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Query: UMLS:C0030305 (pancreatitis)
 16,014 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Evidence is presented that supports a role of oxygen free radicals in the pathogenesis of various disorders of the digestive system. In the intestine, there is evidence that oxygen radicals play an important role in the endothelial and epithelial damage associated with certain models of ischemia. The mechanism for superoxide production in this condition differs from that described for other pathologic states (i.e., oxygen toxicity and neutrophil-mediated inflammation). This mechanism involves the reaction of xanthine oxidase, hypoxanthine, and molecular oxygen to produce a burst of oxygen radicals with reperfusion of the ischemic bowel. Evidence implicating oxygen radicals in inflammatory disorders of the digestive tract (i.e., pancreatitis), radiation injury, and hepatic cirrhosis is also presented. The available data suggest that oxygen radicals appear to be a fundamental mechanism of tissue injury in the pathogenesis of various disorders of the digestive system.
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PMID:Role of oxygen-derived free radicals in digestive tract diseases. 635 11

The authors examined 40 patients with chronic ischemic pancreatitis without concomitant pathology of the alimentary organs in order to define the features of the disease clinical picture and progress. It was found that patients with disseminated atherosclerosis, especially when it is coupled with essential hypertension, and with extravasal stenosis of the celiac trunk are predisposed to the development of chronic ischemic pancreatitis. Factors promoting pancreatic ischemia include abnormalities of the blood rheological properties seen in vascular pathology and alimentary hyperlipidemia.
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PMID:[Various characteristics of chronic ischemic pancreatitis]. 652 92

Acute hemorrhagic pancreatitis was induced in rats by injecting sodium taurocholate into the common biliopancreatic duct. The extent of pancreatic necrosis was quantified in histological sections during the course of the disease. The proportion of necrotic acini was low, although the amount of necrosis increased from 3.3% of pancreatic parenchyma at 15 min to 10.5% at 12 h. The degree of ischemia in the inflamed pancreas was estimated by extracting intravenously injected toluidine blue from the gland. The amount of the dye in the gland decreased progressively during 12 h to 58.8% of the amount in normal pancreas. The development of pancreatic edema was studied by recording the water content of the gland. The edema was maximal at 3 h and resolved partly in 12 h after the induction of the disease. Necrosis and ischemia become progressively more pronounced in the edematous pancreas during sodium taurocholate-induced acute hemorrhagic pancreatitis. This kind of pathophysiologic course is also thought to characterize human pancreatitis. The present simple model of acute hemorrhagic pancreatitis in the rat is suitable for quantitative observations on the development of pancreatic damage under various experimental conditions.
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PMID:Experimental pancreatitis in the rat. Development of pancreatic necrosis, ischemia and edema after intraductal sodium taurocholate injection. 684 Jan 52

The etiology and pathogenesis of acute necrotizing hemorrhagic pancreatitis remain controversial. Recent work has suggested that an early fall in pancreatic blood flow, causing ischemia, may be the initiating factor. Using an established rat model of hemorrhagic pancreatitis and the fractional indicator distribution technique with 86RbCl, pancreatic blood flow and tissue perfusion have been measured at various times in the condition. Six groups of ten rats were studied: control sham operation and pancreatitis groups were sacrificed at 1, 6, and 24 hr. Pancreatic blood flow (% of cardiac output) and perfusion (blood flow/g tissue) were measured. Blood flow was increased by a maximum of 53% at 1 hr (P less than 0.001) and remained elevated for 24 hr, and perfusion was increased by a maximum of 70% (P less than 0.001) at 1 hr and remained elevated at 6 hr. Pancreatic perfusion declines after 6 hr due to increasing gland edema. The results demonstrate a significant increase in pancreatic blood flow and perfusion in experimentally induced acute pancreatitis, suggesting a primary inflammatory response, and refute the ischemic etiological theory.
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PMID:Pancreatic blood flow in experimental acute pancreatitis. 707 32

Extraintestinal trypsinogen activation peptides (TAP) have been shown to correlate with severity of acute pancreatitis in humans as well as in various animal models. Ischemia superimposed on experimental pancreatitis, however, increases acinar cell injury without increasing TAP in plasma. We speculated that TAP generated in the pancreas might not reach the circulation in necrotizing pancreatitis due to decreased pancreatic perfusion. To test the hypothesis that generation of TAP in plasma is related to pancreatic perfusion and that plasma TAP may therefore underestimate acinar cell injury in necrotizing disease, we correlated TAP in pancreatic tissue and body fluids with capillary pancreatic blood flow in necrotizing and edematous pancreatitis. The ratio between necrosis and TAP in tissue was similar in both models; the ratio between TAP in plasma and tissue, however, was significantly lower in necrotizing pancreatitis, indicating that a certain amount of TAP generated in the pancreas did not reach the circulation. Decreased pancreatic perfusion found in necrotizing pancreatitis was consistent with this finding. Our data suggest that TAP in tissue is most reliable to indicate severity of acute pancreatitis, whereas plasma TAP may underestimate pancreatic injury in necrotizing disease due to decreased pancreatic perfusion.
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PMID:Effect of microcirculatory perfusion on distribution of trypsinogen activation peptides in acute experimental pancreatitis. 758 86

Acinar necrosis in patients with acute pancreatitis can be due to enzymatic injury, ischemia, or both. We hypothesized that novel therapy aimed at an improvement of pancreatic microcirculation early in the course of pancreatitis may reduce the lethality and acinar damage. Forty-six dextran-resistant rats received controlled intraductal infusion of glycodeoxycholic acid (10 mmol/L), followed by intravenous cerulein (5 micrograms/kg/h) for 6 hours. Beginning 30 minutes after the induction of pancreatitis, all animals were resuscitated with Ringer's lactate (RL) (8 mL/kg/h intravenously for 9 hours). In addition, they were given intra-aortic bolus infusions (2 mL/kg at 30, 60, 90, and 150 minutes) of either RL, sodium chloride (NaCl) (7.5%) and dextran 60,000 (10%) (HHS-60), NaCl (7.5%) and dextran 500,000 (10%) (HHS-500), or NaCl (0.9%) and dextran 500,000 (10%) (DEX-500). Despite high-volume fluid resuscitation in the groups that received RL and HHS-60, 70% of the animals in each of these groups died within 24 hours. In contrast, the mortality rates in the groups of animals that received HHS-500 and DEX-500 were dramatically reduced to 0% and 10%, respectively (p = 0.005, p = 0.02). Histopathologic scores for acinar necrosis were significantly lower in the group of animals that received DEX-500 (p < 0.009) compared with those that received RL and HHS-60. Finally, total amounts of trypsinogen activation peptides in ascites were significantly lower in the animals that received HHS-500 (p < 0.004) and DEX-500 (p < 0.02) compared with those that received RL and HHS-60. Rapid bolus infusion of hyperoncotic ultrahigh molecular weight dextran solution with or without hypertonic saline but not RL or hypertonic-hyperoncotic saline-dextran significantly reduced pathologic trypsinogen activation, prevented acinar necrosis, and improved survival in acute experimental pancreatitis. We speculate that a sustained improvement of pancreatic microcirculation by ultrahigh molecular weight dextran is the mechanism of action.
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PMID:Hyperoncotic ultrahigh molecular weight dextran solutions reduce trypsinogen activation, prevent acinar necrosis, and lower mortality in rodent pancreatitis. 767 89

The current organ shortage has made utilization of organs from less-than-ideal donors more common. Although several transplant centers use kidneys from non-heart-beating donors (NHBDs), there has been reluctance to extend the use of these donors to extrarenal organs. Of the 130 donors referred to our organ procurement organization between January 1993 and May 1994, 16 (12.3%) were NHBDs. Organ retrieval from 10 of these resulted in extrarenal donation, 5 resulted in renal donation only, and 1 resulted in no retrieval as a result of prolonged warm ischemia (> 2 hr). A total of 39 organs were transplanted from these NHBDs. A rapid en bloc retrieval technique was used for extrarenal NHBDs. The mean warm ischemic time was 15.4 min; preservation times were similar for both NHBDs and heart-beating donors. After liver transplantation (n = 5), one episode of primary nonfunction that was technical in origin required retransplantation. Following simultaneous pancreas-kidney transplantation (n = 6), all patients were insulin independent and free of graft pancreatitis; one patient required hemodialysis (16.7%). After isolated renal transplantation (n = 21), 3 patients (14.3%) required hemodialysis. Three of 4 liver recipients are alive after a mean follow-up period of 12.7 months; all simultaneous pancreas-kidney and renal transplant recipients are alive after a mean follow-up period of 8.4 and 8.3 months, respectively. Three liver allografts, 5 pancreas and kidney allografts, and 19 renal allografts are functioning. The lung allograft was lost to rejection 81 days after transplantation; however, the recipient is alive 3 months after retransplantation. Our results demonstrate that in controlled situations, extrarenal organs can be utilized from NHBDs and can be expected to function similarly to organs retrieved from heart-beating donors. We increased the number of transplanted organs by 8.6% using NHBDs for both renal and extrarenal donation. Continued application of these techniques will likely further increase the number of organs retrieved for transplantation.
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PMID:Successful extrarenal transplantation from non-heart-beating donors. 770 58

The early pathogenetic steps that finally lead to acinar cell necrosis in acute pancreatitis have been characterized only scarcely as yet. Among a lot of hypotheses, one concept favors disturbances of cellular energy metabolism as a major factor that contributes to preterm cell decline. To investigate, whether an experimental acute pancreatitis alters cell respiration, the respiratory capacities of acinar cells isolated from rats with acute pancreatitis were measured. Acute pancreatitis was induced using Popper's model, i.e., a combination of duct obstruction, secretory stimulation, and mesenteric short-term ischemia with subsequent reperfusion. Acinar cells were isolated using a collagenase digestion technique. The respiratory rates of the isolated cells in suspension were measured at 37 degrees C in 100% oxygen-saturated N-(2-hydroxyethyl)piperazine-N'-2-ethanesulfonic acid-buffered Eagle's-minimal essential medium. Resting respiration of the acinar cells uniformly amounted to about 60 pmol of O2/s x 10(6) cells in both the control and the pancreatitis group. Cellular respiration could significantly be stimulated by stepwise uncoupling of oxidative phosphorylation by means of 2,4-dinitrophenol in all cell suspensions investigated. The maximum rate of stimulated respiration was diminished in the cells isolated from rats with acute pancreatitis as compared with the controls (79.3 +/- 5.0 vs. 160.2 +/- 15.5 pmol of O2/s x 10(6) cells, p < .05), however. This reduced respiratory load capacity of the acinar cells in acute pancreatitis reflects the restricted ability of the cells to increase respiration on enhanced cellular demand. Since mitochondrial respiration is coupled to oxidative phosphorylation, an altered energy-transforming potential of the acinar cells in acute pancreatitis becomes evident.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Acinar cell respiration in experimental acute pancreatitis. 777 97

Evidence is increasing that individuals vary in their susceptibility to alcoholic pancreatitis. Numerous investigators have attempted to account for this individual susceptibility by studying associations between alcoholic pancreatitis and potential risk factors. Those studies, reviewed here, have focused on the amount, type, and pattern of alcohol consumption, genetic markers (such as blood groups, HLA phenotypes, alpha 1-antitrypsin, and alcohol dehydrogenase isoenzyme distribution), diet, hypertriglyceridemia, tobacco consumption, and pancreatic ischemia. Associations between pancreatitis and several of these factors have been reported, but many studies offer conflicting conclusions. A number of studies are difficult to interpret because of methodologic problems, particularly with regard to inadequate controls and small numbers of index subjects. At present, the evidence is insufficient for one to conclude that any of the above-mentioned factors are well-established risk factors for pancreatitis. As a result, individual susceptibility to alcoholic pancreatitis remains unexplained. Clarification of potential risk factors may ultimately lead to the ability to prevent this relatively common disorder, but additional, appropriately designed studies are required.
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PMID:Individual susceptibility to alcoholic pancreatitis: still an enigma. 789 93

The pancreatic lesions in 6- to 36-week-old spontaneously hypertensive rats (SHR), stroke prone SHR (SHRSP) and Wistar-Kyoto rats (WKY) were examined histopathologically. Inflammatory cell infiltration with hemorrhage and stromal fibrosis became evident in 12-week-old SHR and SHRSP together with acinar atrophy and/or degeneration and ductular proliferation. These changes in SHR and SHRSP were even more prominent at the age of 24 weeks and extremely severe at 36 weeks. In addition, in SHR and SHRSP over 12 weeks of age, small necrosis of acinar cells was found occasionally together with fibrosis and arteriosclerosis. Pancreatic arteriosclerosis was marked in SHR and SHRSP over 24 weeks of age at the level of arterioles < 200 microns in diameter. Adrenergic nerve fibers stained by fluorescence histochemistry were present around the pancreatic arteries and ducts and within the parenchyma, and they were denser in SHR and SHRSP than in WKY, indicating hyperinnervation of the sympathetic nervous system in SHR and SHRSP. It is suggested that the pancreatic ischemia caused by arteriosclerosis due to facilitation of the sympathetic nervous system is an important factor in the pathogenesis of the spontaneous pancreatitis of SHR and SHRSP.
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PMID:Spontaneous pancreatitis in spontaneously hypertensive rats. 810 72


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