213 research outputs found

    Segregation distortion of wild-type alleles at the Machado-Joseph disease locus: a study in normal families from the Azores islands (Portugal)

    Get PDF
    Machado-Joseph disease (MJD) is caused by an expansion of a triplet repeat with a CAG motif at the ATXN3 gene. The putative segregation ratio distortion (SRD) of alleles can play an important role in the non-Mendelian behaviour of triplet repeat loci. To study the stability and infer the segregation patterns of wild-type MJD alleles, the size of the (CAG)(n) tract was analysed in 102 normal sibships, representing 428 meioses. No mutational events were detected during the transmission of alleles. Segregation analysis showed that the smaller alleles were preferentially transmitted (56.9%). Considering maternal meioses alone, such preference was still detected (55.7%) but without statistical significance. A positive correlation was observed for the difference in length between the two alleles constituting the transmitters' genotype (D) and the frequency of transmission of the smaller alleles. The results suggest that small D values are not enough to modify the probability of allele transmission. When transmissions involving genotypes with D <or= 2 were excluded, SRD in favour of the smaller allele became significant for both maternal and paternal transmissions. Therefore, the genotypic composition of the transmitters in a sample to be analysed should influence the ability to detect SRD, acting as a confounding factor.This work was supported by ‘‘Projecto Regional Integrado— DMJ (PRI-DMJ)’’ (funded by Regional Government of the Azores), ‘‘Construyendo una Bio-Región Europea—Biopolis’’ (05/MAC/2.3/ C14, funded by PIC Interreg III B, Azores—Madeira—Canarias) and MANSEEBMO (MI.2.1/004/2005, funded by ‘‘Direcção Regional da Ciência e Tecnologia’’). CB (SFRH/BD/21875/2005) is a recipient of a Ph.D. grant, and RM (SFRH/BPD/32473/2006) and CS (SFRH/BPD/ 20944/2004) are postdoctoral fellows from ‘‘Fundação para a Ciência e a Tecnologia’’ (FCT)

    Population genetics of wild-type CAG repeats in the Machado-Joseph disease gene in Portugal

    Get PDF
    To gain insights on the molecular mechanisms of mutation that led to the emergence of expanded alleles in the MJD gene, by studying the behavior of wild-type alleles and testing the association of its distribution with the representation of the disease. Methods: The number of CAG motifs in the MJD gene was determined in a representative sample of 1000 unrelated individuals. Associations between the repeat size and the epidemiological representation of MJD were tested. Results: The allelic profi le of the total sample was in the normal range (13–41 repeats), with mode (CAG) 23 . No intermediate alleles were present. Allelic size distribution showed a negative skew. The correlation between the epidemiological representation of MJD in each district and the frequency of small, medium and large normal alleles was not signifi cant. Further correlations performed grouping the districts also failed to produce signifi cant results. Conclusions: The absence of association between the size of the repeats and the representation of MJD demonstrates that prevalence is not an indirect refl ection of the frequency of large normal alleles. Globally the results obtained are in accordance with a model that postulates the occurrence of a few mutations on the basis of most of the MJD cases worldwide

    The CAG repeat at the Huntington disease gene in the Portuguese population : insights into its dynamics and to the origin of the mutation

    Get PDF
    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

    Preclinical Evidence Supporting Early Initiation of Citalopram Treatment in Machado-Joseph Disease

    Get PDF
    Spinocerebellar ataxias are dominantly inherited neurodegenerative disorders with no disease-modifying treatment. We previously identified the selective serotonin reuptake inhibitor citalopram as a safe and effective drug to be repurposed for Machado-Joseph disease. Pre-symptomatic treatment of transgenic (CMVMJD135) mice strikingly ameliorated mutant ataxin-3 (ATXN3) pathogenesis. Here, we asked whether citalopram treatment initiated at a post-symptomatic age would still show efficacy. We used a cohort of CMVMJD135 mice that shows increased phenotypic severity and faster disease progression (CMVMJD135hi) compared to the mice used in the first trial. Groups of hemizygous CMVMJD135hi mice were orally treated with citalopram. Behavior, protein analysis, and pathology assessment were performed blindly to treatment. Our results show that even when initiated after symptom onset, treatment of CMVMJD135hi mice with citalopram ameliorated motor coordination and balance, attenuating disease progression, albeit to a lesser extent than that seen with pre-symptomatic treatment initiation. There was no impact on ATXN3 aggregation, which contrasts with the robust reduction in ATXN3-positive inclusions observed in CMVMJD135 mice, when treated pre-symptomatically. Post-symptomatic treatment of CMVMJD135hi mice revealed, however, a limited neuroprotective effect by showing a tendency to repair cerebellar calbindin staining, and to increase the number of motor neurons and of NeuN-positive cells in certain brain regions. While supporting that early initiation of treatment with citalopram leads to a marked increase in efficacy, these results strengthen our previous observation that modulation of serotonergic signaling by citalopram is a promising therapeutic approach for Machado-Joseph disease even after symptom onset.European Regional Development Funds (FEDER), through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT), under the scope of the project POCI-01-0145-FEDER-007038. This article has been developed under the scope of the project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the FEDER. This work was also supported by FCT and COMPETE through the projects [PTDC/SAU-GMG/112617/2009] (to PM) and [EXPL/BIM-MEC/0239/2012] (to AT-C), by FCT through the project [POCI-01-0145-FEDER-016818 (PTDC/NEU-NMC/3648/2014)] (to PM), by National Ataxia foundation (to PM and to AT-C), and by Ataxia UK (to PM). SE, SD-S, SO, and AT-C were supported by the FCT individual fellowships, SFRH/BD/78554/2011, SFRH/BD/78388/2011, PD/BD/127818/2016, and SFRH/BPD/102317/2014, respectively. FCT fellowships are co-financed by POPH, QREN, Governo da República Portuguesa, and EU/FSEinfo:eu-repo/semantics/publishedVersio

    Budget impact analysis of medicines : updated systematic review and implications

    Get PDF
    This evaluation determines whether published studies to date meet the key characteristics identified for budget impact analyses (BIA) for medicines, accomplished through a systematic review and assessment against identified key characteristics. Studies from 2001 to 2015 on "budget impact analysis" with "drug" interventions were assessed, selected based on their titles/abstracts and full texts, with their characteristics checked according to key criteria. Out of 1984 studies, 92 were identified. Of these, 95% were published in Europe and the USA. 2012 saw the largest number of publications (16%) with a decline thereafter. 48% met up to 6 or 7 out of the 9 key characteristics. Only 22% stated no conflict of interest. The results indicate low adherence to the key characteristics that should be considered for BIAs and strong conflict of interest. This is an issue since BIAs can be of fundamental importance in managing the entry of new medicines including reimbursement decisions

    Lithium chloride therapy fails to improve motor function in a transgenic mouse model of Machado-Joseph disease

    Get PDF
    The accumulation of misfolded proteins in neurons, leading to the formation of cytoplasmic and nuclear aggregates, is a common theme in age-related neurodegenerative diseases, possibly due to disturbances of the proteostasis and insufficient activity of cellular protein clearance pathways. Lithium is a well-known autophagy inducer that exerts neuroprotective effects in different conditions and has been proposed as a promising therapeutic agent for several neurodegenerative diseases. We tested the efficacy of chronic lithium 10.4 mg/kg) treatment in a transgenic mouse model of Machado-Joseph disease, an inherited neurodegenerative disease, caused by an expansion of a polyglutamine tract within the protein ataxin-3. A battery of behavioral tests was used to assess disease progression. In spite of activating autophagy, as suggested by the increased levels of Beclin-1, Atg7, and LC3II, and a reduction in the p62 protein levels, lithium administration showed no overall beneficial effects in this model concerning motor performance, showing a positive impact only in the reduction of tremors at 24 weeks of age. Our results do not support lithiumchronic treatment as a promising strategy for the treatment of Machado-Joseph disease (MJD).FCT -Fundação para a Ciência e a Tecnologia(SFRH/BD/51059/2010

    DNA Encoding an HIV-1 Gag/Human Lysosome-Associated Membrane Protein-1 Chimera Elicits a Broad Cellular and Humoral Immune Response in Rhesus Macaques

    Get PDF
    Previous studies of HIV-1 p55Gag immunization of mice have demonstrated the usefulness of targeting antigens to the cellular compartment containing the major histocompatibility complex type II (MHC II) complex molecules by use of a DNA antigen formulation encoding Gag as a chimera with the mouse lysosome-associated membrane protein (mLAMP/gag). In the present study, we have analyzed the magnitude and breadth of Gag-specific T-lymphocyte and antibody responses elicited in Rhesus macaques after immunization with DNA encoding a human LAMP/gag (hLAMP/gag) chimera. ELISPOT analyses indicated that the average Gag-specific IFN-γ response elicited by the hLAMP/gag chimera was detectable after only two or three naked DNA immunizations in all five immunized macaques and reached an average of 1000 spot-forming cells (SFC)/10(6) PBMCs. High IFN-γ ELISPOT responses were detected in CD8(+)-depleted cells, indicating that CD4(+) T-cells play a major role in these responses. The T-cell responses of four of the macaques were also tested by use of ELISPOT to 12 overlapping 15-amino acids (aa) peptide pools containing ten peptides each, encompassing the complete Gag protein sequence. The two Mamu 08 immunized macaques responded to eight and twelve of the pools, the Mamu B01 to six, and the other macaque to five pools indicating that the hLAMP/gag DNA antigen formulation elicits a broad T-cell response against Gag. Additionally, there was a strong HIV-1-specific IgG response. The IgG antibody titers increased after each DNA injection, indicating a strong amnestic B-cell response, and were highly elevated in all the macaques after three immunizations. Moreover, the serum of each macaque recognized 13 of the 49 peptides of a 20-aa peptide library covering the complete Gag amino acid sequence. In addition, HIV-1-specific IgA antibodies were present in the plasma and external secretions, including nasal washes. These data support the findings of increased immunogenicity of genetic vaccines encoded as LAMP chimeras, including the response to DNA vaccines by non-human primates

    Early childhood caries in preschool children of Kosovo - a serious public health problem

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Even though it has been widely studied, early childhood caries (ECC) remains a serious public health problem, especially in countries where there is no national program of oral health assessment and no genuine primary oral health care, such as in Kosovo. The purpose of this study was to assess the prevalence of ECC and analyze caries risk factors.</p> <p>Methods</p> <p>The subjects were 1,008 preschool children, selected by stratified random cluster sampling, in the municipality of Prishtina, capital of Kosovo. Data were collected through clinical examination and interviews. Dmft data were recorded according to WHO criteria. Bacterial examination (CRT bacteria test) and plaque test of Greene-Vermillion were used.</p> <p>Results</p> <p>The mean dmft of preschool children was found to be 5.8. The prevalence of ECC was 17.36%, with a mean dmft of 11 ± 3.6. Streptococcus mutans prevalence in ECC children was 98%. A significant correlation between dmft and S mutans counts (≥10<sup>5 </sup>CFU/mL saliva) was demonstrated. A correlation was also found between daily sweets consumption and dmft in children with ECC (<it>P </it>< 0.001). Comparing the dmft of ECC children and duration of bottle feeding showed a statistical correlation (<it>P </it>< 0.001). The mean plaque test was 1.52. None of the examined children had ever used fluoride.</p> <p>Conclusion</p> <p>The prevalence of ECC was high among preschool children in the municipality of Kosovo. We recommend increasing parents' knowledge of proper feeding habits and oral health practices, and increasing preschool children's accessibility to dental services.</p
    corecore