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PubMed2005

Heparan sulfate proteoglycans mediate Staphylococcus aureus interactions with intestinal epithelium.

Staphylococcus aureus can be internalized by non-professional phagocytes, and may colonize the intestine in normal and antibiotic-treated individuals. Intestinal colonization may depend on the interactions of S. aureus with the intestinal epithelium. The best described mechanism of S. aureus binding to eukaryotic cells involves S. aureus fibronectin binding proteins (FnBPs), using fibronectin as a bridging molecule to beta1 integrins on the eukaryotic cell surface. Because S. aureus can be internalized by enterocytes, and because S. aureus is known to bind heparan sulfate (HS), we hypothesized that heparan sulfate proteoglycans (HSPGs) widely expressed on epithelia may mediate S. aureus interactions with intestinal epithelial cells. Internalization of S. aureus RN6390 by cultured intestinal epithelial cells was inhibited in a dose-dependent fashion by the HS mimic heparin, and by HS itself. Internalization of S. aureus DU5883, which lacks expression of staphylococcal FnBPs, was also inhibited by heparin. S. aureus adherence to ARH-77 cells, transfected to express the HSPG syndecan-1, was greatly increased when compared to adherence to plasmid control ARH-77 cells which have little detergent extractable HS. In addition, compared to wild-type HS-expressing Chinese hamster ovary (CHO) cells, internalization of S. aureus was decreased using mutant CHO cells with decreased HS expression. These findings are consistent with a model wherein S. aureus internalization by intestinal epithelial cells (and perhaps other epithelia) is mediated by S. aureus binding to the HS moiety of cell-surface HSPGs, and this interaction appears independent of fibronectin binding.

Animals↗
PubMed1998

Determination of p185 and adenylosuccinate lyase (ASL) activity in preneoplastic colon lesions and intestinal mucosa of human subjects.

OBJECTIVES: The HER2 gene has been found amplified in a number of human adenocarcinoma leading to elevated levels of expression of its encoded product, p185 protein. Because little information is available on the tissue and tumor specificity of this gene product, we studied the expression of p185 protein in preneoplastic colon lesions. Adenylosuccinate lyase (ASL, EC 4.3.2.2) is known to increase in malignancies such as colorectal, breast, and prostate cancer. In order to evaluate the potential of ASL as a tumor marker, its activity was determined and compared with the expression of p185. DESIGN AND METHODS: p185 was determined by an immunohistochemical procedure in patients with the preneoplastic lesions. ASL activity was evaluated in intestinal mucosa adjacent to colorectal cancers (patient group A) and in preneoplastic colorectal lesions (group B). The enzyme activity was evaluated in dialyzed supernatants, following the disappearance of substrate (adenylosuccinate AMP-S) and the formation of product (adenosine 5'-monophosphate-AMP), separated by high performance liquid chromatography. RESULTS AND CONCLUSIONS: Increased expression of p185 and elevated ASL activity were observed in tubular and tubulo-villous adenoma and may, therefore, be associated with the early stages of colorectal cancer.

Adenoma↗
PubMed1992

Effect of hyperthyroidism on the transit of a caloric solid-liquid meal through the stomach, the small intestine, and the colon in man.

Gastric emptying, mouth-to-cecum transit, and whole gut transit of a solid-liquid meal was measured in 20 hyperthyroid patients and in 30 control subjects by using scintigraphic techniques, the hydrogen breath test, and stool markers. In the hyperthyroid patients predefined gastrointestinal symptoms were determined and related to gastrointestinal transit. There was no significant overall difference of gastric emptying between the hyperthyroid patients and the control subjects, whereas both mouth-to-cecum transit time (mainly reflecting small intestinal transit) and whole gut transit time (mainly reflecting large intestinal transit) were significantly accelerated in hyperthyroid patients as compared to the control subjects (P less than 0.005). Mouth-to-cecum transit in hyperthyroid patients with diarrhea tended to be more rapid than in those without diarrhea (P = 0.094) and the T3 concentrations were inversely correlated with mouth-to-cecum transit time. It is concluded that in thyrotoxicosis 1) small and large intestinal transit is accelerated, while gastric emptying remains unchanged and 2) rapid intestinal transit is likely to be one factor among others implicated in the generation of diarrhea.

Adult↗
PubMed1996

Activation of delayed rectifier potassium channels in canine proximal colon by vasoactive intestinal peptide.

1. Vasoactive intestinal peptide (VIP) inhibits phasic contractions and tone of gastrointestinal smooth muscles. This study examines electrical mechanisms that may mediate the inhibitory actions of VIP. 2. Electrical slow waves were recorded from canine proximal colon circular muscles. VIP (0.1 microM) decreased basal slow wave frequency but had no effect on amplitude or duration. When slow waves were enhanced with Bay K 8644 (1 microM), VIP decreased slow wave duration and inhibited contractions. 3. VIP inhibited slow waves and phasic contractions stimulated by tetraethylammonium chloride (TEA; 10 mM), but did not significantly reduce events stimulated by 4-amino-pyridine (4-AP; 10 mM). 4. Whole-cell outward currents were recorded from isolated myocytes, using the amphotericin B perforated patch technique. VIP (1 microM) increased charybdotoxin-insensitive outward currents. 5. Single voltage-dependent K+ channels were recorded in cell-attached patches. VIP increased reversibly the open probability, mean open time and mean burst duration of 4-AP-sensitive, charybdotoxin-insensitive K+ channels (KDR1). Two additional 4-AP- and charybdotoxin-insensitive K+ channels (approximately 90 pS and < 4 pS) were also observed in these patches, but were not significantly affected by VIP. 6. In summary, the effects of VIP on electrical slow waves may be due, in part, to activation of 4-AP-sensitive, 'delayed rectifier' K+ channels. Activation of these channels may contribute to premature slow wave repolarization, reduced Ca2+ entry, and inhibition of contractile force.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed2003

Enhancement of aquaporin-3 by vasoactive intestinal polypeptide in a human colonic epithelial cell line.

BACKGROUND: Vasoactive intestinal polypeptide (VIP) plays an important role in water transport in the intestine. Several specialized channels termed aquaporins (AQP) facilitate water transport in the gastrointestinal tract. Aquaporin-3 localizes to epithelial cells in the human small intestine and colon. However, the regulatory mechanisms underlying the functions of AQP3 remain unclear. To characterize the regulation of AQP3 expression by VIP, we studied messenger (m)RNA expression, protein expression and DNA binding activity in a human colonic epithelial cell line, HT-29. METHOD: Human colonic epithelial cells, HT-29, were incubated with VIP (10-12-10-7 M). The cells were treated with protein kinase-A (PK-A) inhibitors (H-89, H-9) or chloride channel-blockers (diphenylamine-2-carboxylate (DPC), 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPD)). The expression of AQP3 mRNA and protein was determined by Northern blot and Western blot, respectively. The DNA-binding activities of cyclic adenosine monophosphate (cAMP) response elements/activating transcription factor (CRE/ATF)) in the nuclear extract were determined by electrophoretic mobility shift assay. RESULTS: Aquaporin-3 mRNA was up-regulated at a concentration of 10-10 M VIP. The expression of AQP3 protein was enhanced at 3 h after addition of VIP. The PK-A inhibitors (H-89, H-9) inhibited the expression of AQP3 mRNA enhanced by VIP and cAMP. The gel shift assay of CRE/ATF in HT-29 cells revealed a single band. CONCLUSION: These results indicate that VIP upregulated the expression of AQP3 mRNA and protein, and that a cAMP-dependent pathway mediated this effect in a human colonic epithelial cell line, HT-29.

Aquaporin 3↗
PubMedDate not supplied

Decreased galactose absorption in dumping after colon interposition.

Intestinal absorption was examined using an oral galactose test in colon interposition patients with dumping (no. 4) and without symptoms (no. 5). Normal subjects (no. 5), and patients after total gastrectomy (no. 7) and gastric resection (no. 4) served as controls. Galactose is absorbed in the same way as glucose, but does not stimulate insulin secretion. Colon interposition patients presented abnormally rapid postprandial transit and absorption for 20 minutes after the meal. After this rapid phase, colon interposition patients with dumping demonstrated a strong decrease in absorption rate, whereas the asymptomatic patients presented a normal rate during the whole follow-up period. The elimination of galactose from the blood was studied in eight patients after intravenous infusion of galactose; the disappearance was linear during 10 to 30 min after injection and did not explain the differences in blood galactose levels in the oral galactose test. We suggest a reactive reflux back to the intra-abdominal colon graft loop in the avagotonic intestinal tract as the mechanism for the differences in absorption. The most likely reason for this is the rapid initial phase transit through the coloantral anastomosis and pyloroplasty. To normalize postprandial transit and absorption as much as possible after colon interposition, a short intra-abdominal colon graft loop anastomosed to the posterior proximal stomach is suggested.

Colon↗
PubMed1988

Role of intestinal anaerobic bacteria in colonization resistance.

The purpose of this study was to clarify the role of the intestinal anaerobe bacteria in colonization resistance. Germfree mice were associated with Escherichia coli C25 and either (a) no other species; (b) enterococcus; (c) Escherichia coli M14 and Proteus mirabilis, or (d) Bacteroides fragilis and Bacteroides vulgatus. All species colonized the cecum in high numbers, but only enterococcus significantly limited the translocation of Escherichia coli C25 to mesenteric lymph nodes. However, the overall translocation rates were similar in all groups and ranged from 60% to 100%, due to translocation of other intestinal flora in addition to Escherichia coli C25. Conventionally reared mice were given either streptomycin, bacitracin/streptomycin or metronidazole which selectively eliminated facultative gram-negative bacteria, nearly all bacterial species or strictly anaerobic bacteria respectively. Only metronidazole significantly increased the rates of translocation of normal intestinal bacteria into mesenteric lymph nodes. Cohort groups of mice were then orally inoculated with drug resistant Escherichia coli C25, which actively colonized the cecum of all drug treated mice and translocated to the mesenteric lymph nodes of approximately half the streptomycin and metronidazole treated mice and nearly all the bacitracin/streptomycin treated mice. These results indicate that anaerobic bacteria play a pivotal role in limiting the translocation of normal intestinal bacteria, but that other bacterial groups also have a role in preventing the intestinal colonization and translocation of potential pathogens.

Animals↗
PubMed2004

Adaptation of Campylobacter jejuni NCTC11168 to high-level colonization of the avian gastrointestinal tract.

The genome sequence of the human pathogen Campylobacter jejuni NCTC11168 has been determined recently, but studies on colonization and persistence in chickens have been limited due to reports that this strain is a poor colonizer. Experimental colonization and persistence studies were carried out with C. jejuni NCTC11168 by using 2-week-old Light Sussex chickens possessing an acquired natural gut flora. After inoculation, NCTC11168 initially colonized the intestine poorly. However, after 5 weeks we observed adaptation to high-level colonization, which was maintained after in vitro passage. The adapted strain exhibited greatly increased motility. A second strain, C. jejuni 11168H, which had been selected under in vitro conditions for increased motility (A. V. Karlyshev, D. Linton, N. A. Gregson, and B. W. Wren, Microbiology 148:473-480, 2002), also showed high-level intestinal colonization. The levels of colonization were equivalent to those of six other strains, assessed under the same conditions. There were four mutations in C. jejuni 11168H that reduced colonization; maf5, flaA (motility and flagellation), and kpsM (capsule deficiency) eliminated colonization, whereas pglH (general glycosylation system deficient) reduced but did not eliminate colonization. This study showed that there was colonization of the avian intestinal tract by a Campylobacter strain having a known genome sequence, and it provides a model for colonization and persistence studies with specific mutations.

Adaptation, Biological↗
PubMed1992

Effect of fermented oatmeal soup on the cholesterol level and the Lactobacillus colonization of rat intestinal mucosa.

Rats were fed with freeze-dried oatmeal soup fermented by six different Lactobacillus strains from rat and man; the formula is intended for enteral feeding. The serum cholesterol levels after 10 d were lower for rats eating oatmeal as compared to a commercial product, Biosorb Sond. Colonizing ability of the administered strains were evaluated in vivo. Only Lactobacillus reuteri R21c were able to, effectively, colonizing the mucosa; it represented about 30% of the Lactobacillus population 24 d after termination of the administration. L. reuteri R21c was easily recognized by the ability to produce a yellow pigment on agar plates. The identity was confirmed by carbohydrate fermentations (API 50CH), plasmid pattern and endonuclease restriction analysis of the chromosomal DNA.

Animals↗
PubMed1996

Phenotypic expression of a mannose-sensitive hemagglutinin by a Vibrio cholerae O1 E1Tor strain and evaluation of its role in intestinal adherence and colonization.

A Vibrio cholerae O1 strain (1150) of the EIT or biotype and Ogawa serotype with haemagglutination (HA) activity was subjected to TnphoA mutagenesis. Out of several mutants isolated, one HA- and another HA+ mutant were further characterised. The HA- mutant showed about 50% reduction in its intestinal adherence capacity in vitro and about 9-fold decrease of its colonisation ability in vivo, as compared to the wild-type strain. Subsequent studies showed that the HA activity of strain 1150 was mediated by a mannose-sensitive haemagglutinin (MSHA). Thus, the phenotypic expression of MSHA appears to be partly responsible for the intestinal adherence and colonisation properties of strain 1150.

Animals↗
PubMedDate not supplied

[Comparative experimental study of left colonic anastomoses in intestinal obstruction; the value of anastomoses protection with free peritoneal graft].

The paper describes the concept of peritoneal graft used to reinforce the colo-colic anastomoses made in emergency conditions of left colic obstruction, experimentally induced by surgical ligature, on Wistar rats. The comparative study was done on 24 rats, divided in 3 groups: group A with colic anastomoses protected with peritoneal graft, group B with one-layer colic anastomoses and group C with two-layer colic anastomoses. After 8 days, 7 rats survived in group A, 2 rats in group B and 3 rats in group C. All surviving rats in groups B and C presented anastomotic leak with local peritonitis, while in group A the anastomosis were healed. For group A, bursting strength of the anastomosis was measured and the mean value found was 63.64 cmH2O. It was proved the importance of protecting the colic anastomosis with supplementary layers, which increase the mechanical resistance and also prevents minor spillage of the colic content during the first postoperative days.

Anastomosis, Surgical↗
PubMed1977

Isolated small bowel obstruction as the presenting feature of colonic disease.

Small intestinal obstruction without colonic dilation can be the mode of presentation in a variety of colonic diseases, including carcinoma, diverticulitis, and colitis. Plain abdominal roentgenograms may lead the unwary physician into errors of diagnosis and treatment by suggesting primary small bowel disease. Barium enema examination of the colon will keep the wary physician out of such traps. We describe five patients with small bowel obstruction who had a variety of colonic diseases diagnosed by barium contrast studies. If the reason for intestinal obstruction is not apparent and the need for emergency surgery is not compelling, we recommend an immediate contrast study of the colon to aid in evaluating possible colonic pathology.

Adult↗
PubMed2001

Modulation of inducible nitric oxide synthase expression in rat intestinal cells by colon tumor promoters.

Metabolic epidemiological studies in humans and laboratory animal models demonstrate that consumption of diets high in fat and low in fiber excrete increased levels of 1,2-diacyl-sn-glycerol (DAG) and secondary bile acids such as deoxycholic acid (DA) and lithocholic acid that have been shown to promote colon carcinogenesis. The secondary bile acids and DAG have been shown to activate protein kinase C (PKC) and induce colonic cell proliferation. A large body of evidence indicates that iNOS, an inducible isoform of nitric oxide synthase, is over-expressed in human colon adenomas and in chemically-induced colon tumors of laboratory animals. However, the precise cascade of intracellular events that leads to the iNOS over-expression remains to be fully explored. In this study, we investigated the relationship between induction of iNOS and activation of the PKC pathway by DAG and DC, in an in vitro system using the rat intestinal cell line, RIE-1. As an initial step, we determined whether lipopolysaccharide (LPS) and phorbol 12-myristate 13-acetate (PMA) modulate iNOS protein expression in RIE-1 cells. Treatment of RIE-1 cells with LPS and PMA for 4 h significantly elevated the iNOS protein expression. The induction of iNOS by the treatment with LPS/PMA was concentration- and time-dependent. Treatment with LPS/DAG or LPS/DC also caused iNOS over-expression in a concentration- and time-dependent fashion suggesting that DAG and DC induce iNOS activity in intestinal cells. Pretreatment with specific PKC inhibitors, bisindolylmaleimide I or Gö 6976, inhibited LPS/PMA, LPS/DAG, or LPS/DC-induced iNOS expression and activity. Extracts of the cells treated with LPS/PMA, LPS/DAG or LPS/DC had a high iNOS activity compared to that of control (p<0.04 to p<0.0001). Taken together, our data suggest a possible role of colon tumor promoters, DAG and DC, for iNOS over-expression through activation of the PKC pathway.

Animals↗
PubMed1999

[Endometriosis of the ileum and colon complicated by intestinal obstruction. Report of two cases].

The authors report two cases of intestinal occlusion, one ileal and the other colic, caused by endometriosis. Both patients underwent surgery. Following a review of data in the literature regarding the frequency, pathogenesis, diagnosis and management, the authors conclude that pre- and intraoperative diagnosis is often impossible in these cases and must be postponed to histological analysis. Full remission was achieved after surgery.

Adult↗
PubMed1979

[Peritoneal drainage in emergency surgery of the appendix, colon and small intestine].

Retrospective study of patients who underwent as an emergency, a peritoneal drainage during laparotomy for peritonitis with perforated appendix (147 cases), or operation for lage bowel (68 cases) or small bowel (46 cases) pathology. The technique of drainage number of drains, duration of drainage, and length of stay in hospital are examined, as well as antibiotherapy. The conclusions do not allow us to attribute a harmful influence to peritoneal drainage, except perhaps that the duration of stay in hospital can be longer. The absence of a comparison group does not allow us to prove the utility of peritoneal drainage. The literature at our disposal is discussed, the majority of which is opposed to peritoneal drainage.

Adolescent↗
PubMed1977

[Effects of loperamide on the motility of the isolated intestine in guinea pigs, rats and dogs (author's transl)].

Effects of Loperamide on the motility of the isolated intestine in guinea-pigs, puppies and rats were examined. The spontaneous contractions of the small intestine and colon in puppies were inhibited at relatively high concentration of the agent (10(-5) g/ml). The peristaltic reflex in the guinea-pig ileum was slightly inhibited at concentrations of 10(-8) to 10(-7) g/ml, and was completely abolished at 10(-6) g/ml. The agent (2X10(-7) g/ml) inhibited the longitudinal contraction of the guinea-pig ileum elicited by transmural electric stimulation. The agent (10(-5) g/ml) inhibited the acetylcholine-induced contraction of the colon and small intestine in puppies, and induced the hyperpolarization of the membrane potential and the abolition of spike potentials of the intestinal muscle in rats.

Action Potentials↗
PubMed1989

[Effect of sisomicin on intestinal microflora and colonization resistance in rats and their offspring].

In experiments with Wistar female rats it was shown that after administration in the form of inhalations (10.87 mg/m3) sisomicin was present in the animal feces in a concentration of 26.6 micrograms/g. Prolonged exposure to the antibiotic during the pregnancy term led to changes in microbiocenosis of the animal large intestine which was observed even a month after the delivery. The progeny of the animals was characterized by the presence of significant numbers of aerobic bacteria resistant to sisomicin and potentially pathogenic gram-negative bacteria including various species of Proteus in the intestine, as well as by higher periods of persistence of Klebsiella indicator strains administered orally.

Animals↗