115 resultados para Gateway constructs
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Plant membrane compartments and trafficking pathways are highly complex, and are often distinct from those of animals and fungi. Progress has been made in defining trafficking in plants using transient expression systems. However, many processes require a precise understanding of plant membrane trafficking in a developmental context, and in diverse, specialized cell types. These include defense responses to pathogens, regulation of transporter accumulation in plant nutrition or polar auxin transport in development. In all of these cases a central role is played by the endosomal membrane system, which, however, is the most divergent and ill-defined aspect of plant cell compartmentation. We have designed a new vector series, and have generated a large number of stably transformed plants expressing membrane protein fusions to spectrally distinct, fluorescent tags. We selected lines with distinct subcellular localization patterns, and stable, non-toxic expression. We demonstrate the power of this multicolor 'Wave' marker set for rapid, combinatorial analysis of plant cell membrane compartments, both in live-imaging and immunoelectron microscopy. Among other findings, our systematic co-localization analysis revealed that a class of plant Rab1-homologs has a much more extended localization than was previously assumed, and also localizes to trans-Golgi/endosomal compartments. Constructs that can be transformed into any genetic background or species, as well as seeds from transgenic Arabidopsis plants, will be freely available, and will promote rapid progress in diverse areas of plant cell biology.
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Per definition, alcohol expectancies (after alcohol I expect X), and drinking motives (I drink to achieve X) are conceptually distinct constructs. Theorists have argued that motives mediate the association between expectancies and drinking outcomes. Yet, given the use of different instruments, do these constructs remain distinct when assessment items are matched? The present study tested to what extent motives mediated the link between expectancies and alcohol outcomes when identical items were used, first as expectancies and then as motives. A linear structural equation model was estimated based on a national representative sample of 5,779 alcohol-using students in Switzerland (mean age = 15.2 years). The results showed that expectancies explained up to 38% of the variance in motives. Together with motives, they explained up to 48% of the variance in alcohol outcomes (volume, 5+ drinking, and problems). In 10 of 12 outcomes, there was a significant mediated effect that was often higher than the direct expectancy effect. For coping, the expectancy effect was close to zero, indicating the strongest form of mediation. In only one case (conformity and 5+ drinking), there was a direct expectancy effect but no mediation. To conclude, the study demonstrates that motives are distinct from expectancies even when identical items are used. Motives are more proximally related to different alcohol outcomes, often mediating the effects of expectancies. Consequently, the effectiveness of interventions, particularly those aimed at coping drinkers, should be improved through a shift in focus from expectancies to drinking motives.
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ABSTRACT Malaria is a major worldwide public health problem, with transmission occurring throughout Africa, Asia, Oceania and Latin America. Over two billion people live in malarious areas of the world and it is estimated that 300-500 million cases and 1.5-2.7 million deaths occur annually. The increase in multi-drug resistant parasites and insecticide-resistant vectors has made the development of malaria vaccine a public health priority. The published genome offers tremendous opportunity for the identification of new antigens that can befast-tracked for vaccine development. We identified potential protein antigens present on the surface of asexual malaria blood stages through bioinformatics and published transcriptome and proteorné analysis. Amongst the proteins identified, we selected those that contain predicted a-helical coiled-coil regions, which are generally short and structurally stable as isolated fragments. Peptides were synthesized and used to immunize mice. Most peptides tested were immunogenic as demonstrated in ELISA assays, and induced antibodies of varying titres. In immunofluorescence assays, anti-sera from immunized mice reacted with native proteins expressed at different intraerythrocytic developmental stages of the parasite's cycle. In parallel in vitro ADCI functional studies, human antibodies affinity purified on some of these peptides inhibited parasite growth in association with monocytes in magnitudes similar to that seen in semiimmune African adults. Siudies using human immune sera taken from different malaria endemic regions, demonstrated that majority of peptides were recognized at high prevalence. 73 peptides were next tested in longitudinal studies in two cohorts separated in space and time in coastal Kenya. In these longitudinal analyses, antibody responses to peptides were sequentially examined in two cohorts of children at risk of clinical malaria in order to characterize the level of peptide recognition by age, and the role of anti-peptide antibodies in protection from clinical malaria. Ten peptides were associated ?with a significantly reduced odds ratio for an episode of clinical malaria in the first cohort of children and two of these peptides (LR146 and ÁS202.11) were associated with a significantly reduced odds ratio in both cohorts. This study has identified proteins PFB0145c and MAL6P1.37 among others as likely targets of protective antibodies. Our findings support further studies to systematically assess immunogenicity of peptides of interest in order to establish clear criteria for optimal design of potential vaccine constructs to be tested in clinical trials. RESUME La malaria est un problème de santé publique mondial principalement en Afrique, en Asie, en Océanie et en Amérique latine. Plus de 2 milliards de personnes vivent dans des régions endémiques et le nombre de cas par année est estimé entre 300 et 500 millions. 1.5 à 2.7 millions de décès surviennent annuellement dans ces zones. L'augmentation de la résistance aux médicaments et aux insecticides fait du développement d'un vaccin une priorité. Le séquençage complet du génome du parasite offre l'opportunité d'identifier de nouveaux antigènes qui peuvent rapidement mener au développement d'un vaccin. Des protéines antigéniques potentielles présentes à la surface des globules rouges infectés ont été identifiées par bioinformatique et par l'analyse du protéome et du transcriptome. Nous avons sélectionné, parmi ces protéines, celles contenant des motifs dits "a helical coiled-coil" qui sont généralement courts et structurellement stables. Ces régions ont été obtenues par synthèse peptidique et utilisées pour immuniser des souris. La plupart des peptides testés sont immunogéniques et induisent un titre variable d'anticorps déterminé par ELISA. Les résultats de tests d'immunofluorescence indiquent que les sera produits chez la souris reconnaissent les protéines natives exprimées aux différents stades de développement du parasite. En parallèle, des études d'ADCI in vitro montrent qué des anticorps humains purifiés à partir de ces peptides associés à des monocytes inhibent la croissance du parasite aussi bien que celle observée chez des adultes africains protégés. Des études d'antigénicité utilisant des sera de personnes protégées de différents âges vivant dans des régions endémiques montrent que la majorité des peptides sont reconnus avec une haute prévalence. 73 peptides ont été testés dans une étude longitudinale avec 2 cohortes de la côte du Kenya. Ces 2 groupes viennent de zones bien distinctes et les prélèvements n'ont pas été effectués pendant la même période. Dans cette étude, la réponse anticorps contre les peptides synthétiques a été testée dans les 2 cohortes d'enfants à risque de développer un épisode de malaria afin de caractériser le niveau de reconnaissance des peptides en fonction de l'âge et de déterminer le rôle des anticorps anti-peptides dans la protection contre la malaria. Parmi ces peptides, 10 sont associés à une réduction significative des risques de développer un épisode de malaria dans la première cohorte alors qu'un seul (LR146 et AS202.11) l'est dans les 2 cohortes. Cette étude a identifié, parmi d'autres, les protéines PFB0145c et MAL6P1.37 comme pouvant être la cible d'anticorps. Ces résultats sont en faveur de futures études qui évalueraient systématiquement l'immunogénicité des peptides d'intérêt dans le but d'établir des critères de sélection clairs pour le développement d'un vaccin. Résumé pour un large public La malaria est un problème de santé publique mondial principalement en Afrique, en Asie, en Océanie et en Amérique latine. Plus de 2 milliards de personnes vivent dans des régions endémiques et le nombre de cas par année est estimé entre 300 et 500 millions. 1.5 à 2.7 millions de décès surviennent annuellement dans ces zones. La résistance aux médicaments et aux insecticides augmente de plus en plus d'où la nécessité de développer un vaccin. Le séquençage complet du génome (ensemble des gènes) de P. falciparum a conduit au développement de nouvelles .études à large échelle dans le domaine des protéines du parasite (protéome) ; dans l'utilisation d'algorithmes, de techniques informatiques et statistiques pour l'analyse de données biologiques (bioinformatique) et dans les technologies de transcription et de profiles d'expression (transcriptome). Nous avons identifié, en utilisant les outils ci-dessus, des nouvelles protéines antigéniques qui sont présentes au stade sanguin de la malaria. Nous avons sélectionné, parmi ces protéines, celles contenant un motif dit "a-helical coiled-coil" qui sont des domaines impliqués dans un large éventail de fonctions biologiques. Des peptides représentant ces régions structurellement stables ont été synthétisés et utilisés pour immuniser des souris. La plupart des peptides testés sont immunogéniques et induisent un titre variable d'anticorps déterminé par ELISA. Les résultats de tests d'immunofluorescence indiquent que plusieurs sera de souris immunisées avec ces peptides reconnaissent les protéines natives exprimées à la surface des globules rouges infectés. En parallèle, des études d'ADCI in vitro montrent que des anticorps humains purifiés à partir de ces peptides en présence de monocytes inhibent la croissance du parasite de manière similaire à celle observée chez des adultes africains protégés. Des études d'antigénicité utilisant des sera de personnes immunes de différents âges (adultes et enfants) vivant dans des régions endémiques montrent que la majorité des peptides sont reconnus avec une haute prévalence. 73 peptides ont été testés dans des études épidémiologiques dans 2 villages côtiers du Kenya Ces 2 groupes vivent dans des zones bien distinctes et les prélèvements n'ont pas été effectués pendant la même période. Dans ces études, la réponse anticorps dirigée contre les peptides synthétiques a été testée en utilisant 467 échantillons sanguins d'enfants à risque de développer un épisode de malaria afin de caractériser le niveau de reconnaissance des peptides en fonction de l'âge et de déterminer le rôle des anticorps anti-peptides dans la protection contre la malaria cérébrale. Parmi ces peptides, 10 sont associés à une protection contre un épisode de malaria dans le premier village alors qu'un seul l'est dans les 2 villages. Ces résultats sont en faveur de futures études qui évalueraient systématiquement l'immunogénicité des peptides intéressants dans le but d'établir des critères de sélection clairs pour le développement d'un vaccin.
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In pancreatic beta-cells, the high Km glucose transporter GLUT2 catalyzes the first step in glucose-induced insulin secretion by glucose uptake. Expression of the transporter has been reported to be modulated by glucose either at the protein or mRNA levels. In this study we used the differentiated insulinoma cell line INS-1 which expresses high levels of GLUT2 and show that the expression of GLUT2 is regulated by glucose at the transcriptional level. By run-on transcription assays we showed that glucose induced GLUT2 gene transcription 3-4-fold in INS-1 cells which was paralleled by a 1.7-2.3-fold increase in cytoplasmic GLUT2 mRNA levels. To determine whether glucose regulatory sequences were present in the promoter region of GLUT2, we cloned and characterized a 1.4-kilobase region of mouse genomic DNA located 5' of the translation initiation site. By RNase protection assays and primer extension, we determined that multiple transcription initiation sites were present at positions -55, -64, and -115 from the first coding ATG and which were identified in liver, intestine, kidney, and beta-cells mRNAs. Plasmids were constructed with the mouse promoter region linked to the reporter gene chloramphenicol acetyltransferase (CAT), and transiently and stably transfected in the INS-1 cells. Glucose induced a concentration-dependent increase in CAT activity which reached a maximum of 3.6-fold at 20 mM glucose. Similar CAT constructs made of the human GLUT2 promoter region and the CAT gene displayed the same glucose-dependent increase in transcriptional activity when transfected into INS-1 cells. Comparison of the mouse and human promoter regions revealed sequence identity restricted to a few stretches of sequences which suggests that the glucose responsive element(s) may be conserved in these common sequences.
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Using genetically matched azole-susceptible (AS) and azole-resistant (AR) clinical isolates of Candida albicans, we recently demonstrated that CDR1 overexpression in AR isolates is due to its enhanced transcriptional activation and mRNA stability. This study examines the molecular mechanisms underlying enhanced CDR1 mRNA stability in AR isolates. Mapping of the 3' untranslated region (3' UTR) of CDR1 revealed that it was rich in adenylate/uridylate (AU) elements, possessed heterogeneous polyadenylation sites, and had putative consensus sequences for RNA-binding proteins. Swapping of heterologous and chimeric lacZ-CDR1 3' UTR transcriptional reporter fusion constructs did not alter the reporter activity in AS and AR isolates, indicating that cis-acting sequences within the CDR1 3' UTR itself are not sufficient to confer the observed differential mRNA decay. Interestingly, the poly(A) tail of the CDR1 mRNA of AR isolates was approximately 35-50 % hyperadenylated as compared with AS isolates. C. albicans poly(A) polymerase (PAP1), responsible for mRNA adenylation, resides on chromosome 5 in close proximity to the mating type-like (MTL) locus. Two different PAP1 alleles, PAP1-a/PAP1-alpha, were recovered from AS (MTL-a/MTL-alpha), while a single type of PAP1 allele (PAP1-alpha) was recovered from AR isolates (MTL-alpha/MTL-alpha). Among the heterozygous deletions of PAP1-a (Deltapap1-a/PAP1-alpha) and PAP1-alpha (PAP1-a/Deltapap1-alpha), only the former led to relatively enhanced drug resistance, to polyadenylation and to transcript stability of CDR1 in the AS isolate. This suggests a dominant negative role of PAP1-a in CDR1 transcript polyadenylation and stability. Taken together, our study provides the first evidence, to our knowledge, that loss of heterozygosity at the PAP1 locus is linked to hyperadenylation and subsequent increased stability of CDR1 transcripts, thus contributing to enhanced drug resistance.
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This study on determinants of sexual protection behavior among HIV-positive gay men used the empirically tested information-motivation-behavioral skills (IMB) model. HIV-specific variables were added to the model to determine factors decisive for condom use with steady and casual partners. Data were collected using an anonymous, standardized self-administered questionnaire. Study participants were recruited at HIV outpatient clinics associated with the Eurosupport Study Group and the Swiss HIV Cohort Study. To identify factors associated with condom use, backward elimination regression analyses were performed. Overall, 838 HIV-infected gay men from 14 European countries were included in this analysis. About 53% of them reported at least one sexual contact with a steady partner; 62.5% had sex with a casual partner during the last 6 months. Forty-three percent always used condoms with steady partners and 44% with casual partners. High self-efficacy and subjective norms in favor of condom-use were associated with increased condom use with casual and steady partners, whereas feeling depressed was associated with decreased condom use with casual partners. Condoms were used less often with HIV-positive partners. Self-efficacy as an important behavioral skill to perform protection behavior was influenced by lower perceived vulnerability, higher subjective norms, and more positive safer sex attitudes. The IMB-model constructs appeared to be valid; however, not all the model predictors could be determined as hypothesized. Besides the original IMB constructs, HIV-specific variables, including sexual partners' serostatus and mental health, explained condom use. Such factors should be considered in clinical interventions to promote "positive prevention."
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OBJECTIVE: To investigate the involvement of the nuclear factor (NF)-kappaB in the interleukin (IL)-1 beta-mediated macrophage migration inhibitory factor (MIF) gene activation. DESIGN: Prospective study. SETTING: Human reproduction research laboratory. PATIENT(S): Nine women with endometriotic lesions. INTERVENTION(S): Endometriotic lesions were obtained during laparoscopic surgery. MAIN OUTCOME MEASURE(S): The MIF protein secretion was analyzed by ELISA, MIF mRNA expression by quantitative real-time polymerase chain reaction (PCR), NF-kappaB translocation into the nucleus by electrophoresis mobility shift assay, I kappaB phosphorylation and degradation by Western blot, and human MIF promoter activity by transient cell transfection. RESULT(S): This study showed a significant dose-dependent increase of MIF protein secretion and mRNA expression, the NF-kappaB translocation into the nucleus, I kappaB phosphorylation, I kappaB degradation, and human MIF promoter activity in endometriotic stromal cells in response to IL-1 beta. Curcumin (NF-kappaB inhibitor) significantly inhibited all these IL-1 beta-mediated effects. Analysis of the activity of deletion constructs of the human MIF promoter and a computer search localized two putative regulatory elements corresponding to NF-kappaB binding sites at positions -2538/-2528 bp and -1389/-1380 bp. CONCLUSION(S): This study suggests the involvement of the nuclear transcription factor NF-kappaB in MIF gene activation in ectopic endometrial cells in response to IL-1 beta and identifies a possible pathway of endometriosis-associated inflammation and ectopic cell growth.
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To produce agronomically competitive rice with nutritionally superior, environmentally safe phytic acid (PA) levels, hairpin RNA (hpRNA)- and artificial microRNA (amiRNA)-mediated gene silencing approaches were explored to reduce both myo-inositol kinase gene (OsMIK) expression and PA accumulation in rice seeds. hpRNA and amiRNA sequences targeted to OsMIK (hpMIK and amiMIK), under the control of a rice Ole18 promoter, were transformed into the rice cultivar Nippon-bare. Fourteen and 21 independent transgenic events were identified containing the hpMIK and amiMIK constructs, respectively, from which five stable homozygous transgenic lines of each were developed together with their null siblings. Southern blotting demonstrated transgene integration into the genome and quantitative real-time PCR showed that gene silencing was restricted to seeds. OsMIK transcripts were significantly reduced in both transgenic amiMIK and hpMIK seeds, which had PA levels reduced by 14.9-50.2 and 38.1-50.7 %, respectively, compared with their respective null siblings. There were no systematic significant differences in agronomic traits between the transgenic lines and their non-transgenic siblings, and no correlation between seed PA contents and decreased rates of seed germination and seedling emergence. The results of the present study suggest that Ole 18-driven OsMIK silencing via hpRNA and amiRNA could be an effective way to develop agronomically competitive low phytic acid rice.
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Astrocytes are the brain non-nerve cells competent for the expression of clear and dense-core vesicles (DCVs) and for their regulated exocytosis. This process, called gliosecretion, nearly resembles the neurosecretion occurring in neurons and neurosecretory cells. REST/NRSF is a transcription repressor known to orchestrate nerve-cell differentiation, governing the expression of hundreds of neuron-specific genes through their repression in the non-nerve and their fine modulation in the nerve cells. Our previous studies in neurosecretory rat PC12 cells identified REST as the critical factor for the expression not only of individual genes, but also of the whole neurosecretory process via multiple, direct and indirect mechanisms (D'Alessandro et al., J. Neurochem., 2008; Klajn et al., J. Neurosci., 2009). Therefore we wondered whether gliosecretion was governed by REST. We investigated rat astrocyte primary cultures: they exhibited high REST, which directly represses the transcription of at least one target gene, and expressed neither DCVs nor their markers (granins, peptides, membrane proteins). Transfection of a dominant-negative construct of REST (REST/ DBD-GFP) induced the appearance of DCVs filled with secretogranin2 and NPY that are distinct from other intracellular organelles. TIRF analysis of astrocytes co-transfected with REST/DBD-GFP and NPY-mRFP constructs revealed NPY-mRFP-positive DCVs undergoing Ca2þ-dependent exocytosis, largely prevented by BoNT/B. Immunohistochemistry of the I-II layers of the human temporal brain cortex showed all neurons and microglia exhibiting the expected inappreciable and high levels of REST, respectively. In contrast astrocyte RESTwas variable, going from inappreciable to high, accompanied by variable expression of DCVs. In this work it has been demonstrated that astrocyte DCV expression and gliosecretion are governed by REST (Prada et al., 2011 in press). The variable in situ REST levels may contribute to the well known structural/functional heterogeneity of astrocytes and this new observation might be of great interest for the understanding of both astrocyte physiology and pathology.
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Glucose homoeostasis necessitates the presence in the liver of the high Km glucose transporter GLUT2. In hepatocytes, we and others have demonstrated that glucose stimulates GLUT2 gene expression in vivo and in vitro. This effect is transcriptionally regulated and requires glucose metabolism within the hepatocytes. In this report, we further characterized the cis-elements of the murine GLUT2 promoter, which confers glucose responsiveness on a reporter gene coding the chloramphenicol acetyl transferase (CAT) gene. 5'-Deletions of the murine GLUT2 promoter linked to the CAT reporter gene were transfected into a GLUT2 expressing hepatoma cell line (mhAT3F) and into primary cultured rat hepatocytes, and subsequently incubated at low and high glucose concentrations. Glucose stimulates gene transcription in a manner similar to that observed for the endogenous GLUT2 mRNA in both cell types; the -1308 to -212 bp region of the promoter contains the glucose-responsive elements. Furthermore, the -1308 to -338 bp region of the promoter contains repressor elements when tested in an heterologous thymidine kinase promoter. The glucose-induced GLUT2 mRNA accumulation was decreased by dibutyryl-cAMP both in mhAT3F cells and in primary hepatocytes. A putative cAMP-responsive element (CRE) is localized at the -1074/-1068 bp region of the promoter. The inhibitory effect of cAMP on GLUT2 gene expression was observed in hepatocytes transfected with constructs containing this CRE (-1308/+49 bp fragment), as well as with constructs not containing the consensus CRE (-312/+49 bp fragment). This suggests that the inhibitory effect of cAMP is not mediated by the putative binding site located in the repressor fragment of the GLUT2 promoter. Taken together, these data demonstrate that the elements conferring glucose and cAMP responsiveness on the GLUT2 gene are located within the -312/+49 region of the promoter.
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HIV-1 infects CD4+ T cells and completes its replication cycle in approximately 24 hours. We employed repeated measurements in a standardized cell system and rigorous mathematical modeling to characterize the emergence of the viral replication intermediates and their impact on the cellular transcriptional response with high temporal resolution. We observed 7,991 (73%) of the 10,958 expressed genes to be modulated in concordance with key steps of viral replication. Fifty-two percent of the overall variability in the host transcriptome was explained by linear regression on the viral life cycle. This profound perturbation of cellular physiology was investigated in the light of several regulatory mechanisms, including transcription factors, miRNAs, host-pathogen interaction, and proviral integration. Key features were validated in primary CD4+ T cells, and with viral constructs using alternative entry strategies. We propose a model of early massive cellular shutdown and progressive upregulation of the cellular machinery to complete the viral life cycle.
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The epithelial sodium channel (ENaC) is a key element for the maintenance of sodium balance and the regulation of blood pressure. Three homologous ENaC subunits (alpha, beta and gamma) assemble to form a highly Na+-selective channel. However, the subunit stoichiometry of ENaC has not yet been solved. Quantitative analysis of cell surface expression of ENaC alpha, beta and gamma subunits shows that they assemble according to a fixed stoichiometry, with alpha ENaC as the most abundant subunit. Functional assays based on differential sensitivities to channel blockers elicited by mutations tagging each alpha, beta and gamma subunit are consistent with a four subunit stoichiometry composed of two alpha, one beta and one gamma. Expression of concatameric cDNA constructs made of different combinations of ENaC subunits confirmed the four subunit channel stoichiometry and showed that the arrangement of the subunits around the channel pore consists of two alpha subunits separated by beta and gamma subunits.
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INTRODUCTION: Numerous instruments have been developed to assess spirituality and measure its association with health outcomes. This study's aims were to identify instruments used in clinical research that measure spirituality; to propose a classification of these instruments; and to identify those instruments that could provide information on the need for spiritual intervention. METHODS: A systematic literature search in MEDLINE, CINHAL, PsycINFO, ATLA, and EMBASE databases, using the terms "spirituality" and "adult$," and limited to journal articles was performed to identify clinical studies that used a spiritual assessment instrument. For each instrument identified, measured constructs, intended goals, and data on psychometric properties were retrieved. A conceptual and a functional classification of instruments were developed. RESULTS: Thirty-five instruments were retrieved and classified into measures of general spirituality (N = 22), spiritual well-being (N = 5), spiritual coping (N = 4), and spiritual needs (N = 4) according to the conceptual classification. Instruments most frequently used in clinical research were the FACIT-Sp and the Spiritual Well-Being Scale. Data on psychometric properties were mostly limited to content validity and inter-item reliability. According to the functional classification, 16 instruments were identified that included at least one item measuring a current spiritual state, but only three of those appeared suitable to address the need for spiritual intervention. CONCLUSIONS: Instruments identified in this systematic review assess multiple dimensions of spirituality, and the proposed classifications should help clinical researchers interested in investigating the complex relationship between spirituality and health. Findings underscore the scarcity of instruments specifically designed to measure a patient's current spiritual state. Moreover, the relatively limited data available on psychometric properties of these instruments highlight the need for additional research to determine whether they are suitable in identifying the need for spiritual interventions.
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Amantadine is an antiviral and antiparkinsonian drug that has been evaluated in combination therapies against hepatitis C virus (HCV) infection. Controversial results have been reported concerning its efficacy, and its mechanism of action remains unclear. Data obtained in vitro suggested a role of amantadine in inhibiting HCV p7-mediated cation conductance. In keeping with the fact that mitochondria are responsible to ionic fluxes and that HCV infection impairs mitochondrial function, we investigated a potential role of amantadine in modulating mitochondrial function. Using a well-characterized inducible cell line expressing the full-length HCV polyprotein, we found that amantadine not only prevented but also rescued HCV protein-mediated mitochondrial dysfunction. Specifically, amantadine corrected (i) overload of mitochondrial Ca(2+); (ii) inhibition of respiratory chain activity and oxidative phosphorylation; (iii) reduction of membrane potential; and (iv) overproduction of reactive oxygen species. The effects of amantadine were observed within 15 min following drug administration and confirmed in Huh-7.5 cells transfected with an infectious HCV genome. These effects were also observed in cells expressing subgenomic HCV constructs, indicating that they are not mediated or only in part mediated by p7. Single organelle analyzes carried out on isolated mouse liver mitochondria demonstrated that amantadine induces hyperpolarization of the membrane potential. Moreover, amantadine treatment increased the calcium threshold required to trigger mitochondrial permeability transition opening. In conclusion, these results support a role of amantadine in preserving cellular bioenergetics and redox homeostasis in HCV-infected cells and unveil an effect of the drug which might be exploited for a broader therapeutic utilization.
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The Wechsler Intelligence Scale for Children-fourth edition (i.e. WISC-IV) recognizes a four-factor scoring structure in addition to the Full Scale IQ (FSIQ) score: Verbal Comprehension (VCI), Perceptual Reasoning (PRI), Working Memory (WMI), and Processing Speed (PSI) indices. However, several authors suggested that models based on the Cattell-Horn-Carroll (CHC) theory with 5 or 6 factors provided a better fit to the data than does the current four-factor solution. By comparing the current four-factor structure to CHC-based models, this research aimed to investigate the factorial structure and the constructs underlying the WISC-IV subtest scores with French-speaking Swiss children (N = 249). To deal with this goal, confirmatory factor analyses (CFAs) were conducted. Results showed that a CHC-based model with five factors better fitted the French-Swiss data than did the current WISC-IV scoring structure. All together, these results support the hypothesis of the appropriateness of the CHC model with French-speaking children.