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Pham A, Greer MD, Mitchell M, Li A, Stamm A, Salazar M, Hsi R. Long-Term Effectiveness of a Nonsurgical BPH Treatment System in Prostate Radiation Patients with Medication-Refractory Lower Urinary Tract Symptoms. Int J Radiat Oncol Biol Phys 2023; 117:e428. [PMID: 37785399 DOI: 10.1016/j.ijrobp.2023.06.1590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) To evaluate the long-term outcomes and toxicity of a nonsurgical prostatic urethral lift system in patients with prior prostate cancer radiation therapy (RT). MATERIALS/METHODS From 2018 to 2020, nineteen patients with a history of prior prostate RT underwent a nonsurgical prostatic urethral lift (PUL) procedure for lower urinary track symptoms (LUTS) refractory to alpha blocker medications. Prostate cancer RT was completed a median of 17.8 months (IQR 13.4-27.4) prior to PUL procedure. All patients were assessed with IPSS/quality of life (QOL) scores and urinary post void residual (PVR) ultrasound before and after PUL. Patients were also assessed for ability to discontinue alpha blockade medications for their LUTS and any post PUL toxicity based on CTCAE v5.0 criteria. RESULTS All patients underwent successful placement of the PUL implants. Median pre-PUL IPSS score was 20 (IOR 17.5-22.5) and the median prostate volume was 41cc (IQR 33-49). Median follow up was 22 months (IQR 5-30). The average improvement in IPSS score was 8.5 points (IRQ 5.5-11) at 3 months and 7.5 points (IQR 6-10) at last follow-up. Two patients (10%) initially had improvement in IPSS score at 3 months with subsequent significant increase in IPSS (>5 points) at last follow-up. Overall, there was minimal change in reported QOL scores (median 0, IQR 0-1.75). The average reduction in PVR was 90cc. The percentage of patients able to discontinue alpha blockade at last follow-up was 68%. There was no grade 3 or higher GU toxicity in either group. CONCLUSION Use of a nonsurgical prostatic urethral lift system in patients with prior prostate RT refractory to alpha blocker medications results in significant long-term improvement of LUTS after radiation therapy for the majority of patients with minimal toxicity.
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Affiliation(s)
- A Pham
- University of Washington, Department of Radiation Oncology, Seattle, WA
| | - M D Greer
- Department of Radiation Oncology, University of Arizona Cancer Center, Tucson, AZ
| | | | - A Li
- The Doctors Clinic, Silverdale, WA
| | - A Stamm
- The Doctors Clinic, Silverdale, WA
| | - M Salazar
- Evergreen Health Urology, Kirkland, WA
| | - R Hsi
- University of Washington, Department of Radiation Oncology, Seattle, WA
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2
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Ballante E, Bellanger L, Drouin P, Figini S, Stamm A. Smoothing method for unit quaternion time series in a classification problem: an application to motion data. Sci Rep 2023; 13:9366. [PMID: 37296200 DOI: 10.1038/s41598-023-36480-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 06/04/2023] [Indexed: 06/12/2023] Open
Abstract
Smoothing orientation data is a fundamental task in different fields of research. Different methods of smoothing time series in quaternion algebras have been described in the literature, but their application is still an open point. This paper develops a smoothing approach for smoothing quaternion time series to obtain good performance in classification problems. Starting from an existing method which involves an angular velocity transformation of unit quaternion time series, a new method which employ the logarithm function to transform the quaternion time series to a real three-dimensional time series is proposed. Empirical evidences achieved on real data set and artificially noisy data sets confirm the effectiveness of the proposed method compared with the classical approach based on angular velocity transformation. The R functions developed for this paper will be provided in a Github repository.
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Affiliation(s)
- Elena Ballante
- Department of Political and Social Sciences, University of Pavia, Pavia, Italy.
- BioData Science Unit, IRCCS Mondino Foundation, Pavia, Italy.
| | - Lise Bellanger
- Department of Mathematics Jean Leray, UMR CNRS 6629, Nantes University, 44322, Nantes, France
| | - Pierre Drouin
- Department of Mathematics Jean Leray, UMR CNRS 6629, Nantes University, 44322, Nantes, France
- Department of Research and Development, UmanIT, Nantes, France
| | - Silvia Figini
- Department of Political and Social Sciences, University of Pavia, Pavia, Italy
| | - Aymeric Stamm
- Department of Mathematics Jean Leray, UMR CNRS 6629, Nantes University, 44322, Nantes, France
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3
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Drouin P, Stamm A, Chevreuil L, Graillot V, Barbin L, Gourraud PA, Laplaud DA, Bellanger L. Semi-supervised clustering of quaternion time series: Application to gait analysis in multiple sclerosis using motion sensor data. Stat Med 2023; 42:433-456. [PMID: 36509423 PMCID: PMC10108058 DOI: 10.1002/sim.9625] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 09/02/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022]
Abstract
Recent approaches in gait analysis involve the use of wearable motion sensors to extract spatio-temporal parameters that characterize multiple aspects of an individual's gait. In particular, the medical community could largely benefit from this type of devices as they could provide the clinicians with a valuable tool for assessing gait impairment. Motion sensor data are however complex and there is an urgent unmet need to develop sound statistical methods for analyzing such data and extracting clinically relevant information. In this article, we measure gait by following the hip rotation over time and the resulting statistical unit is a time series of unit quaternions. We explore the possibility to form groups of patients with similar walking impairment by taking into account their walking data and their global decease severity with semi-supervised clustering. We generalize a compromise-based method named hclustcompro to unit quaternion time series by combining it with the proper dissimilarity quaternion dynamic time warping. We apply this method on patients diagnosed with multiple sclerosis to form groups of patients with similar walking deficiencies while accounting for the clinical assessment of their overall disability. We also compare the compromise-based clustering approach with the method mergeTrees that falls into a sub-class of ensemble clustering named collaborative clustering. The results provide a first proof of both the interest of using wearable motion sensors for assessing gait impairment and the use of prior knowledge to guide the clustering process. It also demonstrates that compromise-based clustering is a more appropriate approach in this context.
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Affiliation(s)
- Pierre Drouin
- Laboratoire de Mathématiques Jean Leray, Université de Nantes, Nantes, France.,UmanIT, Nantes, France
| | - Aymeric Stamm
- Laboratoire de Mathématiques Jean Leray, Université de Nantes, Nantes, France
| | | | | | - Laetitia Barbin
- CRTI-Inserm U1064, CIC, Service de Neurologie, CHU et Université de Nantes, Nantes, France
| | - Pierre-Antoine Gourraud
- Centre de Recherche en Transplantation et Immunologie, UMR 1064, ATIP-Avenir, Université de Nantes, CHU de Nantes, INSERM, Nantes, France
| | - David-Axel Laplaud
- CRTI-Inserm U1064, CIC, Service de Neurologie, CHU et Université de Nantes, Nantes, France
| | - Lise Bellanger
- Laboratoire de Mathématiques Jean Leray, Université de Nantes, Nantes, France
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Abramowicz K, Pini A, Schelin L, de Luna SS, Stamm A, Vantini S. Domain selection and family-wise error rate for functional data: a unified framework. Biometrics 2022. [PMID: 35352337 DOI: 10.1111/biom.13669] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/23/2022] [Indexed: 11/26/2022]
Abstract
Functional data are smooth, often continuous, random curves, which can be seen as an extreme case of multivariate data with infinite dimensionality. Just as component-wise inference for multivariate data naturally performs feature selection, subset-wise inference for functional data performs domain selection. In this paper, we present a unified testing framework for domain selection on populations of functional data. In detail, p-values of hypothesis tests performed on point-wise evaluations of functional data are suitably adjusted for providing a control of the family-wise error rate (FWER) over a family of subsets of the domain. We show that several state-of-the-art domain selection methods fit within this framework and differ from each other by the choice of the family over which the control of the FWER is provided. In the existing literature, these families are always defined a priori. In this work, we also propose a novel approach, coined threshold-wise testing, in which the family of subsets is instead built in a data-driven fashion. The method seamlessly generalizes to multidimensional domains in contrast to methods based on a-priori defined families. We provide theoretical results with respect to consistency and control of the FWER for the methods within the unified framework. We illustrate the performance of the methods within the unified framework on simulated and real data examples, and compare their performance with other existing methods. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Konrad Abramowicz
- Department of Mathematics and Mathematical Statistics, Umeå University, Umeå, Sweden
| | - Alessia Pini
- Department of Statistical Sciences, Università Cattolica del Sacro Cuore, Milan, Italy
| | - Lina Schelin
- Department of Statistics, Umeå School of Business, Economics and Statistics, UmeåUniversity, Umeå, Sweden
| | - Sara Sjöstedt de Luna
- Department of Mathematics and Mathematical Statistics, Umeå University, Umeå, Sweden
| | - Aymeric Stamm
- Department of Mathematics Jean Leray, UMR CNRS 6629, Nantes University, Nantes, France
| | - Simone Vantini
- MOX - Modelling and Scientific Computing Laboratory, Department of Mathematics, Politecnico di Milano, Milan, Italy
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5
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Lovato I, Pini A, Stamm A, Taquet M, Vantini S. Multiscale null hypothesis testing for network‐valued data: Analysis of brain networks of patients with autism. J R Stat Soc Ser C Appl Stat 2021. [DOI: 10.1111/rssc.12463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ilenia Lovato
- Department of Mathematics Università di Pavia Pavia MI Italy
| | - Alessia Pini
- Department of Statistical Sciences Università Cattolica del Sacro Cuore Milan MI Italy
| | - Aymeric Stamm
- Laboratoire de Mathématiques Jean Leray, CNRS UMR 6629 Nantes Pays de la Loire France
| | - Maxime Taquet
- Department of Psychiatry University of Oxford Oxford UK
| | - Simone Vantini
- Department of Mathematics Politecnico di Milano Milan MI Italy
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6
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Bizzi A, Pascuzzo R, Blevins J, Moscatelli MEM, Grisoli M, Lodi R, Doniselli FM, Castelli G, Cohen ML, Stamm A, Schonberger LB, Appleby BS, Gambetti P. Subtype Diagnosis of Sporadic Creutzfeldt-Jakob Disease with Diffusion Magnetic Resonance Imaging. Ann Neurol 2020; 89:560-572. [PMID: 33274461 PMCID: PMC7986086 DOI: 10.1002/ana.25983] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 11/26/2020] [Accepted: 11/29/2020] [Indexed: 12/12/2022]
Abstract
Objective Sporadic Creutzfeldt–Jakob disease (sCJD) comprises several subtypes as defined by genetic and prion protein characteristics, which are associated with distinct clinical and pathological phenotypes. To date, no clinical test can reliably diagnose the subtype. We established two procedures for the antemortem diagnosis of sCJD subtype using diffusion magnetic resonance imaging (MRI). Methods MRI of 1,458 patients referred to the National Prion Disease Pathology Surveillance Center were collected through its consultation service. One neuroradiologist blind to the diagnosis scored 12 brain regions and generated a lesion profile for each MRI scan. We selected 487 patients with autopsy‐confirmed diagnosis of “pure” sCJD subtype and at least one positive diffusion MRI examination. We designed and tested two data‐driven procedures for subtype diagnosis: the first procedure—prion subtype classification algorithm with MRI (PriSCA_MRI)—uses only MRI examinations; the second—PriSCA_MRI + Gen—includes knowledge of the prion protein codon 129 genotype, a major determinant of sCJD subtypes. Both procedures were tested on the first MRI and the last MRI follow‐up. Results PriSCA_MRI classified the 3 most prevalent subtypes with 82% accuracy. PriSCA_MRI + Gen raised the accuracy to 89% and identified all subtypes. Individually, the 2 most prevalent sCJD subtypes, MM1 and VV2, were diagnosed with sensitivities up to 95 and 97%, respectively. The performances of both procedures did not change in 168 patients with longitudinal MRI studies when the last examination was used. Interpretation This study provides the first practical algorithms for antemortem diagnosis of sCJD subtypes. MRI diagnosis of subtype is likely to be attainable at early disease stages to prognosticate clinical course and design future therapeutic trials. ANN NEUROL 2021;89:560–572
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Affiliation(s)
- Alberto Bizzi
- Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Riccardo Pascuzzo
- Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Janis Blevins
- National Prion Disease Pathology Surveillance Center, Case Western Reserve University, School of Medicine, Cleveland, OH
| | - Marco E M Moscatelli
- Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Marina Grisoli
- Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Raffaele Lodi
- Dipartimento di Scienze Biomediche e Neuromotorie, Università di Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Fabio M Doniselli
- Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Gianmarco Castelli
- Neuroradiology Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Mark L Cohen
- National Prion Disease Pathology Surveillance Center, Case Western Reserve University, School of Medicine, Cleveland, OH.,Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH.,Department of Neurology, University Hospitals Cleveland Medical Center, Case Western Reserve University, Cleveland, OH
| | - Aymeric Stamm
- Department of Mathematics Jean Leray, CNRS (National Center for Scientific Research), Nantes, France
| | - Lawrence B Schonberger
- National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, GA
| | - Brian S Appleby
- National Prion Disease Pathology Surveillance Center, Case Western Reserve University, School of Medicine, Cleveland, OH.,Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH.,Department of Neurology, University Hospitals Cleveland Medical Center, Case Western Reserve University, Cleveland, OH.,Department of Psychiatry, University Hospitals Cleveland Medical Center, Case Western Reserve University, Cleveland, OH
| | - Pierluigi Gambetti
- Department of Pathology, Case Western Reserve University, School of Medicine, Cleveland, OH
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7
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Fatima M, Maué D, Pérez C, Tikhonov DS, Bernhard D, Stamm A, Medcraft C, Gerhards M, Schnell M. Structures and internal dynamics of diphenylether and its aggregates with water. Phys Chem Chem Phys 2020; 22:27966-27978. [DOI: 10.1039/d0cp04104a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
We report on a detailed multi-spectroscopic analysis of the structures and internal dynamics of diphenylether and its aggregates with up to three water molecules by employing molecular beam experiments.
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Affiliation(s)
- M. Fatima
- Deutsches Elektronen-Synchrotron (DESY)
- D-22607 Hamburg
- Germany
- Institute of Physical Chemistry
- Christian-Albrechts-Universität zu Kiel
| | - D. Maué
- TU Kaiserslautern
- Fachbereich Chemie & Research Center Optimas
- D-67663 Kaiserslautern
- Germany
| | - C. Pérez
- Deutsches Elektronen-Synchrotron (DESY)
- D-22607 Hamburg
- Germany
- Institute of Physical Chemistry
- Christian-Albrechts-Universität zu Kiel
| | - D. S. Tikhonov
- Deutsches Elektronen-Synchrotron (DESY)
- D-22607 Hamburg
- Germany
- Institute of Physical Chemistry
- Christian-Albrechts-Universität zu Kiel
| | - D. Bernhard
- TU Kaiserslautern
- Fachbereich Chemie & Research Center Optimas
- D-67663 Kaiserslautern
- Germany
| | - A. Stamm
- TU Kaiserslautern
- Fachbereich Chemie & Research Center Optimas
- D-67663 Kaiserslautern
- Germany
| | - C. Medcraft
- Deutsches Elektronen-Synchrotron (DESY)
- D-22607 Hamburg
- Germany
- Institute of Physical Chemistry
- Christian-Albrechts-Universität zu Kiel
| | - M. Gerhards
- TU Kaiserslautern
- Fachbereich Chemie & Research Center Optimas
- D-67663 Kaiserslautern
- Germany
| | - M. Schnell
- Deutsches Elektronen-Synchrotron (DESY)
- D-22607 Hamburg
- Germany
- Institute of Physical Chemistry
- Christian-Albrechts-Universität zu Kiel
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8
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Baumer FM, Peters JM, Clancy S, Prohl AK, Prabhu SP, Scherrer B, Jansen FE, Braun KPJ, Sahin M, Stamm A, Warfield SK. Corpus Callosum White Matter Diffusivity Reflects Cumulative Neurological Comorbidity in Tuberous Sclerosis Complex. Cereb Cortex 2019; 28:3665-3672. [PMID: 29939236 DOI: 10.1093/cercor/bhx247] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Indexed: 02/02/2023] Open
Abstract
INTRODUCTION Neurological manifestations in Tuberous Sclerosis Complex (TSC) are highly variable. Diffusion tensor imaging (DTI) may reflect the neurological disease burden. We analyzed the association of autism spectrum disorder (ASD), intellectual disability (ID) and epilepsy with callosal DTI metrics in subjects with and without TSC. METHODS 186 children underwent 3T MRI DTI: 51 with TSC (19 with concurrent ASD), 46 with non-syndromic ASD and 89 healthy controls (HC). Subgroups were based on presence of TSC, ASD, ID, and epilepsy. Density-weighted DTI metrics obtained from tractography of the corpus callosum were fitted using a 2-parameter growth model. We estimated distributions using bootstrapping and calculated half-life and asymptote of the fitted curves. RESULTS TSC was associated with a lower callosal fractional anisotropy (FA) than ASD, and ASD with a lower FA than HC. ID, epilepsy and ASD diagnosis were each associated with lower FA values, demonstrating additive effects. In TSC, the largest change in FA was related to a comorbid diagnosis of ASD. Mean diffusivity (MD) showed an inverse relationship to FA. Some subgroups were too small for reliable data fitting. CONCLUSIONS Using a cross-disorder approach, this study demonstrates cumulative abnormality of callosal white matter diffusion with increasing neurological comorbidity.
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Affiliation(s)
- Fiona M Baumer
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Jurriaan M Peters
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.,Computational Radiology Laboratory, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.,Brain Center Rudolf Magnus, Department of Pediatric Neurology, University Medical Center Utrecht, The Netherlands
| | - Sean Clancy
- Computational Radiology Laboratory, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.,Department of Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Anna K Prohl
- Computational Radiology Laboratory, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.,Department of Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Sanjay P Prabhu
- Computational Radiology Laboratory, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.,Department of Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Benoit Scherrer
- Computational Radiology Laboratory, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.,Department of Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Floor E Jansen
- Brain Center Rudolf Magnus, Department of Pediatric Neurology, University Medical Center Utrecht, The Netherlands
| | - Kees P J Braun
- Brain Center Rudolf Magnus, Department of Pediatric Neurology, University Medical Center Utrecht, The Netherlands
| | - Mustafa Sahin
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Aymeric Stamm
- Computational Radiology Laboratory, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.,Department of Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.,Laboratory for Modeling and Scientific Computing (MOX), Dipartimento di Matematica, Politecnico di Milano, Italy
| | - Simon K Warfield
- Computational Radiology Laboratory, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.,Department of Radiology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
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10
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Velasco-Annis C, Akhondi-Asl A, Stamm A, Warfield SK. Reproducibility of Brain MRI Segmentation Algorithms: Empirical Comparison of Local MAP PSTAPLE, FreeSurfer, and FSL-FIRST. J Neuroimaging 2017; 28:162-172. [PMID: 29134725 DOI: 10.1111/jon.12483] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 10/06/2017] [Accepted: 10/16/2017] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Segmentation of human brain structures is crucial for the volumetric quantification of brain disease. Advances in algorithmic approaches have led to automated techniques that save time compared to interactive methods. Recently, the utility and accuracy of template library fusion algorithms, such as Local MAP PSTAPLE (PSTAPLE), have been demonstrated but there is little guidance regarding its reproducibility compared to single template-based algorithms such as FreeSurfer and FSL-FIRST. METHODS Eight repeated magnetic resonance imagings of 20 subjects were segmented using FreeSurfer, FSL-FIRST, and PSTAPLE. We reported the reproducibility of segmentation-derived volume measurements for brain structures and calculated sample size estimates for detecting hypothetical rates of tissue atrophy given the observed variances. RESULTS PSTAPLE had the most reproducible volume measurements for hippocampus, putamen, thalamus, caudate, pallidum, amygdala, Accumbens area, and cortical regions. FreeSurfer was most reproducible for brainstem. PSTAPLE was the most accurate algorithm in terms of several metrics include Dice's coefficient. The sample size estimates showed that a study utilizing PSTAPLE would require tens to hundreds less subjects than the other algorithms for detecting atrophy rates typically observed in brain disease. CONCLUSIONS PSTAPLE is a useful tool for automatic human brain segmentation due to its precision and accuracy, which enable the detection of the size of the effect typically reported for neurological disorders with a substantially reduced sample size, in comparison to the other tools we assessed. This enables randomized controlled trials to be executed with reduced cost and duration, in turn, facilitating the assessment of new therapeutic interventions.
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Affiliation(s)
- Clemente Velasco-Annis
- Computational Radiology Laboratory, Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA
| | - Alireza Akhondi-Asl
- Computational Radiology Laboratory, Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA
| | - Aymeric Stamm
- Computational Radiology Laboratory, Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA
| | - Simon K Warfield
- Computational Radiology Laboratory, Department of Radiology, Boston Children's Hospital, and Harvard Medical School, Boston, MA
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11
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Stamm A, Maué D, Schaly A, Schlicher S, Bartl J, Kubik S, Gerhards M. Structural analyses of isolated cyclic tetrapeptides with varying amino acid residues. Phys Chem Chem Phys 2017; 19:10718-10726. [DOI: 10.1039/c6cp08696a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Structural analyses of isolated cyclic tetrapeptides with varying amino acid residues were performed by applying combined IR/UV spectroscopy in the molecular beam and DFT calculations. The intrinsic structural properties especially with regard to the influence of different amino acid residues are fundamental for optimizing their binding ability.
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Affiliation(s)
- A. Stamm
- TU Kaiserslautern
- Fachbereich Chemie & Research Center Optimas
- Physikalische Chemie
- D-67663 Kaiserslautern
- Germany
| | - D. Maué
- TU Kaiserslautern
- Fachbereich Chemie & Research Center Optimas
- Physikalische Chemie
- D-67663 Kaiserslautern
- Germany
| | - A. Schaly
- TU Kaiserslautern
- Fachbereich Chemie
- Organische Chemie
- D-67663 Kaiserslautern
- Germany
| | - S. Schlicher
- TU Kaiserslautern
- Fachbereich Chemie
- Organische Chemie
- D-67663 Kaiserslautern
- Germany
| | - J. Bartl
- TU Kaiserslautern
- Fachbereich Chemie
- Organische Chemie
- D-67663 Kaiserslautern
- Germany
| | - S. Kubik
- TU Kaiserslautern
- Fachbereich Chemie
- Organische Chemie
- D-67663 Kaiserslautern
- Germany
| | - M. Gerhards
- TU Kaiserslautern
- Fachbereich Chemie & Research Center Optimas
- Physikalische Chemie
- D-67663 Kaiserslautern
- Germany
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12
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Stamm A, Scheper T, Pepelanova I. Produktion und Analyse epidermaler Lipoxygenasen mittels biotechnologischer Methoden. CHEM-ING-TECH 2016. [DOI: 10.1002/cite.201650079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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13
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Stamm A, Bernhard D, Gerhards M. Structural investigations on a linear isolated depsipeptide: the importance of dispersion interactions. Phys Chem Chem Phys 2016; 18:15327-36. [DOI: 10.1039/c6cp01675h] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The first molecular beam investigations of an isolated linear depsipeptide are presented. By applying IR/UV spectroscopic methods and DFT calculations three structural arrangements are identified with the most stable structure being only stable by including dispersion interactions.
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Affiliation(s)
- A. Stamm
- TU Kaiserslautern, Fachbereich Chemie & Research Center Optimas
- D-67663 Kaiserslautern
- Germany
| | - D. Bernhard
- TU Kaiserslautern, Fachbereich Chemie & Research Center Optimas
- D-67663 Kaiserslautern
- Germany
| | - M. Gerhards
- TU Kaiserslautern, Fachbereich Chemie & Research Center Optimas
- D-67663 Kaiserslautern
- Germany
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Peters JM, Prohl AK, Tomas-Fernandez XK, Taquet M, Scherrer B, Prabhu SP, Lidov HG, Singh JM, Jansen FE, Braun KPJ, Sahin M, Warfield SK, Stamm A. Tubers are neither static nor discrete: Evidence from serial diffusion tensor imaging. Neurology 2015; 85:1536-45. [PMID: 26432846 DOI: 10.1212/wnl.0000000000002055] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 05/18/2015] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To assess the extent and evolution of tissue abnormality of tubers, perituber tissue, and normal-appearing white matter (NAWM) in patients with tuberous sclerosis complex using serial diffusion tensor imaging. METHODS We applied automatic segmentation based on a combined global-local intensity mixture model of 3T structural and 35 direction diffusion tensor MRIs (diffusion tensor imaging) to define 3 regions: tuber tissue, an equal volume perituber rim, and the remaining NAWM. For each patient, scan, lobe, and tissue type, we analyzed the averages of mean diffusivity (MD) and fractional anisotropy (FA) in a generalized additive mixed model. RESULTS Twenty-five patients (mean age 5.9 years; range 0.5-24.5 years) underwent 2 to 6 scans each, totaling 70 scans. Average time between scans was 1.2 years (range 0.4-2.9). Patient scans were compared with those of 73 healthy controls. FA values were lowest, and MD values were highest in tubers, next in perituber tissue, then in NAWM. Longitudinal analysis showed a positive (FA) and negative (MD) correlation with age in tubers, perituber tissue, and NAWM. All 3 tissue types followed a biexponential developmental trajectory, similar to the white matter of controls. An additional qualitative analysis showed a gradual transition of diffusion values across the tissue type boundaries. CONCLUSIONS Similar to NAWM, tuber and perituber tissues in tuberous sclerosis complex undergo microstructural evolution with age. The extent of diffusion abnormality decreases with distance to the tuber, in line with known extension of histologic, immunohistochemical, and molecular abnormalities beyond tuber pathology.
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Affiliation(s)
- Jurriaan M Peters
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
| | - Anna K Prohl
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
| | - Xavier K Tomas-Fernandez
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
| | - Maxime Taquet
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
| | - Benoit Scherrer
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
| | - Sanjay P Prabhu
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
| | - Hart G Lidov
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
| | - Jolene M Singh
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
| | - Floor E Jansen
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
| | - Kees P J Braun
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
| | - Mustafa Sahin
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
| | - Simon K Warfield
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands.
| | - Aymeric Stamm
- From the Division of Epilepsy and Clinical Neurophysiology, Department of Neurology (J.M.P., M.S.), Computational Radiology Laboratory, Department of Radiology (J.M.P., A.K.P., X.K.T.-F., M.T., B.S., S.P.P., J.M.S., S.K.W., A.S.), and Department of Pathology (H.G.L.), Boston Children's Hospital and Harvard Medical School, MA; ICTEAM Institute (M.T.), Université catholique de Louvain, Louvain-la-Neuve, Belgium; and Brain Center Rudolf Magnus (F.E.J., K.P.J.B.), Department of Pediatric Neurology, University Medical Center Utrecht, the Netherlands
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Pujol S, Wells W, Pierpaoli C, Brun C, Gee J, Cheng G, Vemuri B, Commowick O, Prima S, Stamm A, Goubran M, Khan A, Peters T, Neher P, Maier-Hein KH, Shi Y, Tristan-Vega A, Veni G, Whitaker R, Styner M, Westin CF, Gouttard S, Norton I, Chauvin L, Mamata H, Gerig G, Nabavi A, Golby A, Kikinis R. The DTI Challenge: Toward Standardized Evaluation of Diffusion Tensor Imaging Tractography for Neurosurgery. J Neuroimaging 2015; 25:875-82. [PMID: 26259925 DOI: 10.1111/jon.12283] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 06/23/2015] [Accepted: 06/24/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE Diffusion tensor imaging (DTI) tractography reconstruction of white matter pathways can help guide brain tumor resection. However, DTI tracts are complex mathematical objects and the validity of tractography-derived information in clinical settings has yet to be fully established. To address this issue, we initiated the DTI Challenge, an international working group of clinicians and scientists whose goal was to provide standardized evaluation of tractography methods for neurosurgery. The purpose of this empirical study was to evaluate different tractography techniques in the first DTI Challenge workshop. METHODS Eight international teams from leading institutions reconstructed the pyramidal tract in four neurosurgical cases presenting with a glioma near the motor cortex. Tractography methods included deterministic, probabilistic, filtered, and global approaches. Standardized evaluation of the tracts consisted in the qualitative review of the pyramidal pathways by a panel of neurosurgeons and DTI experts and the quantitative evaluation of the degree of agreement among methods. RESULTS The evaluation of tractography reconstructions showed a great interalgorithm variability. Although most methods found projections of the pyramidal tract from the medial portion of the motor strip, only a few algorithms could trace the lateral projections from the hand, face, and tongue area. In addition, the structure of disagreement among methods was similar across hemispheres despite the anatomical distortions caused by pathological tissues. CONCLUSIONS The DTI Challenge provides a benchmark for the standardized evaluation of tractography methods on neurosurgical data. This study suggests that there are still limitations to the clinical use of tractography for neurosurgical decision making.
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Affiliation(s)
- Sonia Pujol
- Surgical Planning Laboratory, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - William Wells
- Surgical Planning Laboratory, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Carlo Pierpaoli
- Program on Pediatric Imaging and Tissue Sciences, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda
| | - Caroline Brun
- Penn Image Computing and Science Laboratory, Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - James Gee
- Penn Image Computing and Science Laboratory, Department of Radiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia
| | - Guang Cheng
- Department of Computer and Information Science and Engineering, University of Florida, Gainesville
| | - Baba Vemuri
- Department of Computer and Information Science and Engineering, University of Florida, Gainesville
| | - Olivier Commowick
- University of Rennes I, VISAGES INSERM - U746 CNRS UMR6074 - INRIA, Rennes, France
| | - Sylvain Prima
- University of Rennes I, VISAGES INSERM - U746 CNRS UMR6074 - INRIA, Rennes, France
| | - Aymeric Stamm
- University of Rennes I, VISAGES INSERM - U746 CNRS UMR6074 - INRIA, Rennes, France
| | - Maged Goubran
- Imaging Laboratories, Robarts Research Institute, Western University, London, ON, Canada
| | - Ali Khan
- Imaging Laboratories, Robarts Research Institute, Western University, London, ON, Canada
| | - Terry Peters
- Imaging Laboratories, Robarts Research Institute, Western University, London, ON, Canada
| | - Peter Neher
- Junior Group Medical Image Computing, Division of Medical and Biological Informatics, German Cancer Research Center, Heidelberg, Germany
| | - Klaus H Maier-Hein
- Junior Group Medical Image Computing, Division of Medical and Biological Informatics, German Cancer Research Center, Heidelberg, Germany
| | - Yundi Shi
- Department of Psychiatry and Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Antonio Tristan-Vega
- Department of Mechanical Engineering, Universidad de Valladolid, Valladolid, Spain
| | - Gopalkrishna Veni
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT
| | - Ross Whitaker
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT
| | - Martin Styner
- Department of Psychiatry and Computer Science, University of North Carolina at Chapel Hill, Chapel Hill, NC
| | - Carl-Fredrik Westin
- Laboratory of Mathematics in Imaging, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Sylvain Gouttard
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT
| | - Isaiah Norton
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Laurent Chauvin
- Surgical Navigation and Robotics Laboratory, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Hatsuho Mamata
- Surgical Planning Laboratory, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Guido Gerig
- Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT
| | - Arya Nabavi
- International Neuroscience Institute (INI), Hannover, Germany
| | - Alexandra Golby
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
| | - Ron Kikinis
- Surgical Planning Laboratory, Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA
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Stamm A, Schwing K, Gerhards M. Investigation of the hydrated 7-hydroxy-4-methylcoumarin dimer by combined IR/UV spectroscopy. J Chem Phys 2014; 141:194304. [DOI: 10.1063/1.4900893] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- A. Stamm
- TU Kaiserslautern, Fachbereich Chemie and Research Center Optimas, Erwin-Schroedinger-Straße 52, D-67663 Kaiserslautern, Germany
| | - K. Schwing
- TU Kaiserslautern, Fachbereich Chemie and Research Center Optimas, Erwin-Schroedinger-Straße 52, D-67663 Kaiserslautern, Germany
| | - M. Gerhards
- TU Kaiserslautern, Fachbereich Chemie and Research Center Optimas, Erwin-Schroedinger-Straße 52, D-67663 Kaiserslautern, Germany
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Stamm A, Weiler M, Brächer A, Schwing K, Gerhards M. A combined IR/IR and IR/UV spectroscopy study on the proton transfer coordinate of isolated 3-hydroxychromone in the electronic ground and excited state. Phys Chem Chem Phys 2014; 16:21795-803. [DOI: 10.1039/c4cp02546f] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Raoult H, Eugène F, Ferré JC, Gentric JC, Ronzière T, Stamm A, Gauvrit JY. Prognostic factors for outcomes after mechanical thrombectomy with solitaire stent. J Neuroradiol 2013; 40:252-9. [DOI: 10.1016/j.neurad.2013.04.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2012] [Revised: 03/27/2013] [Accepted: 04/04/2013] [Indexed: 10/26/2022]
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Esquevin A, Raoult H, Ferré JC, Ronzière T, Stamm A, Perennes M, Bellou A, Gauvrit JY. Systematic combined noncontrast CT-CT angiography in the management of unexplained nontraumatic coma. Am J Emerg Med 2013; 31:494-8. [PMID: 23347713 DOI: 10.1016/j.ajem.2012.09.024] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Revised: 09/20/2012] [Accepted: 09/20/2012] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Nontraumatic impaired consciousness is a common issue in emergency departments with a serious but widely variable prognosis. STUDY OBJECTIVES The aim of this prospective study was to evaluate the ability of systematic combined noncontrast computed tomography (NCCT)/computed tomography angiography (CTA) imaging, firstly to provide a neurologic prognosis and secondly to ensure early detection of basilar artery occlusion (BAO), in unexplained nontraumatic impaired consciousness management. METHODS Combined NCCT/CTA imaging was performed on 65 patients with impaired consciousness and no history of trauma prospectively over 14 months in a single center. Images were assessed based on visual and quantitative criteria. Clinical outcome was assessed using the modified Rankin Scale at 3 months. Statistical analysis aimed to identify the prognostic value of combined NCCT/CTA imaging and its ability for early BAO detection. RESULTS This study shows that combined NCCT/CTA imaging was a significant predictor of poor neurological outcome, with a positive predictive value of 94.6%. The combination was also crucial for early detection of BAO, given that 42.8% of cases were misdiagnosed with NCCT alone. Basilar artery occlusion represented 10.8% of all unexplained nontraumatic impaired consciousness. CONCLUSIONS Systematic combined NCCT/CTA imaging is an efficient tool for predicting poor neurologic prognosis in cases of unexplained nontraumatic impaired consciousness and is also essential for detecting BAO.
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Affiliation(s)
- Aurore Esquevin
- University Hospital, Department of Neuroradiology, 2 rue H. Le Guillou, Hôpital Pontchaillou, CHU Rennes, 35000 Rennes, France
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Secchi P, Stamm A, Vantini S. Inference for the mean of large $p$ small $n$ data: A finite-sample high-dimensional generalization of Hotelling’s theorem. Electron J Stat 2013. [DOI: 10.1214/13-ejs833] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Raoult H, Ferré JC, Petr J, Bannier E, Stamm A, Barillot C, Gauvrit JY. Functional arterial spin labeling: Optimal sequence duration for motor activation mapping in clinical practice. J Magn Reson Imaging 2012; 36:1435-44. [PMID: 22926803 DOI: 10.1002/jmri.23782] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 07/20/2012] [Indexed: 11/05/2022] Open
Abstract
PURPOSE To determine the minimal optimal functional arterial spin labeling (fASL) sequence duration allowing steady and reproducible motor activation mapping. MATERIALS AND METHODS Three magnetic resonance imaging (MRI) sessions including fASL and blood oxygenation level-dependent (BOLD) functional MRI (fMRI) sequences were performed on 12 healthy subjects at 3T with a 32-channel coil. The raw 7-minute fASL sequence was truncated to obtain six fASL sequences with durations ranging from 1-6 minutes. All the resulting fASL activations were compared between themselves and with both the 7-minute fASL and BOLD activations. Quantitative parameters assessed activation location (activated volume, barycenter, and distance between barycenters), activation quantification (activation-related cerebral blood flow), and intraindividual reproducibility across fMRI sessions. The statistical analysis was based on analysis of variance (ANOVA) and Tukey's multiple comparisons. RESULTS Four-minute fASL achieved steady location and quantification of activation with the activated volume corresponding to 81% of the 7-minute fASL volume and a barycenter located 1.2 mm from the 7-minute fASL barycenter and 3.0 mm from the BOLD fMRI barycenter. Four-minute fASL reproducibility was high and statistically equivalent to 7-minute values. CONCLUSION A 4-minute fASL sequence is thus a reliable tool for motor activation mapping and suitable for use in clinical practice.
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Affiliation(s)
- Hélène Raoult
- CHU Rennes, Department of Neuroradiology, Rennes, France.
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Gurfein B, Stamm A, Bacchetti P, Dallman M, Nadkarni N, Milush J, Touma C, Palme R, Pozzo Di Borgo C, Fromentin G, Lown-Hecht R, Konsman J, Acree M, Premenko-Lanier M, Darcel N, Hecht F, Nixon D. P01.43. The calm mouse: an animal model of stress reduction. Altern Ther Health Med 2012. [PMCID: PMC3373842 DOI: 10.1186/1472-6882-12-s1-p43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Lu H, Liu X, Burton JD, Bark CW, Wang Y, Zhang Y, Kim DJ, Stamm A, Lukashev P, Felker DA, Folkman CM, Gao P, Rzchowski MS, Pan XQ, Eom CB, Tsymbal EY, Gruverman A. Enhancement of ferroelectric polarization stability by interface engineering. Adv Mater 2012; 24:1209-1216. [PMID: 22278910 DOI: 10.1002/adma.201104398] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 12/23/2011] [Indexed: 05/31/2023]
Abstract
By using theoretical predictions based on first-principle calculations, we explore an interface engineering approach to stabilize polarization states in ferroelectric heterostructures with a thickness of just several nanometers.
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Affiliation(s)
- H Lu
- Department of Physics and Astronomy, Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, NE 68588, USA
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Commowick O, Stamm A. Non-local robust detection of DTI white matter differences with small databases. Med Image Comput Comput Assist Interv 2012; 15:476-84. [PMID: 23286165 DOI: 10.1007/978-3-642-33454-2_59] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Diffusion imaging, through the study of water diffusion, allows for the characterization of brain white matter, both at the population and individual level. In recent years, it has been employed to detect brain abnormalities in patients suffering from a disease, e.g., from multiple sclerosis (MS). State-of-the-art methods usually utilize a database of matched (age, sex, ...) controls, registered onto a template, to test for differences in the patient white matter. Such approaches however suffer from two main drawbacks. First, registration algorithms are prone to local errors, thereby degrading the comparison results. Second, the database needs to be large enough to obtain reliable results. However, in medical imaging, such large databases are hardly available. In this paper, we propose a new method that addresses these two issues. It relies on the search for samples in a local neighborhood of each pixel to increase the size of the database. Then, we propose a new test based on these samples to perform a voxelwise comparison of a patient image with respect to a population of controls. We demonstrate on simulated and real MS patient data how such a framework allows for an improve detection power and a better robustness and reproducibility, even with a small database.
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Affiliation(s)
- Olivier Commowick
- VISAGES: INSERM U746, CNRS UMR6074, INRIA, Univ. of Rennes I, France.
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Raoult H, Petr J, Bannier E, Stamm A, Gauvrit JY, Barillot C, Ferré JC. Arterial spin labeling for motor activation mapping at 3T with a 32-channel coil: Reproducibility and spatial accuracy in comparison with BOLD fMRI. Neuroimage 2011; 58:157-67. [DOI: 10.1016/j.neuroimage.2011.06.011] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2011] [Revised: 04/19/2011] [Accepted: 06/06/2011] [Indexed: 10/18/2022] Open
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Heverhagen T, Stamm A, Knopp MV, Schmalbrock P. Time-of-Flight und Phase Contrast Magnetresonanzangiographie der intrazerebralen Arterien im Ultrahochfeld. ROFO-FORTSCHR RONTG 2009. [DOI: 10.1055/s-0029-1221751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Paris L, Stamm A. Optimal Massing Liquid Volume Determination by Energy Consumption Measurement: Study of the Influence of Some Physical Properties of Solvents and Products Used. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639048509056876] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Wehrlé P, Nobelis P, Cuiné A, Stamm A. Response Surface Methodology: an Interesting Statistical Tool for Process Optimization and Validation: Example of Wet Granulation in a High-Shear Mixer. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639049309069333] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Wehrlé P, Palmieri GF, Stamm A. The Taguchi's Performance Statistic to Optimize Theophylline Beads Production in a High-Speed Granulator. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639049409042683] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Stamm A, Paris L. Influence of Technological Factors on the Optimal Granulation Liquid Requirement Measured by Power Consumption. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639048509056875] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Goldbach P, Brochart H, Stamm A. Spray-Drying of Liposomes for a Pulmonary Administration. II. Retention of Encapsulated Materials. Drug Dev Ind Pharm 2008. [DOI: 10.3109/03639049309047205] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Tita A, Owen J, Stamm A, Hauth J, Andrews W. 228: Impact of extended-spectrum antibiotic prophylaxis on incidence of post-cesarean surgical wound infection. Am J Obstet Gynecol 2007. [DOI: 10.1016/j.ajog.2007.10.242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Altenhöner T, Stamm A, Zeeb H, Piepenbrock H, Zapf O. Effekte eines physiotherapeutisch geleiteten Sportunterrichts in der Grundschule - Analyse ausgewählter Parameter der Dehnfähigkeit und Koordination. physioscience 2007. [DOI: 10.1055/s-2007-962886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Andrews W, Schelonka R, Cliver S, Lyon M, Waites K, Moser S, Stamm A. Genital tract colonization with methicillin-resistant staphylococcus aureus (MRSA) is not associated with a high risk for early-onset invasive neonatal infection. Am J Obstet Gynecol 2006. [DOI: 10.1016/j.ajog.2006.10.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Rücker M, Schäfer T, Stamm A, Saueressig K, Vollmar B, Spitzer WJ, Menger MD. New model for in vivo quantification of microvascular embolization, thrombus formation, and recanalization in composite flaps. J Surg Res 2002; 108:129-37. [PMID: 12443725 DOI: 10.1006/jsre.2002.6531] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Microthrombi are suggested to be involved in the pathogenesis of composite flap failure. Due to the lack of appropriate experimental models, however, the significance of microvascular thrombus formation and microthromboembolization in free flap failure remains poorly understood. The purpose of this study was therefore to develop a rat hindlimb model that allows tissue-confined in vivo analysis of thrombus formation, thromboembolization, and recanalization within the microcirculation of osteomyocutaneous flaps using intravital fluorescence microscopy. MATERIALS AND METHODS Thrombus formation was induced photochemically in individual arterioles and venules of muscle, subcutis, and periosteum. To study thromboembolization, autologous arterial thrombi (40 microm) were preformed in vitro and were injected into the femoral artery supplying the osteomyocutaneous flap. RESULTS First platelet deposition was found independent from microvascular red blood cell velocity, while the subsequent growth of thrombus correlated inversely with red blood cell flow measured in the respective microvessel. Time required for complete thrombotic arteriolar occlusion exceeded 700 s, whereas thrombus growth in venules was found to be significantly accelerated ( approximately 300 s) without differences between the individual tissues analyzed. The embolization resulted in a complete shutdown of capillary perfusion in muscle, subcutis, skin, and periosteum. During subsequent spontaneous recanalization, capillary perfusion increased in all tissues to approximately half of baseline, however, without further recovery during the 4-h postembolization period. CONCLUSIONS The model presented is suitable to quantitatively study the pathophysiology of microvascular thrombus formation, thromboembolization, and recanalization in composite flaps, and may thus be used to evaluate the effectiveness of novel therapeutic strategies to prevent flap failure.
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Affiliation(s)
- M Rücker
- Institute for Clinical and Experimental Surgery, University of Saarland, D-66421, Homburg/Saar, Germany.
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Michaelis J, Schüz J, Meinert R, Menger M, Grigat JP, Kaatsch P, Kaletsch U, Miesner A, Stamm A, Brinkmann K, Kärner H. Childhood leukemia and electromagnetic fields: results of a population-based case-control study in Germany. Cancer Causes Control 1997; 8:167-74. [PMID: 9134240 DOI: 10.1023/a:1018464012055] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The investigation of an association between increased exposure to residential extremely-low frequency electromagnetic fields (ELF-EMF) and childhood leukemia was part of a population-based case-control study carried out between 1992 and 1995 in the northwestern part of Germany. A total of 129 children with leukemia and 328 controls participated in the EMF-study. Exposure assessment comprised measurements of the magnetic field over 24 hours in the child's bedroom at the residence where the child had been living for the longest period before the date of diagnosis, and spot measurements at all residences where the child had been living for more than one year. The median of the 24h-measurement in the child's bedroom was regarded as the most valid exposure variable. For children exposed to more than 0.2 microT, an elevated but not significant odds ratio (OR) was observed (OR = 3.2, 95 percent confidence interval = 0.7-14.9). These figures are based on only four leukemia cases and three controls since only 1.5 percent of the study population was classified as highly exposed. Exploratory analyses revealed ORs that were not statistically significantly increased for other characteristics of the magnetic field at varying cut-points. The results are comparable with those from other studies. Although not statistically significant, they may indicate a positive association between EMF and childhood leukemia.
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Affiliation(s)
- J Michaelis
- Institut für Medizinische Statistik und Dokumentation, Johannes-Gutenberg-University, Mainz, Germany
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Goldbach P, Dumont S, Kessler R, Poindron P, Stamm A. In situ activation of mouse alveolar macrophages by aerosolized liposomal IFN-gamma and muramyl tripeptide. Am J Physiol 1996; 270:L429-34. [PMID: 8638735 DOI: 10.1152/ajplung.1996.270.3.l429] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Interferon-gamma (IFN-gamma) was entrapped with an efficiency of 30-40% in muramyl tripeptide-containing liposomes by a freeze-thawing procedure. A microcytotoxicity assay was developed to measure the tumoricidal activity of mouse alveolar macrophages (AM) against tumoral target cells with a colorimetric viability test. Free IFN-gamma and liposomal muramyl tripeptide phosphatidylethanolamine (MTP-PE) were found to be only slightly effective to activate in vitro AM, whereas encapsulation of both INF-gamma and MTP-PE within the same liposomes produced higher activation of AM. Aerosolized IFN-gamma and liposomal immunomodulators enhanced antitumor properties of AM recovered in mice 24 h postinhalation. Whereas free IFN-gamma also induced a substantial activation of peritoneal macrophages, liposomal encapsulation significantly reduced the systemic activity of inhaled immunomodulators. This approach provides a useful model for the compartmentalized organ-specific activation of AM in mice.
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Affiliation(s)
- P Goldbach
- Laboratoire de Pharmacotechnie, Université Louis Pasteur, Strasbourg, France
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Bury M, Gerhards J, Erni W, Stamm A. Application of a new method based on conductivity measurements to determine the creaming stability of o/w emulsions. Int J Pharm 1995. [DOI: 10.1016/0378-5173(95)00075-t] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Abstract
Incubation of human peripheral blood cultures in the presence of an electromagnetic field (EMF) of 50 Hz and 5 mT leads to stimulation of the cell cycle of dividing lymphocytes but has no influence on the frequencies of sister-chromatid exchanges. Comparative studies with two different exposure systems and with different culture temperatures indicate that the effect on the cell cycle results from the EMF and is not a thermal effect. These data support the assumption that with respect to their suspected carcinogenic effects EMFs have no initiating but probably promoting effects.
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Löscher W, Wahnschaffe U, Mevissen M, Lerchl A, Stamm A. Effects of weak alternating magnetic fields on nocturnal melatonin production and mammary carcinogenesis in rats. Oncology 1994; 51:288-95. [PMID: 8196914 DOI: 10.1159/000227352] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Since extremely low frequency (i.e., 50- or 60-Hz) magnetic fields (MFs) from overhead power lines and other electromagnetic sources are ubiquitous in modern societies, the possible carcinogenic effect of such fields recently suggested by epidemiological studies has engendered much concern. However, in view of various unknown and uncontrolled variables which may bias epidemiological studies on MF interactions, a causal relationship between MFs and tumorigenesis can only be determined precisely in animal experiments. The goal of the study reported here was to determine if low frequency MFs at the low flux densities which are relevant for human populations induce tumor-promoting or copromoting effects in a model of breast cancer. Furthermore, since reduction in pineal production of melatonin has been implicated as a cause of tumor promotion by electromagnetic fields, determinations of nocturnal melatonin peak levels in serum were performed during MF exposure. Mammary tumors were induced by intragastric administration of 20 mg (5 mg/week) 7,12-dimethylbenz(a)anthracene (DMBA) in female Sprague-Dawley rats. Groups of 36 rats were either sham-exposed or exposed for 91 days at a 50-Hz gradient MF of 0.3-1 microT, which is a relevant range for elevated domestic MF exposure as arising from neighboring power lines. Nocturnal melatonin levels were significantly reduced by exposure to this weak alternating MF. However, histopathological evaluation of mammary lesions did not disclose any significant difference between MF- and sham-exposed animals. Incidence of mammary tumors was 61% in controls versus 67% in MF-exposed rats. The predominant tumor type was the invasive adenocarcinoma, which was found in 21 rats of both groups. Examination of tumor size did not indicate significant differences in tumor burden between both groups. Furthermore, the incidence of preneoplastic lesions was not altered by MF exposure. Thus, the data of this study indicate that alternating MF do not exert significant tumor promoting or copromoting effects at environmentally relevant flux densities in the rat mammary cancer system.
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Affiliation(s)
- W Löscher
- Department of Pharmacology, Toxicology and Pharmacy, School of Veterinary Medicine, Hannover, FRG
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Long M, Wickstrom G, Grimes A, Belcher B, Benton C, Stamm A. A prospective, randomized study of ventilator-associated pneumonia in patients with one vs. three ventilator circuit changes per week. Am J Infect Control 1994. [DOI: 10.1016/0196-6553(94)90180-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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