bluuebunny/crossref_metadata_2025 huggingface dataset:
Linear age‐correlated functional development of right inferior fronto‐striato‐cerebellar networks during response inhibition and anterior cingulate during error‐related processes
Authors: Rubia Katya , Smith Anna B. , Taylor Eric , Brammer Michael
Published: May 2007

Inhibitory and performance‐monitoring functions have been shown to develop throughout adolescence. The developmental functional magnetic resonance imaging (fMRI) literature on inhibitory control, however, has been relatively inconsistent with respect to functional development of prefrontal cortex in the progression from childhood to adulthood. Age‐related performance differences between adults and children have been shown to be a confound and may explain inconsistencies in findings. The development of error‐related processes has not been studied so far using fMRI. The aim of this study was to investigate the neural substrates of the development of inhibitory control and error‐related functions by use of an individually adjusted task design that forced subjects to fail on 50% of trials, and therefore controlled for differences in task difficulty and performance between different age groups. Event‐related fMRI was used to compare brain activation between 21 adults and 26 children/adolescents during successful motor inhibition and inhibition failure. Adults compared with children/adolescents showed increased brain activation in right inferior prefrontal cortex during successful inhibition and in anterior cingulate during inhibition failure. A whole‐brain age‐regression analysis between 10 and 42 years showed progressive age‐related changes in activation in these two brain regions, with additional changes in thalamus, striatum, and cerebellum. Age‐correlated brain regions correlated with each other and with inhibitory performance, suggesting they form developing fronto‐striato‐thalamic and fronto‐cerebellar neural pathways for inhibitory control. This study shows developmental specialization of the integrated function of right inferior prefrontal cortex, basal ganglia, thalamus, and cerebellum for inhibitory control and of anterior cingulate gyrus for error‐related processes. Hum Brain Mapp 2007. © 2007 Wiley‐Liss, Inc.
Remarkable heterogeneity displayed by oval cells in rat and mouse models of stem cell–mediated liver regeneration
Authors: Jelnes Peter , Santoni-Rugiu Eric , Rasmussen Morten , Friis Susanne Lunφe , Nielsen Jens Hφiriis , Tygstrup Niels , Bisgaard Hanne Cathrine
Published: May 2007

The experimental protocols used in the investigation of stem cell–mediated liver regeneration in rodents are characterized by activation of the hepatic stem cell compartment in the canals of Hering followed by transit amplification of oval cells and their subsequent differentiation along hepatic lineages. Although the protocols are numerous and often used interchangeably across species, a thorough comparative phenotypic analysis of oval cells in rats and mice using well-established and generally acknowledged molecular markers has not been provided. In the present study, we evaluated and compared the molecular phenotypes of oval cells in several of the most commonly used protocols of stem cell–mediated liver regeneration—namely, treatment with 2-acetylaminofluorene and partial (70%) hepatectomy (AAF/PHx); a choline-deficient, ethionine-supplemented (CDE) diet; a 3,5-diethoxycarbonyl-1,4-dihydro-collidin (DDC) diet; and

N

-acetyl-paraaminophen (APAP). Reproducibly, oval cells showing reactivity for cytokeratins (CKs), muscle pyruvate kinase (MPK), the adenosine triphosphate–binding cassette transporter ABCG2/BCRP1 (ABCG2), alpha-fetoprotein (AFP), and delta-like protein 1/preadipocyte factor 1 (Dlk/Pref-1) were induced in rat liver treated according to the AAF/PHx and CDE but not the DDC protocol. In mouse liver, the CDE, DDC, and APAP protocols all induced CKs and ABCG2-positive oval cells. However, AFP and Dlk/Pref-1 expression was rarely detected in oval cells.

Conclusion:

Our results delineate remarkable phenotypic discrepancies exhibited by oval cells in stem cell–mediated liver regeneration between rats and mice and underline the importance of careful extrapolation between individual species. (Hepatology 2007;45:1462–1470.)
Hepatitis B viral load predicts survival of HCC patients undergoing systemic chemotherapy
Authors: Yeo Winnie , Mo Frankie K. F. , Chan Stephen L. , Leung Nancy W. Y. , Hui Pun , Lam Wai-Yip , Mok Tony S. K. , Lam Kowk C. , Ho Wing M. , Koh Jane , Tang Julian W. , Chan Anthony T. , Chan Paul K. S.
Published: May 2007

HCC is a common cause of morbidity and mortality. For patients who are not candidates for curative surgery, systemic chemotherapy is one of the standard treatments. In parts of China and the Far East, over 80% of HCC patients have chronic HBV infection. In this study, we aimed to assess the relationship between pre-chemotherapy HBV viral load and the survival of HCC patients. HBV infection status was determined prior to chemotherapy in 188 patients, 170 of whom had evidence of HBV chronic infection/exposure (160 hepatitis B surface antigen [HBsAg]-positive, 10 HBsAg-negative/hepatitis B core antibody–positive). Of these, 125 had pretreatment HBV DNA levels determined via real-time PCR. Virological data were analyzed using conventional clinical variables to identify factors that influenced survival. Multivariate analysis revealed that high total bilirubin (

P

= 0.0016; hazard ratio = 1.040 per 1 μM increase; 95% CI 1.015–1.065), HCV infection (

P

= 0.0095; hazard ratio = 6.955; 95% CI 1.606–30.129), and high HBV DNA level (

P

= 0.0217; hazard ratio = 1.650; 95% CI 1.076–2.531) affected survival significantly. Exploratory analysis revealed that high levels of pretreatment HBV DNA had a significantly higher incidence of severe hepatitis during chemotherapy.

Conclusion:

For HCC patients with HBV chronic infection/exposure, a high viral load prior to treatment is an adverse factor for survival and may be associated with a higher incidence of severe hepatitis during chemotherapy. Future strategies to improve the prognosis of HCC patients undergoing chemotherapy should consider supportive therapy that incorporates antiviral therapies to reduce HBV viral load. (Hepatology 2007;45:1382–1389.)
Tissue-type plasminogen activator deficiency exacerbates cholestatic liver injury in mice
Authors: Wang Hongtao , Zhang Yan , Heuckeroth Robert O.
Published: May 2007

Recent studies demonstrating a role for plasminogen activator inhibitor (PAI)-1 in cholestatic liver disease in mice suggested that tissue-type plasminogen activator (tPA) or urokinase plasminogen activator (uPA) might be important after biliary tract obstruction. We now demonstrate that blocking tPA exacerbates liver injury after bile duct ligation (BDL). tPA deficient mice have increased bile infarcts, increased TUNEL positive cells, increased neutrophil infiltration, reduced hepatocyte proliferation and reduced ductular reaction 72 hours after BDL compared to wild type mice. In addition, the protective and proliferative effects of plasminogen activator inhibitor 1 (PAI-1) deficiency after BDL are dramatically blocked by the tPA inhibitor tPA-STOP. One potential mechanism for these effects is that both tPA deficiency and tPA-STOP reduce hepatocyte growth factor (HGF) activation and c-Met phosphorylation in the liver after BDL. In support of this hypothesis, HGF treatment reverses the effects of tPA deficiency in mice. Furthermore, preferential tPA activation in areas of injury after BDL might occur because fibrin accumulates in bile infarcts and activates tPA.

Conclusion:

tPA inactivation accelerates liver injury after BDL and reduces HGF activation. These data suggest that strategies to increase HGF activation might be protective in liver diseases with biliary tract obstruction even without increased HGF production. (Hepatology 2007;45:1527–1537.)
Elevated troponin I levels in acute liver failure: Is myocardial injury an integral part of acute liver failure?
Authors: Parekh Nimisha K. , Hynan Linda S. , De Lemos James , Lee William M.
Published: May 2007

Although rare instances of cardiac injury or arrhythmias have been reported in acute liver failure (ALF), overall, the heart is considered to be spared in this condition. Troponin I, a sensitive and specific marker of myocardial injury, may be elevated in patients with sepsis and acute stroke without underlying acute coronary syndrome, indicating unrecognized cardiac injury in these settings. We sought to determine whether subclinical cardiac injury might also occur in acute liver failure. Serum troponin I levels were measured in 187 patients enrolled in the US Acute Liver Failure Study Group registry, and correlated with clinical variables and outcomes. Diagnoses were representative of the larger group of >1000 patients thus far enrolled and included 80 with acetaminophen-related injury, 26 with viral hepatitis, 19 with ischemic injury, and 62 others. Overall, 74% of patients had elevated troponin I levels (>0.1 ng/ml). Patients with elevated troponin I levels were more likely to have advanced hepatic coma (grades III or IV) or to die (for troponin I levels >0.1 ng/ml, odds ratio 3.88 and 4.69 for advanced coma or death, respectively).

Conclusion:

In acute liver failure, subclinical myocardial injury appears to occur more commonly than has been recognized, and its pathogenesis in the context of acute liver failure is unclear. Elevated troponin levels are associated with a significant increase in morbidity and mortality. Measurement of troponin I levels may be helpful in patients with acute liver failure, to detect unrecognized myocardial damage and as a marker of unfavorable outcome. (Hepatology 2007;45:1489–1495.)
Ethanol and fish oil induce NFκB transactivation of the collagen α2(I) promoter through lipid peroxidation–driven activation of the PKC-PI3K-Akt pathway
Authors: Nieto Natalia
Published: May 2007

To analyze whether fish oil, as a source of polyunsaturated fatty acids from the n-3 series, could synergize with ethanol to promote collagen I upregulation

in vivo

, collagen α2(I) promoter-
βGal

(

COL1A2-βGal

) transgenic mice were fed a diet enriched in fish oil in the presence of ethanol (ethanol group) or dextrose (control group). Ethanol-fed mice showed mild steatosis, increased alanine aminotransferase (ALT), aspartate aminotransferase (AST), nonsterified fatty acids, and plasma alcohol levels along with elevated cytochrome P450 2E1 activity, lipid peroxidation end products, and low glutathione (GSH) levels, which suggested enhanced oxidant stress and liver injury. Increased transactivation of the

COL1A2

promoter assessed by βGal activity was shown

in vivo

and by transfection with deletion constructs for the collagen α1(I) promoter (

COL1A1

) and

COL1A2

promoters

in vitro

. Transcriptional regulation of both

COL1A1

and

COL1A2

promoters was validated by nuclear

in vitro

transcription run-on, northern blot analysis, and quantitative polymerase chain reaction, which was followed by the subsequent upregulation of collagen I protein with no changes in matrix metalloproteinase 13 (MMP 13). To further analyze the potential mechanism for collagen I upregulation, an

in vitro

coculture model was designed with primary stellate cells seeded on the bottom plate of a Boyden chamber and the rest of the liver cells plated on a cell culture insert, and fish oil or fish oil plus ethanol were added. The combination of fish oil plus ethanol increased nuclear factor κB binding to the

COL1A2

promoter both

in vivo

and in the cocultures and also resulted in increased phosphorylation of protein kinase

C

, activation of PI3 kinase, and phosphorylation of Akt. The

in vitro

addition of vitamin E prevented such activation and collagen I increase. Furthermore, inhibitors of all 3 kinases blocked the increase in collagen I and NFκB binding to the

COL1A2

promoter; the latter was also prevented by vitamin E.

Conclusion:

These results suggest that fish oil (mainly n-3 polyunsaturated fatty acids [PUFAs]) can synergize with ethanol to induce collagen I, transactivating the

COL1A2

promoter through a lipid peroxidation-PKC-PI3K-Akt-NFκB-driven mechanism in the absence of overt steatosis and inflammation. (Hepatology 2007;45:1433–1445.)
T cells in the liver: There is life beyond the graveyard
Authors: Bertolino Patrick , Bowen David G. , Benseler Volker , Kowdley Kris , McCaughan Geoffrey , Trautwein Christian
Published: May 2007

Influenza A virus infection of C57BL/6 mice is a well-characterized model for studying CD8+ T cell-mediated immunity. Analysis of primary and secondary responses showed that the liver is highly enriched for CD8+ T cells specific for the immunodominant H2DbNP366-374 (DbNP366) epitope. Functional analysis established that these liver-derived virus-specific CD8+ T cells are fully competent cytotoxic effectors and IFN-gamma secretors. In addition, flow cytometric analysis of early apoptotic cells showed that these influenza-specific CD8+ T cells from liver are as viable as those in the spleen, bronchoalveolar lavage, mediastinal lymph nodes, or lung. Moreover, cytokine profiles of the influenza-specific CD8+ T cells recovered from different sites were consistent with the bronchoalveolar lavage, rather than liver population, being the most susceptible to activation-induced cell death. Importantly, adoptively transferred influenza virus-specific CD8+ T cells from the liver survived and were readily recalled after virus challenge. Together, these results show clearly that the liver is not a “graveyard” for influenza virus-specific CD8+ T cells.
Restoration of p53 function: A new therapeutic strategy to induce tumor regression?
Authors: Beraza Naiara , Trautwein Christian , Kowdley Kris , McCaughan Geoffrey
Published: May 2007

Although cancer arises from a combination of mutations in oncogenes and tumour suppressor genes, the extent to which tumour suppressor gene loss is required for maintaining established tumours is poorly understood. p53 is an important tumour suppressor that acts to restrict proliferation in response to DNA damage or deregulation of mitogenic oncogenes, by leading to the induction of various cell cycle checkpoints, apoptosis or cellular senescence. Consequently, p53 mutations increase cell proliferation and survival, and in some settings promote genomic instability and resistance to certain chemotherapies. To determine the consequences of reactivating the p53 pathway in tumours, we used RNA interference (RNAi) to conditionally regulate endogenous p53 expression in a mosaic mouse model of liver carcinoma. We show that even brief reactivation of endogenous p53 in p53-deficient tumours can produce complete tumour regressions. The primary response to p53 was not apoptosis, but instead involved the induction of a cellular senescence program that was associated with differentiation and the upregulation of inflammatory cytokines. This program, although producing only cell cycle arrest in vitro, also triggered an innate immune response that targeted the tumour cells in vivo, thereby contributing to tumour clearance. Our study indicates that p53 loss can be required for the maintenance of aggressive carcinomas, and illustrates how the cellular senescence program can act together with the innate immune system to potently limit tumour growth.
Tyrosine phosphorylation of the GluR2 subunit is required for long‐term depression of synaptic efficacy in young animals in vivo
Authors: Fox Christopher J. , Russell Kyle , Titterness Andrea K. , Wang Yu Tian , Christie Brian R.
Published: May 2007

The study of the intracellular mechanics that underlay changes in synaptic efficacy is a rapidly evolving field of research. It is currently believed that NMDA receptors play a significant role in the induction of synaptic plasticity, whereas AMPA receptors play a significant role in its expression. For AMPA receptors, it has been shown that tyrosine phosphorylation of the GluR2 carboxyl termini is required for the expression of long‐term depression of synaptic efficacy (LTD) in vitro (Ahmadian et al. (2004) EMBO J 23:1040–1050). In the present study, we sought to determine whether similar mechanisms are involved in vivo, where different stimulation parameters are required for the induction of LTD. We initially used a paired‐burst (PB) paradigm that reliably induces LTD in vivo. In these animals we were able to prevent the induction and expression of PB‐LTD by administering a peptide (GluR‐3Y) that acted as a competitive inhibitor of tyrosine phosphorylation. In a separate set of animals, we exposed animals to brief periods of stress (S) before using low‐frequency stimuli to induce LTD (S‐LTD). Again, GluR2–3Y blocked both the induction and expression of S‐LTD. In contrast, an inert version of the peptide, with alanine replacing the three tyrosine residues, did not inhibit LTD induction. In addition, we demonstrated that GluR2–3Y did not affect the induction of long‐term potentiation in vivo. These findings support the hypothesis that tyrosine phosphorylation and AMPA receptor endocytosis are necessary steps for the induction and maintenance of two forms of LTD in the CA1 region. © 2007 Wiley‐Liss, Inc.
Occurrence of phthalate diesters in rivers of the Paris district (France)
Authors: Teil Marie‐Jeanne , Blanchard Martine , Dargnat Cendrine , Larcher‐Tiphagne Karen , Chevreuil Marc
Published: May 2007

The occurrence and fate of six phthalate esters were investigated in the River Seine and two tributaries in the Paris area, at six sites from upstream to downstream, throughout different seasons, with special attention given to a flood episode. At all sites, except the River Marne, whatever the period, diethylhexyl phthalate (DEHP) displayed the highest concentration (0·323–0·779 µg l−1 as mean values), followed by di‐n‐butyl phthalate (DnBP; 0·211–0·526 µg l−1 as mean values), which is consistent with the production pattern. High phthalate concentrations appeared to be related to population density and industrial distribution. The strongest values were located downstream from wastewater treatment plant effluent inputs. Seasonal variations were closely related to river flow and air and water temperature. The annual evolution of phthalates was linked to the hydrological conditions. During the flood episode at Paris, the DEHP concentration displayed a sharp increase (260 to 1123 ng l−1) occurring 9 days before the flood peak. The simultaneous fluctuations of NH4, typical of domestic origin, and of DEHP suggests a similar origin from combined sewer overflows for both compounds. Other elevated values corresponded to the highest precipitation amounts, and demonstrated the contribution of non‐point‐source runoff and wastewater overflow to DEHP inputs. The DEHP concentration relationship with river flow displayed a clockwise hysteresis loop, corresponding to a ‘first‐flush’ effect in which the finite supplies are swept along in the early stage of the flood. Annual fluxes for 2004 at Paris were 2257 kg of DEHP and 1613 kg of DnBP. The flood period seemed to have a minor impact on annual phthalate transport (29·5% and 41% of the total for DEHP and for DnBP, respectively), which is contrary to annual suspended solids transport (69%). Copyright © 2007 John Wiley & Sons, Ltd.
Comparison of acid mucin goblet cell distribution and Hox13 expression patterns in the developing vertebrate digestive tract
Authors: Theodosiou Nicole A. , Hall Daniel A. , Jowdry Andrea L.
Published: May 2007

The digestive tract of vertebrates is a complex organ system required for the digestion of food and the absorption of nutrients. The colon evolved as a water absorption organ essential for vertebrates to survive on land. In contrast to land vertebrates, the Chondrichthyes (sharks, skates and rays) are nearly iso‐osmotic with their ocean environment and do not reabsorb water from food waste. To understand the origin of the vertebrate colon, we examined the distribution of sulfated and sialyated mucus‐producing cells in the little skate, Raja erinacea, as an indication of water absorption function in the chondrichthian digestive tract. The percentage of acid mucin producing goblet cells was analyzed in the spiral valve and hindgut of little skate and the small intestine and colon of mouse embryos. Levels of acid mucins in the hindgut of the little skate was comparable to that of the small intestines of terrestrial vertebrates, whereas the distal region of the spiral valve contained high levels of acid mucin producing cells similar to the colon of mouse and chick. The low numbers of acid mucins in the little skate hindgut confirms that a functional colon for water absorption is absent in the Chondrichthyes. Interestingly, the presence of high levels of acid mucins in the posterior spiral valve provides evidence for a possible primordial water‐absorbing organ in the elasmobranchs. Hoxd13 patterns acid mucins in the colons of terrestrial vertebrates. Expression of Hoxd13 and Hoxa13 in R. erinacea suggests conserved roles for Hox genes in patterning the early hindgut. J. Exp. Zool. (Mol. Dev. Evol.) 308B:442–453, 2007. © 2007 Wiley‐Liss, Inc.
Fiber introduction mass spectrometry: determination of pesticides in herbal infusions using a novel sol–gel PDMS/PVA fiber for solid‐phase microextraction
Authors: da Silva Rogério Cesar , Zuin Vânia Gomes , Yariwake Janete Harumi , Eberlin Marcos Nogueira , Augusto Fabio
Published: May 2007

An application of the direct coupling of solid‐phase microextraction (SPME) with mass spectrometry (MS), a technique known as fiber introduction mass spectrometry (FIMS), is described to determine organochlorine (OCP) and organophosphorus (OPP) pesticides in herbal infusions of Passiflora L. A new fiber coated with a composite of poly(dimethylsiloxane) and poly(vinyl alcohol) (PDMS/PVA) was used. Sensitive, selective, simple and simultaneous quantification of several OCP and OPP was achieved by monitoring diagnostic fragment ions of m/z 266 (chlorothalonil), m/z 195 (α‐endosulfan), m/z 278 (fenthion), m/z 263 (methyl parathion) and m/z 173 (malathion). Simple headspace SPME extraction (25 min) and fast FIMS detection (less than 40 s) of OCP and OPP from a highly complex herbal matrix provided good linearity with correlation coefficients of 0.991–0.999 for concentrations ranging from 10 to 140 ng ml−1 of each compound. Good accuracy (80 to 110%), precision (0.6–14.9%) and low limits of detection (0.3–3.9 ng ml−1) were also obtained. Even after 400 desorption cycles inside the ionization source of the mass spectrometer, no visible degradation of the novel PDMS/PVA fiber was detected, confirming its suitability for FIMS. Fast (ca 20 s) pesticide desorption occurs for the PDMS/PVA fiber owing to the small thickness of the film and its reduced water sorption. Copyright © 2007 John Wiley & Sons, Ltd.
Laser desorption/ionization determination of molecular weight distributions of polyaromatic carbonaceous compounds and their aggregates
Authors: Martínez‐Haya Bruno , Hortal Ana R. , Hurtado Paola , Lobato Marcos D. , Pedrosa José M.
Published: May 2007

Molecular weight distributions (MWDs) of model polyaromatic hydrocarbons (PAHs) and complex asphaltene samples have been investigated in laser desorption/ionization mass spectrometry (LDI–MS) experiments. Special efforts are devoted to the characterization of aggregation effects during the desorption process. It is found that non‐covalent clusters of the PAHs and asphaltenes form readily in the desorbing plume. Aggregation is favoured in the experiments performed on dense samples at high laser energy and under continuous ion extraction conditions. In the absence of polar groups in the analyte molecules, the aggregation propensity correlates well with the size of the polycondensed system and with its degree of pericondensation, in qualitative agreement with previous theoretical predictions. For the polydispersed asphaltenes from two different crude oils, MWDs peaking at masses smaller than 500 amu with a high‐mass tail extending up to about 3000 amu have been observed, yielding average weights around 900 amu. Such MWDs are in good agreement with previous mass spectrometric measurement, as well as with diffusion studies in solution. In addition, stable asphaltene aggregates have been detected giving rise to two broad bands in the mass spectrum corresponding to average molecular weights of 2200–3100 amu and 15 000–19 000 amu, respectively. It is concluded that the strong aggregation propensity of asphaltenes is likely to be responsible for the apparent inconsistency between the MWD for these compounds determined by different groups in independent LDI‐MS experiments. The reliability of different sample preparation procedures, including solvent‐free methods, is discussed, and strategies are outlined that serve to apply the potentiality of LDI mass spectrometry to the characterization of covalent and non‐covalent compounds in complex carbonaceous systems. Copyright © 2007 John Wiley & Sons, Ltd.
Does Middle Hepatic Vein Omission in a Right Split Graft Affect the Outcome of Liver Transplantation? a Comparative Study of Right Split Livers with and Without the Middle Hepatic Vein
Authors: Adham Mustapha , Dumortier Jérôme , Abdelaal Amr , Sagnard Pierre , Boucaud Catherine , Boillot Olivier
Published: May 2007

Preservation of the middle hepatic vein (MHV) for a right split liver transplantation (SLT) in an adult recipient is still controversial. The aim of this study was to evaluate the graft and patient outcomes after liver transplantation (LT) using a right split graft, according to the type of venous drainage. From February 2000 to May 2006, 33 patients received 34 cadaveric right split liver grafts. According to the type of recipient pairs (adult/adult or adult/child), the right liver graft was deprived of the MHV or not. The first group (GI, n = 15) included grafts with only the right hepatic vein (RHV) outflow, the second (GII, n = 18) included grafts with both right and MHV outflows. The 2 groups were similar for patient demographics, initial liver disease, and donor characteristics. In GI and GII, graft-to-recipient-weight ratio (GRWR) was 1.2 ± 0% and 1.6 ± 0.3% (P < 0.05), and cold ischemia time was 10 hours 55 minutes ± 2 hours 49 minutes and 10 hours 47 minutes ± 3 hours 32 minutes, respectively (P = not significant). Postoperative death occurred in 1 patient in each group. Vascular complications included anastomotic strictures: 2 portal vein (PV), 1 hepatic artery (HA), and 1 RHV anastomotic strictures; all in GI. Biliary complications occurred in 20% and 22% of the patients, in GI and GII, respectively (P = not significant). There were no differences between both groups regarding postoperative outcome and blood tests at day 1-15 except for a significantly higher cholestasis in GI. At 1 and 3 yr, patient survival was 94% for both groups and graft survival was 93% for GI and 90% for GII (P = not significant). In conclusion, our results suggest that adult right SLT without the MHV is safe and associated with similar long-term results as compared with those of the right graft including the MHV, despite that early liver function recovered more slowly. Technical refinements in outflow drainage should be evaluated in selected cases. Liver Transpl 13:829–837, 2007. © 2007 AASLD.
Intrinsically Hyperarithmetical Sets
Authors: Soskov Ivan N.
Published: May 2007

The main result proved in the paper is that on every recursive structure the intrinsically hyperarithmetical sets coincide with the relatively intrinsically hyperarithmetical sets. As a side effect of the proof an effective version of the Kueker's theorem on definability by means of infinitary formulas is obtained.

Mathematics Subject Classification: 03D70, 03D75.
Regular Subgraphs in Graphs and Rooted Graphs and Definability in Monadic Second ‐ Order Logic
Authors: Stewart Iain A.
Published: May 2007

We investigate the definability in monadic ∑11and monadic Π11of the problems REGk, of whether there is a regular subgraph of degreekin some given graph, and XREGk, of whether, for a given rooted graph, there is a regular subgraph of degreekin which the root has degreek, and their restrictions to graphs in which every vertex has degree at mostk, namely REGkkand XREGkk, respectively, fork≥ 2 (all our graphs are undirected). Our motivation partly stems from the fact (which we prove here) that REGkkand XREGkkare logspace equivalent to CONN and REACH, respectively, fork≥ 3, where CONN is the problem of whether a given graph is connected and REACH is the problem of whether a given graph has a path joining two given vertices. We use monadic first ‐ order reductions, monadic ∑11games and a recent technique due to Fagin, Stockmeyer and Vardi to almost completely classify whether these problems are definable in monadic ∑11and monadic Π11, and we compare the definability of these problems (in monadic ∑11and monadic Π11with their computational complexity (which varies from solvable using logspace to NP ‐ complete).
Strongly Amorphous Sets and Dual Dedekind Infinity
Authors: Goldstern Martin
Published: May 2007

1. If A is strongly amorphous (i.e., all relations on A are definable), then its power set P(A) is dually Dedekind infinite, i. e., every function from P(A) onto P(A) is injective. 2. The class of “inexhaustible” sets is not closed under supersets unless AC holds.
On the Difficulty of Writing Out formal Proofs in Arithmetic
Authors: Kashima Ryo , Yamaguchi Takeshi
Published: May 2007

Let ℸ be the set of Gödel numbers Gn(f) of function symbols f such that PRA ⊢ and let γ be the function such that

We prove: (1) The r. e. set ℸ is m‐complete; (2) the function γ is not primitive recursive in any class of functions {f1, f2, ⃛} so long as each fi has a recursive upper bound. This implies that γ is not primitive recursive in ℸ although it is recursive in ℸ.
Combinatorics for Small Ideals on Pkλ
Authors: Abe Yoshihiro
Published: May 2007

We study the distributivity of the bounded ideal on Pkλ and answer negatively to a question of Johnson in [13]. The size of non‐normal ideals with the partition property is also studied.
Basic Propositional Calculus I
Authors: Ardeshir Mohammad , Ruitenburg Wim
Published: May 2007

We present an axiomatization for Basic Propositional Calculus BPC and give a completeness theorem for the class of transitive Kripke structures. We present several refinements, including a completeness theorem for irreflexive trees. The class of intermediate logics includes two maximal nodes, one being Classical Propositional Calculus CPC, the other being E1, a theory axiomatized by T → ⊥. The intersection CPC ∩ E1 is axiomatizable by the Principle of the Excluded Middle A V ∨ ⌝A. If B is a formula such that (T → B) → B is not derivable, then the lattice of formulas built from one propositional variable p using only the binary connectives, is isomorphically preserved if B is substituted for p. A formula (T → B) → B is derivable exactly when B is provably equivalent to a formula of the form ((T → A) → A) → (T → A).
Retinoids and skin: Microarrays shed new light on chemopreventive action of all‐trans retinoic acid
Authors: Cheepala Satish B. , Syed Zanobia , Trutschl Marjan , Cvek Urska , Clifford John L.
Published: May 2007

Despite the use of retinoids in the clinic for many years, their mode of action in the prevention of skin cancer is still unclear. Recent microarray analyses of the chemopreventive effect of all‐trans retinoic acid (ATRA), one of the primary naturally occurring biologically active retinoids, in the two‐stage mouse skin chemical carcinogenesis model have provided novel insight into their action. Comparison of the gene expression profiles of control skin to skin subjected to the two‐stage protocol for 3 wk, with or without ATRA, has shown that approximately half of the genes regulated by 12‐o‐tetradecanoylphorbol‐13‐acetate (TPA) are oppositely regulated when ATRA is coadministered with TPA. It was further shown the Raf/Mek/Erk branch of mitogen‐activated protein (MAP) kinase pathway contains a disproportionate number of oppositely regulated genes, thereby implicating it as one of the key pathways involved in tumor promotion by TPA, that is blocked by ATRA. This result has pointed the way toward the detailed study of Raf/Mek/Erk pathway signaling in skin cancer development and its potential as a target pathway for chemoprevention by ATRA and other chemopreventive drugs. © 2007 Wiley‐Liss, Inc.
Possible cross‐regulation of the E prostanoid receptors
Authors: Tober Kathleen L. , Thomas‐Ahner Jennifer M. , Maruyama Takayuki , Oberyszyn Tatiana M.
Published: May 2007

Exposure to UVB induces an inflammatory response in the skin that results in high levels of cyclooxygenase‐2 (COX‐2) and its enzymatic product, prostaglandin E2 (PGE2). PGE2 signals via one of four E prostanoid (EP) receptors, EP1–4, but the roles of each of these receptors in UVB‐mediated inflammation and skin carcinogenesis have not been fully defined. Topical application of ONO‐8713, an EP1 antagonist, reduced the acute inflammatory effects of UVB irradiation. This compound also reduced UVB‐induced tumor formation by approximately 50%, suggesting that signaling of PGE2 via the EP1 receptor may play a role in UVB‐mediated inflammation and carcinogenesis. Our laboratory has demonstrated that the EP1 receptor localized to the suprabasal layers of the epidermis and the EP3 receptor was found in the basal keratinocytes of unirradiated murine skin. While UVB exposure induced no change in the localization of the EP1 receptor, the EP3 receptor was detected in all layers of the epidermis in response to UVB. In mice that were topically treated with ONO‐8713, UVB‐induced changes in EP3 localization were prevented. This alteration in EP3 receptor localization was not seen following topical application of the anti‐inflammatory drug celecoxib, indicating that the effects of ONO‐8713 were not because of its anti‐inflammatory properties. These results suggest a previously undescribed interaction between the EP1 and EP3 receptors in the epidermis. © 2007 Wiley‐Liss, Inc.
The functional contrariety of JNK
Authors: Bode Ann M. , Dong Zigang
Published: May 2007

The JNK proteins are activated by multiple and diverse stimuli, leading to varied and seemingly contradictory cellular responses. In particular, JNKs have been reported to have a role in the induction of apoptosis, but have also been implicated in enhancing cell survival and proliferation. Thus the JNK proteins seem to represent an archetype of contrariety of intracellular signaling. The opposing roles of JNKs have been attributed to the observation that JNKs activate different substrates based on specific stimulus, cell type or temporal aspects. Because of their analogous expression in apparently almost every tissue, JNK1 and JNK2 have most often been considered to have overlapping or redundant functions. In spite of this assessment, research evidence suggests that the functions of JNKs should be addressed in a manner that differentiates between their precise contributions. Specifically in this review, we examine evidence regarding whether the JNKs proteins might play distinctive roles in cellular processes associated with carcinogenesis. © 2007 Wiley‐Liss, Inc.
The mechanisms of tumor suppressor effect of glucocorticoid receptor in skin
Authors: Chebotaev Dmitry , Yemelyanov Alexander , Budunova Irina
Published: May 2007

Glucocorticoid hormones exert a tumor suppressor effect in different experimental models, including mouse skin carcinogenesis. The glucocorticoid control of cellular functions is mediated via the glucocorticoid receptor (GR), a well‐known transcription factor that regulates genes by DNA‐binding dependent transactivation, and DNA‐binding independent transrepression through negative interaction with other transcription factors. In this perspective, we analyze known mechanisms that underlie the anticancer effect of GR signaling, including effects on cell growth, differentiation, apoptosis, and angiogenesis. We also discuss a novel mechanism for the tumor suppressor effect of the GR in skin: through the regulation of the number and status of follicular epithelial stem cells (SC), which are a target cell population for skin carcinogenesis. Our studies on keratin5.GR transgenic animals that are resistant to skin carcinogenesis, demonstrated that the GR diminishes the number of follicular epithelial SCs, reduces their proliferative and survival potential and affects the expression of follicular SC “signature” genes. The analysis of global effect of the GR on gene expression in follicular epithelial SCs, basal keratinocytes, and mouse skin tumors provided an unexpected evidence that gene transrepression by GR plays an important role in the maintenance of SC and in inhibition of skin carcinogenesis by this steroid hormone receptor. It is known that antiinflammatory effect of glucocorticoids is chiefly mediated by GR transrepression. Thus, our findings suggest the similarity between the mechanisms of antiinflammatory and anticancer effects of the GR signaling. We discuss the potential clinical applications of our findings in light of drug discovery programs focused on the development of selective GR modulators that preferentially induce GR transrepression. © 2007 Wiley‐Liss, Inc.
Basal ganglia cholinergic and dopaminergic function in progressive supranuclear palsy
Authors: Warren Naomi M. , Piggott Margaret A. , Greally Elizabeth , Lake Michelle , Lees Andrew J. , Burn David J.
Published: May 2007

Progressive Supranuclear Palsy (PSP) is a progressive neurodegenerative disorder. In contrast to Parkinson's disease (PD) and dementia with Lewy bodies (DLB), replacement therapy with dopaminergic and cholinergic agents in PSP has been disappointing. The neurochemical basis for this is unclear. Our objective was to measure dopaminergic and cholinergic receptors in the basal ganglia of PSP and control brains. We measured, autoradiographically, dopaminergic (dopamine transporter,125I PE2I and dopamine D2 receptors,125I epidepride) and cholinergic (nicotinic α4β2 receptors,125I 5IA85380 and muscarinic M1 receptors,3H pirenzepine) parameters in the striatum and pallidum of pathologically confirmed PSP cases (n = 15) and controls (n = 32). In PSP, there was a marked loss of dopamine transporter and nicotinic α4β2 binding in the striatum and pallidum, consistent with loss of nigrostriatal neurones. Striatal D2 receptors were increased in the caudate and muscarinic M1 receptors were unchanged compared with controls. These results do not account for the poor response to dopaminergic and cholinergic replacement therapies in PSP, and suggest relative preservation of postsynaptic striatal projection neurones bearing D2/M1 receptors. © 2007 Movement Disorder Society
Lorenz‐gauged vector potential formulations for the time‐harmonic eddy‐current problem with L∞‐regularity of material properties
Authors: Fernandes Paolo , valli Alberto
Published: May 2007

In this paper, we consider some Lorenz‐gauged vector potential formulations of the eddy‐current problem for the time‐harmonic Maxwell equations with material properties having only L∞‐regularity. We prove that there exists a unique solution of these problems, and we show the convergence of a suitable finite element approximation scheme. Moreover, we show that some previously proposed Lorenz‐gauged formulations are indeed formulations in terms of the modified magnetic vector potential, for which the electric scalar potential is vanishing. Copyright © 2007 John Wiley & Sons, Ltd.
Towards a ZP‐based contraceptive for marsupials: Comparative analysis and developmental expression of marsupial ZP genes
Authors: McCartney Carmen A. , Harris Merrilee S. , Rodger John C. , Mate Karen E.
Published: May 2007

Fertility control in the form of a zona pellucida (ZP)‐based immunocontraceptive has shown potential as a humane form of control for overabundant marsupials including the brushtail possum and macropods. Further refinement and development of a ZP‐based vaccine requires detailed knowledge of the protein structure and expression in order to ensure maximum efficacy and specificity. Sequencing and comparative analysis of the ZP3 protein from three marsupial orders in this study found a high overall level of conservation; within order Diprotodontia, the ZP3 protein is 86.9–98.9% identical. ZP3 identity falls to 56.6–57.2%, when the grey, short‐tailed opossum (a Didelphimorphian) is compared to dasyurid and diprotodontan marsupials. This is similar to its amino acid identity with ZP3 from eutherian species (50.7–52.8%). Comparison of a 21 amino acid epitope in marsupial ZP3 that has shown contraceptive effects, reveals 95–100% identity between the four macropodid species, 81–86% amino acid identity between brushtail possum and the macropods and 67–71% identity between the diprotodontans and the fat‐tailed dunnart (a dasyurid). This is comparable to the level of identity between related eutherian mammals. The expression pattern of three ZP genes during brushtail possum and tammar wallaby pouch young development was examined by RT‐PCR. This analysis of ZP gene expression has confirmed that ZP mRNA transcription begins in the ovary during pouch young development by about 51 days of age. The presence of ZP transcripts at this stage in pouch young development suggests that marsupial ZP gene transcription begins before the onset of follicular development. Mol. Reprod. Dev. 74: 1581–1589, 2007. © 2007 Wiley‐Liss, Inc.
Treatment of carpal tunnel syndrome
Authors: Bland Jeremy D. P.
Published: May 2007

Fifty years after its widespread recognition, a significant minority of patients with carpal tunnel syndrome continue to experience poor outcomes from treatment. Much current treatment is supported by an inadequate or nonexistent evidence base. Surgical decompression, often considered the definitive solution, gives excellent results in only 75% of cases in ordinary practice and leaves 8% of patients worse than previously. The only other interventions that are clearly of benefit are neutral‐angle wrist splinting, with a success rate of 37%, and steroids, which are better given by local injection than as oral treatment. The initial response rate to injection is 70% but there are frequent relapses. Nevertheless, these conservative treatments have a negligible incidence of serious complications and should be used more widely until surgical failures can be reduced to similar levels. Muscle Nerve, 2007
A new result for closed‐loop poles region of LQ‐optimal discrete‐time systems
Authors: Khaloozadeh Hamid
Published: May 2007

This paper deals with a new result for pole location of linear quadratic (LQ) optimal discrete‐time systems. In this paper a new region in which the closed‐loop eigenvalues of an LQ‐optimal discrete time system are located is determined. It has been shown that this region is bounded by four lines parallel to the real and imaginary axes, creating a square region. This region is symmetric with respect to the real axis ofz‐plane, but not with respect to the imaginary axis. Inequality constraints, which bound the closed‐loop eigenvalues in a discrete‐time LQ‐optimal system, are also presentedviatwo theorems. These theorems cover all systems except the ones whereAis singular andHis positive semidefinite at the same time. The result is also extended to the problem of the prescribed degree of stability for LQ optimal discrete‐time systems. Copyright © 2007 John Wiley & Sons, Ltd.
Measurement and prediction of thermal conductivity for hemp fiber reinforced composites
Authors: Behzad T. , Sain M.
Published: May 2007

The thermal conductivity of hemp fiber reinforced polymer composites were studied from the steady state temperature drop across samples exposed to a known heat flux. The transverse and in‐plane thermal conductivities for oriented and randomly oriented composites for different volume fractions of fiber were investigated. Experimental results showed that the orientation of fibers has a significant effect on the thermal conductivity of composites. To validate the experimental results, the heating tests for the thermal conductivity measurements were simulated by a finite element model using the thermal conductivity values obtained from the experiments. Predicted temperatures show close agreement with measured temperatures. Moreover, the experimental results of thermal conductivities of composites at different directions were compared with two theoretical models and illustrated good agreement between the obtained results and models. POLYM. ENG. SCI. 47:977–983, 2007. © 2007 Society of Plastics Engineers
Intrinsic viscosities of sodium carboxymethylcellose in acetonitrile–water mixed solvent media using isoionic dilution method
Authors: Nandi Prabir , Bhattarai Ajaya , Das Bijan
Published: May 2007

Precise measurements on the viscosities of the solutions of sodium carboxymethylcellulose in water and in two acetonitrile–water mixtures containing 10 and 20 vol % of acetonitrile have been reported at 35, 40 and 50 °C. Isoionic dilutions were performed with the total ionic strengths of the solutions maintained with sodium chloride at ∼4.20 × 10−4 and 1.45 × 10−3 mol dm−3 of NaCl to obtain the intrinsic viscosities. The Huggins constants were also obtained from the experimental results. The influences of the medium, the temperature, and the total ionic strength on the intrinsic viscosities as well as on the Huggins constants have been interpreted from the points of view of the solvodynamic and thermodynamic interactions prevailing in the polyelectrolyte solution under investigation. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1765–1770, 2007
Exposure to environmental tobacco smoke among children presenting to the emergency department with acute asthma: A multicenter study
Authors: Vargas Perla A. , Brenner Barry , Clark Sunday , Boudreaux Edwin D. , Camargo Carlos A.
Published: May 2007

Environmental tobacco smoke (ETS) exposure has been associated with increased use of the emergency department (ED) for acute asthma care. The purpose of this study was to determine the prevalence of ETS exposure among children presenting to the ED for acute asthma care and whether ETS exposure affects acute asthma severity or response to therapy. We conducted a multi‐center study of children 2–11 years with physician‐diagnosed acute asthma presenting to 44 EDs in 18 states. Chi‐square test, Student's t‐test, Wilcoxon rank sum test, and logistic regression were used for the analyses. The study population included 954 children. Thirty‐six percent (95% CI, 33–39%) of caregivers reported that their child was exposed to ETS. Among exposed children, 35% were exposed 1–6 days/week, and 65% were exposed daily. Compared to unexposed children, ETS‐exposed children were older at asthma diagnosis, older at ED presentation, and were less likely to be Hispanic. Indicators of chronic asthma severity were higher among unexposed children (i.e., total number of medications, use of controller medications, use of β2 agonists, number of urgent clinic visits, and lifetime hospitalizations). There was a weak association between ETS and acute asthma severity. Response to therapy (including ED disposition) did not differ between groups. On multivariate analysis, ETS‐exposed children were more likely to be older, female, non‐Hispanic, have lower household income, not use controller medications, and have a pet at home (all P < 0.05). Our study showed that the prevalence of ETS exposure among children presenting to the ED with acute asthma differs across demographic factors. There were no significant differences in acute asthma symptoms or response to ED therapy between ETS‐exposed and unexposed children. Lower use of controller medications and less frequent urgent clinic visits among ETS‐exposed children suggest inadequate asthma care or milder disease. The weak association between ETS exposure and acute asthma severity might reflect confounding by psychological factors and/or chronic asthma severity. The frequency of ETS exposure suggests that the ED may be an appropriate venue to engage caregivers of children with asthma in asthma education and smoking cessation efforts. Pediatr Pulmonol. 2007; 42:646–655. © 2007 Wiley‐Liss, inc.