415 research outputs found
The CAG repeat at the Huntington disease gene in the Portuguese population : insights into its dynamics and to the origin of the mutation
Huntington disease (HD) is caused by an
expansion of a CAG repeat. This repeat is a dynamic
mutation that tends to undergo intergenerational instability.
We report the analysis of the CAG repeat in a large
population sample (2,000 chromosomes) covering all regions
of Portugal, and a haplotype study of (CAG)n and
(CCG)n repeats in 140 HD Portuguese families. Intermediate
class 2 alleles represented 3.0% of the population;
and two expanded alleles (36 and 40 repeats, 0.11%) were
found. There was no evidence for geographical clustering
of the intermediate or expanded alleles. The Portuguese
families showed three different HD founder haplotypes
associated with 7-, 9- or 10-CCG repeats, suggesting the
possibility of different origins for theHDmutation among
this population. The haplotype carrying the 7-CCG repeat
was the most frequent, both in normal and in expanded
alleles. In general, we propose that three mechanisms,
occurring at different times,may lead to the evolution from
normal CAGs to full expansion: first, a mutation bias towards
larger alleles; then, a stepwise process that could
explain the CAGdistributions observed in themore recent
haplotypes; and, finally, a pool of intermediate (class 2)
alleles more prone to give rise to expanded HD alleles.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BD/9759/
2003.Instituto de Genética Médica Jacinto Magalhães
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Candidate glutamatergic and dopaminergic pathway gene variants do not influence Huntington’s disease motor onset
Huntington’s disease (HD) is a neurodegenerative disorder characterized by motor, cognitive, and behavioral disturbances. It is caused by the expansion of the HTT CAG repeat, which is the major determinant of age at onset (AO) of motor symptoms. Aberrant function of N-methyl-D-aspartate receptors and/or overexposure to dopamine has been suggested to cause significant neurotoxicity, contributing to HD pathogenesis. We used genetic association analysis in 1,628 HD patients to evaluate candidate polymorphisms in N-methyl-D-aspartate receptor subtype genes (GRIN2A rs4998386 and rs2650427, and GRIN2B rs1806201) and functional polymorphisms in genes in the dopamine pathway (DAT1 3′ UTR 40-bp variable number tandem repeat (VNTR), DRD4 exon 3 48-bp VNTR, DRD2 rs1800497, and COMT rs4608) as potential modifiers of the disease process. None of the seven polymorphisms tested was found to be associated with significant modification of motor AO, either in a dominant or additive model, after adjusting for ancestry. The results of this candidate-genetic study therefore do not provide strong evidence to support a modulatory role for these variations within glutamatergic and dopaminergic genes in the AO of HD motor manifestations
Verification of the Vitek Reveal System for Direct Antimicrobial Susceptibility Testing in Gram-Negative Positive Blood Cultures
Background/Objectives: The International Organization for Standardization (ISO) 20776-2:2021, which replaces ISO 20776-2:2007, focuses solely on the performance of antimicrobial susceptibility testing (AST) assays, emphasizing the ISO 20776-1 broth microdilution method as the reference standard. Consequently, categorical agreement (CA) and associated errors should not be applied. We verified the Vitek Reveal AST assay according to both ISO 20776-2:2021 and ISO 20776-2:2007 criteria. Methods: Samples from 100 simulated and clinical Gram-negative (GN) positive blood cultures (PBCs) were tested at a large teaching hospital. The simulated GN-PBCs were obtained from a hospital collection of isolates selected to represent diverse antimicrobial resistance profiles. The Reveal assay results were compared with those from the reference assay, and the time to result (TTR) for the Reveal assay was calculated. Results: The essential agreement rates were 96.1% (816/849) for simulated and 98.8% (929/940) for clinical GN-PBC samples. The bias values were −3.1 for simulated and −11.0 for clinical samples. The CA rates were 97.7% (808/827) for simulated and 99.2% (924/931) for clinical samples. The mean TTR ± SD (hours) for resistant organisms was significantly lower (4.40 ± 1.15) than that for susceptible, increased exposure (5.52 ± 0.48) and susceptible (5.54 ± 0.49) organisms. Conclusions: Our findings reinforce the potential of the Reveal assay as a valuable tool and support its implementation in clinical microbiology laboratories
Efficacy and Safety of the Association of Nimodipine and Choline Alphoscerate in the Treatment of Cognitive Impairment in Patients with Cerebral Small Vessel Disease : The CONIVaD Trial
Background: No approved treatment is available for patients with vascular cognitive impairment (VCI) due to cerebral small vessel disease (SVD). Objective: The CONIVaD (Choline Alphoscerate and Nimodipine in Vascular Dementia) study aimed to investigate the feasibility, efficacy, and safety of a combined treatment with choline alphoscerate and nimodipine in patients with SVD and mild-to-moderate cognitive impairment. Methods: Within this pilot, single-center (university hospital), double-blinded, randomized clinical trial, patients were randomized to two arms: 1-year treatment with nimodipine 30 mg three times a day (TID) plus choline alphoscerate 600 mg twice a day (BID) (arm 1) or nimodipine 30 mg TID plus placebo BID (arm 2). Patients underwent an evaluation at baseline and after 12 months. Cognitive decline, defined as a ≥ 2-point loss on the Montreal Cognitive Assessment, was the primary endpoint. Functional, quality of life, other cognitive measures, and safety were secondary endpoints. Treatment adherence was measured by the count of medicine bottles returned by patients. Results: Sixty-two patients were randomized (31 each arm). Fourteen patients (22%) dropped out for reasons including consent withdrawal (n = 9), adverse reactions (n = 4), and stroke (n = 1). Forty-eight patients (mean ± SD age 75.1 ± 6.8 years), well balanced between arms, completed the study. Regarding adherence, of the prescribed total drug dose, > 75% was taken by 96% of patients for choline alphoscerate, 87.5% for placebo, and 15% for nimodipine. No statistically significant differences were found between the treatment groups for the primary cognitive outcome, nor for the secondary outcomes. Eight patients had non-serious adverse reactions; five presented adverse events. Conclusion: Patients’ adherence to treatment was low. With this limitation, the combined choline alphoscerate–nimodipine treatment showed no significant effect in our cohort of VCI patients with SVD. The safety profile was good overall. Trial Registration: Clinical Trial NCT03228498. Registered 25 July 2017
How to reinforce governance in water-tourism nexus research? Updating the Hydrosocial Cycle to loop into stakeholders’ roles, interactions, and power dynamics
Over the years, a substantial body of knowledge has emerged to analyse the water–tourism nexus, shifting from setting agendas to problem-solving approaches, while highlighting the importance of involving stakeholders in effective governance. In this respect, the hydrosocial cycle approach has demonstrated its effectiveness in assessing the human–nature dimension of water resources by examining the roles and narratives of stakeholders, as well as the asymmetrical power dynamics influencing decision-making processes. This study establishes a framework aimed at enhancing governance in hydrosocial research related to the intersection of water and tourism by exploring stakeholders' interactions across five key dimensions: relevance, representativeness, recognition, performance, and collaboration. Additionally, it articulates each dimension using a triple-loop factor scheme that considers stakeholders' knowledge (to be), actions (to do), and relationships (to share). This framework was implemented in two Mediterranean coastal hotspots, Benidorm (Spain) and Rimini (Italy), which exemplify complex water management contexts marked by competing water needs. Data were gathered through questionnaires distributed to key stakeholders, such as municipalities, regional authorities, water suppliers, irrigation districts, and tourism associations. Our findings illustrate that within the water–tourism nexus, governance tends to favour the water component over the tourism dimension, as evidenced by water stakeholders' leadership roles, player status, and their greater relevance and recognition in terms of their responsibilities and actions. Moreover, although some stakeholders lack awareness of others' roles within the system, no stakeholder was seen as redundant, which suggests potential for fostering engagement by pinpointing most influential stakeholders and reassessing their positions in power-imbalanced contexts. The proposed framework introduces a straightforward, flexible, and easily replicable strategy for dealing with context-dependent issues and challenges, such as the water–tourism nexus, and can enhance the effectiveness of broader participatory tools, such as semi-structured interviews and workshops, improving its applicability in a range of governance environments
Generation of induced pluripotent stem cell line, CSSi002-A (2851), from a patient with juvenile huntington disease
Huntington Disease (HD) is an autosomal dominant disorder characterized by motor, cognitive and behavioral features caused by a CAG expansion in the HTT gene beyond 35 repeats. The juvenile form (JHD) may begin before the age of 20 years and is associated with expanded alleles as long as 60 or more CAG repeats. In this study, induced pluripotent stem cells were generated from skin fibroblasts of a 8-year-old child carrying a large size mutation of 84 CAG repeats in the HTT gene. HD appeared at age 3 with mixed psychiatric (i.e. autistic spectrum disorder) and motor (i.e. dystonia) manifestations
Emotion recognition and inhibitory control in manifest and pre-manifest Huntington's disease: Evidence from a new Stroop task
Huntington's disease (HD) is a genetic neurodegenerative disorder that affects not only the motor but also the cognitive domain. In particular, cognitive symptoms such as impaired executive skills and deficits in recognizing other individuals' mental state may emerge many years before the motor symptoms. This study was aimed at testing two cognitive hypotheses suggested by previous research with a new Stroop task created for the purpose: 1) the impairment of emotion recognition in HD is moderated by the emotions' valence, and 2) inhibitory control is impaired in HD. Forty manifest and 20 pre-manifest HD patients and their age- and gender-matched controls completed both the traditional 'Stroop Color and Word Test' (SCWT) and the newly created 'Stroop Emotion Recognition under Word Interference Task' (SERWIT), which consist in 120 photographs of sad, calm, or happy faces with either congruent or incongruent word interference. On the SERWIT, impaired emotion recognition in manifest HD was moderated by emotion type, with deficits being larger in recognizing sadness and calmness than in recognizing happiness, but it was not moderated by stimulus congruency. On the SCWT, six different interference scores yielded as many different patterns of group effects. Overall our results corroborate the hypothesis that impaired emotion recognition in HD is moderated by the emotions' valence, but do not provide evidence for the hypothesis that inhibitory control is impaired in HD. Further research is needed to learn more about the psychological mechanisms underlying the moderating effect of emotional valence on impaired emotion recognition in HD, and to corroborate the hypothesis that the inhibitory processes involved in Stroop tasks are not impaired in HD. Looking beyond this study, the SERWIT promises to make important contributions to disentangling the cognitive and the psychomotor aspects of neurological disorders. The research was approved by the Ethics Committee of the 'Istituto Leonarda Vaccari', Rome on January 24, 2018
Known drugs identified by structure-based virtual screening are able to bind sigma-1 receptor and increase growth of huntington disease patient-derived cells
Huntington disease (HD) is a devastating and presently untreatable neurodegenerative disease characterized by progressively disabling motor and mental manifestations. The sigma-1 receptor (σ1R) is a protein expressed in the central nervous system, whose 3D structure has been recently determined by X-ray crystallography and whose agonists have been shown to have neuro-protective activity in neurodegenerative diseases. To identify therapeutic agents against HD, we have implemented a drug repositioning strategy consisting of: (i) Prediction of the ability of the FDA-approved drugs publicly available through the ZINC database to interact with σ1R by virtual screening, followed by computational docking and visual examination of the 20 highest scoring drugs; and (ii) Assessment of the ability of the six drugs selected by computational analyses to directly bind purified σ1R in vitro by Surface Plasmon Resonance and improve the growth of fibro-blasts obtained from HD patients, which is significantly impaired with respect to control cells. All six of the selected drugs proved able to directly bind purified σ1R in vitro and improve the growth of HD cells from both or one HD patient. These results support the validity of the drug repositioning procedure implemented herein for the identification of new therapeutic tools against HD
Cognitive Impairment in Relapsing-Remitting Multiple Sclerosis Patients with Very Mild Clinical Disability
Cognitive dysfunction affects 40–65% of multiple sclerosis (MS) patients and can occur in the early stages of the disease. This study aimed to explore cognitive functions by means of the Italian version of the minimal assessment of cognitive function in MS (MACFIMS) in relapsing-remitting MS (RRMS) patients with very mild clinical disability to identify the primarily involved cognitive functions. Ninety-two consecutive RRMS patients with Expanded Disability Status Scale (EDSS) scores ≤ 2.5 and forty-two healthy controls (HC) were investigated. Our results show that 51.1% of MS patients have cognitive dysfunction compared to HC. An impairment of verbal and visual memory, working memory, and executive functions was found in the RRMS group. After subgrouping RRMS by EDSS, group 1 (EDSS ≤ 1.5) showed involvement of verbal memory and executive functions; moreover, group 2 (2 ≤ EDSS ≤ 2.5) patients were also impaired in information processing speed and visual memory. Our results show that utilizing a comprehensive neuropsychological assessment, approximately half of MS patients with very mild physical disability exhibit cognitive impairment with a primary involvement of prefrontal cognitive functions. Detecting impairment of executive functions at an early clinical stage of disease could be useful to promptly enroll MS patients in targeted rehabilitation
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