AIM:To study the diagnosis of Helicobacter pylori(H pylori) infection through the determination of serum levels of anti- H pylori IgG and IgA antibodies,and the levels of anti-H pylori IgA antibodies in duodenal fluid...AIM:To study the diagnosis of Helicobacter pylori(H pylori) infection through the determination of serum levels of anti- H pylori IgG and IgA antibodies,and the levels of anti-H pylori IgA antibodies in duodenal fluid. METHODS:Data were collected from 93 patients submitted to upper digestive endoscopy due to dyspeptic symptoms. The patients were either negative(group A)or positive (group B)to H pylori by means of both histological detection and urease tests.Before endoscopy,peripheral blood was collected for the investigation of anti-H pylori IgG and IgA antibodies.To perform the urease test,biopsies were obtained from the gastric antrum.For the histological evaluation,biopsies were collected from the gastric antrum (greater and lesser curvatures)and the gastric body. Following this,duodenal fluid was collected from the first and second portions of the duodenum.For the serological assaying of anti-Hpylori IgG and IgA,and anti-Hpylori IgA in duodenal fluids,the ELISA method was utilized. RESULTS:The concentration of serum IgG showed sensitivity of 64.0%,specificity of 83.7%,positive predictive value of 82.0%,negative predictive value of 66.6% and accuracy of 73.1% for the diagnosis of H pylori infection.For the same purpose,serum IgA showed sensitivity of 72.0%, specificity of 65.9%,positive predictive value of 72.0%, negative predictive value of 67.4% and accuracy of 69.8%. If the serological tests were considered together,i.e.when both were positive or negative,the accuracy was 80.0%, sensitivity was 86.6%,specificity was 74.2%,positive predictive value was 74.2% and negative predictive value was 86.6%.When values obtained in the test for detecting IgA in the duodenal fluid were analyzed,no significant difference(P=0.43)was observed between the values obtained from patients with or without H pylori infection. CONCLUSION:The results of serum IgG and IgA tests for H pylori detection when used simultaneously,are more efficient in accuracy,sensitivity and negative predictive value, than those when used alone.The concentration of IgA antibodies in duodenal fluid is not useful in identifying patients with or without H pylori.展开更多
Focus in nutritional science has turned towards components in, or added to, foods that may possess health beneficial activities beyond the classical nutritional value, namely functional food. Bioactive peptides are ex...Focus in nutritional science has turned towards components in, or added to, foods that may possess health beneficial activities beyond the classical nutritional value, namely functional food. Bioactive peptides are examples of such components. In vitro studies on bioactivities have mainly been executed without concerning subsequent digestion after intake and the aim of this work was hence to investigate how the in vitro antioxidative, antihypertensive and caspase activating activities of peptides are affected by digestion with gastrointestinal （GI） proteases. Five different fish protein hydrolysates were chosen to study the effect of in vitro digestion on bioactivity. The protein concentration decreased in all samples during digestion and the molecular weight distribution of the peptides shifted towards lower values. Thus, in vitro digestion with GI proteases resulted in a further degradation of the peptides obtained by hydrolysis. The antihypertensive effect increased in all samples after digestion with GI proteases whereas the antioxidative capacity decreased. The effect on the caspase activity depended on the proteases used in the preparation of hydrolysates. In conclusion, the caspase activity and antihypertensive activity are maintained during digestion with GI proteases, while the antioxidative capacity seems to be reduced.展开更多
Research on marine bioactive peptides has mainly focused on characterization of peptides in hydrolysates prepared with commercial industrial enzymes and the usefulness of such hydrolysates in health and functional foo...Research on marine bioactive peptides has mainly focused on characterization of peptides in hydrolysates prepared with commercial industrial enzymes and the usefulness of such hydrolysates in health and functional foods. However, a relevant question is whether digestion of fish proteins with gastrointestinal proteases per se generates peptides that also can have health promoting properties and can reduce, e.g., diabetes 2, inflammation and hypertension either in relation to gastrointestinal digestion or as alternative to industrial proteases. The aim of the study was to investigate hydrolysates obtained from in vitro sequential digestion of salmon muscle and skin with gastrointestinal proteases including pepsin, pancreatic and pancreatic ＋ mucosal proteases for their ability to scavenge ABTS^＋ radicals and inhibit activity of angiotensin I-converting enzyme （ACE） and dipeptidyl peptidase 4 （DPP-4）. Furthermore, it was the aim to study the inhibitory mechanism and stability towards ACE and DPP-4 activity. Analysis of〈 10 kDa hydrolysates showed that gastrointestinal proteases generated peptides with clear radical scavenging activity and DPP-4 and ACE inhibiting activity as well. Hydrolysates from pepsin digestion exhibited the lowest ECso values for radical scavenging activity and ACE inhibition, whereas ECso increased in hydrolysates after subsequent digestion with pancreatic and mucosal proteases. Interestingly, ECso values for the DPP-4 inhibition were hardly affected by sequential digestion. Inhibition modes for the muscle hydrolysates were both competitive and non-competitive, but prolonged incubation showed that the inhibitory properties were unstable and therefore they were probably digested as competitive substrates by gastrointestinal proteases.展开更多
文摘AIM:To study the diagnosis of Helicobacter pylori(H pylori) infection through the determination of serum levels of anti- H pylori IgG and IgA antibodies,and the levels of anti-H pylori IgA antibodies in duodenal fluid. METHODS:Data were collected from 93 patients submitted to upper digestive endoscopy due to dyspeptic symptoms. The patients were either negative(group A)or positive (group B)to H pylori by means of both histological detection and urease tests.Before endoscopy,peripheral blood was collected for the investigation of anti-H pylori IgG and IgA antibodies.To perform the urease test,biopsies were obtained from the gastric antrum.For the histological evaluation,biopsies were collected from the gastric antrum (greater and lesser curvatures)and the gastric body. Following this,duodenal fluid was collected from the first and second portions of the duodenum.For the serological assaying of anti-Hpylori IgG and IgA,and anti-Hpylori IgA in duodenal fluids,the ELISA method was utilized. RESULTS:The concentration of serum IgG showed sensitivity of 64.0%,specificity of 83.7%,positive predictive value of 82.0%,negative predictive value of 66.6% and accuracy of 73.1% for the diagnosis of H pylori infection.For the same purpose,serum IgA showed sensitivity of 72.0%, specificity of 65.9%,positive predictive value of 72.0%, negative predictive value of 67.4% and accuracy of 69.8%. If the serological tests were considered together,i.e.when both were positive or negative,the accuracy was 80.0%, sensitivity was 86.6%,specificity was 74.2%,positive predictive value was 74.2% and negative predictive value was 86.6%.When values obtained in the test for detecting IgA in the duodenal fluid were analyzed,no significant difference(P=0.43)was observed between the values obtained from patients with or without H pylori infection. CONCLUSION:The results of serum IgG and IgA tests for H pylori detection when used simultaneously,are more efficient in accuracy,sensitivity and negative predictive value, than those when used alone.The concentration of IgA antibodies in duodenal fluid is not useful in identifying patients with or without H pylori.
文摘Focus in nutritional science has turned towards components in, or added to, foods that may possess health beneficial activities beyond the classical nutritional value, namely functional food. Bioactive peptides are examples of such components. In vitro studies on bioactivities have mainly been executed without concerning subsequent digestion after intake and the aim of this work was hence to investigate how the in vitro antioxidative, antihypertensive and caspase activating activities of peptides are affected by digestion with gastrointestinal （GI） proteases. Five different fish protein hydrolysates were chosen to study the effect of in vitro digestion on bioactivity. The protein concentration decreased in all samples during digestion and the molecular weight distribution of the peptides shifted towards lower values. Thus, in vitro digestion with GI proteases resulted in a further degradation of the peptides obtained by hydrolysis. The antihypertensive effect increased in all samples after digestion with GI proteases whereas the antioxidative capacity decreased. The effect on the caspase activity depended on the proteases used in the preparation of hydrolysates. In conclusion, the caspase activity and antihypertensive activity are maintained during digestion with GI proteases, while the antioxidative capacity seems to be reduced.
文摘Research on marine bioactive peptides has mainly focused on characterization of peptides in hydrolysates prepared with commercial industrial enzymes and the usefulness of such hydrolysates in health and functional foods. However, a relevant question is whether digestion of fish proteins with gastrointestinal proteases per se generates peptides that also can have health promoting properties and can reduce, e.g., diabetes 2, inflammation and hypertension either in relation to gastrointestinal digestion or as alternative to industrial proteases. The aim of the study was to investigate hydrolysates obtained from in vitro sequential digestion of salmon muscle and skin with gastrointestinal proteases including pepsin, pancreatic and pancreatic ＋ mucosal proteases for their ability to scavenge ABTS^＋ radicals and inhibit activity of angiotensin I-converting enzyme （ACE） and dipeptidyl peptidase 4 （DPP-4）. Furthermore, it was the aim to study the inhibitory mechanism and stability towards ACE and DPP-4 activity. Analysis of〈 10 kDa hydrolysates showed that gastrointestinal proteases generated peptides with clear radical scavenging activity and DPP-4 and ACE inhibiting activity as well. Hydrolysates from pepsin digestion exhibited the lowest ECso values for radical scavenging activity and ACE inhibition, whereas ECso increased in hydrolysates after subsequent digestion with pancreatic and mucosal proteases. Interestingly, ECso values for the DPP-4 inhibition were hardly affected by sequential digestion. Inhibition modes for the muscle hydrolysates were both competitive and non-competitive, but prolonged incubation showed that the inhibitory properties were unstable and therefore they were probably digested as competitive substrates by gastrointestinal proteases.
