48 research outputs found
A ROLE FOR THE ANTERIOR CINGULATE CORTEX IN REINFORCEMENT-GUIDED LEARNING FOR COVERT ATTENTIONAL SELECTION
The anterior cingulate cortex (ACC) has been associated with a variety of functions including conflict monitoring, error detection and more recently reward based learning. In this study we recorded from the ACC, the ventromedial prefrontal cortex (vmPFC) and the dorsolateral prefrontal cortex (dlPFC) while macaque monkeys performed a variably rewarded spatial attention task. First, we found dynamic encoding of reward outcome and reward expectancy associated with attentional targets within the ACC, mPFC and dlPFC. These results expand the function of the ACC beyond merely action value associations and suggest this area serves a broader role in reinforcement guided learning and decision making. Secondly, analysis of outcome encoding relative to reward reversal revealed two distinct types of neurons: positive/negative prediction error neurons and positive/negative prediction certainty neurons. Prediction error neurons encoded outcome information only when reward associations had recently changed and thus new outcome information was most informative for establishing new reward expectations. Prediction certainty neurons on the other hand signaled the certainty of the reward prediction itself and encoded outcome information only later, when reward expectations had been built up. Prediction error neurons showed a correlation between reward selectivity during outcome periods and reward selectivity preceding subsequent reward predictive events. This finding could serve as a link between prediction error signals and behavioural adjustment. Finally, prediction error neurons predominated in the ventral ACC whereas prediction certainty neurons predominated in dlPFC area 9. Though not definitive this supports proposals that outcome predictions are developed and adjusted within the ACC and mPFC and these predictions are used by the dlPFC to determine the behavioural response
Oral administration of morphine versus ibuprofen to manage postfracture pain in children: A randomized trial
Background: Recent warnings from Health Canada regarding codeine for children have led to increased use of nonsteroidal anti-inflammatory drugs and morphine for common injuries such as fractures. Our objective was to determine whether morphine administered orally has superior efficacy to ibuprofen in fracture-related pain
Pregnancy and neonatal outcomes of COVID-19: The PAN-COVID study
Objective
To assess perinatal outcomes for pregnancies affected by suspected or confirmed SARS-CoV-2 infection.
Methods
Prospective, web-based registry. Pregnant women were invited to participate if they had suspected or confirmed SARS-CoV-2 infection between 1st January 2020 and 31st March 2021 to assess the impact of infection on maternal and perinatal outcomes including miscarriage, stillbirth, fetal growth restriction, pre-term birth and transmission to the infant.
Results
Between April 2020 and March 2021, the study recruited 8239 participants who had suspected or confirmed SARs-CoV-2 infection episodes in pregnancy between January 2020 and March 2021.
Maternal death affected 14/8197 (0.2%) participants, 176/8187 (2.2%) of participants required ventilatory support. Pre-eclampsia affected 389/8189 (4.8%) participants, eclampsia was reported in 40/ 8024 (0.5%) of all participants.
Stillbirth affected 35/8187 (0.4 %) participants. In participants delivering within 2 weeks of delivery 21/2686 (0.8 %) were affected by stillbirth compared with 8/4596 (0.2 %) delivering ≥ 2 weeks after infection (95 % CI 0.3–1.0). SGA affected 744/7696 (9.3 %) of livebirths, FGR affected 360/8175 (4.4 %) of all pregnancies.
Pre-term birth occurred in 922/8066 (11.5%), the majority of these were indicated pre-term births, 220/7987 (2.8%) participants experienced spontaneous pre-term births. Early neonatal deaths affected 11/8050 livebirths. Of all neonates, 80/7993 (1.0%) tested positive for SARS-CoV-2.
Conclusions
Infection was associated with indicated pre-term birth, most commonly for fetal compromise. The overall proportions of women affected by SGA and FGR were not higher than expected, however there was the proportion affected by stillbirth in participants delivering within 2 weeks of infection was significantly higher than those delivering ≥ 2 weeks after infection. We suggest that clinicians’ threshold for delivery should be low if there are concerns with fetal movements or fetal heart rate monitoring in the time around infection
Multi-ancestry genome-wide association meta-analysis of Parkinson?s disease
Although over 90 independent risk variants have been identified for Parkinson’s disease using genome-wide association studies, most studies have been performed in just one population at a time. Here we performed a large-scale multi-ancestry meta-analysis of Parkinson’s disease with 49,049 cases, 18,785 proxy cases and 2,458,063 controls including individuals of European, East Asian, Latin American and African ancestry. In a meta-analysis, we identified 78 independent genome-wide significant loci, including 12 potentially novel loci (MTF2, PIK3CA, ADD1, SYBU, IRS2, USP8, PIGL, FASN, MYLK2, USP25, EP300 and PPP6R2) and fine-mapped 6 putative causal variants at 6 known PD loci. By combining our results with publicly available eQTL data, we identified 25 putative risk genes in these novel loci whose expression is associated with PD risk. This work lays the groundwork for future efforts aimed at identifying PD loci in non-European populations
Effects of Corticotropin-Releasing Factor 1 Receptor Antagonism on the Hypothalamic-Pituitary-Adrenal Axis of Rodents
Mutations in PATCHED-1, the receptor for SONIC HEDGEHOG, are associated with holoprosencephaly
Holoprosencephaly (HPE) is the most commonly occurring congenital structural forebrain anomaly in humans. HPE is associated with mental retardation and craniofacial malformations. The genetic causes of HPE have recently begun to be identified, and we have previously shown that HPE can be caused by haploinsufficiency for SONIC HEDGEHOG ( SHH). We hypothesize that mutations in genes encoding other components of the SHH signaling pathway could also be associated with HPE. PATCHED-1 (PTCH), the receptor for SHH, normally acts to repress SHH signaling. This repression is relieved when SHH binds to PTCH. We analyzed PTCH as a candidate gene for HPE. Four different mutations in PTCHwere detected in five unrelated affected individuals. We predict that by enhancing the repressive activity of PTCH on the SHH pathway, these mutations cause decreased SHH signaling, and HPE results. The mutations could affect the ability of PTCH to bind SHH or perturb the intracellular interactions of PTCH with other proteins involved in SHH signaling. These findings further demonstrate the genetic heterogeneity associated with HPE, as well as showing that mutations in different components of a single signaling pathway can result in the same clinical condition
Chemoradiation versus radiation alone in stage IIIB cervical cancer patients with or without human immunodeficiency virus
ObjectiveCervical cancer remains the most common cancer among women in sub-Saharan Africa and is also a leading cause of cancer related deaths among these women. The benefit of chemoradiation in comparison with radiation alone for patients with stage IIIB disease has not been evaluated prospectively in women living with human immunodeficiency virus (HIV). We assessed the survival of chemoradiation versus radiation alone among stage IIIB cervical cancer patients based on HIV status.MethodsBetween February 2013 and June 2018, patients with International Federation of Gynecology and Obstetrics (FIGO) 2009 stage IIIB cervical cancer with or without HIV and treated with chemoradiation or radiation alone, were prospectively enrolled in an observational cohort study. Overall survival was evaluated using the Kaplan-Meier method. Cox proportional hazards modeling was used to analyze associations with survival.ResultsAmong 187 patients, 63% (n=118) of women had co-infection with HIV, and 48% (n=69) received chemoradiation. Regardless of HIV status, patients who received chemoradiation had improved 2 year overall survival compared with those receiving radiation alone (59% vs 41%, p<0.01), even among women living with HIV (60% vs 38%, p=0.02). On multivariable Cox regression analysis, including all patients regardless of HIV status, 2 year overall survival was associated with receipt of chemoradiation (hazard ratio (HR) 0.63, p=0.04) and total radiation dose ≥80 Gy (HR 0.57, p=0.02). Among patients who received an adequate radiation dose of ≥80 Gy, adjusted overall survival rates were similar between chemoradiation versus radiation alone groups (HR 1.07; p=0.90). However, patients who received an inadequate radiation dose of <80 Gy, adjusted survival was significantly higher in chemoradiation versus radiation alone group (HR 0.45, p=0.01).ConclusionsAddition of chemotherapy to standard radiation improved overall survival, regardless of HIV status, and is even more essential in women who cannot receive full doses of radiation
The Effects of Chronic Treatment with the Mood Stabilizers Valproic Acid and Lithium on Corticotropin-Releasing Factor Neuronal Systems
Marburg Virus VP35 Can Both Fully Coat the Backbone and Cap the Ends of dsRNA for Interferon Antagonism
<div><p>Filoviruses, including Marburg virus (MARV) and Ebola virus (EBOV), cause fatal hemorrhagic fever in humans and non-human primates. All filoviruses encode a unique multi-functional protein termed VP35. The C-terminal double-stranded (ds)RNA-binding domain (RBD) of VP35 has been implicated in interferon antagonism and immune evasion. Crystal structures of the VP35 RBD from two ebolaviruses have previously demonstrated that the viral protein caps the ends of dsRNA. However, it is not yet understood how the expanses of dsRNA backbone, between the ends, are masked from immune surveillance during filovirus infection. Here, we report the crystal structure of MARV VP35 RBD bound to dsRNA. In the crystal structure, molecules of dsRNA stack end-to-end to form a pseudo-continuous oligonucleotide. This oligonucleotide is continuously and completely coated along its sugar-phosphate backbone by the MARV VP35 RBD. Analysis of dsRNA binding by dot-blot and isothermal titration calorimetry reveals that multiple copies of MARV VP35 RBD can indeed bind the dsRNA sugar-phosphate backbone in a cooperative manner in solution. Further, MARV VP35 RBD can also cap the ends of the dsRNA in solution, although this arrangement was not captured in crystals. Together, these studies suggest that MARV VP35 can both coat the backbone and cap the ends, and that for MARV, coating of the dsRNA backbone may be an essential mechanism by which dsRNA is masked from backbone-sensing immune surveillance molecules.</p> </div