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Biomedical subjects

A Paerregaard

Publications and source records attributed to A Paerregaard.

At least 55 records · Page 3Linked to original sources

Comparison of crossed immunoelectrophoresis, enzyme-linked immunosorbent assays, and tube agglutination for serodiagnosis of Yersinia enterocolitica serotype O:3 infection.

Antibodies against Yersinia enterocolitica serotype O:3 were measured by crossed immunoelectrophoresis (XIE) using whole-cell sonic extract as antigen and by enzyme-linked immunosorbent assays (ELISAs) using either purified lipopolysaccharide or whole formalinized cells expressing virulence plasmid-encoded surface antigens (pYV+ cells). The results were compared with those obtained with the standard tube agglutination method. Sera from three groups of people were examined by using these assays. The first group consisted of healthy blood donors, the second consisted of patients with recent infection due to microorganisms other than Y. enterocolitica O:3, and the third consisted of patients with recent Y. enterocolitica O:3 infection. Sera from the last group were also obtained at regular intervals for 12 months postinfection. Results obtained with XIE and the ELISAs were in good agreement with those obtained with tube agglutination. Variation, diagnostic sensitivity, and diagnostic specificity were satisfactory for all the assays studied. However, the lipopolysaccharide ELISA was less laborious than tube agglutination and XIE and carried a somewhat greater diagnostic specificity than the pYV+ ELISA. XIE and the pYV+ ELISA, on the other hand, also had advantages. XIE enabled simultaneous examination of the individual antibody response against a wide range of chromosome-encoded antigens, and the pYV+ ELISA enabled detection of specific pYV antibodies when sera were adsorbed with formalinized pYV-cured Y. enterocolitica O:3 cells prior to the assay.

Adolescent↗

Inhibition of plasmid-encoded adhesion of Yersinia enterocolitica by non-immunoglobulin fraction of human milk.

The inhibitory effect of human milk on plasmid-encoded adhesion of Yersinia enterocolitica to rabbit ileal brush border membrane vesicles immobilized on polystyrene was evaluated. Adhesion was reduced to about 50% after incubation of equal volumes of bacteria and undiluted human milk, but a significant reduction was also detectable after incubation with milk samples at a final 1:10 dilution. Removal of immunoglobulins from human milk by means of immunoadsorption did not change the inhibitory effect on adhesion. Both milk fat, proteins, and factors resistant to proteolytic and heat treatment contributed to the reduction in adhesion.

Animals↗

Vitamin B12 and folic acid absorption and hematological status in children with postenteritis enteropathy.

In a group of nine children with postenteritis enteropathy (i.e., persisting small-intestinal mucosal damage and failure-to-thrive after an acute episode of gastroenteritis), absorption capacities for vitamin B12 and folic acid were studied and compared with hematological status in peripheral blood. The fractional absorptions of vitamin B12 (FAB12) and folic acid (FAFol) were determined by means of a double-isotope technique employing a single-stool-sample test. The children were examined when growth retardation was maximal, and examinations were repeated during the late recovery period. In spite of considerable small-intestinal mucosal damage, only the absorption of vitamin B12 was markedly affected, while that of folic acid was almost intact. When growth retardation was maximal, FAB12 was below the normal age-correlated range in half of the children. FAB12 was also severely reduced in all longitudinally observed children when compared with the results obtained during the late recovery period (p less than 0.005). FAFol was below the normal range in one fourth of the children, but the reduction was modest and insignificant when compared with the results of repeated examinations during the late recovery period. A moderate iron deficiency was detected in half the children. High levels of plasma vitamin B12, folic acid, and erythrocyte folate were detected at both early and later examinations, indicating that these parameters were not affected by the reduced absorption capacities. However, if malabsorption and chronic diarrhea are combined with low dietary intake of vitamin B12, as is the case for many children in the Third World, depletion of vitamin B12 stores may result.

Absorption↗

Postenteritis enteropathy in infancy. A prospective study of 10 patients with special reference to growth pattern, long-term outcome and incidence.

Ten patients, who developed postenteritis enteropathy with chronic diarrhoea, failure to thrive and small intestinal mucosal damage after an episode of acute gastroenteritis, were studied prospectively. All patients experienced severe growth retardation. Maximum deviation of height and weight from mean values of age-correlated normal children were -1.7 and -3.1 SD (median values), respectively, as compared to -0.1 and 0 SD before onset of the illness. One child died after 14 months of illness. The long-term outcome was satisfactory for the 9 surviving children. For these children, treatment with an elemental diet (in some cases supplemented initially with parenteral nutrition) and later a lactose-free diet lead to resolution of diarrhoea within periods ranging from 0.5 to 10 months. The phase of catch-up growth lasted from 4 to 36 months, resulting in final height and weight deviating -0.6 and -0.8 SD (median values), respectively, from normal mean values. Attempt to predict duration of diarrhoea or length of catch-up growth phase by means of age, weight before illness, characteristics of small intestinal biopsy or maximum deviation of height or weight were unsuccessful. The incidence of postenteritis enteropathy for children of North European ethnic origin was estimated to be 7.6/1,000,000 children below 7 years of age/year, corresponding to 1.2/1,000 children hospitalized for acute gastroenteritis.

Chronic Disease↗

The influence of properties encoded by the Yersinia virulence plasmid on adhesion of Yersinia enterocolitica to ileal brush border membrane vesicles.

The influence of plasmid-associated cell surface structures on the ability of Yersinia enterocolitica to bind to ileal brush border membrane vesicles (BBVs) was investigated. Rabbit or human BBVs were immobilized on polystyrene microtiter plates and adhesion of radiolabeled cells of Y. enterocolitica was determined. Strains of pathogenic serotypes carrying the Yersinia virulence plasmid (pYV+), as well as their isogenic plasmid cured derivatives (pYV-), adhered to immobilized BBVs, but adhesion of pYV+ organisms was markedly greater than that of pYV- ones. Strains belonging to non-pathogenic serotypes did not adhere significantly. The pYV+ strain Ye0301P+ did not express specific adhesion to glycolipids, nor was adhesion to BBVs reduced in the presence of various monosaccharides. Proteolytic digestion of surface structures on strain Ye0301P+ markedly reduced adhesion. pYV+ strains also demonstrated greater adhesion to a non-biological surface (polystyrene) and showed a higher degree of hydrophobicity than pYV- organisms as evaluated in a two-phase partitioning system. It is therefore likely that the plasmid-associated adhesion of Y. enterocolitica is promoted by one or more outer membrane proteins, that confer hydrophobicity to the bacterial surface.

Animals↗

Adhesion of Yersinia enterocolitica to human epithelial cell lines and to rabbit and human small intestinal tissue.

In assays to determine adherence of Yersinia enterocolitica, virulence plasmid-containing (pYV+) strains and strains of their plasmid-cured (pYV-) derivatives adhered equally efficiently to HeLa cells and fetal intestinal epithelial INT 407 cells. Non-pathogenic strains of Y. enterocolitica did not adhere. In contrast, pYV+ strains adhered more efficiently to rabbit and human intestine than did pYV(-)-strains, as evaluated by an in vitro assay, measuring adhesion of radiolabeled bacteria to disks of intestinal tissue. Thus, even if pathogenic strains of Y. enterocolitica are able to adhere to cultured epithelial cell lines and intestinal tissue by means of chromosome-encoded properties alone, properties encoded by the pYV plasmid significantly enhance and contribute to adhesion to intestinal tissue.

Animals↗

Rapid versus gradual refeeding in acute gastroenteritis in childhood: energy intake and weight gain.

Fifty-two children aged 6-46 months (mean 19 months), hospitalized for acute gastroenteritis (GE), were randomized after oral rehydration to receive 7 days of either traditional gradual refeeding (GR) or rapid refeeding (RR), the latter consisting of a full-strength lactose-limited diet, including lactase-treated whole milk. The study focused on the effect of a high energy intake, excluding possible negative effects of lactose. Both dietary regimens were well tolerated, the only difference in the clinical symptoms between the two regimens being a higher stool frequency within the RR group (p less than 0.02). The total energy intake, as well as energy derived from fat and protein, was significantly higher in the RR than in the GR group (p less than 0.0001). The mean daily energy intake of the latter group never reached recommended daily allowance (RDA) levels, while that of the RR group did on day 5. Moreover, during the whole period of dietary regimen, the RR group exceeded the RDA protein requirements (mean intake ranged 175-252%), while the GR group did not reach this RDA level until day 4. Milk was a major source of energy in the RR group, providing 47-59% of the daily energy intake. The short- and long-term weight gains in the RR group were only a little higher than those of the GR group, the difference being insignificant.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗

Supposed coeliac disease during childhood and its presentation 14-38 years later.

Thirty-five subjects treated with a gluten-free diet for a chronic gastrointestinal disorder (no biopsy performed) in early childhood were re-examined 14-38 (median, 28) years later. Twenty-one accepted jejunal biopsy at re-examination. None of those studied were on a gluten-free diet at the time of the study. Ten of 21 biopsy specimens were abnormal--6 with flat mucosa and very low disaccharidase levels, indicating coeliac disease, and 4 with low disaccharidase activity but morphologically normal mucosa. Three of the six subjects with flat mucosa showed a slight fat and lactose malabsorption, but their clinical condition did not suggest serious intestinal disease. Ingestion of gluten throughout most of childhood did not appear to affect growth, as evaluated by final height. Jejunal biopsy is recommended in all patients with gastrointestinal symptoms that are not otherwise explainable if their medical history shows a period of gluten-free diet for a chronic gastrointestinal disorder in childhood.

Adolescent↗