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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 -
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 -
Nutrients Oct 2022The current bibliometric review evaluated recent papers that researched dietary protein sources to generate antidiabetic bioactive peptides/hydrolysates for the... (Review)
Review
The current bibliometric review evaluated recent papers that researched dietary protein sources to generate antidiabetic bioactive peptides/hydrolysates for the management of diabetes. Scopus and PubMed databases were searched to extract bibliometric data and, after a systematic four-step process was performed to select the articles, 75 papers were included in this review. The countries of origin of the authors who published the most were China (67%); Ireland (59%); and Spain (37%). The journals that published most articles on the subject were Food Chemistry (n = 12); Food & Function (n = 8); and Food Research International (n = 6). The most used keywords were 'bioactive peptides' (occurrence 28) and 'antidiabetic' (occurrence 10). The most used enzymes were Alcalase (17%), Trypsin (17%), Pepsin, and Flavourzyme (15% each). It was found that different sources of protein have been used to generate dipeptidyl peptidase IV (DPP-IV), α-amylase, and α-glucosidase inhibitory peptides. In addition to antidiabetic properties, some articles (n = 30) carried out studies on multifunctional bioactive peptides, and the most cited were reported to have antioxidant and antihypertensive activities (n = 19 and 17, respectively). The present review intended to offer bibliometric data on the most recent research on the production of antidiabetic peptides from dietary proteins to those interested in their obtention to act as hypoglycemic functional ingredients. The studies available in this period, compiled, are not yet enough to point out the best strategies for the production of antidiabetic peptides from food proteins and a more systematic effort in this direction is necessary to allow a future scale-up for the production of these possible functional ingredients.
Topics: Dipeptidyl Peptidase 4; Hypoglycemic Agents; Dipeptidyl-Peptidase IV Inhibitors; alpha-Glucosidases; Pepsin A; Antioxidants; Trypsin; Antihypertensive Agents; Peptides; alpha-Amylases; Subtilisins; Dietary Proteins; Bibliometrics
PubMed: 36296965
DOI: 10.3390/nu14204275 -
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 -
Bioscience Reports Nov 2020The current study was performed to determine the presence of pepsin in saliva and laryngeal tissue among participants with benign and malignant laryngeal neoplasms. (Comparative Study)
Comparative Study
OBJECTIVES
The current study was performed to determine the presence of pepsin in saliva and laryngeal tissue among participants with benign and malignant laryngeal neoplasms.
STUDY DESIGN
Case-control study included three groups of patients with: (1) benign laryngeal neoplasms, (2) malignant laryngeal neoplasms and (3) control subjects without symptoms or signs of laryngopharyngeal reflux (LPR).
METHODS
Eighty-one voluntary participants were included into study. They were recruited from a group of patients with histologically proven benign and malignant laryngeal neoplasms and in case of control subjects among patients with nasal septum deformation without symptoms of LPR. Morning saliva samples were collected preoperatively. Tumor biopsies were collected by directoscopy of larynx and the control samples from interarytenoid unit of larynx. All samples were analyzed by Enzyme-Linked Immunosorbent Assay (ELISA) and Immunohistochemistry.
RESULTS
Pepsin was found in all samples of saliva and tissue biopsies in groups with malignant and benign neoplasms. The highest concentration of pepsin was found in a group of patients with malignant laryngeal neoplasms. Patients with benign laryngeal neoplasms had lower concentrations and the control subjects presented with the lowest concentration of pepsin measured from their saliva. Differences were not statistically significant. Immunohistochemical (IHC) analysis showed the largest number of high positive samples in the group of malignant lesions.
CONCLUSION
These results suggest that pepsin and LPR can contribute to the development of benign and malignant laryngeal neoplasms. Further prospective studies, with far more patients, are necessary to prove the role of pepsin in multifactorial etiology of laryngeal neoplasms.
Topics: Adult; Aged; Biomarkers, Tumor; Case-Control Studies; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunohistochemistry; Laryngeal Neoplasms; Laryngopharyngeal Reflux; Larynx; Male; Middle Aged; Pepsin A; Saliva; Young Adult
PubMed: 33103719
DOI: 10.1042/BSR20200216 -
American Journal of Respiratory and... Dec 2022
Topics: Humans; Pepsin A; Primary Graft Dysfunction; Lung Transplantation; Lung; Inflammation; Allografts; Microbiota
PubMed: 36222878
DOI: 10.1164/rccm.202210-1873ED -
Molecules (Basel, Switzerland) Apr 2023Skin aging represents a health and aesthetic problem that could result in infections and skin diseases. Bioactive peptides can potentially be used in skin aging...
Skin aging represents a health and aesthetic problem that could result in infections and skin diseases. Bioactive peptides can potentially be used in skin aging regulation. Chickpea ( L.) selenoproteins were obtained from germination with 2 mg NaSeO/100 g of seeds for 2 days. Alcalase, pepsin, and trypsin were used as hydrolyzers, and a membrane < 10 kDa was used to fractionate the hydrolysate. Se content, antioxidant capacity, elastase and collagen inhibition, functional stability, and preventative capacity were analyzed. Significant increases in Se content were found in germinated chickpea flour and protein related to the control. An increase of 38% in protein was observed in the selenized flour related to the control. A band (600-550 cm) observed in the selenized hydrolysates suggested the insertion of Se into the protein. Hydrolysates from pepsin and trypsin had the highest antioxidant potential. Se enhanced the stability of total protein and protein hydrolysates through time and increased their antioxidant capacity. Hydrolysates > 10 kDa had higher elastase and collagenase inhibition than the total protein and hydrolysates < 10 kDa. Protein hydrolysates < 10 kDa 6 h before UVA radiation had the highest inhibition of collagen degradation. Selenized protein hydrolysates showed promising antioxidant effects that could be related to skin anti-aging effects.
Topics: Antioxidants; Cicer; Protein Hydrolysates; Pepsin A; Trypsin; Pancreatic Elastase
PubMed: 37110634
DOI: 10.3390/molecules28083402 -
Journal of Chemical Information and... Feb 2022The flexibility of β hairpin structure known as the flap plays a key role in catalytic activity and substrate intake in pepsin-like aspartic proteases. Most of these...
The flexibility of β hairpin structure known as the flap plays a key role in catalytic activity and substrate intake in pepsin-like aspartic proteases. Most of these enzymes share structural and sequential similarity. In this study, we have used apo Plm-II and BACE-1 as model systems. In the apo form of the proteases, a conserved tyrosine residue in the flap region remains in a dynamic equilibrium between the normal and flipped states through rotation of the χ and χ angles. Independent MD simulations of Plm-II and BACE-1 remained stuck either in the normal or flipped state. Metadynamics simulations using side-chain torsion angles (χ and χ of tyrosine) as collective variables sampled the transition between the normal and flipped states. Qualitatively, the two states were predicted to be equally populated. The normal and flipped states were stabilized by H-bond interactions to a tryptophan residue and to the catalytic aspartate, respectively. Further, mutation of tyrosine to an amino-acid with smaller side-chain, such as alanine, reduced the flexibility of the flap and resulted in a flap collapse (flap loses flexibility and remains stuck in a particular state). This is in accordance with previous experimental studies, which showed that mutation to alanine resulted in loss of activity in pepsin-like aspartic proteases. Our results suggest that the ring flipping associated with the tyrosine side-chain is the key order parameter that governs flap dynamics and opening of the binding pocket in most pepsin-like aspartic proteases.
Topics: Aspartic Acid Endopeptidases; Catalysis; Pepsin A
PubMed: 35138093
DOI: 10.1021/acs.jcim.1c00840