Publications by authors named "Menard A"

The structure of the basal ganglia appears to be conserved throughout vertebrate evolution, with characteristic cellular and transmitter components in each area, and the same types of afferent input. As described in rodents and primates, depletion of the striatal dopamine results in characteristic motor deficits. To explore if this role of the basal ganglia in modulating motor function was present early in vertebrate evolution, we investigated here the effects of striatal dopamine depletion in the lamprey, a cyclostome, which diverged from the main vertebrate line around 560 million years ago.

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The spinal circuitry underlying the generation of basic locomotor synergies has been described in substantial detail in lampreys and the cellular mechanisms have been identified. The initiation of locomotion, on the other hand, relies on supraspinal networks and the cellular mechanisms involved are only beginning to be understood. This review examines some of the findings relative to the neural mechanisms involved in the initiation of locomotion of lampreys.

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Background: The Burkholderia cepacia complex (Bcc) groups bacterial species with beneficial properties that can improve crop yields or remediate polluted sites but can also lead to dramatic human clinical outcomes among cystic fibrosis (CF) or immuno-compromised individuals. Genome-wide regulatory processes of gene expression could explain parts of this bacterial duality. Transcriptional sigma70 factors are components of these processes.

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A real-time PCR targeting the gyrase A subunit gene outside the quinolone resistance-determining region has been developed to detect Arcobacter species. The species identification was done by probe hybridization and melting curve analysis, using fluorescence resonance energy transfer technology. Discrimination between Arcobacter species was straightforward, as the corresponding melting points showed significant differences with the characteristic melting temperatures of 63.

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The localization of gamma-aminobutyric acid (GABA) has been well described in most classes of vertebrates but not in adult lampreys. The question if the GABA distribution is similar throughout the vertebrate subphylum is therefore still to be addressed. We here investigate two lamprey species, the sea lamprey, Petromyzon marinus, and the river lamprey, Lampetra fluviatilis, and compare the GABA pattern with that of other vertebrates.

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Burkholderia vietnamiensis is the third most prevalent species of the Burkholderia cepacia complex (Bcc) found in cystic fibrosis (CF) patients. Its ability at fixing nitrogen makes it one of the main Bcc species showing strong filiations with environmental reservoirs. In this study, 83% (29 over 35) of the B.

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The nucleotide sequence of the gyrA gene of Arcobacter butzleri, Arcobacter cryaerophilus, Arcobacter cibarius, and Arcobacter skirrowii was determined. The deduced GyrA proteins are closely related to those of Wolinella succinogenes and Helicobacter pullorum, whereas those of Campylobacter species showed less sequence identity. The phylogenetic analysis of GyrA sequences provides a result similar to 16S rRNA gene sequence phylogenetic analysis and allows the discrimination among A.

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This study describes a real-time PCR assay for the detection and identification of Bordetella pertussis and Bordetella parapertussis. The assay is based on amplification of a fragment from the repeat sequence regions IS481 and IS1001 found in B. pertussis and B.

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Helicobacter pylori is unique because of the unusually high number and diversity of its restriction modification (R-M) systems. HpyC1I R-M was recently characterized and contains an endonuclease which is an isoschizomer of the endonuclease BccI. This R-M is involved in adherence to gastric epithelial cells, a crucial step in bacterial pathogenesis.

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The intrinsic function of the brain stem-spinal cord networks eliciting the locomotor synergy is well described in the lamprey-a vertebrate model system. This study addresses the role of tectum in integrating eye, body orientation, and locomotor movements as in steering and goal-directed behavior. Electrical stimuli were applied to different areas within the optic tectum in head-restrained semi-intact lampreys (n = 40).

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The mesencephalic locomotor region (MLR) plays a significant role in the control of locomotion in all vertebrate species investigated. Forebrain neurons are likely to modulate MLR activity, but little is known about their inputs. Descending GABAergic projections to the MLR were identified by double-labeling neurons using Neurobiotin injected into the MLR combined with immunofluorescence against GABA.

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The aim of the study was to investigate the relationship between gastritis and leptin and ghrelin in elderly patients. Patients older than 75 years undergoing an endoscopy were included. We reported data on nutritional status and Helicobacter pylori infection diagnosis (serology, 13C-urea breath test, culture, histology, and polymerase chain reaction on gastric biopsies).

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Aim: To determine the presence of Helicobacter species DNA in the liver of chronic hepatitis C (CHC) patients with and without cirrhosis as compared to controls, and to identify the bacterial species involved.

Methods: Seventy-nine consecutive patients (HBV and HIV negative) with a liver sample obtained after liver biopsy or hepatic resection were studied: 41 with CHC without cirrhosis, 12 with CHC and cirrhosis, and 26 controls (HCV negative). Polymerase chain reactions (PCRs) targeting Helicobacter 16S rDNA and species-specific were performed on DNA extracted from the liver.

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Blood pressure (BP) is largely determined by quantitative trait loci (QTLs) in Dahl salt-sensitive (DSS) rats. Little is known about QTLs controlling kidney (K), cardiac (C), and aortic (A) mass (i.e.

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We studied three possible genotypes at 10 well-defined blood pressure (BP) QTLs using congenic rat lines. The central question was whether the hypertensive or normotensive allele is dominant, or whether there is partial dominance. The congenic strains were employed to investigate the BP effects of alleles originating from normotensive rats in the background of hypertensive Dahl salt-sensitive (DSS) rats.

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The study of protein interactions constitutes an important domain to understand the physiology and pathogenesis of microorganisms. The two-dimensional blue native/SDS-PAGE was initially reported to analyze membrane protein complexes. In this study, both cytoplasmic and membrane complexes of a bacterium, the strain J99 of the gastric pathogen Helicobacter pylori, were analyzed by this method.

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The optic tectum in the lamprey midbrain, homologue of the superior colliculus in mammals, is important for eye movement control and orienting responses. There is, however, only limited information regarding the afferent input to the optic tectum except for that from the eyes. The objective of this study was to define specifically the gamma-aminobutyric acid (GABA)-ergic projections to the optic tectum in the river lamprey (Lampetra fluviatilis) and also to describe the tectal afferent input in general.

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Article Synopsis
  • Xanthine-guanine phosphoribosyltransferase (XGPRTase) in Helicobacter pylori is essential for the bacterium's survival, and its structure was analyzed to compare it with similar enzymes.
  • Researchers measured the enzyme's activity in H. pylori and in a lab-produced version, using bioinformatics to understand its evolutionary relationships and to model its structure.
  • The study confirmed that H. pylori's XGPRTase is functional and distinct from mammalian variants, identifying unique features and differences in how it interacts with inhibitors compared to human enzymes.
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Peptic ulcer disease (PUD) occurs after a long-term Helicobacter pylori infection. However, the disease can develop earlier, and rare cases have been observed in children, suggesting that these H. pylori strains may be more virulent.

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Molecular methods applied to 2,855 strains of Campylobacter-like organisms received from a surveillance network of Campylobacter infections in France identified 29 Arcobacter butzleri infections. This species ranks fourth for Campylobacteraceae isolation and appears to have the same pathogenic potential as the other species in the genus.

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Quantitative trait loci (QTLs) for blood pressure (BP) were found on chromosome 10 of Dahl salt-sensitive rats and are potentially important to human essential hypertension. But their identities and how they influence BP together were not known. Presently, we first fine mapped existing QTLs, C10QTL1, C10QTL2, and C10QTL3, by constructing congenic strains.

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Essential hypertension is a complex trait influenced by multiple genes known as quantitative trait loci (QTLs) for blood pressure (BP). It is not clear, however, what roles these QTLs play in maintaining normotension. Insights gained toward the maintenance of normotension will shed light on how hypertension can result from a deficiency or malfunctioning of this maintenance.

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Purpose: Several randomized trials have found that discharge planning improves outcomes for hospitalized patients. We do not know if adding a clinical nurse specialist (CNS) to physician teams in hospitals that already have discharge planning services makes a difference.

Methods: In 2 teaching hospitals, patients were randomly assigned to regular hospital care or care with a clinical nurse specialist.

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