bluuebunny/crossref_metadata_2025 huggingface dataset:
Ras/ERK signalling in cannabinoid tolerance: from behaviour to cellular aspects
Authors: Rubino Tiziana , Forlani Greta , Viganò Daniela , Zippel Renata , Parolaro Daniela
Published: April 2005

We investigated the role of the Ras/extracellular‐regulated kinase (ERK) pathway in the development of tolerance to Δ9‐tetrahydrocannabinol (THC)‐induced reduction in spontaneous locomotor activity by a genetic (Ras‐specific guanine nucleotide exchange factor (Ras‐GRF1) knock‐out mice) and pharmacological approach. Pre‐treatment of wild‐type mice with SL327 (50 mg/kg i.p.), a specific inhibitor of mitogen‐activated protein kinase kinase (MEK), the upstream kinase of ERK, fully prevented the development of tolerance to THC‐induced hypolocomotion. We investigated the impact of the inhibition of ERK activation on the biological processes involved in cannabinoid tolerance (receptor down‐regulation and desensitization), by autoradiographic cannabinoid CB1 receptor and cannabinoid‐stimulated [35S]GTPγS binding studies in subchronically treated mice (THC, 10 mg/kg s.c., twice a day for 5 days). In the caudate putamen and cerebellum of Ras‐GRF1 knock‐out mice and SL327 pre‐treated wild‐type mice, CB1 receptor down‐regulation and desensitization did not occur, suggesting that ERK activation might account for CB1 receptor plasticity involved in the development of tolerance to THC hypolocomotor effect. In contrast, the hippocampus and prefrontal cortex showed CB1 receptor adaptations regardless of the genetic or pharmacological inhibition of the ERK pathway, suggesting regional variability in the cellular events underlying the altered CB1 receptor function. These findings suggest that at least in the caudate putamen and cerebellum, the Ras/ERK pathway is essential for triggering the alteration in CB1 receptor function responsible for tolerance to THC‐induced hypomotility.
Role of glutathione in intracellular amyloid‐α precursor protein/carboxy‐terminal fragment aggregation and associated cytotoxicity
Authors: Woltjer Randall L. , Nghiem William , Maezawa Izumi , Milatovic Dejan , Vaisar Tomas , Montine Kathleen S. , Montine Thomas J.
Published: April 2005

Alterations in glutathione (GSH) metabolism are associated with neurodegeneration in Alzheimer's disease (AD), and GSH depletion follows application of exogenous fibrillar amyloid β (Aβ) peptides in experimental systems; these results are commonly cited as evidence of oxidative damage in AD. We used MC65 human neuroblastoma cells that conditionally express carboxy‐terminal fragments of the Aβ precursor protein (Aβ/CTFs) to directly test the hypothesis that GSH is part of the cellular response to stressors associated with Aβ/CTF accumulation and not simply a marker of oxidative damage. Our data showed that Aβ/CTFs accumulated by post‐translational processes and were associated with progressive increases in oxidative damage and cytotoxicity. Ethycrinic acid (EA) or diethyl maleate (DEM), reagents that deplete GSH through non‐specific thiol adduction, gave rise to dose‐dependent cytotoxicity that was independent of Aβ/CTF expression and minimally responsive to α‐tocopherol (AT). In contrast, buthionine sulfoximine (BSO), a selective inhibitor of GSH synthase, not only augmented Aβ/CTF‐associated cell death but unexpectedly potentiated Aβ/CTF accumulation; both outcomes were completely suppressed by AT. These data suggest that antioxidants may serve as ‘Aβ targeting’ therapies that suppress toxic protein aggregation rather than simply acting as downstream radical scavengers.
INPUT/OUTPUT ANALYSIS—AN APPRAISAL IN THE CONTEXT OF AS YET AN UNFINISHED EXPERIMENT IN KENYA
Authors: Singh Parmeet
Published: April 2005

The paper discusses the relevance of input/output tables as a tool for economic analysis and planning in developing countries. It contends that this is so only to the extent that the input out‐put tables enable consistency of production accounts to be verified while providing a suitable basis for macro projections at the same time. As a by‐product, such input out put tables, the paper adds, also provide a convenient framework for estimating the needs for extensions and improvements in basic statistics.

All these requirements, it is stated, can be fulfilled by a relatively aggregated format of an input/output table—which some of the developing countries are in a position to compile. However, the paper states, it is feared that the case for input/output analysis is not based on these requirements. The main force of arguments is in fact based on the uses of input/output tables for more detailed sectoral analysis and projections. The current state of basic statistics on some key sectors, it is stated, is not sufficiently sound to yield an end‐product which is reliable. In the case of sectors where this is so the input/output analysis is not relevant either because of concentration of production in a relatively few establishments or because of limited amount of inter‐sectoral interaction. It is further felt that if such arguments were to be accepted by developing countries the result would be a distorted disposition of statistical resources. Immediate needs of the developing countries require concentration of effort in development of more reliable and relevant series on basic statistics.
Plasma Concentrations of Risperidone and Olanzapine during Coadministration with Oxcarbazepine
Authors: Rosaria Muscatello Maria , Pacetti Monica , Cacciola Massimo , La Torre Diletta , Zoccali Rocco , Arrigo Concetta D' , Migliardi Gaetana , Spina Edoardo
Published: April 2005

Summary:  Purpose: Oxcarbazepine (OZC) is a second‐generation antiepileptic drug (AED) that also may be used as a mood stabilizer. Unlike carbamazepine (CBZ), which is an inducer of the cytochrome P‐450 isoforms and may accelerate the elimination of several therapeutic agents, OXC seems to have only a modest inducing action. The aim of this investigation was to evaluate the effect of a treatment with OXC on plasma concentrations of the new antipsychotics risperidone and olanzapine.

Methods: OXC, at a dosage of 900–1,200 mg/day, was administered for 5 consecutive weeks to 25 outpatients, 10 men and 15 women, aged 25 to 64 years, with bipolar or schizoaffective disorder. Twelve patients were stabilized on risperidone therapy (2–6 mg/day) and 13 on olanzapine (5–20 mg/day). Steady‐state plasma concentrations of risperidone and its active metabolite 9‐hydroxyrisperidone (9‐OH‐risperidone) and olanzapine were measured by high‐pressure liquid chromatography (HPLC) before addition of OXC and after 5 weeks from the start of adjunctive treatment.

Results: OXC caused only minimal and no significant changes in the mean plasma levels of risperidone (from 5.6 ± 3.6 ng/ml at baseline to 4.8 ± 2.6 ng/ml at week 5), 9‐OH‐risperidone (from 23.6 ± 7.5 to 24.7 ± 7.4 ng/ml), and olanzapine (from 26.5 ± 5.7 ng/ml at baseline to 27.8 ± 5.1 ng/ml). OXC coadministration with either risperidone or olanzapine was well tolerated.

Conclusions: Our findings indicate that OXC does not affect the elimination of risperidone and olanzapine, thus confirming its weak inducing effect on hepatic drug‐metabolizing enzymes.
Expression levels of genes for ATP‐binding cassette transporters and sterol 27‐hydroxylase in liver and intestine of baboons with high and low cholesterolemic responses to dietary lipids
Authors: Kushwaha Rampratap S. , Rosillo Aurora , McGill Henry C.
Published: April 2005

Abstract:  Baboons with high and low lipemic responses to dietary lipids differ in intestinal cholesterol absorption and hepatic cholesterol metabolism. ATP‐binding cassette (ABC) transporters play an important role in cholesterol absorption and hepatic cholesterol metabolism. Using frozen tissues from high‐ and low‐responding baboons maintained on the cholesterol and fat‐enriched diet, we determined the relative expression of ABCA1, ABCG5, ABCG8, and 27‐hydroxylase genes in the liver and intestine using TaqMan® real‐time polymerase chain reaction. There was no consistent difference in the expression of ABC‐transporters and 27‐hydroxylase in the intestine between high‐ and low‐responding baboons. However, hepatic expression of sterol 27‐hydroxylase, ABCG5, and ABCG8 was higher in low‐responding baboons than in high‐responding baboons. There was also a significant correlation between the expression of sterol 27‐hydroxylase and ABCG5, and ABCG8 in both the liver and the intestine. These results suggest that differences in hepatic lipid metabolism but not in cholesterol absorption between high‐ and low‐responding baboons observed previously may be mediated by the differences in the expression levels of 27‐hydroxylase, ABCG5, and ABCG8.
Risks associated with environmental enrichment: intestinal obstruction caused by foraging substrate
Authors: Seier J.V. , Dhansay M.A. , Davids A.
Published: April 2005

Abstract:  Questions are occasionally asked about the safety of enrichment techniques, considering that many novel ways are frequently employed to ensure environmental complexity. A juvenile male vervet monkey was found with a phytobezoar of straw obstructing the sigmoid colon. The straw was foraging substrate, which is used in communal cages. Due to the extent of the resulting necrosis in the sigmoid and descending colon, the monkey had to be killed. This is the only individual to have suffered a harmful effect from the foraging substrate from amongst 120 vervet monkeys, which have been permanently housed on straw for over 5 years.
Phenotypic Hypersusceptibility to Multiple Protease Inhibitors and Low Replicative Capacity in Patients Who Are Chronically Infected with Human Immunodeficiency Virus Type 1
Authors: Martinez-Picado Javier , Wrin Terri , Frost Simon D. W. , Clotet Bonaventura , Ruiz Lidia , Brown Andrew J. Leigh , Petropoulos Christos J. , Parkin Neil T.
Published: April 2005

Increased susceptibility to the protease inhibitors saquinavir and amprenavir has been observed in human immunodeficiency virus type 1 (HIV-1) with specific mutations in protease (V82T and N88S). Increased susceptibility to ritonavir has also been described in some viruses from antiretroviral agent-naïve patients with primary HIV-1 infection in association with combinations of amino acid changes at polymorphic sites in the protease. Many of the viruses displaying increased susceptibility to protease inhibitors also had low replication capacity. In this retrospective study, we analyze the drug susceptibility phenotype and the replication capacity of virus isolates obtained at the peaks of viremia during five consecutive structured treatment interruptions in 12 chronically HIV-1-infected patients. Ten out of 12 patients had at least one sample with protease inhibitor hypersusceptibility (change ≤0.4-fold) to one or more protease inhibitor. Hypersusceptibility to different protease inhibitors was observed at variable frequency, ranging from 38% to amprenavir to 11% to nelfinavir. Pairwise comparisons between susceptibilities for the protease inhibitors showed a consistent correlation among all pairs. There was also a significant relationship between susceptibility to protease inhibitors and replication capacity in all patients. Replication capacity remained stable over the course of repetitive cycles of structured treatment interruptions. We could find no association between in vitro replication capacity and in vivo plasma viral load doubling time and CD4
+
and CD8
+
T-cell counts at each treatment interruption. Several mutations were associated with hypersusceptibility to each protease inhibitor in a univariate analysis. This study extends the association between hypersusceptibility to protease inhibitors and low replication capacity to virus isolated from chronically infected patients and highlights the complexity of determining the genetic basis of this phenomenon. The potential clinical relevance of protease inhibitor hypersusceptibility and low replication capacity to virologic response to protease inhibitor-based therapies deserves to be investigated further.
Exploiting
cis
-Acting Replication Elements To Direct Hepatitis C Virus-Dependent Transgene Expression
Authors: Zhang Jing , Yamada Osamu , Sakamoto Takashi , Yoshida Hiroshi , Araki Hiromasa , Shimotohno Kunitada
Published: April 2005

We describe here a novel targeting gene therapy strategy to direct gene expression responsive to hepatitis C virus (HCV). The goal was approached by engineering a construct containing the antisense sequence of the transgene and internal ribosome entry site of encephalomyocarditis virus flanked by 5′- and 3′-end sequences of HCV cDNA that contain
cis
-acting replication elements. Thus, expression of the transgene is only promoted when the minus-strand RNA has been synthesized by the functional replication machinery present in infected cells. Reporter assay and strand-specific reverse transcription-PCR showed selective transgene expression in Huh-7 cells harboring an autonomously replicating HCV subgenome but remaining silent in uninfected cells. Furthermore, using the cytosine deaminase suicide gene as a transgene coupled with recombinant adenovirus delivery, we demonstrated that cytosine deaminase was specifically expressed in replicon cells, resulting in marked chemosensitization of replicon cells to the cytotoxic effects of flucytosine. This new targeting strategy could be extended to other single-stranded RNA viruses encoding the unique RNA-dependent RNA polymerase that has no parallel in mammalian cells.
Human Rhinovirus Type 89 Variants Use Heparan Sulfate Proteoglycan for Cell Attachment
Authors: Vlasak Markete , Goesler Irene , Blaas Dieter
Published: April 2005

We have previously isolated mutants of the major-group human rhinovirus type 89 that grow in cells deficient in intercellular adhesion molecule 1 (ICAM-1), the receptor used by the wild-type virus for cell entry [A. Reischl, M. Reithmayer, G. Winsauer, R. Moser, I. Goesler, and D. Blaas., J. Virol.
75:
9312-9319, 2001]. We now demonstrate that one of these variants utilizes heparan sulfate proteoglycan (HSPG) as a cellular receptor. Adaptation to ICAM-1-deficient cells not only resulted in the newly acquired receptor specificity but also rendered the virus less stable at low pH and at elevated temperatures. This instability might compensate for the absence of the uncoating activity of ICAM-1. Whereas wild-type virus infection via ICAM-1 proceeded in the presence of the vesicular H
+
-ATPase inhibitor bafilomycin A1, infection by the mutant via HSPG was prevented by the drug. This suggests that the low pH prevailing in endosomal compartments is required for uncoating in the absence of the catalytic activity of ICAM-1.
Chinchilla and Murine Models of Upper Respiratory Tract Infections with Respiratory Syncytial Virus
Authors: Gitiban Negin , Jurcisek Joseph A. , Harris Randall H. , Mertz Sara E. , Durbin Russell K. , Bakaletz Lauren O. , Durbin Joan E.
Published: April 2005

Respiratory syncytial virus (RSV) is a major cause of lower respiratory tract infections in infants and the elderly. While the primary infection is the most serious, reinfection of the upper airway throughout life is the rule. Although relatively little is known about either RSV infection of the upper respiratory tract or host mucosal immunity to RSV, recent literature suggests that RSV is the predominant viral pathogen predisposing to bacterial otitis media (OM). Herein, we describe mouse and chinchilla models of RSV infection of the nasopharynx and Eustachian tube. Both rodent hosts were susceptible to RSV infection of the upper airway following intranasal challenge; however, the chinchilla proved to be more permissive than the mouse. The chinchilla model will likely be extremely useful to test the role of RSV in bacterial OM and the efficacy of RSV vaccine candidates designed to provide mucosal and cytotoxic T-lymphocyte immunity. Ultimately, we hope to investigate the relative ability of these candidates to potentially protect against viral predisposal to bacterial OM.
Structural Basis for the Physiological Temperature Dependence of the Association of VP16 with the Cytoplasmic Tail of Herpes Simplex Virus Glycoprotein H
Authors: Kamen Douglas E. , Gross Sarah T. , Girvin Mark E. , Wilson Duncan W.
Published: April 2005

Critical events in the life cycle of herpes simplex virus (HSV) are the binding of cytoplasmic capsids to cellular organelles and subsequent envelopment. Work from several laboratories suggests that these events occur as a result of a network of partially redundant interactions among the capsid surface, tegument components, and cytoplasmic tails of virally encoded glycoproteins. Consistent with this model, we previously showed that tegument protein VP16 can specifically interact with the cytoplasmic tail of envelope protein gH in vitro and in vivo when fused to glutathione
S
-transferase and to green fluorescent protein, respectively. In both instances, this association was strikingly temperature dependent: binding occurred only at 37°C and not at lower temperatures. Here we demonstrate that virally expressed full-length gH and VP16 can be coimmunoprecipitated from HSV-infected cells and that this association is also critically dependent upon the physiological temperature. To investigate the basis of this temperature requirement, we performed one- and two-dimensional nuclear magnetic resonance spectroscopy on peptides with the sequence of the gH tail. We found that the gH tail is disorganized at temperatures permissive for binding but becomes structured at lower temperatures. Furthermore, a mutated tail unable to adopt this rigid conformation binds VP16 even at 4°C. We hypothesize that the gH tail is unstructured under physiological conditions in order to maximize the number of potential tegument partners with which it may associate. Being initially disordered, the gH tail may adopt one of several induced conformations as it associates with VP16 or alternative components of the tegument, maximizing redundancy during particle assembly.
Analysis of the Contribution of Reverse Transcriptase and Integrase Proteins to Retroviral RNA Dimer Conformation
Authors: Buxton Penelope , Tachedjian Gilda , Mak Johnson
Published: April 2005

All retroviruses contain two copies of genomic RNA that are linked noncovalently. The dimeric RNA of human immunodeficiency virus type 1 (HIV-1) undergoes rearrangement during virion maturation, whereby the dimeric RNA genome assumes a more stable conformation. Previously, we have shown that the packaging of the HIV-1 polymerase (Pol) proteins reverse transcriptase (RT) and integrase (IN) is essential for the generation of the mature RNA dimer conformation. Analysis of HIV-1 mutants that are defective in processing of Pol showed that these mutant virions contained altered dimeric RNA conformation, indicating that the mature RNA dimer conformation in HIV-1 requires the correct proteolytic processing of Pol. The HIV-1 Pol proteins are multimeric in their mature enzymatically active forms; RT forms a heterodimer, and IN appears to form a homotetramer. Using RT and IN multimerization defective mutants, we have found that dimeric RNA from these mutant virions has the same stability and conformation as wild-type RNA dimers, showing that the mature enzymatically active RT and IN proteins are dispensable for the generation of mature RNA dimer conformation. This also indicated that formation of the mature RNA dimer structure occurs prior to RT or IN maturation. We have also investigated the requirement of Pol for RNA dimerization in both Mason-Pfizer monkey virus (M-PMV) and Moloney murine leukemia virus (MoMuLV) and found that in contrast to HIV-1, Pol is dispensable for RNA dimer maturation in M-PMV and MoMuLV, demonstrating that the requirement of Pol in retroviral RNA dimer maturation is not conserved among all retroviruses.
The Nef-Mediated AIDS-Like Disease of CD4C/Human Immunodeficiency Virus Transgenic Mice Is Associated with Increased Fas/FasL Expression on T Cells and T-Cell Death but Is Not Prevented in Fas-, FasL-, Tumor Necrosis Factor Receptor 1-, or Interleukin-1β-Converting Enzyme-Deficient or Bcl2-Expressing Transgenic Mice
Authors: Priceputu Elena , Rodrigue Isabelle , Chrobak Pavel , Poudrier Johanne , Mak Tak W. , Hanna Zaher , Hu Chunyan , Kay Denis G. , Jolicoeur Paul
Published: April 2005

CD4+- and CD8+-T-cell death is a frequent immunological dysfunction associated with the development of human AIDS. We studied a murine model of AIDS, the CD4C/HIV transgenic (Tg) mouse model, to assess the importance of the apoptotic pathway in human immunodeficiency virus type 1 (HIV-1) pathogenesis. In these Tg mice, Nef is the major determinant of the disease and is expressed in immature and mature CD4+T cells and in cells of the macrophage/myeloid lineage. We report here a novel AIDS-like phenotype: enhanced death, most likely by apoptosis (as assessed by 7-aminoactinomycin D and annexin V/propidium iodide staining), of Tg thymic and peripheral CD4+and CD8+T cells. The Tg CD4+and CD8+T cells were also more susceptible to cell death after activation in vitro in mixed lymph node (LN) cultures. However, activation-induced cell death was not higher in Tg than in non-Tg-purified CD4+T cells. In addition, expression of Fas and FasL, assessed by flow cytometry, was increased in CD4+and CD8+T cells from Tg mice compared to that of non-Tg littermates. Despite the enhanced expression of Fas and FasL on Tg CD4+and CD8+T cells, Fas (lpr/lpr) and FasL (gld/gld) mutant CD4C/HIV Tg mice developed an AIDS-like disease indistinguishable from lpr/+ and gld/+ CD4C/HIV Tg mice, including loss of CD4+T cells. Similarly, CD4C/HIV Tg mice homozygous for mutations of two other genes implicated in cell death (interleukin-1β-converting enzyme [ICE], tumor necrosis factor receptor 1 [TNFR-1]) developed similar AIDS-like disease as their respective heterozygous controls. Moreover, the double-Tg mice from a cross between the Bcl2/Wehi25 and CD4C/HIV Tg mice showed no major protection against disease. These results represent genetic evidence for the dispensable role of Fas, FasL, ICE, and TNFR-1 on the development of both T-cell loss and organ disease of these Tg mice. They also provide compelling evidence on the lack of protection by Bcl2 against Tg CD4+-T-cell death. In view of the high resemblance between numerous phenotypes observed in the CD4C/HIV Tg mice and in human AIDS, our findings are likely to be relevant for the human disease.
Identification of Domains in Gag Important for Prototypic Foamy Virus Egress
Authors: Patton Gillian S. , Morris Stephen A. , Chung Wayne , Bieniasz Paul D. , McClure Myra O.
Published: April 2005

Sequence motifs (L domains) have been described in viral structural proteins. Mutations in these lead to a defect at a late stage in virus assembly and budding. For several viruses, recruitment of an endosomal sorting complexes required for transport 1 subunit (Tsg101), a component of the class E vacuolar protein sorting (EVPS) machinery, is a prerequisite for virion budding. To effect this, Tsg101 interacts with the PT/SAP L domain. We have identified candidate L-domain motifs, PSAP, PPPI, and YEIL, in the prototypic foamy virus (PFV) Gag protein, based on their homology to known viral L domains. Mutation of the PSAP and PPPI motifs individually reduced PFV egress, and their combined mutation had an additive effect. When PSAP was mutated, residual infectious PFV release was unaffected by dominant negative Vps4 (an ATPase involved in the final stages of budding), and sensitivity to dominant negative Tsg101 was dramatically reduced, suggesting that the PSAP motif functions as a conventional class E VPS-dependent L domain. Consistent with this notion, yeast two-hybrid analysis showed a PSAP motif-dependent interaction between PFV Gag and Tsg101. Surprisingly, PFV release which is dependent on the PPPI motif was Vps4-independent and was partially inhibited by dominant negative Tsg101, suggesting that PPPI functions by an unconventional mechanism to facilitate PFV egress. Mutation of the YEIL sequence completely abolished particle formation and also reduced the rate of Gag processing by the viral protease, suggesting that the integrity of YEIL is required at an assembly step prior to budding and YEIL is not acting as an L domain.
Rhesus Cytomegalovirus Particles Prevent Activation of Interferon Regulatory Factor 3
Authors: DeFilippis Victor , Früh Klaus
Published: April 2005

One of the most important innate host defense mechanisms against viral infection is the induction of interferon (IFN)-stimulated genes (ISGs). Immediately upon entry, viruses activate interferon-regulatory factor 3 (IRF3), as well as nuclear factor κB (NF-κB), which transactivate a subset of ISGs, proinflammatory genes, as well as IFN genes. Most large DNA viruses exhibit countermeasures against induction of this response. However, whereas human cytomegalovirus (HCMV) inhibits IFN-dependent induction of ISGs, IFN-independent induction of ISGs is observed both in the presence and, even moreso, in the absence of viral gene expression. Rhesus CMV (RhCMV) is an emerging animal model for HCMV sharing important similarities in primary structure, epidemiology, and pathogenesis. To determine whether RhCMV would similarly induce ISGs, we performed DNA microarray and quantitative PCR analysis of ISG expression in rhesus fibroblasts infected with RhCMV or HCMV. In contrast to HCMV, however, RhCMV did not induce expression of ISGs or proinflammatory genes at any time after infection. Moreover, dimerization and nuclear accumulation of IRF3, readily observed in HCMV-infected cells, was absent from RhCMV-infected cells, whereas neither virus seemed to activate NFκB. RhCMV also blocked IRF3 activation by live or UV-inactivated HCMV, suggesting that RhCMV inhibits viral IRF3 activation and the resultant ISG induction with extraordinary efficiency. Since infection during inhibition of protein expression by cycloheximide or inactivation of viral gene expression by UV treatment did not trigger IRF3 activation or ISG expression by RhCMV, we conclude that RhCMV virions contain a novel inhibitor of IFN-independent viral induction of ISG expression by IRF3.
Metal Ion Transport Through Bulk Liquid Membrane Mediated by Cationic Ligand Surfactants
Authors: Svobodová Eva , Cibulka Radek , Hampl František , Šmidrkal Jan , Liška František
Published: April 2005

A series of N,N,N-trialkyl-2-(hydroxyimino)-2-(pyridin-2-yl)ethan-1-aminium nitrates 3a-3h and N,N,N-trialkyl-4-(hydroxyimino)-4-(pyridin-2-yl)butan-1-aminium nitrates 3i-3l representing cationic surfactants with a powerful 1-(hydroxyimino)-1-(pyridin-2-yl)alkyl chelating subunit were prepared as potential selective metal ion extractants. Their extraction ability was tested in transport of Cu2+, Ni2+, Co2+, and Pd2+ through a bulk liquid membrane. The introduction of the cationic group into the extractant molecule increases the selectivity and facilitates the metal ion transport as shown by comparing the transports carried out with ligand surfactants 3 and lipophilic alkyl pyridin-2-yl ketoximes 2. The efficiency and selectivity of the metal ion transport mediated by ligand surfactants 3 depends predominantly on their structure and lipophilicity, i.e. on the number and length of hydrophobic alkyl chains and on the length of the spacer connecting the chelating moiety with the cationic head group of the surfactant.
Implications of increased haemoglobin A2values in HIV positive women in the antenatal clinic
Authors: Howard J , Henthorn J S , Murphy S , Davies S C
Published: April 2005

Universal antenatal haemoglobinopathy screening in this hospital has identified several women with increased haemoglobin A2values, but without hypochromic microcytic red cell indices. This report describes two cases where there is evidence that the raised haemoglobin A2value is not caused by heterozygous β thalassaemia, but rather results from these patients being human immunodeficiency virus (HIV) positive and on antiretroviral therapy. This will have important implications as universal antenatal haemoglobinopathy screening becomes more widespread, and as the number of HIV positive women of childbearing age increases.
A novel BRCA2 mutation in an Indonesian family found with a new, rapid, and sensitive mutation detection method based on pooled denaturing gradient gel electrophoresis and targeted sequencing
Authors: Purnomosari D , Paramita D K , Aryandono T , Pals G , van Diest P J
Published: April 2005

Background:Breast cancer is increasing in Indonesia and other developing countries. Germline mutations in the BRCA1/2 genes are most strongly associated with a high risk for breast cancer development. There have been no reports on BRCA1/2 gene mutations in the Indonesian population. Genetic research yielding insight into mutations affecting the Indonesian population can help in risk assessment of individual patients.

Aims:To screen the BRCA1/2 genes for mutations in early onset Indonesian breast cancer patients and their families with a new, simple, and sensitive BRCA1/2 mutation screening strategy based on denaturing gradient gel electrophoresis (DGGE) and targeted sequencing.

Methods:DNA was isolated from the blood of four Indonesian breast cancer patients from high risk families and seven family members, and the polymerase chain reaction was performed with specially designed primers throughout the BRCA1/2 coding sequences to produce fragments suitable for pooled DGGE analysis. The aberrantly migrating samples were reamplified and sequenced.

Results:Two mutations were found in exons 13 and 16 of BRCA1 and two mutations in exons 2 and 14 of BRCA2, which turned out to be established polymorphisms according to the Breast Cancer Information Core. In addition, a novel 6 bp deletion in exon 11, leading to a premature stop, was found in BRCA2.

Conclusion:Pooled DGGE and targeted sequencing revealed four BRCA1/2 polymorphisms and one novel BRCA2 mutation in a group of Indonesian patients at high risk of hereditary breast cancer. This illustrates that the proposed method is sensitive and particularly suited for screening unknown populations.
Synthesis and structure of a (NacNac)rhodium terminal dinitrogen complex
Authors: Masuda Jason D , Stephan Douglas W
Published: April 2005

Reaction of the ligand salt CH[C(Me)(N-i-Pr2C6H3)]2Li(Et2O) with [Rh(COE)(µ-Cl)]2 proceeds to give the brown crystalline product CH[C(Me)(N-i-Pr2C6H3)]2Rh(N2)(COE) (1) in 38% yield. X-ray crystallographic study of 1 confirmed the formulation and revealed that the terminally bound dinitrogen molecule exhibits a RhN distance of 1.943(4) Å and an NN distance of 1.091(6) Å. Comparison to other RhN2 complexes shows that the NN distances reflect a complex admixture of the trans influence and the net electron density at the metal center.Key words: rhodium, dinitrogen, diimine, structure.
ROUTING IN OPTICAL MULTISTAGE NETWORKS WITH LIMITED CROSSTALK USING ANT COLONY OPTIMIZATION
Authors: KATANGUR AJAY K. , AKKALADEVI SOMASHEKER , PAN YI , FRASER MARTIN D.
Published: April 2005

Ant Colony Optimization (ACO) techniques can be successfully implemented to solve many combinatorial optimization problems. After the traveling salesman problem was successfully solved using the ACO technique, other researchers have concentrated on solving other problems like the quadratic assignment and the job-shop scheduling problems using the same technique. In this paper we use the ACO technique to route messages through an N × N Optical Multistage Interconnection Network (OMIN) allowing upto ' C ' limited crosstalk's (conflicts between messages within a switch) where ' C ' is a technology driven parameter and is always less than log 2 N . Messages with switch conflicts satisfying the crosstalk constraint are allowed to pass in the same group, but if there is any link conflict, then messages have to be routed in a different group. The focus is to minimize the number of passes required for routing allowing upto ' C ' limited crosstalks in an N × N optical network. This routing problem is an NP-hard problem. In this paper we show how the ACO technique can be applied to the routing problem and compare the performance of the ACO technique to that of the degree-descending algorithm using simulation techniques. Finally the lower bound estimate on the minimum number of passes required is calculated and compared to the results obtained using the two algorithms discussed. The results obtained show that the ACO technique performs better than the degree-descending algorithm and is quite close to optimal algorithms to the problem.
DECENTRALIZED PACKET CLUSTERING IN ROUTER-BASED NETWORKS
Authors: MERKLE DANIEL , MIDDENDORF MARTIN , SCHEIDLER ALEXANDER
Published: April 2005

Different types of decentralized clustering problems have been studied so far for networks and multi-agent systems. In this paper we introduce a new type of a decentralized clustering problem for networks. The so called Decentralized Packet Clustering (DPC) problem is to find for packets that are sent around in a network a clustering. This clustering has to be done by the routers using only few computational power and only a small amount of memory. No direct information transfer between the routers is allowed. We investigate the behavior of new a type of decentralized k-means algorithm — called DPClust — for solving the DPC problem. DPClust has some similarities with ant based clustering algorithms. We investigate the behavior of DPClust for different clustering problems and for networks that consist of several subnetworks. The amount of packet exchange between these subnetworks is limited. Networks with different connection topologies for the subnetworks are considered. A dynamic situation where the packet exchange rates between the subnetworks varies over time is also investigated. The proposed DPC problem leads to interesting research problems for network clustering.
ON THE BEHAVIOR OF PARALLEL GENETIC ALGORITHMS FOR OPTIMAL PLACEMENT OF ANTENNAE IN TELECOMMUNICATIONS
Authors: ALBA E. , CHICANO F.
Published: April 2005

In this article, evolutionary algorithms (EAs) are applied to solve the radio network design problem (RND). The task is to find the best set of transmitter locations in order to cover a given geographical region at an optimal cost. Usually, parallel EAs are needed to cope with the high computational requirements of such a problem. Here, we develop and evaluate a set of sequential and parallel genetic algorithms (GAs) to solve the RND problem efficiently. The results show that our distributed steady state GA is an efficient and accurate tool for solving RND that even outperforms existing parallel solutions. The sequential algorithm performs very efficiently from a numerical point of view, although the distributed version is much faster.
Chronic umbilical cord compression results in accelerated maturation of lung and brown adipose tissue in the sheep fetus during late gestation
Authors: Gnanalingham M. G. , Giussani D. A. , Sivathondan P. , Forhead A. J. , Stephenson T. , Symonds M. E. , Gardner D. S.
Published: April 2005

Umbilical cord compression (UCC) sufficient to reduce umbilical blood flow by 30% for 3 days, results in increased fetal plasma cortisol and catecholamines that are likely to promote maturation of the fetal lung and brown adipose tissue (BAT). We determined the effect of UCC on the abundance of uncoupling protein (UCP)1 (BAT only) and -2, glucocorticoid receptor (GR), and 11β-hydroxysteroid dehydrogenase (11β-HSD)1 and -2 mRNA, and mitochondrial protein voltage-dependent anion channel (VDAC) and cytochrome c in these tissues. At 118 ± 2 days of gestation (dGA; term ∼145 days), 14 fetuses were chronically instrumented. Eight fetuses were then subjected to 3 days of UCC from 125 dGA, and the remaining fetuses were sham operated. All fetuses were then exposed to two 1-h episodes of hypoxemia at 130 ± 1 and 134 ± 1 dGA before tissue sampling at 137 ± 2 dGA. In both tissues, UCC upregulated UCP2 and GR mRNA, plus VDAC and cytochrome c mitochondrial proteins. In lung, UCC increased 11β-HSD1 mRNA but decreased 11β-HSD2 mRNA abundance, a pattern reversed for BAT. UCC increased UCP1 mRNA and its translated protein in BAT. UCP2, GR, 11β-HSD1 and -2 mRNA, plus VDAC and cytochrome c protein abundance were all significantly correlated with fetal plasma cortisol and catecholamine levels, but not thyroid hormone concentrations, in the lung and BAT of UCC fetuses. In conclusion, chronic UCC results in precocious maturation of the fetal lung and BAT mitochondria, an adaptation largely mediated by the surge in fetal plasma cortisol and catecholamines that accompanies UCC.
A mathematical model of rat distal convoluted tubule. I. Cotransporter function in early DCT
Authors: Weinstein Alan M.
Published: April 2005

A model of rat early distal convoluted tubule (DCT) is developed in conjunction with a kinetic representation of the thiazide-sensitive NaCl cotransporter (TSC). Realistic constraints on cell membrane electrical conductance require that most of the peritubular Cl−reabsorption proceeds via a KCl cotransporter,along with most of the K+recycled from the Na-K-ATPase. The model tubule reproduces the saturable Cl−reabsorption of DCT but not the micropuncture finding of linear Na+flux in response to load, more likely a feature of late DCT (CNT). As in proximal tubule, early DCT HCO3−reabsorption is mediated by a luminal Na+/H+exchanger (NHE), but in contrast to proximal tubule, the DCT exchanger is operating closer to equilibrium. In the model DCT, two consequences of the lesser driving force for NHE exchange are an acidic cytosol and wider swings in NHE flux with perturbations of luminal composition. Variations in luminal NaCl provide a challenge to cell volume, which can be blunted by volume dependence of the KCl cotransporter. Cell swelling can also be induced by increases in peritubular K+concentration. In this case, volume-dependent inhibition of TSC could provide volume homeostasis that also enhances distal Na+delivery, and ultimately enhances renal K+excretion. In the model DCT, proton secretion is blunted by peritubular HCO3−, so that there is little contribution by this segment to the maintenance of metabolic alkalosis. During alkalosis, the model predicts that increasing luminal NaCl concentration enhances NHE flux, so that these calculations provide no support for a role of early DCT in recovery from Cl−depletion alkalosis.
Error Parsing in Visuomotor Pointing Reveals Independent Processing of Amplitude and Direction
Authors: Vindras Philippe , Desmurget Michel , Viviani Paolo
Published: April 2005

An experiment investigated systematic pointing errors in horizontal movements performed without visual feedback toward 48 targets placed symmetrically around two initial hand positions. Our main goal was to provide evidence in favor of the hypothesis that amplitude and direction of the movements are planned independently on the basis of the hand-target vector (vectorial parametric hypothesis, VP). The analysis was carried out mainly at the individual level. By screening a number of formal models of the potential error components, we found that only models compatible with the VP hypothesis provide an accurate description of the error pattern. A quantitative analysis showed that errors are explained mostly by a bias in the represented initial hand position (46% of the sum of squared errors) and a visuomotor gain bias (26%). Range effect (3%), directional biases (3%), and inertia-dependent amplitude modulations (1%) also provided significant contributions. The error pattern was incompatible with the view that movements are planned by specifying either a final posture or a final position. Instead, the results fully supported the view that, at least in the horizontal plane, amplitude, and direction of pointing movements are planned independently in a hand- or target-centered frame of reference.
Risk of Hemorrhagic Stroke in Asian American Ethnic Groups
Authors: Klatsky Arthur L. , Friedman Gary D. , Sidney Stephen , Kipp Harald , Kubo Ai , Armstrong Mary Anne
Published: April 2005

The sparseness of prospective data about hemorrhagic stroke (HS) risk among Asian American ethnic groups led to the investigation of 128,934 persons with self-classified ethnicity at health examinations in 1978–1985. Subsequently, 431 persons were hospitalized for HS; 31% for subarachnoid hemorrhage (SAH) and 69% for intracerebral hemorrhage (ICH). Ethnic predictors of HS were studied by Cox proportional hazard models with 7 covariates. With whites as reference, the adjusted relative risk (95% CI) of all Asians for HS was 1.6 (1.1–2.3, p = 0.01), due substantially to increased risks of SAH in Japanese people and ICH in Filipinos. These data mandate emphasis upon preventive measures in these groups.
Über die Herkunft der Frau des Mose
Authors: Gerhards Meik
Published: April 2005

The quest for the historical Moses has to start from two motifs in the biblical account, which are not deducible from the interests of later times, i.e., the Egyptian name of Moses and his non-Israelite wife. Concerning the latter motif the Old Testament account includes three versions about the origin of the woman (Midianite, Cushite, Qenite). The paper wants to show, how these differences could be explained as variations of an originally unique information, so that they can be taken as an indication of the long tradition the motif has undergone. The two non-deducible motifs indicate that the historical Moses was indeed the leader of the Exodus as well as the mediator of the revelation of Yahweh.
Development of a lung slice preparation for recording ion channel activity in alveolar epithelial type I cells
Authors: Bourke Steven , Mason Helen S , Borok Zea , Kim Kwang-Jin , Crandall Edward D , Kemp Paul J
Published: April 2005

Background

Lung fluid balance in the healthy lung is dependent upon finely regulated vectorial transport of ions across the alveolar epithelium. Classically, the cellular locus of the major ion transport processes has been widely accepted to be the alveolar type II cell. Although evidence is now emerging to suggest that the alveolar type I cell might significantly contribute to the overall ion and fluid homeostasis of the lung, direct assessment of functional ion channels in type I cells has remained elusive.

Methods

Here we describe a development of a lung slice preparation that has allowed positive identification of alveolar type I cells within an intact and viable alveolar epithelium using living cell immunohistochemistry.

Results

This technique has allowed, for the first time, single ion channels of identified alveolar type I cells to be recorded using the cell-attached configuration of the patch-clamp technique.

Conclusion

This exciting new development should facilitate the ascription of function to alveolar type I cells and allow us to integrate this cell type into the general model of alveolar ion and fluid balance in health and disease.
Some statistical properties of regulatory DNA sequences, and their use in predicting regulatory regions in the Drosophila genome: the fluffy-tail test
Authors: Abnizova Irina , te Boekhorst Rene , Walter Klaudia , Gilks Walter R
Published: April 2005

Background

This paper addresses the problem of recognising DNA cis-regulatory modules which are located far from genes. Experimental procedures for this are slow and costly, and computational methods are hard, because they lack positional information.

Results

We present a novel statistical method, the "fluffy-tail test", to recognise regulatory DNA. We exploit one of the basic informational properties of regulatory DNA: abundance of over-represented transcription factor binding site (TFBS) motifs, although we do not look for specific TFBS motifs, per se . Though overrepresentation of TFBS motifs in regulatory DNA has been intensively exploited by many algorithms, it is still a difficult problem to distinguish regulatory from other genomic DNA.

Conclusion

We show that, in the data used, our method is able to distinguish cis-regulatory modules by exploiting statistical differences between the probability distributions of similar words in regulatory and other DNA. The potential application of our method includes annotation of new genomic sequences and motif discovery.
Proliferative activity of extracellular HIV-1 Tat protein in human epithelial cells: expression profile of pathogenetically relevant genes
Authors: Bettaccini Alessia A , Baj Andreina , Accolla Roberto S , Basolo Fulvio , Toniolo Antonio Q
Published: April 2005

Background

Tat is being tested as a component of HIV vaccines. Tat activity has been mainly investigated on cells of lymphoid/hematopoietic lineages. HIV-1, however, is known to infect many different cells of both solid organs and mucosal surfaces. The activity of two-exon (aa 1–101) and synthetic (aa 1–86) Tat was studied on mammary and amniotic epithelial cells cultured under low serum conditions.

Results

small concentrations of Tat (100 ng/ml) stimulated cell proliferation. Tat antibodies neutralized the mitogenic Tat activity. Changes of gene expression in Tat-treated cells were evaluated by RT-PCR and gene-array methods. Within 4 hours of treatment, exposure to Tat is followed by up-regulation of some cell cycle-associated genes (transcription factors, cyclin/cdk complexes, genes of apoptotic pathways) and of genes relevant to HIV pathogenesis [chemokine receptors (CXCR4, CCR3), chemotactic cytokines (SDF-1, RANTES, SCYC1, SCYE1), IL6 family cytokines, inflammatory cytokines, factors of the TGF-beta family (TGFb, BMP-1, BMP-2)]. Up-regulation of anti-inflammatory cytokines (IL-10, IL-19, IL-20), a hallmark of other persistent viral infections, was a remarkable feature of Tat-treated epithelial cell lines.

Conclusion

extracellular Tat is mitogenic for mammary and amniotic epithelial cells and stimulates the expression of genes of pathogenetic interest in HIV infection. These effects may favor virus replication and may facilitate the mother-to-child transmission of virus.
The minimally invasive open video-assisted approach in surgical thyroid diseases
Authors: Ruggieri Massimo , Straniero Andrea , Mascaro Alessandra , Genderini Mariapia , D'Armiento Massimino , Gargiulo Patrizia , Fumarola Angela , Trimboli Pierpaolo
Published: April 2005

Background

The targets of minimally invasive surgery (MIVA) could be summarised by: achievement of the same results as those obtained with traditional surgery, less trauma, better post-operative course, early discharge from hospital and improved cosmetic results. The minimally invasive techniques in thyroid surgery can be described as either endoscopic "pure" approach (completely closed approach with or without CO2 insufflation), or "open approach" with central neck mini-incision or "open video-assisted approach". Traditionally, open thyroidectomy requires a 6 to 8 cm, or bigger, transverse wound on the lower neck. The minimally invasive approach wound is much shorter (1.5 cm for small nodules, up to 2–3 cm for the largest ones, in respect of the exclusion criteria) upon the suprasternal notch.

Patients also experience much less pain after MIVA surgery than after conventional thyroidectomy. This is due to less dissection and destruction of tissues.

Pathologies treated are mainly nodular goiter; the only kind of thyroid cancer which may be approached with endoscopic surgery is a small differentiated carcinoma without lymph node involvement.

The patients were considered eligible for MIVA hemithyroidectomy and thyroidectomy on the basis of some criteria, such as gland volume and the kind of disease. In our experience we have chosen the minimally invasive open video-assisted approach of Miccoli et al. (2002). The aim of this work was to verify the suitability of the technique and the applicability in clinical practice.

Methods

A completely gasless procedure was carried out through a 15–30 mm central incision about 20 mm above the sternal notch. Dissection was mainly performed under endoscopic vision using conventional endoscopic instruments. The video aided group included 11 patients. All patients were women with a average age of 54.

Results

We performed thyroidectomy in 8 cases and hemithyroidectomy in 3 cases. The operative average time has been 170 minutes.

Conclusion

Nowadays this minimally invasive surgery, in selected patients, clearly demonstrates excellent results regarding patient cure rate and comfort, with shorter hospital stay, reduced postoperative pain and most attractive cosmetic results.