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Analysis of the ouabain-induced increase in transepithelial electrical resistance in the goldfish intestinal mucosa.

1. The ouabain-induced increase in transmural resistance of goldfish intestinal mucosa stripped free from underlying muscular layers is analysed by comparing the resistance increase in normal and in low chloride saline, the resistance increased induced by anaerobic conditions and the resistance increase provoked by hypotonicity. 2. It is concluded that the collapse of the lateral intercellular space is the prime reason for the resistance increase and that the lateral intercellular space is maintained dilated by a ouabain-sensitive solute transport mechanism. 3. This mechanism can be either a rheogenic or a neutral Na/K-pump. In the latter case additional conditions have to be specified concerning values for ion concentrations in the lateral intercellular space and in the unstirred layer adjacent to the luminal membrane. 4. There are no indications for a chloride dependent mechanism involved in the maintenance of the width of the lateral intercellular spaces in the goldfish intestinal mucosa.

Animals↗

Clinical, HLA, and small bowel immunohistochemical features of children with positive serum antiendomysium antibodies and architecturally normal small intestinal mucosa.

BACKGROUND: Antiendomysium antibodies have a high sensitivity and specificity for celiac disease. A small percentage of subjects positive for these antibodies have a small intestinal mucosa hitherto considered normal. OBJECTIVES: The aim of this study was to characterize the clinical, serological, immunogenetic, and immunohistological features of these subjects. METHODS: From 409 patients who were positive for celiac-related antibodies, we selected 24 (5.9%) patients who had an architecturally normal small intestinal mucosa. One hundred age-matched celiac patients with a "flat" small intestinal mucosa, and 50 age-matched nonceliac children were also studied. The number of CD3+ and gammadelta+ intraepithelial lymphocytes and of CD25+ lamina propria mononuclear cells, and the expression of crypt HLA-DR and lamina propria ICAM-1 were assessed. HLA haplotyping was also performed. RESULTS: Eleven (45.8%) of the 24 patients had a distinct infiltrative pattern, i.e., an increase in CD3+ intraepithelial lymphocytes (> 2SD of the nonceliac group), whereas 17 (70.8%) had a higher density of intraepithelial gammadelta+ cells. In 17 (70.8%) patients, the number of lamina propria CD25+ cells was increased and/or the expression of ICAM-1 and crypt HLA-DR was enhanced. All 24 patients carried the celiac disease-associated HLA haplotypes. Two of the six patients who remained on a normal diet and underwent a second jejunal biopsy developed villous atrophy. CONCLUSIONS: Most of the patients with serum antiendomysium antibodies and normal jejunal histology showed immunohistochemical signs of immune activation in the epithelium, lamina propria, and crypts. We recommend that such patients be monitored to assess their progress and to determine whether they need a gluten-free diet.

Adolescent↗

Kinetic, chromatographic and electrophoretic studies on glucose-phosphorylating enzymes of rat intestinal mucosa.

The number and nature of glucose-phosphorylating enzymes of rat intestinal mucosa were investigated by chromatographic, electrophoretic, and kinetic methods. Three fractions with glucose-phosphorylating activity were obtained from the supernatant fluid of mucosa homogenate by means of DEAE-cellulose chromatography, corresponding to hexokinases A and B (EC 2.7.1.1.), and N-acetyl-D-glucosamine kinase (EC 2.7.1.59). Although the latter uses N-acetylglucosamine as the main substrate, it is also able to phosphorylate glucose. Electrophoresis in polyacrylamide and in cellulose acetate gels showed the same three enzyme activities. None of these procedures revealed the presence of either hexokinase D ("glucokinase") or hexokinase C in the intestinal mucosa. In the sediment fractions hexokinase A and B, but not N-acetylglucosamine kinase, were found. The Km values for glucose of partially purified hexokinases A and B were 0.025 and 0.174 mM, respectively, and their substrate specificity was the same as that of hexokinases A or B from other tissues. Partially purified N-acetylglucosamine kinase showed hyperbolic saturation functions for N-acetylglucosamine and ATP, with Km values of 0.021 and 0.38 mM, respectively. This enzyme also phosphorylated glucose, mannose, fructose, 2-deoxyglucose, and glucosamine. The dependence of velocity on glucose concentrations was complex, mimicking negative cooperativity. The molecular weight of both hexokinases A and B was 98,000 and that of N-acetylglucosamine kinase was 59,000. The kinetic properties, as well as the chromatographic and electrophoretic mobilities, of N-acetylglucosamine kinase may serve to confuse it with hexokinase D, and thus several criteria should be applied for correct identification.

Animals↗

Estrogen-induced alterations of hematoside of rat small intestinal mucosa.

Prior studies have suggested that sex hormones could influence the ganglioside and/or neutral glycosphingolipid composition of various organs. To date, the effects of sex hormones on the glycosphingolipid composition of the rat small intestinal mucosa, however, have not been examined. In the present studies, male albino rats of the Sherman strain were subcutaneously administered the synthetic estrogen, ethinylestradiol (5 mg/kg body wt. per day), or diluent for 5 days, and the ganglioside, neutral glycosphingolipid and ceramide composition of the small intestinal mucosa of these animals were analyzed and compared. The results of these experiments demonstrate that estrogen administration: increased the ganglioside concentration of this tissue, including hematoside (Gm3); increased the percentage of the long-chain base phytosphingosine of hematoside; and did not appear to significantly influence the concentration or composition of the neutral glycosphingolipids or ceramide in this tissue. These data, therefore, indicate that estrogen administration induces quantitative and qualitative alterations in the gangliosides but not in the neutral glycosphingolipids or ceramide of rat small intestinal mucosa.

Animals↗

[Expression of HLA-DR antigen in small intestinal mucosa of children infected with Giardia intestinalis].

HLA-DR Antigen expression was shown in the small intestinal mucosa sampled by aspiration biopsy in 12 children infected with Giardia intestinalis. The studies were performed by using three immunohistochemical techniques, with the best results achieved by use of fluorescein- stained avidin biotin system. HLA-DR Antigen expression in Giardiasis was slightly enhanced in the enterocytes of the absorption region; an increased number of HLA-DR positive cells was also found in the lamina propria of the small intestine as compared with controls. This phenomenon is recognized in various inflammations of the small intestinal mucosa.

Child↗

[Expression of heat shock protein 70 in intestinal mucosa during the early stage after severe burns and its significance].

OBJECTIVE: To study the expression of heat shock protein 70 (HSP70) in intestinal mucosa during the early stage after severe burn injury and its significance. METHODS: With a model of 30% total body surface area (TBSA) full-thickness burned rats, the expression and distribution of HSP70 and heat shock factor-1 (HSF1) in intestinal mucosal were determined by reverse transcription-polymerase chain reaction (RT-PCR), Western blot and immunohistochemistry at 3, 6, 12, 24 and 48 hours postburn. RESULTS: The expression of HSP70 mRNA and protein in intestinal mucosa increased markedly at 3 hours after severe burns, peaked at 6 and 12 hours, and lasted for 48 hours postburn (all P<0.01). Following a slight decline at 3 hours postburn, the expression of HSF1 increased gradually, and reached a highest level at 48 hours postburn (all P<0.01). CONCLUSION: The expression of HSP70 and HSF1 markedly increase in intestinal mucosa following severe burn injury. It is suggested that the self-protective mechanism of cells might explain the increase of HSP70 expression.

Animals↗

CD19+ in intestinal mucosa predict the response to infliximab in Crohn's disease.

BACKGROUND/AIMS: Infliximab is an effective treatment for Crohn's disease, yet about 30% of patients have a weak or no response. The aim of the study was to determine if the likelihood of a patient achieving complete remission 3 months after treatment with infliximab can be predicted from immunological parameters measured in peripheral blood and inflamed intestinal mucosa before the treatment. METHODOLOGY: 25 patients with Crohn's disease resistant to conventional therapy underwent treatment with infliximab. Samples of peripheral blood and inflamed intestinal mucosa were analyzed by flow-cytometry before infliximab administration. The clinical response was evaluated after 3 months. RESULTS: At 3 months post-treatment, 11 (44%) patients were in complete remission, while 14 (56%) had no remission. Logistic regression analysis revealed that 50% of patients having 2.29% of CD19+ cells in inflamed intestinal mucosa may be expected to achieve complete remission. If the proportion of CD19+ cells in the inflamed mucosa is 5%, the probability of the patient achieving complete remission following treatment rises to 85%. CONCLUSIONS: This is the first study which found that a high percentage of CD19+ cells in the inflamed intestinal mucosa of a patient with Crohn's disease may predict long remission after infliximnab therapy.

Antibodies, Monoclonal↗

Severe growth failure associated with atrophic intestinal mucosa and ring chromosome 15.

Ring chromosome 15 was detected in a boy with severe growth failure and no dysmorphic features who had previously been found to have an atrophic intestinal mucosa, a finding not observed in about 300 patients with ring autosome reported so far. Of the 137 metaphases examined, 8.1% had secondary aneuploidy produced by the structural and behavioural instability of the ring. Ring derivatives could also be seen in lymphocytes after only one cycle in the culture, indicating that such cells are also generated in vivo. We observed an increased cell death rate in fibroblast culture by Trypan Blue exclusion. These results suggest that there is a continuous in vivo generation of cells with increased mortality resulting in both growth failure and atrophic intestinal mucosa in the patient. The atrophic intestinal mucosa might be a manifestation of ring instability.

Atrophy↗

Diamine oxidase (DAO) activity and intestinal mucosa integrity: influence of suture techniques.

After various kinds of intestinal mucosal injuries, whether by disease or by experiment, the diamine oxidase activity is reduced. Therefore, we studied the effect of surgical manipulations on the intestinal mucosa and diamine oxidase activity. The reaction of the gut on the insertion of sutures was a transient increase of the enzymic activity followed by reduction as soon as the mucosa started to gain weight. After a standardized pressure injury only a reduction of the diamine oxidase activity together with an enhancement of the mass of the intestinal wall was found. A hypothesis of a feed-back regulation of the diamine oxidase activity connected with mucosal proliferation is proposed.

Amine Oxidase (Copper-Containing)↗

Species-specific binding of purified pili (AF/R1) from the Escherichia coli RDEC-1 to rabbit intestinal mucosa.

Species-specific colonization of rabbit intestine by RDEC-1 Escherichia coli is an accepted animal model for bacterial mucosal adherence. To determine whether RDEC-1 pili are functional as adherence factors for this organism, we grew the organism under conditions that promoted pilus expression; we isolated the pili, documented their purity, and compared their mucosal adherence properties with those of whole organisms using an indirect immunofluorescence technique. Frozen sections of rabbit, rat, guinea pig, and human small intestine were incubated with either piliated or nonpiliated RDEC-1 organisms or purified RDEC-1 pili and observed for the distribution and intensity (0-4+) of fluorescence. Piliated RDEC-1 organisms fluoresced brightly (4+) and were distributed along the entire mucosal surface of the rabbit ileum. Only a few nonpiliated RDEC-1 attached to rabbit ileum, and they were randomly scattered across the entire section of tissue. Rabbit ileum overlain with pure RDEC-1 pili showed a specific, D-mannose resistant (2-3+) fluorescence on the mucosal surface from the crypts to the villus tips. No fluorescence was seen on the guinea pig, rat, or human mucosal surface overlain with RDEC-1 pili. Purified RDEC-1 pili adhere to the rabbit intestinal mucosa in a species-specific manner and with the same distribution as whole piliated organisms. The data suggest that RDEC-1 produce pili (distinct from type 1 pili) that determine the specificity of the mucosal adherence of RDEC-1 to rabbit ileum.

Adhesiveness↗

Demonstration of two different vitamin D-dependent calcium-binding proteins in rat intestinal mucosa.

The characteristics and location of rat intestinal proteins with calcium binding properties were reexamined using both a 45Ca-equilibrated Sephadex G-100 column and the chelex 100 method in the assay of 45Ca binding activity. The rat intestinal mucosa was found to have three different proteins with calcium binding properties. Two of these proteins were found to be vitamin D-dependent and were examined in detail. The larger vitamin D-dependent protein, found predominantly in the jejunum and ileum, had a molecular weight of 27,000 and demonstrated low affinity for calcium; the detection of this protein by the chelex 100 assay was very difficult. The smaller vitamin D-dependent protein, which was associated mainly with duodenum and jejunum, had a molecular weight of 12,500, and demonstrated a high affinity for calcium.

Animals↗

Mucinous adenocarcinoma of the colon metastatic to the intestinal mucosa.

Autometastasis of colon cancer to the intestinal mucosa is a condition that has not been previously described. The 70-year-old man presented in this case report was seen for routine surveillance colonoscopy 14 months after low anterior resection, without anastomosis, of a Dukes' stage C mucinous adenocarcinoma of the rectosigmoid. The patient had received adjuvant chemotherapy according to Southwest Oncology Group protocol 8899. The routine colonoscopy revealed many new polypoid lesions in the remaining left and transverse colon, and the patient underwent completion total abdominal colectomy. Examination of the specimen revealed more than 100 polyps; the histologic examination identified these polyps as metastatic signet ring mucinous adenocarcinoma.

Adenocarcinoma, Mucinous↗

UDP-glucuronosyltransferase UGT1A7 induced in rat small intestinal mucosa by oral administration of 2-naphthoflavone.

In the rat intestine, UDP-glucuronosyltransferase (UGT) isoforms were highly induced by oral administration of 2-naphthoflavone, as shown by intestinal UGT activity toward 1-naphthol (1-NA). The greatest increase in UGT activity occurred in the duodenum. Using UGT1A6 cDNA as a probe, we obtained three types of clones corresponding to UGT1A2, UGT1A6 and UGT1A7, in a ratio of 1:1:8, from a cDNA library constructed from the 2-naphthoflavone-treated rat intestine. The induction of each isoform was evaluated by means of Northern blotting with isoform-specific probes. The mRNAs of UGT1A6 (glucuronizing various phenolic xenobiotics) and the mRNAs of UGT1A7 (glucuronizing the ultimate carcinogenic metabolite of benzo(a)pyrene) were expressed constitutively and were highly induced in the duodenum and proximal jejunum. S1 mapping showed that induction of the isoforms of the UGT1 family was more pronounced in the liver than in the small intestine and that UGT1A7 was the major UGT1 isoform in the small intestine of vehicle-treated rats and in that of 2-naphthoflavone-treated rats. These results indicate that, in rats, UGT1A7 is expressed constitutively and is particularly inducible in the small intestine. In the light of these results, we believe that the UGT1A7 isoform would play an important role in glucuronidation in the small intestinal mucosa of rats.

Administration, Oral↗

Morphological changes of urothelial and intestinal mucosa after ureterosigmoidostomy during experimental urogenic carcinogenesis.

To analyze the effect of chemical carcinogens on urothelial and intestinal mucosa on 214 female Wistar rats an ureterosigmoidostomy was performed. After 10-14 days 123 surviving rats were randomly divided into 4 groups: Group I-III received 0.05 per cent N-Butyl-N-(4-hydroxybutyl)-nitrosamine (BBN) in drinking water over a period of 15 weeks. Group IV received normal drinking water over the same period. The defunctionalized bladders were instilled each second day: Group I: physiologic saline solution, Group II: urine of normal rats, Group III and IV: urine of BBN-treated rats. 30 rats without diversion but BBN treatment served as a control. The evaluation of the histological data gave the following results: In the control group urothelial tumors were found in the bladder exclusively. Dependent on the grade of obstruction in the BBN-treated groups, with diversion urothelial tumors in the renal pelvis and ureter could be documented, whereas in the bladder no tumor growth could be shown. In the intestinal mucosa of BBN-treated animals a high incidence of adenocarcinoma was found. The chemical tumor induction by BBN is related to the urine and takes place by direct contact to the mucosa when the metabolites excreted by the kidneys are activated in the urine. BBN or other urogenic carcinogens seem to have no urothelial specificity. The incidence of bowel carcinoma after diversion must lead to intensive long-term follow up.

Adenocarcinoma↗

Role of metal ions on the secondary and quaternary structure of alkaline phosphatase from bovine intestinal mucosa.

Alkaline phosphatase (EC 3.1.3.1) from bovine intestinal mucosa (BIAP) is an homodimeric metalloenzyme, containing one Mg2+ and two Zn2+ ions in each active site. ApoBIAP, prepared using ion-chelating agents, exhibited a dramatic decrease of its hydrolase activity, concomittant to conformational changes in its quaternary structure. By rate-zonal centrifugation and electrophoresis, we demonstrated, for the first time, that the loss of divalent ions leads to some monomerization process for a metal-depleted alkaline phosphatase. Divalent ions are also involved in the secondary and tertiary structures. Metal-depletion induced more exposure of some Trp residues and hydrophobic regions to the solvent (as proved by intrinsic and ANS fluorescences). These changes might correspond to the disappearance of alpha-helices and/or turns with a concomittant appearance of unordered structures and beta-sheets (as probed by FTIR spectroscopy). For BIAP, three steps of temperature-induced changes were exhibited, while for apoBIAP, only one step was exhibited at 55 degrees C. Our work on BIAP showed two main differences with alkaline phosphatase from Escherichia coli. The loss of the divalent ions induces protein monomerization and the total recovery of enzyme activity by divalent ion addition to apoBIAP was not obtained.

Alkaline Phosphatase↗

Subcellular distribution of PRibPP synthetase activity of rat intestinal mucosa.

5-Phosphoribosyl 1-pyrophosphate synthetase (PRibPP synthetase EC 2.7.6.1) isolated from rat intestinal mucosa was found to be membrane associated. The subcellular distribution of PRibPP synthetase activity seems to parallel that of gamma-glutamyl transpeptidase, indicating it to be in the brush border. The tip cells of rat intestinal mucosa were richer in PRibPP synthetase than the crypt cells. Chromatography of a Triton-solubilized particulate fraction unmasked a peak of hypoxanthine phosphoribosyltransferase activity that was not detectable before. The activity, too, was concentrated in the brush border. The coexistence of these two activities in the fraction of the bowl involved in absorption has led to the suggestin that the synthetase and phosphoribosyl-transferase are part of a coupled transport system.

Animals↗

Morphogenesis of rabbit small intestinal mucosa.

The sequential morphologic changes of rabbit small intestinal mucosa were studied from primodial stage to birth in 86 fetuses and during the early days of life in 18 rabbit newborns. In 13-day-old fetuses, the epithelium was flat and stratified. By the 17th day, epithelial ridges were formed. The first evidence of rudimentary villus formation was noted in 20-day-old fetuses and true villi appeared by 24 days of the gestation. Intestinal glands (crypts of Lieberkühn) were first observed at 29 days. The intestine of the newborn rabbit did not possess all mucosal constituents present in the adult. The duodenal glands (Brunner's glands) appeared in the first 2 days after birth, and the muscularis mucosa, on the 5th day. The histological maturity of the intestine occurred 20 days after the rabbit was born. At all stages, the morphogenesis followed a cranio-caudal gradient developmental pattern.

Aging↗

Morphology and ultrastructure of small intestine mucosa in gilts with zearalenone mycotoxicosis.

Zearalenone (ZEA) is a mycotoxin produced by Fusarium. It evokes disruptions in sex cycle and changes in the morphology of the reproductive organs in pigs. The morphology and ultrastructure of the small intestine mucosa were assessed after the course of the experimental zearalenone mycotoxicosis. During the experiment, pigs were fed feed containing low doses of ZEA. The experiment lasted 7 days and it was carried out on sexually immature gilts that were divided into 3 groups: control group (C) and 2 experimental groups (E1, E2; n=8). Groups E1 and E2 were given ZEA every day at a dose of 200 and 400 microg/kg b.w. The samples of tissues were taken for examinations after the slaughter on the last day of the experiment. No significant changes in the morphology of the intestinal mucosa were found in the experimental animals. Increased activity of the goblet cells and high content of mucinogen vesicles, lymphocytic infiltration, increased activity of endocrine cells and the presence of Paneth cells on the bottom of intestinal crypts, which sugest mobilisation of the local defence mechanisms in the intestinal mucosa, were obseved in group E2.

Animals↗