bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of CMOS integrated optical receiver for short‐range data communication
Authors: Kuwabara Kei , Matsumoto Yoshinori
Published: November 2004

Reduction of the size and cost of optical receivers is important to the proliferation of optical communications technology for short‐distance communications. In the present research, an integrated optical receiver is fabricated with a standard 0.35‐µm CMOS process targeting the POF optical transmission system. A photodiode, a trans‐impedance amplifier, a limiting amplifier, and a buffer are integrated in this optical receiver. The photodiode is formed with an N‐well and a P‐diffused layer of stripe configuration and has an optical receiving surface area of 150 × 150 µm and a response sensitivity of about 0.04 A/W (at a wavelength of 650 nm). In the CMOS process, the large junction capacitance of the photodiode is problematic. Therefore, the input impedance of the circuit is lowered by means of an RGC‐type trans‐impedance amplifier and LC resonance is suppressed by optimization of the package and circuit. The chip is mounted in a small ceramic package for measurement. Excellent eye patterns are obtained. The minimum receiving sensitivity for a bit error rate of less than 10−9 is −10 dBm at 600 Mbit/s and −4.5 dBm at 1 Gbit/s. © 2004 Wiley Periodicals, Inc. Electron Comm Jpn Pt 2, 87(12): 10–18, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecjb.20099
Oxidative Dehydrogenation of Secondary Amines: The Case of the N,N,N′‐Tris(2‐pyridylmethyl)‐o‐phenylenediamine Ligand when Coordinated to Iron Dichloride
Authors: Machkour Ahmed , Mandon Dominique , Lachkar Mohammed , Welter Richard
Published: November 2004

We report the preparation and the X‐ray crystal structure of the iron complex [Fe(L1)Cl][Cl] [L1 = N,N,N′‐tris(2‐pyridylmethyl)‐o‐phenylenediamine], and its reactivity towards molecular dioxygen. Upon exposure to dry O2, coordinated L1 is oxidatively dehydrogenated to the aldimine ligand L2. The ferric cation [Fe(L2)(CH3CN)]3+ is thus obtained, and characterized by UV/Vis and EPR spectroscopy, and X‐ray diffraction analysis. The free L2 ligand can be recovered after decomplexation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Construction of Nano‐Channels Based on Zinc(II) Pyrazine‐2‐carboxylate Complexes
Authors: Sunahara Tetsuya , Onaka Satoru , Ito Mitsuhiro , Imai Hiroyuki , Inoue Katsuya , Ozeki Tomoji
Published: November 2004

The reaction of pyrazine‐2‐carboxylate (pca) and bis(pyridine) derivatives, such as 4,4′‐bipyridine (bipy), 1,2‐bis(4‐pyridyl)ethylene (bpen), 1,2‐bis(4‐pyridyl)ethane (bpea), 1,3‐bis(4‐pyridyl)propane (bpp), and 4,4′‐azopyridine (azp), with zinc perchlorate gives supramolecules with grid and/or channel structures. The new complexes reported here are trans‐[Zn(bipy)(pca)(H2O)]ClO4·(EtOH)0.5·(H2O)0.5 (1), [Zn(μ‐bpen)(bpen)(pca)(H2O)]·ClO4·2H2O (2), [Zn(bpea)(pca)]ClO4·(EtOH)0.5 (3), and [Zn(bpp)(pca)(MeOH)]ClO4 (4). Their structures have been established by single‐crystal X‐ray diffraction. Some of these complexes contain voids with nanometer dimensions. Small molecules such as H2O, MeOH, and EtOH contained in these voids can be removed without destruction of the parental suprastructure. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Switching of Molecular Spin States in Inorganic Complexes by Temperature, Pressure, Magnetic Field and Light: Towards Molecular Devices
Authors: Bousseksou Azzedine , Molnár Gábor , Matouzenko Galina
Published: November 2004

The spin crossover phenomenon in molecular inorganic compounds is one of the most spectacular examples of bistability phenomena leading to a switching between the high‐spin and the low‐spin states of the molecule by several means such as temperature, pressure, light and magnetic field (multi‐property molecular switching). In the present microreview we report our most important findings, both experimental results and theoretical approaches, and discuss possible technological applications for each switching method as well as the recent synthesis of new spin crossover molecular materials. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Induction of micronucleated cells in the shed skin of salamanders (Ambystoma sp.) treated with colchicine or cyclophosphamide
Authors: Zamora‐Perez Ana , Zúñiga‐González Guillermo M. , Gómez‐Meda Belinda C. , Ramos‐Ibarra M. Luisa , Batista‐González Cecilia M. , Torres‐Bugarín Olivia
Published: November 2004

The micronucleus (MN) assay can be used to detect the genotoxic effects of chemical agents in virtually any cell that divides frequently. Salamanders (Ambystoma sp.) are amphibians that can be easily maintained and bred in the laboratory and spontaneously shed their skin every 2.5–4 days. In this present study, we have evaluated the usefulness of this shed skin for the MN assay. We exposed salamanders to different concentrations of both the aneugen colchicine (COL) and the clastogen cyclophosphamide (CP) and we determined the frequency of micronucleated cells (MNCs) in their sheds. Fragments of shed skin were placed on clean slides, fixed, stained, observed with a light microscope, and the number of MNCs was counted. The MNC frequency was increased significantly by all doses of COL and CP tested, administered either as single or repeated exposures. The presence of MNCs in the shed skin and the speed of sloughing lead us to propose that the sheds of Ambystoma sp., or other amphibians that slough their skin, are suitable alternative models for detecting genotoxic exposures relevant to aquatic environments. Environ. Mol. Mutagen., 2004. © 2004 Wiley‐Liss, Inc.
Predicting binary time series of SO2 using generalized additive models with unknown link function
Authors: Roca‐Pardiñas J. , González‐Manteiga W. , Febrero‐Bande M. , Prada‐Sánchez J. M. , Cadarso‐Suárez C.
Published: November 2004

The goal of article paper is to use the generalized additive model with unknown link function to predict the binary time series of SO2 concentration. The authors propose a modified version of the local scoring algorithm that allows for the non‐parametric estimation of the link function, by using local linear kernel smoothers. Results derived from the simulation study and the application to real data reveal that the predictor obtained with the proposed model presents a better performance in comparison with those obtained by using alternative transformed binary regression models. Copyright © 2004 John Wiley & Sons, Ltd.
Haplotype analysis and age estimation of the 113insR CDKN2A founder mutation in Swedish melanoma families
Authors: Hashemi Jamileh , Bendahl Pär‐Ola , Sandberg Therese , Platz Anton , Linder Stig , Stierner Ulrika , Olsson Håkan , Ingvar Christian , Hansson Johan , Borg Åke
Published: November 2004

Germline mutations in the CDKN2A tumor suppressor gene located on 9p21 have been linked to development of melanomas in some families. A germline 3‐bp insertion in exon 2 of CDKN2A, leading to an extra arginine at codon 113 (113insR), has been identified in 17 Swedish melanoma families. Analysis of 10 microsatellite markers, spanning approximately 1 Mbp in the 9p21 region, showed that all families share a common allele for at least one of the markers closest to the CDKN2A gene, suggesting that the 113insR mutation is an ancestral founder mutation. Differences in the segregating haplotypes, due to meiotic recombinations and/or mutations in the short‐tandem‐repeat markers, were analyzed further to estimate the age of the mutation. Statistical analysis using a maximum likelihood approach indicated that the mutation arose 98 generations (90% confidence interval: 52–167 generations), or approximately 2,000 years, ago. Thus, 113insR would be expected to have a more widespread geographic distribution in European and North American regions with ancestral connections to Sweden. Alternatively, CDKN2A may lie in a recombination hot spot region, as suggested by the many meiotic recombinations in this narrow ∼1‐cM region on 9p21. © 2001 Wiley‐Liss, Inc.
Three chromosomal rearrangements in neuroblastoma cluster within a 300‐kb region on 1p36.1
Authors: Spieker Nicole , Beitsma Mabel , Van Sluis Peter , Chan Alvin , Caron Huib , Versteeg Rogier
Published: November 2004

Deletions in the short arm of chromosome 1 (1p36) and MYCN amplification are common in neuroblastoma. Previously we showed evidence of at least two different neuroblastoma tumor‐suppressor loci on 1p. One is associated with MYCN single‐copy tumors and maps distal on 1p36.3. A second, more proximal locus maps to 1p36.1 and is deleted in about 90% of neuroblastomas with MYCN amplification. The cell line UHG‐NP has the smallest 1p36 deletion of all neuroblastoma cell lines with MYCN amplifications. We assume that the more proximal locus maps within this deletion, close to its proximal border. Here we present the exact localization of the 1p deletion breakpoint of UHG‐NP. A 600‐kb PAC contig spanning the breakpoint was analyzed for genes and aberrations. Two more neuroblastoma‐associated aberrations were mapped within 150 kb of the UHG‐NP breakpoint. Within the contig, we identified nine genes expressed in neuroblastoma cells. One of these genes, AML2, maps 200 kb distal to the UHG‐NP breakpoint but is expressed only rarely in neuroblastoma and showed no mutations. © 2001 Wiley‐Liss, Inc.
CDK4 is a probable target gene in a novel amplicon at 12q13.3–q14.1 in lung cancer
Authors: Wikman Harriet , Nymark Penny , Väyrynen Aki , Jarmalaite Sonata , Kallioniemi Anne , Salmenkivi Kaisa , Vainio‐Siukola Katri , Husgafvel‐Pursiainen Kirsti , Knuutila Sakari , Wolf Maija , Anttila Sisko
Published: November 2004

Several chromosomal regions are recurrently amplified or deleted in lung tumors, but little is known about the underlying genes, which could be important mediators in tumor formation or progression. In lung cancer, the RB1–CCND1–CDKN2A pathway, involved in the G1–S transition, is damaged in nearly all tumors. In the present study, we localized a novel amplicon in lung tumors to a fragment of less than 0.5 Mb at 12q13.3–q14.1 by using comparative genomic hybridization (CGH) on cDNA microarrays. This approach enabled us to identify 10–15 genes with the most consistent amplifications. Semiquantitative RT‐PCR analyses of 13 genes in this region showed that four of them (CDK4, CYP27B1, METTL1, and TSFM) were also highly up‐regulated. Immunohistochemical (IHC) analysis of 141 tumor samples on a tissue microarray showed that CDK4 was expressed at a high level in 23% of lung tumors. Six (21.4%) of the tumors with high CDK4 expression (n = 28) were shown by fluorescence in situ hybridization (FISH) to contain the 12q13.3–q14.1 amplification. For CDK4, a positive correlation was found between gene copy number (FISH and CGH array), mRNA expression (RT‐PCR), and level of protein expression (IHC). CDK4 expression did not correlate with CDKN2A methylation status. Amplification of CDK4 has been described in other tumor types, but its role in lung cancer remains to be elucidated. Although CDK4 amplification seems to be a relatively rare event (4.3%) in lung tumors, it indicates the significance of the RB1–CCND1 pathway in lung tumorigenesis. © 2004 Wiley‐Liss, Inc.
Archaeological site distribution by geomorphic setting in the southern lower Cuyahoga River Valley, northeastern Ohio: Initial observations from a GIS database
Authors: Bauer Andrew , Nicoll Kathleen , Park Lisa , Matney Timothy
Published: November 2004

In this study, we compiled unpublished archival documentation of archaeological site locations from the southern part of the Cuyahoga River Valley in northeastern Ohio, USA, registered at the State of Ohio Historic Preservation Office into a Geographic Information Systems (GIS) database. Using digitized soil shapefiles to generate a geomorphic data layer, we assessed the spatial and temporal distribution of 79 known archaeological sites by landform association. This digital compilation indicates that Woodland period, Late Prehistoric, and Historic sites occur in most geomorphic settings along the river valley. In contrast, Paleoindian and Archaic sites only occur on Wisconsinan cut terraces and in upland interfluve settings, indicating that most of these documented sites are in primary contexts and have not been reworked. We discuss the distribution of archaeological sites in the study region as a function of various factors, including cultural activities, taphonomic processes, landform development, and the nature and extent of the original archaeological surveys. Observed spatial patterns of known sites clearly reflect local geomorphological controls; artifactual contexts from the earlier prehistoric periods are underrepresented in the database. We conclude that additional site surveys, as well as the excavation and documentation of new sites in this part of Ohio, are required to understand local prehistoric economies and to ascertain patterns of culturally mediated land use. © 2004 Wiley Periodicals, Inc.
Allelic association patterns for a dense SNP map
Authors: Weir B.S. , Hill W.G. , Cardon L.R.
Published: November 2004

A dense set of 5,000 SNPs on a 10‐Mb region of human chromosome 20 has been typed on samples of African Americans, East Asians, and United Kingdom Caucasians. There are departures from Hardy‐Weinberg equilibrium beyond the level at which markers are often discarded because of possible genotyping errors. The observation that markers showing such departures are often close together on the chromosome confirms the result that Hardy‐Weinberg tests at two loci are correlated to an extent that depends on the linkage disequilibrium between those two markers. Linkage disequilibrium can be described by the composite linkage disequilibrium coefficient, the parameter that determines the behavior of case‐control allelic tests of association. A useful preliminary investigation of datasets of this type is provided by counting the numbers of distinct multi‐locus genotypes in windows of a few markers. Genet. Epidemiol. © 2004 Wiley‐Liss, Inc.
High‐resolution MRI reflects myeloarchitecture and cytoarchitecture of human cerebral cortex
Authors: Eickhoff Simon , Walters Nathan B. , Schleicher Axel , Kril Jillian , Egan Gary F. , Zilles Karl , Watson John D.G. , Amunts Katrin
Published: November 2004

Maps of cytoarchitectonically defined cortical areas have proven to be a valuable tool for anatomic localization of activated brain regions revealed by functional imaging studies. However, architectonic data require observations in a sample of postmortem brains. They can only be used reliably for comparison with functional data as probabilistic maps after spatial normalization to a common reference space. The complete architectonic analysis of an individual living brain has not been achievable to date, because the relationship remains unclear between laminar gray value changes of cerebral cortex in magnetic resonance (MR) images and those of cyto‐ and myeloarchitectonic histologic sections. We examined intensity profiles through the cortex in five imaging modalities: in vivo T1 and postmortem T2 MRI, one cell body stain, and two myelin stains. After visualizing the dissimilarities in the shapes of these profiles using a canonical analysis, differences between the profiles from the different image modalities were compared quantitatively. Subsequently, the profiles extracted from the in vivo T1‐weighted images were estimated from profiles extracted from cyto‐ and myeloarchitectonic sections using linear combinations. We could verify statistically the mixed nature of the cortical T1 signal obtained in vivo: The MR intensity profiles were significantly more similar to myeloarchitectonic than to cytoarchitectonic profiles, but a weighted sum of both fitted the T1 profiles best. Hum. Brain Mapping 24:206–215, 2005. © 2004 Wiley‐Liss, Inc.
Distinct neural systems underlie learning visuomotor and spatial representations of motor skills
Authors: Parsons Michael W. , Harrington Deborah L. , Rao Stephen M.
Published: November 2004

Motor skill learning depends upon acquiring knowledge about multiple features of sequential behaviors, including their visuomotor and spatial properties. To investigate the neural systems that distinguish these representations, we carried out functional magnetic resonance imaging (fMRI) as healthy adults learned to type sequences on a novel keyboard. On the initial training day, learning‐related changes in brain activation were found in distributed cortical regions, only a subset of which correlated with improvements in movement time (MT), suggesting their preeminence in controlling movements online. Subjects received extended training on the sequences during the ensuing week, after which they returned to the scanner for another imaging session. Relative to performance at the end of the first training day, continued plasticity was most striking in the inferior parietal cortex and new areas of plasticity were uncovered in the caudate and cerebellum. Plasticity in these regions correlated with reaction time (RT), suggesting their role in planning sequences before movement onset. Two transfer conditions probed for “what” subjects learned. The probe for visuomotor learning produced increased activation in visual analysis (left inferior visual cortex) and advance planning (left caudate) systems. The probe for spatial learning produced increased activation in visuomotor‐transformation (left dorsal visual pathway) and retrieval (left precuneus) systems. Increased activity in all of these regions correlated with increased RT, but not MT, indicating that both transfer conditions interfered with the neural representation of plans for the sequences, but not processes that controlled their implementation. These findings demonstrated that neuroanatomically dissociable systems support the acquisition of visuomotor and spatial representations of actions. Hum Brain Mapping 24:229–247, 2005. © 2004 Wiley‐Liss, Inc.
Effect of interferon alfa on the dynamics of hepatitis C virus turnover in vivo
Authors: Zeuzem S , Schmidt J M , Lee J , Ruster B , Roth W K
Published: November 2004

In about 30% to 40% of patients with chronic hepatitis C, treatment with recombinant interferon alfa (r-IFNα) causes a decrease of serum aminotransferases and hepatitis C virus (HCV) RNA. The antiviral mechanism of interferon alfa (IFNα) in vivo is unknown. From serial measurements of serum HCV-RNA concentrations following IFNα induced perturbation of the balance between virus production and clearance, we obtained kinetic information on the pretreatment steady-state of HCV. In patients with chronic hepatitis C responding to IFNα, HCV-RNA declined exponentially with a half life of approximately 2 days. Modeling of the data predicts that in patients with chronic hepatitis C responding to IFNα this cytokine predominantly acts as an inhibitor of de novo infection of susceptible cells. HCV is released from infected cells with a mean half life of 2.7 ± 1.3 days, whereas the clearance rate from serum is faster (mean half life, 0.7 ± 0.4 days). The minimum virus production and clearance per day in patients with chronic hepatitis C was calculated to be 6.7 × 1010 virions/d (range, 0.2 to 43.8 × 1010 virions/d). These values showed no correlation with the HCV genotype, aminotransferase levels, or the histological activity as assessed before the administration of r-IFNα. Simultaneous kinetic analysis of serum aminotransferases as surrogate markers of hepatocyte integrity revealed half lifes for the release of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) from hepatocytes of 4.7 ± 3.8 and 3.0 ± 3.5 days, respectively. The half life data for HCV in chronically infected patients are remarkably similar to recently published data on human immunodeficiency virus type 1 (HIV-1) suggesting that both RNA viruses replicate continuously and highly productive in vivo. The turnover rates explain the rapid generation of viral diversity and the opportunity for viral escape phenomena from the host immune surveillance.
Prospective assessment of donor blood screening for antibody to hepatitis C virus by first- and second-generation assays as a means of preventing posttransfusion hepatitis
Authors: Takano S , Nakamura K , Kawai S , Yokosuka O , Satomura Y , Omata M
Published: November 2004

In November 1989, the Japanese Red Cross began screening blood donors for the hepatitis C virus antibody (anti-HCV) by first-generation assay and high-titer hepatitis B virus core antigen antibody. A significant reduction in the incidence of acute posttransfusion hepatitis was reported; however, the incidence still ranged from 2% to 4%. The Red Cross changed to the second-generation assay in February 1992, the objective being the complete elimination of potential posttransfusion hepatitis. The aim was to elucidate the advantage of second-generation assay as a blood-donor screening test. The incidence of posttransfusion hepatitis after the introduction of second-generation assay was compared with that before the introduction of the first-generation assay and with that during its use. The incidence of posttransfusion hepatitis was 9.6% (216/2,240) before anti-HCV-s donor screening. It was 3.7% (24/655) and 0.9% (3/326) after the introductions of the first-and second-generation hepatitis C virus (HCV) assays, respectively (χ2 = 50.0, P < .01). Blood-donor screening by second-generation anti-HCV provided a significant benefit compared with the first-generation assay.
Selective intestinal decontamination with norfloxacin reduces bacterial translocation in ascitic cirrhotic rats exposed to hemorrhagic shock
Authors: Llovet J M , Bartoli R , Planas R , Vinado B , Perez J , Cabre E , Arnal J , Ojanguren I , Ausina V , Gassull M A
Published: November 2004

Bacterial translocation (BT) can be involved in the pathogenesis of severe infections due to bacteria of enteric origin that complicates bleeding cirrhotic patients. To assess the effect of hemorrhagic shock (HS) on the incidence of BT and if selective intestinal decontamination (SID) reduces this incidence, we studied six groups of Sprague-Dawley rats: ascitic rats, ascitic rats exposed to HS with and without previous norfloxacin prophylaxis, healthy rats, and healthy shocked rats with and without previous norfloxacin prophylaxis. BT tended to be higher in ascitic rats with shock than without shock (69% vs. 41%, P = .15) and was significantly higher in healthy rats with than without shock (50 percent vs. 0 percent, P = .01). Norfloxacin significantly reduced translocation in ascitic shocked rats in comparison with nondecontaminated ascitic shocked rats (31 percent vs. 69 percent, P = .038). This effect was due mainly to a reduction of gram-negative BT (O percent vs. 37 percent, P = .008). In addition, norfloxacin prevented translocation in healthy shocked rats. Accordingly, aerobic gram-negative bacteria disappeared from fecal flora in all rats administered norfloxacin, except for Klebsiella species in one control rat. Cecal severe submucosal edema, chronic inflammatory infiltrate, and intestinal lymphangiectasia were significantly more frequent in ascitic rats than in control rats. Intestinal mucosal injury related with HS, particularly subepithelial cecal edema, was observed only in ascitic shocked rats. In conclusion, HS increases the incidence of BT both in ascitic cirrhotic and healthy rats. Norfloxacin reduces significantly the incidence of translocation after shock, especially in those cases caused by aerobic gram-negative bacilli.
A comparison of the effect of inducers on the expression of glutathione- S -transferases in the liver of the intact rat and in hepatocytes in primary culture
Authors: Langouet S , Morel F , Meyer D J , Fardel O , Corcos L , Ketterer B , Guillouzo A
Published: November 2004

Recently, we used human hepatocytes in primary culture to study the effects of inducers of glutathione-S-transferases (GSTs) in the expectation that information obtained can be used to predict the value of particular inducers for use in the chemoprevention of cancer and other toxicities. However, in vitro human studies cannot readily be confirmed by studies in vivo. This problem does not arise in experimental animals. In the current studies, the response of male rat hepatocytes in primary culture to the following inducers of GST isoenzymes has been determined: 3-methylcholanthrene (MC); phenobarbital (PB); 1,2-dithiole-3-thione and its 5-(2-pyrazinyl)-4-methyl derivative, oltipraz (OPZ), and the results have been compared with induction obtained in livers of MC- and OPZ-treated rats. Each type of inducer was found to elicit a different response. In vitro, phenobarbital increased messenger RNA (mRNA) levels of subunits 1b and 3 after 12 and 72 hours, respectively; MC had a rapid effect on GST alpha class mRNAs (bringing about increase after only 2 hours of treatment), increased subunit 7 mRNA slightly, and had no effect on mu class mRNAs; dithiolethiones induced both subunit lb and 7 mRNAs after 4 hours and, to a much lower extent, subunit 3 mRNA after 72 hours. In vivo, MC induced significantly both subunit lb and 7 mRNAs whereas OPZ increased significantly subunits lb, 3 and 7 mRNA levels, and to a lower extent those of subunit 2, after 3 days and beyond to at least 5 days of treatment. Results obtained in mRNA studies were confirmed by high-pressure liquid chromatography (HPLC) analysis of GST subunits. HPLC also showed an induction of subunit 10 at the protein level of which the mRNA was not analyzed. Our results show that rat hepatocytes in primary culture prove to be a good model for the effect of inducers on both the expression of GST mRNA and protein levels in the rat liver in vivo. The demonstration of this good correlation in the rat with respect to increases gives support for the use of human hepatocytes for predictive studies of chemoprotection in human pharmacology.
Defect of multidrug-resistance 3 gene expression in a subtype of progressive familial intrahepatic cholestasis
Authors: Deleuze J , Jacquemin E , Dubuisson C , Cresteil D , Dumont M , Erlinger S , Bernard O , Hadchouel M
Published: November 2004

Disruption of the murine mdr2 (multidrug-resistance) gene, which encodes a phosphatidylcholine flippase, leads to a hepatic disorder because of loss of biliary phospholipid secretion. Among the hereditary human cholestasis, a subtype of progressive familial intrahepatic cholestasis with high gamma-glutamyltranspeptidase (GGT) serum activity shares histological, biochemical, and genetic features with mice lacking mdr2 gene expression (mdr2 -/- mice). No mdr3 (human mdr2 homolog) messenger RNA (mRNA) was detected by Northern blotting in the liver of a patient suffering from this form of PFIC, and the biliary phospholipid level in a second patient was substantially decreased. Thus, the absence of the mdr3 P-glycoprotein may be responsible for this type of PFIC, which, as in the murine model, may be due to a toxic effect of bile acids on the biliary epithelium in absence of biliary phospholipids.
Gene Therapy for α–Fetoprotein–Producing Human Hepatoma Cells by Adenovirus–Mediated Transfer of the Herpes Simplex Virus Thymidine Kinase Gene
Authors: Kanai F , Shiratori Y , Yoshida Y , Wakimoto H , Hamada H , Kanegae Y , Saito I , Nakabayashi H , Tamaoki T , Tanaka T , Lan K , Kato N , Shiina S , Omata M
Published: November 2004

We have developed a recombinant replication–defective adenovirus containing human α–fetoprotein (AFP) promoter/enhancer to direct cell type–specific expression of the herpes simplex virus thymidine kinase (HSV

tk

) gene to AFP–producing hepatocellular carcinoma (HCC) cells. After an

in vitro

infection by a recombinant adenovirus carrying the lacZ gene under the control of human AFP promoter/enhancer (AdAFP

lacZ

), an expression of the

lacZ

gene was demonstrated efficiently in AFP–producing HuH–7 and HepG2 cell lines, but not in AFP–nonproducing HLE and HLF cell lines, although

lacZ

gene expression was demonstrated in all these cell lines when infected with adenovirus vector carrying

lacZ

gene driven by the β–actin–based promoter. Expression of the HSV

tk

gene by adenovirus, from AFP promoter/enhancer (AdAFP

tk

) induced the cells sensitive to ganciclovir (GCV) in the AFP–producing cell line efficiently, but not in AFP–nonproducing HLF hepatoma cells. An

in vitro

bystander effect was observed when only 10% of the cells were infected with AdAFP

tk

. These findings suggest that the AFP promoter/enhancer sequence can provide the tumor–specific activity for the therapeutic gene expression, and that the AdAFP

tk

vector induces the selective growth inhibition by GCV in the adenovirus–infected human hepatoma cells

in vitro

. Recombinant adenovirus transfer of the HSV

tk

gene under the control of tumor–specific promoter followed by GCV may have promise as a targeted in situ treatment for solid neoplasms.
Features of Autoimmune Hepatitis in Primary Sclerosing Cholangitis: An Evaluation of 114 Primary Sclerosing Cholangitis Patients According to A Scoring System for the Diagnosis of Autoimmune Hepatitis
Authors: Boberg K M , Fausa O , Haaland T , Holter E , Mellbye O J , Spurkland A , Schrumpf E
Published: November 2004

Overlapping features between primary sclerosing cholangitis (PSC and autoimmune hepatitis (AIH) have previously been noted. To assess systematically similarities between these disorders, we have evaluated 114 PSC patients (36 women; 78 men), all confirmed by endoscopic retrograde cholangiography (ERC), according to a scoring system proposed by The International Autoimmune Hepatitis Group for the diagnosis of AIH. The scoring system attributes positive or negative scores to the parameters sex, ratio of elevation of serum levels of alkaline phosphatase (ALP) vs. aminotransferase, serum levels of immunoglobulins and autoantibodies, viral markers, history of drug and alcohol intake, genetic factors, liver histology, and response to therapy. Two of the PSC patients (2%) obtained scores above 15 before treatment, satisfying the diagnostic criterion of “definite” AIH. Thirty–eight patients (33%) scored between 10 and 15 points and could be classified as “probable” AIH. The serum level of immunoglobulin G (IgG) was elevated in 68 patients (61% of 111 cases tested), and positive titers of antinuclear antibodies (ANA) or smooth muscle antibodies (SMA) were detected in 24 patients (22% of 111 cases tested). Thirty–five of the PSC patients (33% of 105 evaluable biopsy specimens) obtained positive scores for histological features similar to those of AIH, but the total score for histology was in the negative range in 72 patients (69%) because of the presence of biliary changes. The frequent finding of high scores in PSC patients underlines the similarities PSC may have with AIH. A modification of the scoring system, in particular by increasing the negative score for histological biliary changes, would improve its potential to discriminate between AIH and PSC.
Regulation of the Last Two Enzymatic Reactions in Cholesterol Biosynthesis in Rats: Effects of Bm 15.766, Cholesterol, Cholic Acid, Lovastatin, and Their Combinations
Authors: Honda A , Shefer S , Salen G , Xu G , Batta A K , Tint G S , Honda M , Chen T C , Holick M F
Published: November 2004

The Smith–Lemli–Opitz syndrome is a common inherited birth disorder caused by markedly reduced 7–dehydrocholesterol δ7–reductase activity, the final enzyme in the cholesterol biosynthetic pathway. BM 15.766 (4–[2–[1–(4–chlorocinnamyl)piperazin–4–yl]ethyl]–benzoic acid) inhibits 7–dehydrocholesterol delta 7–reductase activity, reduces plasma cholesterol levels, and increases 7–dehydrocholesterol levels to reproduce the biochemical abnormalities of the syndrome in rats. Cholesterol, cholic acid, and lovastatin, alone or in combinations, were fed to rats given BM 15.766, and hepatic activities of the last two enzymes in the cholesterol biosynthetic pathway, lathosterol 5– dehydrogenase and 7–dehydrocholesterol delta 7–reductase, were measured. After feeding BM 15.766, hepatic 7–dehydrocholesterol delta 7–reductase activity decreased by 77% while lathosterol 5–dehydrogenase activity tended to increase, so that the ratio of 5–dehydrogenase to delta 7–reductase activities increased from 0.33 to 2.8. In BM 15.766– fed rats, treatment with cholesterol suppressed both 5–dehydrogenase and delta 7–reductase activities by 76% and 66%, respectively, and decreased the 5–dehydrogenase: delta 7–reductase activities ratio from 2.8 to 2.2. In contrast, treatment with cholic acid and BM 15.766 further inhibited delta 7–reductase activity by 67% without changing significantly the 5–dehydrogenase activity that had increased the ratio to 5.5. Combining BM 15.766 with lovastatin increased 5–dehydrogenase activity fivefold but did not change delta 7–reductase activity, raising the ratio to 14.3. In BM 15.766–treated rats, the first and last two enzymatic reactions in the cholesterol biosynthetic pathway catalyzed by 3–hydroxy–3–methylglutaryl coenzyme A (HMG–CoA) reductase, lathosterol 5–dehydrogenase, and 7–dehydrocholesterol delta 7–reductase are down–regulated by cholesterol. Thus, only cholesterol and not cholic acid or lovastatin could reduce elevated plasma 7– dehydrocholesterol levels induced by BM 15.766.
Progressive Liver Injury in Chronic Hepatitis C Infection Correlates With Increased Intrahepatic Expression of Th1–Associated Cytokines
Authors: Napoli J , Bishop G A , McGuinness P H , Painter D M , McCaughan G W
Published: November 2004

An imbalance between T helper cell (Th)1 and Th2–like cytokines has been described in several chronic infectious diseases. We therefore analyzed the intrahepatic messenger RNA (mRNA) expression of Th1–like (interleukin [IL]–2, interferon [IFN]–gamma) and Th2–like (IL–4, IL–10) cytokines in chronic hepatitis C patients (n = 17) and controls (n = 6) and correlated the results with liver histology and intrahepatic viral load. Intrahepatic cytokine mRNA and hepatitis C virus (HCV) RNA were quantitatively assessed by polymerase chain reaction (PCR) using a dot– blot hybridization technique. Liver biopsy specimens were histologically graded using the Scheuer Score. IFN–gamma and IL–2 mRNA expression were significantly upregulated in chronic HCV vs. controls (

P

< .002,

P

< .04, respectively). Both correlated significantly with histological fibrosis and portal tract inflammation. In contrast, the expression of IL–10 mRNA was decreased in cirrhosis and chronic HCV compared with controls (

P

< .02,

P

< .0001, respectively). IL–4 mRNA was detected inconsistently at low levels in all groups. Intrahepatic viral load did not correlate with either cytokine expression or tissue injury. In conclusion, the progressive liver injury seen in chronic HCV is associated with the upregulation of intrahepatic Th1–like cytokines and the downregulation of IL–10, a Th2–like cytokine. These results suggest a role for delayed–type hypersensitivity immune reactions in HCV related liver injury.
Meta–Analysis of Interferon Randomized Trials in the Treatment of Viral Hepatitis C: Effects of Dose and Duration
Authors: Poynard T , Leroy V , Cohard M , Thevenot T , Mathurin P , Opolon P , Zarski J P
Published: November 2004

The aims of this study were to evaluate the benefits of higher doses or of longer duration in comparison with a standard interferon regimen (3 MU three times per week for 6 months) in chronic hepatitis C, and to assess the efficacy of interferon in acute hepatitis C. Meta–analysis made use of the Peto et al. and the Der Simonian and Laird methods, with heterogeneity and sensitivity analyses. In chronic hepatitis, a total of 17 trials versus controls and of 16 trials comparing different interferon regimens were included. Standard regimen, 3 MU three times per week for 6 months, was associated with an increase of the complete alanine transaminase (ALT) response rate and sustained (ALT) response rate by 45% (95% confidence interval: 35% to 55%;

P

< .001) and 21% (13% to 28%;

P

< .001), respectively, with the natural course being less than 2% of spontaneous responses. There was a significant dose effect (6 vs. 3 MU three times per week) upon the sustained response rate at 12 months, with a mean 17% increase (7% to 28%;

P

< .001), but not at 6 months. There was a significant duration effect (12 vs. 6 months) upon the sustained response rate both at the dose of 3 MU with a mean of 16% (9% to 23%;

P

< .001), and at the dose of 6 MU three times per week with a mean of 20% (7% to 33%;

P

= .003). In acute hepatitis C, 3 months of interferon treatment showed significant efficacy versus controls (4 trials), upon the complete ALT response (69% vs. 29%;

P

< .001), the sustained response rate during the 12 months following treatment (53% vs. 32%;

P

= .02), and hepatitis C virus (HCV)–RNA clearance (41% vs. 4%;

P

< .001). The best efficacy/risk ratio was in favor of 3 MU three times per week for at least 12 months in patients with chronic hepatitis C who had never been treated with interferon. Patients with acute hepatitis should be treated with at least 3 MU three times per week for 3 months.
Portacaval Anastomosis Induces Region–Selective Alterations of the Endogenous Opioid System in the Rat Brain
Authors: de Waele J , Audet R M , Leong D K , Butterworth R F
Published: November 2004

Portacaval anastomosis (PCA) in the rat results in a broad spectrum of neurological and neurobehavioral changes, including alterations of circadian rhythms, impaired locomotor activity, and reflexes, as well as decreased threshold to noxious stimuli. In addition, following portacaval shunting, rats drink significantly more ethanol in a free– choice drinking paradigm. Available evidence suggests that many of these behavioral changes may be modulated by the endogenous opioid system of the brain. To evaluate this possibility, the effects of PCA on circulating β–endorphin (β–EP), as well as β–EP content in the pituitary and specific brain nuclei, was evaluated using a sensitive radioimmunoassay. Furthermore, the characteristics and regional densities of mu and delta opioid receptors in the brains of PCA and sham–operated control rats were studied using an in vitro technique, as well as quantitative receptor autoradiography and the specific ligands 125I [D–Ala2, MePhe4, Met(o)ol5]enkephalin (FK 33–824) and 125I [2–d–penicillamine, 5–d–penicillamine]–enkephalin (DPDPE) for micro and delta sites, respectively. PCA resulted in region–selective modifications of β–EP in brain, but not in pituitary or blood. Autoradiographic studies revealed a generalized decrease in mu binding sites (up to 70% decreases compared with sham–operated controls) and region–selective alterations of delta receptor densities following PCA. Portacaval–shunted rats drank significantly more ethanol in a free– choice drinking paradigm, an effect that was significantly attenuated by the administration of the opiate antagonist naloxone. Increased ethanol preference thus appeared to result from modifications of the endogenous opioid system in nucleus accumbens of rats following PCA.
Subcellular Distribution of Glucocorticoid Receptor in Cultured Rat and Human Liver–Derived Cells and Cell Lines: Influence of Dexamethasone
Authors: Raddatz D , Henneken M , Armbrust T , Ramadori G
Published: November 2004

Glucocorticoid receptor (GR) distribution in isolated rat hepatocytes and nonparenchymal hepatic stellate cells, Kupffer cells, and liver fibroblasts with and without dexamethasone treatment was investigated by immunostaining and confocal laser scanning microscopy. In addition, human liver fibroblasts, Hep3B and HepG2 cells were investigated. Subcellular distribution of GR immunostaining was assessed semiquantitatively by digital image analysis. Short–term incubation of rat liver cells with dexamethasone resulted in an increase of nuclear staining. The same was true for human liver fibroblasts. In contrast, predominant nuclear staining could be observed in untreated as well as in dexamethasone–treated Hep3B and HepG2 cells. By means of reverse–transcription polymerase chain reaction, it could be shown that messenger RNA of both known human GR isoforms, hGR α and nonhormone–binding hGR β, are present in human cells. Furthermore, dexamethasone binding indicates that hGR α protein is expressed in all human cells investigated. The data of this study show that GR is present in all cells investigated. Rat liver cells and human liver fibroblasts contain a translocating GR, suggesting that glucocorticoid action is receptor mediated in these cells. Nuclear localization of unliganded GR in Hep3B and HepG2 indicates that factors other than glucocorticoids may direct subcellular GR distribution.
Use of Dominant Negative Mutants of the Hepadnaviral Core Protein As Antiviral Agents
Authors: Scaglioni P , Melegari M , Takahashi M , Chowdhury J R , Wands J
Published: November 2004

Chronic hepatitis B virus (HBV) infection is a major cause of acute and chronic liver diseases. We have recently described HBV and woodchuck hepatitis virus (WHV) dominant negative (DN) core mutants that were capable of inhibiting wild–type viral replication by 95%. These mutants may represent a potent class of antiviral agents that act as “intracellular immunogens.” To facilitate their potential use in animal model systems, we now have studied the duck HBV (DHBV) and placed the DN mutant constructs in recombinant retroviral and adenoviral expression vectors. Transient expression of the DHBV molecular equivalent of the WHV and HBV DN constructs inhibited wild–type DHBV replication by 98%. Recombinant retroviral and adenoviral vectors containing the HBV and DHBV DN complementary DNAs (cDNAs) were used to transiently and stably transduce hepatoma–derived cell lines constitutively expressing replicating wild–type virus. These investigations show that the DN core mutants were powerful inhibitors of HBV and DHBV replication when delivered intracellularly and appear as promising antiviral agents for gene therapy of persistent viral infection of the liver.
Cyclosporin A: Drug Discontinuation for the Management of Long–Term Toxicity After Liver Transplantation
Authors: Chan C , DasGupta K , Baker A L
Published: November 2004

After liver transplantation, long–term cyclosporin A (CsA) administration is commonly complicated by renal insufficiency and other side effects. To manage these problems, 1.5 to 2.0 mg · kg–1 · day–1 of azathioprine for at least 6 weeks was prescribed; CsA was then discontinued or reduced to < or = 2.5 mg · kg–1 · day–1 for several months. The dose of prednisone was kept constant. CsA was discontinued in 14 patients because of nephrotoxicity (three or more serum creatinine levels of > or = 1.5 mg/dL), in 1 patient because of headaches and in 1 patient because of a generalized sensory neuropathy; 1 patient refused to continue taking the drug. The CsA dose was reduced in 13 patients, 12 because of nephrotoxicity and 1 because of headaches. One patient in whom administration of CsA was stopped developed azathioprine hepatotoxicity, whereas 1 patient whose dose was reduced developed acute cellular rejection. These complications were controlled by discontinuing azathioprine and reinitiating CsA. In the patients in whom CsA was discontinued, the mean serum creatinine level decreased from 2.42 +/– 0.48 to 1.72 +/– 0.39 mg/dL (

P

= .00004); in the patients in whom CsA was reduced, the mean serum creatinine level decreased less markedly. This report suggests that discontinuation of CsA along with increased doses of azathioprine is safe for some patients and may be effective in managing CsA–related nephrotoxicity and other side effects after liver transplantation. Additional studies are needed to determine whether this approach is safe and effective for the growing number of post–transplantation patients who may be candidates for such therapy.
A Randomized Trial Comparing Colchicine and Ursodeoxycholic Acid Combination to Ursodeoxycholic Acid in Primary Biliary Cirrhosis
Authors: Poupon R E , Huet P M , Poupon R , Bonnand A , Van Nhieu J T , Zafrani E S
Published: November 2004

The efficacy of colchicine combined with ursodeoxycholic acid (UDCA) and UDCA alone in the treatment of patients with nonadvanced primary biliary cirrhosis (PBC) was evaluated in a 2–year controlled study. Seventy–four patients with PBC who had been treated previously with UDCA (at least 8 months) but still had abnormal liver test results, especially elevated alkaline phosphatase activity, were randomized to be administered colchicine (1 mg/d, 5 days per week) (n = 37) or a placebo (n = 37). In addition, the patients were treated with UDCA (13–15 mg · kg–1 · day–1). The patients underwent clinical examination and liver tests every 6 months and upper endoscopy and liver biopsy at entry and at 2 years. Procollagen type III aminoterminal peptide (PIIINP), hyaluronic acid, and sulfobromophthalein (BSP) elimination kinetics were determined at entry and after 2 years. After 2 years of treatment, relative to UDCA, colchicine combined with UDCA did not significantly improve symptoms, laboratory findings (serum bilirubin level, alkaline phosphatase and alanine transaminase [ALT] activities, immunoglobulin [Ig] M level), serum markers of fibrosis, or histological features, except lobular inflammation. Colchicine did tend to slightly reduce the progression of esophageal varices; however, the difference was not significant. BSP elimination kinetics (45–minute retention percentage) was significantly improved when treated with colchicine. During the 2–year study, the only clinical complications were variceal bleeding in one patient administered colchicine and two administered the placebo. Two patients died from nonliver causes. One severe adverse effect (peripheral neuromyopathy) was observed in a colchicine–treated patient. In conclusion, this study suggests that colchicine appears to provide a slight advantage relative to UDCA alone in patients with nonadvanced PBC.
Indocyanine Green Elimination Test in Orthotopic Liver Recipients
Authors: Tsubono T , Todo S , Jabbour N , Mizoe A , Warty V , Demetris A J , Starzl T E
Published: November 2004

Objective:

To determine its predictive capability on graft quality and resultant clinical outcome, the indocyanine green (ICG) elimination test was performed by a spectrophotometric method and a noninvasive finger–piece method with 50 orthotopic liver transplantations.

Background:

Early detection of poor–functioning hepatic grafts is one of the most important issues in liver transplantation, but no reliable methods exist.

Methods:

The ICG test was performed after 50 orthotopic liver transplantations on postoperative days 1, 3, and 7. Indocyanine green elimination constants (KICG) were measured by both a standard spectrophotometric analysis (KICG–B) and by a finger–piece method (KICG–F). The patients were followed for a minimum of 3 months after transplantation. Results of ICG tests were correlated with various clinical determinations.

Results:

Twelve of the 50 grafts were lost within three months, of which 7 were related to graft failure. Multivariate analysis using the Cox proportional hazard model revealed that KICG on postoperative day 1 was a better predictor of liver– related graft outcome than any of the conventional liver function tests. Furthermore, KICG values showed significant correlation with the severity of preservation injury, longer intensive care unit (ICU) and hospital stay, prolonged liver dysfunction, and septic complications. Correlation of KICG values by the spectrophotometric method with those by the finger–piece method was highly satisfactory in the grafts that had KICG–B <0.15 min–1 (y = 0.868x –0.011,

r

= .955).

Conclusion:

The ICG elimination test, conducted spectrophotometrically or optically on the day after liver transplantation, is a reliable indicator of graft quality and subsequent graft outcome early after liver transplantation.