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Sánchez-Alonso I, Carballeda-Sangiao N, Rodríguez S, Tejada M, Navas A, Arcos SC, González-Muñoz M, Careche M. Anisakis simplex (s.l.) resistance to the action of gastric enzymes depends upon previous treatments applied to infected fish mince and affects antigen release. J Sci Food Agric 2021; 101:3908-3916. [PMID: 33348457 DOI: 10.1002/jsfa.11031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 11/27/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
BACKGROUND Freezing is considered the most suitable technological treatment to avoid Anisakis infection from eating raw or undercooked fish but modifications of their cuticles upon freezing may reduce their resistance to gastric fluids, provoking a greater release of allergens. This work aimed to study the relationship between freezing-induced modifications of Anisakis simplex s.l., antigen recognition, and resistance to oral and gastric digestion in spiked fish mince. RESULTS (i) Differences between non-treated larvae and larvae that survived freezing / thawing were studied in terms of respiratory capacity, survival in simulated gastric fluid (SGF), recognition of antigens and allergens. (ii) Untreated (i.e. chilled) mince containing live larvae, mince frozen at two freezing rates, with a negative (uninfected) mince and a positive mince (infected with broken larvae) as controls, were subjected to the oral and gastric phases of a simulated digestion process. Anisakis able to survive freezing showed lower resistance to gastric fluid (i.e. faster mortality as compared to controls). Untreated larvae released significantly more antigens than freeze-surviving larvae but only after 96 h in SGF. In treatments rendering complete larvae mortality, the highest loss of larvae integrity was found upon fast freezing. There was a positive correlation between antigen release and the number of ruptures of larvae after the oral digestion phase, whereas a more complex trend was observed after oral plus gastric digestion phases. CONCLUSION These results suggest a new factor to consider for sensitized patients and suggest that the numbers of L3 should be reduced before industrial freezing to minimize risk. © 2020 Society of Chemical Industry.
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Affiliation(s)
- Isabel Sánchez-Alonso
- Department of Products, Institute of Food Science, Technology and Nutrition, Agencia Estatal Consejo Superior de Investigaciones Científicas (ICTAN-CSIC), Madrid, Spain
| | - Noelia Carballeda-Sangiao
- Department of Products, Institute of Food Science, Technology and Nutrition, Agencia Estatal Consejo Superior de Investigaciones Científicas (ICTAN-CSIC), Madrid, Spain
| | - Santiago Rodríguez
- Department of Products, Institute of Food Science, Technology and Nutrition, Agencia Estatal Consejo Superior de Investigaciones Científicas (ICTAN-CSIC), Madrid, Spain
| | - Margarita Tejada
- Department of Products, Institute of Food Science, Technology and Nutrition, Agencia Estatal Consejo Superior de Investigaciones Científicas (ICTAN-CSIC), Madrid, Spain
| | - Alfonso Navas
- Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain
| | - Susana C Arcos
- Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales (MNCN-CSIC), Madrid, Spain
| | | | - Mercedes Careche
- Department of Products, Institute of Food Science, Technology and Nutrition, Agencia Estatal Consejo Superior de Investigaciones Científicas (ICTAN-CSIC), Madrid, Spain
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Buddhiwant P, Bhavsar K, Kumar VR, Khire JM. Phytase production by solid-state fermentation of groundnut oil cake by Aspergillus niger: A bioprocess optimization study for animal feedstock applications. Prep Biochem Biotechnol 2016; 46:531-8. [PMID: 26176365 DOI: 10.1080/10826068.2015.1045606] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This investigation deals with the use of agro-industrial waste, namely groundnut oil cake (GOC), for phytase production by the fungi Aspergillus niger NCIM 563. Plackett-Burman design (PBD) was used to evaluate the effect of 11 process variables and studies here showed that phytase production was significantly influenced by glucose, dextrin, distilled water, and MgSO4 · 7H2O. The use of response surface methodology (RSM) by Box-Behnken design (BBD) of experiments further enhanced the production by a remarkable 36.67-fold from the original finding of 15 IU/gds (grams of dry substrate) to 550 IU/gds. This is the highest solid-state fermentation (SSF) phytase production reported when compared to other microorganisms and in fact betters the best known by a factor of 2. Experiments carried out using dried fermented koji for phosphorus and mineral release and also thermal stability have shown the phytase to be as efficient as the liquid enzyme extract. Also, the enzyme, while exhibiting optimal activity under acidic conditions, was found to have significant activity in a broad range of pH values (1.5-6.5). The studies suggest the suitability of the koji supplemented with phytase produced in an SSF process by the "generally regarded as safe" (GRAS) microorganism A. niger as a cost-effective value-added livestock feed when compared to that obtained by submerged fermentation (SmF).
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Affiliation(s)
- Priyanka Buddhiwant
- a National Collection of Industrial Micro-organisms (NCIM) , CSIR-National Chemical Laboratory (CSIR-NCL) , Pune , India
- b Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory (CSIR-NCL) , Pune , India
| | - Kavita Bhavsar
- a National Collection of Industrial Micro-organisms (NCIM) , CSIR-National Chemical Laboratory (CSIR-NCL) , Pune , India
| | - V Ravi Kumar
- b Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory (CSIR-NCL) , Pune , India
- c Chemical Engineering and Process Development Division , CSIR-National Chemical Laboratory (CSIR-NCL) , Pune , India
| | - Jayant M Khire
- a National Collection of Industrial Micro-organisms (NCIM) , CSIR-National Chemical Laboratory (CSIR-NCL) , Pune , India
- b Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory (CSIR-NCL) , Pune , India
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Bibo-Verdugo B, O'Donoghue AJ, Rojo-Arreola L, Craik CS, García-Carreño F. Complementary Proteomic and Biochemical Analysis of Peptidases in Lobster Gastric Juice Uncovers the Functional Role of Individual Enzymes in Food Digestion. Mar Biotechnol (NY) 2016; 18:201-214. [PMID: 26613762 DOI: 10.1007/s10126-015-9681-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 11/10/2015] [Indexed: 06/05/2023]
Abstract
Crustaceans are a diverse group, distributed in widely variable environmental conditions for which they show an equally extensive range of biochemical adaptations. Some digestive enzymes have been studied by purification/characterization approaches. However, global analysis is crucial to understand how digestive enzymes interplay. Here, we present the first proteomic analysis of the digestive fluid from a crustacean (Homarus americanus) and identify glycosidases and peptidases as the most abundant classes of hydrolytic enzymes. The digestion pathway of complex carbohydrates was predicted by comparing the lobster enzymes to similar enzymes from other crustaceans. A novel and unbiased substrate profiling approach was used to uncover the global proteolytic specificity of gastric juice and determine the contribution of cysteine and aspartic acid peptidases. These enzymes were separated by gel electrophoresis and their individual substrate specificities uncovered from the resulting gel bands. This new technique is called zymoMSP. Each cysteine peptidase cleaves a set of unique peptide bonds and the S2 pocket determines their substrate specificity. Finally, affinity chromatography was used to enrich for a digestive cathepsin D1 to compare its substrate specificity and cold-adapted enzymatic properties to mammalian enzymes. We conclude that the H. americanus digestive peptidases may have useful therapeutic applications, due to their cold-adaptation properties and ability to hydrolyze collagen.
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Affiliation(s)
- Betsaida Bibo-Verdugo
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Calle IPN 195, Col. Playa Palo de Santa Rita, La Paz, B.C.S., 23096, Mexico
| | - Anthony J O'Donoghue
- Department of Pharmaceutical Chemistry, University of California San Francisco, 600 16th Street, San Francisco, CA, 94158, USA
| | - Liliana Rojo-Arreola
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Calle IPN 195, Col. Playa Palo de Santa Rita, La Paz, B.C.S., 23096, Mexico
- Center for Discovery and Innovation in Parasitic Diseases, University of California San Francisco, 1700 4th Street, San Francisco, CA, 94158, USA
| | - Charles S Craik
- Department of Pharmaceutical Chemistry, University of California San Francisco, 600 16th Street, San Francisco, CA, 94158, USA
| | - Fernando García-Carreño
- Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Calle IPN 195, Col. Playa Palo de Santa Rita, La Paz, B.C.S., 23096, Mexico.
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Makkhun S, Khosla A, Foster T, McClements DJ, Grundy MML, Gray DA. Impact of extraneous proteins on the gastrointestinal fate of sunflower seed (Helianthus annuus) oil bodies: a simulated gastrointestinal tract study. Food Funct 2015; 6:125-34. [PMID: 25284307 DOI: 10.1039/c4fo00422a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2024]
Abstract
In this study, we examined the physicochemical nature of sunflower seed oil bodies (in the absence and presence of added protein) exposed to gastrointestinal conditions in vitro: crude oil bodies (COB); washed oil bodies (WOB); whey protein isolate-enriched oil bodies (WOB-WPI); and, sodium caseinate enriched-oil bodies (WOB-SC). All oil body emulsions were passed through an in vitro digestion model that mimicked the stomach and duodenal environments, and their physicochemical properties were measured before, during, and after digestion. Oil bodies had a positive charge under gastric conditions because the pH was below the isoelectric point of the adsorbed protein layer, but they had a negative charge under duodenal conditions which was attributed to changes in interfacial composition resulting from adsorption of bile salts. Oil bodies were highly susceptible to flocculation and coalescence in both gastric and duodenal conditions. SDS-PAGE analysis indicated degradation of oleosin proteins (ca. 18-21 kDa) to a greater or lesser extent (dependent on the emulsion) during the gastric phase in all emulsions tested; there is evidence that some oleosin remained intact in the crude oil body preparation during this phase of the digestion process. Measurements of protein displacement from the surface of COBs during direct exposure to bile salts, without inclusion of a gastric phase, indicated the removal of intact oleosin from native oil bodies.
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Affiliation(s)
- Sakunkhun Makkhun
- University of Phayao, Division of Food Science and Technology, School of Agriculture and Natural Resources, Muang, Phayao, 56000 Thailand
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Abstract
BACKGROUND Endotracheal intubation increases the risk for microaspiration of secretions around the tube cuff. Pepsin has been used as a biomarker for gastric aspiration. Amylase is a newer proposed biomarker for aspiration of oral contents. OBJECTIVE To assess the presence of pepsin and amylase in paired oral-tracheal secretions of adult patients treated with mechanical ventilation. METHODS In this descriptive study, paired samples of oral and tracheal secretions were obtained from adult patients at baseline and again within 4 hours when a need for endotracheal suctioning was assessed. Assays of pepsin and amylase were processed in a specialty diagnostic laboratory. RESULTS The sample consisted of 10 men and 3 women with a median age of 56 years. The majority were intubated with a subglottic suction endotracheal tube (9 patients, 69%), receiving synchronized intermittent mandatory ventilation (10 patients; 77%), and receiving enteral feedings (11 patients; 85%) through a tube distally placed in the stomach (8 patients; 67%). Pepsin was present in oral secretions of 9 patients (69%), and in tracheal specimens of 7 patients (54%) at one or both sampling times. Amylase was detected in all patients' oral secretions and in tracheal secretions of 5 patients (38%) at one or both sampling times. CONCLUSIONS Many patients had pepsin, amylase, or both in tracheal aspirates. Pepsin was more commonly detected than was amylase. Although the relationship of this finding to long-term outcomes was not assessed, findings indicate that microaspiration of oral and gastric secretions occurs frequently.
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Affiliation(s)
- Mary Lou Sole
- Mary Lou Sole is Orlando Health Distinguished Professor, University of Central Florida, and a research scientist at Orlando Health, Orlando, Florida. Janet Conrad is a clinical scientist in the pediatric specialty diagnostic laboratory and Devendra Indulal Mehta is the director of the pediatric gastroenterology laboratory, Arnold Palmer Hospital for Children, Orlando, Florida. Melody Bennett is a member of the adjunct faculty, University of Central Florida, and a staff nurse at Orlando Health. Aurea Middleton is a staff nurse at Orlando Health. Katherine Hay is a staff nurse at University of Alabama at Birmingham, Birmingham, Alabama. Suzanne Ashworth is a clinical nurse specialist in neurological critical care, Orlando Regional Medical Center, Orlando, Florida.
| | - Janet Conrad
- Mary Lou Sole is Orlando Health Distinguished Professor, University of Central Florida, and a research scientist at Orlando Health, Orlando, Florida. Janet Conrad is a clinical scientist in the pediatric specialty diagnostic laboratory and Devendra Indulal Mehta is the director of the pediatric gastroenterology laboratory, Arnold Palmer Hospital for Children, Orlando, Florida. Melody Bennett is a member of the adjunct faculty, University of Central Florida, and a staff nurse at Orlando Health. Aurea Middleton is a staff nurse at Orlando Health. Katherine Hay is a staff nurse at University of Alabama at Birmingham, Birmingham, Alabama. Suzanne Ashworth is a clinical nurse specialist in neurological critical care, Orlando Regional Medical Center, Orlando, Florida
| | - Melody Bennett
- Mary Lou Sole is Orlando Health Distinguished Professor, University of Central Florida, and a research scientist at Orlando Health, Orlando, Florida. Janet Conrad is a clinical scientist in the pediatric specialty diagnostic laboratory and Devendra Indulal Mehta is the director of the pediatric gastroenterology laboratory, Arnold Palmer Hospital for Children, Orlando, Florida. Melody Bennett is a member of the adjunct faculty, University of Central Florida, and a staff nurse at Orlando Health. Aurea Middleton is a staff nurse at Orlando Health. Katherine Hay is a staff nurse at University of Alabama at Birmingham, Birmingham, Alabama. Suzanne Ashworth is a clinical nurse specialist in neurological critical care, Orlando Regional Medical Center, Orlando, Florida
| | - Aurea Middleton
- Mary Lou Sole is Orlando Health Distinguished Professor, University of Central Florida, and a research scientist at Orlando Health, Orlando, Florida. Janet Conrad is a clinical scientist in the pediatric specialty diagnostic laboratory and Devendra Indulal Mehta is the director of the pediatric gastroenterology laboratory, Arnold Palmer Hospital for Children, Orlando, Florida. Melody Bennett is a member of the adjunct faculty, University of Central Florida, and a staff nurse at Orlando Health. Aurea Middleton is a staff nurse at Orlando Health. Katherine Hay is a staff nurse at University of Alabama at Birmingham, Birmingham, Alabama. Suzanne Ashworth is a clinical nurse specialist in neurological critical care, Orlando Regional Medical Center, Orlando, Florida
| | - Katherine Hay
- Mary Lou Sole is Orlando Health Distinguished Professor, University of Central Florida, and a research scientist at Orlando Health, Orlando, Florida. Janet Conrad is a clinical scientist in the pediatric specialty diagnostic laboratory and Devendra Indulal Mehta is the director of the pediatric gastroenterology laboratory, Arnold Palmer Hospital for Children, Orlando, Florida. Melody Bennett is a member of the adjunct faculty, University of Central Florida, and a staff nurse at Orlando Health. Aurea Middleton is a staff nurse at Orlando Health. Katherine Hay is a staff nurse at University of Alabama at Birmingham, Birmingham, Alabama. Suzanne Ashworth is a clinical nurse specialist in neurological critical care, Orlando Regional Medical Center, Orlando, Florida
| | - Suzanne Ash-worth
- Mary Lou Sole is Orlando Health Distinguished Professor, University of Central Florida, and a research scientist at Orlando Health, Orlando, Florida. Janet Conrad is a clinical scientist in the pediatric specialty diagnostic laboratory and Devendra Indulal Mehta is the director of the pediatric gastroenterology laboratory, Arnold Palmer Hospital for Children, Orlando, Florida. Melody Bennett is a member of the adjunct faculty, University of Central Florida, and a staff nurse at Orlando Health. Aurea Middleton is a staff nurse at Orlando Health. Katherine Hay is a staff nurse at University of Alabama at Birmingham, Birmingham, Alabama. Suzanne Ashworth is a clinical nurse specialist in neurological critical care, Orlando Regional Medical Center, Orlando, Florida
| | - Devendra Indulal Mehta
- Mary Lou Sole is Orlando Health Distinguished Professor, University of Central Florida, and a research scientist at Orlando Health, Orlando, Florida. Janet Conrad is a clinical scientist in the pediatric specialty diagnostic laboratory and Devendra Indulal Mehta is the director of the pediatric gastroenterology laboratory, Arnold Palmer Hospital for Children, Orlando, Florida. Melody Bennett is a member of the adjunct faculty, University of Central Florida, and a staff nurse at Orlando Health. Aurea Middleton is a staff nurse at Orlando Health. Katherine Hay is a staff nurse at University of Alabama at Birmingham, Birmingham, Alabama. Suzanne Ashworth is a clinical nurse specialist in neurological critical care, Orlando Regional Medical Center, Orlando, Florida
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Selot R, Kumar V, Shukla S, Chandrakuntal K, Brahmaraju M, Dandin SB, Laloraya M, Kumar PG. Identification of a Soluble NADPH Oxidoreductase (BmNOX) with Antiviral Activites in the Gut Juice ofBombyx mori. Biosci Biotechnol Biochem 2014; 71:200-5. [PMID: 17213661 DOI: 10.1271/bbb.60450] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Silkworms show high variability in silk quality and disease resistance. Attempts are on to combine the disease tolerance of multivoltine races and the silk quality of bivoltine races to generate new races with desirable phenotypic traits. We report the identification of a 26.5-kDa protein that is overexpressed in the gut juice of disease-resistant multivoltine races and that has anti-BmNPV activity. We have characterized this protein as a soluble NADH-oxidoreductase-like protein (BmNOX). Treatment of live BmNPV particles with BmNOX inhibited the capability of the viral particles to infect BmN cells in vitro.
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Affiliation(s)
- Ruchita Selot
- Central Sericultural Research and Training Institute, Mysore, India
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van den Braak CCM, Klebach M, Abrahamse E, Minor M, Hofman Z, Knol J, Ludwig T. A novel protein mixture containing vegetable proteins renders enteral nutrition products non-coagulating after in vitro gastric digestion. Clin Nutr 2013; 32:765-71. [PMID: 23274146 DOI: 10.1016/j.clnu.2012.11.016] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Revised: 11/14/2012] [Accepted: 11/14/2012] [Indexed: 12/26/2022]
Abstract
BACKGROUND & AIMS Non-coagulation of protein from enteral nutrition (EN) in the stomach is considered to improve gastric emptying and may result in reduced upper gastrointestinal complications such as reflux and aspiration pneumonia. For the development of a new EN protein mixture with reduced gastric coagulation, the coagulating properties of individual proteins, a novel blend of four proteins (P4 protein blend) and commercial EN products were investigated. METHODS A semi-dynamic, computer controlled setup was developed to mimic gastric digestion. The coagulation behaviour of 150 ml protein solutions and EN products was investigated. These were heat-treated calcium caseinate, sodium caseinate, whey, soy and pea protein, and the P4 protein blend comprising of the latter four (all solutions 6% w/v protein), four new enteral nutrition product varieties (New Nutrison® .0 or 1.5 kcal/ml, with and without MultiFibre MF6™) based on the P4 protein blend and two other commercially available casein dominant EN products (T1 and T2). RESULTS Calcium caseinate and sodium caseinate yielded a total wet coagulate of 43.5 ± 0.7 g and 52.7 ± 6.2 g, respectively. Whey, soy, pea and the P4 protein blend did not produce any measurable coagulate. T1 and T2 resulted in a total wet coagulate of 37.5 ± 0.8 g and 57.3 ± 0.8 g, respectively, while all new EN product varieties based on the P4 protein blend did not produce any measurable coagulate. CONCLUSIONS The P4 protein blend renders EN product varieties non-coagulating after in vitro gastric digestion.
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Masoero F, Gallo A, Giuberti G, Fiorentini L, Moschini M. Effect of water-saving irrigation regime on whole-plant yield and nutritive value of maize hybrids. J Sci Food Agric 2013; 93:3040-3045. [PMID: 23512720 DOI: 10.1002/jsfa.6137] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2012] [Revised: 01/30/2013] [Accepted: 03/19/2013] [Indexed: 06/01/2023]
Abstract
BACKGROUND The effect of a water-saving irrigation regime on yield, chemical composition, rumen in situ dry matter disappearance (DMD) and neutral detergent fiber disappearance (NDFD), along with 7 h in vitro starch degradability (7 h IVSD), in maize hybrids selected for whole-plant silage making was investigated. A plot experiment was conducted in a continental climate location and four commercial maize hybrids (FAO class 700) were used in a completely randomized design with a factorial arrangement of irrigation treatments (fully irrigated (FI) and water-saving regime (WS)) and four replicates/treatment. The total amount of irrigation water was 494 mm in FI plots and 367 mm in WS plots, the latter achieved by skipping irrigations at vegetative growth stage, silking and blistering. RESULTS Whole-plant yield, chemical composition, DMD, NDFD and 7 h IVSD slightly differed among hybrids and were not influenced by irrigation treatments. Plant dry matter content was lower in FI than WS plots (320 vs. 341 g kg⁻¹) , respectively; P < 0.05). Differences among hybrids were recorded for starch and acid detergent fiber contents (P < 0.05). CONCLUSIONS The lack of differences on yield and nutritive value in tested maize hybrids grown under different water supply suggests the water-saving regime could be suitable for an optimal use of available water in maize management.
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Affiliation(s)
- Francesco Masoero
- Feed and Food Science and Nutrition Institute, Faculty of Agriculture, Università Cattolica del Sacro Cuore, 29122 Piacenza, Italy.
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Abstract
An oil body dispersion (11.3% fat) was prepared by wet disintegration of walnuts and was then subjected to a two-step model of in vitro digestion. In a gastric environment, proteolysis by pepsin led to the destabilization and coalescence of the oil bodies. Aggregation of the coalesced oil bodies was apparent under a confocal microscope, with aggregates up to 275 μm in size. Pepsin-resistant peptides and proteins remained at the surface of the oil bodies, and some were further resistant to intestinal proteases. Under intestinal conditions, the hydrolysis of walnut triglycerides led to the spontaneous formation of a new type of multiple emulsions, ranging from 2 to 45 μm in size and with protein material inside the inner water droplets. Transmission electron microscopy revealed the presence of a liquid-crystalline phase of bile salts and lipolytic products at the surface of the oil droplets and some bile salt crystals at the surface of the inner water droplets.
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Affiliation(s)
- Sophie Gallier
- Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand.
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Yu HL, Ruan WW, Cao MJ, Cai QF, Shen HW, Liu GM. Identification of physicochemical properties of Scylla paramamosain allergen, arginin kinase. J Sci Food Agric 2013; 93:245-253. [PMID: 22674459 DOI: 10.1002/jsfa.5748] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2012] [Revised: 04/02/2012] [Accepted: 04/25/2012] [Indexed: 06/01/2023]
Abstract
BACKGROUND Arginine kinase (AK) is expressed in a wide variety of species, including human food sources (seafood) and pests (cockroaches and moths), and has been reported as a novel allergen. However, there has been little research on the allergenicity of AK in crustaceans. In this study the physicochemical properties of AK from mud crab (Scylla paramamosain) were investigated. RESULTS Analysis by sodium dodecyl sulfate polyacrylamide gel electrophoresis, immunoblotting and inhibition enzyme-linked immunosorbent assay revealed that purified AK was unstable in thermal processing and in acid buffer. Under simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) conditions, purified AK was much more readily degraded by pepsin than by trypsin or chymotrypsin. The unpurified AK in crab myogen degraded more markedly than purified AK. In addition, in two-phase gastrointestinal digestion, AK was rapidly degraded by pepsin but resistant to trypsin and chymotrypsin digestion, while tropomyosin derived from mud crab was resistant to pepsin digestion but digested readily by trypsin or chymotrypsin. Further study of serum samples obtained from crab-allergic human patients indicated that the allergenicity of AK was markedly reduced by digestion with SGF but not SIF. CONCLUSION AK is an important food allergen despite its unstable physicochemical properties of digestibility.
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Affiliation(s)
- Hui-Lin Yu
- College of Biological Engineering, The Key Laboratory of Science and Technology for Aquaculture and Food Safety, Jimei University, 43 Yindou Road, Xiamen 361021, Fujian, China
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Baintner K. Study of lysozyme and lysozyme inhibitor activities in saliva, rumen liquor and intestinal fluid of sheep and cattle. Zentralbl Veterinarmed A 2010; 28:790-5. [PMID: 6807021 DOI: 10.1111/j.1439-0442.1981.tb01252.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Abstract
Two esterases previously identified in seminal plasma, on the basis of their electrophoretic mobility, immunogenicity and sensitivity to organophosphorus esters were detected in various human external secretions and leucocyte extracts. alpha-Esterase was found to be abundant in urine and milk whereas this enzyme occurred in a low concentration in seminal plasma, leucocyte extract, cervical mucus and sweat. The concentration of betagamma-esterase was high in seminal plasma and leucocyte extract. The enzyme was present in small amounts in urine, milk, gastric juice, saliva, sputum, tears, cervical mucus and sweat.
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He Z, O'Reilly RC, Bolling L, Soundar S, Shah M, Cook S, Schmidt RJ, Bloedon E, Mehta DI. Detection of gastric pepsin in middle ear fluid of children with otitis media. Otolaryngol Head Neck Surg 2007; 137:59-64. [PMID: 17599566 DOI: 10.1016/j.otohns.2007.02.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2006] [Accepted: 02/01/2007] [Indexed: 12/21/2022]
Abstract
OBJECTIVE We sought to confirm the finding of pepsin/pepsinogen in the middle ear fluid of children with otitis media in a larger sample size using a sensitive and specific pepsin assay. STUDY DESIGN AND SETTING We evaluated 152 children (225 ear samples) in a prospective study at a tertiary care children's hospital. The presence of pepsin in middle ear aspirates was determined using enzymatic assay. RESULTS Of the patients, 14.4 percent (22 of 152) had detectable pepsin activity in one or both of the ear samples with no pepsin activity detected in control serum. Average pepsin concentration in the samples was 96.6 +/- 170.8 ng/ml, ranging from 13 to 687 ng/ml. Pepsin concentration in the middle ear of children younger than 1.0 year was significantly higher than in older age groups. CONCLUSION AND SIGNIFICANCE Results indicate that pepsin/pepsinogen is present in the middle ears of children with otitis media, although not at the high rate previously reported. Gastric reflux may be one causative factor in the pathogenesis of otitis media.
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Affiliation(s)
- Zhaoping He
- Nemours Biomedical Research, Alfred I. duPont Hospital for Children, Wilmington, DE 19899, USA.
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Masco L, Crockaert C, Van Hoorde K, Swings J, Huys G. In Vitro Assessment of the Gastrointestinal Transit Tolerance of Taxonomic Reference Strains from Human Origin and Probiotic Product Isolates of Bifidobacterium. J Dairy Sci 2007; 90:3572-8. [PMID: 17638965 DOI: 10.3168/jds.2006-548] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Next to health promoting effects, the functional aspect of probiotic strains also involves their capacity to reach the colon as viable metabolically active cells. The present study aimed to assess the potential of 24 probiotic product isolates and 42 human reference strains of Bifidobacterium to survive gastrointestinal transit under in vitro conditions. The survival capacity of exponential and stationary phase cultures upon exposure to gastric and small intestinal juices was determined using a recently developed microplate-based assay in combination with the LIVE/DEAD BacLight Bacterial Viability kit. All 66 strains tested displayed a considerable loss in viability during exposure to an acidic pepsin containing solution (pH 2.0). Among the 10 taxa tested, cultures of B. animalis ssp. lactis appeared to be most capable to survive gastric transit. Although to a lesser extent, the presence of bile salts also affected the viability of most of the strains tested. Except for 3 strains, all 66 strains showed bile salt hydrolase activity using an agar-based assay. In contrast, the bifidobacterial strains used in this study appeared to possess a natural ability to survive the presence of pancreatin (pH 8.0). Although the effect was not significant, a slightly enhanced tolerance to gastrointestinal transit was observed when cells were in the stationary phase, especially when exposed to acid, compared with cells being in the exponential phase. Survival in the gastrointestinal tract appeared to be largely strain-dependent and hence implies that different strains will likely display a different behavior in functionality. The assay used in this study allows an initial assessment of strains for use as probiotic cultures prior to selecting potential candidate strains for further investigation in vivo.
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Affiliation(s)
- L Masco
- Laboratory of Microbiology, Ghent University, K. L. Ledeganckstraat 35, B-9000 Gent, Belgium.
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Paoletti MG, Norberto L, Damini R, Musumeci S. Human gastric juice contains chitinase that can degrade chitin. Ann Nutr Metab 2007; 51:244-51. [PMID: 17587796 DOI: 10.1159/000104144] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2006] [Accepted: 03/09/2007] [Indexed: 11/19/2022]
Abstract
Chitin digestion by humans has generally been questioned or denied. Only recently chitinases have been found in several human tissues and their role has been associated with defense against parasite infections and to some allergic conditions. In this pilot study we tested the gastric juices of 25 Italian subjects on the artificial substrates 4-methylumbelliferyl-beta-D-N,N',diacetylchitobiose or/and fluorescein isothiocyanate (FITC) chitin to demonstrate the presence of a chitinase activity. Since this chitinase activity was demonstrated at acidic pH, it is currently referred to acidic mammalian chitinase (AMCase). AMCase activity was present in gastric juices of twenty of 25 Italian patients in a range of activity from 0.21 to 36.27 nmol/ml/h and from 8,881 to 1,254,782 fluorescence emission (CPS), according to the used methods. In the remaining five of 25 gastric juices, AMCase activity was almost absent in both assay methods. An allosamidine inhibition test and the measurement at different pH values confirmed that this activity was characteristic of AMCase. The absence of activity in 20% of the gastric juices may be a consequence of virtual absence of chitinous food in the Western diet.
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Affiliation(s)
- Maurizio G Paoletti
- Department of Biology, Laboratory Agroecology and Ethnobiology, University of Padova, Padova, Italy
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Hehemann JH, Redecke L, Perbandt M, Saborowski R, Betzel C. Crystallization and preliminary X-ray diffraction studies of trypsin-like proteases from the gastric fluid of the marine crab Cancer pagurus. Acta Crystallogr Sect F Struct Biol Cryst Commun 2007; 63:242-5. [PMID: 17329824 PMCID: PMC2330177 DOI: 10.1107/s1744309107008524] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Accepted: 02/20/2007] [Indexed: 11/10/2022]
Abstract
The digestive fluid of the marine crab Cancer pagurus (Decapoda, Brachyura) contains highly stable proteases which display enhanced activity in aqueous mixtures of organic solvents. Three trypsins were isolated from the gastric fluid and two of them, C.p.TryII and C.p.TryIII, were purified to homogeneity by anion-exchange chromatography and crystallized by hanging-drop vapour diffusion. Diffraction data were collected at a synchrotron to 0.97 and 3.2 A resolution, respectively. The crystal of C.p.TryII belongs to the orthorhombic space group P2(1)2(1)2(1), with unit-cell parameters a = 52.06, b = 62.00, c = 71.66 A. Based on the Matthews coefficient, one protein molecule per asymmetric unit is suggested. In contrast, crystals of C.p.TryIII, which belong to the cubic space group P2(1)3 with unit-cell parameters a = b = c = 215.4 A, are assumed to contain 12 molecules per asymmetric unit.
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Affiliation(s)
- Jan-Hendrik Hehemann
- Institute of Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Lars Redecke
- Center of Experimental Medicine, Institute of Biochemistry and Molecular Biology I, University Hospital Hamburg-Eppendorf, c/o DESY, 22603 Hamburg, Germany
| | - Markus Perbandt
- Institute of Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
| | - Reinhard Saborowski
- Biologische Anstalt Helgoland, Alfred Wegener Institute for Polar and Marine Research, 27483 Helgoland, Germany
| | - Christian Betzel
- Institute of Biochemistry and Molecular Biology, University of Hamburg, 20146 Hamburg, Germany
- Correspondence e-mail:
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Brandi G, Biavati B, Calabrese C, Granata M, Nannetti A, Mattarelli P, Di Febo G, Saccoccio G, Biasco G. Urease-positive bacteria other than Helicobacter pylori in human gastric juice and mucosa. Am J Gastroenterol 2006; 101:1756-61. [PMID: 16780553 DOI: 10.1111/j.1572-0241.2006.00698.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND AIM Many bacteria carry the urease enzyme in different human ecosystems, but Helicobacter pylori is the only known bacterium showing urease activity in gastric ecosystems. For this reason, the rapid urease test (RUT) on gastric biopsies and urea breath test (C-UBT) are used to detect H. pylori infection. The aim of this study was to evaluate the presence of urease-positive bacteria other than H. pylori in gastric juice and mucosa in hypochlorhydric subjects. METHODS Twenty-five hypochlorhydric and 10 normochlorhydric patients were analyzed for the presence of H. pylori and bacterial overgrowth both in gastric juice and on the mucosa. During upper gastrointestinal endoscopy at 8.00 a.m. gastric juice samples and biopsy specimens were taken from the antrum and corpus. All samples were analyzed using standard microbiological procedures like aerobic/anaerobic growth, gram-staining, gas chromatography, API test, 96-clone method, and selective medium to search for specific bacteria. In addition, all strains isolated were screened for urease activity using the CP-test. Urease positive strains were tested for the capacity to survive in an acid environment with or without urea (10 mM/L), at pH 7, 4, 3, and 2, respectively, at different times (0, 20, 30, and 60 min). RESULTS Six hypochlorhydric patients had 10 strains of urease-positive non-H. pylori bacteria among which Staphylococcus capitis urealiticum showed the strongest urease activity. CONCLUSIONS Hypochlorhydric patients present many urease-positive bacteria other than H. pylori. The strong urease activity may be responsible for false positive results at RUT or UBT test in patients with suspected H. pylori infection.
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Affiliation(s)
- Giovanni Brandi
- Institute of Haematology and Medical Oncology (L. e A. Seragnoli), University of Bologna, Bologna, Italy
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Yamagata T, Morishita M, Kavimandan NJ, Nakamura K, Fukuoka Y, Takayama K, Peppas NA. Characterization of insulin protection properties of complexation hydrogels in gastric and intestinal enzyme fluids. J Control Release 2006; 112:343-9. [PMID: 16631271 DOI: 10.1016/j.jconrel.2006.03.005] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2005] [Revised: 03/06/2006] [Accepted: 03/10/2006] [Indexed: 11/21/2022]
Abstract
The objective of this study was to elucidate the mechanisms contributing to oral bioavailability of insulin by poly(methacrylic acid grafted with poly(ethylene glycol)) (P(MAA-g-EG)) hydrogels using the gastric and intestinal fluids from rats. P(MAA-g-EG) hydrogels successfully protected the incorporated insulin from enzymatic degradation by forming interpolymer complexes in the gastric fluid. The hydrogels also showed the insulin protection ability by itself. In the intestinal fluid, P(MAA-g-EG) hydrogels significantly decreased the insulin degradation rate and calcium ion levels, while protein levels was not changed. Insulin protecting effects were dependent on the fraction of the carboxylic group in the polymer networks. Moreover, the insulin degradation inhibitory effect was significantly correlated with Ca2+ deprivation ability of P(MAA-g-EG) hydrogels in the intestinal fluid, implying that the Ca2+ deprivation ability plays an important role in the inhibition of the intestinal enzyme activities. Insulin-loaded P(MAA-g-EG) (ILPs) hydrogels showed a rapid and almost complete insulin release even in the presence of intestinal proteases. These results suggested that the insulin protection ability of the hydrogels contributed to improve oral insulin absorption and that P(MAA-g-EG) hydrogels can be an excellent carrier for protecting insulin during their transit through the GI tract.
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Affiliation(s)
- Tetsuo Yamagata
- Department of Pharmaceutics, Hoshi University, Ebara 2-4-41, Shinagawa, Tokyo, 142-8501, Japan
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Li YH, Guo R, Yin QY, Ding M, Zhang SL, Xu GJ, Zhao FK. Purification and characterization of two endo-beta-1,4-glucanases from mollusca, Ampullaria crossean. Acta Biochim Biophys Sin (Shanghai) 2005; 37:702-8. [PMID: 16215638 DOI: 10.1111/j.1745-7270.2005.00099.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Two novel endo-beta-1,4-glucanases, EG45 and EG27, were isolated from the gastric juice of mollusca, Ampullaria crossean, by anion exchange, hydrophobic interaction, gel filtration and a second round of anion exchange chromatography. The purified proteins EG45 and EG27 appeared as a single band on sodium dodecylsulfate polyacrylamide gel electrophoresis with a molecular mass of 45 kDa and 27 kDa, respectively. The optimum pH for CMC activity was 5.5 for EG45 and 4.4-4.8 for EG27. The optimum temperature range for EG27 was broad, between 50 degrees and 60 degrees; for EG45 it was 50 degrees. The analysis on the stability of these two endo-beta-1,4-glucanases showed that EG27 was acceptably stable at pH 3.0-11.0 even when the incubation time was prolonged to 24 h at 30 degrees, whereas EG45 remained relatively stable at pH 5.0-8.0. About 85% of the activity of EG27 could be retained upon incubation at 60 degrees for 24 h. However, less than 10% residual activity of EG45 was detected at 50 degrees. Among different kinds of substrates, both enzymes showed a high preference for carboxymethyl cellulose. EG45, in particular, showed a carboxymethyl cellulose hydrolytic activity of 146.5 IU/mg protein. Both enzymes showed low activities to xylan (from oat spelt) and Sigmacell 101, and they were inactive to p-nitrophenyl-beta-D-cellobioside, salicin and starch.
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Affiliation(s)
- Yan-Hong Li
- Key Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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Shinchi H, Takao S, Maemura K, Fukukura Y, Noma H, Matsuo Y, Mataki Y, Mori S, Iino S, Ehi K, Aikou T. Value of magnetic resonance cholangiopancreatography with secretin stimulation in the evaluation of pancreatic exocrine function after pancreaticogastrostomy. ACTA ACUST UNITED AC 2005; 11:50-5. [PMID: 15754047 DOI: 10.1007/s00534-003-0868-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2003] [Accepted: 09/01/2003] [Indexed: 11/29/2022]
Abstract
BACKGROUND/PURPOSE The aim of this study was to assess the value of magnetic resonance cholangiopancreatography with secretin stimulation (secretin-MRCP) in evaluating the remnant pancreatic exocrine reserve after pancreaticogastrostomy with pancreaticoduodenectomy. METHODS Forty-three patients who had undergone pancreaticoduodenectomies and who were given pancreaticogastrostomies for reconstruction were studied. Dynamic MRCPs, using a half-Fourier acquisition single-shot turbo spin-echo (HASTE) sequence were obtained before and up to 10 min after secretin administration. The morphologic features and diameter of the main pancreatic duct were monitored and graded before and after secretin stimulation. The results were compared with those of endoscopic findings, secretin stimulation testing with a collection of pancreatic fluid, N-benzoyl- L-tyrosyl-p-aminobenzoic acid (BT-PABA) excretion testing, and fecal chymotrypsin concentration. RESULTS The results of secretin-MRCP were classified into three distinct groups: a good-secretion group (group 1; n=22; 51%), a moderate-secretion group (group 2; n=10; 23%), and a poor-secretion group (group 3; n=11; 26%). This MRCP classification correlated significantly with the concentrations of the pancreatic enzymes p-type amylase, lipase, and trypsin in the gastric juice. The BT-PABA test value was 59.8% in group 1, 46.1% in group 2, and 46.5% in group 3, and was significantly higher in group 1 than in groups 2 or 3. The fecal chymotrypsin concentration was 20.5 U/g in group 1, 14.5 U/g in group 2, and 0.7 U/g in group 3, and there was a significant correlation between the MRCP classification and fecal chymotrypsin concentration. CONCLUSIONS MRCP with secretin stimulation favorably reflected the presence of remnant pancreatic exocrine function. Therefore, secretin-MRCP is a feasible and effective follow-up examination method to evaluate remnant pancreatic exocrine function after pancreaticogastrostomy.
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Affiliation(s)
- Hiroyuki Shinchi
- First Department of Surgery, Kagoshima University School of Medicine, 8-35-1 Sakuragaoka, 890-8520, Kagoshima, Japan
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Lee K, Kye M, Jang JS, Lee OJ, Kim T, Lim D. Proteomic analysis revealed a strong association of a high level of alpha1-antitrypsin in gastric juice with gastric cancer. Proteomics 2005; 4:3343-52. [PMID: 15378737 DOI: 10.1002/pmic.200400960] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
To investigate the pathology of gastric disorders, we compared the proteomic patterns of gastric juice from patients with various gastric disorders. In healthy subjects pepsin A, pepsin B and gastric lipase were the major proteins detected by two-dimensional gel electrophoresis. These digestive enzymes were not detected in 60% of gastric cancer cases (18 out of 30 analyzed cases). Interestingly, an extraordinary amount of alpha(1)-antitrypsin was observed in these cases. In contrast to gastric cancer cases, alpha(1)-antitrypsin was detected in only 5% of patients (three out of 56) with chronic atrophic gastritis, and the detection frequency went up as the disease developed (one of four intestinal metaplasia cases, two of seven tubular adenoma cases, a single examined case of hyperplastic polyp and 60% of gastric cancer). Zymography showed that a 60 kDa protease strongly associated with alpha(1)-antitrypsin and mass spectrometric analysis revealed that the gastric alpha(1)-antitrypsin was a protease-cleaved form. Our data suggest that alpha(1)-antitrypsin and 60 kDa protease may serve as good diagnostic and prognostic markers for conditions associated with gastric cancer.
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Affiliation(s)
- Kyunghee Lee
- Graduate School of Applied Life Science and Division of Life Science, College of Natural Sciences, Gyeongsang National University, Chinju, Korea
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Abstract
The human fetus and neonate swallow biologically significant quantities of IL-8/CXC ligand 8 (CXCL8) in amniotic fluid and breast milk, and this remains measurable through simulated neonatal gastric and proximal intestinal digestions. We sought to confirm the structural and functional integrity of IL-8/CXCL8 in digestates and determine the mechanisms underlying this protease resistance. We observed that in comparison with BSA, IL-8/CXCL8 is highly resistant to pepsin and can be detected intact in assays for structural, immunologic, and functional integrity. In a computational molecular docking simulation, IL-8/CXCL8 was observed to fit poorly in the pepsin active site. On the basis of simulated mutation analyses, we hypothesized that this protease resistance is due to disulfide bond-related tertiary folding in IL-8/CXCL8. This was confirmed on chemical reduction of these groups.
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Affiliation(s)
- Akhil Maheshwari
- Division of Neonatology, Deparment of Pediatrics, University of South Florida College of Medicine and All Children's Hospital, St. Petersburg, FL 33701, USA.
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Gridneva VI. [The self-regulation elements in the stomach secretor response to perturbing effects]. Ross Fiziol Zh Im I M Sechenova 2004; 90:1417-25. [PMID: 15646210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
By the levels of stomach juice volume, its proteolytic activity, hydrogen ion activity, secreted mucus volume, the experimental dogs with stomach fistula were divided into two groups: with low and with high levels of secretion. The perturbing effects involved immobilization stress, mineral water, prolin-containing peptide Gly-Pro. One of the self-regulation mechanisms involved an "initial background rule": if the initial level of the secretion parameters is low, then it grows following the effect, whereas if it is high--it becomes lower. The rule was most evident in the stomach juice secretion complex-reflex phase.
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Kopper RA, Odum NJ, Sen M, Helm RM, Steve Stanley J, Wesley Burks A. Peanut protein allergens: Gastric digestion is carried out exclusively by pepsin☆. J Allergy Clin Immunol 2004; 114:614-8. [PMID: 15356566 DOI: 10.1016/j.jaci.2004.05.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND A major characteristic of many food allergens, including Ara h 1, a major peanut allergen, is their resistance to gastric digestion. One estimate of the allergenic potential of a possible protein allergen is its stability under simulated gastric conditions. OBJECTIVE Because the rate and extent of digestion of allergenic proteins will affect the severity of any subsequent allergic response, it is important to correlate protein allergen digestion in simulated gastric fluid with that in actual gastric fluid. METHODS A major peanut allergen, Ara h 1, was digested in vitro by using both pepsin and porcine gastric fluid. Several comparisons between the 2 sets of proteolytic conditions were assessed including pH optima and the effect of temperature, denaturants, and specific enzyme inhibitors. RESULTS In vitro digestion of Ara h 1 with pepsin and porcine gastric fluid resulted in virtually identical hydrolysis patterns as observed on SDS-PAGE. The protease activity of both pepsin and gastric fluid were inhibited at high pH and in the presence of pepstatin. However, both remained active in 4 mol/L urea and at 60 degrees C. CONCLUSIONS Protein digestion in the porcine stomach is carried out by pepsin. In vivo gastric digestion is modeled accurately by peptic hydrolysis. Digestion conditions in vivo are comparable to experimental conditions in vitro provided that the acidic nature of the stomach contents is optimal for characterization of the allergen under standard pepsin digestion conditions. Additional experimentation using crude food extracts, both in the presence and absence of a complete meal, is needed to elucidate the complete physiologic nature of food allergen digestion.
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Garrett JB, Kretz KA, O'Donoghue E, Kerovuo J, Kim W, Barton NR, Hazlewood GP, Short JM, Robertson DE, Gray KA. Enhancing the thermal tolerance and gastric performance of a microbial phytase for use as a phosphate-mobilizing monogastric-feed supplement. Appl Environ Microbiol 2004; 70:3041-6. [PMID: 15128565 PMCID: PMC404394 DOI: 10.1128/aem.70.5.3041-3046.2004] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2003] [Accepted: 01/17/2004] [Indexed: 11/20/2022] Open
Abstract
The inclusion of phytase in monogastric animal feed has the benefit of hydrolyzing indigestible plant phytate (myo-inositol 1,2,3,4,5,6-hexakis dihydrogen phosphate) to provide poultry and swine with dietary phosphorus. An ideal phytase supplement should have a high temperature tolerance, allowing it to survive the feed pelleting process, a high specific activity at low pHs, and adequate gastric performance. For this study, the performance of a bacterial phytase was optimized by the use of gene site saturation mutagenesis technology. Beginning with the appA gene from Escherichia coli, a library of clones incorporating all 19 possible amino acid changes and 32 possible codon variations in 431 residues of the sequence was generated and screened for mutants exhibiting improved thermal tolerance. Fourteen single site variants were discovered that retained as much as 10 times the residual activity of the wild-type enzyme after a heated incubation regimen. The addition of eight individual mutations into a single construct (Phy9X) resulted in a protein of maximal fitness, i.e., a highly active phytase with no loss of activity after heating at 62 degrees C for 1 h and 27% of its initial activity after 10 min at 85 degrees C, which was a significant improvement over the appA parental phytase. Phy9X also showed a 3.5-fold enhancement in gastric stability.
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Bah A, van Frankenhuyzen K, Brousseau R, Masson L. The Bacillus thuringiensis Cry1Aa toxin: effects of trypsin and chymotrypsin site mutations on toxicity and stability. J Invertebr Pathol 2004; 85:120-7. [PMID: 15050842 DOI: 10.1016/j.jip.2004.02.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2003] [Accepted: 02/02/2004] [Indexed: 11/20/2022]
Abstract
The objective of the present work was to create an active Cry1Aa toxin showing enhanced resistance to degradation by spruce budworm (Choristoneura fumiferana) midgut proteases by mutating potential chymotrypsin and trypsin sites. Fourteen Cry1Aa mutants were created in an Escherichia coli-Bacillus shuttle vector and expressed in a crystal minus Bacillus thuringiensis host. Using spruce budworm gut juice, commercial bovine trypsin and chymotrypsin we performed protease resistance assays with Cry1Aa wild type and mutant toxins. Although many mutants showed little or no change, several mutants showed a > 2-fold increase (R543S, R566G, and F570S) up to a > 4-fold increase in toxicity (F576S), in bioassay studies against C. fumiferana. The in vitro protease resistance assay results indicated a possible involvement of other gut juice components in toxin overdigestion.
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Affiliation(s)
- Aliou Bah
- Biotechnology Research Institute, National Research, Council, Montreal, Que., Canada H4P 2R2
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Abstract
A cellulose hydrolytic enzyme was isolated from the stomach juice of Ampullaria crossean, a kind of herbivorous mollusca. The enzyme was purified 45.3-fold to homogenety by ammonium sulfate precipitation, DEAE-Sephadex A-50 column, Bio-gel P-100 gel filtration column, and phenyl-Sepharose CL-4B column chromatography. The enzyme was designated as cellulase EGX. The purified enzyme is a multi-functional enzyme with the activities of exo-beta-1,4-glucanase (14.84 U/mg for p-nitrophenyl beta-D-cellobioside), endo-beta-1,4-glucanase (40.3 U/mg for carboxymethyl cellulose), and endo-beta-1,4-xylanase (196 U/mg for soluble xylan from birchwood). The monovalent anions such as F(-), Cl(-), Br(-), I(-), and NO(3)(-) are essential for its exo-beta-1,4-glucanase activity but have no effect on the activity for xylan, while I(-) higher than 5mM would inhibit the exo-beta-1,4-glucanase activity. The monovalent anions Cl(-) and Br(-) activate its endo-beta-1,4-glucanase activity. Binding of Cl(-) enhances the thermostability of EGX, but does not affect its fluorescence emission spectrum. The molecular mass of EGX is 41.5 kDa, as determined by SDS-PAGE. The pI value is about pH 7.35. The xylan hydrolytic activity of EGX reaches to the maximum between pH 4.8 and 6.0 and the pNPC hydrolytic activity reaches the maximum between pH 4.8 and 5.6, while that for CMC hydrolytic activity is between pH 4.4 and 4.8. Preliminary results showed that the enzyme was secreted by the mollusca itself.
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Affiliation(s)
- Ji Wang
- Key Laboratory of Proteomics, Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, 320 Yue-Yang Road, 200031, Shanghai, China
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Abstract
An intramolecularly quenched fluorogenic peptide containing o-aminobenzoyl (Abz) and ethylenediamine 2,4-dinitrophenyl (Eddnp) groups at amino- and carboxyl-terminal amino acid residues, Abz-Lys-Pro-Ile-Glu-Phe-Phe-Arg-Leu-Eddnp, was hydrolyzed by purified human pepsin, gastricsin, and gastric juice uniquely at the Phe-Phe bond. Kinetic parameters determined for purified pepsin were K(m)=0.68+/-0.11 microM; k(cat)=6.3+/-0.16s(-1); k(cat)/K(m)=9.26s(-1) microM(-1); Gastricsin showed K(m)=2.69+/-0.18 microM; k(cat)=0.03+/-0.005s(-1); k(cat)/K(m)=0.011s(-1) microM(-1). Gastric juice (21 samples) from subjects without gastric disorders at endoscopy examination showed activities varying from 0.0008 to 9.72 micromolml(-1)min(-1). Pepstatin A inhibition of gastric juice enzymatic activity was complete at 3.4x10(-5)M (final concentration) inhibitor. In the proposed method the presence of a unique scissile bond in the synthetic substrate provides a direct ratio between enzymatic activity and amount of substrate hydrolyzed, and a unique step reaction facilitates the use of this assay for the determination of the activity of aspartic proteinases in biological fluids and during enzyme purification procedures.
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Abstract
BACKGROUND/AIMS The aim of this study was to exactly determine the pH stability of human gastric lipase (HGL) and to investigate the mechanism underlying the inactivation of HGL which occurs in gastric juice. METHODS Samples of human gastric juice and purified HGL were incubated at various pH values ranging from 0.5 to 8.0, and the residual HGL activity was measured as a function of time using the pHstat technique. Samples of purified HGL were also incubated in the presence of human pepsin. Electrophoresis and Western blot analysis were performed on all the samples in which HGL was inactivated. RESULTS HGL was found to be stable in gastric juice at pH values ranging from 2.0 to 7.0, especially between pH 3.0 and 5.0 (half-inactivation time >24 h). HGL activity decreased rapidly below pH 2.0 and above pH 7.0. The inactivation half times were only 43 +/- 9 and 24 +/- 18 min at pH 1 and pH 8, respectively. The pH stability of purified HGL was much lower than that of HGL in gastric juice. Acid or alkaline inactivation of HGL could occur without any prior proteolytic degradation, and this inactivation was irreversible. However, proteolytic degradation of HGL by pepsin also occurred at very low pH values, probably because the acid-denatured HGL is more sensitive to proteolytic cleavage by pepsin. An ex vivo study of HGL activity in several gastric juice samples showed that the HGL activity decreased with the pH of the sample, in both basal and pentagastrin-stimulated gastric juice. CONCLUSION Although HGL is not as stable as it was previously thought to be under acidic conditions, it is nevertheless the most stable acid lipase and constitutes a good candidate tool for enzyme substitution therapy.
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Affiliation(s)
- Eric Ville
- La Timone Hospital, Gastroenterology Department, Marseille, France
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Carrière F, Renou C, Ville E, Grandval P, Laugier R. Advantage of expressing the variations in some digestive parameters as a function of gastric emptying instead of time. Digestion 2003; 64:46-53. [PMID: 11549836 DOI: 10.1159/000048838] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND/AIM Gastric emptying is a major cause of variability when studying gastrointestinal parameters as a function of time. Here, we investigate whether the parametric variability could be reduced by running experiments on a gastric emptying basis rather than on a time basis. METHODS Healthy volunteers were intubated with gastric and duodenal tubes and were given a liquid meal containing polyethylene glycol to monitor gastric emptying. Gastric pH and human gastric lipase (HGL) concentrations were measured. Their variations were plotted as a function of either time or gastric emptying (%). In both cases, mean curves of variation were established by polynomial regression. RESULTS When time was the variable used, the overall deviation of the experimental values from the values given by the best-fitting curve was high (chi2 = 33 for gastric pH; chi2 = 1,744 for HGL), and the individual deviations increased with time. When gastric emptying was the variable used, the overall deviation of the experimental values from the values given by the best-fitting curve was much lower (chi2 = 10 for gastric pH; chi2 = 642 for HGL). CONCLUSIONS Expressing gastric pH or HGL concentration as a function of gastric emptying instead of time makes it possible to reduce the individual variability. This new type of data analysis may be of a general interest to observe specific variations of gastrointestinal parameters induced by drugs, hormones, and meals, and that might be masked by the large intrinsic variability induced by gastric emptying.
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Affiliation(s)
- F Carrière
- Laboratoire de Lipolyse Enzymatique du CNRS, Institut de Biologie Structurale et Microbiologie, Marseille, France.
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32
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Babich IA, Kubyshkin AV, Semenets PF, Kravchenko NG. [Changes in the local proteinase-inhibitor system in children with chronic erosive gastritis]. Lik Sprava 2002:69-72. [PMID: 11944386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
In 26 children presenting with chronic erosive gastritis, an unspecific proteinase-inhibitor potential was identified in the basal portion of the gastric juice in the period of exacerbation and incomplete remission. Revealed in the gastric content in the period of exacerbation was augmentation of the activity of elastase- and tripsinlike proteinases. In the period of remission, the indices have been shown to be lower but insignificantly, remaining significantly higher compared to those indices in the control group. There was a decrease in the antiproteinase potential in the period of exacerbation getting even more lowered during the period of incomplete remission. The findings secured suggest to us a manifest imbalance in the local proteinase-inhibitor system. A conclusion has been reached that exhaustion of the local inhibitor potential and ensuing high activity of unspecific proteinases result in destructive changes in the gastric mucosa, thus, having pathogenetic significance in the development of chronic inflammatory-and-destructive diseases.
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Abstract
Gastric juice contains both pancreatic group I phospholipase A2 (PLA2-I) and synovial-type group II phospholipase A2 (PLA2-II), which may play a crucial role in Helicobacter pylori infection and gastric mucosal injury. PLA2-I present in gastric juice is derived from pancreatic acinar cells. The cellular source of PLA2-II found in gastric juice is unknown. A specific cell type of the intestinal mucosa, the Paneth cell, is known to secrete PLA2-II. The purpose of the present study was to define the source of PLA2-II present in gastric juice. For this purpose, gastric juice was collected from 29 individuals during gastroscopy, and mucosal biopsies were taken from the antrum and body of the stomach and from the duodenum as well as from the jejunum of individuals with resected stomach, for immunohistochemical detection of PLA2-II. The concentration of bilirubin in the gastric juice samples was determined to identify duodenogastric regurgitation. The PLA2-II content was significantly higher in bilirubin-positive than in bilirubin-negative gastric juice samples. PLA2-II was localized by immunohistochemistry in Paneth cells in three patients with areas of intestinal metaplasia of the gastric mucosa and in Paneth cells of duodenal and jejunal mucosa in all patients, but not in any other epithelial cell type of the mucosa of the stomach or the small intestine. Inflammatory cells did not contain PLA2-II. The current results suggest that PLA2-II found in gastric juice is derived from the Paneth cells of the small intestinal mucosa.
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Affiliation(s)
- H T Huhtinen
- Department of Surgery, University of Turku, Finland.
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34
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Sternby B, Hartmann D, Borgström B, Nilsson A. Degree of in vivo inhibition of human gastric and pancreatic lipases by Orlistat (Tetrahydrolipstatin, THL) in the stomach and small intestine. Clin Nutr 2002; 21:395-402. [PMID: 12381337 DOI: 10.1054/clnu.2002.0565] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND AND AIMS Orlistat, a lipase inhibitor, strongly inhibits the activities of all gastric/pancreatic lipases except pancreatic phospholipase A(2)in vitro. In clinical use, for obesity treatment, it induces a variable degree of weight loss and steatorrhoéa. The aim of this study was to examine the degree of in vivo inhibition of individual gastric/pancreatic lipases by Orlistat in man, when given as a capsule or mixed into a test meal in the form of an optimal substrate for the lipases. METHODS Twelve male volunteers were intubated twice with a triple lumen nasal-gastric-duodenal tube and were given a balanced test meal with or without 60 mg Orlistat. Three conditions were compared: (a) Orlistat given as a capsule with the meal, (b) Orlistat mixed into the test meal before ingestion, and (c) test meal without Orlistat. Samples were collected at six 30 min intervals, from stomach, mid-duodenum, and ligament of TreitY. Activities and immune-reactive masses of gastric lipase, pancreatic lipase, carboxyl ester lipase, colipase, and mass of non-polar lipid classes were determined. RESULTS In vivo effects on the enzyme activities were more pronounced when Orlistat was mixed with the meal than when given as a capsule (7%, 10%, 1% vs 49%, 54%, 34% of normal activity), respectively. Despite efficient inhibition of the lipases, an extensive hydrolysis of the emulsified lipids of the test meal occurred. Orlistat did not affect the immune-reactive amounts of lipases. CONCLUSIONS Orlistat causes a pronounced in vivo inhibition of gastric and pancreatic lipases in humans. The mixing with the substrate and the fact that little residual lipase activity is necessary to hydrolyse optimally emulsified lipids are likely to be limiting factors for the effect of the drug in clinical practice.
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Affiliation(s)
- Berit Sternby
- Department of Medicine, University of Lund, Lund, Sweden
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35
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Pafumi Y, Lairon D, de la Porte PL, Juhel C, Storch J, Hamosh M, Armand M. Mechanisms of inhibition of triacylglycerol hydrolysis by human gastric lipase. J Biol Chem 2002; 277:28070-9. [PMID: 11940604 DOI: 10.1074/jbc.m202839200] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the human stomach, gastric lipase hydrolyzes only 10 to 30% of ingested triacylglycerols because of an inhibition process induced by the long chain free fatty acids generated, which are mostly protonated at gastric pH. The aim of this work was to elucidate the mechanisms by which free fatty acids inhibit further hydrolysis. In vitro experiments examined gastric lipolysis of differently sized phospholipid-triolein emulsions by human gastric juice or purified human gastric lipase, under close to physiological conditions. The lipolysis process was further investigated by scanning electron microscopy, and gastric lipase and free fatty acid movement during lipolysis were followed by fluorescence microscopy. The results demonstrate that: 1) free fatty acids generated during lipolysis partition between the surface and core of lipid droplets with a molar phase distribution coefficient of 7.4 at pH 5.40; 2) the long chain free fatty acids have an inhibitory effect only when generated during lipolysis; 3) inhibition of gastric lipolysis can be delayed by the use of lipid emulsions composed of small-size lipid droplets; 4) the release of free fatty acids during lipolysis induces a marked increase in droplet surface area, leading to the formation of novel particles at the lipid droplet surface; and 5) the gastric lipase is trapped in these free fatty acid-rich particles during their formation. In conclusion, we propose a model in which the sequential physicochemical events occurring during gastric lipolysis lead to the inhibition of further triacylglycerol lipolysis.
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Affiliation(s)
- Yan Pafumi
- Unité 476-INSERM (National Institute of Health and Medical Research)/Université de la Méditerranée, 18 avenue Mozart, 13009 Marseille, France
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36
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Nijevitch AA, Shcherbakov PL. Quantitative assessment of gastric juice urease activity in children infected with Helicobacter pylori. Am J Gastroenterol 2002; 97:1845-6. [PMID: 12135053 DOI: 10.1111/j.1572-0241.2002.05866.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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37
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Metheny NA, Chang YH, Ye JS, Edwards SJ, Defer J, Dahms TE, Stewart BJ, Stone KS, Clouse RE. Pepsin as a marker for pulmonary aspiration. Am J Crit Care 2002; 11:150-4. [PMID: 11888127 PMCID: PMC2408999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
BACKGROUND Although assessment for aspiration of small volumes of gastric contents in tube-fed patients receiving mechanical ventilation is important, available methods for this purpose are not wholly satisfactory. A potential method is immunoassay of tracheal secretions for the gastric enzyme pepsin. OBJECTIVES To determine the frequency with which pepsin in suctioned tracheal secretions from acutely ill, tube-fed patients receiving mechanical ventilation could be detected via an immunoassay. METHODS A convenience sample of 136 specimens of suctioned tracheal secretions was collected from 30 acutely ill, tube-fed adults receiving mechanical ventilation. Multiple samples were obtained from 26 of the 30 patients (range, 2-11 per subject). An immunoassay with rooster polyclonal antibodies to purified human pepsin was used to detect pepsin in the secretions. RESULTS Fourteen specimens tested positive for pepsin. Secretions from 5 patients accounted for the 14 pepsin-positive results. A significant relationship was found between the position of the head of the bed and the presence of pepsin in tracheal secretions (P<.001). Of the 14 pepsin-positive specimens, 13 (92.9%) were obtained from subjects in a flat position. CONCLUSIONS A pepsin immunoassay can be used to detect pepsin in human tracheal secretions. If pepsin in tracheal secretions is considered an indicator of aspiration of gastric contents, aspiration occurred in 5 of the 30 subjects. A flat position is strongly associated with the presence of pepsin in tracheal secretions.
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38
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Carrière F, Renou C, Lopez V, De Caro J, Ferrato F, Lengsfeld H, De Caro A, Laugier R, Verger R. The specific activities of human digestive lipases measured from the in vivo and in vitro lipolysis of test meals. Gastroenterology 2000; 119:949-60. [PMID: 11040182 DOI: 10.1053/gast.2000.18140] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS The lipolytic potential of digestive lipases in vivo has always been deduced so far from their in vitro activities under nonphysiologic conditions. In the present study, the specific activities of human gastric lipase (HGL) and pancreatic lipase (HPL) were measured on dietary triglycerides (TGs) during test meal lipolysis. METHODS Healthy human volunteers ingested a liquid or solid meal. The specific activities of HGL and HPL were estimated from the lipase and free fatty acid (FFA) outputs at the postpyloric and duodenal levels, respectively. Based on the in vivo data, lipolysis was also performed in vitro by mixing the meal either with gastric juice and subsequently with pancreatic juice and bile or with purified HGL and HPL. FFAs were measured by thin-layer chromatography, and the specific activities of HGL and HPL were expressed as micromoles of FFA per minute per milligram of lipase. RESULTS In vitro, the specific activities on the liquid meal TGs were 32 (gastric juice) and 34 (pure lipase) micromol x min(-1) x mg(-1) with HGL and 47 (pancreatic juice) and 43 (pure lipase) micromol x min(-1). mg(-1) with HPL. The specific activities on the solid meal TGs were 33 (gastric juice) and 32 (pure lipase) micromol x min(-1) x mg(-1) with HGL and 12 (pancreatic juice) and 15 (pure lipase) micromol x min(-1) x mg(-1) with HPL. The in vivo values obtained were in the same range. The secretory lipase outputs were 21.6+/-14.5 mg HGL and 253.5+/-95.5 mg HPL with the liquid test meal and 15.2+/-5.1 mg HGL and 202.9+/-96.1 mg HPL with the solid test meal. CONCLUSIONS The specific activities of HGL and HPL on meal TGs were much lower than those measured in vitro under optimized assay conditions (1300-8000). However, these low specific activities are enough for the meal TGs to be completely lipolysed, given the amounts of HGL and HPL secreted during a meal.
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Affiliation(s)
- F Carrière
- Laboratoire de Lipolyse Enzymatique du Centre National de la Recherche Scientifique, Marseille, France.
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Zárate G, Chaia AP, González S, Oliver G. Viability and beta-galactosidase activity of dairy propionibacteria subjected to digestion by artificial gastric and intestinal fluids. J Food Prot 2000; 63:1214-21. [PMID: 10983795 DOI: 10.4315/0362-028x-63.9.1214] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
An important criterion to consider in the selection of strains for dietary adjuncts is the ability of the microorganisms to survive the severe conditions of acidity and bile concentrations usually found in the gastrointestinal tract. In the present work, we report the effects of digestions by artificial gastric and intestinal fluids on beta-galactosidase activity and survival of four strains of dairy propionibacteria previously selected by their bile tolerance and beta-galactosidase activity. The strains were exposed to artificial gastric juice at pH values between 2 and 7 and then subjected to artificial intestinal digestion. Both viability and beta-galactosidase activity were seriously affected at pH 2. Skim milk and Emmental cheese juice exerted a protective effect on the parameters tested. The trypsin present in the intestinal fluid inactivated the enzyme beta-galactosidase in strains of Propionibacterium freudenreichii but not in Propionibacterium acidipropionici. Moreover, the presence of bile salts enhanced the beta-galactosidase activity of these strains by permeabilization of the cells during the first hour of exposure. The intestinal transit rate confirmed the permanence of the bacteria in the intestine for long enough to be permeabilized. These results suggest that P. acidipropionici would be a good source of beta-galactosidase activity in the intestine. We also propose a practical and effective in vitro method as a tool of screening and selection of potential probiotic bacteria.
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Affiliation(s)
- G Zárate
- Centro de Referencias para Lactobacilos (CERELA), San Miguel de Tucumán, Argentina
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40
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Shepoval'nikov NP. [Discovery of enterokinase (1899-1999)]. Ross Fiziol Zh Im I M Sechenova 1999; 85:328-36. [PMID: 10389192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
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41
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Huhtinen HT, Grönroos JM, Haapamäki MM, Nevalainen TJ. Phospholipases A2 in gastric juice of Helicobacter pylori--positive and negative individuals. Clin Chem Lab Med 1999; 37:61-4. [PMID: 10094380 DOI: 10.1515/cclm.1999.009] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Gastric juice is known to have phospholipase A2 catalytic activity. Helicobacter pylori (H. pylori) has been reported to produce phospholipase A2, which is believed to hydrolyse the protective layer of gastric mucosal phospholipids and to promote mucosal damage. The current study aimed at identifying secretory phospholipase A2 subtypes (pancreatic group I phospholipase A2 and synovial-type group II phospholipase A2) in gastric juice and their relation to the presence of H. pylori in gastric mucosal biopsies in the same individuals. Gastric juice was collected from 29 individuals during gastroscopy. Biopsies were taken from the antrum and body of the stomach to determine the H. pylori status. We found catalytically active phospholipase A2 and both group I and group II phospholipases A2 in the gastric juice samples. The catalytic activity and the mass concentrations of group I and group II phospholipases A2 correlated significantly with the pH value in gastric juice. The gastric juice of H. pylori positive individuals did not contain higher amounts of phospholipases A2 than the juice of H. pylori negative individuals. Rather, the mass concentration of group II phospholipase A2 in gastric juice seemed to be somewhat lower in individuals with H. pylori infection than in uninfected individuals. The results of the current study show that both group I and group II phospholipases A2 are present in gastric juice. The main sources of phospholipases A2 in gastric juice are probably other than H. pylori.
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Affiliation(s)
- H T Huhtinen
- Department of Surgery, University of Turku, Finland
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Abstract
BACKGROUND Gastric lipase secretion is stimulated by gastrin in plasma, but its regulation by secretin is unknown. METHODS In 7 normal persons we investigated the effect of exogenous secretin on the output of gastric lipase stimulated by intravenous gastrin-17. The gastric content was measured using a nasogastric tube for aspiration. The quantitative lipase secretion was measured by an enzyme-linked immunosorbant assay (ELISA) and the lipolytic activity by a kinetic assay. Plasma concentrations of secretin and gastrin were measured by radioimmunoassay. RESULTS Gastric lipase secretion (the quantity as well as the lipolytic activity) was significantly stimulated by gastrin. In response to secretin infusion, the lipolytic activity increased as acid secretion decreased. CONCLUSION Secretin in postprandial concentrations does not influence the quantitative gastric lipase secretion stimulated by gastrin, but it increases lipolytic activity due to inhibition of acid secretion.
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Affiliation(s)
- O Olsen
- Department of Surgery D, Glostrup Hospital, University of Copenhagen, Sweden
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43
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Berstad AE, Berstad K, Berstad A. [Physiopathology of Helicobacter pylori infection]. Tidsskr Nor Laegeforen 1998; 118:2790-3. [PMID: 9748810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The gastric juice of Helicobacter pylori-infected individuals contains substantially higher levels of phospholipase A2 (PLA2) than that of individuals who are not infected. We present a new theory for how this H. pylori-induced PLA2 activity in gastric juice may play a major role in the development of peptic ulcer disease. When activated at neutral pH (pH 6.5-7.0), PLA2 may damage the surfactant-like, phospholipid-rich layer which constitutes an important part of the mucus barrier. Pepsin and other proteases, activated at low pH (pH 1.0-3.5), may then denature and cleave PLA2-exposed proteins. Peptic ulcers therefore tend to develop in regions exposed to changing luminal pH, such as the duodenal bulb when acid production is high or normal, or in the stomach when acid secretion is low.
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Affiliation(s)
- A E Berstad
- Laboratorium for immunhistokjemi og immunpatologi, Institutt for patologi, Universitetet i Oslo Rikshospitalet
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44
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Marino Alarcón O, Concho Lugo H, Silva Larralte T, Tauil Bsereni E, Solano Nava P, Machado D, Chacón Patiño A. [Enzymes in gastric juice. An aid in the diagnosis of gastric cancer]. Acta Cient Venez 1998; 47:172-7. [PMID: 9433822] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In the present study we measured the activities of the following enzymes: LDH (lactic dehydrogenase), beta-glucuronidase, acid maltase, phosphohexoseisomerase (PHI) and acid proteases in the gastric juice of patients with gastric cancer (n = 50) (Case Group), in endoscopically normal subjects (n = 50) and in subjects with different non tumor-like digestive pathologies (n = 55) (Control Groups). In the patients with gastric carcinoma we found a significant increase in LDH, beta-glucuronidase, PHI and acid maltase activities and a decreased activity of acid proteases. The results agree with previous findings from other workers. The variations of enzyme activities in gastric juice can help to differentiate between malignant and benign processes of the gastric mucosa.
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Affiliation(s)
- O Marino Alarcón
- Laboratorio de Bioquímica Nutricional, Escuela de Nutrición y Dietética, Mérida, Venezuela
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45
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Affiliation(s)
- M Aoubala
- Laboratorie de Lipolyse Enzymatique, UPR 9025, IFRC1 du CNRS, Marseille, France
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46
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Metheny NA, Stewart BJ, Smith L, Yan H, Diebold M, Clouse RE. pH and concentrations of pepsin and trypsin in feeding tube aspirates as predictors of tube placement. JPEN J Parenter Enteral Nutr 1997; 21:279-85. [PMID: 9323690 DOI: 10.1177/0148607197021005279] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND The purpose of this study was to determine the extent to which pepsin and trypsin concentrations in feeding tube aspirates, in addition to pH, contribute to predicting feeding tube position. METHODS Aspirates from 742 feeding tubes (nasogastric, n = 343; nasointestinal, n = 399) were tested for pH and enzyme concentrations. Also tested were aspirates from two feeding tubes inadvertently positioned into the lung (one in the pleural space and one in the tracheobronchial tree) and 146 samples of tracheobronchial and pleural fluids collected by other methods. Enzyme assays were conducted in a research laboratory. Results of the pH and enzyme tests were compared with radiologic reports of tube location. RESULTS Gastric fluid had a mean low pH (4.06), a high mean pepsin concentration (349.1 micrograms/mL), and a low mean trypsin concentration (19.3 micrograms/mL). In contrast, intestinal fluid had a mean high pH (7.40), a high mean trypsin concentration (143.0 micrograms/mL), and a low mean pepsin concentration (24.2 micrograms/mL). Respiratory samples also had a high mean pH (7.89) but contained little or no pepsin or trypsin. Using a logistic regression equation with all three variables to differentiate between respiratory and gastrointestinal placement, it was possible to correctly classify 100% of the respiratory cases and 93.4% of the gastrointestinal cases. Another equation used to differentiate between gastric and intestinal sites was able to classify correctly 91.2% of the gastric cases and 91.5% of the intestinal cases. CONCLUSIONS The results clearly indicate that laboratory-determined enzyme concentrations in feeding tube aspirates are helpful in predicting tube location. Thus, it is desirable that inexpensive, simple bedside tests be developed so that they can be used in conjunction with pH measurements to help predict tube position.
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Affiliation(s)
- N A Metheny
- Saint Louis University, Missouri 63104-1099, USA
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47
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Asante M, Ahmed H, Patel P, Davis T, Finlayson C, Mendall M, Northfield T. Gastric mucosal hydrophobicity in duodenal ulceration: role of Helicobacter pylori infection density and mucus lipids. Gastroenterology 1997; 113:449-54. [PMID: 9247463 DOI: 10.1053/gast.1997.v113.pm9247463] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
BACKGROUND & AIMS Gastric mucosal hydrophobicity is reduced in Helicobacter pylori infection. Infection density is increased in duodenal ulcer (DU) compared with H. pylori gastritis alone, but it is unknown whether there is a corresponding difference in hydrophobicity or whether hydrophobicity is related to infection density or to mucus lipids. The aim of this study was to determine the relationship between H. pylori infection density and mucosal hydrophobicity, and between mucus lipids and hydrophobicity, and to compare results in patients with H. pylori-induced gastritis with and without DU. METHODS Fifty-four patients, including 29 H. pylori-positive (15 with DU and 14 with gastritis alone) and 25 H. pylori-negative controls, were studied. Hydrophobicity was determined by goniometry and infection density by histology. Mucus lipids were determined by colorimetry and phospholipase A2 activity by radioenzymatic assay. RESULTS Hydrophobicity was reduced in DU compared with gastritis alone (39 degrees vs. 48 degrees; P < 0.05) and with healthy controls (39 degrees vs. 60 degrees; P < 0.0001). Hydrophobicity correlated with infection density (Rs = -0.55; P < 0.01). Mucus triglyceride level was modestly increased with infection, but mucus phospholipids or lipolysis were unrelated to H. pylori and hydrophobicity. CONCLUSIONS Mucosal hydrophobicity is reduced in H. pylori-positive patients with DU compared with those having gastritic only. Hydrophobicity correlates with infection density but not with mucus lipid levels.
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Affiliation(s)
- M Asante
- Department of Medicine, St. George's Hospital Medical School, London, England
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48
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Abstract
The rat stress model of restraint and cold water immersion was used to investigate the effect of stimulating the paraventricular nucleus (PVN) of hypothalamus on the development of stress-induced gastric ulceration. The results were (1) electric stimulation of the PVN increased the stress ulceration, while electrolytic lesion of the PVN decreased it; (2) intracerebroventricular injection (i.c.v.) of acetylcholine (Ach) enhanced the effect of PVN stimulation on stress ulcers, and the M-receptor was involved; (3) i.c.v. norepinephrine (NE) attenuated the effect of PVN stimulation on stress ulcers in a dose-dependent manner, and the beta-receptor was involved; (4) i.c.v. 5-hydroxytryptamine (5-HT) enhanced the effect of PVN stimulation on stress ulcers; (5) electrolytic lesions of dorsal raphe nucleus (DR) attenuated the effect of PVN stimulation on stress ulcers, while electrolytic lesions of the locus ceruleus (LC) aggravated the effect; (6) thyroidectomy, adrenalectomy, ovariectomy, vagotomy and sympathectomy all attenuated the effect of PVN stimulation on stress ulcers; (7) electric stimulation of the PVN produced no effect on gastric juice volume, acidity, total acid output, pepsin activity or the gastric barrier mucus; but greatly reduced gastric mucosal blood flow. These results indicate that the PVN is an important brain site regulating the development of stress-induced gastric ulcers, that the classical neurotransmitters Ach, NE and 5-HT are involved, and that in the periphery, both the parasympathetic and sympathetic nervous systems and the three endocrine glands (thyroid, adrenal and gonad) take part in the effect.
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Affiliation(s)
- J F Zhang
- Department of Physiology, Xuzhou Medical College, Jiangsu, Peoples Republic of China
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49
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Abstract
Previously our laboratory reported increased activity of the thiol proteinase cathepsin B in gastric juice after ethanol-induced mucosal injury. In this study we measured proteinase activity (PA) and proteinase inhibitory activity (PIA) with the general substrates hemoglobin, azocasein, and bovine serum albumin (BSA) at optimal pH (2.0, 5.6, and 7.4) of aspartic, cysteine, and serine proteinases. Homogenates of glandular stomach mucosa and gastric juice from fasted rats were incubated in the presence or absence of specific inhibitors and sulfhydryl (SH) alkylators N-ethylmaleimide and iodoacetate. PIA was measured after acid and heat inactivation of endogenous proteinases and addition of 20 micrograms/ml pepsin, 20 or 100 micrograms/ml thiol proteinase papain, or 20 micrograms/ml trypsin for 5 min before digestion at 37 degrees C. The highest proteolytic activity was found at pH 2.0 (pepsin) in juice and mucosal homogenate, but proteases were also found at pH 5.6 and 7.4, where pepsin was inactive. Pepstatin inhibited most proteolytic activity at pH 2.0. The SH protease inhibitor leupeptin diminished PA mainly at pH 5.6. N-ethylmaleimide or iodoacetate substantially reduced the PA in acidic milieu, with maximum effect at pH 5.6. Endogenous PIA, expressed as inhibition of the effect of 1 microgram of pepsin, papain, and trypsin on BSA, was 13.1, 1.4, and 9.2% in gastric mucosa and 15.3, 22.5, and 6.2% in gastric juice at pH 2.0, 5.6, and 7.4, respectively. We have concluded that 1) endogenous proteinases and inhibitors in rat stomach can be measured using BSA and hemoglobin as substrates, 2) of the proteinases found in the stomach, 98% was pepsin at pH 2.0 and up to 27% or 17% was SH sensitive at pH 5.6 or 7.4, respectively, and 3) proteinases and their specific endogenous inhibitors may play a role in gastric mucosal injury and protection.
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Affiliation(s)
- L Nagy
- Department of Pathology, Brigham and Women's Hospital, Boston, Massachusetts, USA
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Mokuolu AO, Sigal SH, Lieber CS. Gastric juice urease activity as a diagnostic test for Helicobacter pylori infection. Am J Gastroenterol 1997; 92:644-8. [PMID: 9128315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE An ideal assay (inexpensive, sensitive, specific, and readily available) for Helicobacter pylori is lacking. Urease activity is an important characteristic of the organism and is employed in the rapid urease and urea breath tests. In this study, we assessed whether a simpler test, namely, measurement of gastric juice urease activity, would provide comparable results. METHODS Gastric juice was analyzed for urea and ammonia in 57 patients evaluated with rapid urease test and histology. Urease activity was assessed by the fraction of urea hydrolyzed to ammonia. RESULTS Thirty-five subjects were H. pylori positive and 22 were H. pylori negative. Compared with noninfected subjects, H. pylori-positive patients had lower urea levels (0.52 +/- 0.10 vs. 2.77 +/- 0.48 mM, p < 0.01), higher ammonia concentrations (6.59 +/- 1.06 vs. 1.64 +/- 0.25 mM, p < 0.01), and higher gastric urease activity (0.83 +/- 0.03 vs. 0.24 +/- 0.14, p < 0.01). In H. pylori-negative patients, there was a correlation between blood and gastric urea (r = 0.61, p < 0.01). However, in H. pylori-positive patients, no such relationship existed (r = 0.30, p = 0.11). The ratio of gastric to blood urea was lower in infected patients (0.11 +/- 0.02 vs. 0.45+/- 0.04, p < 0.01). The sensitivity and specificity of gastric urease activity for diagnosis of H. pylori were 91% and 100%, respectively, and for the ratio of gastric to blood urea, 89% and 95%, respectively. CONCLUSION Gastric juice urease activity is a simple, sensitive, and specific means to detect H. pylori.
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Affiliation(s)
- A O Mokuolu
- Gastroenterology and Liver Programs, Bronx VA Medical Center, Mt. Sinai School of Medicine, New York 10468, USA
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