with the development of LV dysfunction in severe sepsis patients and in a mouse model of endotoxemia. Pharmacological blockade of S100A8/A9 with ABR-238901 has potent anti-inflammatory effects, mitigates myocardial dysfunction and might represent a novel therapeutic strategy for patients with severe sepsis. Graphical Abstract: [Figure not available: see fulltext.].
  •  
44.
  • Kaijser, Magnus, et al. (författare)
  • Two years of neurosurgical intraoperative MRI in Sweden : evaluation of use and costs
  • 2024
  • Ingår i: Acta Neurochirurgica. - : Springer. - 0001-6268 .- 0942-0940. ; 166:1
  • Tidskriftsartikel (refereegranskat)abstract
    • BACKGROUND: The current shortage of radiology staff in healthcare provides a challenge for departments all over the world. This leads to more evaluation of how the radiology resources are used and a demand to use them in the most efficient way. Intraoperative MRI is one of many recent advancements in radiological practice. If radiology staff is performing intraoperative MRI at the operation ward, they may be impeded from performing other examinations at the radiology department, creating costs in terms of exams not being performed. Since this is a kind of cost whose importance is likely to increase, we have studied the practice of intraoperative MRI in Sweden.METHODS: The study includes data from the first four hospitals in Sweden that installed MRI scanners adjacent to the operating theaters. In addition, we included data from Karolinska University Hospital in Solna where intraoperative MRI is carried out at the radiology department.RESULTS: Scanners that were moved into the operation theater and doing no or few other scans were used 11-12% of the days. Stationary scanners adjacent to the operation room were used 35-41% of the days. For scanners situated at the radiology department doing intraoperative scans interspersed among all other scans, the proportion was 92%.CONCLUSION: Our study suggests that performing exams at the radiology department rather than at several locations throughout the hospital may be an efficient approach to tackle the simultaneous trends of increasing demands for imaging and increasing staff shortages at radiology departments.
  •  
45.
  • Khazaei, Somayeh, et al. (författare)
  • Research Paper Impact of combining vitamin C with radiation therapy in human breast cancer : Does it matter?
  • 2022
  • Ingår i: Oncotarget. - 1949-2553. ; 13:1, s. 439-453
  • Tidskriftsartikel (refereegranskat)abstract
    • Vitamin C may impact the efficiency of radiation therapy (RT) in breast cancer. The effects of RT alone or in combination with vitamin C in SKBR3, MDA-MB-231, and MCF7 cells were compared using clonogenic assay, proliferation assay (MTT), cell cycle analysis, and Western blot. Vitamin C use was assessed in 1803 breast cancer patients 2002–2017 in relation to clinicopathological features and recurrences after RT. Vitamin C combined with RT resulted in non-significant increases in colony formation and minor differences in cell cycle arrest and expression of studied proteins, compared to RT alone. Lower vitamin C doses alone or in combination with RT, resulted in higher proliferation with MTT than higher vitamin C doses in a cell line-dependent manner. Vitamin C use was associated with lower histological grade and BMI but not recurrence risk in RT-treated patients (LogRank P = 0.54). Vitamin C impacted RT efficiency differently depending on breast cancer subtype and vitamin C concentration. Lower doses of vitamin C, achievable with oral administration, might increase breast cancer cell proliferation and decrease radiosensitivity. Despite vitamin C users having less aggressive tumors than non-users, the recurrence risk in RT-treated patients was similar in vitamin C users and non-users.
  •  
46.
  • Konradsson, Elise, et al. (författare)
  • Comparable Long-Term Tumor Control for Hypofractionated FLASH Versus Conventional Radiation Therapy in an Immunocompetent Rat Glioma Model
  • 2022
  • Ingår i: Advances in Radiation Oncology. - : Elsevier BV. - 2452-1094. ; 7:6
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: To ensure a clinical translation of FLASH radiation therapy (FLASH-RT) for a specific tumor type, studies on tumor control and toxicity within the same biological system are needed. In this study, our objective was to evaluate tumor control and toxicity for hypofractionated FLASH-RT and conventional radiation therapy (CONV-RT) in an immunocompetent rat glioma model. Methods and Materials: Fisher 344 rats (N = 68) were inoculated subcutaneously with NS1 glioma cells and randomized into groups (n = 9-10 per group). CONV-RT (∼8 Gy/min) or FLASH-RT (70-90 Gy/s) was administered in 3 fractions of either 8 Gy, 12.5 Gy, or 15 Gy using a 10-MeV electron beam. The maximum tumor diameter was measured weekly, and overall survival was determined until day 100. Long-term tumor control was defined as no evident tumor on day 100. Animals were evaluated for acute dermal side effects at 2 to 5 weeks after completed RT and for late dermal side effects at 3 months after initiation of treatment. Results: Survival was significantly increased in all irradiated groups compared with control animals (P <.001). In general, irradiated tumors started to shrink at 1 week post–completed RT. In 40% (23 of 58) of the irradiated animals, long-term tumor control was achieved. Radiation-induced skin toxic effects were mild and consisted of hair loss, erythema, and dry desquamation. No severe toxic effect was observed. There was no significant difference between FLASH-RT and CONV-RT in overall survival, acute side effects, or late side effects for any of the dose levels. Conclusions: This study shows that hypofractionated FLASH-RT results in long-term tumor control rates similar to those of CONV-RT for the treatment of large subcutaneous glioblastomas in immunocompetent rats. Neither treatment technique induced severe skin toxic effects. Consequently, no significant difference in toxicity could be resolved, suggesting that higher doses may be required to detect a FLASH sparing of skin.
  •  
47.
  • Konradsson, Elise, et al. (författare)
  • Evaluation of intensity-modulated electron FLASH radiotherapy in a clinical setting using veterinary cases
  • 2023
  • Ingår i: Medical Physics. - 0094-2405. ; 50:10, s. 6569-6579
  • Tidskriftsartikel (refereegranskat)abstract
    • Purpose: The increased normal tissue tolerance for FLASH radiotherapy (FLASH-RT), as compared to conventional radiotherapy, was first observed in ultra-high dose rate electron beams. Initial clinical trials in companion animals have revealed a high risk of developing osteoradionecrosis following high-dose single-fraction electron FLASH-RT, which may be related to inhomogeneities in the dose distribution. In the current study, we aim to evaluate the possibilities of intensity-modulated electron FLASH-RT in a clinical setting to ensure a homogeneous dose distribution in future veterinary and human clinical trials. Methods: Our beam model in the treatment planning system electronRT (.decimal, LLC, Sanford, FL, USA) was based on a 10-MeV electron beam from a clinical linear accelerator used to treat veterinary patients with FLASH-RT in a clinical setting. In electronRT, the beam can be intensity-modulated using tungsten island blocks in the electron block cutout, and range-modulated using a customized bolus with variable thickness. Modulations were first validated in a heterogeneous phantom by comparing measured and calculated dose distributions. To evaluate the impact of intensity modulation in superficial single-fraction FLASH-RT, a treatment planning study was conducted, including eight canine cancer patient cases with simulated tumors in the head-and-neck region. For each case, treatment plans with and without intensity modulation were created for a uniform bolus and a range-modulating bolus. Treatment plans were evaluated using a target dose homogeneity index (HI), a conformity index (CI), the near-maximum dose outside the target ((Figure presented.)), and the near-minimum dose to the target ((Figure presented.)). Results: By adding intensity modulation to plans with a uniform bolus, the HI could be improved (p = 0.017). The combination of a range-modulating bolus and intensity modulation provided a further significant improvement of the HI as compared to using intensity modulation in combination with a uniform bolus (p = 0.036). The range-modulating bolus also improved the CI compared to using a uniform bolus, both with an open beam (p = 0.046) and with intensity modulation (p = 0.018), as well as increased the (Figure presented.) (p = 0.036 with open beam and p = 0.05 with intensity modulation) and reduced the median (Figure presented.) (not significant). Conclusions: By using intensity-modulated electron FLASH-RT in combination with range-modulating bolus, the target dose homogeneity and conformity in canine patients with simulated tumors in complex areas in the head-and-neck region could be improved. By utilizing this technique, we hope to decrease the dose outside the target volume and avoid hot spots in future clinical electron FLASH-RT studies, thereby reducing the risk of radiation-induced toxicity.
  •  
48.
  • Lempart, Michael, et al. (författare)
  • Pelvic U-Net : multi-label semantic segmentation of pelvic organs at risk for radiation therapy anal cancer patients using a deeply supervised shuffle attention convolutional neural network
  • 2022
  • Ingår i: Radiation Oncology. - : Springer Science and Business Media LLC. - 1748-717X. ; 17:1
  • Tidskriftsartikel (refereegranskat)abstract
    • Background: Delineation of organs at risk (OAR) for anal cancer radiation therapy treatment planning is a manual and time-consuming process. Deep learning-based methods can accelerate and partially automate this task. The aim of this study was to develop and evaluate a deep learning model for automated and improved segmentations of OAR in the pelvic region. Methods: A 3D, deeply supervised U-Net architecture with shuffle attention, referred to as Pelvic U-Net, was trained on 143 computed tomography (CT) volumes, to segment OAR in the pelvic region, such as total bone marrow, rectum, bladder, and bowel structures. Model predictions were evaluated on an independent test dataset (n = 15) using the Dice similarity coefficient (DSC), the 95th percentile of the Hausdorff distance (HD95), and the mean surface distance (MSD). In addition, three experienced radiation oncologists rated model predictions on a scale between 1–4 (excellent, good, acceptable, not acceptable). Model performance was also evaluated with respect to segmentation time, by comparing complete manual delineation time against model prediction time without and with manual correction of the predictions. Furthermore, dosimetric implications to treatment plans were evaluated using different dose-volume histogram (DVH) indices. Results: Without any manual corrections, mean DSC values of 97%, 87% and 94% were found for total bone marrow, rectum, and bladder. Mean DSC values for bowel cavity, all bowel, small bowel, and large bowel were 95%, 91%, 87% and 81%, respectively. Total bone marrow, bladder, and bowel cavity segmentations derived from our model were rated excellent (89%, 93%, 42%), good (9%, 5%, 42%), or acceptable (2%, 2%, 16%) on average. For almost all the evaluated DVH indices, no significant difference between model predictions and manual delineations was found. Delineation time per patient could be reduced from 40 to 12 min, including manual corrections of model predictions, and to 4 min without corrections. Conclusions: Our Pelvic U-Net led to credible and clinically applicable OAR segmentations and showed improved performance compared to previous studies. Even though manual adjustments were needed for some predicted structures, segmentation time could be reduced by 70% on average. This allows for an accelerated radiation therapy treatment planning workflow for anal cancer patients.
  •  
49.
  • Menkveld, Albert J., et al. (författare)
  • Nonstandard Errors
  • 2024
  • Ingår i: JOURNAL OF FINANCE. - : Wiley-Blackwell. - 0022-1082 .- 1540-6261. ; 79:3, s. 2339-2390
  • Tidskriftsartikel (refereegranskat)abstract
    • In statistics, samples are drawn from a population in a data-generating process (DGP). Standard errors measure the uncertainty in estimates of population parameters. In science, evidence is generated to test hypotheses in an evidence-generating process (EGP). We claim that EGP variation across researchers adds uncertainty-nonstandard errors (NSEs). We study NSEs by letting 164 teams test the same hypotheses on the same data. NSEs turn out to be sizable, but smaller for more reproducible or higher rated research. Adding peer-review stages reduces NSEs. We further find that this type of uncertainty is underestimated by participants.
  •  
50.
  • Mensah, Rhoda Afriyie, et al. (författare)
  • Biochar-Added Cementitious Materials—A Review on Mechanical, Thermal, and Environmental Properties
  • 2021
  • Ingår i: Sustainability. - : MDPI. - 2071-1050. ; 13:16
  • Forskningsöversikt (refereegranskat)abstract
    • The enhanced carbon footprint of the construction sector has created the need for CO2 emission control and mitigation. CO2 emissions in the construction sector are influenced by a variety of factors, including raw material preparation, cement production, and, most notably, the construction process. Thus, using biobased constituents in cement could reduce CO2 emissions. However, biobased constituents can degrade and have a negative impact on cement performance. Recently, carbonised biomass known as biochar has been found to be an effective partial replacement for cement. Various studies have reported improved mechanical strength and thermal properties with the inclusion of biochar in concrete. To comprehend the properties of biochar-added cementitious materials, the properties of biochar and their effect on concrete need to be examined. This review provides a critical examination of the mechanical and thermal properties of biochar and biochar-added cementitious materials. The study also covers biochar’s life cycle assessment and economic benefits. Overall, the purpose of this review article is to provide a means for researchers in the relevant field to gain a deeper understanding of the innate properties of biochar imparted into biochar-added cementitious materials for property enhancement and reduction of CO2 emissions.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-50 av 72
Typ av publikation
tidskriftsartikel (49)
forskningsöversikt (14)
konferensbidrag (7)
doktorsavhandling (1)
licentiatavhandling (1)
Typ av innehåll
refereegranskat (67)
övrigt vetenskapligt/konstnärligt (5)
Författare/redaktör
Adrian, Gabriel (19)
Gerdhem, Paul (9)
Sas, Gabriel (9)
Ulfberg, Adrian (9)
Das, Oisik (6)
Petersson, Kristoffe ... (6)
visa fler...
Gebre-Medhin, Maria (5)
Nilsson, Per (5)
Nilsson, Gunnar (5)
Kjellén, Elisabeth (4)
Konradsson, Elise (4)
Ceberg, Crister (4)
Gonzalez-Libreros, J ... (4)
Johansson, Fredrik (3)
von Vogelsang, Ann-C ... (3)
Andersson, Magnus (2)
Malm, Richard (2)
Johansson, Fredrik, ... (2)
Raza, Ali (2)
Ciais, Philippe (2)
Borgquist, Signe (2)
Stattin, Pär (2)
Zackrisson, Björn (2)
Garmo, Hans (2)
Widmark, Anders (2)
Beyer, Sarah (2)
McMahon, Stephen J. (2)
Sjövall, Johanna (2)
Dezecache, Guillaume (2)
Bastviken, David (2)
Gonzalez, Jaime (2)
McNorton, Joe (2)
Haussaire, Jean Matt ... (2)
Janssens-Maenhout, G ... (2)
Kaijser, Magnus (2)
Akrawi, Narin (2)
Harris, Elizabeth (2)
Peters, Glen P. (2)
McGrath, Matthew J. (2)
Schiopu, Alexandru (2)
Kantorowicz, Jarosła ... (2)
Peylin, Philippe (2)
Romero, Mario, 1973- (2)
Gomez-Baggethun, Eri ... (2)
Westberg Wilde, Mari ... (2)
Van Lange, Paul A. M ... (2)
Jernström, Helena (2)
Arnberg, Fabian (2)
Olsson, Andreas (2)
Otterbring, Tobias (2)
visa färre...
Lärosäte
Lunds universitet (25)
Karolinska Institutet (23)
Uppsala universitet (19)
Örebro universitet (16)
Luleå tekniska universitet (9)
Kungliga Tekniska Högskolan (6)
visa fler...
Linköpings universitet (5)
Göteborgs universitet (3)
Stockholms universitet (3)
Handelshögskolan i Stockholm (3)
Umeå universitet (2)
Sveriges Lantbruksuniversitet (2)
Malmö universitet (1)
Chalmers tekniska högskola (1)
visa färre...
Språk
Engelska (71)
Svenska (1)
Forskningsämne (UKÄ/SCB)
Medicin och hälsovetenskap (53)
Teknik (12)
Naturvetenskap (11)
Samhällsvetenskap (4)

År

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy