bluuebunny/crossref_metadata_2025 huggingface dataset:
Dominant influence of an HLA-B27 restricted CD8+ T cell response in mediating HCV clearance and evolution
Authors: Neumann-Haefelin Christoph , McKiernan Susan , Ward Scott , Viazov Sergei , Spangenberg Hans Christian , Killinger Thomas , Baumert Thomas F. , Nazarova Natalja , Sheridan Isabelle , Pybus Oliver , von Weizsäcker Fritz , Roggendorf Michael , Kelleher Dermot , Klenerman Paul , Blum Hubert E. , Thimme Robert
Published: February 2006

Virus-specific CD8+ T cell responses play an important role in the natural course of infection; however, the impact of certain CD8+ T cell responses in determining clinical outcome has not been fully defined. A well-defined cohort of women inoculated with HCV from a single source showed that HLA-B27 has a strong association with spontaneous clearance. The immunological basis for this association is unknown. However, the finding is especially significant because HLA-B27 has also been shown to have a protective role in HIV infection. We report the identification of an HLA-B27 restricted hepatitis C virus (HCV)-specific CD8+ T cell epitope that is recognized in the majority of recovered HLA-B27 positive women. In chronically HCV-infected individuals, analysis of the corresponding viral sequence showed a strong association between sequence variations within this epitope and expression of HLA-B27, indicating allele-specific selection pressure at the population level. Functional analysis in 3 chronically HCV-infected patients showed that the emerging variant viral epitopes represent escape mutations.

In conclusion,

our results suggest a dominant role of HLA-B27 in mediating spontaneous viral clearance as well as viral evolution in HCV infection and mechanistically link both associations to a dominant novel CD8+ T cell epitope. These results support the central role of virus-specific CD8+ T cells and the genetically determined restriction of the virus-specific T cell repertoire in HCV infection.

Supplementary material for this article can be found on the HEPATOLOGY website (

http://www.interscience.wiley.com/jpages/0270-9139/suppmat/index.html

.)

(Hepatology 2006;43:563–572.)
Anti-hepatitis B virus efficacy of tenofovir disoproxil fumarate in HIV-infected patients
Authors: Benhamou Yves , Fleury Herve , Trimoulet Pascale , Pellegrin Isabelle , Urbinelli Renaud , Katlama Christine , Rozenbaum Willy , Le Teuff Gwenael , Trylesinski Aldo , Piketty Christophe
Published: February 2006

Tenofovir disoproxil fumarate (TDF) has shown

in vitro

activity against both HIV and hepatitis B virus (HBV). We retrospectively evaluated the efficacy of TDF (300 mg/d), administered as a part of anti-retroviral therapy, in a large cohort of HIV/HBV-coinfected patients. Sixty-five HIV/HBV-coinfected patients who received TDF for at least 6 months with serum HBV DNA levels above 2.3 log10 copies/mL at TDF initiation and who had stored serum samples before and during TDF therapy were included. Serum HBV DNA was measured on stored samples. The median follow-up period was 12 (Q1-Q3: 8-17) months. Serum hepatitis B e antigen (HBeAg) was positive in 54 patients (83.1%). Fifty-two patients (80.0%) were receiving lamivudine (LAM) (150 mg twice a day), and 68.8% had documented LAM resistance at baseline. Among HBeAg-positive patients, the median reduction from baseline (8.17; Q1-Q3 = 7.30-8.30 log10 copies/mL) of serum HBV DNA was 4.56 log10 copies/mL (Q1-Q3 = 3.33-5.55) (

P

< .0001). In HBeAg-negative patients, serum HBV DNA decline from baseline (4.83; Q1-Q3 = 2.69-6.40 log10 copies/mL) was 2.53 log10 copies/mL (Q1-Q3 = 0.39-4.10). At the end of the study, HBV DNA became undetectable in 29.6% and 81.6% of the HBeAg-positive and HBeAg -negative patients, respectively. Serum HBeAg became negative in 4 patients, 2 of whom acquired serum hepatitis B e antibody.

In conclusion

, this retrospective analysis demonstrates the efficacy of TDF against wild-type, presumed precore mutants and LAM-resistant HBV when used as a part of anti-retroviral therapy in HIV-coinfected patients. (Hepatology 2006;43:548–555.)
Donor graft adenoviral iNOS gene transfer ameliorates rat liver transplant preservation injury and improves survival
Authors: Kaizu Takashi , Ikeda Atsushi , Nakao Atsunori , Takahashi Yoshihito , Tsung Allan , Kohmoto Junichi , Toyokawa Hideyoshi , Shao Lifang , Bucher Brian T. , Tomiyama Koji , Nalesnik Michael A. , Murase Noriko , Geller David A.
Published: February 2006

The exact role of inducible NOS (iNOS) in liver ischemia/reperfusion (I/R) injury is controversial. This study was designed to investigate whether donor liver pretreatment with adenovirus encoding iNOS (AdiNOS) ameliorates I/R injury associated with liver transplantation. Orthotopic syngeneic LEW rat liver transplantation (OLT) was performed after 18 or 24 hours' preservation in cold UW. AdiNOS or control gene vector (AdLacZ) was delivered to the liver by donor intravenous pretreatment 4 days before graft harvesting. Uninfected grafts also served as control. Recipients were sacrificed 1 to 48 hours posttransplantation. An abundant hepatic iNOS protein expression and marked serum NO elevation was observed in the AdiNOS-treated group, without affecting endothelial nitric oxide synthase (eNOS) expression, before harvesting and after OLT. AdiNOS pretreatment markedly improved liver function assessed by serum aspartate aminotransferase/alanine aminotransferase levels and reduced liver necrosis formation. AdiNOS treatment also was associated with reduced ICAM-1 mRNA expression and neutrophil accumulation in the liver graft after OLT compared with untransfected or AdLacZ-treated group. Furthermore, AdiNOS delivery significantly improved transplant survival, compared with AdLacZ or saline controls. AdiNOS pretreatment did not attenuate I/R-induced apoptotic cell death in the liver graft. Administration of a selective inhibitor for iNOS abrogated the protection afforded by AdiNOS pretreatment.

In conclusion,

donor pretreatment with AdiNOS led to improved liver graft injury and posttransplantation survival. Downregulation of ICAM-1 mRNA and neutrophil infiltration may be associated with the mechanisms by which AdiNOS pretreatment confer the protection against transplant-associated hepatic I/R injury. (Hepatology 2006;43:464–473.)
Localization of oxidized phosphatidylcholine in nonalcoholic fatty liver disease: Impact on disease progression
Authors: Ikura Yoshihiro , Ohsawa Masahiko , Suekane Takehisa , Fukushima Hiroko , Itabe Hiroyuki , Jomura Hisato , Nishiguchi Shuhei , Inoue Takeshi , Naruko Takahiko , Ehara Shoichi , Kawada Norifumi , Arakawa Tetsuo , Ueda Makiko
Published: February 2006

Nonalcoholic steatohepatitis/nonalcoholic fatty liver disease is considered to be a hepatic manifestation of various metabolic disorders. However, its precise pathogenic mechanism is obscure. Oxidative stress and consequent lipid peroxidation seem to play a pivotal role in disease progression. In this study, we analyzed the localization of oxidized phosphatidylcholine (oxPC), a lipid peroxide that serves as a ligand for scavenger receptors, in livers of patients with this steatotic disorder. Specimens of non-alcoholic fatty liver disease (15 autopsy livers with simple steatosis and 32 biopsy livers with steatohepatitis) were examined via immunohistochemistry and immunoelectron microscopy using a specific antibody against oxPC. In addition, scavenger receptor expression, hepatocyte apoptosis, iron deposition, and inflammatory cell infiltration in the diseased livers were also assessed. Oxidized phosphatidylcholine was mainly localized to steatotic hepatocytes and some macrophages/Kupffer cells. A few degenerative or apoptotic hepatocytes were also positive for oxPC. Immunoelectron microscopy showed oxPC localized to cytoplasmic/intracytoplasmic membranes including lipid droplets. Steatotic livers showed enhanced expression of scavenger receptors. The number of oxPC cells was correlated with disease severity and the number of myeloperoxidase-positive neutrophils, but not with the degree of iron deposition.

In conclusion

, distinct localization of oxPC in liver tissues suggest that neutrophil myeloperoxidase-derived oxidative stress may be crucial in the formation of oxPC and the progression of steatotic liver disease. (Hepatology 2006;43:506–514.)
Changes in liver and plasma acetylcholinesterase in rats with cirrhosis induced by bile duct ligation
Authors: García-Ayllón Salud M. , Silveyra Ximena M. , Candela Asunción , Compañ Antonio , Clària Joan , Jover Rodrigo , Pérez-Mateo Miguel , Felipo Vicente , Martínez Salvador , Galcerán Joan , Sáez-Valero Javier
Published: February 2006

Classical studies of cholinesterase activity during liver dysfunction have focused on butyrylcholinesterase (BuChE), whereas acetylcholinesterase (AChE) has not received much attention. In the current study, liver and plasma AChE levels were investigated in rats with cirrhosis induced after 3 weeks of bile duct ligation (BDL). BDL rats showed a pronounced decrease in liver AChE levels (˜50%) compared with sham-operated (non-ligated, NL) controls; whereas liver BuChE appeared unaffected. A selective loss of tetrameric (G4) AChE was detected in BDL rats, an effect also observed in rats with carbon tetrachloride-induced cirrhosis. In accordance, SDS-PAGE analysis showed that the major 55-kd immunoreactive AChE band was decreased in BDL as compared with NL. A 65-kd band, attributed in part to inactive AChE, was increased as became the most abundant AChE subunit in BDL liver. The overall decrease in AChE activity in BDL liver was not accompanied by a reduction of AChE transcripts. The loss of G4 was also reflected by changes observed in AChE glycosylation pattern attributable to different liver AChE forms being differentially glycosylated. BDL affects AChE levels in both hepatocytes and Kupffer cells; however, altered AChE expression was mainly reflected in an alteration in hepatocyte AChE pattern. Plasma from BDL rats had approximately 45% lower AChE activity than controls, displaying decreased G4 levels and altered lectin-binding patterns.

In conclusion

, the liver is an important source of serum AChE; altered AChE levels may be a useful biomarker for liver cirrhosis. (Hepatology 2006;43:444–453.)
Decreased NK cell frequency in chronic hepatitis C does not affect ex vivo cytolytic killing
Authors: Morishima Chihiro , Paschal Denise M. , Wang Chia C. , Yoshihara Christina S. , Wood Brent L. , Yeo Anthony E. T. , Emerson Scott S. , Shuhart Margaret C. , Gretch David R.
Published: February 2006

Prior studies have suggested that natural killer (NK) cell function might be impaired in chronic hepatitis C virus (HCV) infection. Circulating NK cell frequency and cytolytic activity were examined freshly

ex vivo

in HCV-infected and uninfected subjects. Surprisingly, the intrinsic cytolytic activity of peripheral blood NK-enriched cells was similar between HCV-infected and uninfected groups (

P

= .91). Although the percentage of circulating CD3−CD16/56+NK cells was 30% lower in HCV-infected compared with uninfected subjects (

P

= .02) paralleled by a decrease of CD56dim cytolytic NK cells (

P

= .02), overall K562 cytolysis by unfractionated peripheral blood mononuclear cells was not affected (

P

= .29). Analysis of the relationships between NK cytolytic activity and other clinical information revealed an inverse association with liver fibrosis stage (

P

= .035).

In conclusion

, NK cell cytolytic function does not appear to be impaired in chronic hepatitis C, but higher levels of NK cell cytolysis are associated with less liver fibrosis. (Hepatology 2006;43:573–580.)
Distinctive clinical phenotype and treatment outcome of type 1 autoimmune hepatitis in the elderly
Authors: Czaja Albert J. , Carpenter Herschel A.
Published: February 2006

Autoimmune hepatitis is classically a disease of young women. Our aims were to determine its occurrence, clinical phenotype, and outcome in elderly patients and contrast findings to young adults. Two-hundred-and-five white North American adults with definite type 1 autoimmune hepatitis were grouped according to age at presentation and the groups compared. Forty-seven patients (23%) were aged ≥60 years (median age, 68 years), and 31 patients (15%) were aged ≤30 years (median age, 25 years). The patients ≥60 years had a higher frequency of cirrhosis at presentation than the patients ≤30 years (33% versus 10%,

P

= .03). They also had thyroid or rheumatic diseases more commonly (42% vs. 13%,

P

= .006). HLA DR3 occurred more frequently in the patients ≤30 years than in those ≥60 years (58% vs. 23%,

P

= .004), and HLA DR4 occurred more often in the patients ≥60 years (47% vs. 13%,

P

= .003). Patients aged ≥60 years failed corticosteroid treatment less commonly than those aged ≤30 years (5% vs. 24%,

P

= .03). Autoimmune hepatitis occurred in patients aged 18-30 years (15%), 31-39 years (15%), 40-49 years (21%), 50-59 years (25%), and ≥60 years (23%). Differences in age distribution, HLA frequencies, and treatment outcome occurred after age ≥40 years.

In conclusion

, elderly patients have a greater frequency of cirrhosis at presentation and HLA DR4 than patients ≤30 years, and they have a lower occurrence of treatment failure. Transitions in clinical and genetic phenotypes occur after age ≥40 years. Genetic susceptibilities may favor etiologic factors that are age-related. (Hepatology 2006;43:532–538.)
The influence of T cell cross-reactivity on HCV-peptide specific human T cell response
Authors: Kennedy Patrick T.F. , Urbani Simonetta , Moses Rebecca A. , Amadei Barbara , Fisicaro Paola , Lloyd Jilly , Maini Mala K. , Dusheiko Geoffrey , Ferrari Carlo , Bertoletti Antonio
Published: February 2006

Detection of hepatitis C virus (HCV)-specific T cell response after exposure to hepatitis C in anti-HCV–positive or anti-HCV–negative patients has been associated with an ability to successfully control the infection. However, cross-reactivity between common human pathogens and HCV sequences has been demonstrated. The aim of this study was to investigate the impact of T cell cross-reactivity on HCV-specific T cell responses and their detection in HCV infected and non-infected subjects. The magnitude, function, and cross-reactivity of HCV peptide reactive T cells were studied in non–HCV-infected newborns and adults using a broad array of HCV peptides (601 peptides) spanning the entire HCV sequence. Comparisons were made with responses present in recovered and in chronically HCV-infected patients. HCV peptide reactive T cells are detectable in adults irrespective of previous HCV exposure and cross-reactivity between HCV peptides, and sequences of common pathogens, such as human herpes virus 1, can be demonstrated. Furthermore, the comprehensive magnitude of HCV-peptide reactive T cells present in chronically HCV-infected patients is similar and in some cases even lower than that of HCV-peptide reactive T cell response found in HCV-negative adults.

In conclusion

, the presence of oligo-specific HCV-peptide reactive T cells in humans does not always reflect a demonstration of previous HCV contact, whereas cross-reactivity with other common pathogens can potentially influence the HCV-specific T cell profile. The conspicuous deficit of HCV-peptide–specific T cells found in chronically HCV-infected patients confirms the profound collapse of virus-specific T cell response caused by HCV persistence. (Hepatology 2006;43:602–611.)
Paradoxical effects of short- and long-term interleukin-6 exposure on liver injury and repair
Authors: Jin Xiaoling , Zimmers Teresa A. , Perez Eduardo A. , Pierce Robert H. , Zhang Zongxiu , Koniaris Leonidas G.
Published: February 2006

Interleukin-6 (IL-6) is an important mediator of liver regeneration and repair that is also elevated in chronic liver diseases, including fatty liver of obesity and cirrhosis. IL-6 has been reported both to delay and accelerate liver regeneration. We examined the effects on liver injury and regeneration of a continuous administration of exogenous IL-6 to mice by injection of an IL-6–expressing CHO-cell line in athymic nude mice and by osmotic mini-pump delivery of recombinant murine IL-6. Short-term IL-6 administration (1-2 days) accelerated early recovery of liver mass, whereas more long-term administration (5-7 days) markedly impaired liver regeneration. Similarly, short-term IL-6 treatment increased hepatic resistance to the lethal effects of the Fas agonist Jo-2, but on more prolonged IL-6 exposure the Jo-2 resistance vanished. IL-6 administration initially induced expression of the anti-apoptotic proteins Bcl-2 and Bcl-xL, correlating with protection against Fas-mediated cell death. More prolonged IL-6 administration, however, resulted in marked induction of the pro-apoptotic protein Bax. This result coincided with increased activation of the type II or intrinsic, mitochondrial path to cell death, manifested by increased caspase-9 activation and increased cytochrome c release after Jo-2 exposure. These data demonstrate that IL-6 can function acutely to improve hepatic regeneration and repair, but that more chronic exposure not only abolishes the protective effects of IL-6, but actually sensitizes the liver to injury and death.

In conclusion,

elevated IL-6 in certain chronic liver diseases contributes to an increased likelihood of liver failure after injury. (Hepatology 2006;43:474–484.)
Characterization of the hepatitis C virus E2 epitope defined by the broadly neutralizing monoclonal antibody AP33
Authors: Tarr Alexander W. , Owsianka Ania M. , Timms Judith M. , McClure Patrick C. , Brown Richard J. P. , Hickling Timothy P. , Pietschmann Thomas , Bartenschlager Ralf , Patel Arvind H. , Ball Jonathan K.
Published: February 2006

The mouse monoclonal antibody (MAb) AP33, recognizing a 12 amino acid linear epitope in the hepatitis C virus (HCV) E2 glycoprotein, potently neutralizes retroviral pseudoparticles (HCVpp) carrying genetically diverse HCV envelope glycoproteins. Consequently, this antibody and its epitope are highly relevant to vaccine design and immunotherapeutic development. The rational design of immunogens capable of inducing antibodies that target the AP33 epitope will benefit from a better understanding of this region. We have used complementary approaches, which include random peptide phage display mapping and alanine scanning mutagenesis, to identify residues in the HCV E2 protein critical for MAb AP33 binding. Four residues crucial for MAb binding were identified, which are highly conserved in HCV E2 sequences. Three residues within E2 were shown to be critical for binding to the rat MAb 3/11, which previously was shown to recognize the same 12 amino acid E2 epitope as MAb AP33 antibody, although only two of these were shared with MAb AP33. MAb AP33 bound to a panel of functional E2 proteins representative of genotypes 1-6 with higher affinity than MAb 3/11. Similarly, MAb AP33 was consistently more efficient at neutralizing infectivity by diverse HCVpp than MAb 3/11. Importantly, MAb AP33 was also able to neutralize the cell culture infectious HCV clone JFH-1.

In conclusion,

these data identify important protective determinants and will greatly assist the development of vaccine candidates based on the AP33 epitope. (Hepatology 2006;43:492–601.)
A novel function for a micro RNA: Negative regulators can do positive for the hepatitis C virus
Authors: Appel Nicole , Bartenschlager Ralf
Published: February 2006

MicroRNAs are small RNA molecules that regulate messenger RNA (mRNA) expression. MicroRNA 122 (miR-122) is specifically expressed and highly abundant in the human liver. We show that the sequestration of miR-122 in liver cells results in marked loss of autonomously replicating hepatitis C viral RNAs. A genetic interaction between miR-122 and the 5′ noncoding region of the viral genome was revealed by mutational analyses of the predicted microRNA binding site and ectopic expression of miR-122 molecules containing compensatory mutations. Studies with replication-defective RNAs suggested that miR-122 did not detectably affect mRNA translation or RNA stability. Therefore, miR-122 is likely to facilitate replication of the viral RNA, suggesting that miR-122 may present a target for antiviral intervention.
Glucocorticoids interfere with therapeutic efficacy of paclitaxel against human breast and ovarian xenograft tumors
Authors: Sui Meihua , Chen Feng , Chen Zhi , Fan Weimin
Published: February 2006

Paclitaxel is a widely used naturally occurring antineoplastic agent that has shown great promise in the treatment of a variety of human solid tumors, particularly for advanced breast and ovarian cancers. Recent studies in our laboratory discovered that glucocorticoids could selectively inhibit paclitaxel‐induced apoptosis in a number of human solid tumor cell lines in vitro. Since glucocorticoids (such as dexamethasone) are routinely used as a premedication in the clinical application of paclitaxel to prevent hypersensitivity reactions and other adverse effects, the inhibitory effect of glucocorticoids on paclitaxel‐induced apoptosis has raised a clinically relevant question as to whether the pretreatment with glucocorticoids might interfere with the therapeutic efficacy of paclitaxel. In the present study, through development of animal models bearing human breast and ovarian xenograft tumors, we evaluated the potential influence of dexamethasone on antitumor activity of paclitaxel in vivo. The results demonstrated that pretreatment of dexamethasone significantly attenuated therapeutic efficacy of paclitaxel against human breast and ovarian xenograft tumors. The inhibition rate of 20 mg paclitaxel/kg on the growth of breast and ovarian xenograft tumors was around 20–25% less when the animals were pretreated with 1 mg dexamethasone/kg. Further analyses with histological examination and TdT‐mediated dUTP nick end labeling assay indicate that pretreatment with dexamethasone clearly interferes with the cytotoxic effects of paclitaxel on both morphological alterations and induction of cell death. Additionally, immunohistochemical staining of proliferation marker Ki‐67 indicates that the percentage of proliferating cells in xenograft tumors with pretreatment of dexamethasone is much higher than that in the tumors treated with paclitaxel alone. Put together, the results obtained from the animal experiments show that pretreatment of xenograft tumors with dexamethasone results in significant inhibition of the therapeutic efficacy of paclitaxel in vivo. This finding may have a potential implication on the clinical practice of paclitaxel‐based chemotherapy. © 2006 Wiley‐Liss, Inc.
Novel role of TGF‐β in differential astrocyte‐TIMP‐1 regulation: Implications for HIV‐1‐dementia and neuroinflammation
Authors: Dhar Alok , Gardner Jessica , Borgmann Kathleen , Wu Li , Ghorpade Anuja
Published: February 2006

Astrocyte production of tissue inhibitor of metalloproteinase (TIMP)‐1 is important in central nervous system (CNS) homeostasis and inflammatory diseases such as HIV‐1‐associated dementia (HAD). TIMPs and matrix metalloproteinases (MMPs) regulate the remodeling of the extracellular matrix. An imbalance between TIMPs and MMPs is associated with many pathologic conditions. Our recently published studies uniquely demonstrate that HAD patients have reduced levels of TIMP‐1 in the brain. Astrocyte‐TIMP‐1 expression is differentially regulated in acute and chronic inflammatory conditions. In this and the adjoining report (Gardner et al., 2006), we investigate the mechanisms that may be involved in differential TIMP‐1 regulation. One mechanism for TIMP‐1 downregulation is the production of anti‐inflammatory molecules, which can activate signaling pathways during chronic inflammation. We investigated the contribution of transforming growth factor (TGF)‐signaling in astrocyte‐MMP/TIMP‐1‐astrocyte regulation. TGF‐β1 and β2 levels were upregulated in HAD brain tissues. Co‐stimulation of astrocytes with IL‐1β and TGF‐β mimicked the TIMP‐1 downregulation observed with IL‐1β chronic activation. Measurement of astrocyte‐MMP protein levels showed that TGF‐β combined with IL‐1β increased MMP‐2 and decreased proMMP‐1 expression compared to IL‐1β alone. We propose that one of the mechanisms involved in TIMP‐1 downregulation may be through TGF‐signaling in chronic immune activation. These studies show a novel extracellular regulatory loop in astrocyte‐TIMP‐1 regulation. © 2006 Wiley‐Liss, Inc.
Generation of graftable dopaminergic neuron progenitors from mouse ES cells by a combination of coculture and neurosphere methods
Authors: Morizane Asuka , Takahashi Jun , Shinoyama Mizuya , Ideguchi Makoto , Takagi Yasushi , Fukuda Hitoshi , Koyanagi Masaomi , Sasai Yoshiki , Hashimoto Nobuo
Published: February 2006

Parkinson's disease is characterized by a loss of midbrain dopamine (DA) neurons and is generally viewed as a potential target for stem cell therapy. Although several studies have reported the generation of postmitotic DA neurons from embryonic stem (ES) cells, it is unknown whether the proliferative progenitors of DA neurons can be isolated in vitro. To investigate this possibility, we have developed a combined approach in which ES cells are cocultured with PA6 stromal cells to expose them to stromal cell‐derived inducing activity (SDIA) and are then cultured as neurospheres. Mouse ES cell colonies were detached from PA6 feeder cells after 8 days of SDIA treatment and then expanded as spheres for another 4 days in serum‐free medium supplemented with fibroblast growth factor‐2. The spheres exhibited neural stem cell characteristics and contained few DA neurons at this stage of culture. After being induced to differentiate on polyornithine/laminin‐coated dishes for 7 days, these spheres generated DA neurons in vitro at a relatively low frequency. Intriguingly, addition of PA6 cell conditioned medium to the sphere culture medium significantly increased the percentage of DA neurons to 25–30% of the total number of neurons. Transplantation of conditioned medium‐treated day 4 spheres, which contained DA neuron progenitors, into the mouse striatum resulted in the generation of a significant number of graft‐derived DA neurons. These findings suggest that progenitors of DA neurons are generated and can proliferate in ES cell‐derived neurospheres induced by serial SDIA and PA6 conditioned medium treatment. © 2006 Wiley‐Liss, Inc.
Hippocampal neurodegeneration, spontaneous seizures, and mossy fiber sprouting in the F344 rat model of temporal lobe epilepsy
Authors: Rao Muddanna S. , Hattiangady Bharathi , Reddy Doodipala S. , Shetty Ashok K.
Published: February 2006

The links among the extent of hippocampal neurodegeneration, the frequency of spontaneous recurrent motor seizures (SRMS), and the degree of aberrant mossy fiber sprouting (MFS) in temporal lobe epilepsy (TLE) are a subject of contention because of variable findings in different animal models and human studies. To understand these issues further, we quantified these parameters at 3–5 months after graded injections of low doses of kainic acid (KA) in adult F344 rats. KA was administered every 1 hr for 4 hr, for a cumulative dose of 10.5 mg/kg bw, to induce continuous stages III–V motor seizures for >3 hr. At 4 days post‐KA, the majority of rats (77%) exhibited moderate bilateral neurodegeneration in different regions of the hippocampus; however, 23% of rats exhibited massive neurodegeneration in all hippocampal regions. All KA‐treated rats displayed robust SRMS at 3 months post‐KA, and the severity of SRMS increased over time. Analyses of surviving neurons at 5 months post‐KA revealed two subgroups of rats, one with moderate hippocampal injury (HI; 55% of rats) and another with widespread HI (45%). Rats with widespread HI exhibited greater loss of CA3 pyramidal neurons and robust aberrant MFS than rats with moderate HI. However, the frequency of SRMS (∼3/hr) was comparable between rats with moderate and widespread HI. Thus, in comparison with TLE model using Sprague‐Dawley rats (Hellier et al. [1998] Epilepsy Res. 31:73–84), a much lower cumulative dose of KA leads to robust chronic epilepsy in F344 rats. Furthermore, the occurrence of SRMS in this model is always associated with considerable bilateral hippocampal neurodegeneration and aberrant MFS. However, more extensive hippocampal CA3 cell loss and aberrant MFS do not appear to increase the frequency of SRMS. Because most of the features are consistent with mesial TLE in humans, the F344 model appears ideal for testing the efficacy of potential treatment strategies for mesial TLE. © 2006 Wiley‐Liss, Inc.
Adipocyte‐derived angiopoietin‐1 supports neurite outgrowth and synaptogenesis of sensory neurons
Authors: Kosacka Joanna , Nowicki Marcin , Kacza Johannes , Borlak Jürgen , Engele Jürgen , Spanel‐Borowski Katharina
Published: February 2006

Sensory and sympathetic innervation of the white fat tissue (WAT) contributes to lipolysis. In addition, both fiber types adapt in density to weight gain and loss. Because these findings are indicative for a tight control of nerve fiber plasticity by adipokines, we tested whether adipocytes control neurite growth of sensory neurons through angiopoietin‐1 (Ang‐1). We further considered initial hints that Ang‐1‐induced neuritogenesis involves transactivation of the high‐affinity nerve growth factor (NGF) receptor trkA. Coculturing dorsal root ganglion (DRG) cells with 3T3‐L1 adipocytes supported neurite outgrowth. These neurotrophic effects were associated with the increased expression of Ang‐1 (presumably in adipocytes) as well as of trkA. The effects were abolished upon inactivating Ang‐1 in culture with selective antibodies. Likewise, neurite outgrowth was impaired in the presence of inactivating NGF antibodies as well as upon inhibition of the NGF high‐affinity trkA receptor with the antagonist K252a, indicating a tight cooperation of Ang‐1 and NGF in the control of neuritogenesis. DRG‐adipipocyte cocultures were further used to establish whether sensory neurons would form synaptic contacts with adipocytes. Electron microscopy demonstrated that cultured sensory neurons develop predominantly neuroneuronal synapses but seem to affect adipocytes by synapses en passant. Comparably to the case for neuritogenesis, expression of the presynaptic protein synaptophysin as well of the postsynaptic protein PSD‐95 correlated with Ang‐1 levels in culture. It is concluded that adipocyte‐secreted Ang‐1 supports neurite outgrowth, which is involved in synaptogenesis. The novel function of Ang‐1 appears to play a physiological role in WAT plasticity. © 2006 Wiley‐Liss, Inc.
Modulation of apoptosis in the mouse brain after morphine treatments and morphine withdrawal
Authors: Emeterio Estela Pérez‐San , Tramullas Mónica , Hurlé María A.
Published: February 2006

We have examined the effects of acute or chronic morphine and naltrexone‐precipitated withdrawal on mouse brain apoptotic cell death. The associated changes in the expression of apoptosis regulatory proteins were also analyzed. After a single dose of morphine, no apoptotic cells were detected by TUNEL or active caspase‐3 immunocytochemistry. Concurrently, a down‐regulation of the proapoptotic proteins FasL and Bad was detected in cortical lysates. On the other hand, the brains of chronic‐morphine‐treated mice and abstinent mice exhibited scattered apoptotic neurons and astrocytes throughout the brain. This neurotoxic effect was accompanied by up‐regulation of the proapoptotic proteins FasL, Fas, and Bad and the active fragments of caspases‐8 and ‐3 in cortical and hippocampal lysates. Abstinent mice also displayed a reduced expression of the antiapoptotic protein Bcl‐2. No changes on t‐Bid expression were detected under any experimental condition. These results suggest a neurotoxic effect exerted by chronic, but not acute, morphine and its withdrawal by activating both the intrinsic and the extrinsic apoptotic pathways. The possible clinical implications of our findings are discussed. © 2006 Wiley‐Liss, Inc.
Prolonged dark adaptation changes connexin expression in the mouse retina
Authors: Kihara Alexandre Hiroaki , Mantovani de Castro Leandro , Moriscot Anselmo Sigari , Hamassaki Dânia Emi
Published: February 2006

In the retina, ambient light levels influence the cell coupling provided by gap junction (GJ) channels, to compensate the visual function for various lighting conditions. However, the effects of ambient light levels on expression of connexins (Cx), the proteins that form the GJ channels, are poorly understood. In the present study, we first determined whether gene expression of specific Cx (Cx26, Cx31.1, Cx36, Cx37, Cx40, Cx43, Cx45, Cx50, and Cx57) was affected by prolonged dark adaptation. Cx mRNA relative levels were determined in mouse retinas dark adapted for 3 hr, 1 day, and 7 days by using quantitative real‐time PCR. Transcript levels of some Cx were repressed after 3 hr (Cx57), 1 day (Cx45), or 7 days (Cx36 and Cx43) of dark adaptation; others were increased after 1 day (Cx50) or 7 days (Cx31.1 and Cx37); and two of them (Cx26 and Cx40) were not significantly altered. The second aim was to determine whether prolonged dark adaptation affects protein expression of two important Cx in retina: neuronal Cx36 and glial Cx43. We were able to demonstrate that important changes in protein distribution and expression also took place in retina during long‐term dark adaptation. Given their localization, the specific alterations in Cx expression may reflect their distinct response to ambient light levels. © 2006 Wiley‐Liss, Inc.
Radical excision of malignant sacral tumors using a modified threadwire saw
Authors: Osaka Shunzo , Kondoh Osamu , Yoshida Yukihiro , Ryu Junnosuke
Published: February 2006

Background

Surgical treatment of malignant sacral tumors is difficult, and has a high rate of recurrence.

Objectives

The aim of this study was to examine the wide margin of large and small malignant sacral tumors using a threadwire saw (T‐saw).

Materials and Methods

We devised a flexible silver guide probe connected to a modified threadwire saw by a suture thread to perform osteotomies. We operated on 10 patients with sacral tumors using this device. The sacral excisions were performed via a posterior approach by four surgeons (two on each side) working simultaneously.

Results

We obtained a wide margin in all cases and no recurrence, after a mean follow‐up of 4 years 2 months (range, 1 year 8 months–7 years 8 months). In one case, one nerve root on the right side was injured.

Conclusions

Our new method is easier and faster than the conventional method in cases in which bilateral sacral nerve root canals require sectioning, and it produces a wide tumor margin. J. Surg. Oncol. 2006;93:312–317. © 2006 Wiley‐Liss, Inc.
Liver resection for hepatocellular carcinoma in patients who have undergone prior renal transplantation
Authors: Cheng Shao‐Bin , Yeh Dah‐Cherng , Shu Kuo‐Hsiung , Wu Cheng‐Chung , Wen Mei‐Chin , Liu Tse‐Jia , P'eng Fang‐Ku
Published: February 2006

Background and Objectives

Because renal transplantation recipients require immunosuppressive drugs, they have a higher incidence of subsequent malignancies. Among them, hepatocellular carcinoma (HCC) is common. Although liver resection remains an option for curing HCC, the role of liver resection in renal transplantation recipients remains unclear.

Methods

A retrospective review of liver resection for newly diagnosed HCC in 680 patients was conducted. Among them, 18 patients had undergone prior renal transplantation (RT group). The patient background, tumor characteristics, early and long‐term results after liver resection were compared with the other 662 patients who had not previously undergone renal transplantation (non‐RT group).

Results

The patient's background characteristics were comparable between RT and non‐RT group. The tumor characteristics, postoperative morbidity, and mortality were not significantly different between the two groups. The 5‐year disease‐free survival rates in RT and non‐RT groups were 18.8% and 41.2%, respectively (P = 0.242), whereas 5‐year actuarial survival rates in RT and non‐RT groups were 59.1% and 58.3%, respectively (P = 0.738). Two patients lost their graft kidney 3 and 8 years after liver resection.

Conclusion

With careful protection of the graft kidney, liver resection is still a justified treatment option for HCC in patients who have undergone renal transplantation. J. Surg. Oncol. 2006;93: 273–278. © 2006 Wiley‐Liss, Inc.
Major influence of liver function itself but not of immunosuppression determines glucose tolerance after living-donor liver transplantation
Authors: Stockmann Martin , Konrad Thomas , Nolting Sabine , Hünerbein Diana , Wernecke Klaus-Dieter , Döbling Helena , Steinmüller Thomas , Neuhaus Peter
Published: February 2006

Controversial data exists concerning the impact of immunosuppressive therapy on the development of post-transplantation diabetes mellitus (PTDM). Therefore, we investigated glucose metabolism in healthy donors and in recipients of living-donor liver transplants (LD-LTX, n=18) without pre-existing diabetes mellitus before, on day 10, month 6, and month 12 after intervention. The computer-assisted analysis of glucose, insulin, and C-peptide profiles obtained from frequently sampled intravenous glucose tolerance tests allows to achieve an integrated view of factors controlling glucose tolerance, i.e., insulin sensitivity (SI), first and second phase insulin secretion (Φ1 and Φ2). SI of donors declined by day 10 after operation (SI 2.65 ± 0.41 vs. 4.90 ± 0.50 10−4 minute−1 μU ml−1, P < 0.01) but returned to values as before after 6 months. Φ1 did not change. Φ2, however, significantly increased by day 10 (8.57 ± 0.82 109 minute−1 to 13.77 ± 1.53 109 minute−1, P < 0.01) but was in the same range as before after 6 months. In parallel to donors SI of recipients progressively increased after LD-LTX. Φ1 did not alter in recipients. Φ2 continuously decreased and was not different from donors by month 12. The extent of liver injury assessed by liver enzyme concentrations and liver function represented by cholinesterase activity, albumin, and INR were closely related with changes of SI in donors and recipients during the first year after intervention. In conclusion, the extent of liver damage plays a predominant role in regulating glucose tolerance. No impact of immunosuppressive therapy on SI, Φ1 and Φ2 was detected.
Liver Transpl 12:535–543, 2006.

© 2006 AASLD.
Transdifferentiation of bioencapsulated bone marrow cells into hepatocyte-like cells in the 90% hepatectomized rat model
Authors: Liu Zun Chang , Chang Thomas Ming Swi
Published: February 2006

Under specific conditions, bone marrow cells can transdifferentiate into a variety of cell types including hepatocytes. In this study, bioencapsulated bone marrow cells were transplanted intraperitoneally into 90% hepatectomized rats. We then followed the transdifferentiation of the bone marrow cells and the effect of this on liver regeneration in this liver failure model. Bone marrow cells isolated from Wistar rats were bioencapsulated using alginate-polylysine-alginate method. These bioencapsulated bone marrow cells were transplanted intraperitoneally into 90% hepatectomized Wistar rats. Blood chemistry, HGF, liver weight, and survival of the recipient rats were evaluated. Histology and immunocytochemistry were used to analyze the bioencapsulated cells before and 14 days after transplantation. Unlike free bone marrow cells, transplantation of bioencapsulated bone marrow cells improved the survival of 90% hepatectomized rats and improved the blood chemistry with an efficacy similar to that of bioencapsulated hepatocytes or free hepatocytes transplantation. Some bioencapsulated bone marrow cells expressed hepatocytes markers of cytokeratins 8, cytokeratins 18, albumin, and AFP after 2 weeks of transplantation. These results suggest that syngeneic bioencapsulated bone marrow cells can transdifferentiate into hepatocyte-like cells in the peritoneal cavity of 90% hepatectomized rats and increased the survival rates of these rats. In conclusion, these findings suggest the potential for a new alternative to hepatoctye transplantation for cellular therapy of acute liver failure.
Liver Transpl 12:566–572, 2006.

© 2006 AASLD.
Dephosphorylation of p‐ERK1/2 in relation to tumor remission after HER‐2 and Raf1 blocking therapy in a conditional mouse tumor model
Authors: Hausherr Carolin K. , Schiffer Ilka B. , Gebhard Susanne , Banić Andreas , Tanner Berno , Kolbl Heinz , Thoenes Eric , Beckers Thomas , Spangenberg Christian , Prawitt Dirk , Trost Tatjana , Zabel Bernhard , Oesch Franz , Hermes Matthias , Hengstler Jan G.
Published: February 2006

Several studies have shown that HER‐2/neu (erbB‐2) blocking therapy strategies can cause tumor remission. However, the responsible molecular mechanisms are not yet known. Both ERK1/2 and Akt/PKB are critical for HER‐2‐mediated signal transduction. Therefore, we used a mouse tumor model that allows downregulation of HER‐2 in tumor tissue by administration of anhydrotetracycline (ATc). Switching‐off HER‐2 caused a rapid tumor remission by more than 95% within 7 d of ATc administration compared to the volume before switching‐off HER‐2. Interestingly, HER‐2 downregulation caused a dephosphorylation of p‐ERK1/2 by more than 80% already before tumor remission occurred. Levels of total ERK protein were not influenced. In contrast, dephosphorylation of p‐Akt occurred later, when the tumor was already in remission. These data suggest that in our HER‐2 tumor model dephosphorylation of p‐ERK1/2 may be more critical for tumor remission than dephosphorylation of p‐Akt. To test this hypothesis we used a second mouse tumor model that allows ATc controlled expression of BXB‐Raf1 because the latter constitutively signals to ERK1/2, but cannot activate Akt/PKB. As expected, downregulation of BXB‐Raf1 in tumor tissue caused a strong dephosphorylation of p‐ERK1/2, but did not decrease levels of p‐Akt. Interestingly, tumor remission after switching‐off BXB‐Raf1 was similarly efficient as the effect of HER‐2 downregulation, despite the lack of p‐Akt dephosphorylation. In conclusion, two lines of evidence strongly suggest that dephosphorylation of p‐ERK1/2 and not that of p‐Akt is critical for the rapid tumor remission after downregulation of HER‐2 or BXB‐Raf1 in our tumor model: (i) dephosphorylation of p‐ERK1/2 but not that of p‐Akt precedes tumor remission after switching‐off HER‐2 and (ii) downregulation of BXB‐Raf1 leads to a similarly efficient tumor remission as downregulation of HER‐2, although no p‐Akt dephosphorylation was observed after switching‐off BXB‐Raf1. © 2006 Wiley‐Liss, Inc.
US‐style contingent fees and UK‐style conditional fees: agency problems and the supply of legal services
Authors: Emons Winand , Garoupa Nuno
Published: February 2006

Under contingent fees, the attorney gets a share of the judgment; under conditional fees, the lawyer gets an upscale premium if the case is won which is, however, unrelated to the adjudicated amount. We compare conditional and contingent fees in a principal–agent framework where the lawyer chooses unobservable effort after she has observed the amount at stake. Contingent fees provide better incentives than conditional fees independently of whether upfront payments are restricted to be non‐negative or not. Under contingent fees, the attorney uses her information about what is at stake more efficiently. Copyright © 2006 John Wiley & Sons, Ltd.
Glutathione content and glutathione peroxidase expression in in vivo and in vitro matured equine oocytes
Authors: Luciano Alberto M. , Goudet Ghylène , Perazzoli Federica , Lahuec Cecile , Gérard Nadine
Published: February 2006

The in vitro developmental competence of equine oocytes is still low in comparison with other domestic mammals. A major factor affecting the viability of cells during in vitro culture is the increased oxidative stress. Oxidative modifications could be responsible for oocyte incompetence for in vitro maturation (IVM). Cysteamine, a glutathione (GSH) synthesis enhancer, has been shown to increase intracellular GSH content and to improve embryo development when added during IVM of bovine, porcine, and ovine oocytes. The aim of the present study was (1) to determine whether equine cumulus–oocyte complexes (COCs) benefit from the addition of cysteamine during IVM, (2) to compare the GSH content of oocytes after in vivo maturation and IVM, (3) to assess whether cysteamine administration during IVM of equine oocyte enhances early embryonic developmental capability following ICSI, (4) to study the glutathione peroxidase (GPX) mRNA level in COCs. In vivo matured COCs were collected by aspiration from preovulatory follicles, and analyzed at collection. Immature COCs were collected in vivo or from slaughterhouse ovaries and matured in culture media supplemented or not with 100 µM cysteamine. After nuclear stage assessment, oocytes were analyzed for GSH concentration and both oocytes and cumulus cells were analyzed for GPX and GAPDH mRNA. Our data showed that the maturation capability was similar in both in vivo aspirated oocytes and in those isolated from slaughterhouse ovaries. Moreover, the addition of cysteamine during IVM affected neither GSH content nor maturation rate. At the time of collection, intra‐oocyte GSH content was not influenced by the chromatin status. GSH concentration was similar in in vivo and in vitro matured metaphase II (MII) stage oocytes, and was significantly higher in MII than immature germinal vesicle stage oocytes. Moreover, the presence of serum inhibited whereas its absence stimulated the accumulation of GSH within oocytes during IVM. After ICSI, a similar proportion of zygotes in each group developed beyond the two‐cell stage after 72 hr of culture. Cumulus cells expressed GPX mRNA, while GPX transcript was absent in both immature and mature oocytes. Cumulus expression of GPX mRNA was significantly higher when analyzed at collection than after IVM. Taken together, our results demonstrate that in equine oocytes, GSH increases during IVM but the relative intra‐oocyte content of this thiol does not affect maturation and early development efficiency after fertilization. We hypothesize that factor(s) other than GSH/GPX are responsible for the limited in vitro early developmental capability of equine oocytes. Mol. Reprod. Dev. 73: 658–666, 2006 © 2006 Wiley‐Liss, Inc.
Ovarian and sperm regulatory peptides regulate ovulation in the oyster Crassostrea gigas
Authors: Bernay Benoît , Baudy‐Floc'h Michèle , Zanuttini Bruno , Zatylny Céline , Pouvreau Stéphane , Henry Joël
Published: February 2006

For more than six decades, several studies have shown that genital products to entering the mantle cavity via the incurrent siphon, initiate in oyster, strong and rhythmic contractions of the adductor muscle (AM). In order to characterize the regulatory peptides capable of triggering AM contractions, we focused on the identification of putative myotropic peptides from genital products. Two experimental approaches were developed. The first one, based on a mass spectrometry screening of the male genital products, led to the identification of the tetrapeptide APGWamide. This neuropeptide was also detected in the seminal secretions of the cephalopod Sepia officinalis. In this species, APGWamide is directly involved in the oocyte transport. In Crassostrea, in vitro bioassay demonstrated that APGWamide modulates the AM contractions that insure the release of oocytes in the external medium. Exposure of oysters to a physiological concentration of APGWamide triggered repetitive shell closures. The second experimental approach was based on the monitoring of HPLC purification by a myotropic bioassay using the cuttlefish oviduct contractions as a target. The successive purification steps of the acidic extraction of ovaries from mature female oysters, led to the characterization of the hexapeptide PIESVD. When applied to mature female oysters, this peptide triggered the increase of shell closure frequency. The activity of these two regulatory peptides is the first experimental evidence of a peptidergic control of egg‐laying in oyster. APGWamide and PIESVD could be used, in commercial and experimental hatcheries, for the identification of mature females to be selected for in vitro fertilization. Mol. Reprod. Dev. © 2006 Wiley‐Liss, Inc.