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Kuhar S, Seo JH, Pasricha PJ, Mittal R. In silico modelling of the effect of pyloric intervention procedures on gastric flow and emptying in a stomach with gastroparesis. J R Soc Interface 2024; 21:20230567. [PMID: 38263890 PMCID: PMC10824103 DOI: 10.1098/rsif.2023.0567] [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: 09/27/2023] [Accepted: 01/02/2024] [Indexed: 01/25/2024] Open
Abstract
Pyloric interventions are surgical procedures employed to increase the gastric emptying rate in gastroparesis patients. In this study, we use an in silico model to investigate the consequences of pyloric intervention on gastric flow and emptying for two phenotypes of gastroparesis: antral hypomotility and decreased gastric tone. The transpyloric pressure gradient predicted by the in silico model, based on viscous fluid flow equations, is compared against in vivo measurements. Both phenotypes exhibit a similar pre-procedural emptying rate reduction, but after pyloric surgery, antral hypomotility case with preserved gastric tone shows significant improvements in emptying rates, up to 131%, accompanied by bile reflux from the duodenum into the stomach. Conversely, severely reduced gastric tone cases exhibited a post-procedural reduction in the net emptying rate due to the relatively larger bile reflux. In cases with a combination of antral hypomotility and reduced gastric tone, post-procedural improvements were observed only when both conditions were mild. Our findings highlight the pivotal role of the relative increase in pyloric orifice diameter in determining post-operative emptying rates. The study suggests a possible explanation for the selective response of patients toward these procedures and underscores the potential of in silico modelling to generate valuable insights to inform gastric surgery.
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Affiliation(s)
- Sharun Kuhar
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jung-Hee Seo
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
| | | | - Rajat Mittal
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
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2
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Hosseini S, Palmada N, Avci R, Suresh V, Cheng LK. MRI Derived Simulations of Flow Patterns in the Stomach. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2023; 2023:1-4. [PMID: 38083297 DOI: 10.1109/embc40787.2023.10340717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2023]
Abstract
A framework to simulate the flow in the stomach using subject-specific motility patterns and geometries was developed. Dynamic 2D magnetic resonance images (MRIs) were obtained. Motility parameters such as contraction speed and occlusion were quantified, and 3D stomach geometries were reconstructed using a semi-automated approach. Computational fluid dynamics (CFD) simulations were performed, and flow patterns were investigated. The stomach of both subjects had distinct anatomical features with computed volumes of 789 mL and 619 mL. For the one subject, the occlusion (i.e., normalized contraction size) was 12% while it was around 25% for the other subject. Contraction speeds were also different (1.9-2.8 mm/s vs 3.0-5.1 mm/s) for each subject. CFD simulations resulted in unsteady laminar flow for both subjects with average velocities of 2.1 and 3.2 mm/s. While antegrade flow was mainly observed in the simulations, a retropulsive jet was also present in both stomachs. The versatile framework developed within this study would allow the generation of CFD models of gastric motility from dynamic MRIs.Clinical Relevance- Subject-specific models of flow patterns informed by gastric motility features can elucidate the impact of contractions and anatomical variations on digestion. Such models can inform therapies to treat gastric dysfunctions and improve their efficacy.
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3
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Ebara R, Ishida S, Miyagawa T, Imai Y. Effects of peristaltic amplitude and frequency on gastric emptying and mixing: a simulation study. J R Soc Interface 2023; 20:20220780. [PMID: 36596453 PMCID: PMC9810435 DOI: 10.1098/rsif.2022.0780] [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: 10/25/2022] [Accepted: 12/05/2022] [Indexed: 01/05/2023] Open
Abstract
The amplitude and frequency of peristaltic contractions are two major parameters for assessing gastric motility. However, it is not fully understood how these parameters affect the important functions of the stomach, such as gastric mixing and emptying. This study aimed to quantify the effects of peristaltic amplitude and frequency on gastric mixing and emptying using computational fluid dynamics simulation of gastric flow with an anatomically realistic model of the stomach. Our results suggest that both the increase and decrease in peristaltic amplitude have a significant impact on mixing strength and emptying rate. For example, when the peristaltic amplitude was 1.2 times higher than normal, the emptying rate was 2.7 times faster, whereas when the amplitude was half, the emptying rate was 4.2 times slower. Moreover, the emptying rate increased more than proportionally with the peristaltic frequency. The nearest contraction wave to the pylorus and the subsequent waves promoted gastric emptying. These results suggest the importance of maintaining parameters within normal ranges to achieve healthy gastric function.
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Affiliation(s)
- Rika Ebara
- Graduate School of Engineering, Kobe University, Kobe, Japan
| | - Shunichi Ishida
- Graduate School of Engineering, Kobe University, Kobe, Japan
| | - Taimei Miyagawa
- Graduate School of Science and Technology, Hirosaki University, Hirosaki, Japan
| | - Yohsuke Imai
- Graduate School of Engineering, Kobe University, Kobe, Japan
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4
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Kuhar S, Lee JH, Seo JH, Pasricha PJ, Mittal R. Effect of stomach motility on food hydrolysis and gastric emptying: Insight from computational models. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2022; 34:111909. [PMID: 36407285 PMCID: PMC9667910 DOI: 10.1063/5.0120933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 10/13/2022] [Indexed: 06/16/2023]
Abstract
The peristaltic motion of stomach walls combines with the secretion of digestive enzymes to initiate the process that breaks down food. In this study, the mixing, breakdown, and emptying of a liquid meal containing protein is simulated in a model of a human stomach. In this model, pepsin, the gastric enzyme responsible for protein hydrolysis, is secreted from the proximal region of the stomach walls and allowed to react with the contents of the stomach. The velocities of the retropulsive jet induced by the peristaltic motion, the emptying rate, and the extent of hydrolysis are quantified for a control case as well as for three other cases with reduced motility of the stomach, which may result from conditions such as diabetes mellitus. This study quantifies the effect of stomach motility on the rate of food breakdown and its emptying into the duodenum and we correlate these observations with the mixing in the stomach induced by the wall motion.
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Affiliation(s)
- Sharun Kuhar
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | | | | | - Pankaj J Pasricha
- Division of Gastroenterology and Hepatology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
| | - Rajat Mittal
- Author to whom correspondence should be addressed:
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5
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Lee JH, Kuhar S, Seo JH, Pasricha PJ, Mittal R. Computational modeling of drug dissolution in the human stomach: Effects of posture and gastroparesis on drug bioavailability. PHYSICS OF FLUIDS (WOODBURY, N.Y. : 1994) 2022; 34:081904. [PMID: 35971381 PMCID: PMC9372820 DOI: 10.1063/5.0096877] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/23/2022] [Indexed: 05/25/2023]
Abstract
The oral route is the most common choice for drug administration because of several advantages, such as convenience, low cost, and high patient compliance, and the demand and investment in research and development for oral drugs continue to grow. The rate of dissolution and gastric emptying of the dissolved active pharmaceutical ingredient (API) into the duodenum is modulated by gastric motility, physical properties of the pill, and the contents of the stomach, but current in vitro procedures for assessing dissolution of oral drugs are limited in their ability to recapitulate this process. This is particularly relevant for disease conditions, such as gastroparesis, that alter the anatomy and/or physiology of the stomach. In silico models of gastric biomechanics offer the potential for overcoming these limitations of existing methods. In the current study, we employ a biomimetic in silico simulator based on the realistic anatomy and morphology of the stomach (referred to as "StomachSim") to investigate and quantify the effect of body posture and stomach motility on drug bioavailability. The simulations show that changes in posture can potentially have a significant (up to 83%) effect on the emptying rate of the API into the duodenum. Similarly, a reduction in antral contractility associated with gastroparesis can also be found to significantly reduce the dissolution of the pill as well as emptying of the API into the duodenum. The simulations show that for an equivalent motility index, the reduction in gastric emptying due to neuropathic gastroparesis is larger by a factor of about five compared to myopathic gastroparesis.
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Affiliation(s)
| | - S. Kuhar
- Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA
| | | | - P. J. Pasricha
- Division of Gastroenterology and Hepatology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, USA
| | - R. Mittal
- Author to whom correspondence should be addressed:
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6
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Acharya S, Halder S, Kou W, Kahrilas PJ, Pandolfino JE, Patankar NA. A fully resolved multiphysics model of gastric peristalsis and bolus emptying in the upper gastrointestinal tract. Comput Biol Med 2022; 143:104948. [PMID: 35091365 PMCID: PMC9014465 DOI: 10.1016/j.compbiomed.2021.104948] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/09/2021] [Accepted: 10/13/2021] [Indexed: 11/22/2022]
Abstract
Over the past few decades, in silico modeling of organ systems has significantly furthered our understanding of their physiology and biomechanical function. In spite of the relative importance of the digestive system in normal functioning of the human body, there is a scarcity of high-fidelity models for the upper gastrointestinal tract including the esophagus and the stomach. In this work, we present a detailed numerical model of the upper gastrointestinal tract that not only accounts for the fiber architecture of the muscle walls, but also the multiphasic components they help transport during normal digestive function. Construction details for 3D models of representative stomach geometry are presented along with a simple strategy for assigning circular and longitudinal muscle fiber orientations for each layer. We developed a fully resolved model of the stomach to simulate gastric peristalsis by systematically activating muscle fibers embedded in the stomach. Following this, for the first time, we simulate gravity-driven bolus emptying into the stomach due to density differences between ingested contents and fluid contents of the stomach. Finally, we present a case of retrograde flow of fluid from the stomach into the esophagus, resembling the phenomenon of acid reflux. This detailed computational model of the upper gastrointestinal tract provides a foundation for future models to investigate the biomechanics of acid reflux and probe various strategies for gastric bypass surgeries to address the growing problem of obesity.
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Affiliation(s)
- Shashank Acharya
- Department of Mechanical Engineering, Northwestern University, Evanston, IL, 60208, USA
| | - Sourav Halder
- Theoretical and Applied Mechanics Program, Northwestern University, Evanston, IL, 60208, USA
| | - Wenjun Kou
- Division of Gastroenterology and Hepatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Peter J Kahrilas
- Division of Gastroenterology and Hepatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - John E Pandolfino
- Division of Gastroenterology and Hepatology, Feinberg School of Medicine, Northwestern University, Chicago, IL, 60611, USA
| | - Neelesh A Patankar
- Department of Mechanical Engineering, Northwestern University, Evanston, IL, 60208, USA; Theoretical and Applied Mechanics Program, Northwestern University, Evanston, IL, 60208, USA.
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7
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Tablet Disintegration and Dispersion under In Vivo-like Hydrodynamic Conditions. Pharmaceutics 2022; 14:pharmaceutics14010208. [PMID: 35057103 PMCID: PMC8779444 DOI: 10.3390/pharmaceutics14010208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 02/05/2023] Open
Abstract
Disintegration and dispersion are functional properties of tablets relevant for the desired API release. The standard disintegration test (SDT) described in different pharmacopoeias provides only limited information on these complex processes. It is considered not to be comparable to the biorelevant conditions due to the frequent occurrence of high hydrodynamic forces, among other reasons. In this study, 3D tomographic laser-induced fluorescence imaging (3D Tomo-LIF) is applied to analyse tablet disintegration and dispersion. Disintegration time (DT) and time-resolved particle size distribution in close proximity to the tablet are determined in a continuously operated flow channel, adjustable to very low fluid velocities. A case study on tablets of different porosity, which are composed of pharmaceutical polymers labelled with a fluorescent dye, a filler, and disintegrants, is presented to demonstrate the functionality and precision of the novel method. DT results from 3D Tomo-LIF are compared with results from the SDT, confirming the analytical limitations of the pharmacopoeial disintegration test. Results from the 3D Tomo-LIF method proved a strong impact of fluid velocity on disintegration and dispersion. Generally, shorter DTs were determined when cross-linked sodium carboxymethly cellulose (NaCMCXL) was used as disintegrant compared to polyvinyl polypyrrolidone (PVPP). Tablets containing Kollidon VA64 were found to disintegrate by surface erosion. The novel method provides an in-depth understanding of the functional behaviour of the tablet material, composition and structural properties under in vivo-like hydrodynamic forces regarding disintegration and the temporal progress of dispersion. We consider the 3D Tomo-LIF in vitro method to be of improved biorelevance in terms of hydrodynamic conditions in the human stomach.
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8
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O'Farrell C, Stamatopoulos K, Simmons M, Batchelor H. In vitro models to evaluate ingestible devices: Present status and current trends. Adv Drug Deliv Rev 2021; 178:113924. [PMID: 34390774 DOI: 10.1016/j.addr.2021.113924] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/03/2021] [Accepted: 08/09/2021] [Indexed: 12/14/2022]
Abstract
Orally ingestible medical devices offer significant opportunity in the diagnosis and treatment of gastrointestinal conditions. Their development necessitates the use of models that simulate the gastrointestinal environment on both a macro and micro scale. An evolution in scientific technology has enabled a wide range of in vitro, ex vivo and in vivo models to be developed that replicate the gastrointestinal tract. This review describes the landscape of the existing range of in vitro tools that are available to characterize ingestible devices. Models are presented with details on their benefits and limitations with regards to the evaluation of ingestible devices and examples of their use in the evaluation of such devices is presented where available. The multitude of models available provides a suite of tools that can be used in the evaluation of ingestible devices that should be selected on the functionality of the device and the mechanism of its function.
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Affiliation(s)
- Connor O'Farrell
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - 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
| | - 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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In Vitro Simulation of the Environment in the Upper Gastrointestinal Lumen After Drug Administration in the Fed State Using the TIM-1 System and Comparison With Luminal Data in Adults. J Pharm Sci 2021; 111:197-205. [PMID: 34673096 DOI: 10.1016/j.xphs.2021.10.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 10/11/2021] [Accepted: 10/11/2021] [Indexed: 10/20/2022]
Abstract
We evaluated the environment in TIM-1 luminal compartments using paracetamol and danazol solutions and suspensions and the fed state configuration. Data were compared with recently published data in healthy adults. TIM-1 experiments were performed with a 3-fold downscale. Volumes of secretions in gastric and duodenal compartments adequately reflected the luminal data in adults up to 3 h post drug dosing. pH values in duodenal and jejunal compartments adequately reflected average pH values in adults. In gastric compartment pH values where initially higher than average values in adults and reached baseline levels earlier than in adults. The environment in the TIM-1 gastric compartment and jejunal compartment adequately reflected the average total paracetamol and danazol amounts per volume of contents in the adult stomach and upper small intestine, respectively. Total bile acids concentrations in the micellar phase of contents in duodenal and jejunal compartments overestimated micellar concentrations in the upper small intestine of adults. Adjustments in gastric emptying/acid secretion rates and bile acids identities in the duodenal and jejunal compartments, and application of dynamic bile acids secretion rates are expected to further improve the relevance of luminal conditions in TIM-1 compartments with those in adults.
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10
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Bhattarai A, Kowalczyk W, Tran TN. A literature review on large intestinal hyperelastic constitutive modeling. Clin Biomech (Bristol, Avon) 2021; 88:105445. [PMID: 34416632 DOI: 10.1016/j.clinbiomech.2021.105445] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 06/29/2021] [Accepted: 07/29/2021] [Indexed: 02/07/2023]
Abstract
Impacts, traumas and strokes are spontaneously life-threatening, but chronic symptoms strangle patient every day. Colorectal tissue mechanics in such chronic situations not only regulates the physio-psychological well-being of the patient, but also confirms the level of comfort and post-operative clinical outcomes. Numerous uniaxial and multiaxial tensile experiments on healthy and affected samples have evidenced significant differences in tissue mechanical behavior and strong colorectal anisotropy across each layer in thickness direction and along the length. Furthermore, this study reviewed various forms of passive constitutive models for the highly fibrous colorectal tissue ranging from the simplest linearly elastic and the conventional isotropic hyperelastic to the most sophisticated second harmonic generation image based anisotropic mathematical formulation. Under large deformation, the isotropic description of tissue mechanics is unequivocally ineffective which demands a microstructural based tissue definition. Therefore, the information collected in this review paper would present the current state-of-the-art in colorectal biomechanics and profoundly serve as updated computational resources to develop a sophisticated characterization of colorectal tissues.
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Affiliation(s)
- Aroj Bhattarai
- Department of Orthopaedic Surgery, University of Saarland, Germany
| | | | - Thanh Ngoc Tran
- Department of Orthopaedic Surgery, University of Saarland, Germany.
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11
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Li C, Jin Y. A CFD model for investigating the dynamics of liquid gastric contents in human-stomach induced by gastric motility. J FOOD ENG 2021. [DOI: 10.1016/j.jfoodeng.2020.110461] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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12
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Cheng LK, Nagahawatte ND, Avci R, Du P, Liu Z, Paskaranandavadivel N. Strategies to Refine Gastric Stimulation and Pacing Protocols: Experimental and Modeling Approaches. Front Neurosci 2021; 15:645472. [PMID: 33967679 PMCID: PMC8100207 DOI: 10.3389/fnins.2021.645472] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 03/22/2021] [Indexed: 12/13/2022] Open
Abstract
Gastric pacing and stimulation strategies were first proposed in the 1960s to treat motility disorders. However, there has been relatively limited clinical translation of these techniques. Experimental investigations have been critical in advancing our understanding of the control mechanisms that innervate gut function. In this review, we will discuss the use of pacing to modulate the rhythmic slow wave conduction patterns generated by interstitial cells of Cajal in the gastric musculature. In addition, the use of gastric high-frequency stimulation methods that target nerves in the stomach to either inhibit or enhance stomach function will be discussed. Pacing and stimulation protocols to modulate gastric activity, effective parameters and limitations in the existing studies are summarized. Mathematical models are useful to understand complex and dynamic systems. A review of existing mathematical models and techniques that aim to help refine pacing and stimulation protocols are provided. Finally, some future directions and challenges that should be investigated are discussed.
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Affiliation(s)
- Leo K Cheng
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand.,Department of General Surgery, Vanderbilt University Medical Center, Nashville, TN, United States.,Riddet Institute, Palmerston North, New Zealand
| | - Nipuni D Nagahawatte
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Recep Avci
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Peng Du
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Zhongming Liu
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States.,Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, United States
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13
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Wang TH, Angeli TR, Ishida S, Du P, Gharibans A, Paskaranandavadivel N, Imai Y, Miyagawa T, Abell TL, Farrugia G, Cheng LK, O’Grady G. The influence of interstitial cells of Cajal loss and aging on slow wave conduction velocity in the human stomach. Physiol Rep 2021; 8:e14659. [PMID: 33355992 PMCID: PMC7757374 DOI: 10.14814/phy2.14659] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 11/08/2020] [Accepted: 11/09/2020] [Indexed: 12/14/2022] Open
Abstract
Loss of interstitial cells of Cajal (ICC) has been associated with gastric dysfunction and is also observed during normal aging at ~13% reduction per decade. The impact of ICC loss on gastric slow wave conduction velocity is currently undefined. This study correlated human gastric slow wave velocity with ICC loss and aging. High-resolution gastric slow wave mapping data were screened from a database of 42 patients with severe gastric dysfunction (n = 20) and controls (n = 22). Correlations were performed between corpus slow wave conduction parameters (frequency, velocity, and amplitude) and corpus ICC counts in patients, and with age in controls. Physiological parameters were further integrated into computational models of gastric mixing. Patients: ICC count demonstrated a negative correlation with slow wave velocity in the corpus (i.e., higher velocities with reduced ICC; r2 = .55; p = .03). ICC count did not correlate with extracellular slow wave amplitude (p = .12) or frequency (p = .84). Aging: Age was positively correlated with slow wave velocity in the corpus (range: 25-74 years; r2 = .32; p = .02). Age did not correlate with extracellular slow wave amplitude (p = .40) or frequency (p = .34). Computational simulations demonstrated that the gastric emptying rate would increase at higher slow wave velocities. ICC loss and aging are associated with a higher slow wave velocity. The reason for these relationships is unexplained and merit further investigation. Increased slow wave velocity may modulate gastric emptying higher, although in gastroparesis other pathological factors must dominate to prevent emptying.
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Affiliation(s)
| | - Timothy R. Angeli
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | | | - Peng Du
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | - Armen Gharibans
- Department of SurgeryUniversity of AucklandAucklandNew Zealand
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | | | - Yohsuke Imai
- Graduate School of EngineeringKobe UniversityKobeJapan
| | - Taimei Miyagawa
- Graduate School of Science and TechnologyHirosaki UniversityHirosakiJapan
| | - Thomas L. Abell
- Division of GastroenterologyUniversity of LouisvilleLouisvilleKYUSA
| | | | - Leo K. Cheng
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
| | - Gregory O’Grady
- Department of SurgeryUniversity of AucklandAucklandNew Zealand
- Auckland Bioengineering InstituteUniversity of AucklandAucklandNew Zealand
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14
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Skamniotis C, Edwards CH, Bakalis S, Frost G, Charalambides M. Eulerian-Lagrangian finite element modelling of food flow-fracture in the stomach to engineer digestion. INNOV FOOD SCI EMERG 2020. [DOI: 10.1016/j.ifset.2020.102510] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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15
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Le Feunteun S, Mackie AR, Dupont D. In silico trials of food digestion and absorption: how far are we? Curr Opin Food Sci 2020. [DOI: 10.1016/j.cofs.2020.04.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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16
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Keppler S, O'Meara S, Bakalis S, Fryer P, Bornhorst G. Characterization of individual particle movement during in vitro gastric digestion in the Human Gastric Simulator (HGS). J FOOD ENG 2020. [DOI: 10.1016/j.jfoodeng.2019.07.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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17
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Özdel D, Sarı HY. Effects of the prone position and kangaroo care on gastric residual volume, vital signs and comfort in preterm infants. Jpn J Nurs Sci 2019; 17:e12287. [DOI: 10.1111/jjns.12287] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 02/08/2019] [Accepted: 04/24/2019] [Indexed: 01/14/2023]
Affiliation(s)
- Deniz Özdel
- Department of NICU Dokuz Eylül University Hospital, İnciraltı Mahallesi Izmir Türkiye
| | - Hatice Yıldırım Sarı
- Pediatric Nursing Department, Faculty of Health Science Izmir Kâtip Çelebi University İzmir Türkiye
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18
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Intestinal flow after anastomotic operations in neonates. Comput Biol Med 2019; 118:103471. [PMID: 31610882 DOI: 10.1016/j.compbiomed.2019.103471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/30/2019] [Accepted: 09/23/2019] [Indexed: 11/22/2022]
Abstract
Stagnation of contents at the anastomotic site for intestinal flows after anastomotic operation is a critical issue in neonates. Although various anastomosis methods have been developed, in the clinical field, poor passage at the anastomotic site in cases of jejunal atresia is still observed. A CFD study was carried out to clarify the reasons for the stagnation and to find favorable anastomosis methods from a fluid dynamical point of view. Direct numerical simulations were performed using OpenFOAM. The boundaries of the computational domain were peristaltically moved to reproduce flow. The results reveal that the peristaltic motion on the distal side dominates the flow and that on the proximal side has a negligible influence. In particular, the contents do not pass the anastomotic site when the peristaltic motion on the distal side is not active. The flow rate as a measure of the driving force of the flow on the proximal side is large when the amplitude of the peristaltic motion is large and the diameter is small. It was also found that anastomosis methods do not affect flow resistance.
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Ishida S, Miyagawa T, O'Grady G, Cheng LK, Imai Y. Quantification of gastric emptying caused by impaired coordination of pyloric closure with antral contraction: a simulation study. J R Soc Interface 2019; 16:20190266. [PMID: 31387481 PMCID: PMC6731493 DOI: 10.1098/rsif.2019.0266] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 07/04/2019] [Indexed: 12/18/2022] Open
Abstract
Proper coordination of gastric motor functions is required for healthy gastric emptying. However, pyloric function may be impaired by functional disorders or surgical procedures. Here, we show how coordination between pyloric closure and antral contraction affects the emptying of liquid contents. We numerically simulated fluid dynamics using an anatomically realistic gastrointestinal geometry. Peristaltic contractions in the proximal stomach resulted in gastric emptying at a rate of 3-8 ml min-1. When the pylorus was unable to close, the emptying rate increased to 10-30 ml min-1, and instantaneous retrograde flow from the duodenum to the antrum occurred during antral relaxation. Rapid emptying occurred if the pylorus began to open during the terminal antral contraction, and the emptying rate was negative if the pylorus only opened during the antral relaxation phase. Our results showed that impaired coordination between antral contraction and pyloric closure can result in delayed gastric emptying, rapid gastric emptying and bile reflux.
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Affiliation(s)
- Shunichi Ishida
- Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Taimei Miyagawa
- Graduate School of Science and Technology, Hirosaki University, Hirosaki, Japan
| | - Gregory O'Grady
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Leo K. Cheng
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
- Riddet Institute, Palmerston North, New Zealand
| | - Yohsuke Imai
- Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
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Simons FJ, Wagner KG. Modeling, design and manufacture of innovative floating gastroretentive drug delivery systems based on hot-melt extruded tubes. Eur J Pharm Biopharm 2019; 137:196-208. [PMID: 30826475 DOI: 10.1016/j.ejpb.2019.02.022] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/23/2019] [Accepted: 02/26/2019] [Indexed: 01/07/2023]
Abstract
The problem of many gastroretentive systems is the mechanistic connection of drug release and gastric retention control. This connection could be successfully separated by formulating hollow tubes via hot-melt extrusion and sealing both tube ends, which led to immediately floating devices. The tube wall consisted of metformin crystals embedded in an inert polymer matrix of Eudragit® RS PO and E PO. Very high drug loadings of up to 80% (w/w) were used without generating a 'burst release'. Sustained release profiles from four to more than twelve hours were achieved by varying the polymer proportions without affecting the floatability. Buoyancy was found to mainly depend on the cylinder design, i.e. the outer to inner diameter ratio. This allowed the polymer/metformin composition to be changed without affecting buoyancy, i.e. a separation of floatability and release control was achieved. A prediction model was implemented that allowed for the buoyancy force to be determined with high accuracy by selecting a suitable ratio of outer to inner diameter of the modular tube die. Wall thickness and mass normalized surface area were identified as geometric parameters that mainly influenced the release properties. Conclusively, this study offers a highly flexible and rational manufacturing approach for the development of gastroretentive floating drug delivery systems.
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Affiliation(s)
- Fabian J Simons
- Department of Pharmaceutical Technology and Biopharmaceutics, University of Bonn, Bonn, Germany
| | - Karl G Wagner
- Department of Pharmaceutical Technology and Biopharmaceutics, University of Bonn, Bonn, Germany.
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D’Arcy DM, Persoons T. Understanding the Potential for Dissolution Simulation to Explore the Effects of Medium Viscosity on Particulate Dissolution. AAPS PharmSciTech 2019; 20:47. [PMID: 30617668 DOI: 10.1208/s12249-018-1260-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 11/24/2018] [Indexed: 02/06/2023] Open
Abstract
Viscosity, influenced by medium composition, will affect the hydrodynamics of a dissolution system. Dissolution simulation methods are valuable tools to explore mechanistic dissolution effects, with an understanding of limitations of any simulation method essential to its appropriate use. The aims of this paper were a) to explore, using dissolution simulation, the effects of slightly viscous media on particulate dissolution and b) to illustrate approaches to, and limitations of, the dissolution simulations. A lumped parameter fluid dynamics dissolution simulation model (SIMDISSO™) was used to simulate particulate (20 and 200 μm diameter) dissolution in media with viscosity at 37 °C of water (0.7 mPa.s), milk (1.4 mPa.s) and a nutrient drink (12.3 mPa.s). Effects of flow rate, modality (constant vs pulsing), viscosity and gravitational and particle motion/sedimentation effects on simulated dissolution were explored, in the flow through and paddle apparatuses as appropriate. Shadowgraph imaging (SGI) was used to visualise particle suspension behaviour. Flow rate, hydrodynamic viscous effects and disabling particle motion and gravitational effects affected simulated dissolution of larger particles. SGI imaging revealed retention of particles in suspension in 1.4 mPa.s medium, which sedimented in water. The effect of diffusion adjusted for viscosity was significant for both particle sizes. The limitations of this 1D simulation approach would be greater for larger particles in low velocity regions of the paddle apparatus. Even slightly viscous media can affect dissolution of larger particles with dissolution simulation affording insight into the mechanisms involved, provided the assumptions and limitations of the simulation approach are clarified and understood.
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Paixão P, Bermejo M, Hens B, Tsume Y, Dickens J, Shedden K, Salehi N, Koenigsknecht MJ, Baker JR, Hasler WL, Lionberger R, Fan J, Wysocki J, Wen B, Lee A, Frances A, Amidon GE, Yu A, Benninghoff G, Löbenberg R, Talattof A, Sun D, Amidon GL. Gastric emptying and intestinal appearance of nonabsorbable drugs phenol red and paromomycin in human subjects: A multi-compartment stomach approach. Eur J Pharm Biopharm 2018; 129:162-174. [DOI: 10.1016/j.ejpb.2018.05.033] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 05/21/2018] [Accepted: 05/28/2018] [Indexed: 10/16/2022]
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Cascone S, De Santis F, Lamberti G. Mimicking the contractions of a human stomach and their effect on pharmaceuticals. J Drug Deliv Sci Technol 2017. [DOI: 10.1016/j.jddst.2017.09.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Kozu H, Kobayashi I, Nakajima M, Neves MA, Uemura K, Isoda H, Ichikawa S. Mixing characterization of liquid contents in human gastric digestion simulator equipped with gastric secretion and emptying. Biochem Eng J 2017. [DOI: 10.1016/j.bej.2016.10.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Miyagawa T, Imai Y, Ishida S, Ishikawa T. Relationship between gastric motility and liquid mixing in the stomach. Am J Physiol Gastrointest Liver Physiol 2016; 311:G1114-G1121. [PMID: 27789458 DOI: 10.1152/ajpgi.00346.2016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Accepted: 10/25/2016] [Indexed: 01/31/2023]
Abstract
The relationship between gastric motility and the mixing of liquid food in the stomach was investigated with a numerical analysis. Three parameters of gastric motility were considered: the propagation velocity, frequency, and terminal acceleration of peristaltic contractions. We simulated gastric flow with an anatomically realistic geometric model of the stomach, considering free surface flow and moving boundaries. When a peristaltic contraction approaches the pylorus, retropulsive flow is generated in the antrum. Flow separation then occurs behind the contraction. The extent of flow separation depends on the Reynolds number (Re), which quantifies the inertial forces due to the peristaltic contractions relative to the viscous forces of the gastric contents; no separation is observed at low Re, while an increase in reattachment length is observed at high Re. While mixing efficiency is nearly constant for low Re, it increases with Re for high Re because of flow separation. Hence, the effect of the propagation velocity, frequency, or terminal acceleration of peristaltic contractions on mixing efficiency increases with Re.
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Affiliation(s)
- Taimei Miyagawa
- Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan; and
| | - Yohsuke Imai
- School of Engineering, Tohoku University, Aoba, Sendai, Japan
| | - Shunichi Ishida
- Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan; and
| | - Takuji Ishikawa
- Graduate School of Biomedical Engineering, Tohoku University, Aoba, Sendai, Japan; and.,School of Engineering, Tohoku University, Aoba, Sendai, Japan
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Berry R, Miyagawa T, Paskaranandavadivel N, Du P, Angeli TR, Trew ML, Windsor JA, Imai Y, O'Grady G, Cheng LK. Functional physiology of the human terminal antrum defined by high-resolution electrical mapping and computational modeling. Am J Physiol Gastrointest Liver Physiol 2016; 311:G895-G902. [PMID: 27659422 PMCID: PMC5130547 DOI: 10.1152/ajpgi.00255.2016] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 09/14/2016] [Indexed: 01/31/2023]
Abstract
High-resolution (HR) mapping has been used to study gastric slow-wave activation; however, the specific characteristics of antral electrophysiology remain poorly defined. This study applied HR mapping and computational modeling to define functional human antral physiology. HR mapping was performed in 10 subjects using flexible electrode arrays (128-192 electrodes; 16-24 cm2) arranged from the pylorus to mid-corpus. Anatomical registration was by photographs and anatomical landmarks. Slow-wave parameters were computed, and resultant data were incorporated into a computational fluid dynamics (CFD) model of gastric flow to calculate impact on gastric mixing. In all subjects, extracellular mapping demonstrated normal aboral slow-wave propagation and a region of increased amplitude and velocity in the prepyloric antrum. On average, the high-velocity region commenced 28 mm proximal to the pylorus, and activation ceased 6 mm from the pylorus. Within this region, velocity increased 0.2 mm/s per mm of tissue, from the mean 3.3 ± 0.1 mm/s to 7.5 ± 0.6 mm/s (P < 0.001), and extracellular amplitude increased from 1.5 ± 0.1 mV to 2.5 ± 0.1 mV (P < 0.001). CFD modeling using representative parameters quantified a marked increase in antral recirculation, resulting in an enhanced gastric mixing, due to the accelerating terminal antral contraction. The extent of gastric mixing increased almost linearly with the maximal velocity of the contraction. In conclusion, the human terminal antral contraction is controlled by a short region of rapid high-amplitude slow-wave activity. Distal antral wave acceleration plays a major role in antral flow and mixing, increasing particle strain and trituration.
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Affiliation(s)
- Rachel Berry
- 1Auckland Bioengineering Institute, University of Auckland, Aukland, New Zealand;
| | - Taimei Miyagawa
- 2Department of Biomedical Engineering, Tohoku University, Sendai, Japan;
| | | | - Peng Du
- 1Auckland Bioengineering Institute, University of Auckland, Aukland, New Zealand;
| | - Timothy R. Angeli
- 1Auckland Bioengineering Institute, University of Auckland, Aukland, New Zealand;
| | - Mark L. Trew
- 1Auckland Bioengineering Institute, University of Auckland, Aukland, New Zealand;
| | - John A. Windsor
- 3Department of Surgery, University of Auckland, Auckland, New Zealand;
| | - Yohsuke Imai
- 4School of Engineering, Tohoku University, Sendai, Japan; and
| | - Gregory O'Grady
- 1Auckland Bioengineering Institute, University of Auckland, Aukland, New Zealand; ,3Department of Surgery, University of Auckland, Auckland, New Zealand;
| | - Leo K. Cheng
- 1Auckland Bioengineering Institute, University of Auckland, Aukland, New Zealand; ,5Department of Surgery, Vanderbilt University, Nashville, Tennessee
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28
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Development of an advanced in vitro model of the stomach and its evaluation versus human gastric physiology. Food Res Int 2016. [DOI: 10.1016/j.foodres.2016.01.030] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Lamberti G, Cascone S, Marra F, Titomanlio G, d’Amore M, Barba AA. Gastrointestinal behavior and ADME phenomena: II. In silico simulation. J Drug Deliv Sci Technol 2016. [DOI: 10.1016/j.jddst.2016.06.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Trusov PV, Zaitseva NV, Kamaltdinov MR. A Multiphase Flow in the Antroduodenal Portion of the Gastrointestinal Tract: A Mathematical Model. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2016; 2016:5164029. [PMID: 27413393 PMCID: PMC4930828 DOI: 10.1155/2016/5164029] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 04/25/2016] [Accepted: 05/19/2016] [Indexed: 12/16/2022]
Abstract
A group of authors has developed a multilevel mathematical model that focuses on functional disorders in a human body associated with various chemical, physical, social, and other factors. At this point, the researchers have come up with structure, basic definitions and concepts of a mathematical model at the "macrolevel" that allow describing processes in a human body as a whole. Currently we are working at the "mesolevel" of organs and systems. Due to complexity of the tasks, this paper deals with only one meso-fragment of a digestive system model. It describes some aspects related to modeling multiphase flow in the antroduodenal portion of the gastrointestinal tract. Biochemical reactions, dissolution of food particles, and motor, secretory, and absorbing functions of the tract are taken into consideration. The paper outlines some results concerning influence of secretory function disorders on food dissolution rate and tract contents acidity. The effect which food density has on inflow of food masses from a stomach to a bowel is analyzed. We assume that the future development of the model will include digestive enzymes and related reactions of lipolysis, proteolysis, and carbohydrates breakdown.
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Affiliation(s)
- P. V. Trusov
- Federal Scientific Center For Medical and Preventive Health Risk Management Technologies, 82 Monastyrskaya Street, Perm 614000, Russia
- Department of Mathematical Simulation of Systems and Processes, Perm National Research Polytechnic University, 29 Komsomolsky Avenue, Perm 614000, Russia
| | - N. V. Zaitseva
- Federal Scientific Center For Medical and Preventive Health Risk Management Technologies, 82 Monastyrskaya Street, Perm 614000, Russia
| | - M. R. Kamaltdinov
- Federal Scientific Center For Medical and Preventive Health Risk Management Technologies, 82 Monastyrskaya Street, Perm 614000, Russia
- Department of Mathematical Simulation of Systems and Processes, Perm National Research Polytechnic University, 29 Komsomolsky Avenue, Perm 614000, Russia
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Body Position Modulates Gastric Emptying and Affects the Post-Prandial Rise in Plasma Amino Acid Concentrations Following Protein Ingestion in Humans. Nutrients 2016; 8:221. [PMID: 27089362 PMCID: PMC4848689 DOI: 10.3390/nu8040221] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 04/05/2016] [Accepted: 04/08/2016] [Indexed: 02/06/2023] Open
Abstract
Dietary protein digestion and amino acid absorption kinetics determine the post-prandial muscle protein synthetic response. Body position may affect gastrointestinal function and modulate the post-prandial rise in plasma amino acid availability. We aimed to assess the impact of body position on gastric emptying rate and the post-prandial rise in plasma amino acid concentrations following ingestion of a single, meal-like amount of protein. In a randomized, cross-over design, eight healthy males (25 ± 2 years, 23.9 ± 0.8 kg·m−2) ingested 22 g protein and 1.5 g paracetamol (acetaminophen) in an upright seated position (control) and in a −20° head-down tilted position (inversion). Blood samples were collected during a 240-min post-prandial period and analyzed for paracetamol and plasma amino acid concentrations to assess gastric emptying rate and post-prandial amino acid availability, respectively. Peak plasma leucine concentrations were lower in the inversion compared with the control treatment (177 ± 15 vs. 236 ± 15 mmol·L−1, p < 0.05), which was accompanied by a lower plasma essential amino acid (EAA) response over 240 min (31,956 ± 6441 vs. 50,351 ± 4015 AU; p < 0.05). Peak plasma paracetamol concentrations were lower in the inversion vs. control treatment (5.8 ± 1.1 vs. 10.0 ± 0.6 mg·L−1, p < 0.05). Gastric emptying rate and post-prandial plasma amino acid availability are significantly decreased after protein ingestion in a head-down tilted position. Therefore, upright body positioning should be considered when aiming to augment post-prandial muscle protein accretion in both health and disease.
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Gopirajah R, Anandharamakrishnan C. Advancement of Imaging and Modeling Techniques for Understanding Gastric Physical Forces on Food. FOOD ENGINEERING REVIEWS 2016. [DOI: 10.1007/s12393-016-9140-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Mao XY, Xu SF, Liu Q, Jiang JX, Zhang HH, Sang HM, Zhang GX. Anatomical predilection of intestinal metaplasia based on 78,335 endoscopic cases. Saudi J Gastroenterol 2016; 22:154-60. [PMID: 26997223 PMCID: PMC4817300 DOI: 10.4103/1319-3767.178528] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND/AIMS Gastric intestinal metaplasia (IM) is an important risk factor for intestinal-type gastric carcinoma, and successful treatment critically depends on its timely detection. In order to guide appropriate endoscopic surveillance, objective knowledge on the anatomical predilection of intestinal metaplasia development is urgently needed. MATERIALS AND METHODS A total of 78,335 cases who underwent gastroduodenoscopy from 2008 to 2013 in Jiangsu and Anhui provinces in China, were studied. Demographic and clinical characteristics, as well as biopsy location and histological results, were analyzed. RESULTS This study revealed that intestinal metaplasia incidence was 28.5% in angulus, 20.24% in lesser curvature of the antrum, and 25.48% in corpus; and all these were significantly higher than those observed in other sites (P < 0.01). Histological grading of intestinal metaplasia in the lesser curvature of the antrum and angulus was generally worse than the grading observed in the greater curvature of the antrum. For Helicobacter pylori-positive patients, acute inflammation was more severe in the lesser curvature of the antrum compared with the greater curvature. In the H. Pylori-negative group, both acute and chronic inflammations were more severe in the lesser curvature of the antrum. CONCLUSIONS The angulus, lesser curvature in the antrum, and corpus are most prone to the development of intestinal metaplasia. Inflammation is most severe in the lesser curvature of the antrum, which corresponds to a higher predilection to develop intestinal metaplasia at this site. The lesser curvature of the antrum and corpus require the most attention during endoscopic biopsy surveillance.
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Affiliation(s)
- Xin-Yi Mao
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Shun-Fu Xu
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Qing Liu
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Jian-Xia Jiang
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China,Address for correspondence: Dr. Jian-Xia Jiang, Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing - 210 029, China. E-mail:
| | - Hai-Han Zhang
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Huai-Ming Sang
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Guo-Xin Zhang
- Department of Gastroenterology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
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34
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Ferrua MJ, Singh RP. Computational modelling of gastric digestion: current challenges and future directions. Curr Opin Food Sci 2015. [DOI: 10.1016/j.cofs.2015.06.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Arrieta J, Cartwright JHE, Gouillart E, Piro N, Piro O, Tuval I. Geometric Mixing, Peristalsis, and the Geometric Phase of the Stomach. PLoS One 2015; 10:e0130735. [PMID: 26154384 PMCID: PMC4496066 DOI: 10.1371/journal.pone.0130735] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2013] [Accepted: 05/23/2015] [Indexed: 12/29/2022] Open
Abstract
Mixing fluid in a container at low Reynolds number— in an inertialess environment—is not a trivial task. Reciprocating motions merely lead to cycles of mixing and unmixing, so continuous rotation, as used in many technological applications, would appear to be necessary. However, there is another solution: movement of the walls in a cyclical fashion to introduce a geometric phase. We show using journal-bearing flow as a model that such geometric mixing is a general tool for using deformable boundaries that return to the same position to mix fluid at low Reynolds number. We then simulate a biological example: we show that mixing in the stomach functions because of the “belly phase,” peristaltic movement of the walls in a cyclical fashion introduces a geometric phase that avoids unmixing.
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Affiliation(s)
- Jorge Arrieta
- Mediterranean Institute for Advanced Studies (CSIC-UIB), E-07190 Esporles, Spain
- Área de Mecánica de Fluidos, Universidad Carlos III de Madrid, E-28911, Leganés, Spain
| | - Julyan H. E. Cartwright
- Instituto Andaluz de Ciencias de la Tierra, CSIC–Universidad de Granada, Campus Fuentenueva, E-18071 Granada, Spain
| | - Emmanuelle Gouillart
- Surface du Verre et Interfaces, UMR 125 CNRS/Saint-Gobain, 93303 Aubervilliers, France
| | - Nicolas Piro
- École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland
- * E-mail:
| | - Oreste Piro
- Departament de Física, Universitat de les Illes Balears, E-07071 Palma de Mallorca, Spain
| | - Idan Tuval
- Mediterranean Institute for Advanced Studies (CSIC-UIB), E-07190 Esporles, Spain
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37
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Schulze KS. The imaging and modelling of the physical processes involved in digestion and absorption. Acta Physiol (Oxf) 2015; 213:394-405. [PMID: 25313872 DOI: 10.1111/apha.12407] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 06/17/2014] [Accepted: 10/07/2014] [Indexed: 01/18/2023]
Abstract
The mechanical activity of the gastro-intestinal tract serves to store, propel and digest food. Contractions disperse particles and transform solids and secretions into the two-phase slurry called chyme; movements of the intestine deliver nutrients to mucosal sites of absorption, and from the submucosa into the lymphatic and portal venous circulation. Colonic motor activity helps to extract fluid and electrolytes from chyme and to compound and compact luminal debris into faeces for elimination. We outline how dynamic imaging by ultrasound and magnetic resonance can demonstrate intestinal flow processes critical to digestion like mixing, dilution, swelling, dispersion and elution. Computational fluid mechanics enables a numerical rendition of the forces promoting digestion: pressure and flow fields, the shear stresses dispersing particles or the effectiveness of bolus mixing can be calculated. These technologies provide new insights into the mechanical processes that promote digestion and absorption.
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Affiliation(s)
- K. S. Schulze
- Department of Internal Medicine; University of Iowa; Iowa City IA USA
- VAMC; Iowa City IA USA
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38
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On the kinematics and efficiency of advective mixing during gastric digestion – A numerical analysis. J Biomech 2014; 47:3664-73. [DOI: 10.1016/j.jbiomech.2014.09.033] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 09/05/2014] [Accepted: 09/25/2014] [Indexed: 11/19/2022]
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39
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Yoshimoto K, Yamada K, Watabe K, Takeda M, Nishimura T, Kido M, Nagakura T, Takahashi H, Nishida T, Iijima H, Tsujii M, Takehara T, Ohno Y. Gastric Contraction Imaging System Using a 3-D Endoscope. IEEE JOURNAL OF TRANSLATIONAL ENGINEERING IN HEALTH AND MEDICINE-JTEHM 2014; 2:1800208. [PMID: 27170867 PMCID: PMC4861546 DOI: 10.1109/jtehm.2014.2298852] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 11/08/2013] [Accepted: 12/09/2013] [Indexed: 11/06/2022]
Abstract
This paper presents a gastric contraction imaging system for assessment of gastric motility using a 3-D endoscope. Gastrointestinal diseases are mainly based on morphological abnormalities. However, gastrointestinal symptoms are sometimes apparent without visible abnormalities. One of the major factors for these diseases is abnormal gastrointestinal motility. For assessment of gastric motility, a gastric motility imaging system is needed. To assess the dynamic motility of the stomach, the proposed system measures 3-D gastric contractions derived from a 3-D profile of the stomach wall obtained with a developed 3-D endoscope. After obtaining contraction waves, their frequency, amplitude, and speed of propagation can be calculated using a Gaussian function. The proposed system was evaluated for 3-D measurements of several objects with known geometries. The results showed that the surface profiles could be obtained with an error of [Formula: see text] of the distance between two different points on images. Subsequently, we evaluated the validity of a prototype system using a wave simulated model. In the experiment, the amplitude and position of waves could be measured with 1-mm accuracy. The present results suggest that the proposed system can measure the speed and amplitude of contractions. This system has low invasiveness and can assess the motility of the stomach wall directly in a 3-D manner. Our method can be used for examination of gastric morphological and functional abnormalities.
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Affiliation(s)
- Kayo Yoshimoto
- Osaka University Division of Health Sciences Graduate School of Medicine Osaka Japan 565-0871
| | - Kenji Yamada
- Osaka University Division of Health Sciences Graduate School of Medicine Osaka Japan 565-0871
| | - Kenji Watabe
- Osaka University Department of Gastroenterology and Hepatology Graduate School of Medicine Osaka Japan 565-0871
| | - Maki Takeda
- Osaka University Division of Health Sciences Graduate School of Medicine Osaka Japan 565-0871
| | - Takahiro Nishimura
- Osaka University Division of Health Sciences Graduate School of Medicine Osaka Japan 565-0871
| | - Michiko Kido
- Osaka University Division of Health Sciences Graduate School of Medicine Osaka Japan 565-0871
| | - Toshiaki Nagakura
- Osaka Electro-Communication University Department of Biomedical Engineering Graduate School of Biomedical Engineering Osaka Japan 575-0063
| | - Hideya Takahashi
- Osaka University Division of Health Sciences Graduate School of Medicine Osaka Japan 565-0871
| | - Tsutomu Nishida
- Osaka University Department of Gastroenterology and Hepatology Graduate School of Medicine Osaka Japan 565-0871
| | - Hideki Iijima
- Osaka University Department of Gastroenterology and Hepatology Graduate School of Medicine Osaka Japan 565-0871
| | - Masahiko Tsujii
- Osaka University Department of Gastroenterology and Hepatology Graduate School of Medicine Osaka Japan 565-0871
| | - Tetsuo Takehara
- Osaka University Department of Gastroenterology and Hepatology Graduate School of Medicine Osaka Japan 565-0871
| | - Yuko Ohno
- Osaka University Division of Health Sciences Graduate School of Medicine Osaka Japan 565-0871
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MATSUNAGA D, IMAI Y, OMORI T, ISHIKAWA T, YAMAGUCHI T. A full GPU implementation of a numerical method for simulating capsule suspensions. ACTA ACUST UNITED AC 2014. [DOI: 10.1299/jbse.14-00039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Daiki MATSUNAGA
- Department of Bioengineering and Robotics, Tohoku University
| | - Yohsuke IMAI
- Department of Bioengineering and Robotics, Tohoku University
| | - Toshihiro OMORI
- Department of Bioengineering and Robotics, Tohoku University
| | - Takuji ISHIKAWA
- Department of Biomedical Engineering, Tohoku University
- Department of Bioengineering and Robotics, Tohoku University
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41
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Cheng LK, Du P, O'Grady G. Mapping and modeling gastrointestinal bioelectricity: from engineering bench to bedside. Physiology (Bethesda) 2013; 28:310-7. [PMID: 23997190 PMCID: PMC3768093 DOI: 10.1152/physiol.00022.2013] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
A key discovery in gastrointestinal motility has been the central role played by interstitial cells of Cajal (ICC) in generating electrical slow waves that coordinate contractions. Multielectrode mapping and multiscale modeling are two emerging interdisciplinary strategies now showing translational promise to investigate ICC function, electrophysiology, and contractions in the human gut.
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Affiliation(s)
- L K Cheng
- Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand.
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