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Clinical Otolaryngology : Official... Jan 2021The primary end point of this study was to evaluate the impact of bile acids on severity of laryngo-pharyngeal reflux (LPR) and the possible correlation with esophagitis... (Comparative Study)
Comparative Study Observational Study
OBJECTIVES
The primary end point of this study was to evaluate the impact of bile acids on severity of laryngo-pharyngeal reflux (LPR) and the possible correlation with esophagitis and upper airway malignancies. The second end point was to evaluate if salivary bile acids and molecules other than pepsin might serve as diagnostic biomarkers of LPR.
DESIGN
Observational prospective comparative study.
SETTING
Otorhinolaryngology unit of a tertiary hospital.
PARTICIPANTS
Sixty-two consecutive adult outpatients suspected of LPR.
MAIN OUTCOME MEASURES
Bile acids, bilirubin and pepsinogen I-II were measured in saliva. Patients underwent pH metry and based on the results of bile acids were subdivided as acid, mixed and alkaline LPR.
RESULTS
Significantly higher Reflux Findings Score (RFS) and Reflux Symptoms Index (RSI) were seen in patients with alkaline and mixed LPR compared to acid LPR. Salivary bile acids >1 µmol/L seem to be a reliable indicator of the severity of LPR. Compared to those without, patients with esophagitis or a history of upper airway malignancy have high concentrations of bile acids in saliva. Among the molecules studied, bile acids were the most suitable for diagnosis of LPR, with a sensitivity of 86% and a positive predictive value of 80.7%.
CONCLUSIONS
Our data suggest that high concentrations of bile acids are associated with higher values of RSI and RFS in LPR as well as a higher risk of esophagitis and history of upper airway malignancies. We finally observed that bile acids provided the best biometric parameters for diagnosis of LPR among the molecules tested.
Topics: Adult; Aged; Bile Acids and Salts; Biomarkers; Esophageal pH Monitoring; Esophagitis, Peptic; Female; Humans; Laryngopharyngeal Reflux; Male; Middle Aged; Pepsin A; Predictive Value of Tests; Prospective Studies; Saliva; Severity of Illness Index
PubMed: 32876387
DOI: 10.1111/coa.13643 -
Journal of Otolaryngology - Head & Neck... Oct 2023To investigate the association between obstructive sleep apnea (OSA) and laryngopharyngeal reflux (LPR) through oropharyngeal pH-monitoring and pepsin saliva...
OBJECTIVE
To investigate the association between obstructive sleep apnea (OSA) and laryngopharyngeal reflux (LPR) through oropharyngeal pH-monitoring and pepsin saliva measurements.
DESIGN
Prospective uncontrolled study.
METHODS
Patients with sleep disturbances and reflux symptoms underwent polysomnography, 24-h oropharyngeal pH-monitoring and saliva pepsin collections. The prevalence of LPR was investigated in OSA patients according to oropharyngeal pH-monitoring and pepsin measurements. A correlation analysis was performed between pH-monitoring findings, pepsin saliva levels, reflux symptom score-12 (RSS-12), reflux sign assessment (RSA), Apnea-Hypopnea Index (AHI), Epworth Sleepiness Scale, Pichot and arousal findings.
RESULTS
Thirty-seven patients completed the evaluations. LPR was detected in 34/37 (92%) and 29/34 (85%) patients at the oropharyngeal-pH monitoring and pepsin test, respectively. OSA was detected in 30 patients (81%). Among them, LPR was detected in 28/30 (93%) cases. Pharyngeal reflux events mainly occurred nighttime/supine in OSA patients. Both Ryan score and supine reflux time at pH < 6.5 were significantly associated with BMI and the RSA sub- and total scores (p < 0.02). Tongue-base hypertrophy score was positively associated with the number of micro-arousals (p = 0.027); the supine percent of pH < 6.5 (p = 0.030); morning (p = 0.030) and bedtime pepsin saliva measurements (p = 0.037). The bedtime pepsin saliva level was significantly associated with Ryan Score (p = 0.047); AHI (p = 0.017) and the sleep saturation < 90% time (p = 0.040). The saliva level of the morning pepsin was associated with a shortest paradoxical sleep phase (p = 0.013).
CONCLUSION
OSA patients may have high prevalence of pharyngeal reflux events at the oropharyngeal pH-monitoring and high pepsin saliva measurements. Oropharyngeal pH-monitoring should be useful for the correlation between reflux and sleep findings in OSA patients. Future large cohort controlled studies are needed to determine the prevalence of LPR in OSA and healthy individuals.
Topics: Humans; Saliva; Pepsin A; Prospective Studies; Laryngopharyngeal Reflux; Sleep Apnea, Obstructive; Hydrogen-Ion Concentration
PubMed: 37838710
DOI: 10.1186/s40463-023-00675-0 -
Food & Function Dec 2021The activity of pepsin, the gastric protease, is generally considered to be negligible for pH ≥ 4, based on the results obtained with a few purified globular proteins....
The activity of pepsin, the gastric protease, is generally considered to be negligible for pH ≥ 4, based on the results obtained with a few purified globular proteins. The present study aimed at studying the activity of porcine pepsin on egg white proteins (EWP) and casein micelle micro-aggregates (CA) over a broad range of pH (from 1 to 7) for short (3 min) and long (2 h) digestion times. For a short time, the results confirmed a tendency for a higher rate of hydrolysis with decreasing pH, but with different pH activity profiles for both the substrates. More remarkably, the degree of hydrolysis of CA after 2 h of digestion was constant from pH 1 to pH 5, and was only reduced by half at pH 6. This finding demonstrates that pepsin can hydrolyse caseins from the very beginning of gastric digestion. Interestingly, the trend of the reaction kinetics over 2 h appeared to be rather characteristic of the type of the substrate and was largely independent in terms of pH. Most hydrolysis profiles could be accurately fitted by a power law, an empirical model that was then successfully applied to the static gastric proteolysis of 6 other food matrices. Overall, our results support the idea that pepsin activity under weakly acidic conditions (pH ≥ 4) should not always be neglected, in particular, for milk caseins, and that pepsin reaction kinetics during static gastric digestion seems to evolve proportionally to the power of the digestion time.
Topics: Animals; Caseins; Digestion; Egg Proteins; Hydrogen-Ion Concentration; Hydrolysis; In Vitro Techniques; Pepsin A; Proteolysis; Swine
PubMed: 34788782
DOI: 10.1039/d1fo02453a -
Food Chemistry Jan 2022One major pepsinogen, PG-I, and two minor pepsinogens, PG-II and PG-III were purified from lizardfish stomach by ammonium sulfate precipitation and two chromatographic...
One major pepsinogen, PG-I, and two minor pepsinogens, PG-II and PG-III were purified from lizardfish stomach by ammonium sulfate precipitation and two chromatographic columns. The three purified PGs migrated as single bands in native-PAGE gels with molecular weights (MW) ranging from 36 to 38 kDa. Each PG was converted to pepsin (P) at pH 2.0, and the MW were determined as 32 kDa (for P-I), 31 kDa (for P-II) and 30 kDa (for P-III). The optimum pH and temperature of pepsins were 2.0-3.5, and 40-50 °C. All 3 pepsins were strongly inhibited by pepstatin A. Divalent cations slightly stimulated the pepsin activities, but ATP had no effect on the pepsins. Purified pepsins were effective in the hydrolysis of various proteins. K and k of the three pepsins for hemoglobin hydrolysis were 107.64-276.61 µM and 18.30-32.68 s, respectively. The new pepsins have potential for use in protein food procession and modification.
Topics: Amino Acid Sequence; Animals; Fishes; Pepsin A; Pepsinogens; Stomach
PubMed: 34274702
DOI: 10.1016/j.foodchem.2021.130532 -
Pharmaceutical Research Jan 2024The purpose of the present study was to investigate the effect of food viscosity on the dissolution rate of a drug. There are two types of viscosity, macroviscosity and...
PURPOSE
The purpose of the present study was to investigate the effect of food viscosity on the dissolution rate of a drug. There are two types of viscosity, macroviscosity and microviscosity. Macroviscosity affects the diffusion layer thickness, whereas microviscosity affects the molecular diffusion coefficient. The mass transfer coefficient (k) in the intrinsic dissolution rate (IDR) depends on the viscosity (η) as k ∝ η (a is an exponent on η). In theory, for rotating flow over a disk, if a thickener increases only macroviscosity, a = -1/6, and if it increases both macroviscosity and microviscosity equally, a = -7/6.
METHOD
Benzocaine was used as a model drug. Hydroxypropyl cellulose (HPC) and methylcellulose (MC) were employed as control thickeners that increase only macroviscosity. Sucrose was employed as a control thickener for both macroviscosity and microviscosity. The FDA breakfast homogenate (BFH) was diluted with distilled water or 1 mM HCl with/without pepsin digestion. The IDR value was measured by the paddle-over-disk method.
RESULTS
The η value of 30% BFH distilled water was 209 mPa∙s, about 300 times higher than distilled water. It was further increased by HCl (430 mPa∙s), and reduced by pepsin digestion (35 mPa∙s). The k value was little affected by BFH (a = 0.00 to -0.09), slightly less than those in HPC (a = -0.19) and MC (a = -0.21). Sucrose decreased the k value more significantly (a = -0.70).
CONCLUSION
The IDR and k values of benzocaine were little affected by BFH, suggesting that BFH increased only macroviscosity.
Topics: Drug Liberation; Benzocaine; Viscosity; Pepsin A; Methylcellulose; Water; Sucrose
PubMed: 37884679
DOI: 10.1007/s11095-023-03620-y -
JPGN Reports Feb 2023Aspiration is common in mechanically ventilated patients and may predispose patients to aspiration pneumonia, chemical pneumonitis, and chronic lung damage. Pepsin A is...
UNLABELLED
Aspiration is common in mechanically ventilated patients and may predispose patients to aspiration pneumonia, chemical pneumonitis, and chronic lung damage. Pepsin A is a specific marker of gastric fluid aspiration and is often detected in ventilated pediatric patients. We investigated the effect of oral care and throat suctioning in the detection of pepsin A in tracheal aspirates (TAs) up to 4 hours after these procedures.
METHODS
Twelve pediatric patients between age 2 weeks to 14 years who underwent intubation for cardiac surgery were enrolled in this study. Six of the 12 patients were consented before their surgery with initial specimen collected at the time of intubation and last one shortly before extubation (intubation duration < 24 hours). The remaining 6 patients were consented after cardiac surgery. All specimens were collected per routine care per respiratory therapy protocol and shortly before extubation (intubation duration > 24 hours). Tracheal fluid aspirates were collected every 4 to 12 hours in the ventilated patients. Enzymatic assay for gastric pepsin A and protein determination were performed. The time of oral care and throat suctioning within 4 hours prior was recorded prospectively.
RESULTS
A total of 342 TA specimens were obtained from the 12 intubated pediatric patients during their course of hospitalization; 287 (83.9%) showed detectable total pepsin (pepsin A and C) enzyme activity (> 6 ng/mL) and 176 (51.5%) samples had detectable pepsin A enzyme levels (>6 ng/mL of pepsin A). Only 29 samples of 76 samples (38.2%) had evidence of microaspiration after receiving oral care, while 147 of 266 (55.3%) samples were pepsin A positive when no oral care was provided. Odds ratio is 0.50 (Cl 0.30-0.84), and the number needed to treat is 5.8 (Confidence interval 3.4-22.3). Testing air filters for pepsin was not beneficial.
CONCLUSION
Oral care is a highly effective measure to prevent microaspiration of gastric fluid in ventilated pediatric patients. The number needed to treat (5.8) suggests this is a very effective prevention strategy. Our study suggests that pepsin A is a useful and sensitive biomarker that allows identification of gastric aspiration.
PubMed: 37181916
DOI: 10.1097/PG9.0000000000000290 -
Journal of the American Society For... Sep 2021Hydrogen/deuterium exchange with mass spectrometry (HDX-MS) is a widely used technique to probe protein structural dynamics, track conformational changes, and map...
Hydrogen/deuterium exchange with mass spectrometry (HDX-MS) is a widely used technique to probe protein structural dynamics, track conformational changes, and map protein-protein interactions. Most HDX-MS studies employ a bottom-up approach utilizing the acid active protease pepsin to digest the protein of interest, often utilizing immobilized protease in a column format. The extent of proteolytic cleavage will greatly influence data quality and presents a major source of variation in HDX-MS studies. Here, we present a simple cocktail of commonly available peptides that are substrates of pepsin and can serve as a rapid check of pepsin column activity. The peptide-based assay requires no system modifications and provides an immediate readout to check and benchmark pepsin activity across different HDX-MS platforms.
Topics: Animals; Chromatography, Liquid; Enzymes, Immobilized; Hydrogen Deuterium Exchange-Mass Spectrometry; Pepsin A; Peptide Fragments; Protein Conformation; Proteins; Reproducibility of Results; Swine
PubMed: 33984240
DOI: 10.1021/jasms.1c00080 -
International Journal of Antimicrobial... Sep 2023We recently designed a series of cationic deoxythymidine-based amphiphiles that mimic the cationic amphipathic structure of antimicrobial peptides (AMPs). Among these...
OBJECTIVES
We recently designed a series of cationic deoxythymidine-based amphiphiles that mimic the cationic amphipathic structure of antimicrobial peptides (AMPs). Among these amphiphiles, ADG-2e and ADL-3e displayed the highest selectivity against bacterial cells. In this study, ADG-2e and ADL-3e were evaluated for their potential as novel classes of antimicrobial, antibiofilm, and anti-inflammatory agents.
METHODS
Minimum inhibitory concentrations of ADG-2e and ADL-3e against bacteria were determined using the broth microdilution method. Proteolytic resistance against pepsin, trypsin, α-chymotrypsin, and proteinase K was determined by radial diffusion and HPLC analysis. Biofilm activity was investigated using the broth microdilution and confocal microscopy. The antimicrobial mechanism was investigated by membrane depolarization, cell membrane integrity analysis, scanning electron microscopy (SEM), genomic DNA influence and genomic DNA binding assay. Synergistic activity was evaluated using checkerboard method. Anti-inflammatory activity was investigated using ELISA and RT-PCR.
RESULTS
ADG-2e and ADL-3e showed good resistance to physiological salts and human serum, and a low incidence of drug resistance. Moreover, they exhibit proteolytic resistance against pepsin, trypsin, α-chymotrypsin, and proteinase K. ADG-2e and ADL-3e were found to kill bacteria by an intracellular target mechanism and bacterial cell membrane-disrupting mechanism, respectively. Furthermore, ADG-2e and ADL-3e showed effective synergistic effects when combined with several conventional antibiotics against methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant Pseudomonas aeruginosa (MDRPA). Importantly, ADG-2e and ADL-3e not only suppressed MDRPA biofilm formation but also effectively eradicated mature MDRPA biofilms. Furthermore, ADG-2e and ADL-3e drastically decreased tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) gene expression and protein secretion in lipopolysaccharide (LPS)-stimulated macrophages, implying potent anti-inflammatory activity in LPS-induced inflammation.
CONCLUSION
Our findings suggest that ADG-2e and ADL-3e could be further developed as novel antimicrobial, antibiofilm, and anti-inflammatory agents to combat bacterial infections.
Topics: Humans; Antimicrobial Cationic Peptides; Methicillin-Resistant Staphylococcus aureus; Lipopolysaccharides; Endopeptidase K; Pepsin A; Trypsin; Anti-Infective Agents; Anti-Bacterial Agents; Anti-Inflammatory Agents; Bacteria; Biofilms; Thymidine; Microbial Sensitivity Tests
PubMed: 37419291
DOI: 10.1016/j.ijantimicag.2023.106909 -
International Journal of Biological... Feb 2023The ability of a therapeutic compound to bind to proteins is critical for characterizing its therapeutic impacts. We have selected quercetin (Qu), a most common...
The ability of a therapeutic compound to bind to proteins is critical for characterizing its therapeutic impacts. We have selected quercetin (Qu), a most common flavonoid found in plants and vegetables among therapeutic molecules that are known to have anti-inflammatory, antioxidant, anti-genotoxic, and anti-cancer effects. The current study aimed to see how quercetin interacts with pepsin in an aqueous environment under physiological conditions. Absorbance and emission spectroscopy, circular dichroism (CD), and kinetic methods, as well as molecular dynamic (MD) simulation and docking, were applied to study the effects of Qu on the structure, dynamics, and kinetics of pepsin. Stern-Volmer (K) constants were computed for the pepsin-quercetin complex at three temperatures, showing that Qu reduces enzyme emission spectra using a static quenching. With Qu binding, the V and the k/K values decreased. UV-vis absorption spectra, fluorescence emission spectroscopy, and CD result indicated that Qu binding to pepsin leads to microenvironmental changes around the enzyme, which can alter the enzyme's secondary structure. Therefore, quercetin caused alterations in the function and structure of pepsin. Thermodynamic parameters, MD binding, and docking simulation analysis showed that non-covalent reactions, including the hydrophobic forces, played a key role in the interaction of Qu with pepsin. The findings conclude of spectroscopic experiments were supported by molecular dynamics simulations and molecular docking results.
Topics: Molecular Dynamics Simulation; Quercetin; Pepsin A; Molecular Docking Simulation; Binding Sites; Circular Dichroism; Spectrometry, Fluorescence; Thermodynamics; Protein Binding
PubMed: 36464189
DOI: 10.1016/j.ijbiomac.2022.11.296 -
HNO Nov 2021Laryngopharyngeal reflux (LPR) is defined as backflow of gastral or gastroduodenal content into the upper aerodigestive tract and characterized by a variety of... (Review)
Review
Laryngopharyngeal reflux (LPR) is defined as backflow of gastral or gastroduodenal content into the upper aerodigestive tract and characterized by a variety of unspecific symptoms such as chronic cough, globus sensation, or mucus hypersecretion. Due to the lack of a gold standard and the heterogeneity of studies, the diagnosis of LPR is still problematic and challenging. However, in patients with characteristic symptoms and endoscopic findings, with an increased reflux symptom index, a pathologic reflux finding score (RFS), pathologic 24 h esophageal or oropharyngeal pH monitoring, and without any other underlying condition, the diagnosis of LPR is probable. In the following review, we critically discuss the abovementioned methods as well as more recent tools such as measurements of pepsin concentrations in the saliva for diagnosis of LPR.
Topics: Esophageal pH Monitoring; Humans; Laryngopharyngeal Reflux; Pepsin A; Saliva
PubMed: 33619606
DOI: 10.1007/s00106-021-01006-3