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 253 records · Page 14Linked to original sources
PubMed2001

Bifidobacterium bifidum monoassociation of gnotobiotic mice: effect on enterocyte brush-border enzymes.

The effect of intestinal colonization with Bifidobacterium bifidum (Gram-positive anaerobic bacterium colonizing the intestine of healthy new-born mammals, exhibiting a probiotic effect, protecting the intestinal mucosa against colonization by pathogenic microflora) on enterocyte brush-border enzymes was examined in weaned 23-d- and in 2-month-old gnotobiotic inbred mice and compared with that in corresponding germ-free (GF) and conventional (CV) controls. The two groups of GF mice were associated with human B. bifidum 11 d before the end of the experiment. Specific activity of enterocyte brush-border enzymes--lactase, alkaline phosphatase and gamma-glutamyltranspeptidase was significantly higher in both age groups of GF mice in comparison with CV ones; on the other hand, sucrase and glucoamylase activities were higher in CV mice. Monoassociation with B. bifidum accelerates biochemical maturation of enterocytes resulting in a shift of specific activities of brush-border enzymes between the values found for GF and CV mice. This effect of B. bifidum supplementation was less pronounced for alkaline phosphatase, sucrase, glucoamylase and dipeptidyl peptidase i.v. in immature gut of weaned mice than of 2-month-old ones.

Alkaline Phosphatase↗
PubMedDate not supplied

[The Amben correction of disorders in the intestinal microbial colonization of newborn infants with perinatal pathology].

The examination of 49 newborn infants revealed that at the early neonatal period the character of the microbial colonization of the intestine depended on the kind of perinatal pathology: in lesions of the central nervous system and conjugation jaundice the deficiency of Bifidobacterium and Escherichia was detected; in hemolytic disease opportunistic bacteria were dominant simultaneously with the deficiency of lactoflora. The study of these infants, divided into two groups differing in the administration of Amben (an inhibitor of proteolytic enzymes), showed the efficiency of Amben which stimulated the growth and development of resident microflora in the intestine, thus contributing to the maintenance of eubiosis in a given group of infants with perinatal pathology.

4-Aminobenzoic Acid↗
PubMed1994

Subcellular distribution of proteolytic activities degrading bioactive peptides and analogues in the rat small intestinal and colonic enterocytes.

The objective of this study was to compare, in rat small intestinal and colonic enterocytes, subcellular distributions of activities degrading the large peptides, neurotensin, acetylneurotensin (8-13), GRF(1-29)NH2 (human growth hormone releasing factor fragment), (desNH2Tyr1,D-Ala2,Ala15)-GRF(1-29)NH2, insulin, and insulin B-chain. Proteolytic activities degrading individual peptides in the 10,000-g pellet, rich in intracellular organelles, 27,000-g pellet, rich in brush-border membrane, 100,000-g pellet, and 100,000-g supernatant, rich in cytosol, were determined and compared for both the small intestine and colon. In colonic fractions, the cytosol had highest activity (g protein)-1 degrading three out of four peptides tested, while in small intestinal fractions, the 27,000-g pellet had the highest activity (g protein)-1, degrading four out of five peptides tested. In both small intestine and colon, the cytosol had a higher percentage of total proteolytic activity degrading each of the above polypeptides and the highest insulin-degrading activity (g protein)-1. The results suggest that at pH 7.5, proteolytic activities (g protein)-1 in the fraction of subcellular organelles are much lower than those in cytosol and that cytosolic proteolytic activities degrading polypeptides and analogues are significant.

Amino Acid Sequence↗
PubMed1988

Idiopathic chronic constipation is associated with decreased colonic vasoactive intestinal peptide.

To investigate the reported association between idiopathic chronic constipation and morphologic abnormalities of enteric nerves, we measured the concentrations of six neuropeptides, vasoactive intestinal peptide, peptide histidine-methionine, substance P, methionine5-enkephalin, neuropeptide Y, and the bombesinlike intestinal peptides, in descending colon from 4 patients with idiopathic chronic constipation. Decreased concentrations of vasoactive intestinal peptide (707 +/- 112 ng/g wet tissue) and peptide histidine-methionine (543 +/- 58 ng/g) were found in the muscularis externa obtained from constipated patients compared with normal concentrations (40 patients) of vasoactive intestinal peptide (1199 +/- 47 ng/g) and peptide histidine-methionine (815 +/- 45 ng/g). Vasoactive intestinal peptide was identified by immunocytochemistry in nerve fibers within the circular smooth muscle layer of descending colon obtained from 6 control patients, but not in nerve fibers within the circular smooth muscle of descending colon obtained from 3 patients with idiopathic chronic constipation. By contrast, the distribution of immunoreactive met5-enkephalin was similar in normal descending colon and in descending colon obtained from patients with idiopathic chronic constipation. Decreased colonic concentrations of vasoactive intestinal peptide (a candidate nonadrenergic, noncholinergic inhibitory neurotransmitter) may be associated with diminution of inhibitory innervation of colonic circular smooth muscle in some patients with idiopathic chronic constipation.

Adult↗
PubMed2000

Effect of ischemia/reperfusion as a systemic phenomenon on anastomotic healing in the left colon.

Intestinal ischemia/reperfusion provokes a local inflammatory response leading to a systemic inflammatory state. In this study we aimed to assess the effects of intestinal ischemia/reperfusion injury on anastomotic healing in the left colon with an intact vascular supply. A total of 94 Wistar albino rats were divided into three groups: sham-operated control (group I, n = 25), 30 minutes of intestinal ischemia/reperfusion (group II, n = 40), and 7-day allopurinol pretreatment and intestinal ischemia/reperfusion (group III, n = 29). After the reperfusion experiment, a segmental left colon resection and anastomosis were done. On postoperative days 3 and 7 anastomotic bursting pressure, anastomotic and operative complications, and intraabdominal adhesions were assessed. Mortality rates were 1/25, 16/40, and 4/29 for groups I, II, and III, respectively (p = 0.001). There was no difference among the groups for wound and anastomotic healing parameters evaluated by macroscopic criteria. On postoperative day 7 the mean bursting pressures were 220.3 +/- 18.5, 162.0 +/- 21.0, and 213.9 +/- 24.7 for groups I, II, and II, respectively (p = 0.000). Significantly dense adhesions were found in group II (p = 0.000). Allopurinol pretreatment prevented the effects of ischemia/reperfusion on anastomotic healing of the left colon. Intestinal/ischemia reperfusion causes impairment of anastomotic healing of the left colon. In addition to remote organ effects, reperfusion injury may affect anastomotic healing in the viscera with an intact vascular supply.

Allopurinol↗
PubMed1979

Effects of age, ambient temperature, and heat-stable Escherichia coli enterotoxin on intestinal transit in infant mice.

Some interrelationships among age, ambient temperature, intestinal transit, and enterotoxigenic Escherichia coli infection were studied in an infant mouse model. The transit of dye in the small intestine was accelerated during the response to heat-stable E. coli enterotoxin. Transit in the small intestine of normal mice accelerated with increased age (from less than 17 h to 8 days old) and accelerated with increased ambient temperature (from 25 to 37 degrees C). Transit was more rapid in the jejunum than in the ileum throughout the range of experimental conditions studied. E. coli strains that do not produce any of the pili known facilitate intestinal colonization were cleared from the small intestine more rapidly at 37 degrees C than at 25 degrees C. This clearance was thought to be due to accelerated transit at the higher temperature. In contrast, a strain of E. coli that produces K99 (pili previously shown to facilitate intestinal colonization in other species) was not cleared from the small intestine and colonized more intensively at 37 degrees C than at 25 degrees C. Intensified colonization by this strain was thought to be due to increased production of K99 at the higher temperature. It was suggested that sluggish intestinal transit may also be characteristic of the neonates of other species and be one of the factors predisposing them to intestinal colonization by enteropathogens. It was speculated that this predisposition may be enhanced if the neonates are chilled. However, the effect of ambient temperature on intestinal transit in homeothermic neonates such as pigs, calves, and humans may be different from that in mice because neonatal mice are poikilothermic.

Aging↗
PubMed1999

Three-dimensional structures of c-Kit-positive cellular networks in the guinea pig small intestine and colon.

Cryosections and whole-mount preparations of the guinea pig small intestine and colon were single or double immunolabeled using the anti-c-Kit and protein gene product 9.5 antibodies. Immunolabeled specimens were observed under a confocal laser scanning microscope. The main findings of the present study are: (1) the distribution and profiles of three-dimensional structures of c-Kit-positive cellular networks in the small intestine and colon, and (2) the anatomical relations of c-Kit-positive cells to the enteric nerves in the layers. In the small intestine, c-Kit-positive cellular networks were observed at levels of the deep muscular plexus and myenteric plexus. The c-Kit-positive cellular networks ran along or overlay the nerve fibers at the deep muscular plexus, while they showed the reticular structures intermingled with the nerve elements at the myenteric plexus. In the colon, c-Kit-positive cellular networks were observed at levels of the submuscular plexus and myenteric plexus, and were further identified within the circular and longitudinal muscle layers as well as in the subserosal layer. In the circular muscle layer, c-Kit-positive cells surrounded the associated nerve fibers and extended several long processes toward the adjacent c-Kit-positive cells. The c-Kit-positive cellular networks within the longitudinal muscle layer as well as in the subserosal layer were not associated with the nerve fibers. In the layers of the intestinal wall with c-Kit-positive cells, the cellular networks of the interstitial cells were identified in ultrastructure. The characteristic profiles of c-Kit-positive cellular networks provide a morphological basis upon which to investigate the mechanisms regulating intestinal movement.

Animals↗
PubMed1975

Angiographic spectrum in Crohn's disease of the small intestine and colon.

Barium and angiographic examinations of the small intestine and colon were performed in 34 patients with histopathologically verified Crohn's disease. The spectrum of angiographic findings varied from hypervascularity with no morphologic changes of the vasa recta to complete obstruction of the vasa recta resulting in hypovascularity of the diseased intestine. A distinctive angiographic pattern was present in the distal part of the small intestine in those patients with advanced narrowing of the intestinal lumen as demonstrated on barium examination.

Adolescent↗
PubMed1993

Localization of transforming growth factor beta isoforms in the normal murine small intestine and colon.

BACKGROUND: The transforming growth factor beta (TGF-beta) proteins are key regulators of cellular growth and differentiation. Previous studies have shown that TGF-beta 1 is a potent growth inhibitor of cultured jejunal epithelial cells. The reported distribution of TGF-beta 1 messenger RNA (mRNA) expression along the intestinal villus has been controversial. The purpose of the current study is to determine the loci of TGF-beta protein expression in the normal small intestine and colon. METHODS: Intestinal localization of TGF-beta isoform mRNA and protein was examined by Northern blot analysis and immunohistochemistry using isoform specific reagents. RESULTS: TGF-beta 1, TGF-beta 2, and TGF-beta 3 mRNA were found in homogenates from the intact mouse jejunum and colon. The three isoforms colocalized in these tissues. Expression in the small intestinal epithelium was most prominent in cells located on the villus tip, and no staining was detected in the crypt. Occasional lymphocytes in the lamina propria were immunopositive, and all layers of the muscularis were moderately stained. This pattern was seen in all regions of the small intestine. The surface epithelium of the colon was intensely immunopositive, whereas cells in the glands were only weakly stained. CONCLUSIONS: TGF-beta molecules may serve overlapping functions in the intestinal tract, and expression in the epithelium may function to arrest growth of cells emerging from the crypt and induce or maintain the terminally differentiated state.

Animals↗
PubMed2006

Expression of CD147 and monocarboxylate transporters MCT1, MCT2 and MCT4 in porcine small intestine and colon.

Lactate, formed mainly in the stomach and small intestines, and short-chain fatty acids (SCFAs) formed in the colon, are ionised and require transporter proteins such as monocarboxylate transporters (MCTs) for absorption. The amounts of MCT1, MCT2, MCT4 and CD147, an ancillary protein for MCT1 and MCT4, were measured by immunoblotting the small intestine and colon of 40 pigs (Landrace, Yorkshire and LandracexYorkshire). MCT1 and MCT4 were found in both small intestine and colon, but MCT2 only in the small intestine. In both small intestine and colon, Yorkshire pigs had more CD147 than Landrace pigs, while no interbreed differences were found in MCT isoforms. Since CD147 is essential for the activity of MCT1 and MCT4, the breed difference suggests that MCT activity is higher in Yorkshire than in Landrace pigs. The absence of MCT2 in the colon suggests that it is mainly a lactate transporter, while MCT1 and MCT4 facilitate the transport of both lactate and SCFA.

Amino Acid Sequence↗
PubMed1992

Gastric, intestinal and colonic absorption of a series of beta-blockers in the rat.

Gastric, intestinal and colonic absorption rates of a series of eleven beta-blockers (alprenolol hydrochloride, atenolol, bunolol hydrochloride, penbutolol sulphate, pronethalol hydrochloride, metoprolol, oxprenolol, bevantolol, bufuralol, propranolol hydrochloride and timolol maleate) were estimated using Doluisio's method. The gastric absorption rate was very low and the absorption rate constant could not be assessed accurately in all cases. In the small intestine, the absorption rate constants, Ka, at pH 6.2 ranged between 0.38 h-1 for atenolol and 4.28 h-1 for penbutolol. In the colon, the rate of drug absorption at pH 7.5 ranged between 0.12 h-1 for atenolol and 2.15 h-1 for penbutolol. In most cases, colonic absorption rate constants were of the same order as those obtained in the small intestine, demonstrating the good penetrability through colonic membrane of the series studied. The relationship between absorption rate constants found in the small intestine and colon and the partition constant ([1/Rf]-1), was studied for this non-homologous series of beta-blocker drugs. In both cases, the functional hyperbolic absorption model proposed by Wagner and Sedman [1973] was the most representative.

Absorption↗
PubMed2004

Water and electrolyte absorption from hypotonic oral rehydration solution in rat small intestine and colon.

BACKGROUND: The authors evaluated and compared the efficacy of hypotonic oral rehydration solutions (ORS), isotonic ion solutions, and distilled water to elucidate the relation between net water absorption and osmolality, or between electrolyte absorption and their ion concentrations in rat small intestine and colon. METHODS: Water and electrolyte absorption from two hypotonic ORS (Solita-T granules No. 2 [STG2]; sodium 60 mEq/L, osmolality 249 mOsm/L, Solita-T granules No. 3 [STG3]; sodium 35 mEq/L, osmolality 199 mOsm/L), two isotonic ion solutions (Aqualight [AL]; sodium 30 mEq/L, osmolality 290 mOsm/L, Pocarisweat [PS]; sodium 21 mEq/L, osmolality 300 mOsm/L), and distilled water, were evaluated by an in vivo perfusion technique with the small intestine and colon of anesthetized rats. RESULTS: In the small intestine and colon, two hypotonic ORS significantly promoted net water absorption much greater than did two isotonic ion solutions (P < 0.05). Net sodium absorption from two hypotonic ORS was significantly greater than that from two isotonic ion solutions (P < 0.05). Sodium absorption from all solutions was greater in the colon than in the small intestine. Distilled water did not contribute to give net water absorption in the small intestine, but in the colon, it caused almost equivalent net water absorption to that by two hypotonic ORS. The largest amount of sodium secretion from the small intestine and colon was induced by distilled water. CONCLUSIONS: These data indicate that low osmolality is a crucial factor to facilitate water absorption, and the electrolytes, sodium and chloride, can effectively be salvaged in the colon.

Animals↗
PubMedDate not supplied

Differential distribution of digestive enzymes in isolated epithelial cells from developing human fetal small intestine and colon.

The human fetal colon has morphological and biochemical characteristics similar to that of the small intestine during development. A comparative study of these two organs was undertaken by selectively isolating their respective epithelium at different ages of gestation. Histological and biochemical analysis revealed a complete and selective removal of the epithelium from the underlying tissue regardless of their stage of development. Intestinal and colonic epithelial cells showed substantial differences with respect to protein content and distribution. All brush border membrane enzymes studied were present in the colon, although in much lower quantities than in the corresponding intestine. Between 90 and 99% of total disaccharidases, glucoamylase and gamma-glutamyl transpeptidase activities were recovered in the isolated cells. Epithelial content and distribution of alkaline phosphatase (ALP) activity differed markedly, however, between these two tissues. More than 45% of intestinal ALP activity was of nonepithelial origin at 15 weeks, and this percentage increased in a craniocaudal fashion to reach greater than 93% in the 18-week-old colon. Inhibition studies using phenylalanine and levamisole showed that these intestinal and colonic isoenzymes are similar in nature although they differ in their respective distribution. The use of pure fractions of epithelial cells provides an ideal system in which to compare specifically the functional development of intestinal and colonic epithelium.

Alkaline Phosphatase↗
PubMed1989

[The adhesive properties of a nonenteropathogenic strain of Escherichia coli in systems in vitro on isolated rat enterocytes and in vivo].

The adhesive properties and colonizing capacity of E. coli strain O83, isolated from feces of healthy humans and marked according to its resistance to rifampicin and nalidixic acid, were studied. In vivo experiments on germ-free rats revealed that these bacteria were capable of colonizing intestinal mucosa; colonization increased from the small to large intestine and E. coli cells were mainly concentrated in the intestinal lumen and in mucin. In vitro studies showed that this nonenteropathogenic E. coli strain possessed pronounced adhesive properties with respect to the colonic cells of germ-free rats; these properties were considerably less pronounced with respect to the enteric cells of the small intestine. The electron microscopic study of E. coli cells revealed the presence of fimbriae and fibrillae on their surface.

Animals↗
PubMed2026

Genomic Characterization of Antimicrobial Resistance and Virulence in ST11 Carbapenem-Resistant Klebsiella Pneumoniae Colonizing the Intestinal Tract of Elderly Inpatients.

BACKGROUND: This study aimed to elucidate the molecular epidemiology and virulence characteristics of ST11 carbapenem-resistant Klebsiella pneumoniae (CRKP) colonizing the intestinal tract of elderly inpatients in the Chongzhou region, providing a basis for controlling the transmission of such resistant bacteria in high-risk populations. METHODS: CRKP strains isolated from the intestines of elderly inpatients in this region between January 2023 and June 2024 were collected. ST11 strains were identified via multilocus sequence typing (MLST). Whole-genome sequencing, antimicrobial susceptibility testing, and string test, serum killing, biofilm formation, capsular polysaccharide quantification were employed to characterize their resistance genes, virulence genes, and molecular typing profiles. RESULTS: Among 58 CRKP isolates, 17 (29.3%) were ST11. ST11-KL64 was the dominant clone (70.6%). All isolates carried the carbapenemase gene bla KPC-2 and exhibited extensive drug resistance, with tigecycline retaining the highest susceptibility (64.7%). The yersiniabactin system genes (ybtS, fyuA, entB) were universally present, whereas the aerobactin gene cluster (iucABCD-iutA) was detected in only 17.6% of isolates. The virulence regulator rmpA2 was incomplete in all carriers. The hypermucoviscosity phenotype was observed in 35.3% of isolates, which correlated with serum resistance in some strains. Biofilm formation was variable. The mortality rate among colonized patients was 35.3%. CONCLUSION: The ST11-KL64 clone is dominant among CRKP strains colonizing the intestinal tract of elderly patients in this region. This clone universally carries the&#xa0;bla KPC-2&#xa0;gene conferring carbapenem resistance and exhibits a unique virulence gene profile characterized by a low carriage rate of classical hypervirulence markers and an incomplete&#xa0;rmpA2&#xa0;regulator gene. This finding clarifies the local epidemic status of this clone and underscores the importance of implementing active surveillance and targeted prevention strategies for high-risk populations.

KL64 serotype↗
PubMed1978

Carcinoid tumors of the alimentary tract. II. Angiographic diagnosis of small intestinal and colonic lesions.

The angiographic findings of five small intestinal and two colonic carcinoids are described and illustrated, together with a review of the pertinent literature. It is pointed out that the demonstration of a complex of angiographic findings related to the primary site, mesentery, and liver is highly specific. It helps in the preoperative diagnosis as well as in the localization and stage of development of the gastrointestinal carcinoid. The triad of findings is composed of: (a) faint to moderate staining at the primary site; (b) narrowing, obstruction of the distal mesenteric arcade, cluster of irregular kinked vessels, and encasement in the more central areas of mesentery; and (c) hypervascular liver metastasis. The colonic lesions examined are unique in the literature, and exhibited angiographic findings similar to the small bowel carcinoids.

Adult↗
PubMed2002

Differential expression of glutathione S-transferase isoenzymes in murine small intestine and colon.

Glutathione (GSH) S-transferase (GST) isoenzymes of the small intestine and colon of female A/J mice have been purified and characterized to determine their interrelationships with other murine GSTs. Cytosolic GST activity in the small intestine was at least due to six isoenzymes with isoelectric points (pI) of 9.5, 9.3, 9.1, 8.5, 6.2 and 5.5. Small intestine isoenzymes with pI values of 9.5, 9.3, 8.5, and 6.2 were identical to the mGSTA1-1 (Alpha class), mGSTP1-1 (Pi class), mGSTM1-1 (Mu class) and mGSTA4-4 (Alpha class), respectively, of other A/J mouse tissues on the basis of their reverse-phase HPLC elution profile, immunological cross-reactivity and/or N-terminal region amino acid sequence. Even though GST9.1 of the small intestine cross-reacted with the antibodies raised against Pi class GST, reverse-phase HPLC and N-terminal amino acid sequence analyses suggested that this isoenzyme may be structurally different from mGSTP1-1 as well as mGSTP2-2. Likewise, despite immunological similarity with the Mu class GSTs, small intestine GST5.5 appeared to be different from other Mu class murine GSTs characterized previously. Cytosolic GST activity in the colon was mainly due to four isoenzymes with pI values of 9.8, 9.4, 6.6 and 5.8. While the identity of colon GST6.6 could not be established due to its low abundance, GST9.8, GST9.4 and GST5.8 were identical to mGSTP1-1, mGSTM1-1 and mGSTA4-4, respectively, of other A/J mouse tissues including the small intestine. Isoenzymes corresponding to small intestine GST9.1 and GST5.5 could not be detected in the colon. The results of the present study indicate that the small intestine of female A/J mice is better equipped for protection against toxic effects of electrophiles than colon.

Animals↗