The ischemic perinatal brain damage

International Nuclear Information System (INIS)

Crisi, G.; Mauri, C.; Canossi, G.; Della Giustina, E.

1986-01-01

The term ''hypoxic-ischemic encephalopathy'' covers a large part of neonatal neuropathology including the various forms of intracerebral haemorrhage. In the present work the term is confined to ischemic brain edema and actual infarction, be it diffuse or focal. Eighteen newborns with CT evidence of ischemic brain lesions and infarctual necrosis were selected. Emphasis is placed on current data on neuropathology of ischemic brain edema and its CT appearance. Particular entities such as periventricular leukomalacia and multicystic encephalopathy are discussed. Relationship between CT and temporal profile of cerebral damage is emphasized in order to predict the structural sequelae and the longterm prognosis

The experimental study of CT-guided hepatocyte growth factor gene therapy for cerebral ischemic diseases

International Nuclear Information System (INIS)

Zhang Xiaobo; Jin Zhengyu; Li Mingli; Wang Renzhi; Li Guilin; Kong Yanguo; Wang Jianming; Gao Shan; Guan Hongzhi; Wang Detian; Luo Yufeng

2006-01-01

Objectives: To investigate the feasibility of CT guided hepatocyte growth factor (HGF) gene therapy for cerebral ischemic diseases. Methods: Human HGF cDNA was ligated to pIRES 2 -EGFP vector. The recombinant plasmid was transfected into the penumbra tissue with liposome, guided by CT perfusion images. After seven days of transfer with recombinant plasmid, the cut sections of rat brain tissues of the treated and control groups were analyzed including immunohistochemistry, vessel count, cerebral blood flow and infarct volume etc. in order to investigate HGF gene expression and biological effect. Results: Enzymatic digestion and electrophoresis confirmed that HGF fragments had been correctly cloned into the space between the BamH I and Sal I sites of pIRES 2 -EGFP. After 7 days of HGF gene transfection, expression of HGF in transfected neurocytes of treated group was observed with immunohistochemistry. The number of vessels in penumbra tissues transfected with HGF vectors and the CBF measured by perfusion CT all were significantly increased than those of the controls (P 2 -EGFP-HGF complexes can transfect the penumbra tissues and definitely express HGF protein. The HGF gene products can stimulate angiogenesis, promote collateral circulation formation and reduce infarct volume in vivo and therefore is beneficial to the treatment of cerebral ischemia. (authors)

Angiotensin II protects primary rat hepatocytes against bile salt-induced apoptosis.

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Golnar Karimian

Full Text Available UNLABELLED: Angiotensin II (AT-II is a pro-fibrotic compound that acts via membrane-bound receptors (AT-1R/AT-2R and thereby activates hepatic stellate cells (HSCs. AT-II receptor blockers (ARBs are thus important candidates in the treatment of liver fibrosis. However, multiple case reports suggest that AT-1R blockers may induce hepatocyte injury. Therefore, we investigated the effect of AT-II and its receptor blockers on cytokine-, oxidative stress- and bile salt-induced cell death in hepatocytes. Primary rat hepatocytes were exposed to TNF-α/Actinomycin D, the ROS-generating agent menadione or the bile salts: glycochenodeoxycholic acid (GCDCA and tauro-lithocholic acid-3 sulfate (TLCS, to induce apoptosis. AT-II (100 nmol/L was added 10 minutes prior to the cell death-inducing agent. AT-1R antagonists (Sartans and the AT-2R antagonist PD123319 were used at 1 µmol/L. Apoptosis (caspase-3 activity, acridine orange staining and necrosis (Sytox green staining were quantified. Expression of CHOP (marker for ER stress and AT-II receptor mRNAs were quantified by Q-PCR. AT-II dose-dependently reduced GCDCA-induced apoptosis of hepatocytes (-50%, p<0.05 without inducing necrosis. In addition, AT-II reduced TLCS-induced apoptosis of hepatocytes (-50%, p<0.05. However, AT-II did not suppress TNF/Act-D and menadione-induced apoptosis. Only the AT-1R antagonists abolished the protective effect of AT-II against GCDCA-induced apoptosis. AT-II increased phosphorylation of ERK and a significant reversal of the protective effect of AT-II was observed when signaling kinases, including ERK, were inhibited. Moreover, AT-II prevented the GCDCA-induced expression of CHOP (the marker of the ER-mediated apoptosis. CONCLUSION: Angiotensin II protects hepatocytes from bile salt-induced apoptosis through a combined activation of PI3-kinase, MAPKs, PKC pathways and inhibition of bile salt-induced ER stress. Our results suggest a mechanism for the observed hepatocyte

Diclofenac inhibits tumor necrosis factor-a-induced nuclear factor-kB activation causing synergic hepatocyte apoptosis

NARCIS (Netherlands)

Frederiksson, L; Herpers, B; Benedetti, G; Matadin, Q; Puigvert, J.C.; de Bont, H; Dragovic, S.; Vermeulen, N.P.E.; Commandeur, J.N.M.; Danen, E; de Graauw, M; van de Water, B.

2011-01-01

Drug-induced liver injury (DILI) is an important clinical problem. It involves crosstalk between drug toxicity and the immune system, but the exact mechanism at the cellular hepatocyte level is not well understood. Here we studied the mechanism of crosstalk in hepatocyte apoptosis caused by

Pertussis toxin, an inhibitor of G(αi PCR, inhibits bile acid- and cytokine-induced apoptosis in primary rat hepatocytes.

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Golnar Karimian

Full Text Available Excessive hepatocyte apoptosis is a common event in acute and chronic liver diseases leading to loss of functional liver tissue. Approaches to prevent apoptosis have therefore high potential for the treatment of liver disease. G-protein coupled receptors (GPCR play crucial roles in cell fate (proliferation, cell death and act through heterotrimeric G-proteins. G(αiPCRs have been shown to regulate lipoapoptosis in hepatocytes, but their role in inflammation- or bile acid-induced apoptosis is unknown. Here, we analyzed the effect of inhibiting G(αiPCR function, using pertussis toxin (PT, on bile acid- and cytokine-induced apoptosis in hepatocytes. Primary rat hepatocytes, HepG2-rNtcp cells (human hepatocellular carcinoma cells or H-4-II-E cells (rat hepatoma cells were exposed to glycochenodeoxycholic acid (GCDCA or tumor necrosis factor-α (TNFα/actinomycin D (ActD. PT (50-200 nmol/L was added 30 minutes prior to the apoptotic stimulus. Apoptosis (caspase-3 activity, acridine orange staining and necrosis (sytox green staining were assessed. PT significantly reduced GCDCA- and TNFα/ActD-induced apoptosis in rat hepatocytes (-60%, p<0.05 in a dose-dependent manner (with no shift to necrosis, but not in HepG2-rNtcp cells or rat H-4-II-E cells. The protective effect of pertussis toxin was independent of the activation of selected cell survival signal transduction pathways, including ERK, p38 MAPK, PI3K and PKC pathways, as specific protein kinase inhibitors did not reverse the protective effects of pertussis toxin in GCDCA-exposed hepatocytes.Pertussis toxin, an inhibitor of G(αiPCRs, protects hepatocytes, but not hepatocellular carcinoma cells, against bile acid- and cytokine-induced apoptosis and has therapeutic potential as primary hepatoprotective drug, as well as adjuvant in anti-cancer therapy.

Ischemic perinatal brain damage. Neuropathologic and CT correlations

Energy Technology Data Exchange (ETDEWEB)

Crisi, G; Mauri, C; Canossi, G; Della Giustina, E

1986-01-01

The term ''hypoxic-ischemic encephalopathy'' covers a large part of neonatal neuropathology including the various forms of intracerebral haemorrhage. In the present work the term is confined to ischemic brain edema and actual infarction, be it diffuse or focal. Eighteen newborns with CT evidence of ischemic brain lesions and infarctual necrosis were selected. Emphasis is placed on current data on neuropathology of ischemic brain edema and its CT appearance. Particular entities such as periventricular leukomalacia and multicystic encephalopathy are discussed. Relationship between CT and temporal profile of cerebral damage is emphasized in order to predict the structural sequelae and the longterm prognosis. 31 refs.

Evaluation of 99mTc-nitroimidazole in animal of myocardial necrosis

International Nuclear Information System (INIS)

Shimpi, H.H.; Mahapatra, S.; Noronha, O.P.D.

1998-01-01

Full text: Extensive studies carried out using 99m Tc-nitroimidazole (BMS 181321) suggested that it is a useful agent to investigate the status of hypoxia in solid tumors and ischemic myocardium. In vitro studies also showed that 99m Tc nitroimidazole is preferentially trapped in and retained by hypoxic, but viable cardiac muscle. We have evaluated the compound in an animal (rat) model of myocardial necrosis. 99m Tc-nitromidazole was labelled with 99m Tc by using cyclan and Sn-glucaric acid. The radiochemical purity was >95%. It was found to be very stable. Experimental (rat) animal of myocardial necrosis or ischemic necrosis was obtained by injecting iso proternol HCl subcutaneously (S.C.) at a dose of 5.25 mg/kg body weight. After 48 h, gross and microscopic necrotic changes were seen in the heart which closely resembled the myocardial infarct of necrotic lesion akin to ischemic necrosis of the myocardium. Animal biodistribution study demonstrated that 99m Tc nitroimidazole cleared very fast from the blood stream of both normal system. Significantly higher uptake was seen in heart of experimental animals compared to normal animals at 60 min. The ratios of heart to blood, liver and kidneys in both normal and experimental animals showed significantly higher ratios in experimental animals. The heart to blood ratio of experimental animal remained same up to 60 min. compared to a sharp decline with time in normal animals. The above results show that 99m Tc-nitroimidazole could be used for detection of myocardial necrosis or myocardial infarct in clinical conditions

alpha-Amanitin induced apoptosis in primary cultured dog hepatocytes.

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Adam Szelag

2010-06-01

Full Text Available Amatoxin poisoning is caused by mushroom species belonging to the genera Amanita, Galerina and Lepiota with the majority of lethal mushroom exposures attributable to Amanita phalloides. High mortality rate in intoxications with these mushrooms is principally a result of the acute liver failure following significant hepatocyte damage due to hepatocellular uptake of amatoxins. A wide variety of amatoxins have been isolated; however, alpha-amanitin (alpha-AMA appears to be the primary toxin. Studies in vitro and in vivo suggest that alpha-AMA does not only cause hepatocyte necrosis, but also may lead to apoptotic cell death. The objective of this study was to evaluate the complex hepatocyte apoptosis in alpha-AMA cytotoxicity. All experiments were performed on primary cultured canine hepatocytes. The cells were incubated for 12 h with alpha-AMA at a final concentration of 1, 5, 10 and 20 microM. Viability test (MTT assay, apoptosis evaluation (TUNEL reaction, detection of DNA laddering and electron microscopy were performed at 6 and 12 h of exposure to alpha-AMA. There was a clear correlation between hepatocyte viability, concentration of alpha-AMA and time of exposure to this toxin. The decline in cultured dog hepatocyte viability during the exposure to alpha-AMA is most likely preceded by enhanced cellular apoptosis. Our results demonstrate that apoptosis might contribute to pathogenesis of the severe liver injury in the course of amanitin intoxication, particularly during the early phase of poisoning.

Actualities on molecular pathogenesis and repairing processes of cerebral damage in perinatal hypoxic-ischemic encephalopathy

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Praticò Andrea D

2010-09-01

Full Text Available Abstract Hypoxic-ischemic encephalopathy (HIE is the most important cause of cerebral damage and long-term neurological sequelae in the perinatal period both in term and preterm infant. Hypoxic-ischemic (H-I injuries develop in two phases: the ischemic phase, dominated by necrotic processes, and the reperfusion phase, dominated by apoptotic processes extending beyond ischemic areas. Due to selective ischemic vulnerability, cerebral damage affects gray matter in term newborns and white matter in preterm newborns with the typical neuropathological aspects of laminar cortical necrosis in the former and periventricular leukomalacia in the latter. This article summarises the principal physiopathological and biochemical processes leading to necrosis and/or apoptosis of neuronal and glial cells and reports recent insights into some endogenous and exogenous cellular and molecular mechanisms aimed at repairing H-I cerebral damage.

Apoptosis and Necrosis in the Liver

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Guicciardi, Maria Eugenia; Malhi, Harmeet; Mott, Justin L.; Gores, Gregory J.

2013-01-01

Because of its unique function and anatomical location, the liver is exposed to a multitude of toxins and xenobiotics, including medications and alcohol, as well as to infection by hepatotropic viruses, and therefore, is highly susceptible to tissue injury. Cell death in the liver occurs mainly by apoptosis or necrosis, with apoptosis also being the physiologic route to eliminate damaged or infected cells and to maintain tissue homeostasis. Liver cells, especially hepatocytes and cholangiocytes, are particularly susceptible to death receptor-mediated apoptosis, given the ubiquitous expression of the death receptors in the organ. In a quite unique way, death receptor-induced apoptosis in these cells is mediated by both mitochondrial and lysosomal permeabilization. Signaling between the endoplasmic reticulum and the mitochondria promotes hepatocyte apoptosis in response to excessive free fatty acid generation during the metabolic syndrome. These cell death pathways are partially regulated by microRNAs. Necrosis in the liver is generally associated with acute injury (i.e., ischemia/reperfusion injury) and has been long considered an unregulated process. Recently, a new form of “programmed” necrosis (named necroptosis) has been described: the role of necroptosis in the liver has yet to be explored. However, the minimal expression of a key player in this process in the liver suggests this form of cell death may be uncommon in liver diseases. Because apoptosis is a key feature of so many diseases of the liver, therapeutic modulation of liver cell death holds promise. An updated overview of these concepts is given in this article. PMID:23720337

Severe ischemic colitis following olanzapine use: a Case Report

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Samuel Raimundo Fernandes

Full Text Available Ischemic colitis is the most common subtype of intestinal ischemia usually resulting from vasospasm, vessel occlusion or mesenteric hypoperfusion. Neuroleptics have seldom been linked to ischemic colitis by blocking peripheral anticholinergic and antiserotonergic receptors inducing severe gastrointestinal paresis. We report a young patient with severe ischemic colitis requiring surgery due to necrosis of the bowel. After exclusion of other potential causes, olanzapine was admitted as the cause of ischemia. Clinicians should be aware of how to recognize and treat the potentially life-threatening effects of neuroleptics.

Drug-Induced Liver Injury: Cascade of Events Leading to Cell Death, Apoptosis or Necrosis

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Andrea Iorga

2017-05-01

Full Text Available Drug-induced liver injury (DILI can broadly be divided into predictable and dose dependent such as acetaminophen (APAP and unpredictable or idiosyncratic DILI (IDILI. Liver injury from drug hepatotoxicity (whether idiosyncratic or predictable results in hepatocyte cell death and inflammation. The cascade of events leading to DILI and the cell death subroutine (apoptosis or necrosis of the cell depend largely on the culprit drug. Direct toxins to hepatocytes likely induce oxidative organelle stress (such as endoplasmic reticulum (ER and mitochondrial stress leading to necrosis or apoptosis, while cell death in idiosyncratic DILI (IDILI is usually the result of engagement of the innate and adaptive immune system (likely apoptotic, involving death receptors (DR. Here, we review the hepatocyte cell death pathways both in direct hepatotoxicity such as in APAP DILI as well as in IDILI. We examine the known signaling pathways in APAP toxicity, a model of necrotic liver cell death. We also explore what is known about the genetic basis of IDILI and the molecular pathways leading to immune activation and how these events can trigger hepatotoxicity and cell death.

Leptin ameliorates ischemic necrosis of the femoral head in rats with obesity induced by a high-fat diet.

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Zhou, Lu; Jang, Kyu Yun; Moon, Young Jae; Wagle, Sajeev; Kim, Kyoung Min; Lee, Kwang Bok; Park, Byung-Hyun; Kim, Jung Ryul

2015-03-23

Obesity is a risk factor for ischemic necrosis of the femoral head (INFH). The purpose of this study was to determine if leptin treatment of INFH stimulates new bone formation to preserve femoral head shape in rats with diet-induced obesity. Rats were fed a high-fat diet (HFD) or normal chow diet (NCD) for 16 weeks to induce progressive development of obesity. Avascular necrosis of the femoral head (AVN) was surgically induced. Adenovirus-mediated introduction of the leptin gene was by intravenous injection 2 days before surgery-induced AVN. At 6 weeks post-surgery, radiologic and histomorphometric assessments were performed. Leptin signaling in tissues was examined by Western blot. Osteogenic markers were analyzed by real-time RT-PCR. Radiographs showed better preservation of femoral head architecture in the HFD-AVN-Leptin group than the HFD-AVN and HFD-AVN-LacZ groups. Histology and immunohistochemistry revealed the HFD-AVN-Leptin group had significantly increased osteoblastic proliferation and vascularity in infarcted femoral heads compared with the HFD-AVN and HFD-AVN-LacZ groups. Intravenous injection of leptin enhanced serum VEGF levels and activated HIF-1α pathways. Runx 2 and its target genes were significantly upregulated in the HFD-AVN-Leptin group. These results indicate that leptin resistance is important in INFH pathogenesis. Leptin therapy could be a new strategy for INFH.

Carbon Tetrachloride Increases Intracellular Calcium in Rat Liver and Hepatocyte Cultures

Science.gov (United States)

1986-05-12

tible to destruction by CC14 ( Head ~ al., 1981). Thus, the activation of CC14 to a toxic moiety clearly depends upon metabolism by one or more... embryologic development (Wyllie, 1986). In contrast, Toyo-oka et al. (1985) could not establish that phospholipase& or proteases were involved in ischemic...D. M. Bissell, and u. A Meyer. (1977) Drug Metabolism in Adult Rat Hepatocyte& in Primary Monolayer Culture. Gastroenterology 72:1232-1239. Head , B

Newer concepts in the pathophysiology of ischemic heart disease.

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Kirk, E S; Factor, S; Sonnenblick, E H

1984-11-01

Thus the thrust of these studies suggests that blood flow is the overwhelming factor in determining the consequences of the imbalance of oxygen supply and demand. Moreover, the factors that determine the requirements for tissue survival in the presence of deep ischemia are not the same as those shown for the normal myocardium in figure 1. In deep ischemia, contraction ceases, and metabolism shifts from aerobic to anaerobic pathways. Survival rather than contractile function then becomes the agenda. Not only does supply tend to overshadow demand in determining extent of transmural necrosis, but the anatomical pattern of supply precisely delineates the region at risk following a coronary occlusion as well as the ultimate extent of infarction. These views are summarized in the model presented in figures 12 and 13. The anatomic distribution of the ligated artery determines the lateral limits of the ischemic region (Fig. 12) and thus the lateral extension of necrosis (Fig. 13). The extension of the necrosis across the heart wall depends largely on the status of perfusion within the ischemic region. Extension of an infarct, should it occur, has to be explained by other mechanisms. These might include: (i) vascular obstruction in adjacent vascular systems that were not involved in the first occlusion, (ii) relative ischemia in the normal tissue surrounding the ischemic tissue due to an increased wall stress at the demarcation between contracting and noncontracting tissue, or (9) interruption of vessels supplying large interdigitations of normal tissue within the originally ischemic tissue due to changes associated with the process of infarction of ischemia. Alternatively, much that is called extension of infarction may involve more of the wall transmurally without lateral extension. Additional features of the development of myocardial infarction in figures 12 and 13 include: (i) the development of collateral vessel function resulting in an increased capacity to supply the

Controlled cell morphology and liver-specific function of engineered primary hepatocytes by fibroblast layer cell densities.

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Sakai, Yusuke; Koike, Makiko; Kawahara, Daisuke; Hasegawa, Hideko; Murai, Tomomi; Yamanouchi, Kosho; Soyama, Akihiko; Hidaka, Masaaki; Takatsuki, Mitsuhisa; Fujita, Fumihiko; Kuroki, Tamotsu; Eguchi, Susumu

2018-03-05

Engineered primary hepatocytes, including co-cultured hepatocyte sheets, are an attractive to basic scientific and clinical researchers because they maintain liver-specific functions, have reconstructed cell polarity, and have high transplantation efficiency. However, co-culture conditions regarding engineered primary hepatocytes were suboptimal in promoting these advantages. Here we report that the hepatocyte morphology and liver-specific function levels are controlled by the normal human diploid fibroblast (TIG-118 cell) layer cell density. Primary rat hepatocytes were plated onto TIG-118 cells, previously plated 3 days before at 1.04, 5.21, and 26.1×10 3  cells/cm 2 . Hepatocytes plated onto lower TIG-118 cell densities expanded better during the early culture period. The hepatocytes gathered as colonies and only exhibited small adhesion areas because of the pushing force from proliferating TIG-118 cells. The smaller areas of each hepatocyte result in the development of bile canaliculi. The highest density of TIG-118 cells downregulated albumin synthesis activity of hepatocytes. The hepatocytes may have undergone apoptosis associated with high TGF-β1 concentration and necrosis due to a lack of oxygen. These occurrences were supported by apoptotic chromatin condensation and high expression of both proteins HIF-1a and HIF-1b. Three types of engineered hepatocyte/fibroblast sheets comprising different TIG-118 cell densities were harvested after 4 days of hepatocyte culture and showed a complete cell sheet format without any holes. Hepatocyte morphology and liver-specific function levels are controlled by TIG-118 cell density, which helps to design better engineered hepatocytes for future applications such as in vitro cell-based assays and transplantable hepatocyte tissues. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Investigation of Epidermal Growth Factor, Tumor Necrosis Factor-alpha and Thioredoxin System in Rats Exposed to Cerebral Ischemia

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Erol-Demirbilek Melike

2016-09-01

Full Text Available Background: Thioredoxin reductase (TrxR, epidermal growth factor (EGF and tumor necrosis factor-α (TNF-α have neuroprotective/neurotoxic effects in cerebral ischemia. We aimed to investigate the TrxR activity, EGF and TNF-α levels in cerebral ischemic, sham-operated and non-ischemic rat brains.

DISTINCT FUNCTIONS OF JNK AND C-JUN IN OXIDANT-INDUCED HEPATOCYTE DEATH

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Amir, Muhammad; Liu, Kun; Zhao, Enpeng; Czaja, Mark J.

2013-01-01

Overactivation of c-Jun N-terminal kinase (JNK)/c-Jun signaling is a central mechanism of hepatocyte injury and death including that from oxidative stress. However, the functions of JNK and c-Jun are still unclear, and this pathway also inhibits hepatocyte death. Previous studies of menadione-induced oxidant stress demonstrated that toxicity resulted from sustained JNK/c-Jun activation as death was blocked by the c-Jun dominant negative TAM67. To further delineate the function of JNK/c-Jun signaling in hepatocyte injury from oxidant stress, the effects of direct JNK inhibition on menadione-induced death were examined. In contrast to the inhibitory effect of TAM67, pharmacological JNK inhibition by SP600125 sensitized the rat hepatocyte cell line RALA255-10G to death from menadione. SP600125 similarly sensitized mouse primary hepatocytes to menadione toxicity. Death from SP600125/menadione was c-Jun dependent as it was blocked by TAM67, but independent of c-Jun phosphorylation. Death occurred by apoptosis and necrosis and activation of the mitochondrial death pathway. Short hairpin RNA knockdowns of total JNK or JNK2 sensitized to death from menadione, whereas a jnk1 knockdown was protective. Jnk2 null mouse primary hepatocytes were also sensitized to menadione death. JNK inhibition magnified decreases in cellular ATP content and β-oxidation induced by menadione. This effect mediated cell death as chemical inhibition of β-oxidation also sensitized cells to death from menadione, and supplementation with the β-oxidation substrate oleate blocked death. Components of the JNK/c-Jun signaling pathway have opposing functions in hepatocyte oxidant stress with JNK2 mediating resistance to cell death and c-Jun promoting death. PMID:22644775

A Rare Cause of Acute Abdomen: Idiopathic Isolated Cecal Necrosis

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Ender Özer

2015-03-01

Full Text Available Idiopathic isolated cecal necrosis is a clinical problem characterized by right-sided inferior abdominal pain. It is rarely seen, develops due to decreased blood flow to the colon and, imitates acute appendicitis. Its clinical signs are similar to many illnesses causing sensitivity in the right inferior quadrant and, the diagnosis is generally determined during surgery. An 86-year-old male patient presented with the complaints of abdominal pain, trichiniasis, nausea and vomiting. Surgical intervention was decided when physical examination and laboratory results were taken into consideration. After diagnostic laparoscopy, right hemicolectomy was performed because of cecal necrosis. While the mortality and morbidity rates for ischemic bowel disease are high, prognosis for early diagnosed patients with isolated cecal necrosis is better, provided that timely surgical treatment is decided.

Generation of human hepatocytes by stem cell technology: definition of the hepatocyte.

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Hengstler, Jan G; Brulport, Marc; Schormann, Wiebke; Bauer, Alexander; Hermes, Matthias; Nussler, Andreas K; Fandrich, Fred; Ruhnke, Maren; Ungefroren, Hendrik; Griffin, Louise; Bockamp, Ernesto; Oesch, Franz; von Mach, Marc-Alexander

2005-06-01

Since 1999, numerous articles have reported the generation of hepatocytes from different types of extrahepatic stem or precursor cells. This opens exciting new possibilities for pharmacology and toxicology, as well as for cell therapy. Hepatocyte marker expression, including albumin, cytokeratin 18, c-met, alpha-fetoprotein and cytochrome P450 3A4 and -2B6, has been observed after transplantation of different types of human stem cells into the liver of laboratory animals or in vitro after incubation with cytokines. These intriguing observations have prompted scientists to classify stem cell-derived cell populations as hepatocytes. However, this conclusion may be premature. It has been shown that factors of the liver microenvironment can induce expression of a limited number of hepatocyte marker genes in nonhepatic cell types. To conclude on the grounds of a limited number of markers that these cells are true hepatocytes is not indicated. In this case one should carefully evaluate crucial hepatocyte-defining enzymatic properties. The present article: i) reviews studies describing the fate of extrahepatic human stem and precursor cells in livers of laboratory animals, including the possibility of cell fusion; and ii) critically discusses the phenotype of stem cells after application of various differentiation protocols aimed at generating human hepatocytes. In addition, the necessary criteria needed for defining a true hepatocyte are suggested. Establishing the necessary properties for stem cell-derived hepatocytes is timely and reasonable, and thus avoids further misleading semantic confusion. Finally, it is essential to understand that the definition of a bona fide hepatocyte should not be limited to qualitative assays, such as reverse transcriptase polymerase chain reaction and immunohistochemistry, but has to include a quantitative analysis of enzymatic activities, which allows direct comparison with primary hepatocytes. Although the stem cell-derived-hepatocyte

Ischemia leads to apoptosis--and necrosis-like neuron death in the ischemic rat hippocampus

DEFF Research Database (Denmark)

Müller, Georg Johannes; Stadelmann, Christine; Bastholm, Lone

2004-01-01

necrosis; its expression peaked on days 3 to 4. Silver staining for nucleoli, which are a substrate for caspase-3, revealed a profound loss of nucleoli in cells with apoptosis-like morphology, whereas cells with necrosis-like morphology showed intact nucleoli. Overall, cells with apoptosis-like morphology...

Hepatocyte membrane injury and bleb formation following low dose comfrey toxicity in rats.

Science.gov (United States)

Yeong, M L; Wakefield, S J; Ford, H C

1993-04-01

Comfrey, a popular herbal remedy, contains hepatotoxic pyrrolizidine alkaloids and has been implicated in recent human toxicity. Although alkaloids from other plant sources have been extensively researched, studies on the hepatotoxic effects of comfrey alkaloids are scant. The effects of high dose comfrey toxicity have been studied and the present investigation was undertaken to identify changes associated with relatively low dose toxicity. Eight young adult rats were dosed weekly for six weeks with 50 mg/kg of comfrey derived alkaloids. The animals were dissected one week after the last dose and the livers examined by light and electron microscopy. Changes at the light microscopic level showed vascular congestion, mild zone 3 necrosis and loss of definition of hepatocyte cellular membranes. Extensive ultrastructural abnormalities were identified in the form of endothelial sloughing and the loss of hepatocyte microvilli. A striking finding was florid bleb formation on the sinusoidal borders of hepatocytes. Many blebs were shed into the space of Disse and extruded to fill, and sometimes occlude, sinusoidal lumina. Platelets were frequently found in areas of bleb formation. There was evidence of late damage in collagenization of Disse's space. Hepatocyte bleb formation is known to occur under a variety of pathological conditions but there is little to no information in the literature on the effects, if any, of bleb formation on fibrogenesis and the microcirculation and its role in the pathogenesis of liver disease. The pyrrolizidine alkaloids of comfrey may serve as an experimental tool to study the process of bleb formation and the intimate relationship between hepatocyte and sinusoidal injury in the liver.

Radiation-associated ischemic coloproctitis. Report of two cases

Energy Technology Data Exchange (ETDEWEB)

Tomori, Hirofumi; Yasuda, Takashi; Shiraishi, Masayuki; Isa, Tsutomu; Muto, Yoshihiro; Egawa, Haruhiko [Ryukyus Univ., Nishihara, Okinawa (Japan). Faculty of Medicine

1999-10-01

Radiation-associated ischemic coloproctitis is a rare clinical entity caused by vascular insufficiency to the rectosigmoid colon. It most commonly occurs after radiotherapy for gynecological cancer. We present herein the cases of two patients who developed radiation-associated coloproctitis with transmural necrosis and eventual perforation. Perforation of the rectosigmoid colon occurred 3.5 years after radiotherapy in case 1, a 46-year-old woman, and presented as a well-defined small area of transmural necrosis. Conversely, in case 2, a 55-year-old woman, it occurred 1.5 years after radiotherapy, and presented as segmental, diffuse transmural necrosis. The lesion in case 1 had been caused by intramural vascular obliteration due to marked fibrosis of the bowel wall, while that in case 2 had been caused by occlusion of the mesenteric artery with thrombosis. Both patients underwent Hartmann's resection without rectal excision, and survived the perforative event. (author)

Radiation-associated ischemic coloproctitis. Report of two cases

International Nuclear Information System (INIS)

Tomori, Hirofumi; Yasuda, Takashi; Shiraishi, Masayuki; Isa, Tsutomu; Muto, Yoshihiro; Egawa, Haruhiko

1999-01-01

Radiation-associated ischemic coloproctitis is a rare clinical entity caused by vascular insufficiency to the rectosigmoid colon. It most commonly occurs after radiotherapy for gynecological cancer. We present herein the cases of two patients who developed radiation-associated coloproctitis with transmural necrosis and eventual perforation. Perforation of the rectosigmoid colon occurred 3.5 years after radiotherapy in case 1, a 46-year-old woman, and presented as a well-defined small area of transmural necrosis. Conversely, in case 2, a 55-year-old woman, it occurred 1.5 years after radiotherapy, and presented as segmental, diffuse transmural necrosis. The lesion in case 1 had been caused by intramural vascular obliteration due to marked fibrosis of the bowel wall, while that in case 2 had been caused by occlusion of the mesenteric artery with thrombosis. Both patients underwent Hartmann's resection without rectal excision, and survived the perforative event. (author)

Individuals with Primary Sclerosing Cholangitis Have Elevated Levels of Biomarkers for Apoptosis but Not Necrosis.

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Masuoka, Howard C; Vuppalanchi, Raj; Deppe, Ross; Bybee, Phelan; Comerford, Megan; Liangpunsakul, Suthat; Ghabril, Marwan; Chalasani, Naga

2015-12-01

Hepatocyte apoptosis or necrosis from accumulation of bile salts may play an important role in the disease progression of primary sclerosing cholangitis (PSC). The aim of the current study was to measure serum markers of hepatocyte apoptosis (cytokeratin-18 fragments--K18) and necrosis (high-mobility group protein B1--HMGB1) in adults with PSC and examine the relationship with disease severity. We measured serum levels of K18 and HMGB1 in well-phenotyped PSC (N = 37) and 39 control subjects (N = 39). Severity of PSC was assessed biochemically, histologically, and PSC Mayo risk score. Quantification of hepatocyte apoptosis was performed using TUNEL assay. The mean age of the study cohort was 49.7 ± 13.3 years and comprised of 67% men and 93% Caucasian. Serum K18 levels were significantly higher in the PSC patients compared to control (217.4 ± 78.1 vs. 157.0 ± 58.2 U/L, p = 0.001). However, HMGB1 levels were not different between the two groups (5.38 ± 2.99 vs. 6.28 ± 2.85 ng/mL, p = 0.15). Within the PSC group, K18 levels significantly correlated with AST (r = 0.5, p = 0.002), alkaline phosphatase (r = 0.5, p = 0.001), total bilirubin (r = 0.61, p ≤ 0.001), and albumin (r = -0.4, p = 0.02). Serum K18 levels also correlated with the level of apoptosis present on the liver biopsy (r = 0.8, p ≤ 0.001) and Mayo risk score (r = 0.4, p = 0.015). Serum K18 but not HMGB1 levels were increased in PSC and associated with severity of underlying liver disease and the degree of hepatocyte apoptosis.

Role of nuclear medicine in ischemic heart disease

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Hayashida, Kohei; Nishimura, Tsunehiko; Uehara, Toshiisa; Naito, Hiroaki; Omine, Hiromi; Kozuka, Takahiro [National Cardiovascular Center, Suita, Osaka (Japan)

1982-08-01

With the progress in gamma camera and computer system, nuclear medicine has been applied for diagnostic tool in ischemic heart disease. There are two devices for cardiac images; (1) Radionuclide angiocardiography (RNA) by in vivo sup(99m)Tc-RBC labeling (2) Myocardial imaging by /sup 201/Tlcl. RNA can evaluate the kinesis of wall motion of left ventricle with gated pool scan and also detect reserve of cardiac function with exercise study. Myocardial imaging at rest can identify myocardial necrosis and the imaging in exercise can detect myocardial ischemia. The elaborateness and reproducibility of cardiac image in nuclear medicine will play the great role to evaluate clinical stage of ischemic heart disease by not only imaging but also functional diagnosis.

Autologous Platelet Concentrates as Treatment for Avascular Necrosis of Femoral Head in a Dog.

Science.gov (United States)

Parra, Estefanía; Vergara, Andrea; Silva, Raúl F

2017-03-01

Avascular necrosis of the femoral head is a developmental disturbance that generally affects young dogs of small breeds and produces ischemic necrosis of the femoral head resulting in an incongruous and malformed joint. The most common treatment is the excisional arthroplasty of the head and femoral neck. The aim of this study is to describe the treatment of avascular necrosis in a Yorkshire dog using intra-articular injections of autologous platelet concentrate. Evaluations were made at 0, 15, 30, 60, and 120 days of treatment, describing the following parameters: clinical gait analysis, perimetry, goniometry, and radiographic evaluations. The results obtained in this case suggest that the autologous platelet concentrate may be an alternative for the treatment of avascular necrosis of the femoral head in dogs. Copyright © 2017 Elsevier Inc. All rights reserved.

A Case of Unresectable Rectal Necrosis

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Mohammed Nassif

2011-01-01

Full Text Available Introduction. Necrosis of the rectum is an uncommon finding due to abundant collateral vasculature. Its management remains challenging, without clear consensus in the literature. Case Report. We describe a case of a 53-year-old woman with multiple medical comorbidities that presented in septic shock and hematochezia. Colonoscopy revealed ischemic colitis. Conservative management was instituted. At two weeks, she presented evidence of peritonitis. Exploratory laparotomy revealed extensive necrosis of the left colon and rectum. Due to dense inflammation, resection was deemed unsafe. Therefore, a transverse ostomy with mucosal fistula was preformed. Multiple drains were left in place. The patient healed uneventfully. Conclusion. This case illustrates that, if extensive dissection of the distal colon and rectum is unsafe due to the patient's critical condition or technical feasibility, then a diverting ostomy of the proximal viable bowel along with a mucus fistula and good drainage of the abdomen represents an acceptable alternative.

Low-density lipoprotein subfraction, carotid artery intima-media thickness, nitric oxide, and tumor necrosis factor alpha are associated with newly diagnosed ischemic stroke

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Medine Cumhur Cure

2013-01-01

Full Text Available Objectives: Small dense (sd low-density lipoprotein (LDL, tumor necrosis factor (TNF alpha (a, and nitric oxide (NO have recently emerged as important stroke risk factors. The aim of the study was to investigate the effects of increased levels of small LDL particle size, TNF-a and NO on the developed ischemic stroke and increased carotid artery intima-media thickness (CIMT. Materials and Methods: A total of 29 women and 25 men (a total of 54 ischemic stroke patients and a similar age group of 50 controls (29 females and 21 males were included in the study. CIMT, C-reactive protein (CRP, TNF-a, NO, and lipid subfraction test of the two groups were measured. Results: The mean LDL particle size was smaller in patients with stroke than in the controls (26.8 ± 0.31 nm vs. 27.0 ± 0.31 nm, P = 0.003. sd-LDL, TNF-a, NO, CRP, right CIMT, and left CIMT were higher in patients with stroke than in the controls (respectively; 8.2 ± 7.8 mg/dL vs. 3.3 ± 3.5 mg/dL, P < 0.001;75.6 ± 25.0 pg/mL vs. 65.4 ± 9.1 pg/mL, P = 0.009;76.4 ± 53.3 mmol/L vs. 41.5 ± 27.0 mmol/L, P < 0.001;1.9 ± 2.6 mm vs. 0.4 ± 0.3 mm P < 0.001;0.97 ± 0.38 mm vs. 0.83 ± 0.15 mm, P = 0.007;1.04 ± 0.44 mm vs. 0.87 ± 0.19 mm, P = 0.010. Conclusion: These results show that sd-LDL is independently associated with the incidence of stroke and may be a risk factor in the development of stroke. In addition, TNF-a, NO, right CIMT, and left CIMT may be a risk factor in the development of ischemic stroke.

A role for tumor necrosis factor-alpha in ischemia and ischemic preconditioning

LENUS (Irish Health Repository)

Watters, Orla

2011-08-02

Abstract During cerebral ischemia, elevation of TNF-α and glutamate to pathophysiological levels may induce dysregulation of normal synaptic processes, leading ultimately to cell death. Previous studies have shown that patients subjected to a mild transient ischemic attack within a critical time window prior to a more severe ischemic episode may show attenuation in the clinical severity of the stroke and result in a more positive functional outcome. Studies with organotypic hippocampal cultures and mixed primary hippocampal cultures have shown that prior incubation with low concentrations of glutamate and TNF-α increase the resistance of neurones to a subsequent insult from glutamate, AMPA and NMDA, while co-exposure of TNF-α and for example AMPA may have neuroprotective effects compared to cultures exposed to excitotoxic agents alone. In addition our work has shown that although glutamate and TNF-α pretreatment induces analogous levels of desensitisation of the intracellular calcium dynamics of neurons under resting conditions and in response to acute glutamate stimulation, their downstream signalling pathways involved in this response do not converge. Glutamate and TNF-α would appear to have opposing effects on resting Ca2+ levels which supports the proposal that they have distinct modes of preconditioning.

Comparison of the biological features between human fetal hepatocyte and immortalized L-02 hepatocyte in vitro

International Nuclear Information System (INIS)

Kong Weiwei; Teng Gaojun

2004-01-01

Objective: To evaluate the feasibilities of the potential donors in liver cell transplantation using the human fetal hepatocytes and immortalized L-02 hepatocytes by comparing their biological features. Methods: Human fetal hepatocytes were isolated from aborted fetal livers (gestational ages from 14 w to 24 w) by an improved two-stage perfusion method and cultured in a conditioned medium without any growth factors. α-fetal protein (AFP) and albumin (ALB) were detected by radioimmunoassay (RIA) and cytokeratin-19 (CK-19 ) was identified by cellular immunochemistry study. Immortalized L-02 hepatocytes were cultured in the same condition and the characteristic proteins were detected by the same methods. Results: The viability of human fetal hepatocytes was approximately 95% using the perfusion method, and the maximum survival time of the cultured hepatocytes was 3 weeks. The expression of AFP, ALB, and CK19 was detected at the same time, especially during Day 3 to Day 7 in the culture. By comparison, the proliferation ability of L-02 hepatocyte was greater, although with a lower level of ALB secretion. The expression of AFP and CK19 was not detected. Furthermore, during the long culture, L-02 hepatocytes may undergo a morphologic change and fail to express ALB. Conclusion: Human fetal hepatocyte may be a practical donor for hepatocyte transplantation with its high-level protein expression and potential bi-differentiation ability. In view of the absent expression of ALB and the morphologic change in culture, although with better proliferation, L-02 hepatocyte seems not useful for hepatocyte transplantation

Dexamethasone enhances necrosis-like neuronal death in ischemic rat hippocampus involving μ-calpain activation

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Müller, Georg Johannes; Hasseldam, Henrik; Rasmussen, Rune Skovgaard

2014-01-01

- and necrosis-like cell death morphologies in CA1 of rats treated with dexamethasone prior to TFI (DPTI). In addition, apoptosis- (casp-9, casp-3, casp-3-cleaved PARP and cleaved α-spectrin 145/150 and 120kDa) and necrosis-related (calpain-specific casp-9 cleavage, μ-calpain upregulation and cleaved α......Transient forebrain ischemia (TFI) leads to hippocampal CA1 pyramidal cell death which is aggravated by glucocorticoids (GC). It is unknown how GC affect apoptosis and necrosis in cerebral ischemia. We therefore investigated the co-localization of activated caspase-3 (casp-3) with apoptosis......-spectrin 145/150kDa) cell death mechanisms were investigated by Western blot analysis. DPTI expedited CA1 neuronal death from day 4 to day 1 and increased the magnitude of CA1 neuronal death from 66.2% to 91.3% at day 7. Furthermore, DPTI decreased the overall (days 1-7) percentage of dying neurons displaying...

Isolation and characterization of adult human liver progenitors from ischemic liver tissue derived from therapeutic hepatectomies.

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Stachelscheid, Harald; Urbaniak, Thomas; Ring, Alexander; Spengler, Berlind; Gerlach, Jörg C; Zeilinger, Katrin

2009-07-01

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.

Myoglobinaemia in relation to cardiac necrosis

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McComb, J M

1981-01-01

An evaluation of the usefulness of estimation of the serum myoglobin in the detection of myocardial necrosis was made in patients with suspected acute ischemic heart disease and in patients in whom elective cardiac catheterization was performed. Measurement of serum myoglobin, by radioimmunoassay, in patients admitted with suspected acute myocardial infarction, suggested that a raised serum myoglobin level was a sensitive indicator of myocardial necrosis. It also showed that the serum myoglobin rose to abnormal levels before the serum creatine kinase. A study of 70 consecutive patients confirmed that the serum myoglobin level is a sensitive indicator of acute myocardial infarction and showed that its sensitivity was greater, and its specificity similar to that of serum creatine kinase. This study allowed calculation of a predictive index for the diagnosis of acute myocardial infarction from the serum myoglobin and serum creatine kinase six hours after the onset of symptoms. The use of a single myoglobin measurement in 114 patients admitted to a coronary care unit was then studied. The proposition that myocardial damage might results from cardiac catheterization was investigated in 115 patients.

Evidence of necroptosis in hearts subjected to various forms of ischemic insults

Czech Academy of Sciences Publication Activity Database

Adameová, A.; Hrdlička, Jaroslav; Szobi, A.; Farkašová, V.; Kopasková, K.; Muráriková, M.; Neckář, Jan; Kolář, František; Ravingerová, T.; Dhalla, N. S.

2017-01-01

Roč. 95, č. 10 (2017), s. 1163-1169 ISSN 0008-4212 R&D Projects: GA MZd(CZ) NV15-27735A Institutional support: RVO:67985823 Keywords : myocardial ischemia * ischemic preconditioning * heart failure * cell death * necroptosis * passive necrosis Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery OBOR OECD: Physiology (including cytology) Impact factor: 1.822, year: 2016

Anatomy of the Le Fort I segment: Are arterial variations a potential risk factor for avascular bone necrosis in Le Fort I osteotomies?

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Bruneder, Simon; Wallner, Jürgen; Weiglein, Andreas; Kmečová, Ĺudmila; Egger, Jan; Pilsl, Ulrike; Zemann, Wolfgang

2018-05-02

Osteotomies of the Le Fort I segment are routine operations with low complication rates. Ischemic complications are rare, but can have severe consequences that may lead to avascular bone necrosis of the Le Fort I segment. Therefore the aim of this study was to investigate the blood supply and special arterial variants of the Le Fort I segment responsible for arterial hypoperfusion or ischemic avascular necrosis after surgery. The arterial anatomy of the Le Fort I segment's blood supply using 30 halved human cadaver head specimens was analyzed after complete dissection until the submicroscopic level. In all specimens the arterial variants of the Le Fort I segment and also the arterial diameters measured at two points were evaluated. The typical known vascularization pattern was apparent in 90% of all specimens, in which the ascending palatine (D1: 1,2 mm ± 0,34 mm; D2: 0,8 mm ± 0,34 mm) and ascending pharyngeal artery (D1: 1,3 mm ± 0,58 mm; D2: avascular segment necrosis after surgery. An individualized operation plan may prevent ischemic complications in at-risk patients. Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Calciphylaxis: Temporal Artery Calcification Preceding Widespread Skin Lesions and Penile Necrosis

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Manzoor A. Shah

2012-01-01

Full Text Available Temporal artery calciphylaxis has rarely been described in chronic kidney disease patients on dialysis. We report a case of 72-year-old Caucasian man with multiple comorbidities and end-stage renal disease on dialysis who presented with temporal artery calcification leading to bilateral loss of vision followed by extensive skin lesions including one on glans penis. While on peritoneal dialysis, he developed anterior ischemic optic neuropathy, had no improvement on high dose steroids, and temporal artery biopsy showed marked calcification without any evidence of vasculitis. Few weeks later on hemodialysis, he developed widespread cutaneous lesions on extremities and penile necrosis with skin biopsy revealing calciphylaxis. On literature review of calciphylaxis in chronic kidney disease, we found only four cases of temporal artery calciphylaxis leading to anterior ischemic optic neuropathy and blindness. We believe this is the first case in which the rare temporal artery calciphylaxis and the uncommon penile necrosis are being described together. The objective is to emphasize the need to recognize this condition early in the CKD patients on dialysis presenting with visual symptoms as the different treatment strategies may help prevent complete loss of vision and also modify or prevent a full blown calciphylaxis.

Ischemic colitis complicating reconstruction of the abdominal aorta

DEFF Research Database (Denmark)

Schroeder, T V; Christoffersen, J K; Andersen, J

1985-01-01

A review of 23 patients with ischemic colitis after surgical treatment of the abdominal aorta disclosed a pathogenetic heterogeneous finding. Ligation of the inferior mesenteric artery, abolished collateral blood supply or nonocclusive low flow state, or both, was a common feature. An incidence o...... of 0.5 per cent was revealed for full-thickness necrosis. The mortality was 70 per cent since diagnosis was made first since perforation and peritonitis had occurred. On the basis of these findings vital prophylactic measures and diagnostic possibilities are discussed herein....

Programmed Necrosis: A Prominent Mechanism of Cell Death following Neonatal Brain Injury

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Raul Chavez-Valdez

2012-01-01

Full Text Available Despite the introduction of therapeutic hypothermia, neonatal hypoxic ischemic (HI brain injury remains a common cause of developmental disability. Development of rational adjuvant therapies to hypothermia requires understanding of the pathways of cell death and survival modulated by HI. The conceptualization of the apoptosis-necrosis “continuum” in neonatal brain injury predicts mechanistic interactions between cell death and hydrid forms of cell death such as programmed or regulated necrosis. Many of the components of the signaling pathway regulating programmed necrosis have been studied previously in models of neonatal HI. In some of these investigations, they participate as part of the apoptotic pathways demonstrating clear overlap of programmed death pathways. Receptor interacting protein (RIP-1 is at the crossroads between types of cellular death and survival and RIP-1 kinase activity triggers formation of the necrosome (in complex with RIP-3 leading to programmed necrosis. Neuroprotection afforded by the blockade of RIP-1 kinase following neonatal HI suggests a role for programmed necrosis in the HI injury to the developing brain. Here, we briefly review the state of the knowledge about the mechanisms behind programmed necrosis in neonatal brain injury recognizing that a significant proportion of these data derive from experiments in cultured cell and some from in vivo adult animal models. There are still more questions than answers, yet the fascinating new perspectives provided by the understanding of programmed necrosis in the developing brain may lay the foundation for new therapies for neonatal HI.

Effects of hepatocyte growth factor on glutathione synthesis, growth, and apoptosis is cell density-dependent

International Nuclear Information System (INIS)

Yang Heping; Magilnick, Nathaniel; Xia Meng; Lu, Shelly C.

2008-01-01

Hepatocyte growth factor (HGF) is a potent hepatocyte mitogen that exerts opposing effects depending on cell density. Glutathione (GSH) is the main non-protein thiol in mammalian cells that modulates growth and apoptosis. We previously showed that GSH level is inversely related to cell density of hepatocytes and is positively related to growth. Our current work examined whether HGF can modulate GSH synthesis in a cell density-dependent manner and how GSH in turn influence HGF's effects. We found HGF treatment of H4IIE cells increased cell GSH levels only under subconfluent density. The increase in cell GSH under low density was due to increased transcription of GSH synthetic enzymes. This correlated with increased protein levels and nuclear binding activities of c-Jun, c-Fos, p65, p50, Nrf1 and Nrf2 to the promoter region of these genes. HGF acts as a mitogen in H4IIE cells under low cell density and protects against tumor necrosis factor α (TNFα)-induced apoptosis by limiting JNK activation. However, HGF is pro-apoptotic under high cell density and exacerbates TNFα-induced apoptosis by potentiating JNK activation. The increase in cell GSH under low cell density allows HGF to exert its full mitogenic effect but is not necessary for its anti-apoptotic effect

Cutaneous necrosis secondary to terlipressin therapy. A rare but serious side effect: case report and literature review

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Enrique Iglesias-Julián

Full Text Available Terlipressin is a vasopressin analogue used in esophageal variceal bleeding and hepatorenal syndrome management. It is a safe drug with mild secondary effects. However, potentially serious ischemic complications may occur, such as cutaneous necrosis. It is useful to recognize these events early, in order to withdraw terlipressin and introduce other adjuvant drugs if needed. We report a detailed case of cutaneous necrosis secondary to terlipressin administration and present a case review of patients, describing their characteristics, risk factors, lesion locations, doses, methods of administration and possible treatments.

Gold nanoparticles induced cloudy swelling to hydropic degeneration, cytoplasmic hyaline vacuolation, polymorphism, binucleation, karyopyknosis, karyolysis, karyorrhexis and necrosis in the liver

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Jarrar Bashir M

2011-09-01

Full Text Available Abstract Background Nanoparticles (NPs can potentially cause adverse effects on organ, tissue, cellular, subcellular and protein levels due to their unusual physicochemical properties. Advances in nanotechnology have identified promising candidates for many biological and biomedical applications. The aim of the present study was to investigate the particle-size, dose and exposure duration effects of gold nanoparticles (GNPs on the hepatic tissue in an attempt to cover and understand the toxicity and their potential therapeutic and diagnostic use. Methods A total of 70 healthy male Wistar-Kyoto rats were exposed to GNPs received 50 or 100 ul of GNPs infusion of size (10, 20 and 50 nm for 3 or 7 days to investigate particle-size, dose and exposure duration effects of GNPs on the hepatic tissue. Results In comparison with respective control rats, exposure to GNPs doses has produced alterations in the hepatocytes, portal triads and the sinusoids. The alterations in the hepatocytes were mainly vacuolar to hydropic degeneration, cytopasmic hyaline vacuolation, polymorphism, binucleation, karyopyknosis, karyolysis, karyorrhexis and necrosis. Conclusions The hepatocytes swelling might be exhibited as a result of disturbances of membranes function that lead to massive influx of water and Na+ due to GNPs effects accompanied by leakage of lysosomal hydrolytic enzymes that lead to cytoplasmic degeneration and macromolecular crowding. Hydropic degeneration is a result of ion and fluid homestasis that lead to an increase of intracellular water. The vacuolated swelling of the cytoplasm of the hepatocytes of the GNPs treated rats might indicate acute and subacute liver injury induced by the GNPs. Binucleation represents a consequence of cell injury and is a sort of chromosomes hyperplasia which is usually seen in regenerating cells. The induced histological alterations might be an indication of injured hepatocytes due to GNPs toxicity that became unable to deal

Metformin protects rat hepatocytes against bile acid-induced apoptosis.

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Titia E Woudenberg-Vrenken

Full Text Available BACKGROUND: Metformin is used in the treatment of Diabetes Mellitus type II and improves liver function in patients with non-alcoholic fatty liver disease (NAFLD. Metformin activates AMP-activated protein kinase (AMPK, the cellular energy sensor that is sensitive to changes in the AMP/ATP-ratio. AMPK is an inhibitor of mammalian target of rapamycin (mTOR. Both AMPK and mTOR are able to modulate cell death. AIM: To evaluate the effects of metformin on hepatocyte cell death. METHODS: Apoptotic cell death was induced in primary rat hepatocytes using either the bile acid glycochenodeoxycholic acid (GCDCA or TNFα in combination with actinomycin D (actD. AMPK, mTOR and phosphoinositide-3 kinase (PI3K/Akt were inhibited using pharmacological inhibitors. Apoptosis and necrosis were quantified by caspase activation, acridine orange staining and Sytox green staining respectively. RESULTS: Metformin dose-dependently reduces GCDCA-induced apoptosis, even when added 2 hours after GCDCA, without increasing necrotic cell death. Metformin does not protect against TNFα/ActD-induced apoptosis. The protective effect of metformin is dependent on an intact PI3-kinase/Akt pathway, but does not require AMPK/mTOR-signaling. Metformin does not inhibit NF-κB activation. CONCLUSION: Metformin protects against bile acid-induced apoptosis and could be considered in the treatment of chronic liver diseases accompanied by inflammation.

MR of the normal and ischemic hip

International Nuclear Information System (INIS)

Mitchell, D.G.

1988-01-01

Magnetic resonance imaging (MRI) appears to be more sensitive than traditional radiographic and radionuclide methods for detecting early avascular necrosis (AVN) of the femoral head. The authors have found that in addition to its proven value for early detection, MRI can help us characterize individual lesions and understand the pathophysiology of AVN. This chapter reviews the clinical and pathological features of AVN of the femoral head, and describes recent contributions of MRI toward understanding the normal and ischemic hip. This review summarizes the 5-year experience of the MR group at the Hospital of the University of Pennsylvania

Ischemic preconditioning protects against ischemic brain injury

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Xiao-meng Ma

2016-01-01

Full Text Available In this study, we hypothesized that an increase in integrin αv ß 3 and its co-activator vascular endothelial growth factor play important neuroprotective roles in ischemic injury. We performed ischemic preconditioning with bilateral common carotid artery occlusion for 5 minutes in C57BL/6J mice. This was followed by ischemic injury with bilateral common carotid artery occlusion for 30 minutes. The time interval between ischemic preconditioning and lethal ischemia was 48 hours. Histopathological analysis showed that ischemic preconditioning substantially diminished damage to neurons in the hippocampus 7 days after ischemia. Evans Blue dye assay showed that ischemic preconditioning reduced damage to the blood-brain barrier 24 hours after ischemia. This demonstrates the neuroprotective effect of ischemic preconditioning. Western blot assay revealed a significant reduction in protein levels of integrin αv ß 3, vascular endothelial growth factor and its receptor in mice given ischemic preconditioning compared with mice not given ischemic preconditioning 24 hours after ischemia. These findings suggest that the neuroprotective effect of ischemic preconditioning is associated with lower integrin αv ß 3 and vascular endothelial growth factor levels in the brain following ischemia.

Modulation of macrophage activation state protects tissue from necrosis during critical limb ischemia in thrombospondin-1-deficient mice.

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Nicolas Bréchot

Full Text Available BACKGROUND: Macrophages, key regulators of healing/regeneration processes, strongly infiltrate ischemic tissues from patients suffering from critical limb ischemia (CLI. However pro-inflammatory markers correlate with disease progression and risk of amputation, suggesting that modulating macrophage activation state might be beneficial. We previously reported that thrombospondin-1 (TSP-1 is highly expressed in ischemic tissues during CLI in humans. TSP-1 is a matricellular protein that displays well-known angiostatic properties in cancer, and regulates inflammation in vivo and macrophages properties in vitro. We therefore sought to investigate its function in a mouse model of CLI. METHODS AND FINDINGS: Using a genetic model of tsp-1(-/- mice subjected to femoral artery excision, we report that tsp-1(-/- mice were clinically and histologically protected from necrosis compared to controls. Tissue protection was associated with increased postischemic angiogenesis and muscle regeneration. We next showed that macrophages present in ischemic tissues exhibited distinct phenotypes in tsp-1(-/- and wt mice. A strong reduction of necrotic myofibers phagocytosis was observed in tsp-1(-/- mice. We next demonstrated that phagocytosis of muscle cell debris is a potent pro-inflammatory signal for macrophages in vitro. Consistently with these findings, macrophages that infiltrated ischemic tissues exhibited a reduced postischemic pro-inflammatory activation state in tsp-1(-/- mice, characterized by a reduced Ly-6C expression and a less pro-inflammatory cytokine expression profile. Finally, we showed that monocyte depletion reversed clinical and histological protection from necrosis observed in tsp-1(-/- mice, thereby demonstrating that macrophages mediated tissue protection in these mice. CONCLUSION: This study defines targeting postischemic macrophage activation state as a new potential therapeutic approach to protect tissues from necrosis and promote tissue

Repolarization of hepatocytes in culture.

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Talamini, M A; Kappus, B; Hubbard, A

1997-01-01

We have evaluated the biochemical, morphological, and functional redevelopment of polarity in freshly isolated hepatocytes cultured using a double layer collagen gel sandwich technique. Western blot analysis showed increased cellular levels of the cell adhesion protein uvomorulin as cultured hepatocytes repolarized. Immunofluorescence studies using antibodies against domain-specific membrane proteins showed polarity as early as 48 hours, although the pattern of the polymeric Immunoglobulin-A receptor (pIgA-R) differed from in vivo liver. Electron microscopy showed developing bile canaliculi at 1 day. However, the functional presence of tight junctions was absent at 1 day, but present at 5 days. We further showed functional polarity to be present at 4 days by documenting the ability of cultured hepatocytes to metabolize and excrete fluorescein diacetate into visible bile canaliculi. We conclude that hepatocytes cultured appropriately develop morphological and functional polarity. Hepatocyte culture is therefore a useful tool for the study of mechanisms responsible for the development of polarized function.

Multiparametric MRI of Epiphyseal Cartilage Necrosis (Osteochondrosis with Histological Validation in a Goat Model.

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Luning Wang

Full Text Available To evaluate multiple MRI parameters in a surgical model of osteochondrosis (OC in goats.Focal ischemic lesions of two different sizes were induced in the epiphyseal cartilage of the medial femoral condyles of goats at 4 days of age by surgical transection of cartilage canal blood vessels. Goats were euthanized and specimens harvested 3, 4, 5, 6, 9 and 10 weeks post-op. Ex vivo MRI scans were conducted at 9.4 Tesla for mapping the T1, T2, T1ρ, adiabatic T1ρ and TRAFF relaxation times of articular cartilage, unaffected epiphyseal cartilage, and epiphyseal cartilage within the area of the induced lesion. After MRI scans, safranin O staining was conducted to validate areas of ischemic necrosis induced in the medial femoral condyles of six goats, and to allow comparison of MRI findings with the semi-quantitative proteoglycan assessment in corresponding safranin O-stained histological sections.All relaxation time constants differentiated normal epiphyseal cartilage from lesions of ischemic cartilage necrosis, and the histological staining results confirmed the proteoglycan (PG loss in the areas of ischemia. In the scanned specimens, all of the measured relaxation time constants were higher in the articular than in the normal epiphyseal cartilage, consistently allowing differentiation between these two tissues.Multiparametric MRI provided a sensitive approach to discriminate between necrotic and viable epiphyseal cartilage and between articular and epiphyseal cartilage, which may be useful for diagnosing and monitoring OC lesions and, potentially, for assessing effectiveness of treatment interventions.

Histopathology of motor cortex in an experimental focal ischemic stroke in mouse model.

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de Oliveira, Juçara Loli; Crispin, Pedro di Tárique Barreto; Duarte, Elisa Cristiana Winkelmann; Marloch, Gilberto Domingos; Gargioni, Rogério; Trentin, Andréa Gonçalves; Alvarez-Silva, Marcio

2014-05-01

Experimental ischemia results in cortical brain lesion followed by ischemic stroke. In this study, focal cerebral ischemia was induced in mice by occlusion of the middle cerebral artery. We studied cortical layers I, II/III, V and VI in the caudal forelimb area (CFA) and medial agranular cortex (AGm) from control and C57BL/6 mice induced with ischemic stroke. Based on our analysis of CFA and AGm motor cortex, significant differences were observed in the numbers of neurons, astrocytes and microglia in the superficial II/III and deep V cortical layers. Cellular changes were more prominent in layer V of the CFA with nuclear pyknosis, chromatin fragmentation, necrosis and degeneration, as well as, morphological evidence of apoptosis, mainly in neurons. As result, the CFA was more severely impaired than the AGm in this focal cerebral ischemic model, as evidenced by the proliferation of astrocytes, potentially resulting in neuroinflammation by microglia-like cells. Copyright © 2014 Elsevier B.V. All rights reserved.

Hepatocyte cytoskeleton during ischemia and reperfusion influence of ANP-mediated p38 MAPK activation

Institute of Scientific and Technical Information of China (English)

Melanie Keller; Alexander L Gerbes; Stefanie Kulhanek-Heinze; Tobias Gerwig; Uwe Grützner; Nico van Rooijen; Angelika M Vollmar; Alexandra K Kiemer

2005-01-01

AIM: To determine functional consequences of this activation, whereby we focused on a potential regulation of the hepatocyte cytoskeleton during ischemia and reperfusion.METHODS: For in vivo experiments, animals received ANP (5 μg/kg) intravenously. In a different experimental setting, isolated rat livers were perfused with KH-buffer ±ANP (200 nmol/L)±SB203580 (2 μmol/L). Liverswere then kept under ischemic conditions for 24 h, and either transplanted or reperfused. Actin, Hsp27, and phosphorylated Hsp27 were determined by Western blotting, p38 MAPK activity by in vitro phosphorylation assay. F-actin distribution was determined by confocal microscopy.RESULTS: We first confirmed that ANP preconditioning leads to an activation of p38 MAPK and observedalterations of the cytoskeleton in hepatocytes of ANPpreconditioned organs. ANP induced an increase of hepatic F-actin after ischemia, which could be prevented by the p38 MAPK inhibitor SB203580 but had no effect on bile flow. After ischemia untreated livers showed a translocation of Hsp27 towards the cytoskeleton and an increase in total Hsp27, whereas ANP preconditioning prohibited translocation but caused an augmentation of Hsp27 phosphorylation. This effect is also mediated via p38 MAPK, since it was abrogated by the p38 MAPK inhibitor SB203580.CONCLUSION: This study reveals that ANP-mediated p38 MAPK activation leads to changes in hepatocyte cytoskeleton involving an elevation of phosphorylated Hsp27 and thereby for the first time shows functional consequences of ANP-induced hepatic p38 MAPK activation.

Hepatocyte nuclear factor 4A improves hepatic differentiation of immortalized adult human hepatocytes and improves liver function and survival.

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Hang, Hua-Lian; Liu, Xin-Yu; Wang, Hai-Tian; Xu, Ning; Bian, Jian-Min; Zhang, Jian-Jun; Xia, Lei; Xia, Qiang

2017-11-15

Immortalized human hepatocytes (IHH) could provide an unlimited supply of hepatocytes, but insufficient differentiation and phenotypic instability restrict their clinical application. This study aimed to determine the role of hepatocyte nuclear factor 4A (HNF4A) in hepatic differentiation of IHH, and whether encapsulation of IHH overexpressing HNF4A could improve liver function and survival in rats with acute liver failure (ALF). Primary human hepatocytes were transduced with lentivirus-mediated catalytic subunit of human telomerase reverse transcriptase (hTERT) to establish IHH. Cells were analyzed for telomerase activity, proliferative capacity, hepatocyte markers, and tumorigenicity (c-myc) expression. Hepatocyte markers, hepatocellular functions, and morphology were studied in the HNF4A-overexpressing IHH. Hepatocyte markers and karyotype analysis were completed in the primary hepatocytes using shRNA knockdown of HNF4A. Nuclear translocation of β-catenin was assessed. Rat models of ALF were treated with encapsulated IHH or HNF4A-overexpressing IHH. A HNF4A-positive IHH line was established, which was non-tumorigenic and conserved properties of primary hepatocytes. HNF4A overexpression significantly enhanced mRNA levels of genes related to hepatic differentiation in IHH. Urea levels were increased by the overexpression of HNF4A, as measured 24h after ammonium chloride addition, similar to that of primary hepatocytes. Chromosomal abnormalities were observed in primary hepatocytes transfected with HNF4A shRNA. HNF4α overexpression could significantly promote β-catenin activation. Transplantation of HNF4A overexpressing IHH resulted in better liver function and survival of rats with ALF compared with IHH. HNF4A improved hepatic differentiation of IHH. Transplantation of HNF4A-overexpressing IHH could improve the liver function and survival in a rat model of ALF. Copyright © 2017 Elsevier Inc. All rights reserved.

Fournier gangrene with extensive necrosis of urethra and bladder mucosa: A rare occurrence in a patient with advanced prostate cancer.

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Paonam, Somorendro S; Bag, Sananda

2015-01-01

Fournier gangrene (FG) is polymicrobial necrotizing infection of subcutaneous tissues and deep fascia, commonly involving the perineum, external genitalia, anterior abdominal wall and medial aspect of thighs. Urethral pathology, although often the inciting factor for FG, extensive involvement with urethral necrosis is very rare. This is the first report in English literature, describing complete sloughing of the bulbar urethra with ischemic necrosis of the bladder mucosa from FG. Such extensive disease is associated with high mortality, despite higher antibiotics, through debridement and intensive care. Urethral involvement needs extensive debridement and temporary or permanent urinary diversion.

Inflammatory cascades driven by tumor necrosis factor-alpha play a major role in the progression of acute liver failure and its neurological complications.

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Anne Chastre

Full Text Available Acute liver failure (ALF due to ischemic or toxic liver injury is a clinical condition that results from massive loss of hepatocytes and may lead to hepatic encephalopathy (HE, a serious neuropsychiatric complication. Although increased expression of tumor necrosis factor-alpha (TNF-α in liver, plasma and brain has been observed, conflicting results exist concerning its roles in drug-induced liver injury and on the progression of HE. The present study aimed to investigate the therapeutic value of etanercept, a TNF-α neutralizing molecule, on the progression of liver injury and HE in mice with ALF resulting from azoxymethane (AOM hepatotoxicity.Mice were administered saline or etanercept (10 mg/kg; i.p. 30 minutes prior to, or up to 6 h after AOM. Etanercept-treated ALF mice were sacrificed in parallel with vehicle-treated comatose ALF mice and controls. AOM induced severe hepatic necrosis, leading to HE, and etanercept administered prior or up to 3 h after AOM significantly delayed the onset of coma stages of HE. Etanercept pretreatment attenuated AOM-induced liver injury, as assessed by histological examination, plasma ammonia and transaminase levels, and by hepatic glutathione content. Peripheral inflammation was significantly reduced by etanercept as shown by decreased plasma IL-6 (4.1-fold; p<0.001 and CD40L levels (3.7-fold; p<0.001 compared to saline-treated ALF mice. Etanercept also decreased IL-6 levels in brain (1.2-fold; p<0.05, attenuated microglial activation (assessed by OX-42 immunoreactivity, and increased brain glutathione concentrations.These results indicate that systemic sequestration of TNF-α attenuates both peripheral and cerebral inflammation leading to delayed progression of liver disease and HE in mice with ALF due to toxic liver injury. These results suggest that etanercept may provide a novel therapeutic approach for the management of ALF patients awaiting liver transplantation.

Dabrafenib, an inhibitor of RIP3 kinase-dependent necroptosis, reduces ischemic brain injury

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Shelly A Cruz

2018-01-01

Full Text Available Ischemic brain injury triggers neuronal cell death by apoptosis via caspase activation and by necroptosis through activation of the receptor-interacting protein kinases (RIPK associated with the tumor necrosis factor-alpha (TNF-α/death receptor. Recent evidence shows RIPK inhibitors are neuroprotective and alleviate ischemic brain injury in a number of animal models, however, most have not yet undergone clinical trials and safety in humans remains in question. Dabrafenib, originally identified as a B-raf inhibitor that is currently used to treat melanoma, was later revealed to be a potent RIPK3 inhibitor at micromolar concentrations. Here, we investigated whether Dabrafenib would show a similar neuroprotective effect in mice subjected to ischemic brain injury by photothrombosis. Dabrafenib administered intraperitoneally at 10 mg/kg one hour after photothrombosis-induced focal ischemic injury significantly reduced infarct lesion size in C57BL6 mice the following day, accompanied by a markedly attenuated upregulation of TNF-α. However, subsequent lower doses (5 mg/kg/day failed to sustain this neuroprotective effect after 4 days. Dabrafenib blocked lipopolysaccharides-induced activation of TNF-α in bone marrow-derived macrophages, suggesting that Dabrafenib may attenuate TNF-α-induced necroptotic pathway after ischemic brain injury. Since Dabrafenib is already in clinical use for the treatment of melanoma, it might be repurposed for stroke therapy.

Effects of carbon tetrachloride on oxidative stress, inflammatory response and hepatocyte apoptosis in common carp (Cyprinus carpio)

International Nuclear Information System (INIS)

Jia, Rui; Cao, Li-Ping; Du, Jin-Liang; Wang, Jia-Hao; Liu, Ying-Juan; Jeney, Galina; Xu, Pao; Yin, Guo-Jun

2014-01-01

Highlights: • We explored the underlying toxicology of CCl 4 at the cellular and molecular levels. • QRT-PCR detected the gene expression of NF-κB and inflammatory cytokines. • The apoptosis and necrosis occurred simultaneously in carp liver damage. • CCl 4 activated the TNF-α/NF-κB and TRL4/NF-κB signaling pathways. - Abstract: In the present study, the cellular and molecular mechanism of carbon tetrachloride (CCl 4 )-induced hepatotoxicity in fish was investigated by studying the effects of CCl 4 on the oxidative stress, inflammatory response and hepatocyte apoptosis. Common carp were given an intraperitoneal injection of 30% CCl 4 in arachis oil (0.5 ml/kg body weight). At 72 h post-injection, blood were collected to measure glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione (GSH), total antioxidant capacity (T-AOC) and malondialdehyde (MDA), liver samples were taken to analyze toll-like receptor 4 (TLR4), cytochrome P450 2E1 (CYP2E1) and gene expressions of inflammatory cytokines and nuclear factor-κB (NF-κB/cREL). Cell viability and apoptosis were analyzed after treatment of the primary hepatocytes with CCl 4 at 8 mM. The results showed that CCl 4 significantly increased the levels of GPT, GOT, MDA, TLR4 and CYP2E1, reduced the levels of SOD, GPx, CAT, GSH and T-AOC, and up-regulated the gene expressions of NF-κB/cREL and inflammatory cytokines including tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), IL-1β, IL-6 and IL-12. In vitro, CCl 4 caused a dramatic loss in cell viability and induced hepatocyte apoptosis. Overall results suggest that oxidative stress lipid peroxidation, and TNF-α/NF-κB and TRL4/NF-κB signaling pathways play important roles in CCl 4 -induced hepatotoxicity in fish

Effects of carbon tetrachloride on oxidative stress, inflammatory response and hepatocyte apoptosis in common carp (Cyprinus carpio)

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Jia, Rui [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Cao, Li-Ping; Du, Jin-Liang [Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); International Joint Research Laboratory for Fish Immunopharmacology, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Wang, Jia-Hao; Liu, Ying-Juan [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Jeney, Galina [National Agricultural Research Center, Research Institute for Fisherie and, Aquaculture, Anna Light 8, Szarvas 5440 (Hungary); Xu, Pao, E-mail: xup@ffrc.cn [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); Yin, Guo-Jun, E-mail: yingj@ffrc.cn [Wuxi Fisheries College, Nanjing Agricultural University, Wuxi 214081 (China); Key Laboratory of Freshwater Fisheries and Germplasm Resources Utilization, Ministry of Agriculture, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China); International Joint Research Laboratory for Fish Immunopharmacology, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi 214081 (China)

2014-07-01

Highlights: • We explored the underlying toxicology of CCl{sub 4} at the cellular and molecular levels. • QRT-PCR detected the gene expression of NF-κB and inflammatory cytokines. • The apoptosis and necrosis occurred simultaneously in carp liver damage. • CCl{sub 4} activated the TNF-α/NF-κB and TRL4/NF-κB signaling pathways. - Abstract: In the present study, the cellular and molecular mechanism of carbon tetrachloride (CCl{sub 4})-induced hepatotoxicity in fish was investigated by studying the effects of CCl{sub 4} on the oxidative stress, inflammatory response and hepatocyte apoptosis. Common carp were given an intraperitoneal injection of 30% CCl{sub 4} in arachis oil (0.5 ml/kg body weight). At 72 h post-injection, blood were collected to measure glutamate pyruvate transaminase (GPT), glutamate oxalate transaminase (GOT), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione (GSH), total antioxidant capacity (T-AOC) and malondialdehyde (MDA), liver samples were taken to analyze toll-like receptor 4 (TLR4), cytochrome P450 2E1 (CYP2E1) and gene expressions of inflammatory cytokines and nuclear factor-κB (NF-κB/cREL). Cell viability and apoptosis were analyzed after treatment of the primary hepatocytes with CCl{sub 4} at 8 mM. The results showed that CCl{sub 4} significantly increased the levels of GPT, GOT, MDA, TLR4 and CYP2E1, reduced the levels of SOD, GPx, CAT, GSH and T-AOC, and up-regulated the gene expressions of NF-κB/cREL and inflammatory cytokines including tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), IL-1β, IL-6 and IL-12. In vitro, CCl{sub 4} caused a dramatic loss in cell viability and induced hepatocyte apoptosis. Overall results suggest that oxidative stress lipid peroxidation, and TNF-α/NF-κB and TRL4/NF-κB signaling pathways play important roles in CCl{sub 4}-induced hepatotoxicity in fish.

Phenotypic and functional analyses show stem cell-derived hepatocyte-like cells better mimic fetal rather than adult hepatocytes.

Science.gov (United States)

Baxter, Melissa; Withey, Sarah; Harrison, Sean; Segeritz, Charis-Patricia; Zhang, Fang; Atkinson-Dell, Rebecca; Rowe, Cliff; Gerrard, Dave T; Sison-Young, Rowena; Jenkins, Roz; Henry, Joanne; Berry, Andrew A; Mohamet, Lisa; Best, Marie; Fenwick, Stephen W; Malik, Hassan; Kitteringham, Neil R; Goldring, Chris E; Piper Hanley, Karen; Vallier, Ludovic; Hanley, Neil A

2015-03-01

Hepatocyte-like cells (HLCs), differentiated from pluripotent stem cells by the use of soluble factors, can model human liver function and toxicity. However, at present HLC maturity and whether any deficit represents a true fetal state or aberrant differentiation is unclear and compounded by comparison to potentially deteriorated adult hepatocytes. Therefore, we generated HLCs from multiple lineages, using two different protocols, for direct comparison with fresh fetal and adult hepatocytes. Protocols were developed for robust differentiation. Multiple transcript, protein and functional analyses compared HLCs to fresh human fetal and adult hepatocytes. HLCs were comparable to those of other laboratories by multiple parameters. Transcriptional changes during differentiation mimicked human embryogenesis and showed more similarity to pericentral than periportal hepatocytes. Unbiased proteomics demonstrated greater proximity to liver than 30 other human organs or tissues. However, by comparison to fresh material, HLC maturity was proven by transcript, protein and function to be fetal-like and short of the adult phenotype. The expression of 81% phase 1 enzymes in HLCs was significantly upregulated and half were statistically not different from fetal hepatocytes. HLCs secreted albumin and metabolized testosterone (CYP3A) and dextrorphan (CYP2D6) like fetal hepatocytes. In seven bespoke tests, devised by principal components analysis to distinguish fetal from adult hepatocytes, HLCs from two different source laboratories consistently demonstrated fetal characteristics. HLCs from different sources are broadly comparable with unbiased proteomic evidence for faithful differentiation down the liver lineage. This current phenotype mimics human fetal rather than adult hepatocytes. Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

IQGAP1 is involved in post-ischemic neovascularization by regulating angiogenesis and macrophage infiltration.

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Norifumi Urao

2010-10-01

Full Text Available Neovascularization is an important repair mechanism in response to ischemic injury and is dependent on inflammation, angiogenesis and reactive oxygen species (ROS. IQGAP1, an actin-binding scaffold protein, is a key regulator for actin cytoskeleton and motility. We previously demonstrated that IQGAP1 mediates vascular endothelial growth factor (VEGF-induced ROS production and migration of cultured endothelial cells (ECs; however, its role in post-ischemic neovascularization is unknown.Ischemia was induced by left femoral artery ligation, which resulted in increased IQGAP1 expression in Mac3(+ macrophages and CD31(+ capillary-like ECs in ischemic legs. Mice lacking IQGAP1 exhibited a significant reduction in the post-ischemic neovascularization as evaluated by laser Doppler blood flow, capillary density and α-actin positive arterioles. Furthermore, IQGAP1(-/- mice showed a decrease in macrophage infiltration and ROS production in ischemic muscles, leading to impaired muscle regeneration and increased necrosis and fibrosis. The numbers of bone marrow (BM-derived cells in the peripheral blood were not affected in these knockout mice. BM transplantation revealed that IQGAP1 expressed in both BM-derived cells and tissue resident cells, such as ECs, is required for post-ischemic neovascularization. Moreover, thioglycollate-induced peritoneal macrophage recruitment and ROS production were inhibited in IQGAP1(-/- mice. In vitro, IQGAP1(-/- BM-derived macrophages showed inhibition of migration and adhesion capacity, which may explain the defective macrophage recruitment into the ischemic tissue in IQGAP1(-/- mice.IQGAP1 plays a key role in post-ischemic neovascularization by regulating, not only, ECs-mediated angiogenesis but also macrophage infiltration as well as ROS production. Thus, IQGAP1 is a potential therapeutic target for inflammation- and angiogenesis-dependent ischemic cardiovascular diseases.

Erythrocyte deformation in ischemic acute tubular necrosis and amelioration by splenectomy in the dog.

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Mandal, A K; Taylor, C A; Bell, R D; Hillman, N M; Jarnot, M D; Cunningham, J D; Phillips, L G

1991-11-01

Bilateral renal artery occlusion (RAO) for 120 minutes in dogs results in acute tubular necrosis (ATN) and peritubular capillary (PTC) congestion with rapidly deteriorating renal function. We have shown that prior splenectomy minimizes RAO-induced renal functional and histopathologic changes. The purpose of this study was to examine whether this renal protection is due to prevention of red blood cell echinocyte formation and resultant renal PTC congestion. Echinocytes (burr cells) are poorly deformable, impart high viscosity to the blood, and may hinder reperfusion by increasing resistance to renal capillary blood flow. Splenectomized (SPLX) or sham-SPLX dogs were treated with bilateral RAO for 120 minutes. After RAO, renal function and renal blood flow were monitored, and peripheral blood red blood cells were examined at 1 hour and at 24-hour intervals for 96 hours. Renal biopsies were taken 1 hour after RAO and the kidneys removed 96 hours after RAO. The RBCs and renal tissues were studied using scanning electron microscopy. Renal function was assessed by endogenous creatinine clearance. Sham-SPLX animals showed a marked and sustained decrease in creatinine clearance, consistently elevated serum creatinine levels and fractional excretion of sodium, and diffuse ATN and PTC congestion with echinocytes. These animals had a peak in circulating echinocytes 1 hour after RAO (p less than 0.05), which showed an excellent negative correlation with creatinine clearance (r = -0.999; p less than 0.001). On the contrary, SPLX animals had essentially no change in serum creatinine or fractional excretion of sodium, minimal tubular changes, no PTC congestion, and no rise in circulating echinocytes during the 96-hour observation. In vitro treatment of the postischemic red blood cells from sham animals with adenosine-inosine or fresh postischemic plasma from the SPLX animals showed almost complete reversal to discocytes (normal red blood cells), whereas in vitro treatment of

Magnetic cell labeling of primary and stem cell-derived pig hepatocytes for MRI-based cell tracking of hepatocyte transplantation.

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Dwayne R Roach

Full Text Available Pig hepatocytes are an important investigational tool for optimizing hepatocyte transplantation schemes in both allogeneic and xenogeneic transplant scenarios. MRI can be used to serially monitor the transplanted cells, but only if the hepatocytes can be labeled with a magnetic particle. In this work, we describe culture conditions for magnetic cell labeling of cells from two different pig hepatocyte cell sources; primary pig hepatocytes (ppHEP and stem cell-derived hepatocytes (PICM-19FF. The magnetic particle is a micron-sized iron oxide particle (MPIO that has been extensively studied for magnetic cell labeling for MRI-based cell tracking. ppHEP could endocytose MPIO with labeling percentages as high as 70%, achieving iron content as high as ~55 pg/cell, with >75% viability. PICM-19FF had labeling >97%, achieving iron content ~38 pg/cell, with viability >99%. Extensive morphological and functional assays indicated that magnetic cell labeling was benign to the cells. The results encourage the use of MRI-based cell tracking for the development and clinical use of hepatocyte transplantation methodologies. Further, these results generally highlight the importance of functional cell assays in the evaluation of contrast agent biocompatibility.

Characterization of neuronal damage by iomazenil binding and cerebral blood flow in an ischemic rat model

International Nuclear Information System (INIS)

Toyama, Hiroshi; Takeuchi, Akira; Koga, Sukehiko; Matsumura, Kaname; Nakashima, Hiromichi; Takeda, Kan; Yoshida, Toshimichi; Ichise, Masanori

1998-01-01

I-123-iomazenil is a SPECT probe for central benzodiazepine receptors (BZR) which may reflect intact cortical neuron density after ischemic insults. We evaluated whether neuronal damage in rats could be characterized by iomazenil as compared with cerebral blood flow (CBF). Serial changes in I-125-iomazenil for BZR and I-123-IMP for CBF were analyzed after the unilateral middle cerebral artery occlusion in rats by using an in vivo dualtracer technique. Uptake ratios of affected to contralateral regions were calculated. The iomazenil as well as IMP were decreased in all regions except for the cerebellum (remote area). Both iomazenil and IMP increased over time except in the temporal region (ischemic core). The iomazenil uptake was higher than IMP except in the ischemic core between 1 and 3-4 wk when iomazenil was lower than IMP. Iomazenil showed a moderate decrease in the proximal and middle parietal regions (peri-infarct areas) at 3-4 wk. The triphenyl-tetrazolium-chloride (TTC) stain at 1 wk demonstrated unstained tissue in the temporal region indicating tissue necrosis. With hematoxylin-eosin (HE) stain at 1 wk, widespread neuronal necrosis with occasional intact neurons were found in the proximal parietal region, and isolated necrotic neurons were represented in the distal parietal region. Iomazenil correlated well with the neuron distribution and the finding of a discrepancy between iomazenil and IMP might be useful in evaluating the neuronal damage. (author)

Rational modulation of the innate immune system for neuroprotection in ischemic stroke

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Diana eAmantea

2015-04-01

Full Text Available The innate immune system plays a dualistic role in the evolution of ischemic brain damage and has also been implicated in ischemic tolerance produced by different conditioning stimuli. Early after ischemia, perivascular astrocytes release cytokines and activate metalloproteases (MMPs that contribute to blood–brain barrier (BBB disruption and vasogenic oedema; whereas at later stages, they provide extracellular glutamate uptake, BBB regeneration and neurotrophic factors release. Similarly, early activation of microglia contributes to ischemic brain injury via the production of inflammatory cytokines, including tumor necrosis factor (TNF and interleukin (IL-1, reactive oxygen and nitrogen species and proteases. Nevertheless, microglia also contributes to the resolution of inflammation, by releasing IL-10 and tumor growth factor (TGF-beta, and to the late reparative processes by phagocytic activity and growth factors production. Indeed, after ischemia, microglia/macrophages differentiate towards several phenotypes: the M1 pro-inflammatory phenotype is classically activated via toll-like receptors or interferon-γ, whereas M2 phenotypes are alternatively activated by regulatory mediators, such as ILs 4, 10, 13 or TGF-beta. Thus, immune cells exert a dualistic role on the evolution of ischemic brain damage, since the classic phenotypes promote injury, whereas alternatively activated M2 macrophages or N2 neutrophils prompt tissue remodeling and repair.Moreover, a subdued activation of the immune system has been involved in ischemic tolerance, since different preconditioning stimuli act via modulation of inflammatory mediators, including toll-like receptors and cytokine signaling pathways. This further underscores that the immuno-modulatory approach for the treatment of ischemic stroke should be aimed at blocking the detrimental effects, while promoting the beneficial responses of the immune reaction.

BAG3 (Bcl-2-Associated Athanogene-3) Coding Variant in Mice Determines Susceptibility to Ischemic Limb Muscle Myopathy by Directing Autophagy.

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McClung, Joseph M; McCord, Timothy J; Ryan, Terence E; Schmidt, Cameron A; Green, Tom D; Southerland, Kevin W; Reinardy, Jessica L; Mueller, Sarah B; Venkatraman, Talaignair N; Lascola, Christopher D; Keum, Sehoon; Marchuk, Douglas A; Spangenburg, Espen E; Dokun, Ayotunde; Annex, Brian H; Kontos, Christopher D

2017-07-18

Critical limb ischemia is a manifestation of peripheral artery disease that carries significant mortality and morbidity risk in humans, although its genetic determinants remain largely unknown. We previously discovered 2 overlapping quantitative trait loci in mice, Lsq-1 and Civq-1 , that affected limb muscle survival and stroke volume after femoral artery or middle cerebral artery ligation, respectively. Here, we report that a Bag3 variant (Ile81Met) segregates with tissue protection from hind-limb ischemia. We treated mice with either adeno-associated viruses encoding a control (green fluorescent protein) or 2 BAG3 (Bcl-2-associated athanogene-3) variants, namely Met81 or Ile81, and subjected the mice to hind-limb ischemia. We found that the BAG3 Ile81Met variant in the C57BL/6 (BL6) mouse background segregates with protection from tissue necrosis in a shorter congenic fragment of Lsq-1 (C.B6- Lsq1-3 ). BALB/c mice treated with adeno-associated virus encoding the BL6 BAG3 variant (Ile81; n=25) displayed reduced limb-tissue necrosis and increased limb tissue perfusion compared with Met81- (n=25) or green fluorescent protein- (n=29) expressing animals. BAG3 Ile81 , but not BAG3 Met81 , improved ischemic muscle myopathy and muscle precursor cell differentiation and improved muscle regeneration in a separate, toxin-induced model of injury. Systemic injection of adeno-associated virus-BAG3 Ile81 (n=9), but not BAG3 Met81 (n=10) or green fluorescent protein (n=5), improved ischemic limb blood flow and limb muscle histology and restored muscle function (force production). Compared with BAG3 Met81 , BAG3 Ile81 displayed improved binding to the small heat shock protein (HspB8) in ischemic skeletal muscle cells and enhanced ischemic muscle autophagic flux. Taken together, our data demonstrate that genetic variation in BAG3 plays an important role in the prevention of ischemic tissue necrosis. These results highlight a pathway that preserves tissue survival and muscle

Fournier gangrene with extensive necrosis of urethra and bladder mucosa: A rare occurrence in a patient with advanced prostate cancer

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Somorendro S Paonam

2015-01-01

Full Text Available Fournier gangrene (FG is polymicrobial necrotizing infection of subcutaneous tissues and deep fascia, commonly involving the perineum, external genitalia, anterior abdominal wall and medial aspect of thighs. Urethral pathology, although often the inciting factor for FG, extensive involvement with urethral necrosis is very rare. This is the first report in English literature, describing complete sloughing of the bulbar urethra with ischemic necrosis of the bladder mucosa from FG. Such extensive disease is associated with high mortality, despite higher antibiotics, through debridement and intensive care. Urethral involvement needs extensive debridement and temporary or permanent urinary diversion.

Hepatocyte Growth Factor Reduces Free Cholesterol-Mediated Lipotoxicity in Primary Hepatocytes by Countering Oxidative Stress

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Mayra Domínguez-Pérez

2016-01-01

Full Text Available Cholesterol overload in the liver has shown toxic effects by inducing the aggravation of nonalcoholic fatty liver disease to steatohepatitis and sensitizing to damage. Although the mechanism of damage is complex, it has been demonstrated that oxidative stress plays a prominent role in the process. In addition, we have proved that hepatocyte growth factor induces an antioxidant response in hepatic cells; in the present work we aimed to figure out the protective effect of this growth factor in hepatocytes overloaded with free cholesterol. Hepatocytes from mice fed with a high-cholesterol diet were treated or not with HGF, reactive oxygen species present in cholesterol overloaded hepatocytes significantly decreased, and this effect was particularly associated with the increase in glutathione and related enzymes, such as γ-gamma glutamyl cysteine synthetase, GSH peroxidase, and GSH-S-transferase. Our data clearly indicate that HGF displays an antioxidant response by inducing the glutathione-related protection system.

Assessment of hepatocyte and kupffer cell function using Tc-99m DISIDA/Tc-99m tin colloid in thioacetamide-induced liver injury

International Nuclear Information System (INIS)

Ahn, B. C.; Chun, K. A.; Lee, J.; Lee, K. B.

1997-01-01

Toxic liver injury is not unusual in clinical field and liver biopsy is one of the most accurate method to define the severity of liver injury. But occasionally, it is impossible to obtain liver tissue in patients with acute toxic liver injury. The aim of this study is to evaluate the possibility of liver scintigraphy with Tc-99m DISIDA or Tc-99m tin colloid as a non-invasive tool in predicting functional status of hepatocyte and Kupffer cell and severity of liver injury. Intraperitoneal injection of thioacetamide was performed to make acute liver injury in mice and rats, and liver status was assessed by pathologic specimen and scintigraphic methods. Scintigraphic evaluation were performed by biodistribution of Tc-99m DISIDA or Tc-99m tin colloid in thioacetamide-treated mice. Liver time-activity curves were generated. Comparison between histologic data and scintigraphic data was done with SAS program. Thioacetamide-treated mice demonstrated hepatocyte necrosis in histologic examination and low liver/blood uptake ratios in biodistribution studies using both radiotracers. Biodistribution study using Tc-99m tin colloid revealed increased lung radioactivity in thioacetamide-treated mice. Twenty-four hours after thioacetamide administration, thioacetamide-treated rats demonstrated maximal hepatocyte necrosis and inflammation in histologic finding and delayed maximal uptake time (Tmax) and prolonged half time (T 1/2 ) of liver time-activity curve in liver scintigraphy. Histologic results and scintigraphic data were well correlated, and these two scintigraphic parameters (Tmax T 1/2 ) seemed to be good predictors of histologic change of liver. These data showed that liver injury could be assessed by non-invasive scintigraphic study in rat and mouse. This experimental study might be used as a animal model to evaluate the liver protecting drugs, and this scintigraphic study could be applied to acute toxic hepatitis for assessment of liver status in men

Factor VIIa binding and internalization in hepatocytes

DEFF Research Database (Denmark)

Hjortoe, G; Sorensen, B B; Petersen, L C

2005-01-01

The liver is believed to be the primary clearance organ for coagulation proteases, including factor VIIa (FVIIa). However, at present, clearance mechanisms for FVIIa in liver are unknown. To obtain information on the FVIIa clearance mechanism, we investigated the binding and internalization...... no effect. HEPG2 cells internalized FVIIa with a rate of 10 fmol 10(-5) cells h(-1). In contrast to HEPG2 cells, FVIIa binding to primary rat hepatocytes was completely independent of TF, and excess unlabeled FVIIa partly reduced the binding of 125I-FVIIa to rat hepatocytes. Further, compared with HEPG2...... cells, three- to fourfold more FVIIa bound to rat primary hepatocytes, and the bound FVIIa was internalized at a faster rate. Similar FVIIa binding and internalization profiles were observed in primary human hepatocytes. Plasma inhibitors had no effect on FVIIa binding and internalization in hepatocytes...

Mechanisms of acetaminophen-induced cell death in primary human hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Xie, Yuchao; McGill, Mitchell R.; Dorko, Kenneth [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Kumer, Sean C.; Schmitt, Timothy M.; Forster, Jameson [Department of Surgery, University of Kansas Medical Center, Kansas City, KS 66160 (United States); Jaeschke, Hartmut, E-mail: hjaeschke@kumc.edu [Department of Pharmacology, Toxicology and Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160 (United States)

2014-09-15

Acetaminophen (APAP) overdose is the most prevalent cause of drug-induced liver injury in western countries. Numerous studies have been conducted to investigate the mechanisms of injury after APAP overdose in various animal models; however, the importance of these mechanisms for humans remains unclear. Here we investigated APAP hepatotoxicity using freshly isolated primary human hepatocytes (PHH) from either donor livers or liver resections. PHH were exposed to 5 mM, 10 mM or 20 mM APAP over a period of 48 h and multiple parameters were assessed. APAP dose-dependently induced significant hepatocyte necrosis starting from 24 h, which correlated with the clinical onset of human liver injury after APAP overdose. Interestingly, cellular glutathione was depleted rapidly during the first 3 h. APAP also resulted in early formation of APAP-protein adducts (measured in whole cell lysate and in mitochondria) and mitochondrial dysfunction, indicated by the loss of mitochondrial membrane potential after 12 h. Furthermore, APAP time-dependently triggered c-Jun N-terminal kinase (JNK) activation in the cytosol and translocation of phospho-JNK to the mitochondria. Both co-treatment and post-treatment (3 h) with the JNK inhibitor SP600125 reduced JNK activation and significantly attenuated cell death at 24 h and 48 h after APAP. The clinical antidote N-acetylcysteine offered almost complete protection even if administered 6 h after APAP and a partial protection when given at 15 h. Conclusion: These data highlight important mechanistic events in APAP toxicity in PHH and indicate a critical role of JNK in the progression of injury after APAP in humans. The JNK pathway may represent a therapeutic target in the clinic. - Highlights: • APAP reproducibly causes cell death in freshly isolated primary human hepatocytes. • APAP induces adduct formation, JNK activation and mitochondrial dysfunction in PHH. • Mitochondrial adducts and JNK translocation are delayed in PHH compared to

Selective insulin resistance in hepatocyte senescence

International Nuclear Information System (INIS)

Aravinthan, Aloysious; Challis, Benjamin; Shannon, Nicholas; Hoare, Matthew; Heaney, Judith; Alexander, Graeme J.M.

2015-01-01

Insulin resistance has been described in association with chronic liver disease for decades. Hepatocyte senescence has been demonstrated in chronic liver disease and as many as 80% of hepatocytes show a senescent phenotype in advanced liver disease. The aim of this study was to understand the role of hepatocyte senescence in the development of insulin resistance. Senescence was induced in HepG2 cells via oxidative stress. The insulin metabolic pathway was studied in control and senescent cells following insulin stimulation. GLUT2 and GLUT4 expressions were studied in HepG2 cells and human liver tissue. Further, GLUT2 and GLUT4 expressions were studied in three independent chronic liver disease cohorts. Signalling impairment distal to Akt in phosphorylation of AS160 and FoxO1 was evident in senescent HepG2 cells. Persistent nuclear localisation of FoxO1 was demonstrated in senescent cells despite insulin stimulation. Increased GLUT4 and decreased GLUT2 expressions were evident in senescent cells, human cirrhotic liver tissue and publically available liver disease datasets. Changes in GLUT expressions were associated with a poor clinical prognosis. In conclusion, selective insulin resistance is evident in senescent HepG2 cells and changes in GLUT expressions can be used as surrogate markers of hepatocyte senescence. - Highlights: • Senescent hepatocytes demonstrate selective insulin resistance. • GLUT changes act as markers of hepatocyte senescence and have prognostic value. • Study offers insight into long noticed intimacy of cirrhosis and insulin resistance

Selective insulin resistance in hepatocyte senescence

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Aravinthan, Aloysious [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Challis, Benjamin [Institute of Metabolic Sciences, University of Cambridge, Cambridge (United Kingdom); Shannon, Nicholas [Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Hoare, Matthew [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Cancer Research UK Cambridge Institute, Cambridge (United Kingdom); Heaney, Judith [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom); Foundation for Liver Research, Institute of Hepatology, London (United Kingdom); Alexander, Graeme J.M., E-mail: gja1000@doctors.org.uk [Division of Gastroenterology and Hepatology, Department of Medicine, University of Cambridge, Cambridge (United Kingdom)

2015-02-01

Insulin resistance has been described in association with chronic liver disease for decades. Hepatocyte senescence has been demonstrated in chronic liver disease and as many as 80% of hepatocytes show a senescent phenotype in advanced liver disease. The aim of this study was to understand the role of hepatocyte senescence in the development of insulin resistance. Senescence was induced in HepG2 cells via oxidative stress. The insulin metabolic pathway was studied in control and senescent cells following insulin stimulation. GLUT2 and GLUT4 expressions were studied in HepG2 cells and human liver tissue. Further, GLUT2 and GLUT4 expressions were studied in three independent chronic liver disease cohorts. Signalling impairment distal to Akt in phosphorylation of AS160 and FoxO1 was evident in senescent HepG2 cells. Persistent nuclear localisation of FoxO1 was demonstrated in senescent cells despite insulin stimulation. Increased GLUT4 and decreased GLUT2 expressions were evident in senescent cells, human cirrhotic liver tissue and publically available liver disease datasets. Changes in GLUT expressions were associated with a poor clinical prognosis. In conclusion, selective insulin resistance is evident in senescent HepG2 cells and changes in GLUT expressions can be used as surrogate markers of hepatocyte senescence. - Highlights: • Senescent hepatocytes demonstrate selective insulin resistance. • GLUT changes act as markers of hepatocyte senescence and have prognostic value. • Study offers insight into long noticed intimacy of cirrhosis and insulin resistance.

Targeted deletion of hepatocyte Ikkβ confers growth advantages

International Nuclear Information System (INIS)

Koch, Katherine S.; Maeda, Shin; He, Guobin; Karin, Michael; Leffert, Hyam L.

2009-01-01

Mice lacking hepatocyte IKKβ (Ikkβ Δhep ) are defective in TNFα-activation of hepatocellular transcription factor NF-κB, and highly susceptible to hepatotoxicity. Following diethylnitrosamine (DEN) exposure, Ikkβ Δhep mice develop more hepatocellular carcinoma (HCC) than control mice due partly to enhanced DEN-induced hepatocyte death. Here we show that Ikkβ Δhep hepatocytes display growth advantages over normal hepatocytes consisting of precocious PCNA and cyclin D1 expression during liver regeneration (shortened hepatocyte G 0 → G 1 transitions), and enhanced recovery efficiency, cyclin D1 expression and cell proliferation after plating. Ex vivo deletion of Ikkβ also accelerates hepatocyte growth. Ikkβ Δhep hepatocyte proliferative responses show heightened sensitivity to TGFα and TNFα, and heightened expression of fibronectin, collagens I/III, nidogen, β-actin and integrin β1 mRNAs. These findings suggest that altered mitogen signaling and expression of extracellular matrix and its associated components underlie growth advantages. Increased HCC development in Ikkβ Δhep mice may also be caused by growth advantages of surviving Ikkβ-deleted hepatocytes.

Potential etiopathogenesis of seventh day syndrome following living donor liver transplantation: ischemia of the graft?

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Lan, Xiang; Li, Bo; Wang, Xiao-Fei; Wei, Yong-Gang; Yan, Lu-Nan; Zhao, Ji-Chun

2010-02-01

Seventh-day syndrome (7DS) is an early serious complication following liver transplantation with a high mortality because of its unknown etiopathogenesis. This study aimed to analyze the potential etiopathogenesis of 7DS. A retrospective analysis of 98 consecutive living donor liver transplants performed from 2001 to 2007 at our center revealed that 5 patients had suffered from 7DS; their age, MELD score, portal vein inflow and other parameters were compared with those of the other recipients. The 5 patients showed common features: (a) initial uneventful recovery, and a dramatic rise of serum liver enzyme levels 1 to 2 weeks later; (b) decreased inflow in the portal vein accompanied by augmentation of serum creatinine and urea nitrogen level; and (c) serial liver biopsy findings of apoptosis and ischemic necrosis of hepatocytes. Four of the 5 patients died. Age, waiting time to transplantation, MELD score, operation time, cold ischemic time, portal interceptive time and diameter of the portal vein were not significantly different between the 2 groups, but a difference was found in the flow rate of the portal vein (t=3.234, P<0.001). The 5 patients suffered from a decreased portal vein inflow, ischemic liver necrosis, and renal failure. Hence, hypoperfusion of the liver graft was considered to be the etiopathogenesis of 7DS, for which, however sufficient evidence is lacking. More studies of 7DS are needed.

Hepatic ischemia-reperfusion injury: roles of Ca2+ and other intracellular mediators of impaired bile flow and hepatocyte damage.

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Nieuwenhuijs, Vincent B; De Bruijn, Menno T; Padbury, Robert T A; Barritt, Gregory J

2006-06-01

Liver resection and liver transplantation have been successful in the treatment of liver tumors and end-stage liver disease. This success has led to an expansion in the pool of patients potentially treatable by liver surgery and, in the case of transplantation, to a shortage of liver donors. At present, there are significant numbers of potential candidates for liver resection and liver donation who have fatty livers, are aged, or have livers damaged by chemotherapy. All of these are at high risk for ischemic reperfusion (IR) injury. The aims of this review are to assess current knowledge of the clinical effectiveness of ischemic preconditioning and intermittent ischemia in reducing IR damage in liver surgery; to evaluate the use of bile flow as a sensitive indicator of IR liver damage; and to analyze the molecular mechanisms, especially intracellular Ca2+, involved in IR injury and ischemic preconditioning. It is concluded that bile flow is a sensitive indicator of IR injury. Together with reactive oxygen species (ROS) and other extracellular and intracellular signaling molecules, intracellular Ca2+ in hepatocytes plays a key role in the normal regulation of bile flow and in IR-induced injury and cell death. Ischemic preconditioning is an effective strategy to reduce IR injury but there is considerable scope for improvement, especially in patients with fatty and aged livers. The development of effective new strategies to reduce IR injury will depend on improved understanding of the molecular mechanisms involved, especially by gaining a better perspective of the relative importance of the various intrahepatocyte signaling pathways involved.

Hepatitis isquémica Ischemic hepatitis

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Marcos Amuchástegui (h

2006-10-01

Full Text Available La hepatitis isquémica es una complicación sumamente infrecuente de cirugía cardiovascular. Las biopsias muestran necrosis centrolobulillar. El término de "hepatitis" fue propuesto debido al aumento de transaminasas similar a aquellas de origen infeccioso, e "isquémica" por falla en la perfusión hepática. Posteriormente se definió el término de hepatitis isquémica como cuadro de elevación aguda y reversible (dentro de las 72 horas de transaminasas de hasta 20 veces el valor normal, asociado a trastornos en la perfusión hepática, luego de haber excluido otras causas de hepatitis aguda o daño hepatocelular. Se describe el caso de un paciente de 53 años que consulta por dolor epigástrico de 12 h de evolución sin fiebre, náuseas ni vómitos, resistente a la medicación. Tenía antecedentes inmediatos de reemplazo de válvula aórtica, y estaba anticoagulado. Evolucionó con shock y fallo multiorgánico. El examen evidenció marcada ictericia y signos de taponamiento pericárdico, asociado a un aumento considerable de enzimas hepáticas. Un ecocardiograma informó signos de taponamiento cardíaco y ausencia de disección aórtica. Se decidió pericardiocentesis, extrayéndose 970 cc. de líquido sanguinolento, y hemodiálisis, con notable mejoría de su estado hemodinámico. Los valores enzimáticos disminuyeron. Los marcadores virales fueron negativos.Ischemic hepatitis is an uncommon cardiovascular surgery complication. Hepatic biopsies show centrolobulillar necrosis. The term "hepatitis" was proposed because of a raise in hepatic enzymes similar with infectious disease, and "ischemic" because of failure in hepatic perfusion. Ischemic hepatitis was then defined as an acute and reversible elevation of hepatic enzymes (within 72 h, associated with disturbance in hepatic perfusion after excluding other causes of acute hepatitis. A 53 year-old male presented complaining of a 12 h epigastric pain, without nausea or vomiting, resistant

Avascular Necrosis

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... Financial Reports Watchdog Ratings Feedback Contact Select Page Avascular Necrosis Home > Cancer Resources > Late Effects of Treatment > Avascular Necrosis Avascular necrosis (AVN) is a disorder resulting from ...

Hepatocyte polyploidization and its association with pathophysiological processes.

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Wang, Min-Jun; Chen, Fei; Lau, Joseph T Y; Hu, Yi-Ping

2017-05-18

A characteristic cellular feature of the mammalian liver is the progressive polyploidization of the hepatocytes, where individual cells acquire more than two sets of chromosomes. Polyploidization results from cytokinesis failure that takes place progressively during the course of postnatal development. The proportion of polyploidy also increases with the aging process or with cellular stress such as surgical resection, toxic stimulation, metabolic overload, or oxidative damage, to involve as much as 90% of the hepatocytes in mice and 40% in humans. Hepatocyte polyploidization is generally considered an indicator of terminal differentiation and cellular senescence, and related to the dysfunction of insulin and p53/p21 signaling pathways. Interestingly, the high prevalence of hepatocyte polyploidization in the aged mouse liver can be reversed when the senescent hepatocytes are serially transplanted into young mouse livers. Here we review the current knowledge on the mechanism of hepatocytes polyploidization during postnatal growth, aging, and liver diseases. The biologic significance of polyploidization in senescent reversal, within the context of new ways to think of liver aging and liver diseases is considered.

Integrin-linked kinase is involved in matrix-induced hepatocyte differentiation

International Nuclear Information System (INIS)

Gkretsi, Vasiliki; Bowen, William C.; Yang, Yu; Wu, Chuanyue; Michalopoulos, George K.

2007-01-01

Hepatocytes have restricted proliferative capacity in culture and when cultured without matrix, lose the hepatocyte-specific gene expression and characteristic cellular micro-architecture. Overlay of matrix-preparations on de-differentiated hepatocytes restores differentiation. Integrin-linked kinase (ILK) is a cell-matrix-adhesion protein crucial in fundamental processes such as differentiation and survival. In this study, we investigated the role of ILK, and its binding partners PINCH, α-parvin, and Mig-2 in matrix-induced hepatocyte differentiation. We report here that ILK is present in the liver and localizes at cell-matrix adhesions of cultured hepatocytes. We also show that ILK, PINCH, α-parvin, and Mig-2 expression level is dramatically reduced in the re-differentiated hepatocytes. Interestingly, hepatocytes lacking ILK undergo matrix-induced differentiation but their differentiation is incomplete, as judged by monitoring cell morphology and production of albumin. Our results show that ILK and cell-matrix adhesion proteins play an important role in the process of matrix-induced hepatocyte differentiation

Advances in gene therapy and early imaging monitoring for avascular necrosis of the femoral head

International Nuclear Information System (INIS)

Wang Peng; Lan Xiaoli; Zhang Yongxue; Qi Hongyan

2012-01-01

Gene therapy is a method that transfers foreign gene to target cells, so as to correct or compensate the disease which is caused by the gene defects and abnormalities. As a new technology, gene therapy has been used in many fields, such as cancer, cardiovascular and nervous system disease, and it brings some hope for patients with difficult and complicated disease. Avascular necrosis of femoral head is a refractory and common disease in clinical, but the traditional surgery therapy and conservative treatment both have many shortcomings,and the effect is unsatisfactory. As a new technology,gene therapy showed bright future in orthopedics ischemic disease, and its potential feasibility has been confirmed by many animal experiments. This article focuses on the research progress of gene therapy and early monitoring in the avascular necrosis of the femoral head. (authors)

Long-term culture and expansion of primary human hepatocytes

NARCIS (Netherlands)

Levy, G.; Bomze, D.; Heinz, S.; Ramachandran, S.D.; Noerenberg, A.; Cohen, M.; Shibolet, O.; Sklan, E.; Braspenning, J.C.; Nahmias, Y.

2015-01-01

Hepatocytes have a critical role in metabolism, but their study is limited by the inability to expand primary hepatocytes in vitro while maintaining proliferative capacity and metabolic function. Here we describe the oncostatin M (OSM)-dependent expansion of primary human hepatocytes by low

The Myocardial Unfolded Protein Response during Ischemic Cardiovascular Disease

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Edward B. Thorp

2012-01-01

Full Text Available Heart failure is a progressive and disabling disease. The incidence of heart failure is also on the rise, particularly in the elderly of industrialized societies. This is in part due to an increased ageing population, whom initially benefits from improved, and life-extending cardiovascular therapy, yet ultimately succumb to myocardial failure. A major cause of heart failure is ischemia secondary to the sequence of events that is dyslipidemia, atherosclerosis, and myocardial infarction. In the case of heart failure postmyocardial infarction, ischemia can lead to myocardial cell death by both necrosis and apoptosis. The extent of myocyte death postinfarction is associated with adverse cardiac remodeling that can contribute to progressive heart chamber dilation, ventricular wall thinning, and the onset of loss of cardiac function. In cardiomyocytes, recent studies indicate that myocardial ischemic injury activates the unfolded protein stress response (UPR and this is associated with increased apoptosis. This paper focuses on the intersection of ischemia, the UPR, and cell death in cardiomyocytes. Targeting of the myocardial UPR may prove to be a viable target for the prevention of myocyte cell loss and the progression of heart failure due to ischemic injury.

The potential of induced pluripotent stem cell derived hepatocytes.

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Hannoun, Zara; Steichen, Clara; Dianat, Noushin; Weber, Anne; Dubart-Kupperschmitt, Anne

2016-07-01

Orthotopic liver transplantation remains the only curative treatment for liver disease. However, the number of patients who die while on the waiting list (15%) has increased in recent years as a result of severe organ shortages; furthermore the incidence of liver disease is increasing worldwide. Clinical trials involving hepatocyte transplantation have provided encouraging results. However, transplanted cell function appears to often decline after several months, necessitating liver transplantation. The precise aetiology of the loss of cell function is not clear, but poor engraftment and immune-mediated loss appear to be important factors. Also, primary human hepatocytes (PHH) are not readily available, de-differentiate, and die rapidly in culture. Hepatocytes are available from other sources, such as tumour-derived human hepatocyte cell lines and immortalised human hepatocyte cell lines or porcine hepatocytes. However, all these cells suffer from various limitations such as reduced or differences in functions or risk of zoonotic infections. Due to their significant potential, one possible inexhaustible source of hepatocytes is through the directed differentiation of human induced pluripotent stem cells (hiPSCs). This review will discuss the potential applications and existing limitations of hiPSC-derived hepatocytes in regenerative medicine, drug screening, in vitro disease modelling and bioartificial livers. Copyright © 2016 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Metabolism of para-aminophenol by rat hepatocytes.

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Yan, Z; Nikelly, J G; Killmer, L; Tarloff, J B

2000-08-01

Autoxidation of para-aminophenol (PAP) has been proposed to account for the selective nephrotoxicity of this compound. However, other studies suggest that hepatic metabolites of PAP rather than the parent compound may be responsible for renal damage. These studies were designed to investigate PAP metabolism in isolated hepatocytes. We synthesized several proposed metabolites for analysis by HPLC/mass spectrometry and compared those results with HPLC/mass spectrometric analyses of metabolites found after incubating hepatocytes with PAP. Hepatocytes prepared from male Sprague-Dawley rats were incubated in Krebs-Henseleit buffer at 37 degrees C for 5 h with 2.3 mM PAP under an atmosphere of 5% CO2/95% O2. Aliquots were withdrawn at 0.1 h of incubation and then hourly through 5 h of incubation. Reactions were terminated by the addition of acetonitrile. Hepatocyte viability was unaltered with PAP present in the incubation medium. We found that hepatocytes converted PAP to two major metabolites (PAP-GSH conjugates and PAP-N-acetylcysteine conjugates) and several minor metabolites [PAP-O-glucuronide, acetaminophen (APAP), APAP-O-glucuronide, APAP-GSH conjugates, and 4-hydroxyformanilide]. Preincubating hepatoyctes with 1-aminobenzotriazole, an inhibitor of cytochromes P450, did not alter the pattern of PAP metabolism. In conclusion, we found that PAP was metabolized in hepatocytes predominantly to PAP-GSH conjugates and PAP-N-acetylcysteine conjugates in sufficient quantities to account for the nephrotoxicity of PAP.

Adrenomedulline improves ischemic left colonic anastomotic healing in an experimental rodent model

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Oguzhan Karatepe

2011-01-01

Full Text Available BACKGROUND: Leakage from colonic anastomosis is a major complication causing increased mortality and morbidity. Ischemia is a well-known cause of this event. This study was designed to investigate the effects of adrenomedullin on the healing of ischemic colon anastomosis in a rat model. METHODS: Standardized left colon resection 3 cm above the peritoneal reflection and colonic anastomosis were performed in 40 Wistar rats that were divided into four groups. To mimic ischemia, the mesocolon was ligated 2 cm from either side of the anastomosis in all of the groups. The control groups (1 and 2 received no further treatment. The experimental groups (3 and 4 received adrenomedullin treatment. Adrenomedullin therapy was started in the perioperative period in group 3 and 4 rats (the therapeutic groups. Group 1 and group 3 rats were sacrificed on postoperative day 3. Group 2 and group 4 rats were sacrificed on postoperative day 7. After careful relaparotomy, bursting pressure, hydroxyproline, malondialdehyde, interleukin 6, nitric oxide, vascular endothelial growth factor, and tumor necrosis factor alpha levels were measured. Histopathological characteristics of the anastomosis were analyzed. RESULTS: The group 3 animals had a significantly higher bursting pressure than group 1 (p<0.05. Hydroxyproline levels in group 1 were significantly lower than in group 3 (p<0.05. The mean bursting pressure was significantly different between group 2 and group 4 (p<0.05. Hydroxyproline levels in groups 3 and 4 were significantly increased by adrenomedullin therapy relative to the control groups (p<0.05. When all groups were compared, malondialdehyde and nitric oxide were significantly lower in the control groups (p<0.05. When vascular endothelial growth factor levels were compared, no statistically significant difference between groups was observed. Interleukin 6 and tumor necrosis factor alpha were significantly decreased by adrenomedullin therapy (p<0.05. The

Water and nonelectrolyte permeability of isolated rat hepatocytes

International Nuclear Information System (INIS)

Alpini, G.; Garrick, R.A.; Jones, M.J.; Nunes, R.; Tavoloni, N.

1986-01-01

We have measured the diffusive permeability coefficients of isolated rat hepatocytes to 3 H 2 O, [ 14 C]urea, [ 14 C]erythritol, [ 14 C]mannitol, [ 3 H]sucrose, and [ 3 H]inulin, employing a technique previously developed for erythrocytes (Redwood et al., J. Gen. Physiol 64:706-729, 1974). Diffusion coefficients for the tracer molecules were measured in packed hepatocytes, supernatant fluid, and intracellular medium (lysed hepatocytes) and were calculated assuming one-dimensional semi-infinite diffusion through a homogeneous medium. By applying the series-parallel pathway model, the following permeability coefficients (10(-5) cm/sec) for the hepatocyte plasma membrane were obtained. 3 H 2 O, 98.6 +/- 18.4; [ 14 C]urea, 18.2 +/- 5.3; [ 14 C]erythritol, 4.8 +/- 1.6; [ 14 C]mannitol, 3.1 +/- 1.4; [ 3 H]sucrose, 0; [ 3 H]inulin, 0. These results indicate that isolated rat hepatocytes are highly permeable to water and polar nonelectrolytes, when compared with other transporting epithelia. This relatively high cellular permeability is consistent with a model in which nonelectrolyte permeation is via an aqueous pathway of equivalent pore diameter of 8-12 A. The finding that [ 14 C]erythritol and [ 14 C]mannitol cross the hepatocyte plasma membrane indicates that these molecules enter the bile canaliculus through the transcellular route. Conversely, the failure of [ 3 H]sucrose and [ 3 H]inulin to permeate the hepatocyte in the isolated condition supports the concept that biliary entry of these large carbohydrates, at least that fraction which cannot be accounted for by a vesicular mechanism, must occur via the transjunctional shunt pathway

Characteristics of Misclassified CT Perfusion Ischemic Core in Patients with Acute Ischemic Stroke.

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Ralph R E G Geuskens

Full Text Available CT perfusion (CTP is used to estimate the extent of ischemic core and penumbra in patients with acute ischemic stroke. CTP reliability, however, is limited. This study aims to identify regions misclassified as ischemic core on CTP, using infarct on follow-up noncontrast CT. We aim to assess differences in volumetric and perfusion characteristics in these regions compared to areas that ended up as infarct on follow-up.This study included 35 patients with >100 mm brain coverage CTP. CTP processing was performed using Philips software (IntelliSpace 7.0. Final infarct was automatically segmented on follow-up noncontrast CT and used as reference. CTP and follow-up noncontrast CT image data were registered. This allowed classification of ischemic lesion agreement (core on CTP: rMTT≥145%, aCBV<2.0 ml/100g and infarct on follow-up noncontrast CT and misclassified ischemic core (core on CTP, not identified on follow-up noncontrast CT regions. False discovery ratio (FDR, defined as misclassified ischemic core volume divided by total CTP ischemic core volume, was calculated. Absolute and relative CTP parameters (CBV, CBF, and MTT were calculated for both misclassified CTP ischemic core and ischemic lesion agreement regions and compared using paired rank-sum tests.Median total CTP ischemic core volume was 49.7ml (IQR:29.9ml-132ml; median misclassified ischemic core volume was 30.4ml (IQR:20.9ml-77.0ml. Median FDR between patients was 62% (IQR:49%-80%. Median relative mean transit time was 243% (IQR:198%-289% and 342% (IQR:249%-432% for misclassified and ischemic lesion agreement regions, respectively. Median absolute cerebral blood volume was 1.59 (IQR:1.43-1.79 ml/100g (P<0.01 and 1.38 (IQR:1.15-1.49 ml/100g (P<0.01 for misclassified ischemic core and ischemic lesion agreement, respectively. All CTP parameter values differed significantly.For all patients a considerable region of the CTP ischemic core is misclassified. CTP parameters significantly

cAMP prevents TNF-induced apoptosis through inhibiting DISC complex formation in rat hepatocytes

International Nuclear Information System (INIS)

Bhattacharjee, Rajesh; Xiang, Wenpei; Wang, Yinna; Zhang, Xiaoying; Billiar, Timothy R.

2012-01-01

Highlights: ► cAMP blocks cell death induced by TNF and actinomycin D in cultured hepatocytes. ► cAMP blocks NF-κB activation induced by TNF and actinomycin D. ► cAMP blocks DISC formation following TNF and actinomycin D exposure. ► cAMP blocks TNF signaling at a proximal step. -- Abstract: Tumor necrosis factor α (TNF) is a pleiotropic proinflammatory cytokine that plays a role in immunity and the control of cell proliferation, cell differentiation, and apoptosis. The pleiotropic nature of TNF is due to the formation of different signaling complexes upon the binding of TNF to its receptor, TNF receptor type 1 (TNFR1). TNF induces apoptosis in various mammalian cells when the cells are co-treated with a transcription inhibitor like actinomycin D (ActD). When TNFR1 is activated, it recruits an adaptor protein, TNF receptor-associated protein with death domain (TRADD), through its cytoplasmic death effector domain (DED). TRADD, in turn, recruits other signaling proteins, including TNF receptor-associated protein 2 (TRAF2) and receptor-associated protein kinase (RIPK) 1, to form a complex. Subsequently, this complex combines with FADD and procaspase-8, converts into a death-inducing signaling complex (DISC) to induce apoptosis. Cyclic AMP (cAMP) is a second messenger that regulates various cellular processes such as cell proliferation, gene expression, and apoptosis. cAMP analogues are reported to act as anti-apoptotic agents in various cell types, including hepatocytes. We found that a cAMP analogue, dibutyryl cAMP (db-cAMP), inhibits TNF + ActD-induced apoptosis in rat hepatocytes. The protein kinase A (PKA) inhibitor KT-5720 reverses this inhibitory effect of cAMP on apoptosis. Cytoprotection by cAMP involves down-regulation of various apoptotic signal regulators like TRADD and FADD and inhibition of caspase-8 and caspase-3 cleavage. We also found that cAMP exerts its affect at the proximal level of TNF signaling by inhibiting the formation of the DISC

cAMP prevents TNF-induced apoptosis through inhibiting DISC complex formation in rat hepatocytes

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Bhattacharjee, Rajesh [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States); Xiang, Wenpei [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States); Family Planning Research Institute, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People' s Republic of China (China); Wang, Yinna [Vascular Medicine Institute, University of Pittsburgh School of Medicine, 10051-5A BST 3, 3501 Fifth Avenue, Pittsburgh, PA 15261 (United States); Zhang, Xiaoying [Department of Medicine/Endocrinology Division, University of Pittsburgh Medical Center, 200 Lothrop St., Pittsburgh, PA 15213 (United States); Billiar, Timothy R., E-mail: billiartr@upmc.edu [Department of Surgery, University of Pittsburgh Medical Center, Pittsburgh, PA 15213 (United States)

2012-06-22

Highlights: Black-Right-Pointing-Pointer cAMP blocks cell death induced by TNF and actinomycin D in cultured hepatocytes. Black-Right-Pointing-Pointer cAMP blocks NF-{kappa}B activation induced by TNF and actinomycin D. Black-Right-Pointing-Pointer cAMP blocks DISC formation following TNF and actinomycin D exposure. Black-Right-Pointing-Pointer cAMP blocks TNF signaling at a proximal step. -- Abstract: Tumor necrosis factor {alpha} (TNF) is a pleiotropic proinflammatory cytokine that plays a role in immunity and the control of cell proliferation, cell differentiation, and apoptosis. The pleiotropic nature of TNF is due to the formation of different signaling complexes upon the binding of TNF to its receptor, TNF receptor type 1 (TNFR1). TNF induces apoptosis in various mammalian cells when the cells are co-treated with a transcription inhibitor like actinomycin D (ActD). When TNFR1 is activated, it recruits an adaptor protein, TNF receptor-associated protein with death domain (TRADD), through its cytoplasmic death effector domain (DED). TRADD, in turn, recruits other signaling proteins, including TNF receptor-associated protein 2 (TRAF2) and receptor-associated protein kinase (RIPK) 1, to form a complex. Subsequently, this complex combines with FADD and procaspase-8, converts into a death-inducing signaling complex (DISC) to induce apoptosis. Cyclic AMP (cAMP) is a second messenger that regulates various cellular processes such as cell proliferation, gene expression, and apoptosis. cAMP analogues are reported to act as anti-apoptotic agents in various cell types, including hepatocytes. We found that a cAMP analogue, dibutyryl cAMP (db-cAMP), inhibits TNF + ActD-induced apoptosis in rat hepatocytes. The protein kinase A (PKA) inhibitor KT-5720 reverses this inhibitory effect of cAMP on apoptosis. Cytoprotection by cAMP involves down-regulation of various apoptotic signal regulators like TRADD and FADD and inhibition of caspase-8 and caspase-3 cleavage. We also found

Transcriptome of extracellular vesicles released by hepatocytes.

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Felix Royo

Full Text Available The discovery that the cells communicate through emission of vesicles has opened new opportunities for better understanding of physiological and pathological mechanisms. This discovery also provides a novel source for non-invasive disease biomarker research. Our group has previously reported that hepatocytes release extracellular vesicles with protein content reflecting the cell-type of origin. Here, we show that the extracellular vesicles released by hepatocytes also carry RNA. We report the messenger RNA composition of extracellular vesicles released in two non-tumoral hepatic models: primary culture of rat hepatocytes and a progenitor cell line obtained from a mouse foetal liver. We describe different subpopulations of extracellular vesicles with different densities and protein and RNA content. We also show that the RNA cargo of extracellular vesicles released by primary hepatocytes can be transferred to rat liver stellate-like cells and promote their activation. Finally, we provide in vitro and in vivo evidence that liver-damaging drugs galactosamine, acetaminophen, and diclofenac modify the RNA content of these vesicles. To summarize, we show that the extracellular vesicles secreted by hepatocytes contain various RNAs. These vesicles, likely to be involved in the activation of stellate cells, might become a new source for non-invasive identification of the liver toxicity markers.

Inhibition of hepatocyte gap junctional intercellular communication by tumor promoters

International Nuclear Information System (INIS)

Ruch, R.J.

1988-01-01

The mechanisms by which tumor promoters enhance neoplasia are poorly understood. One effect common to most tumor promoters is their ability to inhibit the cell-to-cell exchange of small molecules and ions through gap junctions, i.e., gap junctional intercellular communication (IC). IC maybe necessary for normal growth control and the loss of IC may predispose cells to enhanced growth. In the present studies, the effects of liver tumor promoters and other agents on IC between rodent hepatocytes in primary culture has been studied. IC was detected between hepatocytes: (1) autoradiographically following the passage and incorporation of [5- 3 H]uridine nucleotides from pre-labeled donor hepatocytes to non-labeled, adjacent recipient hepatocytes and (2) by fluorescence microscopy after microinjection of fluorescent Lucifer Yellow CH dye into hepatocytes and visualizing dye spread into adjacent hepatocytes

Whole-body γ-irradiation decelerates rat hepatocyte polyploidization.

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Ikhtiar, Adnan M

2015-07-01

To characterize hepatocyte polyploidization induced by intermediate dose of γ-ray. Male Wistar strain rats were whole-body irradiated (WBI) with 2 Gy of γ-ray at the age of 1 month, and 5-6 rats were sacrificed monthly at 0-25 months after irradiation. The nuclear DNA content of individual hepatocytes was measured by flow cytometry, then hepatocytes were classified into various ploidy classes. Survival percentage, after exposure up to the end of the study, did not indicate any differences between the irradiated groups and controls. The degree of polyploidization in hepatocytes of irradiated rats, was significantly lower than that for the control after 1 month of exposure, and it continued to be lower after up to 8 months. Thereafter, the degree of polyploidization in the irradiated group slowly returned to the control level when the irradiated rats reached the age of 10 months. Intermediate dose of ionizing radiation, in contrast to high doses, decelerate hepatocyte polyploidization, which may coincides with the hypothesis of the beneficial effects of low doses of ionizing radiation.

Fas Ligand Has a Greater Impact than TNF-α on Apoptosis and Inflammation in Ischemic Acute Kidney Injury

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Kengo Furuichi

2012-02-01

Full Text Available Background/Aim: Fas ligand (FasL and tumor necrosis factor (TNF-α are major pro-apoptotic molecules and also induce inflammation through cytokine and chemokine production. Although precise intracellular mechanisms of action have been reported for each molecule, the differential impact of these molecules on kidney injury in vivo still requires clarification. Methods: We explored the differential impact of FasL and TNF-α upon apoptosis and inflammation in ischemic acute kidney injury using neutralizing anti-FasL antibodies and TNF-α receptor 1 (TNFR1-deficient mice. Results: TNFR1 deficiency was associated with a lesser anti-inflammatory effect upon leukocyte infiltration and tubular necrosis than treatment with anti-FasL antibody. Furthermore, the number of TUNEL-positive cells was significantly reduced in anti-FasL antibody-treated mice, whereas it was only partially diminished in TNFR1-deficient mice. In vitro studies confirmed these findings. FasL administration induced both apoptosis and cytokine/chemokine production from cultured tubular epithelial cells. However, TNF-α had a limited effect upon tubular epithelial cells. Conclusion: In ischemic acute kidney injury, FasL has a greater impact than TNF-α on the apoptosis and inflammatory reaction through cytokine/chemokine production from tubular epithelial cells.

Property of hepatitis B virus replication in Tupaia belangeri hepatocytes

International Nuclear Information System (INIS)

Sanada, Takahiro; Tsukiyama-Kohara, Kyoko; Yamamoto, Naoki; Ezzikouri, Sayeh; Benjelloun, Soumaya; Murakami, Shuko; Tanaka, Yasuhito; Tateno, Chise; Kohara, Michinori

2016-01-01

The northern treeshrew (Tupaia belangeri) has been reported to be an effective candidate for animal infection model with hepatitis B virus (HBV). The objective of our study was to analyze the growth characteristics of HBV in tupaia hepatocytes and the host response to HBV infection. We established primary tupaia hepatocytes (3–6-week old tupaia) and infected them with HBV genotypes A, B and C, and all the genotypes proliferated as well as those in human primary hepatocytes (>10"5 copies/ml in culture supernatant). We next generated a chimeric mouse with tupaia liver by transplantation of tupaia primary hepatocytes to urokinase-type plasminogen activator cDNA (cDNA-uPA)/severe combined immunodeficient (SCID) mice and the replacement ratio with tupaia hepatocytes was found to be more than 95%. Infection of chimeric mice with HBV (genotypes B, C, and D) resulted in HBV-DNA level of 10"4-10"6 copies/ml after 8 weeks of infection, which were almost similar to that in humanized chimeric mouse. In contrast, serum HBV level in adult tupaia (1-year-old tupaia) was quite low (<10"3 copies/ml). Understanding the differences in the response to HBV infection in primary tupaia hepatocytes, chimeric mouse, and adult tupaia will contribute to elucidating the mechanism of persistent HBV infection and viral eradication. Thus, T. belangeri was found to be efficient for studying the host response to HBV infection, thereby providing novel insight into the pathogenesis of HBV. - Highlights: • Primary hepatocytes were established from tupaia that is a novel HBV infection model. • Tupaia primary hepatocytes were susceptible for HBV infection. • The immunodeficient chimeric mice with tupaia hepatocytes were established. • The chimeric mice with tupaia hepatocytes were susceptible for HBV infection.

Property of hepatitis B virus replication in Tupaia belangeri hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Sanada, Takahiro [Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506 (Japan); Tsukiyama-Kohara, Kyoko, E-mail: kkohara@vet.kagoshima-u.ac.jp [Transboundary Animal Diseases Centre, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24, Korimoto, Kagoshima-city, Kagoshima 890-0065 (Japan); Laboratory of Animal Hygiene, Joint Faculty of Veterinary Medicine, Kagoshima University, 1-21-24, Korimoto, Kagoshima, Kagoshima 890-0065 (Japan); Yamamoto, Naoki [Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506 (Japan); Ezzikouri, Sayeh; Benjelloun, Soumaya [Viral Hepatitis Laboratory, Virology Unit, Institut Pasteur du Maroc, 1, Louis Pasteur, Casablanca 20360 (Morocco); Murakami, Shuko; Tanaka, Yasuhito [Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Kawasumi 1, Mizuho-ku, Nagoya, Aichi 467-8601 (Japan); Tateno, Chise [PhoenixBio Co. Ltd., 3-4-1, Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046 (Japan); Kohara, Michinori, E-mail: kohara-mc@igakuken.or.jp [Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6, Kamikitazawa, Setagaya-ku, Tokyo 156-8506 (Japan)

2016-01-08

The northern treeshrew (Tupaia belangeri) has been reported to be an effective candidate for animal infection model with hepatitis B virus (HBV). The objective of our study was to analyze the growth characteristics of HBV in tupaia hepatocytes and the host response to HBV infection. We established primary tupaia hepatocytes (3–6-week old tupaia) and infected them with HBV genotypes A, B and C, and all the genotypes proliferated as well as those in human primary hepatocytes (>10{sup 5} copies/ml in culture supernatant). We next generated a chimeric mouse with tupaia liver by transplantation of tupaia primary hepatocytes to urokinase-type plasminogen activator cDNA (cDNA-uPA)/severe combined immunodeficient (SCID) mice and the replacement ratio with tupaia hepatocytes was found to be more than 95%. Infection of chimeric mice with HBV (genotypes B, C, and D) resulted in HBV-DNA level of 10{sup 4}-10{sup 6} copies/ml after 8 weeks of infection, which were almost similar to that in humanized chimeric mouse. In contrast, serum HBV level in adult tupaia (1-year-old tupaia) was quite low (<10{sup 3} copies/ml). Understanding the differences in the response to HBV infection in primary tupaia hepatocytes, chimeric mouse, and adult tupaia will contribute to elucidating the mechanism of persistent HBV infection and viral eradication. Thus, T. belangeri was found to be efficient for studying the host response to HBV infection, thereby providing novel insight into the pathogenesis of HBV. - Highlights: • Primary hepatocytes were established from tupaia that is a novel HBV infection model. • Tupaia primary hepatocytes were susceptible for HBV infection. • The immunodeficient chimeric mice with tupaia hepatocytes were established. • The chimeric mice with tupaia hepatocytes were susceptible for HBV infection.

Metabolic borderzone in acutely ischemic canine myocardium demonstrated by positron-CT (PCT)

International Nuclear Information System (INIS)

Schwaiger, M.; Hansen, H.; Selin, C.; Wittmer, S.; Barrio, J.; Schelbert, H.R.

1984-01-01

Acute coronary ligation in dogs results in an area of myocardial dysfunction that exceeds the area of subsequent necrosis suggesting the existence of an ischemic ''borderzone'' of reversibly injured myocardium. The authors tested this hypothesis in 9 closed chest dogs with C-11 plamitate (CPA) and serial PCT imaging after an LAD occlusion. Using a blood flow (MBF) image obtained with iv N-13 ammonia prior to CPA, regions of interest were assigned on the serial CPA cross-sectional images to the center (IC) and border (IB) of the ischemic segment and to control myocardium (CO). CPA uptake was closely related to MBF (r=0.88) implicating flow as a major determinant of CPA uptake. Clearance helftimes (T 1/2) and relative sizes (RS) of the early rapid phase on the C-11 tissue time activity curves were determined for IC, IB and CO. In IC, MBF, RS and T 1/2 were markedly depressed indicating impaired CPA utilization and oxidation. In IB, MBF was less than in CO though only insignificantly, while RS and T 1/2 were highly abnormal. The authors conclude that FFA metabolism in areas adjacent to ischemic segments but without significant MBF decreases in abnormal, presenting evidence for a metabolic borderzone which now can be identified noninvasively with positron emission tomography

Functional assessment of hepatocytes after transplantation into rat spleen

International Nuclear Information System (INIS)

Woods, R.J.; Fuller, B.J.; Attenburrow, V.D.; Nutt, L.H.; Hobbs, K.E.

1982-01-01

The retention of structural integrity and metabolic function by isolated hepatocytes after ectopic transplantation has been investigated in autografted rats. Rats were partially hepatectomized and isolated hepatocytes prepared from the excised liver lobes were implanted into their spleens. Histological examination of the spleens 7 or more weeks after implantation revealed aggregates of hepatocytes in the red pulp. Two tests of biochemical function were applied to the hepatocytes after transplantation. In the first the hepatobiliary imaging agent technetium-99m N-[N'-(2, 6-dimethylphenyl)carbamoylmethyl]iminodiacetic acid (99mTc HIDA), which was shown to be avidly taken up by isolated hepatocytes in vitro, was infused into the tail veins of autograft and control rats. Radioactivity accumulating in the spleens of autografted rats was markedly greater than that in controls implanted with lethally damaged cells or in nontransplanted rats. In the second the presence of bilirubin metabolites was sought in autograft spleens after intravenous infusion of bilirubin. Both mono- and diglucuronides of bilirubin were recovered from the spleens of autograft rats but no conjugates were recovered from the spleens of unoperated controls. We conclude that after autotransplantation isolated hepatocytes retain their morphology and at least some of their functional activities

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Billion-scale production of hepatocyte-like cells from human induced pluripotent stem cells.

Science.gov (United States)

Yamashita, Tomoki; Takayama, Kazuo; Sakurai, Fuminori; Mizuguchi, Hiroyuki

2018-02-19

Human induced pluripotent stem (iPS) cell-derived hepatocyte-like cells are expected to be utilized in drug screening and regenerative medicine. However, hepatocyte-like cells have not been fully used in such applications because it is difficult to produce such cells on a large scale. In this study, we tried to establish a method to mass produce hepatocyte-like cells using a three-dimensional (3D) cell culture bioreactor called the Rotary Cell Culture System (RCCS). RCCS enabled us to obtain homogenous hepatocyte-like cells on a billion scale (>10 9  cells). The gene expression levels of some hepatocyte markers (alpha-1 antitrypsin, cytochrome (CYP) 1A2, CYP2D6, and hepatocyte nuclear factor 4alpha) were higher in 3D-cultured hepatocyte-like cells than in 2D-cultured hepatocyte-like cells. This result suggests that RCCS could provide more suitable conditions for hepatocyte maturation than the conventional 2D cell culture conditions. In addition, more than 90% of hepatocyte-like cells were positive for albumin and could uptake low-density lipoprotein in the culture medium. We succeeded in the large-scale production of homogenous and functional hepatocyte-like cells from human iPS cells. This technology will be useful in drug screening and regenerative medicine, which require enormous numbers of hepatocyte-like cells. Copyright © 2018 Elsevier Inc. All rights reserved.

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Role of macrophages in the immune response to hepatocytes

International Nuclear Information System (INIS)

Bumgardner, G.L.; Chen, S.; Almond, S.P.; Ascher, N.L.; Payne, W.D.; Matas, A.J.

1990-01-01

The purpose of this study was to determine the role of host macrophages in the development of allospecific cytolytic T cells (allo-CTLs) in response to purified allogeneic MHC Class I+, Class II- hepatocytes in vivo in hepatocyte sponge matrix allografts (HC-SMA). Depletion of antigen-presenting cells (APCs) from responder splenocytes in mixed lymphocyte hepatocyte culture (MLHC) inhibits the development of allo-CTLs in response to purified hepatocytes. First the ability of sponge macrophages to function as accessory cells in indirect presentation of hepatocyte Class I antigen was tested in MLHC. We found that addition of irradiated sponge cells (a source of sponge macrophages) restored the development of allo-CTLs in MLHC depleted of responder APCs. Therefore, radioresistant sponge macrophages can function as accessory cells in MLHC. We next employed silica as an immunotherapy targeted against host macrophages and assessed the effect on development of allo-CTLs in HC-SMA. We found that local (intrasponge) silica treatment completely inhibited the development of allo-CTLs in HC-SMA. Combined local and systemic silica treatment resulted in inhibition of allocytotoxicity comparable to local silica treatment alone in the doses tested. We conclude that host macrophages which infiltrate HC-SMA can function as accessory cells in vitro in MLHC and that both infiltrating host macrophages and lymphocytes participate in the development of an alloimmune response to purified hepatocytes in vivo. This interaction may involve indirect antigen presentation of hepatocyte Class I antigen by macrophages to host lymphocytes which accumulate in HC-SMA

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High throughput micro-well generation of hepatocyte micro-aggregates for tissue engineering.

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Elien Gevaert

Full Text Available The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the high throughput generation of hepatocyte aggregates, uniform in size. In our study we observed that aggregation of hepatocytes had a beneficial effect on the expression of certain hepatocyte specific markers. Moreover we observed that the beneficial effect was dependent on the aggregate dimensions, indicating that aggregate parameters should be carefully considered. In a second part of the study, the selected aggregates were immobilized by encapsulation in methacrylamide-modified gelatin. Phenotype evaluations revealed that a stable hepatocyte phenotype could be maintained during 21 days when encapsulated in the hydrogel. In conclusion we have demonstrated the beneficial use of micro-well chips for hepatocyte aggregation and the size-dependent effects on hepatocyte phenotype. We also pointed out that methacrylamide-modified gelatin is suitable for the encapsulation of these aggregates.

High throughput micro-well generation of hepatocyte micro-aggregates for tissue engineering.

Science.gov (United States)

Gevaert, Elien; Dollé, Laurent; Billiet, Thomas; Dubruel, Peter; van Grunsven, Leo; van Apeldoorn, Aart; Cornelissen, Ria

2014-01-01

The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the high throughput generation of hepatocyte aggregates, uniform in size. In our study we observed that aggregation of hepatocytes had a beneficial effect on the expression of certain hepatocyte specific markers. Moreover we observed that the beneficial effect was dependent on the aggregate dimensions, indicating that aggregate parameters should be carefully considered. In a second part of the study, the selected aggregates were immobilized by encapsulation in methacrylamide-modified gelatin. Phenotype evaluations revealed that a stable hepatocyte phenotype could be maintained during 21 days when encapsulated in the hydrogel. In conclusion we have demonstrated the beneficial use of micro-well chips for hepatocyte aggregation and the size-dependent effects on hepatocyte phenotype. We also pointed out that methacrylamide-modified gelatin is suitable for the encapsulation of these aggregates.

Hepatocyte and keratinocyte growth factors and their receptors in human lung emphysema

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Marchal Joëlle

2005-10-01

Full Text Available Abstract Background Hepatocyte and keratinocyte growth factors are key growth factors in the process of alveolar repair. We hypothesized that excessive alveolar destruction observed in lung emphysema involves impaired expression of hepatocyte and keratinocyte growth factors or their respective receptors, c-met and keratinocyte growth factor receptor. The aim of our study was to compare the expression of hepatocyte and keratinocyte growth factors and their receptors in lung samples from 3 groups of patients: emphysema; smokers without emphysema and non-smokers without emphysema. Methods Hepatocyte and keratinocyte growth factor proteins were analysed by immunoassay and western blot; mRNA expression was measured by real time quantitative polymerase chain reaction. Results Hepatocyte and keratinocyte growth factors, c-met and keratinocyte growth factor receptor mRNA levels were similar in emphysema and non-emphysema patients. Hepatocyte growth factor mRNA correlated negatively with FEV1 and the FEV1/FVC ratio both in emphysema patients and in smokers with or without emphysema. Hepatocyte and keratinocyte growth factor protein concentrations were similar in all patients' groups. Conclusion The expression of hepatocyte and keratinocyte growth factors and their receptors is preserved in patients with lung emphysema as compared to patients without emphysema. Hepatocyte growth factor mRNA correlates with the severity of airflow obstruction in smokers.

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The synergetic effect of edaravone and borneol in the rat model of ischemic stroke.

Science.gov (United States)

Wu, Hai-Yin; Tang, Ying; Gao, Li-Yan; Sun, Wei-Xiang; Hua, Yao; Yang, Shi-Bao; Zhang, Zheng-Ping; Liao, Gao-Yong; Zhou, Qi-Gang; Luo, Chun-Xia; Zhu, Dong-Ya

2014-10-05

Free radical production contributes to the early ischemic response and the neuroinflammatory response to injury initiates the second wave of cell death following ischemic stroke. Edaravone is a free radical scavenger, and borneol has shown anti-inflammatory effect. We investigated the synergistic effect of these two drugs in the rat model of transient cerebral ischemia. Edaravone scavenged OH, NO and ONOO─ concentration-dependently, and borneol inhibited ischemia/reperfusion-induced tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2) expressions. In the rat model of transient cerebral ischemia and reperfusion, the combination of edaravone and borneol significantly ameliorated ischemic damage with an optimal proportion of 4:1. Emax (% inhibition) of edaravone, borneol and two drugs in combination was 55.7%, 65.8% and 74.3% respectively. ED50 of edaravone and borneol was 7.17 and 0.36 mg/kg respectively. When two drugs in combination, ED50 was 0.484 mg/kg, in which edaravone was 0.387 mg/kg (ineffective dose) and borneol was 0.097 mg/kg (ineffective dose). Combination index (CI)edaravone and borneol. The combination exhibited a therapeutic time window of 6h in ischemia/reperfusion model, and significantly ameliorated damages in permanent ischemia model. Moreover, two drugs in combination promoted long-term effect, including improved elemental vital signs, sensorimotor functions and spatial cognition. Our results suggest that the combination of edaravone and borneol have a synergistic effect for treating ischemic stroke. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of hepatocyte-derived microRNA-122 for diagnosis of acute and chronic hepatitis of dogs

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S. R. Eman

2018-05-01

Full Text Available Aim: This study was performed to evaluate the diagnostic value of hepatocyte-derived microRNA (miRNA-122 in acute and chronic hepatitis of dogs. Materials and Methods: A total of 26 dogs presented at Veterinary Teaching Hospital, Faculty of Veterinary Medicine, Cairo University, 16 dogs out of 26 showing clinical signs of hepatic insufficiency were subjected to clinical, ultrasonographic, hematobiochemical and ultrasound-guided fine-needle biopsy for cytological and histopathological investigations. On the basis of these results, 7 dogs out of 16 dogs were found to be suffering from acute hepatitis and 9 dogs suffering from chronic hepatitis. 10 clinically healthy dogs were kept as control. Serum hepatocyte-derived miRNA-122 was analyzed by real-time quantitative polymerase chain reaction in all dogs. Results: The dogs suffering from acute hepatitis manifested jaundice, vomiting, and depression while dogs with chronic hepatitis manifested anorexia, abdominal distension, weight loss, and melena. Hematological parameters showed normocytic normochromic anemia and thrombocytopenia in both acute and chronic hepatitis groups. Alanine aminotransferase (ALT, aspartate aminotransferase (AST, alkaline phosphatase (ALP, and total bilirubin were significantly higher than control values in acute hepatitis. In chronic hepatitis, total protein and albumin were significantly lower than control values with normal ALT, AST, ALP, and gamma-glutamyltransferase values. Ultrasonography revealed a diffuse decrease in hepatic echogenicity in acute hepatitis while the increase in hepatic echogenicity and anechoic ascetic fluid in chronic hepatitis. Cytology revealed hepatic vacuolar degeneration and histopathology revealed necrosis and apoptosis of hepatocyte in acute hepatitis while revealed massive fibrous tissue proliferation in hepatic parenchyma in chronic hepatitis. Serum miRNA-122 analysis, normalized for glyceraldehyde-3- phosphate dehydrogenase expression

Necrose isquêmica hepática e diabete melito: relato de caso Liver ischemic necrosis and diabetes mellitus: case report

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Ticiana Paes

2007-12-01

. Ultrasonografia abdominal não apresentou alterações significativas. Evoluiu com importante piora clínica, parada cardiorrespiratória e óbito. A necrópsia evidenciou múltiplas áreas de infarto hepático, trombose vascular, infarto esplênico, congestão visceral e aterosclerose de aorta e seus ramos e pâncreas normal. CONCLUSÕES: Os mecanismos de infarto hepático e esplênico neste caso não foram bem elucidados. Alguns fatores devem ter contribuído, tais como: desidratação e hipotensão devido a episódios de vômitos e febre que contribuem para diminuição do fluxo sanguíneo da veia porta e artéria hepática; o nível elevado de catecolaminas que ocorre em estado de hiperglicemia e cetoacidose metabólica pode induzir à vasoconstrição; aterosclerose difusa que é comumente vista em pacientes diabéticos e hipertensos. Este caso enfatiza a necessidade de investigar infarto hepático em pacientes diabéticos com cetonemia e com aumento de enzimas hepáticas. Anticoagulantes devem ser prontamente instituídos se houver trombose vascular.BACKGROUND AND OBJECTIVES: Hepatic infarction is characterized by parenchyma ischemic necrosis involving at least two acinis. It is extremely uncommon due to the arterial and portal venous blood supply. We report a case of a patient not know to have diabetes who developed massive areas of ischemic infarcts of the liver after episode of acutely diabetes decompensated. CASE REPORT: A 67 year-old hypertensive female who has been presenting, for the last 10 days, polydipsia, high urinary volume, visual and gait impairment, nausea and vomiting was admitted to the emergency room (ER. During the physical examination it was observed dehydration, skin discoloration, peripheral cyanosis, hypothermia, tachycardia, hypotension and mild diffuse abdominal pain. Admissional laboratory exams demonstrated total leukocytes: 16.800, Cr: 3.7, Ur: 167, Na: 133, K: 6.9, glucose: 561; arterial gasometry (O2 catheter: 2 L/min: pH: 6.93, pCO2: 12.1, pO2

Gel entrapment culture of rat hepatocytes for investigation of tetracycline-induced toxicity

International Nuclear Information System (INIS)

Shen Chong; Meng Qin; Schmelzer, Eva; Bader, Augustinus

2009-01-01

This paper aimed to explore three-dimensionally cultured hepatocytes for testing drug-induced nonalcoholic steatohepatitis. Gel entrapped rat hepatocytes were applied for investigation of the tetracycline-induced steatohepatitis, while hepatocyte monolayer was set as a control. The toxic responses of hepatocytes were systematically evaluated by measuring cell viability, liver-specific function, lipid accumulation, oxidative stress, adenosine triphosphate content and mitochondrial membrane potential. The results suggested that gel entrapped hepatocytes showed cell death after 96 h of tetracycline treatment at 25 μM which is equivalent to toxic serum concentration in rats, while hepatocyte monolayer showed cell death at a high dose of 200 μM. The concentration-dependent accumulation of lipid as well as mitochondrial damage were regarded as two early events for tetracycline hepatotoxicity in gel entrapment culture due to their detectability ahead of subsequent increase of oxidative stress and a final cell death. Furthermore, the potent protection of fenofibrate and fructose-1,6-diphosphate were evidenced in only gel entrapment culture with higher expressions on the genes related to β-oxidation than hepatocyte monolayer, suggesting the mediation of lipid metabolism and mitochondrial damage in tetracycline toxicity. Overall, gel entrapped hepatocytes in three-dimension reflected more of the tetracycline toxicity in vivo than hepatocyte monolayer and thus was suggested as a more relevant system for evaluating steatogenic drugs.

Glutathione depletion by valproic acid in sandwich-cultured rat hepatocytes: Role of biotransformation and temporal relationship with onset of toxicity

International Nuclear Information System (INIS)

Kiang, Tony K.L.; Teng Xiaowei; Surendradoss, Jayakumar; Karagiozov, Stoyan; Abbott, Frank S.; Chang, Thomas K.H.

2011-01-01

The present study was conducted in sandwich-cultured rat hepatocytes to investigate the chemical basis of glutathione (GSH) depletion by valproic acid (VPA) and evaluate the role of GSH depletion in VPA toxicity. Among the synthetic metabolites of VPA investigated, 4-ene-VPA and (E)-2,4-diene-VPA decreased cellular levels of total GSH, but only (E)-2,4-diene-VPA was more effective and more potent than the parent drug. The in situ generated, cytochrome P450-dependent 4-ene-VPA did not contribute to GSH depletion by VPA, as suggested by the experiment with a cytochrome P450 inhibitor, 1-aminobenzotriazole, to decrease the formation of this metabolite. In support of a role for metabolites, alpha-F-VPA and octanoic acid, which do not undergo biotransformation to form a 2,4-diene metabolite, CoA ester, or glucuronide, did not deplete GSH. A time course experiment showed that GSH depletion did not occur prior to the increase in 2',7'-dichlorofluorescein (a marker of oxidative stress), the decrease in [2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium] (WST-1) product formation (a marker of cell viability), or the increase in lactate dehydrogenase (LDH) release (a marker of necrosis) in VPA-treated hepatocytes. In conclusion, the cytochrome P450-mediated 4-ene-VPA pathway does not play a role in the in situ depletion of GSH by VPA, and GSH depletion is not an initiating event in VPA toxicity in sandwich-cultured rat hepatocytes.

TGFbeta Induces Binucleation/Polyploidization in Hepatocytes through a Src-Dependent Cytokinesis Failure.

Science.gov (United States)

De Santis Puzzonia, Marco; Cozzolino, Angela Maria; Grassi, Germana; Bisceglia, Francesca; Strippoli, Raffaele; Guarguaglini, Giulia; Citarella, Franca; Sacchetti, Benedetto; Tripodi, Marco; Marchetti, Alessandra; Amicone, Laura

2016-01-01

In all mammals, the adult liver shows binucleated as well as mononucleated polyploid hepatocytes. The hepatic polyploidization starts after birth with an extensive hepatocyte binucleation and generates hepatocytes of several ploidy classes. While the functional significance of hepatocyte polyploidy is becoming clearer, how it is triggered and maintained needs to be clarified. Aim of this study was to identify a major inducer of hepatocyte binucleation/polyploidization and the cellular and molecular mechanisms involved. We found that, among several cytokines analyzed, known to be involved in early liver development and/or mass control, TGFbeta1 was capable to induce, together with the expected morphological changes, binucleation in hepatocytes in culture. Most importantly, the pharmacological inhibition of TGFbeta signaling in healthy mice during weaning, when the physiological binucleation occurs, induced a significant decrease of hepatocyte binucleation rate, without affecting cell proliferation and hepatic index. The TGFbeta-induced hepatocyte binucleation resulted from a cytokinesis failure, as assessed by video microscopy, and is associated with a delocalization of the cytokinesis regulator RhoA-GTPase from the mid-body of dividing cells. The use of specific chemical inhibitors demonstrated that the observed events are Src-dependent. Finally, the restoration of a fully epithelial phenotype by TGFbeta withdrawal gave rise to a cell progeny capable to maintain the polyploid state. In conclusion, we identified TGFbeta as a major inducer of hepatocyte binucleation both in vitro and in vivo, thus ascribing a novel role to this pleiotropic cytokine. The production of binucleated/tetraploid hepatocytes is due to a cytokinesis failure controlled by the molecular axis TGFbeta/Src/RhoA.

A case of acute ischemic colitis after endovascular abdominal aortic aneurysm repair

Directory of Open Access Journals (Sweden)

Grigorios Voulalas

2016-01-01

Full Text Available Colonic ischemia is a recognized complication of either open or endovascular abdominal aortic aneurysm repair. The clinical difficulty in establishing the diagnosis, the severity of this complication and the patient's poor physiological status may lead to a fatal outcome. We presented a case of ischemic colitis in a patient with patent hypogastric arteries that occurred after an endovascular abdominal aortic aneurysm repair as well as a review of the available literature. The patient's preoperative, intraoperative and postoperative data were recorded. A thorough search through the Google data and Medline to review similar cases or any analyses that referred to ischemic colitis after endovascular abdominal aneurysm repair was conducted. A 76-year-old male was admitted to our department for an elective endovascular repair of an 8 cm in diameter abdominal aortic aneurysm. A Zenith bifurcation graft was implanted. The whole procedure was uneventful and the final angiogram showed an accurate deployment of the endograft without endoleaks and patency of both hypogastric arteries. During the 1st postoperative day, the patient developed symptoms of acute abdomen in combination with metabolic acidosis and oliguria. He underwent an exploratory laparotomy, which revealed necrosis of the sigmoid. A Hartmann's procedure was performed; the patient was transferred to the intensive care unit where he deceased after 24 h. Postoperative ischemic colitis has been described after open abdominal aneurysm repair. The description of this complication has been reported since the early phase of endovascular abdominal aneurysm repair development with a current incidence of 1.5%–3.0%. Possible mechanisms that may contribute to ischemic colitis in spite of the presence of patent hypogastric arteries include atheroembolization, shock, vasopressive drugs and inferior mesenteric artery occlusion.

The approach of ischemic colitis case followed by the lower gastrointesitnal bleeding

Directory of Open Access Journals (Sweden)

YUKSEL ALTINEL

2017-03-01

Full Text Available Colonic vascular ischemia is commonly seen in the descending colon and causes malnutrition and is to be commensurate with the duration of clinical myocardial ischemia. History of cerebrovascular disease, hypertension, with coronary hearth disease, 68-year-old female patient was followed for about 2 weeks with the occasional massive gastrointestinal bleeding complaint. After ceasing oral intake, fluid and electrolyte replacement and a broad-spectrum antibiotic therapy was established. Abdomen bowel wall thickening of the colon in continuity in the CT results were observed with the open SMA SMV. Follow-up colonoscopy was performed from the dentate line at 5 cm starting hemorrhagic and ischemic segments was seen as an area of ​​about 40 cm long. After hemodynamic deterioration she was underwent emergency surgery because of abdominal sensitivity increase. Hartman procedure was performed. Postop pneumonia and pulmonary embolism were suspected. Candida was observed in urine infection. The sudden improving of the patient's postoperative bleeding from the rectal stump where the staple line was, has evolved on the 7th day. The sponges with the adrenaline stopped the bleeding and the hemodynamic support was stabilized with it. The minimal fluid in pelvis was also monitored by ultrasound . The colostomy was fine following the blood supply to the bowel. Later oral intake was started, the general condition of the patient was improved. But on the postoperative day 12 she had suddenly respiratory and cardiac arrest . Finally, the histopathological examination revealed that the ischemic necrosis and purulent some areas could be selected as a morphologic ischemic and necrotic (the intraoperative peritoneal reflection of the level of false membrane formation at the perforation focus off ischemic colitis. Approximately 20% of similar cases were followed with the clinical practice under medical treatment and surgical approach. [J Contemp Med 2017; 7(1.000: 74-76

Electrical stimulation of the vagus nerve protects against cerebral ischemic injury through an anti-infammatory mechanism

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Yao-xian Xiang

2015-01-01

Full Text Available Vagus nerve stimulation exerts protective effects against ischemic brain injury; however, the underlying mechanisms remain unclear. In this study, a rat model of focal cerebral ischemia was established using the occlusion method, and the right vagus nerve was given electrical stimulation (constant current of 0.5 mA; pulse width, 0.5 ms; frequency, 20 Hz; duration, 30 seconds; every 5 minutes for a total of 60 minutes 30 minutes, 12 hours, and 1, 2, 3, 7 and 14 days after surgery. Electrical stimulation of the vagus nerve substantially reduced infarct volume, improved neurological function, and decreased the expression levels of tumor necrosis factor-and interleukin- 6 in rats with focal cerebral ischemia. The experimental findings indicate that the neuroprotective effect of vagus nerve stimulation following cerebral ischemia may be associated with the inhibition of tumor necrosis factor- and interleukin-6 expression.

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Assessment of the role of in situ generated (E)-2,4-diene-valproic acid in the toxicity of valproic acid and (E)-2-ene-valproic acid in sandwich-cultured rat hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Surendradoss, Jayakumar; Chang, Thomas K.H.; Abbott, Frank S., E-mail: frank.abbott@ubc.ca

2012-11-01

Valproic acid (VPA) undergoes cytochrome P450-mediated desaturation to form 4-ene-VPA, which subsequently yields (E)-2,4-diene-VPA by β-oxidation. Another biotransformation pathway involves β-oxidation of VPA to form (E)-2-ene-VPA, which also generates (E)-2,4-diene-VPA by cytochrome P450-mediated desaturation. Although the synthetic form of (E)-2,4-diene-VPA is more hepatotoxic than VPA as shown in various experimental models, there is no conclusive evidence to implicate the in situ generated (E)-2,4-diene-VPA in VPA hepatotoxicity. The present study investigated the effects of modulating the in situ formation of (E)-2,4-diene-VPA on markers of oxidative stress (formation of 2′,7′-dichlorofluorescein; DCF), steatosis (accumulation of BODIPY 558/568 C{sub 12}), necrosis (release of lactate dehydrogenase; LDH), and on cellular total glutathione (GSH) levels in sandwich-cultured rat hepatocytes treated with VPA or (E)-2-ene-VPA. Treatment with either of these chemicals alone increased each of the toxicity endpoints. In VPA-treated hepatocytes, (E)-2,4-diene-VPA was detected only at trace levels, even after phenobarbital (PB) pretreatment and there was no effect on the toxicity of VPA. Furthermore, pretreatment with a cytochrome P450 enzyme inhibitor, 1-aminobenzotriazole (1-ABT), did not influence the extent of VPA toxicity in both PB-pretreated and vehicle-pretreated hepatocytes. However, in (E)-2-ene-VPA-treated hepatocytes, PB pretreatment greatly enhanced the levels of (E)-2,4-diene-VPA and this was accompanied by a further enhancement of the effects of (E)-2-ene-VPA on DCF formation, BODIPY accumulation, LDH release, and GSH depletion. Pretreatment with 1-ABT reduced the concentrations of (E)-2,4-diene-VPA and the extent of (E)-2-ene-VPA toxicity; however, this occurred in PB-pretreated hepatocytes, but not in control hepatocytes. In conclusion, in situ generated (E)-2,4-diene-VPA is not responsible for the hepatocyte toxicity of VPA, whereas it

RNA synthesis in primary cultures of adult rat hepatocytes

International Nuclear Information System (INIS)

Fugassa, E.; Gallo, G.; Voci, A.; Cordone, A.

1983-01-01

The ability of hepatocyte monolayers to synthesize RNA was investigated by measuring [3H]orotic acid incorporation into RNA and the total nuclear RNA polymerase activity as a function of the time in culture. The results demonstrate that primary cultures of hepatocytes maintained in a chemically defined serum- and hormone-free medium are able to synthesize RNA actively. This ability increases within the first 2 d of culture, despite the concomitant decrease in [3H]orotic acid uptake, and decreases only after 3 d. Factors such as serum, insulin, and dexamethasone, known to improve maintenance of functional hepatocytes, markedly stimulate the uptake of labeled precursor without apparently affecting the rate of RNA synthesis by cultured cells. It is suggested that the culture of adult rat hepatocytes provides a useful experimental model for the studies of hormonal regulation of transcription in liver

TGFbeta Induces Binucleation/Polyploidization in Hepatocytes through a Src-Dependent Cytokinesis Failure.

Directory of Open Access Journals (Sweden)

Marco De Santis Puzzonia

Full Text Available In all mammals, the adult liver shows binucleated as well as mononucleated polyploid hepatocytes. The hepatic polyploidization starts after birth with an extensive hepatocyte binucleation and generates hepatocytes of several ploidy classes. While the functional significance of hepatocyte polyploidy is becoming clearer, how it is triggered and maintained needs to be clarified. Aim of this study was to identify a major inducer of hepatocyte binucleation/polyploidization and the cellular and molecular mechanisms involved. We found that, among several cytokines analyzed, known to be involved in early liver development and/or mass control, TGFbeta1 was capable to induce, together with the expected morphological changes, binucleation in hepatocytes in culture. Most importantly, the pharmacological inhibition of TGFbeta signaling in healthy mice during weaning, when the physiological binucleation occurs, induced a significant decrease of hepatocyte binucleation rate, without affecting cell proliferation and hepatic index. The TGFbeta-induced hepatocyte binucleation resulted from a cytokinesis failure, as assessed by video microscopy, and is associated with a delocalization of the cytokinesis regulator RhoA-GTPase from the mid-body of dividing cells. The use of specific chemical inhibitors demonstrated that the observed events are Src-dependent. Finally, the restoration of a fully epithelial phenotype by TGFbeta withdrawal gave rise to a cell progeny capable to maintain the polyploid state. In conclusion, we identified TGFbeta as a major inducer of hepatocyte binucleation both in vitro and in vivo, thus ascribing a novel role to this pleiotropic cytokine. The production of binucleated/tetraploid hepatocytes is due to a cytokinesis failure controlled by the molecular axis TGFbeta/Src/RhoA.

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High efficient differentiation of functional hepatocytes from porcine induced pluripotent stem cells.

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Ying Ao

Full Text Available Hepatocyte transplantation is considered to be a promising therapy for patients with liver diseases. Induced pluripotent stem cells (iPSCs provide an unlimited source for the generation of functional hepatocytes. In this study, we generated iPSCs from porcine ear fibroblasts (PEFs by overexpressing Sox2, Klf4, Oct4, and c-Myc (SKOM, and developed a novel strategy for the efficient differentiation of hepatocyte-like cells from porcine iPSCs by following the processes of early liver development. The differentiated cells displayed the phenotypes of hepatocytes, exhibited classic hepatocyte-associated bio-functions, such as LDL uptake, glycogen storage and urea secretion, as well as possessed the metabolic activities of cytochrome P-450 (CYP 3A and 2C. Furthermore, we compared the hepatocyte differentiation efficacy of our protocol with another published method, and the results demonstrated that our differentiation strategy could significantly improve the generation of morphological and functional hepatocyte-like cells from porcine iPSCs. In conclusion, this study establishes an efficient method for in vitro generation of functional hepatocytes from porcine iPSCs, which could represent a promising cell source for preclinical testing of cell-based therapeutics for liver failure and for pharmacological applications.

Clinical evaluation of ischemic heart diagnosis

International Nuclear Information System (INIS)

Kamei, Fumio

1983-01-01

Attempt were made to detect the existence of myocardial ischemia by means of both radiographic and scintigraphic techniques. Firstly, a new polygraph was especially designed for selecting the arbitrary phases in a cardiac cycle at which the corresponding radiogram should be synchronously obtained. A comparative investigation on the difference between end-systolic and-diastolic cardiac transverse diameters revealed a remarkable difference of 3.6% in normal subjects and 0.6% in patients with ischemic heart disease. These data indicating the difference of overall heart size was reflected in local dyskinesis documentation of recently developed techniques. For daily clinical purposes, radiography of the chest based on synchronously selected phases would contribute to accurate diagnosis and treatment of heart disease. Secondly, scintigraphic display using intravenously injected thallium-201 was clinically applied. For detection of ischemia, comparative study was performed of initial image relative to selective coronary cineangiography and stress scintigraphy. The former indicated a good correlation of 90%, whereas the latter served to enhnace sensitivity. Sequential images (initial and delayed) facilitated the distinction of normal, necrotic, and ischemic areas. Scintigram was used for objective evaluation of coronary dilator (dilazep), either at immediate or follow-up stage. In the same way, it was also possible to indicate the effectiveness of sublingually given nitroglycerin by myocardial scintigram, where by significant increase of uptake was observed 20 minutes after administration. Rehabilitation after acute heart disease was discussed, especially on the peripheral effect. Ratio of the thigh muscle to myocardium shown in this study was useful fer objective evaluation. Another preliminary study is to separate normal coronary arteries from myocardial necrosis. (J.P.N.)

Clinical evaluation of ischemic heart diagnosis

Energy Technology Data Exchange (ETDEWEB)

Kamei, Fumio [Sendai Railway Hospital (Japan)

1983-09-01

Attempt were made to detect the existence of myocardial ischemia by means of both radiographic and scintigraphic techniques. Firstly, a new polygraph was especially designed for selecting the arbitrary phases in a cardiac cycle at which the corresponding radiogram should be synchronously obtained. A comparative investigation on the difference between end-systolic and-diastolic cardiac transverse diameters revealed a remarkable difference of 3.6% in normal subjects and 0.6% in patients with ischemic heart disease. These data indicating the difference of overall heart size was reflected in local dyskinesis documentation of recently developed techniques. For daily clinical purposes, radiography of the chest based on synchronously selected phases would contribute to accurate diagnosis and treatment of heart disease. Secondly, scintigraphic display using intravenously injected thallium-201 was clinically applied. For detection of ischemia, comparative study was performed of initial image relative to selective coronary cineangiography and stress scintigraphy. The former indicated a good correlation of 90%, whereas the latter served to enhance sensitivity. Sequential images (initial and delayed) facilitated the distinction of normal, necrotic, and ischemic areas. Scintigram was used for objective evaluation of coronary dilator (dilazep), either at immediate or follow-up stage. In the same way, it was also possible to indicate the effectiveness of sublingually given nitroglycerin by myocardial scintigram, where by significant increase of uptake was observed 20 minutes after administration. Rehabilitation after acute heart disease was discussed, especially on the peripheral effect. Ratio of the thigh muscle to myocardium shown in this study was useful for objective evaluation. Another preliminary study is to separate normal coronary arteries from myocardial necrosis.

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Renal medullary AA amyloidosis, hepatocyte dissociation and multinucleated hepatocytes in a 14-year-old free-ranging lioness (Panthera leo

Directory of Open Access Journals (Sweden)

J.H. Williams

2005-06-01

Full Text Available A 14-year-old lioness, originating from Etosha in Namibia, and a member of a pride in Pilanesberg National Park since translocation in 1994, was euthanased due to fight-related vertebral fracture and spinal injury, incurred approximately 6-8 weeks previously. Blood specimens collected at the time of death showed mild anaemia and a leukogram reflecting stress and chronic infection. Necropsy conducted within 2 hours of death was on a dehydrated, emaciated animal with hindquarter wasting and chronic traumatic friction injuries from dragging her hindlegs. There was cellulitis in the region of bite-wounds adjacent to the thoraco-lumbar vertebral fracture, at which site there was spinal cord compression, and there was marked intestinal helminthiasis. The outer renal medullae appeared pale and waxy and the liver was macroscopically unremarkable. Histopathology and electron microscopy of the kidneys revealed multifocal to coalescing deposits of proximal medullary interstitial amyloid, which fluoresced strongly with thioflavine T, and was sensitive to potassium permanganate treatment prior to Congo Red staining, thus indicating inflammatory (AA origin. There was diffuse hepatocyte dissociation, as well as numerous binucleated and scattered multinucleated (up to 8 nuclei/cell hepatocytes, with swollen hepatocyte mitochondria, in liver examined light microscopically. Ultrastructurally, the mono-, bi- and multinucleated hepatocytes contained multifocal irregular membrane-bound accumulations of finely-granular, amorphous material both intra-cytoplasmically and intra-nuclearly, as well as evidence of irreversible mitochondrial injury. The incidence and relevance in cats and other species of amyloidosis, particularly with renal medullary distribution, as well as of hepatocyte dissociation and multinucleation, as reported in selected literature, is briefly overviewed and their occurrence in this lioness is discussed.

Cholesterol Enhances the Toxic Effect of Ethanol and Acetaldehyde in Primary Mouse Hepatocytes

Directory of Open Access Journals (Sweden)

Anayelly López-Islas

2016-01-01

Full Text Available Obesity and alcohol consumption are risk factors for hepatic steatosis, and both commonly coexist. Our objective was to evaluate the effect of ethanol and acetaldehyde on primary hepatocytes obtained from mice fed for two days with a high cholesterol (HC diet. HC hepatocytes increased lipid and cholesterol content. HC diet sensitized hepatocytes to the toxic effect of ethanol and acetaldehyde. Cyp2E1 content increased with HC diet, as well as in those treated with ethanol or acetaldehyde, while the activity of this enzyme determined in microsomes increased in the HC and in all ethanol treated hepatocytes, HC and CW. Oxidized proteins were increased in the HC cultures treated or not with the toxins. Transmission electron microscopy showed endoplasmic reticulum (ER stress and megamitochondria in hepatocytes treated with ethanol as in HC and the ethanol HC treated hepatocytes. ER stress determined by PERK content was increased in ethanol treated hepatocytes from HC mice and CW. Nuclear translocation of ATF6 was observed in HC hepatocytes treated with ethanol, results that indicate that lipids overload and ethanol treatment favor ER stress. Oxidative stress, ER stress, and mitochondrial damage underlie potential mechanisms for increased damage in steatotic hepatocyte treated with ethanol.

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Hepatocyte produced matrix metalloproteinases are regulated by CD147 in liver fibrogenesis.

Science.gov (United States)

Calabro, Sarah R; Maczurek, Annette E; Morgan, Alison J; Tu, Thomas; Wen, Victoria W; Yee, Christine; Mridha, Auvro; Lee, Maggie; d'Avigdor, William; Locarnini, Stephen A; McCaughan, Geoffrey W; Warner, Fiona J; McLennan, Susan V; Shackel, Nicholas A

2014-01-01

The classical paradigm of liver injury asserts that hepatic stellate cells (HSC) produce, remodel and turnover the abnormal extracellular matrix (ECM) of fibrosis via matrix metalloproteinases (MMPs). In extrahepatic tissues MMP production is regulated by a number of mechanisms including expression of the glycoprotein CD147. Previously, we have shown that CD147 is expressed on hepatocytes but not within the fibrotic septa in cirrhosis [1]. Therefore, we investigated if hepatocytes produce MMPs, regulated by CD147, which are capable of remodelling fibrotic ECM independent of the HSC. Non-diseased, fibrotic and cirrhotic livers were examined for MMP activity and markers of fibrosis in humans and mice. CD147 expression and MMP activity were co-localised by in-situ zymography. The role of CD147 was studied in-vitro with siRNA to CD147 in hepatocytes and in-vivo in mice with CCl4 induced liver injury using ãCD147 antibody intervention. In liver fibrosis in both human and mouse tissue MMP expression and activity (MMP-2, -9, -13 and -14) increased with progressive injury and localised to hepatocytes. Additionally, as expected, MMPs were abundantly expressed by activated HSC. Further, with progressive fibrosis there was expression of CD147, which localised to hepatocytes but not to HSC. Functionally significant in-vitro regulation of hepatocyte MMP production by CD147 was demonstrated using siRNA to CD147 that decreased hepatocyte MMP-2 and -9 expression/activity. Further, in-vivo α-CD147 antibody intervention decreased liver MMP-2, -9, -13, -14, TGF-β and α-SMA expression in CCl4 treated mice compared to controls. We have shown that hepatocytes produce active MMPs and that the glycoprotein CD147 regulates hepatocyte MMP expression. Targeting CD147 regulates hepatocyte MMP production both in-vitro and in-vivo, with the net result being reduced fibrotic matrix turnover in-vivo. Therefore, CD147 regulation of hepatocyte MMP is a novel pathway that could be targeted by

Hepatocyte produced matrix metalloproteinases are regulated by CD147 in liver fibrogenesis.

Directory of Open Access Journals (Sweden)

Sarah R Calabro

Full Text Available The classical paradigm of liver injury asserts that hepatic stellate cells (HSC produce, remodel and turnover the abnormal extracellular matrix (ECM of fibrosis via matrix metalloproteinases (MMPs. In extrahepatic tissues MMP production is regulated by a number of mechanisms including expression of the glycoprotein CD147. Previously, we have shown that CD147 is expressed on hepatocytes but not within the fibrotic septa in cirrhosis [1]. Therefore, we investigated if hepatocytes produce MMPs, regulated by CD147, which are capable of remodelling fibrotic ECM independent of the HSC.Non-diseased, fibrotic and cirrhotic livers were examined for MMP activity and markers of fibrosis in humans and mice. CD147 expression and MMP activity were co-localised by in-situ zymography. The role of CD147 was studied in-vitro with siRNA to CD147 in hepatocytes and in-vivo in mice with CCl4 induced liver injury using ãCD147 antibody intervention.In liver fibrosis in both human and mouse tissue MMP expression and activity (MMP-2, -9, -13 and -14 increased with progressive injury and localised to hepatocytes. Additionally, as expected, MMPs were abundantly expressed by activated HSC. Further, with progressive fibrosis there was expression of CD147, which localised to hepatocytes but not to HSC. Functionally significant in-vitro regulation of hepatocyte MMP production by CD147 was demonstrated using siRNA to CD147 that decreased hepatocyte MMP-2 and -9 expression/activity. Further, in-vivo α-CD147 antibody intervention decreased liver MMP-2, -9, -13, -14, TGF-β and α-SMA expression in CCl4 treated mice compared to controls.We have shown that hepatocytes produce active MMPs and that the glycoprotein CD147 regulates hepatocyte MMP expression. Targeting CD147 regulates hepatocyte MMP production both in-vitro and in-vivo, with the net result being reduced fibrotic matrix turnover in-vivo. Therefore, CD147 regulation of hepatocyte MMP is a novel pathway that could be

PO-62 - Remote ischemic preconditioning in head and neck cancer reconstruction - a randomized controlled trial

DEFF Research Database (Denmark)

Krag, A E; Kiil, B J; Hvas, Christine Lodberg

2016-01-01

flap anastomoses or microcirculation is the main reason for total flap necrosis with potential fatal consequences for the patient. Remote ischemic preconditioning (RIPC), where brief cycles of upper extremity ischemia are induced with an inflatable tourniquet, triggers a global protection of tissues...... will be included in the trial. The subjects will be randomized to RIPC or sham during surgery. RIPC is administered by four 5-minute cycles of upper extremity ischemia, each separated by five minutes of reperfusion. Blood samples will be drawn preoperatively, before RIPC/sham, 3 hours after RIPC/ sham, 6 hours...... oncologic therapy can be initiated in timely fashion....

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File list: NoD.Liv.20.AllAg.Hepatocytes [Chip-atlas[Archive

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File list: NoD.Liv.10.AllAg.Hepatocytes [Chip-atlas[Archive

Lifescience Database Archive (English)

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Functional and toxicological consequences of metabolic bioactivation of methapyrilene via thiophene S-oxidation: Induction of cell defence, apoptosis and hepatic necrosis

International Nuclear Information System (INIS)

Mercer, Amy E.; Regan, Sophie L.; Hirst, Charlotte M.; Graham, Emma E.; Antoine, Daniel J.; Benson, Craig A.; Williams, Dominic P.; Foster, John; Kenna, J. Gerry; Park, B. Kevin

2009-01-01

Methapyrilene, [N,N-dimethyl-N'-pyridyl-N'(2-thienylmethyl)-1,2-ethanediamine] (MP) was withdrawn from, clinical use due to reported periportal hepatic necrosis and hepatocarcinogenicity in the rat, via S-oxidation of the thiophene group. In this study MP is used as a model hepatotoxin to further characterise the functional consequences of S-oxidation of the thiophene group in vivo, in rat models and in vitro, in freshly isolated rat hepatocyte suspensions. In vivo histological studies revealed the early depletion of glutathione (GSH), which was confined to the damaged periportal area, in contrast to an increase in GSH levels in the centrilobular region. Additionally, the induction of cell defence was demonstrated by an increase in the protein levels of heme-oxygenase 1 (HO-1) and glutamate cysteine ligase, catalytic subunit (GCLC) in vivo. Histological examination demonstrated that cytotoxicity progresses initially via apoptosis before an increase in necrosis over the 3-day administration. An apoptotic-like mechanism was observed in vitro via the measurement of cytochrome c release and caspase activation. Conclusion: This study provides evidence for a complex pathway of MP-induced hepatotoxicity which progresses through early adaptation, apoptosis, necrosis and inflammation, all underpinned by the zonal induction and depletion of GSH within the liver.

Scintigraphic evidence of transplanted hepatocytes in spleen and liver

International Nuclear Information System (INIS)

Henne-Bruns, D.; Kremer, B.; Gramminger, K.; Broelsch, C.

1986-01-01

In rats suffering from hepatic enzymatic deficiency transplanted hepatocytes could be evidenced scintigraphically in liver, spleen and granulomas. In pigs, however, it is very difficult to demonstrate transplanted hepatocytes by scintiscanning because of the thickness of the tissues and the high background radiation in large animals

Transplant of Hepatocytes, Undifferentiated Mesenchymal Stem Cells, and In Vitro Hepatocyte-Differentiated Mesenchymal Stem Cells in a Chronic Liver Failure Experimental Model: A Comparative Study.

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El Baz, Hanan; Demerdash, Zeinab; Kamel, Manal; Atta, Shimaa; Salah, Faten; Hassan, Salwa; Hammam, Olfat; Khalil, Heba; Meshaal, Safa; Raafat, Inas

2018-02-01

Liver transplant is the cornerstone line of treatment for chronic liver diseases; however, the long list of complications and obstacles stand against this operation. Searching for new modalities for treatment of chronic liver illness is a must. In the present research, we aimed to compare the effects of transplant of undifferentiated human mesenchymal stem cells, in vitro differentiated mesenchymal stem cells, and adult hepatocytes in an experimental model of chronic liver failure. Undifferentiated human cord blood mesenchymal stem cells were isolated, pro-pagated, and characterized by morphology, gene expression analysis, and flow cytometry of surface markers and in vitro differentiated into hepatocyte-like cells. Rat hepatocytes were isolated by double perfusion technique. An animal model of chronic liver failure was developed, and undifferentiated human cord blood mesenchymal stem cells, in vitro hepato-genically differentiated mesenchymal stem cells, or freshly isolated rat hepatocytes were transplanted into a CCL4 cirrhotic experimental model. Animals were killed 3 months after transplant, and liver functions and histopathology were assessed. Compared with the cirrhotic control group, the 3 cell-treated groups showed improved alanine aminotransferase, aspartate aminotransferase, albumin, and bilirubin levels, with best results shown in the hepatocyte-treated group. Histopathologic examination of the treated groups showed improved fibrosis, with best results obtained in the undifferentiated mesenchymal stem cell-treated group. Both adult hepatocytes and cord blood mesenchymal stem cells proved to be promising candidates for cell-based therapy in liver regeneration on an experimental level. Improved liver function was evident in the hepatocyte-treated group, and fibrosis control was more evident in the undifferentiated mesenchymal stem cell-treated group.

Renal papillary necrosis

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... asking your provider. Alternative Names Necrosis - renal papillae; Renal medullary necrosis Images Kidney anatomy Kidney - blood and urine flow References Bushinsky DA, Monk RD. Nephrolithiasis and nephrocalcinosis. ...

A refined characterisation of the NeoHepatocyte phenotype necessitates a reappraisal of the transdifferentiation hypothesis.

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Riquelme, Paloma; Wundt, Judith; Hutchinson, James A; Brulport, Marc; Jun, Yu; Sotnikova, Anna; Girreser, Ulrich; Braun, Felix; Gövert, Felix; Soria, Bernat; Nüssler, Andreas; Clement, Bernd; Hengstler, Jan G; Fändrich, Fred

2009-03-01

Under certain culture conditions human peripheral blood monocytes may be induced to express phenotypic markers of non-haematopoietic lineages, including hepatocyte-defining traits. One such example, the NeoHepatocyte, was previously shown to express a broad panel of hepatocyte-like marker antigens and metabolic activities, both in vitro and following engraftment in the liver of immunodeficient mice. In this report, a refined description of NeoHepatocytes, with regard to their expression of xenobiotic-metabolising enzymes, morphology, hepatocyte marker expression and cell surface phenotype, is presented in comparison with human macrophages in defined states of activation. Contrary to prior assertions, it would seem more likely that NeoHepatocytes express particular hepatocyte-defining genes during a normal programme of macrophage differentiation rather than undergoing a process of transdifferentiation to become hepatocyte-like cells.

In vitro culture of functionally active buffalo hepatocytes isolated by using a simplified manual perfusion method.

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Santanu Panda

Full Text Available In farm animals, there is no suitable cell line available to understand liver-specific functions. This has limited our understanding of liver function and metabolism in farm animals. Culturing and maintenance of functionally active hepatocytes is difficult, since they survive no more than few days. Establishing primary culture of hepatocytes can help in studying cellular metabolism, drug toxicity, hepatocyte specific gene function and regulation. Here we provide a simple in vitro method for isolation and short-term culture of functionally active buffalo hepatocytes.Buffalo hepatocytes were isolated from caudate lobes by using manual enzymatic perfusion and mechanical disruption of liver tissue. Hepatocyte yield was (5.3 ± 0.66×107 cells per gram of liver tissue with a viability of 82.3 ± 3.5%. Freshly isolated hepatocytes were spherical with well contrasted border. After 24 hours of seeding onto fibroblast feeder layer and different extracellular matrices like dry collagen, matrigel and sandwich collagen coated plates, hepatocytes formed confluent monolayer with frequent clusters. Cultured hepatocytes exhibited typical cuboidal and polygonal shape with restored cellular polarity. Cells expressed hepatocyte-specific marker genes or proteins like albumin, hepatocyte nuclear factor 4α, glucose-6-phosphatase, tyrosine aminotransferase, cytochromes, cytokeratin and α1-antitrypsin. Hepatocytes could be immunostained with anti-cytokeratins, anti-albumin and anti α1-antitrypsin antibodies. Abundant lipid droplets were detected in the cytosol of hepatocytes using oil red stain. In vitro cultured hepatocytes could be grown for five days and maintained for up to nine days on buffalo skin fibroblast feeder layer. Cultured hepatocytes were viable for functional studies.We developed a convenient and cost effective technique for hepatocytes isolation for short-term culture that exhibited morphological and functional characteristics of active hepatocytes

Colon Necrosis Due to Sodium Polystyrene Sulfonate with and without Sorbitol: An Experimental Study in Rats.

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Ayoub, Isabelle; Oh, Man S; Gupta, Raavi; McFarlane, Michael; Babinska, Anna; Salifu, Moro O

2015-01-01

Based on a single rat study by Lillemoe et al, the consensus has been formed to implicate sorbitol rather than sodium polystyrene sulfonate (SPS) as the culprit for colon necrosis in humans treated with SPS and sorbitol. We tested the hypothesis that colon necrosis by sorbitol in the experiment was due to the high osmolality and volume of sorbitol rather than its chemical nature. 26 rats underwent 5/6 nephrectomy. They were divided into 6 groups and given enema solutions under anesthesia (normal saline, 33% sorbitol, 33% mannitol, SPS in 33% sorbitol, SPS in normal saline, and SPS in distilled water). They were sacrificed after 48 hours of enema administration or earlier if they were very sick. The gross appearance of the colon was visually inspected, and then sliced colon tissues were examined under light microscopy. 1 rat from the sorbitol and 1 from the mannitol group had foci of ischemic colonic changes. The rats receiving SPS enema, in sorbitol, normal saline, distilled water, had crystal deposition with colonic necrosis and mucosal erosion. All the rats not given SPS survived until sacrificed at 48 h whereas 11 of 13 rats that received SPS in sorbitol, normal saline or distilled water died or were clearly dying and sacrificed sooner. There was no difference between sorbitol and mannitol when given without SPS. In a surgical uremic rat model, SPS enema given alone or with sorbitol or mannitol seemed to cause colon necrosis and high mortality rate, whereas 33% sorbitol without SPS did not.

Predictors of early infection in cerebral ischemic stroke.

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Ashour, Wmr; Al-Anwar, A D; Kamel, A E; Aidaros, M A

2016-01-01

Infection is the most common complication of stroke. To determine the risk factors and predictors of post-stroke infection (PSI), which developed within 7 days from the onset of acute ischemic stroke. The study included 60 ischemic stroke patients admitted in the Neurology Department of Zagazig University, Egypt, who were subdivided into: [Non Stroke Associated Infection group (nSAI); 30 patients having stroke without any criteria of infection within 7 days from the onset and Stroke Associated Infection group (SAI); 30 patients having stroke with respiratory tract infection (RTI) or urinary tract infection within 7 days], in addition to 30 healthy sex and age-matching subjects as control. All the patients had a detailed history taking, thorough clinical general and neurological examination, laboratory tests (Urine analysis & urine culture, blood sugar, lipid profile and serum tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-10), a chest radiography to assess RTI and brain computed tomography (CT) to exclude the hemorrhagic stroke and to confirm the ischemic stroke. SAI patients were found to be significantly older with higher baseline blood glucose level. Also the number of patients with tube feeding, lower conscious level, more stroke severity and more large size infarcts were significantly higher in SAI patients. There was a significant elevation in the IL-10, a significant decrease in the TNF-α and a significant decrease in the TNF-α/ IL-10 ratio, in the SAI group. The baseline serum level of IL-10 ≥ 14.5 pg/ ml and size of infarct area > 3.5 cm3 were found to be the independent predictors of PSI. Patients with older age, tube feeding, lower conscious level, worse baseline stroke severity, large cerebral infarcts in CT scan, and increased IL-10 serum level were more susceptible to infection. The baseline serum level of IL-10 ≥ 14.5 pg/ ml and the size of infarct area > 3.5 cm3 were the independent predictors of PSI.

Lack of direct mitogenic activity of dichloroacetate and trichloroacetate in cultured rat hepatocytes

International Nuclear Information System (INIS)

Walgren, Jennie L.; Kurtz, David T.; McMillan, JoEllyn M.

2005-01-01

Dichloroacetate (DCA) and trichloroacetate (TCA) are hepatocarcinogenic metabolites of the common groundwater contaminant, 1,1,2-trichloroethylene. DCA and TCA have been shown to induce hepatocyte proliferation in vivo, but it is not known if this response is the result of direct mitogenic activity or whether cell replication occurs indirectly in response to tissue injury or inflammation. In this study we used primary cultures of rat hepatocytes, a species susceptible to DCA- but not TCA-induced hepatocarcinogenesis, to determine whether DCA and TCA are direct hepatocyte mitogens. Rat hepatocytes, cultured in growth factor-free medium, were treated with 0.01-1.0 mM DCA or TCA for 10-40 h; cell replication was then assessed by measuring incorporation of 3 H-thymidine into DNA and by cell counts. DCA or TCA treatment did not alter 3 H-thymidine incorporation in the cultured hepatocytes. Although an increase in cell number was not observed, DCA treatment significantly abrogated the normal background cell loss, suggesting an ability to inhibit apoptotic cell death in primary hepatocyte cultures. Furthermore, treatment with DCA synergistically enhanced the mitogenic response to epidermal growth factor. The data indicate that DCA and TCA are not direct mitogens in hepatocyte cultures, which is of interest in view of their ability to stimulate hepatocyte replication in vivo. Nevertheless, the synergistic enhancement of epidermal growth factor-induced hepatocyte replication by DCA is of particular interest and warrants further study

Immortalized human hepatocytes as a tool for the study of hepatocytic (de-)differentiation

NARCIS (Netherlands)

Schippers, IJ; Moshage, H; Roelofsen, H; Muller, M; Heymans, HSA; Ruiters, M; Kuipers, F

Primary human hepatocytes were immortalized by stable transfection with a recombinant plasmid containing the early region of simian virus (SV) 40. The cells were cultured in serum-free, hormonally defined medium during the immortalization procedure. Foci of dividing cells were seen after 3 months.

Hypoxia-inducible factor-dependent production of profibrotic mediators by hypoxic hepatocytes.

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Copple, Bryan L; Bustamante, Juan J; Welch, Timothy P; Kim, Nam Deuk; Moon, Jeon-Ok

2009-08-01

During the development of liver fibrosis, mediators are produced that stimulate cells in the liver to differentiate into myofibroblasts and to produce collagen. Recent studies demonstrated that the transcription factor, hypoxia-inducible factor-1alpha (HIF-1alpha), is critical for upregulation of profibrotic mediators, such as platelet-derived growth factor-A (PDGF-A), PDGF-B and plasminogen activator inhibitor-1 (PAI-1) in the liver, during the development of fibrosis. What remains unknown is the cell type-specific regulation of these genes by HIF-1alpha in liver cell types. Accordingly, the hypothesis was tested that HIF-1alpha is activated in hypoxic hepatocytes and regulates the production of profibrotic mediators by these cells. In this study, hepatocytes were isolated from the livers of control and HIF-1alpha- or HIF-1beta-deficient mice and exposed to hypoxia. Exposure of primary mouse hepatocytes to 1% oxygen stimulated nuclear accumulation of HIF-1alpha and upregulated PAI-1, vascular endothelial cell growth factor and the vasoactive peptides adrenomedullin-1 (ADM-1) and ADM-2. In contrast, the levels of PDGF-A and PDGF-B mRNAs were unaffected in these cells by hypoxia. Exposure of HIF-1alpha-deficient hepatocytes to 1% oxygen only partially prevented upregulation of these genes, suggesting that other hypoxia-regulated transcription factors, such as HIF-2alpha, may also regulate these genes. In support of this, HIF-2alpha was activated in hypoxic hepatocytes, and exposure of HIF-1beta-deficient hepatocytes to 1% oxygen completely prevented upregulation of PAI-1, vascular endothelial cell growth factor and ADM-1, suggesting that HIF-2alpha may also contribute to upregulation of these genes in hypoxic hepatocytes. Collectively, our results suggest that HIFs may be important regulators of profibrotic and vasoactive mediators by hypoxic hepatocytes.

Comparison of para-aminophenol cytotoxicity in rat renal epithelial cells and hepatocytes.

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Li, Ying; Bentzley, Catherine M; Tarloff, Joan B

2005-04-01

Several chemicals, including para-aminophenol (PAP), produce kidney damage in the absence of hepatic damage. Selective nephrotoxicity may be related to the ability of the kidney to reabsorb filtered water, thereby raising the intraluminal concentration of toxicants and exposing tubular epithelial cells to higher concentrations than would be present in other tissues. The present experiments tested the hypothesis that hepatocytes and renal epithelial cells exposed to equivalent concentrations of PAP would be equally susceptible to toxicity. Hepatocytes and renal epithelial cells were prepared by collagenase digestion of tissues obtained from female Sprague-Dawley rats. Toxicity was monitored using trypan blue exclusion, oxygen consumption and ATP content. We measured the rate of PAP clearance and formation of PAP-glutathione conjugate by HPLC. We found that renal epithelial cells accumulated trypan blue and showed declines in oxygen consumption and ATP content at significantly lower concentrations of PAP and at earlier time points than hepatocytes. The half-life of PAP in hepatocyte incubations was significantly shorter (0.71+/-0.07 h) than in renal epithelial cell incubations (1.33+/-0.23 h), suggesting that renal epithelial cells were exposed to PAP for longer time periods than hepatocytes. Renal epithelial cells formed significantly less glutathione conjugates of PAP (PAP-SG) than did hepatocytes, consistent with less efficient detoxification of reactive PAP intermediates by renal epithelial cells. Finally, hepatocytes contained significant more reduced glutathione (NPSH) than did renal epithelial cells, possibly explaining the enhanced formation of PAP-SG by this cell population. In conclusion, our data indicates that renal epithelial cells are intrinsically more susceptible to PAP cytotoxicity than are hepatocytes. This enhanced cytotoxicity may be due to longer exposure to PAP and/or reduced detoxification of reactive intermediates due to lower concentrations

YAP Inhibition Restores Hepatocyte Differentiation in Advanced HCC, Leading to Tumor Regression

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Julien Fitamant

2015-03-01

Full Text Available Defective Hippo/YAP signaling in the liver results in tissue overgrowth and development of hepatocellular carcinoma (HCC. Here, we uncover mechanisms of YAP-mediated hepatocyte reprogramming and HCC pathogenesis. YAP functions as a rheostat in maintaining metabolic specialization, differentiation, and quiescence within the hepatocyte compartment. Increased or decreased YAP activity reprograms subsets of hepatocytes to different fates associated with deregulation of the HNF4A, CTNNB1, and E2F transcriptional programs that control hepatocyte quiescence and differentiation. Importantly, treatment with small interfering RNA-lipid nanoparticles (siRNA-LNPs targeting YAP restores hepatocyte differentiation and causes pronounced tumor regression in a genetically engineered mouse HCC model. Furthermore, YAP targets are enriched in an aggressive human HCC subtype characterized by a proliferative signature and absence of CTNNB1 mutations. Thus, our work reveals Hippo signaling as a key regulator of the positional identity of hepatocytes, supports targeting of YAP using siRNA-LNPs as a paradigm of differentiation-based therapy, and identifies an HCC subtype that is potentially responsive to this approach.

Gender differences in methionine accumulation and metabolism in freshly isolated mouse hepatocytes: Potential roles in toxicity

International Nuclear Information System (INIS)

Dever, Joseph T.; Elfarra, Adnan A.

2009-01-01

L-Methionine (Met) is hepatotoxic at high concentrations. Because Met toxicity in freshly isolated mouse hepatocytes is gender-dependent, the goal of this study was to assess the roles of Met accumulation and metabolism in the increased sensitivity of male hepatocytes to Met toxicity compared with female hepatocytes. Male hepatocytes incubated with Met (30 mM) at 37 o C exhibited higher levels of intracellular Met at 0.5, 1.0, and 1.5 h, respectively, compared to female hepatocytes. Conversely, female hepatocytes had higher levels of S-adenosyl-L-methionine compared to male hepatocytes. Female hepatocytes also exhibited higher L-methionine-L-sulfoxide levels relative to control hepatocytes, whereas the increases in L-methionine-D-sulfoxide (Met-D-O) levels were similar in hepatocytes of both genders. Addition of aminooxyacetic acid (AOAA), an inhibitor of Met transamination, significantly increased Met levels at 1.5 h and increased Met-D-O levels at 1.0 and 1.5 h only in Met-exposed male hepatocytes. No gender differences in cytosolic Met transamination activity by glutamine transaminase K were detected. However, female mouse liver cytosol exhibited higher methionine-DL-sulfoxide (MetO) reductase activity than male mouse liver cytosol at low (0.25 and 0.5 mM) MetO concentrations. Collectively, these results suggest that increased cellular Met accumulation, decreased Met transmethylation, and increased Met and MetO transamination in male mouse hepatocytes may be contributing to the higher sensitivity of the male mouse hepatocytes to Met toxicity in comparison with female mouse hepatocytes.

Interspecies differences in metabolism of arsenic by cultured primary hepatocytes

International Nuclear Information System (INIS)

Drobna, Zuzana; Walton, Felecia S.; Harmon, Anne W.; Thomas, David J.; Styblo, Miroslav

2010-01-01

Biomethylation is the major pathway for the metabolism of inorganic arsenic (iAs) in many mammalian species, including the human. However, significant interspecies differences have been reported in the rate of in vivo metabolism of iAs and in yields of iAs metabolites found in urine. Liver is considered the primary site for the methylation of iAs and arsenic (+3 oxidation state) methyltransferase (As3mt) is the key enzyme in this pathway. Thus, the As3mt-catalyzed methylation of iAs in the liver determines in part the rate and the pattern of iAs metabolism in various species. We examined kinetics and concentration-response patterns for iAs methylation by cultured primary hepatocytes derived from human, rat, mice, dog, rabbit, and rhesus monkey. Hepatocytes were exposed to [ 73 As]arsenite (iAs III ; 0.3, 0.9, 3.0, 9.0 or 30 nmol As/mg protein) for 24 h and radiolabeled metabolites were analyzed in cells and culture media. Hepatocytes from all six species methylated iAs III to methylarsenic (MAs) and dimethylarsenic (DMAs). Notably, dog, rat and monkey hepatocytes were considerably more efficient methylators of iAs III than mouse, rabbit or human hepatocytes. The low efficiency of mouse, rabbit and human hepatocytes to methylate iAs III was associated with inhibition of DMAs production by moderate concentrations of iAs III and with retention of iAs and MAs in cells. No significant correlations were found between the rate of iAs methylation and the thioredoxin reductase activity or glutathione concentration, two factors that modulate the activity of recombinant As3mt. No associations between the rates of iAs methylation and As3mt protein structures were found for the six species examined. Immunoblot analyses indicate that the superior arsenic methylation capacities of dog, rat and monkey hepatocytes examined in this study may be associated with a higher As3mt expression. However, factors other than As3mt expression may also contribute to the interspecies differences

No evidence for protective erythropoietin alpha signalling in rat hepatocytes

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Frede Stilla

2009-04-01

Full Text Available Abstract Background Recombinant human erythropoietin alpha (rHu-EPO has been reported to protect the liver of rats and mice from ischemia-reperfusion injury. However, direct protective effects of rHu-EPO on hepatocytes and the responsible signalling pathways have not yet been described. The aim of the present work was to study the protective effect of rHu-EPO on warm hypoxia-reoxygenation and cold-induced injury to hepatocytes and the rHu-EPO-dependent signalling involved. Methods Loss of viability of isolated rat hepatocytes subjected to hypoxia/reoxygenation or incubated at 4°C followed by rewarming was determined from released lactate dehydrogenase activity in the absence and presence of rHu-EPO (0.2–100 U/ml. Apoptotic nuclear morphology was assessed by fluorescence microscopy using the nuclear fluorophores H33342 and propidium iodide. Erythropoietin receptor (EPOR, EPO and Bcl-2 mRNAs were quantified by real time PCR. Activation of JAK-2, STAT-3 and STAT-5 in hepatocytes and rat livers perfused in situ was assessed by Western blotting. Results In contrast to previous in vivo studies on ischemia-reperfusion injury to the liver, rHu-EPO was without any protective effect on hypoxic injury, hypoxia-reoxygenation injury and cold-induced apoptosis to isolated cultured rat hepatocytes. EPOR mRNA was identified in these cells but specific detection of the EPO receptor protein was not possible due to the lack of antibody specificity. Both, in the cultured rat hepatocytes (10 U/ml for 15 minutes and in the rat liver perfused in situ with rHu-EPO (8.9 U/ml for 15 minutes no evidence for EPO-dependent signalling was found as indicated by missing effects of rHu-EPO on phosphorylation of JAK-2, STAT-3 and STAT-5 and on the induction of Bcl-2 mRNA. Conclusion Together, these results indicate the absence of any protective EPO signalling in rat hepatocytes. This implies that the protection provided by rHu-EPO in vivo against ischemia-reperfusion and

Cerebral ischemic stroke: is gender important?

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Gibson, Claire L

2013-09-01

Cerebral stroke continues to be a major cause of death and the leading cause of long-term disability in developed countries. Evidence reviewed here suggests that gender influences various aspects of the clinical spectrum of ischemic stroke, in terms of influencing how a patients present with ischemic stroke through to how they respond to treatment. In addition, this review focuses on discussing the various pathologic mechanisms of ischemic stroke that may differ according to gender and compares how intrinsic and hormonal mechanisms may account for such gender differences. All clinical trials to date investigating putative neuroprotective treatments for ischemic stroke have failed, and it may be that our understanding of the injury cascade initiated after ischemic injury is incomplete. Revealing aspects of the pathophysiological consequences of ischemic stroke that are gender specific may enable gender relevant and effective neuroprotective strategies to be identified. Thus, it is possible to conclude that gender does, in fact, have an important role in ischemic stroke and must be factored into experimental and clinical investigations of ischemic stroke.

Cell swelling and glycogen metabolism in hepatocytes from fasted rats

NARCIS (Netherlands)

Gustafson, L. A.; Jumelle-Laclau, M. N.; van Woerkom, G. M.; van Kuilenburg, A. B.; Meijer, A. J.

1997-01-01

Cell swelling is known to increase net glycogen production from glucose in hepatocytes from fasted rats by activating glycogen synthase. Since both active glycogen synthase and phosphorylase are present in hepatocytes, suppression of flux through phosphorylase may also contribute to the net increase

Sodium-independent, bicuculline-sensitive [3H]GABA binding to isolated rat hepatocytes

International Nuclear Information System (INIS)

Minuk, G.Y.; Bear, C.E.; Sarjeant, E.J.

1987-01-01

To determine whether hepatocytes possess specific receptor sites for gamma-aminobutyric acid (GABA), a potent amino acid neurotransmitter, [ 3 H]GABA, was added to sodium-free suspensions of Percoll-purified hepatocytes derived from collagenase-perfused rat livers under various experimental conditions and in the presence or absence of specific GABA receptor agonists (muscimol) and antagonists (bicuculline). The effects of GABA, muscimol, and bicuculline on hepatocyte resting membrane potentials were also determined. Specific binding of [ 3 H]GABA to hepatocytes was a consistent finding. GABA-hepatocyte interactions were reversible and temperature dependent. Muscimol and bicuculline inhibited binding in a dose-dependent manner (IC50, 30 nM and 50 microM, respectively), whereas strychnine (1.0-100 microM), a nonspecific central nervous system stimulant, had no appreciable effect. Both GABA and muscimol (100 microM) caused significant hyperpolarization of hepatocyte resting membrane potential (delta PD 5.4 +/- 3.1 and 22.2 +/- 16.2 mV, respectively, means +/- SD, P less than 0.0005). Bicuculline (100 microM) inhibited the effect of muscimol (P less than 0.05). The results of this study suggest that specific GABA receptor sites exist on the surface of isolated rat hepatocytes. The presence of such sites raises the possibility that, in addition to adrenergic and cholinergic innervation, hepatic function may be influenced by GABA-ergic neurotransmitter mechanisms

Property of hepatitis B virus replication in Tupaia belangeri hepatocytes.

Science.gov (United States)

Sanada, Takahiro; Tsukiyama-Kohara, Kyoko; Yamamoto, Naoki; Ezzikouri, Sayeh; Benjelloun, Soumaya; Murakami, Shuko; Tanaka, Yasuhito; Tateno, Chise; Kohara, Michinori

2016-01-08

The northern treeshrew (Tupaia belangeri) has been reported to be an effective candidate for animal infection model with hepatitis B virus (HBV). The objective of our study was to analyze the growth characteristics of HBV in tupaia hepatocytes and the host response to HBV infection. We established primary tupaia hepatocytes (3-6-week old tupaia) and infected them with HBV genotypes A, B and C, and all the genotypes proliferated as well as those in human primary hepatocytes (>10(5) copies/ml in culture supernatant). We next generated a chimeric mouse with tupaia liver by transplantation of tupaia primary hepatocytes to urokinase-type plasminogen activator cDNA (cDNA-uPA)/severe combined immunodeficient (SCID) mice and the replacement ratio with tupaia hepatocytes was found to be more than 95%. Infection of chimeric mice with HBV (genotypes B, C, and D) resulted in HBV-DNA level of 10(4)-10(6) copies/ml after 8 weeks of infection, which were almost similar to that in humanized chimeric mouse. In contrast, serum HBV level in adult tupaia (1-year-old tupaia) was quite low (<10(3) copies/ml). Understanding the differences in the response to HBV infection in primary tupaia hepatocytes, chimeric mouse, and adult tupaia will contribute to elucidating the mechanism of persistent HBV infection and viral eradication. Thus, T. belangeri was found to be efficient for studying the host response to HBV infection, thereby providing novel insight into the pathogenesis of HBV. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Effect of hepatocyte growth factor on radiation response of HeLa, V79, CHO and primary cultured parenchymal hepatocyte in vitro

International Nuclear Information System (INIS)

Yamazaki, Hideya; Inoue, Takehiro; Nose, Takayuki; Murayama, Shigeyuki; Teshima, Teruki; Ozeki, Syuji; Koizumi, Masahiko; Inoue, Toshihiko.

1996-01-01

Hepatocyte growth factor (HGF) is a multipotent cytokine enhancing regeneration of injured organs as liver, kidney and lung after injury. HGF enhances proliferation of various type of cells, inhibits proliferation of carcinoma cells, enhances motility of epithelial cells. We examined three cell lines (CHO, HeLa, V79) and primary cultured normal rat parenchymal hepatocytes to determine the effect of HGF on radiation response. HGF diminished survival of CHO and V79 cells determined by colony formation assay, whereas no significant change of survival was found in HeLa cells. No synergistic changes of survival were found when these three cell lines were irradiated with the addition of HGF. Thus, HGF did not enhance the radiation effect. We also analyzed the impact of irradiation with HGF on primary cultured normal rat parenchymal hepatocytes. At first, the release of glutamic-oxaloacetic amino-transaminase (GOT) in the supernatant was estimated. Irradiation (40 Gy) with or without HGF did not change GOT release in acute phase by 4 days after irradiation compared with the unirradiated control. Second, the DNA synthesis of rat parenchymal hepatocytes was analyzed using radioactive iodine-labeled deoxyuridine incorporation. HGF counteracted the suppression of DNA synthesis induced by irradiation. Thus, HGF may act as a mitogen even for irradiation-damaged normal cells. (author)

Extracellular matrix components influence DNA synthesis of rat hepatocytes in primary culture

International Nuclear Information System (INIS)

Sawada, N.; Tomomura, A.; Sattler, C.A.; Sattler, G.L.; Kleinman, H.K.; Pitot, H.C.

1986-01-01

The effects of several extracellular matrix components (EMCs) - fibronectin (Fn), laminin (Ln), type I (C-I) and type IV (C-IV) collagen - on DNA synthesis in rat hepatocytes in primary culture were examined by both quantitative scintillation spectrometry and autoradiography of [ 3 H]thymidine incorporation. Hepatocytes cultured on Fn showed the most active DNA synthesis initiated by epidermal growth factor (EGF) with decreasing levels of [ 3 H]thymidine uptake exhibited in the cell cultured on C-IV, C-I, and Ln, respectively. The decreasing level of DNA synthesis in hepatocytes cultured on Fn, C-IV, C-I, and Ln respectively was not influenced by cell density. The number of EGF receptors of hepatocytes was also not influenced by EMCs. These data suggest that EMCs modify hepatocyte DNA synthesis by means of post-EGF-receptor mechanisms which are regulated by both growth factors and cell density

Differential Impacts of Soybean and Fish Oils on Hepatocyte Lipid Droplet Accumulation and Endoplasmic Reticulum Stress in Primary Rabbit Hepatocytes

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Xueping Zhu

2016-01-01

Full Text Available Parenteral nutrition-associated liver disease (PNALD is a severe ailment associated with long-term parenteral nutrition. Soybean oil-based lipid emulsions (SOLE are thought to promote PNALD development, whereas fish oil-based lipid emulsions (FOLE are thought to protect against PNALD. This study aimed to investigate the effects of SOLE and FOLE on primary rabbit hepatocytes. The results reveal that SOLE caused significant endoplasmic reticulum (ER and mitochondrial damage, ultimately resulting in lipid droplets accumulation and ER stress. While these deleterious events induce hepatocyte injury, FOLE at high doses cause only minor ER and mitochondrial damage, which has no effect on hepatic function. SOLE also significantly upregulated glucose-regulated protein 94 mRNA and protein expression. These data indicate that SOLE, but not FOLE, damage the ER and mitochondria, resulting in lipid droplets accumulation and ER stress and, finally, hepatocyte injury. This likely contributes to the differential impacts of SOLE and FOLE on PNALD development and progression.

Stimulation of neurotrophic factors and inhibition of proinflammatory cytokines by exogenous application of triiodothyronine in the rat model of ischemic stroke.

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Sabbaghziarani, Fatemeh; Mortezaee, Keywan; Akbari, Mohammad; Kashani, Iraj Ragerdi; Soleimani, Mansooreh; Hassanzadeh, Gholamreza; Zendedel, Adib

2017-01-01

There is a positive relation between decreases of triiodothyronine (T3) amounts and severity of stroke. The aim of this study was to evaluate the effect of exogenous T3 application on levels of neurogenesis markers in the subventricular zone. Cerebral ischemia was induced by middle cerebral artery occlusion in male Wistar rats. There were 4 experimental groups: sham, ischemic, vehicle, and treatment. Rats were injected with T3 (25 μg/kg, IV injection) at 24 hours after ischemia. Animals were sacrificed at day 7 after ischemia. There were high levels of brain-derived neurotrophic factor, nestin, and Sox2 expressions in gene and protein levels in the T3 treatment group (P ≤ .05 vs ischemic group). Treatment group showed high levels of sera T3 and thyroxine (T4) but low levels of thyrotropin (TSH), tumor necrosis factor-α, and interleukin-6 (P ≤ .05 vs ischemic group) at day 4 after ischemia induction. Findings of this study revealed the effectiveness of exogenous T3 application in the improvement of neurogenesis possibly via regulation of proinflammatory cytokines. Copyright © 2017 John Wiley & Sons, Ltd.

[Cadmium citotoxicity in mice hepatocytes and implications on tropical environments].

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Marcano, Letty; Faría, Clarisa de R; Carruyo, Ingrid; Montiel, Xiomara

2006-06-01

We analyzed phenotypic, structural and ultrastructural alterations induced by Cd+2 in hepatocytes extracted from Swiss Albino mice. Cadmium was given orally in watery solution of CdCl2 during 100 days at concentrations of 50 ppm, 100 ppm and 150 ppm. In controls, distilled water alone was used. The samples were processed with the paraffin inclusion and hematoxilin-eosin coloration techniques for light microscopy. For transmission electron microscopy we used the conventional technique. We found phenotypic (size and weight differences) and physiologic changes (muscular weakness, unrest); at the structural level we noticed loss of trabecular disposition and of lobulillar architecture, lymphocyte agglomeration, vacuolization, dilatation of sinusoid and central vein, among others. The ultrastructural study evidenced alterations coincident with those seen with light microscopy, which were accentuated with the increase of metal concentration: nucleolus with a high number of fibrillar centers (50 ppm); voluminous lipidic drops in the cytoplasm, loose endoplasmic rough reticulum, citoplasmatic vacuolization, altered lisosomes and peroxisomes (100 ppm); contracted nuclei with condensed cromatine, dilatation of intracellular space and mitochondria, and loss of fibrillar areas (150 ppm). Cadmium produces a toxic effect in the hepatic cells; the effect is more severe at higher concentration, leading to cellular necrosis.

Metabolism of lipoproteins by human fetal hepatocytes

International Nuclear Information System (INIS)

Carr, B.R.

1987-01-01

The rate of clearance of lipoproteins from plasma appears to play a role in the development of atherogenesis. The liver may account for as much as two thirds of the removal of low-density lipoprotein and one third of the clearance of high-density lipoprotein in certain animal species and humans, mainly by receptor-mediated pathways. The purpose of the present investigation was to determine if human fetal hepatocytes maintained in vitro take up and degrade lipoproteins. We first determined that the maximal binding capacity of iodine 125-iodo-LDL was approximately 300 ng of low-density lipoprotein protein/mg of membrane protein and an apparent dissociation constant of approximately 60 micrograms low-density lipoprotein protein/ml in membranes prepared from human fetal liver. We found that the maximal uptake of [ 125 I]iodo-LDL and [ 125 I]iodo-HDL by fetal hepatocytes occurred after 12 hours of incubation. Low-density lipoprotein uptake preceded the appearance of degradation products by 4 hours, and thereafter the degradation of low-density lipoprotein increased linearly for at least 24 hours. In contrast, high-density lipoprotein was not degraded to any extent by fetal hepatocytes. [ 125 I]Iodo-LDL uptake and degradation were inhibited more than 75% by preincubation with low-density lipoprotein but not significantly by high-density lipoprotein, whereas [ 125 I]iodo-HDL uptake was inhibited 70% by preincubation with high-density lipoprotein but not by low-density lipoprotein. In summary, human fetal hepatocytes take up and degrade low-density lipoprotein by a receptor-mediated process similar to that described for human extrahepatic tissues

Airway necrosis after salvage esophagectomy

International Nuclear Information System (INIS)

Tanaka, Norimitsu; Hokamura, Nobukazu; Tachimori, Yuji

2010-01-01

Salvage esophagectomy is the sole curative intent treatment for patients with persistent or recurrent locoregional disease after definitive chemoradiotherapy (CRT) for esophageal carcinoma. However, salvage esophagectomy is a very high-risk operation, and airway necrosis is a fatal complication. Between 1997 and 2007, 49 patients with thoracic esophageal cancer underwent salvage esophagectomy after definitive CRT. We retrospectively compared patients with and without airway necrosis, and investigated operative procedures related to airway necrosis. Airway necrosis occurred in five patients (10.2%), of four patients (80%) died during their hospitalization. Airway necrosis seemed to be closely related to operative procedures, such as resection of bronchial artery and cervical and subcarinal lymph node dissection. Bronchogastric fistula following necrosis of gastric conduit occured in 2 patients reconstructed through posterior mediastinal route. Airway necrosis is a highly lethal complication after salvage esophagectomy. It is important in salvage esophagectomy to take airway blood supply into consideration sufficiently and to reconstruct through retrosternal route to prevent bronchogastric fistula. (author)

Role of CYP2B in Phenobarbital-Induced Hepatocyte Proliferation in Mice.

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Li, Lei; Bao, Xiaochen; Zhang, Qing-Yu; Negishi, Masahiko; Ding, Xinxin

2017-08-01

Phenobarbital (PB) promotes liver tumorigenesis in rodents, in part through activation of the constitutive androstane receptor (CAR) and the consequent changes in hepatic gene expression and increases in hepatocyte proliferation. A typical effect of CAR activation by PB is a marked induction of Cyp2b10 expression in the liver; the latter has been suspected to be vital for PB-induced hepatocellular proliferation. This hypothesis was tested here by using a Cyp2a(4/5)bgs -null (null) mouse model in which all Cyp2b genes are deleted. Adult male and female wild-type (WT) and null mice were treated intraperitoneally with PB at 50 mg/kg once daily for 5 successive days and tested on day 6. The liver-to-body weight ratio, an indicator of liver hypertrophy, was increased by 47% in male WT mice, but by only 22% in male Cyp2a(4/5)bgs -null mice, by the PB treatment. The fractions of bromodeoxyuridine-positive hepatocyte nuclei, assessed as a measure of the rate of hepatocyte proliferation, were also significantly lower in PB-treated male null mice compared with PB-treated male WT mice. However, whereas few proliferating hepatocytes were detected in saline-treated mice, many proliferating hepatocytes were still detected in PB-treated male null mice. In contrast, female WT mice were much less sensitive than male WT mice to PB-induced hepatocyte proliferation, and PB-treated female WT and PB-treated female null mice did not show significant difference in rates of hepatocyte proliferation. These results indicate that CYP2B induction plays a significant, but partial, role in PB-induced hepatocyte proliferation in male mice. U.S. Government work not protected by U.S. copyright.

Hepatocyte growth factor in renal failure: promise and reality.

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Vargas, G A; Hoeflich, A; Jehle, P M

2000-04-01

Can science discover some secrets of Greek mythology? In the case of Prometheus, we can now suppose that his amazing hepatic regeneration was caused by a peptide growth factor called hepatocyte growth factor (HGF). Increasing evidence indicates that HGF acts as a multifunctional cytokine on different cell types. This review addresses the molecular mechanisms that are responsible for the pleiotropic effects of HGF. HGF binds with high affinity to its specific tyrosine kinase receptor c-met, thereby stimulating not only cell proliferation and differentiation, but also cell migration and tumorigenesis. The three fundamental principles of medicine-prevention, diagnosis, and therapy-may be benefited by the rational use of HGF. In renal tubular cells, HGF induces mitogenic and morphogenetic responses. In animal models of toxic or ischemic acute renal failure, HGF acts in a renotropic and nephroprotective manner. HGF expression is rapidly up-regulated in the remnant kidney of nephrectomized rats, inducing compensatory growth. In a mouse model of chronic renal disease, HGF inhibits the progression of tubulointerstitial fibrosis and kidney dysfunction. Increased HGF mRNA transcripts were detected in mesenchymal and tubular epithelial cells of rejecting kidney. In transplanted patients, elevated HGF levels may indicate renal rejection. When HGF is considered as a therapeutic agent in human medicine, for example, to stimulate kidney regeneration after acute injury, strategies need to be developed to stimulate cell regeneration and differentiation without an induction of tumorigenesis.

Effects of Ischemic Preconditioning of Different Intraoperative Ischemic Times of Vascularized Bone Graft Rabbit Models

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Ahmad Sukari Halim

2013-11-01

Full Text Available BackgroundIschemic preconditioning has been shown to improve the outcomes of hypoxic tolerance of the heart, brain, lung, liver, jejunum, skin, and muscle tissues. However, to date, no report of ischemic preconditioning on vascularized bone grafts has been published.MethodsSixteen rabbits were divided into four groups with ischemic times of 2, 6, 14, and 18 hours. Half of the rabbits in each group underwent ischemic preconditioning. The osteomyocutaneous flaps consisted of the tibia bone, from which the overlying muscle and skin were raised. The technique of ischemic preconditioning involved applying a vascular clamp to the pedicle for 3 cycles of 10 minutes each. The rabbits then underwent serial plain radiography and computed tomography imaging on the first, second, fourth, and sixth postoperative weeks. Following this, all of the rabbits were sacrificed and histological examinations were performed.ResultsThe results showed that for clinical analysis of the skin flaps and bone grafts, the preconditioned groups showed better survivability. In the plain radiographs, except for two non-preconditioned rabbits with intraoperative ischemic times of 6 hours, all began to show early callus formation at the fourth week. The computed tomography findings showed more callus formation in the preconditioned groups for all of the ischemic times except for the 18-hour group. The histological findings correlated with the radiological findings. There was no statistical significance in the difference between the two groups.ConclusionsIn conclusion, ischemic preconditioning improved the survivability of skin flaps and increased callus formation during the healing process of vascularized bone grafts.

Lipopolysaccharide stimulates p62-dependent autophagy-like aggregate clearance in hepatocytes.

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Chen, Christine; Deng, Meihong; Sun, Qian; Loughran, Patricia; Billiar, Timothy R; Scott, Melanie J

2014-01-01

Impairment of autophagy has been associated with liver injury. TLR4-stimulation by LPS upregulates autophagy in hepatocytes, although the signaling pathways involved remain elusive. The objective of this study was to determine the signaling pathway leading to LPS-stimulated autophagy in hepatocytes. Cell lysates from livers of wild type (WT; C57BL/6) mice given LPS (5 mg/kg-IP) and hepatocytes from WT, TLR4ko, and MyD88ko mice treated with LPS (100 ng/mL) up to 24 h were collected. LC3II, p62/SQSTM1, Nrf2, and beclin1 levels were determined by immunoblot, immunofluorescence, and qPCR. Autophagy-like activation was measured by GFP-LC3-puncta formation and LC3II-expression. Beclin1, Nrf2, p62, MyD88, and TIRAP were knocked-down using siRNA. LC3II-expression increased in both liver and hepatocytes after LPS and was dependent on TLR4. Beclin1 expression did not increase after LPS in hepatocytes and beclin1-knockdown did not affect LC3II levels. In hepatocytes given LPS, expression of p62 increased and p62 colocalized with LC3. p62-knockdown prevented LC3II puncta formation. LPS-induced LC3II/p62-puncta also required MyD88/TIRAP signaling and localization of both Nrf2 and NF κ B transcription factors to the nucleus to upregulate p62-expression. Therefore, TLR4-activation by LPS in hepatocytes induces a p62-mediated, not beclin1-mediated, autophagy-like clearance pathway that is hepatoprotective by clearing aggregate-prone or misfolded proteins from the cytosol and preserving energy homeostasis under stress.

DNA synthesis in periportal and perivenous hepatocytes of intact and hepatectomized young mice.

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Fernández-Blanco, A; Inda, A M; Errecalde, A L

2015-01-01

DNA synthesis of hepatocytes in two areas of Intact and Hepatectomized young mice liver along a circadian period was studied. DNA synthesis was significantly different at all analyzed time points in Intact and Hepatectomized animals. Differences between periportal and perivenous hepatocytes were found in hepatectomized animals at 04/42 and 08/46 hr of day/hour post-hepatectomy. DNAs peak in periportal hepatocytes regenerating liver occurs 4 hr earlier than in perivenous hepatocytes, probably reflecting their shorter G1 phase. Besides, daily mean values of regenerating livers were higher than those observed in Intact animals, as a consequence of surgical removal.

Induction of hepatocyte polyploidization in rats of different age by ionizing radiation of different LET

International Nuclear Information System (INIS)

Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.

1992-01-01

A decrease in the effectiveness of neutron-irradiation with respect to fusion of nonproliferating hepatocytes of animals with age was shown by the method of flow cytometry. There was an inverse relationship between the effectiveness of induction of non-proliferating hepatocytes fusion and neutron energy. The process of hepatocyte fusion induced by neutrons was inhibited by uranyl acetate. No age-dependent changes were noted in the induction of polyploidization of proliferating hepatocytes by sparsely ionizing radiation. A hypothesis is proposed concerning a membrane nature of the target responsible for hepatocyte polyploidization induced by densely ionizing radiation. (authors). 8 refs., 4 figs., 5 tabs

Induction of hepatocyte polyploidization in rats of different age by ionizing radiation of different LET

International Nuclear Information System (INIS)

Gil'yano, N.Ya.; Malinovskij, O.V.; Khair, M.B.

1990-01-01

A decrease in the effectiveness of neutron-irradiation with respect to fusion of nonproliferating hepatocytes of animals with age was shown by the method of flow cytometry. There was an inverse relationship between the effectiveness of induction of non-proliferating hepatocytes fusion and neutron energy. The process of hepatocyte fusion induced by neutrons was inhibited by uranyl acetate. No age-dependent changes were noted in the induction of polyploidization of proliferating hepatocytes by sparsely ionizing radiation. A hypothesis is proposed concerning a membrane nature of the target responsible for hepatocyte polyploidization induced by densely ionizing radiation

Hepatocyte growth factor/c-MET axis-mediated tropism of cord blood-derived unrestricted somatic stem cells for neuronal injury.

Science.gov (United States)

Trapp, Thorsten; Kögler, Gesine; El-Khattouti, Abdelouahid; Sorg, Rüdiger V; Besselmann, Michael; Föcking, Melanie; Bührle, Christian P; Trompeter, Ingo; Fischer, Johannes C; Wernet, Peter

2008-11-21

An under-agarose chemotaxis assay was used to investigate whether unrestricted somatic stem cells (USSC) that were recently characterized in human cord blood are attracted by neuronal injury in vitro. USSC migrated toward extracts of post-ischemic brain tissue of mice in which stroke had been induced. Moreover, apoptotic neurons secrete factors that strongly attracted USSC, whereas necrotic and healthy neurons did not. Investigating the expression of growth factors and chemokines in lesioned brain tissue and neurons and of their respective receptors in USSC revealed expression of hepatocyte growth factor (HGF) in post-ischemic brain and in apoptotic but not in necrotic neurons and of the HGF receptor c-MET in USSC. Neuronal lesion-triggered migration was observed in vitro and in vivo only when c-MET was expressed at a high level in USSC. Neutralization of the bioactivity of HGF with an antibody inhibited migration of USSC toward neuronal injury. This, together with the finding that human recombinant HGF attracts USSC, document that HGF signaling is necessary for the tropism of USSC for neuronal injury. Our data demonstrate that USSC have the capacity to migrate toward apoptotic neurons and injured brain. Together with their neural differentiation potential, this suggests a neuroregenerative potential of USSC. Moreover, we provide evidence for a hitherto unrecognized pivotal role of the HGF/c-MET axis in guiding stem cells toward brain injury, which may partly account for the capability of HGF to improve function in the diseased central nervous system.

Blood pressure, risk of ischemic cerebrovascular and ischemic heart disease, and longevity in alpha(1)-antitrypsin deficiency

DEFF Research Database (Denmark)

Dahl, Morten; Tybjaerg-Hansen, Anne; Sillesen, Henrik

2003-01-01

Because elastase in alpha(1)-antitrypsin deficiency may attack elastin in the arterial wall, we tested whether alpha(1)-antitrypsin deficiency is associated with reduced blood pressure, risk of ischemic cerebrovascular (ICVD) and ischemic heart disease (IHD), and longevity.......Because elastase in alpha(1)-antitrypsin deficiency may attack elastin in the arterial wall, we tested whether alpha(1)-antitrypsin deficiency is associated with reduced blood pressure, risk of ischemic cerebrovascular (ICVD) and ischemic heart disease (IHD), and longevity....

Hepatocyte transplantation and advancements in alternative cell sources for liver-based regenerative medicine.

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Lee, Charlotte A; Sinha, Siddharth; Fitzpatrick, Emer; Dhawan, Anil

2018-06-01

Human hepatocyte transplantation has been actively perused as an alternative to liver replacement for acute liver failure and liver-based metabolic defects. Current challenges in this field include a limited cell source, reduced cell viability following cryopreservation and poor engraftment of cells into the recipient liver with consequent limited life span. As a result, alternative stem cell sources such as pluripotent stem cells, fibroblasts, hepatic progenitor cells, amniotic epithelial cells and mesenchymal stem/stromal cells (MSCs) can be used to generate induced hepatocyte like cells (HLC) with each technique exhibiting advantages and disadvantages. HLCs may have comparable function to primary human hepatocytes and could offer patient-specific treatment. However, long-term functionality of transplanted HLCs and the potential oncogenic risks of using stem cells have yet to be established. The immunomodulatory effects of MSCs are promising, and multiple clinical trials are investigating their effect in cirrhosis and acute liver failure. Here, we review the current status of hepatocyte transplantation, alternative cell sources to primary human hepatocytes and their potential in liver regeneration. We also describe recent clinical trials using hepatocytes derived from stem cells and their role in improving the phenotype of several liver diseases.

[Unilateral acute pulmonary edema and ischemic myocardial process: a case report].

Science.gov (United States)

Bentaleb, A; Tagu, P; Vascaut, L

2008-08-01

Unilateral acute pulmonary oedema (APO) is a rare radioclinical finding. It occurs secondary to multiple specific and rare pathological processes. Functional ischemic mitral regurgitation (FIMR) secondary to myocardial necrosis is one of the rare aetiologies involved in its pathogenesis. This concerns a 94-year-old male patient with a history of myocardial infarction who presented with a clinical picture of unilateral APO secondary to functional mitral regurgitation as a complication of myocardial necrosis. In addition to the clinical presentation and unilateral radiological findings, the diagnosis was based essentially on the electrocardiographic tracing, as well as changes in cardiac enzyme levels and transthoracic echocardiogram coupled with Doppler tissue imaging. This resulted after ruling out many differential diagnoses. Unilateral APO secondary to functional mitral regurgitation often presents diagnostic challenges and problems of initial management for the clinician. There are multiple aetiologies of acute unilateral pulmonary oedema, namely mechanical (re-expansion), lesional, vascular, bronchial obstructions, as well as iatrogenic causes, as is the case with some lung transplantations. As with all cases of APO, the treatment is based mainly on diuretics with high-flow oxygen therapy in association with an anticoagulant, which is usually effectively combined with a platelet aggregation inhibiting drug and sometimes with vasodilators and beta-blockers. Surgical treatment with valvuloplasty or valvular replacement appears to be the most effective means for preventing relapse.

Functional properties of hepatocytes in vitro are correlated with cell polarity maintenance.

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Zeigerer, Anja; Wuttke, Anne; Marsico, Giovanni; Seifert, Sarah; Kalaidzidis, Yannis; Zerial, Marino

2017-01-01

Exploring the cell biology of hepatocytes in vitro could be a powerful strategy to dissect the molecular mechanisms underlying the structure and function of the liver in vivo. However, this approach relies on appropriate in vitro cell culture systems that can recapitulate the cell biological and metabolic features of the hepatocytes in the liver whilst being accessible to experimental manipulations. Here, we adapted protocols for high-resolution fluorescence microscopy and quantitative image analysis to compare two primary hepatocyte culture systems, monolayer and collagen sandwich, with respect to the distribution of two distinct populations of early endosomes (APPL1 and EEA1-positive), endocytic capacity, metabolic and signaling activities. In addition to the re-acquisition of hepatocellular polarity, primary hepatocytes grown in collagen sandwich but not in monolayer culture recapitulated the apico-basal distribution of EEA1 endosomes observed in liver tissue. We found that such distribution correlated with the organization of the actin cytoskeleton in vitro and, surprisingly, was dependent on the nutritional state in vivo. Hepatocytes in collagen sandwich also exhibited faster kinetics of low-density lipoprotein (LDL) and epidermal growth factor (EGF) internalization, showed improved insulin sensitivity and preserved their ability for glucose production, compared to hepatocytes in monolayer cultures. Although no in vitro culture system can reproduce the exquisite structural features of liver tissue, our data nevertheless highlight the ability of the collagen sandwich system to recapitulate key structural and functional properties of the hepatocytes in the liver and, therefore, support the usage of this system to study aspects of hepatocellular biology in vitro. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

A fat option for the pig: Hepatocytic differentiated mesenchymal stem cells for translational research

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Brückner, Sandra, E-mail: sandra.brueckner@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); Tautenhahn, Hans-Michael, E-mail: hans-michael.tautenhahn@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); TRM, Translational Centre for Regenerative Medicine, Philipp-Rosenthal-Str. 55, Leipzig D-04103 (Germany); Winkler, Sandra, E-mail: sandra.pelz@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); Stock, Peggy, E-mail: peggy.stock@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); Dollinger, Matthias, E-mail: matthias.dollinger@uniklinik-ulm.de [University Hospital Ulm, First Department of Medicine, Albert-Einstein-Allee 23, Ulm D-89081 (Germany); Christ, Bruno, E-mail: bruno.christ@medizin.uni-leipzig.de [University Hospital Leipzig, Department of Visceral, Transplantation, Thoracic and Vascular Surgery, Liebigstraße 21, Leipzig D-04103 (Germany); TRM, Translational Centre for Regenerative Medicine, Philipp-Rosenthal-Str. 55, Leipzig D-04103 (Germany)

2014-02-15

Study background: Extended liver resection is the only curative treatment option of liver cancer. Yet, the residual liver may not accomplish the high metabolic and regenerative capacity needed, which frequently leads to acute liver failure. Because of their anti-inflammatory and -apoptotic as well as pro-proliferative features, mesenchymal stem cells differentiated into hepatocyte-like cells might provide functional and regenerative compensation. Clinical translation of basic research requires pre-clinical approval in large animals. Therefore, we characterized porcine mesenchymal stem cells (MSC) from adipose tissue and bone marrow and their hepatocyte differentiation potential for future assessment of functional liver support after surgical intervention in the pig model. Methods: Mesenchymal surface antigens and multi-lineage differentiation potential of porcine MSC isolated by collagenase digestion either from bone marrow or adipose tissue (subcutaneous/visceral) were assessed by flow cytometry. Morphology and functional properties (urea-, glycogen synthesis and cytochrome P450 activity) were determined during culture under differentiation conditions and compared with primary porcine hepatocytes. Results: MSC from porcine adipose tissue and from bone marrow express the typical mesenchymal markers CD44, CD29, CD90 and CD105 but not haematopoietic markers. MSC from both sources displayed differentiation into the osteogenic as well as adipogenic lineage. After hepatocyte differentiation, expression of CD105 decreased significantly and cells adopted the typical polygonal morphology of hepatocytes. Glycogen storage was comparable in adipose tissue- and bone marrow-derived cells. Urea synthesis was about 35% lower in visceral than in subcutaneous adipose tissue-derived MSC. Cytochrome P450 activity increased significantly during differentiation and was twice as high in hepatocyte-like cells generated from bone marrow as from adipose tissue. Conclusion: The hepatocyte

A fat option for the pig: Hepatocytic differentiated mesenchymal stem cells for translational research

International Nuclear Information System (INIS)

Brückner, Sandra; Tautenhahn, Hans-Michael; Winkler, Sandra; Stock, Peggy; Dollinger, Matthias; Christ, Bruno

2014-01-01

Study background: Extended liver resection is the only curative treatment option of liver cancer. Yet, the residual liver may not accomplish the high metabolic and regenerative capacity needed, which frequently leads to acute liver failure. Because of their anti-inflammatory and -apoptotic as well as pro-proliferative features, mesenchymal stem cells differentiated into hepatocyte-like cells might provide functional and regenerative compensation. Clinical translation of basic research requires pre-clinical approval in large animals. Therefore, we characterized porcine mesenchymal stem cells (MSC) from adipose tissue and bone marrow and their hepatocyte differentiation potential for future assessment of functional liver support after surgical intervention in the pig model. Methods: Mesenchymal surface antigens and multi-lineage differentiation potential of porcine MSC isolated by collagenase digestion either from bone marrow or adipose tissue (subcutaneous/visceral) were assessed by flow cytometry. Morphology and functional properties (urea-, glycogen synthesis and cytochrome P450 activity) were determined during culture under differentiation conditions and compared with primary porcine hepatocytes. Results: MSC from porcine adipose tissue and from bone marrow express the typical mesenchymal markers CD44, CD29, CD90 and CD105 but not haematopoietic markers. MSC from both sources displayed differentiation into the osteogenic as well as adipogenic lineage. After hepatocyte differentiation, expression of CD105 decreased significantly and cells adopted the typical polygonal morphology of hepatocytes. Glycogen storage was comparable in adipose tissue- and bone marrow-derived cells. Urea synthesis was about 35% lower in visceral than in subcutaneous adipose tissue-derived MSC. Cytochrome P450 activity increased significantly during differentiation and was twice as high in hepatocyte-like cells generated from bone marrow as from adipose tissue. Conclusion: The hepatocyte

Important hypercalcemia due to subcutaneous fat necrosis treated with pamidronate in an infant with severe hypoxic-ischemic encephalopathy

OpenAIRE

Pasqua Anna Quitadamo; Antonio Villani; Piero Paolo Cristalli; Marina Marinelli; Anita Riganti; Michele Bisceglia; Alberto Gatta

2016-01-01

Subcutaneous fat necrosis (SCFN) of the newborn is an uncommon form of panniculitis that occurs after fetal distress and involves fatty areas during the first weeks of life. This rare disorder is generally self-limiting and undergoes complete regression. However, it can be complicated with a potentially life-threatening hypercalcemia. We report a case of severe hypercalcemia due to SCFN occurring after serious perinatal hypoxic injury, which resolved by intravenous administration of pamidrona...

Circadian rhythms of Per2::Luc in individual primary mouse hepatocytes and cultures.

Directory of Open Access Journals (Sweden)

Casey J Guenthner

Full Text Available BACKGROUND: Hepatocytes, the parenchymal cells of the liver, express core clock genes, such as Period2 and Cryptochrome2, which are involved in the transcriptional/translational feedback loop of the circadian clock. Whether or not the liver is capable of sustaining rhythms independent of a central pacemaker is controversial. Whether and how circadian information may be shared among cells in the liver in order to sustain oscillations is currently unknown. RESULTS: In this study we isolated primary hepatocytes from transgenic Per2(Luc mice and used bioluminescence as a read-out of the state of the circadian clock. Hepatocytes cultured in a collagen gel sandwich configuration exhibited persistent circadian rhythms for several weeks. The amplitude of the rhythms damped, but medium changes consistently reset the phase and amplitude of the cultures. Cry2(-/- Per2(Luc cells oscillated robustly and expressed a longer period. Co-culturing with wildtype cells did not significantly shorten the period, indicating that coupling among hepatocytes is insufficient to synchronize cells with significantly differing periods. However, spatial patterns revealed by cellular imaging of wildtype cultures provided evidence of weak local coupling among the hepatocytes. CONCLUSIONS: Our results with primary hepatocyte cultures demonstrate that cultured hepatocytes are weakly coupled. While this coupling is not sufficient to sustain global synchrony, it does increase local synchrony, which may stabilize the circadian rhythms of peripheral oscillators, such as the liver, against noise in the entraining signals.

Segmental small bowel necrosis associated with antiphospholipid syndrome: a case report.

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Wang, Qun-Ying; Ye, Xiao-Hua; Ding, Jin; Wu, Xiao-Kang

2015-04-07

Antiphospholipid syndrome is a multi-system disease characterized by the formation of thromboembolic complications and/or pregnancy morbidity, and with persistently increased titers of antiphospholipid antibodies. We report the case of a 50-year-old, previously healthy man who presented with fever and new-onset, dull abdominal pain. A contrast-enhanced computed tomography scan showed segmental small bowel obstruction, for which an emergency laparotomy was performed. Histopathologic examination of resected tissues revealed multiple intestinal and mesenteric thromboses of small vessels. Laboratory tests for serum antiphospholipid (anticardiolipin IgM) and anti-β2-glycoprotein I antibodies were positive. Despite proactive implementation of anticoagulation, steroid, and antibiotic therapies, the patient's condition rapidly deteriorated, and he died 22 d after admission. This case highlights that antiphospholipid syndrome should be suspected in patients with unexplainable ischemic bowel and intestinal necrosis presenting with insidious clinical features that may be secondary to the disease, as early diagnosis is critical to implement timely treatments in order to ameliorate the disease course.

Quantitative Measurement of Physical Activity in Acute Ischemic Stroke and Transient Ischemic Attack

DEFF Research Database (Denmark)

Strømmen, Anna Maria; Christensen, Thomas; Jensen, Kai

2014-01-01

BACKGROUND AND PURPOSE: The purpose of this study was to quantitatively measure and describe the amount and pattern of physical activity in patients within the first week after acute ischemic stroke and transient ischemic attack using accelerometers. METHODS: A total of 100 patients with acute is...

Can Vascular Patterns on Preoperative Magnetic Resonance Imaging Help Predict Skin Necrosis after Nipple-Sparing Mastectomy?

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Bahl, Manisha; Pien, Irene J; Buretta, Kate J; Hwang, E Shelley; Greenup, Rachel A; Ghate, Sujata V; Hollenbeck, Scott T

2016-08-01

Nipple-areola complex (NAC) and skin flap ischemia and necrosis can occur after nipple-sparing mastectomy (NSM). The purpose of this study was to correlate vascular findings on MRI with outcomes in patients who underwent NSM. Female patients at a single institution who underwent NSM and had a preoperative breast MRI between 2010 and 2014 were identified. Medical records were reviewed for patient demographics, surgical factors, and complications. Magnetic resonance images were reviewed by 2 radiologists, blinded to outcomes, for the presence of dual vs single blood supply to the breast. The association between blood supply on MRI with ischemic and necrotic complications after NSM was analyzed. One hundred and sixty-four NSM procedures were performed in 105 patients (mean age 45.5 years, range 25 to 69 years) who had a preoperative MRI. The majority of procedures were performed for malignancy (89 of 164 [54.3%]) or prophylaxis (73 of 164 [44.5%]). Nipple-areola complex or skin flap ischemia or necrosis occurred in 40 (24.4%) breasts. Ischemia or necrosis after NSM was less likely to occur in breasts with dual compared with single blood supply (20.8% vs 38.2%; p = 0.03). There was no association between surgical complications and age, BMI, smoking history, previous radiation therapy, indication for NSM, surgical specimen weight, surgical incision type, reconstruction approach, or operating surgeon on univariate analysis. Preoperative MRI characterization of breast vascularity can be considered when planning NSM. The presence of a dual blood supply to the breast on MRI is associated with a decreased risk of nipple-areola complex and skin flap ischemia and necrosis after NSM. Copyright © 2016 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

The effects of profound hypothermia on pancreas ischemic injury: a new experimental model.

Science.gov (United States)

Rocha-Santos, Vinicius; Ferro, Oscar Cavalcante; Pantanali, Carlos Andrés; Seixas, Marcel Povlovistsch; Pecora, Rafael Antonio Arruda; Pinheiro, Rafael Soares; Claro, Laura Carolina López; Abdo, Emílio Elias; Chaib, Eleazar; D'Albuquerque, Luiz Augusto Carneiro

2014-08-01

Pancreatic ischemia-reperfusion (IR) has a key role in pancreas surgery and transplantation. Most experimental models evaluate the normothermic phase of the IR. We proposed a hypothermic model of pancreas IR to evaluate the benefic effects of the cold ischemic phase. We performed a reproducible model of hypothermic pancreatic IR. The ischemia was induced in the pancreatic tail portion (1-hour ischemia, 4-hour reperfusion) in 36 Wistar rats. They are divided in 3 groups as follows: group 1 (control), sham; group 2, normothermic IR; and group 3, hypothermic IR. In group 3, the temperature was maintained as close to 4.5°C. After reperfusion, serum amylase and lipase levels, inflammatory mediators (tumor necrosis factor α, interleukin 6), and pancreas histology were evaluated. In pancreatic IR groups, amylase, cytokines, and histological damage were significantly increased when compared with group 1. In the group 3, we observed a significant decrease in tumor necrosis factor α (P = 0.004) and interleukin 6 (P = 0.001) when compared with group 2. We did not observe significant difference in amylase (P = 0.867), lipase (P = 0.993), and histology (P = 0.201). In our experimental model, we reproduced the cold phase of pancreas IR, and the pancreas hypothermia reduced the inflammatory mediators after reperfusion.

Cell proliferation studies in rodent hepatocytes during 1,4-dichlorobenzene administration

International Nuclear Information System (INIS)

Eldridge, S.R.; Tilbury, L.F.; Randall, H.; Goldsworthy, T.L.; Butterworth, B.E.

1990-01-01

In the NTP bioassay, 1,4-dichlorobenzene (DCB) induced hepatocellular carcinomas in mice, but not in rats. Because DCB is not DNA reactive, a cell proliferation study under conditions of the bioassay was undertaken to determine whether increased cell proliferation might play a role in DCB-induced hepatocarcinogenicity. DCB was administered in corn oil by gavage at the highest bioassay dose to male B6C3F1 mice (600 mg/kg) and male F344 rats (300 mg/kg) for five consecutive days. Cell proliferation was detected by labeling hepatocytes with either 5-bromo-2'-deoxyuridine (BRDU) or 3 H-thymidine delivered during the entire treatment period by subcutaneously implanted osmotic pumps. An increase in liver weight as a percentage of body weight was observed in treated mice (6.7±0.6 vs. 5.9±0.2) and rats (4.7±0.1 vs. 4.0±0.2) compared to controls. No significant elevations in plasma enzymes were found in either treated species, indicating a lack of overt hepatotoxicity. Histopathological evaluation revealed no evidence of hepatotoxicity in either species. The percentage of hepatocytes in S-phase was increased approximately 10-fold in both treated mice and rats compared to the respective control animals. Mice exhibited a centrilobular pattern of labeled hepatocytes, whereas rat hepatocytes were labeled hepatocytes, whereas rat hepatocytes were labeled throughout the lobules. These data demonstrate the hepatic mitogenic activity of DCB in mice and rats. However, this response dose not correlate with DCB-induced hepatocarcinogenicity. Further studies are required to examine the extent, duration and nature of the proliferative response in order to understand the species-specific effects of DCB

Hepatocyte transplants improve liver function and encephalopathy in portacaval shunted rats.

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Fogel, Wieslawa Agnieszka; Stasiak, Anna; Maksymowicz, Michał; Kobos, Jozef; Unzeta, Mercedes; Mussur, Miroslaw

2014-07-01

Rats with portacaval shunt (PCS) are useful experimental models of human hepatic encephalopathy in chronic liver dysfunction. We have previously shown that PCS modifies amine neurotransmitter systems in the CNS and increases voluntary alcohol intake by rats. Hepatocyte transplantation, used in acute liver failure, has recently also been applied to chronic liver diseases, which prompted us to investigate whether the altered brain amine system and the drinking behavior in long-term shunted rats could be normalized by hepatocyte transplants. Hepatocytes, isolated from syngeneic donors by collagenase digestion, were injected (3 × 10(6) cells/rat) into the pancreatic tail region, 6 months after PCS. Hepatic function was evaluated by measuring urine urea and plasma L-histidine concentrations. A free choice test with two bottles (tap water and 10% ethyl alcohol) was performed for 3 days to assess the rats' preference for alcohol. The rats were euthanized 2 months posttransplantation. Brain histamine and 5-hydroxyindoleacetic acid (5-HIAA) levels were measured by radioenzymatic assay and by HPLC-EC, respectively, N-tele-methylhistamine by GC/MS while MAOA and MAOB activities by isotopic procedures. Portacaval shunt rats with hepatocyte transplants gave more urea than before transplantation, with lower plasma L-His levels and higher body weight versus the PCS counterparts. Also, those rats consumed less alcohol. The CNS amines and 5-HIAA concentrations, as well as MAO-B activity, being abnormally high in untreated PCS rats, significantly reduced after PCS hepatocyte treatment. The results support the therapeutic values of hepatocyte transplants in chronic liver diseases and the temporary character of PCS-exerted CNS dysfunctions. © 2014 John Wiley & Sons Ltd.

β-Adrenergic induction of lipolysis in hepatocytes is inhibited by ethanol exposure.

Science.gov (United States)

Schott, Micah B; Rasineni, Karuna; Weller, Shaun G; Schulze, Ryan J; Sletten, Arthur C; Casey, Carol A; McNiven, Mark A

2017-07-14

In liver steatosis ( i.e. fatty liver), hepatocytes accumulate many large neutral lipid storage organelles known as lipid droplets (LDs). LDs are important in the maintenance of energy homeostasis, but the signaling mechanisms that stimulate LD metabolism in hepatocytes are poorly defined. In adipocytes, catecholamines target the β-adrenergic (β-AR)/cAMP pathway to activate cytosolic lipases and induce their recruitment to the LD surface. Therefore, the goal of this study was to determine whether hepatocytes, like adipocytes, also undergo cAMP-mediated lipolysis in response to β-AR stimulation. Using primary rat hepatocytes and human hepatoma cells, we found that treatment with the β-AR agent isoproterenol caused substantial LD loss via activation of cytosolic lipases adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL). β-Adrenergic stimulation rapidly activated PKA, which led to the phosphorylation of ATGL and HSL and their recruitment to the LD surface. To test whether this β-AR-dependent lipolysis pathway was altered in a model of alcoholic fatty liver, primary hepatocytes from rats fed a 6-week EtOH-containing Lieber-DeCarli diet were treated with cAMP agonists. Compared with controls, EtOH-exposed hepatocytes showed a drastic inhibition in β-AR/cAMP-induced LD breakdown and the phosphorylation of PKA substrates, including HSL. This observation was supported in VA-13 cells, an EtOH-metabolizing human hepatoma cell line, which displayed marked defects in both PKA activation and isoproterenol-induced ATGL translocation to the LD periphery. In summary, these findings suggest that β-AR stimulation mobilizes cytosolic lipases for LD breakdown in hepatocytes, and perturbation of this pathway could be a major consequence of chronic EtOH insult leading to fatty liver.

Oxidative stress is involved in Dasatinib-induced apoptosis in rat primary hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Xue, Tao; Luo, Peihua; Zhu, Hong; Zhao, Yuqin [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Wu, Honghai; Gai, Renhua; Wu, Youping [Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China); Yang, Bo [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Yang, Xiaochun, E-mail: yangxiaochun@zju.edu.cn [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China); He, Qiaojun, E-mail: qiaojunhe@zju.edu.cn [Institute of Pharmacology and Toxicology, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Center for Drug Safety Evaluation and Research of Zhejiang University, Hangzhou 310058 (China)

2012-06-15

Dasatinib, a multitargeted inhibitor of BCR–ABL and SRC kinases, exhibits antitumor activity and extends the survival of patients with chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL). However, some patients suffer from hepatotoxicity, which occurs through an unknown mechanism. In the present study, we found that Dasatinib could induce hepatotoxicity both in vitro and in vivo. Dasatinib reduced the cell viability of rat primary hepatocytes, induced the release of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) in vitro, and triggered the ballooning degeneration of hepatocytes in Sprague–Dawley rats in vivo. Apoptotic markers (chromatin condensation, cleaved caspase-3 and cleaved PARP) were detected to indicate that the injury induced by Dasatinib in hepatocytes in vitro was mediated by apoptosis. This result was further validated in vivo using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assays. Here we found that Dasatinib dramatically increased the level of reactive oxygen species (ROS) in hepatocytes, reduced the intracellular glutathione (GSH) content, attenuated the activity of superoxide dismutase (SOD), generated malondialdehyde (MDA), a product of lipid peroxidation, decreased the mitochondrial membrane potential, and activated nuclear factor erythroid 2-related factor 2 (Nrf2) and mitogen-activated protein kinases (MAPK) related to oxidative stress and survival. These results confirm that oxidative stress plays a pivotal role in Dasatinib-mediated hepatotoxicity. N-acetylcysteine (NAC), a typical antioxidant, can scavenge free radicals, attenuate oxidative stress, and protect hepatocytes against Dasatinib-induced injury. Thus, relieving oxidative stress is a viable strategy for reducing Dasatinib-induced hepatotoxicity. -- Highlights: ►Dasatinib shows potential hepatotoxicity both in vitro and in vivo. ►Apoptosis plays a vital role in Dasatinib

Propofol pretreatment attenuates LPS-induced granulocyte-macrophage colony-stimulating factor production in cultured hepatocytes by suppressing MAPK/ERK activity and NF-κB translocation

International Nuclear Information System (INIS)

Jawan, Bruno; Kao, Y.-H.; Goto, Shigeru; Pan, M.-C.; Lin, Y.-C.; Hsu, L.-W.; Nakano, Toshiaki; Lai, C.-Y.; Sun, C.-K.; Cheng, Y.-F.; Tai, M.-H.

2008-01-01

Propofol (PPF), a widely used intravenous anesthetic for induction and maintenance of anesthesia during surgeries, was found to possess suppressive effect on host immunity. This study aimed at investigating whether PPF plays a modulatory role in the lipopolysaccharide (LPS)-induced inflammatory cytokine expression in a cell line of rat hepatocytes. Morphological observation and viability assay showed that PPF exhibits no cytotoxicity at concentrations up to 300 μM after 48 h incubation. Pretreatment with 100 μM PPF for 24 h prior to LPS stimulation was performed to investigate the modulatory effect on LPS-induced inflammatory gene production. The results of semi-quantitative RT-PCR demonstrated that PPF pretreatment significantly suppressed the LPS-induced toll-like receptor (TLR)-4, CD14, tumor necrosis factor (TNF)-α, and granulocyte-macrophage colony-stimulating factor (GM-CSF) gene expression. Western blotting analysis showed that PPF pretreatment potentiated the LPS-induced TLR-4 downregulation. Flow cytometrical analysis revealed that PPF pretreatment showed no modulatory effect on the LPS-upregulated CD14 expression on hepatocytes. In addition, PPF pretreatment attenuated the phosphorylation of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) and IκBα, as well as the nuclear translocation of NF-κB primed by LPS. Moreover, addition of PD98059, a MAPK kinase inhibitor, significantly suppressed the LPS-induced NF-κB nuclear translocation and GM-CSF production, suggesting that the PPF-attenuated GM-CSF production in hepatocytes may be attributed to its suppressive effect on MAPK/ERK signaling pathway. In conclusion, PPF as an anesthetic may clinically benefit those patients who are vulnerable to sepsis by alleviating sepsis-related inflammatory response in livers

Determination of metabolic stability using cryopreserved hepatocytes from rainbow trout (Oncorhynchus mykiss)

Science.gov (United States)

Standard protocols for isolating, cryopreserving, and thawing rainbow trout hepatocytes are described, along with procedures for using fresh or cryopreserved hepatocytes to assess chemical metabolic stability in fish by means of a substrate depletion approach. Variations on thes...

Evaluation of perfluoroalkyl acid activity using primary mouse and human hepatocytes

International Nuclear Information System (INIS)

Rosen, Mitchell B.; Das, Kaberi P.; Wood, Carmen R.; Wolf, Cynthia J.; Abbott, Barbara D.; Lau, Christopher

2013-01-01

While perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have been studied at length, less is known about the biological activity of other perfluoroalkyl acids (PFAAs) detected in the environment. Using a transient transfection assay developed in COS-1 cells, our group has previously evaluated a variety of PFAAs for activity associated with activation of peroxisome proliferator-activated receptor alpha (PPARα). Here we use primary heptatocytes to further assess the biological activity of a similar group of PFAAs using custom designed Taqman Low Density Arrays. Primary mouse and human hepatoyctes were cultured for 48 h in the presence of varying concentrations of 12 different PFAAs or Wy14,643, a known activator of PPARα. Total RNA was collected and the expression of 48 mouse or human genes evaluated. Gene selection was based on either in-house liver microarray data (mouse) or published data using primary hepatocytes (human). Gene expression in primary mouse hepatocytes was more restricted than expected. Genes typically regulated in whole tissue by PPARα agonists were not altered in mouse cells including Acox1, Me1, Acaa1a, Hmgcs1, and Slc27a1. Cyp2b10, a gene regulated by the constitutive androstane receptor and a transcript normally up-regulated by in vivo exposure to PFAAs, was also unchanged in cultured mouse hepatocytes. Cyp4a14, Ehhadh, Pdk4, Cpt1b, and Fabp1 were regulated as expected in mouse cells. A larger group of genes were differentially expressed in human primary hepatocytes, however, little consistency was observed across compounds with respect to which genes produced a significant dose response making the determination of relative biological activity difficult. This likely reflects weaker activation of PPARα in human versus rodent cells as well as variation among individual cell donors. Unlike mouse cells, CYP2B6 was up-regulated in human hepatocytes by a number of PFAAs as was PPARδ. Rankings were conducted on the limited

Bidirectional transport of iminodiacetic organic anion analogues between plasma and hepatocyte

International Nuclear Information System (INIS)

Peters, A.M.; Myers, M.J.; Mohammadtaghi, S.; Mubashar, M.; Mathie, R.T.

1998-01-01

The kinetics of organic anions are well described and back-diffusion from hepatocyte to plasma is accepted. Although iminodiacetic (IDA) analogues, as organic anions, should also show bidirectional transport between hepatocyte and plasma, this has not been directly demonstrated heretofore. The aim of this study was to directly demonstrate back-diffusion and to quantify it in terms of its fractional rate constant. Kinetics of diethyl IDA were studied in three anaesthetised dogs in which femoral arterial and hepatic venous samples were obtained after injection of tracer into (a) a peripheral vein or (b) hepatic artery or portal vein. Arterial time-concentration curves were also compared between peripheral venous and either hepatic arterial or portal venous injections. Time-activity curves were recorded from regions of interest over the cardiac blood pool and peripheral hepatic parenchyma in 30 patients undergoing routine IDA hepatobiliary imaging with diethyl IDA or mebrofenin and fractional rate constants of clearance of IDA from the hepatocyte compared between compartmental and deconvolution analyses. After peripheral injection in dogs, there was an early arteriovenous concentration gradient across the liver indicating an hepatocyte extraction fraction in the three animals of 0.9, 0.8 and 0.6. The net extraction fraction decreased exponentially over 40 min. Time-concentration curves from hepatic vein and femoral artery were virtually superimposed following intrahepatic injections. Peripheral arterial curves, however, had different shapes according to whether injections were intrahepatic or peripheral, and were consistent with significant back-diffusion. In clinical studies, the blood disappearance curves were fitted as the sum of two exponentials and the liver curves as the difference of two exponentials (with rate constants denoted α 1 h and α 2 h ). Based on compartmental analysis of the blood curves, the sum of the fractional rate constants of tracer movement

Micropatterned co-culture of hepatocyte spheroids layered on non-parenchymal cells to understand heterotypic cellular interactions

International Nuclear Information System (INIS)

Otsuka, Hidenori; Sasaki, Kohei; Okimura, Saya; Nagamura, Masako; Nakasone, Yuichi

2013-01-01

Microfabrication and micropatterning techniques in tissue engineering offer great potential for creating and controlling cellular microenvironments including cell–matrix interactions, soluble stimuli and cell–cell interactions. Here, we present a novel approach to generate layered patterning of hepatocyte spheroids on micropatterned non-parenchymal feeder cells using microfabricated poly(ethylene glycol) (PEG) hydrogels. Micropatterned PEG-hydrogel-treated substrates with two-dimensional arrays of gelatin circular domains (ϕ = 100 μm) were prepared by photolithographic method. Only on the critical structure of PEG hydrogel with perfect protein rejection, hepatocytes were co-cultured with non-parenchymal cells to be led to enhanced hepatocyte functions. Then, we investigated the mechanism of the functional enhancement in co-culture with respect to the contributions of soluble factors and direct cell–cell interactions. In particular, to elucidate the influence of soluble factors on hepatocyte function, hepatocyte spheroids underlaid with fibroblasts (NIH/3T3 mouse fibroblasts) or endothelial cells (BAECs: bovine aortic endothelial cells) were compared with physically separated co-culture of hepatocyte monospheroids with NIH3T3 or BAEC using trans-well culture systems. Our results suggested that direct heterotypic cell-to-cell contact and soluble factors, both of these between hepatocytes and fibroblasts, significantly enhanced hepatocyte functions. In contrast, direct heterotypic cell-to-cell contact between hepatocytes and endothelial cells only contributed to enhance hepatocyte functions. This patterning technique can be a useful experimental tool for applications in basic science, drug screening and tissue engineering, as well as in the design of artificial liver devices. (paper)

Acidosis-induced downregulation of hepatocyte mitochondrial aquaporin-8 and ureagenesis from ammonia.

Science.gov (United States)

Molinas, Sara M; Soria, Leandro R; Marrone, Julieta; Danielli, Mauro; Trumper, Laura; Marinelli, Raúl A

2015-08-01

It has been proposed that, during metabolic acidosis, the liver downregulates mitochondrial ammonia detoxification via ureagenesis, a bicarbonate-consuming process. Since we previously demonstrated that hepatocyte mitochondrial aquaporin-8 channels (mtAQP8) facilitate the uptake of ammonia and its metabolism into urea, we studied whether mtAQP8 is involved in the liver adaptive response to acidosis. Primary cultured rat hepatocytes were adapted to acidosis by exposing them to culture medium at pH 7.0 for 40 h. Control cells were exposed to pH 7.4. Hepatocytes exposed to acid medium showed a decrease in mtAQP8 protein expression (-30%, p ammonia was assessed by incubating the cells with (15)N-labeled ammonia and measuring (15)N-labeled urea synthesis by nuclear magnetic resonance. Reduced ureagenesis was found in acidified hepatocytes (-31%, p ammonia in response to acidosis.

Hepatocyte heterogeneity in the metabolism of carbohydrates.

Science.gov (United States)

Jungermann, K; Thurman, R G

1992-01-01

Periportal and perivenous hepatocytes possess different amounts and activities of the rate-generating enzymes of carbohydrate and oxidative energy metabolism and thus different metabolic capacities. This is the basis of the model of metabolic zonation, according to which periportal cells catalyze predominantly the oxidative catabolism of fatty and amino acids as well as glucose release and glycogen formation via gluconeogenesis, and perivenous cells carry out preferentially glucose uptake for glycogen synthesis and glycolysis coupled to liponeogenesis. The input of humoral and nervous signals into the periportal and perivenous zones is different; gradients of oxygen, substrates and products, hormones and mediators and nerve densities exist which are important not only for the short-term regulation of carbohydrate metabolism but also for the long-term regulation of zonal gene expression. The specialization of periportal and perivenous hepatocytes in carbohydrate metabolism has been well characterized. In vivo evidence is provided by the complex metabolic situation termed the 'glucose paradox' and by zonal flux differences calculated on the basis of the distribution of enzymes and metabolites. In vitro evidence is given by the different flux rates determined with classical invasive techniques, e.g. in periportal-like and perivenous-like hepatocytes in cell culture, in periportal- and perivenous-enriched hepatocyte populations and in perfused livers during orthograde and retrograde flow, as well as with noninvasive techniques using miniature oxygen electrodes, e.g. in livers perfused in either direction. Differences of opinion in the interpretation of studies with invasive and noninvasive techniques by the authors are discussed. The declining gradient in oxygen concentrations, the decreasing glucagon/insulin ratio and the different innervation could be important factors in the zonal expression of the genes of carbohydrate-metabolizing enzymes. While it is clear that

Edaravone attenuates neuronal apoptosis in hypoxic-ischemic brain damage rat model via suppression of TRAIL signaling pathway.

Science.gov (United States)

Li, Chunyi; Mo, Zhihuai; Lei, Junjie; Li, Huiqing; Fu, Ruying; Huang, Yanxia; Luo, Shijian; Zhang, Lei

2018-06-01

Edaravone is a new type of oxygen free radical scavenger and able to attenuate various brain damage including hypoxic-ischemic brain damage (HIBD). This study was aimed at investigating the neuroprotective mechanism of edaravone in rat hypoxic-ischemic brain damage model and its correlation with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) signaling pathway. 75 seven-day-old Sprague-Dawley neonatal rats were equally divided into three groups: sham-operated group (sham), HIBD group and HIBD rats injected with edaravone (HIBD + EDA) group. Neurological severity and space cognitive ability of rats in each group were evaluated using Longa neurological severity score and Morris water maze testing. TUNEL assay and flow cytometry were used to determine brain cell apoptosis. Western blot was used to estimate the expression level of death receptor-5 (DR5), Fas-associated protein with death domain (FADD), caspase 8, B-cell lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax). In addition, immunofluorescence was performed to detect caspase 3. Edaravone reduced neurofunctional damage caused by HIBD and improved the cognitive capability of rats. The above experiment results suggested that edaravone could down-regulate the expression of active caspase 3 protein, thereby relieving neuronal apoptosis. Taken together, edaravone could attenuate neuronal apoptosis in rat hypoxic-ischemic brain damage model via suppression of TRAIL signaling pathway, which also suggested that edaravone might be an effective therapeutic strategy for HIBD clinical treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Live cell imaging of cytosolic NADH/NAD+ ratio in hepatocytes and liver slices.

Science.gov (United States)

Masia, Ricard; McCarty, William J; Lahmann, Carolina; Luther, Jay; Chung, Raymond T; Yarmush, Martin L; Yellen, Gary

2018-01-01

Fatty liver disease (FLD), the most common chronic liver disease in the United States, may be caused by alcohol or the metabolic syndrome. Alcohol is oxidized in the cytosol of hepatocytes by alcohol dehydrogenase (ADH), which generates NADH and increases cytosolic NADH/NAD + ratio. The increased ratio may be important for development of FLD, but our ability to examine this question is hindered by methodological limitations. To address this, we used the genetically encoded fluorescent sensor Peredox to obtain dynamic, real-time measurements of cytosolic NADH/NAD + ratio in living hepatocytes. Peredox was expressed in dissociated rat hepatocytes and HepG2 cells by transfection, and in mouse liver slices by tail-vein injection of adeno-associated virus (AAV)-encoded sensor. Under control conditions, hepatocytes and liver slices exhibit a relatively low (oxidized) cytosolic NADH/NAD + ratio as reported by Peredox. The ratio responds rapidly and reversibly to substrates of lactate dehydrogenase (LDH) and sorbitol dehydrogenase (SDH). Ethanol causes a robust dose-dependent increase in cytosolic NADH/NAD + ratio, and this increase is mitigated by the presence of NAD + -generating substrates of LDH or SDH. In contrast to hepatocytes and slices, HepG2 cells exhibit a relatively high (reduced) ratio and show minimal responses to substrates of ADH and SDH. In slices, we show that comparable results are obtained with epifluorescence imaging and two-photon fluorescence lifetime imaging (2p-FLIM). Live cell imaging with Peredox is a promising new approach to investigate cytosolic NADH/NAD + ratio in hepatocytes. Imaging in liver slices is particularly attractive because it allows preservation of liver microanatomy and metabolic zonation of hepatocytes. NEW & NOTEWORTHY We describe and validate a new approach for measuring free cytosolic NADH/NAD + ratio in hepatocytes and liver slices: live cell imaging with the fluorescent biosensor Peredox. This approach yields dynamic, real

A rare case of avascular necrosis in sickle cell trait: a case report.

Science.gov (United States)

Sanders, William J

2018-01-01

Sickle cell trait is usually an asymptomatic presentation of a patient with slightly different hemoglobin molecule makeup than normal. It is similar to a more serious disease, sickle cell disease, in which a person's hemoglobin is mutated in such a way that causes their red blood cells to easily change shape in certain environmental and internal states; this causes red blood cells to adhere to the walls and occlude the lumen of the arteries in which they travel, leading to downstream effects secondary to ischemia. Sickle cell trait does not have these ischemic effects, usually. In this case, a young African American female patient presents to the clinic with severe right hip pain. Her past medical history includes sickle cell trait and asthma. She has not been symptomatic of her asthma for years and is not on therapy for it. The pain has lasted for several months and has not improved with anti-inflammatory medication. There is severe pain with internal and external rotation of the hip. The neurovascularity of the lower extremities is intact bilaterally. MRI of the femur shows stage 2 or 3 avascular necrosis of the femoral head, while X-rays of the femur are unremarkable. Non weight-bearing for several weeks was unsuccessful; shortly thereafter, the patient underwent core decompression of the right femoral head as well as starting bisphosphonates. The patient improved temporarily but regressed shortly thereafter. Her avascular necrosis worsened radiographically over the next several months. At this point, the only other option would be to do a total hip arthroplasty, but the patient may need several more throughout her lifetime due to the lifespan of the artificial replacement. There have only been scarce reports of avascular necrosis in patients with sickle cell trait. This manuscript presents such a case and includes the trials and tribulations associated with its management.

Genetically elevated C-reactive protein and ischemic vascular disease

DEFF Research Database (Denmark)

Zacho, J.; Tybjaerg-Hansen, A.; Jensen, J.S.

2008-01-01

Background: Elevated levels of C-reactive protein (CRP) are associated with increased risks of ischemic heart disease and ischemic cerebrovascular disease. We tested whether this is a causal association. Methods: We studied 10,276 persons from a general population cohort, including 1786 in whom...... ischemic heart disease developed and 741 in whom ischemic cerebrovascular disease developed. We examined another 31,992 persons from a cross-sectional general population study, of whom 2521 had ischemic heart disease and 1483 had ischemic cerebrovascular disease. Finally, we compared 2238 patients...... with ischemic heart disease with 4474 control subjects and 612 patients with ischemic cerebrovascular disease with 1224 control subjects. We measured levels of high-sensitivity CRP and conducted genotyping for four CRP polymorphisms and two apolipoprotein E polymorphisms. Results: The risk of ischemic heart...

IL-6 modulates hepatocyte proliferation via induction of HGF/p21cip1: Regulation by SOCS3

International Nuclear Information System (INIS)

Sun Rui; Jaruga, Barbara; Kulkarni, Shailin; Sun Haoyu; Gao Bin

2005-01-01

The precise role of IL-6 in liver regeneration and hepatocyte proliferation is controversial and the role of SOCS3 in liver regeneration remains unknown. Here we show that in vitro treatment with IL-6 inhibited primary mouse hepatocyte proliferation. IL-6 induced p21 cip1 protein expression in primary mouse hepatocytes. Disruption of the p21 cip1 gene abolished the inhibitory effect of IL-6 on cell proliferation. Co-culture with nonparenchymal liver cells diminished IL-6 inhibition of hepatocyte proliferation, which was likely due to IL-6 stimulation of nonparenchymal cells to produce HGF. Finally, IL-6 induced higher levels of p21 cip1 protein expression and a slightly stronger inhibition of cell proliferation in SOCS3 +/- mouse hepatocytes compared to wild-type hepatocytes, while liver regeneration was enhanced and prolonged in SOCS3 +/- mice. Our findings suggest that IL-6 directly inhibits hepatocyte proliferation via a p21 cip1 -dependent mechanism and indirectly enhances hepatocyte proliferation via stimulating nonparenchymal cells to produce HGF. SOCS3 negatively regulates liver regeneration

Assessment of mitochondrial dysfunction-related, drug-induced hepatotoxicity in primary rat hepatocytes

International Nuclear Information System (INIS)

Liu, Cong; Sekine, Shuichi; Ito, Kousei

2016-01-01

Evidence that mitochondrial dysfunction plays a central role in drug-induced liver injury is rapidly accumulating. In contrast to physiological conditions, in which almost all adenosine triphosphate (ATP) in hepatocytes is generated in mitochondria via aerobic respiration, the high glucose content and limited oxygen supply of conventional culture systems force primary hepatocytes to generate most ATP via cytosolic glycolysis. Thus, such anaerobically poised cells are resistant to xenobiotics that impair mitochondrial function, and are not suitable to identify drugs with mitochondrial liabilities. In this study, primary rat hepatocytes were cultured in galactose-based medium, instead of the conventional glucose-based medium, and in hyperoxia to improve the reliance of energy generation on aerobic respiration. Activation of mitochondria was verified by diminished cellular lactate release and increased oxygen consumption. These conditions improved sensitivity to the mitochondrial complex I inhibitor rotenone. Since oxidative stress is also a general cause of mitochondrial impairment, cells were exposed to test compounds in the presence of transferrin to increase the generation of reactive oxygen species via increased uptake of iron. Finally, 14 compounds with reported mitochondrial liabilities were tested to validate this new drug-induced mitochondrial toxicity assay. Overall, the culture of primary rat hepatocytes in galactose, hyperoxia and transferrin is a useful model for the identification of mitochondrial dysfunction-related drug-induced hepatotoxicity. - Highlights: • Drug-induced mitochondrial toxicity was evaluated using primary rat hepatocytes. • Galactose and hyperoxia could activate OXPHOS in primary rat hepatocytes. • Cells with enhanced OXPHOS exhibit improved sensitivity to mitochondrial toxins. • Transferrin potentiate mitochondrial toxicity via increased ROS production.

Assessment of mitochondrial dysfunction-related, drug-induced hepatotoxicity in primary rat hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Liu, Cong; Sekine, Shuichi, E-mail: ssekine@faculty.chiba-u.jp; Ito, Kousei

2016-07-01

Evidence that mitochondrial dysfunction plays a central role in drug-induced liver injury is rapidly accumulating. In contrast to physiological conditions, in which almost all adenosine triphosphate (ATP) in hepatocytes is generated in mitochondria via aerobic respiration, the high glucose content and limited oxygen supply of conventional culture systems force primary hepatocytes to generate most ATP via cytosolic glycolysis. Thus, such anaerobically poised cells are resistant to xenobiotics that impair mitochondrial function, and are not suitable to identify drugs with mitochondrial liabilities. In this study, primary rat hepatocytes were cultured in galactose-based medium, instead of the conventional glucose-based medium, and in hyperoxia to improve the reliance of energy generation on aerobic respiration. Activation of mitochondria was verified by diminished cellular lactate release and increased oxygen consumption. These conditions improved sensitivity to the mitochondrial complex I inhibitor rotenone. Since oxidative stress is also a general cause of mitochondrial impairment, cells were exposed to test compounds in the presence of transferrin to increase the generation of reactive oxygen species via increased uptake of iron. Finally, 14 compounds with reported mitochondrial liabilities were tested to validate this new drug-induced mitochondrial toxicity assay. Overall, the culture of primary rat hepatocytes in galactose, hyperoxia and transferrin is a useful model for the identification of mitochondrial dysfunction-related drug-induced hepatotoxicity. - Highlights: • Drug-induced mitochondrial toxicity was evaluated using primary rat hepatocytes. • Galactose and hyperoxia could activate OXPHOS in primary rat hepatocytes. • Cells with enhanced OXPHOS exhibit improved sensitivity to mitochondrial toxins. • Transferrin potentiate mitochondrial toxicity via increased ROS production.

Possibility of Undifferentiated Human Thigh Adipose Stem Cells Differentiating into Functional Hepatocytes

Directory of Open Access Journals (Sweden)

Jong Hoon Lee

2012-11-01

Full Text Available BackgroundThis study aimed to investigate the possibility of isolating mesenchymal stem cells (MSCs from human thigh adipose tissue and the ability of human thigh adipose stem cells (HTASCs to differentiate into hepatocytes.MethodsThe adipose-derived stem cells (ADSCs were isolated from thigh adipose tissue. Growth factors, cytokines, and hormones were added to the collagen coated dishes to induce the undifferentiated HTASCs to differentiate into hepatocyte-like cells. To confirm the experimental results, the expression of hepatocyte-specific markers on undifferentiated and differentiated HTASCs was analyzed using reverse transcription polymerase chain reaction and immunocytochemical staining. Differentiation efficiency was evaluated using functional tests such as periodic acid schiff (PAS staining and detection of the albumin secretion level using enzyme-linked immunosorbent assay (ELISA.ResultsThe majority of the undifferentiated HTASCs were changed into a more polygonal shape showing tight interactions between the cells. The differentiated HTASCs up-regulated mRNA of hepatocyte markers. Immunocytochemical analysis showed that they were intensely stained with anti-albumin antibody compared with undifferentiated HTASCs. PAS staining showed that HTASCs submitted to the hepatocyte differentiation protocol were able to more specifically store glycogen than undifferentiated HTASCs, displaying a purple color in the cytoplasm of the differentiated HTASCs. ELISA analyses showed that differentiated HTASCs could secrete albumin, which is one of the hepatocyte markers.ConclusionsMSCs were islolated from human thigh adipose tissue differentiate to heapatocytes. The source of ADSCs is not only abundant abdominal adipose tissue, but also thigh adipose tissue for cell therapy in liver regeneration and tissue regeneration.

3D hepatic cultures simultaneously maintain primary hepatocyte and liver sinusoidal endothelial cell phenotypes.

Directory of Open Access Journals (Sweden)

Yeonhee Kim

Full Text Available Developing in vitro engineered hepatic tissues that exhibit stable phenotype is a major challenge in the field of hepatic tissue engineering. However, the rapid dedifferentiation of hepatic parenchymal (hepatocytes and non-parenchymal (liver sinusoidal endothelial, LSEC cell types when removed from their natural environment in vivo remains a major obstacle. The primary goal of this study was to demonstrate that hepatic cells cultured in layered architectures could preserve or potentially enhance liver-specific behavior of both cell types. Primary rat hepatocytes and rat LSECs (rLSECs were cultured in a layered three-dimensional (3D configuration. The cell layers were separated by a chitosan-hyaluronic acid polyelectrolyte multilayer (PEM, which served to mimic the Space of Disse. Hepatocytes and rLSECs exhibited several key phenotypic characteristics over a twelve day culture period. Immunostaining for the sinusoidal endothelial 1 antibody (SE-1 demonstrated that rLSECs cultured in the 3D hepatic model maintained this unique feature over twelve days. In contrast, rLSECs cultured in monolayers lost their phenotype within three days. The unique stratified structure of the 3D culture resulted in enhanced heterotypic cell-cell interactions, which led to improvements in hepatocyte functions. Albumin production increased three to six fold in the rLSEC-PEM-Hepatocyte cultures. Only rLSEC-PEM-Hepatocyte cultures exhibited increasing CYP1A1/2 and CYP3A activity. Well-defined bile canaliculi were observed only in the rLSEC-PEM-Hepatocyte cultures. Together, these data suggest that rLSEC-PEM-Hepatocyte cultures are highly suitable models to monitor the transformation of toxins in the liver and their transport out of this organ. In summary, these results indicate that the layered rLSEC-PEM-hepatocyte model, which recapitulates key features of hepatic sinusoids, is a potentially powerful medium for obtaining comprehensive knowledge on liver metabolism

Rehabilitation Outcomes: Ischemic versus Hemorrhagic Strokes

OpenAIRE

Perna, Robert; Temple, Jessica

2015-01-01

Background. Ischemic and hemorrhagic strokes have different pathophysiologies and possibly different long-term cerebral and functional implications. Hemorrhagic strokes expose the brain to irritating effects of blood and ischemic strokes reflect localized or diffuse cerebral vascular pathology. Methods. Participants were individuals who suffered either an ischemic (n = 172) or hemorrhagic stroke (n = 112) within the past six months and were involved in a postacute neurorehabilitation program....

Pretreatment with mixed-function oxidase inducers increases the sensitivity of the hepatocyte/DNA repair assay

International Nuclear Information System (INIS)

Shaddock, J.G.; Heflich, R.H.; McMillan, D.C.; Hinson, J.A.; Casciano, D.A.

1989-01-01

A recent National Toxicology Program evaluation indicates that the rat hepatocyte/DNA repair assay has a high false-negative rate and that it is insensitive to some genotoxic hepatocarcinogens as well as other species and organ-specific carcinogens. In this study, the authors examined whether the sensitivity of the hepatocyte/DNA repair assay might be increased through animal pretreatment with various hepatic mixed-function oxidase inducers, i.e., Aroclor 1254, phenobarbital, and 3,3',4,4'-tetrachloroazobenzene (TCAB). The effects on unscheduled DNA synthesis (UDS), a measured of DNA damage and repair, were studied in cultures exposed to known and/or potential carcinogens that had been evaluated as negative or questionable or that produced conflicting results with hepatocytes isolated from uninduced animals. 4,4'-Oxydianiline, 1-nitropy-rene, and TCAB produced concentration-dependent increases in UDS in hepatocytes from rats pretreated with Aroclor 1254. 4,4'-Oxydianiline and TCAB also induced a dose-dependent increase in DNA repair in hepatocytes from rats pretreated with phenobarbital, whereas 1-nitropyrene was negative. These data indicate that the limited sensitivity to chemical carcinogens displayed by the hepatocyte/DNA repair assay may be increased by using hepatocytes isolated from animals exposed to hepatic mixed-function oxidase inducers

Pretreatment with mixed-function oxidase inducers increases the sensitivity of the hepatocyte/DNA repair assay

Energy Technology Data Exchange (ETDEWEB)

Shaddock, J.G.; Heflich, R.H.; McMillan, D.C.; Hinson, J.A.; Casciano, D.A. (National Center for Toxicological Research, Jefferson, AK (USA) Univ. of Arkansas for Medical Sciences, Little Rock (USA))

1989-01-01

A recent National Toxicology Program evaluation indicates that the rat hepatocyte/DNA repair assay has a high false-negative rate and that it is insensitive to some genotoxic hepatocarcinogens as well as other species and organ-specific carcinogens. In this study, the authors examined whether the sensitivity of the hepatocyte/DNA repair assay might be increased through animal pretreatment with various hepatic mixed-function oxidase inducers, i.e., Aroclor 1254, phenobarbital, and 3,3{prime},4,4{prime}-tetrachloroazobenzene (TCAB). The effects on unscheduled DNA synthesis (UDS), a measured of DNA damage and repair, were studied in cultures exposed to known and/or potential carcinogens that had been evaluated as negative or questionable or that produced conflicting results with hepatocytes isolated from uninduced animals. 4,4{prime}-Oxydianiline, 1-nitropy-rene, and TCAB produced concentration-dependent increases in UDS in hepatocytes from rats pretreated with Aroclor 1254. 4,4{prime}-Oxydianiline and TCAB also induced a dose-dependent increase in DNA repair in hepatocytes from rats pretreated with phenobarbital, whereas 1-nitropyrene was negative. These data indicate that the limited sensitivity to chemical carcinogens displayed by the hepatocyte/DNA repair assay may be increased by using hepatocytes isolated from animals exposed to hepatic mixed-function oxidase inducers.

Cardioprotective Effects of Pomegranate (Punica granatum) Juice in Patients with Ischemic Heart Disease.

Science.gov (United States)

Razani, Zahra; Dastani, Mostafa; Kazerani, Hamid Reza

2017-11-01

Ischemic heart disease is the leading cause of mortality worldwide. The purpose of this study was to evaluate the cardioprotective effects of pomegranate juice in patients with ischemic heart disease. One hundred patients, diagnosed with unstable angina or myocardial infarction, were randomly assigned to the test and the control groups (n = 50, each). During 5 days of hospitalization, in addition to the conventional medical therapies, the test groups received 220 mL pomegranate juice, daily. During the hospitalization period, the blood pressure, heart rate, as well as the intensity, occurrence, and duration of the angina were evaluated on a regular basis. At the end of the hospitalization period, the serum levels of malondialdehyde, interleukin-6, and tumor necrosis factor alpha were measured in all patients. The levels of serum troponin and high-sensitive C-reactive protein levels were also assayed in patients diagnosed with myocardial infarction. Pomegranate juice caused significant reductions in the intensity, occurrence, and duration of angina pectoris in patients with unstable angina. Consistently, the test patients had significantly lower levels of serum troponin and malondialdehyde. Other studied parameters did not change significantly. The results of this study suggest protective effects of pomegranate juice against myocardial ischemia and reperfusion injury. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Metabolism of methyl-branched iodo palmitic acids in cultured hepatocytes

International Nuclear Information System (INIS)

Thomas, G.; Pepin, D.; Loriette, C.; Chambaz, J.; Bereziat, G.; Vidal, M.; Apparu, M.; Coornaert, S.

1989-01-01

The metabolic fate of methyl-branched iodo fatty acids was studied in primary culture of rat hepatocytes. We compared 16-iodo-2-R,S-methyl palmitic acid (2-Me), which can be β oxidized, with 16-iodo-3-R,S-methyl palmitic acid (3-Me) which can be β oxidized only after an initial α oxydation and with 16-iodo-2,2-dimethyl palmitic acid (2,2-Me 2 ) and 16-iodo-3,3-dimethyl palmitic acid (3,3-Me 2 ) which cannot be β oxidized at all. The normal fate of natural fatty acids was given by comparative experiments with [1- 14 C] palmitic acid. Monomethyl-branched iodo fatty acids were taken up in the same range as palmitic acid but more than dimethyl-branched iodo fatty acids. After a 15-h incubation, acido-soluble products (ASP) accounted for 75% of the radioactivity taken up as 16-iodo-2-methyl palmitic acid, 50% as other methyl-branched iodo fatty acids and only 30% as palmitic acid. Cultured hepatocytes, labelled for 3 h with the various fatty acids and reincubated for 12 h without fatty acid, secreted large amounts of free dimethyl-branched iodo fatty acids as compared to the monomethyl ones and palmitic acid. Only hepatocytes prelabelled with 16-[ 125 I]iodo-2,2-dimethyl palmitic acid exhibited an appreciable secretion of labeled triglycerides, but at a lower rate than with [1- 14 C] palmitic acid. Conversely, the 16-iodo-monomethyl palmitic acids remained chiefly in hepatocyte triglycerides. Minute amounts of 16-iodo-methyl-branched palmitic acids were found in hepatocyte or secreted phospholipids as compared with palmitic acid. (orig.)

Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation

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Yeom, Chul-gon; Kim, Dong-il; Park, Min-jung; Choi, Joo-hee [College of Veterinary Medicine, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Jeong, Jieun; Wi, Anjin; Park, Whoashig [Jeollanamdo Forest Resources Research Institute, Naju 520-833 (Korea, Republic of); Han, Ho-jae [College of Veterinary Medicine, Seoul National University, Seoul 151-741 (Korea, Republic of); Park, Soo-hyun, E-mail: parksh@chonnam.ac.kr [College of Veterinary Medicine, Chonnam National University, Gwangju 500-757 (Korea, Republic of)

2015-06-05

Previously, we reported that CARM1 undergoes ubiquitination-dependent degradation in renal podocytes. It was also reported that CARM1 is necessary for fasting-induced hepatic gluconeogenesis. Based on these reports, we hypothesized that treatment with insulin, a hormone typically present under the ‘fed’ condition, would inhibit gluconeogenesis via CARM1 degradation. HepG2 cells, AML-12 cells, and rat primary hepatocytes were treated with insulin to confirm CARM1 downregulation. Surprisingly, insulin treatment increased CARM1 expression in all cell types examined. Furthermore, treatment with insulin increased histone 3 methylation at arginine 17 and 26 in HepG2 cells. To elucidate the role of insulin-induced CARM1 upregulation, the HA-CARM1 plasmid was transfected into HepG2 cells. CARM1 overexpression did not increase the expression of lipogenic proteins generally increased by insulin signaling. Moreover, CARM1 knockdown did not influence insulin sensitivity. Insulin is known to facilitate hepatic proliferation. Like insulin, CARM1 overexpression increased CDK2 and CDK4 expression. In addition, CARM1 knockdown reduced the number of insulin-induced G2/M phase cells. Moreover, GFP-CARM1 overexpression increased the number of G2/M phase cells. Based on these results, we concluded that insulin-induced CARM1 upregulation facilitates hepatocyte proliferation. These observations indicate that CARM1 plays an important role in liver pathophysiology. - Highlights: • Insulin treatment increases CARM1 expression in hepatocytes. • CARM1 overexpression does not increase the expression of lipogenic proteins. • CARM1 knockdown does not influence insulin sensitivity. • Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation.

Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation

International Nuclear Information System (INIS)

Yeom, Chul-gon; Kim, Dong-il; Park, Min-jung; Choi, Joo-hee; Jeong, Jieun; Wi, Anjin; Park, Whoashig; Han, Ho-jae; Park, Soo-hyun

2015-01-01

Previously, we reported that CARM1 undergoes ubiquitination-dependent degradation in renal podocytes. It was also reported that CARM1 is necessary for fasting-induced hepatic gluconeogenesis. Based on these reports, we hypothesized that treatment with insulin, a hormone typically present under the ‘fed’ condition, would inhibit gluconeogenesis via CARM1 degradation. HepG2 cells, AML-12 cells, and rat primary hepatocytes were treated with insulin to confirm CARM1 downregulation. Surprisingly, insulin treatment increased CARM1 expression in all cell types examined. Furthermore, treatment with insulin increased histone 3 methylation at arginine 17 and 26 in HepG2 cells. To elucidate the role of insulin-induced CARM1 upregulation, the HA-CARM1 plasmid was transfected into HepG2 cells. CARM1 overexpression did not increase the expression of lipogenic proteins generally increased by insulin signaling. Moreover, CARM1 knockdown did not influence insulin sensitivity. Insulin is known to facilitate hepatic proliferation. Like insulin, CARM1 overexpression increased CDK2 and CDK4 expression. In addition, CARM1 knockdown reduced the number of insulin-induced G2/M phase cells. Moreover, GFP-CARM1 overexpression increased the number of G2/M phase cells. Based on these results, we concluded that insulin-induced CARM1 upregulation facilitates hepatocyte proliferation. These observations indicate that CARM1 plays an important role in liver pathophysiology. - Highlights: • Insulin treatment increases CARM1 expression in hepatocytes. • CARM1 overexpression does not increase the expression of lipogenic proteins. • CARM1 knockdown does not influence insulin sensitivity. • Insulin-induced CARM1 upregulation facilitates hepatocyte proliferation

Ammonia-induced energy disorders interfere with bilirubin metabolism in hepatocytes.

Science.gov (United States)

Wang, Qiongye; Wang, Yanfang; Yu, Zujiang; Li, Duolu; Jia, Bin; Li, Jingjing; Guan, Kelei; Zhou, Yubing; Chen, Yanling; Kan, Quancheng

2014-08-01

Hyperammonemia and jaundice are the most common clinical symptoms of hepatic failure. Decreasing the level of ammonia in the blood is often accompanied by a reduction in bilirubin in patients with hepatic failure. Previous studies have shown that hyperammonemia can cause bilirubin metabolism disorders, however it is unclear exactly how hyperammonemia interferes with bilirubin metabolism in hepatocytes. The purpose of the current study was to determine the mechanism or mechanisms by which hyperammonemia interferes with bilirubin metabolism in hepatocytes. Cell viability and apoptosis were analyzed in primary hepatocytes that had been exposed to ammonium chloride. Mitochondrial morphology and permeability were observed and analyzed, intermediates of the tricarboxylic acid (TCA) cycle were determined and changes in the expression of enzymes related to bilirubin metabolism were analyzed after ammonia exposure. Hyperammonemia inhibited cell growth, induced apoptosis, damaged the mitochondria and hindered the TCA cycle in hepatocytes. This led to a reduction in energy synthesis, eventually affecting the expression of enzymes related to bilirubin metabolism, which then caused further problems with bilirubin metabolism. These effects were significant, but could be reversed with the addition of adenosine triphosphate (ATP). This study demonstrates that ammonia can cause problems with bilirubin metabolism by interfering with energy synthesis. Copyright © 2014 Elsevier Inc. All rights reserved.

Optimization of the isolation and cultivation of Cyprinus carpio primary hepatocytes.

Science.gov (United States)

Yanhong, Fan; Chenghua, He; Guofang, Liu; Haibin, Zhang

2008-10-01

The aquatic environment is affected by numerous chemical contaminants. There is an increasing need to identify these chemicals and to evaluate their potential toxicity towards aquatic life. In this research we optimized techniques for primary cell culture of Cyprinus carpio hepatocytes as one adjunct model for ecotoxicological evaluation of the potential hazards of xenobiotics in the aquatic environment. In this study, Cyprinus carpio hepatocytes were isolated by mechanical separation, two-step collagenase perfusion, and pancreatin digestion. The hepatocytes or parenchymal cells could be separated from cell debris and from non-parenchymal cells by low-speed centrifugation (Percoll gradient centrifugation). The harvested hepatocytes were suspended in DMEM, M199 (cultured in 5% CO(2)), or L-15 (cultured without 5% CO(2)) medium then cultured at 17, 27, or 37 degrees C. Cell yield was counted by use of a hemocytometer, and the viability of the cells was assessed by use of the Trypan blue exclusion test. Results from these studies showed that the best method of isolation was pancreatin digestion (the cell yield was 2.7 x 10(8) per g (liver weight) and the viability was 98.4%) and the best medium was M199 (cultured in 5% CO(2)) or L-15 (cultured without 5% CO(2)). The optimum culture temperature was 27 degrees C. The primary hepatocytes culture of Cyprimus carpio grew well and satisfied requirements for most toxicological experiments in this condition.

Inducibility of carbamoylphosphate synthetase (ammonia) in cultures of embryonic hepatocytes: ontogenesis of the responsiveness to hormones

NARCIS (Netherlands)

Lamers, W. H.; Zonneveld, D.; Charles, R.

1984-01-01

Glucocorticosteroids and cyclic AMP induce carbamoylphosphate synthetase (ammonia) (CPS) in rat hepatocytes. Using an enzyme immunoassay applied to hepatocyte cultures fixed in situ, it has been demonstrated that the capacity of hepatocytes to synthesize CPS in the presence of both hormones is

Alternative Cell Sources to Adult Hepatocytes for Hepatic Cell Therapy.

Science.gov (United States)

Pareja, Eugenia; Gómez-Lechón, María José; Tolosa, Laia

2017-01-01

Adult hepatocyte transplantation is limited by scarce availability of suitable donor liver tissue for hepatocyte isolation. New cell-based therapies are being developed to supplement whole-organ liver transplantation, to reduce the waiting-list mortality rate, and to obtain more sustained and significant metabolic correction. Fetal livers and unsuitable neonatal livers for organ transplantation have been proposed as potential useful sources of hepatic cells for cell therapy. However, the major challenge is to use alternative cell sources for transplantation that can be derived from reproducible methods. Different types of stem cells with hepatic differentiation potential are eligible for generating large numbers of functional hepatocytes for liver cell therapy to treat degenerative disorders, inborn hepatic metabolic diseases, and organ failure. Clinical trials are designed to fully establish the safety profile of such therapies and to define target patient groups and standardized protocols.

High Throughput Micro-Well Generation of Hepatocyte Micro-Aggregates for Tissue Engineering

NARCIS (Netherlands)

Gevaert, Elien; Dollé, Laurent; Billiet, Thomas; Dubruel, Peter; van Grunsven, Leo; van Apeldoorn, Aart A.; Cornelissen, Ria

2014-01-01

The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the

Subtoxic Alterations in Hepatocyte-Derived Exosomes: An Early Step in Drug-Induced Liver Injury?

Science.gov (United States)

Holman, Natalie S; Mosedale, Merrie; Wolf, Kristina K; LeCluyse, Edward L; Watkins, Paul B

2016-06-01

Drug-induced liver injury (DILI) is a significant clinical and economic problem in the United States, yet the mechanisms that underlie DILI remain poorly understood. Recent evidence suggests that signaling molecules released by stressed hepatocytes can trigger immune responses that may be common across DILI mechanisms. Extracellular vesicles released by hepatocytes, principally hepatocyte-derived exosomes (HDEs), may constitute one such signal. To examine HDE alterations as a function of drug-induced stress, this work utilized prototypical hepatotoxicant acetaminophen (APAP) in male Sprague-Dawley (SD) rats, SD rat hepatocytes, and primary human hepatocytes. HDE were isolated using ExoQuick precipitation reagent and analyzed by quantification of the liver-specific RNAs albumin and microRNA-122 (miR-122). In vivo, significant elevations in circulating exosomal albumin mRNA were observed at subtoxic APAP exposures. Significant increases in exosomal albumin mRNA were also observed in primary rat hepatocytes at subtoxic APAP concentrations. In primary human hepatocytes, APAP elicited increases in both exosomal albumin mRNA and exosomal miR-122 without overt cytotoxicity. However, the number of HDE produced in vitro in response to APAP did not increase with exosomal RNA quantity. We conclude that significant drug-induced alterations in the liver-specific RNA content of HDE occur at subtoxic APAP exposures in vivo and in vitro, and that these changes appear to reflect selective packaging rather than changes in exosome number. The current findings demonstrate that translationally relevant HDE alterations occur in the absence of overt hepatocellular toxicity, and support the hypothesis that HDE released by stressed hepatocytes may mediate early immune responses in DILI. © The Author 2016. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Targeting of regulated necrosis in kidney disease

Directory of Open Access Journals (Sweden)

Diego Martin-Sanchez

2018-03-01

Full Text Available The term acute tubular necrosis was thought to represent a misnomer derived from morphological studies of human necropsies and necrosis was thought to represent an unregulated passive form of cell death which was not amenable to therapeutic manipulation. Recent advances have improved our understanding of cell death in acute kidney injury. First, apoptosis results in cell loss, but does not trigger an inflammatory response. However, clumsy attempts at interfering with apoptosis (e.g. certain caspase inhibitors may trigger necrosis and, thus, inflammation-mediated kidney injury. Second, and most revolutionary, the concept of regulated necrosis emerged. Several modalities of regulated necrosis were described, such as necroptosis, ferroptosis, pyroptosis and mitochondria permeability transition regulated necrosis. Similar to apoptosis, regulated necrosis is modulated by specific molecules that behave as therapeutic targets. Contrary to apoptosis, regulated necrosis may be extremely pro-inflammatory and, importantly for kidney transplantation, immunogenic. Furthermore, regulated necrosis may trigger synchronized necrosis, in which all cells within a given tubule die in a synchronized manner. We now review the different modalities of regulated necrosis, the evidence for a role in diverse forms of kidney injury and the new opportunities for therapeutic intervention. Resumen: La idea de que el término necrosis tubular aguda supone una denominación inapropiada se deriva de estudios morfológicos de necropsias humanas. La opinión generalizada ha sido que la necrosis representa una forma pasiva de muerte celular no regulada que no es susceptible de manipulación terapéutica. Los recientes avances han mejorado nuestra comprensión de la muerte celular en la lesión renal aguda. En primer lugar, la apoptosis origina una pérdida celular, pero no desencadena una respuesta inflamatoria. Sin embargo, los intentos rudimentarios de interferir en la apoptosis

Comparison of characteristics and healing course of diabetic foot ulcers by etiological classification: neuropathic, ischemic, and neuro-ischemic type.

Science.gov (United States)

Yotsu, Rie Roselyne; Pham, Ngoc Minh; Oe, Makoto; Nagase, Takeshi; Sanada, Hiromi; Hara, Hisao; Fukuda, Shoji; Fujitani, Junko; Yamamoto-Honda, Ritsuko; Kajio, Hiroshi; Noda, Mitsuhiko; Tamaki, Takeshi

2014-01-01

To identify differences in the characteristics of patients with diabetic foot ulcers (DFUs) according to their etiological classification and to compare their healing time. Over a 4.5-year period, 73 patients with DFUs were recruited. DFUs were etiologically classified as being of neuropathic, ischemic, or neuro-ischemic origin. Descriptive analyses were performed to characterize study subjects, foot-related factors, and healing outcome and time. Duration of healing was assessed using the Kaplan-Meier method. Healing time among the three types was compared using the log rank test. The number of patients manifesting neuropathic, ischemic, and neuro-ischemic ulcers was 30, 20, and 14, respectively. Differences were identified for age, diabetes duration, body mass index, hypertension, and estimated glomerular filtration rate. Patients with neuro-ischemic ulcers had better ankle-brachial index, skin perfusion pressure (SPP), and transcutaneous oxygen pressure values compared to those with ischemic ulcers. The average time in which 50% of patients had healed wounds was 70, 113, and 233 days for neuropathic, neuro-ischemic, and ischemic ulcers, respectively. Main factors associated with healing were age and SPP values. Based on the etiological ulcer type, DFU healing course and several patient factors differed. Failure to consider the differences in DFU etiology may have led to heterogeneity of results in previous studies on DFUs. Copyright © 2014 Elsevier Inc. All rights reserved.

Smoking Cessation Intervention After Ischemic Stroke or Transient Ischemic Attack. A Randomized Controlled Pilot Trial

DEFF Research Database (Denmark)

Brunner Frandsen, Nicole; Sørensen, Margit; Hyldahl, Tanja Kirstine

2012-01-01

BACKGROUND: Smoking cessation is widely recommended for secondary stroke prevention. However, little is known about the efficacy of smoking cessation intervention after stroke or transient ischemic attack (TIA). METHODS: Ninety-four smokers under age 76, admitted with ischemic stroke or TIA were ...

Hepatocyte polarization is essential for the productive entry of the hepatitis B virus.

Science.gov (United States)

Schulze, Andreas; Mills, Kerry; Weiss, Thomas S; Urban, Stephan

2012-02-01

Human hepatitis B virus (HBV) is characterized by a high species specificity and a distinct liver tropism. Within the liver, HBV replication occurs in differentiated and polarized hepatocytes. Accordingly, the in vitro HBV infection of primary human hepatocytes (PHHs) and the human hepatoma cell line, HepaRG, is restricted to differentiated, hepatocyte-like cells. Though preparations of PHH contain up to 100% hepatic cells, cultures of differentiated HepaRG cells are a mixture of hepatocyte-like and biliary-like epithelial cells. We used PHH and HepaRG cells and compared the influence of virus inoculation dose, cell differentiation, and polarization on productive HBV infection. At multiplicities of genome equivalents (mge) >8,000, almost 100% of PHHs could be infected. In contrast, only a subset of HepaRG cells stained positive for HBcAg at comparable or even higher mge. Infection predominantly occurred at the edges of islands of hepatocyte-like HepaRG cells. This indicates a limited accessibility of the HBV receptor, possibly as a result of its polar sorting. Multidrug resistance protein 2 (MRP2), a marker selectively transported to the apical (i.e., canalicular) cell membrane, revealed two polarization phenotypes of HepaRG cells. HBV infection within the islands of hepatocyte-like HepaRG cells preferentially occurred in cells that resemble PHH, exhibiting canalicular structures. However, disruption of cell-cell junctions allowed the additional infection of cells that do not display a PHH-like polarization. HBV enters hepatocytes via the basolateral membrane. This model, at least partially, explains the difference of PHH and HepaRG cells in infection efficacy, provides insights into natural HBV infection, and establishes a basis for optimization of the HepaRG infection system. Copyright © 2011 American Association for the Study of Liver Diseases.

[The polyploidization characteristics of the hepatocytes of the mouse-like hamster Calomyscus mystax].

Science.gov (United States)

Anatskaia, O V; Malikov, V G; Meĭer, M N; Kudriavtsev, B N

1995-01-01

A cytophotometric measurement of DNA content in hepatocytes of maturing mouse-like hamsters was made. Cells belonging to ordinary mammalian ploidy classes 2c, 2c x 2, 4c, and 4c x 2 made about 90% of the hepatocyte population. The share of binucleated cells wa high (about 80%), the majority of these cells being 2c X 2 hepatocytes. Binucleated cells with tetraploid and diploid nuclei occur in almost every animal. An average hepatocyte ploidy level in mouse-like hamster is 4.6c. The main peculiarity of parenchymal liver cell populations is that up 5% of hepatocytes contain 3--11 nuclei of different ploidy classes. Multinucleated cells increase in number from 1.5% to 4% within the period from one year (the age of maturation) to two years. Later on their percentage does not change. It is found that in binucleated and multinucleated hepatocytes DNA synthesis can proceed asynchronously. Asynchrony in DNA synthesis elevates as the number of nuclei increases. Among the 2c x 2 and 2c x 3 cells an uneven distribution of 3H-thymidine label can occur, respectively, in 5 and in 50% cases, whereas all the cells with more than 3 nuclei display an uneven an uneven 3H-thymidin label distribution. The formation of multinucleated cells is supposed to be associated with asynchrony in DNA-synthesis in binucleated cells and with the restitution of mitosis.

Mitochondria Play a Central Role in Nonischemic Cardiomyocyte Necrosis: Common to Acute and Chronic Stressor States

Science.gov (United States)

Khan, M. Usman; Cheema, Yaser; Shahbaz, Atta U.; Ahokas, Robert A.; Sun, Yao; Gerling, Ivan C.; Bhattacharya, Syamal K.; Weber, Karl T.

2012-01-01

The survival of cardiomyocytes must be ensured as the myocardium adjusts to a myriad of competing physiologic and pathophysiologic demands. A significant loss of these contractile cells, together with their replacement by stiff fibrillar collagen in the form of fibrous tissue accounts for a transition from a usually efficient muscular pump into one that is failing. Cellular and subcellular mechanisms involved in the pathogenic origins of cardiomyocyte cell death have long been of interest. This includes programmed molecular pathways to either necrosis or apoptosis which are initiated from ischemic or nonischemic origins. Herein we focus on the central role played by a mitochondriocentric signal-transducer-effector pathway to nonischemic cardiomyocyte necrosis which is common to acute and chronic stressor states. We begin by building upon the hypothesis advanced by Albrecht Fleckenstein and coworkers some 40 years ago based on the importance of calcitropic hormone- mediated intracellular Ca2+ overloading which predominantly involves subsarcolemmal mitochondria and is the signal to pathway activation. Other pathway components, which came to be recognized in subsequent years, include the induction of oxidative stress and opening of the mitochondrial inner membrane permeability transition pore. The ensuing loss of cardiomyocytes and consequent replacement fibrosis, or scarring, represents a disease of adaptation and a classic example of when homeostasis begets dyshomeostasis. PMID:22328074

Dendritic cells and hepatocytes use distinct pathways to process protective antigen from plasmodium in vivo.

Directory of Open Access Journals (Sweden)

Ian A Cockburn

2011-03-01

Full Text Available Malaria-protective CD8+ T cells specific for the circumsporozoite (CS protein are primed by dendritic cells (DCs after sporozoite injection by infected mosquitoes. The primed cells then eliminate parasite liver stages after recognizing the CS epitopes presented by hepatocytes. To define the in vivo processing of CS by DCs and hepatocytes, we generated parasites carrying a mutant CS protein containing the H-2K(b epitope SIINFEKL, and evaluated the T cell response using transgenic and mutant mice. We determined that in both DCs and hepatocytes CS epitopes must reach the cytosol and use the TAP transporters to access the ER. Furthermore, we used endosomal mutant (3d and cytochrome c treated mice to address the role of cross-presentation in the priming and effector phases of the T cell response. We determined that in DCs, CS is cross-presented via endosomes while, conversely, in hepatocytes protein must be secreted directly into the cytosol. This suggests that the main targets of protective CD8+ T cells are parasite proteins exported to the hepatocyte cytosol. Surprisingly, however, secretion of the CS protein into hepatocytes was not dependent upon parasite-export (Pexel/VTS motifs in this protein. Together, these results indicate that the presentation of epitopes to CD8+ T cells follows distinct pathways in DCs when the immune response is induced and in hepatocytes during the effector phase.

Cell therapy from bench to bedside: Hepatocytes from fibroblasts - the truth and myth of transdifferentiation.

Science.gov (United States)

Sanal, Madhusudana Girija

2015-06-07

Hepatocyte transplantation is an alternative to liver transplantation in certain disorders such as inherited liver diseases and liver failure. It is a relatively less complicated surgical procedure, and has the advantage that it can be repeated several times if unsuccessful. Another advantage is that hepatocytes can be isolated from partly damaged livers which are not suitable for liver transplantation. Despite these advantages hepatocyte transplantation is less popular. Important issues are poor engraftment of the transplanted cells and the scarcity of donor hepatocytes. Generation of "hepatocyte like cells"/iHeps from embryonic stem cells (ES) and induced pluripotent stem cells (iPSCs) by directed differentiation is an emerging solution to the latter issue. Direct conversation or trans-differentiation of fibroblasts to "hepatocyte like cells" is another way which is, being explored. However this method has several inherent and technical disadvantages compared to the directed differentiation from ES or iPSC. There are several methods claiming to be "highly efficient" for generating "highly functional" "hepatocyte like cells". Currently different groups are working independently and coming up with differentiation protocols and each group claiming an advantage for their protocol. Directed differentiation protocols need to be designed, compared, analyzed and tweaked systematically and logically than empirically. There is a need for a well-coordinated global initiative comparable to the Human Genome Project to achieve this goal in the near future.

Chronic alcohol feeding potentiates hormone-induced calcium signalling in hepatocytes.

Science.gov (United States)

Bartlett, Paula J; Antony, Anil Noronha; Agarwal, Amit; Hilly, Mauricette; Prince, Victoria L; Combettes, Laurent; Hoek, Jan B; Gaspers, Lawrence D

2017-05-15

Chronic alcohol consumption causes a spectrum of liver diseases, but the pathogenic mechanisms driving the onset and progression of disease are not clearly defined. We show that chronic alcohol feeding sensitizes rat hepatocytes to Ca 2+ -mobilizing hormones resulting in a leftward shift in the concentration-response relationship and the transition from oscillatory to more sustained and prolonged Ca 2+ increases. Our data demonstrate that alcohol-dependent adaptation in the Ca 2+ signalling pathway occurs at the level of hormone-induced inositol 1,4,5 trisphosphate (IP 3 ) production and does not involve changes in the sensitivity of the IP 3 receptor or size of internal Ca 2+ stores. We suggest that prolonged and aberrant hormone-evoked Ca 2+ increases may stimulate the production of mitochondrial reactive oxygen species and contribute to alcohol-induced hepatocyte injury. ABSTRACT: 'Adaptive' responses of the liver to chronic alcohol consumption may underlie the development of cell and tissue injury. Alcohol administration can perturb multiple signalling pathways including phosphoinositide-dependent cytosolic calcium ([Ca 2+ ] i ) increases, which can adversely affect mitochondrial Ca 2+ levels, reactive oxygen species production and energy metabolism. Our data indicate that chronic alcohol feeding induces a leftward shift in the dose-response for Ca 2+ -mobilizing hormones resulting in more sustained and prolonged [Ca 2+ ] i increases in both cultured hepatocytes and hepatocytes within the intact perfused liver. Ca 2+ increases were initiated at lower hormone concentrations, and intercellular calcium wave propagation rates were faster in alcoholics compared to controls. Acute alcohol treatment (25 mm) completely inhibited hormone-induced calcium increases in control livers, but not after chronic alcohol-feeding, suggesting desensitization to the inhibitory actions of ethanol. Hormone-induced inositol 1,4,5 trisphosphate (IP 3 ) accumulation and phospholipase C

MRI study of avascular necrosis of the knee

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Simizu, Koh; Suguro, Toru; Tsuchiya, Akihiro; Moriya, Hideshige; Nishikawa, Satoru; Arimizu, Noboru [Chiba Univ. (Japan). School of Medicine

1990-10-01

Magnetic resonance (MR) images of 70 joints were reviewed in 38 patients with avascular necrosis of the knee or hip joint, whose ages ranged from 19 to 62 years with an average of 41 years. According to causes, steroid induced avascular necrosis was the commonest, accounting for 87% of cases. The remainer of the cases were alcoholic avascular necrosis (8%) and idiopathic avascular necrosis (5%). Steroid induced avascular necrosis was greatly different from idiopathic avascular necrosis in view of clinical manifestations, common sites, and complications of femur head necrosis. Idiopathic avascular necrosis was common in the central part of internal condyle and was confined to one joint. Steroid induced avascular necrosis was common in the posterior part of external condyle and was frequently associated with multiple necroses of the diaphysis. Seventy five percent of the cases were associated with avascular necrosis of the knee. The diagnostic accuracy of the other imaging modalities in avascular necrosis was low (33% for plain roentgenography and 50% for RI examination). Thus, MR was the imaging procedure of choice for detecting avascular necrotic lesions. (N.K.).

MRI study of avascular necrosis of the knee

International Nuclear Information System (INIS)

Simizu, Koh; Suguro, Toru; Tsuchiya, Akihiro; Moriya, Hideshige; Nishikawa, Satoru; Arimizu, Noboru

1990-01-01

Magnetic resonance (MR) images of 70 joints were reviewed in 38 patients with avascular necrosis of the knee or hip joint, whose ages ranged from 19 to 62 years with an average of 41 years. According to causes, steroid induced avascular necrosis was the commonest, accounting for 87% of cases. The remainer of the cases were alcoholic avascular necrosis (8%) and idiopathic avascular necrosis (5%). Steroid induced avascular necrosis was greatly different from idiopathic avascular necrosis in view of clinical manifestations, common sites, and complications of femur head necrosis. Idiopathic avascular necrosis was common in the central part of internal condyle and was confined to one joint. Steroid induced avascular necrosis was common in the posterior part of external condyle and was frequently associated with multiple necroses of the diaphysis. Seventy five percent of the cases were associated with avascular necrosis of the knee. The diagnostic accuracy of the other imaging modalities in avascular necrosis was low (33% for plain roentgenography and 50% for RI examination). Thus, MR was the imaging procedure of choice for detecting avascular necrotic lesions. (N.K.)

Comparison of trout hepatocytes and liver S9 fractions as in ...

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Isolated hepatocytes and liver S9 fractions have been used to collect in vitro biotransformation data for fish as a means of improving modeled estimates of chemical bioaccumulation. To date, however, there have been few direct comparisons of these two methods. In the present study, cryopreserved trout hepatocytes were used to measure in vitro intrinsic clearance rates for 6 polycyclic aromatic hydrocarbons (PAHs). These rates were extrapolated to estimates of in vivo intrinsic clearance and used as inputs to a well-stirred liver model to predict hepatic clearance. Predicted rates of hepatic clearance were then evaluated by comparison to measured rates determined previously using isolated perfused livers. Hepatic clearance rates predicted using hepatocytes were in good agreement with measured values (fractions. For one compound (benzo[a]pyrene), the in vivo intrinsic clearance rate calculated using S9 data was 10-fold higher than that determined using hepatocytes, possibly due to a diffusion limitation on cellular uptake. Generally, however, there was good agreement between calculated in vivo intrinsic clearance rates obtained using either in vitro test system. These results suggest that both systems can be used to improve

Whole-body X-irradiation of mice accelerates polyploidization of hepatocytes

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Shima, A.; Egami, N.

1985-01-01

Male C57BL/6 mice were whole-body irradiated with 4.75 gy of X-rays at the age of 2 months and killed at 2, 6, 12 and 19 months after irradiation. The percentage survival began to decline earlier and faster in the irradiated group than the controls up to 19 months after exposure when the study was terminated. The nuclear DNA content of individual hepatocytes was measured by a Feulgen-DNA microfluorometric method, and hepatocytes were classified into various ploidy classes. In the irradiated mice, the degree of polyploidization was significantly higher than the controls by 2 months after exposure and steadily increased up to 6 months after exposure. Thereafter, however, a slow return to the control level was found up to 19 months after irradiation. These results appear to support a hypothesis that radiation accelerates the ageing process as judged from hepatocyte polyploidization. (author)

Augmenter of liver regeneration (ALR) protects human hepatocytes against apoptosis

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Ilowski, Maren [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Kleespies, Axel [Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Toni, Enrico N. de [Department of Medicine II, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Donabauer, Barbara [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Jauch, Karl-Walter [Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Hengstler, Jan G. [Leibniz Research Centre for Working Environment and Human Factors, Technical University, Dortmund (Germany); Thasler, Wolfgang E., E-mail: wolfgang.thasler@med.uni-muenchen.de [Liver Regeneration Group, Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany); Department of Surgery, Grosshadern Hospital, Ludwig Maximilians University, Munich (Germany)

2011-01-07

Research highlights: {yields} ALR decreases cytochrome c release from mitochondria. {yields} ALR protects hepatocytes against apoptosis induction by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. {yields} ALR exerts a liver-specific anti-apoptotic effect. {yields} A possible medical usage of ALR regarding protection of liver cells during apoptosis inducing therapies. -- Abstract: Augmenter of liver regeneration (ALR) is known to support liver regeneration and to stimulate proliferation of hepatocytes. However, it is not known if ALR exerts anti-apoptotic effects in human hepatocytes and whether this protective effect is cell type specific. This is relevant, because compounds that protect the liver against apoptosis without undesired effects, such as protection of metastatic tumour cells, would be appreciated in several clinical settings. Primary human hepatocytes (phH) and organotypic cancer cell lines were exposed to different concentrations of apoptosis inducers (ethanol, TRAIL, anti-Apo, TGF-{beta}, actinomycin D) and cultured with or without recombinant human ALR (rhALR). Apoptosis was evaluated by the release of cytochrome c from mitochondria and by FACS with propidium iodide (PI) staining. ALR significantly decreased apoptosis induced by ethanol, TRAIL, anti-Apo, TGF-{beta} and actinomycin D. Further, the anti-apoptotic effect of ALR was observed in primary human hepatocytes and in HepG2 cells but not in bronchial (BC1), colonic (SW480), gastric (GC1) and pancreatic (L3.6PL) cell lines. Therefore, the hepatotrophic growth factor ALR acts in a liver specific manner with regards to both its mitogenic and its anti-apoptotic effect. Unlike the growth factors HGF and EGF, rhALR acts in a liver specific manner. Therefore, ALR is a promising candidate for further evaluation as a possible hepatoprotective factor in clinical settings.

Augmenter of liver regeneration (ALR) protects human hepatocytes against apoptosis

International Nuclear Information System (INIS)

Ilowski, Maren; Kleespies, Axel; Toni, Enrico N. de; Donabauer, Barbara; Jauch, Karl-Walter; Hengstler, Jan G.; Thasler, Wolfgang E.

2011-01-01

Research highlights: → ALR decreases cytochrome c release from mitochondria. → ALR protects hepatocytes against apoptosis induction by ethanol, TRAIL, anti-Apo, TGF-β and actinomycin D. → ALR exerts a liver-specific anti-apoptotic effect. → A possible medical usage of ALR regarding protection of liver cells during apoptosis inducing therapies. -- Abstract: Augmenter of liver regeneration (ALR) is known to support liver regeneration and to stimulate proliferation of hepatocytes. However, it is not known if ALR exerts anti-apoptotic effects in human hepatocytes and whether this protective effect is cell type specific. This is relevant, because compounds that protect the liver against apoptosis without undesired effects, such as protection of metastatic tumour cells, would be appreciated in several clinical settings. Primary human hepatocytes (phH) and organotypic cancer cell lines were exposed to different concentrations of apoptosis inducers (ethanol, TRAIL, anti-Apo, TGF-β, actinomycin D) and cultured with or without recombinant human ALR (rhALR). Apoptosis was evaluated by the release of cytochrome c from mitochondria and by FACS with propidium iodide (PI) staining. ALR significantly decreased apoptosis induced by ethanol, TRAIL, anti-Apo, TGF-β and actinomycin D. Further, the anti-apoptotic effect of ALR was observed in primary human hepatocytes and in HepG2 cells but not in bronchial (BC1), colonic (SW480), gastric (GC1) and pancreatic (L3.6PL) cell lines. Therefore, the hepatotrophic growth factor ALR acts in a liver specific manner with regards to both its mitogenic and its anti-apoptotic effect. Unlike the growth factors HGF and EGF, rhALR acts in a liver specific manner. Therefore, ALR is a promising candidate for further evaluation as a possible hepatoprotective factor in clinical settings.

Thrombophilia testing in young patients with ischemic stroke.

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Pahus, Sidse Høst; Hansen, Anette Tarp; Hvas, Anne-Mette

2016-01-01

The possible significance of thrombophilia in ischemic stroke remains controversial. We aimed to study inherited and acquired thrombophilias as risk factors for ischemic stroke, transient ischemic attack (TIA) and amaurosis fugax in young patients. We included patients aged 18 to 50 years with ischemic stroke, TIA or amaurosis fugax referred to thrombophilia investigation at Aarhus University Hospital, Denmark from 1 January 2004 to 31 December 2012 (N=685). Clinical information was obtained from the Danish Stroke Registry and medical records. Thrombophilia investigation results were obtained from the laboratory information system. Absolute thrombophilia prevalences and associated odds ratios (OR) with 95% confidence intervals (95% CI) were reported for ischemic stroke (N=377) and TIA or amaurosis fugax (N=308). Thrombophilia prevalences for the general population were obtained from published data. No strong associations were found between thrombophilia and ischemic stroke, but patients with persistent presence of lupus anticoagulant (3%) had an OR at 2.66 (95% CI 0.84-9.15) for ischemic stroke. A significantly higher risk of TIA/amaurosis fugax was found for factor V Leiden heterozygote (12%) (OR: 1.99 (95% CI 1.14-3.28)). No other inherited or acquired thrombophilia was associated with ischemic stroke, TIA or amaurosis fugax. In young patients, thrombophilia did not infer an increased risk of ischemic stroke. Only factor V Leiden heterozygote patients had an increased risk of TIA/amaurosis fugax, and persistent presence of lupus anticoagulant was likely associated with ischemic stroke. We suggest the testing restricted to investigation of persistent presence of lupus anticoagulant. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hydrodynamic Delivery of Cre Protein to Lineage-Mark or Time-Stamp Mouse Hepatocytes In situ

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Sonsteng, Katherine M.; Prigge, Justin R.; Talago, Emily A.; June, Ronald K.; Schmidt, Edward E.

2014-01-01

Cre-responsive fluorescent marker alleles are powerful tools for cell lineage tracing in mice; however their utility is limited by regulation of Cre activity. When targeting hepatocytes, hydrodynamic delivery of a Cre-expression plasmid can convert Cre-responsive alleles without inducing the intracellular or systemic antiviral responses often associated with viral-derived Cre-expression vectors. In this method, rapid high-volume intravenous inoculation induces hepatocyte-targeted uptake of extracellular molecules. Here we tested whether hydrodynamic delivery of Cre protein or Cre fused to the HIV-TAT cell-penetrating peptide could convert Cre-responsive reporters in hepatocytes of mice. Hydrodynamic delivery of 2 nmol of either Cre or TAT-Cre protein converted the reporter allele in 5 to 20% of hepatocytes. Neither protein gave detectable Cre activity in endothelia, non-liver organs, or non-hepatocyte cells in liver. Using mice homozygous for a Cre-responsive marker that directs red- (Cre-naïve) or green- (Cre-converted) fluorescent proteins to the nucleus, we assessed sub-saturation Cre-activity. One month after hydrodynamic inoculation with Cre protein, 58% of hepatocyte nuclei that were green were also red, indicating that less than half of the hepatocytes that had obtained enough Cre to convert one marker allele to green were able to convert all alleles. For comparison, one month after hydrodynamic delivery of a Cre-expression plasmid with a weak promoter, only 26% of the green nuclei were also red. Our results show that hydrodynamic delivery of Cre protein allows rapid allelic conversion in hepatocytes, but Cre-activity is sub-saturating so many cells will not convert multiple Cre-responsive alleles. PMID:24626158

Intracellular pH regulation in hepatocytes isolated from three teleost species.

Science.gov (United States)

Furimsky, M; Moon, T W; Perry, S F

1999-09-01

The mechanisms of intracellular pH (pH(i)) regulation were studied in hepatocytes isolated from three species of teleost: rainbow trout (Oncorhynchus mykiss), black bullhead (Ameiurus melas) and American eel (Anguilla rostrata). Intracellular pH was monitored over time using the pH-sensitive fluorescent dye BCECF in response to acid loading under control conditions and in different experimental media containing either low Na(+) or Cl(-) concentrations, the Na(+)-H(+) exchanger blocker amiloride or the blocker of the V-type H(+)-ATPase, bafilomycin A(1). In trout and bullhead hepatocytes, recovery to an intracellular acid load occurred principally by way of a Na(+)-dependent amiloride-sensitive Na(+)-H(+) exchanger. In eel hepatocytes, the Na(+)-H(+) exchanger did not contribute to recovery to an acid load though evidence suggests that it is present on the cell membrane and participates in the maintenance of steady-state pH(i). The V-type H(+)-ATPase did not participate in recovery to an acid load in any species. A Cl(-)-HCO(3)(-) exchanger may play a role in recovery to an acid load in eel hepatocytes by switching off and retaining base that would normally be tonically extruded. Thus, it is clear that hepatocytes isolated from the three species are capable of regulating pH(i), principally by way of a Na(+)-H(+) exchanger and a Cl(-)-HCO(3)(-) exchanger, but do not exploit identical mechanisms for pH(i) recovery. J. Exp. Zool. 284:361-367, 1999. Copyright 1999 Wiley-Liss, Inc.

Metabolism of cysteine by cyteinesulfinate-independent pathway(s) in rat hepatocytes

International Nuclear Information System (INIS)

Stipanuk, M.H.; De La Rosa, J.; Drake, M.R.

1986-01-01

The metabolism of cysteine (CYS) and that of cysteinesulfinate (CSA) were studied in freshly isolated hepatocytes from fed rats. In incubations of rat hepatocytes with either 1 or 25 mM CSA, over 90% of the 14 CO 2 formed from [1- 14 C]CSA could be accounted for by production of hypotaurine plus taurine. In similar incubations with 1 or 25 mM CYS, only 4% of 14 CO 2 evolution from [1- 14 C]CYS could be accounted for by production of hypotaurine plus taurine. Addition of unlabeled CSA inhibited recovery of label from [1- 14 C]CYS as 14 CO 2 by 33%. Metabolism of CYS and of CSA were affected differently by addition of α-ketoglutarate, a cosubstrate for transamination, or of propargylglycine, an inhibitor of cystathionase activity. These data suggest that a substantial proportion of CYS is catabolized by CSA-independent pathways in the rat hepatocyte. Although addition of α-ketoglutarate to incubations of hepatocytes with CSA resulted in a marked increase in CSA catabolism via the transamination pathway, addition of keto acids to incubation systems had little or no effect on production of any metabolite from CYS. Thus, CYS transamination does not appear to be a major pathway of CYS metabolism in the hepatocyte. Inhibition of cystathionase with propargylglycine reduced both 14 CO 2 production from [1- 14 C]CYS and ammonia plus urea nitrogen production from CYS by about 50%; CSA catabolism was not affected. Thus, cleavage of cyst(e)ine by cystathionase may be an important physiological pathway for CYS catabolism in the liver

Induced Mitogenic Activity in AML-12 Mouse Hepatocytes Exposed to Low-dose Ultra-Wideband Electromagnetic Radiation

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P. B. Tchounwou

2005-04-01

Full Text Available Ultra–wideband (UWB technology has increased with the use of various civilian and military applications. In the present study, we hypothesized that low-dose UWB electromagnetic radiation (UWBR could elicit a mitogenic effect in AML-12 mouse hepatocytes, in vitro. To test this hypothesis, we exposed AML-12 mouse hepatocytes, to UWBR in a specially constructed gigahertz transverse electromagnetic mode (GTEM cell. Cells were exposed to UWBR for 2 h at a temperature of 23°C, a pulse width of 10 ns, a repetition rate of 1 kHz, and field strength of 5-20 kV/m. UWB pulses were triggered by an external pulse generator for UWBR exposure but were not triggered for the sham exposure. We performed an MTT Assay to assess cell viability for UWBR-treated and sham-exposed hepatocytes. Data from viability studies indicated a time-related increase in hepatocytes at time intervals from 8-24 h post exposure. UWBR exerted a statistically significant (p < 0.05 dose-dependent response in cell viability in both serum-treated and serum free medium (SFM -treated hepatocytes. Western blot analysis of hepatocyte lysates demonstrated that cyclin A protein was induced in hepatocytes, suggesting that increased MTT activity after UWBR exposure was due to cell proliferation. This study indicates that UWBR has a mitogenic effect on AML-12 mouse hepatocytes and implicates a possible role for UWBR in hepatocarcinoma.

Lipopolysaccharide impairs hepatocyte ureagenesis from ammonia: involvement of mitochondrial aquaporin-8.

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Soria, Leandro R; Marrone, Julieta; Molinas, Sara M; Lehmann, Guillermo L; Calamita, Giuseppe; Marinelli, Raúl A

2014-05-02

We recently reported that hepatocyte mitochondrial aquaporin-8 (mtAQP8) channels facilitate the uptake of ammonia and its metabolism into urea. Here we studied the effect of bacterial lipopolysaccharides (LPS) on ammonia-derived ureagenesis. In LPS-treated rats, hepatic mtAQP8 protein expression and diffusional ammonia permeability (measured utilizing ammonia analogues) of liver inner mitochondrial membranes were downregulated. NMR studies using 15N-labeled ammonia indicated that basal and glucagon-induced ureagenesis from ammonia were significantly reduced in hepatocytes from LPS-treated rats. Our data suggest that hepatocyte mtAQP8-mediated ammonia removal via ureagenesis is impaired by LPS, a mechanism potentially relevant to the molecular pathogenesis of defective hepatic ammonia detoxification in sepsis. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Regulation of lipid synthesis in hepatocytes from lean and obese Zucker rats

International Nuclear Information System (INIS)

Triscari, J.; Greenwood, M.R.; Sullivan, A.C.

1981-01-01

Fatty acid synthesis and CO 2 production were evaluated in hepatocytes from lean and obese Zucker rats in the presence of 3 H 2 O, and several carbon precursors. The incorporation of 3 H 2 O into fatty acids was greater in obese compared to lean rats in both the isolated hepatocyte and in vivo. The rates of incorporation of 3 H 2 O into fatty acids and cholesterol in hepatocytes of both lean and obese rats were linear for 2 hr, in the absence or presence of 16.7 mM glucose. Rates of fatty acid synthesis were higher in the presence of 16.7 mM glucose compared to the absence of glucose in both lean and obese while rates of cholesterol synthesis were similar. The incorporation of 3H2O into fatty acids, but not into cholesterol, was correlated with increasing glucose concentration and was 2 to three-fold higher in hepatocytes of obese compared to lean rats in the presence of several carbon precursors. Differences in CO 2 production between lean and obese rats suggested increased pentose phosphate shunt activity, decreased pyruvate dehydrogenase activity, and lower tricarboxylic acid cycle activity in obese rats. Fatty acid synthesis and CO 2 production from 3 H 2 O and [U- 14 C]glucose in hepatocytes of lean and obese rats was similarly elevated by insulin and depressed by glucagon at several concentrations, suggesting that hepatocytes of obese animals respond to these hormones. These data indicate that rates of hepatic fatty acid synthesis although higher in obese rats respond to modulation in a fashion which is similar to the response in lean rats. The present studies suggest that the oxidation of several carbon precursors in the tricarboxylic acid cycle is diminished in obese compared to lean rats, but pentose phosphate shunt activity is greater in the obese Zucker rats

Occurrence and predictors of persistent impaired glucose tolerance after acute ischemic stroke or transient ischemic attack

NARCIS (Netherlands)

S. Fonville (Susanne); H.M. den Hertog (Heleen); A.A.M. Zandbergen (Adrienne); P.J. Koudstaal (Peter Jan); H.F. Lingsma (Hester)

2014-01-01

textabstractBackground Impaired glucose tolerance is often present in patients with a transient ischemic attack (TIA) or ischemic stroke and doubles the risk of recurrent stroke. This impaired glucose tolerance can be transient, reflecting an acute stress response, or persistent, representing

Septic Shock following Prostate Biopsy: Aggressive Limb Salvage for Extremities after Pressor-Induced Ischemic Gangrene

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Jocelyn Lu, BS

2017-09-01

Full Text Available Summary:. Vasopressors used to treat patients with septic shock can cause ischemic necrosis of appendages such as the ears and nose, as well as the extremities. Cases of quadruple-extremity necrosis have high morbidity and mortality, and a profound negative impact on quality of life. This case report details the successful limb salvage and return to function using free tissue transfer as a means to salvage bilateral lower extremities in a patient who suffered vasopressor-induced ischemia of upper and lower extremities after prostate biopsy–induced septic shock. Septic shock following transrectal ultrasound–guided prostate biopsy is a rare, yet life-threatening complication. Successful treatment included thorough planning and staging of therapies such as awaiting tissue demarcation and serial surgical debridement to adequately prepare the tissue bed for free tissue transfer. Adjunctive treatments such as hyperbaric oxygen therapy, negative-pressure wound therapy, and meticulous wound care played a crucial role in wound healing. This vigilant planning and coordinated care resulted in the successful lower extremity salvage, consisting of bilateral transmetatarsal amputations and free tissue transfer to both limbs. We present our long-term follow-up of a functional ambulatory patient after catastrophic, life-threatening infection and appropriate multidisciplinary care.

Important hypercalcemia due to subcutaneous fat necrosis treated with pamidronate in an infant with severe hypoxic-ischemic encephalopathy

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Pasqua Anna Quitadamo

2016-08-01

Full Text Available Subcutaneous fat necrosis (SCFN of the newborn is an uncommon form of panniculitis that occurs after fetal distress and involves fatty areas during the first weeks of life. This rare disorder is generally self-limiting and undergoes complete regression. However, it can be complicated with a potentially life-threatening hypercalcemia. We report a case of severe hypercalcemia due to SCFN occurring after serious perinatal hypoxic injury, which resolved by intravenous administration of pamidronate. This treatment was rapidly effective and well tolerated. We suggest that pamidronate could be the first-line therapy for severe hypercalcemia in SCFN.

The role of hepatocyte nuclear factor 4 alpha in development and progression of liver diseases

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YANG Jinlian

2016-02-01

Full Text Available Hepatocyte nuclear factor 4 alpha (HNF4α, a member of the nuclear receptor superfamily, has a high expression level in mature hepatocytes. HNF4α can regulate hepatocyte-specific gene expression at a transcriptional level, promote hepatocyte development and differentiation, participate in establishment and maintenance of hepatocyte polarity, and enhance the synthetic, metabolic, and detoxifying functions of the liver. Through inhibiting the activation of hepatic stellate cells, reversing epithelial-mesenchymal transition, and inhibiting the proliferation, invasion, and metastasis of hepatoma cells, HNF4α may be involved in the development and progression of various liver diseases including liver fibrosis, liver cirrhosis, and hepatocellular carcinoma. This paper elaborates on the biological functions of HNF4α, and summarizes and analyzes the research advances in the mechanisms of action of HNF4α in the pathological process of liver diseases, in order to provide references for further investigation of the potential targeted therapies for liver diseases.

Glutamic Acid as Enhancer of Protein Synthesis Kinetics in Hepatocytes from Old Rats.

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Brodsky, V Y; Malchenko, L A; Butorina, N N; Lazarev Konchenko, D S; Zvezdina, N D; Dubovaya, T K

2017-08-01

Dense cultures of hepatocytes from old rats (~2 years old, body weight 530-610 g) are different from similar cultures of hepatocytes from young rats by the low amplitude of protein synthesis rhythm. Addition of glutamic acid (0.2, 0.4, or 0.6 mg/ml) into the culture medium with hepatocytes of old rats resulted in increase in the oscillation amplitudes of the protein synthesis rhythm to the level of young rats. A similar action of glutamic acid on the protein synthesis kinetics was observed in vivo after feeding old rats with glutamic acid. Inhibition of metabotropic receptors of glutamic acid with α-methyl-4-carboxyphenylglycine (0.01 mg/ml) abolished the effect of glutamic acid. The amplitude of oscillation of the protein synthesis rhythm in a cell population characterizes synchronization of individual oscillations caused by direct cell-cell communications. Hence, glutamic acid, acting as a receptor-dependent transmitter, enhanced direct cell-cell communications of hepatocytes that were decreased with aging. As differentiated from other known membrane signaling factors (gangliosides, norepinephrine, serotonin, dopamine), glutamic acid can penetrate into the brain and thus influence the communications and protein synthesis kinetics that are disturbed with aging not only in hepatocytes, but also in neurons.

Pre-Ischemic Treadmill Training for Prevention of Ischemic Brain Injury via Regulation of Glutamate and Its Transporter GLT-1

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Jingchun Guo

2012-07-01

Full Text Available Pre-ischemic treadmill training exerts cerebral protection in the prevention of cerebral ischemia by alleviating neurotoxicity induced by excessive glutamate release following ischemic stroke. However, the underlying mechanism of this process remains unclear. Cerebral ischemia-reperfusion injury was observed in a rat model after 2 weeks of pre-ischemic treadmill training. Cerebrospinal fluid was collected using the microdialysis sampling method, and the concentration of glutamate was determined every 40 min from the beginning of ischemia to 4 h after reperfusion with high-performance liquid chromatography (HPLC-fluorescence detection. At 3, 12, 24, and 48 h after ischemia, the expression of the glutamate transporter-1 (GLT-1 protein in brain tissues was determined by Western blot respectively. The effect of pre-ischemic treadmill training on glutamate concentration and GLT-1 expression after cerebral ischemia in rats along with changes in neurobehavioral score and cerebral infarct volume after 24 h ischemia yields critical information necessary to understand the protection mechanism exhibited by pre-ischemic treadmill training. The results demonstrated that pre-ischemic treadmill training up-regulates GLT-1 expression, decreases extracellular glutamate concentration, reduces cerebral infarct volume, and improves neurobehavioral score. Pre-ischemic treadmill training is likely to induce neuroprotection after cerebral ischemia by regulating GLT-1 expression, which results in re-uptake of excessive glutamate.

Ischemic Tolerance of the Brain and Spinal Cord: A Review.

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Yunoki, Masatoshi; Kanda, Takahiro; Suzuki, Kenta; Uneda, Atsuhito; Hirashita, Koji; Yoshino, Kimihiro

2017-11-15

Ischemic tolerance is an endogenous neuroprotective phenomenon induced by sublethal ischemia. Ischemic preconditioning (IPC), the first discovered form of ischemic tolerance, is widely seen in many species and in various organs including the brain and the spinal cord. Ischemic tolerance of the spinal cord is less familiar among neurosurgeons, although it has been reported from the viewpoint of preventing ischemic spinal cord injury during aortic surgery. It is important for neurosurgeons to have opportunities to see patients with spinal cord ischemia, and to understand ischemic tolerance of the spinal cord as well as the brain. IPC has a strong neuroprotective effect in animal models of ischemia; however, clinical application of IPC for ischemic brain and spinal diseases is difficult because they cannot be predicted. In addition, one drawback of preconditioning stimuli is that they are also capable of producing injury with only minor changes to their intensity or duration. Numerous methods to induce ischemic tolerance have been discovered that vary in their timing and the site at which short-term ischemia occurs. These methods include ischemic postconditioning (IPoC), remote ischemic preconditioning (RIPC), remote ischemic perconditioning (RIPerC) and remote ischemic postconditioning (RIPoC), which has had a great impact on clinical approaches to treatment of ischemic brain and spinal cord injury. Especially RIPerC and RIPoC to induce spinal cord tolerance are considered clinically useful, however the evidence supporting these methods is currently insufficient; further experimental or clinical research in this area is thus necessary.

Imaging of ischemic heart disease

International Nuclear Information System (INIS)

Lipton, Martin J.; Reba, Richard C.; Bogaert, Jan; Boxt, Larry M.

2002-01-01

Despite advances in the understanding and treatment of ischemic cardiomyopathy, characterized by extensive coronary artery disease and left ventricular (LV) dysfunction, the prognosis remains poor with only a 50-60% 5-year survival rate. The composition of atherosclerotic lesions is currently regarded as being more important than the degree of stenosis in determining acute events. If imaging techniques could distinguish vulnerable from stable plaques, then high-risk patient subgroups could be identified. Another important concept is that LV dysfunction may be the result of either scarring due to necrosis or to the presence of myocardial hibernation, in which there is sufficient blood flow to sustain viable myocytes, but insufficient to maintain systolic contraction. This concept of myocardial viability is critical for making optimal clinical management decisions. This review describes how noninvasive imaging methods can be used to distinguish regions of irreversibly injured myocardium from viable but hibernating segments. Technical advances in CT and MR have made imaging of the beating heart possible. Considerable clinical progress has already been made and further cardiac applications are expected. Radiologists therefore have new opportunities for involvement in cardiac imaging but must recognize the political implications as well as the diagnostic potential of these modalities not only for the heart, but also for the whole vascular system. This review focuses on imaging myocardial injury. It compares state-of-the-art CT and MR with more established yet contemporary echocardiography and nuclear scintigraphy. (orig.)

Optimization of the isolation and cultivation of Cyprinus carpio primary hepatocytes

Science.gov (United States)

Yanhong, Fan; Chenghua, He; Guofang, Liu

2008-01-01

The aquatic environment is affected by numerous chemical contaminants. There is an increasing need to identify these chemicals and to evaluate their potential toxicity towards aquatic life. In this research we optimized techniques for primary cell culture of Cyprinus carpio hepatocytes as one adjunct model for ecotoxicological evaluation of the potential hazards of xenobiotics in the aquatic environment. In this study, Cyprinus carpio hepatocytes were isolated by mechanical separation, two-step collagenase perfusion, and pancreatin digestion. The hepatocytes or parenchymal cells could be separated from cell debris and from non-parenchymal cells by low-speed centrifugation (Percoll gradient centrifugation). The harvested hepatocytes were suspended in DMEM, M199 (cultured in 5% CO2), or L-15 (cultured without 5% CO2) medium then cultured at 17, 27, or 37 °C. Cell yield was counted by use of a hemocytometer, and the viability of the cells was assessed by use of the Trypan blue exclusion test. Results from these studies showed that the best method of isolation was pancreatin digestion (the cell yield was 2.7 × 108 per g (liver weight) and the viability was 98.4%) and the best medium was M199 (cultured in 5% CO2) or L-15 (cultured without 5% CO2). The optimum culture temperature was 27 °C. The primary hepatocytes culture of Cyprimus carpio grew well and satisfied requirements for most toxicological experiments in this condition. PMID:19002769

Impaired mitochondrial function in chronically ischemic human heart

DEFF Research Database (Denmark)

Stride, Nis Ottesen; Larsen, Steen; Hey-Mogensen, Martin

2013-01-01

, and finally to assess myocardial antioxidant levels. Mitochondrial respiration in biopsies from ischemic and nonischemic regions from the left ventricle of the same heart was compared in nine human subjects. Maximal oxidative phosphorylation capacity in fresh muscle fibers was lower in ischemic compared.......05), and the levels of antioxidant protein expression was lower. Diminished mitochondrial respiration capacity and excessive ROS production demonstrate an impaired mitochondrial function in ischemic human heart muscle. No chronic ischemic preconditioning effect was found....

Independent, parallel pathways to CXCL10 induction in HCV-infected hepatocytes.

Science.gov (United States)

Brownell, Jessica; Wagoner, Jessica; Lovelace, Erica S; Thirstrup, Derek; Mohar, Isaac; Smith, Wesley; Giugliano, Silvia; Li, Kui; Crispe, I Nicholas; Rosen, Hugo R; Polyak, Stephen J

2013-10-01

The pro-inflammatory chemokine CXCL10 is induced by HCV infection in vitro and in vivo, and is associated with outcome of IFN (interferon)-based therapy. We studied how hepatocyte sensing of early HCV infection via TLR3 (Toll-like receptor 3) and RIG-I (retinoic acid inducible gene I) led to expression of CXCL10. CXCL10, type I IFN, and type III IFN mRNAs and proteins were measured in PHH (primary human hepatocytes) and hepatocyte lines harboring functional or non-functional TLR3 and RIG-I pathways following HCV infection or exposure to receptor-specific stimuli. HuH7 human hepatoma cells expressing both TLR3 and RIG-I produced maximal CXCL10 during early HCV infection. Neutralization of type I and type III IFNs had no impact on virus-induced CXCL10 expression in TLR3+/RIG-I+ HuH7 cells, but reduced CXCL10 expression in PHH. PHH cultures were positive for monocyte, macrophage, and dendritic cell mRNAs. Immunodepletion of non-parenchymal cells (NPCs) eliminated marker expression in PHH cultures, which then showed no IFN requirement for CXCL10 induction during HCV infection. Immunofluorescence studies also revealed a positive correlation between intracellular HCV Core and CXCL10 protein expression (r(2) = 0.88, p ≤ 0.001). While CXCL10 induction in hepatocytes during the initial phase of HCV infection is independent of hepatocyte-derived type I and type III IFNs, NPC-derived IFNs contribute to CXCL10 induction during HCV infection in PHH cultures. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

MRI in ischemic heart disease

International Nuclear Information System (INIS)

Hazirolan, T.

2012-01-01

Full text: The role of magnetic resonance imaging in the evaluation of ischemic heart disease has increased over the last years. Cardiac MRI is the only imaging modality that provides 'one stop shop' assessment. Information about ventricular function, myocardial ischemia and myocardial viability can be obtained in a single cardiac MRI session. Additionally, Cardiac MRI has become a gold standard method in evaluation of myocardial viability and in assessment of ventricular mass and function. As a result, cardiac MRI enable radiologist to comprehensively assess ischemic heart disease. The aim of this presentation is to provide the reader a state-of-the art on how the newest cardiac MRI techniques can be used to study ischemic heart disease patients.

Genetic variation in WRN and ischemic stroke

DEFF Research Database (Denmark)

Christoffersen, Mette; Frikke-Schmidt, Ruth; Nordestgaard, Børge G.

2017-01-01

trends for ischemic cerebrovascular disease (P = 0.06). In meta-analyses including 59,190 individuals in 5 studies, the hazard ratio for ischemic stroke for C1367R TT homozygotes versus CC/CT was 1.14 (1.04–1.25; P = 0.008). Conclusions This study suggests that common genetic variation in WRN......Background Werner syndrome, a premature genetic aging syndrome, shares many clinical features reminiscent of normal physiological aging, and ischemic vascular disease is a frequent cause of death. We tested the hypothesis that genetic variation in the WRN gene was associated with risk of ischemic...... vascular disease in the general population. Methods We included 58,284 participants from two general population cohorts, the Copenhagen City Heart Study (CCHS) and the Copenhagen General Population Study (CGPS). Of these, 6,312 developed ischemic vascular disease during follow-up. In the CCHS (n = 10...

Impaired mitochondrial metabolism and protein synthesis in streptozotocin diabetic rat hepatocytes

International Nuclear Information System (INIS)

Memon, R.A.; Bessman, S.P.; Mohan, C.

1990-01-01

Isolated hepatocytes prepared from control, streptozotocin diabetic rats were incubated at 30 degrees C in Krebs-Henseleit bicarbonate buffer, pH 7.4, containing 0.5 mM concentration of each of the 20 natural amino acids. Effect of insulin on the oxidation of 2,3- 14 C and 1,4- 14 C succinate (suc) carbons and their incorporation into hepatocyte protein, lipid and various metabolic intermediates was studied. Mitochondrial oxidation of suc carbons and their incorporation into protein and lipid was significantly lower in diabetic and insulin treated diabetic rats. Diabetic rats failed to exhibit any significant insulin effect on the oxidation of either 2,3 or 1,4- 14 C suc carbons. Amphibolic channeling of 2,3- 14 C suc carbons into amino acids was significantly reduced in hepatocytes of diabetic rats, however, more of these carbons were diverted into the gluconeogenesis pathway. Diabetes caused a far greater decrease in the oxidation of 2,3- 14 C suc carbons as compared to 1,4- 14 C suc. Based on an earlier report that insulin stimulates only the intramitochondrial Krebs cycle reactions, the authors conclude that the diminished level of anabolic activities in the diabetic rat hepatocytes is due to the subsequent reduction in amphibolic channeling of metabolic intermediates

Requirements of glycerol and fatty acid for triglyceride synthesis and ketogenesis by hepatocytes from normal and triiodothyronine-treated rats

International Nuclear Information System (INIS)

Olubadewo, J.O.; Heimberg, M.

1985-01-01

Hepatocytes from T3-treated rats synthesized less triglyceride and more ketone bodies from [1- 14 C]oleate at all concentrations from 0-2 mM, than did hepatocytes from euthyroid animals; addition of 1.0 mM glycerol increased triglyceride synthesis and reduced ketogenesis in hepatocytes from T3-treated rats to the rates observed in euthyroid hepatocytes in the absence of added glycerol. Glycerol did not alter triglyceride synthesis, but reduced ketogenesis genesis by euthyroid hepatocytes. It is probable from these and other data that, in the hyperthyroid rat, glycero-3-P, and not fatty acid, is rate limiting for synthesis of triglyceride, and, secondarily for reducing rates of ketogenesis in the hepatocyte

Cadmium cytotoxicity in albino mice hepatocytes and its possible implications on tropical environments

International Nuclear Information System (INIS)

Marcano, Letty; Carruyo, Ingrid; Montiel, Xiomara; Faria, Clarisa de R.

2006-01-01

Analyzed phenotypic, structural and ultrastructural alterations induced by Cd +2 in hepatocytes extracted from Swiss Albino mice. Cadmium was given orally in watery solution of CdCl 2 during 100 days at concentrations of 50 ppm, 100 ppm and 150 ppm. In controls, distilled water alone was used. The samples were processed with the paraffin inclusion and hematoxylin-eosin coloration techniques for light microscopy. The conventional technique was used for transmission electron microscopy . Phenotypic (size and weight differences) and physiologic changes (muscular weakness, unrest) were found; at the structural level it was noticed loss of trabecular disposition and of lobular architecture, lymphocyte agglomeration, vacuolisation, dilatation of sinusoid and central vein, among others. The ultrastructural study evidenced alterations coincident with those seen with light microscopy, which were accentuated with the increase of metal concentration: nucleolus with a high number of fibrillar centers (50 ppm); voluminous lipidic drops in the cytoplasm, loose endoplasmic rough reticulum, cytoplasmic vacuolisation, altered lysosomes and peroxisomes (100 ppm); contracted nucleis with condensed chromatin, dilatation of intracellular space and mitochondria, and loss of fibrillar areas (150 ppm). Cadmium produces a toxic effect in the hepatic cells; the effect is more severe at higher concentration, leading to cellular necrosis. (author) [es

Preventing hepatocyte oxidative stress cytotoxicity with Mangifera indica L. extract (Vimang).

Science.gov (United States)

Remirez, Diadelis; Tafazoli, Shahrzad; Delgado, Rene; Harandi, Asghar A; O'Brien, Peter J

2005-01-01

Vimang is an aqueous extract of Mangifera indica used in Cuba to improve the quality of life in patients suffering from inflammatory diseases. In the present study we evaluated the effects of Vimang at preventing reactive oxygen species (ROS) formation and lipid peroxidation in intact isolated rat hepatocytes. Vimang at 20, 50 and 100 microg/ml inhibited hepatocyte ROS formation induced by glucose-glucose oxidase. Hepatocyte cytotoxicity and lipid peroxidation induced by cumene hydroperoxide was also inhibited by Vimang in a dose and time dependent manner at the same concentration. Vimang also inhibited superoxide radical formation by xanthine oxidase and hypoxanthine. The superoxide radical scavenging and antioxidant activity of the Vimang extract was likely related to its gallates, catechins and mangiferin content. To our knowledge, this is the first report of cytoprotective antioxidant effects of Vimang in cellular oxidative stress models.

U.V.-enhanced reactivation of u.v.-irradiated herpes virus by primary cultures of rat hepatocytes

International Nuclear Information System (INIS)

Zurlo, J.; Yager, J.D.

1984-01-01

Carcinogen treatment of cultured mammalian cells prior to infection with u.v.-irradiated virus results in enhanced virus survival and mutagenesis suggesting the induction of SOS-type processes. In this paper, we report the development of a primary rat hepatocyte culture system to investigate cellular responses to DNA damage which may be relevant to hepatocarcinogenesis in vivo. We have obtained data demonstrating that enhanced reactivation of u.v.-irradiated Herpes simplex virus type 1 (HSV-1) occurs in hepatocytes irradiated with u.v. Cultured hepatocytes were pretreated with u.v. at the time of enhanced DNA synthesis. These treatments caused an inhibition followed by a recovery of DNA synthesis. At various times after pretreatment, the hepatocytes were infected with control or u.v.-irradiated HSV-1 at low multiplicity, and virus survival was measured by direct plaque assay. U.v.-irradiated HSV-1 exhibited the expected two-component survival curve in control or u.v. pretreated hepatocytes. The magnitude of enhanced reactivation of HSV-1 was dependent on the u.v. dose to the hepatocytes, the time of infection following u.v. pretreatment, and the level of DNA synthesis at the time of pretreatment. These results suggest that u.v. treatment of rat hepatocytes causes the induction of SOS-type functions that may have a role in the initiation of hepatocarcinogenesis

Improved antitumor activity and reduced cardiotoxicity of epirubicin using hepatocyte-targeted nanoparticles combined with tocotrienols against hepatocellular carcinoma in mice.

Science.gov (United States)

Nasr, Magda; Nafee, Noha; Saad, Hoda; Kazem, Amani

2014-09-01

Hepatocellular carcinoma (HCC) is the third most common cause of cancer death worldwide. Epirubicin (EPI), an anthracycline derivative, is one of the main line treatments for HCC. However, serious side effects including cardiomyopathy and congestive heart failure limit its long term administration. Our main goal is to develop a delivery strategy that ensures improved efficacy of the chemotherapeutic agent together with reduced cardiotoxicity. In this context, EPI was loaded in chitosan-PLGA nanoparticles linked with asialofetuin (EPI-NPs) selectively targeting hepatocytes. In an attempt to reduce cardiotoxicity, targeted EPI-NPs were coadministered with tocotrienols. EPI-NPs significantly enhanced the antiproliferative effect compared to free EPI as studied on Hep G2 cell line. Nanoencapsulated EPI injected in HCC mouse model revealed higher p53-mediated apoptosis and reduced angiogenesis in the tumor. Combined therapy of EPI-NPs with tocotrienols further enhanced apoptosis and reduced VEGF level in a dose dependent manner. Assessment of cardiotoxicity indicated that EPI-NPs diminished the high level of proinflammatory cytokine tumor necrosis factor-α (TNF-α) as well as oxidative stress-induced cardiotoxicity as manifested by reduced level of lipid peroxidation products (TBARS) and nitric oxide (NO). EPI-NPs additionally restored the diminished level of superoxide dismutase (SOD) and reduced glutathione (GSH) in the heart. Interestingly, tocotrienols provided both antitumor activity and higher protection against oxidative stress and inflammation induced by EPI in the heart. This hepatocyte-targeted biodegradable nanoparticle/tocotrienol combined therapy represents intriguing therapeutic strategy for EPI providing not only superior efficacy but also higher safety levels. Copyright © 2014 Elsevier B.V. All rights reserved.

Human hepatocyte depletion in the presence of HIV-1 infection in dual reconstituted humanized mice

Science.gov (United States)

Wang, Weimin; Cheng, Yan; Makarov, Edward; Ganesan, Murali; Gebhart, Catherine L.; Gorantla, Santhi; Osna, Natalia

2018-01-01

ABSTRACT Human immunodeficiency virus type 1 (HIV-1) infection impairs liver function, and liver diseases have become a leading cause of morbidity in infected patients. The immunopathology of liver damage caused by HIV-1 remains unclear. We used chimeric mice dually reconstituted with a human immune system and hepatocytes to address the relevance of the model to pathobiology questions related to human hepatocyte survival in the presence of systemic infection. TK-NOG males were transplanted with mismatched human hematopoietic stem/progenitor cells and hepatocytes, human albumin concentration and the presence of human immune cells in blood were monitored for hepatocytes and immune reconstitution, and mice were infected with HIV-1. HIV-1-infected animals showed a decline in human albumin concentration with a significant reduction in percentage of human hepatocytes compared to uninfected mice. The decrease in human albumin levels correlated with a decline in CD4+ cells in the liver and with an increase in HIV-1 viral load. HIV-1 infection elicited proinflammatory response in the immunological milieu of the liver in HIV-infected mice compared to uninfected animals, as determined by upregulation of IL23, CXCL10 and multiple toll-like receptor expression. The inflammatory reaction associated with HIV-1 infection in vivo could contribute to the depletion and dysfunction of hepatocytes. The dual reconstituted TK-NOG mouse model is a feasible platform to investigate hepatocyte-related HIV-1 immunopathogenesis. This article has an associated First Person interview with the first author of the paper. PMID:29361613

Human hepatocyte depletion in the presence of HIV-1 infection in dual reconstituted humanized mice

Directory of Open Access Journals (Sweden)

Raghubendra Singh Dagur

2018-02-01

Full Text Available Human immunodeficiency virus type 1 (HIV-1 infection impairs liver function, and liver diseases have become a leading cause of morbidity in infected patients. The immunopathology of liver damage caused by HIV-1 remains unclear. We used chimeric mice dually reconstituted with a human immune system and hepatocytes to address the relevance of the model to pathobiology questions related to human hepatocyte survival in the presence of systemic infection. TK-NOG males were transplanted with mismatched human hematopoietic stem/progenitor cells and hepatocytes, human albumin concentration and the presence of human immune cells in blood were monitored for hepatocytes and immune reconstitution, and mice were infected with HIV-1. HIV-1-infected animals showed a decline in human albumin concentration with a significant reduction in percentage of human hepatocytes compared to uninfected mice. The decrease in human albumin levels correlated with a decline in CD4+ cells in the liver and with an increase in HIV-1 viral load. HIV-1 infection elicited proinflammatory response in the immunological milieu of the liver in HIV-infected mice compared to uninfected animals, as determined by upregulation of IL23, CXCL10 and multiple toll-like receptor expression. The inflammatory reaction associated with HIV-1 infection in vivo could contribute to the depletion and dysfunction of hepatocytes. The dual reconstituted TK-NOG mouse model is a feasible platform to investigate hepatocyte-related HIV-1 immunopathogenesis. This article has an associated First Person interview with the first author of the paper.

[Current status and future perspectives of hepatocyte transplantation].

Science.gov (United States)

Pareja, Eugenia; Cortés, Miriam; Gómez-Lechón, M José; Maupoey, Javier; San Juan, Fernando; López, Rafael; Mir, Jose

2014-02-01

The imbalance between the number of potential beneficiaries and available organs, originates the search for new therapeutic alternatives, such as Hepatocyte transplantation (HT).Even though this is a treatment option for these patients, the lack of unanimity of criteria regarding indications and technique, different cryopreservation protocols, as well as the different methodology to assess the response to this therapy, highlights the need of a Consensus Conference to standardize criteria and consider future strategies to improve the technique and optimize the results.Our aim is to review and update the current state of hepatocyte transplantation, emphasizing the future research attempting to solve the problems and improve the results of this treatment. Copyright © 2013 AEC. Published by Elsevier Espana. All rights reserved.

Effects of Cytochrome P 450 Inhibitors on Itraconazole and Fluconazole Induced Cytotoxicity in Hepatocytes

International Nuclear Information System (INIS)

Somchit, N.; Ngee, C.S.; Yaakob, A.; Ahmad, Z.; Zakaria, Z.A.

2009-01-01

Itraconazole and fluconazole have been reported to induce hepatotoxicity in patients. The present study was designed to investigate the role of cytochrome P450 inhibitors, SKF 525A, and curcumin pretreatment on the cytotoxicity of antifungal drugs fluconazole and itraconazole. For 3 consecutive days, female rats were administered daily SKF 525A or curcumin (5 and 25?mg/kg). Control rats received an equivalent amount of dosed vehicle. The animals were anaesthetised 24 hours after receiving the last dose for liver perfusion. Hepatocytes were then exposed to various concentrations of antifungal drugs. In vitro incubation of hepatocytes with itraconazole revealed significantly lower viability when compared to fluconazole as assessed by lactate dehydrogenase, aspartate aminotransferase and alanine aminotransferase activities. The cytotoxicity of itraconazole was enhanced when incubated with hepatocytes pretreated with SKF 525A. SKF 525A had no effects on the cytotoxicity of fluconazole. Curcumin failed to either increase or decrease the cytotoxicity of both antifungal drugs. ATP levels also showed significant decrease in both itraconazole and fluconazole incubated hepatocytes. However, SKF 525A pretreated hepatocytes had significantly lower ATP levels after itraconazole incubations. Collectively, these results confirm the involvement of cytochrome P450 in the cytoprotection in itraconazole induced hepatocyte toxicity. Differences of the effects of SKF 525A on the cytotoxicity induced by itraconazole and fluconazole may be due to the differences on the metabolism of each antifungal drug in vivo.

Effects of clofibric acid on mRNA expression profiles in primary cultures of rat, mouse and human hepatocytes.

Science.gov (United States)

Richert, Lysiane; Lamboley, Christelle; Viollon-Abadie, Catherine; Grass, Peter; Hartmann, Nicole; Laurent, Stephane; Heyd, Bruno; Mantion, Georges; Chibout, Salah-Dine; Staedtler, Frank

2003-09-01

The mRNA expression profile in control and clofibric acid (CLO)-treated mouse, rat, and human hepatocytes was analyzed using species-specific oligonucleotide DNA microarrays (Affymetrix). A statistical empirical Bayes procedure was applied in order to select the significantly differentially expressed genes. Treatment with the peroxisome proliferator CLO induced up-regulation of genes involved in peroxisome proliferation and in cell proliferation as well as down-regulation of genes involved in apoptosis in hepatocytes of rodent but not of human origin. CLO treatment induced up-regulation of microsomal cytochrome P450 4a genes in rodent hepatocytes and in two of six human hepatocyte cultures. In addition, genes encoding phenobarbital-inducible cytochrome P450s were also up-regulated by CLO in rodent and human hepatocyte cultures. Up-regulation of phenobarbital-inducible UDP-glucuronosyl-transferase genes by CLO was observed in both rat and human but not in mouse hepatocytes. CLO treatment induced up-regulation of L-fatty acid binding protein (L-FABP) gene in hepatocytes of both rodent and human origin. However, while genes of the cytosolic, microsomal, and mitochondrial pathways involved in fatty acid transport and metabolism were up-regulated by CLO in both rodent and human hepatocyte cultures, genes of the peroxisomal pathway of lipid metabolism were up-regulated in rodents only. An up-regulation of hepatocyte nuclear factor 1alpha (HNF1alpha) by CLO was observed only in human hepatocyte cultures, suggesting that this trans-activating factor may play a key role in the regulation of fatty acid metabolism in human liver as well as in the nonresponsiveness of human liver to CLO-induced regulation of cell proliferation and apoptosis.

Effects of clofibric acid on mRNA expression profiles in primary cultures of rat, mouse and human hepatocytes

International Nuclear Information System (INIS)

Richert, Lysiane; Lamboley, Christelle; Viollon-Abadie, Catherine; Grass, Peter; Hartmann, Nicole; Laurent, Stephane; Heyd, Bruno; Mantion, Georges; Chibout, Salah-Dine; Staedtler, Frank

2003-01-01

The mRNA expression profile in control and clofibric acid (CLO)-treated mouse, rat, and human hepatocytes was analyzed using species-specific oligonucleotide DNA microarrays (Affymetrix). A statistical empirical Bayes procedure was applied in order to select the significantly differentially expressed genes. Treatment with the peroxisome proliferator CLO induced up-regulation of genes involved in peroxisome proliferation and in cell proliferation as well as down-regulation of genes involved in apoptosis in hepatocytes of rodent but not of human origin. CLO treatment induced up-regulation of microsomal cytochrome P450 4a genes in rodent hepatocytes and in two of six human hepatocyte cultures. In addition, genes encoding phenobarbital-inducible cytochrome P450s were also up-regulated by CLO in rodent and human hepatocyte cultures. Up-regulation of phenobarbital-inducible UDP-glucuronosyl-transferase genes by CLO was observed in both rat and human but not in mouse hepatocytes. CLO treatment induced up-regulation of L-fatty acid binding protein (L-FABP) gene in hepatocytes of both rodent and human origin. However, while genes of the cytosolic, microsomal, and mitochondrial pathways involved in fatty acid transport and metabolism were up-regulated by CLO in both rodent and human hepatocyte cultures, genes of the peroxisomal pathway of lipid metabolism were up-regulated in rodents only. An up-regulation of hepatocyte nuclear factor 1α (HNF1α) by CLO was observed only in human hepatocyte cultures, suggesting that this trans-activating factor may play a key role in the regulation of fatty acid metabolism in human liver as well as in the nonresponsiveness of human liver to CLO-induced regulation of cell proliferation and apoptosis

Modelling Ischemic Stroke and Temperature Intervention Using Vascular Porous Method

Science.gov (United States)

Blowers, Stephen; Valluri, Prashant; Marshall, Ian; Andrews, Peter; Harris, Bridget; Thrippleton, Michael

2017-11-01

In the event of cerebral infarction, a region of tissue is supplied with insufficient blood flow to support normal metabolism. This can lead to an ischemic reaction which incurs cell death. Through a reduction of temperature, the metabolic demand can be reduced, which then offsets the onset of necrosis. This allows extra time for the patient to receive medical attention and could help prevent permanent brain damage from occurring. Here, we present a vascular-porous (VaPor) blood flow model that can simulate such an event. Cerebral blood flow is simulated using a combination of 1-Dimensional vessels embedded in 3-Dimensional porous media. This allows for simple manipulation of the structure and determining the effect of an obstructed vessel. Results show regional temperature increase of 1-1.5°C comparable with results from literature (in contrast to previous simpler models). Additionally, the application of scalp cooling in such an event dramatically reduces the temperature in the affected region to near hypothermic temperatures, which points to a potential rapid form of first intervention.

Aniline Induces Oxidative Stress and Apoptosis of Primary Cultured Hepatocytes

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Yue Wang

2016-11-01

Full Text Available The toxicity and carcinogenicity of aniline in humans and animals have been well documented. However, the molecular mechanism involved in aniline-induced liver toxicity and carcinogenesis remains unclear. In our research, primary cultured hepatocytes were exposed to aniline (0, 1.25, 2.50, 5.0 and 10.0 μg/mL for 24 h in the presence or absence of N-acetyl-l-cysteine (NAC. Levels of reactive oxygen species (ROS, malondialdehyde (MDA, and glutathione (GSH, activities of superoxide dismutase (SOD and catalase (CAT, mitochondrial membrane potential, DNA damage, cell viability, and apoptosis were detected. Levels of ROS and MDA were significantly increased and levels of GSH and CAT, activity of SOD, and mitochondrial membrane potential in hepatocytes were significantly decreased by aniline compared with the negative control group. The tail moment and DNA content of the tail in exposed groups were significantly higher than those in the negative control group. Cell viability was reduced and apoptotic death was induced by aniline in a concentration-dependent manner. The phenomena of ROS generation, oxidative damage, loss of mitochondrial membrane potential, DNA damage and apoptosis could be prevented if ROS inhibitor NAC was added. ROS generation is involved in the loss of mitochondrial membrane potential and DNA injury, which may play a role in aniline-induced apoptosis in hepatocytes. Our study provides insight into the mechanism of aniline-induced toxicity and apoptosis of hepatocytes.

Functional reconstruction of ischemic contracture in the

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TANG Hao

2011-04-01

Full Text Available 【Abstract】Objective: To discuss the method of functional reconstruction of ischemic contracture in the lower limb and propose a classification protocol for ischemic contracture in the lower limb based on its severity and prognosis. Methods: A total of 42 patients with ischemic contracture in the lower limb were included in this study. According to different types of disturbance and degrees of severity, surgical reconstructions consisting of nerve decompression, tendon lengthening or transfer, intrinsic foot muscle release and sural-tibial nerve anastomosis were performed in every patient. Results: Postoperatively, all patients were able to walk on flat ground. Drop foot was corrected in 10 patients, and 5 patients still felt some difficulty during stair activity. Split Achilles tendon transfer to flexor hallucis longus tendon was performed in 12 patients, and their walking stability was improved. Seven patients accepted ipsilateral suraltibial nerve anastomosis, and sensitivity recovery reached to S2 in 2 patients and S3 in 5 patients. Conclusions: Ischemic contracture in the lower limb is a devastating complication after lower limb trauma. The prevention of contracture is much more important than the treatment of an established contracture. Split Achilles tendon transfer to flexor hallucis longus tendon and sural-tibial nerve anastomosis, which was initially implemented by us, could improve the functional recovery of ischemic contracture in lower limbs, and thus provides a new alternative for functional reconstruction of ischemic contracture in the lower limb. Key words: Ischemic contracture; Classification; Recovery of function

EXPERIMENTAL SUBSTANTIATION OF PERMEABILIZED HEPATOCYTES MODEL FOR INVESTIGATION OF MITOCHONDRIA IN SITU RESPIRATION.

Science.gov (United States)

Merlavsky, V M; Manko, B O; Ikkert, O V; Manko, V V

2015-01-01

To verify experimentally the model of permeabilized hepatocytes, the degree of cell permeability was assessed using trypan blue and polarographycally determined cell respiration rate upon succinate (0.35 mM) and a-ketoglutarate (1 mM) oxidation. Oxidative phosphorylation was stimulated by ADP (750 μM). Hepatocyte permeabilization depends on digitonin concentraion in medium and on the number of cells in suspension. Thus, the permeabilization of 0.9-1.7 million cells/ml was completed by 25 μg/ml of digitonin, permeabilization of 2.0-3.0 million cells/ml--by 50 μg/ml of digitonin and permeabilization of 4.0-5.6 million cells/ml--by 100 μg/ml. Thus, the higher is the suspension density, the higher digitonin concentration is required. Treatment of hepatocytes with digitonin resulted in a decrease of endogenous respiration rate to a minimum upon 20-22 μg of digitonin per 1 million cells. Supplementation of permeabilized hepatocytes with α-ketoglutarate maintained stable respiration rate, on the level higher than endogenous respiration at the corresponding digitonin concentration, unlike the intact cells. Respiration rate of permeabilized hepatocytes at the simultaneous addition of α-ketoglutarate and ADP increased to the level of intact cell respiration, irrespective of digitonin concentration. Addition of solely succinate and especially succinate plus ADP markedly intensified the respiration of permeabilized hepatocytes to the level higher than that of intact cells. The dependence of succinate-stimulated respiration on digitonin concentration reached maximum at 20-22 αg of digitonin per 1 million cells. Optimal ratio of digitonin amount and the cell number in suspension is expected to be different in various tissues.

Influence of minoxidil on ischemic cutaneous flaps in rats Influência do minoxidil sobre retalhos cutâneos isquêmicos em ratos

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Rogério de Castro Bittencourt

2005-12-01

Full Text Available PURPOSE: To evaluate the influence of minoxidil, a well known vasodilator, on ischemic flap necrosis prevention in rats. METHODS: Ventral cutaneous flaps, measuring 8x4cm, were designed in 20 Wistar rats based on the right cranial epigastric artery. In the experiment group, 50 mg/kg/day of minoxidil sulfate was administered by orogastric tube and the same amount of saline solution was administered to the control group. Such procedure was initiated 24h before surgery and kept once a day through the 7th postoperative day. Microcirculation was evaluated with laser fluxometry 24h before surgical procedure, at immediate postoperative and at the 7th postoperative day. Flap necrosis area was evaluated by 2 methods: planimetry and weight/paper ratio. RESULTS: A significant flow increase in distal and medial extremity at M1 (medial point 1 (p=0,0484 was observed in the experiment group. There was significant difference in flap necrosis prevention in the experiment group (p=0,0433, although after necrosis took place there was no significant difference in necrosis size. (p=0,1051 and p=0,2799. CONCLUSION: Minoxidil sulfate is effective in avoiding necrosis in ischemic flaps, but after necrosis is present there is no difference in survival area between experimental and control groups.OBJETIVOS: Avaliar a influência do minoxidil, um vasodilatador, na prevenção de necrose, em retalhos isquêmicos, em ratos. MÉTODOS: Preparam-se retalhos cutâneos ventrais, medindo 8x4 cm, baseados na artéria epigástrica cranial direita, em 20 ratos - Wistar. Administrou-se 50 mg/kg/dia de sulfato de minoxidil aos ratos do grupo experimento e o mesmo volume de solução salina isotônica aos do grupo controle, por sonda oro-gástrica. Iniciou-se o tratamento 24 horas antes da operação e manteve-se, diariamente, por 7 dias, no pós-operatório. Realizou-se a avaliação da microcirculação dos retalhos fluxometria a laser 24 horas antes da operação, no p

Non-viral ex vivo hepatic gene transfer by in situ lipofection of liver and intraperitoneal transplantation of hepatocytes.

Science.gov (United States)

Rangarajan, P N; Vatsala, P G; Ashok, M S; Srinivas, V K; Habibullah, C M; Padmanaban, G

1997-04-29

Perfusion of liver with plasmid DNA-lipofectin complexes via the portal vein results in efficient accumulation of the vector in hepatocytes. Such hepatocytes, when administered intraperitoneally into a hepatectomized rat, repopulate the liver and express the transgene efficiently. This procedure obviates the need for large-scale hepatocyte culture for ex vivo gene transfer. Further, intraperitoneal transplantation is a simple and cost-effective strategy of introducing genetically modified hepatocytes into liver. Thus, in situ lipofection of liver and intraperitoneal transfer of hepatocytes can be developed into a novel method of non-viral ex vivo gene transfer technique that has applications in the treatment of metabolic disorders of liver and hepatic gene therapy.

The Neuroprotective Effect Of Electro-Acupuncture Against Ischemic ...

African Journals Online (AJOL)

The Neuroprotective Effect Of Electro-Acupuncture Against Ischemic Stroke In Animal Model: A Review. ... Conclusion: An awareness of the benefits of acupuncture might lead more patients into accepting acupuncture therapy for the management of patients with ischemic stroke and patients with high risk of ischemic stroke.

Pioglitazone after Ischemic Stroke or Transient Ischemic Attack.

Science.gov (United States)

Kernan, Walter N; Viscoli, Catherine M; Furie, Karen L; Young, Lawrence H; Inzucchi, Silvio E; Gorman, Mark; Guarino, Peter D; Lovejoy, Anne M; Peduzzi, Peter N; Conwit, Robin; Brass, Lawrence M; Schwartz, Gregory G; Adams, Harold P; Berger, Leo; Carolei, Antonio; Clark, Wayne; Coull, Bruce; Ford, Gary A; Kleindorfer, Dawn; O'Leary, John R; Parsons, Mark W; Ringleb, Peter; Sen, Souvik; Spence, J David; Tanne, David; Wang, David; Winder, Toni R

2016-04-07

Patients with ischemic stroke or transient ischemic attack (TIA) are at increased risk for future cardiovascular events despite current preventive therapies. The identification of insulin resistance as a risk factor for stroke and myocardial infarction raised the possibility that pioglitazone, which improves insulin sensitivity, might benefit patients with cerebrovascular disease. In this multicenter, double-blind trial, we randomly assigned 3876 patients who had had a recent ischemic stroke or TIA to receive either pioglitazone (target dose, 45 mg daily) or placebo. Eligible patients did not have diabetes but were found to have insulin resistance on the basis of a score of more than 3.0 on the homeostasis model assessment of insulin resistance (HOMA-IR) index. The primary outcome was fatal or nonfatal stroke or myocardial infarction. By 4.8 years, a primary outcome had occurred in 175 of 1939 patients (9.0%) in the pioglitazone group and in 228 of 1937 (11.8%) in the placebo group (hazard ratio in the pioglitazone group, 0.76; 95% confidence interval [CI], 0.62 to 0.93; P=0.007). Diabetes developed in 73 patients (3.8%) and 149 patients (7.7%), respectively (hazard ratio, 0.48; 95% CI, 0.33 to 0.69; Pischemic stroke or TIA, the risk of stroke or myocardial infarction was lower among patients who received pioglitazone than among those who received placebo. Pioglitazone was also associated with a lower risk of diabetes but with higher risks of weight gain, edema, and fracture. (Funded by the National Institute of Neurological Disorders and Stroke; ClinicalTrials.gov number, NCT00091949.).

Genetic ablation of soluble tumor necrosis factor with preservation of membrane tumor necrosis factor is associated with neuroprotection after focal cerebral ischemia

DEFF Research Database (Denmark)

Madsen, Pernille M; Clausen, Bettina H; Degn, Matilda

2016-01-01

Microglia respond to focal cerebral ischemia by increasing their production of the neuromodulatory cytokine tumor necrosis factor, which exists both as membrane-anchored tumor necrosis factor and as cleaved soluble tumor necrosis factor forms. We previously demonstrated that tumor necrosis factor...... reduced infarct volumes at one and five days after stroke. This was associated with improved functional outcome after experimental stroke. No changes were found in the mRNA levels of tumor necrosis factor and tumor necrosis factor-related genes (TNFR1, TNFR2, TACE), pro-inflammatory cytokines (IL-1β, IL-6...... knockout mice display increased lesion volume after focal cerebral ischemia, suggesting that tumor necrosis factor is neuroprotective in experimental stroke. Here, we extend our studies to show that mice with intact membrane-anchored tumor necrosis factor, but no soluble tumor necrosis factor, display...

Microencapsulation of Hepatocytes and Mesenchymal Stem Cells for Therapeutic Applications.

Science.gov (United States)

Meier, Raphael P H; Montanari, Elisa; Morel, Philippe; Pimenta, Joël; Schuurman, Henk-Jan; Wandrey, Christine; Gerber-Lemaire, Sandrine; Mahou, Redouan; Bühler, Leo H

2017-01-01

Encapsulated hepatocyte transplantation and encapsulated mesenchymal stem cell transplantation are newly developed potential treatments for acute and chronic liver diseases, respectively. Cells are microencapsulated in biocompatible semipermeable alginate-based hydrogels. Microspheres protect cells against antibodies and immune cells, while allowing nutrients, small/medium size proteins and drugs to diffuse inside and outside the polymer matrix. Microencapsulated cells are assessed in vitro and designed for experimental transplantation and for future clinical applications.Here, we describe the protocol for microencapsulation of hepatocytes and mesenchymal stem cells within hybrid poly(ethylene glycol)-alginate hydrogels.

Antiplatelet Treatment After Transient Ischemic Attack and Ischemic Stroke in Patients With Cerebral Microbleeds in 2 Large Cohorts and an Updated Systematic Review.

Science.gov (United States)

Lau, Kui Kai; Lovelock, Caroline E; Li, Linxin; Simoni, Michela; Gutnikov, Sergei; Küker, Wilhelm; Mak, Henry Ka Fung; Rothwell, Peter M

2018-06-01

In patients with transient ischemic attack/ischemic stroke, microbleed burden predicts intracerebral hemorrhage (ICH), and ischemic stroke, but implications for antiplatelet treatment are uncertain. Previous cohort studies have had insufficient follow-up to assess the time course of risks, have not stratified risks by antithrombotic use, and have not reported extracranial bleeds or functional outcome of ICH versus ischemic stroke. In 2 independent prospective cohorts with transient ischemic attack/ischemic stroke (Oxford Vascular Study/mainly white; University of Hong Kong/mainly Chinese), antiplatelet treatment was started routinely irrespective of microbleed burden. Risks, time course and outcome of ICH, extracranial bleeds, and recurrent ischemic events were determined and stratified by microbleed burden (0 versus 1, 2-4, and ≥5), adjusting for age, sex, and vascular risk factors. Microbleeds were more frequent in the Chinese cohort (450 of 1003 versus 165 of 1080; P <0.0001), but risk associations were similar during 7433 patient-years of follow-up. Among 1811 patients on antiplatelet drugs, risk of major extracranial bleeds was unrelated to microbleed burden ( P trend =0.87), but the 5-year risk of ICH was steeply related ( P trend <0.0001), with 11 of 15 (73%) of ICH in 140 of 1811 (7.7%) patients with ≥5 microbleeds. However, risk of ischemic stroke also increased with microbleed burden ( P trend =0.013), such that risk of ischemic stroke and coronary events exceeded ICH and major extracranial bleeds during the first year, even among patients with ≥5 microbleeds (11.6% versus 3.9%). However, this ratio changed over time, with risk of hemorrhage (11.2%) matching that of ischemic events (12.0%) after 1 year. Moreover, whereas the association between microbleed burden and risk of ischemic stroke was due mainly to nondisabling events ( P trend =0.007), the association with ICH was accounted for ( P trend <0.0001) by disabling/fatal events (≥5 microbleeds

Avascular Necrosis of the Capitate

OpenAIRE

Bekele, Wosen; Escobedo, Eva; Allen, Robert

2011-01-01

Avascular necrosis of the capitate is a rare entity. The most common reported etiology is trauma. We report a case of avascular necrosis of the capitate in a patient with chronic wrist pain that began after a single episode of remote trauma.

Prothrombin and risk of venous thromboembolism, ischemic heart disease and ischemic cerebrovascular disease in the general population

DEFF Research Database (Denmark)

Weischer, Maren; Juul, Klaus; Zacho, Jeppe

2010-01-01

OBJECTIVE: We tested the hypotheses that Prothrombin G20210A heterozygosity associate with increased risk of venous thromboembolism (VTE), ischemic heart disease (IHD), and ischemic cerebrovascular disease (ICVD) in the general population and re-tested risk of IHD and ICVD in two case......-control studies. METHODS: 9231 individuals from the Danish general population were followed for VTE (VTE=DVT+PE), deep venous thrombosis (DVT), pulmonary embolism (PE), IHD, myocardial infarction (MI), ICVD, and ischemic stroke (IS) for a median of 24 years. Case-control studies included 2461 IHD cases and 867...

Hepatocyte transplantation improves early survival after partial hepatic resection and irradiation

International Nuclear Information System (INIS)

Guha, C.; Sharma, A.; Alfieri, A.; Guha, U.; Sokhi, R.; Gagandeep, S.; Gupta, S.; Vikram, B.; RoyChowdhury, J.

1997-01-01

Purpose: Radiation therapy (RT) is limited in its role as an adjuvant therapy of intrahepatic malignancies because of lower tolerance of human liver to irradiation (TD (5(5)) -TD (50(5)) ∼ 30-40 Gy). Although, surgical resection of primary or metastatic hepatic tumors has been shown to prolong survival, it is often limited by the presence of residual disease. RT could potentially improve survival of patients with positive surgical margins. However, radiation damage to the liver may be enhanced by hepatocellular proliferation induced by partial hepatic (PH) resection. We hypothesize that hepatocyte transplantation would be able to provide metabolic support and modulate the development of radiation-induced liver disease post-resection. The present study was designed to test the potential of hepatocyte transplantation in modifying the outcome of hepatocellular damage induced by PH and RT. Methods: Adult male Fischer 344 rats (Charles River) received hepatic irradiation of 50 Gy in a single fraction, after surgical exposure and shielding of the stomach and intestine, using a 320 MGC Philips orthovoltage unit. Immediately following irradiation, a two-third partial hepatectomy was performed. Four days post-radiation, the treatment group was injected with 5 x 10 6 syngeneic hepatocytes into the splenic pulp after a left subcostal incision, which allows homogeneous liver engraftment of the transplanted hepatocytes. Hematoxylin and eosin stains of liver biopsies, performed at various time points (3 days, 1, 2, 3 weeks or, anytime when animals died) were used for histologic evaluation. Time-adjusted survival was calculated from the date of irradiation by the product-limit Kaplan-Meier method, adjusting the denominator at every time point for the number of rats at risk. Results: Eight weeks after RT, 30% (n = 11) of the control animals (PH + 50 Gy) were alive compared to 100% (n = 9) of the transplant recipients (p <0.05). The median survival of the control group was 15

The Ubiquitin E3 Ligase TRAF6 Exacerbates Ischemic Stroke by Ubiquitinating and Activating Rac1.

Science.gov (United States)

Li, Tao; Qin, Juan-Juan; Yang, Xia; Ji, Yan-Xiao; Guo, Fangliang; Cheng, Wen-Lin; Wu, Xiaolin; Gong, Fu-Han; Hong, Ying; Zhu, Xue-Yong; Gong, Jun; Wang, Zhihua; Huang, Zan; She, Zhi-Gang; Li, Hongliang

2017-12-13

Stroke is one of the leading causes of morbidity and mortality worldwide. Inflammation, oxidative stress, apoptosis, and excitotoxicity contribute to neuronal death during ischemic stroke; however, the mechanisms underlying these complicated pathophysiological processes remain to be fully elucidated. Here, we found that the expression of tumor necrosis factor receptor-associated factor 6 (TRAF6) was markedly increased after cerebral ischemia/reperfusion (I/R) in mice. TRAF6 ablation in male mice decreased the infarct volume and neurological deficit scores and decreased proinflammatory signaling, oxidative stress, and neuronal death after cerebral I/R, whereas transgenic overexpression of TRAF6 in male mice exhibited the opposite effects. Mechanistically, we demonstrated that TRAF6 induced Rac1 activation and consequently promoted I/R injury by directly binding and ubiquitinating Rac1. Either functionally mutating the TRAF6 ubiquitination site on Rac1 or inactivating Rac1 with a specific inhibitor reversed the deleterious effects of TRAF6 overexpression during I/R injury. In conclusion, our study demonstrated that TRAF6 is a key promoter of ischemic signaling cascades and neuronal death after cerebral I/R injury. Therefore, the TRAF6/Rac1 pathway might be a promising target to attenuate cerebral I/R injury. SIGNIFICANCE STATEMENT Stroke is one of the most severe and devastating neurological diseases globally. The complicated pathophysiological processes restrict the translation of potential therapeutic targets into medicine. Further elucidating the molecular mechanisms underlying cerebral ischemia/reperfusion injury may open a new window for pharmacological interventions to promote recovery from stroke. Our study revealed that ischemia-induced tumor necrosis factor receptor-associated factor 6 (TRAF6) upregulation binds and ubiquitinates Rac1 directly, which promotes neuron death through neuroinflammation and neuro-oxidative signals. Therefore, precisely targeting

Genetics of ischemic stroke: future clinical applications.

Science.gov (United States)

Wang, Michael M

2006-11-01

Ischemic stroke has long been thought to have a genetic component that is independent of conventional vascular risk factors. It has been estimated that over one half of stroke risk is determined by inherited genes. However, until recently, strong evidence of genetic influence on ischemic stroke has been subject to criticism because the risk factors for stroke are also inherited and because previous studies suffered from limitations imposed by this highly heterogeneous neurological disorder. Recent advances in molecular genetics have led to the identification of specific genetic loci that impart susceptibility to ischemic stroke. We review the studies of these genes and discuss the future potential applications of genetic markers on the management of ischemic stroke patients.

Ketoconazole attenuates radiation-induction of tumor necrosis factor

Energy Technology Data Exchange (ETDEWEB)

Hallahan, D.E.; Virudachalam, S.; Kufe, D.W.; Weichselbaum, R.R. [Dana Farber Cancer Institute, Boston, MA (United States)

1994-07-01

Previous work has demonstrated that inhibitors of phospholipase A2 attenuate ionizing radiation-induced arachidonic acid production, protein kinase C activation, and prevent subsequent induction of the tumor necrosis factor gene. Because arachidonic acid contributes to radiation-induced tumor necrosis factor expression, the authors analyzed the effects of agents which alter arachidonate metabolism on the regulation of this gene. Phospholipase A2 inhibitors quinicrine, bromphenyl bromide, and pentoxyfylline or the inhibitor of lipoxygenase (ketoconazole) or the inhibitor of cycloxygenase (indomethacine) were added to cell culture 1 h prior to irradiation. Radiation-induced tumor necrosis factor gene expression was attenuated by each of the phospholipase A2 inhibitors (quinicrine, bromphenylbromide, and pentoxyfylline). Furthermore, ketoconazole attenuated X ray induced tumor necrosis factor gene expression. Conversely, indomethacin enhanced tumor necrosis factor expression following irradiation. The finding that radiation-induced tumor necrosis factor gene expression was attenuated by ketoconazole suggests that the lipoxygenase pathway participates in signal transduction preceding tumor necrosis factor induction. Enhancement of tumor necrosis factor expression by indomethacin following irradiation suggests that prostaglandins produced by cyclooxygenase act as negative regulators of tumor necrosis factor expression. Inhibitors of tumor necrosis factor induction ameliorate acute and subacute sequelae of radiotherapy. The authors propose therefore, that ketoconazole may reduce acute radiation sequelae such as mucositis and esophagitis through a reduction in tumor necrosis factor induction or inhibition of phospholipase A2 in addition to its antifungal activity. 25 refs., 2 figs.

Homocysteine inhibits hepatocyte proliferation via endoplasmic reticulum stress.

Directory of Open Access Journals (Sweden)

Xue Yu

Full Text Available Homocysteine is an independent risk factor for coronary, cerebral, and peripheral vascular diseases. Recent studies have shown that levels of homocysteine are elevated in patients with impaired hepatic function, but the precise role of homocysteine in the development of hepatic dysfunction is unclear. In this study, we examined the effect of homocysteine on hepatocyte proliferation in vitro. Our results demonstrated that homocysteine inhibited hepatocyte proliferation by up-regulating protein levels of p53 as well as mRNA and protein levels of p21(Cip1 in primary cultured hepatocytes. Homocysteine induced cell growth arrest in p53-positive hepatocarcinoma cell line HepG2, but not in p53-null hepatocarcinoma cell line Hep3B. A p53 inhibitor pifithrin-α inhibited the expression of p21(Cip1 and attenuated homocysteine-induced cell growth arrest. Homocysteine induced TRB3 expression via endoplasmic reticulum stress pathway, resulting in Akt dephosphorylation. Knock-down of endogenous TRB3 significantly suppressed the inhibitory effect of homocysteine on cell proliferation and the phosphorylation of Akt. LiCl reversed homocysteine-mediated cell growth arrest by inhibiting TRB3-mediated Akt dephosphorylation. These results demonstrate that both TRB3 and p21(Cip1 are critical molecules in the homocysteine signaling cascade and provide a mechanistic explanation for impairment of liver regeneration in hyperhomocysteinemia.

Predictors of ischemic versus hemorrhagic strokes in hypertensive patients

International Nuclear Information System (INIS)

Khealani, B.A.; Syed, N.A.; Maken, S.; Mapari, U.U.; Hameed, B.; Ali, S.; Qureshi, R.; Akhter, N.; Hassan, A.; Sonawalla, A.B.; Baig, S.M.; Wasay, M.

2005-01-01

Objective: To identify the factors that predispose to ischemic versus hemorrhagic stroke in hypertensive patients. Materials and Methods: All the hypertensive patients, who were registered in AKUH acute stroke outcome data base, over a period of 22 months, were identified and from this cohort the patients with first ever stroke were selected. The data regarding demographics, stroke type (ischemic vs. hemorrhagic), pre-existing medical problems, laboratory and radiological investigations was recorded and analyzed. Results: Five hundred and nineteen patients with either ischemic stroke or parenchymal hemorrhage were registered over a period of 22 months. Three hundred and forty-eight patients (67%) had hypertension and of these, 250 had first ever stroke at the time of admission. Presence of diabetes mellitus (OR: 3.76; Cl:1.67-8.46) and ischemic heart disease (OR: 6.97; Cl:1.57-30.98) were found to be independent predictors of ischemic strokes. Conclusion: Presence of diabetes mellitus and ischemic heart disease predict ischemic stroke in a patient with hypertension. (author)

Evaluation and optimization of hepatocyte culture media factors by design of experiments (DoE) methodology.

Science.gov (United States)

Dong, Jia; Mandenius, Carl-Fredrik; Lübberstedt, Marc; Urbaniak, Thomas; Nüssler, Andreas K N; Knobeloch, Daniel; Gerlach, Jörg C; Zeilinger, Katrin

2008-07-01

Optimization of cell culture media based on statistical experimental design methodology is a widely used approach for improving cultivation conditions. We applied this methodology to refine the composition of an established culture medium for growth of a human hepatoma cell line, C3A. A selection of growth factors and nutrient supplements were systematically screened according to standard design of experiments (DoE) procedures. The results of the screening indicated that the medium additives hepatocyte growth factor, oncostatin M, and fibroblast growth factor 4 significantly influenced the metabolic activities of the C3A cell line. Surface response methodology revealed that the optimum levels for these factors were 30 ng/ml for hepatocyte growth factor and 35 ng/ml for oncostatin M. Additional experiments on primary human hepatocyte cultures showed high variance in metabolic activities between cells from different individuals, making determination of optimal levels of factors more difficult. Still, it was possible to conclude that hepatocyte growth factor, epidermal growth factor, and oncostatin M had decisive effects on the metabolic functions of primary human hepatocytes.

Avascular Necrosis of the Capitate

Science.gov (United States)

Bekele, Wosen; Escobedo, Eva; Allen, Robert

2011-01-01

Avascular necrosis of the capitate is a rare entity. The most common reported etiology is trauma. We report a case of avascular necrosis of the capitate in a patient with chronic wrist pain that began after a single episode of remote trauma. PMID:22470799

Inhibition of the release of soluble tumor necrosis factor receptors in experimental endotoxemia by an anti-tumor necrosis factor-alpha antibody

NARCIS (Netherlands)

Jansen, J.; van der Poll, T.; Levi, M. [=Marcel M.; ten Cate, H.; Gallati, H.; ten Cate, J. W.; van Deventer, S. J.

1995-01-01

The role of tumor necrosis factor-alpha in the shedding of soluble tumor necrosis factor receptors in endotoxemia was investigated. The appearance of the soluble tumor necrosis factor receptors was assessed in four healthy volunteers following an intravenous injection of tumor necrosis factor-alpha

Hepatitis E Virus Induces Hepatocyte Apoptosis via Mitochondrial Pathway in Mongolian Gerbils

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Yifei Yang

2018-03-01

Full Text Available Previous studies demonstrated that Mongolian gerbils can be infected by hepatitis E virus (HEV, which induces the hepatic injury. Here, the mitochondria in hepatocytes from HEV-infected gerbils were considerably swollen, thin cristae. After HEV infection, the activity of superoxide dismutase significantly decreased (p < 0.01, while malondialdehyde concentrations significantly increased, compared with those in the control group (p < 0.01. Adenosine triphosphatase levels decreased significantly in the hepatocyte of the inoculated groups, compared with those in control group (p < 0.05 at days 21, 28, 42 post-inoculation (dpi as well. Furthermore, the levels of ATP synthetase ATP5A1 significantly decreased during HEV infection, compared with those in the control group (p < 0.05. According to the TdT mediated dUTP nick end labeling (TUNEL detection, TUNEL positive hepatocytes increased in the inoculated group, compared with that in the control group (p < 0.05. Up-regulation of the mitochondrion-mediated apoptosis regulating proteins, Bax and Bcl-2, in the HEV-infected gerbils (p < 0.05 was observed. However, cytochrome c levels in mitochondria decreased, while this molecule was detected in the cytoplasm of the infected animals, in contrast to that in the control group. Apaf-1, and active caspase-9 and -3 levels were shown to be significantly higher in the inoculated group compared with those in the control group (p < 0.05. Taken together, our results demonstrated that HEV infection induces hepatocyte injuries and activity of the mitochondrial apoptotic pathway, which trigger the hepatocyte apoptosis in Mongolian gerbils.

Glucose production and storage in hepatocytes isolated from normal versus diabetic rats

International Nuclear Information System (INIS)

Olivieri, M.C.; Dragland-Meserve, C.J.; Parker Botelho, L.H.

1987-01-01

The rates of glucose production and storage were compared in hepatocytes isolated from normal versus insulin-resistant diabetic rats. A single low-dose (40 mg/kg) IV injection of streptozotocin to 250 g rats resulted in a Type II diabetic animal model which was hyperglycemic with normal insulin levels. Addition of 8 mM 14 C-lactate and 2 mM pyruvate to hepatocytes resulted in a linear increase in total glucose production ( 14 C-glucose and unlabeled glucose) and incorporation into glycogen measured over 120 min. The rate of gluconeogenesis was estimated from the production of 14 C-glucose and the rate of glycogenolysis was estimated from the production of unlabeled glucose in cells incubated in the presence or absence of 14 C-labelled substrate. There was not significant difference in total glucose production in hepatocytes isolated from normal versus diabetic rats, however, the contribution from gluconeogenesis versus glycogenolysis was significantly different. Following a 1 h incubation of cells from normal rats, 42% of the total glucose production was due to gluconeogenesis and 58% was due to glycogenolysis. In cells from diabetic rats, 83% of total glucose production was from gluconeogenesis and 17% from glycogenolysis. Also, incubation with 14 C-lactate/pyruvate resulted in a 3.3-fold increase in 14 C-glucose incorporation into glycogen in hepatocytes isolated from normal rats compared to diabetic rats. These data suggest that alterations occur in the rate-limiting enzymes responsible for glucose production and storage in hepatocytes isolated from a rat model of insulin-resistant Type II diabetes

Endothelial cell-derived matrix promotes the metabolic functional maturation of hepatocyte via integrin-Src signalling.

Science.gov (United States)

Guo, Xinyue; Li, Weihong; Ma, Minghui; Lu, Xin; Zhang, Haiyan

2017-11-01

The extracellular matrix (ECM) microenvironment is involved in the regulation of hepatocyte phenotype and function. Recently, the cell-derived extracellular matrix has been proposed to represent the bioactive and biocompatible materials of the native ECM. Here, we show that the endothelial cell-derived matrix (EC matrix) promotes the metabolic maturation of human adipose stem cell-derived hepatocyte-like cells (hASC-HLCs) through the activation of the transcription factor forkhead box protein A2 (FOXA2) and the nuclear receptors hepatocyte nuclear factor 4 alpha (HNF4α) and pregnane X receptor (PXR). Reducing the fibronectin content in the EC matrix or silencing the expression of α5 integrin in the hASC-HLCs inhibited the effect of the EC matrix on Src phosphorylation and hepatocyte maturation. The inhibition of Src phosphorylation using the inhibitor PP2 or silencing the expression of Src in hASC-HLCs also attenuated the up-regulation of the metabolic function of hASC-HLCs in a nuclear receptor-dependent manner. These data elucidate integrin-Src signalling linking the extrinsic EC matrix signals and metabolic functional maturation of hepatocyte. This study provides a model for studying the interaction between hepatocytes and non-parenchymal cell-derived matrix. © 2017 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Protective effects of melittin on transforming growth factor-β1 injury to hepatocytes via anti-apoptotic mechanism

International Nuclear Information System (INIS)

Lee, Woo-Ram; Park, Ji-Hyun; Kim, Kyung-Hyun; Park, Yoon-Yub; Han, Sang-Mi; Park, Kwan-kyu

2011-01-01

Melittin is a cationic, hemolytic peptide that is the main toxic component in the venom of the honey bee (Apis mellifera). Melittin has multiple effects, including anti-bacterial, anti-viral and anti-inflammatory, in various cell types. However, the anti-apoptotic mechanisms of melittin have not been fully elucidated in hepatocytes. Apoptosis contributes to liver inflammation and fibrosis. Knowledge of the apoptotic mechanisms is important to develop new and effective therapies for treatment of cirrhosis, portal hypertension, liver cancer, and other liver diseases. In the present study, we investigated the anti-apoptotic effect of melittin on transforming growth factor (TGF)-β1-induced apoptosis in hepatocytes. TGF-β1-treated hepatocytes were exposed to low doses (0.5 and 1 μg/mL) and high dose (2 μg/mL) of melittin. The low doses significantly protected these cells from DNA damage in TGF-β1-induced apoptosis compared to the high dose. Also, melittin suppressed TGF-β1-induced apoptotic activation of the Bcl-2 family and caspase family of proteins, which resulted in the inhibition of poly-ADP-ribose polymerase (PARP) cleavage. These results demonstrate that TGF-β1 induces hepatocyte apoptosis and that an optimal dose of melittin exerts anti-apoptotic effects against TGF-β1-induced injury to hepatocytes via the mitochondrial pathway. These results suggest that an optimal dose of melittin can serve to protect cells against TGF-β1-mediated injury. - Highlights: → We investigated the anti-apoptotic effect of melittin on TGF-β1-induced hepatocyte. → TGF-β1 induces hepatocyte apoptosis. → TGF-β1-treated hepatocytes were exposed to low doses and high dose of melittin. → Optimal dose of melittin exerts anti-apoptotic effects to hepatocytes.

AR42J-B-13 cell: An expandable progenitor to generate an unlimited supply of functional hepatocytes

International Nuclear Information System (INIS)

Wallace, Karen; Fairhall, Emma A.; Charlton, Keith A.; Wright, Matthew C.

2010-01-01

Hepatocytes are the preparation of choice for Toxicological research in vitro. However, despite the fact that hepatocytes proliferate in vivo during liver regeneration, they are resistant to proliferation in vitro, do not tolerate sub-culture and tend to enter a de-differentiation program that results in a loss of hepatic function. These limitations have resulted in the search for expandable rodent and human cells capable of being directed to differentiate into functional hepatocytes. Research with stem cells suggests that it may be possible to provide the research community with hepatocytes in vitro although to date, significant challenges remain, notably generating a sufficiently pure population of hepatocytes with a quantitative functionality comparable with hepatocytes. This paper reviews work with the AR42J-B-13 (B-13) cell line. The B-13 cell was cloned from the rodent AR42J pancreatic cell line, express genes associated with pancreatic acinar cells and readily proliferates in simple culture media. When exposed to glucocorticoid, 75-85% of the cells trans-differentiate into hepatocyte-like (B-13/H) cells functioning at a level quantitatively similar to freshly isolated rat hepatocytes (with the remaining cells retaining the B-13 phenotype). Trans-differentiation of pancreatic acinar cells also appears to occur in vivo in rats treated with glucocorticoid; in mice with elevated circulating glucocorticoid and in humans treated for long periods with glucocorticoid. The B-13 response to glucocorticoid therefore appears to be related to a real pathophysiological response of a pancreatic cell to glucocorticoid. An understanding of how this process occurs and if it can be generated or engineered in human cells would result in a cell line with the ability to generate an unlimited supply of functional human hepatocytes in a cost effective manner.

NecroQuant: quantitative assessment of radiological necrosis

Science.gov (United States)

Hwang, Darryl H.; Mohamed, Passant; Varghese, Bino A.; Cen, Steven Y.; Duddalwar, Vinay

2017-11-01

Clinicians can now objectively quantify tumor necrosis by Hounsfield units and enhancement characteristics from multiphase contrast enhanced CT imaging. NecroQuant has been designed to work as part of a radiomics pipelines. The software is a departure from the conventional qualitative assessment of tumor necrosis, as it provides the user (radiologists and researchers) a simple interface to precisely and interactively define and measure necrosis in contrast-enhanced CT images. Although, the software is tested here on renal masses, it can be re-configured to assess tumor necrosis across variety of tumors from different body sites, providing a generalized, open, portable, and extensible quantitative analysis platform that is widely applicable across cancer types to quantify tumor necrosis.

Polymorphisms in apolipoprotein B and risk of ischemic stroke

DEFF Research Database (Denmark)

Benn, Marianne; Nordestgaard, Børge G; Jensen, Jan Skov

2007-01-01

Apolipoprotein B levels associate with risk of ischemic stroke. APOB polymorphisms may influence levels of apolipoprotein B and low-density lipoprotein (LDL), but whether they associate with risk of ischemic stroke is unknown.......Apolipoprotein B levels associate with risk of ischemic stroke. APOB polymorphisms may influence levels of apolipoprotein B and low-density lipoprotein (LDL), but whether they associate with risk of ischemic stroke is unknown....

Programmed necrosis and necroptosis – molecular mechanisms

Directory of Open Access Journals (Sweden)

Agata Giżycka

2015-12-01

Full Text Available Programmed necrosis has been proven vital for organism development and homeostasis maintenance. Its regulatory effects on functional activity of the immune system, as well as on pathways regulating the death mechanisms in cells with diminished apoptotic activity, including malignant cells, have been confirmed. There is also increasing evidence indicating necrosis involvement in many human pathologies. Contrary to previous beliefs, necrosis is not only a passive, pathological, gene-independent process. However, the current knowledge regarding molecular regulation of programmed necrosis is scarce. In part this is due to the multiplicity and complexity of signaling pathways involved in programmed necrosis, as well as the absence of specific cellular markers identifying this process, but also the ambiguous and imprecise international terminology. This review presents the current state of the art on molecular mechanisms of programmed necrosis. In particular, its specific and frequent form, necroptosis, is discussed. The role of RIP1 and RIP3 kinases in this process is presented, as well as the diverse pathways induced by ligation of tumor necrosis factor α, to its receptor, TNFR1, i.e. cell survival, apoptosis or necroptosis.

Isolation of primary human hepatocytes from normal and diseased liver tissue: a one hundred liver experience.

Directory of Open Access Journals (Sweden)

Ricky H Bhogal

2011-03-01

Full Text Available Successful and consistent isolation of primary human hepatocytes remains a challenge for both cell-based therapeutics/transplantation and laboratory research. Several centres around the world have extensive experience in the isolation of human hepatocytes from non-diseased livers obtained from donor liver surplus to surgical requirement or at hepatic resection for tumours. These livers are an important but limited source of cells for therapy or research. The capacity to isolate cells from diseased liver tissue removed at transplantation would substantially increase availability of cells for research. However no studies comparing the outcome of human hepatocytes isolation from diseased and non-diseased livers presently exist. Here we report our experience isolating human hepatocytes from organ donors, non-diseased resected liver and cirrhotic tissue. We report the cell yields and functional qualities of cells isolated from the different types of liver and demonstrate that a single rigorous protocol allows the routine harvest of good quality primary hepatocytes from the most commonly accessible human liver tissue samples.

Cytotoxic mechanisms of hydrosulfide anion and cyanide anion in primary rat hepatocyte cultures

International Nuclear Information System (INIS)

Thompson, Rodney W.; Valentine, Holly L.; Valentine, William M.

2003-01-01

Hydrogen sulfide and hydrogen cyanide are known to compromise mitochondrial respiration through inhibition of cytochrome c oxidase and this is generally considered to be their primary mechanism of toxicity. Experimental studies and the efficiency of current treatment protocols suggest that H 2 S may exert adverse physiological effects through additional mechanisms. To evaluate the role of alternative mechanisms in H 2 S toxicity, the relative contributions of electron transport inhibition, uncoupling of mitochondrial respiration, and opening of the mitochondrial permeability transition pore (MPTP) to hydrosulfide and cyanide anion cytotoxicity in primary hepatocyte cultures were examined. Supplementation of hepatocytes with the glycolytic substrate, fructose, rescued hepatocytes from cyanide anion induced toxicity, whereas fructose supplementation increased hydrosulfide anion toxicity suggesting that hydrosulfide anion may compromise glycolysis in hepatocytes. Although inhibitors of the MPTP opening were protective for hydrosulfide anion, they had no effect on cyanide anion toxicity, consistent with an involvement of the permeability transition pore in hydrosulfide anion toxicity but not cyanide anion toxicity. Exposure of isolated rat liver mitochondria to hydrosulfide did not result in large amplitude swelling suggesting that if H 2 S induces the permeability transition it does so indirectly through a mechanism requiring other cellular components. Hydrosulfide anion did not appear to be an uncoupler of mitochondrial respiration in hepatocytes based upon the inability of oligomycin and fructose to protect hepatocytes from hydrosulfide anion toxicity. These findings support mechanisms additional to inhibition of cytochrome c oxidase in hydrogen sulfide toxicity. Further investigations are required to assess the role of the permeability transition in H 2 S toxicity, determine whether similar affects occur in other cell types or in vivo and evaluate whether this may

[Changes in the chromatin structure of hepatocyte nuclei of rats trained to hypoxia].

Science.gov (United States)

Domkina, L K; Bresler, V M; Simanovskiĭ, L N

1976-03-01

Structure of chromatin in the nuclei of the isolated surviving hepatocytes and in the isolated nuclei of hepatocytes were studied by fluorochroming with acridine orange and by microfluorimetry of fluorescenc connected with the stain chromatin at 530 and 590 nm in intact rats and in the animals trained to hypoxia in a pressure chamber for 60 days. The nuclei of hepatocytes of intact rats were distributed by fluorescence at 530 nm into three classes with the intensity ratio of 1:2:4; as to the nuclei of hepatocytes of the rats trained to hypoxia - they formed a single class corresponding to the second class of control. In intact rats the ratio of the fluorescence intensity at 590 nm to such at 530 nm (alpha coefficient) formed normal distribution; in trained rats - a bimodal distribution with a shift of the maximum in the direction of reduction and increase of alpha in comparison with control. It is supposed that in hypoxia there is a repression of one and depression of other genes in the chromatine of the nuclei of the liver.

Necrostatin-1 protects against reactive oxygen species (ROS-induced hepatotoxicity in acetaminophen-induced acute liver failure

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Kenji Takemoto

2014-01-01

Full Text Available Excessive acetaminophen (APAP use is one of the most common causes of acute liver failure. Various types of cell death in the damaged liver are linked to APAP-induced hepatotoxicity, and, of these, necrotic cell death of hepatocytes has been shown to be involved in disease pathogenesis. Until recently, necrosis was commonly considered to be a random and unregulated form of cell death; however, recent studies have identified a previously unknown form of programmed necrosis called receptor-interacting protein kinase (RIPK-dependent necrosis (or necroptosis, which is controlled by the kinases RIPK1 and RIPK3. Although RIPK-dependent necrosis has been implicated in a variety of disease states, including atherosclerosis, myocardial organ damage, stroke, ischemia–reperfusion injury, pancreatitis, and inflammatory bowel disease. However its involvement in APAP-induced hepatocyte necrosis remains elusive. Here, we showed that RIPK1 phosphorylation, which is a hallmark of RIPK-dependent necrosis, was induced by APAP, and the expression pattern of RIPK1 and RIPK3 in the liver overlapped with that of CYP2E1, whose activity around the central vein area has been demonstrated to be critical for the development of APAP-induced hepatic injury. Moreover, a RIPK1 inhibitor ameliorated APAP-induced hepatotoxicity in an animal model, which was underscored by significant suppression of the release of hepatic enzymes and cytokine expression levels. RIPK1 inhibition decreased reactive oxygen species levels produced in APAP-injured hepatocytes, whereas CYP2E1 expression and the depletion rate of total glutathione were unaffected. Of note, RIPK1 inhibition also conferred resistance to oxidative stress in hepatocytes. These data collectively demonstrated a RIPK-dependent necrotic mechanism operates in the APAP-injured liver and inhibition of this pathway may be beneficial for APAP-induced fulminant hepatic failure.

Basic and clinical research advances in ischemic stroke

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Yuan-yuan MA

2018-01-01

Full Text Available Stroke is the most common cerebrovascular disease worldwide, which seriously affects life quality of survivals and results in huge economic burden of families and society. In terms of clinical treatment for ischemic stroke, apart from thrombolytic therapy with recombinant tissue-type plasminogen activator (rt-PA, the occurrence and successful application of endovascular thrombectomy in patients of ischemic stroke is a major breakthrough. Meanwhile, many novel clinical drugs for ischemic stroke therapy have entered into clinical trials. Most of basic and clinical researches have showed promising results in ischemic stroke therapy. This review mainly summarizes the progress of research during the period of Twelfth Five-Year Plan for National Economic and Social Development on treatment of ischemic stroke, including omics technologies, gene therapy, microRNA (miRNA interference and stem cell therapy. Stem cell therapy has shown great potential since many clinical trials have been completed or are ongoing. The development and mutual transformation of basic and clinical research will provide valuable and comprehensive information for the precise treatment of ischemic stroke.

Deletion of hepatocyte nuclear factor-1-beta in an infant with prune belly syndrome.

Science.gov (United States)

Haeri, Sina; Devers, Patricia L; Kaiser-Rogers, Kathleen A; Moylan, Vincent J; Torchia, Beth S; Horton, Amanda L; Wolfe, Honor M; Aylsworth, Arthur S

2010-08-01

Prune belly syndrome is a rare congenital disorder characterized by deficiency of abdominal wall muscles, cryptorchidism, and urinary tract anomalies. We have had the opportunity to study a baby with prune belly syndrome associated with an apparently de novo 1.3-megabase interstitial 17q12 microdeletion that includes the hepatocyte nuclear factor-1-beta gene at 17q12. One previous patient, an adult, has been reported with prune belly syndrome and a hepatocyte nuclear factor-1-beta microdeletion. Hepatocyte nuclear factor-1-beta is a widely expressed transcription factor that regulates tissue-specific gene expression and is expressed in numerous tissues including mesonephric duct derivatives, the renal tubule of the metanephros, and the developing prostate of the mouse. Mutations in hepatocyte nuclear factor-1-beta cause the "renal cysts and diabetes syndrome," isolated renal cystic dysplasia, and a variety of other malformations. Based on its expression pattern and the observation of two affected cases, we propose that haploinsufficiency of hepatocyte nuclear factor-1-beta may be causally related to the production of the prune belly syndrome phenotype through a mechanism of prostatic and ureteral hypoplasia that results in severe obstructive uropathy with urinary tract and abdominal distension. Copyright Thieme Medical Publishers.

Olanzapine-induced ischemic colitis

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Esteban Sáez-González

Full Text Available Background: Ischemic colitis (IC is an uncommon adverse event associated with antipsychotic agents, more commonly found with phenothiazine drugs and atypical neuroleptics such as clozapine. The risk of developing ischemic colitis increases when anticholinergic drugs are associated. Case report: We report the case of a 38-year-old woman with a history of schizoaffective disorder who had been on chronic quetiapine for 3 years, and presented to the ER because of diarrhea for 5 days. Four months previously, olanzapine had been added to her psychiatric drug regimen. Physical examination revealed abdominal distension with abdominal tympanic sounds and tenderness. Emergency laboratory tests were notable for increased acute phase reagents. Tomography revealed a concentric thickening of the colonic wall in the transverse, descending and sigmoid segments, with no signs of intestinal perforation. Colonoscopy demonstrated severe mucosal involvement from the sigmoid to the hepatic flexure, with ulcerations and fibrinoid exudate. Biopsies confirmed the diagnosis of ischemic colitis. The only relevant finding in her history was the newly added drug to her baseline regimen. An adverse effect was suspected because of its anticholinergic action at the intestinal level, and the drug was withdrawn. After 6 months of follow-up clinical, laboratory and endoscopic recovery was achieved. Discussion: Antipsychotic medication should be considered as a potential cause of ischemic colitis, particularly atypical antipsychotics such as clozapine and olanzapine; despite being uncommon, this adverse event may result in high morbidity and mortality.

Swelling of rat hepatocytes stimulates glycogen synthesis

NARCIS (Netherlands)

Baquet, A.; Hue, L.; Meijer, A. J.; van Woerkom, G. M.; Plomp, P. J.

1990-01-01

In hepatocytes from fasted rats, several amino acids are known to stimulate glycogen synthesis via activation of glycogen synthase. The hypothesis that an increase in cell volume resulting from amino acid uptake may be involved in the stimulation of glycogen synthesis is supported by the following

MR imaging of ischemic penumbra

International Nuclear Information System (INIS)

Abe, Osamu; Aoki, Shigeki; Shirouzu, Ichiro; Kunimatsu, Akira; Hayashi, Naoto; Masumoto, Tomohiko; Mori, Harushi; Yamada, Haruyasu; Watanabe, Makoto; Masutani, Yoshitaka; Ohtomo, Kuni

2003-01-01

Cerebral ischemic stroke is one of the most fatal diseases despite current advances in medical science. Recent demonstration of efficacy using intravenous and intra-arterial thrombolysis demands therapeutic intervention tailored to the physiologic state of the individual tissue and stratification of patients according to the potential risks for therapies. In such an era, the role of the neuroimaging becomes increasingly important to evaluate the extent and location of tissues at risk of infarction (ischemic penumbra), to distinguish it from unsalvageable infarcted tissues or doomed hemorrhagic parenchyma. In this review, we present briefly the current role and limitation of computed tomography and conventional magnetic resonance imaging (MRI). We also present the possible applications of advanced MR techniques, such as diffusion and perfusion imaging, concentrating on the delineation or detection of ischemic penumbra

The cytoskeleton of digitonin-treated rat hepatocytes.

Science.gov (United States)

Fiskum, G; Craig, S W; Decker, G L; Lehninger, A L

1980-06-01

Treatment of isolated rat hepatocptes with low concentrations of digitonin increases the permeability of the plsma membrane to cytosolic proteins without causing release of organelles such as mitochondria into the surrounding medium. Electron microscopy showed that treatment of the cells with increasing concentations of digitonin results in a progressive loss in the continuity of the plasma membrane, while most other aspects of cellular morphology remain normal. Depletion of background staining material from the cytosol by digitonin treatment of the cells greatly enhances the visualization of the cytoskeleton. The use of this technique, together with immunofluorescent light microscopy, has verified the presence of an actin-containing filamentous network at the hepatocyte cortex as well as intermediate filaments distributed throughout the cell. Digitonin is thus useful both for selectively permeabilizing the plasma membrane and for intensifying the appearance of intracellular structures such as microfilaments that are normally difficult to observe in cells such as hepatocytes.

Local cerebral blood flow (1CBF) and oxygen consumption (1CMRO2) in evolving irreversible ischemic infarction: a study with positron tomography and oxygen-15

International Nuclear Information System (INIS)

Baron, J.C.; Rougemont, D.; Lebrun-Grandie, P.; Comar, D.; Bousser, M.G.; Bories, J.; Castaigne, P.; Cabanis, E.

1982-09-01

In 25 patients suffering from cerebral ischemia set up in the area of the internal carotid artery the local cerebral blood flow (lCBF) and local cerebral oxygen consumption (lCMRO 2 ) were measured by the method of continuous inhalation of oxygen 15-labelled gas combined with positron emission tomography. These two local parameters and their ratio, the local oxygen extraction rate (lO 2 E), were studied inside the brain region tending spontaneously towards ischemic necrosis, a zone defined by means of repeated tomodensitometric examinations. The essential facts observed are the variability of the lCBF and the lO 2 E values, from extremely low to extremely high, whereas the collapse of the lCMRO 2 is constant. Consequently this last parameter alone would be a good prognostic index, an lCMRO 2 decrease to a level below about 70% of the controlateral value indicating that the necrosis is spontaneously irreparable. These results are discussed in the light of published data

Mastectomy skin necrosis after microsurgical breast reconstruction.

Science.gov (United States)

Vargas, Christina R; Koolen, Pieter G; Anderson, Katarina E; Paul, Marek A; Tobias, Adam M; Lin, Samuel J; Lee, Bernard T

2015-10-01

Mastectomy skin necrosis represents a significant clinical morbidity after immediate breast reconstruction. In addition to aesthetic deformity, necrosis of the native mastectomy skin may require debridement, additional reconstruction, or prolonged wound care and potentially delay oncologic treatment. This study aims to evaluate patient and procedural characteristics to identify predictors of mastectomy skin necrosis after microsurgical breast reconstruction. A retrospective review was performed of all immediate microsurgical breast reconstructions performed at a single academic center. Patient records were queried for age, diabetes, active smoking, previous breast surgery, preoperative radiation, preoperative chemotherapy, body mass index, mastectomy type, mastectomy weight, flap type, autologous flap type, and postoperative mastectomy skin flap necrosis. There were 746 immediate autologous microsurgical flaps performed by three plastic surgeons at our institution during the study period. The incidence of mastectomy skin flap necrosis was 13.4%. Univariate analysis revealed a significantly higher incidence of mastectomy skin necrosis in patients with higher mastectomy weight (P mastectomy type. Multivariate analysis demonstrated statistically significant associations between mastectomy skin necrosis and both increasing mastectomy weight (odds ratio 1.348 per quartile increase, P = 0.009) and diabetes (odds ratio 2.356, P = 0.011). Increasing mastectomy weight and coexisting diabetes are significantly associated with postoperative mastectomy skin necrosis after microsurgical reconstruction. These characteristics should be considered during patient counseling, procedure selection, operative planning, and intraoperative tissue viability assessment. Copyright © 2015 Elsevier Inc. All rights reserved.

Drug Delivery to the Ischemic Brain

Science.gov (United States)

Thompson, Brandon J.; Ronaldson, Patrick T.

2014-01-01

Cerebral ischemia occurs when blood flow to the brain is insufficient to meet metabolic demand. This can result from cerebral artery occlusion that interrupts blood flow, limits CNS supply of oxygen and glucose, and causes an infarction/ischemic stroke. Ischemia initiates a cascade of molecular events inneurons and cerebrovascular endothelial cells including energy depletion, dissipation of ion gradients, calcium overload, excitotoxicity, oxidative stress, and accumulation of ions and fluid. Blood-brain barrier (BBB) disruption is associated with cerebral ischemia and leads to vasogenic edema, a primary cause of stroke-associated mortality. To date, only a single drug has received US Food and Drug Administration (FDA) approval for acute ischemic stroke treatment, recombinant tissue plasminogen activator (rt-PA). While rt-PA therapy restores perfusion to ischemic brain, considerable tissue damage occurs when cerebral blood flow is re-established. Therefore, there is a critical need for novel therapeutic approaches that can “rescue” salvageable brain tissue and/or protect BBB integrity during ischemic stroke. One class of drugs that may enable neural cell rescue following cerebral ischemia/reperfusion injury is the HMG-CoA reductase inhibitors (i.e., statins). Understanding potential CNS drug delivery pathways for statins is critical to their utility in ischemic stroke. Here, we review molecular pathways associated with cerebral ischemia and novel approaches for delivering drugs to treat ischemic disease. Specifically, we discuss utility of endogenous BBB drug uptake transporters such as organic anion transporting polypeptides (OATPs/Oatps) and nanotechnology-based carriers for optimization of CNS drug delivery. Overall, this chapter highlights state-of-the-art technologies that may improve pharmacotherapy of cerebral ischemia. PMID:25307217

Retroviral-mediated gene transfer and expression of human phenylalanine hydroxylase in primary mouse hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Peng, H.; Armentano, D.; Mackenzie-Graham, L.; Shen, R.F.; Darlington, G.; Ledley, F.D.; Woo, S.L.C. (Baylor College of Medicine, Houston, TX (USA))

1988-11-01

Genetic therapy for phenylketonuria (severe phenylalanine hydroxylase deficiency) may require introduction of a normal phenylalanine hydroxylase gene into hepatic cells of patients. The authors report development of a recombinant retrovirus based on the N2 vector for gene transfer and expression of human phenylalanine hydroxylase cDNA in primary mouse hepatocytes. This construct contains an internal promoter of the human {alpha}{sub 1}-antitrypsin gene driving transcription of the phenylalanine hydroxylase cDNA. Primary mouse hepatocytes were isolated from newborn mice, infected with the recombinant virus, and selected for expression of the neomycin-resistance gene. Hepatocytes transformed with the recombinant virus contained high levels of human phenylalanine hydroxylase mRNA transcripts originating from the retroviral and internal promoters. These results demonstrate that the transcriptional regulatory elements of the {alpha}{sub 1} antitrypsin gene retain their tissue-specific function in the recombinant provirus and establish a method for efficient transfer and high-level expression of human phenylalanine hydroxylase in primary hepatocytes.

Retroviral-mediated gene transfer and expression of human phenylalanine hydroxylase in primary mouse hepatocytes

International Nuclear Information System (INIS)

Peng, H.; Armentano, D.; Mackenzie-Graham, L.; Shen, R.F.; Darlington, G.; Ledley, F.D.; Woo, S.L.C.

1988-01-01

Genetic therapy for phenylketonuria (severe phenylalanine hydroxylase deficiency) may require introduction of a normal phenylalanine hydroxylase gene into hepatic cells of patients. The authors report development of a recombinant retrovirus based on the N2 vector for gene transfer and expression of human phenylalanine hydroxylase cDNA in primary mouse hepatocytes. This construct contains an internal promoter of the human α 1 -antitrypsin gene driving transcription of the phenylalanine hydroxylase cDNA. Primary mouse hepatocytes were isolated from newborn mice, infected with the recombinant virus, and selected for expression of the neomycin-resistance gene. Hepatocytes transformed with the recombinant virus contained high levels of human phenylalanine hydroxylase mRNA transcripts originating from the retroviral and internal promoters. These results demonstrate that the transcriptional regulatory elements of the α 1 antitrypsin gene retain their tissue-specific function in the recombinant provirus and establish a method for efficient transfer and high-level expression of human phenylalanine hydroxylase in primary hepatocytes

Imaging of cerebral ischemic edema and neuronal death

Energy Technology Data Exchange (ETDEWEB)

Kummer, Ruediger von [Universitaetsklinikum Carl Gustav Carus, Institut fuer Diagnostische und Interventionelle Neuroradiologie, Dresden (Germany); Dzialowski, Imanuel [Elblandklinikum Meissen, Neurologische Rehabilitationsklinik Grossenhain, Meissen (Germany)

2017-06-15

In acute cerebral ischemia, the assessment of irreversible injury is crucial for treatment decisions and the patient's prognosis. There is still uncertainty how imaging can safely differentiate reversible from irreversible ischemic brain tissue in the acute phase of stroke. We have searched PubMed and Google Scholar for experimental and clinical papers describing the pathology and pathophysiology of cerebral ischemia under controlled conditions. Within the first 6 h of stroke onset, ischemic cell injury is subtle and hard to recognize under the microscope. Functional impairment is obvious, but can be induced by ischemic blood flow allowing recovery with flow restoration. The critical cerebral blood flow (CBF) threshold for irreversible injury is ∝15 ml/100 g x min. Below this threshold, ischemic brain tissue takes up water in case of any residual capillary flow (ionic edema). Because tissue water content is linearly related to X-ray attenuation, computed tomography (CT) can detect and measure ionic edema and, thus, determine ischemic brain infarction. In contrast, diffusion-weighted magnetic resonance imaging (DWI) detects cytotoxic edema that develops at higher thresholds of ischemic CBF and is thus highly sensitive for milder levels of brain ischemia, but not specific for irreversible brain tissue injury. CT and MRI are complimentary in the detection of ischemic stroke pathology and are valuable for treatment decisions. (orig.)

Correlation study on cystatin C and ischemic stroke

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CHEN Rong-bo

2013-06-01

Full Text Available Objective To investigate the relationship between serum cystatin C (Cys C and patients with acute ischemic stroke. Methods The clinical and laboratory data of 115 patients with acute ischemic stroke and 110 controls were recorded and analyzed. Results The serum Cys C levels of patients in ischemic stroke group [(1.15 ± 0.34 mg/L] were higher than that of the control group [(0.99 ± 0.25 mg/L]. The difference between two groups was significant after correction of age and cardiovascular risk factors (t = ? 3.889, P = 0.000. It was found that age, Cys C, homocysteine (Hcy, type 2 diabetes mellitus [hemoglobin A1c (HbA1c, fructosamine (FRU], smoking, alcohol consumption, hypertension and intima-media thickness (IMT were risk factors for ischemic stroke on univariate Logistic regression analysis. The difference of serum Cys C level between the patients and controls was significant (P = 0.000, but through covariance analysis, after adjusted other risk factors, it was not significant (P = 0.875. Conclusion The serum Cys C levels of patients in ischemic stroke group is higher than the control group. It can be used as an indicator in the acute phase of ischemic stroke. The elevation of serum Cys C is a risk factor for ischemic stroke, but not an independent risk factor.

Prevalence of electrocardiographic ST-T changes during acute ischemic stroke in patients without known ischemic heart disease

DEFF Research Database (Denmark)

Jensen, Jesper K; Bak, Søren; Flemming Høilund-Carlsen, Poul

2008-01-01

We evaluated characteristics and prevalence of ST-segment depression and/or T-wave inversion in the resting electrocardiogram of 244 consecutive patients with acute ischemic stroke, but without ischemic heart disease. The prevalence of ST-T changes ranged from 13% to 16% and this is what to expect...

Ferritin expression in rat hepatocytes and Kupffer cells after lead nitrate treatment.

Science.gov (United States)

Fan, Yang; Yamada, Toshiyuki; Shimizu, Takeshi; Nanashima, Naoki; Akita, Miki; Suto, Kohji; Tsuchida, Shigeki

2009-02-01

Lead nitrate induces hepatocyte proliferation and subsequent apoptosis in rat livers. Iron is a constituent of heme and is also required for cell proliferation. In this study, the expression of ferritin light-chain (FTL), the major iron storage protein, was investigated in rat livers after a single intravenous injection of lead nitrate. Western blotting and immunohistochemistry revealed that FTL was increased in hepatocytes around the central veins and strongly expressed in nonparenchymal cells. Some FTL-positive nonparenchymal cells were identified as Kupffer cells that were positive for CD68. FTL-positive Kupffer cells occupied about 60% of CD68-positive cells in the periportal and perivenous areas. The relationships between FTL expression and apoptosis induction or the engulfment of apoptotic cells were examined. TUNEL-positive cells were increased in the treatment group, and enhanced expression of milk fat globule EGF-like 8 was demonstrated in some Kupffer cells and hepatocytes, indicating enhanced apoptosis induction and phagocytosis of apoptotic cells. FTL-positive Kupffer cells were not detected without lead nitrate treatment or in rat livers treated with clofibrate, which induces hepatocyte proliferation but not apoptosis. These results suggest that FTL expression in Kupffer cells after lead treatment is dependent on phagocytosis of apoptotic cells.

Electroacupunctre improves motor impairment via inhibition of microglia-mediated neuroinflammation in the sensorimotor cortex after ischemic stroke.

Science.gov (United States)

Liu, Weilin; Wang, Xian; Yang, Shanli; Huang, Jia; Xue, Xiehua; Zheng, Yi; Shang, Guanhao; Tao, Jing; Chen, Lidian

2016-04-15

Electroacupuncture (EA) is one of the safety and effective therapies for improving neurological and sensorimotor impairment via blockade of inappropriate inflammatory responses. However, the mechanisms of anti-inflammation involved is far from been fully elucidated. Focal cerebral ischemic stroke was administered by the middle cerebral artery occlusion and reperfusion (MCAO/R) surgery. The MCAO/R rats were accepted EA treatment at the LI 11 and ST 36 acupoints for consecutive 3days. The neurological outcome, animal behaviors test and molecular biology assays were used to evaluate the MCAO/R model and therapeutic effect of EA. EA treatment for MCAO rats showed a significant reduction in the infarct volumes accompanied by functional recovery in mNSS outcomes, motor function performances. The possible mechanisms that EA treatment attenuated the over-activation of Iba-1 and ED1 positive microglia in the peri-infract sensorimotor cortex. Simultaneously, both tissue and serum protein levels of the tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) were decreased by EA treatment in MCAO/R injured rats. The levels of inflammatory cytokine tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) were decreased in the peri-infract sensorimotor cortex and blood serum of MCAO/R injured rats after EA treatment. Furthermore, we found that EA treatment prevented from the nucleus translocation of NF-κB p65 and suppressed the expression of p38 mitogen-activated protein kinase (p38 MAPK) and myeloid differentiation factor 88 (MyD88) in the peri-infract sensorimotor cortex. The findings from this study indicated that EA improved the motor impairment via inhibition of microglia-mediated neuroinflammation that invoked NF-κB p65, p38 MAPK and MyD88 produced proinflammatory cytokine in the peri-infract sensorimotor cortex of rats following ischemic stroke. Copyright © 2016 Elsevier Inc. All rights reserved.

Resveratrol Differentially Regulates NAMPT and SIRT1 in Hepatocarcinoma Cells and Primary Human Hepatocytes

Science.gov (United States)

Schuster, Susanne; Penke, Melanie; Gorski, Theresa; Petzold-Quinque, Stefanie; Damm, Georg; Gebhardt, Rolf; Kiess, Wieland; Garten, Antje

2014-01-01

Resveratrol is reported to possess chemotherapeutic properties in several cancers. In this study, we wanted to investigate the molecular mechanisms of resveratrol-induced cell cycle arrest and apoptosis as well as the impact of resveratrol on NAMPT and SIRT1 protein function and asked whether there are differences in hepatocarcinoma cells (HepG2, Hep3B cells) and non-cancerous primary human hepatocytes. We found a lower basal NAMPT mRNA and protein expression in hepatocarcinoma cells compared to primary hepatocytes. In contrast, SIRT1 was significantly higher expressed in hepatocarcinoma cells than in primary hepatocytes. Resveratrol induced cell cycle arrest in the S- and G2/M- phase and apoptosis was mediated by activation of p53 and caspase-3 in HepG2 cells. In contrast to primary hepatocytes, resveratrol treated HepG2 cells showed a reduction of NAMPT enzymatic activity and increased p53 acetylation (K382). Resveratrol induced NAMPT release from HepG2 cells which was associated with increased NAMPT mRNA expression. This effect was absent in primary hepatocytes where resveratrol was shown to function as NAMPT and SIRT1 activator. SIRT1 inhibition by EX527 resembled resveratrol effects on HepG2 cells. Furthermore, a SIRT1 overexpression significantly decreased both p53 hyperacetylation and resveratrol-induced NAMPT release as well as S-phase arrest in HepG2 cells. We could show that NAMPT and SIRT1 are differentially regulated by resveratrol in hepatocarcinoma cells and primary hepatocytes and that resveratrol did not act as a SIRT1 activator in hepatocarcinoma cells. PMID:24603648

Resveratrol differentially regulates NAMPT and SIRT1 in Hepatocarcinoma cells and primary human hepatocytes.

Directory of Open Access Journals (Sweden)

Susanne Schuster

Full Text Available Resveratrol is reported to possess chemotherapeutic properties in several cancers. In this study, we wanted to investigate the molecular mechanisms of resveratrol-induced cell cycle arrest and apoptosis as well as the impact of resveratrol on NAMPT and SIRT1 protein function and asked whether there are differences in hepatocarcinoma cells (HepG2, Hep3B cells and non-cancerous primary human hepatocytes. We found a lower basal NAMPT mRNA and protein expression in hepatocarcinoma cells compared to primary hepatocytes. In contrast, SIRT1 was significantly higher expressed in hepatocarcinoma cells than in primary hepatocytes. Resveratrol induced cell cycle arrest in the S- and G2/M- phase and apoptosis was mediated by activation of p53 and caspase-3 in HepG2 cells. In contrast to primary hepatocytes, resveratrol treated HepG2 cells showed a reduction of NAMPT enzymatic activity and increased p53 acetylation (K382. Resveratrol induced NAMPT release from HepG2 cells which was associated with increased NAMPT mRNA expression. This effect was absent in primary hepatocytes where resveratrol was shown to function as NAMPT and SIRT1 activator. SIRT1 inhibition by EX527 resembled resveratrol effects on HepG2 cells. Furthermore, a SIRT1 overexpression significantly decreased both p53 hyperacetylation and resveratrol-induced NAMPT release as well as S-phase arrest in HepG2 cells. We could show that NAMPT and SIRT1 are differentially regulated by resveratrol in hepatocarcinoma cells and primary hepatocytes and that resveratrol did not act as a SIRT1 activator in hepatocarcinoma cells.

[Nonfasting triglycerides and risk of ischemic stroke--secondary publication

DEFF Research Database (Denmark)

Freiberg, J.J.; Tybjaerg-Hansen, A.; Jensen, J.S.

2009-01-01

The role of triglycerides in the risk of ischemic stroke remains controversial. We tested the hypothesis that increased levels of nonfasting triglycerides are associated with ischemic stroke in the general population. Men with a nonfasting triglyceride level 5 mmol/l had a multivariable, adjusted...... hazard ratio for ischemic stroke of 2.5 (95% confidence interval: 1.3-4.8) compared with men with a nonfasting triglyceride level triglycerides is associated with risk of ischemic stroke Udgivelsesdato...

Optimization of the isolation and cultivation of Cyprinus carpio primary hepatocytes

OpenAIRE

Yanhong, Fan; Chenghua, He; Guofang, Liu; Haibin, Zhang

2008-01-01

The aquatic environment is affected by numerous chemical contaminants. There is an increasing need to identify these chemicals and to evaluate their potential toxicity towards aquatic life. In this research we optimized techniques for primary cell culture of Cyprinus carpio hepatocytes as one adjunct model for ecotoxicological evaluation of the potential hazards of xenobiotics in the aquatic environment. In this study, Cyprinus carpio hepatocytes were isolated by mechanical separation, two-st...

Activated human neutrophils release hepatocyte growth factor/scatter factor.

LENUS (Irish Health Repository)

McCourt, M

2012-02-03

BACKGROUND: Hepatocyte growth factor or scatter factor (HGF\\/SF) is a pleiotropic cytokine that has potent angiogenic properties. We have previously demonstrated that neutrophils (PMN) are directly angiogenic by releasing vascular endothelial growth factor (VEGF). We hypothesized that the acute inflammatory response can stimulate PMN to release HGF. AIMS: To examine the effects of inflammatory mediators on PMN HGF release and the effect of recombinant human HGF (rhHGF) on PMN adhesion receptor expression and PMN VEGF release. METHODS: In the first experiment, PMN were isolated from healthy volunteers and stimulated with tumour necrosis factor-alpha (TNF-alpha), lipopolysaccharide (LPS), interleukin-8 (IL-8), and formyl methionyl-leucyl-phenylalanine (fMLP). Culture supernatants were assayed for HGF using ELISA. In the second experiment, PMN were lysed to measure total HGF release and HGF expression in the PMN was detected by Western immunoblotting. Finally, PMN were stimulated with rhHGF. PMN CD 11a, CD 11b, and CD 18 receptor expression and VEGF release was measured using flow cytometry and ELISA respectively. RESULTS: TNF-alpha, LPS and fMLP stimulation resulted in significantly increased release of PMN HGF (755+\\/-216, 484+\\/-221 and 565+\\/-278 pg\\/ml, respectively) compared to controls (118+\\/-42 pg\\/ml). IL-8 had no effect. Total HGF release following cell lysis and Western blot suggests that HGF is released from intracellular stores. Recombinant human HGF did not alter PMN adhesion receptor expression and had no effect on PMN VEGF release. CONCLUSIONS: This study demonstrates that pro-inflammatory mediators can stimulate HGF release from a PMN intracellular store and that activated PMN in addition to secreting VEGF have further angiogenic potential by releasing HGF.

Temporal delta wave and ischemic lesions on MRI

International Nuclear Information System (INIS)

Inui, Koji; Kawamoto, Hozumi; Kawakita, Masahiko; Wako, Kazuhisa; Nakashima, Hiromichi; Kamihara, Masanori; Nomura, Junichi

1994-01-01

The present study was designed to determine the clinical significance of a temporal low-voltage irregular delta wave (TLID) on EEG. Among 808 EEG records examined during one year at our hospital, the TLID was commonly detected in patients with clinically diagnosed ischemic brain diseases such as multiple infarction. Subsequently, a relation of the TLID to ischemic lesions on MRI was examined in 50 elderly depressive patients. It was found that there was a close correlation between the occurrence of the TLID and small ischemic lesions on MRI (p<0.001). These results suggest that the TLID is a valuable indicator of minor ischemic changes of the brain. (author)

Magentic Cell labeling of primary and stem cell-derived pig hepatocytes for MRI-based cell tracking of heptocytes transplantation

Science.gov (United States)

Pig hepatocytes are an important investigational tool for optimizing hepatocyte transplantation schemes in both allogeneic and xenogeneic transplant scenarios. MRI can be used to serially monitor the transplanted cells, but only if the hepatocytes can be labeled with a magnetic particle. In this wo...

Prolongation of liver-specific function for primary hepatocytes maintenance in 3D printed architectures.

Science.gov (United States)

Kim, Yohan; Kang, Kyojin; Yoon, Sangtae; Kim, Ji Sook; Park, Su A; Kim, Wan Doo; Lee, Seung Bum; Ryu, Ki-Young; Jeong, Jaemin; Choi, Dongho

2018-01-23

Isolated primary hepatocytes from the liver are very similar to in vivo native liver hepatocytes, but they have the disadvantage of a limited lifespan in 2D culture. Although a sandwich culture and 3D organoids with mesenchymal stem cells (MSCs) as an attractive assistant cell source to extend lifespan can be used, it cannot fully reproduce the in vivo architecture. Moreover, long-term 3D culture leads to cell death because of hypoxic stress. Therefore, to overcome the drawback of 2D and 3D organoids, we try to use a 3D printing technique using alginate hydrogels with primary hepatocytes and MSCs. The viability of isolated hepatocytes was more than 90%, and the cells remained alive for 7 days without morphological changes in the 3D hepatic architecture with MSCs. Compared to a 2D system, the expression level of functional hepatic genes and proteins was higher for up to 7 days in the 3D hepatic architecture. These results suggest that both the 3D bio-printing technique and paracrine molecules secreted by MSCs supported long-term culture of hepatocytes without morphological changes. Thus, this technique allows for widespread expansion of cells while forming multicellular aggregates, may be applied to drug screening and could be an efficient method for developing an artificial liver.

Hanging Drop, A Best Three-Dimensional (3D) Culture Method for Primary Buffalo and Sheep Hepatocytes.

Science.gov (United States)

Shri, Meena; Agrawal, Himanshu; Rani, Payal; Singh, Dheer; Onteru, Suneel Kumar

2017-04-26

Livestock, having close resemblance to humans, could be a better source of primary hepatocytes than rodents. Herein, we successfully developed three-dimensional (3D) culturing system for primary sheep and buffalo hepatocytes. The 3D-structures of sheep hepatocytes were formed on the fifth-day and maintained until the tenth-day on polyHEMA-coated plates and in hanging drops with William's E media (HDW). Between the cultured and fresh cells, we observed a similar expression of GAPDH, HNF4α, ALB, CYP1A1, CK8 and CK18. Interestingly, a statistically significant increase was noted in the TAT, CPS, AFP, AAT, GSP and PCNA expression. In buffalo hepatocytes culture, 3D-like structures were formed on the third-day and maintained until the sixth-day on polyHEMA and HDW. The expression of HNF4α, GSP, CPS, AFP, AAT, PCNA and CK18 was similar between cultured and fresh cells. Further, a statistically significant increase in the TAT and CK8 expression, and a decrease in the GAPDH, CYP1A1 and ALB expression were noted. Among the culture systems, HDW maintained the liver transcript markers more or less similar to the fresh hepatocytes of the sheep and buffalo for ten and six days, respectively. Taken together, hanging drop is an efficient method for 3D culturing of primary sheep and buffalo hepatocytes.

Activation-dependent mitochondrial translocation of Foxp3 in human hepatocytes

International Nuclear Information System (INIS)

Rojas, Joselyn; Teran-Angel, Guillermo; Barbosa, Luisa; Peterson, Darrell L.; Berrueta, Lisbeth; Salmen, Siham

2016-01-01

Foxp3 is considered to be the master regulator for the development and function of regulatory T cells (Treg). Recently Foxp3, has been detected in extra lymphoid tissue, and in hepatocytes and has been associated with hepatocellular carcinoma (HCC), although its role has not been defined. Since it is expected that there is a relationship between protein localization, activity and cellular function, the aim of this study was to explore the subcellular localization of Foxp3 in resting and stimulated human hepatocytes. Foxp3 expression was measured by flow cytometry, subcellular fractioning, and immunofluorescence, and this data was used to track the shuttling of Foxp3 in different subcellular compartments in hepatocytes (HepG2 cell line), stimulated by using the PKC activators (PMA), core and preS1/2 antigen from hepatitis B virus (HBV). Our data shows that besides the nuclear location, mitochondrial translocation was detected after stimulation with PMA and at to a lesser extent, with preS1/2. In addition, Foxp3 is localizes at outer mitochondrial membrane. These results suggest a non-canonical role of Foxp3 in the mitochondrial compartment in human hepatocytes, and opens a new field about their role in liver damages during HBV infection. - Highlights: • The expression and subcellular distribution of Foxp3, is modulated by PMA and preS1/2. • PMA and preS1/2 increase Foxp3 expression on HepG2. • PMA and preS1/2 induce foxp3 enrichment at mitochondrial, microsomal and nuclear compartments. • Results suggest a non-canonical function of Foxp3 or a mitochondrial transcriptional activity.

Activation-dependent mitochondrial translocation of Foxp3 in human hepatocytes

Energy Technology Data Exchange (ETDEWEB)

Rojas, Joselyn; Teran-Angel, Guillermo; Barbosa, Luisa [Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of); Peterson, Darrell L. [Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA (United States); Berrueta, Lisbeth, E-mail: lberruet@ula.ve [Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of); Division of Preventive Medicine, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States); Salmen, Siham, E-mail: sihamsa@ula.ve [Instituto de Inmunología Clínica, Facultad de Medicina, Universidad de Los Andes, Merida (Venezuela, Bolivarian Republic of)

2016-05-01

Foxp3 is considered to be the master regulator for the development and function of regulatory T cells (Treg). Recently Foxp3, has been detected in extra lymphoid tissue, and in hepatocytes and has been associated with hepatocellular carcinoma (HCC), although its role has not been defined. Since it is expected that there is a relationship between protein localization, activity and cellular function, the aim of this study was to explore the subcellular localization of Foxp3 in resting and stimulated human hepatocytes. Foxp3 expression was measured by flow cytometry, subcellular fractioning, and immunofluorescence, and this data was used to track the shuttling of Foxp3 in different subcellular compartments in hepatocytes (HepG2 cell line), stimulated by using the PKC activators (PMA), core and preS1/2 antigen from hepatitis B virus (HBV). Our data shows that besides the nuclear location, mitochondrial translocation was detected after stimulation with PMA and at to a lesser extent, with preS1/2. In addition, Foxp3 is localizes at outer mitochondrial membrane. These results suggest a non-canonical role of Foxp3 in the mitochondrial compartment in human hepatocytes, and opens a new field about their role in liver damages during HBV infection. - Highlights: • The expression and subcellular distribution of Foxp3, is modulated by PMA and preS1/2. • PMA and preS1/2 increase Foxp3 expression on HepG2. • PMA and preS1/2 induce foxp3 enrichment at mitochondrial, microsomal and nuclear compartments. • Results suggest a non-canonical function of Foxp3 or a mitochondrial transcriptional activity.

Regulation of Tumor Progression by Programmed Necrosis

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Su Yeon Lee

2018-01-01

Full Text Available Rapidly growing malignant tumors frequently encounter hypoxia and nutrient (e.g., glucose deprivation, which occurs because of insufficient blood supply. This results in necrotic cell death in the core region of solid tumors. Necrotic cells release their cellular cytoplasmic contents into the extracellular space, such as high mobility group box 1 (HMGB1, which is a nonhistone nuclear protein, but acts as a proinflammatory and tumor-promoting cytokine when released by necrotic cells. These released molecules recruit immune and inflammatory cells, which exert tumor-promoting activity by inducing angiogenesis, proliferation, and invasion. Development of a necrotic core in cancer patients is also associated with poor prognosis. Conventionally, necrosis has been thought of as an unregulated process, unlike programmed cell death processes like apoptosis and autophagy. Recently, necrosis has been recognized as a programmed cell death, encompassing processes such as oncosis, necroptosis, and others. Metabolic stress-induced necrosis and its regulatory mechanisms have been poorly investigated until recently. Snail and Dlx-2, EMT-inducing transcription factors, are responsible for metabolic stress-induced necrosis in tumors. Snail and Dlx-2 contribute to tumor progression by promoting necrosis and inducing EMT and oncogenic metabolism. Oncogenic metabolism has been shown to play a role(s in initiating necrosis. Here, we discuss the molecular mechanisms underlying metabolic stress-induced programmed necrosis that promote tumor progression and aggressiveness.

A fast and robust hepatocyte quantification algorithm including vein processing

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Homeyer André

2010-03-01

Full Text Available Abstract Background Quantification of different types of cells is often needed for analysis of histological images. In our project, we compute the relative number of proliferating hepatocytes for the evaluation of the regeneration process after partial hepatectomy in normal rat livers. Results Our presented automatic approach for hepatocyte (HC quantification is suitable for the analysis of an entire digitized histological section given in form of a series of images. It is the main part of an automatic hepatocyte quantification tool that allows for the computation of the ratio between the number of proliferating HC-nuclei and the total number of all HC-nuclei for a series of images in one processing run. The processing pipeline allows us to obtain desired and valuable results for a wide range of images with different properties without additional parameter adjustment. Comparing the obtained segmentation results with a manually retrieved segmentation mask which is considered to be the ground truth, we achieve results with sensitivity above 90% and false positive fraction below 15%. Conclusions The proposed automatic procedure gives results with high sensitivity and low false positive fraction and can be applied to process entire stained sections.

Elevated Plasma YKL-40 Levels and Ischemic Stroke in the General Population

DEFF Research Database (Denmark)

Kjaergaard, A.D.; Bojesen, S.E.; Johansen, J.S.

2010-01-01

inside the vessel wall. Methods: We measured plasma YKL-40 in 8,899 21- to 93-year-old participants of the Copenhagen City Heart Study 1991-1994 examination, and followed them for up to 18 years. Endpoints were ischemic stroke, ischemic cerebrovascular disease, myocardial infarction, and ischemic heart......% confidence interval, 11%-30%) for ischemic stroke, 16% (8%-24%) for ischemic cerebrovascular disease, 3% (-5%-11%) for myocardial infarction, and 7% (1%-12%) for ischemic heart disease. Interpretation: In the general population, elevated plasma YKL-40 levels are associated with increased risk of ischemic...... stroke and ischemic cerebrovascular disease, independent of plasma CRP levels. ANN NEUROL 2010;68:672-680...

Stathmin Mediates Hepatocyte Resistance to Death from Oxidative Stress by down Regulating JNK

Science.gov (United States)

Zhao, Enpeng; Amir, Muhammad; Lin, Yu; Czaja, Mark J.

2014-01-01

Stathmin 1 performs a critical function in cell proliferation by regulating microtubule polymerization. This proliferative function is thought to explain the frequent overexpression of stathmin in human cancer and its correlation with a bad prognosis. Whether stathmin also functions in cell death pathways is unclear. Stathmin regulates microtubules in part by binding free tubulin, a process inhibited by stathmin phosphorylation from kinases including c-Jun N-terminal kinase (JNK). The involvement of JNK activation both in stathmin phosphorylation, and in hepatocellular resistance to oxidative stress, led to an examination of the role of stathmin/JNK crosstalk in oxidant-induced hepatocyte death. Oxidative stress from menadione-generated superoxide induced JNK-dependent stathmin phosphorylation at Ser-16, Ser-25 and Ser-38 in hepatocytes. A stathmin knockdown sensitized hepatocytes to both apoptotic and necrotic cell death from menadione without altering levels of oxidant generation. The absence of stathmin during oxidative stress led to JNK overactivation that was the mechanism of cell death as a concomitant knockdown of JNK1 or JNK2 blocked death. Hepatocyte death from JNK overactivation was mediated by the effects of JNK on mitochondria. Mitochondrial outer membrane permeabilization occurred in stathmin knockdown cells at low concentrations of menadione that triggered apoptosis, whereas mitochondrial β-oxidation and ATP homeostasis were compromised at higher, necrotic menadione concentrations. Stathmin therefore mediates hepatocyte resistance to death from oxidative stress by down regulating JNK and maintaining mitochondrial integrity. These findings demonstrate a new mechanism by which stathmin promotes cell survival and potentially tumor growth. PMID:25285524

Stathmin mediates hepatocyte resistance to death from oxidative stress by down regulating JNK.

Directory of Open Access Journals (Sweden)

Enpeng Zhao

Full Text Available Stathmin 1 performs a critical function in cell proliferation by regulating microtubule polymerization. This proliferative function is thought to explain the frequent overexpression of stathmin in human cancer and its correlation with a bad prognosis. Whether stathmin also functions in cell death pathways is unclear. Stathmin regulates microtubules in part by binding free tubulin, a process inhibited by stathmin phosphorylation from kinases including c-Jun N-terminal kinase (JNK. The involvement of JNK activation both in stathmin phosphorylation, and in hepatocellular resistance to oxidative stress, led to an examination of the role of stathmin/JNK crosstalk in oxidant-induced hepatocyte death. Oxidative stress from menadione-generated superoxide induced JNK-dependent stathmin phosphorylation at Ser-16, Ser-25 and Ser-38 in hepatocytes. A stathmin knockdown sensitized hepatocytes to both apoptotic and necrotic cell death from menadione without altering levels of oxidant generation. The absence of stathmin during oxidative stress led to JNK overactivation that was the mechanism of cell death as a concomitant knockdown of JNK1 or JNK2 blocked death. Hepatocyte death from JNK overactivation was mediated by the effects of JNK on mitochondria. Mitochondrial outer membrane permeabilization occurred in stathmin knockdown cells at low concentrations of menadione that triggered apoptosis, whereas mitochondrial β-oxidation and ATP homeostasis were compromised at higher, necrotic menadione concentrations. Stathmin therefore mediates hepatocyte resistance to death from oxidative stress by down regulating JNK and maintaining mitochondrial integrity. These findings demonstrate a new mechanism by which stathmin promotes cell survival and potentially tumor growth.

Hepatocyte-based in vitro model for assessment of drug-induced cholestasis

Energy Technology Data Exchange (ETDEWEB)

Chatterjee, Sagnik, E-mail: Sagnik.Chatterjee@pharm.kuleuven.be [Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, O and N2, Herestraat 49 — bus 921, 3000 Leuven (Belgium); Richert, Lysiane, E-mail: l.richert@kaly-cell.com [KaLy-Cell, 20A rue du Général Leclerc, 67115 Plobsheim (France); Augustijns, Patrick, E-mail: Patrick.Augustijns@pharm.kuleuven.be [Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, O and N2, Herestraat 49 — bus 921, 3000 Leuven (Belgium); Annaert, Pieter, E-mail: Pieter.Annaert@pharm.kuleuven.be [Drug Delivery and Disposition, KU Leuven Department of Pharmaceutical and Pharmacological Sciences, O and N2, Herestraat 49 — bus 921, 3000 Leuven (Belgium)

2014-01-01

Early detection of drug-induced cholestasis remains a challenge during drug development. We have developed and validated a biorelevant sandwich-cultured hepatocytes- (SCH) based model that can identify compounds causing cholestasis by altering bile acid disposition. Human and rat SCH were exposed (24–48 h) to known cholestatic and/or hepatotoxic compounds, in the presence or in the absence of a concentrated mixture of bile acids (BAs). Urea assay was used to assess (compromised) hepatocyte functionality at the end of the incubations. The cholestatic potential of the compounds was expressed by calculating a drug-induced cholestasis index (DICI), reflecting the relative residual urea formation by hepatocytes co-incubated with BAs and test compound as compared to hepatocytes treated with test compound alone. Compounds with clinical reports of cholestasis, including cyclosporin A, troglitazone, chlorpromazine, bosentan, ticlopidine, ritonavir, and midecamycin showed enhanced toxicity in the presence of BAs (DICI ≤ 0.8) for at least one of the tested concentrations. In contrast, the in vitro toxicity of compounds causing hepatotoxicity by other mechanisms (including diclofenac, valproic acid, amiodarone and acetaminophen), remained unchanged in the presence of BAs. A safety margin (SM) for drug-induced cholestasis was calculated as the ratio of lowest in vitro concentration for which was DICI ≤ 0.8, to the reported mean peak therapeutic plasma concentration. SM values obtained in human SCH correlated well with reported % incidence of clinical drug-induced cholestasis, while no correlation was observed in rat SCH. This in vitro model enables early identification of drug candidates causing cholestasis by disturbed BA handling. - Highlights: • Novel in vitro assay to detect drug-induced cholestasis • Rat and human sandwich-cultured hepatocytes (SCH) as in vitro models • Cholestatic compounds sensitize SCH to toxic effects of accumulating bile acids • Drug

Hepatocyte-based in vitro model for assessment of drug-induced cholestasis

International Nuclear Information System (INIS)

Chatterjee, Sagnik; Richert, Lysiane; Augustijns, Patrick; Annaert, Pieter

2014-01-01

Early detection of drug-induced cholestasis remains a challenge during drug development. We have developed and validated a biorelevant sandwich-cultured hepatocytes- (SCH) based model that can identify compounds causing cholestasis by altering bile acid disposition. Human and rat SCH were exposed (24–48 h) to known cholestatic and/or hepatotoxic compounds, in the presence or in the absence of a concentrated mixture of bile acids (BAs). Urea assay was used to assess (compromised) hepatocyte functionality at the end of the incubations. The cholestatic potential of the compounds was expressed by calculating a drug-induced cholestasis index (DICI), reflecting the relative residual urea formation by hepatocytes co-incubated with BAs and test compound as compared to hepatocytes treated with test compound alone. Compounds with clinical reports of cholestasis, including cyclosporin A, troglitazone, chlorpromazine, bosentan, ticlopidine, ritonavir, and midecamycin showed enhanced toxicity in the presence of BAs (DICI ≤ 0.8) for at least one of the tested concentrations. In contrast, the in vitro toxicity of compounds causing hepatotoxicity by other mechanisms (including diclofenac, valproic acid, amiodarone and acetaminophen), remained unchanged in the presence of BAs. A safety margin (SM) for drug-induced cholestasis was calculated as the ratio of lowest in vitro concentration for which was DICI ≤ 0.8, to the reported mean peak therapeutic plasma concentration. SM values obtained in human SCH correlated well with reported % incidence of clinical drug-induced cholestasis, while no correlation was observed in rat SCH. This in vitro model enables early identification of drug candidates causing cholestasis by disturbed BA handling. - Highlights: • Novel in vitro assay to detect drug-induced cholestasis • Rat and human sandwich-cultured hepatocytes (SCH) as in vitro models • Cholestatic compounds sensitize SCH to toxic effects of accumulating bile acids • Drug

Hepatocyte Aggregate Formation on Chitin-Based Anisotropic Microstructures of Butterfly Wings

Directory of Open Access Journals (Sweden)

Abdelrahman Elbaz

2018-01-01

Full Text Available Scaffold nanotopography plays the most significant role in the mimicry of the in vivo microenvironment of the hepatocytes. Several attempts have been made to develop methods and substrates suited to growing hepatocytes into aggregates. Functional biomaterials, particularly biodegradable polymers, have been used in several studies aimed to develop improved scaffolds with ordered geometry and nanofibrous architecture for tissue engineering. However, there are still some limitation in their fabrication: it is not cost-efficient, is time-consuming, and exhibits some technological complications. The synthetic scaffolds are usually non-biodegradable and can be non-biocompatible compared to the naturally derived biomaterials. Here, we utilized a simple, cost-effective, and green method with two-step chemical treatment to get more selected hydrophilic butterfly wings from Morpho menelaus, Papilio ulysses telegonus, and Ornithoptera croesus lydius as a chitin-based natural scaffolds to growing hepatocyte aggregates. We established a three-dimensional (3D in vitro model for culture of HepG2 cells and aggregate formation that maintained the hepatocytes function on these natural anisotropic microstructures. Cells cultured on these substrates show higher viability than those cultured on a two-dimensional (2D culture plate. Methylthiazolyldiphenyl-tetrazolium bromide (MTT assay results revealed excellent viability of HepG2 cells on P. u. telegonus wings (fibrous area. The results also demonstrated appropriate cell activity, cell retention, and stable and functional expression in terms of albumin secretion and urea synthesis activity compared to the 2D monolayer culture of hepatocytes on the culture dish surface. With a slightly different degree, the other substrates also shown similar results. We anticipate that these natural anisotropic, biodegradable, and biocompatible substrates can maintain long-term hepatic culture as an in vitro 3D model for potential

Post-ischemic bowel stricture: CT features in eight cases

Energy Technology Data Exchange (ETDEWEB)

Kim, Jin Sil [Dept. of Radiology, College of Medicine, Ewha Womans University, Mokdong Hospital, Seoul (Korea, Republic of); Kim, Hyun Jin; Hong, Sung Mo; Park, Seong Ho; Lee, Jong Seok; Kim, Ah Young; Ha, Hyun Kwon [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

2017-11-15

To investigate the characteristic radiologic features of post-ischemic stricture, which can then be implemented to differentiate that specific disease from other similar bowel diseases, with an emphasis on computed tomography (CT) features. Eight patients with a diagnosis of ischemic bowel disease, who were also diagnosed with post-ischemic stricture on the basis of clinical or pathologic findings, were included. Detailed clinical data was collected from the available electronic medical records. Two radiologists retrospectively reviewed all CT images. Pathologic findings were also analyzed. The mean interval between the diagnosis of ischemic bowel disease and stricture formation was 57 days. The severity of ischemic bowel disease was variable. Most post-ischemic strictures developed in the ileum (n = 5), followed by the colon (n = 2) and then the jejunum (n = 1). All colonic strictures developed in the “watershed zone.” The pathologic features of post-ischemic stricture were deep ulceration, submucosal/subserosal fibrosis and chronic transmural inflammation. The mean length of the post-ischemic stricture was 7.4 cm. All patients in this study possessed one single stricture. On contrast-enhanced CT, most strictures possessed concentric wall thickening (87.5%), with moderate enhancement (87.5%), mucosal enhancement (50%), or higher enhancement in portal phase than arterial phase (66.7%). Post-ischemic strictures develop in the ileum, jejunum and colon after an interval of several weeks. In the colonic segment, strictures mainly occur in the “watershed zone.” Typical CT findings include a single area of concentric wall thickening of medium length (mean, 7.4 cm), with moderate and higher enhancement in portal phase and vasa recta prominence.

Oncostatin M induces upregulation of claudin-2 in rodent hepatocytes coinciding with changes in morphology and function of tight junctions

International Nuclear Information System (INIS)

Imamura, Masafumi; Kojima, Takashi; Lan, Mengdong; Son, Seiichi; Murata, Masaki; Osanai, Makoto; Chiba, Hideki; Hirata, Koichi; Sawada, Norimasa

2007-01-01

In rodent livers, integral tight junction (TJ) proteins claudin-1, -2, -3, -5 and -14 are detected and play crucial roles in the barrier to keep bile in bile canaculi away from the blood circulation. Claudin-2 shows a lobular gradient increasing from periportal to pericentral hepatocytes, whereas claudin-1 and -3 are expressed in the whole liver lobule. Although claudin-2 expression induces cation-selective channels in tight junctions of epithelial cells, the physiological functions and regulation of claudin-2 in hepatocytes remain unclear. Oncostatin M (OSM) is a multifunctional cytokine implicated in the differentiation of hepatocytes that induces formation of E-cadherin-based adherens junctions in fetal hepatocytes. In this study, we examined whether OSM could induce expression and function of claudin-2 in rodent hepatocytes, immortalized mouse and primary cultured proliferative rat hepatocytes. In the immortalized mouse and primary cultured proliferative rat hepatocytes, treatment with OSM markedly increased mRNA and protein of claudin-2 together with formation of developed networks of TJ strands. The increase of claudin-2 enhanced the paracellular barrier function which depended on molecular size. The increase of claudin-2 expression induced by OSM in rodent hepatocytes was regulated through distinct signaling pathways including PKC. These results suggest that expression of claudin-2 in rodent hepatocytes may play a specific role as controlling the size of paracellular permeability in the barrier to keep bile in bile canaculi

Molecular Mechanisms of Renal Ischemic Conditioning Strategies

DEFF Research Database (Denmark)

Kierulf-Lassen, Casper; Nieuwenhuijs-Moeke, Gertrude J; Krogstrup, Nicoline V

2015-01-01

summarizes research on the molecular mechanisms underlying both local and remote ischemic pre-, per- and postconditioning of the kidney. The different types of conditioning strategies in the kidney recruit similar powerful pro-survival mechanisms. Likewise, renal ischemic conditioning mobilizes many...

Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

International Nuclear Information System (INIS)

Mohammad, Mohammad K.; Avila, Diana; Zhang, Jingwen; Barve, Shirish; Arteel, Gavin; McClain, Craig; Joshi-Barve, Swati

2012-01-01

Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentrations, caused a dose-dependent loss of viability of hepatocytes. The death was apoptotic at moderate and necrotic at high concentrations of acrolein. Acrolein exposure rapidly and dramatically decreased intracellular glutathione and overall antioxidant capacity, and activated the stress-signaling MAP-kinases JNK, p42/44 and p38. Our data demonstrate for the first time in human hepatocytes, that acrolein triggered endoplasmic reticulum (ER) stress and activated eIF2α, ATF-3 and -4, and Gadd153/CHOP, resulting in cell death. Notably, the protective/adaptive component of ER stress was not activated, and acrolein failed to up-regulate the protective ER-chaperones, GRP78 and GRP94. Additionally, exposure to acrolein disrupted mitochondrial integrity/function, and led to the release of pro-apoptotic proteins and ATP depletion. Acrolein-induced cell death was attenuated by N-acetyl cysteine, phenyl-butyric acid, and caspase and JNK inhibitors. Our data demonstrate that exposure to acrolein induces a variety of stress responses in hepatocytes, including GSH depletion, oxidative stress, mitochondrial dysfunction and ER stress (without ER-protective responses) which together contribute to acrolein toxicity. Our study defines basic mechanisms underlying liver injury caused by reactive aldehyde pollutants such as acrolein. -- Highlights: ► Human primary hepatocytes and cultured cell lines are used. ► Multiple cell death signaling pathways are activated by acrolein. ► Novel finding of

Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

Energy Technology Data Exchange (ETDEWEB)

Mohammad, Mohammad K. [Department of Medicine, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Avila, Diana [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Zhang, Jingwen [Department of Medicine, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Barve, Shirish [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Arteel, Gavin [Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); McClain, Craig [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States); Robley Rex VAMC, Louisville, KY (United States); Joshi-Barve, Swati, E-mail: s0josh01@louisville.edu [Department of Medicine, University of Louisville (United States); Department of Pharmacology and Toxicology, University of Louisville (United States); Alcohol Research Center, University of Louisville (United States)

2012-11-15

Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentrations, caused a dose-dependent loss of viability of hepatocytes. The death was apoptotic at moderate and necrotic at high concentrations of acrolein. Acrolein exposure rapidly and dramatically decreased intracellular glutathione and overall antioxidant capacity, and activated the stress-signaling MAP-kinases JNK, p42/44 and p38. Our data demonstrate for the first time in human hepatocytes, that acrolein triggered endoplasmic reticulum (ER) stress and activated eIF2α, ATF-3 and -4, and Gadd153/CHOP, resulting in cell death. Notably, the protective/adaptive component of ER stress was not activated, and acrolein failed to up-regulate the protective ER-chaperones, GRP78 and GRP94. Additionally, exposure to acrolein disrupted mitochondrial integrity/function, and led to the release of pro-apoptotic proteins and ATP depletion. Acrolein-induced cell death was attenuated by N-acetyl cysteine, phenyl-butyric acid, and caspase and JNK inhibitors. Our data demonstrate that exposure to acrolein induces a variety of stress responses in hepatocytes, including GSH depletion, oxidative stress, mitochondrial dysfunction and ER stress (without ER-protective responses) which together contribute to acrolein toxicity. Our study defines basic mechanisms underlying liver injury caused by reactive aldehyde pollutants such as acrolein. -- Highlights: ► Human primary hepatocytes and cultured cell lines are used. ► Multiple cell death signaling pathways are activated by acrolein. ► Novel finding of

Serum Hepatocyte Growth Factor as A Non-Invasive Marker For Evaluation of Hepatocellular Carcinoma

International Nuclear Information System (INIS)

Abdelgawad, M.R.; Wahba, M.A.

2012-01-01

The change and the prognostic value of serum hepatocyte growth factor and AFP level in patients with cirrhosis and/or primary liver cancer (HCC) were investigated. The level of serum hepatocyte growth factor was determined by using enzyme-linked immunosorbent assay, and AFP was determined by using radioimmunoassay in 29 patients with cirrhosis. Twenty five patients with primary liver cancer (13 patients without nodular cirrhosis and 12 patients with nodular cirrhosis) were categorized according to tumour size (≤ or >5 cm) and the level of AFP (≤ or > 200 ng/dl). The correlation between serum AFP and hepatocyte growth factor were significantly increased (P 0.05). Serum AFP can significantly discriminate between all studied groups (P 0.001) except for the comparison between control and cirrhosis (P>0.05), and also between HCC and HCC without nodular cirrhosis and HCC with cirrhosis (P>0.05). Serum HGF and AFP levels were positively affected by tumour size and nodular cirrhosis (P<0.001). Also, serum HGF level was highly affected by the levels of serum AFP in HCC patients. Non-significant correlation was observed between serum hepatocyte growth factor and AFP in control, cirrhosis, cirrhosis and HCC patients with AFP ? 200 ng/dl. It could be concluded that the over expressions of the hepatocyte growth factor and AFP may indicate an adverse prognosis for patients with cirrhosis and/or liver cancer. The sustained high level of serum hepatocyte growth factor in cirrhosis and/or HCC could be considered a factor related to early tumour diagnosis, so, serum HGF level may be used as a non-invasive marker in diagnosis and prognosis of liver malignancy. However, further studies are highly recommended to evaluate the role of HGF or its constituents in diagnosis and/or therapy in the future in a larger cohort of patients with different stages of liver malignancy

Computational Topology Based Quantification Of Hepatocytes Nuclei In Lipopolysaccharide-Induced Liver Injury In Mice

Directory of Open Access Journals (Sweden)

Rodrigo Rojas Moraleda

2016-06-01

The computational topology approach proposed successfully detected hepatocyte cells under several natural variations. We evaluated on a per-pixel basis how the segmentation performs on: i all nuclei in the images, ii big round nuclei considered belonging to hepatocytes cells (accuracy 87.2%, recall 80.3%, and iii nuclei regarded to non-parenchymal cells.  

Histopathological investigation of radiation necrosis. Coagulation necrosis in the irradiated and non-irradiated brain tumors and in the normal brain tissue

Energy Technology Data Exchange (ETDEWEB)

Nakamura, N [Niigata Univ. (Japan). Brain Research Inst.

1977-01-01

Eighty four irradiated tumors (including 59 gliomas) and the surrounding brain tissue were analyzed. In 'normal' brain tissue, typical coagulation necrosis attributable to irradiation was observed in the cerebral white matter, presenting a whitish-yellow color but no remarkable changes in volume. Histologically there was complete desintegration of myelin and axon. Vascular changes included hyalinous thickening, concentric cleavage, fibrinoid degeneration, adventitial fibrosis and edema of small arteries, fibrin thrombi or occlusion of arterioles and capillaries, and telangiectasia of small veins and venules. While other tumors showed hyalinous or fibrous scar tissue and decrease in volume, the gliomas maintained their original volume without residual tumor cells. Massive coagulation necrosis was occasionally found even in full volume, non-irradiated gliomas (controls), although the changes were fewer and not so varied as in typical radiation necrosis. With small dosages, it was difficult to judge whether the necrosis was caused by irradiation or occurred spontaneously. Coagulation necrosis in tumor tissue was found in 25 of 59 cases (42%) of irradiated gliomas, but in only 2 of 49 cases (4%) of the nonirradiated gliomas. In 49 cases no coagulation necrosis of the surrounding tissue was found. Although histopathological judgement is difficult, it is suggested that there is a significant correlation between coagulation necrosis and irradiation. Discussion of the relationship between coagulation necrosis and NSD (nominal standard dose) led to the conclusion that coagulation necrosis will not be caused by irradiation of less than 1400 rets in NSD.

In vitro differentiation and maturation of mouse embryonic stem cells into hepatocytes

International Nuclear Information System (INIS)

Ishii, Takamichi; Yasuchika, Kentaro; Fujii, Hideaki; Hoppo, Toshitaka; Baba, Shinji; Naito, Masato; Machimoto, Takafumi; Kamo, Naoko; Suemori, Hirofumi; Nakatsuji, Norio; Ikai, Iwao

2005-01-01

It is difficult to induce the maturation of embryonic stem (ES) cells into hepatocytes in vitro. We previously reported that Thy1-positive mesenchymal cells derived from the mouse fetal liver promote the maturation of hepatic progenitor cells. Here, we isolated alpha-fetoprotein (AFP)-producing cells from mouse ES cells for subsequent differentiation into hepatocytes in vitro by coculture with Thy1-positive cells. ES cells expressing green fluorescent protein (GFP) under the control of an AFP promoter were cultured under serum- and feeder layer-free culture conditions. The proportion of GFP-positive cells plateaued at 41.6 ± 12.2% (means ± SD) by day 7. GFP-positive cells, isolated by flow cytometry, were cultured in the presence or absence of Thy1-positive cells as a feeder layer. Isolated GFP-positive cells were stained for AFP, Foxa2, and albumin. The expression of mRNAs encoding tyrosine amino transferase, tryptophan 2,3-dioxygenase, and glucose-6-phosphatase were only detected following coculture with Thy1-positive cells. Following coculture with Thy1-positive cells, the isolated cells produced and stored glycogen. Ammonia clearance activity was also enhanced following coculture. Electron microscopic analysis indicated that the cocultured cells exhibited the morphologic features of mature hepatocytes. In conclusion, coculture with Thy1-positive cells in vitro induced the maturation of AFP-producing cells isolated from ES cell cultures into hepatocytes

Purification, characterisation and protective effects of polysaccharides from alfalfa on hepatocytes.

Science.gov (United States)

Wang, Shaopu; Dong, Xiaofang; Ma, Hao; Cui, Yaoming; Tong, Jianming

2014-11-04

The objective of this study was to determine the preliminary characteristics and protective effects of alfalfa polysaccharides (APS) on hepatocytes in vitro. The crude APS was purified by DEAE-cellulose and Sephadex G-100 chromatography, resulting in the four purified fractions: APS-1, APS-2, APS-3 and APS-4. The results indicated that APS-3 had higher carbohydrate and uronic acid contents and that APS-4 had a more complicated monosaccharide composition compared to the other purified fractions. The average molecular weights of APS-1, APS-2, APS-3 and APS-4 were 48,536, 6,221, 66,559 and 13,076 Da, respectively. Furthermore, APS (crude and its purified fractions) restored the activities of antioxidant enzymes and increased the total antioxidant capacity of hepatocytes subjected to H2O2-induced oxidative stress. Furthermore, APS treatment counteracted the increases in lactic dehydrogenase and malonaldehyde in the culture supernatant. These results clearly demonstrate that APS possesses a protective effect against oxidative injury in hepatocytes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Clinical and CT imaging features of abdominal fat necrosis

International Nuclear Information System (INIS)

Zhao Jinkun; Bai Renju

2013-01-01

Fat necrosis is a common pathological change at abdominal cross-sectional imaging, and it may cause abdominal pain, mimic pathological change of acute abdomen, or be asymptomatic and accompany other pathophysiologic processes. Fat necrosis is actually the result of steatosis by metabolism or mechanical injury. Common processes that are present in fat necrosis include epiploic appendagitis, infarction of the greater omentum, pancreatitis, and fat necrosis related to trauma or ischemia. As a common fat disease, fat necrosis should be known by clinicians and radiologists. Main content of this text is the clinical symptoms and CT findings of belly fat necrosis and related diseases. (authors)

The regulation of cytoskeletal and liver-specific gene expression during liver regeneration and primary hepatocyte culture

International Nuclear Information System (INIS)

Robinson, G.S.

1989-01-01

The focus of this dissertation is to determine what role(s) the extracellular matrix and expression of certain cytoskeletal genes play in the regulation of hepatocyte growth and the maintenance of a differential state. The expression of several cytoskeletal and liver-specific genes was examined during liver regeneration and in hepatocyte cultures maintained in a hormonally-defined, serum-free medium and plated on two different matrices: rat tail collagen and the EHS matrix. During liver regeneration and in hepatocytes cultured on rat tail collagen, there was a dramatic increase in tubulin mRNA levels coincident with but not linked to DNA synthesis. The message levels for other cytoskeletal genes similarly increased, while a decrease was observed in the mRNA levels of the liver-specific genes, serum albumin and alpha 1 inhibitor III. Hepatocytes cultured on the EHS matrix resulted in the maintenance of low levels of cytoskeletal gene expression and high levels of liver-specific gene expression, similar to that observed in the normal liver. Results from subcellar fractionation and two-dimensional gel electrophoresis of 35 S-labelled proteins paralleled the results seen at the mRNA level. Preliminary work suggests that microtubule organization may play a role in the expression of the liver-specific genes which encode secreted proteins. These studies, which compare hepatocytes cultured on collagen or the EHS matrix gel, reveal that both cell-cell and cell-matrix interactions play a major role in the maintenance of the differential phenotype in hepatocytes

Hepatic Stellate Cell-Derived Microvesicles Prevent Hepatocytes from Injury Induced by APAP/H2O2

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Renwei Huang

2016-01-01

Full Text Available Hepatic stellate cells (HSCs, previously described for liver-specific mesenchymal stem cells (MSCs, appear to contribute to liver regeneration. Microvesicles (MVs are nanoscale membrane fragments, which can regulate target cell function by transferring contents from their parent cells. The aim of this study was to investigate the effect of HSC-derived MVs on xenobiotic-induced liver injury. Rat and human hepatocytes, BRL-3A and HL-7702, were used to build hepatocytes injury models by n-acetyl-p-aminophenol n-(APAP or H2O2 treatment. MVs were prepared from human and rat HSCs, LX-2, and HST-T6 and, respectively, added to injured BRL-3A and HL-7702 hepatocytes. MTT assay was utilized to determine cell proliferation. Cell apoptosis was analyzed by flow cytometry and hoechst33258 staining. Western blot was used for analyzing the expression of activated caspase-3. Liver injury indicators, alanine aminotransferase (ALT, aspartate aminotransferase (AST, and lactate dehydrogenase (LDH in culture medium were also assessed. Results showed that (1 HSC-MVs derived from LX-2 and HST-T6 were positive to CD90 and annexin V surface markers; (2 HSC-MVs dose-dependently improved the viability of hepatocytes in both injury models; (3 HSC-MVs dose-dependently inhibited the APAP/H2O2 induced hepatocytes apoptosis and activated caspase-3 expression and leakage of LDH, ALT, and AST. Our results demonstrate that HSC-derived MVs protect hepatocytes from toxicant-induced injury.

Nor-ursodeoxycholic acid reverses hepatocyte-specific nemo-dependent steatohepatitis.

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Beraza, Naiara; Ofner-Ziegenfuss, Lisa; Ehedego, Haksier; Boekschoten, Mark; Bischoff, Stephan C; Mueller, Michael; Trauner, Michael; Trautwein, Christian

2011-03-01

Hepatocyte-specific NEMO/NF-κB deleted mice (NEMO(Δhepa)) develop spontaneous non-alcoholic steatohepatitis (NASH). Free fatty acids and bile acids promote DR5 expression. TRAIL/NK cell-mediated activation of TRAIL-R2/DR5 plays an important role during acute injury in NEMO(Δhepa) mice. To inhibit the progression of NASH in the absence of hepatocyte-NEMO/NF-kB signaling. NEMOf/f and NEMO(Δhepa) mice were fed with a low-fat diet, and with two anticholestatic diets; UDCA and NorUDCA. The impact of these treatments on the progression of NASH was evaluated. We show that high expression of DR5 in livers from NEMO(Δhepa) mice is accompanied by an abundant presence of bile acids (BAs), misregulation of BA transporters and significant alteration of lipid metabolism-related genes. Additionally, mice lacking NEMO in hepatocytes spontaneously showed ductular response at young age. Unexpectedly, feeding of NEMO(Δhepa) mice with low-fat diet failed to improve chronic liver injury. Conversely, anti-cholestatic treatment with nor-ursodeoxycholic acid (NorUDCA), but not with ursodeoxycholic acid (UDCA), led to a significant attenuation of liver damage in NEMO(Δhepa) mice. The strong therapeutic effect of NorUDCA relied on a significant downregulation of LXR-dependent lipogenesis and the normalisation of BA metabolism through mechanisms involving cross-talk between Cyp7a1 and SHP. This was associated with the significant improvement of liver histology, NEMO(Δhepa)/NorUDCA-treated mice showed lower apoptosis and reduced CyclinD1 expression, indicating attenuation of the compensatory proliferative response to hepatocellular damage. Finally, fibrosis and ductular reaction markers were significantly reduced in NorUDCA-treated NEMO(Δhepa) mice. Overall, our work demonstrates the contribution of bile acids metabolism to the progression of NASH in the absence of hepatocyte-NF-kB through mechanisms involving DR5-apoptosis, inflammation and fibrosis. Our work suggests a potential

Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

OpenAIRE

Mohammad, Mohammad K; Avila, Diana; Zhang, Jingwen; Barve, Shirish; Arteel, Gavin; McClain, Craig; Joshi-Barve, Swati

2012-01-01

Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentration...

Generation of human pluripotent stem cell-derived hepatocyte-like cells for drug toxicity screening.

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Takayama, Kazuo; Mizuguchi, Hiroyuki

2017-02-01

Because drug-induced liver injury is one of the main reasons for drug development failures, it is important to perform drug toxicity screening in the early phase of pharmaceutical development. Currently, primary human hepatocytes are most widely used for the prediction of drug-induced liver injury. However, the sources of primary human hepatocytes are limited, making it difficult to supply the abundant quantities required for large-scale drug toxicity screening. Therefore, there is an urgent need for a novel unlimited, efficient, inexpensive, and predictive model which can be applied for large-scale drug toxicity screening. Human embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are able to replicate indefinitely and differentiate into most of the body's cell types, including hepatocytes. It is expected that hepatocyte-like cells generated from human ES/iPS cells (human ES/iPS-HLCs) will be a useful tool for drug toxicity screening. To apply human ES/iPS-HLCs to various applications including drug toxicity screening, homogenous and functional HLCs must be differentiated from human ES/iPS cells. In this review, we will introduce the current status of hepatocyte differentiation technology from human ES/iPS cells and a novel method to predict drug-induced liver injury using human ES/iPS-HLCs. Copyright © 2016 The Japanese Society for the Study of Xenobiotics. Published by Elsevier Ltd. All rights reserved.

Acquisition of lipid metabolic capability in hepatocyte-like cells directly induced from mouse fibroblasts

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Shizuka eMiura

2014-08-01

Full Text Available Recently, the numbers of patients with non-alcoholic fatty liver disease (NAFLD and non-alcoholic steatohepatitis (NASH have increased worldwide. NAFLD and NASH are known as risk factors for liver cirrhosis and hepatocellular carcinoma. Because many factors can promote the progression of NAFLD and NASH, the treatment of these patients involves various strategies. Thus, it is desired that drugs for patients with NAFLD and NASH should be developed more easily and rapidly using cultures of primary hepatocytes. However, it is difficult to use hepatocytes as a tool for drug screening, because these cells cannot be functionally maintained in culture. Thus, in this study, we sought to examine whether induced hepatocyte-like (iHep cells, which were directly induced from mouse dermal fibroblasts by infection with a retrovirus expressing Hnf4α and Foxa3, possess the potential for lipid metabolism, similar to hepatocytes. Our data showed that iHep cells were capable of synthesizing lipids from a cis-unsaturated fatty acid, a trans-unsaturated fatty acid, and a saturated fatty acid, accumulating the synthesized lipids in cellular vesicles, and secreting the lipids into the culture medium. Moreover, the lipid synthesis in iHep cells was significantly inhibited in cultures with lipid metabolism improvers. These results demonstrate that iHep cells could be useful not only for screening of drugs for patients with NAFLD and NASH, but also for elucidation of the mechanisms underlying hereditary lipid metabolism disorders, as an alternative to hepatocytes.

Generation, characterization and potential therapeutic applications of mature and functional hepatocytes from stem cells.

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Zhang, Zhenzhen; Liu, Jianfang; Liu, Yang; Li, Zheng; Gao, Wei-Qiang; He, Zuping

2013-02-01

Liver cancer is the sixth most common tumor in the world and the majority of patients with this disease usually die within 1 year. The effective treatment for end-stage liver disease (also known as liver failure), including liver cancer or cirrhosis, is liver transplantation. However, there is a severe shortage of liver donors worldwide, which is the major handicap for the treatment of patients with liver failure. Scarcity of liver donors underscores the urgent need of using stem cell therapy to the end-stage liver disease. Notably, hepatocytes have recently been generated from hepatic and extra-hepatic stem cells. We have obtained mature and functional hepatocytes from rat hepatic stem cells. Here, we review the advancements on hepatic differentiation from various stem cells, including hepatic stem cells, embryonic stem cells, the induced pluripotent stem cells, hematopoietic stem cells, mesenchymal stem cells, and probably spermatogonial stem cells. The advantages, disadvantages, and concerns on differentiation of these stem cells into hepatic cells are highlighted. We further address the methodologies, phenotypes, and functional characterization on the differentiation of numerous stem cells into hepatic cells. Differentiation of stem cells into mature and functional hepatocytes, especially from an extra-hepatic stem cell source, would circumvent the scarcity of liver donors and human hepatocytes, and most importantly it would offer an ideal and promising source of hepatocytes for cell therapy and tissue engineering in treating liver disease. Copyright © 2012 Wiley Periodicals, Inc.

Occurrence and predictors of persistent impaired glucose tolerance after acute ischemic stroke or transient ischemic attack

OpenAIRE

Fonville, Susanne; Hertog, Heleen; Zandbergen, Adrienne; Koudstaal, Peter Jan; Lingsma, Hester

2014-01-01

textabstractBackground Impaired glucose tolerance is often present in patients with a transient ischemic attack (TIA) or ischemic stroke and doubles the risk of recurrent stroke. This impaired glucose tolerance can be transient, reflecting an acute stress response, or persistent, representing undiagnosed impaired glucose metabolism possibly requiring treatment. We aimed to assess the occurrence of persistent impaired glucose tolerance after a stroke or TIA and to develop a prediction model to...

Hepatitis B virus evasion from cGAS sensing in human hepatocytes.

Science.gov (United States)

Verrier, Eloi R; Yim, Seung-Ae; Heydmann, Laura; El Saghire, Houssein; Bach, Charlotte; Turon-Lagot, Vincent; Mailly, Laurent; Durand, Sarah C; Lucifora, Julie; Durantel, David; Pessaux, Patrick; Manel, Nicolas; Hirsch, Ivan; Zeisel, Mirjam B; Pochet, Nathalie; Schuster, Catherine; Baumert, Thomas F

2018-04-20

Chronic hepatitis B virus (HBV) infection is a major cause of chronic liver disease and cancer worldwide. The mechanisms of viral genome sensing and the evasion of innate immune responses by HBV infection are still poorly understood. Recently, the cyclic GMP-AMP synthase (cGAS) was identified as a DNA sensor. In this study, we aimed to investigate the functional role of cGAS in sensing of HBV infection and elucidate the mechanisms of viral evasion. We performed functional studies including loss- and gain-of-function experiments combined with cGAS effector gene expression profiling in an infectious cell culture model, primary human hepatocytes and HBV-infected human liver chimeric mice. Here we show that cGAS is expressed in the human liver, primary human hepatocytes and human liver chimeric mice. While naked relaxed-circular HBV DNA is sensed in a cGAS-dependent manner in hepatoma cell lines and primary human hepatocytes, host cell recognition of viral nucleic acids is abolished during HBV infection, suggesting escape from sensing, likely during packaging of the genome into the viral capsid. While the hepatocyte cGAS pathway is functionally active, as shown by reduction of viral cccDNA levels in gain-of-function studies, HBV infection suppressed cGAS expression and function in cell culture models and humanized mice. HBV exploits multiple strategies to evade sensing and antiviral activity of cGAS and its effector pathways. This article is protected by copyright. All rights reserved. © 2018 by the American Association for the Study of Liver Diseases.

Hyperinsulinemia is associated with increased soluble insulin receptors release from hepatocytes

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Marcia eHiriart

2014-06-01

Full Text Available It has been generally assumed that insulin circulates freely in blood. However it can also interact with plasma proteins. Insulin receptors are located in the membrane of target cells and consist of an alpha and beta subunits with a tyrosine kinase cytoplasmic domain. The ectodomain, called soluble insulin receptor (SIR has been found elevated in patients with diabetes mellitus. We explored if insulin binds to SIRs in circulation under physiological conditions and hypothesize that this SIR may be released by hepatocytes in response to high insulin concentrations. The presence of SIR in rat and human plasmas and the culture medium of hepatocytes was explored using Western blot analysis. A purification protocol was performed to isolated SIR using affinity, gel filtration and ion exchange chromatographies. A modified reverse hemolytic plaque assay was used to measure SIR release from cultured hepatocytes. Incubation with 1 nmol l-1 insulin induces the release of the insulin receptor ectodomains from normal rat hepatocytes. This effect can be partially prevented by blocking protease activity. Furthermore, plasma levels of SIR were higher in a model of metabolic syndrome, where rats are hyperinsulinemic. We also found increased SIR levels in hyperinsulinemic humans. SIR may be an important regulator of the amount of free insulin in circulation. In hyperinsulinemia the amount of this soluble receptor increases, this could lead to higher amounts of insulin bound to this receptor, rather than free insulin, which is the biologically active form of the hormone. This observation could enlighten the mechanisms of insulin resistance.

Hepatocytes in the development of liver support systems

NARCIS (Netherlands)

I.H.M. Borel Rinkes (Inne)

1993-01-01

textabstractThis thesis focuses on the development of alternative strategies in the treatment of patients with acute fulminant hepatic failure and inborn errors of metabolism, using hepatocytes as the basis of liver support. When compared with transplantation of the liver as an organ, the

Frequency of inter-atrial blocks in patients with ischemic stroke

International Nuclear Information System (INIS)

Manzar, A.; Iftikhar, R.; Qadir, A.

2012-01-01

Objective: To determine the frequency and association of Interatrial block in hospitalized patients with Ischemic Stroke. Study Design: A case control study. Place and Duration of Study: Department of medicine, Military Hospital, Rawalpindi from 1 January 2009 to 30 December 2009. Methodology: It included 64 patients, 32 cases of diagnosed ischemic stroke and 32 patients were taken as controls not suffering from ischemic stroke or ischemic heart disease. ECG findings of both selected groups were evaluated for presence or absence of interatrial block. Results: Out of 32 ischemic stroke patients, 14 (43.85%) were found to have interatrial block on electrocardiogram (ECG). Whereas only 6 (18.80%) controls were found to have interatrial block on ECG. Odds ratio was 1.66. Conclusion: Interatrial block is more frequent in ischemic stroke patients and may represent a risk factor for such stroke. (author)

Efficient derivation of functional hepatocytes from mouse induced pluripotent stem cells by a combination of cytokines and sodium butyrate

Institute of Scientific and Technical Information of China (English)

ZHANG Qi; YANG Yang; ZHANG Jian; WANG Guo-ying; LIU Wei; QIU Dong-bo; HEI Zi-qing; YING Qi-long; CHEN Gui-hua

2011-01-01

Background Hepatocyte transplantation has been proposed as an alternative to whole-organ transplantation to support many forms of hepatic insufficiency.Unfortunately,the lack of donor livers makes it difficult to obtain enough viable human hepatocytes for hepatocyte-based therapies.Therefore,it is urgent to find new ways to provide ample hepatocytes.Induced pluripotent stem (iPS) cells,a breakthrough in stem cell research,may terminate these hinders for cell transplantation.For the promise of iPS cells to be realized in liver diseases,it is necessary to determine if and how efficient they can be differentiated into functional hepatocytes.Methods In this study,we directly compared the hepatic-differentiation capacity of mouse iPS cells and embryonic stem (ES) cells with three different induction approaches:conditions via embryonic body (EB) formation plus cytokines,conditions by combination of dimethyl sulfoxide and sodium butyrate and chemically defined,serum free monolayer conditions.Among these three induction conditions,more homogenous populations can be promoted under chemically defined,serum free conditions.The cells generated under these conditions exhibited hepatic functions in vitro,including glycogen storage,indocynine green (ICG) uptake and release as well as urea secretion.Although efficient hepatocytes differentiation from mouse iPS cells were observed,mouse iPS cells showed relatively lower hepatic induction efficiency compared with mouse ES cells.Results Mouse iPS cells would be efficiently differentiated into functional hepatocytes in vitro,which may be helpful in facilitating the development of hepatocytes for transplantation and for research on drug discovery.Conclusion We demonstrate that mouse iPS cells retain full potential for fetal liver development and describe procedures that facilitates the efficient generation of highly differentiated human hepatocyte-like cells from iPS cells in vitro.

Rehabilitation Outcomes: Ischemic versus Hemorrhagic Strokes.

Science.gov (United States)

Perna, Robert; Temple, Jessica

2015-01-01

Background. Ischemic and hemorrhagic strokes have different pathophysiologies and possibly different long-term cerebral and functional implications. Hemorrhagic strokes expose the brain to irritating effects of blood and ischemic strokes reflect localized or diffuse cerebral vascular pathology. Methods. Participants were individuals who suffered either an ischemic (n = 172) or hemorrhagic stroke (n = 112) within the past six months and were involved in a postacute neurorehabilitation program. Participants completed three months of postacute neurorehabilitation and the Mayo Portland Adaptability Inventory-4 (MPAI-4) at admission and discharge. Admission MPAI-4 scores and level of functioning were comparable. Results. Group ANOVA comparisons show no significant group differences at admission or discharge or difference in change scores. Both groups showed considerably reduced levels of productivity/employment after discharge as compared to preinjury levels. Conclusions. Though the pathophysiology of these types of strokes is different, both ultimately result in ischemic injuries, possibly accounting for lack of findings of differences between groups. In the present study, participants in both groups experienced similar functional levels across all three MPAI-4 domains both at admission and discharge. Limitations of this study include a highly educated sample and few outcome measures.

Rehabilitation Outcomes: Ischemic versus Hemorrhagic Strokes

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Robert Perna

2015-01-01

Full Text Available Background. Ischemic and hemorrhagic strokes have different pathophysiologies and possibly different long-term cerebral and functional implications. Hemorrhagic strokes expose the brain to irritating effects of blood and ischemic strokes reflect localized or diffuse cerebral vascular pathology. Methods. Participants were individuals who suffered either an ischemic (n=172 or hemorrhagic stroke (n=112 within the past six months and were involved in a postacute neurorehabilitation program. Participants completed three months of postacute neurorehabilitation and the Mayo Portland Adaptability Inventory-4 (MPAI-4 at admission and discharge. Admission MPAI-4 scores and level of functioning were comparable. Results. Group ANOVA comparisons show no significant group differences at admission or discharge or difference in change scores. Both groups showed considerably reduced levels of productivity/employment after discharge as compared to preinjury levels. Conclusions. Though the pathophysiology of these types of strokes is different, both ultimately result in ischemic injuries, possibly accounting for lack of findings of differences between groups. In the present study, participants in both groups experienced similar functional levels across all three MPAI-4 domains both at admission and discharge. Limitations of this study include a highly educated sample and few outcome measures.

Palm kernel cake extract exerts hepatoprotective activity in heat-induced oxidative stress in chicken hepatocytes.

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Oskoueian, Ehsan; Abdullah, Norhani; Idrus, Zulkifli; Ebrahimi, Mahdi; Goh, Yong Meng; Shakeri, Majid; Oskoueian, Armin

2014-10-02

Palm kernel cake (PKC), the most abundant by-product of oil palm industry is believed to contain bioactive compounds with hepatoprotective potential. These compounds may serve as hepatoprotective agents which could help the poultry industry to alleviate adverse effects of heat stress on liver function in chickens. This study was performed to evaluate the hepatoprotective potential of PKC extract in heat-induced oxidative stress in chicken hepatocytes. The nature of the active metabolites and elucidation of the possible mechanism involved were also investigated. The PKC extract possessed free radical scavenging activity with values significantly (p < 0.05) lower than silymarin as the reference antioxidant. Heat-induced oxidative stress in chicken hepatocyte impaired the total protein, lipid peroxidation and antioxidant enzymes activity significantly (p < 0.05). Treatment of heat-induced hepatocytes with PKC extract (125 μg/ml) and silymarin as positive control increased these values significantly (p < 0.05). The real time PCR and western blot analyses revealed the significant (p < 0.05) up-regulation of oxidative stress biomarkers including TNF-like, IFN-γ and IL-1β genes; NF-κB, COX-2, iNOS and Hsp70 proteins expression upon heat stress in chicken hepatocytes. The PKC extract and silymarin were able to alleviate the expression of all of these biomarkers in heat-induced chicken hepatocytes. The gas chromatography-mass spectrometry analysis of PKC extract showed the presence of fatty acids, phenolic compounds, sugar derivatives and other organic compounds such as furfural which could be responsible for the observed hepatoprotective activity. Palm kernel cake extract could be a potential agent to protect hepatocytes function under heat induced oxidative stress.

Adenoviral-mediated correction of methylmalonyl-CoA mutase deficiency in murine fibroblasts and human hepatocytes

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Korson Mark

2007-04-01

Full Text Available Abstract Background Methylmalonic acidemia (MMA, a common organic aciduria, is caused by deficiency of the mitochondrial localized, 5'deoxyadenosylcobalamin dependent enzyme, methylmalonyl-CoA mutase (MUT. Liver transplantation in the absence of gross hepatic dysfunction provides supportive therapy and metabolic stability in severely affected patients, which invites the concept of using cell and gene delivery as future treatments for this condition. Methods To assess the effectiveness of gene delivery to restore the defective metabolism in this disorder, adenoviral correction experiments were performed using murine Mut embryonic fibroblasts and primary human methylmalonyl-CoA mutase deficient hepatocytes derived from a patient who harbored two early truncating mutations, E224X and R228X, in the MUT gene. Enzymatic and expression studies were used to assess the extent of functional correction. Results Primary hepatocytes, isolated from the native liver after removal subsequent to a combined liver-kidney transplantation procedure, or Mut murine fibroblasts were infected with a second generation recombinant adenoviral vector that expressed the murine methylmalonyl-CoA mutase as well as eGFP from distinct promoters. After transduction, [1-14C] propionate macromolecular incorporation studies and Western analysis demonstrated complete correction of the enzymatic defect in both cell types. Viral reconstitution of enzymatic expression in the human methylmalonyl-CoA mutase deficient hepatocytes exceeded that seen in fibroblasts or control hepatocytes. Conclusion These experiments provide proof of principle for viral correction in methylmalonic acidemia and suggest that hepatocyte-directed gene delivery will be an effective therapeutic treatment strategy in both murine models and in human patients. Primary hepatocytes from a liver that was unsuitable for transplantation provided an important resource for these studies.

New Treatments for Nonarteritic Anterior Ischemic Optic Neuropathy.

Science.gov (United States)

Foroozan, Rod

2017-02-01

Despite increasing knowledge about the risk factors and clinical findings of nonarteritic anterior ischemic optic neuropathy (NAION), the treatment of this optic neuropathy has remained limited and without clear evidence-based benefit. Historical treatments of NAION are reviewed, beginning with the Ischemic Optic Neuropathy Decompression Trial. More recent treatments are placed within the historical context and illustrate the need for evidence-based therapy for ischemic optic neuropathy. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of UV-B (302 nm) irradiation on isolated rat hepatocytes

International Nuclear Information System (INIS)

Lahiri, S.; Habibullah, C.M.; Ayesha, Q.; Khan, A.A.; Srinivas, V.K.; Naithani, R.

1995-01-01

The present study aimed to evaluate the effect of UV-B irradiation on the functional integrity, and the metabolic and detoxifying capacity of isolated rat hepatocytes. Isolated rat hepatocytes were irradiated in various doses (400 Jm -2 , 600 Jm -2 , 800 Jm -2 and 1000 Jm -2 ). The cells were assayed for total lactate dehydrogenase, Na + -K + -ATPase, ATPase, ornithine carbamyltransferase activity (OCT) and urea production capacity. Lactate dehydrogenase and Na + -K + -ATPase activity were significantly decreased in all four irradiated groups (P<0.001), whereas viability, OCT and urea production capacity showed no alterations. (au) 22 refs

Early MR detection of cortical and subcortical hypoxic-ischemic encephalopathy in full-term-infants

International Nuclear Information System (INIS)

Christophe, C.; Clercx, A.; Blum, D.; Hasaerts, D.; Segebarth, C.; Perlmutter, N.

1994-01-01

Four observations illustrate the potential of MR imaging in the early depiction of multiple types of neuropathologic lesions which may coexist in the full-term newborn, upon severe hypoxic-ischemic encephalopathy (HIE). In particular, diffuse, postnatal involvement of cerebral cortex and subcortical white matter (WM) is demonstrated. Cortical hyperintensity on both proton-density- and T1-weighted images is probably related to cellular necrosis which is distributed diffusely or parasigattally. Hyperintense, frontal, subcortical WM edging on proton-density-weighted images results from the increase of water concentration, induced either by infract or by edema. Diffuse WM areas of low intensity on T1-weighted images and of high intensity on T2-weighted images are presumably related to cytotoxic and/or vasogenic edema, proportional to the underlying damaged tissues. On follow-up MR examinations, several months later, the importance of cortical atrophy and of the myelination delay appeared related to the importance of the lesions detected during the post-natal period. (orig.)

Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

Science.gov (United States)

Mohammad, Mohammad K; Avila, Diana; Zhang, Jingwen; Barve, Shirish; Arteel, Gavin; McClain, Craig; Joshi-Barve, Swati

2012-01-01

Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentrations, caused a dose-dependent loss of viability of hepatocytes. The death was apoptotic at moderate and necrotic at high concentrations of acrolein. Acrolein exposure rapidly and dramatically decreased intracellular glutathione and overall antioxidant capacity, and activated the stress-signaling MAP-kinases JNK, p42/44 and p38. Our data demonstrate for the first time in human hepatocytes, that acrolein triggered endoplasmic reticulum (ER) stress and activated eIF2α, ATF-3 and -4, and Gadd153/CHOP, resulting in cell death. Notably, the protective/adaptive component of ER stress was not activated, and acrolein failed to up-regulate the protective ER-chaperones, GRP78 and GRP94. Additionally, exposure to acrolein disrupted mitochondrial integrity/function, and led to the release of pro-apoptotic proteins and ATP depletion. Acrolein-induced cell death was attenuated by N-acetyl cysteine, phenyl-butyric acid, and caspase and JNK inhibitors. Our data demonstrate that exposure to acrolein induces a variety of stress responses in hepatocytes, including GSH depletion, oxidative stress, mitochondrial dysfunction and ER stress (without ER-protective responses) which together contribute to acrolein toxicity. Our study defines basic mechanisms underlying liver injury caused by reactive aldehyde pollutants such as acrolein. PMID:23026831

25-Hydroxyvitamin D and symptomatic ischemic stroke

DEFF Research Database (Denmark)

Brøndum-Jacobsen, Peter; Nordestgaard, Børge G; Schnohr, Peter

2013-01-01

City Heart Study. During 21 years of follow-up, 1,256 and 164 persons developed ischemic and hemorrhagic stroke, respectively. In a meta-analysis of ischemic stroke, we included 10 studies, 58,384 participants, and 2,644 events. RESULTS: Stepwise decreasing plasma 25-hydroxyvitamin D concentrations...

Clinical value of hemoglobin and its association with hepatocyte steatosis in chronic hepatitis B patients

Directory of Open Access Journals (Sweden)

WANG Peng

2017-07-01

Full Text Available :ObjectiveTo investigate the clinical value of hemoglobin and its association with hepatocyte steatosis in chronic hepatitis B (CHB patients. MethodsA retrospective analysis was performed for the clinical and pathological data of 1580 CHB patients who were hospitalized in The First People′s Hospital of Shunde from January 2006 to December 2014 and underwent liver biopsy, among whom 216 (13.67% had hepatocyte steatosis (hepatocyte steatosis group and 1364 had no hepatocyte steatosis (non-hepatocyte steatosis group. The patients were divided into groups 1, 2, and 3 according to hemoglobin level, and the clinical and pathological features were analyzed and compared between the three groups. The t-test was used for comparison of continuous data between group; a one-way analysis of variance was used for comparision between multiple groups. The Mann-Whitney U test was used for ranked data between groups. The Kruskal-wallis H test was used for ranked data between multiple groups; the chi-square test was used for comparison of categorical data between groups. Spearman correlation analysis was also performed to determine the correlation between two variables. Univariate logistic regression analysis and multivariate stepwise regression analysis were used to identify the influencing factors for hepatocyte steatosis. ResultsBody mass index (BMI, systolic pressure, diastolic pressure, uric acid, total cholesterol, low-density lipoprotein, and HBV DNA load increased with the increase in hemoglobin level (F=12718,3024,4026,4624,38276,28108,7358, all P＜0.05. The incidence rates of hepatocyte steatosis in groups 1, 2, and 3 were 7.59%, 1176%,and 21.67%, respectively (χ2=44.23, P＜0.05. Hemoglobin was positively correlated with hepatic steatosis (rs=0.211, P＜0001. The multivariate logistic regression analysis showed that hemoglobin (odds ratio ［OR］=1.066, P＜0.05, BMI (OR=1576, P＜005, age (OR=1.041, P＜0.05, sex

Glycogen content in hepatocytes is related with their size in normal rat liver but not in cirrhotic one.

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Bezborodkina, Natalia N; Chestnova, Anna Yu; Vorobev, Mikhail L; Kudryavtsev, Boris N

2016-04-01

Hepatocytes differ from one another by the degree of the ploidy, size, position in the liver lobule, and level of the DNA-synthetic processes. It is believed, that the cell size exerts substantial influence on the metabolism of the hepatocytes and the glycogen content in them. The aim of the present study was to test this hypothesis. Dry weight of hepatocytes, their ploidy and glycogen content were determined in the normal and the cirrhotic rat liver. Liver cirrhosis in rats was produced by chronic inhalation of CCl4 vapours in the course of 6 months. A combined cytophotometric method was used. Dry weight of the cell, its glycogen and DNA content were successively measured on a mapped preparation. Hepatocytes of each ploidy class in the normal and the cirrhotic rat liver accumulated glycogen at the same rate. In the normal liver, there was a distinct correlation between the size of hepatocytes and glycogen content in them. This correlation was observed in each ploidy class, and was especially pronounced in the class of mononucleate tetraploid hepatocytes. In the cirrhotic liver, there was no correlation between the size of the cells and their glycogen content. The impairment of liver lobular structure probably explains the observed lack of correlation between hepatocyte size and their glycogen content in the cirrhotic liver. © 2016 International Society for Advancement of Cytometry. © 2016 International Society for Advancement of Cytometry.

Interleukin 6 regulates metallothionein gene expression and zinc metabolism in hepatocyte monolayer cultures

International Nuclear Information System (INIS)

Schroeder, J.J.; Cousins, R.J.

1990-01-01

Attention has focused on the cytokine interleukin 6 (IL-6) as a major mediator of acute-phase protein synthesis in hepatocytes in response to infection and tissue injury. The authors have evaluated the effects of IL-6 and IL-1α as well as extracellular zinc and glucocorticoid hormone on metal-lothionein gene expression and cellular zinc accumulation in rat hepatocyte monolayer cultures. Further, they have evaluated the teleological basis for cytokine mediation by examining cyto-protection from CCl 4 -induced damage. Incubation of hepatocytes with IL-6 led to concentration-dependent and time-dependent increases in metallothionein-1 and -2 mRNA and metallothionein protein. The level of each was increased within 3 hr after the addition of IL-6 at 10 ng/ml. Maximal increases the metallothionein mRNA and metallothionein protein were achieved after 12 hr and 36 hr, respectively. Concomitant with the up-regulation of metallothionein gene expression, IL-6 also increased cellular zinc. Responses to IL-6 required the synthetic glucocorticoid hormone dexamethasone and were optimized by increased extracellular zinc. Thus, IL-6 is a major cytokine mediator of metallothionein gene expression and zinc metabolism in hepatocytes and provides cytoprotection from CCl 4 -induced hepatotoxicity via a mode consistent with dependence upon increased cellular metallothionein synthesis and zinc accumulation

[Primary emergencies: management of acute ischemic stroke].

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Leys, Didier; Goldstein, Patrick

2012-01-01

The emergency diagnostic strategy for acute ischemic stroke consists of:--identification of stroke, based on clinical examination (sudden onset of a focal neurological deficit);--identification of the ischemic or hemorrhagic nature by MRI or CT;--determination of the early time-course (clinical examination) and the cause. In all strokes (ischemic or hemorrhagic), treatment consists of:--the same general management (treatment of a life-threatening emergency, ensuring normal biological parameters except for blood pressure, and prevention of complications);--decompressive surgery in the rare cases of intracranial hypertension. For proven ischemic stroke, other therapies consist of: rt-PA for patients admitted with 4.5 hours of stroke onset who have no contraindications, and aspirin (160 to 300 mg) for patients who are not eligible for rt-PA. These treatments should be administered within a few hours. A centralized emergency call system (phone number 15 in France) is the most effective way of achieving this objective.

Paraneoplastic Ischemic Stroke: Case Report and Review

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Murat Sumer

2008-10-01

Full Text Available OBJECTIVE: Paraneoplastic etiology is not frequent among cerebrovascular disorders. This rare disorder is interesting with different mechanisms, clinical manifestations and treatment options. Diagnosis may be overlooked for its rarity. We present a paraneoplastic ischemic stroke patient with its clinical and imaging characteristics for recalling this rare disease. CASE: A sixty years old woman with a history of ovarian and colon cancer and liver metastasis admitted with acute left sided hemiplegia. Brain magnetic resonance imaging showed multiple ischemic lesions at the same age. Laboratory findings were compatible with chronic disseminated intravascular coagulopathy. She was anticoagulated but the clinical findings were not changed. She died one month after her discharge from the hospital. CONCLUSIONS: Paraneoplastic ischemic stroke is rare and it should be recognized by the clinician to differentiate from other ischemic strokes by its different mechanisms, imaging characteristics and treatment modalities. Prognosis depends on the characteristics of the primary tumor

Relationship between hypertensive cerebral hemorrhage and ischemic lesions

International Nuclear Information System (INIS)

Yamaguchi, Shinya; Tsuchiya, Takashi; Yamaguchi, Takenori

1991-01-01

Patchy parenchymal lesions of increased intensity were frequently identified in patients with cerebral hemorrhage in T2-weighted image of high-fields MR imaging. We studied 64 patients with brain hemorrhage to determine the frequency and distribution of those lesions. We defined an area with high intensity in T2 weighted and low or iso-intensity area in T1 weighted images smaller than 1.5 cm in diameter to be 'ischemic lesion'. Ishemic lesions were found in 48 (75%) of all cases; in 25 (75%) of 32 patients with putaminal hemorrhage, in 15 (100%) of 15 with thalamic hemorrhage, in 3 (33%) of 9 with subcortical hemorrhage. Multiple ischemic lesions were more frequently seen in thalamic hemorrhage than in putaminal hemorrhage. Only 5 (10%) of 48 cases with associated ischemic lesions had a previous history related to those lesions. Multivariable regression analysis identified hypertension as the major predictor of the presence of ischemic lesions. Patients with brain hemorrhage frequently accompanied with incidental ischemic lesions, making it difficult to establish a guideline of blood pressure control for prevention of recurrent stroke. (author)

Indomethacin induced avascular necrosis of head of femur

Science.gov (United States)

Prathapkumar, K; Smith, I; Attara, G

2000-01-01

Chemically induced avascular necrosis of bone is a well documented entity. Indomethacin is one of the causes of this condition but is often difficult to recognise. Review of the literature shows that only one case of indomethacin induced avascular necrosis has been reported in the English language between 1966 and the present.
The case of a young healthy man, who developed avascular necrosis of head of femur after prolonged administration of indomethacin, is reported here.


Keywords: indomethacin; avascular necrosis PMID:10964124

CT findings in isolated ischemic proctosigmoiditis

International Nuclear Information System (INIS)

Wiesner, Walter; Mortele, Koenraad J.; Ji, Hoon; Khurana, Bharti; Ros, Pablo R.; Glickman, Jonathan N.

2002-01-01

The purpose of our study was to describe the CT features of ischemic proctosigmoiditis in correlation with clinical, laboratory, endoscopic, and histopathologic findings. Our study included seven patients with isolated ischemic proctosigmoiditis. Patients were identified by a retrospective review of all histopathologic records of colonoscopic biopsies performed during a time period of 4 years. All patients presented with left lower abdominal quadrant pain, bloody stools, and leukocytosis, and four patients had fever at the time of presentation. Four of seven patients suffered from diarrhea, one of seven was constipated and two of seven had normal stool consistency. The CT examinations were reviewed by two authors by consensus and compared with clinical and histopathologic results as well as with the initial CT diagnosis. The CT showed a wall thickening confined to the rectum and sigmoid colon in seven of seven patients, stranding of the pararectal fat in four of seven, and stranding of the perisigmoidal fat in one of seven patients. There were no enlarged lymph nodes, but five of seven patients showed coexistent diverticulosis and in three of these patients CT findings were initially misinterpreted as sigmoid diverticulitis. Endoscopies and histopathologic analyses of endoscopic biopsies confirmed non-transmural ischemic proctosigmoiditis in all patients. Isolated ischemic proctosigmoiditis often presents with unspecific CT features and potentially misleading clinical and laboratory findings. In an elderly patient or a patient with known cardiovascular risk factors the diagnosis of ischemic proctosigmoiditis should be considered when wall thickening confined to the rectum and sigmoid colon is seen that is associated with perirectal fat stranding. (orig.)

Insulin internalization in isolated rat hepatocytes

International Nuclear Information System (INIS)

Galan, J.; Trankina, M.; Noel, R.; Ward, W.

1990-01-01

This project was designed to determine whether neomycin, an aminoglycoside antibiotic, has a significant effect upon the pathways of ligand endocytosis in isolated rat hepatocytes. The pathways studied include receptor-mediated endocytosis and fluid-phase endocytosis. Neomycin causes a dose-dependent acceleration of 125 I-insulin internalization. Since fluid-phase endocytosis can also be a significant factor in 125 I-insulin internalization, lucifer yellow (LY), a marker for fluid-phase endocytosis, was incorporated into an assay similar to the 125 I-insulin internalization procedure. In the presence of 5 mM neomycin, a significant increase in LY uptake was evident at 0.2 and 0.4 mg/ml of LY. At 0.8 mg/ml, a decrease in LY uptake was observed. The increased rate of 125 I-insulin internalization in the presence of neomycin was intriguing. Since one action of neomycin is to inhibit phosphoinositidase C, it suggests that the phosphotidylinositol cycle may be involved in ligand internalization by hepatocytes. At low insulin concentrations, receptor-mediated uptake predominates. Fluid-phase uptake can become an important uptake route as insulin concentrations are increased. Since neomycin stimulates fluid-phase endocytosis, it must also be taken into account when measuring ligand internalization

Relationship between vascular dysfunction in peripheral arteries and ischemic episodes during daily life in patients with ischemic heart disease and hypercholesterolemia

DEFF Research Database (Denmark)

Søndergaard, Eva; Møller, Jacob E; Egstrup, Kenneth

2002-01-01

cardiovascular risk factors. CONCLUSIONS: These results indicate a significant relationship between ischemic episodes and vascular dysfunction in patients with ischemic heart disease and hypercholesterolemia and may justify an aggressive preventive therapy targeted directly at the endothelium.......BACKGROUND: It is well established that endothelial dysfunction is present in patients with ischemic heart disease and hypercholesterolemia. Some of these patients will have signs of transient myocardial ischemia during Holter monitoring. We sought to describe the correlation between daily life...... ischemia and signs of endothelial dysfunction as assessed by means of brachial vasoreactivity. METHODS: We included in the study 131 patients with documented ischemic heart disease and a serum cholesterol level of > or =5 mmol/L before the institution of lipid-lowering treatment and dietary intervention...

Health behavior of patients with ischemic heart disease

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Paweł Węgorowski

2017-06-01

Full Text Available Admission By analyzing the available scientific literature, it is possible to define ischemic heart disease as a set of disease symptoms that are a consequence of a chronic state of imbalance between the ability to supply nutrients and oxygen and the real need of myocardial cells for these substances. Adapting life-style behaviors to healthy living is a priority to prevent the onset and development of cardiovascular disease, especially ischemic heart disease, Purpose of research The aim of the study is to determine the health behavior of patients with ischemic heart disease. Materials and methods The study was conducted from 01.08.2015 to 28.12.2015 in a group of 35 people (15 women and 20 men. The research method used in the work is a diagnostic survey, the research technique used was a survey of its own author. Conclusions By analyzing the data collected, it is important to note that patients with coronary heart disease are often associated with health problems such as hypertension, diabetes and abnormal weight. The nutritional habits of the subjects studied can be described as abnormal, particularly the excessive intake of oily meat and too little fish intake. It has also been observed that most of the patients studied have familial predisposition to ischemic heart disease. Discussion Heart attacks occur mostly in people with obesity, diabetes and atherosclerosis. It is also closely related to ischemic heart disease. The health behaviors of patients suffering from Ischemic Heart Disease are moderately satisfactory and therefore the role of a nurse practitioner as a health educator is very difficult but essential in the prevention of ischemic heart disease.

Advances in endovascular therapy for ischemic cerebrovascular diseases

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Jun Lu

2016-09-01

Full Text Available Endovascular therapy for ischemic cerebrovascular diseases has developed rapidly in recent years. The latest clinical trials of acute ischemic stroke have shown promising results with the continued advancement of concepts, techniques, and materials. Mechanical thrombectomy is recommended in the treatment of acute ischemic stroke caused by large vessel occlusion of the anterior circulation, according to the guidelines updated in Europe, USA, and China. The long-term therapeutic efficacy of endovascular stenting for carotid artery stenosis has also been proved noninferior to that of carotid endarterectomy. However, the latest clinical trials have shown that the efficacy of stenting for intracranial artery and vertebral artery stenosis is inferior to that of medical treatment alone, which needs urgent attention through further development and studies. Keywords: Ischemic cerebrovascular diseases, Interventional surgery, Progress

Changes of resting cerebral activities in subacute ischemic stroke patients

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Ping Wu

2015-01-01

Full Text Available This study aimed to detect the difference in resting cerebral activities between ischemic stroke patients and healthy participants, define the abnormal site, and provide new evidence for pathological mechanisms, clinical diagnosis, prognosis prediction and efficacy evaluation of ischemic stroke. At present, the majority of functional magnetic resonance imaging studies focus on the motor dysfunction and the acute stage of ischemic stroke. This study recruited 15 right-handed ischemic stroke patients at subacute stage (15 days to 11.5 weeks and 15 age-matched healthy participants. A resting-state functional magnetic resonance imaging scan was performed on each subject to detect cerebral activity. Regional homogeneity analysis was used to investigate the difference in cerebral activities between ischemic stroke patients and healthy participants. The results showed that the ischemic stroke patients had lower regional homogeneity in anterior cingulate and left cerebrum and higher regional homogeneity in cerebellum, left precuneus and left frontal lobe, compared with healthy participants. The experimental findings demonstrate that the areas in which regional homogeneity was different between ischemic stroke patients and healthy participants are in the cerebellum, left precuneus, left triangle inferior frontal gyrus, left inferior temporal gyrus and anterior cingulate. These locations, related to the motor, sensory and emotion areas, are likely potential targets for the neural regeneration of subacute ischemic stroke patients.

Fermented Chinese formula Shuan-Tong-Ling attenuates ischemic stroke by inhibiting inflammation and apoptosis

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Zhi-gang Mei

2017-01-01

Full Text Available The fermented Chinese formula Shuan-Tong-Ling is composed of radix puerariae (Gegen, salvia miltiorrhiza (Danshen, radix curcuma (Jianghuang, hawthorn (Shanzha, salvia chinensis (Shijianchuan, sinapis alba (Baijiezi, astragalus (Huangqi, panax japonicas (Zhujieshen, atractylodes macrocephala koidz (Baizhu, radix paeoniae alba (Baishao, bupleurum (Chaihu, chrysanthemum (Juhua, rhizoma cyperi (Xiangfu and gastrodin (Tianma, whose aqueous extract was fermented with lactobacillus, bacillus aceticus and saccharomycetes. Shuan-Tong-Ling is a formula used to treat brain diseases including ischemic stroke, migraine, and vascular dementia. Shuan-Tong-Ling attenuated H2O2-induced oxidative stress in rat microvascular endothelial cells. However, the potential mechanism involved in these effects is poorly understood. Rats were intragastrically treated with 5.7 or 17.2 mL/kg Shuan-Tong-Ling for 7 days before middle cerebral artery occlusion was induced. The results indicated Shuan-Tong-Ling had a cerebral protective effect by reducing infarct volume and increasing neurological scores. Shuan-Tong-Ling also decreased tumor necrosis factor-α and interleukin-1β levels in the hippocampus on the ischemic side. In addition, Shuan-Tong-Ling upregulated the expression of SIRT1 and Bcl-2 and downregulated the expression of acetylated-protein 53 and Bax. Injection of 5 mg/kg silent information regulator 1 (SIRT1 inhibitor EX527 into the subarachnoid space once every 2 days, four times, reversed the above changes. These results demonstrate that Shuan-Tong-Ling might benefit cerebral ischemia/reperfusion injury by reducing inflammation and apoptosis through activation of the SIRT1 signaling pathway.

Development of delayed radiation necrosis

International Nuclear Information System (INIS)

Ohara, ShigFeki; Takagi, Terumasa; Shibata, Taichiro; Nagai, Hajime.

1983-01-01

The authors discussed the developing process of delayed radiation necrosis of the brain from the case of a 42-year-old female who developed intracranial hypertension and left hemiparesis 5 and a half years after radiotherapy for pituitary adenoma. The initial sign of radiation necrosis was from a CT scan taken 3 and a half years after radiotherapy showing an irregular low density lesion in the right temporal lobe. CT scan 2 years later demonstrated displacement of the midline structures to the left and a larger low density lesion with partially high density in the right MCA territory that was enhanced with intravenous contrast medium. Recovery after a right temporal lobectomy and administration of steroid hormone were uneventful. Eight months later there were no signs of raised intracranial pressure nor of neurological deficits. Tissues obtained from the right temporal lobe at lobectomy revealed the characteristic changes of delayed radiation necrosis; a mixture of fresh, recent, and old vascular lesions in the same specimen. From these findings, it was speculated that delayed radiation necrosis might initially occur within several years after radiotherapy and might gradually take a progressive and extended course, even in cases whose clinical symptoms develop much later. (author)

Intralipid minimizes hepatocytes injury after anoxia-reoxygenation in an ex vivo rat liver model.

Science.gov (United States)

Stadler, Michaela; Nuyens, Vincent; Boogaerts, Jean G

2007-01-01

Ischemia-reperfusion injury is a determinant in liver injury occurring during surgical procedures, ischemic states, and multiple organ failure. The pre-existing nutritional status of the liver, i.e., fasting, might contribute to the extent of tissue injury. This study investigated whether Intralipid, a solution containing soybean oil, egg phospholipids, and glycerol, could protect ex vivo perfused livers of fasting rats from anoxia-reoxygenation injury. The portal vein was cannulated, and the liver was removed and perfused in a closed ex vivo system. Isolated livers were perfused with glucose 5.5 and 15 mM, and two different concentrations of Intralipid, i.e., 0.5:100 and 1:100 (v/v) Intralipid 10%:medium (n = 5 in each group). The experiment consisted of perfusion for 15 min, warm anoxia for 60 min, and reoxygenation during 60 min. Hepatic enzymes, potassium, glucose, lactate, bilirubin, dienes, trienes, and cytochrome-c were analyzed in perfusate samples. The proportion of glycogen in hepatocytes was determined in biopsies. Intralipid attenuated transaminases, lactate dehydrogenase, potassium, diene, and triene release in the perfusate (dose-dependant) during the reoxygenation phase when compared with glucose-treated groups. The concentration of cytochrome-c in the medium was the highest in the 5.5-mM glucose group. The glycogen content was low in all livers at the start of the experiment. Intralipid presents, under the present experimental conditions, a better protective effect than glucose in anoxia-reoxygenation injury of the rat liver.

Proteomic Characterization of Primary Mouse Hepatocytes in Collagen Monolayer and Sandwich Culture.

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Orsini, Malina; Sperber, Saskia; Noor, Fozia; Hoffmann, Esther; Weber, Susanne N; Hall, Rabea A; Lammert, Frank; Heinzle, Elmar

2018-01-01

Dedifferentiation of primary hepatocytes in vitro makes their application in long-term studies difficult. Embedding hepatocytes in a sandwich of extracellular matrix is reported to delay the dedifferentiation process to some extent. In this study, we compared the intracellular proteome of primary mouse hepatocytes (PMH) in conventional monolayer cultures (ML) to collagen sandwich culture (SW) after 1 day and 5 days of cultivation. Quantitative proteome analysis of PMH showed no differences between collagen SW and ML cultures after 1 day. Glycolysis and gluconeogenesis were strongly affected by long-term cultivation in both ML and SW cultures. Interestingly, culture conditions had no effect on cellular lipid metabolism. After 5 days, PMH in collagen SW and ML cultures exhibit characteristic indications of oxidative stress. However, in the SW culture the defense system against oxidative stress is significantly up-regulated to deal with this, whereas in the ML culture a down-regulation of these important enzymes takes place. Regarding the multiple effects of ROS and oxidative stress in cells, we conclude that the down-regulation of these enzymes seem to play a role in the loss of hepatic function observed in the ML cultivation. In addition, enzymes of the urea cycle were clearly down-regulated in ML culture. Proteomics confirms lack in oxidative stress defense mechanisms as the major characteristic of hepatocytes in monolayer cultures compared to sandwich cultures. J. Cell. Biochem. 119: 447-454, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Changes in Expression of Connexin 32, Bile Canaliculus-Like Structures, and Localization of Alkaline Phosphatase in Primary Cultures of Fetal Rat Hepatocytes

International Nuclear Information System (INIS)

Fukazawa, Shoko; Chida, Kohsuke; Taguchi, Meiko; Takeuchi, Akihiro; Ikeda, Noriaki

2013-01-01

We devised an experimental design in primary cultures of fetal rat hepatocytes for studying hepatocyte differentiation over a short period. In the present study, hepatocytes were first cultured for 3 days in dexamethasone-supplemented medium and then for an additional 3 days in dexamethasone- or epidermal growth factor-supplemented medium. In hepatocytes cultured continuously in dexamethasone-supplemented medium, the expression of connexin 32 increased and bile canaliculus-like structures and localization of alkaline phosphatase in the plasma membrane around bile canaliculus-like structures were maintained. Few cells incorporated bromodeoxyuridine. On the other hand, in most of the hepatocytes cultured in epidermal growth factor-supplemented medium, the expression of connexin 32 was minimally recognized, bile canaliculus-like structures were shortened or eliminated, and alkaline phosphatase was localized as numerous fine spots throughout the cytoplasm. More than 20% of all hepatocytes incorporated bromodeoxyuridine. The present study suggests that in hepatocytes, there is a close relationship among connexin 32 expression, the maintenance of bile canaliculus-like structures, and the localization of alkaline phosphatase to the plasma membrane around the bile canaliculus-like structures, and this indicates that the present experimental model is useful for studying hepatocyte differentiation over a short period

Adropin induction of lipoprotein lipase expression in tilapia hepatocytes.

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Lian, Anji; Wu, Keqiang; Liu, Tianqiang; Jiang, Nan; Jiang, Quan

2016-01-01

The peptide hormone adropin plays a role in energy homeostasis. However, biological actions of adropin in non-mammalian species are still lacking. Using tilapia as a model, we examined the role of adropin in lipoprotein lipase (LPL) regulation in hepatocytes. To this end, the structural identity of tilapia adropin was established by 5'/3'-rapid amplification of cDNA ends (RACE). The transcripts of tilapia adropin were ubiquitously expressed in various tissues with the highest levels in the liver and hypothalamus. The prolonged fasting could elevate tilapia hepatic adropin gene expression, whereas no effect of fasting was observed on hypothalamic adropin gene levels. In primary cultures of tilapia hepatocytes, synthetic adropin was effective in stimulating LPL release, cellular LPL content, and total LPL production. The increase in LPL production also occurred with parallel rises in LPL gene levels. In parallel experiments, adropin could elevate cAMP production and up-regulate protein kinase A (PKA) and PKC activities. Using a pharmacological approach, cAMP/PKA and PLC/inositol trisphosphate (IP3)/PKC cascades were shown to be involved in adropin-stimulated LPL gene expression. Parallel inhibition of p38MAPK and Erk1/2, however, were not effective in these regards. Our findings provide, for the first time, evidence that adropin could stimulate LPL gene expression via direct actions in tilapia hepatocytes through the activation of multiple signaling mechanisms. © 2016 Society for Endocrinology.

Differentiation of human umbilical cord mesenchymal stromal cells into low immunogenic hepatocyte-like cells.

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Zhao, Qinjun; Ren, Hongying; Li, Xiyuan; Chen, Zhong; Zhang, Xiangyu; Gong, Wei; Liu, Yongjun; Pang, Tianxiang; Han, Zhong Chao

2009-01-01

Mesenchymal stromal cells (MSC) isolated from several human tissues have been known to differentiate into the hepatic lineage in vitro, but the immunogenicity of the differentiated hepatocyte-like cells (DHC) has not been reported. Umbilical cord (UC) MSC are thought to be an attractive cell source for cell therapy because of their young age and low infection rate compared with adult tissue MSC. Hepatic differentiation of UC-MSC was induced with a 2-step protocol. The expressions of hepatic markers were detected by RT-PCR and immunofluorescence staining. Albumin production and urea secretion were measured by ELISA and colorimetric assay respectively. The immunosuppressive properties of DHC was detected by mixed lymphocyte culture. After incubation with specific growth factors, including hepatocyte growth factor (HGF) and basic fibroblast growth factor (bFGF), UC MSC exhibited a high hepatic differentiation ability in an adherent culture condition. The differentiated UC MSC showed hepatocyte-like morphology and expressed several liver-specific markers at gene and protein levels. Furthermore, the DHC exhibited hepatocyte-specific functions, including albumin secretion, low-density lipoprotein uptake and urea production. More importantly, DHC did not express major histocompatibility complex (MHC) II antigen and were not able to induce lymphocyte proliferation in mixed lymphocyte culture, as undifferentiated UC MSC did. Our results indicate that UC MSC are able to differentiate into functional hepatocyte-like cells that still retain their low immunogenicity in vitro. More importantly, DHC incorporated into the parenchyma of liver when transplanted into mice with CCl(4)-induced liver injury. Therefore, DHC may be an ideal source for cell therapy of liver diseases.

Impaired mitochondrial functions contribute to 3-bromopyruvate toxicity in primary rat and mouse hepatocytes.

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Sobotka, Ondřej; Endlicher, René; Drahota, Zdeněk; Kučera, Otto; Rychtrmoc, David; Raad, Marjan; Hakeem, Khurum; Červinková, Zuzana

2016-08-01

A compound with promising anticancer properties, 3-bromopyruvate (3-BP) is a synthetic derivative of a pyruvate molecule; however, its toxicity in non-malignant cells has not yet been fully elucidated. Therefore, we elected to study the effects of 3-BP on primary hepatocytes in monolayer cultures, permeabilized hepatocytes and isolated mitochondria. After a 1-h treatment with 100 μM 3-BP cell viability of rat hepatocytes was decreased by 30 % as measured by the WST-1 test (p < 0.001); after 3-h exposure to ≥200 μM 3-BP lactate dehydrogenase leakage was increased (p < 0.001). Reactive oxygen species production was increased in the cell cultures after a 1-h treatment at concentrations ≥100 μmol/l (p < 0.01), and caspase 3 activity was increased after a 20-h incubation with 150 μM and 200 μM 3-BP (p < 0.001). This toxic effect of 3-BP was also proved using primary mouse hepatocytes. In isolated mitochondria, 3-BP induced a dose- and time-dependent decrease of mitochondrial membrane potential during a 10-min incubation both with Complex I substrates glutamate + malate or Complex II substrate succinate, although this decrease was more pronounced with the latter. We also measured the effect of 3-BP on respiration of isolated mitochondria. ADP-activated respiration was inhibited by 20 μM 3-BP within 10 min. Similar effects were also found in permeabilized hepatocytes of both species.

Insulin-like growth factor-II receptors in cultured rat hepatocytes: regulation by cell density

International Nuclear Information System (INIS)

Scott, C.D.; Baxter, R.C.

1987-01-01

Insulin-like growth factor-II (IGF-II) receptors in primary cultures of adult rat hepatocytes were characterized and their regulation by cell density examined. In hepatocytes cultured at 5 X 10(5) cells per 3.8 cm2 plate [ 125 I]IGF-II bound to specific, high affinity receptors (Ka = 4.4 +/- 0.5 X 10(9) l/mol). Less than 1% cross-reactivity by IGF-I and no cross-reactivity by insulin were observed. IGF-II binding increased when cells were permeabilized with 0.01% digitonin, suggesting the presence of an intracellular receptor pool. Determined by Scatchard analysis and by polyacrylamide gel electrophoresis after affinity labeling, the higher binding was due solely to an increase in binding sites present on 220 kDa type II IGF receptors. In hepatocytes cultured at low densities, the number of cell surface receptors increased markedly, from 10-20,000 receptors per cell at a culture density of 6 X 10(5) cells/well to 70-80,000 receptors per cell at 0.38 X 10(5) cells/well. The increase was not due simply to the exposure of receptors from the intracellular pool, as a density-related increase in receptors was also seen in cells permeabilized with digitonin. There was no evidence that IGF binding proteins, either secreted by hepatocytes or present in fetal calf serum, had any effect on the measurement of receptor concentration or affinity. We conclude that rat hepatocytes in primary culture contain specific IGF-II receptors and that both cell surface and intracellular receptors are regulated by cell density

Differentiation of hepatocytes from induced pluripotent stem cells derived from human hair follicle mesenchymal stem cells.

Science.gov (United States)

Shi, Xu; Lv, Shuang; He, Xia; Liu, Xiaomei; Sun, Meiyu; Li, Meiying; Chi, Guangfan; Li, Yulin

2016-10-01

Due to the limitations of organ donors and immune rejection in severe liver diseases, stem cell-based therapy presents a promising application for tissue repair and regeneration. As a novel cell source, mesenchymal stem cells separated from human hair follicles (HF-MSCs) are convenient to obtain and have no age limit. To date, the differentiation of HF-MSCs into hepatocytes has not been reported. In this study, we explored whether HF-MSCs and HF-MSC-derived-induced pluripotent stem cells (HF-iPS) could differentiate into hepatocytes in vitro. Flow cytometry, Oil Red O stain and Alizarin Red stain were used to identify the characteristics of HF-MSCs. The expression of liver-specific gene was detected by immunofluorescence and Quantitative Polymerase Chain Reaction. Periodic Acid-Schiff stain, Indocyanine Green stain and Low-Density Lipoprotein stain were performed to evaluate the functions of induced hepatocyte-like cells (HLCs). HF-MSCs were unable to differentiate into HLCs using previously reported procedures for MSCs from other tissues. However, HF-iPS efficiently induced the generation of HLCs that expressed hepatocyte markers and drug metabolism-related genes. HF-iPS can be used as novel and alternative cellular tools for inducing hepatocytes in vitro, simultaneously benefiting from utilizing HF-MSCs as a noninvasive and convenient cell source for reprogramming.

Titanium Dioxide Nanoparticles Trigger Loss of Function and Perturbation of Mitochondrial Dynamics in Primary Hepatocytes.

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Vaishaali Natarajan

Full Text Available Titanium dioxide (TiO2 nanoparticles are one of the most highly manufactured and employed nanomaterials in the world with applications in copious industrial and consumer products. The liver is a major accumulation site for many nanoparticles, including TiO2, directly through intentional exposure or indirectly through unintentional ingestion via water, food or animals and increased environmental contamination. Growing concerns over the current usage of TiO2 coupled with the lack of mechanistic understanding of its potential health risk is the motivation for this study. Here we determined the toxic effect of three different TiO2 nanoparticles (commercially available rutile, anatase and P25 on primary rat hepatocytes. Specifically, we evaluated events related to hepatocyte functions and mitochondrial dynamics: (1 urea and albumin synthesis using colorimetric and ELISA assays, respectively; (2 redox signaling mechanisms by measuring reactive oxygen species (ROS production, manganese superoxide dismutase (MnSOD activity and mitochondrial membrane potential (MMP; (3 OPA1 and Mfn-1 expression that mediates the mitochondrial dynamics by PCR; and (4 mitochondrial morphology by MitoTracker Green FM staining. All three TiO2 nanoparticles induced a significant loss (p < 0.05 in hepatocyte functions even at concentrations as low as 50 ppm with commercially used P25 causing maximum damage. TiO2 nanoparticles induced a strong oxidative stress in primary hepatocytes. TiO2 nanoparticles exposure also resulted in morphological changes in mitochondria and substantial loss in the fusion process, thus impairing the mitochondrial dynamics. Although this study demonstrated that TiO2 nanoparticles exposure resulted in substantial damage to primary hepatocytes, more in vitro and in vivo studies are required to determine the complete toxicological mechanism in primary hepatocytes and subsequently liver function.

Metabolism of six CYP probe substrates in fetal hepatocytes

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Abdul Naveed Shaik

2016-06-01

Full Text Available Cytochrome P-450 (CYP are the most common drug metabolizing enzymes and are abundantly expressed in liver apart from kidney, lungs, intestine, brain etc. Their expression levels change with physiological conditions and disease states. The expression of these CYPs is less in human foetus and neonates compared to adults, which results in lower clearance of xenobiotics in infants and neonates compared to adults. Hepatocytes are the cells which are largely used to study these CYPs. We have isolated hepatocytes from aborted foetus to study the metabolism of six probe substrates: phenacetin, diclofenac, S-mephenytoin, dextromethorphan, nifedipine and testosterone. The results obtained show the expression of various CYPs (CYP1A2, CYP2C19, CYP2C9, CYP2D6, and CYP3A4 in human foetus and their involvement in metabolism of CYP probe substrates.

Intracellular cholesterol-binding proteins enhance HDL-mediated cholesterol uptake in cultured primary mouse hepatocytes.

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Storey, Stephen M; McIntosh, Avery L; Huang, Huan; Landrock, Kerstin K; Martin, Gregory G; Landrock, Danilo; Payne, H Ross; Atshaves, Barbara P; Kier, Ann B; Schroeder, Friedhelm

2012-04-15

A major gap in our knowledge of rapid hepatic HDL cholesterol clearance is the role of key intracellular factors that influence this process. Although the reverse cholesterol transport pathway targets HDL to the liver for net elimination of free cholesterol from the body, molecular details governing cholesterol uptake into hepatocytes are not completely understood. Therefore, the effects of sterol carrier protein (SCP)-2 and liver fatty acid-binding protein (L-FABP), high-affinity cholesterol-binding proteins present in hepatocyte cytosol, on HDL-mediated free cholesterol uptake were examined using gene-targeted mouse models, cultured primary hepatocytes, and 22-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)-amino]-23,24-bisnor-5-cholen-3β-ol (NBD-cholesterol). While SCP-2 overexpression enhanced NBD-cholesterol uptake, counterintuitively, SCP-2/SCP-x gene ablation also 1) enhanced the rapid molecular phase of free sterol uptake detectable in rate and maximal uptake of HDL free cholesterol and 2) differentially enhanced free cholesterol uptake mediated by the HDL3, rather than the HDL2, subfraction. The increased HDL free cholesterol uptake was not due to increased expression or distribution of the HDL receptor [scavenger receptor B1 (SRB1)], proteins regulating SRB1 [postsynaptic density protein (PSD-95)/Drosophila disk large tumor suppressor (dlg)/tight junction protein (ZO1) and 17-kDa membrane-associated protein], or other intracellular cholesterol trafficking proteins (steroidogenic acute response protein D, Niemann Pick C, and oxysterol-binding protein-related proteins). However, expression of L-FABP, the single most prevalent hepatic cytosolic protein that binds cholesterol, was upregulated twofold in SCP-2/SCP-x null hepatocytes. Double-immunogold electron microscopy detected L-FABP sufficiently close to SRB1 for direct interaction, similar to SCP-2. These data suggest a role for L-FABP in HDL cholesterol uptake, a finding confirmed with SCP-2/SCP-x/L-FABP null

Effect of disrupted mitochondria as a source of damage-associated molecular patterns on the production of tumor necrosis factor α by splenocytes from dogs.

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Friedenberg, Steven G; Strange, Heather R; Guillaumin, Julien; VanGundy, Zachary C; Crouser, Elliott D; Papenfuss, Tracey L

2016-06-01

OBJECTIVE To evaluate the effects of damage-associated molecular patterns (DAMPs) derived from disrupted mitochondria on canine splenocytes and other immune cells. SAMPLES Liver, spleen, and bone marrow samples obtained from 8 cadavers of healthy research Beagles that had been euthanized for other purposes. PROCEDURES Mitochondria were obtained from canine hepatocytes, and mitochondrial DAMPs (containing approx 75% mitochondrial proteins) were prepared. Mitochondrial DAMPs and the nuclear cytokine high-mobility group box protein 1 were applied to splenocytes, bone marrow-differentiated dendritic cells, and a canine myelomonocytic cell (DH82) line for 6 or 24 hours. Cell culture supernatants from splenocytes, dendritic cells, and DH82 cells were assayed for tumor necrosis factor α with an ELISA. Expression of tumor necrosis factor α mRNA in splenocytes was evaluated with a quantitative real-time PCR assay. RESULTS In all cell populations evaluated, production of tumor necrosis factor α was consistently increased by mitochondrial DAMPs at 6 hours (as measured by an ELISA). In contrast, high-mobility group box protein 1 did not have any independent proinflammatory effects in this experimental system. CONCLUSIONS AND CLINICAL RELEVANCE The study revealed an in vitro inflammatory effect of mitochondrial DAMPs (containing approx 75% mitochondrial proteins) in canine cells and validated the use of an in vitro splenocyte model to assess DAMP-induced inflammation in dogs. This experimental system may aid in understanding the contribution of DAMPs to sepsis and the systemic inflammatory response syndrome in humans. Further studies in dogs are needed to validate the biological importance of these findings and to evaluate the in vivo role of mitochondrial DAMPs in triggering and perpetuating systemic inflammatory states.

Ischemic stroke and transient ischemic attack in young adults: risk factors, diagnostic yield, neuroimaging, and thrombolysis.

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Ji, Ruijun; Schwamm, Lee H; Pervez, Muhammad A; Singhal, Aneesh B

2013-01-01

Approximately 10% to 14% of ischemic strokes occur in young adults. To investigate the yield of diagnostic tests, neuroimaging findings, and treatment of ischemic strokes in young adults. We retrospectively reviewed data from our Get with the Guidelines-Stroke database from 2005 through 2010. University hospital tertiary stroke center. A total of 215 consecutive inpatients aged 18 to 45 years with ischemic stroke/transient ischemic attack. The mean (SD) age was 37.5 (7) years; 51% were male. There were high incidence rates of hypertension (20%), diabetes mellitus (11%), dyslipidemia (38%), and smoking (34%). Relevant abnormalities were shown on cerebral angiography in 136 of 203 patients, on cardiac ultrasonography in 100 of 195, on Holter monitoring in 2 of 192; and on hypercoagulable panel in 30 of 189 patients. Multiple infarcts were observed in 31% and were more prevalent in individuals younger than age 35 years. Relevant arterial lesions were frequently detected in the middle cerebral artery (23%), internal carotid artery (13%), and vertebrobasilar arteries (13%). Cardioembolic stroke occurred in 47% (including 17% with isolated patent foramen ovale), and 11% had undetermined stroke etiology. The median National Institutes of Health Stroke Scale score was 3 (interquartile range, 0-9) and 81% had good outcome at hospital discharge. Of the 29 patients receiving thrombolysis (median National Institutes of Health Stroke Scale score, 14; interquartile range, 9-17), 55% had good outcome at hospital discharge and none developed symptomatic brain hemorrhage. This study shows the contemporary profile of ischemic stroke in young adults admitted to a tertiary stroke center. Stroke etiology can be determined in nearly 90% of patients with modern diagnostic tests. The causes are heterogeneous; however, young adults have a high rate of traditional vascular risk factors. Thrombolysis appears safe and short-term outcomes are favorable.

Atrial fibrillation is not uncommon among patients with ischemic stroke and transient ischemic stroke in China.

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Yang, Xiaomeng; Li, Shuya; Zhao, Xingquan; Liu, Liping; Jiang, Yong; Li, Zixiao; Wang, Yilong; Wang, Yongjun

2017-12-04

Atrial fibrillation (AF) is reported to be a less frequent cause of ischemic stroke in China than in Europe and North America, but it is not clear whether this is due to underestimation. Our aim was to define the true frequency of AF-associated stroke, to determine the yield of 6-day Holter ECG to detect AF in Chinese stroke patients, and to elucidate predictors of newly detected AF. Patients with acute ischemic stroke or transient ischemic attack (TIA) were enrolled in a prospective, multicenter cohort study of 6-day Holter monitoring within 7 days after stroke onset at 20 sites in China between 2013 and 2015. Independent predictors of newly-detected AF were determined by multivariate analysis. Among 1511 patients with ischemic stroke and TIA (mean age 63 years, 33.1% women), 305 (20.2%) had either previously known (196, 13.0%) or AF newly-detected by electrocardiography (53, 3.5%) or by 6-day Holter monitoring (56/1262, 4.4%). A history of heart failure (OR = 4.70, 95%CI, 1.64-13.5), advanced age (OR = 1.06, 95%CI, 1.04-1.09), NIHSS at admission (OR = 1.06, 95%CI, 1.02-1.10), blood high density lipoprotein (HDL) (OR = 1.52, 95%CI, 1.09-2.13), together with blood triglycerides (OR = 0.64, 95%CI, 0.45-0.91) were independently associated with newly-detected AF. Contrary to previous reports, AF-associated stroke is frequent (20%) in China if systemically sought. Prolonged noninvasive cardiac rhythm monitoring importantly increases AF detection in patients with recent ischemic stroke and TIA in China. Advanced age, history of heart failure, and higher admission NIHSS and higher level of HDL were independent indicators of newly-detected AF. NCT02156765 (June 5, 2014).

EFFECTS OF Β-ADRENOBLOCKERS ON MYOCARDIAL REMODELING, IMMUNO-INFLAMMATORY REACTIONS AND ENDOTHELIAL DYSFUNCTION IN PATIENTS WITH ISCHEMIC HEART DISEASE AND CHRONIC HEART FAILURE

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A. N. Zakirova

2015-12-01

Full Text Available Aim. To assess the effect of β-adrenoblockers (BAB on myocardial remodeling, immuno-inflammatory reactions and endothelial dysfunction in patients with ischemic heart disease and chronic heart failure (CHF.Material and methods. 84 patients with ischemic CHF of II-IV functional class were involved in the study. They were randomized in two groups. The first group was presented with 43 patients receiving carvedilol in addition to standard therapy for 24 weeks; the second group was presented with 41patients receiving metoprolol. Echocardiography, 6-minute walk test were applied. Blood levels of primary and secondary lipid peroxidation (LP products, cytokines, endothelin-1 (ET-1, intercellular adhesive molecule (VCAM-1 were determined.Results. Both of BAB improved the clinical condition and physical working ability of patients with CHF. Carvedilol in comparison with metoprolol was more effective in myocardial remodeling prevention, inhibition of pro-inflammatory cytokines [tumor necrosis factor alpha (TNF-α, interleukins (IL-1β IL-6] and LP. Besides carvedilol increased in endothelium-dependent vasodilatation and reduced in ET-1 and VCAM-1 levels.Conclusion. Long-term carvedilol treatment has anti-inflammatory, antioxidant and endothelium-protective effects as well as improves haemodynamics. 

Long-term projections of temperature-related mortality risks for ischemic stroke, hemorrhagic stroke, and acute ischemic heart disease under changing climate in Beijing, China.

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Li, Tiantian; Horton, Radley M; Bader, Daniel A; Liu, Fangchao; Sun, Qinghua; Kinney, Patrick L

2018-03-01

Changing climates have been causing variations in the number of global ischemic heart disease and stroke incidences, and will continue to affect disease occurrence in the future. To project temperature-related mortality for acute ischemic heart disease, and ischemic and hemorrhagic stroke with concomitant climate warming. We estimated the exposure-response relationship between daily cause-specific mortality and daily mean temperature in Beijing. We utilized outputs from 31 downscaled climate models and two representative concentration pathways (RCPs) for the 2020s, 2050s, and 2080s. This strategy was used to estimate future net temperature along with heat- and cold-related deaths. The results for predicted temperature-related deaths were subsequently contrasted with the baseline period. In the 2080s, using the RCP8.5 and no population variation scenarios, the net total number of annual temperature-related deaths exhibited a median value of 637 (with a range across models of 434-874) for ischemic stroke; this is an increase of approximately 100% compared with the 1980s. The median number of projected annual temperature-related deaths was 660 (with a range across models of 580-745) for hemorrhagic stroke (virtually no change compared with the 1980s), and 1683 (with a range across models of 1351-2002) for acute ischemic heart disease (a slight increase of approximately 20% compared with the 1980s). In the 2080s, the monthly death projection for hemorrhagic stroke and acute ischemic heart disease showed that the largest absolute changes occurred in summer and winter while the largest absolute changes for ischemic stroke occurred in summer. We projected that the temperature-related mortality associated with ischemic stroke will increase dramatically due to climate warming. However, projected temperature-related mortality pertaining to acute ischemic heart disease and hemorrhagic stroke should remain relatively stable over time. Copyright © 2017 Elsevier Ltd. All rights

[Study on the interface of human hepatocyte/micropore polypropylene ultrafiltration membrane].

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Peng, Cheng-Hong; Han, Bao-San; Gao, Chang-You; Ma, Zu-Wei; Zhao, Zhi-Ming; Wang, Yong; Liu, Hong; Zhang, Gui-di; Yang, Mei-Juan

2004-09-02

To found a new interface of human hepatocyte/micropore polypropylene ultrafiltration membrane (MPP) with good cytocompatibility so as to construct bioartificial bioreactor with polypropylene hollow fibers in future. MPP ultrafiltration membrane underwent chemical grafting modification through ultraviolet irradiation and Fe(2+) reduction. The contact angles of MPP and the modified MPP membranes were measured. Human hepatic cells L-02 were cultured. MPP and modified MPP membranes were spread on the wells of culture plate and human hepatic cells and cytodex 3 were inoculated on them. Different kinds of microscopy were used to observe the morphology of these cells. The water contact angle of MPP and the modified MPP membranes decreased from 78 degrees +/- 5 degrees to 27 degrees +/- 4 degrees (P < 0.05), which indicated that the hydrophilicity of the membrane was improved obviously after the grafting modification. Human hepatocyte L-02 did not adhere to and spread on the modified MPP membrane surface, and only grew on the microcarrier cytodex 3 with higher density and higher proliferation ratio measured by MTT. Grafting modification of acrylamide on MPP membrane is a good method to improve the human hepatocyte cytocompatibility with MPP ultrafiltration membrane.

Enhancement of the predicted drug hepatotoxicity in gel entrapped hepatocytes within polysulfone-g-poly (ethylene glycol) modified hollow fiber

International Nuclear Information System (INIS)

Shen Chong; Zhang Guoliang; Meng Qin

2010-01-01

Collagen gel-based 3D cultures of hepatocytes have been proposed for evaluation of drug hepatotoxicity because of their more reliability than traditional monolayer culture. The collagen gel entrapment of hepatocytes in hollow fibers has been proven to well reflect the drug hepatotoxicity in vivo but was limited by adsorption of hydrophobic drugs onto hollow fibers. This study aimed to investigate the impact of hollow fibers on hepatocyte performance and drug hepatotoxicity. Polysulfone-g-poly (ethylene glycol) (PSf-g-PEG) hollow fiber was fabricated and applied for the first time to suppress the drug adsorption. Then, the impact of hollow fibers was evaluated by detecting the hepatotoxicity of eight selected drugs to gel entrapped hepatocytes within PSf and PSf-g-PEG hollow fibers, or without hollow fibers. The hepatocytes in PSf-g-PEG hollow fiber showed the highest sensitivity to drug hepatotoxicity, while those in PSf hollow fiber and cylindrical gel without hollow fiber underestimated the hepatotoxicity due to either drug adsorption or low hepatic functions. Therefore, the 3D culture of gel entrapped hepatocytes within PSf-g-PEG hollow fiber would be a promising tool for investigation of drug hepatotoxicity in vitro.

Is opium addiction a risk factor for ischemic heart disease and ischemic stroke?

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Mohammad Reza Rezvani

2012-01-01

Full Text Available Background: The main source of studies about effects of opium consumption on heart and brain attacks originates from Iran Therefore the aim of the present study was to assess opium addiction as a probable influencing factor for ischemic heart disease and ischemic stroke. Materials and Methods: A cross-sectional study was carried out in two Cardiology and Neurology clinics in Eastern Iran in 2011. Diagnosis of Ischemic Heart Disease (IHD and Ischemic Stroke (IS was made by Cardiologist and Stroke Neurologist respectively. The influence of gender, hypertension, diabetes, hyperlipidemia, cigarette smoking, oral and inhaled opium consumption on distribution of IHD and IS were evaluated. Results: Five hundred fifty eight patients (307 females, 251 males with mean age 56.2 years enrolled the study. On adjusted odds ratios of our whole 558 patients, only hypertension and diabetes had a significant influence on occurrence of IHD; (P = 0.000 and P = 0.000 respectively. Oral and inhaled routes of opium addiction did not have a significant effect on occurrence of IHD; [OR = 1.172, 95% CI = 0.624-2.203, P = 0.621] and [OR = 1.820, 95% CI = 0.811-4.085, P = 0.147] respectively. Hypertension and diabetes were significant risk factors of IS in our 558 patients at multivariate analysis; (P = 0.000, P = 0.020. Oral opium addiction was as significant protective factor of IS in our study group; OR = 0.211, 95% CI = 0.079-0.564, P = 0.002, while inhaled opium addiction did not have a significant effect on occurrence of IS in our patients at; OR = 1.760, 95% CI = 0.760-4.076, P = 0.187. Conclusion: Oral opium consumption is a protective factor of IS but not IHD. Inhaled opium addiction does not have a significant influence on occur r ence of IS and IHD.

Is opium addiction a risk factor for ischemic heart disease and ischemic stroke?

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Rezvani, Mohammad Reza; Ghandehari, Kavian

2012-10-01

The main source of studies about effects of opium consumption on heart and brain attacks originates from Iran Therefore the aim of the present study was to assess opium addiction as a probable influencing factor for ischemic heart disease and ischemic stroke. A cross-sectional study was carried out in two Cardiology and Neurology clinics in Eastern Iran in 2011. Diagnosis of Ischemic Heart Disease (IHD) and Ischemic Stroke (IS) was made by Cardiologist and Stroke Neurologist respectively. The influence of gender, hypertension, diabetes, hyperlipidemia, cigarette smoking, oral and inhaled opium consumption on distribution of IHD and IS were evaluated. Five hundred fifty eight patients (307 females, 251 males) with mean age 56.2 years enrolled the study. On adjusted odds ratios of our whole 558 patients, only hypertension and diabetes had a significant influence on occurrence of IHD; (P = 0.000 and P = 0.000) respectively. Oral and inhaled routes of opium addiction did not have a significant effect on occurrence of IHD; [OR = 1.172, 95% CI = 0.624-2.203, P = 0.621] and [OR = 1.820, 95% CI = 0.811-4.085, P = 0.147] respectively. Hypertension and diabetes were significant risk factors of IS in our 558 patients at multivariate analysis; (P = 0.000, P = 0.020). Oral opium addiction was as significant protective factor of IS in our study group; OR = 0.211, 95% CI = 0.079-0.564, P = 0.002, while inhaled opium addiction did not have a significant effect on occurrence of IS in our patients at; OR = 1.760, 95% CI = 0.760-4.076, P = 0.187. Oral opium consumption is a protective factor of IS but not IHD. Inhaled opium addiction does not have a significant influence on occurrence of IS and IHD.

Radiation necrosis of the mandible: a 10 year study. Part II. Dental factors; onset, duration and management of necrosis

International Nuclear Information System (INIS)

Murray, C.G.; Herson, J.; Daly, T.E.; Zimmerman, S.

1980-01-01

In a review of patients receiving radiation for cancer in the oral region the rate of radiation necrosis of the mandible was found to be similar for patients who had dental extractions before radiation therapy and for the remainder of the dentate population. It was suggested that diseased teeth should be removed prior to irradiation and sufficient healing time should be allowed. Teeth should not be extracted after irradiation. Dental prostheses can be provided for most irradiated patients if adequate care is exercised. The probability of necrosis commencing was highest three to twelve months after the start of therapy; it diminished gradually after that period. The duration of necrosis was depicted as an exponential curve with a constant probability of necrosis termination at each time point after onset. In 46.8% of the patients in study II (1971-1975), the necrosis was healed by conservative means. This was a significant increase over study I (1966-1969), and a complementary reduction in the necessity for surgical intervention was also found

Usefulness of colonoscopy in ischemic colitis.

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Lozano-Maya, M; Ponferrada-Díaz, A; González-Asanza, C; Nogales-Rincón, O; Senent-Sánchez, C; Pérez-de-Ayala, V; Jiménez-Aleixandre, P; Cos-Arregui, E; Menchén-Fernández-Pacheco, P

2010-07-01

the ischemic colitis is intestinal the most frequent cause of ischemia. With this work we determine the demographic and clinical characteristics, and the usefulness of the colonoscopy in the patients with ischemic colitis diagnosed in our centre in relation to a change of therapeutic attitude. retrospective study in which were selected 112 patients diagnosed with ischemic colitis by colonoscopy and biopsy, in a period of five years. It was analyzed: age, sex, reason for examination, factors of cardiovascular risk, endoscopic degree of ischemia, change in the therapeutic attitude, treatment and outcome. the average age was of 73.64 + or - 12.10 years with an equal incidence in women (50.9%) and the men (49.1%). The associated factors were the HTA (61.1%), tobacco (37.2%) and antecedents of cardiovascular episode (52.2%). The most frequent reason for colonoscopy was rectorrhagia (53.6%) followed of the abdominal pain (30.4%), being urgent the 65.3%. Colonoscopy allowed a change in the therapeutic attitude in the 50 increasing in the urgent one to the 65.75%. Global mortality was of 27.67%. The serious ischemic colitis (25%) was more frequent in men (64.3%) in urgent indication (85.71%) and attends with high mortality (53.57%). Surgical treatment in the 57.14% was made with a good evolution in the 50%, whereas the patients with mild or moderate ischemic colitis had a better prognosis (favourable evolution in 80.95%) with smaller requirement of the surgical treatment (4.76%), p change of attitude according to the result of the same one. The evidence of a serious colitis supposed an increase of the necessity of surgery and worse prognosis.

Ischemic Stroke during Pregnancy and Puerperium

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Elisabetta Del Zotto

2011-01-01

Full Text Available Ischemic stroke during pregnancy and puerperium represents a rare occurrence but it could be a serious and stressful event for mothers, infants, and also families. Whenever it does occur, many concerns arise about the safety of the mother and the fetus in relation to common diagnostic tests and therapies leading to a more conservative approach. The physiological adaptations in the cardiovascular system and in the coagulability that accompany the pregnant state, which are more significant around delivery and in the postpartum period, likely contribute to increasing the risk of an ischemic stroke. Most of the causes of an ischemic stroke in the young may also occur in pregnant patients. Despite this, there are specific conditions related to pregnancy which may be considered when assessing this particular group of patients such as pre-eclampsia-eclampsia, choriocarcinoma, peripartum cardiomiopathy, amniotic fluid embolization, and postpartum cerebral angiopathy. This article will consider several questions related to pregnancy-associated ischemic stroke, dwelling on epidemiological and specific etiological aspects, diagnostic issue concerning the use of neuroimaging, and the related potential risks to the embryo and fetus. Therapeutic issues surrounding the use of anticoagulant and antiplatelets agents will be discussed along with the few available reports regarding the use of thrombolytic therapy during pregnancy.

CT diagnosis of hypoxic ischemic encephalopathy

International Nuclear Information System (INIS)

Zhao Xiang; Ma Jiwei; Wu Lide

2004-01-01

Objective: To explore CT characteristics of hypoxic ischemic encephalopathy (HIE), and to improve the accuracy of CT diagnosis. Methods: 50 cases of neonatal asphyxia in perinatal period diagnosed as hypoxic ischemic encephalopathy by CT was analyzed. Results: The main manifestation of hypoxic ischemic encephalopathy is cerebral edema and intracranial hemorrhage. Focal or diffuse hypo-dense lesion and hyper-dense area in various location and morphology were seen on CT images. (1) Localized diffuse hypo-dense area in 1 or 2 cerebral lobe were found in 17 cases, and the lesions were localized in frontal lobe (n=6), in frontotemporal lobe (n=5), and in temporo-occipital lobe (n=6). (2) Hypo-density region involving more than three cerebral lobes were found in 18 cases, and abnormalities were found in frontotemporal and parietal lobe (n=8), accompanying with subarachnoid hemorrhage (n=2); in frontal, temporal and occipital lobe (n=6), in which cerebral hemorrhage was complicated (n=1); and in other cerebral lobe (n=4). (3) Diffuse low-density region in all cerebral lobe were found in 15 cases, in which subarachnoid hemorrhage was complicated in 4 cases, and ventricular hemorrhage was found in 2 case. Conclusion: CT imaging plays an important role in diagnosis of hypoxic ischemic encephalopathy and has shown its clinical value

Safety and feasibility of post-stroke care and exercise after minor ischemic stroke or transient ischemic attack: MotiveS & MoveIT

NARCIS (Netherlands)

Boss, H.M.; Van Schaik, S.M.; Deijle, I.A.; de Melker, E.C.; van den Berg, B.M.; Scherder, E.J.A.; Bosboom, W.M.J.; Weinstein, H.C.; van den Berg-Vos, R.M.

2014-01-01

Background: Despite the beneficial effect of cardiac rehabilitation after myocardial infarction, a rehabilitation program to improve cardiorespiratory fitness and influence secondary prevention has not been implemented for ischemic stroke and transient ischemic attack (TIA). Objective: To

Transient Ischemic Attack Caused by Iron Deficiency Anemia

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Ufuk Emre

2006-02-01

Full Text Available Transient Ischemic Attack Caused by Iron Deficiency Anemia Transient ischemic attacks are episodes of transient focal ischemia involving the brain or brainstem. They are commonly two to thirty minutes in duration and lasting less than 24 hours. Anemia of iron deficiency isn’t frequently cause for transient ischemic attack. It has been reported as a risk factor for childhood ischemic strokes. In the iron deficiency anemia, T‹A may develop as result of hypercoagulable state and increased viscosity that is caused by anemic hypoxia that is result of reduce hemoglobine level, seconder thrombosis and microcytose As iron deficiency anemia has been reported so rarely in adult patients with transient ischemic attacks as a cause, we aimed to discuss the clinical and outcome features of two cases with iron deficiency anemia and transient ischemic attacks in this study. Materials and methods: Routine neurologic examination, biochemical screen, serological tests, vasculitic markers, thyroid function tests, vitamin B 12 level, cranial imaging, vertebral carotid doppler USG examination was conducted in the two patients. Anemia of iron deficiency was found as the only risk factor for TIA and the two patients were treated with replacement of iron and antiagregan therapy. Neurological examination revealed no abnormality through the two years of follow-up. The iron deficiency anemia may be cause of many neurologic problems such a irritability, lethargy, headache, development retardation except from T‹A. In the iron deficiency anemia, early diagnosis and treatment is important

Isolation of Kupffer Cells and Hepatocytes from a Single Mouse Liver

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Aparicio-Vergara, Marcela; Tencerova, Michaela; Morgantini, Cecilia

2017-01-01

Liver perfusion is a common technique used to isolate parenchymal and non-parenchymal liver cells for in vitro experiments. This method allows hepatic cells to be separated based on their size and weight, by centrifugation using a density gradient. To date, other methods allow the isolation of only...... one viable hepatic cellular fraction from a single mouse; either parenchymal (hepatocytes) or non-parenchymal cells (i.e., Kupffer cells or hepatic stellate cells). Here, we describe a method to isolate both hepatocytes and Kupffer cells from a single mouse liver, thereby providing the unique...... advantage of studying different liver cell types that have been isolated from the same organism....

Liver system. V. Activation-extinction line of cyclic hepatocyte activities.

Science.gov (United States)

Dioguardi, N; Brambilla, F; Dell'Oca, M; Arosio, E; Parmeggiani, L

1991-01-01

The excitation-extintion line of hepatocytes from an inert state towards the stabilization of a given activity is described. Within the cell, the switching on of any given activity is a competitive process among different activities. The process is driven by the influence field created in the environment of the Rappaport acinus by sinusoidal blood which changes its characteristics during its passage from the portal zone to the central vein. Every step of the excitation-extintion pathway follows the so-called law of autoisodiasostasis (AIS), i.e. it is characterized by an oscillatory motion between restoring (homopoiesis or HP) and working (homeorhesis or HR) states. Since the cyclical bistable equilibrium of AIS characterizes all conditions of hepatocyte activities, the AIS cycle can be defined a limit cycle.

Infection in the ischemic lower extremity.

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Fry, D E; Marek, J M; Langsfeld, M

1998-06-01

Infections in the lower extremity of the patient with ischemia can cover a broad spectrum of different diseases. An understanding of the particular pathophysiologic circumstances in the ischemic extremity can be of great value in understanding the natural history of the disease and the potential complications that may occur. Optimizing blood flow to the extremity by using revascularization techniques is important for any patient with an ischemic lower extremity complicated by infection or ulceration. Infections in the ischemic lower extremity require local débridement and systemic antibiotics. For severe infections, such as necrotizing fasciitis or the fetid foot, more extensive local débridement and even amputation may be required. Fundamentals of managing prosthetic graft infection require removing the infected prosthesis, local wound débridement, and systemic antibiotics while attempting to preserve viability of the lower extremity using autogenous graft reconstruction.

Hepatocytes Determine the Hypoxic Microenvironment and Radiosensitivity of Colorectal Cancer Cells Through Production of Nitric Oxide That Targets Mitochondrial Respiration

International Nuclear Information System (INIS)

Jiang, Heng; Verovski, Valeri N.; Leonard, Wim; Law, Ka Lun; Vermeersch, Marieke; Storme, Guy; Van den Berge, Dirk; Gevaert, Thierry; Sermeus, Alexandra; De Ridder, Mark

2013-01-01

Purpose: To determine whether host hepatocytes may reverse hypoxic radioresistance through nitric oxide (NO)-induced oxygen sparing, in a model relevant to colorectal cancer (CRC) liver metastases. Methods and Materials: Hepatocytes and a panel of CRC cells were incubated in a tissue-mimetic coculture system with diffusion-limited oxygenation, and oxygen levels were monitored by an oxygen-sensing fluorescence probe. To activate endogenous NO production, cocultures were exposed to a cytokine mixture, and the expression of inducible nitric oxide synthase was analyzed by reverse transcription–polymerase chain reaction, Western blotting, and NO/nitrite production. The mitochondrial targets of NO were examined by enzymatic activity. To assess hypoxic radioresponse, cocultures were irradiated and reseeded for colonies. Results: Resting hepatocytes consumed 10-40 times more oxygen than mouse CT26 and human DLD-1, HT29, HCT116, and SW480 CRC cells, and thus seemed to be the major effectors of hypoxic conditioning. As a result, hepatocytes caused uniform radioprotection of tumor cells at a 1:1 ratio. Conversely, NO-producing hepatocytes radiosensitized all CRC cell lines more than 1.5-fold, similar to the effect of selective mitochondrial inhibitors. The radiosensitizing effect was associated with a respiratory self-arrest of hepatocytes at the level of aconitase and complex II, which resulted in profound reoxygenation of tumor cells through oxygen sparing. Nitric oxide–producing hepatocytes were at least 10 times more active than NO-producing macrophages to reverse hypoxia-induced radioresistance. Conclusions: Hepatocytes were the major determinants of the hypoxic microenvironment and radioresponse of CRC cells in our model of metabolic hypoxia. We provide evidence that reoxygenation and radiosensitization of hypoxic CRC cells can be achieved through oxygen sparing induced by endogenous NO production in host hepatocytes

Hepatocytes Determine the Hypoxic Microenvironment and Radiosensitivity of Colorectal Cancer Cells Through Production of Nitric Oxide That Targets Mitochondrial Respiration

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Jiang, Heng; Verovski, Valeri N.; Leonard, Wim; Law, Ka Lun; Vermeersch, Marieke; Storme, Guy; Van den Berge, Dirk; Gevaert, Thierry; Sermeus, Alexandra [Department of Radiotherapy, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels (Belgium); De Ridder, Mark, E-mail: mark.deridder@uzbrussel.be [Department of Radiotherapy, Universitair Ziekenhuis Brussel, Vrije Universiteit Brussel, Brussels (Belgium)

2013-03-01

Purpose: To determine whether host hepatocytes may reverse hypoxic radioresistance through nitric oxide (NO)-induced oxygen sparing, in a model relevant to colorectal cancer (CRC) liver metastases. Methods and Materials: Hepatocytes and a panel of CRC cells were incubated in a tissue-mimetic coculture system with diffusion-limited oxygenation, and oxygen levels were monitored by an oxygen-sensing fluorescence probe. To activate endogenous NO production, cocultures were exposed to a cytokine mixture, and the expression of inducible nitric oxide synthase was analyzed by reverse transcription–polymerase chain reaction, Western blotting, and NO/nitrite production. The mitochondrial targets of NO were examined by enzymatic activity. To assess hypoxic radioresponse, cocultures were irradiated and reseeded for colonies. Results: Resting hepatocytes consumed 10-40 times more oxygen than mouse CT26 and human DLD-1, HT29, HCT116, and SW480 CRC cells, and thus seemed to be the major effectors of hypoxic conditioning. As a result, hepatocytes caused uniform radioprotection of tumor cells at a 1:1 ratio. Conversely, NO-producing hepatocytes radiosensitized all CRC cell lines more than 1.5-fold, similar to the effect of selective mitochondrial inhibitors. The radiosensitizing effect was associated with a respiratory self-arrest of hepatocytes at the level of aconitase and complex II, which resulted in profound reoxygenation of tumor cells through oxygen sparing. Nitric oxide–producing hepatocytes were at least 10 times more active than NO-producing macrophages to reverse hypoxia-induced radioresistance. Conclusions: Hepatocytes were the major determinants of the hypoxic microenvironment and radioresponse of CRC cells in our model of metabolic hypoxia. We provide evidence that reoxygenation and radiosensitization of hypoxic CRC cells can be achieved through oxygen sparing induced by endogenous NO production in host hepatocytes.

Induction of highly functional hepatocytes from human umbilical cord mesenchymal stem cells by HNF4α transduction.

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Hualian Hang

Full Text Available To investigate the differentiation potential of human umbilical mesenchymal stem cells (HuMSCs and the key factors that facilitate hepatic differentiation.HuMSCs were induced to become hepatocyte-like cells according to a previously published protocol. The differentiation status of the hepatocyte-like cells was examined by observing the morphological changes under an inverted microscope and by immunofluorescence analysis. Hepatocyte nuclear factor 4 alpha (HNF4α overexpression was achieved by plasmid transfection of the hepatocyte-like cells. The expression of proteins and genes of interest was then examined by Western blotting and reverse transcription-polymerase chain reaction (RT-PCR or real-time RT-PCR methods.Our results demonstrated that HuMSCs can easily be induced into hepatocyte-like cells using a published differentiation protocol. The overexpression of HNF4α in the induced HuMSCs significantly enhanced the expression levels of hepatic-specific proteins and genes. HNF4α overexpression may be associated with liver-enriched transcription factor networks and the Wnt/β-Catenin pathway.The overexpression of HNF4α improves the hepatic differentiation of HuMSCs and is a simple way to improve cellular sources for clinical applications.

10-Year Associations Between Tumor Necrosis Factor Receptors 1 and 2 and Cardiovascular Events in Patients With Stable Coronary Heart Disease

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Carlsson, Axel C; Ruge, Toralph; Kjøller, Erik

2018-01-01

BACKGROUND: We aimed to assess the associations and predictive powers between the soluble receptors for tumor necrosis factor (TNF)-α (TNFR1 and TNFR2) and cardiovascular outcomes in patients with stable coronary heart disease. METHODS AND RESULTS: CLARICOR (Effect of Clarithromycin on Mortality...... and Morbidity in Patients With Ischemic Heart Disease) is a randomized clinical trial comparing clarithromycin with placebo in patients with stable coronary heart disease. The primary outcome was a composite of nonfatal acute myocardial infarction, unstable angina pectoris, cerebrovascular disease, and all...... factors improved prediction only modestly (concentrations of circulating TNFR1 and TNFR2 were associated with increased risks of cardiovascular events and mortality in patients with stable coronary heart disease. Yet, the utility of measuring TNFR1 and TNFR2 to improve risk...

Insulin infusion reduces hepatocyte growth factor in lean humans

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de Courten, Barbora; de Courten, Maximilian; Dougherty, Sonia

2013-01-01

OBJECTIVE: Plasma Hepatocyte Growth Factor (HGF) is significantly elevated in obesity and may contribute to vascular disease, metabolic syndrome or cancer in obese individuals. The current studies were done to determine if hyperinsulinemia increases plasma HGF. MATERIALS/METHODS: Twenty-two parti...

Effects of dehydroepiandrosterone (DHEA) on glucose metabolism in isolated hepatocytes from Zucker rats

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Finan, A.; Cleary, M.P.

1986-01-01

DHEA has been shown to competitively inhibit the pentose phosphate shunt (PPS) enzyme glucose-6-phosphate dehydrogenase (G6PD) when added in vitro to supernatants or homogenates prepared from mammalian tissues. However, no consistent effect on G6PD activity has been determined in tissue removed from DHEA-treated rats. To explore the effects of DHEA on PPS, glucose utilization was measured in hepatocytes from lean and obese male Zucker rats (8 wks of age) following 1 wk of DHEA treatment (0.6% in diet). Incubation of isolated hepatocytes from treated lean Zucker rats with either [1- 14 C] glucose or [6- 14 C] glucose resulted in significant decreases in CO 2 production and total glucose utilization. DHEA-lean rats also had lowered fat pad weights. In obese rats, there was no effect of 1 wk of treatment on either glucose metabolism or fat pad weight. The calculated percent contribution of the PPS to glucose metabolism in hepatocytes was not changed for either DHEA-lean or obese rats when compared to control rats. In conclusion, 1 wk of DHEA treatment lowered overall glucose metabolism in hepatocytes of lean Zucker rats, but did not selectively affect the PPS. The lack of an effect of short-term treatment in obese rats may be due to differences in their metabolism or storage/release of DHEA in tissues in comparison to lean rats

Metabolism of the synthetic cannabinoid 5F-PY-PICA by human and rat hepatocytes and identification of biliary analytical targets by directional efflux in sandwich-cultured rat hepatocytes using UHPLC-HR-MS/MS

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Mardal, Marie; Annaert, Pieter; Noble, Carolina

2018-01-01

Analytical strategies for detecting drugs in biological samples rely on information on metabolism and elimination. 5F-PY-PICA belongs to the group of synthetic cannabinoids that are known to undergo excretion into the bile. The aims of this study were the in vitro identification of metabolites of 5......F-PY-PICA and to determine which analytical targets are excreted into the bile and urine. Metabolites identified after incubation of 5F-PY-PICA with pooled human liver microsomes (pHLM), pooled human hepatocytes (pHH), or suspended and sandwich-cultured rat hepatocytes (SCRH). Rat hepatocytes were......-PY-PICA, M4, and M22 are proposed as analytical targets for bile analysis in forensic screening protocols, whereas M6 should be one of the main urinary targets for 5F-PY-PICA analysis....

Role of homocysteine in the ischemic stroke nad development of ischemic tolerance

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Jan Lehotsky

2016-11-01

Full Text Available Homocysteine (Hcy is a toxic, sulfur-containing intermediate of methionine metabolism. Hyperhomocysteinemia (hHcy, as a consequence of impaired Hcy metabolism or defects in crucial co-factors that participate in its recycling, is assumed as an independent human stroke risk factor. Neural cells are sensitive to prolonged hHcy treatment, because Hcy cannot be metabolized either by the transsulfuration pathway or by the folate/vitamin B12 independent remethylation pathway. Its detrimental effect after ischemia-induced damage includes accumulation of reactive oxygen species (ROS and posttranslational modifications of proteins via homocysteinylation and thiolation. Ischemic preconditioning (IPC is an adaptive response of the CNS to sub-lethal ischemia, which elevates tissues tolerance to subsequent ischemia. The main focus of this review is on the recent data on homocysteine metabolism and mechanisms of its neurotoxicity. In this context, the review documents an increased oxidative stress and functional modification of enzymes involved in redox balance in experimentally induced hyperhomocysteinemia. It also gives an interpretation whether hyperhomocysteinemia alone or in combination with IPC affects the ischemia-induced neurodegenerative changes as well as intracellular signalling. Studies document that hHcy alone significantly increased Fluoro-Jade C- and TUNEL-positive cell neurodegeneration in the rat hippocampus as well as in the cortex. IPC, even if combined with hHcy, could still preserve the neuronal tissue from the lethal ischemic effects. This review also describes the changes in the mitogen-activated protein kinase (MAPK protein pathways following ischemic injury and IPC. These studies provide evidence for the interplay and tight integration between ERK and p38 MAPK signalling mechanisms in response to the hHcy and also in association of hHcy with ischemia/IPC challenge in the rat brain. Further investigations of the protective factors

Different Recipient Vessels for Free Microsurgical Fibula Flaps in the Treatment of Avascular Necrosis of the Femoral Head: A Systematic Review and Meta-analysis.

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Tu, Yiji; Chen, Zenggan; Lineaweaver, William Charles; Zhang, Feng

2017-12-01

Several recipient vessels can be used in free microsurgical fibula flaps (MFFs) for the treatment of avascular necrosis of the femoral head (ANFH). Few articles investigate the influence of different recipient vessels on outcomes of MFF for ANFH. A comprehensive literature search of databases including PubMed-Medline, Ovid-Embase, and Cochrane Library was performed to collect the related studies. The Medical Subject Headings used were "femur head necrosis" and "bone transplantation." The relevant words in title or abstract included but not limited to "fibula flap," "fibular flap," "vascularized fibula," "vascularized fibular," "free fibula," "free fibular," "femoral head necrosis," "avascular necrosis of femoral head," and "ischemic necrosis of femoral head." The methodological index for nonrandomized studies was adopted for assessing the studies included in this review. Finally, 15 studies encompassing a total of 1267 patients (1603 hips) with ANFH were pooled in the overall analysis. Recipient vessels for MFF included the ascending branch of the lateral circumflex femoral artery and vein in 8 studies, descending branch of the lateral circumflex femoral artery and vein in 2 studies, second perforating branch of the deep femoral artery and vein in 4 studies, and inferior gluteal artery and vein in 1 study. Preoperative and postoperative average Harris hip score and pooled analyses of the rate of conversion, radiographic progression, and hip surgery-related complications showed no significant difference on the outcomes of MFF on ANFH between using different recipient vessels. Different recipient vessels did not affect outcomes in MFF procedures for ANFH. High-quality randomized controlled trials and prospective studies would be necessary to clarify reliable advantages and disadvantages between different recipient vessels. Until then, surgeons are justified in using ascending branch of the lateral circumflex femoral artery and vein, descending branch of the lateral

Avascular necrosis of bone complicating corticosteroid replacement therapy.

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Williams, P L; Corbett, M

1983-01-01

Two patients who developed widespread severe avascular necrosis of bone while on steroid replacement therapy are described. One, a diabetic, underwent yttrium-90 pituitary ablation for retinopathy and developed avascular necrosis within 18 months of starting prednisolone. The other, who had Addison's disease, developed avascular necrosis within 14 months of starting cortisol replacement therapy. Both cases came to bilateral total hip replacement.

Tracheal stoma necrosis: a case repor

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Pak S

2017-04-01

Full Text Available Acute tracheal dilatation, due to an overinflated cuff, has been reported early in the course of mechanical ventilation through an endotracheal tube. Tracheal stoma necrosis is a rare complication, but such can accompany acute tracheal dilation. Herein, we report a case of tracheal necrosis 9 days following tracheostomy placement in a 71-year old woman associated with overinflation of the tracheal tube cuff. This case report aims to 1 add to the scant body of knowledge about the diagnosis and management for the patients with tracheal stoma necrosis and 2 raise awareness for error-traps in interpreting diagnostic images, specifically satisfaction of search error, inattentional blindness error, and alliterative error.

Implications of the simultaneous occurrence of glycolysis and gluconeogenesis in hepatocytes from normal and hyperthyroid rats

International Nuclear Information System (INIS)

Phillips, J.W.; Berry, M.N.

2001-01-01

The mammalian liver has the capability for both glycolysis and gluconeogenesis. In the fasting state, metabolites such as lactate and glycerol, generated in the peripheral tissues, are taken up by the liver and converted to glucose. However, hepatocytes from fasted animals are also capable of substantial rates of glycolysis. It is generally assumed that glycolysis and gluconeogenesis do not occur simultaneously in the same cell, but rather the metabolic conditions that facilitate flux through one pathway impair flow in the opposite direction. The actual direction of flow at any given moment is thought to be determined by regulatory mechanisms that control flux through the enzymatic steps specific to glycolysis and gluconeogenesis. The rates of glycolysis from [6- 3 H]glucose and gluconeogenesis from [U- 14 C]glycerol were determined in isolated hepatocytes from fasted normal and hyperthyroid rats. We observed that glycolysis from glucose and glucose synthesis from glycerol occurred simultaneously at substantial rates in hepatocytes from normal rats and that gluconeogenesis, but not glycolysis, was increased twofold in hepatocytes from thyroid treated rats. In the hyperthyroid state, the rate of glycolysis from glucose was approximately equal to the rate of glucose formation from glycerol. Hence, metabolism and ATP turnover were stimulated without substantially altering steady-state concentrations of glucose. The concomitant operation of hepatic glycolysis and gluconeogenesis may be a mechanism that accounts in part for the calorigenic effect of thyroid hormone. Since hepatocyles are generally impermeable to phosphorylated metabolites, our observations suggest that glycolysis, and phosphorylation of glycerol take place in the same cells, and that the occurrence of simultaneous glycolysis and gluconeogenesis is an indication of channelling within the hepatocyte cytoplasm of individual hepatocytes

Connexin 32 and connexin 43 are involved in lineage restriction of hepatic progenitor cells to hepatocytes

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Haiyun Pei

2017-11-01

Full Text Available Abstract Background Bi-potential hepatic progenitor cells can give rise to both hepatocytes and cholangiocytes, which is the last phase and critical juncture in terms of sequentially hepatic lineage restriction from any kind of stem cells. If their differentiation can be controlled, it might access to functional hepatocytes to develop pharmaceutical and biotechnology industries as well as cell therapies for end-stage liver diseases. Methods In this study, we investigated the influence of Cx32 and Cx43 on hepatocyte differentiation of WB-F344 cells by in vitro gain and loss of function analyses. An inhibitor of Cx32 was also used to make further clarification. To reveal p38 MAPK pathway is closely related to Cxs, rats with 70% partial hepatectomy were injected intraperitoneally with a p38 inhibitor, SB203580. Besides, the effects of p38 MAPK pathway on differentiation of hepatoblasts isolated from fetal rat livers were evaluated by addition of SB203580 in culture medium. Results In vitro gain and loss of function analyses showed overexpression of Connexin 32 and knockdown of Connexin 43 promoted hepatocytes differentiation from hepatic progenitor cells. In addition, in vitro and ex vivo research revealed inhibition of p38 mitogen-activated protein kinase pathway can improve hepatocytes differentiation correlating with upregulation of Connexin 32 expression and downregulation of Connexin 43 expression. Conclusions Here we demonstrate that Connexins play crucial roles in facilitating differentiation of hepatic progenitors. Our work further implicates that regulators of Connexins and their related pathways might provide new insights to improve lineage restriction of stem cells to mature hepatocytes.

Xenobiotic-Metabolizing Enzyme and Transporter Gene Expression in Primary Cultures of Human Hepatocytes Modulated by Toxcast Chemicals

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Primary human hepatocyte cultures are useful in vitro model systems of human liver because when cultured under appropriate conditions the hepatocytes retain liver-like functionality such as metabolism, transport, and cell signaling. This model system was used to characterize the ...

Association between high homocyst(e)ine and ischemic stroke due to large- and small-artery disease but not other etiologic subtypes of ischemic stroke.

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Eikelboom, J W; Hankey, G J; Anand, S S; Lofthouse, E; Staples, N; Baker, R I

2000-05-01

Elevated plasma homocyst(e)ine may be a causal and modifiable risk factor for ischemic stroke, but the results of previous studies have been conflicting. One possible explanation is that homocyst(e)ine may only be associated with certain pathophysiological subtypes of ischemic stroke. We conducted a case-control study of 219 hospital cases with a first-ever ischemic stroke and 205 randomly selected community control subjects stratified by age, sex, and postal code. With the use of established criteria, cases of stroke were classified by etiologic subtype in a blinded fashion. The prevalence of conventional vascular risk factors, fasting plasma homocyst(e)ine levels, vitamin levels, and nucleotide 677 methylene tetrahydrofolate reductase (MTHFR) genotypes were determined in cases and controls. Increasing homocyst(e)ine was a strong and independent risk factor for ischemic stroke (adjusted OR 2.7, 95% CI 1.4 to 5.1 for a 5-micromol/L increase in fasting plasma homocyst(e)ine from 10 to 15 micromol/L). Compared with the lowest quartile, the highest quartile of homocyst(e)ine was associated with an adjusted OR of ischemic stroke of 2.2 (95% CI 1.1 to 4.2). Mean plasma homocyst(e)ine was significantly higher in cases of ischemic stroke due to large-artery disease (14.1 micromol/L, 95% CI 12.5 to 15.9, Pine, the upper 3 quartiles were associated with an adjusted OR of ischemic stroke due to large-artery disease of 3.0 (95% CI 0.8 to 10.8) for the second quartile, 5.6 (95% CI 1.6 to 20) for the third quartile, and 8.7 (95% CI 2.4 to 32) for the fourth quartile (P for trend=0.0005). However, despite a clear association between the TT MTHFR genotype and elevated fasting plasma homocyst(e)ine, there was no association between MTHFR genotype and ischemic stroke or subtype of ischemic stroke. There is a strong, graded association between increasing plasma homocyst(e)ine and ischemic stroke caused by large-artery atherosclerosis and, to a much lesser extent, small

Skin Necrosis from Intra-articular Hyaluronic Acid Injection.

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Kim, Whan B; Alhusayen, Raed O

2015-01-01

Tissue necrosis is a rare yet potentially serious complication of intra-articular (IA) hyaluronic acid (HA) injections for treatment of knee osteoarthritis. To report a case of a patient with cutaneous necrosis after IA HA injection for treatment of knee osteoarthritis, presenting as a livedoid violaceous patch on the right knee. We report a case of cutaneous necrosis as a rare complication of IA HA injection for treatment of knee osteoarthritis. A literature review was undertaken of similar cases. Use of HA IA injections in the treatment of osteoarthritis can result in similar skin necrosis at uncommon anatomic locations corresponding to the site of HA injection. Although tissue necrosis is a rare complication, physicians need to be aware of this possibility as a complication of HA IA injections in the treatment of osteoarthritis and should be mindful of potential treatment options to manage this adverse event. © 2014 Canadian Dermatology Association.

Chronic Exposure to Subtherapeutic Antibiotics Aggravates Ischemic Stroke Outcome in Mice

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Xiao-Hui Dong

2017-10-01

Full Text Available Subtherapeutic antibiotics have been widely used in agriculture since the 1950s, which can be accumulated in human body through various approaches and may have long-term consequences. However, there is limited information about the link between chronic subtherapeutic antibiotic exposure and the outcome of ischemic brain injury. Here we showed that long-term treatment with subtherapeutic chlortetracycline, penicillin or vancomycin, which were widely used in agriculture approved by US Food and Drug Administration (FDA, could impair EPC functions, reduce ischemic brain angiogenesis and aggravate cerebral ischemic injury and long-term stroke outcomes in mice. In addition, transplantated EPCs from chronic antibiotic-treated mice showed a lower therapeutic effect on cerebral ischemic injury reduction and local angiogenesis promotion compared to those from control mice, and EPCs from the donor animals could integrate into the recipient ischemic brain in mice. Furthermore, transplanted EPCs might exert paracrine effects on cerebral ischemic injury reduction in mice, which could be impaired by chronic antibiotic exposure. In conclusion, chronic subtherapeutic antibiotic exposure aggravated cerebral ischemic injury in mice, which might be partly attributed to the impairment of both EPC-mediated angiogenesis and EPCs' paracrine effects. These findings reveal a previously unrecognized impact of chronic subtherapeutic antibiotic exposure on ischemic injury.

Tributyltin induces apoptotic signaling in hepatocytes through pathways involving the endoplasmic reticulum and mitochondria

International Nuclear Information System (INIS)

Grondin, Melanie; Marion, Michel; Denizeau, Francine; Averill-Bates, Diana A.

2007-01-01

Tri-n-butyltin is a widespread environmental toxicant, which accumulates in the liver. This study investigates whether tri-n-butyltin induces pro-apoptotic signaling in rat liver hepatocytes through pathways involving the endoplasmic reticulum and mitochondria. Tri-n-butyltin activated the endoplasmic reticulum pathway of apoptosis, which was demonstrated by the activation of the protease calpain, its translocation to the plasma membrane, followed by cleavage of the calpain substrates, cytoskeletal protein vinculin, and caspase-12. Caspase-12 is localized to the cytoplasmic side of the endoplasmic reticulum and is involved in apoptosis mediated by the endoplasmic reticulum. Tri-n-butyltin also caused translocation of the pro-apoptotic proteins Bax and Bad from the cytosol to mitochondria, as well as changes in mitochondrial membrane permeability, events which can activate the mitochondrial death pathway. Tri-n-butyltin induced downstream apoptotic events in rat hepatocytes at the nuclear level, detected by chromatin condensation and by confocal microscopy using acridine orange. We investigated whether the tri-n-butyltin-induced pro-apoptotic events in hepatocytes could be linked to perturbation of intracellular calcium homeostasis, using confocal microscopy. Tri-n-butyltin caused changes in intracellular calcium distribution, which were similar to those induced by thapsigargin. Calcium was released from a subcellular compartment, which is likely to be the endoplasmic reticulum, into the cytosol. Cytosolic acidification, which is known to trigger apoptosis, also occurred and involved the Cl - /HCO 3 - exchanger. Pro-apoptotic events in hepatocytes were inhibited by the calcium chelator, Bapta-AM, and by a calpain inhibitor, which suggests that changes in intracellular calcium homeostasis are involved in tri-n-butyltin-induced apoptotic signaling in rat hepatocytes

Putative role of ischemic postconditioning in a rat model of limb ischemia and reperfusion: involvement of hypoxia-inducible factor-1α expression