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PubMed1991

Sensory nerves in the gastrointestinal tract: changing concepts and new perspectives.

In recent years great interest has been directed to study the function of capsaicin-sensitive primary afferents in the gastrointestinal tract. It has been demonstrated that these fibers not only have a sensory role but also play a local efferent function through direct and indirect effects of released neurotransmitters. Peptides released by capsaicin-sensitive nerves are involved in several functions modulating either the local blood flow or the gastrointestinal motility. The analysis of the action of released transmitters may serve to understand the physiology and pathophysiology of the gastrointestinal tract. All data here reported demonstrate that the study of capsaicin-sensitive primary afferents may be helpful to develop new pharmacological treatment of various human disease of the gastrointestinal tract.

Animals↗
PubMed2003

Epstein-Barr virus-associated peripheral T-cell lymphoma with gastrointestinal tract involvement.

Peripheral T-cell lymphoma (PTCL) is a group of diseases which are common in Asia and areas of South and Central America. They are highly associated with the Epstein-Barr virus (EBV) infection. In the present study the authors evaluated patients with gastrointestinal involvement of PTCL with respect to clinical findings and outcome, pathologic features, and molecular analysis for EBV infection and the clonality of tumor cells. From January 1997 through December 2000, 7 patients with gastrointestinal tract involvement of PTCL were identified. The frequency of gastrointestinal tract involvement in the various types of PTCL was 5.4 per cent (7 of 129 cases). The pertinent clinical features were prolonged fever, weight loss, anemia, hepatosplenomegaly, lymphadenopathy, multiorgan involvement, and gastrointestinal bleeding. Laboratory results showed a significantly high serum level of alkaline phosphatase and lactate dehydrogenase, and abnormal coagulograms. Five patients died within 4 months after onset of illness, while two were in complete remission after chemotherapy. The tumor cell morphology was classified into three categories: small-sized cells, mixed medium- and large-sized cells, and large-sized cells. The antigenic phenotypes of the tumor cells were LCA+, CD3+, CD15-, CD16-, CD30-, CD45R0+, CD57-, CD68-, EMA-, betaF1-, granzyme B+, TIA-1+, and p53+. The expression of CD4, CD8, CD56 and CD20 was variable. EBV-RNA expression by in situ hybridization (EBER-ISH) study was positive and T-cell receptor (TCR) beta and/or gamma gene rearrangements were detected in all patients. DNA sequence analysis showed high identity to the human TCR germline gene. PTCL with gastrointestinal tract involvement was associated with EBV infection. The tumor cells were mature T cells with some NK-cell antigenic expression and all demonstrated TCR gene rearrangements.

Adult↗
PubMed1977

Clinical findings, early endoscopy, and multivariate analysis in patients bleeding from the upper gastrointestinal tract.

A simple system has been developed to identify patients with upper gastrointestinal tract haemorrhage who run a high risk of continued bleeding or rebleeding. The system is based on six items of patient data available at or soon after arrival in hospital. It was evaluated in a prospective study of 66 patients with upper gastrointestinal tract haemorrhage. Over half of the patients classified by the system into a high-risk category either continued bleeding or rebled after apparent cessation (as against one out of 33 patients in the low-risk category). The high-rish group also had a higher mortality (21%) than those in the low-risk group (nil). The addition or subtraction of early endoscopic findings made little difference to the accuracy of prognosis.

Age Factors↗
PubMed2001

The pathology of epithelial pre-malignancy of the gastrointestinal tract.

This chapter deals with pre-malignant epithelial lesions of the gastrointestinal tract that have the potential to become cancers. Pre-malignant lesions are divided into two types: those characterized by dysplastic mucosa and those without dysplasia. Examples of the two types are present in the oesophagus, stomach and intestine. In the oesophagus, dysplasia of the squamous epithelium is a precursor to squamous carcinoma. There are differences in interpretation between Western and Japanese pathologists in the diagnosis of oesophageal squamous lesions. Dysplasia in Barrett's oesophagus is regarded as a precursor of adenocarcinoma. The goal of endoscopic surveillance in Barrett's mucosa is the detection of high-grade dysplasia. There are several problems with our current knowledge of high-grade dysplasia and controversies regarding its management. There are differences in the interpretation of biopsies of gastric epithelial dysplasia between Japanese and Western pathologists. In the colon, pre-malignant lesions include dysplasia seen in inflammatory bowel disease and colonic adenomas. The most significant predictor of the risk of malignancy in patients with inflammatory bowel disease is the presence of dysplasia in colonic biopsies. Because of the similarity of neoplasia throughout the gastrointestinal tract, there have been attempts to unify its classification, terminology and diagnostic criteria internationally, the most recently proposed modified classification of gastrointestinal neoplasia being the Vienna classification. Dysplasia of the columnar mucosa has a similar appearance in Barrett's oesophagus, the stomach and the colon. Criteria for its histological diagnosis and grading are reviewed, with an emphasis on areas of diagnostic difficulty such as interobserver variation, and discrepancies between Western and Japanese pathologists. Implication of the presence of dysplasia that are specific to each organ site are discussed, highlighting weaknesses and controversies in current knowledge.

Carcinoma↗
PubMed1977

Radiologic spectrum of melanoma metastatic to the gastrointestinal tract.

Radiologic experience in 67 patients with melanoma metastatic to all portions of the gastrointestinal tract is reviewed. Besides the well known "bull's-eye" lesion of the upper gastrointestinal tract, a large variety of radiologic presentations of melanoma metastases is discussed and illustrated. Because of extended survival due to improved chemotherapy and immunotherapy, the importance of careful radiologic examination of the melanoma patient is stressed.

Biliary Tract Diseases↗
PubMed1981

Immunoreactive adrenocorticotropin in the gastrointestinal tract and pancreatic islets of the rat.

Radioimmunoassayable ACTH is detectable in the gastrointestinal tract and pancreatic islets of the rat by using a midportion ACTH antiserum. Portions of the gastrointestinal tract and isolated pancreatic islets were extracted with 0.1 N HCl. Serial dilutions of the extracts resulted in inhibition curves parallel with human alpha ACTH-(1-39). The highest concentrations were in the isolated pancreatic islets (20 pg/ml protein) and the gastric antrum-pylorus (17.9 +/- 1.2 pg/ml protein). Chromatographic characterization of the stomach extract showed a main peak, with an elution constant identical to that of [125I]iodo-ACTH-(1-39) and an elution pattern identical to that of rat pituitary extracts and medium from incubated rat pituitaries.

Adrenocorticotropic Hormone↗
PubMed1989

Endoscopic injection therapy for nonvariceal bleeding lesions of the upper gastrointestinal tract.

A number of techniques have been developed to control active upper gastrointestinal tract bleeding. These include thermal devices such as the laser, heater probe, and bipolar circumactive probe (BICAP). Although these devices have proved effective, they vary in cost and at times are cumbersome to use. A simple, inexpensive, readily available means of treating active bleeding from the gastrointestinal tract is injection of the lesion with a sclerosing substance. This method has proved helpful in stopping variceal hemorrhage, and the simplicity of the equipment and procedure makes it an outstanding candidate therapy for treating other causes of hemorrhage. Although the method is not well known in the United States, it has been applied in Japan and Europe. Most studies so far have been uncontrolled, but in over 700 patients reported in the world literature, effective initial hemostasis has been achieved in about 90% of patients overall. Success rates have been somewhat dependent on the site and rate of bleeding. No deaths have been reported from the procedure. We review the current status, techniques, and types of sclerosing agents and provide a detailed analysis of results of injection sclerotherapy. We propose that although the technique is simple, the effectiveness and routine application to the patient with upper gastrointestinal hemorrhage await careful controlled studies and comparison with other available hemostatic methods.

Animals↗
PubMed1999

Expression of constitutive nitric oxide synthase in rat and human gastrointestinal tract.

The aim of this study was to determine the expression of constitutive NO synthases (ecNOS and bNOS) at the protein level in rat and human gastrointestinal tract. We established a quantitative Western blotting method for detection and quantification of ecNOS and bNOS in both species. Human gastric fundus was further analyzed by immunohistochemistry. EcNOS expression at the protein level could be quantified in different organs of the rat gastrointestinal tract and in human gastric mucosal biopsies. Immunohistochemistry of gastric fundus revealed that immunoreactivity for ecNOS was localized mainly in the endothelium of small vessels. In rats, expression of bNOS at the protein level was highest in esophagus. By means of immunohistochemistry of human gastric fundus, immunoreactivity was detected mainly in the plexus of Auerbach. We conclude that isoforms of constitutive nitric oxide synthase can be identified and quantified at the protein level both in rat and human gastrointestinal tract. The presence of bNOS in nerve tissue supports previous observations that NO serves as a transmitter in non-adrenergic, non-cholinergic nerves in human esophagus and stomach. The observation that ecNOS has been found mainly in endothelial cells suggests the involvement of NO in the regulation of mucosal blood flow.

Aged↗
PubMed2003

p27 Protein and cancers of the gastrointestinal tract and liver: an overview.

GOALS: The purpose of this review is to look at the evidence presented in the literature on the immunoexpression of p27 in cancers of the gastrointestinal tract and liver. BACKGROUND: Cell cycle proteins have been shown to play an important role in the oncogenesis of many tumors. Several of these proteins have been examined in concert and in isolation, and some have been put forward as putative tumor markers. p27, which is an important inhibitory protein in the cell cycle and belonging to a group of cyclin-dependent kinase inhibitors, has also been studied in several malignancies, most notably breast, lung, bladder, and prostate cancers. Considerable work has also been done on the expression of this protein in cancers occurring within the gastrointestinal tract. RESULTS: Cancers occurring in the major sites of the gastrointestinal tract (esophagus, stomach, and colorectum) and liver show a similar pattern with regard to p27 protein levels. p27 emerges as a statistically significant predictor of survival and tumor behavior. It has been suggested that p27 loss occurs early in the carcinogenesis process, with dysplastic epithelium having decreased expression. The more aggressive, metastasizing cancers tend to lack p27 expression as well. Some studies have also invoked the subcellular localization of p27 (cytoplasmic versus nuclear) as also being of prognostic value. CONCLUSION: Therefore, in gastrointestinal and hepatic cancers, low p27 expression is regarded as an important adverse prognostic factor.

Animals↗
PubMed2000

DOPA, dopamine, and DOPAC concentrations in the rat gastrointestinal tract decrease during fasting.

The aim of the present study was to test the hypothesis that 3, 4-dihydroxyphenylalanine (DOPA) and dopamine (DA) in the gastrointestinal tract are to a large extent of exogenous origin and derived from food. Tissue concentrations of norepinephrine (NE), epinephrine (Epi), DA, DOPA, and 3,4-dihydroxyphenylacetic acid (DOPAC), as measured by reverse-phase HPLC with electrochemical detection, were studied in fed and 4-day-fasted Wistar rats as well as in sympathectomized and adrenodemedullated rats. Sympathectomy and adrenal demedullectomy decreased tissue concentrations of NE and Epi, respectively, but had no effect on the level of tissue DOPA. Large amounts of DOPA and DA were present in the gastrointestinal tract. Fasting decreased DOPA and DA in the stomach and DOPA concentrations in the quadriceps muscle but no concentrations in other organs. DOPAC in the heart decreased both in response to sympathectomy and to fasting, whereas DOPAC decreased in plasma after fasting and in skeletal muscle after sympathectomy. We conclude that the food content of DOPA and DA is of major importance for the metabolism of DA and, thus, for the dopamine-sulfate content in the gastrointestinal tract and in plasma. The decrease in muscle DOPA after fasting may be explained by less insulin being available during fasting for stimulation of DOPA uptake in the muscle depot. DOPAC in the organism seems to be of a dual origin, derived partly from DA in the food and partly from DA synthesized in sympathetic nerves.

3,4-Dihydroxyphenylacetic Acid↗
PubMed2002

Alendronate and risedronate: what you need to know about their upper gastrointestinal tract toxicity.

Adverse upper gastrointestinal (GI) tract events can occur with alendronate or risedronate therapy. Although the short-term, non-placebo-controlled comparisons of alendronate and risedronate indicated that risedronate therapy may be associated with a lower risk of upper GI toxicity than alendronate therapy, the placebo-controlled comparison shows no difference in the risk of upper GI toxicity between the two drugs. The risk of an adverse upper GI event increases when these drugs are used concurrently with nonsteroidal anti-inflammatory drug (NSAID) therapy, but this incidence is no more than that observed with concurrent placebo and NSAID therapy. Also, the risk of these adverse GI tract events can be decreased by following the dosing instructions (e.g., avoid lying down for 30 minutes after taking the drug and take the drug with a full glass of water) and may be decreased with once-weekly dosing.

Alendronate↗