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Kersten A, Lorenz A, Nottmeier C, Schmidt M, Roesner A, Richter FC, Röhrborn K, Witte AV, Hahnel S, Koehne T, Blüher M, Stumvoll M, Rohde-Zimmermann K, Schamarek I. The Obese Taste Bud study: Objectives and study design. Diabetes Obes Metab 2024; 26:2054-2068. [PMID: 38618969 DOI: 10.1111/dom.15563] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 03/01/2024] [Accepted: 03/04/2024] [Indexed: 04/16/2024]
Abstract
AIMS Taste modifies eating behaviour, impacting body weight and potentially obesity development. The Obese Taste Bud (OTB) Study is a prospective cohort study launched in 2020 at the University of Leipzig Obesity Centre in cooperation with the HI-MAG Institute. OTB will test the hypothesis that taste cell homeostasis and taste perception are linked to obesity. Here, we provide the study design, data collection process and baseline characteristics. MATERIALS AND METHODS Participants presenting overweight, obesity or normal weight undergo taste and smell tests, anthropometric, and taste bud density (TBD) assessment on Day 1. Information on physical and mental health, eating behaviour, physical activity, and dental hygiene are obtained, while biomaterial (saliva, tongue swap, blood) is collected in the fasted state. Further blood samples are taken during a glucose tolerance test. A stool sample is collected at home prior to Day 2, on which a taste bud biopsy follows dental examination. A subsample undergoes functional magnetic resonance imaging while exposed to eating-related cognitive tasks. Follow-up investigations after conventional weight loss interventions and bariatric surgery will be included. RESULTS Initial results show that glycated haemoglobin levels and age are negatively associated with TBD, while an unfavourable metabolic profile, current dieting, and vegan diet are related to taste perception. Olfactory function negatively correlates with age and high-density lipoprotein cholesterol. CONCLUSION Initial findings suggest that metabolic alterations are relevant for taste and smell function and TBD. By combining omics data from collected biomaterial with physiological, metabolic and psychological data related to taste perception and eating behaviour, the OTB study aims to strengthen our understanding of taste perception in obesity.
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Affiliation(s)
- Alexander Kersten
- Department of Medicine III, Division of Endocrinology, Nephrology and Rheumatology, University of Leipzig, Leipzig, Germany
| | - Andrea Lorenz
- Department of Prosthodontics and Materials Science, University of Leipzig, Leipzig, Germany
| | - Cita Nottmeier
- Department of Orthodontics, University of Leipzig Medical Centre, Leipzig, Germany
| | - Michael Schmidt
- Clinic of Prosthodontics, University Clinic of Regensburg, Regensburg, Germany
| | - Anuschka Roesner
- Department of Prosthetic Dentistry, University Hospital Freiburg Centre for Dental Medicine, Freiburg, Germany
| | - Florian Christoph Richter
- Department of Anaesthesiology and Intensive Care, University of Leipzig Medical Centre, Leipzig, Germany
| | - Kristin Röhrborn
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG), Helmholtz Centre Munich at the University Leipzig and the University Clinic Leipzig, Leipzig, Germany
| | - A Veronica Witte
- Cognitive Neurology, University of Leipzig Medical Centre, Leipzig, Germany
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - Sebastian Hahnel
- Department of Prosthodontics and Materials Science, University of Leipzig, Leipzig, Germany
- Clinic of Prosthodontics, University Clinic of Regensburg, Regensburg, Germany
| | - Till Koehne
- Department of Orthodontics, University of Leipzig Medical Centre, Leipzig, Germany
| | - Matthias Blüher
- Department of Medicine III, Division of Endocrinology, Nephrology and Rheumatology, University of Leipzig, Leipzig, Germany
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG), Helmholtz Centre Munich at the University Leipzig and the University Clinic Leipzig, Leipzig, Germany
| | - Michael Stumvoll
- Department of Medicine III, Division of Endocrinology, Nephrology and Rheumatology, University of Leipzig, Leipzig, Germany
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG), Helmholtz Centre Munich at the University Leipzig and the University Clinic Leipzig, Leipzig, Germany
| | - Kerstin Rohde-Zimmermann
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG), Helmholtz Centre Munich at the University Leipzig and the University Clinic Leipzig, Leipzig, Germany
| | - Imke Schamarek
- Department of Medicine III, Division of Endocrinology, Nephrology and Rheumatology, University of Leipzig, Leipzig, Germany
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG), Helmholtz Centre Munich at the University Leipzig and the University Clinic Leipzig, Leipzig, Germany
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Hatamikia S, Jaksa L, Kronreif G, Birkfellner W, Kettenbach J, Buschmann M, Lorenz A. Silicone phantoms fabricated with multi-material extrusion 3D printing technology mimicking imaging properties of soft tissues in CT. Z Med Phys 2023:S0939-3889(23)00076-4. [PMID: 37380561 DOI: 10.1016/j.zemedi.2023.05.007] [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: 12/30/2022] [Revised: 05/20/2023] [Accepted: 05/21/2023] [Indexed: 06/30/2023]
Abstract
Recently, 3D printing has been widely used to fabricate medical imaging phantoms. So far, various rigid 3D printable materials have been investigated for their radiological properties and efficiency in imaging phantom fabrication. However, flexible, soft tissue materials are also needed for imaging phantoms for simulating several clinical scenarios where anatomical deformations is important. Recently, various additive manufacturing technologies have been used to produce anatomical models based on extrusion techniques that allow the fabrication of soft tissue materials. To date, there is no systematic study in the literature investigating the radiological properties of silicone rubber materials/fluids for imaging phantoms fabricated directly by extrusion using 3D printing techniques. The aim of this study was to investigate the radiological properties of 3D printed phantoms made of silicone in CT imaging. To achieve this goal, the radiodensity as described as Hounsfield Units (HUs) of several samples composed of three different silicone printing materials were evaluated by changing the infill density to adjust their radiological properties. A comparison of HU values with a Gammex Tissue Characterization Phantom was performed. In addition, a reproducibility analysis was performed by creating several replicas for specific infill densities. A scaled down anatomical model derived from an abdominal CT was also fabricated and the resulting HU values were evaluated. For the three different silicone materials, a spectrum ranging from -639 to +780 HU was obtained on CT at a scan setting of 120 kVp. In addition, using different infill densities, the printed materials were able to achieve a similar radiodensity range as obtained in different tissue-equivalent inserts in the Gammex phantom (238 HU to -673 HU). The reproducibility results showed good agreement between the HU values of the replicas compared to the original samples, confirming the reproducibility of the printed materials. A good agreement was observed between the HU target values in abdominal CT and the HU values of the 3D-printed anatomical phantom in all tissues.
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Affiliation(s)
- Sepideh Hatamikia
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria; Research Center for Medical Image Analysis and Artificial Intelligence (MIAAI), Department of Medicine, Danube Private University, Krems, Austria.
| | - Laszlo Jaksa
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
| | - Gernot Kronreif
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
| | - Wolfgang Birkfellner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Joachim Kettenbach
- Institute of Diagnostic, Interventional Radiology and Nuclear Medicine, Landesklinikum Wiener Neustadt, Wiener Neustadt, Austria
| | - Martin Buschmann
- Department of Radiation Oncology, Medical University of Vienna/AKH Wien, Vienna, Austria
| | - Andrea Lorenz
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
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Lorenz A, Winter A, Mederake M, Freidhager C, Hofmann UK, Leichtle UG. Changes in femoral rollback and rotation with increasing coupling in knee arthroplasty-a biomechanical in-vitro study. BMC Musculoskelet Disord 2023; 24:341. [PMID: 37131176 PMCID: PMC10152755 DOI: 10.1186/s12891-023-06430-w] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 04/12/2023] [Indexed: 05/04/2023] Open
Abstract
BACKGROUND After total knee arthroplasty, 10-30% of patients still complain about knee pain, even after exact positioning of the components. Altered knee kinematics are crucial in this regard. The aim of our study was to experimentally determine the influence of different degrees of component coupling of knee prostheses on joint kinematics during muscle-loaded knee flexion in-vitro. METHODS Femoral rollback and femoral rotation of a standard cruciate retaining (GCR), a posterior stabilized (GPS), a rotational hinge (RSL) and a total hinge (SSL) design of the same series of knee replacement implants (SL-series) of one single manufacturer (Waldemar Link GmbH, Hamburg, Germany) were analyzed and set in relation to the motion of the corresponding native knee in a paired study design. All different coupling degrees were analyzed in the same human knees. To simulate muscle loaded knee flexion, a knee simulator was used. Kinematics were measured with an ultrasonic motion capture system and integrated in a calculated coordinate system via CT-imaging. RESULTS The largest posterior motion on the lateral side was found for the native knee (8.7 ± 7.0 mm), followed by the GPS (3.2 ± 5.1 mm) and GCR (2.8 ± 7.3 mm) implants, while no motion was found for the RSL (0.1 ± 3.0 mm) and the SSL (-0.6 ± 2.7 mm) implants. In contrast, on the medial side, only the native knee showed a posterior motion (2.1 ± 3.2 mm). Regarding femoral external rotation, the only implant where the observed difference did not reach statistical significance when compared to the native knee was the GCR (p = 0.007). CONCLUSION The GCR and GPS kinematics closely imitate those of the native joint. Medial femoral rollback is reduced, however, with the joint pivoting around a rotational center located in the medial plateau. Without additional rotational forces, the coupled RSL and SSL prostheses closely resemble each other with no femoral rollback or relevant rotational component. The femoral axis, however, shifts ventrally in both models when compared with their primary counterparts. The positioning of the coupling mechanism in the femoral and tibial component thus can already lead to altered joint kinematics even in prostheses with an identical surface geometry.
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Affiliation(s)
- Andrea Lorenz
- Austrian Center for Medical Innovation and Technology (ACMIT Gmbh), Wr. Neustadt, Austria
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany
- Institute for Lightweight Design and Computational Biomechanics, TU Wien, Vienna, Austria
| | - Alexander Winter
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany
| | - Moritz Mederake
- Department of Trauma and Reconstructive Surgery, BG Klinik, University of Tübingen, 72076, Tübingen, Germany.
| | - Clemens Freidhager
- Institute for Lightweight Design and Computational Biomechanics, TU Wien, Vienna, Austria
| | - Ulf Krister Hofmann
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany
- Department of Orthopedic Trauma and Reconstructive Surgery, University of Aachen Medical Center, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Ulf Gunther Leichtle
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany
- Practice for Orthopaedic, Spine and Trauma Surgery, Rottenburg, Germany
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Jaksa L, Aryeetey OJ, Hatamikia S, Nägl K, Buschmann M, Dieter H. P, Kronreif G, Lorenz A. 3D-Printed multi-material liver model with simultaneous mechanical and radiological tissue-mimicking features for improved realism. Int J Bioprint 2023; 9:721. [PMID: 37323495 PMCID: PMC10261151 DOI: 10.18063/ijb.721] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 01/22/2023] [Indexed: 06/17/2023] Open
Abstract
89Anatomic models have an important role in the medical domain. However, soft tissue mechanical properties' representation is limited in mass-produced and 3D-printed models. In this study, a multi-material 3D printer was used to print a human liver model featuring tuned mechanical and radiological properties, with the goal of comparing the printed model with its printing material and real liver tissue. The main target was mechanical realism, while radiological similarity was a secondary objective. Materials and internal structure were selected such that the printed model would resemble liver tissue in terms of tensile properties. The model was printed at 33% scaling and 40% gyroid infill with a soft silicone rubber, and silicone oil as a filler fluid. After printing, the liver model underwent CT scanning. Since the shape of the liver is incompatible with tensile testing, tensile testing specimens were also printed. Three replicates were printed with the same internal structure as the liver model and three more out of silicone rubber with 100% rectilinear infill to allow a comparison. All specimens were tested in a four-step cyclic loading test protocol to compare elastic moduli and dissipated energy ratios. The fluid-filled and full-silicone specimens had initial elastic moduli of 0.26 MPa and 0.37 MPa, respectively, and featured dissipated energy ratios of 0.140, 0.167, 0.183, and 0.118, 0.093, 0.081, respectively, in the second, third, and fourth loading cycles. The liver model showed 225 ± 30 Hounsfield units (HU) in CT, which is closer to real human liver (70 ± 30 HU) than the printing silicone (340 ± 50 HU). Results suggest that the liver model became more realistic in terms of mechanical and radiological properties with the proposed printing approach as opposed to printing only with silicone rubber. Thus, it has been demonstrated that this printing method enables new customization opportunities in the field of anatomic models.
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Affiliation(s)
- Laszlo Jaksa
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
- Institute of Lightweight Design and Structural Biomechanics, Technical University of Vienna, Vienna, Austria
| | - Othniel James Aryeetey
- Institute of Lightweight Design and Structural Biomechanics, Technical University of Vienna, Vienna, Austria
- Department of Biomechanics, Karl Landsteiner Private University of Health Sciences, Krems an der Donau, Austria
| | - Sepideh Hatamikia
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
- Research Center for Medical Image Analysis and Artificial Intelligence (MIAAI), Department of Medicine, Danube Private University, Krems an der Donau, Austria
| | - Katharina Nägl
- Institute of Lightweight Design and Structural Biomechanics, Technical University of Vienna, Vienna, Austria
- Department of Biomechanics, Karl Landsteiner Private University of Health Sciences, Krems an der Donau, Austria
| | - Martin Buschmann
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
- University Hospital Vienna (AKH), Vienna, Austria
| | - Pahr Dieter H.
- Institute of Lightweight Design and Structural Biomechanics, Technical University of Vienna, Vienna, Austria
- Department of Biomechanics, Karl Landsteiner Private University of Health Sciences, Krems an der Donau, Austria
| | - Gernot Kronreif
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
| | - Andrea Lorenz
- Austrian Center for Medical Innovation and Technology (ACMIT), Wiener Neustadt, Austria
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Hatamikia S, Gulyas I, Birkfellner W, Kronreif G, Unger A, Oberoi G, Lorenz A, Unger E, Kettenbach J, Figl M, Patsch J, Strassl A, Georg D, Renner A. Realistic 3D printed CT imaging tumor phantoms for validation of image processing algorithms. Phys Med 2023; 105:102512. [PMID: 36584415 DOI: 10.1016/j.ejmp.2022.102512] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 11/06/2022] [Accepted: 12/15/2022] [Indexed: 12/30/2022] Open
Abstract
Medical imaging phantoms are widely used for validation and verification of imaging systems and algorithms in surgical guidance and radiation oncology procedures. Especially, for the performance evaluation of new algorithms in the field of medical imaging, manufactured phantoms need to replicate specific properties of the human body, e.g., tissue morphology and radiological properties. Additive manufacturing (AM) technology provides an inexpensive opportunity for accurate anatomical replication with customization capabilities. In this study, we proposed a simple and cheap protocol using Fused Deposition Modeling (FDM) technology to manufacture realistic tumor phantoms based on the filament 3D printing technology. Tumor phantoms with both homogenous and heterogeneous radiodensity were fabricated. The radiodensity similarity between the printed tumor models and real tumor data from CT images of lung cancer patients was evaluated. Additionally, it was investigated whether a heterogeneity in the 3D printed tumor phantoms as observed in the tumor patient data had an influence on the validation of image registration algorithms. A radiodensity range between -217 to 226 HUs was achieved for 3D printed phantoms using different filament materials; this range of radiation attenuation is also observed in the human lung tumor tissue. The resulted HU range could serve as a lookup-table for researchers and phantom manufactures to create realistic CT tumor phantoms with the desired range of radiodensities. The 3D printed tumor phantoms also precisely replicated real lung tumor patient data regarding morphology and could also include life-like heterogeneity of the radiodensity inside the tumor models. An influence of the heterogeneity on accuracy and robustness of the image registration algorithms was not found.
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Affiliation(s)
- Sepideh Hatamikia
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria; Research Center for Medical Image Analysis and Artificial Intelligence (MIAAI), Department of Medicine, Danube Private University, Krems, Austria; Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
| | - Ingo Gulyas
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Birkfellner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Gernot Kronreif
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Alexander Unger
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Gunpreet Oberoi
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Andrea Lorenz
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Ewald Unger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Joachim Kettenbach
- Institute of Diagnostic, Interventional Radiology and Nuclear Medicine, Landesklinikum Wiener Neustadt, Wiener Neustadt, Austria
| | - Michael Figl
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Janina Patsch
- Department of Radiology and Nuclear Medicine, Medical University Vienna, Austria
| | - Andreas Strassl
- Department of Radiology and Nuclear Medicine, Medical University Vienna, Austria
| | - Dietmar Georg
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Andreas Renner
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
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Aryeetey OJ, Frank M, Lorenz A, Pahr DH. Fracture toughness determination of porcine muscle tissue based on AQLV model derived viscous dissipated energy. J Mech Behav Biomed Mater 2022; 135:105429. [DOI: 10.1016/j.jmbbm.2022.105429] [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] [Received: 03/08/2022] [Revised: 08/17/2022] [Accepted: 08/22/2022] [Indexed: 10/31/2022]
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Lorenz A, Augustin C, Konschake M, Gehwolf P, Henninger B, Augustin F, Öfner D. The Preperitoneal Space in Hernia Repair. Front Surg 2022; 9:869731. [PMID: 35711709 PMCID: PMC9197412 DOI: 10.3389/fsurg.2022.869731] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/28/2022] [Indexed: 11/16/2022] Open
Abstract
The preperitoneal spaces relevant for incisional hernia repair and minimally invasive groin hernia repair are described in terms of surgical anatomy. Emphasis is put on the transversalis fascia and the urogenital fascia and its extensions, the vesicoumbilical fascia, and the spermatic sheath of Stoppa procedure. Steps in hernia surgery where these structures are relevant are reviewed.
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Affiliation(s)
- A. Lorenz
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - C. Augustin
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - M. Konschake
- Department of Anatomy, Histology and Embryology, Institute of Clinical and Functional Anatomy, Medical University Innsbruck (MUI), Innsbruck, Austria
| | - P. Gehwolf
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria
| | - B. Henninger
- Department of Radiology, Innsbruck Medical University, Innsbruck, Austria
| | - F. Augustin
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria
- Correspondence: Florian Augustin
| | - D. Öfner
- Department of Visceral, Transplant and Thoracic Surgery, Medical University of Innsbruck, Innsbruck, Austria
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Hatamikia S, Kronreif G, Unger A, Oberoi G, Jaksa L, Unger E, Koschitz S, Gulyas I, Irnstorfer N, Buschmann M, Kettenbach J, Birkfellner W, Lorenz A. 3D printed patient-specific thorax phantom with realistic heterogenous bone radiopacity using filament printer technology. Z Med Phys 2022; 32:438-452. [PMID: 35221154 PMCID: PMC9948829 DOI: 10.1016/j.zemedi.2022.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 12/17/2021] [Accepted: 02/01/2022] [Indexed: 12/11/2022]
Abstract
Current medical imaging phantoms are usually limited by simplified geometry and radiographic skeletal homogeneity, which confines their usage for image quality assessment. In order to fabricate realistic imaging phantoms, replication of the entire tissue morphology and the associated CT numbers, defined as Hounsfield Unit (HU) is required. 3D printing is a promising technology for the production of medical imaging phantoms with accurate anatomical replication. So far, the majority of the imaging phantoms using 3D printing technologies tried to mimic the average HU of soft tissue human organs. One important aspect of the anthropomorphic imaging phantoms is also the replication of realistic radiodensities for bone tissues. In this study, we used filament printing technology to develop a CT-derived 3D printed thorax phantom with realistic bone-equivalent radiodensity using only one single commercially available filament. The generated thorax phantom geometry closely resembles a patient and includes direct manufacturing of bone structures while creating life-like heterogeneity within bone tissues. A HU analysis as well as a physical dimensional comparison were performed in order to evaluate the density and geometry agreement between the proposed phantom and the corresponding CT data. With the achieved density range (-482 to 968 HU) we could successfully mimic the realistic radiodensity of the bone marrow as well as the cortical bone for the ribs, vertebral body and dorsal vertebral column in the thorax skeleton. In addition, considering the large radiodensity range achieved a full thorax imaging phantom mimicking also soft tissues can become feasible. The physical dimensional comparison using both Extrema Analysis and Collision Detection methods confirmed a mean surface overlap of 90% and a mean volumetric overlap of 84,56% between the patient and phantom model. Furthermore, the reproducibility analyses revealed a good geometry and radiodensity duplicability in 24 printed cylinder replicas. Thus, according to our results, the proposed additively manufactured anthropomorphic thorax phantom has the potential to be efficiently used for validation of imaging- and radiation-based procedures in precision medicine.
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Affiliation(s)
- Sepideh Hatamikia
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria; Danube Private University, 3500 Krems an der Donau, Austria; Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
| | - Gernot Kronreif
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Alexander Unger
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Gunpreet Oberoi
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Laszlo Jaksa
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Ewald Unger
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Stefan Koschitz
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
| | - Ingo Gulyas
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Nikolaus Irnstorfer
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy at the Medical University of Vienna
| | - Martin Buschmann
- Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Joachim Kettenbach
- Institute of Diagnostic, Interventional Radiology and Nuclear Medicine, Landesklinikum Wiener Neustadt, Wiener Neustadt, Austria
| | - Wolfgang Birkfellner
- Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Andrea Lorenz
- Austrian Center for Medical Innovation and Technology, Wiener Neustadt, Austria
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Aryeetey OJ, Frank M, Lorenz A, Estermann SJ, Reisinger AG, Pahr DH. A parameter reduced adaptive quasi-linear viscoelastic model for soft biological tissue in uniaxial tension. J Mech Behav Biomed Mater 2022; 126:104999. [PMID: 34999491 DOI: 10.1016/j.jmbbm.2021.104999] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [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: 09/02/2021] [Revised: 11/04/2021] [Accepted: 11/24/2021] [Indexed: 11/15/2022]
Abstract
Mechanical characterisation of soft viscous materials is essential for many applications including aerospace industries, material models for surgical simulation, and tissue mimicking materials for anatomical models. Constitutive material models are, therefore, necessary to describe soft biological tissues in physiologically relevant strain ranges. Hereby, the adaptive quasi-linear viscoelastic (AQLV) model enables accurate modelling of the strain-dependent non-linear viscoelastic behaviour of soft tissues with a high flexibility. However, the higher flexibility produces a large number of model parameters. In this study, porcine muscle and liver tissue samples were modelled in the framework of the originally published AQLV (3-layers of Maxwell elements) model using four incremental ramp-hold experiments in uniaxial tension. AQLV model parameters were reduced by decreasing model layers (M) as well as the number of experimental ramp-hold steps (N). Leave One out cross validation tests show that the original AQLV model (3M4N) with 19 parameters, accurately describes porcine muscle tissue with an average R2 of 0.90 and porcine liver tissue, R2 of 0.86. Reducing the number of layers (N) in the model produced acceptable model fits for 1-layer (R2 of 0.83) and 2-layer models (R2 of 0.89) for porcine muscle tissue and 1-layer (R2 of 0.84) and 2-layer model (R2 of 0.85) for porcine liver tissue. Additionally, a 2 step (2N) ramp-hold experiment was performed on additional samples of porcine muscle tissue only to further reduce model parameters. Calibrated spring constant values for 2N ramp-hold tests parameters k1 and k2 had a 16.8% and 38.0% deviation from those calibrated for a 4 step (4N) ramp hold experiment. This enables further reduction of material parameters by means of step reduction, effectively reducing the number of parameters required to calibrate the AQLV model from 19 for a 3M4N model to 8 for a 2M2N model, with the added advantage of reducing the time per experiment by 50%. This study proposes a 'reduced-parameter' AQLV model (2M2N) for the modelling of soft biological tissues at finite strain ranges. Sequentially, the comparison of model parameters of soft tissues is easier and the experimental burden is reduced.
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Affiliation(s)
- Othniel J Aryeetey
- TU Wien, Institute of Lightweight Design and Structural Biomechanics, Gumpendorfer Straße 7, 1060, Vienna, Austria; Karl Landsteiner University of Health Sciences, Department of Anatomy and Biomechanics, Division Biomechanics, Dr. Karl-Dorrek-Straße 30, 3500, Krems, Austria
| | - Martin Frank
- Karl Landsteiner University of Health Sciences, Department of Anatomy and Biomechanics, Division Biomechanics, Dr. Karl-Dorrek-Straße 30, 3500, Krems, Austria
| | - Andrea Lorenz
- Austrian Center for Medical Innovation & Technology (ACMIT), Viktor Kaplan-Straße 2/1, 2700, Wiener Neustadt, Austria
| | - Sarah-Jane Estermann
- TU Wien, Institute of Lightweight Design and Structural Biomechanics, Gumpendorfer Straße 7, 1060, Vienna, Austria; Karl Landsteiner University of Health Sciences, Department of Anatomy and Biomechanics, Division Biomechanics, Dr. Karl-Dorrek-Straße 30, 3500, Krems, Austria; Austrian Center for Medical Innovation & Technology (ACMIT), Viktor Kaplan-Straße 2/1, 2700, Wiener Neustadt, Austria
| | - Andreas G Reisinger
- TU Wien, Institute of Lightweight Design and Structural Biomechanics, Gumpendorfer Straße 7, 1060, Vienna, Austria; Karl Landsteiner University of Health Sciences, Department of Anatomy and Biomechanics, Division Biomechanics, Dr. Karl-Dorrek-Straße 30, 3500, Krems, Austria
| | - Dieter H Pahr
- TU Wien, Institute of Lightweight Design and Structural Biomechanics, Gumpendorfer Straße 7, 1060, Vienna, Austria; Karl Landsteiner University of Health Sciences, Department of Anatomy and Biomechanics, Division Biomechanics, Dr. Karl-Dorrek-Straße 30, 3500, Krems, Austria.
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Zablah JE, Rodriguez SA, Lorenz A, Morgan GJ. Cardiac catheterization laboratory and the role in effective patient education: A model approach. Progress in Pediatric Cardiology 2021. [DOI: 10.1016/j.ppedcard.2021.101396] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jaksa L, Pahr D, Kronreif G, Lorenz A. Development of a Multi-Material 3D Printer for Functional Anatomic Models. Int J Bioprint 2021; 7:420. [PMID: 34805598 PMCID: PMC8600298 DOI: 10.18063/ijb.v7i4.420] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 09/01/2021] [Indexed: 01/19/2023] Open
Abstract
Anatomic models are important in medical education and pre-operative planning as they help students or doctors prepare for real scenarios in a risk-free way. Several experimental anatomic models were made with additive manufacturing techniques to improve geometric, radiological, or mechanical realism. However, reproducing the mechanical behavior of soft tissues remains a challenge. To solve this problem, multi-material structuring of soft and hard materials was proposed in this study, and a three-dimensional (3D) printer was built to make such structuring possible. The printer relies on extrusion to deposit certain thermoplastic and silicone rubber materials. Various objects were successfully printed for testing the feasibility of geometric features such as thin walls, infill structuring, overhangs, and multi-material interfaces. Finally, a small medical image-based ribcage model was printed as a proof of concept for anatomic model printing. The features enabled by this printer offer a promising outlook on mimicking the mechanical properties of various soft tissues.
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Affiliation(s)
- Laszlo Jaksa
- Austrian Center for Medical Innovation and Technology (ACMIT Gmbh), Viktor-Kaplan-Strasse 2/A, 2700 Wiener Neustadt, Austria.,Technical University of Vienna, Institute of Lightweight Design and Structural Biomechanics, Object 8, Gumpendorfer Strasse 7, 1060 Vienna, Austria
| | - Dieter Pahr
- Technical University of Vienna, Institute of Lightweight Design and Structural Biomechanics, Object 8, Gumpendorfer Strasse 7, 1060 Vienna, Austria.,Karl Landsteiner University of Health Sciences, Department of Anatomy and Biomechanics, Dr.-Karl-Dorrek-Strasse 30, 3500 Krems an der Donau, Austria
| | - Gernot Kronreif
- Austrian Center for Medical Innovation and Technology (ACMIT Gmbh), Viktor-Kaplan-Strasse 2/A, 2700 Wiener Neustadt, Austria
| | - Andrea Lorenz
- Austrian Center for Medical Innovation and Technology (ACMIT Gmbh), Viktor-Kaplan-Strasse 2/A, 2700 Wiener Neustadt, Austria
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Pabinger C, Lothaller H, Lorenz A, Dammerer D. Telemedicine versus on-site treatment at a surgical university clinic: Study of 225 consecutive patients. Int J Med Inform 2021; 151:104460. [PMID: 33965683 DOI: 10.1016/j.ijmedinf.2021.104460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 07/17/2020] [Revised: 03/25/2021] [Accepted: 04/06/2021] [Indexed: 10/21/2022]
Abstract
INTRODUCTION Recently, telemedical services are increasingly used. It remains unclear, if outpatients in general surgery can be treated via telemedicine (e.g. telework). We aimed to evaluate, if diagnosis and therapies of outpatients in general surgery can be found using a mobile healthcare communication app instead of personal contact. MATERIAL AND METHODS In a prospective, double blind, anonymized clinical study we included consecutive outpatients at a general surgery department at a university hospital. For the telemedical "treatment" the on-site doctors uploaded variables (e.g. anamnesis, radiograph, etc.) for each patient. The telemedical doctor received the information only via app and did not see the patient physically. Both, the doctor on-site and the virtual telemedical-doctor then uploaded the diagnosis and their suggested therapy - blinded to each other. The outpatient received the on-site treatment only. The virtual treatment was solely for scientific purposes and had no therapeutic impact. RESULTS 225 consecutive surgical outpatients (53 % female and 47 % male) were included. Mean age was 61 years. In 84 % of cases the telemedical diagnosis matched the on-site diagnosis. The telemedical treatment was not inferior as compared to the on-site treatment in 94 % of all cases and the same therapy was proposed in 76 %. In 6% of all cases the telemedical therapeutic regimen could possibly harm or lead to an over- or under treatment of the patient. CONCLUSION Telemedical consultation seems to work in the field of general surgery. Telemedicine in general surgery potentially could decrease waiting time for an appointment and patient frequency. However, the potential harm of a wrong therapy remains due to the lack of a clinical observation.
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Affiliation(s)
- C Pabinger
- Medical University of Innsbruck, Christoph-Probst-Platz 1, Innrain 52 A, Innsbruck, 6020, Austria.
| | - H Lothaller
- University of Music and Performing Arts Graz, 8010 Graz, Leonhardstraße 15, Graz, 8010, Austria
| | - A Lorenz
- Medical University of Innsbruck, Department of Visceral, Transplantation and Thoracic Surgery, Center of Operative Medicine, Anichstraße 35, Innsbruck, 6020, Austria
| | - D Dammerer
- Medical University of Innsbruck, Anichstraße 35, Innsbruck, 6020, Austria
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Baert Y, Ruetschle I, Cools W, Oehme A, Lorenz A, Marx U, Goossens E, Maschmeyer I. A multi-organ-chip co-culture of liver and testis equivalents: a first step toward a systemic male reprotoxicity model. Hum Reprod 2021; 35:1029-1044. [PMID: 32390056 DOI: 10.1093/humrep/deaa057] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [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: 09/25/2019] [Revised: 01/30/2020] [Accepted: 03/09/2020] [Indexed: 12/15/2022] Open
Abstract
STUDY QUESTION Is it possible to co-culture and functionally link human liver and testis equivalents in the combined medium circuit of a multi-organ chip? SUMMARY ANSWER Multi-organ-chip co-cultures of human liver and testis equivalents were maintained at a steady-state for at least 1 week and the co-cultures reproduced specific natural and drug-induced liver-testis systemic interactions. WHAT IS KNOWN ALREADY Current benchtop reprotoxicity models typically do not include hepatic metabolism and interactions of the liver-testis axis. However, these are important to study the biotransformation of substances. STUDY DESIGN, SIZE, DURATION Testicular organoids derived from primary adult testicular cells and liver spheroids consisting of cultured HepaRG cells and hepatic stellate cells were loaded into separate culture compartments of each multi-organ-chip circuit for co-culture in liver spheroid-specific medium, testicular organoid-specific medium or a combined medium over a week. Additional multi-organ-chips (single) and well plates (static) were loaded only with testicular organoids or liver spheroids for comparison. Subsequently, the selected type of medium was supplemented with cyclophosphamide, an alkylating anti-neoplastic prodrug that has demonstrated germ cell toxicity after its bioactivation in the liver, and added to chip-based co-cultures to replicate a human liver-testis systemic interaction in vitro. Single chip-based testicular organoids were used as a control. Experiments were performed with three biological replicates unless otherwise stated. PARTICIPANTS/MATERIALS, SETTING, METHODS The metabolic activity was determined as glucose consumption and lactate production. The cell viability was measured as lactate dehydrogenase activity in the medium. Additionally, immunohistochemical and real-time quantitative PCR end-point analyses were performed for apoptosis, proliferation and cell-specific phenotypical and functional markers. The functionality of Sertoli and Leydig cells in testicular spheroids was specifically evaluated by measuring daily inhibin B and testosterone release, respectively. MAIN RESULTS AND THE ROLE OF CHANCE Co-culture in multi-organ chips with liver spheroid-specific medium better supported the metabolic activity of the cultured tissues compared to other media tested. The liver spheroids did not show significantly different behaviour during co-culture compared to that in single culture on multi-organ-chips. The testicular organoids also developed accordingly and produced higher inhibin B but lower testosterone levels than the static culture in plates with testicular organoid-specific medium. By comparison, testosterone secretion by testicular organoids cultured individually on multi-organ-chips reached a similar level as the static culture at Day 7. This suggests that the liver spheroids have metabolised the steroids in the co-cultures, a naturally occurring phenomenon. The addition of cyclophosphamide led to upregulation of specific cytochromes in liver spheroids and loss of germ cells in testicular organoids in the multi-organ-chip co-cultures but not in single-testis culture. LARGE-SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION The number of biological replicates included in this study was relatively small due to the limited availability of individual donor testes and the labour-intensive nature of multi-organ-chip co-cultures. Moreover, testicular organoids and liver spheroids are miniaturised organ equivalents that capture key features, but are still simplified versions of the native tissues. Also, it should be noted that only the prodrug cyclophosphamide was administered. The final concentration of the active metabolite was not measured. WIDER IMPLICATIONS OF THE FINDINGS This co-culture model responds to the request of setting up a specific tool that enables the testing of candidate reprotoxic substances with the possibility of human biotransformation. It further allows the inclusion of other human tissue equivalents for chemical risk assessment on the systemic level. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by research grants from the Scientific Research Foundation Flanders (FWO), Universitair Ziekenhuis Brussel (scientific fund Willy Gepts) and the Vrije Universiteit Brussel. Y.B. is a postdoctoral fellow of the FWO. U.M. is founder, shareholder and CEO of TissUse GmbH, Berlin, Germany, a company commercializing the Multi-Organ-Chip platform systems used in the study. The other authors have no conflict of interest to declare.
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Affiliation(s)
- Y Baert
- Biology of the Testis (BITE) Research Group, Department of Reproduction, Genetics and Regenerative Medicine, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium
| | - I Ruetschle
- TissUse GmbH, Oudenarder Str. 16, 13347 Berlin, Germany
| | - W Cools
- Interfaculty Center Data Processing and Statistics (ICDS), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium
| | - A Oehme
- TissUse GmbH, Oudenarder Str. 16, 13347 Berlin, Germany
| | - A Lorenz
- TissUse GmbH, Oudenarder Str. 16, 13347 Berlin, Germany
| | - U Marx
- TissUse GmbH, Oudenarder Str. 16, 13347 Berlin, Germany
| | - E Goossens
- Biology of the Testis (BITE) Research Group, Department of Reproduction, Genetics and Regenerative Medicine, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium
| | - I Maschmeyer
- TissUse GmbH, Oudenarder Str. 16, 13347 Berlin, Germany
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Schafforz S, Nordendorf G, Nava G, Lucchetti L, Lorenz A. Formation of relocatable umbilical defects in a liquid crystal with positive dielectric anisotropy induced via photovoltaic fields. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.112963] [Citation(s) in RCA: 4] [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: 11/29/2022]
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Gehwolf P, Renz O, Brenner E, Cardini B, Lorenz A, Wykypiel H. Laparoscopic fundoplication and new aspects of neural anatomy at the oesophagogastric junction. BJS Open 2020; 4:400-404. [PMID: 32134571 PMCID: PMC7260418 DOI: 10.1002/bjs5.50271] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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: 11/17/2019] [Accepted: 02/03/2020] [Indexed: 11/23/2022] Open
Abstract
Background In fundoplication, mobilization of the distal oesophagus and proximal stomach is essential to obtain a sufficient tension‐free intra‐abdominal oesophageal length for creation of an efficient antireflux barrier. Most surgical literature and anatomical illustrations do not describe nerve branches running from the diaphragm to the stomach. After observing small nerve branches at laparoscopic fundoplication, penetrating the left crus of the diaphragm lateral to the hiatus and apparently running into the stomach, an anatomical cadaver study was undertaken to identify the origin and target organ of these nerves. Methods Fifty‐three human cadavers (23 men, 30 women; age range 35–103 years) were dissected with special attention to the nerves that penetrate the left crus of the diaphragm. The entire course of these nerves was documented with standardized drawings and photos. Results Small nerve branches penetrating the diaphragm lateral to the left crus of the hiatus were found in 17 (32 per cent) of the 53 cadavers. In 14 of these 17 cadavers, one or two splanchnic nerve branches were identified, and in ten of the 17 the nerve branches were found to be phrenic nerves. In seven of these 17 cadavers, two different nerve branches were found and assigned to both splanchnic and phrenic nerves. Conclusion Nerves penetrating the left crus with splanchnic origin or phrenic origin have been identified. Their function remains unclear and their relationship to postfundoplication symptoms remains to be determined.
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Affiliation(s)
- P Gehwolf
- Department of Visceral, Transplant and Thoracic Surgery, Centre for Operative Medicine, Innsbruck, Austria
| | - O Renz
- Department of Visceral, Transplant and Thoracic Surgery, Centre for Operative Medicine, Innsbruck, Austria
| | - E Brenner
- Department of Anatomy, Histology and Embryology, Division of Clinical and Functional Anatomy, Medical University of Innsbruck, Innsbruck, Austria
| | - B Cardini
- Department of Visceral, Transplant and Thoracic Surgery, Centre for Operative Medicine, Innsbruck, Austria
| | - A Lorenz
- Department of Visceral, Transplant and Thoracic Surgery, Centre for Operative Medicine, Innsbruck, Austria
| | - H Wykypiel
- Department of Visceral, Transplant and Thoracic Surgery, Centre for Operative Medicine, Innsbruck, Austria
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Kluess D, Soodmand E, Lorenz A, Pahr D, Schwarze M, Cichon R, Varady PA, Herrmann S, Buchmeier B, Schröder C, Lehner S, Kebbach M. A round-robin finite element analysis of human femur mechanics between seven participating laboratories with experimental validation. Comput Methods Biomech Biomed Engin 2019; 22:1020-1031. [PMID: 31084272 DOI: 10.1080/10255842.2019.1615481] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Finite element analysis is a common tool that has been used for the past few decades to predict the mechanical behavior of bone. However, to our knowledge, there are no round-robin finite element analyses of long human bones with more than two participating biomechanics laboratories published yet, where the results of the experimental tests were not known in advance. We prepared a fresh-frozen human femur for a compression test in a universal testing machine measuring the strains at 10 bone locations as well as the deformation of the bone in terms of the displacement of the loading point at a load of 2 kN. The computed tomography data of the bone with a calibration phantom as well as the orientation of the bone in the testing machine with the according boundary conditions were delivered to seven participating laboratories. These were asked to perform a finite element analysis simulating the experimental setup and deliver their results to the coordinator without knowing the experimental results. Resultantly, four laboratories had deviations from the experimentally measured strains of less than 40%, and three laboratories had deviations of their numerically determined values compared to the experimental data of more than 120%. These deviations are thought to be based on different material laws and material data, as well as different material mapping methods. Investigations will be conducted to clarify and assess the reasons for the large deviations in the numerical data. It was shown that the precision of finite element models of the human femur is not yet as developed as desired by the biomechanics community.
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Affiliation(s)
- Daniel Kluess
- a Department of Orthopaedics , Rostock University Medical Center , Rostock , Germany
| | - Ehsan Soodmand
- a Department of Orthopaedics , Rostock University Medical Center , Rostock , Germany
| | - Andrea Lorenz
- b TU Wien Institute of Lightweight Design and Structural Biomechanics , Vienna , Austria
| | - Dieter Pahr
- b TU Wien Institute of Lightweight Design and Structural Biomechanics , Vienna , Austria
| | - Michael Schwarze
- c Department of Orthopaedic Surgery , Hannover Medical School , Hannover , Germany
| | - Robert Cichon
- d Chair of Mechanics and Robotics , University of Duisburg-Essen , Duisburg , Germany
| | - Patrick A Varady
- e BG Unfallklinik Murnau Institute for Biomechanics , Murnau am Staffelsee , Germany
| | - Sven Herrmann
- e BG Unfallklinik Murnau Institute for Biomechanics , Murnau am Staffelsee , Germany
| | | | - Christian Schröder
- g Orthopädie & Traumatologie/Orthopedics & Traumatology , TÜV SÜD Product Service GmbH , München/Munich , Germany
| | - Stefan Lehner
- h Faculty Mechanical Engineering and Mechatronics , Deggendorf Institute of Technology , Deggendorf , Germany
| | - Maeruan Kebbach
- a Department of Orthopaedics , Rostock University Medical Center , Rostock , Germany
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Lorenz A, Leichtle CI, Frantz S, Bumann M, Tsiflikas I, Shiozawa T, Leichtle UG. Pull out Strength of Dual Outer Diameter Pedicle Screws Compared to Uncemented and Cemented Standard Pedicle Screws: A Biomechanical in vitro Study. Orthop Surg 2017; 9:229-236. [PMID: 28547867 DOI: 10.1111/os.12322] [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] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Accepted: 01/26/2017] [Indexed: 12/21/2022] Open
Abstract
OBJECTIVE To analyze the potential of the dual outer diameter screw and systematically evaluate the pull-out force of the dual outer diameter screw compared to the uncemented and cemented standard pedicle screws with special regard to the pedicle diameter and the vertebra level. METHODS Sixty vertebrae of five human spines (T 6 -L 5 ) were sorted into three study groups for pairwise comparison of the uncemented dual outer diameter screw, the uncemented standard screw, and the cemented standard screw, and randomized with respect to bone mineral density (BMD) and vertebra level. The vertebrae were instrumented, insertion torque was determined, and pull-out testing was performed using a material testing machine. Failure load was evaluated in pairwise comparison within each study group. The screw-to-pedicle diameter ratio was determined and the uncemented dual outer diameter and standard screws were compared for different ratios as well as vertebra levels. RESULTS Significantly increased pull-out forces were measured for the cemented standard screw compared to the uncemented standard screw (+689 N, P < 0.001) and the dual outer diameter screw (+403 N, P < 0.001). Comparing the dual outer diameter screw to the uncemented standard screw in the total study group, a distinct but not significant increase was measured (+149 N, P = 0.114). Further analysis of these two screws, however, revealed a significant increase of pull-out force for the dual outer diameter screw in the lumbar region (+247 N, P = 0.040), as well as for a screw-to-pedicle diameter ratio between 0.6 and 1 (+ 488 N, P = 0.028). CONCLUSIONS For clinical application, cement augmentation remains the gold standard for increasing screw stability. According to our results, the use of a dual outer diameter screw is an interesting option to increase screw stability in the lumbar region without cement augmentation. For the thoracic region, however, the screw-to-pedicle diameter should be checked and attention should be paid to screw cut out, if the dual outer diameter screw is considered.
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Affiliation(s)
- Andrea Lorenz
- Department of Orthopaedic Surgery, University Hospital Tübingen, Tübingen, Germany
| | - Carmen I Leichtle
- Department of Orthopaedic Surgery, University Hospital Tübingen, Tübingen, Germany.,Spine and Orthopaedic Surgery, Rottenburg, Germany
| | - Sandra Frantz
- Department of Orthopaedic Surgery, University Hospital Tübingen, Tübingen, Germany
| | - Marte Bumann
- Department of Orthopaedic Surgery, University Hospital Tübingen, Tübingen, Germany
| | - Ilias Tsiflikas
- Department of Radiology, University Hospital Tübingen, Tübingen, Germany
| | - Thomas Shiozawa
- Department of Clinical Anatomy and Cell Analytics, Institute of Anatomy, University of Tübingen, Tübingen, Germany
| | - Ulf G Leichtle
- Department of Orthopaedic Surgery, University Hospital Tübingen, Tübingen, Germany
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Neumann T, Lorenz A, Volk GF, Hamzei F, Schulz S, Guntinas-Lichius O. [Validation of the German Version of the Sunnybrook Facial Grading System]. Laryngorhinootologie 2016; 96:168-174. [PMID: 27832680 DOI: 10.1055/s-0042-111512] [Citation(s) in RCA: 4] [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] [Indexed: 10/20/2022]
Abstract
Background: The Sunnybrook facial grading system (SFGS) is frequently applied to evaluate facial function in patients with facial palsy, but still now there is no validated German version of this evaluation sheet. Methods: The original English version of the SFGS was translated and validated in accordance with international standards. The interrater reliability from 5 raters (speech therapy students) and the intrarater reliability from repeated ratings at 2 time points using video tapes of 18 patients with different types of facial palsy were analyzed by calculating the intraclass correlation coefficient (ICC) and other reliability measures. Results: ICC for the interrater reliability for the 4 components of the SFGS, resting symmetry, symmetry during voluntary movements, synkinesis, and the composite score were ICC 0.845; 0.903; 0.731 and 0.918, respectively, for the first evaluation and ICC 0.881; 0.932; 0.818 and 0.940, respectively, for the second evaluation. The mean intrarater reliability for the 4 SFGS scores was ICC=0.791; 0.906; 0.770 and 0.905. Discussion: There is now a valid German version of the SFGS available that can be used even by novices. The German version is suitable for evaluation of facial palsies in clinical routine and studies to allow a better comparability of German patients with results of the international literature.
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Affiliation(s)
- T Neumann
- Fachbereich angewandte Gesundheitswissenschaften, Europäische Fachhochschule, Rostock, Rostock
| | - A Lorenz
- Abteilung für Neurologie, Moritz Klinik, Bad Klosterlausnitz
| | - G F Volk
- HNO-Klinik, Universitätsklinikum Jena, Jena
| | - F Hamzei
- Abteilung für Neurologie, Moritz Klinik, Bad Klosterlausnitz
| | - S Schulz
- Fazialis-Nerv-Zentrum, Universitätsklinikum Jena, Jena
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Krychowiak M, Adnan A, Alonso A, Andreeva T, Baldzuhn J, Barbui T, Beurskens M, Biel W, Biedermann C, Blackwell BD, Bosch HS, Bozhenkov S, Brakel R, Bräuer T, Brotas de Carvalho B, Burhenn R, Buttenschön B, Cappa A, Cseh G, Czarnecka A, Dinklage A, Drews P, Dzikowicka A, Effenberg F, Endler M, Erckmann V, Estrada T, Ford O, Fornal T, Frerichs H, Fuchert G, Geiger J, Grulke O, Harris JH, Hartfuß HJ, Hartmann D, Hathiramani D, Hirsch M, Höfel U, Jabłoński S, Jakubowski MW, Kaczmarczyk J, Klinger T, Klose S, Knauer J, Kocsis G, König R, Kornejew P, Krämer-Flecken A, Krawczyk N, Kremeyer T, Książek I, Kubkowska M, Langenberg A, Laqua HP, Laux M, Lazerson S, Liang Y, Liu SC, Lorenz A, Marchuk AO, Marsen S, Moncada V, Naujoks D, Neilson H, Neubauer O, Neuner U, Niemann H, Oosterbeek JW, Otte M, Pablant N, Pasch E, Sunn Pedersen T, Pisano F, Rahbarnia K, Ryć L, Schmitz O, Schmuck S, Schneider W, Schröder T, Schuhmacher H, Schweer B, Standley B, Stange T, Stephey L, Svensson J, Szabolics T, Szepesi T, Thomsen H, Travere JM, Trimino Mora H, Tsuchiya H, Weir GM, Wenzel U, Werner A, Wiegel B, Windisch T, Wolf R, Wurden GA, Zhang D, Zimbal A, Zoletnik S. Overview of diagnostic performance and results for the first operation phase in Wendelstein 7-X (invited). Rev Sci Instrum 2016; 87:11D304. [PMID: 27910389 DOI: 10.1063/1.4964376] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Wendelstein 7-X, a superconducting optimized stellarator built in Greifswald/Germany, started its first plasmas with the last closed flux surface (LCFS) defined by 5 uncooled graphite limiters in December 2015. At the end of the 10 weeks long experimental campaign (OP1.1) more than 20 independent diagnostic systems were in operation, allowing detailed studies of many interesting plasma phenomena. For example, fast neutral gas manometers supported by video cameras (including one fast-frame camera with frame rates of tens of kHz) as well as visible cameras with different interference filters, with field of views covering all ten half-modules of the stellarator, discovered a MARFE-like radiation zone on the inboard side of machine module 4. This structure is presumably triggered by an inadvertent plasma-wall interaction in module 4 resulting in a high impurity influx that terminates some discharges by radiation cooling. The main plasma parameters achieved in OP1.1 exceeded predicted values in discharges of a length reaching 6 s. Although OP1.1 is characterized by short pulses, many of the diagnostics are already designed for quasi-steady state operation of 30 min discharges heated at 10 MW of ECRH. An overview of diagnostic performance for OP1.1 is given, including some highlights from the physics campaigns.
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Affiliation(s)
- M Krychowiak
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - A Adnan
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - A Alonso
- Laboratorio Nacional de Fusión, CIEMAT, Avenida Complutense, Madrid, Spain
| | - T Andreeva
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - J Baldzuhn
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - T Barbui
- University of Wisconsin, Engineering Drive, Madison, Wisconsin 53706, USA
| | - M Beurskens
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - W Biel
- Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung - Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany
| | - C Biedermann
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - B D Blackwell
- Australian National University, Acton ACT, 2601 Canberra, Australia
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Instituto de Plasmas e Fusao Nuclear, Avenue Rovisco Pais 1, 1049-001 Lisboa, Portugal
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Laboratorio Nacional de Fusión, CIEMAT, Avenida Complutense, Madrid, Spain
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- Wigner Research Centre for Physics, Konkoly Thege 29-33, H-1121 Budapest, Hungary
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- Institute of Plasma Physics and Laser Microfusion, Hery Street 23, 01-497 Warsaw, Poland
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung - Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany
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- University of Szczecin, al. Papieża Jana Pawła II 22A, Szczecin, Poland
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- University of Wisconsin, Engineering Drive, Madison, Wisconsin 53706, USA
| | - M Endler
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Laboratorio Nacional de Fusión, CIEMAT, Avenida Complutense, Madrid, Spain
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Institute of Plasma Physics and Laser Microfusion, Hery Street 23, 01-497 Warsaw, Poland
| | - H Frerichs
- University of Wisconsin, Engineering Drive, Madison, Wisconsin 53706, USA
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - J H Harris
- Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - D Hartmann
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - D Hathiramani
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - M Hirsch
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - U Höfel
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - S Jabłoński
- Institute of Plasma Physics and Laser Microfusion, Hery Street 23, 01-497 Warsaw, Poland
| | - M W Jakubowski
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - J Kaczmarczyk
- Institute of Plasma Physics and Laser Microfusion, Hery Street 23, 01-497 Warsaw, Poland
| | - T Klinger
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - S Klose
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - J Knauer
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - G Kocsis
- Wigner Research Centre for Physics, Konkoly Thege 29-33, H-1121 Budapest, Hungary
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung - Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany
| | - N Krawczyk
- Institute of Plasma Physics and Laser Microfusion, Hery Street 23, 01-497 Warsaw, Poland
| | - T Kremeyer
- University of Wisconsin, Engineering Drive, Madison, Wisconsin 53706, USA
| | - I Książek
- Opole University, pl. Kopernika 11a, 45-040 Opole, Poland
| | - M Kubkowska
- Institute of Plasma Physics and Laser Microfusion, Hery Street 23, 01-497 Warsaw, Poland
| | - A Langenberg
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - H P Laqua
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - M Laux
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - Y Liang
- Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung - Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany
| | - S C Liu
- Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung - Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany
| | - A Lorenz
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - A O Marchuk
- Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung - Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany
| | - S Marsen
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - V Moncada
- CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
| | - D Naujoks
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - H Neilson
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
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- Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung - Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, The Netherlands
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - N Pablant
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- University of Cagliari, Via Università, 40, 09124 Cagliari, Italy
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Institute of Plasma Physics and Laser Microfusion, Hery Street 23, 01-497 Warsaw, Poland
| | - O Schmitz
- University of Wisconsin, Engineering Drive, Madison, Wisconsin 53706, USA
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- Culham Science Centre, Abingdon OX14 3DB, United Kingdom
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - B Schweer
- Forschungszentrum Jülich GmbH, Institut für Energie- und Klimaforschung - Plasmaphysik, Partner of the Trilateral Euregio Cluster (TEC), 52425 Jülich, Germany
| | - B Standley
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - T Stange
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - L Stephey
- University of Wisconsin, Engineering Drive, Madison, Wisconsin 53706, USA
| | - J Svensson
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - T Szabolics
- Wigner Research Centre for Physics, Konkoly Thege 29-33, H-1121 Budapest, Hungary
| | - T Szepesi
- Wigner Research Centre for Physics, Konkoly Thege 29-33, H-1121 Budapest, Hungary
| | - H Thomsen
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - J-M Travere
- CEA, IRFM, F-13108 Saint-Paul-lez-Durance, France
| | - H Trimino Mora
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - H Tsuchiya
- NIFS National Institute for Fusion Science, 322-6 Oroshi-cho, Toki 509-5292, Japan
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
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- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - A Werner
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - B Wiegel
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - T Windisch
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - R Wolf
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - G A Wurden
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - D Zhang
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - A Zimbal
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - S Zoletnik
- Wigner Research Centre for Physics, Konkoly Thege 29-33, H-1121 Budapest, Hungary
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Kurbacher C, Fietz T, Trarbach T, Salat C, Rezai M, Lorenz A, Niemeier B. Prophylaxis of chemotherapy-induced neutropenia with lipegfilgrastim in patients with breast cancer: results from an interim analysis of the non-interventional study NADIR. Ann Oncol 2016. [DOI: 10.1093/annonc/mdw390.25] [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: 11/14/2022] Open
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Horland R, Maschmeyer I, Dehne M, Hasenberg T, Ramme A, Lorenz A, Jaenicke A, Hübner J, Schimek K, Atac-Wagegg B, Lauster R, Marx U. Chip based microphysiological systems – A step toward emulation of systemic aspects of human biology in vitro. Toxicol Lett 2016. [DOI: 10.1016/j.toxlet.2016.07.055] [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: 11/30/2022]
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Leichtle CI, Lorenz A, Rothstock S, Happel J, Walter F, Shiozawa T, Leichtle UG. Pull-out strength of cemented solid versus fenestrated pedicle screws in osteoporotic vertebrae. Bone Joint Res 2016; 5:419-26. [PMID: 27678328 PMCID: PMC5041096 DOI: 10.1302/2046-3758.59.2000580] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Accepted: 07/14/2016] [Indexed: 12/15/2022] Open
Abstract
Objectives Cement augmentation of pedicle screws could be used to improve screw stability, especially in osteoporotic vertebrae. However, little is known concerning the influence of different screw types and amount of cement applied. Therefore, the aim of this biomechanical in vitro study was to evaluate the effect of cement augmentation on the screw pull-out force in osteoporotic vertebrae, comparing different pedicle screws (solid and fenestrated) and cement volumes (0 mL, 1 mL or 3 mL). Materials and Methods A total of 54 osteoporotic human cadaver thoracic and lumbar vertebrae were instrumented with pedicle screws (uncemented, solid cemented or fenestrated cemented) and augmented with high-viscosity PMMA cement (0 mL, 1 mL or 3 mL). The insertion torque and bone mineral density were determined. Radiographs and CT scans were undertaken to evaluate cement distribution and cement leakage. Pull-out testing was performed with a material testing machine to measure failure load and stiffness. The paired t-test was used to compare the two screws within each vertebra. Results Mean failure load was significantly greater for fenestrated cemented screws (+622 N; p ⩽ 0.001) and solid cemented screws (+460 N; p ⩽ 0.001) than for uncemented screws. There was no significant difference between the solid and fenestrated cemented screws (p = 0.5). In the lower thoracic vertebrae, 1 mL cement was enough to significantly increase failure load, while 3 mL led to further significant improvement in the upper thoracic, lower thoracic and lumbar regions. Conclusion Conventional, solid pedicle screws augmented with high-viscosity cement provided comparable screw stability in pull-out testing to that of sophisticated and more expensive fenestrated screws. In terms of cement volume, we recommend the use of at least 1 mL in the thoracic and 3 mL in the lumbar spine. Cite this article: C. I. Leichtle, A. Lorenz, S. Rothstock, J. Happel, F. Walter, T. Shiozawa, U. G. Leichtle. Pull-out strength of cemented solid versus fenestrated pedicle screws in osteoporotic vertebrae. Bone Joint Res 2016;5:419–426.
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Affiliation(s)
- C I Leichtle
- Department of Orthopaedic Surgery, University Hospital Tübingen, Tübingen, Germany
| | - A Lorenz
- Department of Orthopaedic Surgery, University Hospital Tübingen, Tübingen, Germany
| | - S Rothstock
- Department of Orthopaedic Surgery, University Hospital Tübingen, Tübingen, Germany
| | - J Happel
- Department of Orthopaedic Surgery, University Hospital Tübingen, Tübingen, Germany
| | - F Walter
- Department of Orthopaedic Surgery, University Hospital Tübingen, Tübingen, Germany
| | - T Shiozawa
- Department of Clinical Anatomy and Cell Analytics, Institute of Anatomy, University of Tübingen, Tübingen, Germany
| | - U G Leichtle
- Department of Orthopaedic Surgery, University Hospital Tübingen, Tübingen, Germany
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Bauer S, Magauer C, Maschmeyer I, Drewell C, Lorenz A, Lauster R, Marx U. Towards a multi-organ-chip platform combining human liver, pancreatic islets, skeletal muscle and kidney equivalents to study metabolic diseases. DIABETOL STOFFWECHS 2016. [DOI: 10.1055/s-0036-1584105] [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: 10/21/2022]
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Abstract
Non-allergic rhinitis is a heterogenous group of medical diseases without an IgE-mediated pathophysiology. In this review, typical subgroups are presented with data regarding their frequency, clinical symptoms and recommendations for an effective and efficient diagnostic and therapeutic approach are indicated. The most common subtype is the non-allergic rhinopathy, also known as idiopathic or vasomotoric rhinitis. Because medication induced rhinitis is still a frequent clinical problem, a step wise approach to wean the patient is presented.
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Affiliation(s)
- A Lorenz
- Klinik und Poliklinik für Hals-Nasen-Ohrenheilkunde, Abteilung Phoniatrie und Pädaudiologie, Universitätsklinikum Regensburg (Direktor: Prof. Dr. J. Strutz)
| | - I Küster
- Klinik für Hals-Nasen-Ohrenheilkunde, Kopf- und Halschirurgie der Universität Greifswald (Direktor: Prof. Dr. W. Hosemann)
| | - A G Beule
- Klinik für Hals-Nasen-Ohrenheilkunde, Kopf- und Halschirurgie der Universität Greifswald (Direktor: Prof. Dr. W. Hosemann)
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Lorenz A, Krickl V, Ipach I, Arlt EM, Wülker N, Leichtle UG. Practicability for robot-aided measurement of knee stability in-vivo. BMC Musculoskelet Disord 2015; 16:373. [PMID: 26634924 PMCID: PMC4669663 DOI: 10.1186/s12891-015-0826-5] [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] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 11/23/2015] [Indexed: 01/17/2023] Open
Abstract
Background For the analysis of different treatments concerning anterior cruciate ligament (ACL) rupture, objective methods for the quantification of knee stability are needed. Therefore, a new method for in-vivo stability measurement using a robotic testing system should be developed and evaluated. Methods A new experimental setting was developed using a KUKA robot and a custom-made chair for the positioning and fixation of the participants. The tibia was connected to the robot via a Vacoped shoe and magnetic buttons, providing adequate safety. Anterior tibial translation and internal tibial rotation were measured on both legs of 40 healthy human subjects at 30°, 60° and 90° of flexion, applying anterior forces of 80 N and internal torques of 4 Nm, respectively. Results While the mean differences between the right and left leg measured for anterior tibial translation were within an acceptable range (<1.5 mm), the absolute values were substantially large (38–40.5 mm). For mean internal tibial rotation, between 17.5 and 20° were measured at the different sides and flexion angles, with a maximal difference of 0.75°. High reproducibility of the measurements could be demonstrated for both, anterior tibial translation (ICC(3,1) = 0.97) and internal tibial rotation (ICC(3,1) = 0.94). Conclusions Excellent results were achieved for internal tibial rotation, almost reproducing current in-vitro studies, but too large anterior tibial translation was measured due to soft-tissue compression. Therefore, high potential for the analysis of ACL related treatments concerning rotational stability is seen for the proposed method, but further optimization is necessary to enhance this method for the reliable measurement of anterior tibial translation.
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Affiliation(s)
- Andrea Lorenz
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, Tübingen, 72076, Germany.
| | - Verena Krickl
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, Tübingen, 72076, Germany.
| | - Ingmar Ipach
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, Tübingen, 72076, Germany.
| | - Eva-Maria Arlt
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, Tübingen, 72076, Germany.
| | - Nikolaus Wülker
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, Tübingen, 72076, Germany.
| | - Ulf G Leichtle
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, Tübingen, 72076, Germany.
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Maschmeyer I, Lorenz A, Ramme A, Hasenberg T, Schimek K, Hübner J, Lauster R, Marx U. A microfluidic four-organ-chip for interconnected long-term co-culture of human intestine, liver, skin and kidney equivalents. Toxicol Lett 2015. [DOI: 10.1016/j.toxlet.2015.08.512] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [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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Johnston EJ, Rylott EL, Beynon E, Lorenz A, Chechik V, Bruce NC. Monodehydroascorbate reductase mediates TNT toxicity in plants. Science 2015; 349:1072-5. [DOI: 10.1126/science.aab3472] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Lorenz A, Bobrowitsch E, Wünschel M, Walter C, Wülker N, Leichtle UG. Robot-aided in vitro measurement of patellar stability with consideration to the influence of muscle loading. Biomed Eng Online 2015. [PMID: 26201401 PMCID: PMC4511523 DOI: 10.1186/s12938-015-0068-7] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Background Anterior knee pain is often associated with patellar maltracking and instability. However, objective measurement of patellar stability under clinical and experimental conditions is difficult, and muscular activity influences the results. In the present study, a new experimental setting for in vitro measurement of patellar stability was developed and the mediolateral force–displacement behavior of the native knee analyzed with special emphasis on patellar tilt and muscle loading. Methods In the new experimental setup, two established testing methods were combined: an upright knee simulator for positioning and loading of the knee specimens, and an industry robot for mediolateral patellar displacement. A minimally invasive coupling and force control mechanism enabled unconstrained motion of the patella as well as measurement of patellar motion in all six degrees of freedom via an external ultrasonic motion-tracking system. Lateral and medial patellar displacement were measured on seven fresh-frozen human knee specimens in six flexion angles with varying muscle force levels, muscle force distributions, and displacement forces. Results Substantial repeatability was achieved for patellar shift (ICC(3,1) = 0.67) and tilt (ICC(3,1) = 0.75). Patellar lateral and medial shift decreased slightly with increasing flexion angle. Additional measurement of patellar tilt provided interesting insights into the different displacement mechanisms in lateral and medial directions. For lateral displacement, the patella tilted in the same (lateral) direction, and tilted in the opposite direction (again laterally) for medial displacement. With regard to asymmetric muscle loading, a significant influence (p < 0.03, up to 5 mm shift and 8° tilt) was found for lateral displacement and a reasonable relationship between muscle and patellar force, whereas no effect was visible in the medial direction. Conclusion The developed experimental setup delivered reproducible results and was found to be an excellent testing method for the in vitro analysis of patellar stability and future investigation of surgical techniques for patellar stabilization and total knee arthroplasty. We demonstrated a significant influence of asymmetric quadriceps loading on patellar stability. In particular, increased force application on the vastus lateralis muscle led to a clear increase of lateral patellar displacement.
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Affiliation(s)
- Andrea Lorenz
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany.
| | - Evgenij Bobrowitsch
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany.
| | - Markus Wünschel
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany.
| | - Christian Walter
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany.
| | - Nikolaus Wülker
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany.
| | - Ulf G Leichtle
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, 72076, Tübingen, Germany.
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Lorenz A, Senne A, Rohde J, Kroh S, Wittenberg M, Krüger K, Clement F, Biro D. Evaluation of Flexographic Printing Technology for Multi-busbar Solar Cells. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.egypro.2015.03.296] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Bobrowitsch E, Lorenz A, Wülker N, Walter C. Simulation of in vivo dynamics during robot assisted joint movement. Biomed Eng Online 2014; 13:167. [PMID: 25516427 PMCID: PMC4279817 DOI: 10.1186/1475-925x-13-167] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [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: 08/27/2014] [Accepted: 12/05/2014] [Indexed: 11/27/2022] Open
Abstract
Background Robots are very useful tools in orthopedic research. They can provide force/torque controlled specimen motion with high repeatability and precision. A method to analyze dissipative energy outcome in an entire joint was developed in our group. In a previous study, a sheep knee was flexed while axial load remained constant during the measurement of dissipated energy. We intend to apply this method for the investigation of osteoarthritis. Additionally, the method should be improved by simulation of in vivo knee dynamics. Thus, a new biomechanical testing tool will be developed for analyzing in vitro joint properties after different treatments. Methods Discretization of passive knee flexion was used to construct a complex flexion movement by a robot and simulate altering axial load similar to in vivo sheep knee dynamics described in a previous experimental study. Results The robot applied an in vivo like axial force profile with high reproducibility during the corresponding knee flexion (total standard deviation of 0.025 body weight (BW)). A total residual error between the in vivo and simulated axial force was 0.16 BW. Posterior-anterior and medio-lateral forces were detected by the robot as a backlash of joint structures. Their curve forms were similar to curve forms of corresponding in vivo measured forces, but in contrast to the axial force, they showed higher total standard deviation of 0.118 and 0.203 BW and higher total residual error of 0.79 and 0.21 BW for posterior-anterior and medio-lateral forces respectively. Conclusions We developed and evaluated an algorithm for the robotic simulation of complex in vivo joint dynamics using a joint specimen. This should be a new biomechanical testing tool for analyzing joint properties after different treatments.
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Affiliation(s)
- Evgenij Bobrowitsch
- Department of Orthopaedic Surgery, Biomechanics Laboratory, University Hospital Tübingen, 72076 Tübingen, Germany.
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Lorenz A, Herzog Y, Schnauffer P, Arnold M, Wülker N, Leichtle UG. Rapid prototyping--a promising technique for orthopaedic implant fabrication: application and validation of TKA prototypes for in-vitro testing. Comput Methods Biomech Biomed Engin 2014; 17 Suppl 1:54-5. [PMID: 25074161 DOI: 10.1080/10255842.2014.931109] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Affiliation(s)
- A Lorenz
- a Department of Orthopaedic Surgery , University Hospital Tübingen , 72076 , Tübingen , Germany
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König R, Biel W, Biedermann C, Burhenn R, Cseh G, Czarnecka A, Endler M, Estrada T, Grulke O, Hathiramani D, Hirsch M, Jabłonski S, Jakubowski M, Kaczmarczyk J, Kasparek W, Kocsis G, Kornejew P, Krämer-Flecken A, Krychowiak M, Kubkowska M, Langenberg A, Laux M, Liang Y, Lorenz A, Neubauer O, Otte M, Pablant N, Pasch E, Pedersen TS, Schmitz O, Schneider W, Schuhmacher H, Schweer B, Thomsen H, Szepesi T, Wiegel B, Windisch T, Wolf S, Zhang D, Zoletnik S. Status of the diagnostics development for the first operation phase of the stellarator Wendelstein 7-X. Rev Sci Instrum 2014; 85:11D818. [PMID: 25430231 DOI: 10.1063/1.4889905] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
An overview of the diagnostics which are essential for the first operational phase of Wendelstein 7-X and the set of diagnostics expected to be ready for operation at this time are presented. The ongoing investigations of how to cope with high levels of stray Electron Cyclotron Resonance Heating (ECRH) radiation in the ultraviolet (UV)/visible/infrared (IR) optical diagnostics are described.
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Affiliation(s)
- R König
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - W Biel
- Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - C Biedermann
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - R Burhenn
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - G Cseh
- Wigner RCP, RMI, Konkoly Thege 219-33, H-1121 Budapest, Hungary
| | - A Czarnecka
- IFPiLM, Hery Street 23, 01-497 Warsaw, Poland
| | - M Endler
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - T Estrada
- Laboratorio Nacional de Fusion, CIEMAT, Avenida Complutense, Madrid, Spain
| | - O Grulke
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - D Hathiramani
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - M Hirsch
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - S Jabłonski
- IFPiLM, Hery Street 23, 01-497 Warsaw, Poland
| | - M Jakubowski
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | | | - W Kasparek
- IGVP, Universität Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart, Germany
| | - G Kocsis
- Wigner RCP, RMI, Konkoly Thege 219-33, H-1121 Budapest, Hungary
| | - P Kornejew
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - A Krämer-Flecken
- Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - M Krychowiak
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - M Kubkowska
- IFPiLM, Hery Street 23, 01-497 Warsaw, Poland
| | - A Langenberg
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - M Laux
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - Y Liang
- Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - A Lorenz
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - O Neubauer
- Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - M Otte
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - N Pablant
- Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543, USA
| | - E Pasch
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - T S Pedersen
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - O Schmitz
- Department of Engineering Physics, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, Wisconsin 53706, USA
| | - W Schneider
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - H Schuhmacher
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - B Schweer
- Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, D-52425 Jülich, Germany
| | - H Thomsen
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - T Szepesi
- Wigner RCP, RMI, Konkoly Thege 219-33, H-1121 Budapest, Hungary
| | - B Wiegel
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - T Windisch
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - S Wolf
- IGVP, Universität Stuttgart, Pfaffenwaldring 31, 70569 Stuttgart, Germany
| | - D Zhang
- Max Planck Institute for Plasma Physics, 17491 Greifswald, Germany
| | - S Zoletnik
- Wigner RCP, RMI, Konkoly Thege 219-33, H-1121 Budapest, Hungary
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Reichl I, Leichtle U, Lorenz A. Functionally computed flexion axis reduces kinematic interspecimen variation inin vitroexperiments. Comput Methods Biomech Biomed Engin 2014; 17 Suppl 1:126-7. [DOI: 10.1080/10255842.2014.931519] [Citation(s) in RCA: 2] [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: 10/25/2022]
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Bobrowitsch E, Lorenz A, Jörg J, Leichtle UG, Wülker N, Walter C. Changes in dissipated energy and contact pressure after osteochondral graft transplantation. Med Eng Phys 2014; 36:1156-61. [PMID: 25066582 DOI: 10.1016/j.medengphy.2014.06.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [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: 07/19/2013] [Revised: 06/10/2014] [Accepted: 06/28/2014] [Indexed: 11/27/2022]
Abstract
Osteochondral autologous transplantation is frequently used to repair small cartilage defects. Incongruence between the osteochondral graft surface and the adjacent cartilage leads to changed friction and contact pressure. The present study wanted to analyze the differences between intact and surgically treated cartilage surface in respect to contact pressure and frictional characteristic (dissipated energy). Six ovine carpometacarpal joints were used in the present study. Dissipated energy during instrumentally controlled joint movement as well as static contact pressure were measured in different cartilage states (intact, defect, deep-, flush-, high-implanted osteochondral graft and cartilage failure simulation on a high-implanted graft). The best contact area restoration was observed after the flush implantation. However, the dissipated energy measurements did not reveal an advantage of the flush implantation compared to the defect and deep-implanted graft states. The high-implanted graft was associated with a significant increase of the mean contact pressure and decrease of the contact area but the dissipated energy was on the level of intact cartilage in contrast to other treatments where the dissipated energy was significantly higher as in the intact state. However the cartilage failure simulation on the high-implanted graft showed the highest increase of the dissipated energy.
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Affiliation(s)
- Evgenij Bobrowitsch
- University Hospital Tübingen, Department of Orthopaedic Surgery, Biomechanics Laboratory, 72076 Tübingen, Germany.
| | - Andrea Lorenz
- University Hospital Tübingen, Department of Orthopaedic Surgery, Biomechanics Laboratory, 72076 Tübingen, Germany.
| | - Johanna Jörg
- University Hospital Tübingen, Department of Orthopaedic Surgery, Biomechanics Laboratory, 72076 Tübingen, Germany.
| | - Ulf G Leichtle
- University Hospital Tübingen, Department of Orthopaedic Surgery, Biomechanics Laboratory, 72076 Tübingen, Germany.
| | - Nikolaus Wülker
- University Hospital Tübingen, Department of Orthopaedic Surgery, Biomechanics Laboratory, 72076 Tübingen, Germany.
| | - Christian Walter
- University Hospital Tübingen, Department of Orthopaedic Surgery, Biomechanics Laboratory, 72076 Tübingen, Germany.
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Lorenz A, Busse M, Dalüge K, Behrendt AK, Hansen G, Meyer-Bahlburg A. Investigating the role of BAFF in different mouse models of allergic asthma. Pneumologie 2014. [DOI: 10.1055/s-0034-1376773] [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: 10/25/2022]
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Stadler R, Vorköper A, Boscary J, Li C, Mendelevitch B, Peacock A, Pirsch H, Freier D, Lorenz A. Challenges in the realization of the In-Vessel-Components of Wendelstein 7-X. Fusion Engineering and Design 2013. [DOI: 10.1016/j.fusengdes.2013.03.054] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Lorenz A, Kleber B, Büttner M, Fuchs M, Mürbe D, Richter B, Sandel M, Nawka T. Validierung des Singing Voice Handicap Index in der deutschen Fassung. HNO 2013; 61:699-706. [DOI: 10.1007/s00106-013-2721-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Lorenz A, Rothstock S, Bobrowitsch E, Beck A, Gruhler G, Ipach I, Leichtle UG, Wülker N, Walter C. Cartilage surface characterization by frictional dissipated energy during axially loaded knee flexion--an in vitro sheep model. J Biomech 2013; 46:1427-32. [PMID: 23587299 DOI: 10.1016/j.jbiomech.2013.03.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Revised: 03/06/2013] [Accepted: 03/10/2013] [Indexed: 11/18/2022]
Abstract
Cartilage defects and osteoarthritis (OA) have an increasing incidence in the aging population. A wide range of treatment options are available. The introduction of each new treatment requires controlled, evidence based, histological and biomechanical studies to identify potential benefits. Especially for the biomechanical testing there is a lack of established methods which combine a physiologic testing environment of complete joints with the possibility of body-weight simulation. The current in-vitro study presents a new method for the measurement of friction properties of cartilage on cartilage in its individual joint environment including the synovial fluid. Seven sheep knee joints were cyclically flexed and extended under constant axial load with intact joint capsule using a 6° of freedom robotic system. During the cyclic motion, the flexion angle and the respective torque were recorded and the dissipated energy was calculated. Different mechanically induced cartilage defect sizes (16 mm², 50 mm², 200 mm²) were examined and compared to the intact situation at varying levels of the axial load. The introduced setup could significantly distinguish between most of the defect sizes for all load levels above 200 N. For these higher load levels, a high reproducibility was achieved (coefficient of variation between 4% and 17%). The proposed method simulates a natural environment for the analysis of cartilage on cartilage friction properties and is able to differentiate between different cartilage defect sizes. Therefore, it is considered as an innovative method for the testing of new treatment options for cartilage defects.
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Affiliation(s)
- Andrea Lorenz
- Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Straße 3, 72076 Tübingen, Germany
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Kruck S, Leichtle U, Lorenz A, Sievert KD, Bedke J, Stenzl A. 1550 NANOTECHNOLOGY: 1.2F BASKETS FURTHER ENHANCE IRRIGATION FLOW IN FLEXIBLE URETERORENOSCOPY. J Urol 2013. [DOI: 10.1016/j.juro.2013.02.3060] [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: 11/29/2022]
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41
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Seidel G, Blessin J, Ringer T, Schulz K, Lorenz A, Witte O, Hamzei F. Wo werden Objekte bei Jungen und Alten gelernt? Eine multimodale Imagingstudie. KLIN NEUROPHYSIOL 2013. [DOI: 10.1055/s-0033-1337214] [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: 10/27/2022]
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Walter C, Leichtle U, Lorenz A, Mittag F, Wülker N, Müller O, Bobrowitsch E, Rothstock S. Dissipated energy as a method to characterize the cartilage damage in large animal joints: an in vitro testing model. Med Eng Phys 2013; 35:1251-5. [PMID: 23375506 DOI: 10.1016/j.medengphy.2013.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [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: 12/02/2011] [Revised: 01/02/2013] [Accepted: 01/08/2013] [Indexed: 11/29/2022]
Abstract
Several quantitative methods for the in vitro characterization of cartilage quality are available. However, only a few of these methods allow surgical cartilage manipulations and the subsequent analysis of the friction properties of complete joints. This study introduces an alternative approach to the characterization of the friction properties of entire joint surfaces using the dissipated energy during motion of the joint surfaces. Seven sheep wrist joints obtained post mortem were proximally and distally fixed to a material testing machine. With the exception of the carpometacarpal articulation surface, all joint articulations were fixed with 'Kirschner' wires. Three cartilage defects were simulated with a surgically introduced groove (16 mm(2), 32 mm(2), 300 mm(2)) and compared to intact cartilage without an artificial defect. The mean dissipated energy per cycle was calculated from the hysteresis curve during ten torsional motion cycles (±10°) under constant axial preload (100-900 N). A significant increase in dissipated energy was observed with increasing cartilage defect size and axial load (p<0.001). At lower load levels, the intact and 16 mm(2) defect showed a similar dissipated energy (p>0.073), while all other defect conditions were significantly different (p=0.015). All defect sizes were significantly different (p=0.049) at 900 N axial load. We conclude that the method introduced here could be an alternative for the study of cartilage damage, and further applications based on the principles of this method could be developed for the evaluation of different cartilage treatments.
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Bedke J, Leichtle U, Lorenz A, Nagele U, Stenzl A, Kruck S. 1.2 French stone retrieval baskets further enhance irrigation flow in flexible ureterorenoscopy. Urolithiasis 2013; 41:153-7. [PMID: 23503877 DOI: 10.1007/s00240-012-0540-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 12/18/2012] [Indexed: 11/25/2022]
Abstract
Ureterorenoscopy (URS) has revolutionized upper urinary tract stone therapy. However, the size of the working channel and the stone baskets limit irrigation flow as well as vision. This study determined further improvements of irrigation flow, deflection capacities and impairments of breaking resistance in a new 1.2 French (F) ultra-miniaturized basket. Irrigation measurements were performed in semirigid URS (semiURS, working channel 5F) and in flexible URS (flexURS, 3.6F) in 0°, 90° and 270° deflection with 1.2F, 1.8F, 1.9F and 2.2F baskets and compared with empty channel. Breaking strength of 1.2F, 1.8F and 1.9F baskets were evaluated using a material testing machine. Tested baskets affected irrigation in semiURS and flexURS (p < 0.05). Mean ± SEM (standard error of the mean) for semiURS flow rates counted 197.1 ± 2.0, 140.9 ± 1.6, 111.1 ± 1.5, 98.0 ± 1.3 and 77.1 ± 0.9 ml/min for empty channel, 1.2F, 1.8F, 1.9F and 2.2F baskets (p < 0.05). Using unbent flexURS flow rates of 44.2 ± 0.4, 20.4 ± 0.2, 5.9 ± 0.1, 5.4 ± 0.1 and 1.5 ± 0.1 ml/min for empty channel, 1.2F, 1.8F, 1.9F and 2.2F baskets, were observed (p < 0.05). The 1.2F versus 2.2F basket showed a 13.6-fold increase in flexURS irrigation (p < 0.05), while only the 2.2F basket reduced deflection by 20.3 %. The breaking strength decreased with a reduced basket size (1.2F: 6.4 ± 0.46 vs. 1.8F: 16.8 ± 2.79 vs. 1.9F: 32.2 ± 2.74 N, p < 0.05). Ultra-miniaturized baskets of 1.2F ensured a sufficient irrigation flow as needed for high quality vision in URS stone management. However, miniaturization of the 1.2F basket resulted in a reduced breaking strength compared with larger sized devices which in turn may hamper stone removal by an increased vulnerability.
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Affiliation(s)
- Jens Bedke
- Department of Urology, University of Tuebingen, Tuebingen, Germany.
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Lorenz A, Müller O, Kohler P, Wünschel M, Wülker N, Leichtle UG. The influence of asymmetric quadriceps loading on patellar tracking--an in vitro study. Knee 2012; 19:818-22. [PMID: 22633902 DOI: 10.1016/j.knee.2012.04.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 04/27/2012] [Accepted: 04/30/2012] [Indexed: 02/02/2023]
Abstract
BACKGROUND In patients with anterior knee pain and patellar instability, a specific training of the quadriceps muscle - especially the vastus medialis - is often recommended, although the practicability is discussed controversially and the proof of a measurable clinical effect is difficult. Therefore, this in vitro study investigates the influence of asymmetric muscle loading on the motion of the human patella. METHODS Seven human knee specimens were tested in a specially developed knee simulator. During simulated weight-bearing knee flexion, the kinematics of tibia, femur and patella were measured using an ultrasound motion capture system. The quadriceps forces were controlled to achieve a constant ankle force over the whole flexion range which is assumed to represent almost physiological loading. Three different force distributions of the quadriceps were tested - a central, equally distributed load as well as mainly lateral and medial loads. RESULTS A significant influence of different quadriceps force distributions was found for patellar tilt around a proximodistal axis (up to 1.7°) and patellar rotation around an anteroposterior axis (up to 3.8°) with respect to the femur. Interestingly, the patellar mediolateral shift was influenced only marginally (<1.5mm). CONCLUSIONS Specific muscle training might help patients with patellofemoral pain and cartilage damage by a slight modification of the kinematics, but we could show that even highly asymmetric quadriceps loads only led to a small alteration of the mediolateral shift in case of a physiologic anatomy of the trochlear groove.
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Affiliation(s)
- Andrea Lorenz
- Biomechanics Research Laboratory, Department of Orthopaedic Surgery, University Hospital Tübingen, Hoppe-Seyler-Strasse 3, 72076 Tübingen, Germany.
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Lorenz A, Herrmann C, Issinger O, Montenarh M. Phosphorylation of wild-type and mutant phenotypes of p53 by an associated protein-kinase. Int J Oncol 2012; 1:571-9. [PMID: 21584583 DOI: 10.3892/ijo.1.5.571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Immunopurified mutant mouse p53 from transformed cells is known to be tightly associated with a protein kinase which phosphorylates p53 in an in vitro kinase reaction. Wild-type p53 from a non-transformed cell line was not associated with a protein kinase whereas immunopurified wild-type p53 from a transformed cell line was tightly associated with a protein kinase which phosphorylated p53. In order to compare wild-type and mutant p53 in the same cellular environment both forms were cloned in a baculovirus expression system and in in vitro transcription/translation vectors and both p53 proteins were expressed in the two systems. Wild-type and mutant p53 from baculovirus infected insect cells were tightly associated with a protein kinase which phosphorylates p53. In contrast, immunopurified wild-type and mutant p53 from an in vitro transcription/translation reaction were not associated with a protein kinase but could be phosphorylated by added casein kinase II. Thus, in the present paper we demonstrate that the association of p53 with a protein kinase and the in vitro phosphorylation of p53 seems to depend on the surrounding cellular environment.
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Affiliation(s)
- A Lorenz
- UNIV SAARLAND,GEBAUDE 44,W-6650 HOMBURG,GERMANY. UNIV SAARLAND,INST HUMAN GENET,W-6650 HOMBURG,GERMANY
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Lorenz A, Lange B, Herzog Y, Schnauffer P, Wünschel M, Wülker N, Leichtle UG. THE INFLUENCE OF THE PATELLOFEMORAL GROOVE DESIGN ON PATELLA KINEMATICS AND PRESSURE IN TKA. J Biomech 2012. [DOI: 10.1016/s0021-9290(12)70386-x] [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: 10/28/2022]
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Rothstock S, Bobrowitsch E, Lorenz A, Beck A, Walter C, Leichtle U, Wülker N. CARTILAGE SURFACE CHARACTERIZATION BY FRICTIONAL DISSIPATIVE ENERGY DURING PASSIVE KNEE FLEXION. J Biomech 2012. [DOI: 10.1016/s0021-9290(12)70079-9] [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: 11/12/2022]
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Frank-Raue K, Leidig-Bruckner G, Lorenz A, Rondot S, Haag C, Schulze E, Büchler M, Raue F. [Hereditary variants of primary hyperparathyroidism--MEN1, MEN2, HPT-JT, FHH, FIHPT]. Dtsch Med Wochenschr 2011; 136:1889-94. [PMID: 21915802 DOI: 10.1055/s-0031-1286358] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
OBJECTIVE The challenge in diagnosing primary hyperparathyroidism (HPT) is to detect hereditary cases before first surgery. About 5% of cases are hereditary and integral component of multiple endocrine neoplasia type 1 and 2 (MEN1/MEN2), hyperparathyroidism-jaw tumor syndrome (HPT-JT), familial hypocalciuric hypercalcemia (FHH), and familial isolated hyperparathyroidism (FIHPT). Aim of this study was to evaluate similarities and differences in hereditary varieties of HPT. PATIENTS 80 patients with hereditary HPT were evaluated in a retrospective analysis between 1980 and 2010 concerning clinical findings, family history, therapy, biochemical and molecular-genetic findings and follow-up. RESULTS 80 patients with hereditary HPT are described, 52 belonged to MEN1, 15 to MEN2, 7 to HPT-JT, 4 to FHH and 2 to FIHPT kindreds. Penetrance of HPT was highest in MEN1 (85%), followed by HPT-JT (64%), FHH (28.5%), and MEN2 (8%). Youngest age at diagnosis of HPT was 7 and 16 years in the MEN2/HPT-JT group. Serum Calcium was highest in the HPT-JT group (3.6 mM), recurrencies of HPT were highest in the MEN1 group (40.5%). Parathyroid cancer solely occurred in the HPT-JT group. In single cases HPT occurs in FHH. CONCLUSION Among the different varieties of hereditary HPT MEN1-HPT is most frequent and carries the utmost recurrence rate. Early diagnosis of HPT-JT syndrome is important because of the occurrence of parathyroid cancer. Single cases of HPT in FHH are described. Preoperative diagnosis of hereditary HPT has therapeutic consequences concerning extent of surgery and implications concerning patient and family care.
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Affiliation(s)
- K Frank-Raue
- Endokrinologische Gemeinschaftspraxis und molekulargenetisches Labor, Heidelberg.
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Schleipen B, Hertrampf T, Fritzemeier KH, Kluxen FM, Lorenz A, Molzberger A, Velders M, Diel P. ERβ-specific agonists and genistein inhibit proliferation and induce apoptosis in the large and small intestine. Carcinogenesis 2011; 32:1675-83. [PMID: 21856997 DOI: 10.1093/carcin/bgr188] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Epidemiological data indicate that intake of estrogens and isoflavones may be beneficial for the prevention of colorectal cancer (CRC). Based on this data, the aim of the study was to investigate estrogen receptor (ER) subtype-specific effects on intestinal homeostasis. Ovariectomized (OVX) female Wistar rats were either treated with 17β-estradiol (4 μg/kg body wt/day) (E2), an ERα-specific agonist (ALPHA) (10 μg/kg body wt/day), an ERβ-specific agonist (BETA) (100 μg/kg body wt/day) or genistein (GEN) (10 mg/kg body wt/day) for three weeks. Vehicle-treated OVX and SHAM animals and those cotreated with BETA and the pure antiestrogen Fulvestrant (ICI 182780) (100 μg/kg body wt/day and 3 mg/kg body wt/day) served as controls. GEN and BETA treatment but not E2 and ALPHA administration reduced proliferation in ileal and colonic mucosa cells. The rate of apoptosis in the small intestine and colon was increased by treatment with BETA and GEN, but not by E2. BETA induced antiproliferative and proapoptotic activity also in SHAM animals. The effects were antagonized by the pure antiestrogen Fulvestrant. Polymerase chain reaction gene array analysis revealed that BETA resulted in the downregulation of the oncogene transformation-related protein 63 (p63). Our data indicate that activation of the ERβ by specific ERβ agonists and GEN induces antiproliferative and proapoptotic effects in the intestinal tract. This observation can be taken as an indication that intake of GEN and specific ERβ agonists may protect the ileal and colonic epithelium from tumor development via modulation of tissue homeostasis.
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Affiliation(s)
- B Schleipen
- Abt. Molekulare und Zelluläre Sportmedizin, Institut für Kreislaufforschung und Sportmedizin, Deutsche Sporthochschule Köln, Am Sportpark Müngersdorf 6, 50933 Cologne, Germany
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Leidig-Bruckner G, Roth HJ, Bruckner T, Lorenz A, Raue F, Frank-Raue K. Are commonly recommended dosages for vitamin D supplementation too low? Vitamin D status and effects of supplementation on serum 25-hydroxyvitamin D levels--an observational study during clinical practice conditions. Osteoporos Int 2011; 22:231-40. [PMID: 20556359 DOI: 10.1007/s00198-010-1214-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Accepted: 01/19/2010] [Indexed: 12/14/2022]
Abstract
UNLABELLED Vitamin D deficiency is associated with increased fracture risk. The observational study aimed to investigate vitamin D status and supplementation in ambulatory patients. Only 20% of patients had optimal serum 25-hydroxyvitamin D [25(OH)D] levels. Commonly recommended dosages were insufficient to achieve clinically relevant increase of 25(OH)D levels. Higher dosages were safe and effective under clinical practice conditions. INTRODUCTION Vitamin D deficiency is associated with adverse health outcome. The study aimed to investigate vitamin D status and supplementation in ambulatory patients. METHODS Nine hundred seventy-five women and 188 men were evaluated for bone status from January 2008 to August 2008 within an observational study; 104 patients (n = 70 osteoporosis) received follow-up after 3 months. Dosage of vitamin D supplementation was documented and serum 25(OH)D and parathyroid hormone (PTH) determined. RESULTS In all patients (age, 60.4 ± 14.1 years), distribution of 25(OH)D was 56.3 ± 22.3 nmol/L (normal range, 52-182 nmol/L) and PTH 53.8 ± 67.5 ng/L (normal range, 11-43 ng/L). The proportion of patients with 25(OH)D < 25, 25 to <50, 50 to <75, ≥75 nmol/L was 7.5%, 33.3%, 38.9% and 20.2% in the total group and 20.1%, 38.5%, 30.8%, 10.6% at baseline in the follow-up group, respectively. After 3 months, 3.9% had still 25(OH)D < 25 nmol/L; only 12.5% achieved 25(OH)D ≥ 75 nmol/L. In osteoporosis patients, 25(OH)D increased more in those taking ≥1,500 (median, 3,000) IU vitamin D per day (33.1 ± 14.7 nmol/L) compared with ≤1,000 (median, 800) IU/day (10.6 ± 20.0 nmol/L) (p < 0.0008). PTH decreased more in patients taking ≥1,500 IU/day (-13.2 ± 15.2 ng/L) compared with ≤1,000 IU/day (-7.6 ± 19.2 ng/L; p = 0.29). 25(OH)D was negatively correlated to PTH (r = -0.49, p < 0.0001). An increase of 25(OH)D ≥ 75 nmol/L resulted in normalised PTH. CONCLUSION Supplementation with higher vitamin D dosages (2,000-3,000 IU/day) is required to achieve a relevant increase of 25(OH)D and normalisation of PTH.
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Affiliation(s)
- G Leidig-Bruckner
- Gemeinschaftspraxis für Endokrinologie, Nuklearmedizin und Humangenetik, Brückenstr. 21, 69120, Heidelberg, Germany.
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