422 results on '"Otto, S."'
Search Results
2. Baseline radiomics features and MYC rearrangement status predict progression in aggressive B-cell lymphoma
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Eertink, Jakoba J., Zwezerijnen, Gerben J. C., Wiegers, Sanne E., Pieplenbosch, Simone, Chamuleau, Martine E. D., Lugtenburg, Pieternella J., de Jong, Daphne, Ylstra, Bauke, Mendeville, Matias, Dührsen, Ulrich, Hanoun, Christine, Hüttmann, Andreas, Richter, Julia, Klapper, Wolfram, Jauw, Yvonne W. S., Hoekstra, Otto S., de Vet, Henrica C. W., Boellaard, Ronald, and Zijlstra, Josée M.
- Abstract
We investigated whether the outcome prediction of patients with aggressive B-cell lymphoma can be improved by combining clinical, molecular genotype, and radiomics features. MYC, BCL2, and BCL6 rearrangements were assessed using fluorescence in situ hybridization. Seventeen radiomics features were extracted from the baseline positron emission tomography–computed tomography of 323 patients, which included maximum standardized uptake value (SUVmax), SUVpeak, SUVmean, metabolic tumor volume (MTV), total lesion glycolysis, and 12 dissemination features pertaining to distance, differences in uptake and volume between lesions, respectively. Logistic regression with backward feature selection was used to predict progression after 2 years. The predictive value of (1) International Prognostic Index (IPI); (2) IPI plus MYC; (3) IPI, MYC, and MTV; (4) radiomics; and (5) MYC plus radiomics models were tested using the cross-validated area under the curve (CV-AUC) and positive predictive values (PPVs). IPI yielded a CV-AUC of 0.65 ± 0.07 with a PPV of 29.6%. The IPI plus MYC model yielded a CV-AUC of 0.68 ± 0.08. IPI, MYC, and MTV yielded a CV-AUC of 0.74 ± 0.08. The highest model performance of the radiomics model was observed for MTV combined with the maximum distance between the largest lesion and another lesion, the maximum difference in SUVpeak between 2 lesions, and the sum of distances between all lesions, yielding an improved CV-AUC of 0.77 ± 0.07. The same radiomics features were retained when adding MYC (CV-AUC, 0.77 ± 0.07). PPV was highest for the MYC plus radiomics model (50.0%) and increased by 20% compared with the IPI (29.6%). Adding radiomics features improved model performance and PPV and can, therefore, aid in identifying poor prognosis patients.
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- 2023
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3. Proposed New Dynamic Prognostic Index for Diffuse Large B-Cell Lymphoma: International Metabolic Prognostic Index.
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Mikhaeel, N. George, Heymans, Martijn W., Eertink, Jakoba J., de Vet, Henrica C.W., Boellaard, Ronald, Dührsen, Ulrich, Ceriani, Luca, Schmitz, Christine, Wiegers, Sanne E., Hüttmann, Andreas, Lugtenburg, Pieternella J., Zucca, Emanuele, Zwezerijnen, Gerben J.C., Hoekstra, Otto S., Zijlstra, Josée M., and Barrington, Sally F.
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- 2022
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4. Comparing [18F]FDG PET/CT response criteria in melanoma and lung cancer patients treated with immunotherapy: a systematic review
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Saadani, Hanna, Aalbersberg, Else A., Schats, Winnie, Hoekstra, Otto S., Stokkel, Marcel P. M., and de Vet, Henrica C. W.
- Abstract
Purpose: To compare the predictive value of new immunotherapy-specific fluorine-18-labeled glucose Positron Emission Tomography/Computed Tomography ([
18 F]FDG PET/CT) response criteria to conventional PET/CT criteria for overall survival (OS) in melanoma and lung cancer patients treated with immunotherapy. Methods: MEDLINE (Ovid), Embase, Scopus, Web of Science and the Cochrane Library databases were searched until June 4, 2021, in line with the PRISMA statement. Two reviewers independently screened resulting records. Quality assessment was performed according to Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) and/or Quality in Prognostic Studies (QUIPS) criteria. PET/CT response assessment was divided in immunotherapy PET/CT response criteria, conventional PET/CT response criteria, and individual Δ[18 F]FDG/PET CT metrics. The main outcome measure extracted was the univariate hazard ratio (HR) for OS. Results: Fifteen studies (n= 565) were included, with ten studies (225 NSCLC, 178 melanoma cases) reporting on PET/CT response criteria and five studies (126 NSCLC, 36 melanoma cases) on individual Δ[18 F]FDG PET/CT metrics. Until 2016, conventional criteria: EORTC and PERCIST1.0 were applied; since then, several new, modified criteria emerged: imPERCIST, PERCIMT, PECRIT and iPERCIST. For both NSCLC and melanoma, univariate HRs did not show substantial differences between immunotherapy and conventional PET/CT response criteria, with overlapping confidence intervals. No individual Δ[18 F]FDG PET/CT metric can yet be recommended. ΔTMTV in melanoma and ΔSUVmax in NSCLC showed the highest univariate HRs. Conclusion: There is insufficient evidence to decide whether the predictive value of immunotherapy PET/CT criteria is superior to conventional ones for OS, in melanoma and lung cancer treated with immunotherapy. A different research strategy is needed to reach the answer: PET/CT research should focus on directly comparing (modifications of) immunotherapy and conventional PET/CT criteria within a homogenous population with standardized PET timing, immunotherapy categories and OS definition. A consortium-based comprehensive database with individual patient data could be the solution.- Published
- 2022
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5. Nurse-Administered Propofol Continuous Infusion Sedation for Gastrointestinal Endoscopy in Patients Who Are Difficult to Sedate.
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Lee, Hyun Seok, Nagra, Navroop, La Selva, Danielle, Kozarek, Richard A., Ross, Andrew, Weigel, Wade, Beecher, Ryan, Chiorean, Michael, Gluck, Michael, Boden, Elisa, Venu, Nanda, Krishnamoorthi, Rajesh, Larsen, Michael, and Lin, Otto S.
- Abstract
Patients who chronically use alcohol, marijuana, or opioids, or suffer from post-traumatic stress disorder (PTSD), can be difficult to sedate with midazolam and fentanyl, and often are referred for monitored anesthesia care during endoscopy. Nurse-administered propofol continuous infusion sedation (NAPCIS), which confers the benefit of propofol-based sedation without the added expense of anesthesia, is effective and safe for sedation of healthy patients. We investigated whether NAPCIS also is effective for patients who are difficult to sedate. We performed a retrospective study of patients who underwent upper endoscopy or colonoscopy with NAPCIS at a single center from January 2018 through April 2018. We reviewed records from patients who were heavy users of alcohol (n = 105), daily users of marijuana (n = 267) or opioids (n = 178), had a diagnosis of PTSD (n = 91), or were none of these (controls, n = 786). We compared mean fentanyl and propofol doses (adjusted for body weight), procedure and recovery times, procedure success rates, and adverse events. Compared with the controls, the marijuana group required higher mean adjusted sedative doses for colonoscopies (0.6 vs 0.4 mcg/kg fentanyl and 5.0 vs 4.7 mg/kg propofol; P ≤.025 for both) and upper endoscopies (0.8 vs 0.3 mcg/kg fentanyl and 3.7 vs 3.2 mg/kg propofol; P ≤.021 for both), the PTSD group required a higher dose of fentanyl for colonoscopies (0.6 vs 0.4 mcg/kg; P =.009), and the alcohol group required a higher dose of fentanyl for upper endoscopies (0.7 vs 0.3 mcg/kg; P <.001). Procedure success rates were high (95.1%–100%) and did not differ significantly between the difficult-to-sedate groups and controls; mean procedure times (7.0–9.0 minutes for upper endoscopies, 21.1–22.9 minutes for colonoscopies) and recovery times (22.5–29.6 minutes) also were similar among groups. Upper endoscopies were associated with lower sedative doses and shorter procedure and recovery times than colonoscopies. Sedation-related adverse events were rare in all groups (only 26 cases total), and there were no serious complications or deaths. NAPCIS seems to be a safe and effective means of providing sedation for endoscopy to patients who may be difficult to sedate owing to alcohol, marijuana, or opioid use, or PTSD. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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6. Optical Sensing and Imaging of pH Values: Spectroscopies, Materials, and Applications.
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Steinegger, Andreas, Wolfbeis, Otto S., and Borisov, Sergey M.
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- 2020
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7. Development and validation of a rating scale for hereditary spastic paraplegia
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Schüle, R, Holland-Letz, T, Klimpe, S, Kassubek, J, Otto, S, and Schöls, L
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- 2024
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8. High throughput genotyping: microarray-based resequencing for autosomal-dominant hereditary spastic paraplegia
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Schlipf, N, Schüle, R, Dufke, C, Bonin, M, Auer-Grumbach, M, Stevanin, G, Brice, A, Beetz, C, Kassubek, J, Klebe, S, Klimpe, S, Klopstock, T, Otto, S, Poths, S, Seibel, A, Stolze, H, Bauer, P, and Schöls, L
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- 2024
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9. SPG10 in German families with hereditary spastic paraplegia
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Schüle, R., Auer-Grumbach, M., Kassubek, J., Klimpe, S., Klopstock, T., Otto, S., van de Warrenburg, B., Seibel, A., and Schöls, L.
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- 2024
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10. Transaction Privilege Tax in the Digital Age.
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SHILL III, OTTO S.
- Published
- 2020
11. Fiber-Optic Chemical Sensors and Biosensors (2015–2019)
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Wang, Xu-dong and Wolfbeis, Otto S.
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- 2020
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12. Changes in Lower Gastrointestinal Bleeding Presentation, Management, and Outcomes Over a 10-Year Span
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Kim, Kyeong Ok, Kozarek, Richard, Gluck, Michael, Ross, Andrew, and Lin, Otto S.
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- 2019
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13. Medication-related osteonecrosis of the jaw in a minipig model: Parameters for developing a macroscopic, radiological, and microscopic grading scheme.
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Nowicki, B., Nehrbass, D., Arens, D., Stadelmann, V.A., Zeiter, S., Otto, S., Kircher, P., and Stoddart, M.J.
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OSTEONECROSIS ,JAWS ,ZOLEDRONIC acid ,DENTAL extraction ,INTRAVENOUS therapy - Abstract
To devise a macroscopic, radiological, and histological scale for assessing pathological changes associated with medication-related osteonecrosis of the jaw in a minipig model. Medication-related osteonecrosis of the jaw was induced in Göttingen minipigs by weekly intravenous administration of bisphosphonate (zoledronic acid) combined with a tooth extraction procedure. Controls either did not receive zoledronic acid or did not undergo tooth extraction. After 20 weeks, minipigs were euthanized and underwent computed tomography and micro-computed tomography scanning. The mandible underwent additional histological examination. The most consistent macroscopic findings in animals that had developed bisphosphonate-related osteonecrosis of the jaw (BRONJ) were necrotic, denuded bone, and formation of fistula and pus. Under radiological examination, impaired extraction socket healing, decrease in attenuation of bone beneath the extraction site, and periosteal reaction were observed. Under histological examination, demineralization of the extracellular bone matrix, denuding of bone, and osteonecrosis were recorded. These parameters were used to develop a scoring system for grading BRONJ. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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14. F8-IL10: A New Potential Antirheumatic Drug Evaluated by a PET-Guided Translational Approach.
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Bruijnen, Stefan T.G., Chandrupatla, Durga M.S.H., Giovanonni, Leonardo, Neri, Dario, Vugts, Danielle J., Huisman, Marc C., Hoekstra, Otto S., Musters, René J.P., Lammertsma, Adriaan A., van Dongen, Guus A.M.S., Jansen, Gerrit, Molthoff, Carla F.M., and van der Laken, Conny J.
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- 2019
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15. Locally Increased Incidence of Periorbital Necrotizing Fasciitis.
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Schuh, A., Keidel, L., Siegmund, B., Otto,, S., Priglinger, S., and Hintschich, C.
- Abstract
The article presents the case of five patients who were rushed to the eye hospital at Ludwig Maximilian University of Munich in Germany to discuss the locally increased incidence of periorbital necrotizing fasciitis (PNF) in the country. Also cited are the possible complications of PNF due to systemic toxicity like septicemia, cutaneous injuries, and multiorgan failures.
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- 2023
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16. Fluorodeoxyglucose-Positron Emission Tomography/Computed Tomography After Concurrent Chemoradiotherapy in Locally Advanced Head-and-Neck Squamous Cell Cancer: The ECLYPS Study.
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Van den Wyngaert, Tim, Helsen, Nils, Carp, Laurens, Hakim, Sara, Martens, Michel J., Hutsebaut, Isabel, Debruyne, Philip R., Maes, Annelies L. M., van Dinther, Joost, Van Laer, Carl G., Hoekstra, Otto S., De Bree, Remco, Meersschout, Sabine A. E., Lenssen, Olivier, Vermorken, Jan B., Van den Weyngaert, Danielle, Stroobants, Sigrid, and ECLYPS investigators
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- 2017
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17. Muscular strength and function after total hip arthroplasty performed with three different surgical approaches: one-year follow-up study
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Winther, Siri B, Foss, Olav A, Husby, Otto S, Wik, Tina S, Klaksvik, Jomar, and Husby, Vigdis S
- Abstract
Background: Surgical approach influences short-term muscular strength, and leg-strength asymmetry has been demonstrated after total hip arthroplasty (THA). We evaluated muscular strength, physical function and patient-reported outcome measures (PROMs) up to 12 months postoperatively, in patients operated on using 3 different surgical approaches.Methods: 60 patients scheduled for primary THA were allocated to the direct lateral (DLA), posterior (PA) or anterior (AA) approach. The following parameters were evaluated: leg press and abduction strength, pain, 6-minute walking test, Harris Hip Score and Hip disability and Osteoarthritis Outcome Score - Physical Function Shortform (HOOS-PS).Results: Abduction strength in the DLA group was significantly more reduced than the PA and AA groups 12 months postoperatively (p< 0.001). A significant interleg difference in abduction (p< 0.01) and leg press (p< 0.03) persisted in all groups up to 6 months, and up to 12 months in the DLA (p< 0.05). In the AA group, interleg difference in leg press was present up to 12 months (p= 0.01). Pain scores were higher in the DLA than the AA group at 6 months (p= 0.01). Patients in the PA group had better HOOS-PS score than those in the DLA group 3 months postoperatively (p= 0.02). No intergroup differences in pain or PROMs were found 12 months postoperatively.Conclusion: Patients operated via the DLA had reduced muscular strength, HOOS-PS scores and higher pain scores than those who underwent PA and AA type surgery. The non-operated leg was significantly stronger than the operated leg in all groups 6 months postoperatively and this persisted up to 12 months postoperatively for the DLA and AA groups. Clinical Trial Protocol number: ClinicalTrials.gov(NCT01506024).
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- 2019
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18. Prediction of unprecedented biological shifts in the global ocean
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Beaugrand, G., Conversi, A., Atkinson, A., Cloern, J., Chiba, S., Fonda-Umani, S., Kirby, R. R., Greene, C. H., Goberville, E., Otto, S. A., Reid, P. C., Stemmann, L., and Edwards, M.
- Abstract
Impermanence is an ecological principle1but there are times when changes occur nonlinearly as abrupt community shifts (ACSs) that transform the ecosystem state and the goods and services it provides2. Here, we present a model based on niche theory3to explain and predict ACSs at the global scale. We test our model using 14 multi-decadal time series of marine metazoans from zooplankton to fish, spanning all latitudes and the shelf to the open ocean. Predicted and observed fluctuations correspond, with both identifying ACSs at the end of the 1980s4–7and 1990s5,8. We show that these ACSs coincide with changes in climate that alter local thermal regimes, which in turn interact with the thermal niche of species to trigger long-term and sometimes abrupt shifts at the community level. A large-scale ACS is predicted after 2014—unprecedented in magnitude and extent—coinciding with a strong El Niño event and major shifts in Northern Hemisphere climate. Our results underline the sensitivity of the Arctic Ocean, where unprecedented melting may reorganize biological communities5,9, and suggest an increase in the size and consequences of ACS events in a warming world.
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- 2019
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19. F8-IL10: A New Potential Antirheumatic Drug Evaluated by a PET-Guided Translational Approach
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Bruijnen, Stefan T.G., Chandrupatla, Durga M.S.H., Giovanonni, Leonardo, Neri, Dario, Vugts, Danielle J., Huisman, Marc C., Hoekstra, Otto S., Musters, René J.P., Lammertsma, Adriaan A., van Dongen, Guus A.M.S., Jansen, Gerrit, Molthoff, Carla F.M., and van der Laken, Conny J.
- Abstract
Antibody fragment F8-mediated interleukin 10 (IL10) delivery is a novel treatment for rheumatoid arthritis (RA). F8 binds to the extra-domain-A of fibronectin (ED-A). In this study, in vivo biodistribution and arthritis targeting of radiolabeled F8-IL10 were investigated in RA patients, followed by further animal studies. Therefore, three RA patients (DAS28 > 3.2) received 0.4 mg of 30–74 megabecquerel [124I]I–F8–IL10 for PET-CT and blood sampling. In visually identified PET-positive joints, target-to-background was calculated. Healthy mice, rats, and arthritic rats were injected with iodinated F8-IL10 or KSF-IL10 control antibody. Various organs were excised, weighed, and counted for radioactivity. Tissue sections were stained for fibronectin ED-A. In RA patients, [124I]I–F8–IL10 was cleared rapidly from the circulation with less than 1% present in blood after 5 min. PET-CT showed targeting in 38 joints (11–15 per patient) and high uptake in the liver and spleen. Mean target-to-background ratios of PET-positive joints were 2.5 ± 1.2, 1.5 times higher for clinically active than clinically silent joints. Biodistribution of radioiodinated F8-IL10 in healthy mice showed no effect of the radioiodination method. [124I]I–F8–IL10 joint uptake was also demonstrated in arthritic rats, ∼14-fold higher than that of the control antibody [124I]I-KSF-IL10 (p< 0.001). Interestingly, liver and spleen uptake were twice as high in arthritic than in healthy rats and were related to increased (∼7×) fibronectin ED-A expression in these tissues. In conclusion, [124I]I–F8–IL10 uptake was observed in arthritic joints in RA patients holding promise for visualization of inflamed joints by PET-CT imaging and therapeutic targeting. Patient observations and, subsequently, arthritic animal studies pointed to awareness of increased [124I]I–F8–IL10 uptake in the liver and spleen associated with moderate systemic inflammation. This translational study demonstrated the value of in vivo biodistribution and PET-CT-guided imaging in development of new and potential antirheumatic drugs’.
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- 2019
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20. External Validation Shows That Baseline PET Radiomics Outperform the IPI Risk Score for Prediction of Outcome in DLBCL
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Eertink, Jakoba J, Zwezerijnen, Gerben JC, Heymans, Martijn W, Pieplenbosch, Simone, Wiegers, Sanne E, Dührsen, Ulrich, Hüttmann, Andreas, Kurch, Lars, Hanoun, Christine, Lugtenburg, Pieternella, Barrington, Sally F, Mikhaeel, George, Ceriani, Luca, Zucca, Emanuele, Czibor, Sandor, Györke, Tamás, Chamuleau, Martine E.D., Hoekstra, Otto S, de Vet, Henrica C.W, Boellaard, Ronald, and Zijlstra, Josée M.
- Published
- 2022
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21. External Validation Shows That Baseline PET Radiomics Outperform the IPI Risk Score for Prediction of Outcome in DLBCL
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Eertink, Jakoba J, Zwezerijnen, Gerben JC, Heymans, Martijn W, Pieplenbosch, Simone, Wiegers, Sanne E, Dührsen, Ulrich, Hüttmann, Andreas, Kurch, Lars, Hanoun, Christine, Lugtenburg, Pieternella, Barrington, Sally F, Mikhaeel, George, Ceriani, Luca, Zucca, Emanuele, Czibor, Sandor, Györke, Tamás, Chamuleau, Martine E.D., Hoekstra, Otto S, de Vet, Henrica C.W, Boellaard, Ronald, and Zijlstra, Josée M.
- Published
- 2022
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22. Comparison of auto-fluorescence and tetracycline fluorescence for guided bone surgery of medication-related osteonecrosis of the jaw: a randomized controlled feasibility study.
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Ristow, O., Berger, M., Freudlsperger, C., Otto, S., Troeltzsch, M., Geiß, C., Pautke, C., Hohlweg-Majert, B., Kehl, V., and Koerdt, S.
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OSTEONECROSIS ,BIOFLUORESCENCE ,TETRACYCLINES ,THERAPEUTICS - Abstract
Recent studies have indicated that bone shows auto-fluorescence under an appropriate fluorescence lamp. The aim of this preliminary study was to compare the success rates of the established tetracycline fluorescence-guided bone surgery with auto-fluorescence-guided bone surgery in the treatment of medication-related osteonecrosis of the jaw (MRONJ). Forty patients suffering from MRONJ were referred for surgical treatment and were divided randomly into two groups: auto-fluorescence ( n = 20) or tetracycline fluorescence ( n = 20) guided bone surgery. The primary endpoint was treatment success, defined as the absence of exposed bone at 8 weeks after surgery. Secondary outcomes assessed were mucosal integrity, signs of infection, pain, and loss of sensitivity; these were evaluated descriptively at 10 days, 8 weeks, 6 months, and 1 year after surgery. At 8 weeks postoperative, 18/20 patients (90%) in the auto-fluorescence group and 17/20 patients (85%) in the tetracycline fluorescence group showed mucosal integrity ( P > 0.05). At the last follow-up, 94% in the auto-fluorescence group and 89% in the tetracycline fluorescence group presented complete mucosal coverage with no exposed bone, infection, or pain ( P > 0.05). There was no significant difference between the two techniques for any of the secondary outcomes ( P > 0.05). The results of this preliminary study show that auto-fluorescence-guided bone surgery has comparable success rates to the established tetracycline fluorescence-guided bone surgery. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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23. Current concepts in salvage procedures for failing microvascular flaps: is there a superior technique? Insights from a systematic review of the literature.
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Troeltzsch, M., Probst, F.A., Ristow, O., Ehrenfeld, M., and Otto, S.
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MICROCIRCULATION disorders ,CATHETERIZATION ,THROMBOLYTIC therapy ,LEECH therapy ,ARTERIOVENOUS fistula - Abstract
Microvascular free tissue transfer is a routine procedure with high predictability and a low complication rate. However, compromised flap perfusion remains a challenge and there is no consensus regarding the appropriate flap salvage protocol. The purpose of this study was to identify techniques with implications for flap salvage procedures and to assess their efficacy. A systematic review of studies published in the literature between 1990 and 2015, with predefined inclusion and exclusion criteria, was performed. The data obtained were pooled and analyzed. A total of 39 studies qualified for data extraction. The overall level of evidence was low and the total number of reported cases was limited (330 flaps). Five studies involved control groups and supplied comparative data. Surgical anastomotic revision and thrombectomy are inevitable in every flap salvage protocol. Four techniques or combinations of these with positive effects on flap salvage success rates were identified: thrombectomy with a Fogarty catheter (six studies, 68 flaps), intraoperative use of thrombolytic drugs (16 studies, 184 flaps), placement of an arteriovenous fistula (five case reports, five flaps), and the postoperative application of medicinal leeches (11 studies, 73 flaps). Currently available data exploring flap salvage procedures are limited. None of the techniques presented yielded superior salvage outcomes. [ABSTRACT FROM AUTHOR]
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- 2016
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24. Accurate Delineation of Glioma Infiltration by Advanced PET/MR Neuro-Imaging (FRONTIER Study): A Diagnostic Study Protocol.
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Verburg, Niels, Pouwels, Petra J. W., Boellaard, Ronald, Barkhof, Frederik, Hoekstra, Otto S., Reijneveld, Jaap C., Vandertop, W. Peter, Wesseling, Pieter, and de Witt Hamer, Philip C.
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- 2016
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25. Nonoperating room anesthesia for gastrointestinal endoscopic procedures
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Lin, Otto S. and Weigel, Wade
- Published
- 2018
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26. MnII-Doped Cesium Lead Chloride Perovskite Nanocrystals: Demonstration of Oxygen Sensing Capability Based on Luminescent Dopants and Host-Dopant Energy Transfer
- Author
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Lin, Fangyuan, Li, Feiming, Lai, Zhiwei, Cai, Zhixiong, Wang, Yiru, Wolfbeis, Otto S., and Chen, Xi
- Abstract
The design of photoluminescence-quenching probes for molecular oxygen (O2) is always a large space to explore. Luminescent semiconductor nanocrystals (NCs) have been proposed as emerging oxygen-responsive probes, but the inherent O2sensing of phosphorescent semiconductor NCs has not been reported so far. Here, we demonstrate the O2sensing capability of MnII-doped CsPbCl3nanocrystals (Mn:CsPbCl3NCs) and reveal the role of O2on the optical de-excitation process of such perovskite nanocrystals (PNCs). By adjusting the amount and distribution of MnIIdopants, as well as the host-dopant energy transfer process in PNCs, we highlight that O2can reversibly quench the MnIIemission due to the temporary disturbance to the ligand field of near-surface MnIIdopants in PNCs. In phosphorescence mode, the photoluminescence intensity of the Mn:CsPbCl3NCs is quenched by 53% on increasing O2concentration from 0 to 100%. The Stern–Volmer plot shows a good linear in the 0–12% O2concentration range. High sensing reversibility and rapid signal response are also achieved. In our perception, the mechanism study makes our PNCs candidates for the optical probes of O2, and it is enlightening to explore more possibilities of the inherent O2sensing based on the semiconductor-doped NCs (not restricted to MnII-doped PNCs) with phosphorescence emission.
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- 2018
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27. Load transfer in the proximal femur and primary stability of a cemented and uncemented femoral stem: An experimental study on cadaver femurs
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Enoksen, Cathrine H, Wik, Tina S, Klaksvik, Jomar, Arthursson, Astvaldur J, Husby, Otto S, and Gjerdet, Nils R
- Abstract
There are principally two fixation methods in total hip arthroplasty, cemented and uncemented. Both methods have in general good long-time survival. Studies comparing cemented and uncemented femoral stems indicate that the cemented stems perform somewhat better, at least in the elderly population. The aim of this study was to compare load transfer and the initial micromotion pattern for an uncemented and a cemented stem. A total of 12 human cadavers were tested in a hip simulator during single leg and stair climbing. Strain was measured on the proximal femur before and after implantation of the prostheses, and the values were presented as percentage of physiological strain. The micromovements between the stem and bone were measured and a total point motion was calculated. The results showed small statistically significant differences between the fixation methods, the largest difference being 8.1 percentage points. The uncemented stem had somewhat higher micromotion than the cemented stem, but less than 10 µm. Both stems thus had acceptable primary stability. The main finding of this study is the strain and micromotion pattern of a cemented and an uncemented stem of similar geometry is overall equal. There were small statistical significant differences between the two fixation methods regarding strain and micromotion levels. The differences are considered too small to be clinically relevant.
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- 2017
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28. Benefits of Using Stereotactic Body Radiotherapy in Patients With Metachronous Oligometastases of Hormone-Sensitive Prostate Cancer Detected by [18F]fluoromethylcholine PET/CT
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Bouman-Wammes, Esther W., van Dodewaard-De Jong, Joyce M., Dahele, Max, Cysouw, Matthijs C.F., Hoekstra, Otto S., van Moorselaar, R. Jeroen A., Piet, Maartje A.H., Verberne, Hein J., Bins, Adriaan D., Verheul, Henk M.W., Slotman, Ben J., Oprea-Lager, Daniela E., and Van den Eertwegh, Alfons J.M.
- Abstract
Stereotactic body radiation therapy (SBRT) might postpone the start of androgen deprivation therapy (ADT) in patients with oligometastatic recurrence of hormone-sensitive prostate cancer. We included 43 SBRT-treated patients, and a control cohort of 20 non–SBRT-treated patients, in this retrospective study. Patients in the SBRT cohort could start ADT significantly later, and the time till castration resistance was significantly longer.
- Published
- 2017
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29. Fiber-Optic Chemical Sensors and Biosensors (2013-2015).
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Xu-dong Wang and Wolfbeis, Otto S.
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- 2016
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30. Glucose Transporter 1 (SLC2A1) and Vascular Endothelial Growth Factor A (VEGFA) Predict Survival After Resection of Colorectal Cancer Liver Metastasis.
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Goos, Jeroen A. C. M., de Cuba, Erienne M. V., Coupé, Veerle M. H., Diosdado, Begonã, Delis-Van Diemen, Pien M., Karga, Cemile, Beliën, Jeroen A. M., der Houven van Oordt, C. Willemien Menke-Van, Geldof, Albert A., Meijer, Gerrit A., Hoekstra, Otto S., and Fijneman, Remond J. A.
- Abstract
Objective: To investigate the individual and combined prognostic value of HIF1α, SLC2A1, and vascular endothelial growth factor A (VEGFA) in a multi-institutional cohort of patients with resected colorectal cancer liver metastasis (CRCLM). Background: In the majority of patients with CRCLM, resection seems not to be curative, despite its curative intent. Overexpression of hypoxia-inducible factor 1a (HIF1α), glucose transporter 1 (SLC2A1; also known as GLUT1), and VEGFA has been associated with tumor progression and poor prognosis of patients with colorectal cancer (CRC). Methods: Tissue microarrays were generated using CRCLM and patientmatched primary CRC from patients who underwent CRCLM resection between 1990 and 2010. Prognostic value of HIF1α, SLC2A1, and VEGFA was determined by immunohistochemistry. A 500-fold cross-validated hazard rate ratio (HRR
av ) for overall survival was calculated. Results: HIF1α, SLC2A1, and VEGFA expression could be evaluated in 328, 350, and 335 patients, respectively. High SLC2A1 expression was associated with good prognosis (HRRav , 0.67; P (HRR >1)<0.01) and high VEGFA expression to poor prognosis (HRRav , 1.84; P (HRR<1)=0.02), also after multivariate analysis including established clinicopathological prognostic variables (HRRav , 0.67; P (HRR >1)<0.01 and HRRav, 1.50; P (HRR<1)=0.02, respectively). SLC2A1 showed prognostic value particularly in patients treated with systemic therapy (P<0.01), whereas the prognostic value of VEGFA expression was mainly observed in patients not treated with systemic therapy (P<0.01). Prognosis was especially poor in patients with both low SLC2A1 and high VEGFA expression (P<0.01). HIF1α expression was not associated with survival. Conclusions: SLC2A1 and VEGFA expression are prognostic molecular biomarkers for patients with CRCLM with added value to established clinicopathological variables. [ABSTRACT FROM AUTHOR]- Published
- 2016
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31. Disparities in prevalence, location, and shape characteristics of colorectal neoplasia between South Korean and U.S. patients.
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Cha, Jae Myung, Kozarek, Richard A., La Selva, Danielle, Gluck, Michael, Ross, Andrew, Chiorean, Michael, Koch, Johannes, and Lin, Otto S.
- Abstract
Background Colon cancer screening is being introduced in many countries, but standard Western screening approaches may not be appropriate for Asian societies if differences in colon cancer epidemiology exist. Comparative analysis of colorectal neoplasia patterns in South Korean and Western subjects has implications for appropriate screening approaches in non-Western societies. Methods The results of concurrent screening colonoscopies performed in average-risk patients 50 to 69 years old in 2 teaching hospitals, Kyung Hee University Hospital (Seoul, South Korea) and Virginia Mason Medical Center (Seattle, Wash), were compared with respect to prevalence, histologic features, anatomic distribution, and shape characteristics of colorectal neoplasia. Results The U.S. (n = 3460) and South Korean (n = 2193) cohorts were similar with regard to the prevalence of adenomas (28.5% vs 29.8%, respectively, P = .312) and advanced neoplasia (6.4% vs 5.4%, respectively, P = .102), but the proportion of proximal adenomas was greater in the U.S. cohort (62.8% vs 45.9%, P < .001). The prevalence of adenomas and advanced neoplasia was similar in male patients, but there was a greater prevalence of neoplasia (23.5% vs 18.8%, P = .006) and advanced neoplasia (5.1% vs 2.7%, P < .001) in U.S. women than South Korean women. When large (≥10 mm) adenomas were considered, proximal location and nonpolypoid (flat) shape were more common in the U.S. cohort (79.4% vs 37.1%, P = .003 and 43.5% vs 12.3%, P < .001, respectively). The overall prevalence of large flat adenomas in the U.S. cohort was 5 times that of the South Korean cohort (2.6% vs 0.5%, P < .001). Adjustment for sex ratio discrepancies (48.3% men in the U.S. cohort vs 60.8% in the South Korean cohort, P < .001) did not result in any significant changes in the conclusions. Conclusion Compared with Westerners, South Koreans have a more distal distribution of adenomas and advanced neoplasia and lower prevalence of large flat adenomas. South Korean women have a lower prevalence of colorectal neoplasia than Western women. Such disparities suggest that Western screening strategies cannot be directly adopted by other countries, but need to be customized by society. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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32. The First US Clinical Experience With Computer-Assisted Propofol Sedation: A Retrospective Observational Comparative Study on Efficacy, Safety, Efficiency, and Endoscopist and Patient Satisfaction
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Lin, Otto S., Kozarek, Richard A., Tombs, Deborah, La Selva, Danielle, Weigel, Wade, Beecher, Ryan, Jensen, Ana, Gluck, Michael, and Ross, Andrew
- Abstract
Supplemental Digital Content is available in the text.Published ahead of print March 17, 2017.
- Published
- 2017
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33. Osteomyelitis der Kieferknochen
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Kakoschke, T. K., Aljohani, S., Kaeppler, G., Ehrenfeld, M., and Otto, S.
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- 2017
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34. Imaging biomarker roadmap for cancer studies
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O'Connor, James P. B., Aboagye, Eric O., Adams, Judith E., Aerts, Hugo J. W. L., Barrington, Sally F., Beer, Ambros J., Boellaard, Ronald, Bohndiek, Sarah E., Brady, Michael, Brown, Gina, Buckley, David L., Chenevert, Thomas L., Clarke, Laurence P., Collette, Sandra, Cook, Gary J., deSouza, Nandita M., Dickson, John C., Dive, Caroline, Evelhoch, Jeffrey L., Faivre-Finn, Corinne, Gallagher, Ferdia A., Gilbert, Fiona J., Gillies, Robert J., Goh, Vicky, Griffiths, John R., Groves, Ashley M., Halligan, Steve, Harris, Adrian L., Hawkes, David J., Hoekstra, Otto S., Huang, Erich P., Hutton, Brian F., Jackson, Edward F., Jayson, Gordon C., Jones, Andrew, Koh, Dow-Mu, Lacombe, Denis, Lambin, Philippe, Lassau, Nathalie, Leach, Martin O., Lee, Ting-Yim, Leen, Edward L., Lewis, Jason S., Liu, Yan, Lythgoe, Mark F., Manoharan, Prakash, Maxwell, Ross J., Miles, Kenneth A., Morgan, Bruno, Morris, Steve, Ng, Tony, Padhani, Anwar R., Parker, Geoff J. M., Partridge, Mike, Pathak, Arvind P., Peet, Andrew C., Punwani, Shonit, Reynolds, Andrew R., Robinson, Simon P., Shankar, Lalitha K., Sharma, Ricky A., Soloviev, Dmitry, Stroobants, Sigrid, Sullivan, Daniel C., Taylor, Stuart A., Tofts, Paul S., Tozer, Gillian M., van Herk, Marcel, Walker-Samuel, Simon, Wason, James, Williams, Kaye J., Workman, Paul, Yankeelov, Thomas E., Brindle, Kevin M., McShane, Lisa M., Jackson, Alan, and Waterton, John C.
- Abstract
Imaging biomarkers (IBs) are used extensively in drug development and cancer research, but important differences exist between IBs and biospecimen-derived biomarkers. A tailored 'roadmap' is required for the development of new IBs to be used either in clinical research or for decision-making in healthcare. In this Consensus statement, a group of experts assembled by CRUK and the EORTC present 14 key recommendations for accelerating the clinical translation of IBs.
- Published
- 2017
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35. Baseline radiomics features and MYCrearrangement status predict progression in aggressive B-cell lymphoma
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Eertink, Jakoba J., Zwezerijnen, Gerben J.C., Wiegers, Sanne E., Pieplenbosch, Simone, Chamuleau, Martine E.D., Lugtenburg, Pieternella J., de Jong, Daphne, Ylstra, Bauke, Mendeville, Matias, Dührsen, Ulrich, Hanoun, Christine, Hüttmann, Andreas, Richter, Julia, Klapper, Wolfram, Jauw, Yvonne W.S., Hoekstra, Otto S., de Vet, Henrica C.W., Boellaard, Ronald, and Zijlstra, Josée M.
- Abstract
We investigated whether the outcome prediction of patients with aggressive B-cell lymphoma can be improved by combining clinical, molecular genotype, and radiomics features. MYC, BCL2, and BCL6rearrangements were assessed using fluorescence in situ hybridization. Seventeen radiomics features were extracted from the baseline positron emission tomography–computed tomography of 323 patients, which included maximum standardized uptake value (SUVmax), SUVpeak, SUVmean, metabolic tumor volume (MTV), total lesion glycolysis, and 12 dissemination features pertaining to distance, differences in uptake and volume between lesions, respectively. Logistic regression with backward feature selection was used to predict progression after 2 years. The predictive value of (1) International Prognostic Index (IPI); (2) IPI plus MYC; (3) IPI, MYC, and MTV; (4) radiomics; and (5) MYCplus radiomics models were tested using the cross-validated area under the curve (CV-AUC) and positive predictive values (PPVs). IPI yielded a CV-AUC of 0.65 ± 0.07 with a PPV of 29.6%. The IPI plus MYCmodel yielded a CV-AUC of 0.68 ± 0.08. IPI, MYC, and MTV yielded a CV-AUC of 0.74 ± 0.08. The highest model performance of the radiomics model was observed for MTV combined with the maximum distance between the largest lesion and another lesion, the maximum difference in SUVpeakbetween 2 lesions, and the sum of distances between all lesions, yielding an improved CV-AUC of 0.77 ± 0.07. The same radiomics features were retained when adding MYC(CV-AUC, 0.77 ± 0.07). PPV was highest for the MYCplus radiomics model (50.0%) and increased by 20% compared with the IPI (29.6%). Adding radiomics features improved model performance and PPV and can, therefore, aid in identifying poor prognosis patients.
- Published
- 2023
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36. Findings of diagnostic colonoscopy in young adults versus findings of screening colonoscopy in patients aged 50 to 54 years: a comparative study stratified by symptom category.
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Cha, Jae-Myung, Kozarek, Richard A., La Selva, Danielle, Gluck, Michael, Ross, Andrew, Chiorean, Michael, Koch, Johannes, and Lin, Otto S.
- Abstract
Background The threshold for diagnostic colonoscopy in symptomatic patients aged <50 years remains controversial. Previous studies on the prevalence of neoplasia or other serious pathology in young patients mostly have been uncontrolled, providing only limited data on the risk associated with specific symptoms. Objective To compare colonoscopy findings in patients aged <50 years who have various symptoms (diagnostic cohort) against those of concurrent patients aged 50 to 54 years who are asymptomatic (screening cohort). Design Retrospective controlled cohort study. Setting Teaching hospital. Patients Symptomatic patients aged between 18 and 49 years and asymptomatic patients aged between 50 and 54 years. Interventions Colonoscopy. Main Outcome Measurements Prevalence of advanced neoplasia. Results During the study period, 1638 patients underwent colonoscopy in the screening cohort (mean [± standard deviation{SD}] age 51.7 ± 1.4 years) and 1266 underwent colonoscopy in the diagnostic cohort (40.4 ± 8.0 years). Despite the age difference, the prevalence of advanced neoplasia in patients with rectal bleeding was comparable with that in the screening controls: 28 of 472 (5.9%) versus 113 of 1638 patients (6.9%) ( P = .459). Furthermore, 10 patients (2.1%) with rectal bleeding were newly diagnosed with inflammatory bowel disease. In contrast, other symptoms that commonly lead to colonoscopy, such as abdominal pain, changes in bowel habits, and weight loss, were associated with much lower risks for neoplasia. As a result, the overall prevalences of neoplasia and advanced neoplasia were significantly higher in the screening cohort than in the diagnostic cohort: 467 of 1638 patients (28.5%) versus 179 of 1266 patients (14.1%), and 113 patients (6.9%) versus 48 patients (3.8%), respectively (both P < .001). Limitations No data on duration of symptoms; discrepant sex ratios between cohorts. Conclusion The threshold for diagnostic colonoscopy in symptomatic young adults should be individualized for each symptom category. Rectal bleeding warrants colonoscopy to detect advanced neoplasia or inflammatory bowel disease in most young patients, especially those aged 40 to 49 years, whereas non-bleeding symptoms, including some traditionally regarded as “alarm” symptoms, were associated with a much lower risk for neoplasia compared with the risk in screening patients aged 50 to 54 years. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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37. Treatment strategies and outcomes of bisphosphonate-related osteonecrosis of the jaw (BRONJ) with characterization of patients: a systematic review.
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Fliefel, R., Tröltzsch, M., Kühnisch, J., Ehrenfeld, M., and Otto, S.
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TREATMENT of bone necrosis ,JAW necrosis ,DIPHOSPHONATES ,JAW surgery ,HYPERBARIC oxygenation ,GROWTH factors - Abstract
The aim of this systematic review was to answer the question: What are the treatments available for bisphosphonate-related osteonecrosis of the jaws (BRONJ) and their outcomes? A literature search of PubMed, Cochrane Library, and Web of Science databases was conducted in accordance with the PRISMA statement, search phrases were (‘jaw osteonecrosis’ OR ‘bisphosphonate-related osteonecrosis’ OR ‘bisphosphonate osteonecrosis’) AND (‘treatment’ OR ‘outcomes’). Ninety-seven articles published between 2003 and February 2014 were reviewed. The studies reported 4879 cases of BRONJ. The mean age of the patients was 66.5 ± 4.7 years. The male to female ratio was 1:2. The mean duration of bisphosphonate (BP) administration was 38.2 ± 15.7 months. The quality of the publications was good, with some moderate and poor. Minimally invasive surgical treatment was the treatment most used. Medical treatment was also used. Adjunctive treatments included laser, growth factors, hyperbaric oxygen and ozone. The articles provided a broad range of outcome variables to assess the treatment of BRONJ and the outcomes of each treatment. Considerable heterogeneity was found regarding study design, sample size, and treatment modalities. Clinical trials with larger samples are required to provide sufficient information for each treatment modality to predict the outcomes of each treatment. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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38. Magnetic resonance imaging: a useful tool to distinguish between keratocystic odontogenic tumours and odontogenic cysts.
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Probst, F.A., Probst, M., Pautke, Ch., Kaltsi, E., Otto, S., Schiel, S., Troeltzsch, M., Ehrenfeld, M., Cornelius, C.P., and Müller-Lisse, U.G.
- Subjects
ODONTOGENIC cysts ,SURGICAL technology ,CONTRAST-enhanced magnetic resonance imaging ,MAXILLOFACIAL surgery ,PANORAMIC radiography ,HISTOPATHOLOGY ,DIAGNOSIS ,THERAPEUTICS - Abstract
In contrast to odontogenic cysts, keratocystic odontogenic tumours often recur and require more aggressive surgical treatment, so we tried to find features that distinguished between them on magnetic resonance imaging (MRI). Without knowing the diagnosis, two radiologists reviewed intensity (low, intermediate, or high) and homogeneity (homogeneous or heterogeneous) of signals in short-tau-inversion-recovery (STIR), T1- and T2-weighted, and fat-suppressed, contrast-enhanced MRI in 20 consecutive patients with oval, radiolucent lesions of the mandible on panoramic radiography, and who were subsequently confirmed histopathologically to have either an odontogenic cyst or a keratocystic odontogenic tumour ( n = 10 in each group). Fisher's exact test was statistically significant at p < 0.05. Delineation of a contrast-enhanced wall of a cyst with high signal intensity distinguished odontogenic cysts (9/10 and 8/10, respectively) from keratocystic odontogenic tumours (3/10, p = 0.02, and 1/10, p = 0.01, respectively). One radiologist found odontogenic cysts were more likely to be homogeneous on unenhanced T1-weighted images (odontogenic cysts 9/10, keratocystic odontogenic tumours 3/10, p = 0.02) and one on contrast-enhanced MRI, when the cyst wall was enhanced (odontogenic cysts 7/9, keratocystic odontogenic tumours 0/3, p = 0.01). There were no other significant distinguishing features on MRI. In conclusion, the signal intensity of the enhanced wall seems to be a feature on contrast-enhanced MRI that differentiates odontogenic cysts from keratocystic odontogenic tumours. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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39. Upconversion Nanoparticles: From Hydrophobic to HydrophilicSurfaces.
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Muhr, Verena, Wilhelm, Stefan, Hirsch, Thomas, and Wolfbeis, Otto S.
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- 2014
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40. Detection of Subclinical Synovitis with Macrophage Targeting and Positron Emission Tomography in Patients with Rheumatoid Arthritis without Clinical Arthritis.
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Gent, Yoony YJ., Ahmadi, Nazanin, Voskuy, Alexandre E., Hoetjes, Nikie, Kuijk, Cornells van, Britsemmer, Karin, Turkstra, Franktien, Boers, Maarten, Hoekstra, Otto S., and der Laken, Conny J. van
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- 2014
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41. New Plastic Microparticles and Nanoparticles for Fluorescent Sensing and Encoding.
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Berberan-Santos, M. N., Borisov, Sergey M., Mayr, Torsten, Karasyov, Alexander A., Klimant, Ingo, Chojnacki, Pawel, Moser, Christoph, Nagl, Stefan, Schaeferling, Michael, Stich, Matthias I., Kocincova, Anna S., and Wolfbeis, Otto S.
- Abstract
We report on the progress that has been made in the area of luminescence sensing and encoding by making use of microparticles and nanoparticles prepared from plastic materials. These are quite different from particles built up from metal sulfides (such as the so-called quantum dots, "Q-dots"; see Michalet et al., Science 307:538, 2005), other semiconductor materials, metal nanoparticles (mainly gold) (see DL Feldheim, CA Foss (eds) Metal Nanoparticles: Synthesis, Characterization, and Applications, p 338, Marcel Dekker, 2002), or glass and its modifications including certain sol-gels. Plastic nanoparticles may contain magnetic beads in order to facilitate separation from the sample solution. All the particles described here are doped with fluorescent dyes, which is in contrast to particles where the material itself displays intrinsic luminescence. Unlike the case of Q-dots, the color of plastic beads can be varied to a wide extent irrespective of their size, as can be the decay times and even anisotropy. This, in fact, is a most attractive feature of such beads and makes them superior in many cases despite the undisputed utility of other types of particles in certain fields. The area of beads was almost exclusively occupied until 10 years ago by polystyrene beads (also referred to as latex beads) 0.1-5 μm in diameter. They are widely used in bioassays and flow cytometry because they can be manufactured with good reproducibility (usually by emulsion polymerization) and because they are rather inert. Other applications include agglutination tests, particle capture ELISAs (e.g., Abbott's IMx and AxSym), solid-phase assays (often used for pregnancy testing), scintillation proximity assays, luminescent oxygen channeling immunoassay (LOCI), and bead-FRET assays. Nanoparticles have been used for labeling purposes, particularly in the context of protein arrays and DNA arrays. In recent years, beads have been fluorescently dyed for purposes of encoding, for example in combination with optical fiber arrays and in microwells, and in methods for homogeneous multiplexed high-throughput screening. The analytical information may be the color of the fluorescence, its intensity (or—even better—the ratio of two intensities), decay time, anisotropy, or combinations thereof. In the first section we will describe dyes for doping plastic particles. The second section will report on chemical sensing with addressable micro- and nanospheres, and the third on the use of dyed microparticles in sensing pH values. We will also report on luminescence lifetime encoded microbeads as carriers for multiplexed bioassays (Sect. 4), the use of dyed polymer microparticles in simultaneous sensing of oxygen and temperature (Sect. 5), and on nanobead labels for homogeneous protein assays and protein arrays (Sect. 6). [ABSTRACT FROM AUTHOR]
- Published
- 2008
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42. Measuring Response to Chemotherapy in Locally Advanced Breast Cancer: Methodological Considerations.
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Bombardieri, Emilio, Gianni, Luca, Bonadonna, Gianni, Krak, Nanda C., Hoekstra, Otto S., and Lammertsma, Adriaan A.
- Abstract
In this chapter the findings of response-monitoring studies in breast cancer, using [18F]2-fluoro-2-deoxy-D-glucose (FDG) and positron emission tomography (PET), are summarised. These studies indicate that there is a strong relationship between response and decrease in FDG signal even at an early stage of therapy. The review concentrates on methodological aspects of monitoring response with FDG: timing of serial scans, ROI definition approach, method of quantification, pitfalls of FDG and future directions in functional imaging. For the sake of optimal clinical applicability there now is need to standardise methodology. This is necessary to establish firm cut-off values for discriminating responders from non-responders, which in turn will provide a means for optimal treatment for as many patients as possible. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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43. Interface Circuits for QCM Sensors.
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Wolfbeis, Otto S., Janshoff, Andreas, Steinem, Claudia, Lucklum, Ralf, and Eichelbaum, Frank
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Oscillators are the standard interface circuits for quartz crystal resonator sensors. When applying these sensors in gases a large set of circuits is available, which can be adapted to particular applications. In liquid applications viscous damping accompanied by a significant loss in the Q factor of the resonator requires specific solutions. We summarize major design rules and discuss approved solutions. We especially address the series resonance frequency and motional resistance determination and parallel capacitance compensation. We furthermore introduce recent developments in network analysis and impulse excitation technique for more sophisticated applications. Impedance analysis especially allows a more complete characterization of the sensor and can nowadays be realized with sensor interface circuitry. The performance of electrical circuitry depends essentially on the stability of the acoustic device. We therefore begin with a discussion of selected quartz crystal properties, disturbances from temperature and mechanical stress, and analyze AT and BT cut from the sensor point of view. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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44. Resonant Acoustic Profiling (RAP™) and Rupture Event Scanning (REVS™).
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Wolfbeis, Otto S., Janshoff, Andreas, Steinem, Claudia, and Cooper, Matthew A.
- Abstract
Following the release of widely available commercial instruments in the 1990s, researchers have driven the development of biosensor-based methods for profiling and screening of small molecule and proteinaceous therapeutic drug candidates. Medicinal chemists have in turn demanded faster and more accurate assays for characterisation of drug candidate interactions with target receptors, serum proteins and side-effect profiling receptors. In response to this challenge, Akubio Ltd. (Cambridge, UK) has been developing an advanced label-free detection platform, resonant acoustic profiling (RAP™). This evolution of the basic QCM approach has the potential to change the way assays are performed and to generate novel information on molecular interactions. Key attributes covered in this chapter include the ability to multiplex to high numbers of resonators, the addition of robust interfacial surface chemistries, fully automated sample handling and sample processing, disposable microfluidic cassettes with submicrolitre dead volumes, and more sensitive detection electronics. Akubio has also developed a sensitive and economical method to directly detect particulate analytes. The technique, which we term rupture event scanning (REVS™), is based on control of the amplitude of oscillation of an acoustic wave device on which the analytes have been captured. In this chapter, example applications of RAP™ for proteins and small molecules and REVS™ for virus detection are presented. The physical forces involved in the processes are also discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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45. The QCM-D Technique for Probing Biomacromolecular Recognition Reactions.
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Wolfbeis, Otto S., Janshoff, Andreas, Steinem, Claudia, Höök, Fredrik, and Kasemo, Bengt
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In recent years there has been an exponential growth in scientific reports in which the quartz crystal microbalance (QCM) technique plays a key role in elucidating various aspects of biomacromolecular recognition reactions. In this short overview, the key steps in the development of a special variant of the QCM technique, generally named quartz crystal microbalance with dissipation monitoring (QCM-D), are summarized. The key feature of the QCM-D technique, in comparison with the traditional variant, is that, in addition to changes in resonance frequency, f, it also provides simultaneous measurements of changes in energy dissipation, D, induced upon interfacial reactions. Although these two parameters can be measured in various ways, focus is herein put on a means to obtain temporal variations in f and D by probing the decay of the crystal's oscillation after a rapid excitation close to the resonance frequency. By highlighting studies focusing on (i) DNA immobilization and subsequent hybridization, (ii) supported cell membrane mimics, and (iii) more complex situations, such as systems displaying film resonance behavior, we highlight both technical and theoretical aspects that have been essential for the increasing popularity of the QCM-D technique. Hence, far from all existing literature will be covered, and this contribution should therefore be read as a brief overview, rather than a comprehensive review, focusing on key components responsible for the high potential of the QCM-D technique to contribute to biointerface science in general, and the fields of research devoted to primarily biomacromolecular interactions in particular. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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46. The Quartz Crystal Microbalance and the Electrochemical QCM: Applications to Studies of Thin Polymer Films, Electron Transfer Systems, Biological Macromolecules, Biosensors, and Cells.
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Wolfbeis, Otto S., Janshoff, Andreas, Steinem, Claudia, and Marx, Kenneth A.
- Abstract
In this chapter we focus on the application of the piezoelectric-based quartz crystal microbalance (QCM) technique to create and study thin polymeric films. The electrochemical variant of the quartz crystal microbalance technique (EQCM) allows one to study changes in the interfacial mass and physical properties associated with electron transfer processes occurring at the electrode surface, such as those accompanying electropolymerization of thin films. We have applied EQCM to study and compare the formation and properties of polymeric thin films formed from amphiphilic and non-amphiphilic phenolic and tyrosine monomers and comonomer systems. Also, we show the applicability of using EQCM to study polymeric films formed as a result of enzymatic polymerization processes, to create enzyme-entrapped polymer electrodes, and to create biosensors. Lastly, we briefly discuss QCM application to studies of cell properties such as adhesion and to create cell QCM biosensors that have interesting applications in the area of drug discovery. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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47. Enzyme Reactions on a 27 MHz Quartz Crystal Microbalance.
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Wolfbeis, Otto S., Janshoff, Andreas, Steinem, Claudia, Okahata, Yoshio, Mori, Toshiaki, Furusawa, Hiroyuki, and Nihira, Takanori
- Abstract
A quartz crystal microbalance (QCM) is known as a useful tool to detect gravimetric molecular interactions. We have developed a 27-MHz QCM (Affinix Q4) to detect various biomolecular interactions such as DNA-DNA hybridization, DNA-protein interactions, glycolipid-protein interactions, and protein-protein interactions. In this chapter, we show that the 27-MHz QCM is also useful to detect the kinetics of enzyme reactions, because all the steps of enzyme reactions, such as the enzyme binding process to substrates, the enzyme catalytic reaction, and the release of enzyme from the product, accompany mass changes. We introduce here kinetic analyses of enzyme reactions on DNA (DNA polymerization, DNA ligation, and DNA cleavage) and enzyme reactions on glycans (glycosylation, phosphorylation, and mutation of enzymes) by using the substrate-immobilized 27-MHz QCM in solution. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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48. The Quartz Crystal Microbalance in Cell Biology: Basics and Applications.
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Wolfbeis, Otto S., Janshoff, Andreas, Steinem, Claudia, Heitmann, Vanessa, Reiß, Björn, and Wegener, Joachim
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This chapter describes recent studies in which the quartz crystal microbalance (QCM) technology has been applied as a monitoring tool for animal cells in vitro. With shear wave resonators used as growth substrates it is possible to follow the de novo formation or the modulation of established cell-substrate contacts from readings of the resonance frequency with a time resolution in the order of seconds. From cell adhesion studies it became clear that different cell types induce an individual shift of the resonance frequency but it has been a matter of debate, which subcellular structures determine the individual impact of a given cell type on the QCM response. This question has been addressed by our group in recent years and a summary of our current understanding of this problem will be given here. Different approaches have been applied to challenge the cells in a well-defined way and to monitor the associated changes of the QCM readout. Taken together, these studies have led us to the following conclusions: (i) The cellular bodies primarily lead to an increased energy dissipation that does not correspond to a simple viscous behavior. (ii) The adhesive proteins underneath the cells provide a measurable contribution to the overall QCM response of adherent cells. (iii) The average distance between lower cell membrane and substrate surface does not have a significant impact on the acoustic load situation. (iv) The QCM is sensitive to cell stiffness and reports in a similar way on changes in cell stiffness, as accessible from scanning force microscopy measurements. (v) The cortical actin cytoskeleton is a dominant contributor to the cells' acoustic response. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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49. Specific Adsorption of Annexin A1 on Solid Supported Membranes: A Model Study.
- Author
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Wolfbeis, Otto S., Steinem, Claudia, and Janshoff, Andreas
- Abstract
The quartz crystal microbalance (QCM) is an invaluable tool to monitor protein-membrane and membrane-membrane interactions mediated by proteins without labeling one of the components. In this chapter we show that the formation process of solid supported membranes by spreading and fusion of lipid vesicles can be readily followed by the QCM technique, and that Monte Carlo simulations allow for a detailed modeling of the process. We further demonstrate that only membranes attached to a solid support make it possible to separate the two binding modes of annexin A1 to membranes, hence allowing a quantitative analysis of the two processes. By monitoring the changes in the resonance frequency of 5-MHz quartz plates combined with Monte Carlo simulations, the kinetics of the annexin A1-membrane interaction can be followed in detail, which contributes to the biological understanding of annexin A1 function in the cell. The simultaneous readout of the change in resonance frequency and dissipation allows one to follow the binding of lipid vesicles, the second membrane binding process, to membrane-bound annexin A1, which gives information on the impact of different parameters, such as the N-terminus of annexin A1 and the protein surface coverage. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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50. Piezoelectric Immunosensors.
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Wolfbeis, Otto S., Janshoff, Andreas, Steinem, Claudia, Vaughan, Robert D., and Guilbault, George G.
- Abstract
This chapter reviews the basic theory and applications of piezoelectric immunosensors. The immunosensor assay formats most often used are introduced as well as a brief explanation of the typical methods of measurement. Immobilisation is discussed, the importance of each characteristic, the basic techniques employed and a comparison of their performance as investigated by many researchers. The main historical developments of piezoelectric sensors and how these have led to early piezoelectric immunosensors are reviewed. Immunosensor applications and a comparison of sensor performance, for various analytes are summarised. The potential future of this field is also discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
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