Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Intestinal colonization”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,801 records · Page 100Linked to original sources
PubMedDate not supplied

Absorption of valproic acid from the gastrointestinal tract of the piglet.

Valproic acid is a commonly used drug for the treatment of epilepsy. Since valproic acid can only be given orally, its absorption from the gastrointestinal (GI) tract especially in patients with short bowel syndrome (SBS) and in neonates is important. The specific sites of absorption for valproic acid in the small intestine and colon have not been investigated. It is currently unknown whether these patients are able to absorb oral valproic acid sufficiently to maintain a therapeutic serum concentration. The primary objectives of the study were to: (a) determine the relative absorption of valproic acid from specific sites in the GI tract; and (b) investigate the influence of intestinal development on valproic acid absorption using the newborn piglet as a model. Two groups were studied: Group I included 5 piglets 18-21 days of age, and Group II included 5 piglets 1-3 days of age. A valproic acid solution was simultaneously perfused through 5 partitioned segments of the gastrointestinal tract: the duodenum, jejunum, ileum, right colon and left colon. Tritiated [3H] polyethylene glycol was co-administered to monitor water movement across the GI mucosa. Following steady state, samples were collected from each segment, and analyzed by a specific enzyme-mediated immunoassay. The absorption rates (micrograms/min/cm) of valproic acid in Group I were as follows: 9.96 +/- 2.8 duodenum; 11.28 +/- 2.79, jejunum; 9.42 +/- 3.34, ileum; 10.88 +/- 3.35, right colon; 10.96 +/- 2.92, left colon.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2002

Transcripts encoding HAND genes are differentially expressed and regulated by BMP4 and GDNF in developing avian gut.

Growth and transcription factors provide important developmental cues to neural crest-derived precursors of enteric neurons. The basic helix-loop-helix transcription factors, HAND2 and HAND1, are expressed in the gastrointestinal tract, but neither the growth factors that induce their expression nor the cell types that express them in the gut are known. We show that transcripts encoding HAND2 are expressed in all segments of the developing gut while those encoding HAND1 are confined to the small intestine and colon. Using in situ hybridization combined with immunostaining using cell type-specific antigens, we demonstrate that transcripts encoding HAND2 are expressed in neurons of both the myenteric and submucosal ganglia. Transcripts encoding HAND1 are expressed by cells in the epithelial lining of the small intestine and colon. The differential localization of HAND2 and HAND1 is reflected in nonoverlapping patterns of regulation by gut-derived factors. The expression of transcripts encoding HAND2 is increased in neural crest-derived cells when cocultured with E4 gut, suggesting a gut-derived factor regulates expression of HAND genes. Exposure of gut-derived neural crest-derived cells to BMP4 significantly increased the expression of HAND2 in all gut segments. In the esophagus and gizzard, where HAND1 is not normally expressed, treatment with BMP4 induced the expression of transcripts encoding HAND1 in nonneural crest-derived cells. GDNF failed to induce consistent expression of transcripts encoding HAND2 in neural crest cells but did support a modest increase in HAND2 expression in gut-derived crest cells obtained from the esophagus and colon. GDNF had no detectable effect on the expression of transcripts encoding HAND1. These results suggest; 1) that HAND2 has a function in the development of enteric neurons, and 2) that BMP and GDNF differentially regulate HAND2 and HAND1 gene expression in the developing gastrointestinal tract.

Animals↗
PubMed1989

Proinflammatory effects of local abdominal irradiation on rat gastrointestinal tract.

Although the role of inflammatory processes in the genesis of late changes in the gastrointestinal tract following exposure to ionizing irradiation has been extensively studied, few studies have concentrated on the presence of an acute inflammatory response in the period immediately following radiation. We therefore examined, in rats, whether the local application of 10 Gy cobalt-60 irradiation to the abdomen led to changes in the gut within the first 24 hr that were consistent with an acute inflammatory response. In stomach, small intestine, and colon, local irradiation led to a significant increase in the accumulation of plasma within the tissue by 4-8 hr following irradiation. This increase in tissue plasma volume, indicative of an increased microvascular permeability, was then sustained until the end of the 24-hr assessment period in all tissues examined. Concurrent with this was a consistent transient increase in tissue red blood cell volume, suggestive of vasodilation. Of particular note, a significant increase in the number of mucosal neutrophils was also observed between 2 and 12 hr following irradiation. This elevation in mucosal neutrophils was particularly marked in the pericryptal or deep mucosal regions of small intestine and colon and consistently preceded the vasodilation and enhanced permeability. Furthermore these pathophysiological alterations occurred at a time when histological changes in the mucosa consistent with an impaired mucosal microcirculation (ie, edema of the lamina propria and subepithelial bleb formation) were present. These results support the hypothesis that an inflammatory response occurs in the gut during the first 24 hr following abdominal irradiation. Such changes may then further exacerbate the damage initiated by the ionizing radiation.

Acute Disease↗
PubMed1994

Immunolocalization of a mesenchymal antigen specific to the gastrointestinal tract.

BACKGROUND: The aim of the present study was to localize, at the fine structural level, a protein found by indirect immunofluorescence to be associated with the mesenchymal tissue 1) closely applied to the intervillus epithelium before the formation of intestinal crypts in the mouse fetus and 2) around intestinal crypts during and after their formation. METHODS: We used a pre-embedding immunolabeling technique for extracellular matrix molecules, and a monoclonal antibody (Mab) directed against antigen MIM-1/130. RESULTS: Immunofluorescence disclosed the presence of antigen 1/130 in the connective tissue closely applied to the epithelium of the gallbladder, pyloric glands, and intestinal and colonic crypts in adult mice. The antigen was absent in all salivary glands, kidney, liver, lung, spleen, and pancreas. At the fine structural level, gold particles in positive organs were associated with the interstitial matrix around collagen fibrils underneath the epithelia; gold particles were completely absent in the basement membranes. In the small intestine, labeling was seen only around crypts from cell position 1 up to the crypt-villus junction; it was totally absent under the villus epithelium. In order to confirm this particular localization in vivo, Mab 1/130 was administered orogastrically to 9-day-old mice: after 3 hours the antibody was found lining the immediate periphery of duodenal crypts as seen by indirect immunofluorescence. In control animals, an anti-mouse laminin Mab of the same subclass as Mab 1/130 was orogastrically fed using the same protocol: basal laminae were labeled under the epithelium of duodenal villi and crypts and also in the lamina propria, with a decreasing gradient from the top of the villi to the bottom of the crypts. CONCLUSION: These observations indicate that the extracellular matrix associated with the epithelium of pyloric glands, of intestinal and colonic crypts, and of gallbladder contains a new antigen whose function remains to be determined. The neonatal mouse hence constitutes a good model to study the role of extracellular matrix components in determining organ differentiation in vivo.

Animals↗
PubMed1971

The intestinal flora of colonization-resistant mice.

To facilitate the isolation of anaerobes from cultures in which swarming organisms were present Roux flasks were adapted to provide anaerobic conditions. Using these flasks, five species of anaerobes were isolated from the caecum of mice resistant to colonization with Escherichia coli and other Gram-negative organisms. These species accounted for the majority of organisms seen in films of caecal material. No aerobes were isolated and the flora of these mice apparently consisted of a limited number of anaerobes representing part of the intestinal flora of conventional mice. Three of the species were clostridia and another was identified as Propionibacterium acnes. One species resembled Catenabacterium but was not identified. One of the Clostridium species could only be isolated when the medium was supplemented with yeast extract and vitamins. This species sporulated on media with ammonium phosphate as the source of nitrogen; tryptone completely suppressed sporulation.

Animals↗
PubMed1997

Ileocecal segment transposition does not alter whole gut transit in humans.

OBJECTIVES: We have recently described a reservoir for rectal replacement after total mesorectal excision for rectal carcinoma. The ileocecal segment with its intact extrinsic nerve and blood supply is placed between the ascending colon and the anal canal. This reconstruction has been shown to provide good defecation quality and anorectal function. Whether gastric emptying and small as well as large bowel transit are affected by this transposition remains unclear. Our aim was to quantify whole gut transit in such patients and compare it with that of a matched group of controls. METHODS: Gastric emptying rates and small intestinal and colonic transit times were assessed scintigraphically in 12 patients aged 46 to 87 years with ileocecal reservoir reconstruction after total mesorectal excision and compared to a sex-matched group of asymptomatic healthy volunteers of similar age. Gastric emptying rates and small intestinal and colonic transit times were calculated as described previously. Data were compared using Wilcoxon's signed rank test for gastric emptying rates and small bowel transit or by analysis of variance for colonic transit; p < 0.05 was considered significant. RESULTS: Gastric time for half of the meal (T50) was 161 +/- 16 minutes for patients and 201 +/- 22 for the controls. Small bowel transit time was 150 +/- 15 minutes for patients and 177 +/- 22 for the controls. Geometric center at 6 hours was 1.53 +/- 0.13 for patients and 1.27 +/- 0.16 for the controls. Geometric center at 24 hours was 2.96 +/- 0.23 for patients and 2.57 +/- 0.25 for the controls. Data are mean +/- SEM. SUMMARY: Gastric emptying rates and small bowel transit and colonic transit times (expressed as geometric center at 6 and 24 hours) were similar in patients with ileocecal reservoir reconstruction and in a sex- and age-matched group of healthy controls. We conclude that the transposition of an ileocecal segment with intact extrinsic neurovascular supply between the sigmoid colon and the anal canal does not alter whole gut transit, not even in any of the presumably key regions.

Age Factors↗
PubMed1981

[Permissive effects of human colonic cancer (HT-29 and Caco-2) on intestinal smooth muscle differentiation].

Human colonic carcinoma cells (lines HT-29 and Caco-2) were associated with 5 1/2 day-old chick embryonic intestinal mesenchyme and grafted for 11 days into 3 day-old Chick embryos. In these conditions, the cancer cells exert on the mesenchyme a supportative effect leading to its differentiation into muscular layers. The results provide additional evidence that HT-29 and Caco-2 cells exhibit common properties to fetal and normal intestinal cells.

Animals↗
PubMed1997

Imbalance of the interleukin 1 system in colonic mucosa--association with intestinal inflammation and interleukin 1 receptor antagonist [corrected] genotype 2.

BACKGROUND: Interleukin 1 (IL-1) alpha and beta are potent cytokines which play key roles in inflammation. They are controlled by IL-1 receptor antagonist (IL-1ra). AIMS: To investigate the influence of mucosal inflammation and IL-1ra genotype on the IL-1ra:IL-1 balance. PATIENTS AND METHODS: IL-1 alpha, IL-1 beta, and IL-1ra were measured by enzyme linked immunosorbent assay (ELISA) in biopsy specimens taken from inflamed and non-inflamed colon of 60 patients with Crohn's disease (CD), 34 with ulcerative colitis (UC), 15 inflammatory controls, and 103 non-inflamed controls. IL-1ra genotype was determined by polymerase chain reaction and gel electrophoresis. RESULTS: IL-1 alpha and IL-1 beta were significantly increased in inflamed mucosa in inflammatory bowel disease (IBD) (CD: 53.5 (22.4) and 409.9 (118.7) pg/mg protein, respectively; UC: 18.9 (6.8) and 214.5 (78.2) pg/mg, respectively) and non-IBD patients (19.2 (7.4) and 281.4 (121.0) pg/mg, respectively; p < 0.0001) compared with normal controls (2.8 (0.6) and 30.6 (5.6) pg/mg, respectively). In CD IL-1 alpha and beta were also significantly increased in non-inflamed mucosa (6.1 (1.3) pg/mg and 88.7 (17.4) pg/mg, respectively; p < 0.0012). IL-1ra:(IL-1 alpha+beta) ratios were significantly decreased in inflamed mucosa of patients with CD (182 (45); p < 0.0001), UC (425 (136); p = 0.0018) and without IBD (221 (76); p < 0.0001), and in non-inflamed mucosa in CD (369 (149); p < 0.0001) compared with normal controls (1307 (245); p < 0.0001). Patients with IL-1ra genotype 2 had slightly but significantly reduced mucosal IL-1ra concentrations (p = 0.003). The greatest difference was seen in colonic biopsy specimens from patients with inflamed Crohn's disease. CONCLUSION: Mucosal inflammation can modulate the balance of the IL-1:IL-1ra system in colonic mucosa.

Adult↗
PubMed1986

Protection of acute and late radiation damage of the gastrointestinal tract by WR-2721.

WR-2721 was investigated for its protective effect against acute and late damage produced by irradiation of the esophagus, small intestine, and colon of mice. The microcolony assay was used to measure the acute response of the small intestine and the colon, and an LD50 assay (within the 28- to 42-day time range) was used to measure acute esophageal damage. A dose of WR-2721 at 400 mg/kg, injected 30 min prior to irradiation, resulted in a protection factor (PF) of 1.6 against radiation damage in these three regions of the gastrointestinal tract. Lethality and histology scores were applied to determine late radiation damage to the rectum, at times ranging from 3 to 15 months after irradiation. Deaths occurred after doses of 20 Gy and above throughout the postirradiation period. WR-2721 increased the survival of mice; the PF calculated from the LD50 values was 1.5. PFs of animal survival did not vary during the observation period. Histological studies showed evidence of ulceration, fibrosis, and vascular changes as late radiation damage. WR-2721 protected against radiation-induced histological damage with a PF of 1.3. There was no qualitative difference between the types of histological damage observed in the group undergoing only irradiation and the group treated with WR-2721. Biochemical measurements of fibrosis by hydroxyproline determination of collagen 16 months after irradiation showed an increase in collagen per milligram wet weight of rectal tissue in all irradiated groups, but no increase in the amount of collagen per 5 mm segment of the rectum. Thus it appears that the apparent fibrosis is a result of atrophy rather than collagen accumulation. We conclude that WR-2721 is indeed effective at protection against late damage from large single doses of radiation to the rectum as measured histologically and also improves the long-term survival of the mice, although the target cells for this damage are not known.

Animals↗
PubMed1983

Bacterial colonization and morphology of the intestine in porcine Escherichia coli enterotoxemia (edema disease).

Twenty-one pigs were divided into three groups. Pigs in one group were inoculated with the intestinal contents which included bacteria from a pig with edema disease. Pigs in another group were inoculated with a culture of Escherichia coli serogroup O 139:K12(B):H1 isolated from the aforementioned contents, and pigs in a third group served as uninoculated controls. The infection was similar following both inocula. Enterotoxemia developed in 11 of the 14 pigs allowed to survive for more than two days. The onset varied from two to seven days after inoculation. There were maximal viable counts of E. coli in the intestine from the second day post-inoculation and thereafter. In frozen and paraffin sections, as well as by scanning electron microscopy, the organisms were seen on the surface of the small intestinal epithelium where they formed either isolated colonies or continuous layers. They colonized the lower small intestine more intensely than the upper section. The intestinal epithelium and the villi of infected pigs were indistinguishable morphologically from the tissues of three uninoculated control pigs. The diarrhea which was observed in controls and inoculated pigs before inoculation and the villus atrophy in controls and inoculated pigs indicated a preexisting infection with at least one other agent.

Animals↗
PubMed1989

Requirement for capsular antigen KX105 and fimbrial antigen CS1541 in the pathogenicity of porcine enterotoxigenic Escherichia coli O8:KX105 strains.

The requirement for capsular antigen KX105 and fimbrial antigen CS1541 in the pathogenicity of porcine enterotoxigenic Escherichia coli O8:KX105 strains lacking the colonization factor antigens K88, K99, 987P and F41 was investigated using two encapsulated strains and their acapsular variants, one of which produced the fimbrial antigen CS1541 in vitro. None of the strains adhered in vitro to enterocytes isolated from newborn colostrum-deprived piglets. All of the strains caused diarrhea in orally infected, hysterotomy-derived, colostrum-deprived piglets although a great variability in the clinical response of the piglets was observed. Colonization of the small intestine of infected piglets by these strains was only moderate and no differences in the ability to colonize the small intestine was noted between the strains. All of the strains reacted in the indirect fluorescent antibody test with both CS1541 and 987P antisera when applied to organisms in the intestines of infected piglets. A control strain expressing the 987P fimbrial adhesin also reacted with the CS1541 antiserum applied to organisms in the intestines of an infected piglet. It was concluded that capsular antigen KX105 was not essential for intestinal colonization and production of diarrhea in hysterotomy-derived colostrum-deprived pigs, and that fimbrial antigen CS1541 does not promote in vitro adherence to enterocyte brush borders but could be important in bacterial colonization in vivo.

Animals↗
PubMed2002

Screening and identification of proteins mediating senna induced gastrointestinal motility enhancement in mouse colon.

AIM: To isolate the proteins involved in pharmacologic action of senna extract (SE) from mouse gastrointestinal tract and to explore the molecular mechanism of gastrointestinal motility change induced by SE. METHODS: SE was administrated to mice by different routes. Gastrointestinal motility of mice was observed using cathartic, gastrointestinal propellant movement experiments and X-ray analysis. Mouse model for gastrointestinal motility enhancement was established through continuous gastric administration of SE at progressively increased dose. At 3 h and week 3, 4, 6 and 10, morphological changes of gastrointestinal tissues were found under light microscope. Ultrastructural changes of intestinal and colonic tissues at week 6 were observed under transmission electron microscope. The colonic proteomic changes in model mice were examined by two-dimension polyacrylamide gel electrophoresis with immobilized pH gradient isoelectric focusing to screen the differentially expressed proteins, and their molecular masses and isoelectric points were determined. Two N-terminal sequences of the samples were also determined by mass spectrometry. RESULTS: SE (0.3g) caused diarrhea after gastric administration in 1-6h and enhanced gastrointestinal propellant (65.1+/-7.5%; 45.8+/-14.6%, P<0.01) in mice, but intramuscular and hypodermic injection had no cathartic effect. X-ray analysis of gastrointestinal motility demonstrated that gastric administration of SE enhanced gastric evacuation and gastrointestinal transferring function. At 3 h and week 3 and 4 after gastric administration of SE, light microscopic examination revealed no apparent change in gastrointestinal mucosal tissues, but transmission electron microscopic examination revealed inflammatory changes in whole layer of intestinal and colonic wall. Twenty differential proteins were detected in the colonic tissues of the model mice by two-dimensional electrophoresis, and the N-terminal amino acid sequences of two proteins were determined. CONCLUSION: SE causes diarrhea and enhances gastrointestinal motility through digestive tract administration. Long-term gastric administration of SE induces inflammatory changes and cell damage in the whole gastrointestinal tract. The differential proteins screened from the colonic tissues of the model mice might mediate the enhancing effect of SE on gastrointestinal motility.

Animals↗
PubMed1996

[Two cases of the congenital posterolateral diaphragmatic hernia were reported].

Case 1, a 9-year-old woman, was admitted to our hospital because of nausea, vomiting, and epigastralgia. Diagnosis of Bochdalek hernia was made by the unusual course of naso-gastric tube. At surgery through the left posterorateral thoracotomy, the herniation of the stomach, small intestine, and colon to the thoracic cavity through the dorsolateral defect of the diaphragm were revealed. Case 2, a 35-year-old man, was admitted to our hospital because of dyspnea. Similar diagnosis was made by the examination of upper G1 series and barium enema, which demonstrated the presence of multiple loops of the small intestine and colon in the left thoracic cavity. Their postoperative courses were uneventful. Most of Bochdalek hernia is observed in infancy, and adolescent or adult case is is rarely reported (approximately 10% of all cases). Since this often misdiagnosed as pleuritis or pulmonary tuberculosis, a cautious examination is necessary for the establishment of the correct diagnosis.

Adult↗
PubMed1996

Preventive effect of atropine on indomethacin-induced gastrointestinal mucosal and vascular damage in rats.

The protective effect of 'chemical vagotomy' (atropine given in three doses: 0.1, 0.5 and 1.0 mg/kg i.p.) was examined on indomethacin (IND, 20 mg/kg s.c.)-induced macroscopic gastrointestinal (GI) mucosal erosions and changes of vascular permeability in the stomach and three equal parts of small intestine and colon in rats. The different doses of atropine were administered at 0, 5, 10, 15 and 20 h after IND administration, then the number and severity of lesions were noted and the vascular damage was measured by Evans blue extravasation into the mucosa and intraluminal juice at 24 h after the IND treatment. Our results indicate that atropine ('chemical vagotomy') dose-dependently and significantly decreases the IND-induced mucosal erosions and vascular permeability in the vagal nerve-innervated parts of GI tract (i.e. the stomach, small intestine and proximal colon). Atropine in 0.5 and 1.0 mg/kg doses has a significantly higher protective effect on the vascular damage than on the macroscopic mucosal lesions in the stomach, small intestine and proximal colon. The vascular permeability is only one of those factors which have a role in the appearance of the GI mucosal erosions after IND treatment. These results suggest that the decrease of vascular permeability is involved in the protective effect of atropine against IND-induced GI mucosal damage.

Animals↗
PubMed1983

Effects of thermal applications on the abdominal temperature of dogs.

The results of thermal applications to the abdomens of unrestrained, unanesthetized dogs are reported. A silicone rubber envelope through which water circulated at 0 degrees, 10 degrees, 20 degrees, 30 degrees, 40 degrees, or 50 degrees C was applied. Skin surface, subcutaneous, intraperitoneal, intestinal, and colonic temperatures were measured after 90 minutes. Pad applications at 0 degrees, 10 degrees, 20 degrees, and 30 degrees C significantly lowered skin surface and subcutaneous temperatures, while pad applications at 40 degrees and 50 degrees C significantly increased subcutaneous and skin surface temperatures. None of the pad applications had a significant effect on intraperitoneal, intestinal, or colonic temperatures. The findings indicate that a wide range of thermal applications to the abdominal skin of the dog do not alter deep abdominal temperatures.

Abdomen↗
PubMed1982

Demonstration of net potassium absorption in mammalian colon.

The present in vivo studies were performed in the rat to determine whether the colon was capable of net potassium absorption, as well as secretion, and to further elucidate the process responsible for net potassium movement. Both the proximal and distal lumina of the colon of control, potassium-deficient, and potassium-loaded animals were perfused with solutions containing either 140 or 20 mmol/l sodium. Net potassium secretion was present in both proximal and distal colon of control animals during perfusion with the 140 mmol/l sodium solution. The rate of net potassium secretion was reduced in the potassium-deficient animals. During perfusion with the 20 mmol/l sodium solution, the rate of potassium secretion was also reduced (compared with control perfusion solution) in both the control and potassium-deficient animals. As a result, there was net potassium absorption (0.94 +/- 0.14 mueq.1-1.g dry wt-1) and zero net potassium movement in the distal and proximal segments, respectively, of the potassium-deficient animals perfused with the low-sodium solution. Additional studies were performed to determine whether net potassium secretion was saturable and showed that, during progressive increases in the plasma potassium level, net secretion was constant at plasma potassium levels above 11-13 meq/l. These data, therefore, demonstrate that the mammalian colon regulates intestinal transport of potassium by both absorptive and secretory mechanisms and that a carrier-mediated process probably regulates both transport processes.

Animals↗

Refine your search to explore more results.