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[Prevention of septicemia caused by gastrointestinal tract organisms in patients with granulopenia. Comparison of three gastrointestinal tract decontamination treatments].

Three gastrointestinal tract decontamination regimens were tested in patients with granulopenia: vancomycin 250 mg, tobramycin 75 mg, and colistin 1 million international units (regimen A); vancomycin 125 mg, tobramycin 75 mg, and colistin 1 million IU (regimen B); and colistin 1 million IU (regimen C); nystatin was added to all three regimens. Effectiveness was evaluated by stool organism counts and blood cultures to detect bacterial translocation (passage of bacteria from the intestinal tract to the bloodstream). Regimen C proved insufficiently effective. Regimen A was found to be poorly tolerated by the digestive mucosa. Regimen B was the best treatment since the low dosage of vancomycin proved effective. Nystatin satisfactorily eliminated yeasts.

Agranulocytosis↗

Acute complications of metastatic melanoma to the gastrointestinal tract.

The gastrointestinal tract is a favoured site for metastatic melanoma. Complications such as obstruction, bleeding or perforation should be alleviated by surgery in order to improve the patient's condition for further systemic therapy. Six patients with melanoma involving the gastrointestinal tract are presented: 3 were operated upon for metastatic lesions in the small bowel causing intussusception, 2 patients were treated for perforation of the small bowel and 1 patient with massive bleeding from metastatic melanoma in the stomach underwent gastrectomy. Two of the patients are alive 6 months and 4 years respectively after these operations. The other 4 survived between 6 months and 2 years.

Adult↗

Diagnostic and prognostic tumor markers in the gastrointestinal tract.

The gastrointestinal tract is the most common site of malignancies of any anatomic system in the body. An early detection of primary tumors of the bowel, pancreas, liver, stomach, and esophagus is often difficult in asymptomatic patients and for this reason these tumors are often detected at a relatively advanced stage, when symptoms lead to a diagnostic evaluation. Furthermore, gastrointestinal tract tumors have an extremely variable prognosis; thus, the identification of new prognostic parameters may be useful for selecting patients to more tailored therapies. In this work, the main molecular, genetic, tissular, and circulating tumor markers proposed for diagnosis and prognosis of gastrointestinal malignancies are reviewed and discussed.

Biomarkers, Tumor↗

Digital radiography of the gastrointestinal tract.

The gastrointestinal tract lends itself quite well to digital imaging. Since fluoroscopy is already employed, the images can easily be obtained in digital format and several manufacturers have now developed systems for commercial use. Because of the type of pathology as well as the inherent subject contrast, it would appear the resolution requirements for digital imaging of the gastrointestinal tract are less than in other organ systems. The necessary resolution level is already technically available and feasible without significant cost. Digital imaging also holds promise of at least a modest reduction in radiation dose to the patient, as well as a reduction in costs, although these factors are operator dependent. However, digital imaging provides a latitude in performing the examination that is not available with screen-film systems. Finally, there is promise that by acquiring gastrointestinal images in digital format, manipulation of the images may help increase diagnostic accuracy by improving both technical and perceptive components of diagnosis. Not only will simple image manipulation be helpful but there is even potential for computer-assisted evaluation of gastrointestinal images.

Colitis, Ulcerative↗

Narcotic smuggling and radiography of the gastrointestinal tract.

The gastrointestinal tract is being used to an increasing extent as a route for smuggling narcotics. Small, swallowed packages overwrapped with condoms or other materials are usually not detected by the customs authorities. Conventional abdominal radiography may indicate foreign bodies surrounded by a characteristic thin layer of gas and located in the gastrointestinal tract. Some short case histories, and the radiologic findings in four heroin 'body packers' are presented.

Adult↗

The growth of mouse hybridoma cells between Peyer's patch lymphocyte and myeloma cell in the gastrointestinal tract. A model for human multiple lymphomatous polyposis of the gastrointestinal tract.

To elucidate the mechanism of multiple lesions in human primary lymphoma or multiple lymphomatous polyposis of the gastrointestinal tract, we developed a experimental model utilizing mouse hybridoma cells. Syngeneic mice were immunized with human hemoglobin via gastric intubation and a hybridoma clone (13c) between the Peyer's patch cell and mouse myeloma cell was obtained. The 13c cells were infused into normal syngeneic mice through a lateral tail vein. About 2 months after injection mice were sacrificed and their viscera were scrutinized histologically. All 11 mice receiving 13c showed multiple tumors at the colon, microscopic massive invasions at the small intestine, and scattered invasions at Peyer's patch, mesenteric lymph nodes and the spleen, exhibiting the similar distribution patterns as in human multiple lymphomatous polyposis of the gastrointestinal tract. ME-1 or MU-1 cells (hybridomas between P3 and mouse spleen cell) were distributed at the liver, spleen and paraaortic lymph nodes. Such migration patterns of 13c cells and their adherence to vessel walls suggest that multiple invasions may be lymphocyte homing receptor-mediated phenomena.

Animals↗

Characterization of PrPc-immunoreactive cells in monkey (Macaca fascicularis) gastrointestinal tract.

The gastrointestinal tract (GIT) is one of the most likely entry sites for the pathological isoform of prions (PrP(sc)). To understand how PrP(sc) crosses the digestive mucosa, it is crucial to characterize the cells expressing normal prion protein (PrP(c)). By means of double immunofluorescence applied to sections of the monkey GIT, we demonstrated that, in the stomach, PrP(c) immunostaining occurs in subsets of histamine, somatostatin (Som), ghrelin (Ghr), gastrin (G), and serotonin (5HT) cells. In the small and large bowels, PrP(c) cells were found in subpopulations of cells immunolabeled for 5HT, Som, G, and peptide YY (PYY).

Animals↗

Comparative study of PrPc expression in rat, monkey, and cow gastrointestinal tract.

The gastrointestinal tract (GIT) appears to be the main site of entry for the pathological isoform of prions (PrP(sc)). To understand how the PrP(sc) internalization process occurs, it is important to characterize the cell types that express normal prion protein (PrP(c)) along the GIT. To do so, we studied the distribution of PrP(c) in the rat, monkey, and cow GIT. Using Western blot analysis, we found that PrP(c) is expressed in all digestive regions of the three species. Immunoreactivity for PrP(c) was found throughout the GIT in epithelial cells sharing the neuroendocrine (NE) phenotype. Immunostained cells appeared scattered throughout the epithelium of fundic and pyloric glands as well as in intestinal villi and crypts.

Animals↗

Epithelial regeneration in the gastrointestinal tract.

The gastrointestinal tract possesses a remarkable regenerative capacity to maintain tissue homeostasis against various injuries. However, the intestine and stomach exhibit distinct regenerative strategies. In the intestine, damage to Lgr5-positive (Lgr5+) stem cells induces cellular plasticity and the emergence of transient Revival stem cells (RevSCs), a process critically dependent on YAP/TAZ signaling. Conversely, the stomach utilizes paligenosis, where quiescent p57-positive (p57+) mature chief cells act as reserve stem cells, dedifferentiating to restore damaged tissue. Although the cellular origins differ, both organs appear to share some common regenerative features, including transient activation of pro-proliferative programs such as YAP/TAZ signaling. In contrast, whether Retinoic Acid (RA) signaling also serves as a conserved mechanism for regenerative resolution in the stomach remains to be determined. In this review, we discuss the cellular and molecular mechanisms governing regeneration in these two organs. This comparative analysis provides a framework for future research.

Regeneration↗

Hormonal regulation of the fish gastrointestinal tract.

The gastrointestinal tracts (GIT) of fish and other vertebrates are challenged with a diversity of functional demands caused by changes and differences in dietary inputs and environmental conditions. This contribution reviews how hormonal regulation plays an essential role in modulating the GIT functions of fish to match changes in functional demands. Exemplary is how hormones produced by the GIT, the associated organs (e.g., pancreas), and other sources (e.g., hypothalamus, adrenal cortex, thyroid, gonads) modulate the digestive processes (motility, secretion, and nutrient absorption) in response to dietary inputs. Hormones regulate the other GIT functions of osmoregulation (secretion and absorption of electrolytes and water), immunity, endocrine secretions, metabolism, and the elimination of toxic metabolites and environmental contaminants to match changes in environmental conditions and physiological states. Although the regulatory molecules and associated signaling pathways have been conserved during evolution of the vertebrate GIT, the specific responses often vary among fish with different feeding habits and from different environments, and can differ from those described for mammals.

Animals↗

Non-Hodgkin lymphoma of the gastrointestinal tract.

The gastrointestinal tract is the most commonly involved extranodal site of lymphoma. Primary gastrointestinal lymphoma must be recognized, characterized, and staged accurately, since, in some areas of the bowel, prognosis and therapy vary substantially when compared with those for other neoplasms, especially carcinoma. Radiologic studies, particularly barium studies of the bowel and computed tomography, may be crucial and only noninvasive modalities to use for the evaluation of gastrointestinal lymphoma. Symptoms are nonspecific and may be present for years before a diagnosis is established. Histologic appearance consists of a dense accumulation of lymphocytic tumor cells in a uniform pattern. Gastrointestinal lymphoma produces a spectrum of pathologic and radiologic appearances. Management of the condition may be accomplished with surgical resection, tumor debulking, or palliation. The advantages of postoperative radiation therapy and chemotherapy are not clear. Primary gastrointestinal lymphoma is encountered often enough to warrant familiarity with the clinical, radiologic, and therapeutic options.

Gastrointestinal Neoplasms↗

Apoptosis and gastrointestinal tract.

The gastrointestinal tract is characterized by a rapid proliferation of stem cells that differentiate to become terminal mature cells and ultimately die through a genetically programmed form of cell death, termed apoptosis, which is responsible for maintaining of tissue size. Apoptosis has also been shown to play an important role in the pathophysiology of several gastrointestinal diseases. The development of many infectious and immune-mediated diseases, such as gastritis, coeliac disease, inflammatory bowel diseases, may be triggered by the prevalence of pro-apoptotic signals, whereas prolonged cell survival, due to apoptosis inhibition, may give rise to neoplastic clones. Elucidation of the biochemical pathways and of specific proteins regulating apoptosis may provide a remarkable opportunity to manipulate the life and death decisions of the gastrointestinal cells and to develop new therapeutic strategies. This review will deal with the mechanisms potentially involved in apoptosis and with the clinical relevance of this phenomenon in gastrointestinal diseases.

Apoptosis↗

[Non-Hodgkin's lymphoma in the gastrointestinal tract].

The gastrointestinal tract is the predominant site of extranodal non-Hodgkin's lymphoma. We present a summary of our recommendations as regards treatment. To avoid serious complications, such as perforation and/or bleeding, surgical resection should be considered before chemotherapy or radiation therapy. The laparotomy gives an opportunity to perform an exact staging procedure, including biopsy from the primary site and the lymph nodes. We recommend that gastrointestinal malignant lymphomas should be referred to medical centers with special competence in this field.

Gastrointestinal Neoplasms↗

Molecular and phenotypic markers of hamartomatous polyposis syndromes in the gastrointestinal tract.

Hamartomatous gastrointestinal polyposis syndromes have always been considered as non-neoplastic. Nevertheless, an increased cancer risk both within and outside the gastrointestinal tract may exist in these syndromes. The hamartomatous polyps may sometimes harbor dysplasia, but their neoplastic potential is unknown. The genetic defects causing the hamartomatous syndromes are less well established than, for example, familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC). The genetic studies on the Mendelian inherited syndromes FAP and HNPCC have made a major contribution to the identification of genes involved in colorectal tumorigenesis. The genes involved in colorectal cancer development may also contribute to cancer development in the hamartomatous polyposis syndromes, and are currently under investigation. Furthermore, new insights into the development of various cancers may be obtained by the isolation and characterization of genes involved in Mendelian inherited hamartomatous polyposis syndromes. This report summarizes the available literature on this subject, and describes the pheno- and genotypic features of the hamartomatous syndromes of juvenile polyposis, Peutz-Jeghers syndrome, and Cowden's disease.

Adenomatous Polyposis Coli↗

Immunology of the porcine gastrointestinal tract.

The gastrointestinal immune system is presented with a contrasting array of antigens, ranging from harmless dietary components to highly pathogenic microorganisms. The mucosal immune system has the ability to recognise different groups of antigens and has evolved a battery of responses from which an appropriate response may be orchestrated. The question as to how the mucosal immune system categories antigens and selects a particular response is central to this process but it remains largely unanswered. The solution to this question is likely to hold the key to the development of safe and effective mucosal vaccines as well as suggesting methods for the prevention and control of allergic responses. Enteric diseases resulting from antigens (microbial and dietary) presented via the gastrointestinal tract are a major cause of morbidity and mortality. In addition to being of substantial economic importance, growing public awareness on animal welfare and food quality confirms the urgent need for new methods of disease control.

Animals↗

Errors and pitfalls in stapling gastrointestinal tract anastomoses.

Gastrointestinal tract anastomoses are safe to perform, provided that the surgeon has acquired the knowledge and skill to avoid certain errors and pitfalls. This paper illustrates important mistakes relative to esophageal, gastric, intestinal, and colorectal anastomoses, and includes methods for avoiding these errors.

Colon↗

Mapping enteroendocrine cell populations in transgenic mice reveals an unexpected degree of complexity in cellular differentiation within the gastrointestinal tract.

The gastrointestinal tract is lined with a monolayer of cells that undergo perpetual and rapid renewal. Four principal, terminally differentiated cell types populate the monolayer, enterocytes, goblet cells, Paneth cells, and enteroendocrine cells. This epithelium exhibits complex patterns of regional differentiation, both from crypt-to-villus and from duodenum-to-colon. The "liver" fatty acid binding protein (L-FABP) gene represents a useful model for analyzing the molecular basis for intestinal epithelial differentiation since it exhibits cell-specific, region-specific, as well as developmental stage specific expression. We have previously linked portions of the 5' nontranscribed domain of the rat L-FABP gene to the human growth hormone (hGH) gene and analyzed expression of the fusion gene in adult transgenic mice. High levels of hGH expression were noted in enterocytes as well as cells that histologically resembled enteroendocrine cells. In the present study, we have used immunocytochemical techniques to map the distribution of enteroendocrine cells in the normal adult mouse gut and to characterize those that synthesize L-FABP. In addition, L-FABP/hGH fusion genes were used to identify subsets of enteroendocrine cells based on their ability to support hGH synthesis in several different pedigrees of transgenic mice. The results reveal remarkable differences in transgene expression between, and within, enteroendocrine cell populations previously classified only on the basis of their neuroendocrine products. In some cases, these differences are related to the position occupied by cells along the duodenal-to-colonic and crypt-to-villus axes of the gut. Thus, transgenes appear to be sensitive tools for examining the cellular and regional differentiation of this class of intestinal epithelial cells.

Animals↗