Helga C.A. Silva

Prof. Dr. Helga C.A. Silva

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Research Focus & Metrics

Academic Career Length

33Years (1994-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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17 June 2011 in Human Molecular Genetics
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Journal Article
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MMMiguel Mitne-Neto
Miguel Mitne-Neto
MMMarcela Machado-Costa
Marcela Machado-Costa
MMMaria C.N. Marchetto
Maria C.N. Marchetto
MBMario H. Bengtson
Mario H. Bengtson
CJClaudio A. Joazeiro
Claudio A. Joazeiro
MZMAYANA ZATZ
MAYANA ZATZ
Amyotrophic lateral sclerosis (ALS) is an incurable neuromuscular disease that leads to a profound loss of life quality and premature death. Around 10% of the cases are inherited and ALS8 is an autosomal dominant form of familial ALS caused by mutations in the vamp-associated protein B/C (VAPB) gene. The VAPB protein is involved in many cellular processes and it likely contributes to the pathogenesis of other forms of ALS besides ALS8. A number of successful drug tests in ALS animal models could not be translated to humans underscoring the need for novel approaches. The induced pluripotent stem cells (iPSC) technology brings new hope, since it can be used to model and investigate diseases in vitro. Here we present an additional tool to study ALS based on ALS8-iPSC. Fibroblasts from ALS8 patients and their non-carrier siblings were successfully reprogrammed to a pluripotent state and differentiated into motor neurons. We show for the first time that VAPB protein levels are reduced in ALS8-derived motor neurons but, in contrast to over-expression systems, cytoplasmic aggregates could not be identified. Our results suggest that optimal levels of VAPB may play a central role in the pathogenesis of ALS8, in agreement with the observed reduction of VAPB in sporadic ALS.

1 January 2008 in Amyotrophic Lateral Sclerosis
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Journal Article
Closed access
CRClarissa Ramirez
Clarissa Ramirez
MPMaria Elisa Pimentel Piemonte
Maria Elisa Pimentel Piemonte
DCDagoberto Callegaro
Dagoberto Callegaro
HSHelga C.A. Silva
Helga C.A. Silva
We aimed to quantify fatigue frequency and evolution in amyotrophic lateral sclerosis (ALS), and to correlate fatigue with factors such as age, sex, educational level, disease duration, functionality, quality of life, dyspnoea, depression and sleepiness. Sixty ALS patients (test group: TG) selected by El Escorial criteria and 60 normal individuals (control group: CG) matched according to sex and age, were followed every three months, during 9 months, by means of self‐report scales: Fatigue Assessment Instrument (Fatigue Severity Scale plus three qualitative subscales); ALS Functional Rating Scale; McGill Quality of Life Questionnaire; dyspnoea analogical scale; Beck Depression Inventory and Epworth Sleepiness Scale. Fatigue was reported by 83% of TG (median: 3.6, interquartile range 1.5−5.4), compared with 20% of CG (median: 1, 1−1), and was significantly greater in the TG (p<0.001, Mann‐Whitney test). Fatigue severity increased by the ninth month of the study (p = 0.0008, Friedman, Müller‐Dunn post test). There was no correlation between fatigue and other parameters, except for an inverse correlation with age at disease onset (p = 0.0395, Spearman rank correlation). In conclusion, fatigue was frequent in ALS, greater in the youngest patients and worsened during follow‐up. Possibly, ALS related fatigue is an independent factor, which deserves individualized approach and treatment.

1 April 2004 in Journal of Medical Genetics
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Journal Article
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ANAgnes Nishimura
Agnes Nishimura
MMM Mitne-Neto
M Mitne-Neto
HSHelga C.A. Silva
Helga C.A. Silva
JOJ R M Oliveira
J R M Oliveira
MVMariz Vainzof
Mariz Vainzof
MZMAYANA ZATZ
MAYANA ZATZ

1 September 2000 in Arquivos de Neuro-Psiquiatria
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FDFlávia Dietrich-Neto
Flávia Dietrich-Neto
DCDagoberto Callegaro
Dagoberto Callegaro
EDElza Dias-Tosta
Elza Dias-Tosta
HSHelga C.A. Silva
Helga C.A. Silva
MFMaria Elizabeth Ferraz
Maria Elizabeth Ferraz
AOAcary Souza Bulle Oliveira
Acary Souza Bulle Oliveira
OBJECTIVES: To assess the epidemiologic characteristics of amyotrophic lateral sclerosis (ALS) in Brazil in 1998. METHOD: Structured Clinical Report Forms (CRFs) sent to 2,505 Brazilian neurologists from January to September 1998 to be filled with demographic and clinical data regarding any ALS patient seen at any time during that year. RESULTS: Five hundred and forty CRFs were returned by 168 neurologists. Data on 443 patients meeting the criteria of probable or definite ALS according to El Escorial definition were analysed: 63 probable (14.2%) and 380 definite (85.8%). Two hundred and fifty-nine (58.5%) of the patients were male, mean age of onset was 52. Spinal onset occurred in 306 patients (69%); bulbar onset in 82 (18.5%), and both in 52 (11.7%). Twenty-six (5.9%) had a family history of ALS. Two hundred and fifty-nine (58.6%) were seen by private practitioners, and 178 (40.2%) at a hospital clinic. Age-ajusted incidence shows a peak incidence at the 65-74 years old range. CONCLUSIONS: The disease's characteristics are similar to those described in international studies, except for age of onset (Brazilian patients are younger). This difference is not confirmed when figures are age-adjusted.

1 October 2002 in Biochimica et Biophysica Acta (BBA) - Molecular Basis of Disease
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Journal Article
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MVMariz Vainzof
Mariz Vainzof
EMEloisa S Moreira
Eloisa S Moreira
OSOscar T Suzuki
Oscar T Suzuki
GFGeorgine Faulkner
Georgine Faulkner
GVGeorgio Valle
Georgio Valle
MZMayana Zatz
Mayana Zatz

14 April 2009 in Proceedings of the National Academy of Sciences
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PAPatricia Arashiro
Patricia Arashiro
IEIris Eisenberg
Iris Eisenberg
AKAlvin T. Kho
Alvin T. Kho
ACAntonia M. P. Cerqueira
Antonia M. P. Cerqueira
MCMarta Canovas
Marta Canovas
MZMAYANA ZATZ
MAYANA ZATZ
Facioscapulohumeral muscular dystrophy (FSHD) is a progressive muscle disorder that has been associated with a contraction of 3.3-kb repeats on chromosome 4q35. FSHD is characterized by a wide clinical inter- and intrafamilial variability, ranging from wheelchair-bound patients to asymptomatic carriers. Our study is unique in comparing the gene expression profiles from related affected, asymptomatic carrier, and control individuals. Our results suggest that the expression of genes on chromosome 4q is altered in affected and asymptomatic individuals. Remarkably, the changes seen in asymptomatic samples are largely in products of genes encoding several chemokines, whereas the changes seen in affected samples are largely in genes governing the synthesis of GPI-linked proteins and histone acetylation. Besides this, the affected patient and related asymptomatic carrier share the 4qA161 haplotype. Thus, these polymorphisms by themselves do not explain the pathogenicity of the contracted allele. Interestingly, our results also suggest that the miRNAs might mediate the regulatory network in FSHD. Together, our results support the previous evidence that FSHD may be caused by transcriptional dysregulation of multiple genes, in cis and in trans , and suggest some factors potentially important for FSHD pathogenesis. The study of the gene expression profiles from asymptomatic carriers and related affected patients is a unique approach to try to enhance our understanding of the missing link between the contraction in D4Z4 repeats and muscle disease, while minimizing the effects of differences resulting from genetic background.