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PubMed2004

Inflammatory fibroid polyps of the gastrointestinal tract: evidence for a dendritic cell origin.

Inflammatory fibroid polyps (IFPs) are rare mesenchymal tumors of the gastrointestinal tract that consist of spindle-shaped stromal cells and an inflammatory infiltrate rich in eosinophils. Their etiology and histogenesis remain unknown. Based on previous reports of their immunoreactivity for CD34 and c-kit biomarkers, IFPs have been thought to be related to gastrointestinal stromal tumors (GISTs). After reviewing the current literature and examining IFPs at the light microscopic level, we evaluated a series of IFPs using an extensive panel of immunohistochemical and in situ hybridization markers in an effort to gain insight into their etiology and histogenesis and to determine their true relationship to GISTs. Sixteen routinely processed IFP specimens (14 gastric, 1 ileal, and 1 rectal) were immunohistochemically stained for antibodies to CD34, HMB-45, desmin, smooth muscle actin, calponin, h-caldesmon, anaplastic lymphoma kinase, S-100 protein, epithelial membrane antigen, c-kit (CD117), stem cell factor (SCF/N19 or kit ligand), p53, bcl-2, cyclin D1, and human herpesvirus-8 (HHV8). In situ hybridization for Epstein-Barr virus-encoded RNA (EBER) was also performed. Ten cases were further evaluated for the dendritic cell markers fascin, CD21, CD23, and CD35. Stromal cells were diffusely positive for CD34 and fascin in all (100%) cases, and these stromal cells were, in addition, immunoreactive for calponin and smooth muscle actin in 88% and 25% of cases, respectively. CD35 was also found to be focally reactive in the stromal cells. Cyclin-D1 was overexpressed in all (100%) IFPs. All other immunohistochemical markers and EBER were negative in the stromal cells. These findings suggest that the proliferating stromal cells in IFPs are of dendritic cell origin, with some cases also exhibiting myofibroblastic features. Absence of c-kit, SCF, and h-caldesmon immunoreactivity fails to support a relationship to GISTs. We also conclude that Epstein Barr virus and HHV8 are unlikely etiologic agents of IFPs. Overexpression of cyclin D1 in all cases suggests that a defect in cell-cycle regulation may be involved in the growth of IFPs.

Adult↗
PubMed2003

Selective expression of glutathione S-transferase genes in the murine gastrointestinal tract in response to dietary organosulfur compounds.

A short-term feeding regimen was designed to analyze the effects of compounds such as diallyl disulfide (DADS), diallylthiosulfinate (allicin) from garlic and butylated hydroxyanisole (BHA) on glutathione S-transferase (GST) expression in the gastrointestinal tract and liver of male mice. After animals were force-fed these compounds, tissue GSTs were purified and individual subunits resolved by HPLC and identified on the basis of mass spectrometry (ESI MS) and immunoreactivity data. The effects of DADS and allicin on GST expression were especially prominent in stomach and small intestine, where there were major coordinate changes in GST subunit profiles. In particular, the transcripts of the mGSTM1 and mGSTM4 genes, which share large segments of common 5'-flanking sequences, and their corresponding subunits were selectively induced. Levels of alpha class subunits also increased, whereas mGSTM3 and mGSTP1 were not affected. The inducible mGSTA5 and non-responsive mGSTM3 subunits had not been identified previously. Liver and colon GSTs were also affected to a lesser extent, but this short-term feeding regimen had no effect on GST subunit patterns from other organs, including heart, brain and testis. Real-time PCR (TaqMan) methods were used for quantitative estimations of relative amounts of the mRNAs encoding the GSTs. Effects on the transcripts generally paralleled changes at the protein level, for the most part, however, the greatest relative increases were observed for those mRNAs that were expressed at low abundance constituitively. Mechanisms by which the organosulfur compounds operate to affect GST transcription could involve reversible modification of certain protein sulfhydryl groups, shifts in reduced glutathione/oxidized glutathione ratios and resultant changes in cellular redox status.

Allyl Compounds↗
PubMed1988

Management of foreign bodies of the upper gastrointestinal tract.

In the United States, 1500 people die yearly of ingested foreign bodies of the upper gastrointestinal tract. The flexible esophagogastroduodenoscope has had a major impact on the treatment of these foreign bodies. The following discussion includes the management of coins, meat impaction, sharp and pointed objects, button batteries, and cocaine packets; and it reflects both a personal experience and a review of the literature. The uses of the rigid and the flexible endoscopes, the Foley catheter, glucagon, papain, and gas-forming agents are presented. The cost-effectiveness impact of the flexible endoscope is also detailed, and morbidity and mortality rates for foreign body management are included.

Airway Obstruction↗
PubMed1985

Distribution and molecular forms of peptides containing somatostatin immunodeterminants in extracts from the entire gastrointestinal tract of man and pig.

Specimens from human porcine mucosal and muscular tissue from the entire gastrointestinal tract were extracted in acid ethanol, subjected to chromatography and analysed for somatostatin-like immunoreactivity by region-specific radioimmunoassays. The concentration of somatostatin-like immunoreactivity from man and pig ranged from 1.13 +/- 0.37 to 101.15 +/- 33.93 pmol/g wet weight, and from 7.64 to 159.48 +/- 23.79 pmol/g wet weight, respectively. In both species the highest concentrations were found in the jejunum. The immunoreactivity in intestinal mucosal extracts was distributed among four major peaks, two of which were identified by HPLC as somatostatin 1-28 and somatostatin 1-14, respectively. A peak of approx. 10 kDa was resolved by ion exchange plus HPLC into three components, two containing at least part of the somatostatin 1-14 sequence as well as (part of) the somatostatin 1-28(1-14) sequence (but differing in charge), the third containing only the 1-28(1-14) sequence. These peptides probably represent uncleaved and partially cleaved prosomatostatin. The fourth component to be identified by gel filtration was slightly larger than somatostatin 1-14. Extracts from the antrum, the pancreas and from muscular tissues contained almost exclusively somatostatin 1-14, and very little somatostatin 1-28, indicating that the somatostatin precursor is processed differently at these sites. Furthermore, extracts of porcine gastric antrum, analysed for somatostatin 1-28(1-14) immunoreactivity, showed two immunoreactive forms in the mucosa and three major forms in the muscular layers.

Animals↗
PubMed1985

Newborn surgical emergencies of the gastrointestinal tract.

Intestinal obstruction and necrotizing enterocolitis are two of the most common surgical emergencies of the gastrointestinal tract. This article reviews the signs and symptoms of these conditions and presents guidelines for their management.

Colon↗
PubMed1997

Nerve-induced release of nitric oxide in the rabbit gastrointestinal tract as measured by in vivo microdialysis.

1. Nitric oxide (NO) has been suggested as a gastrointestinal neurotransmitter, mediating the gastric receptive relaxation and the relaxation in the peristaltic reflex. The aim of the present study was to measure nerve-induced NO formation in vivo in the gastrointestinal tract. 2. Formation of the nitric oxide oxidation products nitrite and nitrate during vagal nerve stimulation were measured in the anaesthetized rabbit. Microdialysis probes were inserted into the wall of the stomach and proximal colon, and nitrite and nitrate in dialysate measured by capillary electrophoresis. 3. During bilateral vagal nerve stimulation there was an increase in nitrite and nitrate formation at the level of the stomach and in nitrite formation at the level of the colon. This increase was inhibited by intravenous administration of the NO synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME 30 mg kg-1). Furthermore, L-NAME significantly increased nerve-induced gastric and colonic contractions, as well as spontaneous colonic contractions. 4. In summary, we present a new methodological procedure for quantification of small changes in nitric oxide formation in vivo. This study provides evidence that nitric oxide is released in the stomach and colonic wall during vagal nerve activity, at concentrations able to cause inhibition of smooth muscle contractions in vivo.

Animals↗
PubMed2000

Yangambin, a lignan obtained from Ocotea duckei, differentiates putative PAF receptor subtypes in the gastrointestinal tract of rats.

We investigated the presence of PAF receptor subtypes in the tissues of the gastrointestinal tract, airways, blood vessels and in murine macrophages. For this purpose we have used a competitive PAF receptor antagonist, yangambin (YAN), extracted from the Brazilian plant "louro de cheiro" (Ocotea duckei Vattimo). Rat duodenum, jejunum, ileum, colon, stomach fundus, trachea and bronchia were removed and 1.5-2 cm muscle segments from those regions were mounted in a 10 ml organ bath with aerated physiological solution at 37 degrees C. PAF evoked a contraction of the rat jejunum, ileum, colon and stomach fundus. The contraction was slow and resistant to wash and was followed by desensitization to further doses of PAF. Contractions induced by PAF (10(-6) M) were inhibited by YAN (10(-7) to M-2 x 10(-5) M) and WEB 2086 (10(-6) m to M-5 M) in rat jejunum, ileum and colon but not in the stomach fundus. In the rat stomach fundus only WEB 2086 (5 x 10(-6) M) was able to block PAF-induced contraction. The contractions induced by acetylcholine, histamine, 5-hydroxytryptamine and vasopressin were not inhibited by prior administration of YAN. Yangambin also significantly inhibited PAF-induced vascular permeability in rat duodenum, jejunum, ileum, colon, and mesentery. Yangambin significantly inhibited PAF-induced lipid body formation in mice peritoneal macrophages. We suggest that YAN is a selective PAF antagonist which is able to discriminate putative PAF receptors subtypes present in the stomach fundus.

Animals↗
PubMed1989

Laser treatment of upper gastrointestinal tract carcinoma: determinants of survival.

Fifty-nine consecutive patients with stenosing carcinoma of the upper gastrointestinal tract were entered into a prospective study defining parameters of survival during laser treatment. A total of 322 laser sessions were performed, 56% of which on an outpatient basis. Life table analysis revealed that survival was poor in the presence of metastases, and in patients under 60 years of age. Survival was statistically independent of tumor histology, location, length or previous treatment of any kind. In contrast, the degree of stenosis both before and after laser treatment was related to survival in a significant fashion. The best separation into groups was achieved with the parameter dysphagia after laser treatment. Thus, the data are compatible with an important role of adequate enteral nutrition in these debilitated patients.

Adenocarcinoma↗
PubMed1986

Palliative laser treatment of malignant stenoses in the upper gastrointestinal tract.

The present state of palliative laser therapy of inoperable malignant tumor stenoses in the upper gastrointestinal tract is reviewed. Indications, contraindications, several different sources of energy and forms of energy application, as also the various technical procedures, are discussed. Finally, the authors' experience with palliative laser therapy in 62 patients, and the results of an international inquiry covering data obtained in 1,359 patients, are presented.

Endoscopy↗
PubMed1980

In vitro studies on distribution of indigenous lactobacilli of the gastrointestinal tract of rats.

To learn the biochemical mechanisms controlling the distribution of indigenous lactobacilli in the gastrointestinal tracts of rats, the effect of pH and stomach and cecal contents on lactobacillus distribution was investigated in vitro with a mixed culture of three lactobacillus strains isolated from the rat intestine. The pH of the growth medium affected the growth of lactobacilli strongly, irrespective of the lumenal contents. Lactobacillus fermentum outnumbered L. acidophilus and L. murini at low pH (PH 4.5; average pH of stomach contents of conventional rats) but at near neutral pH (pH 6.5; average pH of cecal contents of conventional rats), the growth of L. murini was predominant with all strains. More lactic acid was formed by lactobacilli in medium consisting of stomach contents than in cecal contents medium. L. murini grew in the nondialyzable fraction of the stomach contents and L. fermentum grew in the dialyzable fraction, but L. acidophilus did not grow in either fraction. L. murini grew in the nondialyzable fraction treated with hyaluronidase. In contrast, the nondialyzable fraction treated with pronase or chondroitinase did not allow L. murini to grow at all.

Animals↗
PubMed1982

Studies on streptococci. II. Colonization of lactic acid bacteria isolated from rats and humans in the gastrointestinal tract of rats.

The population levels of bacteria in the contents and the walls of the gastrointestinal tract of gnotobiotic rats inoculated with lactic acid bacteria (streptococci, lactobacilli, and bifidobacteria) from humans and rats were determined. Lactobacilli as well as streptococci isolated from rats colonized in the digestive tracts of the gnotobiotic rats at a high population level, characteristically highest in the stomach. On the other hand, in the rats inoculated with human lactic acid bacteria, streptococci were dominant in the lower tract. The human lactobacilli or bifidobacteria did not colonize when the organisms in each genus were inoculated together, lactobacilli and bifidobacteria colonized. Observations on the species of streptococci showed that the intestinal type of streptococci was found to colonize at a high population level, but the oral type was not. Stains of the same genus of lactic acid bacteria from humans and from rats showed different colonization patterns.

Actinomycetaceae↗
PubMed1989

The role of gastrin in the development of the gastrointestinal tract in fetal sheep.

We have investigated the role of gastrin in the development of the gastrointestinal tract during the latter part of gestation in fetal sheep. We surgically removed the major source of gastrin, the gastric (abomasal) antrum, from five fetuses at 90 days of gestation. The remaining abomasum was anastomosed to the pylorus allowing unobstructed flow of luminal contents. Another five fetuses, subjected to sham-antrectomies at 90 days, served as controls. Further surgery was performed in all fetuses at 120 days for the placement of vascular catheters to permit measurement of plasma gastrin concentrations. The fetuses were infused with [3H]thymidine to study villus cell migration rates. At 135 days of gestation samples of gastric (abomasal) fundus, and proximal and distal small intestine, were processed for histology and morphometric analysis. The antrectomized fetuses had significantly lowered plasma gastrin concentrations (P less than 0.025) between 120 and 135 days. At 135 days, the mean body weight, crown-rump length, total gut weight and small intestinal weight and length were not significantly different between the two groups. Similarly, there were no significant differences between groups in the mean thicknesses of the gut wall, mucosa and muscularis externa, or in the mean villus height and crypt depth in the proximal or distal parts of the small intestine. Villus cell migration rate in the proximal and distal small intestine was not affected by antrectomy. No simple relationship could be demonstrated between any of these parameters and plasma gastrin concentration. In the antrectomized fetuses, the mean crypt density and crypt-to-villus ratio were significantly reduced in the proximal small intestine (P less than 0.05), while only the density of villi was reduced in the distal small intestine (P less than 0.05). In the antrectomized fetuses there were significant correlations between plasma gastrin and the fraction of fundic mucosa occupied by gland and pit (P less than 0.005), and between plasma gastrin concentration and villus density (P less than 0.01) and crypt-to-villus ratio (P less than 0.025) in the proximal small intestine. In the sham group these correlations were absent. We conclude that the removal of the gastric antrum in fetal sheep results in decreased plasma gastrin concentration, and that gastrin appears to have a regulatory or trophic role on the gut mucosa in these circumstances.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1979

Characterization of a Haemophilus paracuniculus isolated from gastrointestinal tracts of rabbits with mucoid enteritis.

The isolation, characterization, and identification of a microorganism isolated from gastrointestinal tracts of rabbits with mucoid enteritis are described. The isolated organism did not grow on standard media. This organism grew around colonies of Staphylococcus aureus and Lactobacillus desidiosus and around disks saturated with diphosphopyridin nucleotide (factor V) on brain heart infusion agar. The growth of this organism was also observed on media supplemented with beta-nicotinamide adenine dinucleotide. The organism appeared as gram-negative, pleomorphic rods or coccobacilli. It was positive for urease, oxidase, catalase, glycosidases, porphyrin, and indole, and it fermented glucose and sucrose. All of these characteristics suggest that the organism is a member of the genus Haemophilus. Because of its isolation from rabbits and differences in some characteristics from other species of this genus, the name Haemophilus paracuniculus is proposed for this organism.

Animals↗
PubMed1990

Energy cost of absorption and metabolism in the ruminant gastrointestinal tract and liver: a review.

Contributions of various biochemical processes to overall energy expenditure in the gastrointestinal tract (GIT) and liver have been assessed in this review. The GIT and liver are responsible for a disproportionately high fraction of whole-body energy utilization. The energetic cost of Na+, K(+)-ATPase, protein synthesis and degradation, substrate cycling and urea synthesis contribute substantially to energy expenditure in the ruminant. In the splanchnic bed, these biochemical processes account for approximately 22.8% of whole-body O2 and, consequently, ATP utilization; they are influenced by several factors, including dietary composition, level of intake, age, endocrine status and physiological state. In the GIT and liver, the energetic cost of Na+, K(+)-ATPase is by far the most energetically demanding process; it is related to the active transport of substrates and the maintenance of ionic homeostasis. The high rate of protein synthesis in the GIT is associated with cellular turnover and sloughing, secretion and enzymatic action. In the liver, protein synthesis is important in the mediation of hormonal induction, which influences regulation of body systems, synthesis of plasma proteins, enzymatic and cellular turnover and detoxification of blood. Regulation of these processes and the signals involved in the differential contribution of each biochemical event are not well understood. The large contribution of these biochemical events in the GIT and liver to whole-animal energy utilization suggests that their manipulation may alter the energetic efficiency of meat, milk or wool production.

Absorption↗
PubMed1992

Effect of short-term fasting/refeeding on epidermal growth factor content in the gastrointestinal tract of suckling rats.

Epidermal growth factor (EGF) is trophic for varying regions of the developing gastrointestinal tract (GIT) of suckling rats. The presence of large amounts of EGF in milk from various species, combined with low production of EGF by suckling animals, led to speculation that milk is a major source of EGF for suckling rats. We report that short-term fasting (8 hr) of 12-day-old suckling rats resulted in a significant decrease in the levels of immunoreactive EGF (irEGF) in the GIT. Pups refed by lactating mothers for 1 to 4 hr exhibited an increase in irEGF to original levels, whereas pups fed a rat milk substitute by gastric gavage did not have an increase in irEGF content. The irEGF levels in the GIT of pups that were manually fed normal rat milk, or rat milk substitute supplemented with EGF, returned to the prefasted levels. Fasted suckling rats refed 2 ml of rat milk in 2 h exhibited significantly higher level of irEGF in the GIT than did those refed with 0.5 ml in 45 min. Since rat milk irEGF exists in three distinct forms (A, B, and C; C is equal to authentic submandibular gland EGF, the irEGF forms in the GIT were characterized by native polyacrylamide gel electrophoresis. In the stomach luminal contents of the fed suckling rats, only the larger form, Peak B, was observed. Both the luminal content and the mucosa scrapings of all other segments of all groups contained only Form D (comigrating with desarginyl EGF), a metabolic derivative of EGF. All forms were immunoreactive, exhibited receptor binding, and stimulated DNA synthesis in growth-arrested fibroblasts. The rapid changes in EGF within the GIT of suckling rats suggest the EGF can acutely modify some GIT functions of suckling rats.

Animals↗
PubMed2003

Follow-up evaluation for benign stricture of upper gastrointestinal tract with stent insertion.

AIM: To determine the best method for benign stricture of the upper gastrointestinal tract (UGIT) with stent insertion by follow-up evaluation. METHODS: A total of 110 stents insertions were performed in 110 cases of benign stricture of the UGIT. Permanent (group A) and temporary (group B) placement of an expandable metal stent in 30 cases and 80 cases respectively. All cases were completed under fluoroscopy. RESULTS: In group A, 30 uncovered or antireflux covered or partially covered expandable metal stents were placed permanently. In group A, 5 cases (16.7%) in 3-months, 5 cases (20.0%) in 6-months, 6 cases (25%) in the 1st year, 6 cases (50%) in the 3rd year, and 4 cases (80%) in the 5th year exhibited dysphagia relapse. In group B, a partially-covered expandable metal stent was temporarily placed in each patient and removed after 3-7 days via gastroscopy. Follow-up data in this group showed that 8 cases (7.5%) in 3-months, 9 cases (12.0%) in 6-months, 10 cases (15.4%) in the 1st year, 6 cases (20%) in the 3rd year, and 3 cases (25%) in the 5th year exhibited dysphagia relapse. The placement and withdrawal of all stents were all performed successfully. The follow-up of all cases lasted for 3-99 months (mean 41.6+/-19.7 months). CONCLUSION: The best method for benign stricture of UGIT with stent insertion is temporary placement of a partially-covered expandable metal stent.

Adolescent↗
PubMedDate not supplied

Structure, regulation, and pathophysiology of tight junctions in the gastrointestinal tract.

The tight junction, or zonula occludens, forms an intercellular barrier between epithelial cells within the gastrointestinal tract and liver and, by limiting the movement of water and solutes through the intercellular space, maintains the physicochemical separation of tissue compartments. The paracellular barrier properties of junctions are regulated and quite different among epithelia. The junction also forms an intramembrane barrier between the apical and basolateral membrane domains, contributing to segregation of biochemically distinct components of these plasma membrane surfaces. Here we briefly review three rapidly developing areas of medically relevant basic knowledge about the tight junction. First, we describe the presently incomplete knowledge of the molecular structure of the tight junction as a framework for understanding its functional properties. Second, we consider experimental evidence defining how the barrier properties of junctions are physiologically regulated and, third, how barrier properties are specifically altered in, and contribute to, pathologic processes affecting epithelia.

Animals↗