Publications by authors named "French R"

Reconstitution into planar lipid bilayers of a poly-3-hydroxybutyrate/calcium/polyphosphate (PHB/Ca(2+)/polyP) complex from Escherichia coli membranes yields cationic-selective, 100 pS channels (Das, S., Lengweiler, U.D.

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A Wheat streak mosaic virus (WSMV) genome lacking HC-Pro was constructed and confirmed by reverse transcription-PCR to systemically infect wheat, oat, and corn. Coupled in vitro transcription/translation reactions indicated that WSMV P1 proteinase cleaved the polyprotein at the P1/P3 junction of the HC-Pro null mutant. The WSMV HC-Pro null mutant was competent for virion formation, but the virus titer was reduced 4.

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Purpose: Docetaxel, cisplatin, and capecitabine are three active chemotherapeutic agents with different mechanisms of action. This phase I study investigated the feasibility and pharmacokinetics of this combination given on a weekly schedule.

Experimental Design: Docetaxel and cisplatin were given i.

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Multiple synonymous substitution mutations in the Wheat streak mosaic virus P3 cistron did not affect translation in vitro but rendered the virus incapable of systemic infection. Multiple synonymous substitutions in the cylindrical inclusion cistron did not alter infectivity or in vitro translation. To assess replication and movement phenotypes, P3 mutations were placed in context with a GUS reporter gene.

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Although the occurrence of visual processing and eye-movement disorders in schizophrenia have been widely recognized, their relationship with the symptoms of schizophrenia is less well understood. In two experiments the relationship between directional-motion processing and smooth-pursuit eye movement was investigated in normal observers and in groups with positive and negative symptoms in schizophrenia. The first experiment measured linear smooth-pursuit eye movement at six target velocities from 5.

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One of the main limitations in using inverse methods for non-invasively imaging cardiac electrical activity in a clinical setting is the difficulty in readily obtaining high-quality data sets to reconstruct accurately a patient-specific geometric model of the heart and torso. This issue was addressed by investigation into the feasibility of using a pseudo-3D ultrasound system and a hand-held laser scanner to reconstruct such a model. This information was collected in under 20 min prior to a catheter ablation or pacemaker study in the electrophysiology laboratory.

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The eriophyid mite transmitted Wheat streak mosaic virus (WSMV; genus Tritimovirus, family Potyviridae) shares a common genome organization with aphid transmitted species of the genus Potyvirus. Although both tritimoviruses and potyviruses encode helper component-proteinase (HC-Pro) homologues (required for nonpersistent aphid transmission of potyviruses), sequence conservation is low (amino acid identity, approximately 16%), and a role for HC-Pro in semipersistent transmission of WSMV by the wheat curl mite (Aceria tosichella [Keifer]) has not been investigated. Wheat curl mite transmissibility was abolished by replacement of WSMV HC-Pro with homologues of an aphid transmitted potyvirus (Turnip mosaic virus), a rymovirus (Agropyron mosaic virus) vectored by a different eriophyid mite, or a closely related tritimovirus (Oat necrotic mottle virus; ONMV) with no known vector.

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The use of 157 nm as the next lower wavelength for photolithography for the production of semiconductors has created a need for transparent and radiation-durable polymers for use in soft pellicles, the polymer films which protect the chip from particle deposition. The most promising materials for pellicles are fluorinated polymers, but currently available fluorinated polymers undergo photodegradation and/or photodarkening upon long term exposure to 157 nm irradiation. To understand the mechanism of the photodegradation and photodarkening of fluorinated polymers, mechanistic studies on the photolysis of liquid model fluorocarbons, including perfluorobutylethyl ether and perfluoro-2H-3-oxa-heptane, were performed employing UV, NMR, FTIR, GC, and GC/MS analyses.

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Kinetics and voltage dependence of inactivation of a prokaryotic voltage-gated sodium channel (NaChBac) were investigated in an effort to understand its molecular mechanism. NaChBac inactivation kinetics show strong, bell-shaped voltage dependence with characteristic time constants ranging from approximately 50 ms at depolarized voltages to a maximum of approximately 100 s at the inactivation midpoint. Activation and inactivation parameters for four different covalently linked tandem dimer or tandem tetramer constructs were indistinguishable from those of the wild-type channel.

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We have identified a large population of CD3(-)7(+) cells in human fetal gut. Three- and four-color flow cytometry revealed a distinct surface Ag profile on this population; the majority were negative for CD4 and CD8, whereas most of the remainder expressed the CD8alphaalpha homodimer. In contrast about half of CD3(+) cells expressed CD4 and half expressed CD8alpha.

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Voltage-gated ion channels are membrane proteins which underlie rapid electrical signals among neurons and the spread of excitation in skeletal muscle and heart. We outline some recent advances in the study of voltage-sensitive sodium and calcium channels. Investigations are providing insight into the changes in molecular conformation associated with open-closed gating of the channels, the mechanisms by which they allow only specific ion species to pass through and carry an electric current, and the pathological consequences of small perturbations in channel structure which result from genetic mutations.

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To identify genetic determinants of classical swine fever virus (CSFV) virulence and host range, chimeras of the highly pathogenic Brescia strain and the attenuated vaccine strain CS were constructed and evaluated for viral virulence in swine. Upon initial screening, only chimeras 138.8v and 337.

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We examined ion channels derived from a chloroform extract of isolated, dehydrated rat liver mitochondria. The extraction method was previously used to isolate a channel-forming complex containing poly-3-hydroxybutyrate and calcium polyphosphate from Escherichia coli. This complex is also present in eukaryotic membranes, and is located primarily in mitochondria.

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A fluorogenic probe hydrolysis (TaqMan) PCR assay for African swine fever virus (ASFV) was developed and evaluated in experimentally infected swine. This sensitive and specific one-step single-tube assay, which can be performed in 2 h or less, detected viral DNA in tonsil scraping samples 2 to 4 days prior to onset of clinical disease. Thus, the assay would have application for preclinical diagnosis of African swine fever and surveillance and/or emergency management of a disease outbreak.

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Quantitative analysis of spatially resolved valence electron energy-loss spectra shows strong physical property contrasts for Sigma5 and near Sigma13 grain boundaries in Fe-doped SrTiO3, resulting in London dispersion interaction energies of 14 to 50 mJ/m(2) between the adjacent grains. The determination of local physical properties of grain boundary cores and the appreciable contribution of long-range London dispersion to interface energies provides new information on formation and control of interfaces in materials.

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Bilingual memory research in the past decade and, particularly, in the past five years, has developed a range of sophisticated experimental, neuropsychological and computational techniques that have allowed researchers to begin to answer some of the major long-standing questions of the field. We explore bilingual memory along the lines of the conceptual division of language knowledge and organization, on the one hand, and the mechanisms that operate on that knowledge and organization, on the other. Various interactive-activation and connectionist models of bilingual memory that attempt to incorporate both organizational and operational considerations will serve to bridge these two divisions.

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Sodium channels underlie propagated electrical signalling in most excitable cells, including neurons and the myocytes of skeletal muscle and heart. These proteins are targeted by a variety of current therapeutic drugs to combat such maladies as pain, myotonias, epilepsies and cardiac arrhythmias. Typically, these problems are associated with overactivity of sodium channels leading to hyperexcitability in the relevant tissue.

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Information on age- and gender-specific prevalence of herpes simplex virus (HSV) types 1 and 2 infections is crucial to guide genital herpes control strategies. Such data are not available from the newly independent Eastern European countries. We present of study of the age- and gender-specific prevalence of HSV-1 and HSV-2 in low risk populations in Estonia.

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Assignment of mite-transmitted species to the genus Rymovirus (family Potyviridae) has changed several times, and the status of the genus has been questioned. To address this issue, complete genome sequences of the rymoviruses Agropyron mosaic virus (AgMV) and Hordeum mosaic virus (HoMV) were determined. AgMV (9540 nucleotides) and HoMV (9463 nucleotides) each encode a single polyprotein with proteinase cleavage sites demarcating protein products characteristic of monopartite species of the family Potyviridae.

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We have shown that a multicompartment model accurately predicts end-tidal (ET) sevoflurane (sevo) and isoflurane concentrations. The model has been adapted to use real-time fresh gas flow and vaporizer settings to display a 10-min prediction of ET sevo concentrations. In this study, we evaluated the effect of the predictive display on the speed and accuracy of changes in ET sevo by the anesthesiologist.

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Disentangling bottom-up and top-down processing in adult category learning is notoriously difficult. Studying category learning in infancy provides a simple way of exploring category learning while minimizing the contribution of top-down information. Three- to 4-month-old infants presented with cat or dog images will form a perceptual category representation for cat that excludes dogs and for dog that includes cats.

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Many ethical considerations surround living kidney donation, some of which are not anticipated. We present a case in which misattributed paternity was inadvertently discovered during the workup of a father and son and present arguments for and against disclosure of this information. We recommend that transplant programs advise patients participating in living organ donor programs that misattributed paternity might be discovered during routine preoperative testing and that protocols for dealing with complex ethical issues be in place.

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We describe the first application of a Heck arylation reaction being performed on a meta photocycloadduct. The resulting arylation/fragmentation process leads to the formation of a bridged bicyclic ketone and constitutes a dramatic increase in molecular complexity after just two synthetic operations.

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Background: In the 1970s a new approach to the delivery of hormonal contraception was researched and developed. It was suggested that the addition of a progestogen to a non-medicated contraceptive device improved its contraceptive action. An advantage of these hormonally impregnated intrauterine systems (IUS) is that they are relatively maintenance free, with users having to consciously discontinue using them to become pregnant rather than taking a proactive daily decision to avoid conception.

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Lysophosphatidic acid (LPA; 1-acyl-2-hydroxy-sn-glycero-3-phosphate) is a lipid growth factor that stimulates the proliferation of ovarian cancer cells. Recent studies indicate that elevation of cellular cAMP levels inhibits ovarian epithelial cancer cell growth. In this study, we investigated the effects of elevating cellular cAMP levels on LPA stimulation of OVCAR-3 ovarian cancer cell growth and on LPA stimulation of the serum response factor (SRF) transcription factor.

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