36 research outputs found
The impact of induced anxiety on affective response inhibition
Studying the effects of experimentally induced anxiety in healthy volunteers may increase our understanding of the mechanisms underpinning anxiety disorders. Experimentally induced stress (via threat of unpredictable shock) improves accuracy at withholding a response on the sustained attention to response task (SART), and in separate studies improves accuracy to classify fearful faces, creating an affective bias. Integrating these findings, participants at two public science engagement events (n = 46, n = 55) were recruited to explore the effects of experimentally induced stress on an affective version of the SART. We hypothesized that we would see an improved accuracy at withholding a response to affectively congruent stimuli (i.e. increased accuracy at withholding a response to fearful 'no-go' distractors) under threat of shock. Induced anxiety slowed reaction time, and at the second event quicker responses were made to fearful stimuli. However, we did not observe improved inhibition overall during induced anxiety, and there was no evidence to suggest an interaction between induced anxiety and stimulus valence on response accuracy. Indeed Bayesian analysis provided decisive evidence against this hypothesis. We suggest that the presence of emotional stimuli might make the safe condition more anxiogenic, reducing the differential between conditions and knocking out any threat-potentiated improvement
Improved Survival of HIV-1-Infected Patients with Progressive Multifocal Leukoencephalopathy Receiving Early 5-Drug Combination Antiretroviral Therapy
Progressive multifocal leukoencephalopathy (PML), a rare devastating demyelinating disease caused by the polyomavirus JC (JCV), occurs in severely immunocompromised patients, most of whom have advanced-stage HIV infection. Despite combination antiretroviral therapy (cART), 50% of patients die within 6 months of PML onset. We conducted a multicenter, open-label pilot trial evaluating the survival benefit of a five-drug cART designed to accelerate HIV replication decay and JCV-specific immune recovery.All the patients received an optimized cART with three or more drugs for 12 months, plus the fusion inhibitor enfuvirtide during the first 6 months. The main endpoint was the one-year survival rate. A total of 28 patients were enrolled. At entry, median CD4+ T-cell count was 53 per microliter and 86% of patients had detectable plasma HIV RNA and CSF JCV DNA levels. Seven patients died, all before month 4. The one-year survival estimate was 0.75 (95% confidence interval, 0.61 to 0.93). At month 6, JCV DNA was undetectable in the CSF of 81% of survivors. At month 12, 81% of patients had undetectable plasma HIV RNA, and the median CD4+ T-cell increment was 105 per microliter. In univariate analysis, higher total and naive CD4+ T-cell counts and lower CSF JCV DNA level at baseline were associated with better survival. JCV-specific functional memory CD4+ T-cell responses, based on a proliferation assay, were detected in 4% of patients at baseline and 43% at M12 (P = 0.008).The early use of five-drug cART after PML diagnosis appears to improve survival. This is associated with recovery of anti-JCV T-cell responses and JCV clearance from CSF. A low CD4+ T-cell count (particularly naive subset) and high JCV DNA copies in CSF at PML diagnosis appear to be risk factors for death.ClinicalTrials.gov NCT00120367
Expansion of CD4+CD25+ and CD25- T-Bet, GATA-3, Foxp3 and RORÎłt Cells in Allergic Inflammation, Local Lung Distribution and Chemokine Gene Expression
Allergic asthma is associated with airway eosinophilia, which is regulated by
different T-effector cells. T cells express transcription factors T-bet, GATA-3,
RORÎłt and Foxp3, representing Th1, Th2, Th17 and Treg cells respectively. No
study has directly determined the relative presence of each of these T cell
subsets concomitantly in a model of allergic airway inflammation. In this study
we determined the degree of expansion of these T cell subsets, in the lungs of
allergen challenged mice. Cell proliferation was determined by incorporation of
5-bromo-2′-deoxyuridine (BrdU) together with 7-aminoactnomycin (7-AAD).
The immunohistochemical localisation of T cells in the lung microenvironments
was also quantified. Local expression of cytokines, chemokines and receptor
genes was measured using real-time RT-PCR array analysis in tissue sections
isolated by laser microdissection and pressure catapulting technology. Allergen
exposure increased the numbers of T-bet+,
GATA-3+, RORÎłt+ and
Foxp3+ cells in CD4+CD25+
and CD4+CD25- T cells, with the greatest expansion of
GATA-3+ cells. The majority of
CD4+CD25+ T-bet+,
GATA-3+, RORÎłt+ and
Foxp3+ cells had incorporated BrdU and underwent
proliferation during allergen exposure. Allergen exposure led to the
accumulation of T-bet+, GATA-3+ and
Foxp3+ cells in peribronchial and alveolar tissue,
GATA-3+ and Foxp3+ cells in perivascular
tissue, and RORÎłt+ cells in alveolar tissue. A total of 28
cytokines, chemokines and receptor genes were altered more than 3 fold upon
allergen exposure, with expression of half of the genes claimed in all three
microenvironments. Our study shows that allergen exposure affects all T effector
cells in lung, with a dominant of Th2 cells, but with different local cell
distribution, probably due to a distinguished local inflammatory milieu
Magnetic excitations of a Heisenberg spin glass : evidence for a gap in high magnetic fields
Measurements of the specific heat C(T) of a spin glass Eu 0.44Sr0.56S single crystal have been performed between 0.7 and 10 K, and with applied magnetic fields (H = 0, 4, 6 and 7 T). The application of a large magnetic field strongly modifies the C( T) behaviour, with a large decrease at low temperatures : the quasilinear variation observed in zero field is replaced by an exponential variation characteristic of the opening of a gap in the excitation spectrum. These results, together with those of magneto-thermal resistivity obtained previously, can be described with the assumption of two kinds of magnetic excitations : (i) very low energy collective excitations and (ii) single spin excitations of Eu2+ ions in the external magnetic field augmented by some internal field of 3.2 T, the origin of which is discussed.Nous avons effectué des mesures de chaleur spécifique C(T) sur un monocristal de verre de spin isolant Eu0,44Sr0,56 S entre 0,7 et 10 K, et sous champ magnétique (H = 0, 4, 6 et 7 T). L'application d'un champ magnétique fort modifie profondément le comportement de C(T), avec une très forte diminution à basse température : la variation quasi linéaire observée en champ nul est remplacée par une variation exponentielle caractéristique de l'apparition d'une bande interdite dans le spectre des excitations. Ces résultats, ainsi que ceux de magnétorésistance thermique obtenus antérieurement, peuvent être décrits en supposant l'existence de deux types d'excitations magnétiques : (i) des excitations collectives de très basse énergie et (ii) des excitations à un spin d'ions Eu2+ soumis au champ magnétique extérieur augmenté d'un champ interne égal à 3,2 T dont nous discutons l'origine
The impact of induced anxiety on affective response inhibition
Studying the effects of experimentally induced anxiety in healthy volunteers may increase our understanding of the mechanisms underpinning anxiety disorders. Experimentally induced stress (via threat of unpredictable shock) improves accuracy at withholding a response on the sustained attention to response task (SART), and in separate studies improves accuracy to classify fearful faces, creating an affective bias. Integrating these findings, participants at two public science engagement events (n = 46, n = 55) were recruited to explore the effects of experimentally induced stress on an affective version of the SART. We hypothesized that we would see an improved accuracy at withholding a response to affectively congruent stimuli (i.e. increased accuracy at withholding a response to fearful 'no-go' distractors) under threat of shock. Induced anxiety slowed reaction time, and at the second event quicker responses were made to fearful stimuli. However, we did not observe improved inhibition overall during induced anxiety, and there was no evidence to suggest an interaction between induced anxiety and stimulus valence on response accuracy. Indeed Bayesian analysis provided decisive evidence against this hypothesis. We suggest that the presence of emotional stimuli might make the safe condition more anxiogenic, reducing the differential between conditions and knocking out any threat-potentiated improvement
Childbirth is not an Emergency: Informed Consent in Labor and Delivery
Most agree that informed consent must be obtained for medical procedures. Yet, empirical studies and anecdotal accounts show that women\u27s right to informed consent and to refusal of treatment are routinely undermined or ignored during childbirth. The primary reasons currently accepted for exempting a procedure from the informed consent requirement are life-threatening or emergency circumstances and protecting the life of a minor or incompetent person. We will show that these do not apply in low-risk childbirth, and, thus, that obtaining informed consent throughout the normal course of labor and delivery is morally required