Activity of N-acetyl-beta-D-hexosaminidase (HEX) and its isoenzymes A and B in human milk during the first 3 months of breastfeeding.

PURPOSE: Milk contains free and bound oligo- and heteropolisaccharides, which protect newborns against pathogens and have nutritional value. N-acetyl-beta-D-hexosaminidase (HEX), the most active lysosomal exoglycosidase, modify and degrade oligo- and heteropolysaccharides. The objective of our study was to determine HEX activity and isoenzymes A and B in the progression of lactation. MATERIAL AND METHODS: Human milk samples were collected from 51 women on the 3rd, 21st and 100th day postpartum. Enzymatic activity was determined the Zwierz et al method modified by Marciniak et al. Protein and lactose concentrations were determined by a MilkoScan 4000 apparatus. RESULTS: The total HEX activity decreased by the 21st day in comparison to the 3rd day, and increased by the 100th day as compared to the 21st day. HEX A activity decreased by the 21st and the 100th day as compared to the 3rd day. HEX B activity decreased by 21st day and has the tendency to decrease by the 100th day as compared to the 3rd day. Protein concentration decreased and the lactose concentration increased in milk taken on the 21st day in comparison to concentration of protein and lactose on the 3rd day. HEX and its isoenzymes' activity significantly correlate with the progression of lactation. At the beginning of lactation, HEX A activity, which releases hexosamines from acidic oligosaccharides, dominates; later, HEX B releases hexosamines from neutral oligosaccharides. CONCLUSIONS: To better understand the degradation of human milk oligosaccharides, it would be useful to investigate and document their detailed structures and evaluate the activity of other exoglycosidases' activity in human breast milk over the course of lactation.

Peripheral blood lymphocyte population in children infected with Helicobacter pylori.

PURPOSE: Helicobacter pylori infection in children is associated with a chronic inflammatory process of gastric and duodenal mucosa, which may have a various clinical course ranging from asymptomatic and chronic inflammatory condition to gastric ulceration. The immune system may contribute especially to chronic gastric mucosa inflammation. The aim of our study was to assess the levels of peripheral blood T (CD3+, CD4+, CD8+) and B lymphocyte subpopulation (CD19+) in children with Helicobacter pylori infection and to evaluate their relation to degree of antrum mucosa inflammation. MATERIAL AND METHODS: The study was performed in 32 children aged 7-18 years, hospitalized due to dyspeptic symptoms. The endoscopic examination of upper gastrointestinal tract was performed and gastric and duodenal mucosa was estimated in all patients. The endoscopic and histological evaluation of gastric mucosa was performed according to the Sydney System [4]. The urease test (CLO-test-H. pylori) was made to estimate the severity of the infection. RESULTS: Moderate antrum mucosa inflammation was found in 41.2% of the examined. The highest percentage of children (58.8%) presented marked inflammation. No mild inflammation was found in children examined. CONCLUSIONS: No correlation was found between lymphocyte levels and the degree of the inflammatory changes in antrum mucosa. The evaluation of peripheral blood lymphocytes performed in children with Helicobacter pylori infection suggests that T lymphocytes may play a predominant role in this infection.

Comparative evaluation of gastric mucosa morphological changes in children and adults with positive IgG antibodies to Helicobacter pylori.

PURPOSE: Helicobacter pylori colonization of gastric epithelium causes a local and systemic, cellular and humoral immune response. Despite this immune response involvement in the infection, its elimination from the organism does not take place and the process usually becomes chronic. The purpose of the study was to establish the prevalence of gastric mucosa inflammation in children and adults with serum positive anti-Helicobacter pylori antibodies IgG. MATERIAL AND METHODS: The study included 171 patients comprising 109 (63.7%) children and 62 (36.3%) adults with IgG positive titre against Helicobacter pylori, who were qualified to the study basing on epidemiological examinations estimating the prevalence of Helicobacter pylori infection in the population of north-eastern Poland living in the country, town and city. All patients reported dyspeptic symptoms. The evaluation was performed basing on the morphological (endoscopy) and histopathological examinations estimating the changes in gastric mucosa of these patients. RESULTS: The evaluation of antrum and corpus gastric mucosa proved normal gastric mucosa in 34 children (31.1%) and 10 adults (16.1%) with positive IgG antibodies against Helicobacter pylori. The evaluation of the severity showed the predominance of moderate inflammation within corpus in children (37.6%) and marked inflammation in adults (45.1%). CONCLUSIONS: The concentration of IgG antibodies against Helicobacter pylori in both groups was highest in patients with marked antrum gastric mucosa inflammation.