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

An experimental study was conducted in the rat to evaluate the sensitivity of the liver to hyperthermia and ischemia. A 15-min asanguineous isolated hyperthermic in vivo perfusion of the liver was done in rats with a normal liver and in rats with an hepatocarcinoma induced by chronic 3'-diethylaminoazobenzene intoxication. The perfusion was made using various ranges of temperature of the perfusate. In normal rats, the in vivo perfusion was well tolerated as long as the mean intrahepatic temperature remained under 38 degrees C. Postoperative evolution of serum transaminase level was similar whatever the temperature of the perfusate. Histological lesions of the hepatic parenchyma were as severe as the temperature of the perfusate was elevated. In rats with tumors, the mortality rate was elevated in the animals with large tumors. A moderate decrease in the serum alpha-fetoprotein level was observed during the first days after liver perfusion. In all cases, death occurred apparently as a direct consequence of liver injury. This study defines the sensitivity of the normal or neoplastic rat liver to hyperthermia and ischemia using a model of isolated in vivo perfusion of the liver. It provides a basis for further investigations on the effect of hyperthermia on experimental liver tumors.
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PMID:Asanguineous isolated hyperthermic in vivo perfusion of the liver in the rat. 245 11

Both hepatic injury and partial resection are followed by elevation of serum alpha-fetoprotein (AFP). However, whether injured or regenerating hepatocytes are the site of AFP secretion remains controversial. The effects of 3.5 hr of selective hepatic ischemia to the left (L) lobes (70% hepatic mass) of the canine liver on AFP production and liver regeneration by both L and right (R) hepatic lobes are reported. Twenty-one experimental and 13 control animals were studied. AFP was measured by radioimmunoassay in liver tissue homogenates and serum from both systemic and hepatic venous blood obtained preoperatively and on postoperative Days 2, 4, 6, 7, and 8. Tissue AFP was also assessed by immunofluorescent staining. Hepatic regeneration was quantified by autoradiography and DNA specific activity following the intravenous administration of [3H]thymidine. AFP levels were increased above baseline by postoperative Day 4 in biopsies taken from both L and R liver lobes with peak values occurring on Day 7. Immunofluorescent staining confirmed the presence of intracellular AFP in hepatocytes of both R and L lobes on postoperative Days 2 through 6. Serum AFP became significantly elevated above preoperative values by Day 4 and maximal on Day 6. No difference was observed in AFP levels in systemic, L, or R hepatic venous blood. Hepatocellular DNA synthesis was increased on postoperative Days 2 through 8 in both R and L liver lobes. In conclusion, selective hepatic ischemia results in AFP secretion by both injured and uninjured liver lobes. These results suggest that both regenerating and injured hepatocytes synthesize AFP in the dog.
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PMID:Alpha-fetoprotein secretion by injured and regenerating hepatocytes in the dog. 620 10

Cell transplantation into hepatic sinusoids, which is necessary for liver repopulation, could cause hepatic ischemia. To examine the effects of cell transplantation on host hepatocytes, we transplanted Fisher 344 rat hepatocytes into syngeneic dipeptidyl peptidase IV-deficient rats. Within 24 h of cell transplantation, areas of ischemic necrosis, along with transient disruption of gap junctions, appeared in the liver. Moreover, host hepatocytes expressed gamma-glutamyl transpeptidase (GGT) extensively, which was observed even 2 years after cell transplantation. GGT expression was not associated with alpha-fetoprotein activation, which is present in progenitor cells. Increased GGT expression was apparent after transplantation of nonparenchymal cells and latex beads but not after injection of saline, fragmented hepatocytes, hepatocyte growth factor, or turpentine. Some host hepatocytes exhibited apoptosis, as well as DNA synthesis, between 24 and 48 h after cell transplantation. Changes in gap junctions, GGT expression, DNA synthesis, and apoptosis after cell transplantation were prevented by vasodilators. The findings indicated the onset of ischemic liver injury after cell transplantation. These hepatic perturbations must be considered when transplanted cells are utilized as reporters for biological studies.
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PMID:Cell transplantation causes loss of gap junctions and activates GGT expression permanently in host liver. 1100 70

We report a 72-year-old man with hepatocellular carcinoma, which showed spontaneous regression. He was diagnosed as having chronic hepatitis type C five years before admission. In January 1998, a liver mass was found by ultrasonography. In February, computed tomography showed a low-density mass, 3.5 cm in diameter in the S5 region. Although liver biopsy was not performed, findings obtained by computed tomography and ultrasonography indicated that the tumor was hepatocellular carcinoma. The levels of alpha-fetoprotein and PIVKA (protein induced by vitamin K antagonist)-II were increased to 1000 ng/mL and 2000 mAU/mL, respectively. The patient was admitted to our hospital in March 1998. At the time, the size of liver mass was reduced to 2.5 cm in diameter on computed tomography, and the tumor markers, alpha-fetoprotein and PIVKA-II, spontaneously decreased to the normal range. We considered that hepatocellular carcinoma of this patient regressed spontaneously. Because it was hard to exclude the possibility that the mass contained residual malignant cells, we resected the mass on April 28, 1998. Microscopically, the resected mass did not contain any malignant cells. The parenchyma surrounding tumor necrosis, which is reflected by severe inflammatory infiltration with lymphocytes, indicates spontaneous regression. Although the precise mechanism regarding spontaneous regression of hepatocellular carcinoma is not fully understood, either ischemia due to rapid growth of the tumor or some inflammatory mechanism may be involved in regression of hepatocellular carcinoma.
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PMID:Spontaneous regression of hepatocellular carcinoma--a case report. 1181 13

In animals, the bone marrow (BM) is a source of liver-repopulating cells with therapeutic potential in case of tissue damage. However, the early response of human BM-derived stem cells (SC) to liver injury is still unknown. Here, we studied 24 patients undergoing orthotopic liver transplantation (OLT) for end-stage liver disease or hepatocellularcarcinoma, and 13 patients submitted to liver resection. The concentration of circulating BM-derived SC was determined by phenotypic analysis and clonogenic assays. Moreover, we assessed the serum level of inflammatory and tissue-specific cytokines. Reverse transcriptase-polymerase chain reaction and fluorescence-in situ hybridization were also used to characterize mobilized SC. At baseline, patients showed a significant lower concentration of circulating CD133(+), CD34(+) SC and clonogenic progenitors (colony-forming unit cells) than healthy controls. However, the time-course evaluation of peripheral blood cells after OLT demonstrated the significant early mobilization of multiple subsets of hematopoietic and endothelial stem/progenitor cells. Cytogenetic and molecular analyses of CD34(+) cells showed the host origin of mobilized SC and the expression of transcripts for GATA-4, cytokeratin 19, and alpha-fetoprotein hepatocyte markers. In contrast with OLT, only total circulating CD34(+) cells significantly increased after liver resection. Mobilization of BM cells after OLT or liver surgery was associated with increased serum levels of granulocyte-colony stimulating factor, interleukin-6, stem cell factor, hepatocyte growth factor, and vascular endothelial growth factor. In summary, we demonstrate that tissue damage after OLT and liver resection induces increased serum levels of multiple cytokines but only ischemia/reperfusion injury associated with OLT results in the remarkable mobilization of BM stem/progenitor cells.
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PMID:Mobilization of bone marrow-derived hematopoietic and endothelial stem cells after orthotopic liver transplantation and liver resection. 1693 69

Recent evidence suggests that progenitor cells in adult tissues and embryonic stem cells share a high resistance to hypoxia and ischemic stress. To study the ischemic resistance of adult liver progenitors, we characterized remaining viable cells in human liver tissue after cold ischemic treatment for 24-168 h, applied to the tissue before cell isolation. In vitro cultures of isolated cells showed a rapid decline of the number of different cell types with increasing ischemia length. After all ischemic periods, liver progenitor-like cells could be observed. The comparably small cells exhibited a low cytoplasm-to-nucleus ratio, formed densely packed colonies, and showed a hepatobiliary marker profile. The cells expressed epithelial cell adhesion molecule, epithelial-specific (CK8/18) and biliary-specific (CK7/19) cytokeratins, albumin, alpha-1-antitrypsin, cytochrome-P450 enzymes, as well as weak levels of hepatocyte nuclear factor-4 and gamma-glutamyl transferase, but not alpha-fetoprotein or Thy-1. In vitro survival and expansion was facilitated by coculture with mouse embryonic fibroblasts. Hepatic progenitor-like cells exhibit a high resistance to ischemic stress and can be isolated from human liver tissue after up to 7 days of ischemia. Ischemic liver tissue from various sources, thought to be unsuitable for cell isolation, may be considered as a prospective source of hepatic progenitor cells.
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PMID:Isolation and characterization of adult human liver progenitors from ischemic liver tissue derived from therapeutic hepatectomies. 1910 77

Liver transplantation, utilized routinely for end-stage liver disease, has been constrained by the paucity of organ donors, and is being complemented by alternative strategies such as liver cell transplantation. One of the most promising forms of liver cell transplantation is hepatic stem cell therapies, as the number of human hepatic stem cells (hHpSCs) and other early hepatic progenitor cells (HPCs) are sufficient to provide treatment for multiple patients from a single liver source. In the present study, human adult livers were exposed to cold ischemia and then processed after <24 or 48 h. Cells positive for epithelial cell adhesion molecule (EpCAM), a marker on early lineage stage HPCs, were immunoselected and counted. Approximately 100,000 EpCAM(+) cells/gram of tissue was obtained from surgical resection of livers subjected to cold ischemia up to 24 h and comparable numbers, albeit somewhat lower, were obtained from those exposed to 48 h of cold ischemia. The yields are similar to those reported from livers with minimal exposure to ischemia. When cultured on plastic dishes and in Kubota's Medium, a serum-free medium designed for early lineage stage HPCs, colonies of rapidly expanding cells formed. They were confirmed to be probable hHpSCs by their ability to survive and expand on plastic and in Kubota's Medium for months, by co-expression of EpCAM and neural cell adhesion molecule, minimal if any albumin expression, with EpCAM found throughout the cells, and no expression of alpha-fetoprotein. The yields of viable EpCAM(+) cells were surprisingly large, and the numbers from a single donor liver are sufficient to treat approximately 50-100 patients given the numbers of EpCAM(+) cells currently used in hepatic stem cell therapies. Thus, cold ischemic livers for up to 48 h are a new source of cells that might be used for liver cell therapies.
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PMID:Isolation of viable human hepatic progenitors from adult livers is possible even after 48 hours of cold ischemia. 2319 83

Recombinant human alpha-fetoprotein (rhAFP) expressed in yeast system as a glycoprotein, was isolated and purified to 98% by multistep method. The testing of the rhAFP in the culture of adipose tissue stromal cells (hASC) has revealed its ability to enhance hASC proliferation and migration as well as vascular endothelial growth factor production, with no significant influence on cell invasion and matrix metalloproteinase-2 and -9 secretion. It has been also estimated that rhAFP is internalized in hASC via clathrin-dependent mechanism. A study in the murine experimental model of hindlimb ischemia has shown the capability of rhAFP to enhance blood flow recovery. These data suggest that rhAFP is a promising agent for enhancement of the hASC regenerative ability.
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PMID:[Recombinant human alpha-fetoprotein as a regulator of adipose tissue stromal cell activity]. 2334 86

We present an unusual case of spontaneous regression of hepatocellular carcinoma (HCC). A 77-year-old man with alcoholic liver cirrhosis presented with a 50-mm tumor in the Couinaud's segment 8 (S8) of the liver, a 15-mm tumor in the S8-7 and 10-mm tumors in the other segments (S4, S6). The tumors were diagnosed as HCC by typical imaging findings and elevated serum alpha-fetoprotein (AFP, 1,825.0 ng/ml) and protein induced by vitamin K absence II (PIVKA II, 3,043 mAU/ml). One month later, AFP and PIVKA II decreased to 51.1 ng/ml and 411 mAU/ml, respectively, and the 50-mm tumor in the S8 became small and completely necrotic on angiography and computed tomography arteriography without any treatment. On the other hand, the 15-mm tumor in the S8-7 decreased in size to 10 mm and received blood supply from the right posterior superior arteries (A7). The other 10-mm tumors remained. Ischemia of the tumors due to disruption of the feeding artery (A8) might have induced tumor regression in the present case.
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PMID:Spontaneous Regression of Hepatocellular Carcinoma due to Disruption of the Feeding Artery. 2362 58

The impact of ischemia/reperfusion injury in the setting of transplantation for hepatocellular carcinoma (HCC) has not been thoroughly investigated. The present study examined data from the Scientific Registry of Transplant Recipients for all recipients of deceased donor liver transplants performed between January 1, 1995 and October 31, 2011. In a multivariate Cox analysis, significant predictors of patient survival included the following: HCC diagnosis (P < 0.01), donation after cardiac death (DCD) allograft (P < 0.001), hepatitis C virus-positive status (P < 0.01), recipient age (P < 0.01), donor age (P < 0.001), Model for End-Stage Liver Disease score (P < 0.001), recipient race, and an alpha-fetoprotein level > 400 ng/mL at the time of transplantation. In order to test whether the decreased survival seen for HCC recipients of DCD grafts was more than would be expected because of the inferior nature of DCD grafts and the diagnosis of HCC, a DCD allograft/HCC diagnosis interaction term was created to look for potentiation of effect. In a multivariate analysis adjusted for all other covariates, this interaction term was statistically significant (P = 0.049) and confirmed that there was potentiation of inferior survival with the use of DCD allografts in recipients with HCC. In conclusion, patient survival and graft survival were inferior for HCC recipients of DCD allografts versus recipients of donation after brain death allografts. This potentiation of effect of inferior survival remained even after adjustments for the inherent inferiority observed in DCD allografts as well as other known risk factors. It is hypothesized that this difference could reflect an increased rate of recurrence of HCC.
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PMID:Inferior survival in liver transplant recipients with hepatocellular carcinoma receiving donation after cardiac death liver allografts. 2448 65


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