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Thwaites PA, Yao CK, Halmos EP, Muir JG, Burgell RE, Berean KJ, Kalantar‐zadeh K, Gibson PR. Review article: Current status and future directions of ingestible electronic devices in gastroenterology. Aliment Pharmacol Ther 2024; 59:459-474. [PMID: 38168738 PMCID: PMC10952964 DOI: 10.1111/apt.17844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Revised: 10/15/2023] [Accepted: 12/13/2023] [Indexed: 01/05/2024]
Abstract
BACKGROUND Advances in microelectronics have greatly expanded the capabilities and clinical potential of ingestible electronic devices. AIM To provide an overview of the structure and potential impact of ingestible devices in development that are relevant to the gastrointestinal tract. METHODS We performed a detailed literature search to inform this narrative review. RESULTS Technical success of ingestible electronic devices relies on the ability to miniaturise the microelectronic circuits, sensors and components for interventional functions while being sufficiently powered to fulfil the intended function. These devices offer the advantages of being convenient and minimally invasive, with real-time assessment often possible and with minimal interference to normal physiology. Safety has not been a limitation, but defining and controlling device location in the gastrointestinal tract remains challenging. The success of capsule endoscopy has buoyed enthusiasm for the concepts, but few ingestible devices have reached clinical practice to date, partly due to the novelty of the information they provide and also due to the challenges of adding this novel technology to established clinical paradigms. Nonetheless, with ongoing technological advancement and as understanding of their potential impact emerges, acceptance of such technology will grow. These devices have the capacity to provide unique insight into gastrointestinal physiology and pathophysiology. Interventional functions, such as sampling of tissue or luminal contents and delivery of therapies, may further enhance their ability to sharpen gastroenterological diagnoses, monitoring and treatment. CONCLUSIONS The development of miniaturised ingestible microelectronic-based devices offers exciting prospects for enhancing gastroenterological research and the delivery of personalised, point-of-care medicine.
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Affiliation(s)
- Phoebe A. Thwaites
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
| | - Chu K. Yao
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
| | - Emma P. Halmos
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
| | - Jane G. Muir
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
| | - Rebecca E. Burgell
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
| | - Kyle J. Berean
- Atmo BiosciencesMelbourneVictoriaAustralia
- School of Engineering, RMIT UniversityMelbourneVictoriaAustralia
| | - Kourosh Kalantar‐zadeh
- Faculty of Engineering, School of Chemical and Biomolecular EngineeringThe University of SydneyCamperdownNew South WalesAustralia
| | - Peter R. Gibson
- Department of Gastroenterology, Central Clinical SchoolMonash University and Alfred HealthMelbourneVictoriaAustralia
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2
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Chacon MA, Wilson NA. The Challenge of Small Intestine Length Measurement: A Systematic Review of Imaging Techniques. J Surg Res 2023; 290:71-82. [PMID: 37210758 PMCID: PMC10330168 DOI: 10.1016/j.jss.2023.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 03/22/2023] [Accepted: 04/15/2023] [Indexed: 05/23/2023]
Abstract
BACKGROUND Short bowel syndrome is the most common cause of intestinal failure, with morbidity and mortality linked to remanent small intestine length. There is no current standard for noninvasive bowel length measurement. MATERIALS AND METHODS The literature was systematically searched for articles describing measurements of small intestine length from radiographic studies. Inclusion required reporting intestinal length as an outcome and use of diagnostic imaging for length assessment compared to a ground truth. Two reviewers independently screened studies for inclusion, extracted data, and assessed study quality. RESULTS Eleven studies met the inclusion criteria and reported small intestinal length measurement using four imaging modalities: barium follow-through, ultrasound, computed tomography, and magnetic resonance. Five barium follow-through studies reported variable correlations with intraoperative measurements (r = 0.43-0.93); most (3/5) reported underestimation of length. US studies (n = 2) did not correlate with ground truths. Two computed tomography studies reported moderate-to-strong correlations with pathologic (r = 0.76) and intraoperative measurements (r = 0.99). Five studies of magnetic resonance showed moderate-to-strong correlations with intraoperative or postmortem measurements (r = 0.70-0.90). Vascular imaging software was used in two studies, and a segmentation algorithm was used for measurements in one. CONCLUSIONS Noninvasive measurement of small intestine length is challenging. Three-dimensional imaging modalities reduce the risk of length underestimation, which is common with two-dimensional techniques. However, they also require longer times to perform length measurements. Automated segmentation has been trialed for magnetic resonance enterography, but this method does not translate directly to standard diagnostic imaging. While three-dimensional images are most accurate for length measurement, they are limited in their ability to measure intestinal dysmotility, which is an important functional measure in patients with intestinal failure. Future work should validate automated segmentation and measurement software using standard diagnostic imaging protocols.
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Affiliation(s)
- Miranda A Chacon
- Department of Surgery, University of Rochester Medical Center, Rochester, New York
| | - Nicole A Wilson
- Division of Pediatric Surgery, Department of Surgery, University of Rochester Medical Center, Rochester, New York; Department of Biomedical Engineering, University of Rochester, Rochester, New York.
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3
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Gleich B, Schmale I, Nielsen T, Rahmer J. Miniature magneto-mechanical resonators for wireless tracking and sensing. Science 2023; 380:966-971. [PMID: 37262171 DOI: 10.1126/science.adf5451] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 05/03/2023] [Indexed: 06/03/2023]
Abstract
Sensor miniaturization enables applications such as minimally invasive medical procedures or patient monitoring by providing process feedback in situ. Ideally, miniature sensors should be wireless, inexpensive, and allow for remote detection over sufficient distance by an affordable detection system. We analyze the signal strength of wireless sensors theoretically and derive a simple design of high-signal resonant magneto-mechanical sensors featuring volumes below 1 cubic millimeter. As examples, we demonstrate real-time tracking of position and attitude of a flying bee, navigation of a biopsy needle, tracking of a free-flowing marker, and sensing of pressure and temperature, all in unshielded environments. The achieved sensor size, measurement accuracy, and workspace of ~25 centimeters show the potential for a low-cost wireless tracking and sensing platform for medical and nonmedical applications.
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Avvari RK. Role of segmental contraction in the small intestinal digestion: A computational approach to study the physics behind the luminal mixing and transport. J Theor Biol 2023; 561:111418. [PMID: 36682409 DOI: 10.1016/j.jtbi.2023.111418] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 01/21/2023]
Abstract
Segmentation is well known to digest the food rich in proteins, starch, and lipids; however, the mechanism leading to the digestion remains unclear. In this study, a theoretical model for segmental contractions of the small intestine is developed using lubrication method to explore the mechanisms involved. Here, the nonlinear partial differential equations governing the fluid flow were normalized in viscous regime and solved semi-analytically for a power law fluid under long wavelength approximation on a MatlabTM platform. Study indicates that shearing is highest at the 1st and 4th mid-occlusion in comparison to 2nd and 3rd mid-occlusion. Parametric study indicates that the flow is sensitive to - the span of segmentation or wavelength of the wave, occlusion of the wave and frequency of the contraction; with shearing being highest for dilatants. Shearing is more prominent at higher occlusion (>50 %) and frequency (>6Hz). Further, mixing is more prominent at the steep regions of the wave; having intensity of mixing highest for the outer waves in comparison to waves at mid-region of the segmentation. The power demand is found to be greater in segmentation and has the following precedence - frequency, wavelength, flow behavior index, and occlusion (up to 80 %). Further, multiplicity of the wave gives rise to multiple zones of mixing which increases the rate of mixing of the contents. Suggesting that, the segmentation primarily serves the purpose of mixing. The study will be useful to explore novel therapeutic strategies of managing patients suffering from various motility-associated disorders of the small intestine.
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Affiliation(s)
- Ravi Kant Avvari
- Department of Biotechnology and Medical Engineering, NIT Rourkela, Odisha 769008, India.
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5
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A self-powered ingestible wireless biosensing system for real-time in situ monitoring of gastrointestinal tract metabolites. Nat Commun 2022; 13:7405. [PMID: 36456568 PMCID: PMC9715945 DOI: 10.1038/s41467-022-35074-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 11/17/2022] [Indexed: 12/03/2022] Open
Abstract
Information related to the diverse and dynamic metabolite composition of the small intestine is crucial for the diagnosis and treatment of various diseases. However, our current understanding of the physiochemical dynamics of metabolic processes within the small intestine is limited due to the lack of in situ access to the intestinal environment. Here, we report a demonstration of a battery-free ingestible biosensing system for monitoring metabolites in the small intestine. As a proof of concept, we monitor the intestinal glucose dynamics on a porcine model. Battery-free operation is achieved through a self-powered glucose biofuel cell/biosensor integrated into a circuit that performs energy harvesting, biosensing, and wireless telemetry via a power-to-frequency conversion scheme using magnetic human body communication. Such long-term biochemical analysis could potentially provide critical information regarding the complex and dynamic small intestine metabolic profiles.
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6
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Fredholt F, Di Meo C, Sloth S, Müllertz A, Berthelsen R. Direct visualizing of paracetamol immediate release tablet disintegration in vivo and in vitro. Eur J Pharm Biopharm 2022; 180:63-70. [PMID: 36122785 DOI: 10.1016/j.ejpb.2022.09.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 08/26/2022] [Accepted: 09/11/2022] [Indexed: 11/17/2022]
Abstract
The purpose of the present study was to study tablet disintegration by direct visualization, in vivo and in vitro. Based on literature data, a standard conventional paracetamol (CP) tablet, Panodil®, and a rapidly absorbed paracetamol (RP) tablet, Panodil® Zapp, were chosen as model systems to study tablet disintegration in the human stomach. Based on the obtained in vivo results, an in vitro disintegration method was designed to reproduce the visualized disintegration process occurring in the human stomach. For the clinical study, CP and RP tablets fastened to digital endoscopic camera capsules were administered to fasted human volunteers (n=4). The disintegration time and process were visualized by the real time video recordings, using the endoscopic camera capsule. The average disintegration time was found to be 26 ± 13 min and 10 ± 7 min, for CP (n=4) and RP (n=4) tablets, respectively. It was possible to reproduce the in vivo disintegration data in vitro using a USP 2 dissolution apparatus with 250 mL of viscous Fasted State Simulated Gastric Fluid (vFaSSGF*), simulating the rheological profile of human fasted state gastric fluid following administration of a glass of water. The viscosity of the simulated fasted state gastric fluid was found to have a large impact on the disintegration time of the tested immediate release tablets. Therefore, it is recommended to mimic gastric fluid viscosity during in vitro tablet disintegration studies.
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Affiliation(s)
- Freja Fredholt
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Camilla Di Meo
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Stine Sloth
- Gastro Unit, Division of Endoscopy, Borgmester Ib Huuls vej 1, Hospital Herlev, Copenhagen University, DK-2730 Herlev, Denmark
| | - Anette Müllertz
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark; Bioneer:FARMA, Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Ragna Berthelsen
- Department of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark.
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7
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Schütt M, O’Farrell C, Stamatopoulos K, Hoad CL, Marciani L, Sulaiman S, Simmons MJH, Batchelor HK, Alexiadis A. Simulating the Hydrodynamic Conditions of the Human Ascending Colon: A Digital Twin of the Dynamic Colon Model. Pharmaceutics 2022; 14:pharmaceutics14010184. [PMID: 35057077 PMCID: PMC8778200 DOI: 10.3390/pharmaceutics14010184] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 12/26/2021] [Accepted: 01/11/2022] [Indexed: 12/21/2022] Open
Abstract
The performance of solid oral dosage forms targeting the colon is typically evaluated using standardised pharmacopeial dissolution apparatuses. However, these fail to replicate colonic hydrodynamics. This study develops a digital twin of the Dynamic Colon Model; a physiologically representative in vitro model of the human proximal colon. Magnetic resonance imaging of the Dynamic Colon Model verified that the digital twin robustly replicated flow patterns under different physiological conditions (media viscosity, volume, and peristaltic wave speed). During local contractile activity, antegrade flows of 0.06-0.78 cm s-1 and backflows of -2.16--0.21 cm s-1 were measured. Mean wall shear rates were strongly time and viscosity dependent although peaks were measured between 3.05-10.12 s-1 and 5.11-20.34 s-1 in the Dynamic Colon Model and its digital twin respectively, comparable to previous estimates of the USPII with paddle speeds of 25 and 50 rpm. It is recommended that viscosity and shear rates are considered when designing future dissolution test methodologies for colon-targeted formulations. In the USPII, paddle speeds >50 rpm may not recreate physiologically relevant shear rates. These findings demonstrate how the combination of biorelevant in vitro and in silico models can provide new insights for dissolution testing beyond established pharmacopeial methods.
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Affiliation(s)
- Michael Schütt
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (K.S.); (M.J.H.S.)
- Correspondence: (M.S.); (C.O.); (A.A.)
| | - Connor O’Farrell
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (K.S.); (M.J.H.S.)
- Correspondence: (M.S.); (C.O.); (A.A.)
| | - Konstantinos Stamatopoulos
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (K.S.); (M.J.H.S.)
- Biopharmaceutics, Pharmaceutical Development, PDS, MST, RD Platform Technology & Science, GSK, David Jack Centre, Park Road, Ware, Hertfordshire SG12 0DP, UK
| | - Caroline L. Hoad
- Nottingham Digestive Diseases Centre and National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham NG7 2UK, UK; (C.L.H.); (L.M.); (S.S.)
- Sir Peter Mansfield Imaging Centre, School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
| | - Luca Marciani
- Nottingham Digestive Diseases Centre and National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham NG7 2UK, UK; (C.L.H.); (L.M.); (S.S.)
| | - Sarah Sulaiman
- Nottingham Digestive Diseases Centre and National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and University of Nottingham, Nottingham NG7 2UK, UK; (C.L.H.); (L.M.); (S.S.)
| | - Mark J. H. Simmons
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (K.S.); (M.J.H.S.)
| | - Hannah K. Batchelor
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, 161 Cathedral Street, Glasgow G4 0RE, UK;
| | - Alessio Alexiadis
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; (K.S.); (M.J.H.S.)
- Correspondence: (M.S.); (C.O.); (A.A.)
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8
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Stamatopoulos K, O'Farrell C, Simmons M, Batchelor H. In vivo models to evaluate ingestible devices: Present status and current trends. Adv Drug Deliv Rev 2021; 177:113915. [PMID: 34371085 DOI: 10.1016/j.addr.2021.113915] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/27/2021] [Accepted: 08/02/2021] [Indexed: 12/12/2022]
Abstract
Evaluation of orally ingestible devices is critical to optimize their performance early in development. Using animals as a pre-clinical tool can provide useful information on functionality, yet it is important to recognize that animal gastrointestinal physiology, pathophysiology and anatomy can differ to that in humans and that the most suitable species needs to be selected to inform the evaluation. There has been a move towards in vitro and in silico models rather than animal models in line with the 3Rs (Replacement, Reduction and Refinement) as well as the better control and reproducibility associated with these systems. However, there are still instances where animal models provide the greatest understanding. This paper provides an overview of key aspects of human gastrointestinal anatomy and physiology and compares parameters to those reported in animal species. The value of each species can be determined based upon the parameter of interest from the ingested device when considering the use of pre-clinical animal testing.
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Affiliation(s)
- Konstantinos Stamatopoulos
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK; Biopharmaceutics, Pharmaceutical Development, PDS, MST, RD Platform Technology & Science, GSK, David Jack Centre, Park Road, Ware, Hertfordshire SG12 0DP, UK
| | - Connor O'Farrell
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Mark Simmons
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Hannah Batchelor
- Strathclyde Institute of Pharmacy and Biomedical Sciences, 161 Cathedral Street, Glasgow G4 0RE, UK.
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9
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Tan YJN, Yong WP, Low HR, Kochhar JS, Khanolkar J, Lim TSE, Sun Y, Wong JZE, Soh S. Customizable drug tablets with constant release profiles via 3D printing technology. Int J Pharm 2021; 598:120370. [PMID: 33577911 DOI: 10.1016/j.ijpharm.2021.120370] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/03/2021] [Accepted: 02/05/2021] [Indexed: 12/17/2022]
Abstract
Medicine should ideally be personalized as each individual has his/her own unique biological, physical, and medical dispositions. Medicine can be personalized by customizing drug tablets with the specific drug dosages, release durations, and combinations of multiple drugs. This study presents a method for fabricating drug tablets with customizable dosages, durations, and combinations of multiple drugs by using the 3D printing technology. The method focuses on fabricating customizable drug tablets with a very simple structure for delivering the constant release profile due to its importance in treatment (i.e., the drug may produce side effects if too much is released andmay not have therapeutic value is too little is released). The method is simple: it involves first printing a template using the 3D printer and fabricating the drug tablet via the template. The tablets are customized by varying the amount of excipient used, the height of the tablet, and the numberand amount of drugs used. Three different common drugs (i.e., paracetamol, phenylephrine HCl and diphenhydramine HCl) and FDA-approved excipients are studied. The simplicity of the structure of the tablet and method via templating allows the fabrication of these fully customizable drug tablets to be easily performed, low-cost, efficient, and safe for consumption. These features enable the customizable tablets to be made widely accessible to the public; hence, the concept of personalized medicine can be realized.
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Affiliation(s)
- Yan Jie Neriah Tan
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore
| | - Wai Pong Yong
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore
| | - Han Rou Low
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore
| | - Jaspreet Singh Kochhar
- Procter & Gamble International Operations SA Singapore Branch, 70 Biopolis Street, Singapore 138547, Singapore
| | - Jayant Khanolkar
- Procter & Gamble International Operations SA Singapore Branch, 70 Biopolis Street, Singapore 138547, Singapore
| | - Teng Shuen Ernest Lim
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore
| | - Yajuan Sun
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore
| | - Jonathan Zhi En Wong
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore
| | - Siowling Soh
- Department of Chemical and Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore.
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10
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Brinck CE, Mark EB, Klinge MW, Ejerskov C, Sutter N, Schlageter V, Scott SM, Drewes AM, Krogh K. Magnetic tracking of gastrointestinal motility. Physiol Meas 2020; 41:12TR01. [DOI: 10.1088/1361-6579/abcd1e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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11
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Spiller R, Hoad C. Enhancing our understanding of small bowel function using modern imaging techniques. Neurogastroenterol Motil 2020; 32:e13616. [PMID: 31136064 DOI: 10.1111/nmo.13616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 04/10/2019] [Accepted: 04/17/2019] [Indexed: 02/08/2023]
Abstract
Small intestinal function is critical to digestive health and patients believe an abnormal reaction to food is responsible for many of their symptoms. Despite this, our ability to assess disturbed function in clinical practice has been limited, particularly after ingestion of the complex nutrients which make up normal food. Recent advances in both wireless capsules and magnetic resonance imaging have provided new insights. This review will briefly describe the limitations of past techniques and focus on how these newer techniques are changing our understanding, particularly of how patients' gastrointestinal tracts respond to food.
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Affiliation(s)
- Robin Spiller
- NIHR Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK
| | - Caroline Hoad
- NIHR Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK.,Sir Peter Mansfield Imaging Centre, Department of Physics, University of Nottingham, Nottingham, UK
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12
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Schneider F, Koziolek M, Weitschies W. In Vitro and In Vivo Test Methods for the Evaluation of Gastroretentive Dosage Forms. Pharmaceutics 2019; 11:E416. [PMID: 31426417 PMCID: PMC6723944 DOI: 10.3390/pharmaceutics11080416] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/07/2019] [Accepted: 08/12/2019] [Indexed: 12/16/2022] Open
Abstract
More than 50 years ago, the first concepts for gastroretentive drug delivery systems were developed. Despite extensive research in this field, there is no single formulation concept for which reliable gastroretention has been demonstrated under different prandial conditions. Thus, gastroretention remains the holy grail of oral drug delivery. One of the major reasons for the various setbacks in this field is the lack of predictive in vitro and in vivo test methods used during preclinical development. In most cases, human gastrointestinal physiology is not properly considered, which leads to the application of inappropriate in vitro and animal models. Moreover, conditions in the stomach are often not fully understood. Important aspects such as the kinetics of fluid volumes, gastric pH or mechanical stresses have to be considered in a realistic manner, otherwise, the gastroretentive potential as well as drug release of novel formulations cannot be assessed correctly in preclinical studies. This review, therefore, highlights the most important aspects of human gastrointestinal physiology and discusses their potential implications for the evaluation of gastroretentive drug delivery systems.
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Affiliation(s)
- Felix Schneider
- Department of Biopharmaceutics and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany
| | - Mirko Koziolek
- Department of Biopharmaceutics and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany
| | - Werner Weitschies
- Department of Biopharmaceutics and Pharmaceutical Technology, Institute of Pharmacy, University of Greifswald, 17489 Greifswald, Germany.
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13
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Bharucha AE, Anderson B, Bouchoucha M. More movement with evaluating colonic transit in humans. Neurogastroenterol Motil 2019; 31:e13541. [PMID: 30681255 PMCID: PMC6362846 DOI: 10.1111/nmo.13541] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 12/11/2018] [Accepted: 12/13/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND Colonic functions (ie, absorption of fluids and electrolytes, digestion of selected nutrients, harbor for microbes, and elimination of excreta) necessitate complex patterns of storage and transit. Indeed, colonic transit accounts for a major part of the mouth-to-anus transit time. Colonic transit assessments are useful for understanding the pathophysiology of disease, the pharmacodynamic effects of new medications and to diagnose slow transit constipation. Currently, radiopaque markers, scintigraphy, and a colonic pH-pressure capsule are used to measure overall colonic transit. Radioopaque markers, scintigraphy, and the electromagnetic capsule, which is a newer technique, also evaluate regional colonic transit. The pH-pressure capsule also measures colonic pressures. Magnetic resonance imaging and a radio-frequency identification-based device are evolving methods for assessing colonic transit. PURPOSE This mini-review, which accompanies a study evaluating the assessment of colon transit with the electromagnetic capsule, evaluates and compares existing and evolving methods for evaluating colonic transit in humans (Neurogastroenterol Motil. 2018; in press). In addition to overall and regional colonic transit, the electromagnetic capsule evaluates colonic motor patterns without radiation exposure. These patterns are summarized by analyzing the characteristics (ie, distance and velocity) of discrete antegrade and retrograde capsule movements as they travel in the colon. However, the electromagnetic capsule does not measure pressure or colonic wall movement (ie, contractions). The motor patterns identified by this capsule should be compared with motor patterns identified with manometry. The next challenge is to harness different techniques to evaluate the relationships between colonic pressures and transit or, even better, the trifecta of colonic contractions, pressure events, and transit.
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Affiliation(s)
- Adil E. Bharucha
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota
| | - Bradley Anderson
- Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota
| | - Michel Bouchoucha
- Université Paris V René Descartes, Paris Cedex 06, France
- Hôpital Avicenne, Bobigny, France
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14
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Kalsi GK, Grønlund D, Martin J, Drewes AM, Scott SM, Birch MJ. Technical report: Inter- and intra-rater reliability of regional gastrointestinal transit times measured using the 3D-Transit electromagnet tracking system. Neurogastroenterol Motil 2018; 30:e13396. [PMID: 29971879 DOI: 10.1111/nmo.13396] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 05/23/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND The 3D-Transit electromagnet tracking system is an emerging tool for the ambulatory assessment of gastrointestinal (GI) transit times and motility patterns, based on the anatomical localization of ingestible electromagnetic capsules. Currently, 3D-Transit recordings are manually analyzed to extract GI transit times. As this is a subjective method, there is some inherent variability in the measurements, which may be experience-dependent. We therefore assessed inter- and intra-rater reliability of GI transit times from 3D-Transit recordings. METHODS Thirty-six 3D-Transit recordings (17 female; median age: 34 years [range: 21-80]) were analyzed twice by 3 raters with varying experience. Each rater manually identified the timestamps when a capsule progressed from antrum to duodenum, and from ileum to right colon. These timestamps, along with the ingestion and expulsion times, were used to determine whole gut (WGTT), gastric emptying (GET), small intestinal (SITT) and colonic (CTT) transit times. Reliability was determined using interclass correlation coefficients (ICCs). KEY RESULTS For capsule progression timestamps, the most and mid-experienced raters had fair to good inter- and excellent intra-rater reliability (ICCmin-max = 0.61-1.00), whereas the inexperienced rater had poor to fair inter- and poor intra-rater reliability (ICCmin-max = 0.28-0.55). GET and SITT reliability between the most and mid-experienced raters was fair (ICCmin-max = 0.61-0.73), while reliability between these raters and the inexperienced rater was poor to fair (ICCmin-max = 0.28-0.55). CTT reliability was excellent between and within all raters (ICCmin-max = 0.92-0.99). CONCLUSIONS & INFERENCES Inexperienced raters provide the least reliable measurements from 3D-Transit recordings, which confirms requirement for adequate training. Automation may improve the reliability of measurements.
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Affiliation(s)
- G K Kalsi
- GI Physiology Unit, The Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.,Clinical Physics, Barts Health NHS Trust, The Royal London Hospital, London, UK
| | - D Grønlund
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - J Martin
- Clinical Physics, Barts Health NHS Trust, The Royal London Hospital, London, UK
| | - A M Drewes
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
| | - S M Scott
- GI Physiology Unit, The Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK
| | - M J Birch
- GI Physiology Unit, The Blizard Institute, Barts and the London School of Medicine and Dentistry, Queen Mary University of London, London, UK.,Clinical Physics, Barts Health NHS Trust, The Royal London Hospital, London, UK
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15
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Ni Z, Talattof A, Fan J, Tsakalozou E, Sharan S, Sun D, Wen H, Zhao L, Zhang X. Physiologically Based Pharmacokinetic and Absorption Modeling for Osmotic Pump Products. AAPS JOURNAL 2017; 19:1045-1053. [PMID: 28357656 DOI: 10.1208/s12248-017-0075-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Accepted: 03/11/2017] [Indexed: 01/07/2023]
Abstract
Physiologically based pharmacokinetic (PBPK) and absorption modeling approaches were employed for oral extended-release (ER) drug products based on an osmotic drug delivery system (osmotic pumps). The purpose was to systemically evaluate the in vivo relevance of in vitro dissolution for this type of formulation. As expected, in vitro dissolution appeared to be generally predictive of in vivo PK profiles, because of the unique feature of this delivery system that the in vitro and in vivo release of osmotic pump drug products is less susceptible to surrounding environment in the gastrointestinal (GI) tract such as pH, hydrodynamic, and food effects. The present study considered BCS (Biopharmaceutics Classification System) class 1, 2, and 3 drug products with half-lives ranging from 2 to greater than 24 h. In some cases, the colonic absorption models needed to be adjusted to account for absorption in the colon. C max (maximum plasma concentration) and AUCt (area under the concentration curve) of the studied drug products were sensitive to changes in colon permeability and segmental GI transit times in a drug product-dependent manner. While improvement of the methodology is still warranted for more precise prediction (e.g., colonic absorption and dynamic movement in the GI tract), the results from the present study further emphasized the advantage of using PBPK modeling in addressing product-specific questions arising from regulatory review and drug development.
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Affiliation(s)
- Zhanglin Ni
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Arjang Talattof
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Jianghong Fan
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Eleftheria Tsakalozou
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Satish Sharan
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Dajun Sun
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Hong Wen
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Liang Zhao
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, US Food and Drug Administration, Silver Spring, Maryland, USA
| | - Xinyuan Zhang
- Division of Quantitative Methods and Modeling, Office of Research and Standards, Office of Generic Drugs, US Food and Drug Administration, Silver Spring, Maryland, USA. .,, 10903 New Hampshire Ave., Bldg. 75, Room 4690, Silver Spring, Maryland, 20993, USA.
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16
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Bercik P, Schlageter V, Mauro M, Rawlinson J, Kucera P, Armstrong D. Noninvasive Verification of Nasogastric Tube Placement Using a Magnet-Tracking System: A Pilot Study in Healthy Subjects. JPEN J Parenter Enteral Nutr 2017; 29:305-10. [PMID: 15961688 DOI: 10.1177/0148607105029004305] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Fluoroscopic verification of nasogastric (NG) feeding tube placement is inconvenient and involves radiation exposure. We tested whether the position of an NG tube can be assessed reliably by a recently introduced magnet-tracking system. METHODS A small permanent magnet was attached at the end of an NG tube and its position was monitored using an external sensor array connected to a computer. NG tube trajectory, spontaneous movements of the magnet, and its position relative to the lower esophageal sphincter (LES) and xiphisternum were assessed in 22 healthy subjects and compared with esophageal manometry. In 12 subjects, localization of the magnet was also compared with fluoroscopy. RESULTS Magnet-tracking displayed NG tube tip movement reproducibly as it moved vertically in the esophagus and then laterally into the stomach. Compared with manometry, the accuracy and sensitivity of magnet tracking for localization of the NG tube tip, above or below the diaphragm, were 100%. Compared with fluoroscopy, the accuracy of NG tube localization by magnet tracking was 100%. With the magnet in the stomach, but not in the esophagus or LES, low amplitude displacements at a frequency of 3 per minute, consistent with gastric slow wave activity, were observed. CONCLUSIONS Magnet tracking allows accurate, real-time, 3-dimensional localization of an NG tube with respect to anatomic landmarks. Recorded motor patterns are indicative of the position of the NG tube. Magnet tracking may be a useful tool for bedside placement of nasogastric and enteral feeding tubes.
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Affiliation(s)
- Premysl Bercik
- Division of Gastroenterology and Intestinal Disease Research Program, McMaster University Medical Center, Hamilton, Ontario, Canada
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17
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Poulsen JL, Nilsson M, Brock C, Sandberg TH, Krogh K, Drewes AM. The Impact of Opioid Treatment on Regional Gastrointestinal Transit. J Neurogastroenterol Motil 2016; 22:282-91. [PMID: 26811503 PMCID: PMC4819867 DOI: 10.5056/jnm15175] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 12/22/2015] [Accepted: 12/31/2015] [Indexed: 12/28/2022] Open
Abstract
Background/Aims To employ an experimental model of opioid-induced bowel dysfunction in healthy human volunteers, and evaluate the impact of opioid treatment compared to placebo on gastrointestinal (GI) symptoms and motility assessed by questionnaires and regional GI transit times using the 3-dimensional (3D)-Transit system. Methods Twenty-five healthy males were randomly assigned to oxycodone or placebo for 5 days in a double blind, crossover design. Adverse GI effects were measured with the bowel function index, gastrointestinal symptom rating scale, patient assessment of constipation symptom questionnaire, and Bristol stool form scale. Regional GI transit times were determined using the 3D-Transit system, and segmental transit times in the colon were determined using a custom Matlab® graphical user interface. Results GI symptom scores increased significantly across all applied GI questionnaires during opioid treatment. Oxycodone increased median total GI transit time from 22.2 to 43.9 hours (P < 0.001), segmental transit times in the cecum and ascending colon from 5.7 to 9.9 hours (P = 0.012), rectosigmoid colon transit from 2.7 to 9.0 hours (P = 0.044), and colorectal transit time from 18.6 to 38.6 hours (P = 0.001). No associations between questionnaire scores and segmental transit times were detected. Conclusions Self-assessed GI adverse effects and increased GI transit times in different segments were induced during oxycodone treatment. This detailed information about segmental changes in motility has great potential for future interventional head-to-head trials of different laxative regimes for prevention and treatment of constipation.
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Affiliation(s)
- Jakob L Poulsen
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Matias Nilsson
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Christina Brock
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark.,Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Thomas H Sandberg
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Klaus Krogh
- Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Asbjørn M Drewes
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark.,Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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18
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Li P, Kothari V, Terry BS. Design and Preliminary Experimental Investigation of a Capsule for Measuring the Small Intestine Contraction Pressure. IEEE Trans Biomed Eng 2015; 62:2702-8. [DOI: 10.1109/tbme.2015.2444406] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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19
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Huizinga JD, Parsons SP, Chen JH, Pawelka A, Pistilli M, Li C, Yu Y, Ye P, Liu Q, Tong M, Zhu YF, Wei D. Motor patterns of the small intestine explained by phase-amplitude coupling of two pacemaker activities: the critical importance of propagation velocity. Am J Physiol Cell Physiol 2015; 309:C403-14. [PMID: 26135802 DOI: 10.1152/ajpcell.00414.2014] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2014] [Accepted: 06/26/2015] [Indexed: 12/23/2022]
Abstract
Phase-amplitude coupling of two pacemaker activities of the small intestine, the omnipresent slow wave activity generated by interstitial cells of Cajal of the myenteric plexus (ICC-MP) and the stimulus-dependent rhythmic transient depolarizations generated by ICC of the deep muscular plexus (ICC-DMP), was recently hypothesized to underlie the orchestration of the segmentation motor pattern. The aim of the present study was to increase our understanding of phase-amplitude coupling through modeling. In particular the importance of propagation velocity of the ICC-DMP component was investigated. The outcome of the modeling was compared with motor patterns recorded from the rat or mouse intestine from which propagation velocities within the different patterns were measured. The results show that the classical segmentation motor pattern occurs when the ICC-DMP component has a low propagation velocity (<0.05 cm/s). When the ICC-DMP component has a propagation velocity in the same order of magnitude as that of the slow wave activity (∼1 cm/s), cluster type propulsive activity occurs which is in fact the dominant propulsive activity of the intestine. Hence, the only difference between the generation of propagating cluster contractions and the Cannon-type segmentation motor pattern is the propagation velocity of the low-frequency component, the rhythmic transient depolarizations originating from the ICC-DMP. Importantly, the proposed mechanism explains why both motor patterns have distinct rhythmic waxing and waning of the amplitude of contractions. The hypothesis is brought forward that the velocity is modulated by neural regulation of gap junction conductance within the ICC-DMP network.
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Affiliation(s)
- Jan D Huizinga
- Farncombe Family Digestive Health Research Institute, Department of Medicine, McMaster University, Hamilton, Canada; and Department of Gastroenterology and Hepatology, Renmin Hospital of Wuhan University, Wuhan University Institute of Digestive and Liver Diseases, Key Laboratory of Hubei Province for Digestive System Diseases, Wuhan, China
| | - Sean P Parsons
- Farncombe Family Digestive Health Research Institute, Department of Medicine, McMaster University, Hamilton, Canada; and
| | - Ji-Hong Chen
- Farncombe Family Digestive Health Research Institute, Department of Medicine, McMaster University, Hamilton, Canada; and Department of Gastroenterology and Hepatology, Renmin Hospital of Wuhan University, Wuhan University Institute of Digestive and Liver Diseases, Key Laboratory of Hubei Province for Digestive System Diseases, Wuhan, China
| | - Andrew Pawelka
- Farncombe Family Digestive Health Research Institute, Department of Medicine, McMaster University, Hamilton, Canada; and
| | - Marc Pistilli
- Farncombe Family Digestive Health Research Institute, Department of Medicine, McMaster University, Hamilton, Canada; and
| | - Chunpei Li
- Department of Gastroenterology and Hepatology, Renmin Hospital of Wuhan University, Wuhan University Institute of Digestive and Liver Diseases, Key Laboratory of Hubei Province for Digestive System Diseases, Wuhan, China
| | - Yuanjie Yu
- Department of Gastroenterology and Hepatology, Renmin Hospital of Wuhan University, Wuhan University Institute of Digestive and Liver Diseases, Key Laboratory of Hubei Province for Digestive System Diseases, Wuhan, China
| | - Pengfei Ye
- Department of Gastroenterology and Hepatology, Renmin Hospital of Wuhan University, Wuhan University Institute of Digestive and Liver Diseases, Key Laboratory of Hubei Province for Digestive System Diseases, Wuhan, China
| | - Qing Liu
- Department of Gastroenterology and Hepatology, Renmin Hospital of Wuhan University, Wuhan University Institute of Digestive and Liver Diseases, Key Laboratory of Hubei Province for Digestive System Diseases, Wuhan, China
| | - Mengting Tong
- Department of Gastroenterology and Hepatology, Renmin Hospital of Wuhan University, Wuhan University Institute of Digestive and Liver Diseases, Key Laboratory of Hubei Province for Digestive System Diseases, Wuhan, China
| | - Yong Fang Zhu
- Farncombe Family Digestive Health Research Institute, Department of Medicine, McMaster University, Hamilton, Canada; and
| | - Defei Wei
- Department of Gastroenterology and Hepatology, Renmin Hospital of Wuhan University, Wuhan University Institute of Digestive and Liver Diseases, Key Laboratory of Hubei Province for Digestive System Diseases, Wuhan, China
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20
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Gregersen T, Haase AM, Schlageter V, Gronbaek H, Krogh K. Regional Gastrointestinal Transit Times in Patients With Carcinoid Diarrhea: Assessment With the Novel 3D-Transit System. J Neurogastroenterol Motil 2015; 21:423-32. [PMID: 26130638 PMCID: PMC4496908 DOI: 10.5056/jnm15035] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 04/04/2015] [Accepted: 04/05/2015] [Indexed: 12/13/2022] Open
Abstract
Background/Aims The paucity of knowledge regarding gastrointestinal motility in patients with neuroendocrine tumors and carcinoid diarrhea restricts targeted treatment. 3D-Transit is a novel, minimally invasive, ambulatory method for description of gastrointestinal motility. The system has not yet been evaluated in any group of patients. We aimed to test the performance of 3D-Transit in patients with carcinoid diarrhea and to compare the patients’ regional gastrointestinal transit times (GITT) and colonic motility patterns with those of healthy subjects. Methods Fifteen healthy volunteers and seven patients with neuroendocrine tumor and at least 3 bowel movements per day were investigated with 3D-Transit and standard radiopaque markers. Results Total GITT assessed with 3D-Transit and radiopaque markers were well correlated (Spearman’s rho = 0.64, P = 0.002). Median total GITT was 12.5 (range: 8.5–47.2) hours in patients versus 25.1 (range: 13.1–142.3) hours in healthy (P = 0.007). There was no difference in gastric emptying (P = 0.778). Median small intestinal transit time was 3.8 (range: 1.4–5.5) hours in patients versus 4.4 (range: 1.8–7.2) hours in healthy subjects (P = 0.044). Median colorectal transit time was 5.2 (range: 2.9–40.1) hours in patients versus 18.1 (range: 5.0–134.0) hours in healthy subjects (P = 0.012). Median frequency of pansegmental colonic movements was 0.45 (range: 0.03–1.02) per hour in patients and 0.07 (range: 0–0.61) per hour in healthy subjects (P = 0.045). Conclusions Three-dimensional Transit allows assessment of regional GITT in patients with diarrhea. Patients with carcinoid diarrhea have faster than normal gastrointestinal transit due to faster small intestinal and colorectal transit times. The latter is caused by an increased frequency of pansegmental colonic movements.
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Affiliation(s)
- Tine Gregersen
- Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Anne-Mette Haase
- Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Henning Gronbaek
- Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
| | - Klaus Krogh
- Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
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21
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Haase AM, Gregersen T, Schlageter V, Scott MS, Demierre M, Kucera P, Dahlerup JF, Krogh K. Pilot study trialling a new ambulatory method for the clinical assessment of regional gastrointestinal transit using multiple electromagnetic capsules. Neurogastroenterol Motil 2014; 26:1783-91. [PMID: 25348504 DOI: 10.1111/nmo.12461] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 09/24/2014] [Indexed: 02/08/2023]
Abstract
BACKGROUND Gastrointestinal (GI) motor disorders often involve several regions of the GI tract. Therefore, easy and safe assessment of whole gut and regional motility is valuable for more precise diagnosis. 3D-Transit is a novel method for ambulatory evaluation of total and regional gastrointestinal transit times (GITT) based on the anatomical localization of ingestible electromagnetic capsules. The main purpose of this study was to test the performance of the 3D-Transit system. METHODS Twenty healthy volunteers each ingested three electromagnetic capsules over a period of two consecutive days. Standard radio-opaque markers (ROM) were also ingested to assess the agreement between total GITT obtained with both methods. KEY RESULTS Investigations were well-tolerated and three capsules could be tracked simultaneously with minimal data loss (Capsule 1: median: 0.2% of time (range 0-25.3%). Region specific contraction patterns were identified and used for computation of total and regional GITT in all subjects. Inter-observer agreement was 100% for total GITT (median variation 0%) but less for regional GITT. Day-to-day and diurnal variations were significant for total and regional GITT. Total GITT assessed by 3D-Transit capsules were moderately well-correlated to those assessed with standard ROM (Spearman's rho = 0.7). CONCLUSIONS & INFERENCES 3D-transit is a well-tolerated and minimal invasive ambulatory method for assessment of GI motility. By providing both total and regional transit times, the 3D-Transit system holds great promise for future clinical studies of GI function in health and disease.
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Affiliation(s)
- A M Haase
- Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark
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Poulsen JL, Brock C, Olesen AE, Nilsson M, Drewes AM. Clinical potential of naloxegol in the management of opioid-induced bowel dysfunction. Clin Exp Gastroenterol 2014; 7:345-58. [PMID: 25278772 PMCID: PMC4179399 DOI: 10.2147/ceg.s52097] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Opioid-induced bowel dysfunction (OIBD) is a burdensome condition which limits the therapeutic benefit of analgesia. It affects the entire gastrointestinal tract, predominantly by activating opioid receptors in the enteric nervous system, resulting in a wide range of symptoms, such as reflux, bloating, abdominal cramping, hard, dry stools, and incomplete evacuation. The majority of studies evaluating OIBD focus on constipation experienced in approximately 60% of patients. Nevertheless, other presentations of OIBD seem to be equally frequent. Furthermore, laxative treatment is often insufficient, which in many patients results in decreased quality of life and discontinuation of opioid treatment. Novel mechanism-based pharmacological approaches targeting the gastrointestinal opioid receptors have been marketed recently and even more are in the pipeline. One strategy is prolonged release formulation of the opioid antagonist naloxone (which has limited systemic absorption) and oxycodone in a combined tablet. Another approach is peripherally acting, μ-opioid receptor antagonists (PAMORAs) that selectively target μ-opioid receptors in the gastrointestinal tract. However, in Europe the only PAMORA approved for OIBD is the subcutaneously administered methylnaltrexone. Alvimopan is an oral PAMORA, but only approved in the US for postoperative ileus in hospitalized patients. Finally, naloxegol is a novel, oral PAMORA expected to be approved soon. In this review, the prevalence and pathophysiology of OIBD is presented. As PAMORAs seem to be a promising approach, their potential effect is reviewed with special focus on naloxegol's pharmacological properties, data on safety, efficacy, and patient-focused perspectives. In conclusion, as naloxegol is administered orally once daily, has proven efficacious compared to placebo, has an acceptable safety profile, and can be used as add-on to existing pain treatment, it is a welcoming addition to the targeted treatment possibilities for OIBD.
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Affiliation(s)
- Jakob Lykke Poulsen
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Christina Brock
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark ; Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Anne Estrup Olesen
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark ; Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Matias Nilsson
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark
| | - Asbjørn Mohr Drewes
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg University Hospital, Aalborg, Denmark ; Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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A randomised, controlled study of small intestinal motility in patients treated with sacral nerve stimulation for irritable bowel syndrome. BMC Gastroenterol 2014; 14:111. [PMID: 24965754 PMCID: PMC4099082 DOI: 10.1186/1471-230x-14-111] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 06/02/2014] [Indexed: 12/15/2022] Open
Abstract
Background Irritable bowel syndrome (IBS) is among the most common gastrointestinal disorders worldwide. In selected patients with severe diarrhoea-predominant or mixed IBS subtypes sacral nerve stimulation (SNS) alleviates IBS-specific symptoms and improves quality of life. The mode of action, however, remains unknown. The present study aimed to evaluate the effect of SNS on small intestinal motility in IBS patients. Methods Twenty patients treated with SNS for severe diarrhoea-predominant or mixed IBS were included in a randomised, controlled, crossover study. The neurostimulator was turned ON or OFF for the first one month and then to the opposite setting for the next month. Gastrointestinal transit patterns were investigated with the Motility Tracking System-1 (MTS-1) at the end of each the ON and OFF period. Primary endpoint was change in the velocity of the magnetic pill within the small intestine. Statistical testing was performed with Wilcoxon’s rank sum test and Fisher’s exact test. Results The median velocity of the magnetic pill through the small intestine in the fasting state was not significantly different between periods with and without SNS (Group ON-OFF: median change 0 m/h (range -1.07, 0.63), Group OFF-ON: median change 0.27 m/h (range -0.59, 1.12)) (p = 0.25). Neither, was the median velocity of the magnetic pill through the small intestine in the postprandial state significantly different between periods with and without SNS (Group ON-OFF: median change -0.13 m/h (range -0.46, 0.23), Group OFF-ON: median change 0.015 m/h (range -0.48, 0.59)) (p = 0.14). Conclusion Even though SNS may reduce symptoms of diarrhoea-predominant and mixed IBS, it has no detectable effect on small intestinal transit patterns. Trial registration Clinical.trials.gov, (NCT00919672).
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Brock C, Olesen SS, Olesen AE, Frøkjaer JB, Andresen T, Drewes AM. Opioid-induced bowel dysfunction: pathophysiology and management. Drugs 2012; 72:1847-65. [PMID: 22950533 DOI: 10.2165/11634970-000000000-00000] [Citation(s) in RCA: 137] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Opioids are the most commonly prescribed medications to treat severe pain in the Western world. It has been estimated that up to 90% of American patients presenting to specialized pain centres are treated with opioids. Along with their analgesic properties, opioids have the potential to produce substantial side effects, such as nausea, cognitive impairment, addiction and urinary retention. In the gut, opioids exert their action on the enteric nervous system, where they bind to the myenteric and submucosal plexuses, causing dysmotility, decreased fluid secretion and sphincter dysfunction, which all leads to opioid-induced bowel dysfunction (OIBD). In the clinic, this is reported as nausea, vomiting, gastro-oesophageal reflux-related symptoms, constipation, etc. One of the most severe symptoms is constipation, which can be assessed using different scales for subjective assessment. Objective methods such as radiography and colonic transit time can also be used, together with manometry and evaluation of anorectal function to explore the pathophysiology. Dose-limiting adverse symptoms of OIBD can lead to insufficient pain treatment. Even though several treatment strategies are available, the side effects are still a major challenge. Traditional laxatives are normally prescribed but they are often insufficient to alleviate symptoms, especially those from the upper gastrointestinal tract. Newer prokinetics, such as prucalopride and lubiprostone, may be more effective in alleviating OIBD. Another treatment approach is co-administration of opioid antagonists, which either cannot cross the blood-brain barrier or selectively target opioid receptors in the gastrointestinal tract. However, although these new agents have proved to be more efficacious than placebo, clinical trials still need to prove their superiority to standard co-prescribed laxative regimes.
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Affiliation(s)
- Christina Brock
- Mech-Sense, Department of Gastroenterology and Hepatology, Aalborg Hospital, Aarhus University Hospital, Aalborg, Denmark.
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Karlsen S, Fynne L, Grønbæk H, Krogh K. Small intestinal transit in patients with liver cirrhosis and portal hypertension: a descriptive study. BMC Gastroenterol 2012; 12:176. [PMID: 23216853 PMCID: PMC3520867 DOI: 10.1186/1471-230x-12-176] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 11/30/2012] [Indexed: 02/07/2023] Open
Abstract
Background Gastrointestinal dysmotility may be involved in the development of bacterial translocation and infection in patients with liver cirrhosis. The aim of the present study was to describe gastric, small intestinal and colorectal motility and transit in patients with liver cirrhosis and portal hypertension using a magnet-based Motility Tracking System (MTS-1) and standard radiopaque markers. Methods We included 15 patients with liver cirrhosis (8 Child-Pugh A, 6 Child-Pugh B, and 1 Child-Pugh C) and portal hypertension (11 males, median age 54 years (range 38–73), median hepatic venous pressure gradient 18 mmHg (range 12–37)), and 18 healthy controls (8 males, median age 58 years (range 34–64)). The gastric emptying time and small intestinal motility were evaluated by MTS-1, and the total gastrointestinal transit time was assessed by radiopaque markers and abdominal radiographs. Results The velocity through the proximal small intestine was significantly higher in cirrhotic patients (median 1.27 metres (m)/hour, range 0.82–2.68) than in the healthy controls (median 1.00 m/hour, range 0.46–1.88) (p = 0.03). Likewise, the magnet travelled significantly longer in both fast (p = 0.04) and slow movements (p = 0.05) in the patient group. There was no significant difference in either gastric emptying time—23 minutes (range 5–131) in patients and 29 minutes (range 10.5–182) in healthy controls (p = 0.43)—or total gastrointestinal transit time—1.6 days (range 0.5–2.9) in patients and 2.0 days (range 1.0–3.9) in healthy controls (p = 0.33). No correlation was observed between the hepatic venous pressure gradient and the velocity of the magnet through the small intestine. Conclusion Patients with liver cirrhosis and portal hypertension demonstrated faster-than-normal transit through the proximal small intestine. This may be due to an overactive bowel, as suggested by previous studies.
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Affiliation(s)
- Stine Karlsen
- Department Hepatology and Gastroenterology, Noerrebrogade 44, Aarhus University Hospital, DK-8000, Aarhus C, Denmark.
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Hedsund C, Gregersen T, Joensson IM, Olesen HV, Krogh K. Gastrointestinal transit times and motility in patients with cystic fibrosis. Scand J Gastroenterol 2012; 47:920-6. [PMID: 22746323 DOI: 10.3109/00365521.2012.699548] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Patients with cystic fibrosis (CF) often suffer from gastrointestinal (GI) dysfunction including obstructive symptoms, malabsorption and pain, but the underlying pathophysiology remains obscure. AIM To compare GI motility and transit times in CF patients and healthy controls. MATERIAL AND METHODS Ten CF patients (five women, median age 23) with pancreatic insufficiency were studied. Total gastrointestinal transit time (GITT) and segmental colonic transit times (SCTT) were assessed by radiopaque markers. Gastric emptying and small intestinal transit were evaluated using the magnet-based motility tracking system (MTS-1). With each method patients were compared with 16 healthy controls. RESULTS Basic contraction frequencies of the stomach and small intestine were normal, but the pill reached the cecum after 7 h in only 20% of CF patients while in 88% of controls (p = 0.001). Paradoxically, velocity of the magnetic pill through the upper small intestine tended to be faster in CF patients (median 1.1 cm/min, range 0.7-1.7) compared with controls (median 1.0 cm/min, range 0.6-1.7) (p = 0.09). No statistically significant differences were found in median gastric emptying time (CF: 58 min, range 6-107 vs. healthy: 41 min, range 4-125 (p = 0.24)), GITT (CF: 2 days, range 0.5-3.3 vs. healthy: 1.5 days, range 0.7-2.5 (p = 0.10)), right SCTT (CF: 0.5 day, range 0-1.1 vs. healthy: 0.4 day, range 0-1.0 (p = 0.85)), or left SCTT (CF: 1.0 day, range 0-2.2 vs. healthy 0.6 day, range 0.2-1.2 (p = 0.10)). CONCLUSIONS In spite of normal contraction patterns, overall passage through the small intestine is significantly delayed in CF patients while upper small intestinal transit may be abnormally fast.
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Affiliation(s)
- Caroline Hedsund
- Neurogastroenterology Unit, Department of Hepatology and Gastroenterology, Aarhus University Hospital, Aarhus, Denmark.
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27
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Ciuti G, Menciassi A, Dario P. Capsule endoscopy: from current achievements to open challenges. IEEE Rev Biomed Eng 2012; 4:59-72. [PMID: 22273791 DOI: 10.1109/rbme.2011.2171182] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Wireless capsule endoscopy (WCE) can be considered an example of disruptive technology since it represents an appealing alternative to traditional diagnostic techniques. This technology enables inspection of the digestive system without discomfort or need for sedation, thus preventing the risks of conventional endoscopy, and has the potential of encouraging patients to undergo gastrointestinal (GI) tract examinations. However, currently available clinical products are passive devices whose locomotion is driven by natural peristalsis, with the drawback of failing to capture the images of important GI tract regions, since the doctor is unable to control the capsule's motion and orientation. To address these limitations, many research groups are working to develop active locomotion devices that allow capsule endoscopy to be performed in a totally controlled manner. This would enable the doctor to steer the capsule towards interesting pathological areas and to accomplish medical tasks. This review presents a research update on WCE and describes the state of the art of the basic modules of current swallowable devices, together with a perspective on WCE potential for screening, diagnostic, and therapeutic endoscopic procedures.
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Affiliation(s)
- Gastone Ciuti
- BioRobotics Institute, Scuola Superiore Sant’Anna, 56025 Pisa, Italy.
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Worsøe J, Fynne L, Gregersen T, Schlageter V, Christensen LA, Dahlerup JF, Rijkhoff NJM, Laurberg S, Krogh K. Gastric transit and small intestinal transit time and motility assessed by a magnet tracking system. BMC Gastroenterol 2011; 11:145. [PMID: 22206545 PMCID: PMC3295650 DOI: 10.1186/1471-230x-11-145] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2011] [Accepted: 12/29/2011] [Indexed: 12/22/2022] Open
Abstract
Background Tracking an ingested magnet by the Magnet Tracking System MTS-1 (Motilis, Lausanne, Switzerland) is an easy and minimally-invasive method to assess gastrointestinal transit. The aim was to test the validity of MTS-1 for assessment of gastric transit time and small intestinal transit time, and to illustrate transit patterns detected by the system. Methods A small magnet was ingested and tracked by an external matrix of 16 magnetic field sensors (4 × 4) giving a position defined by 5 coordinates (position: x, y, z, and angle: θ, ϕ). Eight healthy subjects were each investigated three times: (1) with a small magnet mounted on a capsule endoscope (PillCam); (2) with the magnet alone and the small intestine in the fasting state; and (3) with the magnet alone and the small intestine in the postprandial state. Results Experiment (1) showed good agreement and no systematic differences between MTS-1 and capsule endoscopy when assessing gastric transit (median difference 1 min; range: 0-6 min) and small intestinal transit time (median difference 0.5 min; range: 0-52 min). Comparing experiments (1) and (2) there were no systematic differences in gastric transit or small intestinal transit when using the magnet-PillCam unit and the much smaller magnetic pill. In experiments (2) and (3), short bursts of very fast movements lasting less than 5% of the time accounted for more than half the distance covered during the first two hours in the small intestine, irrespective of whether the small intestine was in the fasting or postprandial state. The mean contraction frequency in the small intestine was significantly lower in the fasting state than in the postprandial state (9.90 min-1 vs. 10.53 min-1) (p = 0.03). Conclusion MTS-1 is reliable for determination of gastric transit and small intestinal transit time. It is possible to distinguish between the mean contraction frequency of small intestine in the fasting state and in the postprandial state.
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Affiliation(s)
- Jonas Worsøe
- Department of Surgery P, Aarhus University Hospital, Aarhus, Denmark.
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29
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Fynne L, Worsøe J, Gregersen T, Schlageter V, Laurberg S, Krogh K. Gastrointestinal transit in patients with systemic sclerosis. Scand J Gastroenterol 2011; 46:1187-93. [PMID: 21815862 DOI: 10.3109/00365521.2011.603158] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Systemic sclerosis (SSc) is an autoimmune disease characterized by fibrosis and collagen deposits. Gastrointestinal symptoms of SSc, including abdominal pain, bloating and discomfort, are common but diffuse and their pathophysiology remains obscure. AIM To investigate the pathophysiology of abdominal pain and discomfort in individuals with SSc. METHODS A total of 15 individuals with SSc (13 women, median age 58 years), all suffering from diffuse abdominal symptoms, and 17 healthy volunteers (12 women, median age 52 years) were evaluated with the Motility Tracking System, MTS-1, measuring gastric emptying (GE) and velocity through the small intestine. SSc patients were also examined for bacterial overgrowth using the hydrogen breath test and with radiopaque markers to determine the total gastrointestinal transit time (GITT). RESULTS Assessed with the MTS-1, the velocity through the proximal small intestine was significantly reduced in SSc patients (median 0.525 m/h, range 0.11-1.15) when compared to healthy subjects (median 0.91 m/h, range 0.51-1.74) (p = 0.02). Prolonged GE was found in 4 SSc patients (27%) but in none of the healthy volunteers (p = 0.04). Only 3 SSc patients (21%) had positive breath tests for small intestinal bacterial overgrowth. GITT was >3 days in 8 patients (53%). Slow small intestinal transit was associated with a prolonged GITT (p < 0.05). CONCLUSION Velocity through the small intestine is significantly reduced in SSc patients with diffuse abdominal symptoms.
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Affiliation(s)
- Lotte Fynne
- Department of Hepatology and Gastroenterology V, Neurogastroenterology Unit, Aarhus University Hospital, Denmark.
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30
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Weitschies W, Wilson CG. In vivo imaging of drug delivery systems in the gastrointestinal tract. Int J Pharm 2011; 417:216-26. [DOI: 10.1016/j.ijpharm.2011.07.031] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 07/19/2011] [Accepted: 07/19/2011] [Indexed: 11/17/2022]
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31
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Gregersen T, Grønbæk H, Worsøe J, Schlageter V, Laurberg S, Krogh K. Effects of Sandostatin LAR on gastrointestinal motility in patients with neuroendocrine tumors. Scand J Gastroenterol 2011; 46:895-902. [PMID: 21623673 DOI: 10.3109/00365521.2011.579157] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND Diarrhea is part of the carcinoid syndrome and a significant clinical problem in neuroendocrine tumor (NET) patients. Somatostatin analog (SA) treatment usually alleviates carcinoid diarrhea, but little is known about the objective effects of SA on gastrointestinal transport. AIM To compare gastrointestinal motility in healthy subjects and NET patients before and during SA treatment. METHODS Twelve NET patients were studied before and during 4 weeks of SA treatment and were compared with 12 healthy controls. Radio-opaque markers were used for the assessment of total gastrointestinal transit time (GITT). Gastric and small intestinal (SI) transit patterns were described via the external tracking of a small magnetic pill ingested by the subjects. RESULTS Compared with controls, NET patients had a significantly shorter GITT (0.7 days (0.5-1.5) vs. 1.9 days (1.0-2.3)), a shorter SI transit time (184 min (74-307) vs. 322 min (131-376)), and a faster SI velocity (2.16 cm/min (0.91-3.66) vs. 1.29 cm/min (0.76-2.60)) (all p < 0.05) but a similar gastric emptying time. SA treatment was followed by a reduction in bowel movements (five per day (3-12) vs. four per day (1-7; p < 0.02)) as well as an increase in GITT (1.4 days (0.5-2.2; p < 0.05)). Further, a trend was observed toward increased SI transit time (253 min (145-344; p = 0.08)). Gastric emptying time increased during SA treatment (19 min (4-200) vs. 179 min (5-389; p < 0.02)). Elevated chromogranin A (CgA), serotonin, and urinary 5-hydroxyindoleacetic acid (U-5HIAA) levels decreased during SA treatment. CONCLUSION NET patients have faster than normal total GITT and SI transit times. SA treatment prolongs gastric emptying and GITT, thereby reducing the number of bowel movements.
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Affiliation(s)
- Tine Gregersen
- Neurogastroenterology Unit, Department of Medicine V (Hepatology & Gastroenterology), Aarhus University Hospital, Aarhus, Denmark.
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Hahn T, Kozerke S, Schwizer W, Fried M, Boesiger P, Steingoetter A. Visualization and quantification of intestinal transit and motor function by real-time tracking of 19F labeled capsules in humans. Magn Reson Med 2011; 66:812-20. [PMID: 21381105 DOI: 10.1002/mrm.22822] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 12/06/2010] [Accepted: 12/22/2010] [Indexed: 12/16/2022]
Abstract
A combined (19)F and (1)H MRI framework for the assessment of human intestinal transit and motor function is presented. This framework consists of silicone coated polychlorotrifluoroethylene capsules filled with perfluoro-[15]-crown-5-ether as (19)F marker, a flexible (19)F surface coil and a (19)F projection imaging sequence, allowing for real-time tracking of a single or multiple capsules. The capsules (length 11.5 mm, Ø 7.2 mm) contain 140 μL perfluoro-[15]-crown-5-ether and were tested for cytotoxicity and leakage prior to oral administration. A balanced SSFP projection sequence was implemented, yielding a temporal resolution of 133 ms. Optional multi-frequency excitation, allowing for interleaved tracking of differently labeled (19)F capsules, was incorporated. The passage of the (19)F capsules through intestinal sections was monitored in two healthy volunteers. Capsule coordinates were successfully coregistered with anatomical reference scans. Intestinal motility, residence times, lengths and forward velocities were determined. Simultaneous tracking of two capsules allowed for the assessment of peristaltic patterns with correction for respiratory motion. By providing the means for real-time multiple capsule tracking and high resolution anatomical imaging, the presented multinuclear imaging framework has the potential to provide important supplemental information for physiological and pharmaceutical research.
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Affiliation(s)
- Tobias Hahn
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
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33
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Rao SSC, Camilleri M, Hasler WL, Maurer AH, Parkman HP, Saad R, Scott MS, Simren M, Soffer E, Szarka L. Evaluation of gastrointestinal transit in clinical practice: position paper of the American and European Neurogastroenterology and Motility Societies. Neurogastroenterol Motil 2011; 23:8-23. [PMID: 21138500 DOI: 10.1111/j.1365-2982.2010.01612.x] [Citation(s) in RCA: 239] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
BACKGROUND Disorders of gastrointestinal (GI) transit and motility are common, and cause either delayed or accelerated transit through the stomach, small intestine or colon, and affect one or more regions. Assessment of regional and/or whole gut transit times can provide direct measurements and diagnostic information to explain the cause of symptoms, and plan therapy. PURPOSE Recently, several newer diagnostic tools have become available. The American and European Neurogastroenterology and Motility Societies undertook this review to provide guidelines on the indications and optimal methods for the use of transit measurements in clinical practice. This was based on evidence of validation including performance characteristics, clinical significance, and strengths of various techniques. The tests include measurements of: gastric emptying with scintigraphy, wireless motility capsule, and (13)C breath tests; small bowel transit with breath tests, scintigraphy, and wireless motility capsule; and colonic transit with radioopaque markers, wireless motility capsule, and scintigraphy. Based on the evidence, consensus recommendations are provided for each technique and for the evaluations of regional and whole gut transit. In summary, tests of gastrointestinal transit are available and useful in the evaluation of patients with symptoms suggestive of gastrointestinal dysmotility, since they can provide objective diagnosis and a rational approach to patient management.
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Affiliation(s)
- S S C Rao
- Division of Gastroenterology/Hepatology, University of Iowa Carver College of Medicine, Iowa City, IA 52242-1009, USA.
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34
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Paixao FC, Quini CC, Baffa O, Miranda JRDA. A novel device with 36 channels for imaging and signal acquisition of the gastrointestinal tract based on AC biosusceptometry. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2010; 2010:6457-60. [PMID: 21096717 DOI: 10.1109/iembs.2010.5627341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The alternate current biosusceptometry (ACB) is a biomagnetic technique used to study some physiological parameters associated with gastrointestinal (GI) tract. For this purpose it applies an AC magnetic field and measures the response originating from magnetic marks or tracers. This paper presents an equipment based on the ACB which uses anisotropic magnetoresistive (AMR) sensors and an inexpensive electronic support. The ACB-AMR developed consists of a square array of 6×6 sensors arranged in a first-order gradiometer configuration with one reference sensor. The equipment was applied to capture magnetic images of different phantoms and to acquire gastric contraction activity of healthy rats. The results show a reasonable sensitivity and spatial-temporal resolution, so that it may be applied for imaging of phantoms and signal acquisition of the GI tract of small animals.
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Affiliation(s)
- Fabiano C Paixao
- Faculdade de Física, Pontifical Catholic University of Rio Grande do Sul - PUCRS, Av. Ipiranga, 6681 - Partenon, 90619-900, Porto Alegre-RS, Brazil.
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35
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Guo X, Yan G, He W, Jiang P. Improved modeling of electromagnetic localization for implantable wireless capsules. Biomed Instrum Technol 2010; 44:354-359. [PMID: 20715967 DOI: 10.2345/0899-8205-44.4.354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
An electromagnetic localization method for implantable wireless capsules has been developed that employs a three-axial magnetic sensor embedded in the capsules and three energized coils attached on the abdomen. In order to further improve the localization accuracy, a novel localization model has been derived based on the Biot-Savart Law. For simplicity of the calculation without increasing the position error, the method of truncated series expansion has been used in modeling. The experiment showed that the improved model had higher precision than the original dipole model. Using the improved model, the localization error can be greatly reduced. The improved model is an elementary math function and suitable for resolving some inverse magnetic problems in engineering.
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Affiliation(s)
- Xudong Guo
- Institute of Medical Device Engineering, School of Medical Instrument and Food Engineering, University of Shanghai for Science and Technology, Shanghai, China.
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36
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Wilson CG. The transit of dosage forms through the colon. Int J Pharm 2010; 395:17-25. [PMID: 20576492 DOI: 10.1016/j.ijpharm.2010.04.044] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Accepted: 04/30/2010] [Indexed: 10/19/2022]
Abstract
Colonic transit is a subject of great relevance when considering in vivo/in vitro relationships for oral controlled release dosage forms. Our knowledge of colonic motility has first come from the clinic, where measurement of the whole gut transit of different excreted markers was used as a method of discriminating pathologies. X-ray contrast, although widely available, was used sparing due to the accumulating dosimetry associated with each exposure. Although such methods were used for swallowing studies, gamma scintigraphy allowed physicians to measure colon function with a more moderate radiation burden. The ability to label meal and dosage form separately and to measure dispersion with more certainty, prompted the use in pharmaceutical sciences; finally, the relationship between blood concentrations and transit of different sized dosage began to be understood. This mini-review considers the development of colon transit measurements and how different designs of clinical assessment assist in elucidating size and shape influence on colon transit in man.
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Affiliation(s)
- Clive G Wilson
- Strathclyde Institute of Pharmacy & Biomedical Sciences, Glasgow G4 0NR, Scotland, UK.
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37
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Laulicht B, Tripathi A, Schlageter V, Kucera P, Mathiowitz E. Understanding gastric forces calculated from high-resolution pill tracking. Proc Natl Acad Sci U S A 2010; 107:8201-6. [PMID: 20404209 PMCID: PMC2889561 DOI: 10.1073/pnas.1002292107] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Although other methods exist for monitoring gastrointestinal motility and contractility, this study exclusively provides direct and quantitative measurements of the forces experienced by an orally ingested pill. We report motive forces and torques calculated from real-time, in vivo measurements of the movement of a magnetic pill in the stomachs of fasted and fed humans. Three-dimensional net force and two-dimensional net torque vectors as a function of time data during gastric residence are evaluated using instantaneous translational and rotational position data. Additionally, the net force calculations described can be applied to high-resolution pill tracking acquired by any modality. The fraction of time pills experience ranges of forces and torques are analyzed and correlate with the physiological phases of gastric digestion. We also report the maximum forces and torques experienced in vivo by pills as a quantitative measure of the amount of force pills experience during the muscular contractions leading to gastric emptying. Results calculated from human data are compared with small and large animal models with a translational research focus. The reported magnitude and direction of gastric forces experienced by pills in healthy stomachs serves as a baseline for comparison with pathophysiological states. Of clinical significance, the directionality associated with force vector data may be useful in determining the muscle groups associated with gastrointestinal dysmotility. Additionally, the quantitative comparison between human and animal models improves insight into comparative gastric contractility that will aid rational pill design and provide a quantitative framework for interpreting gastroretentive oral formulation test results.
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Affiliation(s)
- Bryan Laulicht
- Department of Molecular Pharmacology, Physiology, and Biotechnology, and
| | - Anubhav Tripathi
- Division of Engineering and Medical Science, Brown University, Providence, RI 02912
| | | | - Pavel Kucera
- Motilis Sárl, CH-1007 Lausanne, Switzerland
- Department of Physiology, University of Lausanne, CH-1015 Lausanne, Switzerland; and
- Department of Biomedical Engineering, Czech Technical University, 166 36 Prague, Czech Republic
| | - Edith Mathiowitz
- Department of Molecular Pharmacology, Physiology, and Biotechnology, and
- Division of Engineering and Medical Science, Brown University, Providence, RI 02912
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38
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Dinning PG, Arkwright JW, Gregersen H, o'grady G, Scott SM. Technical advances in monitoring human motility patterns. Neurogastroenterol Motil 2010; 22:366-80. [PMID: 20377792 DOI: 10.1111/j.1365-2982.2010.01488.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Abnormal motor patterns are implicated in many motility disorders. However, for many regions of the gut, our knowledge of normal and abnormal motility behaviors and mechanisms remains incomplete. There have been many recent advances in the development of techniques to increase our knowledge of gastrointestinal motility, some readily available while others remain confined to research centers. This review highlights a range of these recent developments and examines their potential to help diagnose and guide treatment for motility disorders.
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Affiliation(s)
- P G Dinning
- University of New South Wales, Department of Gastroenterology, St George Hospital, Sydney, Australia.
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39
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Hiroz P, Schlageter V, Givel JC, Kucera P. Colonic movements in healthy subjects as monitored by a Magnet Tracking System. Neurogastroenterol Motil 2009; 21:838-e57. [PMID: 19400925 DOI: 10.1111/j.1365-2982.2009.01298.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Magnet Tracking System (MTS) is a minimally-invasive technique of continuous evaluation of gastrointestinal motility. In this study, MTS was used to analyse colonic propulsive dynamics and compare the transit of a magnetic pill with that of standard radio-opaque markers. MTS monitors the progress in real time of a magnetic pill through the gut. Ten men and 10 women with regular daily bowel movements swallowed this pill and 10 radio-opaque markers at 8 pm. Five hours of recordings were conducted during 2 following mornings. Origin, direction, amplitude and velocity of movements were analysed relative to space-time plots of the pill trajectory. Abdominal radiographs were taken to compare the progress of both pill and markers. The magnetic pill lay idle for 90% of its sojourn in the colon; its total retrograde displacement accounted for only 20% of its overall movement. Analysis of these movements showed a bimodal distribution of velocities: around 1.5 and 50 cm min(-1), the latter being responsible for 2/3 of distance traversed. There were more movements overall and more mass movements in males. Net hourly forward progress was greater in the left than right colon, and greater in males. The position of the magnetic pill correlated well with the advancement of markers. MTS showed patterns and propulsion dynamics of colonic segments with as yet unmet precision. Detailed analysis of slow and fast patterns of colonic progress makes it possible to specify the motility of colonic segments, and any variability in gender. Such analysis opens up promising avenues in studies of motility disorders.
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Affiliation(s)
- P Hiroz
- Department of Visceral Surgery, University Hospital, Lausanne, Switzerland
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40
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Guo X, Yan G, He W. A novel method of three-dimensional localization based on a neural network algorithm. J Med Eng Technol 2009; 33:192-8. [DOI: 10.1080/03091900701403979] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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41
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Hocke M, Schöne U, Richert H, Görnert P, Keller J, Layer P, Stallmach A. Every slow-wave impulse is associated with motor activity of the human stomach. Am J Physiol Gastrointest Liver Physiol 2009; 296:G709-16. [PMID: 19095766 DOI: 10.1152/ajpgi.90318.2008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Using a newly developed high-resolution three-dimensional magnetic detector system (3D-MAGMA), we observed periodical movements of a small magnetic marker in the human stomach at the typical gastric slow-wave frequency, that is 3 min(-1). Thus we hypothesized that each gastric slow wave induces a motor response that is not strong enough to be detected by conventional methods. Electrogastrographies (EGG, Medtronic, Minneapolis, MN) for measurement of gastric slow waves and 3D-MAGMA (Innovent, Jena, Germany) measurements were simultaneously performed in 21 healthy volunteers (10 men, 40.4+/-13.6 yr; 11 women, 35.8+/-11.6 yr). The 3D-MAGMA system contains 27 highly sensitive magnetic field sensors that are able to locate a magnetic pill inside a human body with an accuracy of +/-5 mm or less in position and +/-2 degrees in orientation at a frequency of 50 Hz. Gastric transit time of the magnetic marker ranged from 19 to 154 min. The mean dominant EGG frequency while the marker was in the stomach was 2.87+/-0.15 cpm. The mean dominant 3D-MAGMA frequency during this interval was nearly identical; that is, 2.85+/-0.15 movements per minute. We observed a strong linear correlation between individual dominant EGG and 3D-MAGMA frequency (R=0.66, P=0.0011). Our findings suggest that each gastric slow wave induces a minute contraction that is too small to be detected by conventional motility investigations but can be recorded by the 3D-MAGMA system. The present slow-wave theory that assumes that the slow wave is a pure electrical signal should be reconsidered.
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Affiliation(s)
- Michael Hocke
- Clinic of Internal Medicine II, Department of Gastroenterology, Hepatology and Infectious Diseases, Friedrich-Schiller-University Jena, Erlanger Allee 101, D-07747 Jena, Germany.
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Aellen S, Wiesel PH, Gardaz JP, Schlageter V, Bertschi M, Virag N, Givel JC. Electrical stimulation induces propagated colonic contractions in an experimental model. Br J Surg 2009; 96:214-20. [PMID: 19160367 DOI: 10.1002/bjs.6455] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND Direct colonic electrical stimulation may prove to be a treatment option for specific motility disorders such as chronic constipation. The aim of this study was to provoke colonic contractions using electrical stimulation delivered from a battery-operated device. METHODS Electrodes were inserted into the caecal seromuscular layer of eight anaesthetized pigs. Contractions were induced by a neurostimulator (Medtronic 3625). Caecal motility was measured simultaneously by video image analysis, manometry and a technique assessing colonic transit. RESULTS Caecal contractions were generated using 8-10 V amplitude, 1000 micros pulse width, 120 Hz frequency for 10-30 s, with an intensity of 7-15 mA. The maximal contraction strength was observed after 20-25 s. Electrical stimulation was followed by a relaxation phase of 1.5-2 min during which contractions propagated orally and aborally over at least 10 cm. Spontaneous and stimulated caecal motility values were significantly different for both intraluminal pressure (mean(s.d.) 332(124) and 463(187) mmHg respectively; P < 0.001, 42 experiments) and movement of contents (1.6(0.9) and 3.9(2.8) mm; P < 0.001, 40 experiments). CONCLUSION Electrical stimulation modulated caecal motility, and provoked localized and propagated colonic contractions.
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Affiliation(s)
- S Aellen
- Services de Chirurgie Viscérale, Gastroentérologie et Hépatologie, Anesthésiologie, Centre Hospitalier Universitaire Vaudois, Switzerland.
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A Real-Time Tracking System for an Endoscopic Capsule using Multiple Magnetic Sensors. SMART SENSORS AND SENSING TECHNOLOGY 2008. [DOI: 10.1007/978-3-540-79590-2_14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Paixão FC, de Moraes R, Stelzer M, Corá LA, Américo MF, Andreis U, Oliveira RB, Baffa O, de A Miranda JR. A novel biomagnetic instrumentation with four magnetoresistive sensors to evaluate gastric motility. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2008; 2007:2215-8. [PMID: 18002430 DOI: 10.1109/iembs.2007.4352764] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A novel instrumentation using anisotropic magnetoresistive (AMR) sensors associated with magnetic coils excitation was developed to evaluate gastrointestinal tract motility parameters. The susceptometer has four sensors that were used to measure the gastric activity contractions (GAC) in anaesthetized dogs, its performance was evaluated by manometry with good results.
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Affiliation(s)
- Fabiano C Paixão
- Departamento de Física e Biofísica, IBB - Universidade Estadual Paulista, Distrito de Rubião Júnior, S/N, 18.618-000, Botucatu-SP, Brazil
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Donovan SM. Role of human milk components in gastrointestinal development: Current knowledge and future NEEDS. The journal The Journal of Pediatrics 2006. [DOI: 10.1016/j.jpeds.2006.06.052] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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Guignet R, Bergonzelli G, Schlageter V, Turini M, Kucera P. Magnet Tracking: a new tool for in vivo studies of the rat gastrointestinal motility. Neurogastroenterol Motil 2006; 18:472-8. [PMID: 16700727 DOI: 10.1111/j.1365-2982.2006.00785.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Digestive motility was studied in the rat using a miniaturized version of the Magnet Tracking system which monitored the progression of a small magnetic pill through the entire digestive tract. The dynamics of movement was followed and three-dimensional (3-D) images of digestive tract were generated. After a retention period in the stomach and rapid passage through duodenum, the magnet progressed along the small intestine with gradually decreasing speed and longer stationary periods. It remained in the caecum for variable intervals. In the colon, periods of progress alternated with long quiescent periods. Gastric activity oscillated at 5-6 min(-1). In the small intestine, two frequency domains coexisted, showing independent modulations and proximo-distal gradients (40 to >32 and 28 to >20 min(-1)). Caecal oscillations were of 1.5 min(-1). The data allowed the magnet location and calculation of gastric and small intestinal transit times (58 +/- 36 and 83 +/- 14 min respectively), both significantly prolonged by oleate administration (243 +/- 130 and 170 +/- 45 min respectively). Magnet Tracking is a non-invasive tool to study the in vivo spatial and temporal organization of gastrointestinal motility in the rat.
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Affiliation(s)
- R Guignet
- Department of Physiology, University of Lausanne, Lausanne, Switzerland
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The welfare and scientific advantages of non-invasive imaging of animals used in biomedical research. Anim Welf 2005. [DOI: 10.1017/s0962728600029638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
AbstractAt present, animal experimentation remains central to our understanding of human disease-related processes and of the biological effects of many substances. Traditional experiments have relied heavily on invasive techniques to monitor changes in blood biochemistry, tissue structure or function, or to phenotype or genotype genetically modified animals. In some cases, a proportion or all of the animals used during the course of a study may be sacrificed for histopathological assessment. In most cases, this is to track the progression or regression of a disease over time, or to determine the levels of toxicity evident in specific organs or tissues. However, many of these techniques fail to provide details of how a disease develops or how a substance elicits its effects. In recent years there has been a gradual increase in the application of imaging techniques that were originally developed and used in fundamental research or in medicine. These non-invasive techniques allow diseases, and responses to exogenous substances, to be monitored in a temporal and spatial manner, therefore allowing a greater amount of information to be derived from smaller numbers of animals, which in turn, increases the statistical validity of the data by reducing the level of experimental variation. Non-invasive imaging also allows more informative and humane endpoints to be used and, perhaps most importantly, allows functional details to be studied in the context of a living animal. Some of the recent developments within the field of non-invasive imaging and their significance with respect to animal welfare and the understanding of human physiology are discussed.
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