Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Eur J Neurol ; 20(10): 1383-9, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23663589

RESUMO

BACKGROUND AND PURPOSE: Anoctamin 5 (ANO5) is a putative intracellular calcium-activated chloride channel. Recessive mutations in ANO5 cause primary skeletal muscle disorders (limb-girdle muscular dystrophy 2L and distal muscular dystrophy), which are phenotypically similar to dysferlinopathy, a muscular dystrophy due to dysferlin-encoding gene (DYSF) mutations. METHODS: This study reports the phenotype and genotype of seven unrelated patients with ANO5-muscular dystrophy. RESULTS: Three patients had amyloid deposition in muscle and two had cardiac involvement. An additional patient without skeletal muscle amyloidosis had cardiac involvement with septal hypokinesis and supraventricular tachycardia requiring ablation. Amyloid subtyping using laser capture microdissection and mass spectrometry-based proteomic analysis did not identify ANO5 or any fragment of ANO5 in the amyloid deposits, but detected other known amyloidogenic proteins. Three patients had myotonic discharges without clinical myotonia. Four ANO5 mutations are novel, including a heterozygous 0.4 Mb deletion involving the entire ANO5 gene. CONCLUSIONS: The results of the present study suggest that ANO5 mutations can be associated with amyloid deposition in muscle, but the nature of the amyloid deposits remains indeterminate, as does their relationship with cardiac involvement. ANO5 analysis should be considered in cases of muscle amyloid deposition of indeterminate etiology. Electrical myotonia can accompany ANO5-muscular dystrophy.


Assuntos
Canais de Cloreto/genética , Distrofias Musculares/genética , Distrofias Musculares/patologia , Adulto , Idoso , Amiloidose/genética , Amiloidose/patologia , Anoctaminas , Feminino , Genótipo , Humanos , Microdissecção e Captura a Laser , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/patologia , Mutação , Miocárdio/patologia , Fenótipo
2.
Biostatistics ; 10(3): 481-500, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19325168

RESUMO

Mass spectrometry is a powerful tool with much promise in global proteomic studies. The discipline of statistics offers robust methodologies to extract and interpret high-dimensional mass-spectrometry data and will be a valuable contributor to the field. Here, we describe the process by which data are produced, characteristics of the data, and the analytical preprocessing steps that are taken in order to interpret the data and use it in downstream statistical analyses. Because of the complexity of data acquisition, statistical methods developed for gene expression microarray data are not directly applicable to proteomic data. Areas in need of statistical research for proteomic data include alignment, experimental design, abundance normalization, and statistical analysis.


Assuntos
Espectrometria de Massas/estatística & dados numéricos , Proteômica/estatística & dados numéricos , Algoritmos , Biometria , Ciclotrons , Interpretação Estatística de Dados , Análise de Fourier , Humanos , Peptídeos/química , Proteínas/química , Alinhamento de Sequência/estatística & dados numéricos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/estatística & dados numéricos , Espectrometria de Massas em Tandem/estatística & dados numéricos
3.
Clin Pharmacol Ther ; 82(6): 644-52, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17971823

RESUMO

The development of new vaccines against pathogens is an important part of infectious disease control. In the last decade, a variety of proteins giving rise to naturally processed pathogen-derived antigenic peptides, representing B-cell and T-cell epitopes, have been characterized. Numerous candidate vaccines consisting of synthetic peptides are being designed and evaluated, with encouraging results. In this context, the application of mass spectrometry based on the isolation and identification of pathogen-derived peptides from the human leukocyte antigen (HLA) molecules is a major focus of peptide-based vaccine development. Dramatic improvements have been made in mass spectrometer performance for peptide sequencing in terms of increased sensitivity, the ability to rapidly obtain data-directed tandem mass spectra, and the accuracy of mass measurement. This review focuses on the efforts to identify T-cell epitopes for viral and microbial pathogens for directed vaccine development.


Assuntos
Epitopos de Linfócito T , Antígenos de Histocompatibilidade Classe II , Antígenos de Histocompatibilidade Classe I , Vírus do Sarampo , Espectrometria de Massas em Tandem , Vacinas , Vaccinia virus , Animais , Vacinas Bacterianas , Linfócitos T CD4-Positivos , Linfócitos T CD8-Positivos , Desenho de Fármacos , Antígenos HLA , Humanos , Isótopos , Vírus do Sarampo/imunologia , Peptídeos , Vaccinia virus/imunologia , Vacinas Virais
4.
Bioinformatics ; 22(22): 2739-45, 2006 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-16954138

RESUMO

MOTIVATION: Using stable isotopes in global proteome scans, labeled molecules from one sample are pooled with unlabeled molecules from another sample and subsequently subjected to mass-spectral analysis. Stable-isotope methodologies make use of the fact that identical molecules of different stable-isotope compositions are differentiated in a mass spectrometer and are represented in a mass spectrum as distinct isotopic clusters with a known mass shift. We describe two multivariable linear regression models for (16)O/(18)O stable-isotope labeled data that jointly model pairs of resolved isotopic clusters from the same peptide and quantify the abundance present in each of the two biological samples while concurrently accounting for peptide-specific incorporation rates of the heavy isotope. The abundance measure for each peptide from the two biological samples is then used in down-stream statistical analyses, e.g. differential expression analysis. Because the multivariable regression models are able to correct for the abundance of the labeled peptide that appear as an unlabeled peptide due to the inability to exchange the natural C-terminal oxygen for the heavy isotope, they are particularly advantageous for a two-step digestion/labeling procedure. We discuss how estimates from the regression model are used to quantify the variability of the estimated abundance measures for the paired samples. Although discussed in the context of (16)O/(18)O stable-isotope labeled data, the multivariable regression models are generalizable to other stable-isotope labeled technologies.


Assuntos
Biologia Computacional/métodos , Espectrometria de Massas/métodos , Proteínas/química , Proteômica/métodos , Análise de Regressão , Algoritmos , Humanos , Isótopos , Cinética , Análise Multivariada , Isótopos de Oxigênio/química , Mapeamento de Peptídeos , Soroalbumina Bovina/química , Transferrina/química , Tripsina/química
5.
Anal Biochem ; 296(1): 122-9, 2001 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-11520040

RESUMO

The serum iron transport protein human transferrin (hTf) is a glycoprotein (MW approximately 79.6 kDa) containing two Asn-linked sites of glycosylation. The presence of specific glycoforms of hTf has been used as an indicator of carbohydrate-deficient glycoprotein syndrome (CDGS) or an indicator of alcohol abuse. The exact nature of the glycoforms described in the literature is controversial. In this work we demonstrate that the altered hTf glycoforms have lost one or both complete glycan side chains. Furthermore, we demonstrate using a combination of online immunoaffinity-postconcentration-mass spectrometry in conjunction with a blood spot cartridge that we can determine the relative quantities of the hTf glycoforms using <5 microL blood in under 30 min. This is in contrast to previous methods that used 1 mL and took 4 days. We show that this method can be useful to analyze hTf from CDGS and alcoholic patients.


Assuntos
Transferrina/análogos & derivados , Transferrina/análise , Glicoproteínas/análise , Humanos , Neuraminidase/análise , Espectrometria de Massas por Ionização por Electrospray
6.
Clin Chem ; 47(3): 513-8, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11238305

RESUMO

BACKGROUND: Congenital disorders of glycosylation (CDG) are autosomal recessive disorders that produce increased serum carbohydrate-deficient transferrin (CDT) isoforms. Methods to resolve CDT from fully glycosylated transferrin (Trf) have been based on a neutral shift in the isoelectric focusing (IEF) pattern or on a reduction in the negative charge, allowing resolution by anion-exchange chromatography. Our purpose was to develop a method of resolution and relative quantification of Trf isoforms using online immunoaffinity liquid chromatography-mass spectrometry (LC-MS). METHODS: Serum (25 microL) was diluted with 100 microL of water before application to an immunoaffinity column that sequestered Trf isoforms. Trf isoforms were eluted from the immunoaffinity column, concentrated on a C4 column, eluted from the C4 column, and introduced into the mass spectrometer. Analysis of the Trf isoforms was entirely automated and completed in <10 min per sample. RESULTS: The LC-MS method demonstrated that the major abnormal Trf isoforms in CDG lack one complete oligosaccharide structure (mono-oligosaccharide) or both oligosaccharide structures (a-oligosaccharide), but not the sialic acids, as presumed on the basis of IEF methods. Calculation of relative ratios among three possible species (mono-/di-oligosaccharide and a-/di-oligosaccharide) is reproducible [mean intra- and interassay CVs were 9.3% (n = 10) and 10% (n = 5), respectively]. A reference range for patients <18 years was determined by analysis of 209 samples (for mono-/di-oligosaccharide, the median was 0.041 and the range was 0.018-0.083; for a-/di-oligosaccharide, the median was 0.007 and the range was 0.002-0.036). Comparison of data obtained with an affinity chromatography-IEF method and the LC-MS method demonstrated equivalence in the interpreted results (n = 170). CONCLUSIONS: Advantages of the LC-MS method include improved sensitivity, minimal sample preparation, and an analysis time of <10 min. The method was automated, which allowed high throughput, with >100 samples analyzed in a single day. Moreover, the nature of the oligosaccharide defect in CDG is accurately reflected by mass resolution, and subtle oligosaccharide truncations may also be detected by this method.


Assuntos
Transferrina/análise , Animais , Anticorpos , Cromatografia Líquida/métodos , Humanos , Focalização Isoelétrica , Isoformas de Proteínas/sangue , Isoformas de Proteínas/imunologia , Coelhos , Valores de Referência , Espectrometria de Massas por Ionização por Electrospray , Transferrina/imunologia
7.
Am J Clin Nutr ; 49(4): 713-6, 1989 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2648799

RESUMO

The vitamin A status in 11 generally healthy surgical patients was estimated by measuring the dilution of a 45-mg oral dose of tetradeuterated retinyl acetate (99% pure). After purification of retinol by high-performance liquid chromatography, the ratio of 2H4-retinol:1H-retinol in plasma was measured by gas chromatography-mass spectrometry. On the basis of the observed ratios of [2H4]retinol:[1H]retinol over 19-47 d, the total body reserves and liver concentrations of vitamin A were calculated. Liver biopsy samples taken at surgery were directly analyzed for vitamin A. The correlation coefficient between calculated and measured liver vitamin A concentrations for 10 of the subjects was 0.88, and the Spearman's rank correlation coefficient was 0.95 (p less than 0.002). Thus, total body reserves of vitamin A in humans can be estimated validly in the marginal and satisfactory ranges by a benign, relatively noninvasive procedure.


Assuntos
Fígado/química , Vitamina A/análise , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , Deutério , Humanos , Técnicas de Diluição do Indicador , Isótopos , Pessoa de Meia-Idade
8.
Am J Clin Nutr ; 48(2): 279-85, 1988 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3407606

RESUMO

Vitamin A and E status was studied in five groups (satisfactory growth, reduced growth, night blindness, Bitot's spots, and corneal xerosis) of rural Indonesian preschool children. All groups except corneal xerosis showed satisfactory weight-height ratios. Initial serum retinol values were less than 0.35 mumol/L in 34% of all children. After oral administration of 24.4 mumol vitamin A, mean serum retinol values rose from 0.42 to 0.70 mumol/L at 10 d. After oral treatment of children with 244 or 314 mumol vitamin A, mean serum retinol remained greater than 0.56 mumol/L for 165 d. Of particular note were the low mean initial serum alpha-tocopherol concentrations (6.3 mumol/L) and alpha-tocopherol-total lipid ratios (1.5 mumol/g). Total serum lipids fell in the normal range. Oral administration of 84 mumol vitamin E raised serum alpha-tocopherol and alpha-tocopherol-total-lipid ratios by 46 and 44%, respectively. Thus, vitamin E inadequacy, which impairs vitamin A absorption and storage, may well contribute to the high incidence of clinical vitamin A deficiency in West Javan children.


Assuntos
Estado Nutricional , Vitamina A/sangue , Vitamina E/sangue , Administração Oral , Pré-Escolar , Feminino , Humanos , Indonésia , Lipídeos/sangue , Masculino
9.
J Immunol ; 139(3): 743-8, 1987 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-3496387

RESUMO

Antibodies reactive with left-handed Z-DNA arise spontaneously in the sera of patients with SLE and rheumatoid arthritis and in autoimmune MRL mice. However, the precise specificity of these autoantibodies has not been established. In this report, we have characterized four monoclonal anti-Z-DNA antibodies from unimmunized MRL/Mp-lpr/lpr mice that do not cross-react with B-DNA and can discriminate between different types of left-handed helices. Two of the monoclonal antibodies (Za and Zi) behaved similarly in that they bound to two forms of Z-DNA (Br-poly(dG-dC).poly(dG-dC) and AAF-poly(dG-dC).poly(dG-dC) but not to two other Z-form DNA (poly(dG-5BrdC).poly(dG-5BrdC) or poly(dG-5MedC).poly(dG-5MedC)). Neither antibody (Za or Zi) bound significantly to B-DNA or to denatured DNA. A third antibody (Ze) exhibited similar binding characteristics for the Z-DNA preparations, but also recognized denatured DNA. In contrast, a fourth antibody (3-7.3) bound preferentially to poly(dG-5BrC).poly(dG-5BrdC) in Z conformation. These results provide the first evidence for anti-Z-DNA autoantibodies in autoimmune mice that do not cross-react with native or denatured DNA and indicate that these antibodies exhibit considerable heterogeneity in their fine binding specificity.


Assuntos
Anticorpos Antinucleares/imunologia , Anticorpos Monoclonais/imunologia , Doenças Autoimunes/imunologia , DNA/imunologia , Camundongos Endogâmicos/imunologia , Camundongos Mutantes/imunologia , Animais , Especificidade de Anticorpos , Camundongos , Camundongos Endogâmicos BALB C/imunologia , Conformação de Ácido Nucleico , Polidesoxirribonucleotídeos/síntese química , Polidesoxirribonucleotídeos/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...