Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The gut organs are vulnerable to injury during shock because of ischemia and reperfusion of the microcirculation. These injuries result in upper GI hemorrhage, liver dysfunction, and pancreatic and mesenteric necrosis. Toxic mediators, released via lymph drainage and with reperfusion, contribute to the failure of other organs and the development of refractory shock. Until single organ perfusion can be measured, the primary goal of care is to maintain systemic perfusion. Secondary goals are to decrease hydrogen ion accumulation, minimize pancreatic stimulation, remove hepatotoxic agents, and reduce blood bacteria. Gut ischemia is simply one piece of the puzzle in the multiple organ response to reduced systemic oxygenation and perfusion that characterizes the clinical syndrome of shock.
 ...
PMID:Gastrointestinal complications in shock. 219 30

Translocation of carbon-14-labeled Escherichia coli from the gut was studied at the specified times in the following groups of rats: Group 1, 5 hours after ligation of the superior mesenteric artery; Group 2, 5 hours after laparotomy and exposure of the superior mesenteric artery with gentle removal and replacement of the intestines; and Group 3, 5 hours after handling but no surgical manipulation. Both living and dead bacteria were administered by means of gavage, and the effect of viability, intestinal ischemia without reperfusion, and bowel manipulation on the translocation of enteric bacteria was assessed. We demonstrated that (1) even gentle bowel manipulation causes bacteremia as great as that associated with ligation of the superior mesenteric artery; (2) dead E. coli are absorbed into the blood in the presence of bowel manipulation or ischemia but less effectively than are live E. coli; (3) live bacteria are found in highest concentration in the lung and in descending order in the liver, kidney, heart, and spleen; (4) dead bacteria absorbed from the gut are found in highest concentration in the kidney and the liver. Lesser amounts are found in the lung, spleen, and heart.
 ...
PMID:Organ distribution of gut-derived bacteria caused by bowel manipulation or ischemia. 240 65

Acute mesenteric ischemia is highly lethal and therefore a serious problem for surgery and intensive care medicine; accordingly its pathophysiology warrants further study. Oxygen free radicals (OFR) play a role in the intestinal mucosal damage that develops during reperfusion after ischemia. Histamine (H) is generally released in various types of tissue ischemia. The link between H release and OFR has only been studied in in vitro systems. We tested the hypothesis that OFR may be involved in H release following reperfusion of the ischemic gut. The artery supplying a segment of the ileum was occluded for 1 or 2 h in anesthetized dogs. On reperfusion, a release of H into the venous effluent of the segment was demonstrated. Pretreatment of the animals with allopurinol (an inhibitor of xanthine oxidase), or with MTDQ-DA [6,6'-methylene-bis(2,2-dimethyl-4-methanesulfonic acid sodium-1,2-dihydroquinoline)], a superoxide anion scavenger, or with a combination of allopurinol and MTDQ-DA resulted in an inhibition of H release. We conclude that OFR may play a role in the local H release following intestinal ischemia.
 ...
PMID:Oxygen free radical-induced histamine release during intestinal ischemia and reperfusion. 248 33

Motility disorders of the gut in children have become a matter of increasing concern for the pediatric surgeon. Infantile hypertrophic pyloric stenosis is the most common disease requiring surgery in early infancy. While this entity was first described as early as 1888 by Hirschsprung, its etiology and pathogenesis are still an enigma. Fortunately, its surgical treatment is simple and safe, which cannot be said of all other motility disorders of the infantile gut. Dysmotility in small bowel atresia and in gastroschisis is related to damaged smooth muscle cells caused by concomitant ischemia of the bowel wall. In contrast, the temporarily adynamic bowel of the prematurely born child, as well as Hirschsprung's disease and related disorders, is the result of anomalies of the intestinal innervation. The pathogenesis of congenital malformations of the enteric nervous system is still a mystery to surgeons and physicians alike. With his pressure studies of the colon, Swenson first recognized Hirschsprung's disease for what it was. This led to the resection of the manometrically diagnosed abnormal colon, which was found to be aganglionic. Histological investigation of the bowel wall became the decisive tool, replacing manometry, in the diagnosis of Hirschsprung's disease. Histochemical investigation of the bowel wall is not conclusive in other malformations of the enteric nervous system, since the presence or absence of enteric neurons is not the definitive factor discriminating between normally and abnormally functioning bowel. Monoclonal antibodies raised against neuron-specific markers may become important tools for differentiation within the spectrum of congenital malformations of the enteric nervous system. The immunocytochemical technique, however, does not provide sufficient information to explain the cause of innervation disorders of the gut in infancy and childhood. Primary migration disturbances or selective disappearance of enteric neurons following ischemia are highly unlikely to cause aganglionosis of the gut. With respect to the pathogenesis and etiology of Hirschsprung's disease, current research is focused on the embryonic bowel (target organ) in plexus formation. The enteric nervous system is still an enigma, although its origin is known, at least in birds. Why neural crest cells travel, along what paths, how they reach their destination, and what may go wrong during the migratory process, are questions that must be answered. There is increasing knowledge concerning the way in which neural crest cells aggregate and form plexuses in the gut. It is largely unknown why neural crest cells settle, in the bowel, at the sites of the myenteric and submucous plexus.(ABSTRACT TRUNCATED AT 400 WORDS)
 ...
PMID:Diagnosis of innervation-related motility disorders of the gut and basic aspects of enteric nervous system development. 251 2

We report our experience in the surgical treatment of visceral arterial occlusive disease in 9 patients. The etiology was atherosclerosis in 7 cases and arteritis in 2. Four patients were admitted because of acute mesenteric ischemia, but only two had a previous history of intestinal angina. Four consulted because of chronic mesenteric angina and only 1 asymptomatic patient received prophylactic revascularization. The clinical picture of postprandial abdominal pain, weight loss, bowel habit disturbance, abdominal bruit or signs of occlusive disease elsewhere, should lead to clinical diagnosis. Angiographic evaluation is mandatory to plan the best surgical approach. In this series we revascularized 14 vessels in 9 patients using different technics. Two patients died (42 and 90 days) following revascularization and partial resection of the gut for extensive infarction. All survivors achieved symptom relief and or recovered or stabilized their weight.
 ...
PMID:[Mesenteric vascular insufficiency caused by chronic occlusive disease: experience with the surgical management of 9 cases]. 251 15

Intestinal ischemia-reperfusion injury is a common and important clinical event associated with the activation of an endogenous inflammatory response. Some of the mediators of this response may be involved in the pathogenesis of multiple organ system failure. The purpose of this study was to determine whether remote organ dysfunction--specifically, acute lung injury--occurs after intestinal ischemia-reperfusion injury. After an ischemia-reperfusion event in rat intestine, whole lungs were obtained for measurement of tissue adenosine triphosphate (ATP) and myeloperoxidase values, and evaluation of histologic condition. In addition, lung microvascular permeability was assessed by determination of the rate at which iodine 125-labeled bovine serum albumin sequestration in the extravascular compartment occurred. Lung tissue ATP levels were no different in sham-operated animals than in those that had undergone 120 minutes of intestinal ischemia. Within 15 minutes of gut reperfusion, however, lung ATP decreased from 3.82 +/- 0.27 to 1.53 +/- 0.90 x 10(-7) moles/50 mg tissue, p less than 0.05. Neutrophil accumulation in the lungs, estimated by tissue myeloperoxidase determination, increased sevenfold (0.13 +/- 0.02 to 0.97 +/- 0.25 units/gm, p less than 0.05) after 120 minutes of ischemia and 15 minutes of reperfusion. Lung microvascular permeability increased threefold after 120 minutes of intestinal ischemia and 120 minutes of reperfusion (0.10 +/- 0.01 vs. 0.35 +/- 0.05 [lung/blood counts per minute], p less than 0.05). Intestinal ischemia followed by reperfusion is associated with acute lung injury characterized by increased microvascular permeability, histologic evidence of alveolar capillary endothelial cell injury, reduced lung tissue ATP levels, and the pulmonary sequestration of neutrophils. These data confirm an acute lung injury associated with intestinal ischemia-reperfusion and suggest a possible pathogenic role for the neutrophil.
 ...
PMID:Evidence for neutrophil-related acute lung injury after intestinal ischemia-reperfusion. 276 27

Acidosis in gastric mucosa (pHi less than 7.32) was evaluated as a diagnostic test for gastric ischemia, using 80 asymptomatic subjects as controls. Mucosal acidosis was found in 6 patients with abdominal pain and 1 with gastrointestinal bleeding. Three had occlusive disease of 2 or more visceral arteries, 3 had occlusive disease of the celiac axis alone, and 1 had an occluded portal vein. One patient had infarcted gut. The abnormal pHi (7.10 +/- 0.11, mean +/- SD) in those with pain was returned to normal levels (7.43 +/- 0.08, p = 0.0003) and the symptoms relieved by revascularization. The abnormal pHi (6.84 +/- .04) in the patient who bled was restored to normal levels (7.48 +/- .03, t = 9.69, p less than .0001) and the bleeding stopped by a central splenorenal shunt. Measurements of pHi in gastrointestinal mucosa may be used as an objective test for evaluating patients suspected of having chronic gastrointestinal ischemia.
 ...
PMID:Chronic gastric ischemia. A cause of abdominal pain or bleeding identified from the presence of gastric mucosal acidosis. 280 10

Seven-day-old mice were infected orally with murine rotavirus (EDIM) and regions of the gut examined at 24 h intervals up to 7 days by electron microscopy. Structural changes were correlated with data on viral antigen production, thymidine kinase activity, and clinical signs of diarrhea. No pathological changes were detected in the colon. Infection and structural damage were confined to the small intestine, with middle regions showing the most pronounced changes. Constriction of villus bases, edema of the lamina propria, and vacuolation of enterocytes occurred at 24 h postinfection (PI), i.e., before evidence of major virus replication. Transient villus atrophy occurred at 48 h PI. Recovery of villus length was evident by 72 h PI accompanied by evidence of marked enterocyte replication at villus bases. Many enterocytes were damaged with little evidence for the presence of virus particles. By 96 h PI, villi had almost recovered from infection although some enterocytes were still damaged; no virus particles were detected in these cells. A second phase of villus damage and edema of the lamina propria occurred at 120 h PI; the pathology resembled that at 24-48 h PI. By 144 to 168 h PI, recovery of the mucosa from infection was virtually complete. We suggest that many of the pathological features following rotavirus infection result from rotavirus-induced ischemia of villi and that diarrhea results from malabsorption of fluid by damaged villi and hypersecretion of ions released from increased numbers of dividing cells at villus-crypt borders.
 ...
PMID:An electron microscopic investigation of time-related changes in the intestine of neonatal mice infected with murine rotavirus. 283 83

Histamine release adjacent to mesenteric arterioles under conditions of ischemia causes vasodilation and increases regional blood flow. This is presumably a protective mechanism which may be blocked by the use of H1 and H2 antagonists. Mesenteric arterioles of 29 rats were observed with intravital microscopy. Diameter and erythrocyte velocity were measured and arteriolar flow was calculated. Histamine was topically applied to the vessels under view in sequentially increasing concentrations (10(-7) to 10(-4) M). Following systemic injection of an H1 or H2 receptor antagonist or ibuprofen, the application of 10(-4) M histamine was repeated. Topical histamine caused vasodilation (122% of control; P less than 0.05) at 10(-4) M with a corresponding increase in erythrocyte velocity and calculated flow (118 and 177% of control, respectively; P less than 0.05 for each). The vasodilatory effects of histamine were blocked by systemic injection of histamine receptor antagonists (H1 + H2 greater than H1 greater than H2), while ibuprofen had no significant effect. In situations in which the gut is at risk for ischemia, the use of H1 and/or H2 receptor antagonists may seriously compromise the mesenteric microcirculation.
 ...
PMID:Effect of histamine and histamine receptor antagonists on rat mesenteric microcirculation. 288 49

Between 1983 and 1986, four newborns who had primary closure of gastroschisis had postoperative ischemic bowel. Suspicion was raised almost immediately after closure that something was wrong inside the abdomen when there was persistent acidosis, sepsis, abdominal wall redness, and a generalized worsening condition. All four neonates were re-explored. Necrotic bowel was found, and three required silon pouch closure. The two survivors were left with a temporary short gut. Whether the cause of the bowel ischemia in the four babies was due to excessive intraabdominal pressure, volvulus, or the intestines being too vigorously manipulated, is speculative. Therefore, excessive manipulation and compression of gastroschisis contents seem unwise; if such a newborn has persistence of the above signs and symptoms, immediate reoperation and decompression are warranted.
 ...
PMID:Ischemic bowel after primary closure for gastroschisis. 297 92


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>