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1.
Org Biomol Chem ; 15(3): 564-569, 2017 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-27991631

RESUMO

The synthesis of a new contrast agent based on a ß-cyclodextrin scaffold and bearing a flexible lipophilic spacer arm on its secondary face is reported. Intermolecular host-guest inclusion complexes were known to undergo an enhancement of the contrast imaging. We extend this concept to intramolecular complexation. Inter- and intramolecular interactions are compared by NMR spectroscopy, circular dichroism and magnetic resonance imaging using hydrocinnamic acid and adamantane carboxylic acid as external guests. This positive variation of the observed relaxivity is a key element of new strategies aiming at developing smart molecular MRI probes.


Assuntos
Imageamento por Ressonância Magnética , beta-Ciclodextrinas/síntese química , Modelos Moleculares , Estrutura Molecular , beta-Ciclodextrinas/química
2.
Nat Genet ; 29(2): 189-93, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11586300

RESUMO

The newly recognized ataxia-ocular apraxia 1 (AOA1; MIM 208920) is the most frequent cause of autosomal recessive ataxia in Japan and is second only to Friedreich ataxia in Portugal. It shares several neurological features with ataxia-telangiectasia, including early onset ataxia, oculomotor apraxia and cerebellar atrophy, but does not share its extraneurological features (immune deficiency, chromosomal instability and hypersensitivity to X-rays). AOA1 is also characterized by axonal motor neuropathy and the later decrease of serum albumin levels and elevation of total cholesterol. We have identified the gene causing AOA1 and the major Portuguese and Japanese mutations. This gene encodes a new, ubiquitously expressed protein that we named aprataxin. This protein is composed of three domains that share distant homology with the amino-terminal domain of polynucleotide kinase 3'- phosphatase (PNKP), with histidine-triad (HIT) proteins and with DNA-binding C2H2 zinc-finger proteins, respectively. PNKP is involved in DNA single-strand break repair (SSBR) following exposure to ionizing radiation and reactive oxygen species. Fragile-HIT proteins (FHIT) cleave diadenosine tetraphosphate, which is potentially produced during activation of the SSBR complex. The results suggest that aprataxin is a nuclear protein with a role in DNA repair reminiscent of the function of the protein defective in ataxia-telangiectasia, but that would cause a phenotype restricted to neurological signs when mutant.


Assuntos
Apraxias/genética , Ataxia/genética , Proteínas de Ligação a DNA/genética , Mutação , Proteínas Nucleares/genética , Músculos Oculomotores/fisiopatologia , Dedos de Zinco , Sequência de Aminoácidos , Apraxias/complicações , Ataxia/complicações , Sequência de Bases , Primers do DNA , Proteínas de Ligação a DNA/química , Heterozigoto , Homozigoto , Humanos , Dados de Sequência Molecular , Proteínas Nucleares/química , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos
3.
J Neurol Neurosurg Psychiatry ; 81(1): 112-4, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20019229

RESUMO

We present clinical and autopsy findings in the first case of variant Creutzfeldt-Jakob disease diagnosed and confirmed in Portugal. Onset was at 11 years, the earliest onset reported, and the course (32 months) relatively long. Western blot showed protease resistant prion protein, mainly of type 4 (2B) isoform. The cerebral cortex revealed severe spongiform change with numerous amyloid plaques, which did not fit the definition of florid plaques. In the striatum, spongiform change was limited but the extracellular space was dilated. Other reports have found marked spongiform change in the striatum and little in the cortex. Massive neuronal loss, in excess of what has been described, was found in the thalamus and pontine grey. The cerebellum showed, as expected, severe loss of granule cells, moderate loss of Purkinje cells and marked immunopositivity for the prion protein. Differences between our findings and previous ones probably result from the patient's long survival.


Assuntos
Síndrome de Creutzfeldt-Jakob/patologia , Idade de Início , Western Blotting , Encéfalo/patologia , Criança , Síndrome de Creutzfeldt-Jakob/epidemiologia , Progressão da Doença , Humanos , Masculino , Portugal/epidemiologia , Príons/metabolismo
4.
Brain ; 132(Pt 10): 2688-98, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19696032

RESUMO

Ataxia with oculomotor apraxia type 2 (AOA2) is an autosomal recessive disease due to mutations in the senataxin gene, causing progressive cerebellar ataxia with peripheral neuropathy, cerebellar atrophy, occasional oculomotor apraxia and elevated alpha-feto-protein (AFP) serum level. We compiled a series of 67 previously reported and 58 novel ataxic patients who underwent senataxin gene sequencing because of suspected AOA2. An AOA2 diagnosis was established for 90 patients, originating from 15 countries worldwide, and 25 new senataxin gene mutations were found. In patients with AOA2, median AFP serum level was 31.0 microg/l at diagnosis, which was higher than the median AFP level of AOA2 negative patients: 13.8 microg/l, P = 0.0004; itself higher than the normal level (3.4 microg/l, range from 0.5 to 17.2 microg/l) because elevated AFP was one of the possible selection criteria. Polyneuropathy was found in 97.5% of AOA2 patients, cerebellar atrophy in 96%, occasional oculomotor apraxia in 51%, pyramidal signs in 20.5%, head tremor in 14%, dystonia in 13.5%, strabismus in 12.3% and chorea in 9.5%. No patient was lacking both peripheral neuropathy and cerebellar atrophy. The age at onset and presence of occasional oculomotor apraxia were negatively correlated to the progression rate of the disease (P = 0.03 and P = 0.009, respectively), whereas strabismus was positively correlated to the progression rate (P = 0.03). An increased AFP level as well as cerebellar atrophy seem to be stable in the course of the disease and to occur mostly at or before the onset of the disease. One of the two patients with a normal AFP level at diagnosis had high AFP levels 4 years later, while the other had borderline levels. The probability of missing AOA2 diagnosis, in case of sequencing senataxin gene only in non-Friedreich ataxia non-ataxia-telangiectasia ataxic patients with AFP level > or =7 microg/l, is 0.23% and the probability for a non-Friedreich ataxia non-ataxia-telangiectasia ataxic patient to be affected with AOA2 with AFP levels > or =7 microg/l is 46%. Therefore, selection of patients with an AFP level above 7 microg/l for senataxin gene sequencing is a good strategy for AOA2 diagnosis. Pyramidal signs and dystonia were more frequent and disease was less severe with missense mutations in the helicase domain of senataxin gene than with missense mutations out of helicase domain and deletion and nonsense mutations (P = 0.001, P = 0.008 and P = 0.01, respectively). The lack of pyramidal signs in most patients may be explained by masking due to severe motor neuropathy.


Assuntos
Apraxia Ideomotora/fisiopatologia , Ataxia/complicações , Ataxia/patologia , Oftalmoplegia/fisiopatologia , Adulto , Idade de Início , Apraxia Ideomotora/genética , Ataxia/genética , Estudos de Coortes , DNA Helicases , Progressão da Doença , Feminino , Genótipo , Humanos , Imageamento por Ressonância Magnética , Masculino , Enzimas Multifuncionais , Mutação de Sentido Incorreto/genética , Oftalmoplegia/genética , Fenótipo , RNA Helicases/genética , RNA Helicases/metabolismo , Estudos Retrospectivos , alfa-Fetoproteínas/genética , alfa-Fetoproteínas/metabolismo
5.
Water Sci Technol ; 61(12): 3198-207, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20555217

RESUMO

Biofilms colonizing pipe surfaces of drinking water distribution systems could provide habitat and shelter for pathogenic viruses present in the water phase. This study aims (i) to develop a method to detect viral particles present in a drinking water biofilm and (ii) to study viral interactions with drinking water biofilms. A pilot scale system was used to develop drinking water biofilms on 3 materials (7 cm(2) discs): PVC, cast iron and cement. Biofilms were inoculated with viral model including MS2, PhiX174 or adenovirus. Five techniques were tested to recover virus from biofilms. The most efficient uses beef extract and glycine at pH = 9. After sonication and centrifugation, the pH of the supernatant is neutralized prior to viral analysis. The calculated recovery rates varied from 29.3 to 74.6% depending on the virus (MS2 or PhiX174) and the material. Applying this protocol, the interactions of virus models (MS2 and adenovirus) with drinking water biofilms were compared. Our results show that adsorption of viruses to biofilms depends on their isoelectric points, the disc material and the hydrodynamic conditions. Applying hydrodynamic conditions similar to those existing in drinking water networks resulted in a viral adsorption corresponding to less than 1% of the initial viral load.


Assuntos
Adenoviridae/isolamento & purificação , Bacteriófago phi X 174/isolamento & purificação , Biofilmes , Levivirus/isolamento & purificação , Adsorção , Cimentos Cermet , Contaminação de Equipamentos , Humanos , Concentração de Íons de Hidrogênio , Ferro , Testes de Neutralização , Projetos Piloto , Abastecimento de Água/normas
6.
Clin Genet ; 74(6): 502-12, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18700894

RESUMO

Congenital muscular dystrophy type 1A (MDC1A) is caused by mutations in the LAMA2 gene encoding laminin-alpha2. We describe the molecular study of 26 patients with clinical presentation, magnetic resonance imaging and/or laminin-alpha2 expression in muscle, compatible with MDC1A. The combination of full genomic sequencing and complementary DNA analysis led to the particularly high mutation detection rate of 96% (50/52 disease alleles). Besides 22 undocumented polymorphisms, 18 different mutations were identified in the course of this work, 14 of which were novel. In particular, we describe the first fully characterized gross deletion in the LAMA2 gene, encompassing exon 56 (c.7750-1713_7899-2153del), detected in 31% of the patients. The only two missense mutations detected were found in heterozygosity with nonsense or truncating mutations in the two patients with the milder clinical presentation and a partial reduction in muscle laminin-alpha2. Our results corroborate the previous few genotype/phenotype correlations in MDC1A and illustrate the importance of screening for gross rearrangements in the LAMA2 gene, which may be underestimated in the literature.


Assuntos
Laminina/genética , Distrofias Musculares/congênito , Distrofias Musculares/genética , Polimorfismo Genético , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Deleção de Genes , Humanos , Lactente , Masculino , Mutação , Adulto Jovem
7.
Hum Mutat ; 26(4): 395-6, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16134148

RESUMO

We studied 21 patients, from 18 families, with L-2-hydroxyglutaric aciduria (L-2-HGA), a rare neurometabolic disorder with a homogeneous presentation: progressive neurodegeneration with extrapyramidal and cerebellar signs, seizures, and subcortical leukoencephalopathy. Increased levels of L-2-hydroxyglutaric acid in body fluids proved the diagnosis of L-2-HGA in all 21 patients. We analyzed the L-2-HGA gene (L2HGDH), recently found to be mutated in consanguineous families with L-2-HGA, and identified seven novel mutations in 15 families. Three mutations appeared to be particularly prevalent in this Portuguese panel: a frameshift mutation (c.529delC) was detected in 12 out of 30 mutant alleles (40%), a nonsense mutation (c.208C>T; p.Arg70X) in 7/30 alleles (23%), and a missense mutation (c.293A>G; p.His98Arg) in four out of 30 mutant alleles (13%), suggesting that common origin may exist. Furthermore, two novel missense (c.169G>A; p.Gly57Arg, c.1301A>C; p.His434Pro) and two splice error (c.257-2A>G, c.907-2A>G) mutations were found. All the mutations presumably lead to loss-of-function with no relationship between clinical signs, progression of the disease, levels of L-2-HGA and site of the mutation. In the three remaining families, no pathogenic mutations in the L-2-HGA were found, which suggests either alterations in regulatory regions of the gene or of its intervening sequences, compound heterozygosity for large genomic deletion and, or further genetic heterogeneity.


Assuntos
Oxirredutases do Álcool/genética , Glutaratos/urina , Mutação , Adolescente , Adulto , Sequência de Aminoácidos , Animais , Criança , Pré-Escolar , Estudos de Coortes , Consanguinidade , Saúde da Família , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Portugal , Alinhamento de Sequência , Análise de Sequência de DNA
8.
Leukemia ; 11(5): 667-73, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9180290

RESUMO

All-trans retinoic acid (ATRA) has recently been shown to synergize with the inhibitory effect of interferon alpha (IFN alpha) on the growth of malignant cells isolated from solid tumors. We investigated whether ATRA could potentiate the inhibitory effects of IFN alpha on the proliferation of leukemic progenitors in chronic myeloid leukemia (CML). CD34+ cells from chronic phase, newly diagnosed patients, were incubated in short-term liquid culture with ATRA, IFN alpha or a combination of both molecules and then plated on semi-solid cultures for colony-forming cell assay. IFN alpha was found to inhibit preferentially the generation of late progenitors. ATRA at a concentration of 10(-8) M was found strongly to inhibit CFU-M colonies. Addition of ATRA to IFN alpha dramatically potentiated the inhibitory effects of INF alpha on CFU-GM growth. In the presence of both molecules the inhibition of day 14 CFU-GM from CD34+ cells was lowered to 27 +/- 4% of control. CFU-M colonies were completely inhibited. RT-PCR analysis of the colonies resulting from the action of the combination IFN alpha plus ATRA showed the presence of an increased number of BCR-ABL-negative colonies relatively to what was observed with IFN alpha alone. FISH analysis showed a higher percentage of Ph-negative cells in the ATRA plus IFN alpha-treated samples, confirming PCR experiments. These results indicate that, in vitro, the combination of IFN alpha and ATRA effectively inhibits CFU-GM colony formation in CML and suggest that it has a potential interest for the treatment of CML.


Assuntos
Células-Tronco Hematopoéticas/patologia , Interferon Tipo I/farmacologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/sangue , Tretinoína/farmacologia , Antígenos CD/sangue , Antígenos CD34/sangue , Divisão Celular/efeitos dos fármacos , Ensaio de Unidades Formadoras de Colônias , Sinergismo Farmacológico , Proteínas de Fusão bcr-abl/biossíntese , Células-Tronco Hematopoéticas/efeitos dos fármacos , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , RNA Mensageiro/biossíntese , Proteínas Recombinantes , Transcrição Gênica , Células Tumorais Cultivadas
9.
J Med Genet ; 41(4): 273-7, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15060101

RESUMO

BACKGROUND: Joubert syndrome (JS) is a recessively inherited disorder characterised by hypotonia at birth and developmental delay, followed by truncal ataxia and cognitive impairment, characteristic neuroimaging findings (cerebellar vermis hypoplasia, "molar tooth sign") and suggestive facial features. JS is clinically heterogeneous with some patients presenting with breathing abnormalities in the neonatal period, oculomotor apraxia, retinal dystrophy, retinal coloboma, ptosis, hexadactyly, and nephronophtisis or cystic dysplastic kidneys. JS is also genetically heterogeneous, with two known loci, on 9q34 (JBTS1) and 11p11-q12 (CORS2), representing only a fraction of cases. METHODS: A large consanguineous Joubert family (five affected) was analysed for linkage with a marker set covering the entire genome and 16 smaller families were subsequently tested for candidate loci. RESULTS: We report here the identification of a third locus in 6q23 (JBTS3) from the study of two consanguineous families. LOD score calculation, including the consanguinity loops, gave a maximum value of 4.1 and 2.3 at q = 0 for the two families, respectively. CONCLUSIONS: Linkage between the disease and the D6S1620-D6S1699 haplotype spanning a 13.1 cM interval is demonstrated. Genotype-phenotype studies indicate that, unlike CORS2, JBTS3 appears not to be associated with renal dysfunction.


Assuntos
Anormalidades Múltiplas/genética , Cromossomos Humanos Par 6 , Anormalidades Múltiplas/diagnóstico , Adolescente , Adulto , Ataxia/diagnóstico , Ataxia Cerebelar/diagnóstico , Mapeamento Cromossômico , Deficiências do Desenvolvimento/diagnóstico , Face/anormalidades , Feminino , Ligação Genética , Genótipo , Homozigoto , Humanos , Masculino , Hipotonia Muscular/diagnóstico , Linhagem , Síndrome
10.
Rev Neurol ; 40(8): 479-81, 2005.
Artigo em Espanhol | MEDLINE | ID: mdl-15861329

RESUMO

INTRODUCTION: Neonatal stroke (NNS) incidence appears to be increasing over the last years. This is believed to be a consequence of diagnostic accuracy rather than a real amplification of this entity. Nowadays, NNS incidence is estimated to be 1:4000 full newborns. CASE REPORT: Child with left middle cerebral artery territory infarction in which several thromboembolic risk factors were documented both in the child (neonatal sepsis and factor V Leiden) and his mother (lupus anticoagulant, pre-eclampsy and factor V Leiden). CONCLUSIONS: This case supports the increasing evidence in recent reports that association of multiple prothrombotic risk factors (maternal and foetal) is present in NNS genesis. This way the authors agree that wide prothrombotic study may be of crucial interest in identifying subjacent thrombophilic disease, even when an exogenous risk factor is present.


Assuntos
Recém-Nascido , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/etiologia , Trombofilia/complicações , Pré-Escolar , Fator V , Humanos , Lactente , Infarto da Artéria Cerebral Média/diagnóstico , Infarto da Artéria Cerebral Média/etiologia , Infarto da Artéria Cerebral Média/patologia , Masculino , Fatores de Risco , Acidente Vascular Cerebral/patologia , Trombofilia/diagnóstico , Trombofilia/patologia
11.
Exp Hematol ; 23(4): 303-8, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7534710

RESUMO

We evaluated the expansion capacity of untreated and 5-fluorouracil (5-FU)-resistant peripheral blood stem cells (PBSC) after 7-day incubation with interleukin-1 (IL-1) plus IL-3 plus stem cell factor (SCF) or with medium alone. We found a significant increase in the proportion of CD34+ cells in the PBSC fraction resistant to 25 micrograms/mL 5-FU after 7-day incubation with IL-1 plus IL-3 plus SCF as compared with the untreated fraction (p = 0.011). We also showed that 5-FU-resistant PBSC have a greater capacity for expansion of IL-1/IL-3/SCF-responsive immature progenitors (p = 0.05), amplification of IL-3 plus GM-CSF responsive progenitors (p = 0.01), and production of committed single growth factor-responsive (granulocyte-macrophage colony-stimulating factor [GM-CSF]) precursors (p = 0.01) than the untreated PBSC. The expansion of all types of progenitors and CD34+ cells was only observed after 7-day incubation with IL-1 plus IL-3 plus SCF. These results suggest that PBSC contain a primitive stem cell population with an enhanced expansion capacity that is identified by 5-FU resistance. As these cells can be expanded in vitro, they may then be suitable for a number of clinical applications.


Assuntos
Fluoruracila/farmacologia , Fatores de Crescimento de Células Hematopoéticas/administração & dosagem , Células-Tronco Hematopoéticas/efeitos dos fármacos , Interleucina-1/administração & dosagem , Interleucina-3/administração & dosagem , Antígenos CD/análise , Antígenos CD34 , Células Sanguíneas/efeitos dos fármacos , Ciclo Celular , Separação Celular/métodos , Citaferese , Resistência a Medicamentos , Humanos , Fator de Células-Tronco
12.
Hum Gene Ther ; 6(1): 13-20, 1995 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-7703283

RESUMO

Congenital erythropoietic porphyria (CEP) is a genetic disease characterized by an overproduction and accumulation of porphyrins in bone marrow. The enzyme defect concerns uroporphyrinogen III synthase (UROIIIS), the fourth enzyme of the heme biosynthetic pathway. It is the most severe porphyria and the treatment is largely symptomatic: gene therapy would represent a great therapeutic improvement. As a step toward the development of an effective gene therapy, we have constructed two retroviral vectors, LUSN and pMFG-US (with and without the selectable marker Neo), containing a full-length human cDNA for UROIIIS. Recombinant retroviruses were obtained by transfection of the LUSN or pMFG-US plasmid into the amphotropic packaging cell line psi CRIP. For each construct, three different producing clones were selected for their high titer (LUSN) or for their ability to express the message at a high level (pMFG-US). In vitro amplification of genomic DNA from target tissue demonstrated the presence of vector sequences. Murine fibroblasts infected in vitro expressed the human enzyme efficiently, as indicated by RNA and enzymatic studies. Retroviral-mediated gene transfer was then used to introduce the UROIIIS cDNA into human deficient cells. Enzyme activity was increased from 2% (deficient fibroblasts) to 121-274% of the normal value for the different clones. Transduced cells selected with G418 presented an 18-fold increase in enzyme activity compared to the normal cells. Furthermore, high gene transfer rate into peripheral blood progenitor cells (PBPB) was documented by in vitro amplification (PCR). These results demonstrate the potential usefulness of somatic gene therapy for the treatment of CEP.


Assuntos
Técnicas de Transferência de Genes , Terapia Genética , Porfiria Eritropoética/terapia , Retroviridae/genética , Uroporfirinogênio III Sintetase/genética , Células 3T3 , Animais , Sequência de Bases , Células Cultivadas , Primers do DNA , Humanos , Camundongos , Dados de Sequência Molecular , Porfiria Eritropoética/enzimologia , Células-Tronco
13.
Arch Neurol ; 58(2): 201-5, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11176957

RESUMO

BACKGROUND: The recessive ataxias are a heterogeneous group of neurodegenerative disorders characterized by cerebellar ataxia associated with a number of different neurologic, ophthalmologic, or general signs. They are often difficult to classify in clinical terms, except for Friedreich ataxia, ataxia-telangiectasia, and a relatively small group of rare conditions for which the molecular basis has already been defined. OBJECTIVES: To study the clinical presentation and to define diagnostic criteria in a group of Portuguese patients with ataxia and ocular apraxia, an autosomal recessive form without the essential clinical and laboratory features of ataxia-telangiectasia. PATIENTS AND METHODS: We reviewed 22 patients in 11 kindreds, identified through a systematic survey of hereditary ataxias being conducted in Portugal. RESULTS: Age at onset ranged from 1 to 15 years, with a mean of 4.7 years. The duration of symptoms at the time of last examination varied from 5 to 58 years. All patients presented with progressive cerebellar ataxia, the characteristic ocular apraxia, and a peripheral neuropathy. Associated neurologic signs included dystonia, scoliosis, and pes cavus. Magnetic resonance imaging was performed in 16 patients, all of whom showed cerebellar atrophy. CONCLUSIONS: Ataxia with ocular apraxia may be more frequent than postulated before, and may be identified clinically using the following criteria: (1) autosomal recessive transmission; (2) early onset (for most patients in early childhood); (3) combination of cerebellar ataxia, ocular apraxia, and early areflexia, with later appearance of the full picture of peripheral neuropathy; (4) absence of mental retardation, telangiectasia, and immunodeficiency; and (5) the possibility of a long survival, although with severe motor handicap.


Assuntos
Apraxias/diagnóstico , Transtornos da Motilidade Ocular/diagnóstico , Degenerações Espinocerebelares/diagnóstico , Adolescente , Adulto , Idade de Início , Apraxias/complicações , Apraxias/epidemiologia , Atrofia , Cerebelo/patologia , Criança , Distonia/complicações , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Transtornos da Motilidade Ocular/complicações , Transtornos da Motilidade Ocular/epidemiologia , Linhagem , Doenças do Sistema Nervoso Periférico/complicações , Portugal , Estudos Retrospectivos , Degenerações Espinocerebelares/complicações , Degenerações Espinocerebelares/epidemiologia
14.
Arch Neurol ; 59(4): 623-9, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11939898

RESUMO

BACKGROUND: Ten neurodegenerative disorders characterized by spinocerebellar ataxia (SCA) are known to be caused by trinucleotide repeat (TNR) expansions. However, in some instances the molecular diagnosis is considered indeterminate because of the overlap between normal and affected allele ranges. In addition, the mechanism that generates expanded alleles is not completely understood. OBJECTIVE: To examine the clinical and molecular characteristics of a large group of Portuguese and Brazilian families with ataxia to improve knowledge of the molecular diagnosis of SCA. PATIENTS AND METHODS: We have (1) assessed repeat sizes at all known TNR loci implicated in SCA; (2) determined frequency distributions of normal alleles and expansions; and (3) looked at genotype-phenotype correlations in 202 unrelated Portuguese and Brazilian patients with SCA. Molecular analysis of TNR expansions was performed using polymerase chain reaction amplification. RESULTS: Patients from 110 unrelated families with SCA showed TNR expansions at 1 of the loci studied. Dominantly transmitted cases had (CAG)(n) expansions at the Machado-Joseph disease gene (MJD1) (63%), at SCA2 (3%), the gene for dentatorubropallidoluysian atrophy (DRPLA) (2%), SCA6 (1%), or SCA7 (1%) loci, or (CTG)(n) expansions at the SCA8 (2%) gene, whereas (GAA)(n) expansions in the Freidreich ataxia gene (FRDA) were found in 64% of families with recessive ataxia. Isolated patients also had TNR expansions at the MJD1 (6%), SCA8 (6%), or FRDA (8%) genes; in addition, an expanded allele at the TATA-binding protein gene (TBP), with 43 CAGs, was present in a patient with ataxia and mental deterioration. Associations between frequencies of SCA2 and SCA6 and a frequency of large normal alleles were found in Portuguese and Brazilian individuals, respectively. Interestingly, no association between the frequencies of DRPLA and large normal alleles was found in the Portuguese group. CONCLUSIONS: Our results show that (1) a significant number of isolated cases of ataxia are due to TNR expansions; (2) expanded DRPLA alleles in Portuguese families may have evolved from an ancestral haplotype; and (3) small (CAG)(n) expansions at the TBP gene may cause SCA17.


Assuntos
Proteínas do Tecido Nervoso/genética , Ataxias Espinocerebelares/diagnóstico , Ataxias Espinocerebelares/genética , Expansão das Repetições de Trinucleotídeos , Adenina/metabolismo , Adulto , Idoso , Alelos , Brasil , Citosina/metabolismo , Feminino , Guanina/metabolismo , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/metabolismo , Reação em Cadeia da Polimerase , Portugal
15.
Leuk Res ; 20(11-12): 915-23, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9009249

RESUMO

Recruitment of quiescent, clonogenic blasts from patients with acute myeloid leukemia (AML) by hematopoietic growth factors (HGFs) may improve the cytotoxic effects of cell-cycle-specific drugs like cytosine-arabinoside (Ara-C). Using the culture methods described by Nara and McCulloch and making a distinction between self-renewing and post-deterministic mitoses, we analyzed the effects of stem cell factor (SCF), a growth factor acting on early hematopoietic progenitor and stem cells. First, we demonstrated that SCF, used in combination with other HGFs included in fetal calf serum (FCS) and/or in 5637 cell line supernatant (5637-CM), stimulated both colony formation and self-renewal of blast progenitors from 10 patients, unlike SCF alone. We tested the effects of SCF on the recruitment of cells in the S-phase by using a bromodeoxyuridine/DNA (BrdUrd/DNA) staining method in flow cytometry (FCM). We showed that SCF stimulated proliferation of AML cells significantly in 9/18 patients with AML. Second, we tested the influence of SCF on the sensitivity to Ara-C of self-renewing leukemic cells from 18 patients with AML. We showed that SCF was efficient in increasing the toxicity of Ara-C on the self-renewing blast progenitors, especially with high concentrations of Ara-C. However, a large patient-to-patient heterogeneity was found and the activity of SCF was not correlated with its effect on the cell cycle. These data indicate that SCF can enhance sensitivity to Ara-C of some leukemic cells with self-renewing capacity.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Citarabina/farmacologia , Leucemia Mieloide/patologia , Células-Tronco Neoplásicas/efeitos dos fármacos , Fator de Células-Tronco/farmacologia , Doença Aguda , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Bovinos , Ciclo Celular/efeitos dos fármacos , Meios de Cultura/farmacologia , Meios de Cultura Livres de Soro/farmacologia , Replicação do DNA/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Sinergismo Farmacológico , Feminino , Sangue Fetal/química , Citometria de Fluxo , Fatores de Crescimento de Células Hematopoéticas/isolamento & purificação , Fatores de Crescimento de Células Hematopoéticas/farmacologia , Humanos , Leucemia Mieloide/metabolismo , Masculino , Metilcelulose , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/metabolismo , Proteínas Recombinantes/farmacologia , Suspensões , Ensaio Tumoral de Célula-Tronco
16.
Leuk Lymphoma ; 19(5-6): 423-9, 1995 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8590842

RESUMO

Antisense oligonucleotides were used to determine the role of the BCR-ABL gene in the proliferation of chronic myeloid leukaemia (CML) clonogenic cells. Peripheral blood Philadelphia chromosome positive cells were obtained from eight CML patients at diagnosis (chronic phase = 7; accelerated phase = 1). Mononuclear cells were incubated with synthetic antisense 18-mer oligonucleotides complementary to the two different junctions b2a2 or b3a2. The type of junction (b2a2 or b3a2) was previously determined by RT-PCR techniques. Cells incubated for 12 to 14 hours with or without sense oligonucleotides served as controls. After incubation with oligonucleotides, the cell DNA synthesis was analysed by flow cytometry using the BrdUrd/DNA method and the cell plating efficiency in methylcellulose was determined. In six of the seven patients in chronic phase, there was a significant inhibition of CFU-GM production which was only 68.4 +/- 19%; (p < .01) of that found in controls. The S phase index, which depends upon the percentage of S phase cells as well as the fluorescence intensity, was 48 +/- 29% (p < .01) of the control values for the seven patients in chronic phase. Interestingly, for the only CML patient in accelerated phase, antisense oligomers had no inhibitory effect on either the production of CFU-GM or the number of S phase cells. In improving the specificity of oligomers, it might be useful for gene-targeted anti-leukemic therapy and/or bone marrow purging.


Assuntos
DNA de Neoplasias/genética , Proteínas de Fusão bcr-abl/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Proteínas de Neoplasias/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Oligonucleotídeos Antissenso/farmacologia , Sequência de Bases , Ciclo Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Replicação do DNA/efeitos dos fármacos , Humanos , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mieloide de Fase Acelerada/genética , Leucemia Mieloide de Fase Acelerada/patologia , Leucemia Mieloide de Fase Crônica/genética , Leucemia Mieloide de Fase Crônica/patologia , Dados de Sequência Molecular , Síndromes Mielodisplásicas/genética , Síndromes Mielodisplásicas/patologia , Células-Tronco Neoplásicas/patologia , Oligonucleotídeos Antissenso/genética , RNA Mensageiro/biossíntese , RNA Neoplásico/biossíntese , Ensaio Tumoral de Célula-Tronco
17.
Brain Dev ; 19(4): 268-73, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9187477

RESUMO

We present clinical, biochemical and cranial magnetic resonance imaging data of six pediatric patients with L-2-hydroxyglutaric aciduria. All the children have the same ethic origin and lived in the northern area of Portugal. Our findings reinforce the described phenotype of this rare metabolic disease with mental deficiency, severe cerebellar dysfunction, mild extrapyramidal and pyramidal symptoms, progressive macrocephaly and seizures. Magnetic resonance imaging revealed subcortical leukoencephalopathy, cerebellar atrophy and signal changes in the putamina and dentate nuclei. These were similar to those of the previous reports in all patients. The urinary excretion of L-2-hydroxyglutaric acid was variably increased in all patients. The other persistent biochemical abnormality was hyperlysinemia. We have found a strong correlation between the severity of the clinical manifestations and the extension of the lesions in the neuroimaging studies. There was no correlation between the clinical findings and the amount of urinary excretion of L-2-hydroxyglutaric acid. We report the second case in the literature of a cerebral thalamic tumor in L-2-hydroxyglutaric aciduria; neuropathological examination of the surgical biopsy demonstrated a diffuse fibrillary astrocytoma.


Assuntos
Glutaratos/urina , Deficiência Intelectual/complicações , Erros Inatos do Metabolismo/complicações , Aminoacidúrias Renais/complicações , Adolescente , Ataxia/complicações , Ataxia/diagnóstico por imagem , Ataxia/patologia , Biópsia , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Criança , Pré-Escolar , Feminino , Humanos , Deficiência Intelectual/diagnóstico por imagem , Deficiência Intelectual/patologia , Imageamento por Ressonância Magnética , Masculino , Erros Inatos do Metabolismo/patologia , Erros Inatos do Metabolismo/urina , Portugal , Aminoacidúrias Renais/patologia , Aminoacidúrias Renais/urina , Tomografia Computadorizada por Raios X
18.
Pediatr Neurol ; 22(1): 29-32, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10669202

RESUMO

The T8993G mutation in the mitochondrial DNA adenosine triphosphatase 6 gene represents an important cause of maternally inherited Leigh's syndrome. Reported are the clinical findings and mutational loads in three Portuguese T8993G pedigrees. Polymerase chain reaction-restriction fragment length polymorphism analyses demonstrated the T8993G mutation in a high percentage of tissues from all patients (97% +/- 2.3%), but it was less abundant in the blood from 14 maternal relatives. The disease progressed severely in the probands but did not have the fatal course reported by others. To test whether this prolonged course was related to the presence of a specific, disease-associated haplogroup the origin of the mutational event in Portugal was traced. Haplotype investigation revealed an independent occurrence of the mutation in the three probands. These analyses represent the first molecular characterization of Portuguese patients with Leigh's syndrome.


Assuntos
Adenosina Trifosfatases/genética , DNA Mitocondrial/análise , Saúde da Família , Doença de Leigh/genética , Mutação Puntual , Atrofia , Gânglios da Base/patologia , Criança , Pré-Escolar , Feminino , Frequência do Gene , Haplótipos , Humanos , Doença de Leigh/patologia , Imageamento por Ressonância Magnética , Masculino , Linhagem , Portugal
19.
Rev Port Cardiol ; 18(5): 497-500, 1999 May.
Artigo em Português | MEDLINE | ID: mdl-10418263

RESUMO

The cardiac manifestation usually associated with Tuberous Sclerosis is rhabdomyoma. The authors present a clinical case of Tuberous Sclerosis with the particular coexistence of congenital heart disease (mitral anomaly and pulmonary stenosis) and a single intracardiac rhabdomyoma that appeared at the age of four years.


Assuntos
Cardiopatias Congênitas/complicações , Neoplasias Cardíacas/complicações , Rabdomioma/complicações , Esclerose Tuberosa/complicações , Pré-Escolar , Feminino , Humanos
20.
Rev Neurol ; 38(12): 1132-5, 2004.
Artigo em Espanhol | MEDLINE | ID: mdl-15229825

RESUMO

INTRODUCTION: Despite early dietary therapy, many patients with galactosemia show a neurodegenerative disease specially evident in speech impairment and movement disorders. Magnetic resonance imaging of the brain, show cerebral white matter changes with hypomielinization bilateral and symetrical periventricular hypersignal in T2. PATIENTS AND METHODS: We presented clinical and neuroradiological data of seven children (3 to 12 years of age) with classical galactosemia. All had a typical presentation in neonatal period. Two children had normal development (10 and 12 years-old), four presented developmental delay (10, 7, 4 and 3 years-old), and one showed a dystonic cerebral palsy (kernicterus). RESULTS: The brain MRI showed the typical involvement of white matter, in five children, and basal ganglia abnormalities in the kernicterus patient. Three patients are homozygous for Q188R mutation and two are compound heterozygous. CONCLUSION: We found a positive correlation among developmental delay, white matter involvement and Q188R mutation.


Assuntos
Galactosemias/genética , Galactosemias/fisiopatologia , Genótipo , Fenótipo , Encéfalo/patologia , Encéfalo/fisiopatologia , Criança , Pré-Escolar , Galactosemias/patologia , Humanos , Imageamento por Ressonância Magnética , Transtornos dos Movimentos/patologia , Transtornos dos Movimentos/fisiopatologia , Doenças Neurodegenerativas/patologia , Doenças Neurodegenerativas/fisiopatologia , Distúrbios da Fala/patologia , Distúrbios da Fala/fisiopatologia
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