131 research outputs found
Acting without being in control: Exploring volition in Parkinson's disease with impulsive compulsive behaviours.
BACKGROUND: Several aspects of volitional control of action may be relevant in the pathophysiology of impulsive-compulsive behaviours (ICB) in Parkinson's disease (PD). We aimed to explore multiple aspects of action control, assessing reward-related behaviour, inhibition (externally and internally triggered) and sense of agency in PD patients, with and without ICB compared to healthy subjects. METHODS: Nineteen PD patients with ICB (PD-ICB), 19 PD without ICB (PD-no-ICB) and 19 healthy controls (HC) underwent a battery of tests including: Intentional Binding task which measures sense of agency; Stop Signal Reaction Time (SSRT) measuring capacity for reactive inhibition; the Marble task, assessing intentional inhibition; Balloon Analog Risk Task for reward sensitivity. RESULTS: One-way ANOVA showed significant main effect of group for action binding (p = 0.004, F = 6.27). Post hoc analysis revealed that PD-ICB had significantly stronger action binding than HC (p = 0.004), and PD-no-ICB (p = 0.04). There was no difference between PD-no-ICB and HC. SSRT did not differ between PD groups, whereas a significant difference between PD-no-ICB and HC was detected (p = 0.01). No other differences were found among groups in the other tasks. CONCLUSIONS: PD patients with ICB have abnormal performance on a psychophysical task assessing sense of agency, which might be related to a deficit in action representation at cognitive/experiential level. Yet, they have no deficit on tasks evaluating externally and internally triggered inhibitory control, or in reward-based decision-making. We conclude that impaired sense of agency may be a factor contributing to ICB in PD patients
Commentary: Anderson-Fabry Disease: A Rare Cause of Levodopa-Responsive Early Onset Parkinsonism
This case had young onset parkinsonism beginning at age 45 mainly affecting the right side with foot dystonia and limb pain as an early and prominent feature.1 There was a family history of renal disease in one sister, stroke like episodes and dementia in another sister, and ischemic cardiac disease in the father. Single-photon emission computed tomography of the dopamine transporter showed bilateral reduced uptake and there was a good levodopa response and later development non-motor fluctuations. Although a number of parkinsonian conditions particularly genetic forms of young onset parkinsonism are in the differential, the patient also showed signs of renal (microalbuminuria) and cardiac (left ventricular hypertrophy) dysfunction which further narrowed the differential to conditions such as mitochondrial disease and neuronal inclusion body disease (though brain MRI did not show characteristic white matter changes). Given the severity of pain and renal involvement, Anderson-Fabry was considered as the most likely diagnosis. This x-linked lysosomal storage disease is caused by absent or minimal enzymatic activity of α-galactosidase and usually affects males in whom its fully penetrant but has been described rarely also to affect women.2 It is important to recognize this condition given the availability of treatment with enzyme replacement therapy (agalsidase alfa). The list of genetic parkinsonian conditions is increasing.2 Involvement of non-neurologic organ systems in patient or family members may offer clues to diagnosis. Anderson-Fabry disease specifically must be kept in mind in anyone with young onset parkinsoni
Lower Prevalence of Chronic Pain in Manifest Huntington’s Disease: A Pilot Observational Study
Pain is a minor problem compared with other Huntington Disease (HD) symptoms. Nevertheless, in HD it is poorly recognized and underestimated. So far, no study evaluated the presence of chronic pain in HD. The aim of this pilot study was to evaluate the presence and features of chronic pain in a cohort of HD gene carriers. An observational cross-sectional study was conducted in a cohort of HD gene carriers compared to not gene carriers (n.134 HD subjects, n.74 not gene mutation carriers). A specific pain interview, alongside a neurological, cognitive and behavioural examination, was performed in order to classify the type of pain, subjective intensity. A significant prevalence of “no Pain” in HD was found, which tended to increase with HD progression and a reduced frequency of pain in the last 3 months. A clear difference was found between manifest and premanifest HD in terms of intensity of pain, which did not change significantly with HD progression; however, a tendency emerges to a progressive reduction. No significant group difference was present in analgesic use, type and the site of pain. These findings could support a lower prevalence of chronic pain in manifest HD. Prevalence and intensity of chronic pain seem directly influenced by the process of neurodegeneration rather than by an incorrect cognitive and emotional functioning.</jats:p
Design, data management, and population baseline characteristics of the PERFORM magnetic resonance imaging project
Quantitative information from magnetic resonance imaging (MRI) may substantiate clinical findings and provide additional insight into the mechanism of clinical interventions in therapeutic stroke trials. The PERFORM study is exploring the efficacy of terutroban versus aspirin for secondary prevention in patients with a history of ischemic stroke. We report on the design of an exploratory longitudinal MRI follow-up study that was performed in a subgroup of the PERFORM trial. An international multi-centre longitudinal follow-up MRI study was designed for different MR systems employing safety and efficacy readouts: new T2 lesions, new DWI lesions, whole brain volume change, hippocampal volume change, changes in tissue microstructure as depicted by mean diffusivity and fractional anisotropy, vessel patency on MR angiography, and the presence of and development of new microbleeds. A total of 1,056 patients (men and women ≥55 years) were included. The data analysis included 3D reformation, image registration of different contrasts, tissue segmentation, and automated lesion detection. This large international multi-centre study demonstrates how new MRI readouts can be used to provide key information on the evolution of cerebral tissue lesions and within the macrovasculature after atherothrombotic stroke in a large sample of patients
Slow Roll Reconstruction: Constraints on Inflation from the 3 Year WMAP Dataset
We study the constraints on the inflationary parameter space derived from the
3 year WMAP dataset using ``slow roll reconstruction'', using the SDSS galaxy
power spectrum to gain further leverage where appropriate. This approach
inserts the inflationary slow roll parameters directly into a Monte Carlo
Markov chain estimate of the cosmological parameters, and uses the inflationary
flow hierarchy to compute the parameters' scale-dependence. We work with the
first three parameters (epsilon, eta and xi) and pay close attention to the
possibility that the 3 year WMAP dataset contains evidence for a ``running''
spectral index, which is dominated by the xi term. Mirroring the WMAP team's
analysis we find that the permitted distribution of xi is broad, and centered
away from zero. However, when we require that inflationary parameters yield at
least 30 additional e-folds of inflation after the largest observable scales
leave the horizon, the bounds on xi tighten dramatically. We make use of the
absence of an explicit pivot scale in the slow roll reconstruction formalism to
determine the dependence of the computed parameter distributions on the pivot.
We show that the choice of pivot has a significant effect on the inferred
constraints on the inflationary variables, and the spectral index and running
derived from them. Finally, we argue that the next round of cosmological data
can be expected to place very stringent constraints on the region of parameter
space open to single field models of slow roll inflation.Comment: 26 pages, 11 figures, JHEP format. v2: version accepted by JCAP:
minor clarifications and references added, 1 figure added, v3: 1 reference
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Molecular analysis of the vaginal response to estrogens in the ovariectomized rat and postmenopausal woman
<p>Abstract</p> <p>Background</p> <p>Vaginal atrophy (VA) is the thinning of the vaginal epithelial lining, typically the result of lowered estrogen levels during menopause. Some of the consequences of VA include increased susceptibility to bacterial infection, pain during sexual intercourse, and vaginal burning or itching. Although estrogen treatment is highly effective, alternative therapies are also desired for women who are not candidates for post-menopausal hormone therapy (HT). The ovariectomized (OVX) rat is widely accepted as an appropriate animal model for many estrogen-dependent responses in humans; however, since reproductive biology can vary significantly between mammalian systems, this study examined how well the OVX rat recapitulates human biology.</p> <p>Methods</p> <p>We analyzed 19 vaginal biopsies from human subjects pre and post 3-month 17β-estradiol treated by expression profiling. Data were compared to transcriptional profiling generated from vaginal samples obtained from ovariectomized rats treated with 17β-estradiol for 6 hrs, 3 days or 5 days. The level of differential expression between pre- vs. post- estrogen treatment was calculated for each of the human and OVX rat datasets. Probe sets corresponding to orthologous rat and human genes were mapped to each other using NCBI Homologene.</p> <p>Results</p> <p>A positive correlation was observed between the rat and human responses to estrogen. Genes belonging to several biological pathways and GO categories were similarly differentially expressed in rat and human. A large number of the coordinately regulated biological processes are already known to be involved in human VA, such as inflammation, epithelial development, and EGF pathway activation.</p> <p>Conclusion</p> <p>At the transcriptional level, there is evidence of significant overlap of the effects of estrogen treatment between the OVX rat and human VA samples.</p
Large Non-Gaussianities in Single Field Inflation
We compute the 3-point correlation function for a general model of inflation
driven by a single, minimally coupled scalar field. Our approach is based on
the numerical evaluation of both the perturbation equations and the integrals
which contribute to the 3-point function. Consequently, we can analyze models
where the potential has a "feature", in the vicinity of which the slow roll
parameters may take on large, transient values. This introduces both scale and
shape dependent non-Gaussianities into the primordial perturbations. As an
example of our methodology, we examine the ``step'' potentials which have been
invoked to improve the fit to the glitch in the for ,
present in both the one and three year WMAP data sets. We show that for the
typical parameter values, the non-Gaussianities associated with the step are
far larger than those in standard slow roll inflation, and may even be within
reach of a next generation CMB experiment such as Planck. More generally, we
use this example to explain that while adding features to potential can improve
the fit to the 2-point function, these are generically associated with a
greatly enhanced signal at the 3-point level. Moreover, this 3-point signal
will have a very nontrivial shape and scale dependence, which is correlated
with the form of the 2-point function, and may thus lead to a consistency check
on the models of inflation with non-smooth potentials.Comment: 23 pages JHEP-style, 7 Figures. Updated with improved results.
Accepted for publication by JCA
New Synthetic Thrombin Inhibitors: Molecular Design and Experimental Verification
BACKGROUND: The development of new anticoagulants is an important goal for the improvement of thromboses treatments. OBJECTIVES: The design, synthesis and experimental testing of new safe and effective small molecule direct thrombin inhibitors for intravenous administration. METHODS: Computer-aided molecular design of new thrombin inhibitors was performed using our original docking program SOL, which is based on the genetic algorithm of global energy minimization in the framework of a Merck Molecular Force Field. This program takes into account the effects of solvent. The designed molecules with the best scoring functions (calculated binding energies) were synthesized and their thrombin inhibitory activity evaluated experimentally in vitro using a chromogenic substrate in a buffer system and using a thrombin generation test in isolated plasma and in vivo using the newly developed model of hemodilution-induced hypercoagulation in rats. The acute toxicities of the most promising new thrombin inhibitors were evaluated in mice, and their stabilities in aqueous solutions were measured. RESULTS: New compounds that are both effective direct thrombin inhibitors (the best K(I) was <1 nM) and strong anticoagulants in plasma (an IC(50) in the thrombin generation assay of approximately 100 nM) were discovered. These compounds contain one of the following new residues as the basic fragment: isothiuronium, 4-aminopyridinium, or 2-aminothiazolinium. LD(50) values for the best new inhibitors ranged from 166.7 to >1111.1 mg/kg. A plasma-substituting solution supplemented with one of the new inhibitors prevented hypercoagulation in the rat model of hemodilution-induced hypercoagulation. Activities of the best new inhibitors in physiological saline (1 µM solutions) were stable after sterilization by autoclaving, and the inhibitors remained stable at long-term storage over more than 1.5 years at room temperature and at 4°C. CONCLUSIONS: The high efficacy, stability and low acute toxicity reveal that the inhibitors that were developed may be promising for potential medical applications
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Levodopa–carbidopa intrajejunal infusion in Parkinson’s disease: untangling the role of age
Objectives
Levodopa–Carbidopa Intrajejunal gel (LCIG) infusion is an effective intervention for people with advanced Parkinson’s disease (PD). Although age may not be a limiting factor for LCIG implant, no data are available on late elderly PD (LE-PD) subjects. In this cross-sectional, we aimed to demonstrate if older age may impact on quality of life (QoL), motor and non-motor symptoms severity, and profile of side effects in PD treated with LCIG.
Methods
Out of 512 PD subjects treated with LCIG at 9 Italian PD centers, we selected 25 LE-PD defined as age ≥ 80 years at last follow-up who were available to attend the study visit. Twenty-five PD patients (Control-PD, defined as age < 75 years at last follow-up) matched to LE-PD by disease and LCIG duration served as control group. The following motor and non-motor variables were ascertained: quality of life (PDQ-8), time spent in ON, wearing-off Questionnaire, Unified PD Rating Scale, freezing of gait questionnaire, Parkinson’s disease sleep scale-2, Non Motor Symptoms Scale (NMSS), and MOCA.
Results
No statistically significant differences were found between LE-PD and Control-PD on PDQ-8 and several motor and non-motor variables. LE-PD had less frequent and milder impulsive–compulsive behaviors and milder dyskinesia. At multivariable regression, worse quality of life was associated with UPDRS-III and NMSS scores but not to age at study visit and age at LICG implant. Rate of adverse effects was similar in both groups. Drop-out rate calculated in the whole PD cohort was comparable between the two groups.
Conclusion
Our data provide evidence that valuable LCIG infusion might be achieved in late elderly PD
Swimming physiology of European silver eels (Anguilla anguilla L.): energetic costs and effects on sexual maturation and reproduction
The European eel migrates 5,000–6,000 km to the Sargasso Sea to reproduce. Because they venture into the ocean in a pre-pubertal state and reproduce after swimming for months, a strong interaction between swimming and sexual maturation is expected. Many swimming trials have been performed in 22 swim tunnels to elucidate their performance and the impact on maturation. European eels are able to swim long distances at a cost of 10–12 mg fat/km which is 4–6 times more efficient than salmonids. The total energy costs of reproduction correspond to 67% of the fat stores. During long distance swimming, the body composition stays the same showing that energy consumption calculations cannot be based on fat alone but need to be compensated for protein oxidation. The optimal swimming speed is 0.61–0.67 m s−1, which is ~60% higher than the generally assumed cruise speed of 0.4 m s−1 and implies that female eels may reach the Sargasso Sea within 3.5 months instead of the assumed 6 months. Swimming trials showed lipid deposition and oocyte growth, which are the first steps of sexual maturation. To investigate effects of oceanic migration on maturation, we simulated group-wise migration in a large swim-gutter with seawater. These trials showed suppressed gonadotropin expression and vitellogenesis in females, while in contrast continued sexual maturation was observed in silver males. The induction of lipid deposition in the oocytes and the inhibition of vitellogenesis by swimming in females suggest a natural sequence of events quite different from artificial maturation protocols
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