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PubMed1999

Steroid metabolism along the gastrointestinal tract of the cannulated pig.

Steroid metabolism along the gastrointestinal tract of the cannulated pig was studied. Thi was achieved by fitting simple gut cannulas in the terminal ileum, caecum and mid-colon of three Landrace x large white boars, which enabled convenient collection of digesta and faecal samples at defined time points. Biochemical analyses showed that the neutral steroid profile of the pig is similar to that of man, dominated by cholesterol and its bacterial metabolite coprostanol. In contrast, pigs consuming a normal diet excrete appreciably lower quantities of neutral sterols in faeces. The major primary bile acids detected were the glycine and taurine amidates of hyocholic and chenodeoxycholic acids, which were rapidly converted to the free bile acids and subsequently dehydroxylated to hyodeoxycholic and lithocholic acids respectively, in the terminal ileum and caecum. Bacterial deconjugation and 7 alpha-dehyrdoxylation are virtually complete in the caecum with negligible further metabolism in the colon and faeces. On a wet weight basis the concentration of both neutral and acid steroids was shown to increase aborally. Inclusion of dietary fibre in the form of cellulose (Solka floc) and guar gum reduced steroid concentration considerably at all sites of the large intestine, which is consistent with their stool bulking effects. In conclusion, this study shows that intestinal steroid metabolism in the pig is similar to that in man despite slightly different bile acid profiles and, therefore, the multicannulated pig may serve as a useful model of man in chemoprevention studies of colorectal cancer.

Animals↗
PubMed1992

Neutrophil recruitment to the gastrointestinal tract.

The infiltration of an organ or tissue by neutrophils is the hallmark of acute inflammation. Recent work from many laboratories suggests that neutrophils may play a role in the development of tissue injury in a variety of disease states in the gastrointestinal tract. These diseases include gastritis, necrotizing enterocolitis, ileitis, ulcerative colitis, and ischemia reperfusion injuries. In view of this recent interest in the neutrophil and its relationship to GI diseases, it seems timely to review what is known about neutrophil recruitment to the gastrointestinal tract. This review will therefore focus on the sojourn of the neutrophil from the circulation to its destination in the GI tract.

Animals↗
PubMed1998

Cytologic examination of exfoliative specimens obtained during endoscopy for diagnosis of gastrointestinal tract disease in dogs and cats.

OBJECTIVE: To determine whether cytologic examination of exfoliative specimens obtained during endoscopy was as useful as histologic examination of mucosal biopsy specimens for the diagnosis of gastrointestinal tract disease in dogs and cats and to compare the diagnostic accuracy of 2 techniques (brush or touch) in preparing specimens for cytologic examination. DESIGN: Prospective case series. ANIMALS: 85 dogs and 23 cats. PROCEDURE: Specimens for cytologic and histologic examination were obtained during routine endoscopic examination of the stomach, small intestine, and colon. A diagnosis was made on the basis of cytologic findings (graded objectively) and compared with the diagnosis on the basis of histologic findings. RESULTS: The diagnostic accuracy of cytologic examination was high for all 3 organs. Sensitivities, specificities, and predictive values of positive and negative results were > 90% in most instances. The diagnostic accuracy of the brush technique was equal or superior to that of the touch technique for 84% of specimens. The brush technique was most useful in detecting cellular infiltrates in the lamina propria, whereas the touch technique was more likely to detect acute mucosal inflammation. Percentages of false-positive (3.2%) and false-negative (6.9%) cytologic interpretations were low. CLINICAL IMPLICATIONS: Endoscopy is safe and requires little time to procure specimens for cytologic examination, which can be obtained concurrently with mucosal biopsy specimens. Cytologic examination of exfoliative specimens obtained during endoscopy is a useful and reliable adjunct to histologic examination of biopsy specimens in the diagnosis of gastrointestinal tract disease in dogs and cats.

Animals↗
PubMed1984

Immunocytochemical investigation of the gastro-entero-pancreatic (GEP) neurohormonal peptides in the pancreas and gastrointestinal tract of the dogfish Squalus acanthias.

The pancreas and gastrointestinal tract (GIT) of adults and of an embryonic stage of 11 cm long (about half the length of newborn fish) of the spiny dogfish, Squalus acanthias, were investigated immunocytochemically for the occurrence of the gastro-entero-pancreatic (GEP) neurohormonal peptides. In the pancreas of adult forms 5 endocrine cell types were seen, namely insulin-, somatostatin-, glucagon-, pancreatic polypeptide (PP)- and gastric inhibitory peptide (GIP)-immunoreactive cells. These cell types form scattered islets and were seen sometimes to surround small ducts. GIP-immunoreactivity cells did not occur in glucagon-containing cells. In the mucosa of GIT of adults 18 endocrine cell types were observed, viz. insulin-, somatostatin-, glucagon-, glicentin, PP-, polypeptide YY (PYY)-, vasoactive intestinal polypeptide (VIP)-, GIP-, gastrin C-terminus, CCK-, neurotensin N-terminus-, bombesin/gastrin releasing peptide (GRP)-, substance P-, enkephalin-, alpha-endorphin, beta-endorphin-, serotonin- and calcitonin immunoreactive cells. These cells occurred mostly in the intestine. All these cell types were of the open type, except glucagon- and glicentin-immunoreactive cells in the stomach, which seemed to be of the closed type. In the muscle layers and the submucosa, VIP and substance P- immunoreactive nerves and neurons were observed. In the pancreas of the dogfish embryo only 3 endocrine cell types could be demonstrated, namely insulin-, somatostatin- and glucagon-immunoreactive cells. In the mucosa of the GIT of the embryos studied 12 endocrine cell types were detected, viz. insulin-, somatostatin-, glucagon-, PP-, PYY-, VIP, GIP, gastrin C-terminus-, CCK-, neurotensin N-terminus-, enkephalin- and serotonin immunoreactive cells. The number of these cells, except that of PYY-immunoreactive cells, was lower than that of adults and in some cases their distribution did not correspond with that of adults.

Animals↗
PubMed2003

Contribution of epidemiology in Poland for better understanding of the natural history of diseases in gastrointestinal tract.

Descriptive epidemiologic studies on the geographical distribution of gastrointestinal diseases in Poland have been conducted in our country since several decades. One of the first descriptive analyses was cancer study in 1967, where age-standardized mortality rates in various regions of Poland by gender and area of residence (urban/rural) were presented. Since 1970 analytical epidemiologic studies aiming at explaining the natural course of various diseases within gastrointestinal tract started to produce interesting results. The first study in this field was the case-control study on the occurrence of peptic ulcer and tobacco smoking performed in 1974. The study provided one of the first epidemiologic evidence on the harmful effect of tobacco smoking in the etiology or peptic ulcers. Subsequent studies dealt with the importance of dietary habits and life style (tobacco smoking and vodka drinking) in the occurrence of gastric cancer. The studies confirmed previous findings that consumption of raw vegetables and fresh fruit is inversely related to risk for stomach cancer in Poland. In addition the results demonstrated, that dietary practices such as the modality of cooking the food, preparation of food products and storing conditions were connected with stomach cancer risk. These factors have also been found to influence the risk for stomach cancer in Poland. The main message of this latter study was that the family as a whole is affected by many risk factors for stomach cancer and families in which stomach cancer has occurred should be therefore targets for preventive measures. Interestingly, analysis of life style factors such as tobacco smoking or vodka drinking has showed that the risk for cardia cancer increased considerably for smokers of cigarettes without filters and in those who consumed large amounts of vodka. For the non-cardia region a uniform increase of risk could be observed for vodka drinking, regardless of cigarette smoking status. The findings of this study suggested the hypothesis that the effect of tobacco smoking and vodka drinking may be different for cardia cancer compared to the distal cancers. Our clinico-epidemiological study suggest that infection with Helicobacter pylori is not sufficient factor for inducing precancer changes in gastric mucosa. Besides, case-controls studies on dietary habits and physical activity level in the etiology of colorectal cancer are in progress. The preliminary results demonstrated the protective effect of higher physical activity in the occurrence of colorectal cancer after accounting for nutritional habits.

Gastrointestinal Diseases↗
PubMedDate not supplied

[Effect of the amount of protein and calcium in the diet on cadmium chloride absorption from the gastrointestinal tract].

Experiments on rats kept on the diets with different content of protein (18, 30 and 5%) and calcium (0,6, 2.4, 0.1%) for a month were made to study the absorption coefficient of labeled cadmium from the gastrointestinal tract. It was established that the quota of calcium and protein in the diet exerts an appreciable effect on cadmium chloride absorption via the gastrointestinal tract. The highest coefficient of cadmium absorption was recorded on excess protein (30%) and calcium deficiency (0,1%) in the diet, whereas the least one in the group of animals fed the diet with a low protein quota (5%).

Animals↗
PubMed2006

Interobserver variability in histologic recognition, interpretation of KIT immunostaining, and determining MIB-1 labeling indices in gastrointestinal stromal tumors and other spindle cell tumors of the gastrointestinal tract.

The authors studied the concordance among seven pathologists for the histologic diagnosis, interpretation of KIT immunostaining, and determining MIB-1 labeling indices (LI) in 80 adult patients with primary spindle cell tumors, mainly of the gastrointestinal tract, mesentery, retroperitoneum, and pelvis, based on the review of tissue sections using an immunohistochemical panel of antibodies for KIT/CD117, CD34, desmin, smooth muscle actin (SMA), and S-100 protein. Tumors included 30 gastrointestinal stromal tumors (GISTs), 10 leiomyomas, 10 leiomyosarcomas, 10 schwannomas, 10 solitary fibrous tumors, and 10 desmoid-type fibromatoses. The overall concordance with the original diagnosis of each histologic type was 97.9%, the kappa value ranging from 0.95 to 1.00 (mean 0.97), indicating a perfect agreement. The overall interlaboratory concordance with the original interpretation of KIT immunostaining was 91.3%, the kappa value ranging from 0.77 to 0.90 (mean 0.86). The overall interlaboratory concordance with the original interpretation of KIT immunostaining was 91.9%, the kappa value ranging from 0.72 to 0.93 (mean 0.85). The overall concordance for determining MIB-1 LI was 90% with the original evaluation, and the overall kappa value ranged from 0.62 to 0.86 (mean 0.77). These results indicate that it is possible to reliably diagnose GIST and other spindle cell tumors of the gastrointestinal tract with the use of an immunohistochemical panel of antibodies for KIT, CD34, desmin, SMA, and S-100 protein. Although there is clearly unavoidable inter-observer and interlaboratory variability in the interpretation of KIT immunostained sections and interobserver variability in the determination of MIB-1 LI, the concordance between observes is very acceptable, and in most instances such variability can be eliminated by careful reviewing of the hematoxylin and eosin and immunostained sections.

Adult↗
PubMed1997

Estrogen receptor alpha and beta expression in upper gastrointestinal tract with regulation of trefoil factor family 2 mRNA levels in ovariectomized rats.

This study compared expression of two estrogen receptor (ER alpha and ER beta) genes in the rat upper gastrointestinal tract and the effects of 17 beta-estradiol administration on gastric trefoil factor family (TFF) mRNA steady-state levels in ovariectomized rats. Estrogen receptor alpha and beta cDNA fragments from fundic mucosa were cloned by reverse transcriptase polymerase chain reaction (RT-PCR) and sequenced. Both ER subtypes were detected in fundus, antrum and duodenum by RT-PCR. Northern analysis of poly(A)+ mRNA from fundic mucosa showed that ER alpha mRNA is expressed as a single transcript at 6.5 kb and ER beta is expressed as multiple transcripts with major transcripts ranging from 1.1-4.7 kb. ER beta mRNA was expressed in greater abundance than ER alpha mRNA. Fundic TFF2 mRNA steady-state levels were increased by 17 beta-estradiol administration in ovariectomized rats with no significant change in TFF1 mRNA levels. These studies show expression of both ER subtypes in the rat upper gastrointestinal tract with regulation of TFF2 mRNA by 17 beta-estradiol. These results suggest that estrogens, probably acting via ER beta, have a direct role in regulating gastric physiology.

Animals↗
PubMed1985

Role of the mucosal barrier in toxin/microbial attachment to the gastrointestinal tract.

An important component of bacterial infection of the gastrointestinal tract, particularly when enterotoxin disruption of gut function occurs, relates to the interaction of the bacterium and toxin with the intestinal surface. Adherence or attachment of bacteria lead to colonization and toxic/invasive diarrhoeal states. The purpose of this review is to consider the intestinal mucosal barrier as a deterrent to microbial/toxin attachment, particularly emphasizing the mucosal surface itself, which includes the mucus coat and microvillous membrane. Consequences of mucosal barrier deficiency, particularly the incomplete development of the mucosal barrier, result in bacterially induced diarrhoeal states such as toxigenic diarrhoea and necrotizing enterocolitis. To illustrate the importance of the mucosal barrier as a factor in controlling the external environment containing bacteria and bacterial toxins, recent research in our laboratory on the development of the mucosal barrier is presented. This compares mucosal surface functional control of antigen/toxin attachment and penetration with mucosal surface compositional changes. Finally, evidence of a preliminary nature will be provided to suggest that modifications of the underdeveloped mucosal barrier of the immature intestine by the ingestion of breast milk may act to prevent pathological interactions between the gut and microbes/toxins.

Bacterial Infections↗
PubMed1997

Differential distribution of the mitochondrial heat-shock protein 60 in rat gastrointestinal tract.

Immunohistochemical studies on various parts of the rat gastrointestinal tract by means of an antibody against the mitochondrial chaperonin, heat-shock protein 60 (hsp60), has revealed a cell-specific distribution pattern. The active form of hsp60 is a heptameric complex that is involved in the import and refolding of nuclear-encoded proteins destined for the mitochondrial matrix. This chaperonin is detectable in highly replicating cells, e. g., keratinizing cells of the esophagus and short-living epithelial cells of the intestine. In the stomach, some of the oxyntic cells contain hsp60-positive mitochondria lying near intracellular canaliculi. Neuronal cells of the enteric nervous system present intense positive staining for hsp60 in some areas. All other non-epithelial cells of the digestive tract show weak or no hsp60 immunoreactivity. The presence of hsp60 in mitochondria seems to reflect two different forms of mitochondrial renewal: (1) total reformation of mitochondria and their content after mitotic division and (2) regeneration of these organelles following high activity, e. g., ATP synthesis.

Adenosine Triphosphate↗
PubMed2003

Oxidation of essential amino acids by the ovine gastrointestinal tract.

It is not known if the ruminant animal gastrointestinal tract (GIT) can oxidise essential amino acids (AA) other than leucine. Therefore, the oxidation of four essential AA (leucine, lysine, methionine and phenylalanine), supplied systemically as labelled 1-13C forms, was monitored across the mesenteric-drained viscera (MDV; small intestine) and portal-drained viscera (PDV; total GIT), as part of a Latin square design, in four wether sheep (35-45 kg) fed at 1.4 x maintenance. Oxidation was assessed primarily by appearance of 13CO2, corrected for sequestration of [13C]bicarbonate. The GIT contributed 25 % (P<0.001) and 10 % (P<0.05) towards whole-body AA oxidation for leucine and methionine respectively. This reduced net appearance across the PDV by 23 and 11 % respectively. The contribution of MDV metabolism to total PDV oxidation was 40 % for leucine and 60 % for methionine. There was no catabolism of systemic lysine or phenylalanine across the GIT. Production and exchange of secondary metabolites (e.g. 4-methyl-2-oxo-pentanoate, homocysteine, 2-aminoadipate) across the GIT was also limited. Less AA appeared across the PDV than MDV (P<0.001), indicative of use by tissues such as the forestomach, large intestine, spleen and pancreas. The PDV: MDV net appearance ratios varied (P<0.001) between AA, e.g. phenylalanine (0.81), lysine (0.71), methionine (0.67), leucine (0.56), histidine (0.71), threonine (0.63) and tryptophan (0.48). These differences probably reflect incomplete re-absorption of endogenous secretions and, together with the varied oxidative losses measured, will alter the pattern of AA net supply to the rest of the animal.

Amino Acids, Essential↗
PubMed1995

Minimal access surgery of the gastrointestinal tract.

In the last 5 years, surgery of the gastrointestinal tract has been revolutionized by the application of minimal access techniques. Following initial enthusiasm, which suggested that most abdominal surgery would ultimately be done via this approach, there is now need for appraisal and evaluation of the role of a number of these minimal access techniques when compared with open surgery. Undoubtedly, the most convincing and total application of minimal access techniques has been in the treatment of gallstone disease. Laparoscopic cholecystectomy is now standard therapy for cholelithiasis and endoscopic sphincterotomy with stone extraction is standard therapy for choledocholithiasis. Where the two conditions co-exist, operative cholangiography allows for the recognition of stones in the bile duct at the time of laparoscopic cholecystectomy and provides the potential avenue for treatment. Most major centres also would recommend routine operative cholangiography during laparoscopic cholecystectomy for the detection of unsuspected stones and as an extra safety procedure in the early identification of potential bile duct injuries. The efficacy of laparoscopic appendicectomy and laparoscopic or thoracoscopic treatment of achalasia of the oesophagus also is supported by data from well conducted prospective studies. Doubt remains regarding the advantage of laparoscopic surgery over other approaches in the treatment of gastro-oesophageal reflux, inguinal hernias and jaundice due to non-resectable cancer. For all three of these conditions, prospective trials are underway and the results of these trials should be assessed prior to widespread adoption of the laparoscopic techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

Cholecystectomy, Laparoscopic↗
PubMed1993

Effects of dopamine on the gastrointestinal tract of chicks.

The effects of dopamine on the gastrointestinal tract of chicks have been investigated. Dopamine caused concentration-related contractions of the upper oesophagus, crop or lower oesophagus but relaxed the duodenum, ileum, large intestine or caecum in a concentration-related fashion. By means of specific antagonists, the presence of muscarinic, histamine (H1), alpha-adrenergic, 5-HT-ergic and dopaminergic receptors were established in the lower oesophagus and their stimulation caused contraction while beta-adrenergic-receptor stimulation caused relaxation. Contraction of the lower oesophagus induced by dopamine was abolished by lysergic acid diethylamide and was antagonized by moderate concentrations of haloperidol or pimozide. Tachyphylaxis developed to repeated administration of a large concentration of dopamine. These findings suggest that contraction of the lower oesophagus of chicks by dopamine is largely mediated by 5-hydroxytryptamine release and that stimulation of dopaminergic receptors contributes to a lesser extent.

Acetylcholine↗
PubMed1998

Contributions of microbes in vertebrate gastrointestinal tract to production and conservation of nutrients.

The vertebrate gastrointestinal tract is populated by bacteria and, in some species, protozoa and fungi that can convert dietary and endogenous substrates into absorbable nutrients. Because of a neutral pH and longer digesta retention time, the largest bacterial populations are found in the hindgut or large intestine of mammals, birds, reptiles, and adult amphibians and in the foregut of a few mammals and at least one species of bird. Bacteria ferment carbohydrates into short-chain fatty acids (SCFA), convert dietary and endogenous nitrogenous compounds into ammonia and microbial protein, and synthesize B vitamins. Absorption of SCFA provides energy for the gut epithelial cells and plays an important role in the absorption of Na and water. Ammonia absorption aids in the conservation of nitrogen and water. A larger gut capacity and longer digesta retention time provide herbivores with additional SCFA for maintenance energy and foregut-fermenting and copoprophagic hindgut-fermenting species with access to microbially synthesized protein and B vitamins. Protozoa and fungi also contribute nutrients to the host. This review discusses the contributions of gut microorganisms common to all vertebrates, the numerous digestive strategies that allow herbivores to maximize these contributions, and the effects of low-fiber diets and discontinuous feeding schedules on these microbial digestive processes.

Animals↗
PubMed1986

Prenatal diagnosis of gastrointestinal tract obstructions.

The types of obstructive lesions of the gastrointestinal tract which can be diagnosed before birth are briefly reviewed. The importance of obtaining a karyotype in certain lesions (such as duodenal atresia) is stressed. The usefulness of the antenatal diagnosis of such lesions in planning obstetric management is stressed.

Duodenal Obstruction↗
PubMed2004

Serum lactic acid determines the outcomes of CT diagnosis of pneumatosis of the gastrointestinal tract.

Computed tomography (CT) diagnosis of pneumatosis involving the gastrointestinal tract can represent a broad range of clinical entities from a benign process to ischemic bowel. The purpose of this study is to define the significance and outcome of pneumatosis intestinalis (PI). All CT scans from 5/93 to 12/01 with the finding of PI were reviewed. Eighty-six CT scans had the finding of PI, with the colon being the most frequent location (51%), followed by small bowel (36%) and gastric (9%). Forty per cent of patients underwent surgery, with an overall mortality rate of 42 per cent and a surgical mortality rate of 47 per cent. Univariate analysis demonstrated significant correlation between serum lactic acid (LA) > 2.0 mmol/L [odds ratio (OR) = 23.4; 95% confidence interval (C.I.), 7.21-75.92] and serum creatinine > 1.5 mg/dL (OR = 3.05; 95% C.I., 1.25-7.42) with mortality. Age was suggestive but not a significant risk factor for mortality (P = 0.09). Multivariate analysis found serum LA > 2.0 (OR = 30.37; 95% C.I., 7.31-126.2) to be the only significant predictor of mortality. CT diagnosis of PI is associated with significant in-hospital mortality, especially in the elderly. Serum LA level > 2.0 mmol/L at time of diagnosis is associated with a greater than 80 per cent mortality. Surgical consultation is necessary to determine which patients need urgent surgical intervention.

Adolescent↗
PubMed1987

[Principles of particle resorption in the gastrointestinal tract].

The uptake of allergens by the epithelium of gastrointestinal tract is not sufficiently investigated. This is true especially for the absorption of small particles like spores and pollen. By means of scanning-electron-microscopy it is possible to locate particles easily and to observe absorption solutions of 0.5 micron and 1 micron latex particles, of 15 microns Urtica pollens and of 35 microns Lycopodium spores and further on by cannulation of the thoracic duct the transport of particles was investigated. After a short time of absorption latex particles were found to be concentrated on M-cells of Peyer's patches (PP) and were found in a close contact to macrophages inside the lymph follicles. There was a constant proportion of M-cells to absorptive-like cells in PP from about 1 to 12. Obviously all particles were also transported by thoracic duct lymph. The results obviously indicate: primary absorption of small particles occurs in M-cells of PP; absorption time is dependent on particle size and transport of particles is achieved by abdominal lymph.

Allergens↗