PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “GASTROINTESTINAL TRACT”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources
PubMed1985

Pathology of gastrointestinal tract in chronic hemodialysis patients: an autopsy study of 78 cases.

The pathological data obtained from postmortem examination of the gastrointestinal tract in 78 chronic hemodialysis patients are reported. All but two of the patients exhibited some gastrointestinal abnormalities. Multiple abnormalities often coexisted in one individual. Esophagitis, gastritis, duodenitis, enteritis, and colitis were seen with considerable frequency. However, extensive hemorrhagic, ulcerative, and pseudomembranous lesions frequently seen in untreated uremia were generally lacking. Evidence of peptic ulcer disease was found in one-fourth of the patients confirming the increased predisposition of dialysis patients to this complication. Several patients exhibited various ischemic phenomena including thrombosis, embolism, and infarction of various segments of the gastrointestinal tract. In addition, numerous other abnormalities were found throughout the gastrointestinal tract with lesser frequency. The data indicate that various gastrointestinal abnormalities commonly occur in patients with endstage renal disease despite uremia control by hemodialysis. However, the observed abnormalities are different from those reported in untreated uremia.

Adult↗
PubMed2003

Role of imprint cytology in the diagnosis of gastrointestinal tract malignancies.

Endoscopic biopsies obtained from 275 patients (180 from the upper gastrointestinal tract and 95 from the lower gastrointestinal tract) were studied to compare the accuracy of biopsy imprint cytology and histology in the diagnosis of gastrointestinal lesions, and also to establish the degree of reliability of imprint cytology alone for an early diagnosis of malignancy. Biopsy histology results were found to be correct in 100% cases. Imprint cytology had an overall accuracy of 100%, 96.7%, 95.8% and 95.8% for the diagnosis of malignancies of the oesophagus, stomach, duodenum and colorectum respectively. False negative results were obtained with lymphomas. Regenerative cellular atypia was an important cause for false positive results. It was concluded that imprint cytology can serve as a useful and simple tool for an immediate diagnosis of malignancy. This should be subsequently correlated with histopathology which facilitates exact tumour typing and assessment of tumour invasion.

Adult↗
PubMed1991

[Ranitidine in the prevention of upper gastrointestinal tract hemorrhage following thermal injury].

This paper reports the use of Ranitidine in preventing upper gastrointestinal tract hemorrhage following thermal injury. In 12 hours after intravenous injection of Ranitidine, gastric pH was elevated from 3.25 +/- 0.26 to 5.16 +/- 0.47 (P less than 0.01) in twenty-one burn patients, with mean TBSA 62.6% +/- 17.2% (31%-87.5%), mean third degree BSA 41.4% +/- 18.3% (0-68%). The volume of gastric secretion was decreased from 15.81 +/- 4.4 ml to 2.85 +/- 0.9 ml. The free acid of gastric secretion was decreased from 25.74 +/- 4.42 mmol/L to 5.98 +/- 3.68 mmol/L (P less than 0.01). The total titratable acidity of gastric secretion was decreased from 44.76 +/- 5.76 mmol/L to 13.85 +/- 0.02 mmol/L (P less than 0.01). Three patients had occult blood in their gastric contents on admission, and it turned negative after Ranitidine therapy. However, during 1987-1988, the incidence of upper gastrointestinal tract hemorrhage of fifty-one patients with similar TBSA and third degree BSA burned was 21.6%. Changes in gastric secretion and lowered incidence of upper gastrointestinal hemorrhage after Ranitidine therapy suggest that Ranitidine may be effective in preventing upper gastrointestinal tract hemorrhage following thermal injury.

Adolescent↗
PubMed2006

Pharmacokinetics of the opioid antagonist N-methylnaltrexone and evaluation of its effects on gastrointestinal tract function in horses treated or not treated with morphine.

OBJECTIVE: To determine the pharmacokinetics and effects of the morphine antagonist N-methylnaltrexone (MNTX) on gastrointestinal tract function in horses when administered alone and in combination with morphine. ANIMALS: 5 healthy adult horses. PROCEDURES: Horses were treated with MNTX (1 mg/kg, IV), and serial blood samples were collected for determination of drug pharmacokinetics. For evaluation of effects on the gastrointestinal tract when administered alone, MNTX was administered at a dosage of 0.75 mg/kg, IV, twice daily for 4 days. For evaluation of effects when administered concurrently with morphine, MNTX (0.75 mg/kg, IV, q 12 hours) and morphine (0.5 mg/kg, IV, q 12 hours) were administered for 6 days. Gastrointestinal variables evaluated were defecation frequency, weight of feces produced, fecal moisture content, intestinal transit time, and borborygmus scores. RESULTS: The time-concentration data for MNTX disposition best fit a 2-compartment model with a steady-state volume of distribution of 244.6 +/- 21.8 mL/kg, t1/2 of 47.04 +/- 11.65 minutes, and clearance of 11.43 +/- 1.06 mL/min/kg. Adverse effects were not observed at doses <or= 1 mg/kg. Administration of MNTX increased daily fecal weight. When administered concurrently with morphine, MNTX partially prevented the effects of morphine on the gastrointestinal tract by increasing defecation frequency, fecal weight, fecal moisture content, and borborygmus score, and by preventing increases in intestinal transit time. CONCLUSIONS AND CLINICAL RELEVANCE: Because MNTX does not cross the blood-brain barrier, administration of the drug should not alter the analgesic effects of opioids and may attenuate the adverse gastrointestinal effects associated with use of opioids in horses.

Analgesics, Opioid↗
PubMed1999

The involvement of the gastrointestinal tract in posttransplant lymphoproliferative disease in pediatric liver transplantation.

BACKGROUND: Posttransplant lymphoproliferative disease (PTLD) is a serious complication associated with the use of immunosuppression after transplantation. In a retrospective study the clinical features of PTLD located primarily in the gastrointestinal tract were analyzed. METHODS: Three hundred ninety-two consecutive pediatric patients who underwent orthotopic liver transplantation (OLT) during a 13-year period with a survival of more than 6 months were reviewed. Two immunosuppression protocols were used: cyclosporin A, or tacrolimus-based primary therapy. Twenty-nine randomly selected liver transplant recipients without PTLD were used for comparison of signs and symptoms of gastrointestinal PTLD. RESULTS: Among the 30 patients identified with PTLD, 9 had gastrointestinal PTLD. The overall incidence density of PTLD was 1.8 per 100 patient-years (30/392). Nine patients (30%) had involvement of the gastrointestinal tract, whereas 7 (23%) had the gastrointestinal tract as the only involved site. When compared with a cohort of liver transplant recipients without PTLD, only gastrointestinal bleeding, weight loss, hypoalbuminemia, and protein-losing enteropathy were signs most likely associated with gastrointestinal PTLD. Hypoalbuminemia was the most sensitive sign of gastrointestinal PTLD. The lower tract (ileum and colon) was the most common site of involvement. CONCLUSIONS: gastrointestinal involvement is common and occurs in 30% of all patients with PTLD. It may be the only affected organ in a subgroup of patients. Hypoalbuminemia, gastrointestinal bleeding, and weight loss are features that are characteristic of gastrointestinal PTLD. Patients with aggressive gastrointestinal signs and symptoms should undergo upper and lower gastrointestinal tract endoscopy with biopsy, to establish the diagnosis.

Adolescent↗
PubMed1989

Deleterious effect of sodium fluoride on gastrointestinal tract.

1. The effect of sodium fluoride (NaF) on gastrointestinal tracts of rats was investigated. 2. Blood flow rate in rat stomach mucosa was only 30% of the initial rate during 30-60 min after a single oral dose (300 mg/kg) of NaF. 3. The addition of NaF (final NaF concentration: 50 and 100 ppm) in vitro gave the reduction of 10 and 28%, respectively, of initial free calcium ion levels in rat blood. 4. These results indicate that oral ingestion of excess amount of NaF caused dilatation of blood vessel and greatly decreased blood flow rate to accumulate the circulating blood in the mucosa of gastrointestinal tract to cause redness.

Animals↗
PubMed2001

Genetic multiplicity of the human UDP-glucuronosyltransferases and regulation in the gastrointestinal tract.

The metabolism of ingested foods and orally administered drugs occurs in the hepato-gastrointestinal tract. This process is facilitated by several supergene families that catalyze oxidative metabolism as well as conjugation of the small molecular weight substances that enter the systemic circulation through resorption in the gastrointestinal tract. The catalytic action carried out by one of several conjugation reactions leads to the eventual elimination of the resultant metabolites from the cell. As early as 1959 (R. T. Williams, Detoxification Mechanisms) it was suggested that the detoxification of most agents is efficiently performed by the phase II conjugation reactions, because the addition of bulky, water-soluble groups to the target substrates facilitates the partitioning of these metabolites from the lipid into the aqueous compartments of the cell. The combined efforts of the phase II reactions provides remarkable redundancy in a biological system that seems to be designed to assure that many endogenously generated catabolic products as well as exogenous agents introduced through the surface tissues of the digestive tracts are efficiently removed through excretion to the bile or urine. In this review, we focus on recent findings that highlight the genetic multiplicity and regulatory patterns of the phase II superfamily UDP-glucuronosyltransferases (UGTs). Although much is known regarding the number of UGTs that make up the UGT1 and UGT2 gene families, as demonstrated after the characterization of expressed cDNAs, examples are also presented in which information obtained from the human genome project will aid in the final characterization of the genetic multiplicity. In addition, tools have now been developed and examples presented to identify the expression patterns of the UGTs in human tissues, paying particular attention to expression patterns of these genes in the hepato-gastrointestinal tract.

Amino Acid Sequence↗
PubMed1981

Gastrointestinal tract O2 uptake and regional blood flows during digestion in conscious newborn lambs.

We determined gastrointestinal tract O2 uptake, cardiac output, regional blood flows, and whole-body O2 uptake before and for 1-6 h after feeding in 10 chronically catheterized unanesthetized lambs (9-15 days of age). Total gastrointestinal blood flow (sum of blood flows to the stomach, small intestine, and colon, as calculated with the radioactive microsphere technique) increased 23% at 1 h postprandially. This increased flow at 1 h was due to a large increase in blood flow to the stomach, whereas blood flows to the small intestine and colon did not change significantly. By 2 h, stomach blood flow and thus total gastrointestinal blood flow had returned to fasting values. In contrast, total O2 uptake by the gastrointestinal tract organs (stomach, small intestine, and colon) increased 65% at 1 h, 51% at 2 h, and 28% at 3 h postprandially in association with increases in O2 extraction (O2 uptake/O2 delivery) of 41% at 1 h, 45% at 2 h, and 27% at 3 h. There were no digestion-related changes in whole-body O2 uptake or in cardiac output and its distribution to the brain, heart, kidney, liver (hepatic artery), and carcass. Our data indicate that postprandial increases in O2 demand by gastrointestinal tract organs of the newborn animal are met primarily by enhanced tissue O2 extraction, rather than by metabolic hyperemia, because the postprandial hyperemia observed in the neonate is of short duration and is confined to the stomach.

Animals↗
PubMed1989

[Endoscopic use of the neodymium YAG laser in the upper and lower gastrointestinal tract].

Endoscopic neodymium-YAG laser therapy for the gastrointestinal tract has been proved since 1975. Mortality and time of convalescence of patients treated with laser for acute or potential bleeding lesions have been markedly reduced in contrast to surgery. Sessile neoplastic polyps can be removed endoscopically by laser. Laser recanalization of obstructed carcinoma or scars in the upper and lower gastrointestinal tract to relieve dysphagia or ileus improves the patient's quality of life and has benefits for subsequent operations.

Colonic Polyps↗
PubMed1996

Activity in the gastrointestinal tract after administration of bone-seeking radiopharmaceuticals. Experimental studies in mice.

PURPOSE: To test the possibility that (radio)activity of non-pertechnetate nature is excreted into the gastrointestinal tract at bone scintigraphy. MATERIAL AND METHODS: The distribution of a bone-seeking radiopharmaceutical (99mTc-HDP) was studied in an experimental mouse system by dissecting different organs and assessing their activity with a gamma-counter. RESULTS: A comparison of the activity of the submandibular glands, which are assumed to accumulate only pertechnetate, and the gastrointestinal tract showed that a significant fraction of the activity excreted into the gastrointestinal tract did not consist of pertechnetate. Part of the excretion took place in the stomach. It was not connected to a specific bone-seeking agent or 99Mo/99mTc generator. Nor did it increase with time between make-up and injection. The excretion of the non-pertechnetate activity was reduced by cimetidine and omeprazole. These gastric-secretion blocking drugs did not reduce excretion of pertechnetate or significantly affect the general distribution of the radiopharmaceutical. CONCLUSION: There is a significant excretion of non-pertechnetate activity in the gastrointestinal tract. Part of this may be caused by excretion of the undegraded radiopharmaceutical by the stomach mucosa.

Animals↗
PubMed1997

Distribution of prostaglandin E receptors in the rat gastrointestinal tract.

AIMS: In order to study the role of prostaglandin in the regulation of the gastrointestinal functions, gene expression of prostaglandin receptors along the rat gastrointestinal tracts were investigated. METHODS: Rats were used for the study. The combination of counterflow elutriation separation of mucosal cells and Northern blot analysis was used to detect the gene expression of prostaglandin receptors in gastrointestinal tracts. RESULTS: In small intestine and colon, prostaglandin E2 EP1 and EP3 receptor mRNAs were mainly localized in the deeper intestinal wall containing muscle layers. EP4 receptor gene expression, on the other hand, was detected in the intestinal mucosal layer. In the stomach, EP1 mRNA was detected in gastric muscle layers, whereas EP3 and EP4 receptor gene expression was mainly present in the gastric mucosal layer containing epithelial cells. In gastric epithelial cells, parietal cells were found to have both EP3 and EP4 receptors. At lower concentrations, prostaglandin E2 inhibited gastric acid secretion by parietal cells probably through EP4 receptors. At higher concentrations, however, it stimulated it. On the other hand, mucous cells possessed only EP4 receptor mRNA. CONCLUSIONS: Thus, it is suggested that prostaglandin E2 modulates gastrointestinal functions through at least three different prostaglandin receptors (EP1, EP3, and EP4), each of which has a distinct contribution in the gastrointestinal tract.

Aminopyrine↗
PubMed2003

Clinical implications of COX-1 and/or COX-2 inhibition for the distal gastrointestinal tract.

Side effects of the distal gastrointestinal tract after NSAID use are common and more frequent than previously recognized. Increased mucosal permeability and mucosal inflammation are often silent but appear after NSAID treatment with most dual COX inhibitors. Other clinical manifestations include: anemia, occult blood loss, malabsorption, protein-loss, ileal dysfunction, diarrhea, mucosal ulceration and strictures due to diaphragm disease. More common complications are lower gastrointestinal bleeding and perforation, which represent at least one third of all gastrointestinal complications observed with NSAID use. Studies with selective COX-2 inhibitors have shown that, in the short term, these agents do not increase mucosal permeability or induce anemia due to occult bleeding and that, when compared to dual COX inhibitors, lower gastrointestinal complications may be reduced by 50%. In order to minimize the impact of these side effects, it is important to increase the current standards of suspicion by physicians who treat these patients, since drug discontinuation may further reduce damage, and clinical experience with agents that may prevent or treat distal tract damage is very limited. From this perspective, selective COX-2 inhibitors may be the drugs of choice in the high-risk patient that needs NSAIDs. Another important area of uncertainty is the impact of NSAID use in patients with inflammatory bowel diseases. Data from different animal models of inflammatory bowel disease suggest that inhibition of both COX-1 and COX-2 derived prostaglandins affects the severity of the mucosal inflammation. However, current epidemiological and clinical data are contradictory. Since many patients.

Animals↗
PubMed1999

[The role of gastrointestinal tract peptides in control glucose homeostasis].

Hormones of the gastrointestinal tract are difficult to study because they are not produced by discrete groups of cells organized into glands. Instead, they are released from single cells scattered along the digestive tract. Furthermore, as several of these peptides are found both in specific endocrine cells and in neurons and their nerve terminals it is difficult to establish which effects are dependent on peptide release from nerve terminals and which represent endocrine activity. The gastrointestinal peptides act locally on various organs and processes within the gastrointestinal system. There is a correlation between carbohydrate absorption, plasma concentration of glucose and release of gastrointestinal tract hormones.

English Abstract↗
PubMedDate not supplied

Performance of gastrointestinal tract endoscopy by primary care physicians. Lessons from the US Medicare database.

Primary care physicians, including family physicians, often perform flexible sigmoidoscopy in their clinical practices. It is unknown how many of these and other endoscopic procedures, such as esophagogastroduodenoscopy and colonoscopy, are performed by these physicians. Therefore, physician reimbursement by the Medicare program was documented for selected endoscopic procedures during the calendar year 1993. Family physicians and general practitioners in the United States were reimbursed for 125,821 flexible sigmoidoscopies, 21,070 upper gastrointestinal tract endoscopic procedures, and 23,841 colonoscopies. General internists performed considerably more endoscopic procedures than did family physicians. Primary care physicians performed 44% of the reimbursable flexible sigmoidoscopies, 17% of upper gastrointestinal tract endoscopies, and 15% of colonoscopies in this patient group. In 1993, primary care physicians generated a total of $175 million in allowed charges by the Medicare program for gastrointestinal tract endoscopic procedures, of which $22.6 million was to general practitioners and family physicians. Family physicians, on average, charged less for gastrointestinal tract endoscopic procedures than did other physician specialists. Primary care physicians, especially general internists, are providing substantial numbers of gastrointestinal tract endoscopic services to their patients. As Medicare does not generally reimburse physicians to perform flexible sigmoidoscopy for colorectal cancer screening, it is likely that primary care physicians performed considerably more procedures than were documented in this study.

Colonoscopy↗
PubMed2002

Ghrelin-producing cells exist as two types of cells, closed- and opened-type cells, in the rat gastrointestinal tract.

Ghrelin was recently isolated from the rat stomach as an endogenous ligand for the growth-hormone secretagogue receptor (GHS-R) and is known to exist in the gastrointestinal tract and hypothalamus. In this study, we investigated in detail the distribution and morphologic characteristics of ghrelin-containing cells (ghrelin cells) in the gastrointestinal tract by immunohistochemistry and in situ hybridization. Ghrelin cells were found to be localized in the mucous membrane of the stomach, duodenum, ileum, cecum and colon but not in myenteric plexus, and they can be classified into open- and closed-type cells. The greatest number of ghrelin cells was found in the stomach, and it was found that the number of the opened-type cells gradually increased in the direction from stomach to the lower gastrointestinal tract. These results suggest that the two types of ghrelin cells may be distinctly regulated and play different physiological roles in various regions of the gastrointestinal tract.

Animals↗
PubMed2001

Clinical impact of endoscopic ultrasound-guided fine needle aspiration biopsy in patients with upper gastrointestinal tract malignancies. A prospective study.

BACKGROUND AND STUDY AIMS: Several studies have evaluated the accuracy of endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB) in the upper gastrointestinal tract, but so far no studies have specifically evaluated the clinical impact of EUS-FNAB in upper gastrointestinal tract cancer patients. In this consecutive and prospective study, EUS-FNAB was only performed if a positive malignant finding would change the therapeutic strategy. PATIENTS AND METHODS: Between 1997 and 1999, 307 consecutive patients were referred for EUS with a diagnosis or strong suspicion of esophageal, gastric or pancreatic cancer; 274 patients were potential candidates for surgical treatment and had EUS. According to predefined impact criteria, 27% (75/274) of the patients had EUS-FNAB for staging or diagnostic reasons. RESULTS: The overall clinical impact of EUS-FNAB was 13%, 14%, and 30% in esophageal, gastric, and pancreatic cancer, respectively. The staging-related clinical impact was similar for all three types of cancer (11-12.5%), whereas the diagnosis-related impact was highest in pancreatic cancer patients (86%). EUS-FNAB was inadequate in 13% and gave false-negative results in 5%. The overall sensitivity, specificity and accuracy for EUS-FNAB were 80%, 78% and 80%, respectively. No complications related to the biopsy procedure were seen. CONCLUSIONS: If EUS-FNAB was performed only in cases where a positive malignant result would change patient management, then approximately one out of four patients with upper gastrointestinal tract cancer would require a biopsy. With this approach the actual clinical impact of EUS-FNAB ranged from 13% in esophageal cancer to 30% in pancreatic cancer. EUS-FNAB plays a limited, but very important clinical role in the assessment of upper gastrointestinal tract cancer.

Adult↗