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Claikens T, Rezaie W, Simons P. Turf Toe Injury: A Pictorial Review and a Didactic Case Report. Semin Musculoskelet Radiol 2024; 28:213-217. [PMID: 38484773 DOI: 10.1055/s-0043-1775863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Hyperextension of the first metatarsophalangeal joint can lead to a turf toe injury of the plantar plate complex, resulting in significant morbidity for athletes. This article reviews the anatomy, pathophysiology, classification, and imaging findings of turf toe injuries. In turf toe trauma, many different structures can be injured, with the sesamoid-phalangeal ligaments the most common. Diagnosis, classification, and treatment options rely on clinical evaluation and specific magnetic resonance imaging findings. It is vital for radiologists to understand the anatomy, pathophysiology, and imaging findings of turf toe injuries to ensure an accurate diagnosis and appropriate management.
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Vaniqui A, Meevisser-Dijcks C, Simons P, Hanbeukers B, de Rooy M, Canters R, van Elmpt W. MO-0643 PlanQA: a tool for treatment planning education through quantitative and qualitative analysis. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)02401-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Van Slycke S, Simons AS, Van Den Heede K, Van Crombrugge P, Tournoy K, Simons P, Vermeersch H, Brusselaers N. Combined cervicosternotomy and cervicotomy for true retrosternal goiters: a surgical cohort study. Updates Surg 2021; 73:1-10. [PMID: 33779950 PMCID: PMC8397680 DOI: 10.1007/s13304-021-01027-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 03/11/2021] [Indexed: 11/28/2022]
Abstract
Objective Intrathoracic goiters are a heterogeneous group characterized by limited or extensive substernal extension. Whereas the former can be treated through cervicotomy, the latter sometimes requires a cervicosternotomy. Whether cervicosternotomy leads to more morbidity remains unclear. This study aimed to compare intra- and postoperative morbidity in patients treated by cervicotomy or cervicosternotomy for intrathoracic goiters and standard thyroidectomy. Methods In a prospectively gathered cohort undergoing thyroid surgery (2010–2019) intra- and postoperative morbidity of cervicotomy (N = 80) and cervicosternotomy (N = 15) for intrathoracic goiters was compared to each other and to a ‘standard’ thyroidectomy (N = 1500). Results An intrathoracic extension prior to surgery was found in 95 (6%) of all thyroidectomies. Eighty patients (84%) were operated by cervicotomy and 15 (16%) by cervicosternotomy. The risk of temporary recurrent laryngeal nerve palsy was much higher in the cervicosternotomy group (21%) compared to cervicotomy (4%) and standard thyroidectomy (3%). The risk of temporary hypocalcemia after cervicotomy (28%) was comparable to a standard thyroidectomy (32%) but higher after cervicosternotomy (20%). No cases of permanent hypocalcemia or laryngeal nerve palsy were observed in both groups with substernal extension. The need for surgical reintervention was significantly higher in the cervicotomy group (6%) compared to cervicosternotomy (0%) and standard thyroidectomy (3%). Conclusion In patients undergoing thyroid surgery for an intrathoracic goiter, cervicosternotomy was associated with more temporary laryngeal nerve palsy, but none of the interventions resulted in higher risks of permanent nerve damage, permanent hypocalcemia, or reintervention for bleeding. Reintervention was even more common after cervicotomy compared to cervicosternotomy. Level of evidence IV Supplementary Information The online version contains supplementary material available at 10.1007/s13304-021-01027-1.
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Logghe Y, Van Hoe L, Vanhoenacker P, Bladt O, Simons P, Kersschot E, Van Mieghem C. Clinical impact of CT coronary angiography without exclusion of small coronary artery segments: a real-world and long-term study. Open Heart 2020; 7:openhrt-2019-001222. [PMID: 32385115 PMCID: PMC7228654 DOI: 10.1136/openhrt-2019-001222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 04/02/2020] [Accepted: 04/03/2020] [Indexed: 11/04/2022] Open
Abstract
OBJECTIVES CT coronary angiography (CTCA) has become a valuable diagnostic test in the workup of patients with possible coronary artery disease (CAD). Because of inherent limitations in spatial resolution, epicardial vessels with a small diameter, in general less than 1.5-2 mm, have so far been excluded in studies assessing clinical utility of CTCA. This study sought to assess the clinical impact of CTCA taking into account pathology in small coronary arteries. METHODS We conducted a retrospective cohort study of all patients with possible CAD who underwent dual-source CTCA and subsequent invasive coronary angiography (ICA) between January 2010 and July 2017. Patients with an Agatston calcium score ≥1000 were reported separately. Diagnostic accuracy of CTCA on a patient, vessel and segment level was calculated. The physician's therapeutic decision was defined as conservative, medical antianginal treatment or revascularisation. Using ICA as the reference, we calculated the precision of CTCA to replicate these therapeutic recommendations. RESULTS In total, 1209 patients underwent both CTCA and ICA. Overall diagnostic performance of CTCA showed a sensitivity of 90% (95% CI 86% to 93%) and specificity of 40% (95% CI 36% to 45%). With regard to clinical decision making, CTCA showed good performance: 91% of patients who were treated medically or by revascularisation were correctly identified. Prevalence of disease in small vessel segments was low: 16% showed significant CAD on ICA. Prevalence of significant disease was 70% in patients with an Agatston score ≥1000: the majority underwent revascularisation. CONCLUSIONS From a true patient perspective, without exclusion of smaller coronary artery segments, CTCA allows safe patient management.
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Monizzi G, Sonck J, Nagumo S, Buytaert D, Van Hoe L, Grancini L, Bartorelli AL, Vanhoenacker P, Simons P, Bladt O, Wyffels E, De Bruyne B, Andreini D, Collet C. Quantification of calcium burden by coronary CT angiography compared to optical coherence tomography. Int J Cardiovasc Imaging 2020; 36:2393-2402. [DOI: 10.1007/s10554-020-01839-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 04/03/2020] [Indexed: 12/26/2022]
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Hulstaert T, Shahabpour M, Provyn S, Lenchik L, Simons P, Vanheste R, De Maeseneer M. Forefoot Pain in the Lesser Toes: Anatomical Considerations and Magnetic Resonance Imaging Findings. Can Assoc Radiol J 2019; 70:408-415. [PMID: 31685098 DOI: 10.1016/j.carj.2019.06.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 06/19/2019] [Accepted: 06/27/2019] [Indexed: 01/29/2023] Open
Abstract
Various conditions may result in forefoot pain. Magnetic resonance (MR) imaging allows accurate assessment of many of these conditions. We provide an overview of forefoot disorders divided into bones, capsule and plantar plate, musculotendinous structures, neurovascular structures, and subcutaneous tissue. We review normal anatomical features as well as MR imaging findings of common disorders.
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Braspenningx S, Rezaie W, Simons P. Stener-like lesion of the lateral collateral ligament of the first metatarsophalangeal joint. Skeletal Radiol 2018; 47:413-417. [PMID: 29038920 DOI: 10.1007/s00256-017-2790-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 10/02/2017] [Accepted: 10/04/2017] [Indexed: 02/02/2023]
Abstract
Displaced ulnar collateral ligament injuries of the metacarpophalangeal joint of the thumb, also known as Stener lesions, are a well-recognized clinical entity, requiring surgical intervention because of the trapped location of the torn lateral collateral ligament superficial to the adductor aponeurosis of the thumb. We report a similar lesion located at the first metatarsophalangeal joint, to our knowledge the first ever described in the literature. In our patient, magnetic resonance imaging showed a full-thickness tear of the lateral collateral ligament of the first metatarsophalangeal joint, as well as a full-thickness tear of the extensor hood, with dislocation of the proximal part of the ruptured lateral collateral ligament to a position superficial to the extensor hood. Analogous to true Stener lesions, we are convinced these patients also need early surgical repair. Therefore, we would like to raise awareness about their existence to ensure adequate management of these lesions, in order to prevent possible long-term complications like chronic pain, instability, and joint degeneration.
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Hallbauer J, Klos K, Gräfenstein A, Simons P, Rausch S, Mückley T, Hofmann GO. Does a polyaxial-locking system confer benefits for osteosynthesis of the distal fibula: A cadaver study. Orthop Traumatol Surg Res 2016; 102:645-9. [PMID: 27179630 DOI: 10.1016/j.otsr.2016.03.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Revised: 03/01/2016] [Accepted: 03/15/2016] [Indexed: 02/02/2023]
Abstract
BACKGROUND In plate osteosynthesis involving the distal fibula, antiglide plating is superior to lateral plating in terms of the biomechanical properties. The goal of this study was to examine whether polyaxial-locking implants confer additional benefits in terms of biomechanical stability. METHODS Seven pairs of human cadaveric fibulae were subjected to osteotomy in a standardized manner to simulate an uncomplicated Weber B fracture. The generated fractures were managed with a dorsolateral antiglide plate. To this end, one fibula of the pair was subjected to non-locking plating and the other to polyaxial-locking plating. Biomechanical tests included quantification of the primary bending and torsional stiffness. In addition, the number of cycles to failure in cyclic bending loading were determined and compared. Bone mineral density was measured in all specimens. RESULTS Bone mineral density was comparable in both groups. Primary stability was higher in the polyaxial-locking group under torsional loading, and higher in the non-locking group under bending loading. The differences, however, were not statistically significant. All specimens except for one fixed-angle construct failed the cyclic loading test. The number of cycles to failure did not differ significantly between polyaxial-locking and non-locking fixation. CONCLUSION In a cadaveric Weber B fracture model, we observed no differences in biomechanical properties between polyaxial-locking and non-locking fixation using an antiglide plate. Based on the biomechanical considerations, no recommendation can be made regarding the choice of the implant. Further biomechanical and clinical studies are required. CLINICAL RELEVANCE Information on the behavior of polyaxial-locking plates is relevant to surgeons performing internal fixation of distal fibula fractures.
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Dullaert K, Hagen J, Klos K, Gueorguiev B, Lenz M, Richards RG, Simons P. The influence of the Peroneus Longus muscle on the foot under axial loading: A CT evaluated dynamic cadaveric model study. Clin Biomech (Bristol, Avon) 2016; 34:7-11. [PMID: 27015031 DOI: 10.1016/j.clinbiomech.2016.03.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 02/29/2016] [Accepted: 03/02/2016] [Indexed: 02/07/2023]
Abstract
BACKGROUND Subtle hypermobility of the first tarsometatarsal joint can occur concomitantly with other pathologies and may be difficult to diagnose. Peroneus Longus muscle might influence stability of this joint. Collapse of the medial longitudinal arch is common in flatfoot deformity and the muscle might also play a role in correcting Meary's angle. METHODS A radiolucent frame was used to simulate weightbearing during CT examination. Eight pairs fresh-frozen lower legs were imaged in neutral position under non-weightbearing (75N), weightbearing (700N) and with 15kg weights hung from Peroneus Longus tendon. Measurements included first metatarsal rotation, intermetatarsal angle, first tarsometatarsal joint subluxation and Meary's angle. FINDINGS Weightbearing significantly increased Meary's angle and significantly decreased first tarsometatarsal joint subluxation (both P<0.01). Pulling Peroneus Longus tendon significantly increased first metatarsal rotation (P<0.01), significantly decreased the intermetatarsal angle (P<0.01) and increased non-significantly Meary's angle (P=0.52). INTERPRETATION A considerable effect weightbearing has on the medial longitudinal arch and first tarsometatarsal joint was observed. Pulling Peroneus Longus tendon improved first metatarsal subluxation but increased its rotation. The study calls into question the importance of this tendon in maintaining the medial longitudinal arch and raises concerns about rotational deformity of the first metatarsal following hallux valgus correction without first tarsometatarsal arthrodesis. CLINICAL RELEVANCE Study outcomes will provide more insight in foot pathology. WHAT IS KNOWN ABOUT THE SUBJECT Weightbearing affects anatomy of the foot. No reliable information is available concerning the influence of the Peroneus muscle. WHAT THIS STUDY ADDS TO EXISTING KNOWLEDGE This study investigates the influence of weightbearing and the impact the Peroneus muscle on the anatomy of the foot.
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Simons P, Houben R, Backes H, Reijnders P, Jacobs M. SP-0601: Does lean management improve patient safety culture? Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)31851-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Bergs J, Hellings J, Cleemput I, Simons P, Zurel Ö, Vertriest S, Vandijck D. Surgical Safety Checklists: an Update. Acta Chir Belg 2016. [DOI: 10.1080/00015458.2014.11681015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Bergs J, Hellings J, Cleemput I, Simons P, Zurel Ö, Vertriest S, Vandijck D. Surgical safety checklists : an update. Acta Chir Belg 2014; 114:219-224. [PMID: 26021414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Surgical safety checklists aim to improve patient safety by prompting the attention of the surgical team towards critical steps during the operation. The checklist's items are aimed to improve compliance with proven interventions, and to facilitate multidisciplinary communication and teamwork. Based on the current literature, corroborated by systematic reviews and meta-analysis, surgical safety checklists have a positive impact on communication and reduce postoperative complications including mortality. However, despite their effectiveness, the implementation of these checklists is not straightforward. Several determinants leading to behaviour were checklists are checked but not properly executed have been highlighted. As surgical safety checklists are in essence complex sociological interventions, they must be implemented accordingly. Key factors for the implementation of these checklists have been suggested in the literature, although, the most profound way of implementation remains unclear.
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Walther M, Simons P, Nass K, Röser A. Die Arthrodese des Tarsometatarsal-I-Gelenks mit einer plantaren Zuggurtungsosteosynthese. OPERATIVE ORTHOPADIE UND TRAUMATOLOGIE 2011; 23:52-9. [DOI: 10.1007/s00064-010-0006-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Kuchta J, Simons P. Spinal neurosurgery with the head-mounted "Varioscope" microscope. CENTRAL EUROPEAN NEUROSURGERY 2009; 70:98-100. [PMID: 19711265 DOI: 10.1055/s-0028-1087213] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We present a preliminary report on the intra-operative use of a head-mounted microscope ("Varioscope" Leica HM500) in spinal neurosurgery. The Varioscope is a dynamic microscope mounted on a head-set. It weights 297 g and measures 73 x 120 x 63 mm (length x width x height). It offers an infinitely variable range of magnification from 3.6x to 7.2x. The working distance ranges from 300 to 600 mm. The field of view varies between 30-144 mm, depending on the selected enlargement factor and the working distance. In addition to the zoom function, the device offers a focus function (automatic or on demand). The optical elements for focus and zoom are located in two separate tubes which are mounted on a middle section containing the mechanical components as well as the receiver unit for the focussing elements. The lenses are adjusted by means of motor-driven push/pull cables. The autofocus works well in larger operative fields and a working distance between 30 and 60 cm. Nevertheless, when used in today's "keyhole" approaches, the autofocus is not helpful when operating in deep structures. Based on the satisfactory results achieved in our series, we can recommend the Varioscope, especially when no stationary microscope is available. The portable device can be packed in a suitcase and can travel with the consultant microsurgeon to different hospitals and distant units. The built-in video camera is ideal for patients, staff, assistant surgeons, and student education with real-time video monitoring of procedures from the microsurgeon's perspective. For daily microsurgery, we felt more comfortable with fixed, stationary operating microscopes.
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Niggemann P, Simons P, Kuchta J, Beyer HK, Frey H, Grosskurth D. Spondylolisthesis and posterior instability. Acta Radiol 2009; 50:301-5. [PMID: 19253068 DOI: 10.1080/02841850902755278] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
We present the case of a patient with a spondylolisthesis of L5 on S1 due to spondylolysis at the level L5/S1. The vertebral slip was fixed and no anterior instability was found. Using functional magnetic resonance imaging (MRI) in an upright MRI scanner, posterior instability at the level of the spondylolytic defect of L5 was demonstrated. A structure, probably the hypertrophic ligament flava, arising from the spondylolytic defect was displaced toward the L5 nerve root, and a bilateral contact of the displaced structure with the L5 nerve root was shown in extension of the spine. To our knowledge, this is the first case described of posterior instability in patients with spondylolisthesis. The clinical implications of posterior instability are unknown; however, it is thought that this disorder is common and that it can only be diagnosed using upright MRI.
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Nonent M, Thouveny F, Simons P, Cappeliez O, Reiser MF, Duddalwar V, Bonomo L, Liessi G. Iodixanol in multidetector-row computed tomography angiography (MDCTA): diagnostic accuracy for abdominal aorta and abdominal aortic major-branch diseases using four-, eight- and 16-detector-row CT scanners. Acta Radiol 2007; 48:48-58. [PMID: 17325925 DOI: 10.1080/02841850601067629] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To compare iodixanol-enhanced multidetector-row computed tomography angiography (MDCTA) with digital subtraction angiography (DSA), perioperative angiography, or surgical findings in the evaluation of the abdominal aorta and its main branches. MATERIAL AND METHODS 173 patients with known or suspected aortic aneurysms or stenosis/occlusion of the abdominal aorta or its major branches were enrolled. The iso-osmolar contrast medium iodixanol (320 mg Iota/ml) was used, and data were acquired using four-, eight-, or 16-active-detector-row scanners. Reference diagnoses were provided by surgical findings, interventional findings, or DSA. Diagnostic accuracy was estimated with reference to surgery or interventional arteriography or DSA. Image quality was assessed as excellent, good, sufficient, or insufficient, and correlations were made with attenuation values in the aortic lumen. Tolerability of iodixanol was monitored during the injection for discomfort and other adverse events, and for 72 hours after contrast injection. RESULTS In 132 of 136 evaluable cases, MDCTA diagnosis matched the reference diagnosis, yielding an agreement rate of 97.1% (95% CI 92.6-99.2%). The quality of most MDCTA scans (147/173) was rated as excellent. Overall mean attenuation was 305.7 HU. MDCTA appeared more accurate than DSA for identification of lesion calcification, thrombus, irregularity, and ulceration. Tolerability of iodixanol was good, and no serious adverse events were reported. CONCLUSION MDCTA using iodixanol is a promising, noninvasive alternative for evaluating patients with abdominal aortic disease.
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Visser P, Reijnders P, van den Boogaard J, Jager J, Simons P, Meertens N, Dautzenberg S, Langen B. 132 Application of a general safety management system in radiotherapy, from an organizational to a national level. Radiother Oncol 2005. [DOI: 10.1016/s0167-8140(05)81108-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Schmitz-Dumont O, Simons P, Broja G. Über Schwermetallamide, V. Mitteilung. Über die Darstellung und Eigenschaften des Titan(III)-amids. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/zaac.19492580319] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Abstract
This is the first case reported of vomiting-induced metabolic alkalosis associated with myoclonus. The report describes an unusual presentation of myoclonus secondary to acid-base disturbance caused by recreational drug-induced vomiting. The severe derangement of hyponatraemia, hypokalaemia, and alkalosis appears to have been reasonably well tolerated due to the gradual onset and relatively long history. The causes, mechanism, and management of metabolic alkalosis are discussed.
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Waller A, Simons P, Prossnitz ER, Edwards BS, Sklar LA. High throughput screening of G-protein coupled receptors via flow cytometry. Comb Chem High Throughput Screen 2003; 6:389-97. [PMID: 12769683 DOI: 10.2174/138620703106298482] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The molecular assemblies of signal transduction components, for example kinases and their target proteins or receptor-ligand complexes and intracellular signaling molecules, are critical for biological functions in cells. To better understand the interactions of these molecular assemblies and to screen for new pharmaceutics that could control and modulate these types of interactions, we have focused on developing high throughput approaches for the analysis of G-protein coupled receptors via flow cytometry. Flow cytometry offers a number of advantages including real-time collection of multicomponent data, and together with improvements in sample handling, the high throughput sampling rate is up to 100 samples per minute. For our targets, assemblies of solubilized GPCRs, a screening platform of a dextran bead has proven to be flexible, allowing different surface chemistries on the beads. The bead can be either ligand-labeled or have epitope-linked proteins attached to the bead surface, enabling several molecular assemblies to be constructed and analyzed. A major improvement with this system is that for screening ligands for GPCRs the underlying mechanism of action for these compounds can be investigated and incorporated into the definition of a 'hit'. Our current screening system is capable of simultaneously distinguishing GPCR agonists and antagonists.
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Buranda T, Lopez GP, Simons P, Pastuszyn A, Sklar LA. Detection of epitope-tagged proteins in flow cytometry: fluorescence resonance energy transfer-based assays on beads with femtomole resolution. Anal Biochem 2001; 298:151-62. [PMID: 11700971 DOI: 10.1006/abio.2001.5363] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Epitope tagging of expressed proteins is a versatile tool for the detection and purification of the proteins. This approach has been used in protein-protein interaction studies, protein localization, and immunoprecipitation. Among the most popular tag systems is the FLAG epitope tag, which is recognized by three monoclonal antibodies M1, M2, and M5. We describe novel approaches to the detection of epitope-tagged proteins via fluorescence resonance energy transfer on beads. We have synthesized and characterized biotinylated and fluorescein-labeled FLAG peptides and examined the binding of FLAG peptides to commercial streptavidin beads using flow cytometric analysis. A requirement of assay development is the elucidation of parameters that characterize the binding interactions between component systems. We have thus compiled a set of Kd values determined from a series of equilibrium binding experiments with beads, peptides, and antibodies. We have defined conditions for binding biotinylated and fluoresceinated FLAG peptides to beads. Site occupancies of the peptides were determined to be on the order of several million sites per bead and Kd values in the 0.3-2.0 nM range. The affinity for antibody attachment to peptides was determined to be in the low nanomolar range (less than 10 nM) for measurements on beads and solution. We demonstrate the applicability of this methodology to assay development, by detecting femtomole amounts of N-terminal FLAG-bacteria alkaline phosphatase fusion protein. These characterizations form the basis of generalizable and high throughput assays for proteins with known epitopes, for research, proteomic, or clinical applications.
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Nieuwkerk P, Gisolf E, Sprangers M, Danner S, Gisolf EH, Reiss P, Weverling GJ, Duurvoort M, Krijger E, Brouwer E, Visser GR, Klotz A, Benschop C, Wulfert F, Danner SA, de Wolf F, Jurriaans S, Portegies P, Colebunders R, Pelgrom J, Wijnants H, de Roo A, Keersmaekers K, Vandenbruane M, van den Brande D, James T, van Wanzeele F, van der Gucht B, van der Ende ME, Nouwen J, Deenenkamp R, van der Meyden D, Koopmans PP, Brinkman K, ter Hofstede H, Zomer B, Blok WL, Ruissen C, Sprenger H, Law G, van der Meulen P, ten Veen C, Juttmann JR, van der Heul C, Santegoets R, van der Ven B, Gasthuis K, haarlem, ten Kate RW, Schoemaker M, Kauffmann RH, Henrichs JM, Maat A, Prins E, ten Napel CH, Pogany K, Duyts T, Lansink T, Simons P, Lacor P, de Waele A, van Wijngaarden E, Lejeune M, Scholte R, Dijkman J. Adherence over 48 Weeks in An Antiretroviral Clinical Trial: Variable within Patients, Affected by Toxicities and Independently Predictive of Virological Response. Antivir Ther 2001. [DOI: 10.1177/135965350100600203] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objectives To investigate adherence to antiretroviral therapy over 48 weeks, to investigate the association between adherence and treatment-related symptoms and to investigate the impact of adherence on virological response over 48 weeks among established predictors of treatment success. Methods One-hundred-and-sixty HIV-1 infected protease inhibitor- and stavudine-naive patients participating in a trial of ritonavir/saquinavir versus ritonavir/saquinavir/ stavudine completed an adherence questionnaire and a symptom checklist at weeks 12, 24, 36 and 48. We calculated odds ratios between experienced symptoms and non-adherence. Regression models were used to determine predictors of HIV-1 RNA below 400 copies/ml at week 48, and of the area about the change from baseline over 48 weeks (ACFB) in serum HIV-1 RNA. Results The percentage of patients reporting missing medication, deviation from time schedule, and dietary prescriptions at separate time-points ranged from 12 to 15%, 32 to 35% and 17 to 22%, respectively. The percentage that changed their level of adherence during 48 weeks ranged from 29% for skipping medication to 48% for deviation from time-schedule. Experienced side-effects were associated with an increased likelihood of non-adherence. Not skipping medication was an independent predictor of both having a serum HIV-1 RNA below 400 copies/ml at week 48 and the ACFB over 48 weeks in serum HIV-1 RNA. Conclusions Adherence was an independent predictor of virological response over 48 weeks. The level of adherence is variable within patients over time. This suggests the need for continued adherence monitoring in all patients as part of standard medical practice.
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Simons P. Doing it for themselves. Br Dent J 2001; Suppl:12. [PMID: 11246992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
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Vanhoenacker P, Vanhoenacker F, Crevits I, Simons P, Van Dyck P. MR arthrography of the rotator cuff and capsulolabral complex. JBR-BTR : ORGANE DE LA SOCIETE ROYALE BELGE DE RADIOLOGIE (SRBR) = ORGAAN VAN DE KONINKLIJKE BELGISCHE VERENIGING VOOR RADIOLOGIE (KBVR) 2000; 83:313-8. [PMID: 11210685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
MR arthrography of the shoulder has reached maturity in recent years. As opposed to conventional MRI of the shoulder it is less prone to artefacts frequently leading to equivocal interpretation. The spectrum of pathology in which MR arthrography has significant advantages is reviewed, with emphasis on the rotator cuff and the capsulolabral complex.
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Kroft LJ, Simons P, van Laar JM, de Roos A. Patients with pulmonary fibrosis: cardiac function assessed with MR imaging. Radiology 2000; 216:464-71. [PMID: 10924571 DOI: 10.1148/radiology.216.2.r00jl06464] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
PURPOSE To detect abnormalities in cardiac function by using magnetic resonance (MR) imaging in patients with mild to moderate pulmonary fibrosis and to evaluate the relationship between pulmonary function and cardiac function. MATERIALS AND METHODS Sixteen patients were compared with 16 sex- and age-matched healthy control subjects. Systolic function was assessed by using multisection multiphase cine MR imaging. Diastolic function was assessed with flow-sensitive MR imaging across the mitral and tricuspid valves. MR imaging results were compared with the severity of impairment in pulmonary function. RESULTS Biventricular systolic function and left ventricular diastolic function were normal in patients, but right ventricular diastolic function was significantly impaired versus that of control subjects, with a ratio of peak flow during early diastolic (E) filling to peak flow during atrial contraction (A) of 0.85 +/- 0.40 versus 1.28 +/- 0.50 (P =.035). Biventricular E/A ratios were strongly correlated to age in patients and control subjects. The right ventricular E/A ratio in patients corresponded with values that are normally expected in people 20 years older. Diastolic left and right ventricular functions were significantly correlated with each other. There was no relationship between pulmonary function and cardiac function. CONCLUSION Impairment of right ventricular diastolic function was found by using MR imaging in patients with mild to moderate pulmonary fibrosis, whereas left ventricular diastolic function and biventricular systolic function were preserved.
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