2,732 research outputs found

    Novel Schizophrenia Risk Gene TCF4 Influences Verbal Learning and Memory Functioning in Schizophrenia Patients

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    Background: Recently, a role of the transcription factor 4 (TCF4) gene in schizophrenia has been reported in a large genome-wide association study. It has been hypothesized that TCF4 affects normal brain development and TCF4 has been related to different forms of neurodevelopmental disorders. Schizophrenia patients exhibit strong impairments of verbal declarative memory (VDM) functions. Thus, we hypothesized that the disease-associated C allele of the rs9960767 polymorphism of the TCF4 gene led to impaired VDM functioning in schizophrenia patients. Method: The TCF4 variant was genotyped in 401 schizophrenia patients. VDM functioning was measured using the Rey Auditory Verbal Learning Test (RAVLT). Results: Carriers of the C allele were less impaired in recognition compared to those carrying the AA genotype (13.76 vs. 13.06; p = 0.049). Moreover, a trend toward higher scores in patients with the risk allele was found for delayed recall (10.24 vs. 9.41; p = 0.088). The TCF4 genotype did not influence intelligence or RAVLT immediate recall or total verbal learning. Conclusion: VDM function is influenced by the TCF4 gene in schizophrenia patients. However, the elevated risk for schizophrenia is not conferred by TCF4-mediated VDM impairment. Copyright (C) 2011 S. Karger AG, Base

    Efficient Expression of <i style="box-sizing: border-box;">Igf-1</i> from Lentiviral Vectors Protects <i style="box-sizing: border-box;">In Vitro</i> but Does Not Mediate Behavioral Recovery of a Parkinsonian Lesion in Rats

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    Gene therapy approaches delivering neurotrophic factors have offered promising results in both preclinical and clinical trials of Parkinson's disease (PD). However, failure of glial cell line-derived neurotrophic factor in phase 2 clinical trials has sparked a search for other trophic factors that may retain efficacy in the clinic. Direct protein injections of one such factor, insulin-like growth factor (IGF)-1, in a rodent model of PD has demonstrated impressive protection of dopaminergic neurons against 6-hydroxydopamine (6-OHDA) toxicity. However, protein infusion is associated with surgical risks, pump failure, and significant costs. We therefore used lentiviral vectors to deliver Igf-1, with a particular focus on the novel integration-deficient lentiviral vectors (IDLVs). A neuron-specific promoter, from the human synapsin 1 gene, excellent for gene expression from IDLVs, was additionally used to enhance Igf-1 expression. An investigation of neurotrophic effects on primary rat neuronal cultures demonstrated that neurons transduced with IDLV-Igf-1 vectors had complete protection on withdrawal of exogenous trophic support. Striatal transduction of such vectors into 6-OHDA-lesioned rats, however, provided neither protection of dopaminergic substantia nigra neurons nor improvement of animal behavior

    Peri- and Postnatal Effects of Prenatal Adenoviral VEGF Gene Therapy in Growth-Restricted Sheep

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    Uterine artery (UtA) adenovirus vector (Ad)-mediated over-expression of vascular endothelial growth factor (VEGF) enhances uterine blood flow in normal sheep pregnancy and increases fetal growth in the overnourished adolescent sheep model of fetal growth restriction (FGR). Herein we examined its impact on gestation length, neonatal survival, early postnatal growth and metabolism. Singleton-bearing ewes were evenly allocated to receive Ad.VEGF-A165(5 x 10(10)particles/ml, 10 ml, n =17) or Saline (10 ml, n = 16) injected into each UtA at laparotomy (0.6 gestation). Fetal growth was serially monitored (blind) by ultrasound until delivery. Lambs were weighed and blood-sampled weekly and a glucose tolerance test performed (68d postnatal age). Hepatic DNA/RNA was extracted at necropsy (83d postnatal age) to examine methylation status of eight somatotropic axis genes. ITALIC! IGF1mRNA and protein expression were measured by RT-PCR and radioimmunoassay, respectively. All pregnancies remained viable following Ad.VEGF-A165treatment. Fetal abdominal circumference and renal volume were greater in Ad.VEGF-A165versus Saline groups at 21/28 days (p ≤ 0.04) post-injection. At delivery, gestation length (p = 0.07), lamb birthweight (p = 0.08), umbilical girth (p = 0.06) and plasma glucose (p=0.09) tended to be greater in Ad.VEGF-A165treated lambs. Levels of neonatal intervention required to ensure survival was equivalent between groups. Absolute postnatal growth rate (p = 0.02), insulin area-under-the-curve (p = 0.04) and carcass weight at necropsy (p = 0.04) were increased by Ad.VEGF-A165treatment. There was no impact on markers of insulin sensitivity or methylation/expression of key genes involved in somatic growth. Ad.VEGF-A165gene therapy increased fetal growth in a sheep FGR model and lambs continued to thrive during the neonatal and early postnatal period

    Evaluation of the efficacy of Alpron disinfectant for dental unit water lines

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    AIMS: To assess the efficacy of a disinfectant, Alpron, for controlling microbial contamination within dental unit water lines. METHODS: The microbiological quality of water emerging from the triple syringe, high speed handpiece, cup filler and surgery hand wash basin from six dental units was assessed for microbiological total viable counts at 22 degrees C and 37 degrees C before and after treatment with Alpron solutions. RESULTS: The study found that the use of Alpron disinfectant solutions could reduce microbial counts in dental unit water lines to similar levels for drinking water. This effect was maintained in all units for up to six weeks following one course of treatment. In four out of six units the low microbial counts were maintained for 13 weeks. CONCLUSIONS: Disinfectants may have a short term role to play in controlling microbial contamination of dental unit water lines to drinking water quality. However, in the longer term attention must be paid to redesigning dental units to discourage the build up of microbial biofilms

    Estimating the number needed to treat from continuous outcomes in randomised controlled trials: methodological challenges and worked example using data from the UK Back Pain Exercise and Manipulation (BEAM) trial

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    Background Reporting numbers needed to treat (NNT) improves interpretability of trial results. It is unusual that continuous outcomes are converted to numbers of individual responders to treatment (i.e., those who reach a particular threshold of change); and deteriorations prevented are only rarely considered. We consider how numbers needed to treat can be derived from continuous outcomes; illustrated with a worked example showing the methods and challenges. Methods We used data from the UK BEAM trial (n = 1, 334) of physical treatments for back pain; originally reported as showing, at best, small to moderate benefits. Participants were randomised to receive 'best care' in general practice, the comparator treatment, or one of three manual and/or exercise treatments: 'best care' plus manipulation, exercise, or manipulation followed by exercise. We used established consensus thresholds for improvement in Roland-Morris disability questionnaire scores at three and twelve months to derive NNTs for improvements and for benefits (improvements gained+deteriorations prevented). Results At three months, NNT estimates ranged from 5.1 (95% CI 3.4 to 10.7) to 9.0 (5.0 to 45.5) for exercise, 5.0 (3.4 to 9.8) to 5.4 (3.8 to 9.9) for manipulation, and 3.3 (2.5 to 4.9) to 4.8 (3.5 to 7.8) for manipulation followed by exercise. Corresponding between-group mean differences in the Roland-Morris disability questionnaire were 1.6 (0.8 to 2.3), 1.4 (0.6 to 2.1), and 1.9 (1.2 to 2.6) points. Conclusion In contrast to small mean differences originally reported, NNTs were small and could be attractive to clinicians, patients, and purchasers. NNTs can aid the interpretation of results of trials using continuous outcomes. Where possible, these should be reported alongside mean differences. Challenges remain in calculating NNTs for some continuous outcomes

    Are isomeric alkenes used in species recognition among neo-tropical stingless bees (Melipona spp)

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    The majority of our understanding of the role of cuticular hydrocarbons (CHC) in recognition is based largely on temperate ant species and honey bees. The stingless bees remain relatively poorly studied, despite being the largest group of eusocial bees, comprising more than 400 species in some 60 genera. The Meliponini and Apini diverged between 80-130 Myr B.P. so the evolutionary trajectories that shaped the chemical communication systems in ants, honeybees and stingless bees may be very different. Therefore, the main aim of this study was to study if a unique species CHC signal existed in Neotropical stingless bees, as shown for many temperate species, and if so what compounds are involved. This was achieved by collecting CHC data from 24 colonies belonging to six species of Melipona from North-eastern Brazil and comparing this new data with all previously published CHC studies on Melipona. We found that each of the eleven Melipona species studied so far each produced a unique species CHC signal based around their alkene isomer production. A remarkable number of alkene isomers, up to 25 in M. asilvai, indicated the diversification of alkene positional isomers among the stingless bees. The only other group to have really diversified in alkene isomer production are the primitively eusocial Bumblebees (Bombus spp), which are the sister group of the stingless bees. Furthermore, among the eleven Neotropical Melipona species we could detect no effect of the environment on the proportion of alkane production as has been suggested for some other species

    Neuroinflammation and structural injury of the fetal ovine brain following intra-amniotic Candida albicans exposure.

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    BackgroundIntra-amniotic Candida albicans (C. Albicans) infection is associated with preterm birth and high morbidity and mortality rates. Survivors are prone to adverse neurodevelopmental outcomes. The mechanisms leading to these adverse neonatal brain outcomes remain largely unknown. To better understand the mechanisms underlying C. albicans-induced fetal brain injury, we studied immunological responses and structural changes of the fetal brain in a well-established translational ovine model of intra-amniotic C. albicans infection. In addition, we tested whether these potential adverse outcomes of the fetal brain were improved in utero by antifungal treatment with fluconazole.MethodsPregnant ewes received an intra-amniotic injection of 10(7) colony-forming units C. albicans or saline (controls) at 3 or 5 days before preterm delivery at 0.8 of gestation (term ~ 150 days). Fetal intra-amniotic/intra-peritoneal injections of fluconazole or saline (controls) were administered 2 days after C. albicans exposure. Post mortem analyses for fungal burden, peripheral immune activation, neuroinflammation, and white matter/neuronal injury were performed to determine the effects of intra-amniotic C. albicans and fluconazole treatment.ResultsIntra-amniotic exposure to C. albicans caused a severe systemic inflammatory response, illustrated by a robust increase of plasma interleukin-6 concentrations. Cerebrospinal fluid cultures were positive for C. albicans in the majority of the 3-day C. albicans-exposed animals whereas no positive cultures were present in the 5-day C. albicans-exposed and fluconazole-treated animals. Although C. albicans was not detected in the brain parenchyma, a neuroinflammatory response in the hippocampus and white matter was seen which was characterized by increased microglial and astrocyte activation. These neuroinflammatory changes were accompanied by structural white matter injury. Intra-amniotic fluconazole reduced fetal mortality but did not attenuate neuroinflammation and white matter injury.ConclusionsIntra-amniotic C. albicans exposure provoked acute systemic and neuroinflammatory responses with concomitant white matter injury. Fluconazole treatment prevented systemic inflammation without attenuating cerebral inflammation and injury

    Maternal corticotropin-releasing hormone is associated with LEP DNA methylation at birth and in childhood: an epigenome-wide study in Project Viva

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    BackgroundCorticotropin-releasing hormone (CRH) plays a central role in regulating the secretion of cortisol which controls a wide range of biological processes. Fetuses overexposed to cortisol have increased risks of disease in later life. DNA methylation may be the underlying association between prenatal cortisol exposure and health effects. We investigated associations between maternal CRH levels and epigenome-wide DNA methylation of cord blood in offsprings and evaluated whether these associations persisted into mid-childhood.MethodsWe investigated mother-child pairs enrolled in the prospective Project Viva pre-birth cohort. We measured DNA methylation in 257 umbilical cord blood samples using the HumanMethylation450 Bead Chip. We tested associations of maternal CRH concentration with cord blood cells DNA methylation, adjusting the model for maternal age at enrollment, education, maternal race/ethnicity, maternal smoking status, pre-pregnancy body mass index, parity, gestational age at delivery, child sex, and cell-type composition in cord blood. We further examined the persistence of associations between maternal CRH levels and DNA methylation in children's blood cells collected at mid-childhood (n = 239, age: 6.7-10.3 years) additionally adjusting for the children's age at blood drawn.ResultsMaternal CRH levels are associated with DNA methylation variability in cord blood cells at 96 individual CpG sites (False Discovery Rate &lt;0.05). Among the 96 CpG sites, we identified 3 CpGs located near the LEP gene. Regional analyses confirmed the association between maternal CRH and DNA methylation near LEP. Moreover, higher maternal CRH levels were associated with higher blood-cell DNA methylation of the promoter region of LEP in mid-childhood (P &lt; 0.05, β = 0.64, SE = 0.30).ConclusionIn our cohort, maternal CRH was associated with DNA methylation levels in newborns at multiple loci, notably in the LEP gene promoter. The association between maternal CRH and LEP DNA methylation levels persisted into mid-childhood

    Multisensory information facilitates reaction speed by enlarging activity difference between superior colliculus hemispheres in rats

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    Animals can make faster behavioral responses to multisensory stimuli than to unisensory stimuli. The superior colliculus (SC), which receives multiple inputs from different sensory modalities, is considered to be involved in the initiation of motor responses. However, the mechanism by which multisensory information facilitates motor responses is not yet understood. Here, we demonstrate that multisensory information modulates competition among SC neurons to elicit faster responses. We conducted multiunit recordings from the SC of rats performing a two-alternative spatial discrimination task using auditory and/or visual stimuli. We found that a large population of SC neurons showed direction-selective activity before the onset of movement in response to the stimuli irrespective of stimulation modality. Trial-by-trial correlation analysis showed that the premovement activity of many SC neurons increased with faster reaction speed for the contraversive movement, whereas the premovement activity of another population of neurons decreased with faster reaction speed for the ipsiversive movement. When visual and auditory stimuli were presented simultaneously, the premovement activity of a population of neurons for the contraversive movement was enhanced, whereas the premovement activity of another population of neurons for the ipsiversive movement was depressed. Unilateral inactivation of SC using muscimol prolonged reaction times of contraversive movements, but it shortened those of ipsiversive movements. These findings suggest that the difference in activity between the SC hemispheres regulates the reaction speed of motor responses, and multisensory information enlarges the activity difference resulting in faster responses
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