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International Journal of Biological... Jun 2022Pepsin is a protease used in many different applications, and in many instances, it is utilized in an immobilized form to prevent contamination of the reaction product.... (Review)
Review
Pepsin is a protease used in many different applications, and in many instances, it is utilized in an immobilized form to prevent contamination of the reaction product. This enzyme has two peculiarities that make its immobilization complex. The first one is related to the poor presence of primary amino groups on its surface (just one Lys and the terminal amino group). The second one is its poor stability at alkaline pH values. Both features make the immobilization of this enzyme to be considered a complicated goal, as most of the immobilization protocols utilize primary amino groups for immobilization. This review presents some of the attempts to get immobilized pepsin biocatalyst and their applications. The high density of anionic groups (Asp and Glu) make the anion exchange of the enzyme simpler, but this makes many of the strategies utilized to immobilize the enzyme (e.g., amino-glutaraldehyde supports) more related to a mixed ion exchange/hydrophobic adsorption than to real covalent immobilization. Finally, we propose some possibilities that can permit not only the covalent immobilization of this enzyme, but also their stabilization via multipoint covalent attachment.
Topics: Enzyme Stability; Enzymes, Immobilized; Glutaral; Hydrogen-Ion Concentration; Pepsin A
PubMed: 35508226
DOI: 10.1016/j.ijbiomac.2022.04.224 -
European Archives of... Jun 2022Laryngopharyngeal reflux disease (LPRD) is a general term for the reflux of gastroduodenal contents into the laryngopharynx, oropharynx and even the nasopharynx, causing... (Review)
Review
PURPOSE
Laryngopharyngeal reflux disease (LPRD) is a general term for the reflux of gastroduodenal contents into the laryngopharynx, oropharynx and even the nasopharynx, causing a series of symptoms and signs. Currently, little is known regarding the physiopathology of LPRD, and proton pump inhibitors (PPIs) are the drugs of choice for treatment. Although acid reflux plays a critical role in LPRD, PPIs fail to relieve symptoms in up to 40% of patients with LPRD. The influence of other reflux substances on LPRD, including pepsin, bile acid, and trypsin, has received increasing attention. Clarification of the substances involved in LPRD is the basis for LPRD treatment.
METHODS
A review of the effects of acids, pepsin, bile acids, and trypsin on laryngopharyngeal reflux diseases was conducted in PubMed.
RESULTS
Different reflux substances have different effects on LPRD, which will cause various symptoms, inflammatory diseases and neoplastic diseases of the laryngopharynx. For LPRD caused by different reflux substances, 24-h multichannel intraluminal impedance combined with pH-metry (MII-pH), salivary pepsin, bile acid and other tests should be established so that different drugs and treatment courses can be used to provide patients with more personalized treatment plans.
CONCLUSION
This article summarizes the research progress of different reflux substances on the pathogenesis, detection index and treatment of LPRD and lays a theoretical foundation to develop target drugs and clinical diagnosis and treatment.
Topics: Bile Acids and Salts; Esophageal pH Monitoring; Humans; Laryngopharyngeal Reflux; Pepsin A; Proton Pump Inhibitors; Trypsin
PubMed: 34860271
DOI: 10.1007/s00405-021-07201-w -
Journal of Voice : Official Journal of... Jul 2023Laryngopharyngeal reflux-associated symptoms embrace a wide variety of head and neck manifestations. Its participation in eye disorders has recently been postulated, and... (Review)
Review
BACKGROUND
Laryngopharyngeal reflux-associated symptoms embrace a wide variety of head and neck manifestations. Its participation in eye disorders has recently been postulated, and there is currently no consensus in this regard. The aim of this manuscript is to review the role of reflux in the development of ocular signs and symptoms, and its physio-pathological mechanisms.
METHODS
A systematic approach based on the preferred reporting Items for a systematic review and meta-analysis checklist with a modified population, intervention, comparison, and outcome framework was used to structure the review process of studies that evaluated the possible association, with clear diagnostic methods, of laryngopharyngeal reflux and ocular signs and symptoms. Search was conducted in different indexed databases (PubMed/MEDLINE, the Cochrane Library, Scielo and Web of Science) and through the meta-searcher Trip Database with the keywords: reflux, laryngitis, laryngopharyngeal, gastroesophageal, ocular, eye, symptoms, signs, conjunctivitis, keratitis, dacryocystitis, dry eye.
RESULTS
Seven studies met the inclusion criteria, in which the primary acquired nasolacrimal duct obstruction and the ocular surface disease were evaluated. The local increase of eye pepsin concentration (>2.5 ng/mL) may affect ocular surface though its direct proteolytic activity and the local expression of proinflammatory cytokines. The H. Pylori, with a similar mechanism to reach the lacrimonasal duct, would be associated with the release of proinflammatory and vasoactive substances that would lead to a mucosa injury and chronic inflammation. Ocular Surface Disease Index seems to correlate directly with the reflux severity, with cut-off of 41.67 score as predictor for disease.
DISCUSSION
The role of laryngopharyngeal reflux in the development of ocular disorders has not yet been demonstrated and data are limited and heterogeneous. It seems theoretically conceivable that pepsin may reach lachrymal duct area through hypopharyngeal-nasal gaseous reflux events. Future studies using objective testing for diagnosis and pepsin detection into the tear and nasal mucosa are needed in order to explore this potential relationship.
Topics: Humans; Lacrimal Duct Obstruction; Laryngitis; Laryngopharyngeal Reflux; Nasolacrimal Duct; Pepsin A
PubMed: 33849761
DOI: 10.1016/j.jvoice.2021.03.010 -
Marine Drugs Feb 2023There is a growing demand for the identification of alternative sources of collagen not derived from land-dwelling animals. The present study explored the use of pepsin-...
There is a growing demand for the identification of alternative sources of collagen not derived from land-dwelling animals. The present study explored the use of pepsin- and acid-based extraction protocols to isolate collagen from the swim bladders of . After extraction, these acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) samples respectively were subjected to spectral analyses and sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) characterization, revealing both to be comprised of type I collagen with a triple-helical structure. The imino acid content of these ASC and PSC samples was 195 and 199 residues per 1000 residues, respectively. Scanning electron microscopy demonstrated that samples of freeze-dried collagen exhibited a compact lamellar structure, while transmission electron microscopy and atomic force microscopy confirmed the ability of these collagens to undergo self-assembly into fibers. ASC samples exhibited a larger fiber diameter than the PSC samples. The solubility of both ASC and PSC was highest under acidic pH conditions. Neither ASC nor PSC caused any cytotoxicity when tested in vitro, which met one of the requirements for the biological evaluation of medical devices. Thus, collagen isolated from the swim bladders of holds great promise as a potential alternative to mammalian collagen.
Topics: Animals; Pepsin A; Fish Proteins; Collagen; Collagen Type I; Acids; Perciformes; Solubility; Skin; Mammals
PubMed: 36976208
DOI: 10.3390/md21030159 -
American Journal of Critical Care : An... Nov 2021In patients in the intensive care unit (ICU) receiving mechanical ventilation, aspiration of gastric contents may lead to ventilator-associated events and other adverse...
BACKGROUND
In patients in the intensive care unit (ICU) receiving mechanical ventilation, aspiration of gastric contents may lead to ventilator-associated events and other adverse outcomes. Pepsin in pulmonary secretions is a biomarker of microaspiration of gastric contents.
OBJECTIVES
To evaluate the association between tracheal pepsin A and clinical outcomes related to ventilator use.
METHODS
A subset of 297 patients from a larger clinical trial on aspiration of oral secretions in adults receiving mechanical ventilation consented to have pepsin A measured in their tracheal aspirate samples. A concentration ≥6.25 ng/mL indicated a positive result. Abundant microaspiration was defined as pepsin A in ≥30% of samples. Statistical analyses included analysis of variance, analysis of covariance, and χ2 tests.
RESULTS
Most patients were White men, mean age 59.7 (SD, 18.8) years. Microaspiration was found in 43.8% of patients (n = 130), with abundant microaspiration detected in 17.5% (n = 52). After acuity was controlled for, patients with tracheal pepsin A had a longer mechanical ventilation duration (155 vs 104 hours, P < .001) and ICU stay (9.9 vs 8.2 days, P = .04), but not a longer hospital stay.
CONCLUSIONS
Microaspiration of gastric contents occurred in nearly half of patients and was associated with a longer duration of mechanical ventilation and a longer stay in the ICU. Additional preventative interventions beyond backrest elevation, oropharyngeal suctioning, and management of endotracheal tube cuff pressure may be needed. Also, the timing of pepsin measurements to capture all microaspiration events requires additional exploration.
Topics: Adult; Humans; Intensive Care Units; Intubation, Intratracheal; Male; Middle Aged; Pepsin A; Respiration, Artificial; Trachea
PubMed: 34719715
DOI: 10.4037/ajcc2021528 -
Clinical Otolaryngology : Official... Jul 2023To investigate the association between laryngopharyngeal reflux (LPR), gastroesophageal reflux disease (GERD) and recalcitrant chronic rhinosinusitis (CRS). (Review)
Review
OBJECTIVE
To investigate the association between laryngopharyngeal reflux (LPR), gastroesophageal reflux disease (GERD) and recalcitrant chronic rhinosinusitis (CRS).
DATA SOURCES
PubMed, Cochrane Library and Scopus.
REVIEW METHODS
Three investigators searched the specified databases for studies investigating the relationship between LPR, GERD and recalcitrant CRS with or without polyposis. The following outcomes were investigated with PRISMA criteria: age; gender; reflux and CRS diagnosis; association outcomes and potential treatment outcomes. The authors performed a bias analysis of papers and provided recommendations for future studies.
RESULTS
A total of 17 studies investigated the association between reflux and recalcitrant CRS. According to pharyngeal pH monitoring, 54% of patients with recalcitrant CRS reported hypo or nasopharyngeal acid reflux events. The number of hypo- and nasopharyngeal acid reflux events was significantly higher in patients compared to healthy individuals in 4 and 2 studies, respectively. Only one study did not report intergroup differences. The proportion of GERD was significantly higher in CRS patients compared to controls, with a prevalence ranging from 32% to 91% of cases. No author considered nonacid reflux events. There was significant heterogeneity in the inclusion criteria; definition of reflux and association outcomes, limiting the ability to draw clear conclusions. Pepsin was found in sinonasal secretions more frequently in CRS patients than controls.
CONCLUSION
Laryngopharyngeal reflux and GERD may be contributing factors of CRS therapeutic resistance, but future studies are needed to confirm the association considering nonacid reflux events.
Topics: Humans; Laryngopharyngeal Reflux; Esophagitis, Peptic; Pepsin A; Sinusitis
PubMed: 36895147
DOI: 10.1111/coa.14047 -
The Laryngoscope Dec 2019Gastroesophageal reflux disease and associated metaplasia of the esophagus (Barrett's esophagus [BE]) are primary risk factors for esophageal adenocarcinoma (EAC)....
OBJECTIVES/HYPOTHESIS
Gastroesophageal reflux disease and associated metaplasia of the esophagus (Barrett's esophagus [BE]) are primary risk factors for esophageal adenocarcinoma (EAC). Widespread use of acid suppression medications has failed to stem the rise of EAC, suggesting that nonacid reflux may underlie its pathophysiology. Pepsin is a tumor promoter in the larynx and has been implicated in esophageal carcinogenesis. Herein, specimens from the esophageal cancer spectrum were tested for pepsin presence. Pepsin-induced carcinogenic changes were assayed in an esophageal cell culture model.
STUDY DESIGN
Laboratory analysis.
METHODS
Pepsin was assayed in reflux and cancer free esophagi, BE, EAC, and esophageal cancer lacking association with reflux (squamous cell carcinoma [SCC]). Refluxed or locally synthesized pepsin was assayed by Western blot. Local synthesis of pepsin and proton pumps was assayed via reverse transcription-polymerase chain reaction. The effect of pepsin on BE and EAC markers was investigated via enzyme-linked immunosorbent assay and quantitative polymerase chain reaction in human esophageal epithelial cells treated with pepsin or control diluent.
RESULTS
Pepsinogen and proton pump mRNA were observed in BE (3/5) and EAC (4/4) samples, but not in normal adjacent specimens, SCC (0/2), or reflux and cancer-free esophagi. Chronic pepsin treatment (0.1-1 mg/mL, 4 weeks) of human esophageal cells in vitro induced BE and EAC markers interleukin 8 and KRT8 and depleted normal esophageal marker KRT10 (P < .05) expression.
CONCLUSIONS
Local synthesis of pepsin and proton pumps in BE and EAC is not uncommon. Absence of these molecules in normal (noncancer) esophagi, SCC, and in vitro data support a role for pepsin in reflux-attributed carcinogenic changes in the esophagus.
LEVEL OF EVIDENCE
NA Laryngoscope, 129:2687-2695, 2019.
Topics: Adenocarcinoma; Barrett Esophagus; Biomarkers, Tumor; Biopsy; Carcinogenesis; Disease Progression; Esophageal Neoplasms; Esophagus; Follow-Up Studies; Gene Expression Regulation, Neoplastic; Humans; Pepsin A; Proton Pumps; RNA, Neoplasm; Retrospective Studies; Risk Factors; Tumor Cells, Cultured
PubMed: 31046139
DOI: 10.1002/lary.28051 -
The Laryngoscope Feb 2021To investigate the profile of patients with laryngopharyngeal reflux (LPR) at hypopharyngeal-esophageal multichannel intraluminal impedance-pH (HEMII-pH) monitoring and... (Observational Study)
Observational Study
OBJECTIVES/HYPOTHESIS
To investigate the profile of patients with laryngopharyngeal reflux (LPR) at hypopharyngeal-esophageal multichannel intraluminal impedance-pH (HEMII-pH) monitoring and the relationship between hypopharyngeal-proximal reflux episodes (HREs) and saliva pepsin concentration.
STUDY DESIGN
Prospective non-controlled.
METHODS
Patients were recruited from three European hospitals from January 2018 to October 2019. Patients benefited from HEMII-pH monitoring and saliva collections to measure saliva pepsin concentration in the same time. Saliva pepsin concentration was measured in the morning (fasting), after lunch, and after dinner. The LPR profile of patients was studied through a breakdown of the HEMII-pH findings over the 24 hours of testing. The relationship between the concentrations of saliva pepsin and 24-hour HREs was studied through linear multiple regression.
RESULTS
One hundred twenty-six patients completed the study. The HEMII-pH analyses revealed that 73.99% of HREs occurred outside 1-hour postmeal times, whereas 20.49% and 5.52% of HREs occurred during the 1-hour postmeal and nighttime, respectively. Seventy-four patients (58.73%) did not have nighttime HREs. Patients with both daytime and nighttime HREs had more severe HEMII-pH parameters and reflux symptom score compared with patients with only daytime HREs. There were no significant associations between HREs and saliva pepsin concentration.
CONCLUSIONS
Unlike gastroesophageal reflux disease, HREs occur less frequently after meals and nighttime. The analysis of the HEMII-pH profile of the LPR patients has to be considered to develop future personalized therapeutic strategies.
LEVEL OF EVIDENCE
4 Laryngoscope, 131:268-276, 2021.
Topics: Adult; Aged; Aged, 80 and over; Electric Impedance; Esophageal pH Monitoring; Esophagus; Female; Humans; Hypopharynx; Laryngopharyngeal Reflux; Male; Middle Aged; Pepsin A; Photoperiod; Postprandial Period; Prospective Studies; Saliva; Young Adult
PubMed: 32438465
DOI: 10.1002/lary.28736 -
International Journal of Molecular... Apr 2023Gastroesophageal reflux disease (GERD) significantly impacts patient quality of life and is a major risk factor for the development of Barrett's esophagus (BE) and...
Gastroesophageal reflux disease (GERD) significantly impacts patient quality of life and is a major risk factor for the development of Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). Proton pump inhibitors (PPIs) are the standard-of-care for GERD and are among the most prescribed drugs in the world, but do not protect against nonacid components of reflux such as pepsin, or prevent reflux-associated carcinogenesis. We recently identified an HIV protease inhibitor amprenavir that inhibits pepsin and demonstrated the antireflux therapeutic potential of its prodrug fosamprenavir in a mouse model of laryngopharyngeal reflux. In this study, we assessed the capacity of amprenavir to protect against esophageal epithelial barrier disruption in vitro and related molecular events, E-cadherin cleavage, and matrix metalloproteinase induction, which are associated with GERD severity and esophageal cancer. Herein, weakly acidified pepsin (though not acid alone) caused cell dissociation accompanied by regulated intramembrane proteolysis of E-cadherin. Soluble E-cadherin responsive matrix metalloproteinases (MMPs) were transcriptionally upregulated 24 h post-treatment. Amprenavir, at serum concentrations achievable given the manufacturer-recommended dose of fosamprenavir, protected against pepsin-induced cell dissociation, E-cadherin cleavage, and MMP induction. These results support a potential therapeutic role for amprenavir in GERD recalcitrant to PPI therapy and for preventing GERD-associated neoplastic changes.
Topics: Animals; Mice; Pepsin A; Protease Inhibitors; Quality of Life; Esophageal Neoplasms; Enzyme Inhibitors; Laryngopharyngeal Reflux; Proton Pump Inhibitors
PubMed: 37047737
DOI: 10.3390/ijms24076765 -
Applied Nursing Research : ANR Oct 2022This study explored relationships between enteral feeding and tracheal pepsin A.
AIM
This study explored relationships between enteral feeding and tracheal pepsin A.
BACKGROUND
Mechanically ventilated (MV) patients receiving enteral feeding are at risk for microaspiration. Tracheal pepsin A, an enzyme specific to gastric cells, was a proxy for microaspiration of gastric secretions.
METHODS
Secondary analysis of RCT data from critically ill, MV adults was conducted. Microaspiration prevention included elevated head of bed, endotracheal tube cuff pressure management, and regular oral care. Tracheal secretions for pepsin A were collected every 12 h. Microaspiration was defined as pepsin A ≥ 6.25 ng/mL. Positive pepsin A in >30 % of individual tracheal samples was defined as abundant microaspiration (frequent aspirator). Chi-squared, Fisher's Exact test, and generalized linear model (GLM) were used.
RESULTS
Tracheal pepsin A was present in 111/283 (39 %) mechanically ventilated patients and 48 (17 %) had abundant microaspiration. Enteral feeding was associated with tracheal pepsin A, which occurred within 24 h of enteral feeding. Of the patients who aspirated, the majority received some enteral feeding 96/111 (86 %), compared to only 15/111 (14 %) who received no feeding. A greater number of positive pepsin A events occurred with post-pyloric feeding tube location (55.6 %) vs. gastric (48.6 %), although significant only at the event-level. Frequent aspirators (abundant pepsin A) had higher pepsin A levels compared to infrequent aspirators.
CONCLUSIONS
Our findings confirmed the stomach as the microaspiration source. Contrary to other studies, distal feeding tube location did not mitigate microaspiration. Timing for first positive pepsin A should be studied for possible association with enteral feeding intolerance.
Topics: Adult; Bodily Secretions; Critical Illness; Enteral Nutrition; Humans; Infant, Newborn; Intubation, Intratracheal; Pepsin A; Respiratory Aspiration of Gastric Contents; Trachea
PubMed: 36116866
DOI: 10.1016/j.apnr.2022.151611