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Query: UMLS:C0020672 (
hypothermia
)
17,327
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
Heat-shock proteins (HSPs) function in the cellular response to injury. Increased expression of these proteins was first described in response to hyperthermia, although their production may be prompted by a variety of metabolic insults. HSPs protect cellular proteins from degradation. The self-limited pancreatitis induced by hyperstimulation with supramaximal doses of cerulein is accompanied by increased HSP expression. It may be that HSPs serve a protective function in pancreatitis. We hypothesized that hyperthermia-induced production of HSP-70 would improve survival in a lethal murine model of necrotizing pancreatitis. Necrotizing pancreatitis was induced in two groups of 30 female Swiss Webster mice by feeding them a choline-deficient diet supplemented with 0.5 g% ethionine (CDE) for 72 hours. Immediately before initiation of the CDE diet, the core body temperatures of the mice in the experimental group were elevated to 42 degrees C for 12.5 minutes. Twenty mice from each group were killed after 24 hours. Pancreata were harvested, and pancreatic proteins were extracted from half of the pancreata. HSP-70 was assessed according to a standard Western blotting protocol. The remaining pancreata were used to make histologic comparisons. Serum interleukin 6 and tumor necrosis factor-alpha were determined by enzyme-linked immunosorbent assay (ELISA). Survival was determined by observation of the remaining mice. HSP-70 was expressed in pancreatic protein from all mice exposed to
hypothermia
but in none of the mice subjected to the CDE diet alone. Mortality was significantly reduced in mice pretreated with hyperthermia compared with control mice (p < 0.05). Survival in the hyperthermia group was 80%, whereas in the control group it was 30%. Hyperthermia resulted in expression of pancreatic HSP-70 in mice. Hyperthermia also reduced mortality in this lethal murine model of necrotizing pancreatitis. It is plausible that a causal relationship exists between HSP-70 production and improved survival in this model.
Pancreas
2000 Aug
PMID:Hyperthermia induces heat-shock protein expression, reduces pancreatic injury, and improves survival in necrotizing pancreatitis. 1097 4
Hypothermia
causes vascular endothelial damage that leads to graft microcirculation disorder and eventually thrombosis after reperfusion. The two-layer cold storage method (TL) was previously demonstrated to supply oxygen to the pancreas graft and maintain high adenosine triphosphate tissue concentration. In this study, we evaluated whether mild hypothermic (20 degrees C) preservation using the TL method could reduce endothelial damage while maintaining parenchymal viability. Graft survival by 20 degrees C preservation was investigated using a dog segmental pancreas autotransplantation model (simple storage in University of Wisconsin solution (UW) for 5 and 8 hours or TL for 5, 8, 12, and 24 hrs. respectively). Subsequently, the grafts were preserved in four different conditions (4 and 20 degrees C UW. 4 and 20 degrees C TL) for 8 hours to evaluate microvascular endothelial damage. Trypan blue uptake of vascular endothelium and pancreatic tissue perfusion were evaluated. No graft preserved by 20 degrees C UW for 5 and 8 hours survived (0/7 and 0/4). In contrast, the graft survival rates by 20 degrees C TL for 5, 8, 12, and 24 hours were 100% (5/5), 80% (4/5), 20% (1/5), and 0% (0/4), respectively. In trypan blue uptake analysis, there were significant differences between 4 and 20 degrees C in both UW and TL (4 degrees C UW, 37% [n = 5) vs. 20 degrees C UW, 13% [n = 4] [p < 0.01]; 4 degrees C TL, 29% [n = 5] vs. 20 degrees C TL, 10% [n = 5] [p < 0.011). The perfusion values in 20 degrees C TL were significantly higher than those in other groups at least for up to 120 minutes after reperfusion (p < 0.01 ). In short-term pancreas preservation, mild hypothermic TL reduced vascular endothelial cell damage and ameliorated graft microcirculation while maintaining parenchymal viability. Mild hypothermic TL may lessen vascular complications in clinical pancreas transplantation when used for several-hour preservation.
Pancreas
2000 Oct
PMID:Superiority of mild hypothermic (20 degrees C) preservation for pancreatic microvasculature using the two-layer storage method. 1103 76
Pancreas
procurement for islet isolation and transplantation is limited by concerns for the detrimental effects of postmortem ischemia.
Hypothermic
machine perfusion (HMP) preservation technology has had a major impact in circumventing ischemic injury in clinical kidney transplantation and is applied here to the preservation and procurement of viable islets after hypothermic perfusion preservation of porcine pancreata because pigs are now considered the donor species of choice for xenogeneic islet transplantation. Pancreases were surgically removed from young (<6 months) domestic Yorkshire pigs (25-32 kg), either before or after 30 min of warm ischemia time (WIT), and cannulated for perfusion. Each pancreas was assigned to one of six preservation treatment groups: fresh controls-processed immediately (cold ischemia <1 h) (G1, n = 7); static cold storage-flushed with cold UW-Viaspan and stored in UW-Viaspan at 2-4 degrees C for 24 h with no prior WIT (G2, n = 9); HMP perfused on a LifePort(R) machine at 4-6 degrees C and low pressure (10 mmHg) for 24 h with either KPS1 solution (G3, n = 7) or Unisol-UHK (G4, n = 7). Additional treatment groups to evaluate the effects of prior warm ischemia examined islet isolation after 30 min WIT in situ without (G5, n = 6) or with subsequent 24-h HMP with KPS1 (G6, n = 7). The pancreas was intraductally distended with Liberase PI enzyme and normothermically digested. The isolated islets were purified by a continuous density-gradient centrifugation. Perfusion-induced glandular edema was G3 = 138 +/- 19%, G4 = 160 +/- 16%, and G6 = 127 +/- 22%. Islet yield (IEQ/g of pancreas) varied between the groups: G1 = 1,425 +/- 610, G2 = 1,002 +/- 262, G3 = 2,242 +/- 449 (p < 0.05 vs. G2), G4 = 1,901 +/- 420 (p < 0.05 vs. G2), G5 = 1,756 +/- 329, and G6 = 1,396 +/- 243. Islet stimulation indices were equivalent between the groups and similar to controls (G1). Insulin content (ng/IE) was different between the treatment groups with the highest insulin content in islets harvested from HMP pancreata. Dithizone staining for islets consistently showed more uniform digestion of the perfused organs, with greater separation of the tissue, less entrapped islets, and higher islet yield and purity. The salutary effects of HMP for 24 h were also manifest after 30-min prior warm ischemia. We conclude that 24 h of HMP is well tolerated, leading to moderate edema but no loss of function of the harvested islets. The edema appears to aid in enzymatic digestion, producing a greater yield and purity of islets compared with pancreas subjected to 24 h of static cold storage.
...
PMID:Islet isolation from juvenile porcine pancreas after 24-h hypothermic machine perfusion preservation. 2014