bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute Regulation of Translation Initiation by Gonadotropin-Releasing Hormone in the Gonadotrope Cell Line LβT2
Authors: Nguyen Kathryn A. , Santos Sharon J. , Kreidel Marit K. , Diaz Alejandro L. , Rey Rodolfo , Lawson Mark A.
Published: February 2004

The hypothalamic neuropeptide hormone GnRH is the central regulator of reproductive function. GnRH stimulates the synthesis and release of the gonadotropins LH and FSH by the gonadotropes of the anterior pituitary through activation of the G-protein-coupled GnRH receptor. In this study, we investigated the role of translational control of hormone synthesis by the GnRH receptor in the novel gonadotrope cell line LβT2. Using immunohistochemical and RIA studies with this model, we show that acute GnRH-induced synthesis and secretion of LH are dependent upon new protein synthesis but not new mRNA synthesis. We examined the response to GnRH and found that activation of cap-dependent translation occurs within 4 h. LHβ promoter activity was also examined, and we found no increases in LHβ promoter activity after 6 h of GnRH stimulation. Additionally, we show that increased phosphorylation of translation initiation proteins, 4E-binding protein 1, eukaryotic initiation factor 4E, and eukaryotic initiation factor 4G, occur in a dose- and time-dependent manner in response to GnRH stimulation. Quantitative luminescent image analysis of Western blots shows that 10 nm GnRH is sufficient to cause a maximal increase in factor phosphorylation, and maximal responses occur within 30 min of stimulation. Further, we demonstrate that the MAPK kinase inhibitor, PD 98059, abolishes the GnRH-mediated stimulation of a cap-dependent translation reporter. More specifically, we demonstrate that PD 98059 abolishes the GnRH-mediated stimulation of a downstream target of the ERK pathway, MAPK-interacting kinase. Based on these findings, we conclude that acute GnRH stimulation of LβT2 cells increases translation initiation through ERK signaling. This may contribute to the acute increases in LHβ subunit production.
Immuno-PCR for Detection of Antigen to Angiostrongylus cantonensis Circulating Fifth-Stage Worms
Authors: Chye Soi-Moi , Lin Shiu-Ru , Chen Ya-Lei , Chung Lee-Yi , Yen Chuan-Min
Published: February 2004

Background: Definitive diagnosis of infestation with Angiostrongylus cantonensis is difficult because the parasitic nematode is undetectable in the cerebrospinal fluid (CSF) of one-half of afflicted patients and the diagnostic sensitivity of ELISA for circulating worm antigens in patient sera is low. We studied immuno-PCR as a diagnostic tool.

Methods: We studied 30 controls and 60 afflicted patients (30 confirmed by parasitologic analysis of CSF). We used a monoclonal antibody to capture circulating A. cantonensis antigens in serum samples. A DNA label generated by PCR amplification with biotinylated primer was bound by use of streptavidin to a biotinylated third antibody. Circulating antigens sandwiched by monoclonal antibody were detected by PCR amplification of the DNA label.

Results: The detection limit of the ELISA was 100–1000 times higher than that of the immuno-PCR. The concentrations of circulating antigens in patients were markedly higher than those in controls (Wilcoxon rank-sum test, P <0.001). At a cutoff of 0.1 ng/L, sensitivity and specificity for immunodiagnosis of patients with angiostrongyliasis by immuno-PCR were 98% (95% confidence interval, 91–99%) and 100% (93–100%), respectively. The test was positive in all parasitologically confirmed cases.

Conclusions: Immuno-PCR is a promising technique for diagnosis of A. cantonensis infestation.
[13C]Nandrolone Excretion in Trained Athletes: Interindividual Variability in Metabolism
Authors: Baume Norbert , Avois Lidia , Schweizer Carine , Cardis Christine , Dvorak Jiri , Cauderay Michel , Mangin Patrice , Saugy Martial
Published: February 2004

Background: Nandrolone is one of the most abused anabolic steroids, and its use in doping is increasing, as revealed by numerous positive cases during recent years in various sports. Different authors have reported the possible natural production of nandrolone metabolites in humans, and some of these authors argued that exhaustive exercise could increase nandrolone production in the body or induce dehydration and consequently lead to an increase of nandrolone metabolites in urine.

Methods: Volunteers (n = 22) ingested two 25-mg doses of [13C]nandrolone at 24-h intervals and collected urine specimens for 5 days. The labeled nandrolone metabolites 19-norandrosterone and 19-noretiocholanolone were identified and quantified by gas chromatography–mass spectrometry.

Results: Interindividual variability was observed in nandrolone excretion patterns and kinetics, as well as for the noretiocholanolone:norandrosterone ratio. The amounts of nandrolone metabolites measured at the excretion peak varied between 1180 and 38 661 μg/L for norandrosterone and 576 and 12 328 μg/L for noretiocholanolone. At the end of the excretion period, the noretiocholanolone:norandrosterone ratio was sometimes >1. The analysis of numerous spot-urine samples allowed the determination of an acceptable correlation between urinary creatinine and specific gravity for placebo- and steroid-treated individuals: y = 0.0052ln(x) + 1.0178 (r2 = 0.8142) and y = 0.0068ln(x) + 1.0172 (r2 = 0.7730), respectively.

Conclusions: The excretion kinetics and patterns of labeled nandrolone show interindividual variability. More investigations are currently underway to estimate the influence of exhaustive exercises on excretion of labeled nandrolone metabolites in urine.
Immunoassay of Estradiol: Unanticipated Suppression by Unconjugated Estriol
Authors: Cao Zhimin (Tim) , Swift Thomas A , West Clint A , Rosano Thomas G , Rej Robert
Published: February 2004

Background: Accurate measurement of estradiol is important in clinical settings. The quality of laboratory estimations of estradiol may be assessed through external quality-assurance surveys.

Methods: Estradiol was measured by microparticle enzyme immunoassay (MEIA) and other immunoassays. Proficiency testing of medical laboratories was conducted using samples prepared from normal male human serum supplemented with exogenous estradiol and other steroid and nonsteroid hormones, and participant laboratories measured estradiol by a variety of commonly used immunoassay techniques.

Results: The imprecision (CV) for measurement of estradiol [100–300 ng/L (367–1102 pmol/L)] was ≤22% for most analytical techniques. Greater imprecision, as high as 40% for the same concentration range, was observed for the (AxSYM) MEIA method in the proficiency testing event of September 2001. Results from this method were bimodal in distribution. We found that unconjugated estriol at concentrations >1.5 μg/L (>5.2 nmol/L) interfered with the MEIA method, leading to decreased recovery of added estradiol by up to 50%. This suppression in estradiol measurement was prevented by dilution of the specimen before measurement. Addition of unconjugated estriol gave a positive bias in some other immunoassay methods for estradiol. Poor comparability among the immunoassay methods for measurement of estradiol at clinically relevant concentrations [∼60 ng/L (220 pmol/L)] was revealed.

Conclusions: A negative interference of unconjugated estriol with the MEIA method is a source of error for estradiol measurement. Lack of specificity and lack of comparability among immunoassay methods for estradiol may have detrimental effects on medical practice.
Invasive Trophoblast Antigen (Hyperglycosylated Human Chorionic Gonadotropin) in Second-Trimester Maternal Urine as a Marker for Down Syndrome: Preliminary Results of an Observational Study on Fresh Samples
Authors: Palomaki Glenn E , Knight George J , Roberson Marie M , Cunningham George C , Lee Jo Ellen , Strom Charles M , Pandian Raj
Published: February 2004

Background: Down syndrome screening is commonly performed in the US using maternal age and three or four second-trimester maternal serum markers that can identify up to 75% of affected pregnancies by offering diagnostic studies to 5% of women. Invasive trophoblast antigen [ITA; hyperglycosylated human chorionic gonadotropin (hCG)] is a promising marker that can be measured in urine or serum in the first or second trimester. We report preliminary results for urinary ITA in an ongoing observational study.

Methods: Women undergoing second-trimester amniocentesis for reasons not associated with biochemical testing provided consent and a urine (and possibly serum) sample that was tested within a few days. Demographic and pregnancy-related information was collected, along with karyotype. Screening performance was modeled for ITA alone and in combination with serum markers

Results: Twelve recruitment centers collected urine from 2055 women with singleton pregnancies between 15 and 20 weeks of gestation (2023 unaffected, 28 Down syndrome, and 4 pregnancies with other chromosome abnormalities). After correction for gestational age, urine concentration, and maternal race and weight, the ITA measurements were higher in women with a Down syndrome pregnancy (median ITA, 4.33 multiples of the median). At a 75% detection rate, the false-positive rate could be reduced by substituting ITA for hCG measurements (from 5.6% to 2.6% for the triple test) or by adding ITA measurements to existing combinations (from 3.3% to 2.0% for the quadruple test).

Conclusions: Our data provide preliminary confirmation of the potential usefulness of urinary ITA measurements in detecting Down syndrome in a setting that simulates routine usage.
Real-Time Quantitative Reverse Transcription-PCR for Cyclin D1 mRNA in Blood, Marrow, and Tissue Specimens for Diagnosis of Mantle Cell Lymphoma
Authors: Howe John Greg , Crouch Jill , Cooper Dennis , Smith Brian R
Published: February 2004

Background: Overexpression of cyclin D1 mRNA, found in mantle cell lymphoma (MCL), is a critical diagnostic marker. We investigated the use of real-time reverse transcription-PCR (RT-PCR) for cyclin D1.

Methods: We studied 97 fresh specimens (50 blood, 30 bone marrow, 15 lymph node, and 2 other samples) from patients diagnosed with a variety of lymphoproliferative diseases, including 25 cases of MCL. We used real-time quantitative RT-PCR to evaluate cyclin D1 mRNA expression. Because blood and marrow specimens may contain only a minority of potentially malignant cells (as opposed to most lymph nodes) and to increase sensitivity, we normalized the cyclin D1 mRNA concentrations to mRNA of a B-cell-specific marker, CD19, as well as to previously characterized β2-microglobulin mRNA.

Results: In 16 of 21 cases of MCL with overt disease, the ratio of cyclin D1 mRNA to β2-microglobulin mRNA was increased, but all 21 cases showed increased ratios of cyclin D1 mRNA to CD19 mRNA. Cyclin D1 mRNA was low or undetectable in various lymphoproliferative diseases, including cases of ambiguous immunophenotype. The mRNA ratios were stable over 3–7 days of sample storage.

Conclusion: Quantitative RT-PCR for cyclin D1 mRNA normalized to CD19 mRNA can be used in the diagnosis of MCL in blood, marrow, and tissue.
Light-Induced Byproducts of Vitamin C in Multivitamin Solutions
Authors: Lavoie Jean-Claude , Chessex Philippe , Rouleau Thérèse , Migneault Diane , Comte Blandine
Published: February 2004

Background: When solutions of multivitamin preparations (MVPs) are exposed to light, H2O2 as well as organic peroxides are generated and the concentration of vitamin C decreases. The aim of this study was to determine, using mass spectrometry, whether the generation of oxidative byproducts of vitamin C, such as dehydroascorbate (DHA) and 2,3-diketogulonic acid (DKG), accounted for the reported decrease in ascorbic acid in MVPs exposed to light.

Methods: Mass spectrometry was used to document the formation of byproducts of ascorbic acid in solutions containing a MVP, vitamin C + riboflavin, and vitamin C + H2O2 + Fe2+. The involvement of ascorbic acid and H2O2 in the formation of organic peroxides was tested by measuring peroxide concentrations in solutions containing H2O2 with or without ascorbic acid and with or without Fe2+ before and after addition of catalase.

Results: The loss of ascorbic acid in photo-exposed MVPs was associated with the concomitant generation of byproducts different from DHA and DKG. Among them, one mass fingerprint was particularly observed with solutions of vitamin C + riboflavin exposed to ambient light as well as with the solution of vitamin C + H2O2 + Fe2+, suggesting a Fenton-like reaction. This fingerprint was associated with the formation of catalase-resistant peroxides.

Conclusion: Exposure of MVPs to light leads to the rapid loss of ascorbic acid and generation of specific byproducts that differ from DHA and DKG. The conversion of vitamin C into byproducts could be of biological importance in accounting for the decrease in ascorbic acid concentrations and the generation of organic peroxides in light-exposed MVPs.
Evaluation of Imprecision for Cardiac Troponin Assays at Low-Range Concentrations
Authors: Panteghini Mauro , Pagani Franca , Yeo Kiang-Teck J , Apple Fred S , Christenson Robert H , Dati Francesco , Mair Johannes , Ravkilde Jan , Wu Alan H B ,   the Committee on Standardization of Markers of Cardiac Damage of the IFCC
Published: February 2004

Background: The European Society of Cardiology/American College of Cardiology Committee for the Redefinition of Myocardial Infarction (MI) has recommended that an increased cardiac troponin should be defined as a measurement above the 99th percentile value of the reference group. A total imprecision (CV) at the decision limit of ≤10% is recommended. However, peer-reviewed data on assay imprecision are lacking. The purpose of this study was to construct the clinically relevant imprecision profiles for each of the commercially available cardiac troponin assays. Pools of human sera containing cardiac troponin concentrations around the MI decision limit were assessed to identify the lowest concentration associated with a 10% CV.

Methods: Eight serum pools targeting different concentrations of cardiac troponin (I and T) were prepared and stored at −70 °C until usage. The cardiac troponin measurement protocol consisted of two replicates per specimen per run, and one run per day for 20 days, using two reagent lots and three calibrations. Manufacturers of each cardiac troponin assay directly performed the measurements. Data analysis for each assay was centralized and performed according to the NCCLS EP5-A guideline.

Results: The lowest concentrations (μg/L) providing a 10% CV were as follows: AxSYM, 1.22; ACS:180, 0.37; Centaur, 0.33; Immuno 1, 0.34; Access, 0.06; Vidas, 0.36; Liaison, 0.065; Dimension, 0.26; Opus, 0.90; Stratus CS, 0.10; Immulite, 0.32; Vitros ECi, 0.44; Elecsys, 0.04; AIA 21, 0.09.

Conclusion: No cardiac troponin assay was able to achieve the 10% CV recommendation at the 99th percentile reference limit defined by the manufacturer.
Profile: air quality regulation policy in Portugal
Authors: Gomes João F. P.
Published: February 2004

Ten years after the publication of the first air quality laws in Portugal, and seven years after the publication of the respective emission limits, it seems appropriate to analyse the degree of law enforcement by the Portuguese manufacturing industry.

Therefore, based on the emission measurements made regularly by ISQ as the only officially accredited laboratory, a set of about 400 sources is analysed in terms of the compliance with the emission limits regarding total suspended particulate, sulphur dioxide, nitrogen oxides and VOCs.

The compliance is evaluated through a non‐dimensional parameter and plotted versus the emission flow rate to derive conclusions: it was noticed that emission limits are generally respected regarding sulphur dioxide and nitrogen oxides, which does not happen for the other pollutants considered in this study. However, the non‐compliance occurs mainly for very low emission flow rates, which suggests some alterations in the emission limits' applicability, which is being revised at the moment. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
The climate change policy network in Germany
Authors: Jost Gesine Foljanty , Jacob Klaus
Published: February 2004

Germany is frequently perceived as a forerunner in environmental policy, particularly since the change of government in 1998. We contribute to the debate on capacities for environmental policy by explaining this position with reference to the configuration of actors in the German policy network. The paper describes and analyses the policy network that determines the national position in international climate change negotiations. We ask what activities have been performed by the members of this network regarding the introduction of eco‐taxation, analyse what resources the various organizations dispose of and consider how far the organizations are interrelated when it comes to the exchange of information, cooperation and opposition. We conclude that NGOs are well integrated despite their comparably low financial resources, that the network is not fragmented and that coalitions are possible among the different types of actor. This may contribute to an explanation of the German position; however, we also conclude that comparative research is needed. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
Federal agency liability under the superfund act: It goes beyond federal facilities
Authors: Swenson Raymond Takashi
Published: February 2004

While many readers of the Federal Facilities Environmental Journal are involved with the performance of Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) cleanup on Department of Defense and Department of Energy facilities, many may be unfamiliar with the much broader CERCLA liability of federal agencies under other circumstances. This article places the various kinds of federal agency CERCLA liability into that wider context and serves as a “lessons learned” for environmental managers who want to avoid creating new CERCLA liability for their agencies. © 2004 Wiley Periodicals, Inc.
Natural resource trustee partnering in the urban river restoration initiative
Authors: Deason Jonathan P.
Published: February 2004

Many urban rivers in the United States contain severely contaminated sediments that adversely affect aquatic life and limit recreational and economic uses. The U.S. Environmental Protection Agency (EPA) estimated in 1997 that more than 1.2 billion cubic yards of contaminated sediment exist nationwide. In response to this situation, a new interagency cooperative program to restore rivers affected by contaminated sediments is being undertaken. This program, called the Urban River Restoration Initiative, offers a new opportunity for natural resource trustee agencies to address problems on a watershed basis in partnership with other federal, state, and local entities.

On July 2, 2002, the U.S. Army Corps of Engineers (Corps) and EPA signed a Memorandum of Understanding (MOU) entitled “Restoration of Degraded Urban Rivers” to coordinate remedial, water quality, and environmental restoration activities under the Clean Water Act, Comprehensive Environmental Response, Compensation, and Liability Act, Resource Conservation and Recovery Act, and the Water Resources Development Acts. The MOU calls for the identification of eight pilot projects to be announced and undertaken within one year of the date of the MOU.

The principal Federal natural resource trustee agencies (Interior and the National Oceanic and Atmospheric Administration [NOAA]) are likely to be heavily involved with the Corps, EPA, and state and local agencies in preparing comprehensive, watershed‐based plans for the eight pilot projects, and in undertaking such plans. A model for such partnering already is evolving in the Passaic River, New Jersey, watershed, where a cooperative study currently is being planned for a project that is likely to be named as one of the eight pilots. The Passaic River, located in the heartland of the U.S. industrial revolution, is one of the most complex riverine restoration challenges in the nation. The Passaic River Restoration Initiative, as the project is called, involves a partnership among four Federal and two state agencies. These are Interior, NOAA, the Corps, EPA, the New Jersey Department of Environmental Protection and the New Jersey Office of Maritime Resources. The U.S. Fish and Wildlife Service has been designated as the administrative trustee for the effort. © 2004 Wiley Periodicals, Inc.
Increased duodenal expression of divalent metal transporter 1 and iron-regulated gene 1 in cirrhosis
Authors: Stuart Katherine Anne , Anderson Gregory Jon , Frazer David Michael , Murphy Therese Luna , Powell Lawrie William , Fletcher Linda Maria , Crawford Darrell Henry
Published: February 2004

Hepatic hemosiderosis and increased iron absorption are common findings in cirrhosis. It has been proposed that a positive relation exists between intestinal iron absorption and the development of hepatic hemosiderosis. The current study investigated the duodenal expression of the iron transport molecules divalent metal transporter 1 (DMT1 [IRE]), iron-regulated gene 1 (Ireg1 [ferroportin]), hephaestin, and duodenal cytochrome b (Dyctb) in 46 patients with cirrhosis and 20 control subjects. Total RNA samples were extracted from duodenal biopsy samples and the expression of the iron transport genes was assessed by ribonuclease protection assays. Expression of DMT1 and Ireg1 was increased 1.5 to 3-fold in subjects with cirrhosis compared with iron-replete control subjects. The presence of cirrhosis per se and serum ferritin (SF) concentration were independent factors that influenced the expression of DMT1. However, only SF concentration was independently associated with Ireg1 expression. In cirrhosis, the expression of DMT1 and Ireg1 was not related to the severity of liver disease or cirrhosis type. There was no correlation between the duodenal expression of DMT1 and Ireg1 and the degree of hepatic siderosis. In conclusion, the presence of cirrhosis is an independent factor associated with increased expression of DMT1 but not Ireg1. The mechanism by which cirrhosis mediates this change in DMT1 expression has yet to be determined. Increased expression of DMT1 may play an important role in the pathogenesis of cirrhosis-associated hepatic iron overload. (Hepatology 2004;39:492-499.)
Activation of NF-κB and STAT3 in rat oval cells during 2-acetylaminofluorene/partial hepatectomy-induced liver regeneration
Authors: Sánchez Aránzazu , Factor Valentina M. , Schroeder Insa S. , Nagy Peter , Thorgeirsson Snorri S.
Published: February 2004

Proliferation and differentiation of hepatic stem cell progenies (i.e., oval cells) sustain liver regeneration when the replicative and functional capacity of hepatocytes is impaired. The signaling pathways that control stem cell activation remain poorly understood. In this study, we investigated the involvement of nuclear factor-kappa B (NF-κB) and signal transducer and activator of transcription 3 (STAT3) in oval cell-mediated liver regeneration induced by 2-acetylaminofluorene/partial hepatectomy (AAF/PH) protocol. Using OV1 as a marker for identification and sorting of oval cells, we established that both NF-κB and STAT3 were highly activated in the OV1+ cell population. Three distinct subpopulations of oval cells were defined as OV1low, OV1medium, and OV1high, based on the intensity of OV1 staining. Quantitative polymerase chain reaction analysis revealed that they represent different stages of oval cell differentiation along hepatocyte lineage. OV1low cells displayed the least differentiated phenotype as judged by high expression of c-kit and lack of hepatocytic differentiation markers, whereas OV1high cells lost c-kit expression, were more proliferative, and acquired more mature hepatocytic phenotype. Notably, NF-κB was activated uniformly in all three subpopulations of oval cells. In contrast, phosphorylation of STAT3 was detected only in OV1high cells. In conclusion, transcriptional activity supported by NF-κB and STAT3 is required for oval cell activation, expansion, and differentiation. The differential induction of NF-κB and STAT3 point to a distinct role for these transcription factors at different stages of hepatic stem cell differentiation. (Hepatology 2004;39:376-385.)
Worsening of cerebral hyperemia by the administration of terlipressin in acute liver failure with severe encephalopathy
Authors: Shawcross Debbie L. , Davies Nathan A. , Mookerjee Rajeshwar P. , Hayes Peter C. , Williams Roger , Lee Alistair , Jalan Rajiv
Published: February 2004

There is increasing evidence that terlipressin is useful in patients with cirrhosis and hepatorenal syndrome, but there are no data of its use in patients with acute liver failure (ALF) in whom hepatorenal syndrome is common. Although terlipressin produces systemic vasoconstriction, it produces cerebral vasodilatation and may increase cerebral blood flow (CBF). Increased CBF contributes to intracranial hypertension in patients with ALF. The aim of this study was to evaluate the safety of terlipressin in patients with ALF with respect to cerebral hemodynamics. Six successive patients with ALF were ventilated electively for grade IV hepatic encephalopathy. Patients were monitored invasively and CBF was measured (Kety-Schmidt technique). Measurements were made before and at 1, 3, and 5 hours after intravenous (single bolus) administration of terlipressin (0.005 mg/kg), median, 0.25 mg (range, 0.2-0.3 mg). There was no significant change in heart rate, mean arterial pressure, or cardiac output. CBF and jugular venous oxygen saturation both increased significantly at 1 hour (P = 0.016). Intracranial pressure increased significantly at 1 hour (P = 0.031), returning back to baseline values at 2 hours. In conclusion, administration of terlipressin, at a dose that did not alter systemic hemodynamics, resulted in worsening of cerebral hyperemia and intracranial hypertension in patients with ALF and severe hepatic encephalopathy. These data suggest the need to exercise extreme caution in the use of terlipressin in these patients in view of its potentially deleterious consequences on cerebral hemodynamics. (Hepatology 2004;39:471-475.)
Blockade of receptor for advanced glycation end product (RAGE) attenuates ischemia and reperfusion injury to the liver in mice
Authors: Zeng Shan , Feirt Nikki , Goldstein Michael , Guarrera James , Ippagunta Nikalesh , Ekong Udeme , Dun Hao , Lu Yan , Qu Wu , Schmidt Ann Marie , Emond Jean C.
Published: February 2004

Hepatic ischemia/reperfusion (I/R) injury associated with liver transplantation and hepatic resection is characterized by hepatocellular damage and a deleterious inflammatory response. In this study, we examined whether receptor for advanced glycation end product (RAGE) activation is linked to mechanisms accentuating inflammation on I/R in a murine model of total hepatic ischemia. Animals treated with soluble RAGE (sRAGE), the extracellular ligand-binding domain of RAGE, displayed increased survival after total hepatic I/R compared with vehicle treatment. TUNEL assay and histologic analysis revealed that blockade of RAGE was highly protective against hepatocellular death and necrosis on I/R; in parallel, proliferating cell nuclear antigen was enhanced in livers of mice treated with sRAGE. Rapid activation of p38, p44/42, stress-activated protein kinase and c-Jun N-terminal kinase mitogen-activated protein kinases, signal transducer and activator of transcription-3, and nuclear translocation of activator protein-1 was evident at early times on I/R. In the remnants of sRAGE-treated livers, however, activation of each of these signaling and transcription factor pathways was strikingly decreased. sRAGE-treated remnants displayed enhanced activation of nuclear factor κB, in parallel with increased transcripts for the proregenerative cytokine, tumor necrosis factor-α. In conclusion, these data suggest that RAGE modulates hepatic I/R injury, at least in part by activation of key signaling pathways linked to proinflammatory and cell death-promoting responses. We propose that blockade of this pathway may represent a novel strategy to attenuate injury in hepatic I/R and to facilitate regeneration. (Hepatology 2004;39:422-432.)
Uncoupling protein-2 deficiency promotes oxidant stress and delays liver regeneration in mice
Authors: Horimoto Masayoshi , Fülöp Péter , Derdák Zoltán , Wands Jack R. , Baffy György
Published: February 2004

The control of liver regeneration remains elusive. Because reactive oxygen species (ROS) are able to mediate cell growth arrest and activate proteins that inhibit the cell cycle, ROS production may have a negative impact on liver regeneration. We examined how liver regeneration is affected by uncoupling protein-2 (UCP2), an inner mitochondrial membrane carrier that senses and negatively regulates superoxide production. Liver regeneration was monitored up to 5 days and was found to be significantly delayed in UCP2−/− mice after partial hepatectomy. Apoptosis rates in UCP2+/+ and UCP2− /− liver remnants were similar, while parameters of cell proliferation indicated a diminished response in UCP2− /− mice with corresponding changes in the expression of key cell cycle regulatory proteins and prolonged activation of stress-responsive protein kinase p38. Levels of malondialdehyde, a marker of ROS generation and oxidant stress, were elevated in UCP2− /− livers at every examined time point. Liver remnants of UCP2+ /+ mice 48 hours post-hepatectomy showed a fourfold increase in the expression of UCP2 protein primarily detected in hepatocytes. In conclusion, our results suggest that absent or insufficient UCP2 function in the regenerating liver results in increased ROS production and negatively modulates the control of cell cycle. (Hepatology 2004;39:386-392.)
Hepatic expression of ANG2 RNA in metastatic colorectal cancer
Authors: Ogawa Minoru , Yamamoto Hirofumi , Nagano Hiroaki , Miyake Yasuhiro , Sugita Yurika , Hata Taishi , Kim Byung-no , Ngan Chew Yee , Damdinsuren Bazarragchaa , Ikenaga Masakazu , Ikeda Masataka , Ohue Masayuki , Nakamori Shoji , Sekimoto Mitsugu , Sakon Masato , Matsuura Nariaki , Monden Morito
Published: February 2004

We examined the RNA content of the gene encoding angiopoietin (Ang)-2, a modifier of angiogenesis, in hepatic metastases of colorectal cancer (CRC) to explore the role of this protein in neovascularization of metastatic foci. Metastatic CRC exhibited notable blood flow and tumor vessel formation at tumor frontiers. Reverse-transcription polymerase chain reaction assays indicated that the ANG2 RNA content was greater in metastatic CRC than in primary CRC. Investigation of metastatic foci using laser capture microdissection revealed that the RNA content of ANG2, but not ANG1, increased from the bordering liver region to the periphery of the metastatic disease, and also from the periphery to the intermediate portion of the metastatic lesion; immunohistochemical analysis confirmed that there was a corresponding gradual increase in Ang-2 protein expression. Tie-2, a receptor for angiopoietins, was preferentially expressed in the bordering liver region rather than in metastatic CRC. Vascular endothelial growth factor (VEGF) also exhibited an expression pattern similar to that of Ang-2, and there was a significant correlation between the RNA content of ANG2 and that of VEGF in dissected samples (P = .002). Western blot analysis suggested that expression of Ang-1, Ang-2, Tie-2, and VEGF may be regulated at a transcriptional level. The increase in ANG2 RNA content from the peripheral portion of the tumor to the intermediate portion, coinciding with the decrease in recruitment of periendothelial supporting cells around the vascular endothelial cells, suggests that Ang-2 may play a role in the immaturity of tumor vessels. In conclusion, the current study suggests that Ang-2 and VEGF may cooperate to enhance the formation of new blood vessels in metastases of CRC to the liver. (Hepatology 2004;39:528-539.)
Cancer-associated molecular signature in the tissue samples of patients with cirrhosis†
Authors: Kim Jin Woo , Ye Qinghai , Forgues Marshonna , Chen Yidong , Budhu Anuradha , Sime Jessica , Hofseth Lorne J. , Kaul Rashmi , Wang Xin Wei
Published: February 2004

Several types of aggressive cancers, including hepatocellular carcinoma (HCC), often arise as a multifocal primary tumor. This suggests a high rate of premalignant changes in noncancerous tissue before the formation of a solitary tumor. Examination of the messenger RNA expression profiles of tissue samples derived from patients with cirrhosis of various etiologies by complementary DNA (cDNA) microarray indicated that they can be grossly separated into two main groups. One group included hepatitis B and C virus infections, hemochromatosis, and Wilson's disease. The other group contained mainly alcoholic liver disease, autoimmune hepatitis, and primary biliary cirrhosis. Analysis of these two groups by the cross-validated leave-one-out machine-learning algorithms revealed a molecular signature containing 556 discriminative genes (P < .001). It is noteworthy that 273 genes in this signature (49%) were also significantly altered in HCC (P < .001). Many genes were previously known to be related to HCC. The 273-gene signature was validated as cancer-associated genes by matching this set to additional independent tumor tissue samples from 163 patients with HCC, 56 patients with lung carcinoma, and 38 patients with breast carcinoma. From this signature, 30 genes were altered most significantly in tissue samples from high-risk individuals with cirrhosis and from patients with HCC. Among them, 12 genes encoded secretory proteins found in sera. In conclusion, we identified a unique gene signature in the tissue samples of patients with cirrhosis, which may be used as candidate markers for diagnosing the early onset of HCC in high-risk populations and may guide new strategies for chemoprevention. Supplementary material for this article can be found on the Hepatology website (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html). (Hepatology 2004;39:518-527.)
A sequential study of serum bacterial DNA in patients with advanced cirrhosis and ascites
Authors: Francés Rubén , Benlloch Susana , Zapater Pedro , González José M. , Lozano Beatriz , Muñoz Carlos , Pascual Sonia , Casellas Juan A. , Uceda Francisco , Palazón José M , Carnicer Fernando , Pérez-Mateo Miguel , Such José
Published: February 2004

Bacterial translocation is currently considered the main pathogenic mechanism leading to spontaneous bacterial peritonitis in patients with advanced cirrhosis and ascites. However, to the authors' knowledge there is no information regarding the characteristics of this process in humans. The goals of the current study were to pursue partially identified bacterial DNA in blood (what the authors consider molecular evidence of bacterial translocation) through its relative quantification in a 72-hour study period by using real-time polymerase chain reaction (PCR). A consecutive series of 17 patients with advanced cirrhosis and culture-negative, nonneutrocytic ascites were studied. Therapeutic paracentesis was performed at the time of admission, and blood samples were obtained at baseline and every 8 hours in a 3-day period. Bacterial DNA was detected by a PCR-based method, relatively quantified by real-time PCR, and identified by automated nucleotide sequencing. Seven of 17 patients demonstrated the simultaneous presence of bacterial DNA in blood and ascitic fluid at the time of admission. After therapeutic paracentesis was performed, bacterial DNA persisted in the blood for a minimum of 24 hours, and was reported to last as long as 72 hours in some patients. In addition, different patterns of bacterial DNA appearance and clearance from the blood were identified. The nucleotide sequencing process demonstrated that bacteria detected in the first sample were identical to those noted in subsequent detections over time. In conclusion, bacterial translocation is a single-species, dynamic process that appears to develop in a subgroup of patients with advanced cirrhosis. (Hepatology 2004;39:484-491.)
The effect of hypertonic sodium chloride on intracranial pressure in patients with acute liver failure
Authors: Murphy Nicholas , Auzinger Georg , Bernel William , Wendon Julia
Published: February 2004

Acute liver failure (ALF) is a rare condition characterized by the development of encephalopathy in the absence of chronic liver disease. Cerebral edema occurs in up to 80% of patients with Grade IV encephalopathy. In the current prospective randomized controlled clinical trial, we examined the effect of induced hypernatremia on the incidence of intracranial hypertension (IH) in patients with ALF. Thirty patients with ALF and Grade III or IV encephalopathy were randomized. Patients in Group 1 (n = 15) received the normal standard of care. Patients in Group 2 (n = 15) received standard care and hypertonic saline (30%) via infusion to maintain serum sodium levels of 145-155 mmol/L. Intracranial pressure (ICP) was monitored in all patients with a subdural catheter (Camino Systems, San Diego, CA) for up to 72 hours after inclusion. Serum sodium levels became significantly different from the levels observed in the control group at 6 hours (P < .01). Over the first 24 hours, norepinephrine dose increased relative to baseline in the control group (P < .001; 13 patients) but not in the treatment group. ICP decreased significantly relative to baseline over the first 24 hours in the treatment group (P = .003; 13 patients) but not in the control group. The incidence of IH, defined as a sustained increase in ICP to a level of 25 mm Hg or greater, was significantly higher in the control group (P = .04). In conclusion, induction and maintenance of hypernatremia can reduce the incidence and severity of IH in patients presenting with ALF. (Hepatology 2004;39:464-470.)
CYP2E1 overexpression alters hepatocyte death from menadione and fatty acids by activation of ERK1/2 signaling
Authors: Schattenberg Jörn M. , Wang Yongjun , Rigoli Raina M. , Koop Dennis R. , Czaja Mark J.
Published: February 2004

Chronic oxidative stress induced by overexpression of the cytochrome P450 isoform 2E1 (CYP2E1) has been implicated in hepatocyte injury and death. However, the mechanism by which CYP2E1 overexpression may promote cell death is unknown. Acute oxidative stress activates mitogen-activated protein kinases (MAPK), suggesting that chronic oxidant generation by CYP2E1 may regulate cellular responses through these signaling pathways. The effect of CYP2E1 overexpression on MAPK activation and their function in altering death responses of CYP2E1-overexpressing hepatocytes were investigated. Chronic CYP2E1 overexpression led to increased extracellular signal-regulated kinase 1/2 (ERK1/2) activation constitutively and in response to oxidant stress from the superoxide generator menadione. CYP2E1-overexpressing cells were resistant to menadione toxicity through an ERK1/2-dependent mechanism. Similar to menadione, the polyunsaturated fatty acid (PUFA) arachidonic acid (AA) induced an increased activation of ERK1/2 in hepatocytes that overexpressed CYP2E1. However, CYP2E1-overexpressing cells were sensitized to necrotic death from AA and the PUFA γ-linolenic acid, but not from saturated or monounsaturated fatty acids. Death from PUFA resulted from oxidative stress and was blocked by inhibition of ERK1/2, but not p38 MAPK or activator protein-1 signaling. CYP2E1 expression induced ERK1/2 activation through increased epidermal growth factor receptor (EGFR)/c-Raf signaling. Inhibition of EGFR signaling reversed CYP2E1-induced resistance to menadione and sensitization to AA toxicity. In conclusion, chronic CYP2E1 overexpression leads to sustained ERK1/2 activation mediated by EGFR/c-Raf signaling. This adaptive response in hepatocytes exposed to chronic oxidative stress confers differential effects on cellular survival, protecting against menadione-induced apoptosis, but sensitizing to necrotic death from PUFA. (Hepatology 2004;39;444-445.)
Stereological measurement of porto-central gradients in gene expression in mouse liver
Authors: Ruijter Jan M. , Gieling Roben G. , Markman Marry M. , Hagoort Jaco , Lamers Wouter H.
Published: February 2004

The liver is thought to consist of lobules, numerous repeating, randomly oriented units. Within these lobules, genes are expressed in gradients along the porto-central axis, which spans the distance between portal and central veins. We have developed a robust stereological method to map all points in an image to their position on this porto-central axis. This approach is based on the distribution of well-characterized periportal and pericentral enzymes, which are visualized on sections preceding and following the section of interest. Because expression of the model genes phosphoenolpyruvate carboxykinase and ornithine aminotransferase declines gradually with increasing distance from the portal vein and central vein, respectively, these genes can be used to prepare images with topographical information without any assumption about the shape of the hepatic unit, or about the direction or shape of the gradient to be determined. The “relative distance” image is a 2-dimensional image that accurately maps the relative position of hepatocytes on the porto-central axis in 3-dimensional space. It is superimposed on the serial section under investigation to relate local staining density to position on the porto-central axis and obtain the gene expression gradient. The method was used to determine the expression gradient of 2 periportal and 2 pericentral enzymes and their response to fasting. The “total distance” image was used to measure the length of the porto-central axis, which was approximately 210 μm in mice and found to decrease 13% after 1 day of starvation. The method can be applied to any tissue component that can be stained quantitatively. (Hepatology 2004;39:343-352.)
A common staging system for hepatocellular carcinoma
Authors: Di Bisceglie Adrian M. , Strasberg Steven
Published: February 2004

The Consensus Panel makes the following recommendations based on the above currently available evidence.
Oval cells compensate for damage and replicative senescence of mature hepatocytes in mice with fatty liver disease
Authors: Yang Shiqi , Koteish Ayman , Lin Huizhi , Huang Jiawen , Roskams Tania , Dawson Valina , Diehl Anna Mae
Published: February 2004

Hepatic steatosis may have a generally benign prognosis, either because most hepatocytes are not significantly injured or mechanisms to replace damaged hepatocytes are induced. To determine the relative importance of these mechanisms, we compared hepatocyte damage and replication in ethanol-fed and ob/ob mice with very indolent fatty liver disease to that of healthy control mice and PARP-1-/- mice with targeted disruption of the DNA repair enzyme, poly(ADP-ribose) polymerase. Compared to the healthy controls, both groups with fatty livers had significantly higher serum alanine aminotransferase values, hepatic mitochondrial H2O2 production, and hepatocyte oxidative DNA damage. A significantly smaller proportion of the hepatocytes from fatty livers entered S phase when cultured with mitogens. Moreover, this replicative senescence was not reversed by treating cultured hepatocytes with agents (i.e., betaine or leptin) that improve liver disease in intact ethanol-fed or leptin-deficient mice. Hepatocytes from PARP1-/- mice also had more DNA damage and reduced DNA synthesis in response to mitogens. However, neither mice with fatty livers nor PARP-1-deficient mice had atrophic livers. All of the mice with senescent mature hepatocytes exhibited hepatic accumulation of liver progenitor (oval) cells and oval cell numbers increased with the demand for hepatocyte replacement. Therefore, although hepatic oxidant production and damage are generally increased in fatty livers, expansion of hepatic progenitor cell populations helps to compensate for the increased turnover of damaged mature hepatocytes. In conclusion, these results demonstrate that induction of mechanisms to replace damaged hepatocytes is important for limiting the progression of fatty liver disease. (Hepatology 2004;39:403-411.)
The routinization of innovation research: a constructively critical review of the state‐of‐the‐science
Authors: Anderson Neil , De Dreu Carsten K. W. , Nijstad Bernard A.
Published: February 2004

In this review we argue that facilitators of innovation at the individual, group, and organizational levels have been reliably identified, and that validated process models of innovation have been developed. However, a content analysis of selected research published between 1997 and 2002 suggests a routinization of innovation research, with a heavy focus on replication–extension, cross‐sectional designs, and a single level of analysis. We discuss five innovative pathways for future work: Study innovation as an independent variable, across cultures, within a multi‐level framework, and use meta‐analysis and triangulation. To illustrate we propose a ‘distress‐related innovation’ model of the relations between negatively connotated variables and innovation at the individual, group, and organizational levels of analysis. Copyright © 2004 John Wiley & Sons, Ltd.
Do personal characteristics and cultural values that promote innovation, quality, and efficiency compete or complement each other?
Authors: Miron Ella , Erez Miriam , Naveh Eitan
Published: February 2004

This study examines whether the same personal and contextual characteristics that enhance innovation could also contribute to quality and efficiency. Three hundred and forty‐nine engineers and technicians in 21 units of a large R&D company participated in the study. Using CFA and HLM models, we demonstrated that people have the ability to both be creative and pay attention to detail, and that an innovative culture does not necessarily compete with a culture of quality and efficiency. Yet, to reach innovative performance creative people need to take the initiative in promoting their ideas, with the possible corresponding price of low performance quality. Copyright © 2004 John Wiley & Sons, Ltd.
Characteristics of wintertime daily and extreme minimum temperature over South Korea
Authors: Ryoo Sang‐Boom , Kwon Won‐Tae , Jhun Jong‐Ghap
Published: February 2004

In South Korea, consecutive positive temperature anomalies have been observed since the mid‐1980s. The objective of this study is to assess the recent trends in, and variability of, daily minimum temperature over South Korea with particular emphasis on its extremes. Temporal characteristics of wintertime daily and extreme minimum temperature‐related variables were analysed on a seasonal basis for the period of 1958–59 to 2000–01. The results show continually fewer days with extreme low minimum temperature since the mid‐1980s. However, no significant change in the 1 day temperature difference was observed during the same period, indicating little change in the frequency of cold surges. Also, during the period analysed, there is a significant positive trend in the seasonal mean temperature, a negative trend in the frequency of the extreme cold days, and no significant trend in the seasonal occurrence of cold surges.

Northern Hemisphere geopotential height fields before and after 1986–87, i.e. the start of successive positive anomalies in the winter surface air temperature over South Korea, showed a substantial decrease throughout the troposphere over the polar region. In the upper levels the overall pattern becomes more wavelike, with eddies embedded between meanders. The differences in the lower troposphere are remarkably similar to the Arctic oscillation, although the centre in the North Atlantic is shifted toward western Europe and differences in the North Pacific are relatively weaker than those in the polar region. The recent positive phase of the Arctic oscillation may contribute to these abrupt changes in wintertime daily minimum temperatures over South Korea. El Niño–southern oscillation phenomena appear to contribute to the interannual variation of cold surge days in South Korea. Years with no cold surges were experienced during La Niña episodes. On the other hand, all years with more than four cases of cold surges were during El Niño episodes. Copyright © 2004 Royal Meteorological Society