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Canadian Journal of Physiology and... May 1990Luminal nutrition is important for the maintenance of small intestinal structure and function. The equilibrium between crypt cell production and villous cell loss in the... (Review)
Review
Luminal nutrition is important for the maintenance of small intestinal structure and function. The equilibrium between crypt cell production and villous cell loss in the mucosal epithelium of the small intestine is altered under certain conditions such as after a small bowel resection. Immediately after resection, there is a marked increase in crypt cell proliferation giving rise to an adaptive hyperplasia in the remnant intestine and for this response luminal nutrition is a critical factor. We have previously demonstrated the presence of a growth-stimulating (GS) activity in a heat-stable acidic extract of the rat proximal intestine 24, 48, and 96 h after resection, which is coincidental with an increase in crypt cell proliferation as measured by thymidine kinase activity. Eight days after resection when the GS activity is no longer detectable, the thymidine kinase activity returns to control values. The molecular weights of the peptides associated with this GS activity are 4500 and 1500, as determined by Sephadex gel filtration. Of note is that the oral intake of food is necessary for the appearance of the GS activity postoperatively. The presence of the GS activity has also been demonstrated upon refeeding after a fast, as well as at weaning in the rat, two physiological situations known to be associated with increased proliferation in the small intestine. This GS activity in the proximal intestine first detected in the resection model may represent a general mechanism by which food controls the cell renewal pattern of the small intestine.
Topics: Adaptation, Physiological; Animals; Humans; Intestine, Small
PubMed: 2187580
DOI: 10.1139/y90-095 -
Clinical and Experimental Pharmacology... Jun 19941. Propulsion of digesta along the intestine appears to occur by the action of a series of local reflexes which cause contraction oral to the digesta and relaxation of... (Review)
Review
1. Propulsion of digesta along the intestine appears to occur by the action of a series of local reflexes which cause contraction oral to the digesta and relaxation of circular muscle on the anal side. 2. There is now substantial evidence available about the identities of the enteric neurons that mediate these reflexes. 3. The motor neurons and interneurons of the reflex pathways lie within the myenteric plexus. These neurons can be classified electrophysiologically as S-neurons and have distinctive projections and neurochemistries. 4. The sensory neurons may lie in the myenteric plexus, but there is some evidence for sensory neurons in the submucous plexus. A contribution from extrinsic sensory neurons to local motility reflexes cannot be ruled out. Intrinsic sensory neurons are probably AH-neurons and are large multi-axonal cells.
Topics: Animals; Gastrointestinal Motility; Guinea Pigs; Intestine, Small
PubMed: 7982274
DOI: 10.1111/j.1440-1681.1994.tb02540.x -
The Proceedings of the Nutrition Society Jun 1984
Review
Topics: Absorption; Animals; Arteries; Biological Transport; Capillaries; Duodenum; Epithelium; Erythrocytes; Glucose; Glutamine; Humans; Ileum; Intestine, Small; Jejunum; Lymphatic System; Models, Biological; Oxygen; Perfusion; Regional Blood Flow; Veins; Viscosity; Water
PubMed: 6382267
DOI: 10.1079/pns19840038 -
Canadian Journal of Gastroenterology =... 1997The small bowel has undergone intense study. Part I of this two-part review of the small bowel focuses on gastrointestinal peptides; intestinal infections and human... (Review)
Review
The small bowel has undergone intense study. Part I of this two-part review of the small bowel focuses on gastrointestinal peptides; intestinal infections and human immunodeficiency virus; drugs; intestinal growth-mucosal proliferation and differentiation; nucleic acids, nucleotides and nucleosides; vitamins and minerals; Whipple's disease; radiation; and early development.
Topics: AIDS-Related Opportunistic Infections; Enteritis; Humans; Intestine, Small
PubMed: 9113800
DOI: 10.1155/1997/472730 -
Mayo Clinic Health Letter (English Ed.) Nov 2007
Topics: Digestion; Duodenum; Humans; Intestine, Small
PubMed: 18229408
DOI: No ID Found -
Arquivos de Gastroenterologia 1998During development the gastrointestinal tract undergoes marked changes in many physiological and anatomic properties. The remarkable degree of coordination between the... (Review)
Review
During development the gastrointestinal tract undergoes marked changes in many physiological and anatomic properties. The remarkable degree of coordination between the development of the gastrointestinal function suggests that the processes may be signalled by some factors, such as weaning, nutrient intake, growth and hormones. The interactions between nutrition and intestinal development begin when fetuses start swallowing amniotic fluid and extend past weaning. Hormonal control plays a major role in the ontogeny of the small intestine. There are late effects of early nutrition, and the normal progress of ontogeny may be important to ensure that the intestine is capable of adaptation in later life.
Topics: Animals; Hormones; Humans; Intestine, Small
PubMed: 10029865
DOI: No ID Found -
Clinical Orthopaedics and Related... Oct 2004The goal of this study is to examine whether porcine small intestine submucosa (SIS) exhibits antimicrobial properties in a standard in vitro system, without...
The goal of this study is to examine whether porcine small intestine submucosa (SIS) exhibits antimicrobial properties in a standard in vitro system, without pretreatment with acetic acid or extraction of soluble proteins. Previous animal studies suggest that porcine SIS may have inherent antibiotic properties. Using the guidelines for disk diffusion susceptibility testing by Bauer, 17/64-inch diameter disks made of porcine small intestine submucosa and of gortex were compared with standard antibiotic-impregnated disks against six organisms. The zone of inhibition was measured after 24 hours and minimum bacterial concentrations were determined by serial dilutions of a solution in which porcine small intestine submucosa was allowed to elute for 24 hours. Neither porcine SIS or gortex discs caused inhibition of the growth of any organism. The porcine small intestine submucosa discs showed bacterial growth on top of the discs whereas the gortex did not. Neither the dilutional concentrations of the porcine small intestine submucosa eluent nor the gortex eluent inhibited the growth of any organism. These findings suggest that the porcine small intestine submucosa does not have intrinsic antimicrobial properties. The growth of bacteria on top of the porcine small intestine submucosa suggests that porcine small intestine submucosa itself may provide a favorable environment for the growth of bacteria. More research is necessary to decide what role porcine small intestine submucosa plays in the treatment of infected surgical sites.
Topics: Animals; Anti-Bacterial Agents; Intestinal Mucosa; Intestine, Small; Swine
PubMed: 15552130
DOI: 10.1097/01.blo.0000143573.03645.b4 -
Shujutsu. Operation May 1969
Topics: Duodenum; Humans; Ileum; Intestine, Small; Jejunum; Meckel Diverticulum
PubMed: 5809617
DOI: No ID Found -
The Journal of Parasitology Dec 2001During its 24-hr migratory cycle in the small intestine, Hymenolepis diminuta is located in the orad part of the small intestine during the early morning hours and then...
During its 24-hr migratory cycle in the small intestine, Hymenolepis diminuta is located in the orad part of the small intestine during the early morning hours and then in the caudad part of the small intestine during the late afternoon and early evening. During the later period, tapeworm-induced alterations of interdigestive myoelectric activity, a correlate of smooth muscle contraction or intestinal motility, are most intense in the ileal region. The hypothesis tested was that the tapeworm-induced changes in intestinal motility are local responses of the intestine responding to the close proximity of the lumenally positioned tapeworm and to the nutritional state of the host. The small intestine was monitored before and for 20 days after infection using electrodes implanted on the serosa of the small intestine. Myoelectric recordings were analyzed for the frequency of the normal patterns of interdigestive myoelectric spiking patterns and the altered myoelectric spiking related to tapeworm infection. During the morning hours, when the tapeworms are situated in the orad small intestine, no changes were observed during the normal myoelectric pattern of the digestive phase in any region of the intestine. When examined after the conversion of the digestive to interdigestive phase of motility, only on day 10 postinfection was the interdigestive phase significantly altered. It was concluded that the presence of the tapeworm in the orad small intestine during the satiety stage of the rat causes no changes in the electric events of the small intestine, with the exception of day 10 postinfection. Because tapeworms in the orad small intestine do not induce the tapeworm-altered myoelectric activity observed in the afternoon and evening with caudally positioned tapeworms, tapeworm-altered motility is not simply a response of the small intestine to the local presence of the tapeworm.
Topics: Animals; Circadian Rhythm; Digestion; Duodenum; Hymenolepiasis; Ileum; Intestine, Small; Jejunum; Male; Myoelectric Complex, Migrating; Rats; Rats, Sprague-Dawley
PubMed: 11780807
DOI: 10.1645/0022-3395(2001)087[1255:MROTSI]2.0.CO;2 -
Tissue Engineering. Part C, Methods Jun 2018Short bowel syndrome (SBS) is a major cause of morbidity and mortality in the pediatric population, for which treatment options are limited. To develop novel approaches...
Short bowel syndrome (SBS) is a major cause of morbidity and mortality in the pediatric population, for which treatment options are limited. To develop novel approaches for the treatment of SBS, we now focus on the development of a tissue-engineered intestine (also known as an "artificial intestine"), in which intestinal stem cells are cultured onto an absorbable bioscaffold, followed by implantation into the host. To enhance the translational potential of these preclinical studies, we have developed three clinically relevant models in neonatal piglets, which approximate the size of the human infant and were evaluated after implantation and establishment of intestinal continuity over the long term. The models included (1) a staged, multioperation approach; (2) a single operation with a de-functionalized loop of small intestine; and (3) a single operation with an intestinal bypass. The first model had complications related to multiple operations in a short time period, including surgical site infections and wound hernias. The second model avoided wound complications, but was associated with high ostomy output, local skin breakdown, and systemic dehydration with associated electrolyte imbalances. The third model was the most effective, although resulted in stoma prolapse. In summary, we have now developed and evaluated three operative methods for the long-term evaluation of the artificial intestine in the piglet, and conclude that a single operation with a de-functionalized loop of small intestine may be an optimal approach for evaluation over the long term.
Topics: Animals; Animals, Newborn; Disease Models, Animal; Intestine, Small; Surgical Wound Infection; Swine; Tissue Engineering
PubMed: 29638197
DOI: 10.1089/ten.TEC.2018.0040