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PubMed1994

Effect of sepsis on mucosal protein synthesis in different parts of the gastrointestinal tract in rats.

1. In a previous study we found that the protein synthesis rate was increased by 50-60% in the mucosa of the jejunum and ileum during sepsis in rats. It is not known if sepsis affects protein turnover in other parts of the gastrointestinal tract as well. 2. In the present study, the influence of sepsis on mucosal protein synthesis in different parts of the gastrointestinal tract, from the stomach to the rectum, was determined in rats. 3. Sepsis was induced by caecal ligation and puncture; control rats underwent sham-operation. Protein synthesis rate was measured in vivo after administration of a flooding dose of [14C]leucine. 4. Basal mucosal protein synthesis rates were lower in the colon than in the rest of the gastrointestinal tract. Sixteen hours after caecal ligation and puncture, the protein synthesis rates were increased by 40-85% in the mucosa of the small and large intestine and the rectum, whereas in the gastric mucosa, the protein synthesis rate was reduced by approximately 40%. 5. The results suggest that mucosal protein synthesis rates differ in the various regions of the gastrointestinal tract, and that the metabolic response to sepsis is different in the stomach than in the rest of the gastrointestinal tract. The finding of a reduced protein synthesis rate in the gastric mucosa may partly explain the tendency to gastric stress ulcers and bleeding seen clinically in sepsis.

Animals↗
PubMed2006

Primary gastrointestinal tract lymphoma: diagnosis and management of common neoplasms.

Primary gastrointestinal lymphoma represents the most common location of extranodal lymphoma. With the bulk of disease manifesting within the gastrointestinal tract and contiguous lymph nodes, many of the lymphomas occurring in the peripheral lymph nodes can also present with primary gastrointestinal tract involvement. Molecular biology has recently enabled significant progress in the diagnosis and management of primary gastrointestinal lymphoma. Herein, we will discuss the major lymphomas affecting the bowel and highlight their key morphological, immunophenotypical and molecular diagnostic attributes. Similarly, in keeping with recent therapeutic advances, we will briefly discuss some important treatment considerations. Thus, this review is intended to offer clinicians and pathologists an overview of primary gastrointestinal lymphomas.

Colonic Neoplasms↗
PubMed2005

Induced growth and maturation of the gastrointestinal tract after Phaseolus vulgaris lectin exposure in suckling rats.

OBJECTIVES: In mammals, the postnatal development of the gastrointestinal tract is characterized by vast structural and functional changes. Using a suckling rat model, we investigated whether red kidney bean lectin, phytohemagglutinin (PHA), a potent gut mitogen in adult rats, can accelerate the growth and maturation of the gastrointestinal tract. METHODS: At either 10 or 14 days of age, suckling rats were daily gavage fed with PHA (0.05 mg/g body weight) or saline for 3 days. At 1 or 3 days after this treatment, gastrointestinal organ growth, intestinal morphology, disaccharidase pattern, macromolecular absorption capacity, and pancreatic enzyme contents were studied. RESULTS: After PHA exposure, increased small intestinal growth and number of crypt cells were observed, whereas the proportion of enterocytes with supranuclear vacuoles in the distal intestine was decreased. The macromolecular absorption of the markers bovine immunoglobulin (Ig)G and bovine serum albumin and plasma levels of maternal IgG decreased, and intestinal disaccharidases switched toward an adult-like pattern. The pancreas weight and pancreatic protein and trypsin contents increased. These changes were partly reversible when the PHA treatment began at 10 days of age, but they persisted when the treatment began at 14 days of age. CONCLUSIONS: PHA induced enhanced growth and precocious functional maturation of the gastrointestinal tract in suckling rats. The effects persisted if the PHA treatment started at 14 days of age, but not before, suggesting an age dependent mechanism. These findings may lead to a better understanding of gastrointestinal maturation and constitute a basis for the treatment of mammals having an immature gut.

Animals↗
PubMed1993

Metastatic disease involving the gastrointestinal tract.

Secondary involvement of the gastrointestinal tract by malignancies is encountered frequently. It usually reflects a poor prognosis because it is often multicentric and associated with metastases in other organs. Any therapy is usually palliative. Because of this, conventional barium studies or CT is sufficient for diagnosis and can obviate further studies.

Esophageal Neoplasms↗
PubMedDate not supplied

Relationship of reproductive hormones and neuromuscular disease of the gastrointestinal tract.

Functional disorders of the gastrointestinal tract comprise a common but ill-defined group of diseases; they primarily afflict women. Although predominantly involving nerve and muscle, the cellular and molecular bases of the pathogenesis of these functional disorders are unknown. Clinical studies indicate that some result from neural dysfunction within the enteric nervous system, others may be due to muscular problems, and the causes of still others remain unknown. Laboratory studies have shown that ovarian products such as progesterone, luteinizing hormone, human chorionic gonadotropin, and relaxin (but not estrogen), are neural antagonists of gastrointestinal motility. The production and secretion of these ovarian substances are controlled by gonadotropin-releasing hormone (GnRH) released from the hypothalamus; they probably act on gamma-aminobutyric acid receptors and alter chloride influx into the cell. GnRH analogs are effective drugs that downmodulate the hypothalamic-pituitary-gonadal axis and inhibit the secretion of gonadal products involved in such hormone-dependent diseases as endometriosis and prostate cancer. Acting on the GnRH receptors (seven transmembrane domain receptors) on myenteric neurons, GnRH analogs are also effective neural modulators in such disorders as functional bowel disease. These analogs are a promising new group of compounds that may be used to treat difficult gastrointestinal problems.

Chorionic Gonadotropin↗
PubMed2003

Reactive nodular fibrous pseudotumor of the gastrointestinal tract and mesentery: a clinicopathologic study of five cases.

Although the majority of mesenchymal lesions of the gastrointestinal tract are neoplastic in nature, nonneoplastic reactive processes may involve the gastrointestinal tract and mesentery, causing diagnostic confusion with more aggressive neoplasms, such as fibromatosis or gastrointestinal stromal tumors. In this study, we report a series of fibroinflammatory lesions of the gastrointestinal tract that we think represent a relatively cohesive group of tumors and describe the clinical and pathologic features of this entity, which we have termed "reactive nodular fibrous pseudotumor." The tumors affected five patients (four male and one female patient) who ranged in age from 48 to 71 years (mean 56 years). Two patients presented with acute abdominal pain without a significant past medical history, two had incidental lesions discovered during evaluation for other medical conditions, and one was found to have an abdominal mass. Three patients had a history of abdominal surgery. The tumors were multiple in three patients and solitary in two patients. In four cases, at least one of the tumors involved the small intestine or colon, and the lesion was confined to the peripancreatic soft tissue in one case. The tumors were firm, tan-white, ranged in size from 4.3 to 6.5 cm in greatest dimension, and were grossly well circumscribed. All of the lesions were of low to moderate cellularity and composed of stellate or spindled fibroblasts arranged haphazardly or in intersecting fascicles. Three cases had microscopically infiltrative borders. The stroma was rich in collagen, which was wire-like, keloidal, or hyalinized. Intralesional mononuclear cells were sparse but were more numerous peripherally and frequently arranged in lymphoid aggregates. Immunohistochemical stains demonstrated that all of the tumors stained for vimentin, 80% stained for CD117 or muscle specific actin, 60% stained for smooth muscle actin or desmin, and none of the tumors stained for CD34, S-100 protein, or anaplastic lymphoma kinase-1. Follow-up information was available in all cases: four patients had no residual disease following surgical resection (mean follow-up 16.3 months) and one patient who had an incomplete surgical resection had stable disease at 26 months. In summary, we report a series of distinct intraabdominal fibroinflammatory pseudotumors that we have collectively termed "reactive nodular fibrous pseudotumors." These lesions are uncommon and may infiltrate the bowel wall, thereby mimicking primary bowel neoplasms or intraabdominal fibromatosis. Recognition of these nonneoplastic lesions is important, as they pursue a benign clinical course, but may be confused with other mesenchymal neoplasms that require more aggressive treatment.

Aged↗
PubMed1999

Parasitic infections of the gastrointestinal tract.

Parasitic infections of the gastrointestinal tract are a major cause of morbidity and mortality worldwide. Increased international travel means that gastroenterologists are now more likely to care for patients with parasitic diseases. This article reviews various aspects of the more common intestinal parasites and their infections, including epidemiology, life cycle, pathogenesis, clinical manifestations, diagnosis, and treatment.

Anti-Infective Agents↗
PubMed1997

Distribution of prohormone convertase-6 expression in the gastrointestinal tract and effects of a fasting-refeeding regimen and a high-fat diet on ileal prohormone convertase-6 expression.

Proforms of gastrointestinal peptide hormones and neuropeptides are processed, in part, by prohormone convertases (PCs) to mature, biologically active peptides. The purpose of this study was to characterize the mRNA levels of PC-6 isoforms, PC-6A and PC-6B, in the gastrointestinal tract and pancreas of the rat, and to investigate the effects of a fasting and refeeding regimen, and a high-fat diet on ileal PC-6A expression. PC-6A mRNA is expressed throughout the entire gastrointestinal tract with the highest levels in the small intestine. Multiple-sized transcripts are present. PC-6B mRNA is expressed in the antrum and fundus of the stomach, in the small intestine, and colon. Ileal PC-6A mRNA expression increases significantly with fasting and then declines with refeeding toward control levels. Increased dietary fat increases PC-6A mRNA levels in the ileum. Since PC-6 is found throughout the entire gastrointestinal tract, it is likely that PC-6 participates in the processing of proforms of gastrointestinal peptides. The two isoforms of PC-6 have different patterns of distribution in the gastrointestinal tract and pancreas, suggesting that they process proforms of different gut peptides.

Animals↗
PubMed2006

[Gastrointestinal bleeding--concepts of surgical therapy in the upper gastrointestinal tract].

Bleeding of the upper gastrointestinal tract is the main symptom of a variety of possible conditions and still results in considerable mortality. Endoscopy is the first diagnostic modality, enabling rapid therapeutic intervention. In case of intractable or relapsing bleeding, surgery is often inevitable. However, emergency operations result in significantly higher mortality rates. Therefore the option of early elective surgical intervention should be considered for patients at increased risk of relapsing bleeding. If bleeding is symptomatic due to a complex underlying condition such as hemosuccus pancreaticus or hemobilia, angiography is now recognized as the definitive investigation. Angiographic hemostasis can be achieved in most cases. Due to the underlying condition, surgical management still remains the mainstay in treating these patients. This paper reviews surgical strategy in handling upper gastrointestinal bleeding.

Angiography↗
PubMed1985

Chemical burns of the upper gastrointestinal tract.

Burns of the upper gastrointestinal tract, caused by acids, alkalis, drugs or heat may lead to stenoses, some of them severe, to perforations, to inanition and to the patient's death. The type of damage differs among the various groups of noxious agents. First aid at home is almost non existent. On admission every effort must be made to identify the ingested material. Parenteral fluids and antibiotics are used and in some patients nutritional support will be required. The extent of the damage must be evaluated endoscopically. Strictures, caused by intramuscular collagen formation, could possibly be prevented by steroid therapy. If stenoses occur, these must be cautiously dilated. A late complication of oesophageal burns is carcinoma. There appears to be a relation between this grave complication and the use of very hot beverages in certain countries where oesophageal cancer is common. Upper gastrointestinal burns are similar to skin burns, however, their dangers may be greater as they occur in a pipe-like structure and very close to vital viscera.

Acids↗
PubMed1986

[Pharmacological studies on proglumetacin maleate, a new non-steroidal anti-inflammatory drug. (3) Damaging effects on the gastrointestinal tract].

Damaging effects on the gastrointestinal tract of proglumetacin maleate (PGM), a new indomethacin (IND) derivative, were examined in comparison with those of IND. Gastric and small intestinal lesions were maximum 4 and 24 hr after a single oral administration of PGM, respectively. Ulcerogenic effects of PGM on the gastric mucosa were approximately 1/7 and 1/10 times as potent as those of IND on a molar ratio 4 hr after single oral dosing to fasting and feeding rats, respectively. PGM was also less active on the small intestinal mucosa 24 hr after single oral dosing. After repeated dosing for 7 days, ulcerogenic effects of PGM were about 1/3 and 1/2 times more potent than those of IND on the gastric and the small intestinal mucosa, respectively. The weak ulcerogenicity of PGM appears to be due to the fact that it has little direct action on the gastrointestinal mucosa. On the other hand, protective effects of PGM on diarrhea induced by arachidonic acid in mice were about 1/2 times as potent as those of IND in both 1 and 4 hr pretreatments. So PGM must have less inhibitory effects on prostaglandin biosynthesis in the intestine than IND. PGM is a safer drug than IND because it has less damaging effect on the gastrointestinal mucosa. Therefore, it may be much more useful for the treatment of chronic inflammatory disorders like rheumatoid arthritis.

Administration, Oral↗
PubMed1977

Roentgen manifestations of radiation injury to the gastrointestinal tract.

Radiation injury of the gastrointestinal tract requires a minimum dose of 4200 to 4500 rads. The symptoms and signs of radiation injury usually appear within 6 to 24 months following therapy. The radiation induced changes include mucosal atrophy and ulceration associated with an obliterative endarteritis in the supportive vasculo-connective tissue. The roentgen manifestations are those of an ischemic process but may also mimic those of recurrent malignant disease. Obstruction, hemorrhage, and fistula formation are common complications. Surgery is frequently required. The morbidity and mortality is considerable.

Colon↗
PubMed1976

Endoscopy of the upper gastrointestinal tract.

Fiberendoscopy of the upper gastrointestinal tract recently has become a routine diagnostic procedure. This is due to its broad spectrum of applications and to its "reputation" of simplicity and innocuousness. The possible complications of fiberendoscopy, however, are similar to those of rigid endoscopy. Most of these complications can and must be avoided by strict adhesion to elementary precautions: adequate teaching and supervision of endoscopists in training; emphasis on all stages of the patient's preparation, psychological and pharmacological, each adopted to the individual patient and constant awareness of the possibility of complications.

Bacterial Infections↗
PubMed1994

Endocrine tumors of the gastrointestinal tract.

Endocrine tumors of the gastrointestinal tract are among the most interesting and heterogeneous of human malignancies. Presenting in highly variable fashions, carcinoid tumors and pancreatic endocrine tumors share natural histories that may range from the serendipitously found, easily cured appendiceal carcinoid to the highly malignant pancreatic islet cell tumors associated with unique endocrine syndromes. The heterogeneity and the relative rarity of these tumors hinder both basic and clinical research. However, new concepts of tumor biology, diagnosis, and treatment are emerging, which will lead to better understanding of the behavior of these tumors and, ultimately, to better treatment of the individual patient.

Gastrointestinal Neoplasms↗
PubMed1994

The ethosuximide-induced hyperpolarization of smooth muscle tissues--a cause of functional changes in the gastrointestinal tract of rats--is provoked by CA(2+)-dependent K(+)-efflux.

Ethosuximide is an antiepileptic drug successfully used in the treatment of petit mal especially in childhood. Clinical investigations reveal that ethosuximide has a number of adverse side effects on the gastrointestinal tract (GIT) of patients which may include heaviness, anorexia, pains in the region of the stomach, accompanied sometimes with nausea and vomiting. In the present study we attempt to explain the mechanisms of some of the drug's adverse side effects using an experimental animal model. White rats were employed in the experiments during which they were treated daily with ethosuximide (100 mg/kg) for 100 days. We made use of the following methods in the study: 1. Contrast X-rays study of the gastrointestinal tract. 2. Recording of the bioelectric activity of isolated smooth muscle strips using the sucrose-gap method. 3. Recording of the contractile activity of isolated smooth muscle. Characteristic changes occurring after treatment of rats with ethosuximide include atony of the stomach and the intestines, hypertonus in separate duodenal segments, diminished peristaltic activity, and delayed passage at the 24th hour. The drug inhibits the spontaneous contractile activity of isolated smooth muscle strips from rat gastrointestinal tract. In some duodenal preparations is minimised in the presence of apamin, an inhibitor of Ca2+(-dependent) K+ channels (Ka+(Ca)), while in duodenal preparations this effect may undergo a reversion. In the presence of coffeine the action of ethosuximide on the smooth musculature of rat gastrointestinal tract is reduced significantly. We hypothesis that the observed functional changes in the gastrointestinal tract occur as a result of the hyperpolarizing effect of ethosuximide on the gastrointestinal musculature caused by the outcoming K+(CA)-efflux.

Administration, Oral↗
PubMed1990

Endothelin in the gastrointestinal tract. Presence of endothelinlike immunoreactivity, endothelin-1 messenger RNA, endothelin receptors, and pharmacological effect.

The possible production and role of endothelin in the gastrointestinal tract was investigated in rats by radioimmunoassay, Northern-blot hybridization, receptor assay using membrane preparations, and pharmacological study using gut strips. Endothelinlike immunoreactivity was detected in all regions (from stomach to colon) of the rat gastrointestinal tract (13-48 fmol/g wet tissue) including the mucosal layer of the ileum and colon (8.4 +/- 2.0 fmol/g wet tissue and 18.4 +/- 2.1 fmol/g wet tissue, respectively, mean +/- SEM; n = 5). Fast protein liquid chromatographic analysis of the endothelinlike immunoreactivity in jejunum, ileum, colon, and colon mucosa extracts showed peaks in the positions of endothelin-1 and endothelin-3. The presence of endothelin-1 messenger RNA was demonstrated by Northern-blot hybridization in the whole colon and pooled ileal and colonic mucosa, but not in the whole jejunum. Specific binding in the rat gastrointestinal tract was particularly high in the fundus of stomach, jejunum, ileum, and colon. In the ileum, many binding sites were found in the circular and longitudinal muscle layers, but few in the mucosal layer. Endothelin-1 and endothelin-3 caused contraction of rat stomach strips, rat colon, and guinea pig ileum. These findings indicate that endothelin is present in the rat gastrointestinal tract, perhaps produced by both vascular endothelial cells and mucosal epithelial cells, and can cause contraction of gastrointestinal smooth muscle. Thus, endothelin may have a physiological role in the control of gastrointestinal function.

Animals↗
PubMed1996

Endocrine tumors of the gastrointestinal tract.

Endocrine tumors of the gastrointestinal tract produce a variety of secretory products that cause unique clinical syndromes. Diagnosis, which is often delayed, requires a strong index of suspicion and must be confirmed by biochemical tests. Precisely where these tumors originate remains a topic of controversy. However, several growth factors that may be involved in tumor development have been identified, and genetic abnormalities in patients with multiple endocrine neoplasia have been described. New pre- and intraoperative localization techniques have greatly increased the ability to identify and resect these tumors. The long-acting somatostatin analogue octreotide is frequently useful as a tracer to localize tumors and as symptomatic therapy for limiting release of secretory products produced by the tumors. In some instances it may also have direct anti-tumor activity.

Carcinoid Tumor↗
PubMed1976

Eosinophilic infiltration of the gastrointestinal tract in children.

Three children had eosinophilic infiltration of the gastrointestinal tract. This entity has two forms--diffuse and circumscribed. The diffuse lesion is confined mainly to the gastric antrum. Surgical resection of this form is seldom necessary. Involvement of the appendix with this form has not been previously described. The polypoid lesion, which may arise in any segment of the gastrointestinal tract, commonly produces secondary gastrointestinal symptoms and is amenable to local surgical excision.

Adolescent↗