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1.
Am Heart J ; 265: 66-76, 2023 11.
Article in English | MEDLINE | ID: mdl-37422010

ABSTRACT

BACKGROUND: Atrial fibrillation (AF) is one of the most frequent causes of stroke. Several randomized trials have shown that prolonged monitoring increases the detection of AF, but the effect on reducing recurrent cardioembolism, ie, ischemic stroke and systemic embolism, remains unknown. We aim to evaluate whether a risk-adapted, intensified heart rhythm monitoring with consequent guideline conform treatment, which implies initiation of oral anticoagulation (OAC), leads to a reduction of recurrent cardioembolism. METHODS: Find-AF 2 is a randomized, controlled, open-label parallel multicenter trial with blinded endpoint assessment. 5,200 patients ≥ 60 years of age with symptomatic ischemic stroke within the last 30 days and without known AF will be included at 52 study centers with a specialized stroke unit in Germany. Patients without AF in an additional 24-hour Holter ECG after the qualifying event will be randomized in a 1:1 fashion to either enhanced, prolonged and intensified ECG-monitoring (intervention arm) or standard of care monitoring (control arm). In the intervention arm, patients with a high risk of underlying AF will receive continuous rhythm monitoring using an implantable cardiac monitor (ICM) whereas those without high risk of underlying AF will receive repeated 7-day Holter ECGs. The duration of rhythm monitoring within the control arm is up to the discretion of the participating centers and is allowed for up to 7 days. Patients will be followed for at least 24 months. The primary efficacy endpoint is the time until recurrent ischemic stroke or systemic embolism occur. CONCLUSIONS: The Find-AF 2 trial aims to demonstrate that enhanced, prolonged and intensified rhythm monitoring results in a more effective prevention of recurrent ischemic stroke and systemic embolism compared to usual care.


Subject(s)
Atrial Fibrillation , Embolism , Ischemic Stroke , Stroke , Humans , Infant , Atrial Fibrillation/complications , Atrial Fibrillation/diagnosis , Furylfuramide , Prospective Studies , Stroke/etiology , Stroke/prevention & control , Stroke/diagnosis , Electrocardiography, Ambulatory/methods , Embolism/diagnosis , Embolism/etiology , Embolism/prevention & control
2.
Int J Mol Sci ; 22(15)2021 Jul 22.
Article in English | MEDLINE | ID: mdl-34360579

ABSTRACT

Ischemic heart disease can lead to myocardial infarction (MI), a major cause of morbidity and mortality worldwide. Multiple stem cell types have been safely transferred into failing human hearts, but the overall clinical cardiovascular benefits have been modest. Therefore, there is a dire need to understand the basic biology of stem cells to enhance therapeutic effects. Bmi1 is part of the polycomb repressive complex 1 (PRC1) that is involved in different processes including proliferation, survival and differentiation of stem cells. We isolated cortical bones stem cells (CBSCs) from bone stroma, and they express significantly high levels of Bmi1 compared to mesenchymal stem cells (MSCs) and cardiac-derived stem cells (CDCs). Using lentiviral transduction, Bmi1 was knocked down in the CBSCs to determine the effect of loss of Bmi1 on proliferation and survival potential with or without Bmi1 in CBSCs. Our data show that with the loss of Bmi1, there is a decrease in CBSC ability to proliferate and survive during stress. This loss of functionality is attributed to changes in histone modification, specifically histone 3 lysine 27 (H3K27). Without the proper epigenetic regulation, due to the loss of the polycomb protein in CBSCs, there is a significant decrease in cell cycle proteins, including Cyclin B, E2F, and WEE as well as an increase in DNA damage genes, including ataxia-telangiectasia mutated (ATM) and ATM and Rad3-related (ATR). In conclusion, in the absence of Bmi1, CBSCs lose their proliferative potential, have increased DNA damage and apoptosis, and more cell cycle arrest due to changes in epigenetic modifications. Consequently, Bmi1 plays a critical role in stem cell proliferation and survival through cell cycle regulation, specifically in the CBSCs. This regulation is associated with the histone modification and regulation of Bmi1, therefore indicating a novel mechanism of Bmi1 and the epigenetic regulation of stem cells.


Subject(s)
Apoptosis , Cell Proliferation , Cortical Bone/cytology , Epigenesis, Genetic , Histones/metabolism , Polycomb Repressive Complex 1/metabolism , Proto-Oncogene Proteins/metabolism , Stem Cells/cytology , Animals , Cell Cycle , Cell Differentiation , Cells, Cultured , Cortical Bone/injuries , Cortical Bone/metabolism , DNA Damage , Histones/genetics , Mice , Mice, Inbred C57BL , Polycomb Repressive Complex 1/genetics , Proto-Oncogene Proteins/genetics , Signal Transduction , Stem Cells/metabolism
3.
Biol Proced Online ; 21: 13, 2019.
Article in English | MEDLINE | ID: mdl-31303867

ABSTRACT

BACKGROUND: For analysis of the tumor microenvironment in diffuse large B-cell lymphoma (DLBCL) tissue samples, it is desirable to obtain information about counts and distribution of different macrophage subtypes. Until now, macrophage counts are mostly inferred from gene expression analysis of whole tissue sections, providing only indirect information. Direct analysis of immunohistochemically (IHC) fluorescence stained tissue samples is confronted with several difficulties, e.g. high variability of shape and size of target macrophages and strongly inhomogeneous intensity of staining. Consequently, application of commercial software is largely restricted to very rough analysis modes, and most macrophage counts are still obtained by manual counting in microarrays or high power fields, thus failing to represent the heterogeneity of tumor microenvironment adequately. METHODS: We describe a Rudin-Osher-Fatemi (ROF) filter based segmentation approach for whole tissue samples, combining floating intensity thresholding and rule-based feature detection. Method is validated against manual counts and compared with two commercial software kits (Tissue Studio 64, Definiens AG, and Halo, Indica Labs) and a straightforward machine-learning approach in a set of 50 test images. Further, the novel method and both commercial packages are applied to a set of 44 whole tissue sections. Outputs are compared with gene expression data available for the same tissue samples. Finally, the ROF based method is applied to 44 expert-specified tumor subregions for testing selection and subsampling strategies. RESULTS: Among all tested methods, the novel approach is best correlated with manual count (0.9297). Automated detection of evaluation subregions proved to be fully reliable. Comparison with gene expression data obtained for the same tissue samples reveals only moderate to low correlation levels. Subsampling within tumor subregions is possible with results almost identical to full sampling. Mean macrophage size in tumor subregions is 152.5±111.3 µm2. CONCLUSIONS: ROF based approach is successfully applied to detection of IHC stained macrophages in DLBCL tissue samples. The method competes well with existing commercial software kits. In difference to them, it is fully automated, externally repeatable, independent on training data and completely documented. Comparison with gene expression data indicates that image morphometry constitutes an independent source of information about antibody-polarized macrophage occurence and distribution.

4.
BMC Ophthalmol ; 13: 59, 2013 Oct 20.
Article in English | MEDLINE | ID: mdl-24138794

ABSTRACT

BACKGROUND: Quantitative evaluation of mosaics of photoreceptors and neurons is essential in studies on development, aging and degeneration of the retina. Manual counting of samples is a time consuming procedure while attempts to automatization are subject to various restrictions from biological and preparation variability leading to both over- and underestimation of cell numbers. Here we present an adaptive algorithm to overcome many of these problems.Digital micrographs were obtained from cone photoreceptor mosaics visualized by anti-opsin immuno-cytochemistry in retinal wholemounts from a variety of mammalian species including primates. Segmentation of photoreceptors (from background, debris, blood vessels, other cell types) was performed by a procedure based on Rudin-Osher-Fatemi total variation (TV) denoising. Once 3 parameters are manually adjusted based on a sample, similarly structured images can be batch processed. The module is implemented in MATLAB and fully documented online. RESULTS: The object recognition procedure was tested on samples with a typical range of signal and background variations. We obtained results with error ratios of less than 10% in 16 of 18 samples and a mean error of less than 6% compared to manual counts. CONCLUSIONS: The presented method provides a traceable module for automated acquisition of retinal cell density data. Remaining errors, including addition of background items, splitting or merging of objects might be further reduced by introduction of additional parameters. The module may be integrated into extended environments with features such as 3D-acquisition and recognition.


Subject(s)
Algorithms , Artificial Intelligence , Image Interpretation, Computer-Assisted/methods , Pattern Recognition, Automated/methods , Photoreceptor Cells, Vertebrate/cytology , Retinoscopy/methods , Animals , Mammals
5.
JACC Basic Transl Sci ; 8(9): 1198-1211, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37791314

ABSTRACT

Variants in the gene myosin-binding protein C3 (MYBPC3) account for approximately 50% of familial hypertrophic cardiomyopathy (HCM), leading to reduced levels of myosin-binding protein C3 (MyBP-C), the protein product made by gene MYBPC3. Elucidation of the pathways that regulate MyBP-C protein homeostasis could uncover new therapeutic strategies. Toward this goal, we screened a library of 2,426 bioactive compounds and identified JG98, an allosteric modulator of heat shock protein 70 that inhibits interaction with Bcl-2-associated athanogene (BAG) domain co-chaperones. JG98 reduces MyBP-C protein levels. Furthermore, genetic reduction of BAG3 phenocopies treatment with JG-98 by reducing MYBP-C protein levels.. Thus, an unbiased compound screen identified the heat shock protein 70-BAG3 complex as a regulator of MyBP-C stability.

6.
Redox Biol ; 67: 102909, 2023 11.
Article in English | MEDLINE | ID: mdl-37801856

ABSTRACT

Few therapies have produced significant improvement in cardiac structure and function after ischemic cardiac injury (ICI). Our possible explanation is activation of local inflammatory responses negatively impact the cardiac repair process following ischemic injury. Factors that can alter immune response, including significantly altered cytokine levels in plasma and polarization of macrophages and T cells towards a pro-reparative phenotype in the myocardium post-MI is a valid strategy for reducing infarct size and damage after myocardial injury. Our previous studies showed that cortical bone stem cells (CBSCs) possess reparative effects after ICI. In our current study, we have identified that the beneficial effects of CBSCs appear to be mediated by miRNA in their extracellular vesicles (CBSC-EV). Our studies showed that CBSC-EV treated animals demonstrated reduced scar size, attenuated structural remodeling, and improved cardiac function versus saline treated animals. These effects were linked to the alteration of immune response, with significantly altered cytokine levels in plasma, and polarization of macrophages and T cells towards a pro-reparative phenotype in the myocardium post-MI. Our detailed in vitro studies demonstrated that CBSC-EV are enriched in miR-182/183 that mediates the pro-reparative polarization and metabolic reprogramming in macrophages, including enhanced OXPHOS rate and reduced ROS, via Ras p21 protein activator 1 (RASA1) axis under Lipopolysaccharides (LPS) stimulation. In summary, CBSC-EV deliver unique molecular cargoes, such as enriched miR-182/183, that modulate the immune response after ICI by regulating macrophage polarization and metabolic reprogramming to enhance repair.


Subject(s)
Heart Injuries , MicroRNAs , Myocardial Infarction , Animals , Mice , Myocardium/metabolism , Myocardial Infarction/genetics , Macrophages/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Cytokines/metabolism , GTPase-Activating Proteins/metabolism , Oxidation-Reduction , Mice, Inbred C57BL
7.
J Clin Med ; 12(5)2023 Feb 25.
Article in English | MEDLINE | ID: mdl-36902631

ABSTRACT

(1) Background: The treatment of proximal humeral fractures (PHFs) is debated controversially. Current clinical knowledge is mainly based on small single-center cohorts. The goal of this study was to evaluate the predictability of risk factors for complications after the treatment of a PHF in a large clinical cohort in a multicentric setting. (2) Methods: Clinical data of 4019 patients with PHFs were retrospectively collected from 9 participating hospitals. Risk factors for local complications of the affected shoulder were assessed using bi- and multivariate analyses. (3) Results: Fracture complexity with n = 3 or more fragments, cigarette smoking, age over 65 years, and female sex were identified as predictable individual risk factors for local complications after surgical therapy as well as the combination of female sex and smoking and the combination of age 65 years or older and ASA class 2 or higher. (4) Conclusion: Humeral head preserving reconstructive surgical therapy should critically be evaluated for patients with the risk factors abovementioned.

8.
Seizure ; 85: 1-5, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33360039

ABSTRACT

OBJECTIVE: It has been debated for decades whether single, self-limited seizures damage cerebral cells. Meanwhile, very sensitive measurements of biomarkers have become available, i.e. tau, neurofilament protein light (NFL), glial fibrillary acidic protein (GFAP) and ubiquitin carboxyterminate hydrolase L1 (UCHL-1), which we explored in this study. METHODS: Adult patients of the epilepsy monitoring unit were admitted to the study after written consent. Blood samples were drawn at baseline, immediately after a TCS and after two, six and 24 h. The markers were measured from frozen samples with a single-molecule array (SIMOA). RESULTS: 20 patients and 20 seizures were included. All markers showed subtle but significant postictal increases and returned to normal within the next few hours (p < 0.05). An increase of at least 100 % from baseline was noted in 30 % of patients for tau, 25 % for UCHL-1 and 15 % for GFAP, while NFL levels never increased above 100 %. Lactate was slightly correlated with the tau increase (r = 0.47, p = 0.037), leukocytes were correlated with postictal changes of GFAP (r = 0.68 p = 0.001). CONCLUSION: Our data supports the assumption that significant cerebral stress occurs in some but not all self-limited TCS. The postictal inflammatory response in particular seems to play an important role.


Subject(s)
Seizures , Adult , Biomarkers , Glial Fibrillary Acidic Protein , Humans
9.
Stem Cells Transl Med ; 10(1): 144-156, 2021 01 01.
Article in English | MEDLINE | ID: mdl-32964621

ABSTRACT

Cellular replacement in the heart is restricted to postnatal stages with the adult heart largely postmitotic. Studies show that loss of regenerative properties in cardiac cells seems to coincide with alterations in metabolism during postnatal development and maturation. Nevertheless, whether changes in cellular metabolism are linked to functional alternations in cardiac cells is not well studied. We report here a novel role for uncoupling protein 2 (UCP2) in regulation of functional properties in cardiac tissue derived stem-like cells (CTSCs). CTSC were isolated from C57BL/6 mice aged 2 days (nCTSC), 2 month (CTSC), and 2 years old (aCTSC), subjected to bulk-RNA sequencing that identifies unique transcriptome significantly different between CTSC populations from young and old heart. Moreover, results show that UCP2 is highly expressed in CTSCs from the neonatal heart and is linked to maintenance of glycolysis, proliferation, and survival. With age, UCP2 is reduced shifting energy metabolism to oxidative phosphorylation inversely affecting cellular proliferation and survival in aged CTSCs. Loss of UCP2 in neonatal CTSCs reduces extracellular acidification rate and glycolysis together with reduced cellular proliferation and survival. Mechanistically, UCP2 silencing is linked to significant alteration of mitochondrial genes together with cell cycle and survival signaling pathways as identified by RNA-sequencing and STRING bioinformatic analysis. Hence, our study shows UCP2-mediated metabolic profile regulates functional properties of cardiac cells during transition from neonatal to aging cardiac states.


Subject(s)
Glycolysis , Heart , Animals , Glycolysis/genetics , Mice , Mice, Inbred C57BL , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Signal Transduction , Uncoupling Protein 2/genetics , Uncoupling Protein 2/metabolism
10.
Front Immunol ; 11: 639, 2020.
Article in English | MEDLINE | ID: mdl-32328072

ABSTRACT

Cardiovascular Disease (CVD) is a leading cause of mortality within the United States. Current treatments being administered to patients who suffered a myocardial infarction (MI) have increased patient survival, but do not facilitate the replacement of damaged myocardium. Recent studies demonstrate that stem cell-based therapies promote myocardial repair; however, the poor engraftment of the transferred stem cell populations within the infarcted myocardium is a major limitation, regardless of the cell type. One explanation for poor cell retention is attributed to the harsh inflammatory response mounted following MI. The inflammatory response coupled to cardiac repair processes is divided into two distinct phases. The first phase is initiated during ischemic injury when necrosed myocardium releases Danger Associated Molecular Patterns (DAMPs) and chemokines/cytokines to induce the activation and recruitment of neutrophils and pro-inflammatory M1 macrophages (MΦs); in turn, facilitating necrotic tissue clearance. During the second phase, a shift from the M1 inflammatory functional phenotype to the M2 anti-inflammatory and pro-reparative functional phenotype, permits the resolution of inflammation and the establishment of tissue repair. T-regulatory cells (Tregs) are also influential in mediating the establishment of the pro-reparative phase by directly regulating M1 to M2 MΦ differentiation. Current studies suggest CD4+ T-lymphocyte populations become activated when presented with autoantigens released from the injured myocardium. The identity of the cardiac autoantigens or paracrine signaling molecules released from the ischemic tissue that directly mediate the phenotypic plasticity of T-lymphocyte populations in the post-MI heart are just beginning to be elucidated. Stem cells are enriched centers that contain a diverse paracrine secretome that can directly regulate responses within neighboring cell populations. Previous studies identify that stem cell mediated paracrine signaling can influence the phenotype and function of immune cell populations in vitro, but how stem cells directly mediate the inflammatory microenvironment of the ischemic heart is poorly characterized and is a topic of extensive investigation. In this review, we summarize the complex literature that details the inflammatory microenvironment of the ischemic heart and provide novel insights regarding how paracrine mediated signaling produced by stem cell-based therapies can regulate immune cell subsets to facilitate pro-reparative myocardial wound healing.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Cardiovascular Diseases/therapy , Inflammation/immunology , Macrophages/immunology , Stem Cell Transplantation , Autoimmunity , Cardiovascular Diseases/immunology , Cellular Microenvironment , Immunomodulation , Th1-Th2 Balance , Wound Healing
11.
Epilepsy Res ; 162: 106301, 2020 05.
Article in English | MEDLINE | ID: mdl-32126476

ABSTRACT

PURPOSE: Neuroinflammation and disruption of blood brain barrier (BBB) are important players in epileptogenesis, ictogenesis and pharmacoresistance. In this context, we investigated blood levels of HMGB1 and other inflammatory and BBB markers after generalized and focal to bilateral tonic-clonic seizures in serum, summarized under the term generalized convulsive seizures (GCS). METHODS: We included consenting adults who were admitted to the epilepsy monitoring unit. Blood samples were drawn at baseline and immediately after a GCS as well as after 2, 6 and 24 h. We measured leukocytes, c-reactive protein (CRP), the danger-associated molecular patterns (DAMPs) high mobility group box 1 (HMGB1) and S100, receptor of advanced glycation end products (RAGE) alongside the BBB markers intercellular adhesion molecule-1 (ICAM1) and matrix metalloproteinase 9 (MMP9). Noradrenaline and lactate measurements were available from a previous study. P-levels <0.05 were regarded as significant. RESULTS: Twenty-eight patients with 28 GCS were included. Leukocytosis occurred immediately after GCS and normalized within two hours (p < 0.001). S100 and HMGB1 both increased by ∼80 % (p < 0.001). MMP9 peaked after six hours with levels at 48.6 % above baseline. RAGE decreased by 17.6 % with a nadir at 24 h. CRP increased by 118 % with a peak at 24 h. ICAM1 remained stable (p = 0.068). Postictal HMGB1 correlated with postictal leukocytosis (r = 0.42; p = 0.025) and with MMP9 levels six hours later (r = 0.374; p = 0.05). Postictal lactate levels correlated with MMP9 at 6 h (r = 0.48; p = 0.01) and CRP at 24 h (r = 0.39; p = 0.04). Postictal noradrenaline correlated with lactate (r = 0.57; p = 0.02) and leukocytes (r = 0.39; p = 0.047). DISCUSSION: The serum level of the DAMPs HMGB1 and S100 increase immediately after GCS. The hypothetical mechanism includes central nervous processes, such as glutamate toxicity and ROS release from seizing neurons but also muscular tissues. BBB breakdown is marked by the release of MMP9. Further research is needed to understand the complex interactions between electrical and metabolic stress, neuroinflammation and BBB mechanics in seizures and epilepsy. CONCLUSION: Our study reveals signs of inflammation, neuronal damage and transitory disruption of BBB following single GCS, underscoring the widespread and possibily detrimental effects of recurrent seizures on brain properties. The long term impact on the disease course, however, is unclear.


Subject(s)
Epilepsy, Generalized/blood , HMGB1 Protein/blood , Intercellular Adhesion Molecule-1/blood , Matrix Metalloproteinase 9/blood , Seizures/blood , Adolescent , Adult , Aged , Biomarkers/blood , Blood-Brain Barrier/metabolism , Epilepsy, Generalized/complications , Female , Humans , Leukocytosis/blood , Leukocytosis/etiology , Male , Middle Aged , Seizures/complications , Time Factors , Young Adult
12.
Gigascience ; 9(3)2020 03 01.
Article in English | MEDLINE | ID: mdl-32161948

ABSTRACT

BACKGROUND: We present an image dataset related to automated segmentation and counting of macrophages in diffuse large B-cell lymphoma (DLBCL) tissue sections. For the classification of DLBCL subtypes, as well as for providing a prognosis of the clinical outcome, the analysis of the tumor microenvironment and, particularly, of the different types and functions of tumor-associated macrophages is indispensable. Until now, however, most information about macrophages has been obtained either in a completely indirect way by gene expression profiling or by manual counts in immunohistochemically (IHC) fluorescence-stained tissue samples while automated recognition of single IHC stained macrophages remains a difficult task. In an accompanying publication, a reliable approach to this problem has been established, and a large set of related images has been generated and analyzed. RESULTS: Provided image data comprise (i) fluorescence microscopy images of 44 multiple immunohistostained DLBCL tumor subregions, captured at 4 channels corresponding to CD14, CD163, Pax5, and DAPI; (ii) "cartoon-like" total variation-filtered versions of these images, generated by Rudin-Osher-Fatemi denoising; (iii) an automatically generated mask of the evaluation subregion, based on information from the DAPI channel; and (iv) automatically generated segmentation masks for macrophages (using information from CD14 and CD163 channels), B-cells (using information from Pax5 channel), and all cell nuclei (using information from DAPI channel). CONCLUSIONS: A large set of IHC stained DLBCL specimens is provided together with segmentation masks for different cell populations generated by a reference method for automated image analysis, thus featuring considerable reuse potential.


Subject(s)
Fluorescent Antibody Technique/methods , Image Interpretation, Computer-Assisted/methods , Lymphoma, Large B-Cell, Diffuse/pathology , Macrophages/pathology , Antigens, CD/metabolism , Antigens, Differentiation, Myelomonocytic/metabolism , Datasets as Topic , Fluorescent Antibody Technique/standards , Image Interpretation, Computer-Assisted/standards , Lipopolysaccharide Receptors/metabolism , Lymphoma, Large B-Cell, Diffuse/classification , Macrophages/metabolism , PAX5 Transcription Factor/metabolism , Receptors, Cell Surface/metabolism
13.
Int J Numer Method Biomed Eng ; 35(11): e3249, 2019 11.
Article in English | MEDLINE | ID: mdl-31400057

ABSTRACT

Finite element (FE)-based studies of preoperative processes such as folding, pleating, and stent crimping with a comparison with experimental inflation tests are not yet available. Therefore, a novel workflow is presented in which residual stresses of balloon folding and pleating, as well as stent crimping, and the geometries of all contact partners were ultimately implemented in an FE code to simulate stent expansion by using an implicit solver. The numerical results demonstrate that the incorporation of residual stresses and strains experienced during the production step significantly increased the accuracy of the subsequent simulations, especially of the stent expansion model. During the preoperative processes, stresses inside the membrane and the stent material also reached a rather high level. Hence, there can be no presumption that balloon catheters or stents are undamaged before the actual surgery. The implementation of the realistic geometry, in particular the balloon tapers, and the blades of the process devices improved the simulation of the expansion mechanisms, such as dogboning, concave bending, or overexpansion of stent cells. This study shows that implicit solvers are able to precisely simulate the mentioned preoperative processes and the stent expansion procedure without a preceding manipulation of the simulation time or physical mass.


Subject(s)
Stents , Catheterization/methods , Elastic Modulus , Finite Element Analysis , Prosthesis Design , Tensile Strength , X-Ray Microtomography
14.
Int J Radiat Oncol Biol Phys ; 70(5): 1492-501, 2008 Apr 01.
Article in English | MEDLINE | ID: mdl-18374228

ABSTRACT

PURPOSE: To determine the impact of prostate motion on dose coverage in proton therapy. METHODS AND MATERIALS: A total of 120 prostate positions were analyzed on 10 treatment plans for 10 prostate patients treated using our low-risk proton therapy prostate protocol (University of Florida Proton Therapy Institute 001). Computed tomography and magnetic resonance imaging T(2)-weighted turbo spin-echo scans were registered for all cases. The planning target volume included the prostate with a 5-mm axial and 8-mm superoinferior expansion. The prostate was repositioned using 5- and 10-mm one-dimensional vectors and 10-mm multidimensional vectors (Points A-D). The beam was realigned for the 5- and 10-mm displacements. The prescription dose was 78 Gy equivalent (GE). RESULTS: The mean percentage of rectum receiving 70 Gy (V(70)) was 7.9%, the bladder V(70) was 14.0%, and the femoral head/neck V(50) was 0.1%, and the mean pelvic dose was 4.6 GE. The percentage of prostate receiving 78 Gy (V(78)) with the 5-mm movements changed by -0.2% (range, 0.006-0.5%, p > 0.7). However, the prostate V(78) after a 10-mm displacement changed significantly (p < 0.003) with different movements: 3.4% (superior), -5.6% (inferior), and -10.2% (posterior). The corresponding minimal doses were also reduced: 4.5 GE, -4.7 GE, and -11.7 GE (p < or = 0.003). For displacement points A-D, the clinical target volume V(78) coverage had a large and significant reduction of 17.4% (range, 13.5-17.4%, p < 0.001) in V(78) coverage of the clinical target volume. The minimal prostate dose was reduced 33% (25.8 GE), on average, for Points A-D. The prostate minimal dose improved from 69.3 GE to 78.2 GE (p < 0.001) with realignment for 10-mm movements. CONCLUSION: The good dose coverage and low normal doses achieved for the initial plan was maintained with movements of < or = 5 mm. Beam realignment improved coverage for 10-mm displacements.


Subject(s)
Movement , Prostate , Prostatic Neoplasms/radiotherapy , Proton Therapy , Aged , Aged, 80 and over , Femur , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Pelvis , Prostate/diagnostic imaging , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/pathology , Radiotherapy Dosage , Rectum , Tomography, X-Ray Computed , Tumor Burden , Urinary Bladder
15.
Int J Radiat Oncol Biol Phys ; 71(5): 1322-8, 2008 Aug 01.
Article in English | MEDLINE | ID: mdl-18472365

ABSTRACT

PURPOSE: To determine the target coverage for proton therapy with and without image guidance and daily prebeam reorientation. METHODS AND MATERIALS: A total of 207 prostate positions were analyzed for 9 prostate cancer patients treated using our low-risk prostate proton therapy protocol (University of Florida Proton Therapy Institute 001). The planning target volume was defined as the prostate plus a 5-mm axial and 8-mm superoinferior extension. The prostate was repositioned using 5- and 10-mm shifts (anteriorly, inferiorly, posteriorly, and superiorly) and for Points A-D using a combination of 10-mm multidimensional movements (anteriorly or inferiorly; posteriorly or superiorly; and left or right). The beams were then realigned using the new prostate position. The prescription dose was 78 Gray equivalent (GE) to 95% of the planning target volume. RESULTS: For small movements in the anterior, inferior, and posterior directions within the planning target volume (< or =5 mm), treatment realignment demonstrated small, but significant, improvements in the clinical target volume (CTV) coverage to the prescribed dose (78 GE). The anterior and posterior shifts also significantly increased the minimal CTV dose (Delta +1.59 GE). For prostate 10-mm movements in the inferior, posterior, and superior directions, the beam realignment produced larger and significant improvements for both the CTV V(78) (Delta +6.4%) and the CTV minimal dose (Delta +8.22 GE). For the compounded 10-mm multidimensional shifts, realignment significantly improved the CTV V(78) (Delta +11.8%) and CTV minimal dose (Delta +23.6 GE). After realignment, the CTV minimal dose was >76.6 GE (>98%) for all points (A-D). CONCLUSION: Proton beam realignment after target shift will enhance CTV coverage for different prostate positions.


Subject(s)
Movement , Prostate , Prostatic Neoplasms/radiotherapy , Proton Therapy , Radiotherapy Planning, Computer-Assisted , Feasibility Studies , Humans , Male , Prostate/pathology , Prostatic Neoplasms/pathology , Radiotherapy Dosage , Tumor Burden
16.
J Biomed Opt ; 22(2): 25004, 2017 02 01.
Article in English | MEDLINE | ID: mdl-28301657

ABSTRACT

A novel method for the automated detection of the outer choroid boundary within spectral-domain optical coherence tomography image data, based on an image model within the space of functions of bounded variation and the application of quadratic measure filters, is presented. The same method is used for the segmentation of retinal layer boundaries and proves to be suitable even for data generated without special imaging modes and moderate line averaging. Based on the segmentations, an automated determination of the central fovea region and choroidal thickness measurements for this and two adjacent 1-mm regions are provided. The quality of the method is assessed by comparison with manual delineations performed by five trained graders. The study is based on data from 50 children of the ages 8 to 13 that were obtained in the framework of the LIFE Child study at Leipzig University.


Subject(s)
Eye/diagnostic imaging , Tomography, Optical Coherence , Adolescent , Child , Choroid/diagnostic imaging , Fovea Centralis/diagnostic imaging , Humans , Retina/diagnostic imaging
17.
Radiat Oncol ; 7: 219, 2012 Dec 21.
Article in English | MEDLINE | ID: mdl-23256610

ABSTRACT

BACKGROUND: The utility of definitive radiotherapy (RT) for locoregionally advanced squamous cell carcinoma (SCC) of the larynx or hypopharynx in the setting of thyroid or cricoid cartilage invasion (TCCI) is controversial. A retrospective review of our experience was performed. METHODS: Our institutional database of patients with SCC of the head and neck treated with radiotherapy (90% received concurrent systemic therapy) between 1995 and 2009 was queried. We identified 87 patients with T3-4 laryngeal or T4 hypopharyngeal cancer for whom initial head and neck imaging was available for review. Imaging of all patients was reviewed by a single radiologist specializing in neuroradiology. The presence and extent of TCCI was determined and used for stratification. RESULTS: Median follow-up was 34 months. TCCI was found in 25 (29%) patients, eight limited to the inner cortex and another 17 involving both cortices. Local control (LC) was not significantly affected by TCCI limited to the inner cortex. However, TCCI involving both cortices was correlated with diminished LC at 2 years compared to the group of patients with no or minor invasion (55% vs. 81%, p=0.045). However, TCCI involving both cortices was not associated with significantly reduced rates of survival with a functional larynx, or overall survival (OS). CONCLUSIONS: Our results suggest that the rate of LC of T3-4 laryngeal or T4 hypopharyngeal SCC treated with definitive RT is not affected by TCCI of the inner cortex. Although decreased LC was significantly associated with TCCI involving both cortices, this factor did not appear to result in reduced rates of survival with a functional larynx or OS. Therefore, organ preservation may remain an option in these patients.


Subject(s)
Carcinoma, Squamous Cell/pathology , Cricoid Cartilage/pathology , Head and Neck Neoplasms/pathology , Hypopharyngeal Neoplasms/pathology , Laryngeal Neoplasms/pathology , Thyroid Cartilage/pathology , Thyroid Neoplasms/secondary , Adult , Aged , Aged, 80 and over , Carcinoma, Squamous Cell/mortality , Carcinoma, Squamous Cell/radiotherapy , Databases, Factual , Female , Head and Neck Neoplasms/mortality , Head and Neck Neoplasms/radiotherapy , Humans , Hypopharyngeal Neoplasms/mortality , Hypopharyngeal Neoplasms/radiotherapy , Laryngeal Neoplasms/mortality , Laryngeal Neoplasms/radiotherapy , Male , Middle Aged , Prognosis , Retrospective Studies , Squamous Cell Carcinoma of Head and Neck , Thyroid Neoplasms/mortality , Tomography, X-Ray Computed/methods , Treatment Outcome
18.
Am J Clin Oncol ; 31(1): 43-8, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18376227

ABSTRACT

OBJECTIVE: Outcomes after radiotherapy for head and neck mucosal melanoma (MMHN). METHODS: From 1974 to 2005, 17 patients with primary MMHN were treated with radiotherapy. Primary sites included nasal cavity, paranasal sinuses, and oral cavity or oropharynx. Thirteen patients received surgery and postoperative radiotherapy; 4 received definitive radiotherapy. RESULTS: Local control was 79% at 1 and 5 years for 13 of 13 patients treated with surgery and postoperative radiotherapy compared with 1 of 4 patients treated with definitive radiotherapy. Three patients recurred in the neck; 13 patients developed distant metastases. Disease-free survival was 23% at 1 year and 18% at 5 years. Absolute and cause-specific survivals were identical (53% and 28% at 1 and 5 years). CONCLUSION: Locoregional control is relatively high after surgery and adjuvant radiotherapy, but most patients recur in distant sites; approximately one fourth of patients are cured at 5 years. Patients with unresectable tumor may be controlled with definitive radiotherapy.


Subject(s)
Head and Neck Neoplasms/radiotherapy , Melanoma/radiotherapy , Mucous Membrane/radiation effects , Neoplasm Recurrence, Local/diagnosis , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Head and Neck Neoplasms/pathology , Head and Neck Neoplasms/surgery , Humans , Male , Melanoma/pathology , Melanoma/surgery , Middle Aged , Mucous Membrane/pathology , Prognosis , Radiotherapy Dosage , Radiotherapy, Adjuvant , Survival Rate
19.
J Environ Manage ; 76(2): 105-18, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15939122

ABSTRACT

This paper discusses the relationship between environmental and economic performance and the influence of corporate strategies with regard to sustainability and the environment. After formulating a theoretical model, results are reported from an empirical analysis of the European paper manufacturing industry. New data are used to test hypotheses derived from the theoretical model, using environmental performance indices representing different corporate environmental strategy orientations. In particular, an emissions-based index largely reflecting end-of-pipe strategies and an inputs-based index reflecting integrated pollution prevention are distinguished. For the emissions-based index, a predominantly negative relationship between environmental and economic performance is found, whereas for the inputs-based index no significant link is found. This is consistent with the theoretical model, which predicts the possibility of different relationships. The results also show that for firms with pollution prevention-oriented corporate environmental strategies, the relationship between environmental and economic performance is more positive, thus making improvements in corporate sustainability more likely. Based on this last insight, managerial implications of this are discussed with regard to strategy choices, investment decisions and operations management.


Subject(s)
Conservation of Natural Resources/economics , Environmental Pollution/economics , Environmental Pollution/prevention & control , Industry/economics , Decision Making , Europe , Humans , Models, Theoretical , Organizational Policy , Paper
20.
J Acoust Soc Am ; 113(1): 313-9, 2003 Jan.
Article in English | MEDLINE | ID: mdl-12558270

ABSTRACT

This paper addresses the efficient solution of acoustic problems in which the primary interest is obtaining the solution only on restricted portions of the domain but over a wide range of frequencies. The exterior acoustics boundary value problem is approximated using the finite element method in combination with the Dirichlet-to-Neumann (DtN) map. The restriction domain problem is formally posed in transfer function form based on the finite element solution. In order to obtain the solution over a range of frequencies, a matrix-valued Padé approximation of the transfer function is employed, using a two-sided block Lanczos algorithm. This approach provides a stable and efficient representation of the Padé approximation. In order to apply the algorithm, it is necessary to reformulate the transfer function due to the frequency dependency in the nonreflecting boundary condition. This is illustrated for the case of the DtN boundary condition, but there is no restriction on the approach which can also be applied to other radiation boundary conditions. Numerical tests confirm that the approach offers significant computational speed-up.

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