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Cells, Tissues, Organs 2023Peristalsis is a nuanced mechanical stimulus comprised of multi-axial strain (radial and axial strain) and shear stress. Forces associated with peristalsis regulate...
Peristalsis is a nuanced mechanical stimulus comprised of multi-axial strain (radial and axial strain) and shear stress. Forces associated with peristalsis regulate diverse biological functions including digestion, reproductive function, and urine dynamics. Given the central role peristalsis plays in physiology and pathophysiology, we were motivated to design a bioreactor capable of holistically mimicking peristalsis. We engineered a novel rotating screw-drive based design combined with a peristaltic pump, in order to deliver multi-axial strain and concurrent shear stress to a biocompatible polydimethylsiloxane (PDMS) membrane "wall." Radial indentation and rotation of the screw drive against the wall demonstrated multi-axial strain evaluated via finite element modeling. Experimental measurements of strain using piezoelectric strain resistors were in close alignment with model-predicted values (15.9 ± 4.2% vs. 15.2% predicted). Modeling of shear stress on the "wall" indicated a uniform velocity profile and a moderate shear stress of 0.4 Pa. Human mesenchymal stem cells (hMSCs) seeded on the PDMS "wall" and stimulated with peristalsis demonstrated dramatic changes in actin filament alignment, proliferation, and nuclear morphology compared to static controls, perfusion, or strain, indicating that hMSCs sensed and responded to peristalsis uniquely. Lastly, significant differences were observed in gene expression patterns of calponin, caldesmon, smooth muscle actin, and transgelin, corroborating the propensity of hMSCs toward myogenic differentiation in response to peristalsis. Collectively, our data suggest that the peristalsis bioreactor is capable of generating concurrent multi-axial strain and shear stress on a "wall." hMSCs experience peristalsis differently than perfusion or strain, resulting in changes in proliferation, actin fiber organization, smooth muscle actin expression, and genetic markers of differentiation. The peristalsis bioreactor device has broad utility in the study of development and disease in several organ systems.
Topics: Humans; Peristalsis; Biomimetics; Actins; Cell Differentiation; Bioreactors
PubMed: 35008089
DOI: 10.1159/000521752 -
American Journal of Physiology.... Nov 2021Gastric peristalsis is critically dependent on an underlying electrical conduction system. Recent years have witnessed substantial progress in clarifying the operations... (Review)
Review
Gastric peristalsis is critically dependent on an underlying electrical conduction system. Recent years have witnessed substantial progress in clarifying the operations of this system, including its pacemaking units, its cellular architecture, and slow-wave propagation patterns. Advanced techniques have been developed for assessing its functions at high spatiotemporal resolutions. This review synthesizes and evaluates this progress, with a focus on human and translational physiology. A current conception of the initiation and conduction of slow-wave activity in the human stomach is provided first, followed by a detailed discussion of its organization at the cellular and tissue level. Particular emphasis is then given to how gastric electrical disorders may contribute to disease states. Gastric dysfunction continues to grow in their prevalence and impact, and while gastric dysrhythmia is established as a clear and pervasive feature in several major gastric disorders, its role in explaining pathophysiology and informing therapy is still emerging. New insights from high-resolution gastric mapping are evaluated, together with historical data from electrogastrography, and the physiological relevance of emerging biomarkers from body surface mapping such as retrograde propagating slow waves. Knowledge gaps requiring further physiological research are highlighted.
Topics: Animals; Biological Clocks; Cell Communication; Gastric Emptying; Gastroparesis; Humans; Interstitial Cells of Cajal; Membrane Potentials; Peristalsis; Stomach; Stomach Diseases
PubMed: 34549598
DOI: 10.1152/ajpgi.00065.2021 -
Cureus May 2021Objective Auscultation of bowel sounds has been taught as a component of the physical examination since the beginning of the 20th century. However, there has been...
Objective Auscultation of bowel sounds has been taught as a component of the physical examination since the beginning of the 20th century. However, there has been little research or consensus on the significance of listening in different quadrants. Some textbooks indicate that bowel sounds are the result of peristalsis in that region, while others state that bowel sounds can be generalized over the entire abdominal wall. With ultrasonography, peristalsis can be visualized in a dynamic and non-invasive manner. The purpose of this study was to determine the relationship between auscultation of bowel sounds and visualization of peristalsis with ultrasound, to understand whether or not bowel sounds and peristalsis are compartmentalized. Methods Study participants quietly lay supine, while one investigator positioned an ultrasound probe on the abdomen visualizing the small intestine, and a second investigator placed an EKO Digital Stethoscope (Eko Devices, Inc., Oakland, CA) directly adjacent to the probe auscultate for bowel sounds. During a two-minute interval, a third investigator noted every time a bowel sound was heard (A+), peristalsis was seen (U+), or a combined event (C+) occurred, recording the total number of events. Measurements were recorded from four quadrants (right upper quadrant {RUQ}, left upper quadrant {LUQ}, right lower quadrant {RLQ}, left lower quadrant {LLQ}) and the periumbilical region (PUR). Fisher Exact test was used to determine whether there were significant differences between the number of bowel sounds heard but not seen (A+) and those seen but not heard (U+) with sounds that were both seen and heard (C+). Significance was determined with p < 0.05. Results A total of 16 participants were included, with a combined 973 discrete bowel events, both auscultated and visualized. No quadrant showed a significant correlation between an isolated sound (A+) or peristalsis (U+) and a combined event (C+), indicating there were many events where an auscultated sound failed to correlate with observed peristalsis, and vice versa. The average p-value was 0.544, with a range of 0.052-1.00. Conclusion This study showed that there is no significant correlation between auscultated bowel sounds and peristalsis within a given region. This study calls into question whether auscultation of all four quadrants provides more meaningful information than auscultation of one central point of the abdomen.
PubMed: 34150368
DOI: 10.7759/cureus.14982 -
Neurogastroenterology and Motility Jul 2021The recommended diagnostic criteria for achalasia have been recently updated by Chicago Classification version 4.0 (CCv4.0), the widely accepted classification scheme...
The recommended diagnostic criteria for achalasia have been recently updated by Chicago Classification version 4.0 (CCv4.0), the widely accepted classification scheme for esophageal motility disorders using metrics from high-resolution manometry (HRM). CCv4.0 continued upon prior versions by subtyping achalasia into type I, type II, and type III on HRM. The achalasia subgroup of the CCv4.0 Working Group developed both conclusive and inconclusive statements for the HRM diagnoses of achalasia subtypes. Conclusive achalasia on HRM is defined as an abnormal median integrated relaxation pressure (IRP) in the primary position of wet swallows along with 100% failed peristalsis, with type I achalasia having 100% failed peristalsis without panesophageal pressurization (PEP), type II achalasia with PEP in at least 20% of swallows, and type III achalasia having at least 20% of swallows premature with no appreciable peristalsis. An inconclusive HRM diagnosis of achalasia can arise when there is an integrated relaxation pressure (IRP) that is borderline or at the upper limit of normal in at least one position, there is an abnormal IRP in both positions but evidence of peristalsis with PEP or premature swallows, or there is peristalsis in the secondary position after apparent achalasia in the primary position. In patients with dysphagia and an inconclusive HRM diagnosis of achalasia, supportive testing beyond HRM such as a timed barium esophagram (TBE) for functional lumen imaging probe (FLIP) is recommended. The review recommends a diagnostic algorithm for achalasia, discusses therapeutic options for the disease, and outlines future needs on this topic.
Topics: Esophageal Achalasia; Humans
PubMed: 34190376
DOI: 10.1111/nmo.14182 -
Revista Espanola de Enfermedades... Jun 2023A 24-year-old male presented with an asymptomatic right perirenal cyst that was detected on ultrasound performed during a physical screening. Abdominal computed...
A 24-year-old male presented with an asymptomatic right perirenal cyst that was detected on ultrasound performed during a physical screening. Abdominal computed tomography showed a hypodense cystic mass between the liver and right kidney. Peristalsis of the cystic mass was observed via multi-phase CT scan, including plain scan, arterial phase, venous phase and delayed phase. The mass was completely resected by laparoscopy.
Topics: Male; Humans; Young Adult; Adult; Peristalsis; Tomography, X-Ray Computed; Ultrasonography; Laparoscopy; Cysts
PubMed: 37232158
DOI: 10.17235/reed.2023.9721/2023 -
Neurogastroenterology and Motility Jul 2022Although esophageal dysmotility is common in systemic sclerosis (SSc)/scleroderma, little is known regarding the pathophysiology of motor abnormalities driving reflux...
BACKGROUND
Although esophageal dysmotility is common in systemic sclerosis (SSc)/scleroderma, little is known regarding the pathophysiology of motor abnormalities driving reflux severity and dysphagia. This study aimed to assess primary and secondary peristalsis in SSc using a comprehensive esophageal motility assessment applying high-resolution manometry (HRM) and functional luminal imaging probe (FLIP) Panometry.
METHODS
A total of 32 patients with scleroderma (28 female; ages 38-77; 20 limited SSc, 12 diffuse SSc) completed FLIP Panometry and HRM. Secondary peristalsis, i.e., contractile responses (CR), was classified on FLIP Panometry by pattern of contractility as normal (NCR), borderline (BCR), impaired/disordered (IDCR), or absent (ACR). Primary peristalsis on HRM was assessed according to the Chicago classification.
RESULTS
The manometric diagnoses were 56% (n = 18) absent contractility, 22% (n = 7) ineffective esophageal motility (IEM), and 22% (n = 7) normal motility. Secondary peristalsis (CRs) included 38% (n = 12) ACR, 38% (n = 12) IDCR, 19% (n = 6) BCR, and 15% (n = 5) NCR. The median (IQR) esophagogastric junction (EGJ) distensibility index (DI) was 5.8 mm /mmHg (4.8-10.1) mm /mmHg; EGJ-DI was >8.0 mm /mmHg in 31%, and >2.0 mm /mmHg in 100% of patients. Among 18 patients with absent contractility on HRM, 11 had ACR, 5 had IDCR, and 2 had BCR. Among 7 patients with IEM, 1 had ACR, 5 had IDCR, and 1 NCR. All of the patients with normal peristalsis had NCR or BCR.
CONCLUSIONS
This was the first study assessing combined HRM and FLIP Panometry in a cohort of SSc patients, which demonstrated heterogeneity in primary and secondary peristalsis. This complementary approach facilitates characterizing esophageal function in SSc, although future study to examine clinical outcomes remains necessary.
Topics: Adult; Aged; Esophageal Motility Disorders; Female; Humans; Manometry; Middle Aged; Peristalsis; Scleroderma, Systemic
PubMed: 34709690
DOI: 10.1111/nmo.14284 -
Advances in Experimental Medicine and... 2022In the last decade, we characterized an enteric neuronal subpopulation of multifunctional mechanosensitive enteric neurons (MEN) while studying the gastrointestinal...
In the last decade, we characterized an enteric neuronal subpopulation of multifunctional mechanosensitive enteric neurons (MEN) while studying the gastrointestinal peristalsis. MEN have been described in a variety of gastrointestinal regions and species. This chapter summarizes existing data on MEN, describing their proportions, firing behaviors, adaptation musters, and chemical phenotypes. We also discuss MEN sensitivity to different mechanical stimulus qualities such as compression and tension along with pharmacology of their responses.
Topics: Neurons; Intestine, Small; Peristalsis; Enteric Nervous System
PubMed: 36587145
DOI: 10.1007/978-3-031-05843-1_5 -
Gastroenterology Oct 2022
Topics: Gastrointestinal Motility; Humans; Indicators and Reagents; Intestinal Obstruction; Intestinal Pseudo-Obstruction; Peristalsis
PubMed: 35643176
DOI: 10.1053/j.gastro.2022.05.033 -
Therapeutic Advances in Gastroenterology 2023Acid sensitivity can be altered in patients with gastroesophageal reflux disease (GERD). Secondary peristalsis helps clear gastro-esophageal refluxate and residual...
BACKGROUND
Acid sensitivity can be altered in patients with gastroesophageal reflux disease (GERD). Secondary peristalsis helps clear gastro-esophageal refluxate and residual ingested food bolus.
OBJECTIVES
The aim of this study was to investigate the associations among acid sensitivity, esophageal mucosal integrity, chemical clearance, and secondary peristalsis before and after esophageal acid infusion.
DESIGN
This was an investigator-initiated, prospective, cross-sectional study.
METHODS
Adult reflux patients underwent high resolution manometry and 24 h impedance-pH monitoring off acid suppression to identify GERD phenotypes, including non-erosive reflux disease (NERD), reflux hypersensitivity (RH), and functional heartburn (FH). Secondary peristalsis was assessed using five rapid 20 mL air injections into the esophagus before and after infusion of hydrochloric acid (0.1 N) into the mid-esophagus. Conventional acid infusion parameters recorded included lag time, intensity rating, and sensitivity score. Chemical clearance was evaluated using the post-reflux swallow-induced peristaltic wave (PSPW), and mucosal integrity was assessed by the mean nocturnal baseline impedance (MNBI) derived from impedance-pH monitoring.
RESULTS
A total of 88 patients (age 21-64 years, 62.5% women) completed the study including 12 patients with NERD, 45 with RH, and 31 with FH. There was no significant difference in acid infusion parameters between patients with NERD, RH, and FH. Upon acid infusion, patients who exhibited successful secondary peristalsis had longer lag time, higher MNBI, and shorter bolus contact time than those without secondary peristalsis. Meanwhile, patients with intact PSPW demonstrated significantly higher intensity ratings in response to acid perfusion and higher MNBI than those with impaired PSPW. The lag time correlated positively with MNBI ( = 0.285; = 0.007).
CONCLUSION
In conclusion, the protective effect of esophageal secondary peristalsis and chemical clearance on esophageal mucosal integrity was demonstrated. Concerning acid sensitivity, longer lag time in patients with intact secondary peristalsis may be attributed to better esophageal mucosal integrity, while stronger intensity ratings may have a greater tendency to induce PSPW and protect esophageal mucosal integrity.
PubMed: 37440930
DOI: 10.1177/17562848231179329 -
Soft Robotics Jun 2021The human stomach breaks down and transports food by coordinated radial contractions of the gastric walls. The radial contractions periodically propagate through the...
The human stomach breaks down and transports food by coordinated radial contractions of the gastric walls. The radial contractions periodically propagate through the stomach and constitute the peristaltic contractions, also called the gastric motility. The force, amplitude, and frequency of peristaltic contractions are relevant to massaging and transporting the food contents in the gastric lumen. However, existing gastric simulators have not faithfully replicated gastric motility. Herein, we report a soft robotic gastric simulator (SoGut) that emulates peristaltic contractions in an anatomically realistic way. SoGut incorporates an array of circular air chambers that generate radial contractions. The design and fabrication of SoGut leverages principles from the soft robotics field, which features compliance and adaptability. We studied the force and amplitude of the contractions when the lumen of SoGut was empty or filled with contents of different viscosity. We examined the contracting force using manometry. SoGut exhibited a similar range of contracting force as the human stomach reported in the literature. Besides, we investigated the amplitude of the contractions through videofluoroscopy where the contraction ratio was derived. The contraction ratio as a function of inflation pressure is found to match the observations of situations. We demonstrated that SoGut can achieve peristaltic contractions by coordinating the inflation sequence of multiple air chambers. It exhibited the functions to massage and transport the food contents. SoGut can simulate the physiological motions of the human stomach to advance research of digestion.
Topics: Digestion; Humans; Manometry; Peristalsis; Robotics; Stomach
PubMed: 32559391
DOI: 10.1089/soro.2019.0136