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PubMed1978

Infrequent patterns of upper gastrointestinal tract malignancy.

The skin and the upper gastrointestinal tract are frequent sites of malignant tumors. However, cutaneous metastasis from primary gastrointestinal tract lesions remains a relative rarity. Similarly rare is spread of primary skin cancer (nonmelanomatous) to upper gastrointestinal tract. This paper presents an unusual example of primary esophageal carcinoma with synchronous skin and bone metastases and a case of squamous cell carcinoma of the stomach, possibly due to spread from a remote squamous cell carcinoma of the skin.

Aged↗
PubMed1992

Immunologic structure and function of the gastrointestinal tract.

Host defenses within the gastrointestinal tract exclude bacteria and other intraluminal substances, which if released into the systemic circulation, would be toxic to the body. This is accomplished via complex interactions between these external pathogens and local immune responses and nonimmunologic processes. In addition to the mechanical and chemical barriers of the nonimmunologic defense system within the gastrointestinal tract, there is an effective immunologic barrier composed of aggregated and nonaggregated lymphoid cells. Gut-associated lymphoid tissue protects the intestinal mucosa from invading pathogens by intricate pathways of antigen processing. Gut-associated lymphoid tissue also transfers protection to other secretory sites within the body through the common mucosal immune system. The integrity of both the immunologic and nonimmunologic barriers may be affected by any number of pathologic insults as well as by nutritional influences. This article reviews the structural and functional characteristics of this complex and critically important host defense system. Specific nutrient requirements of the immunologic processes are discussed.

Critical Illness↗
PubMed2001

Vascular malformations of the gastrointestinal tract.

Vascular malformations of the gastrointestinal tract may be diagnosed at any age. They may present with bleeding, anaemia, or if they form a mass lesion, with intussusception. Many lesions remain asymptomatic. In a minority of patients there are well-defined genetic conditions present, such as hereditary haemorrhagic telangiectasia. In others, particularly the angiodysplastic lesions that occur in the caecum in elderly patients, the lesions appear to be degenerative. Vascular malformations may affect any section of the gastrointestinal tract, and in some patients there are vascular anomalies elsewhere, particularly in the skin. Diagnosis is usually based on recognition endoscopically, or at angiography. Symptomatic lesions that are discrete and localized respond well to local treatment with laser or heat coagulation or sclerotherapy. Mass lesions, diffuse lesions and severe bleeding may require surgery.

Aged↗
PubMed1999

Enteric nervous control of motility in the upper gastrointestinal tract in defensive states.

The gastrointestinal tract exhibits patterns of motor behavior that are characteristic for specific digestive and pathologic states. Activity of the musculature, mucosal epithelium, and blood vasculature are coordinated to produce these specific patterns. A neural program for each pattern is stored in the memory of a program library in the enteric nervous system (brain-in-the-gut). The programs are identified by their motility component. They are: (1) segmentation motility in the digestive state of the small intestine; (2) migrating motor complex in the interdigestive state of the small intestine; (3) orthograde power propulsion in the small and large intestine; (4) retrograde power propulsion in the small intestine during emesis; and (5) physiologic ileus. Selective secretory behavior is organized by each program in concert with the motility pattern. The motor program for emesis in the upper gastrointestinal tract reflects an adaptive defense mechanism for maintaining gut integrity in response to ingested and/or emotionally perceived insults.

Adolescent↗
PubMed2000

Gene therapy for gastrointestinal tract cancer: a review.

Carcinomas of the gastrointestinal tract count as one of the most common causes of cancer-related death in the world. Despite improvement of conventional treatment modalities, the prognosis of patients with gastrointestinal tract cancer remains poor. Progress in understanding the molecular mechanism of gastrointestinal carcinogenesis may facilitate development of gene therapy strategies for the treatment of gastrointestinal tumors. This review describes new developments in vectors (tools for gene transfer) for gene therapy, possible therapeutic genes and the early clinical results of gastrointestinal tract cancer gene therapy. Results of current preclinical studies are promising for the future clinical application of gene therapy for gastrointestinal cancer. The first clinical trials have been initiated recently, the preliminary results reflecting low toxicity and clinical responses. Further clinical studies will be required to confirm the feasibility of gene therapy in the treatment of gastrointestinal cancer. In future, the greatest potential will probably lie in the field of combination strategies of gene therapy and existing treatment modalities, such as surgery combined with molecular chemotherapy.

Carcinoma↗
PubMed2001

Rotavirus and calicivirus infections of the gastrointestinal tract.

Virus infections of the gastrointestinal tract, leading to gastroenteritis, are a common problem in both developed and developing countries. Rotavirus and Norwalk-like viruses are the most common agents responsible for clinically severe disease in humans, and this paper focuses on new information about the mechanisms of pathogenesis and epidemiology of these two pathogens. Rotavirus-induced disease involves a viral enterotoxin and activation of the enteric nervous system, as well as malabsorption, suggesting that common mechanisms of pathogenesis may exist between viral and bacterial pathogens. Each gastrointestinal virus possesses unique molecular properties that can be exploited to discover new information about responses of cells of the gastrointestinal tract. Work continues toward making vaccines for rotavirus and Norwalk-like viruses.

Journal Article↗
PubMed2003

Gastrointestinal tract cytology: advancing horizons.

Tide and ebb of interest in gastrointestinal tract cytology has followed technical advances in this field over the last 60 years. Cytologic samples can be obtained using gastric lavage, abrasive balloons, mucosal brushing, and fine needle aspiration (under percutaneous image guidance, endoscope and endoscopic ultrasound guidance). These advances now allow simultaneous performance of brushing the abnormal mucosa, obtaining fine needle aspirates and excising mucosal biopsy samples for evaluation. Use of endoscopic ultrasound guided fine needle aspirates now help to obtain diagnosis of submucosal lesions, preoperative staging of gastrointestinal tract malignancies and help determine further management of patients. Such advances have brought pathologists to the forefront of the patient management team for the treatment of gastrointestinal tract lesions. This manuscript reviews the advantages and limitations of each cytology associated technique as well as reviews the salient diagnostic features, differential diagnosis and diagnostic pitfalls of gastrointestinal tract lesions. Finally, it suggests the modalities best suited to obtain diagnosis for various gastrointestinal tract lesions.

Cytodiagnosis↗
PubMed2001

Diagnostic techniques in assessing vessels of the gastrointestinal tract.

Vascular disorders of the gastrointestinal tract include a variety of different underlying diseases, thus requiring different and, in many cases, more than one imaging procedure. Only a knowledge of the newest developments in vascular imaging techniques with all the possibilities and limits will ensure a time- and cost-effective, accurate and reliable diagnosis. In many acute cases and also as a screening procedure, ultrasound in combination with colour Doppler and duplex sonography, plays an important role in setting the right course for further imaging techniques, and can provide the correct diagnosis in many cases.Depending on the most prominent symptoms and the expected disease, the right choice of technique saves valuable time. Computed tomography (CT) and magnetic resonance imaging (MRI) are cross-sectional imaging techniques that not only demonstrate lesion vascularization, but also provide information about neighbouring structures and complications in an understandable and demonstrable way. The use of angiography as an invasive tool should be limited to cases where a high temporal and spatial resolution is necessary to make the diagnosis or where therapeutic interventions are also likely to be performed within the same setting. For the diagnosis of gastrointestinal vascular diseases, often no generally valid recommendation can be given, since the impact of all imaging techniques will depend on the examiner's experience, the technical equipment and on their 24-h availability in a hospital. This chapter tries to give some information about the inherent limits and indications of the different imaging techniques, as well as the newest study results concerning the most frequent vascular diseases of the gastrointestinal tract.

Angiography↗
PubMed2006

Molecular characterization and distribution of motilin family receptors in the human gastrointestinal tract.

BACKGROUND: Motilin and ghrelin have been recognized as important endogenous regulators of gastrointestinal motor function in mammals, mediated respectively by the motilin receptor and by the closely related ghrelin receptor. The aims of this study were to explore the distribution of motilin and ghrelin receptors along the human gastrointestinal tract and to establish the molecular nature of the human motilin receptor. METHODS: Post mortem and surgical human tissue specimens with no hemorrhage, necrosis, or tumor were obtained from various parts of the gastrointestinal tract. We analyzed levels of expression of mRNA for motilin and ghrelin receptors and examined their molecular identities. Portions of some specimens were also studied by immunohistochemistry for expression of the motilin and ghrelin receptor. RESULTS: The long form of the motilin receptor, but not the short form, was expressed in all parts of the gastrointestinal tract, and expressed at higher levels in muscle than in mucosa. Motilin receptor immunoreactivity was present in muscle cells and the myenteric plexus, but not in mucosal or submucosal cells. In contrast, ghrelin receptor mRNA was expressed equally in all parts of the gastrointestinal tract, with similar levels of expression in mucosal and muscle layers. CONCLUSIONS: Both the motilin and ghrelin receptors are expressed along the human gastrointestinal tract, but they have clearly distinct distributions in regard to both level and layer. The diffuse muscle expression of the motilin receptor, at both the levels of the gene and the protein product, along the entire gastrointestinal tract makes it a useful potential target for motilide drugs for dysmotility.

Adult↗
PubMed1980

Angiography in the management of massive lower gastrointestinal tract hemorrhage.

Initial stabilization of blood volume and immediate resuscitative measures should be used for lower gastrointestinal tract bleeding. Upper gastrointestinal tract lesions should be excluded with nasogastric intubation and upper endoscopy if the history or nasogastric aspirate suggests an upper gastrointestinal tract source. Proctosigmoidoscopy should be done to exclude mucosal disease, hemorrhoidal bleeding or local carcinoma. If all of these are negative and the patient is bleeding massively, we recommend arteriography with catheterization of the superior mesenteric, inferior mesenteric and celiac arteries. These procedures should be carried out within less than four hours. If a bleeding site is demonstrated, the use of local infusion of vasopressin for permanent control should be considered only in the poor risk patient in whom the operative risk is prohibitive. Massive hemorrhage from the lower gastrointestinal tract in an elderly population is usually due to diverticular bleeding and not to angiodysplasia. The bleeding site was more common in the right than in the left colon. Angiography has been proved to be an important diagnostic procedure to localize the site of the bleeding and has been invaluable in the surgical management of these patients.

Aged↗
PubMed2005

Mucispirillum schaedleri gen. nov., sp. nov., a spiral-shaped bacterium colonizing the mucus layer of the gastrointestinal tract of laboratory rodents.

The mammalian gastrointestinal tract is covered by a layer of mucus that can harbour a range of bacterial species specifically adapted to colonize this ecological niche. Examination of 110 bacterial isolates cultivated from the gastrointestinal tract of 23 mice revealed the presence of a subgroup of 30 isolates that did not correspond genetically with genera commonly associated with this site, i.e. members of the epsilon-Proteobacteria such as Helicobacter and Campylobacter species. Instead this group of isolates was found to lie within the phylum Deferribacteres, a completely distinct lineage in the domain Bacteria. There was a high level of consensus in results obtained from the phenotypic and genotypic characterization of a number of the isolates, which showed they were distinct from other members of the Deferribacteres. As such, they are proposed to constitute a new genus and species, Mucispirillum schaedleri gen. nov., sp. nov. These organisms are anaerobic, Gram-negative, spiral-shaped rods with bipolar flagella. The type strain is HRI I17(T) (= ATCC BAA-1009(T) = ACM 5223(T)).

Anaerobiosis↗
PubMed1983

Upper gastrointestinal tract polyps in familial adenomatosis coli.

Upper gastrointestinal tract polyps were sought prospectively using endoscopy and biopsy in 34 patients with familial adenomatosis coli belonging to 18 unrelated families. Gastric and/or duodenal polyps, usually small and multiple, occurred in 28 patients (82%). Histologically verified extracolonic adenomas were present in 19 patients (56%). Gastric adenomas, all in the antrum, and duodenal adenomas occurred in four (12%) and 16 (48%) patients, respectively. In one patient, a duodenal adenocarcinoma and a bile duct adenoma were also found, and one patient had an adenocarcinoma of the bile ducts. Multiple non-neoplastic polyps were found in 19 patients (56%), most often in the stomach and also in the duodenum in 12 patients; they co-existed often with adenomas. In addition, there were nine patients with ileal polyps, most of them showing lymphoid hyperplasia but also one with adenomas. It is suggested that familial adenomatosis affects the whole gastrointestinal tract, not only the colon and rectum as believed earlier. Although upper gastrointestinal tract adenomas are not as consistent and multiple as those in the colon, and probably do not require prophylactic surgery, regular lifelong endoscopic follow up is warranted because of obviously increased cancer risk.

Adolescent↗
PubMed2003

Identification of Lactobacillus reuteri genes specifically induced in the mouse gastrointestinal tract.

Lactobacilli are common inhabitants of the gastrointestinal tracts of mammals and have received considerable attention due to their putative health-promoting properties. Little is known about the traits that enhance the ability of these bacteria to inhabit the gastrointestinal tract. In this paper we describe the development and application of a strategy based on in vivo expression technology (IVET) that enables detection of Lactobacillus reuteri genes specifically induced in the murine gut. A plasmid-based system was constructed containing 'ermGT (which confers lincomycin resistance) as the primary reporter gene for selection of promoters active in the gastrointestinal tract of mice treated with lincomycin. A second reporter gene, 'bglM (beta-glucanase), allowed differentiation between constitutive and in vivo inducible promoters. The system was successfully tested in vitro and in vivo by using a constitutive promoter. Application of the IVET system with chromosomal DNA of L. reuteri 100-23 and reconstituted lactobacillus-free mice revealed three genes induced specifically during colonization. Two of the sequences showed homology to genes encoding xylose isomerase (xylA) and peptide methionine sulfoxide reductase (msrB), which are involved in nutrient acquisition and stress responses, respectively. The third locus showed homology to the gene encoding a protein whose function is not known. Our IVET system has the potential to identify genes of lactobacilli that have not previously been functionally characterized but which may be essential for growth of these bacteria in the gastrointestinal ecosystem.

Aldose-Ketose Isomerases↗
PubMed2006

Homeobox genes and their functions on development and neoplasm in gastrointestinal tract.

AIM: To describe the role of homeobox genes on development and tumorigenesis in gastrointestinal tract. METHODS AND RESULTS: We searched the MEDLINE database (until March, 2006) with the keywords of homeobox genes, gastrointestinal tract, development, tumorigenesis, carcinogenesis and therapeutic targets. We reviewed the literature on classification of homeobox genes, development of gastrointestinal tract, carcinogenesis of gastrointestinal tract as well as therapeutic targets. CONCLUSIONS: The functional effects of homeobox family in development and tumorigenesis of gastrointestinal tract are identified. The importance of homeobox genes and a possibility of therapeutic intervention in clinical medicine are discussed.

DNA, Neoplasm↗
PubMed1988

Evaluation and treatment of gastrointestinal tract hemorrhage in patients with AIDS.

Hemodynamically significant gastrointestinal tract hemorrhage is infrequently seen among patients with AIDS. During a 35-month period, we evaluated 37 AIDS patients with substantial gastrointestinal tract bleeding: 13 patients had upper gastrointestinal disease; 24 patients had colorectal disease. AIDS-associated lesions were identified as the etiology of the hemorrhage in 8 of 13 patients with upper and 9 of 24 patients with lower gastrointestinal tract bleeding.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Normal length of the human fetal gastrointestinal tract.

Little information is available on the normal length of the gastrointestinal tract in fetuses or on factors that may affect its growth. To determine normal growth patterns of the fetal intestine, 58 fetuses received in the Central Laboratory for Human Embryology between January 1, 1987, and July 1, 1988, in which no abnormalities were noted on autopsy, were studied. The gastrointestinal tract was removed from the fetus en bloc from the esophagogastric junction to the pelvic floor and dissected. Measurements of stomach, small and large intestines, and appendix length were made and correlated with gestational age as determined by footlength. Overall growth of the gastrointestinal tract as well as that of each component was linear with respect to gestational age. In addition, five fetuses with omphalocele, 16 with cardiac malformations, and 20 with chromosomal abnormalities were studied. The total lengths of the gastrointestinal tracts in the first group were below the normal range in four of five fetuses. Those with cardiac defects had intestinal lengths below the mean, but the measurements were abnormal in only three. In both groups those fetuses with chromosomal abnormalities appeared to have shorter intestinal tracts than those with normal or unknown karyotypes. The gastrointestinal tracts of aneuploid fetuses fell within the normal range until approximately 20 weeks gestation, after which growth decreased. This growth failure may reflect the growth retardation seen in fetuses with chromosomal abnormalities.

Aneuploidy↗
PubMed1998

Hepatocyte growth factor activator: a possible regulator of morphogenesis during fetal development of the rat gastrointestinal tract.

The role played by the hepatocyte growth factor activator (HGFA) during morphogenesis of the gastrointestinal tract was investigated in fetal rats between days 16 and 21 of gestation. By our recently established method using chelation and dissecting microscope, samples could be separated into epithelium and mesenchyme, essentially without cross-contamination. The expression of the gene for HGFA together with those for hepatocyte growth factor (HGF) and its receptor, c-met, was investigated in each tissue element by RT-PCR. In the fetal rat gastrointestinal tract, mRNA signals for the HGFA gene were observed only in epithelia expressing c-met mRNA. In contrast, expression of HGF mRNA was limited to the mesenchymal elements, indicating the presence of a local HGF system in the gastrointestinal tract; an inactive form of HGF (proHGF) is secreted from the mesenchyme and then cleaved into the active form by HGFA secreted by the target epithelia. During the period of morphogenesis and histodifferentiation in the gastrointestinal tract, enhanced expression of the genes for HGF and its receptor/c-met was evident, with elevated HGFA mRNA level observed throughout the gastrointestinal tract except in the forestomach, where mRNA expression was barely detectable. These results strongly suggest the possibility that morphogenesis of the gastrointestinal tract is regulated not only by a local increase in production of HGF, but also by enhanced proteolytic activation of proHGF. Thus, it is probable that locally synthesized HGFA plays a significant role as a regulator of the morphogenic action of HGF during gastrointestinal tract development.

Animals↗