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H J Egberts

Publications and source records attributed to H J Egberts.

12 recordsLinked to original sources
PubMed1993

Tight junctional structure and permeability of porcine jejunum after enterotoxic Escherichia coli infection.

Tight junctional structure and macromolecular permeability were tested in four three-week-old piglets, experimentally infected with the enterotoxigenic Escherichia coli (ETEC) strain O149 K91 K88. Histologically, only minor microscopic evidence of inflammation and little or no architectural changes in the jejunal mucosa were observed. A significant decrease in tight junctional strand numbers occurred, without a concomitant decrease in tight junctional depth. The permeability of the porcine jejunal epithelium to horseradish peroxidase did not change after the ETEC infection.

Animals↗
PubMed1992

Thickening of the glycocalyx during methotrexate induced small intestinal mucosal atrophy in the rat.

In this study, the morphology of the glycocalyx of small intestinal enterocytes in the rat was investigated after the induction of mucosal atrophy by methotrexate (MTX) in 18 Wistar rats. On the 2nd, 4th and 6th day after the intraperitoneal administration of MTX, a group of 6 rats was sacrificed and tissue specimens taken at the level of the Treitz' ligament were post fixed in a mixture of 2.0% watery osmiumtetroxide and 1.5% potassium-ferrocyanide to enhance visibility of glycoconjugates and processed for electron microscopy. In the control rats, the glycocalyx was hardly visible on the villous enterocytes, but rather conspicuous on the enterocytes in the crypts. On the second day after injection of MTX, the glycocalyx of the villous enterocytes was more pronounced but on the crypt enterocytes it resembled that of control animals. On the 4th day after MTX administration, a striking reduction and shortening of microvilli of villous enterocytes was seen, together with very pronounced glycocalyces, while crypt cells possessed well developed cell coats. On the 6th day after the injection of MTX, the glycocalyx of both villous and crypt cells appeared almost normal again.

Animals↗
PubMed1992

Intestinal permeability in pigs during rotavirus infection.

Macromolecular permeability of the small intestine was tested in four 3-week-old gnotobiotic pigs inoculated with porcine rotavirus strain RV277 (group A). Pigs were administered 125I-labeled polyvinylpyrrolidone (molecular weight [mol wt], 40,000) orally 1 day before and 2 and 24 hours after virus inoculation, and blood samples were obtained every 6 hours. Eight hours after rotavirus inoculation, pigs had watery diarrhea. Increased permeation of 125I-labeled polyvinylpyrrolidone was not observed after clinical signs of infection had developed. Serum total protein and urea nitrogen concentrations increased slightly at the end of the study, probably as a consequence of dehydration. Differences in blood glucose concentration were not seen. At 48 hours after viral inoculation, macromolecular permeability was tested morphologically by injecting horseradish peroxidase (mol wt, 40,000) into the jejunal lumen just distally to the ligamentum colicoduodenale. After an incubation period of 20 minutes, small segments of jejunum were obtained for stereomicroscopic, histologic, and ultrastructural investigations. Moderate hyperregenerative villus atrophy was found. Ultrastructural changes of the villus epithelium were minor, and increased macromolecular permeation was not observed.

Animals↗
PubMed1991

Intestinal permeability in piglets during transmissible gastroenteritis.

Macromolecular permeability of the small intestine was tested in seven three-week-old piglets infected with porcine transmissible gastroenteritis virus (TGE-strain Miller). Fourteen hours after the infection, the piglets showed loss of appetite and a profuse diarrhoea. In some animals vomiting occurred somewhat earlier. Macromolecular permeability was tested morphologically by injecting horseradish peroxidase (MW = 40,000 Da) into the jejunal lumen just distally to the Treitz' ligament in two piglets at 12 hours and in five piglets at 48 hours after the inoculation in comparison with two control piglets. After a period of 20 minutes, small segments of jejunum were taken for stereomicro-scopical, histological and ultrastructural investigations. An increased permeability for HRP together with a severe, hyper-regenerative villous atrophy was observed in the TGE-infected piglets at 48 hours after the inoculation.

Animals↗
PubMed1991

Different types of peroxisomes in human duodenal epithelium.

Peroxisomes are ubiquitous organelles containing enzyme sequences for beta oxidation of fatty acids, synthesis of bile acids, and ether phospholipids. In the inherited peroxisomal diseases one or more enzymes are deficient in hepatic, renal, and fibroblast peroxisomes. We have examined peroxisomes by light and electron microscopy in 29 duodenal biopsy specimens (21 with normal mucosa) after staining for catalase activity, a marker enzyme. Peroxisomes were most numerous in the apices of the nucleus and at the villus base. Two types were distinguished: rounded to oval forms with a median lesser diameter of 0.23-0.31 microns, and tubular, vermiform organelles 0.1 microns thick and up to 3 microns long. Both types coexist in most patients. Tilting of sections and examination of semithin sections at 120 kV did not show connections between individual organelles. By morphometry, volume density was at least 0.45-0.62% of cellular volume, compared to 1.05% in human liver. In contrast, in four out of five individuals surface density of the peroxisomal membrane was 1.4-2.3 times higher than in control livers; this is expected to favour the exchange of metabolites. We suggest that intestinal peroxisomes contribute substantially to the breakdown of very long chain fatty acids.

Adult↗
PubMed1989

Intestinal permeability to polyethylene glycol 4000 and porcine albumin in piglets infected with transmissible gastroenteritis virus.

The intestinal permeability of specific pathogen free piglets has been studied by measuring the concentration of 14C in the blood after oral administration of 14C polyethylene glycol (14C PEG, MW = 4000) and the concentration of 131I in the faeces after intraperitoneal administration of 131I porcine albumin (131I PA, MW = 68,000). The tests were performed one day before and up to two days after the piglets were infected with transmissible gastroenteritis (TGE) virus. Jejunal biopsies were taken from two piglets before the experimental infection, from two piglets 12 h after the experimental infection and from five piglets at the end of the experiment, 46 h after infection. Blood samples were taken six-hourly and faecal samples several times. Some piglets vomited before diarrhoea and loss of appetite started at 14 h after infection; the packed cell volume decreased before but increased after infection. Morphological examination showed hyperregenerative villous atrophy at 46 h after infection. There was no increase in the permeation of 14C PEG but there was a significant increase in the flux of 131I PA from the blood to the gut lumen.

Administration, Oral↗
PubMed1988

Intestinal permeability to macromolecules during colibacillosis in piglets.

Intestinal macromolecular permeability to macromolecules was determined in a group of specific pathogen free piglets before and after they were infected experimentally with Escherichia coli. Six hours after the infection all piglets developed a profuse diarrhoea. The urea and total protein concentrations in the serum increased markedly after the onset of diarrhoea. Haemoglobin concentration and PCV decreased steadily during the experiment but blood glucose concentration and lipid composition of the faeces did not change. No structural abnormalities in the jejunal and ileal mucosa were seen. No uptake of macromolecules (40,000 KDa) was found suggesting that molecules with a molecular weight of 40,000 or more do not play a role in the persistent diarrhoea sometimes seen in piglets after colibacillosis.

Animals↗
PubMed1988

Intestinal permeability to macromolecules in piglets infected with transmissible gastroenteritis virus.

The permeability of the intestine of specific pathogen free piglets was investigated by measuring the concentration of 125-I in the blood after oral administration of 125-I polyvinylpyrrolidone (125-I PVP, MW = 40,000 Da) and the concentration of 131-I in the faeces after intravenous administration of 131-I porcine albumin (131-I PA, MW = 68,000 Da). The tests were performed one day before and up to two days after the piglets were infected with the Miller strain of transmissible gastroenteritis (TGE) virus. Biopsies of the jejunum were taken at the end of the experiment and blood samples were taken six-hourly. The piglets became anorexic and had diarrhoea 12 hours after infection; the packed cell volume decreased and the concentrations of urea and total serum proteins increased slightly after infection. However, the marked villous atrophy was not accompanied by an increased permeability of the intestine to PVP or PA.

Albumins↗
PubMed1988

Histochemical changes in the composition of mucins in goblet cells during methotrexate-induced mucosal atrophy in rats.

Changes in the composition of mucins in jejunal goblet cells were investigated histochemically after a single intraperitoneal injection of methotrexate in rats (40 mg methotrexate/kg body weight). At 48 h after injection of methotrexate, when mitotic activity in the crypts approximates to zero, an almost complete disappearance of mucin-containing goblet cells can be observed. At 96h, when proliferative activity in crypts is excessive, neutral mucin- and sialomucin-containing goblet cells dominate in the crypts, whereas in controls the crypts display sulphomucin-containing goblet cells. At 144h neutral mucin- and sulphomucin-containing goblet cells dominate in the crypts. Both at 48 and 96h after injection of methotrexate a significant decrease in the number of villous goblet cells takes place, whereas with respect to the quality of the mucins in the goblet cells no difference can be found in comparison with control rats. At 144h the villi have recovered from the preceding temporary decrease of goblet cells. The histochemical composition of the population of goblet cells is still aberrant and shows goblet cells containing neutral mucins and sulphomucins principally, whereas in controls sialomucin-containing goblet cells dominate on the villi. The established changes in the composition of mucins in goblet cells cannot be attributed to methotrexate-induced malnutrition, as pair-fed control rats clearly demonstrate. Our results clearly demonstrate that conspicuous quantitative as well as qualitative changes in the synthesis of mucins in goblet cells occur during the hyporegenerative and hyperregenerative phase of methotrexate-induced mucosal atrophy.

Animals↗
PubMed1985

Biology and pathology of the intestinal M-cell. A review.

The literature of the intestinal M-cell, which is part of the epithelium covering the gut-associated lymphoid tissue (GALT), is reviewed. Attention is paid to the localization, structure, origin and function of this cell, under both normal and pathological conditions.

Animals↗