Method Of Manometry Research Articles

A scanning manometry method to image the atomization pressure field for pre-debugging the nanocomposite spraying system

Spray coating process stands out among film manufacturing techniques to fabricate nanocomposite films because of its high production efficiency, and broad material applicability. However, the issues such as blockages, overspray, and rebound in the spray coating process restrict the fabrication of high-quality nanocomposite films. The atomization pressure field describes the spraying characteristics, and measuring and analyzing this parameter is vital to ensure the spray coating process functions properly. In this paper, a scanning manometry method is proposed to measure the atomization pressure field. The method involves setting a tube array to scan the atomization field, and reconstructing the pressure distribution by applying an imaging algorithm. This paper elaborates on the technical principle, implementation steps, and calibration of the scanning manometry method. Besides, the proposed method was validated by designing an actual testing system, and the 2D and 3D distribution images of the atomization pressure field were successfully obtained. The scanning manometry method features great potential for applications in nanocomposite spraying systems, assisting in fine-tuning the systems and stabilizing the production of nanocomposite films.

Colonic motility adjustments in acute and chronic DSS-induced colitis

AimsInflammatory bowel disease is recurrent inflammation that affects the gastrointestinal tract causing changes in intestinal motility. The evolution of these changes is not completely understood. The aim of this study was to evaluate anatomical and functional changes in the colon during the development of acute and chronic DSS-induced ulcerative colitis (UC) in C57Bl/6 mice. Materials and methodsMice were relocated into 5 groups: control (GC) and groups exposed to DSS 3 % for 2 (DSS2d), 5 (DSS5d) and 7 DSS7d) days (acute UC) or 3 cycles (DSS3C; Chronic UC). Mice were monitored daily. After euthanasia, colonic tissue was assessed with histological, immunofluorescence and colon manometry methods. Key findingsUlcerative Colitis is a chronic disease characterized by overt inflammation of the colon. Here we investigate whether the morphological changes caused by UC in the colonic wall, in tuft cells and in enteric neurons also promote any alteration in colonic motility patterns. UC Promotes thickening in the colonic wall, fibrosis, reduction in the number of tuft cells and consequently goblet cells also, without promoting neuronal death however there is a change in the chemical code of myenteric neurons. All of these morphological changes were responsible for causing a change in colonic contractions, colonic migration motor complex, total time of gastrointestinal transit and therefore promoting dysmotility. Further studies stimulating a hyperplasia of tuft cells may be the way to try to keep the colonic epithelium healthy, reducing the damage caused by UC. SignificanceIncreasing disease pathology of DSS-induced UC induces structural and neuroanatomical changes and driven damage to cholinergic neurons causes colonic dysmotility, including increase of cholinergic myenteric neurons, followed by variations in the motility pattern of different regions of the colon that taking together characterize colonic dysmotility.

Mechanism of Pingyang Jiangya Formula in treating hypertension based on network pharmacology and in vivo study

ObjectiveThis study aimed to analyze the mechanism of action of the Pingyang Jiangya Formula (平阳降压方, PYJYF) in treating hypertension, based on network pharmacology, and to verify the subsequent predictions through animal experiments. MethodsThe active components and related target genes of PYJYF were screened using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine (BATMAN-TCM), Encyclopedia of Traditional Chinese Medicine (ETCM), and DrugBank databases and available literature. The hypertension target genes were screened based on Therapeutic Target Database (TTD), GeneCards, Online Mendelian Inheritance in Man (OMIM), UniProt, and relevant literature. The component-disease-target network intersection target genes were inputted into the STRING database, and the key target genes were selected according to the degree algorithm. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed to explore the multitarget mechanism of action and molecular regulatory network of PYJYF in the treatment of hypertension. To verify this prediction, we used PYJYF to intervene in spontaneously hypertensive rats (SHRs) and Wistar–Kyoto rats (WKY) as normal control, and the noninvasive tail artery manometry method was used to measure systolic blood pressure (SBP) in the rat tail before PYJYF intervention. After drug intervention, the SBP of each group rats were measured and compared every week. Enzyme-linked immunosorbent assay (ELISA) was used to test plasma renin, angiotensin II (Ang II), and aldosterone (Ald) levels, and hematoxylin-eosin (HE) staining was used to observe pathological damage to the renal vessels in each group of rats. Western blot and reverse transcription real-time quantitative PCR (RT-PCR) were used to detect the protein and mRNA expression levels of PI3K, AKT1, BAX, and Bcl-2, respectively. ResultsA total of 4 123 hypertension targets were obtained from related databases. From the TCMSP and chemical databases, 78 active components of PYJYF and the corresponding 401 drug targets were retrieved. Data analysis revealed that 208 drug targets directly interacted with the hypertension targets in PYJYF. The 10 targets most closely related to hypertension target proteins in PYJYF were directly retrieved from relevant databases. GO analysis revealed that 10 direct target proteins were involved in all aspects of the antihypertensive effects of PYJYF, as well as molecular biological processes, such as the regulation of blood pressure, renin-angiotensin-aldosterone system (RAAS), angiotensin-mediated ligand reactions, and biological stimulation of cardiomyocyte apoptosis. KEGG pathway enrichment analysis revealed that PYJYF directly affected 20 signaling pathways associated with hypertension. In animal experiments, PYJYF reduced the protein and mRNA levels of PI3K, Akt, and Bax and upregulated the expression of the protein and mRNA levels of Bcl-2, reduced plasma renin, Ang II, and Ald levels, improved the hyperactivity of RAAS, and significantly reduced SBP in SHRs. ConclusionPYJYF is effective for hypertension therapy that acts through multiple compounds and targets. The possible underlying molecular mechanism includes regulating the PI3K/Akt signaling pathway to suppress RAAS, increasing the ratio of Bcl-2/Bax proteins, and inhibiting apoptosis, thereby mediating the repair of renal and renal vascular damage caused by hypertension. These findings warrant further research for use in clinical settings.

Propagation patterns of jejunal motor activity measured by high-resolution water-perfused manometry.

The manometric diagnosis of severe intestinal dysmotility is performed at most institutions using catheters with 2-8 sensors 5-10cm apart. The recent application of high-resolution manometry catheters with closely spaced sensors to other gut segments has been highly successful. The objective of the present study was to determine the feasibility of a jejunal high-resolution manometry method and to carry out a descriptive analysis of normal jejunal motor function. A 36-channel high-resolution water-perfused manometry catheter (MMS-Laborie, Enschede, The Netherlands) was orally placed in the jejunum of 18 healthy subjects (10 men, eight women; 21-38 age range). Intestinal motility was recorded during 5h, 3 during fasting, and 2 after a 450kcal solid-liquid meal. Analysis of motility patterns was supported by computerized tools. All healthy subjects except one showed at least one complete migrating motor complex during the 3h fasting period. Phase III activity lasted 5±1min and migrated aborally at a velocity of 7±3cm/min. High-resolution spatial analysis showed that during phase III each individual contraction propagated rapidly (75±37cm/min) over a 32±10cm segment of the jejunum. During phase II, most contractile activity corresponded to propagated contractile events which increased in frequency from early to late phase II (0.5±0.9 vs 2.5±1.3 events/10min, respectively; p<0.001). After meal ingestion, non-propagated activity increased, whereas propagated events were less frequent than during late phase II. Jejunal motility analysis with high-resolution manometry identifies propagated contractile patterns which are not apparent with conventional manometric catheters.

Different Effects of Aerobic Exercise and Diaphragmatic Breathing on Lower Esophageal Sphincter Pressure and Quality of Life in Patients with Reflux: A Comparative Study.

BACKGROUNDGastroesophageal reflux disease (GERD) is a worldwide disorder with an increasing prevalence. The quality of life (QOL) of the patients may be influenced by reflux disease. Diaphragmatic breathing (DB), as well as aerobic exercise (AE), may improve the symptoms of reflux disease, although it remains a controversial issue. The aim of this study was to compare the effects of AE and DB on QOL and lower esophageal sphincter (LES) pressure of patients with moderate to severe reflux. METHODS This was a case-control study that was conducted for 8 weeks among patients with moderate to severe GERD. The block randomization method was designed to randomize patients into three groups (AE, DB, and control) to achieve equal sample sizes. The control group received omeprazole 20 mg once daily. The other groups, in addition to omeprazole, received AE and DB. QOL and LES pressure were measured before and after the study by Questionary and Manometry method, respectively. RESULTS 75 patients were enrolled in this study. Positive effects of DB on LES pressure was approved (p = 0.001). DB had significantly more effects on QOL than aerobic exercise (p = 0.003). AE can significantly improve QOL in patients (p = 0.02) but no significant change in LES pressure (p = 0.38). There was no change in the control group for both variables.CONCLUSION AE had no effects on LES pressure but can improve QOL of the patients. DB had more effects on QOL than AE, so injured or disable patients with reflux who cannot do AE, can benefit from DB to improve their reflux symptoms.

On the use of manometry method for measurement of gas adsorption equilibria and characterization of clay texture with Derivative Isotherm Summation

Gas adsorption is widely used for characterization of clays. Apart from “classical” experiment of nitrogen or other gases adsorption/desorption at cryogenic temperatures, allowing the determination of the specific surface area, partial mesopore and micropore volume and size distributions, gas adsorption can also be used for the characterization of clay surface texture (energetic heterogeneity) related to layered structure of clays. Derivative Isotherm Summation applied to high-resolution gas adsorption isotherms was shown to be a powerful tool to access energetic characteristics and ratio between basal and lateral faces of clay particles. To date, the method is not commonly employed for characterization of clays and other heterogeneous solids, probably due to specificity of high-resolution isotherms acquisition technique described in the original literature: quasi-equilibrium volumetry with gas injection by microleak. We illustrated in the present work a possibility to use widely available static manometric commercial gas adsorption analysers for this purpose.

Microfluidic bypass manometry: highly parallelized measurement of flow resistance of complex channel geometries and trapped droplets.

Current lithography methods allow facile fabrication of microfluidic conduits where not only the shape of the bounding walls can be arbitrarily varied but also the internal conduit space can be laden with a variety of microstructures and wetting properties. This virtually infinite design space of microfluidic geometries brings in the challenge of how to quantify fluid resistance in a large number of microfluidic conduits, while maintaining operational simplicity. We report a versatile experimental technique referred to as microfluidic bypass manometry for measurement of pressure drop versus flow rate (ΔP-Q) relations in a parallelized manner. The technique involves introducing co-flowing laminar streams into a microfluidic network that contains a series of loops, where each loop is comprised of a test geometry and a bypass channel as a flow-rate sensing element. We optimize the network geometry and present operational considerations for microfluidic bypass manometry. To demonstrate the power of our technique, we used single-phase fluids and measured ΔP-Q relations simultaneously for forty test geometries ranging from linear to contraction-expansion to serpentine to pillar-laden microchannels. To expand the capabilities of the method, we measured ΔP-Q relations for similar-sized oil droplets trapped in microcavities where the cavity geometry spans from prisms of 3-10 sides to circular disks. We found in all cases, the ΔP-Q relation is nonlinear and the flow resistance of droplets is sensitive to confinement. At high flow rates, the drop resistance depends on the cavity geometry and is higher in a triangular prism compared to a circular disk. We compared the measured flow resistance of single-phase fluids and droplets in different microfluidic geometries to that from computational fluid dynamics simulations and found them to be in excellent agreement. Given the simplicity and versatility of the microfluidic bypass manometry method, we anticipate that it may find broad application in several areas including design of lab-on-chip devices, laminar drag reduction and mechanics of deformable particles.

Selective agonists of somatostatin receptor subtype 1 or 2 injected peripherally induce antihyperalgesic effect in two models of visceral hypersensitivity in mice

Somatostatin interacts with five G-protein-coupled receptor (sst1–5). Octreotide, a stable sst2≫3≥5 agonist, exerts a visceral anti-hyperalgesic effect in experimental and clinical studies. Little is known on the receptor subtypes involved. We investigated the influence of the stable sst1–5 agonist, ODT8-SST and selective receptor subtype peptide agonists (3 or 10μg/mouse) injected intraperitoneally (ip) on visceral hypersensitivity in mice induced by repeated noxious colorectal distensions (four sets of three CRD, each at 55mmHg) or corticotropin-releasing factor receptor 1 agonist, cortagine given between two sets of graded CRD (15, 30, 45, and 60mmHg, three times each pressure). The mean visceromotor response (VMR) was assessed using a non-invasive manometry method and values were expressed as percentage of the VMR to the 1st set of CRD baseline or to the 60mmHg CRD, respectively. ODT8-SST (10μg) and the sst2 agonist, S-346-011 (3 and 10μg) prevented mechanically induced visceral hypersensitivity in the three sets of CRD, the sst1 agonist (10μg) blocked only the 2nd set and showed a trend at 3μg while the sst4 agonist had no effect. The selective sst2 antagonist, S-406-028 blocked the sst2 agonist but not the sst1 agonist effect. The sst1 agonist (3 and 10μg) prevented cortagine-induced hypersensitivity to CRD at each pressure while the sst2 agonist at 10μg reduced it. These data indicate that in addition to sst2, the sst1 agonist may provide a novel promising target to alleviate visceral hypersensitivity induced by mechanoreceptor sensitization and more prominently, stress-related visceral nociceptive sensitization.

Advantages of the experimental animal hollow organ mechanical testing system for the rat colon rupture pressure test

BackgroundMany studies have been conducted on colorectal anastomotic leakage to reduce the incidence of anastomotic leakage. However, how to precisely determine if the bowel can withstand the pressure of a colorectal anastomosis experiment, which is called anastomotic bursting pressure, has not been determined. MethodA task force developed the experimental animal hollow organ mechanical testing system to provide precise measurement of the maximum pressure that an anastomotic colon can withstand, and to compare it with the commonly used method such as the mercury and air bag pressure manometer in a rat colon rupture pressure test. Forty-five male Sprague–Dawley rats were randomly divided into the manual ball manometry (H) group, the tracing machine manometry pressure gauge head (MP) group, and the experimental animal hollow organ mechanical testing system (ME) group. The rats in each group were subjected to a cut colon rupture pressure test after injecting anesthesia in the tail vein. Colonic end-to-end anastomosis was performed, and the rats were rested for 1 week before anastomotic bursting pressure was determined by one of the three methods. ResultsNo differences were observed between the normal colon rupture pressure and colonic anastomotic bursting pressure, which were determined using the three manometry methods. However, several advantages, such as reduction in errors, were identified in the ME group. ConclusionDifferent types of manometry methods can be applied to the normal rat colon, but the colonic anastomotic bursting pressure test using the experimental animal hollow organ mechanical testing system is superior to traditional methods.

Influence of the catheter diameter on the investigation of the esophageal motility through solid-state high-resolution manometry

Past studies have shown that catheter diameter is one of the device-dependent problems which influence the manometric results in the conventional water perfusion esophageal manometry. High-resolution solid-state manometry which abandons water perfusion is thought as an improved manometry method benefited from more pressure sensors, and it is gradually widely used in many present esophageal motility studies. There was no research to evaluate the influence of catheter diameter on the solid-state high-resolution manometry results. The aim of this study was to investigate whether solid-state high-resolution catheters of different diameter provide different data and results. Nine asymptomatic volunteers and 18 gastroesophageal reflux disease patients accepted high-resolution manometry examinations with two solid-state catheters of different outer diameter (4.2 mm and 2.7 mm). Every examination contained 5 minutes resting pressure, 10 water swallows and 10 bread swallows. Some important parameters of the esophageal sphincters and esophageal body peristalsis were analyzed. They included the locations and resting pressure of sphincters, the distal contractile integral, the 4-second integrated relaxation pressure etc. Then, these parameters and the diagnosis of each swallow based on them provided by the two different diameter catheters were compared. (i) The 4.2 mm thick catheter provided higher upper esophageal sphincter resting pressure than the 2.7 mm thick catheter (59.4 ± 21.1 mmHg vs. 49.7 ± 21.4 mmHg); (ii) the 2.7 mm thick catheter provided higher 4-second integrated relaxation pressure than the 4.2 mm thick catheter (10.9 ± 4.5 mmHg vs. 8.5 ± 3.8 mmHg) in water swallows; (iii) the mean distal contractile integral of the water and bread swallows in the large diameter catheter were higher than in the small diameter catheter (989.2 ± 650.0 mmHg/cm/s vs. 806.3 ± 563.7 mmHg/cm/s in water swallows, 1762.5 ± 1440.6 mmHg/cm/s vs. 1275.7 ± 982.0 mmHg/cm/s in bread swallows); (iv) on the lower esophageal sphincter resting pressure, most parameters in bread swallows provided by the two catheters were of no statistical significance; (v) the 2.7 mm thick catheter detected more hypotensive peristalsis swallows than the other catheter in water swallows; and (vi) the final diagnosis of about half of the subjects provided by the two catheters were different. The 2.7 mm thick solid-state high-resolution manometry catheter provides somewhat different data from the usually used 4.2 mm thick catheter. It is needed to set up different and independent series of normative value for the solid-state high-resolution manometry catheters of different outer diameter. The normative value and diagnostic criterion got from one catheter is not universal and acceptable for researches with catheter of different diameter.

Cholinergic giant migrating contractions in conscious mouse colon assessed by using a novel noninvasive solid-state manometry method: modulation by stressors

There is a glaring lack of knowledge on mouse colonic motility in vivo, primarily due to unavailability of adequate recording methods. Using a noninvasive miniature catheter pressure transducer inserted into the distal colon, we assessed changes in colonic motility in conscious mice induced by various acute or chronic stressors and determined the neurotransmitters mediating these changes. Mice exposed to restraint stress (RS) for 60 min displayed distal colonic phasic contractions including high-amplitude giant migrating contractions (GMCs), which had peak amplitudes >25 mmHg and occurred at a rate of 15-25 h(-1) of which over 50% were aborally propagative. Responses during the first 20-min of RS were characterized by high-frequency and high-amplitude contractions that were correlated with defecation. RS-induced GMCs and fecal pellet output were blocked by atropine (0.5 mg/kg ip) or the corticotrophin releasing factor (CRF) receptor antagonist astressin-B (100 microg/kg ip). RS activated colonic myenteric neurons as shown by Fos immunoreactivity. In mice previously exposed to repeated RS (60 min/day, 14 days), or in transgenic mice that overexpress CRF, the duration of stimulation of phasic colonic contractions was significantly shorter (10 vs. 20 min). In contrast to RS, abdominal surgery abolished colonic contractions including GMCs. These findings provide the first evidence for the presence of frequent cholinergic-dependent GMCs in the distal colon of conscious mice and their modulation by acute and chronic stressors. Noninvasive colonic manometry opens new venues to investigate colonic motor function in genetically modified mice relevant to diseases that involve colonic motility alterations.

Intraoperative manometry--a useful tool in biliary surgery?

Intraoperative manometry was performed in 771 patients undergoing cholecystectomy with (n = 158) and without (n = 613) interventions on the common bile duct and papilla. The method measures the resting pressure (RP) and pressure increase (PI) after injection of 1 ml NaCl/s as well as the time (TR) used for return to the initial pressure, using a Statham transducer. All values are recorded and statistically processed by the two-tailed t test. All three manometric parameters (RP, PI and TR) were statistically different (p less than or equal to 0.0001) between patients with and without alterations of the bile duct and papilla respectively. There was also a clear difference (p = 0.0001) of the TR (which is an indirect measure of the bile flow) between patients with stenosis of papilla (n = 55) and those who showed calculi in the bile duct (n = 103). In a further study we could demonstrate that histopathological changes of the papilla (specimen was taken during transduodenal papilloplasty because of isolated papilla stenosis) led to a prolonged TR, whereas TR in patients with negative histology was decreased. The sensitivity and specifity of this manometric method was very high, 92.4 and 98.6% respectively. This method of manometry enables to obtain precise data about pressure and flow in the bile duct uninfluenced by subjective reading errors in a simple and reproducible way. In our opinion it should complete other intraoperative diagnostic methods during cholecystectomy, particularly as manometry was the only method which led to the correct final diagnosis in 2% of 771 patients.

Effect of cigarette smoking on the lower oesophageal sphincter.

Observations on the effect of smoking on lower oesophageal sphincter pressure (LOSP) are based on station pull-through techniques of eosophageal manometry and recent studies have suggested that these techniques are inaccurate. Reproducible measurements of LOSP may be achieved with a rapid pull-through (RPT) method of manometry. This method was used to determine the effect of cigarette smoking on LOSP in 10 asymptomatic volunteers and in a group of 10 patients with symptoms of gastro-oesophageal reflux. Basal LOSP measurements in the two groups were not significantly different but LOSP was reduced by 19% in asymptomatic subjects (p less than 0-01) and by 21% in symptomatic patients (p less than 0-02) during cigarette smoking. The results suggest that smoking should be avoided in the clinical management of gastro-oesophageal reflux.

Optimal selection of flasks for the indirect method of manometry

The selection, on the basis of flask volume and fluid volume, of the members of a flask pair for the indirect method of manometry is very important. A poor choice yields erratic results even with flawless experimental technique. In order to determine optimal combinations, formulae of the indirect method were analyzed, and an expression for the statistical variance associated with different combinations of flask and fluid volumes was derived. Graphs and a table were constructed and can be used to select suitable combinations. As a general rule, in order to obtain the minimum variance, flasks of equal volumes should be selected and used with the maximum practical difference in fluid volumes. It was also found that the choice of flask and fluid volumes does not depend on γ; an optimal combination has a minimum variance for all values of γ.

Miosis and intraocular pressure changes during manometry: mechanically irritated rabbit eyes studied with improved manometric technique.

A spontaneous rise in intraocular pressure during manometry of the anterior segment of the rabbit eye introduces an undesirable variable into an otherwise accurate measurement. The origin of the reaction and the mechanism by which it alters intraocular pressure are not known. The purpose of this paper is first to report an improved method of manometry which avoids the reaction and permits physiologic study for relatively long periods of time in a nonirritated eye, and, second, to discuss the site of origin of the response. A subsequent report will deal with the mechanisms by which the rise in pressure is produced and sustained. The gross characteristics of the spontaneous pressure response during manometry resemble those changes induced following trigeminal stimulation either antidromically,1or by chemical,2,3,4or mechanical5,6irritation of cornea, conjunctiva, iris, and lens, or by paracentesis,7and consist of