RESUMO
Abstract The attention to nuclear clustering has been renewed due to the study of weakly bound nuclei at the drip lines. In particular, clustering structural properties in medium-mass systems have been studied by looking at the competition between the evaporation and pre-equilibrium particle emission in central collisions. Although for light nuclei at an excitation energy close to the particle separation value there are experimental evidence of such structure effects, this is still not the case for heavier systems since the determination of pre-formed clusters within nuclear matter is less obvious. Two systems, leading to the same 81Rb* compound nucleus, have been studied at the same beam velocity 16 AMeV: 16O + 65Cu and 19F + 62Ni. The experiment has been performed using the GARFIELD + RCo detection system installed at the Legnaro National Laboratories.Light charged particles energy distributions and multiplicities have been compared with different statistical and dynamical model calculations. From the first comparison between the two systems a difference in the fast α-decay channel has been evidenced, which can be related to the difference in the projectile structure. Recent data analysis results and comparisons with model calculations are presented in this contribution.
Resumen La atención a la agrupación nuclear se ha renovado debido al estudio de núcleos débilmente unidos en las líneas de goteo. En particular, se han estudiado las propiedades estructurales del agrupamiento en sistemas de masa media al observar la competencia entre la evaporación y la emisión de partículas de preequilibrio en colisiones centrales. Aunque para núcleos ligeros a una energía de excitación cercana al valor de separación de la partícula hay evidencia experimental de tales efectos de estructura, este no es el caso para sistemas más pesados ya que la determinación de agrupamientos preformados dentro de la materia nuclear es menos obvia. Se han estudiado dos sistemas, que conducen al mismo núcleo compuesto 81Rb *, a la misma velocidad de haz 16 AMeV: 16O + 65Cu y 19F + 62Ni. El experimento se ha realizado utilizando el sistema de detección GARFIELD + RCo instalado en los Laboratorios Nacionales Legnaro. Las distribuciones de energía y las multiplicidades de partículas de carga ligera se han comparado con diferentes cálculos de modelos estadísticos y dinámicos. Desde la primera comparación entre los dos sistemas, se ha evidenciado una diferencia en el canal de desintegración α rápida, que se puede relacionar con la diferencia en la estructura del proyectil. En esta contribución se presentan los resultados del análisis de datos recientes y las comparaciones con los cálculos del modelo.
RESUMO
Giara and Sarcidano are 2 of the 15 extant native Italian horse breeds with limited dispersal capability that originated from a larger number of individuals. The 2 breeds live in two distinct isolated locations on the island of Sardinia. To determine the genetic structure and evolutionary history of these 2 Sardinian breeds, the first hypervariable segment of the mitochondrial DNA (mtDNA) was sequenced and analyzed in 40 Giara and Sarcidano horses and compared with publicly available mtDNA data from 43 Old World breeds. Four different analyses, including genetic distance, analysis of molecular variance, haplotype sharing, and clustering methods, were used to study the genetic relationships between the Sardinian and other horse breeds. The analyses yielded similar results, and the FST values indicated that a high percentage of the total genetic variation was explained by between-breed differences. Consistent with their distinct phenotypes and geographic isolation, the two Sardinian breeds were shown to consist of 2 distinct gene pools that had no gene flow between them. Giara horses were clearly separated from the other breeds examined and showed traces of ancient separation from horses of other breeds that share the same mitochondrial lineage. On the other hand, the data from the Sarcidano horses fit well with variation among breeds from the Iberian Peninsula and North-West Europe: genetic relationships among Sarcidano and the other breeds are consistent with the documented history of this breed.
Assuntos
DNA Mitocondrial , Cavalos/genética , Animais , Cruzamento , Análise por Conglomerados , Frequência do Gene , Variação Genética , Genética Populacional , Haplótipos , ItáliaRESUMO
Insulin-degrading enzyme (IDE) or insulysin is a highly conserved Zn(2+) -dependent endopeptidase with an "inverted" HxxEH motif. In vivo, IDE contributes to regulate the steady state levels of peripheral insulin and cerebral amyloid beta peptide (Abeta) of Alzheimer's disease. In vitro, substrates of IDE include a broad spectrum of peptides with relevant physiological functions such as atrial natriuretic factor, insulin-like growth factor-II, transforming growth factor-alpha, beta-endorphin, amylin or glucagon. The recently solved crystal structures of an inactive IDE mutant bound to four different substrates indicate, in accordance with previous compelling biochemical data, that peptide backbone conformation and size are major determinants of IDE recognition and substrate selectivity. IDE-N and IDE-C halves contribute to substrate binding and may rotate away from each other leading to open and closed conformers that permit or preclude the entry of substrates. Noteworthy, stabilization of substrate beta strands in their IDE-bound form may explain the preference of IDE for peptides with a high tendency to self-assembly as amyloid fibrils. These structural requirements may underlie the capability of some amyloid peptides of forming extremely stable complexes with IDE and raise the possibility of a dead-end chaperone-like function of IDE independent of catalysis. Furthermore, the recent recognition of IDE as a varicella zoster virus receptor and its putative involvement in muscle cell differentiation, steroid receptor signaling or proteasome modulation suggest that IDE is a multi-functional protein with broad and relevant roles in several basic cellular processes. Accordingly, IDE functions, regulation or trafficking may partake in the molecular pathogenesis of major human diseases and become potential targets for therapeutic intervention.
Assuntos
Sistemas de Liberação de Medicamentos , Insulisina/metabolismo , Doença de Alzheimer/fisiopatologia , Animais , Varicela/fisiopatologia , Diabetes Mellitus Tipo 2/fisiopatologia , Herpes Zoster/fisiopatologia , Humanos , Insulisina/química , Conformação Proteica , Transdução de Sinais/fisiologia , Especificidade por SubstratoRESUMO
AIMS: The isolation of bovine vaginal lactic acid bacteria (LAB) and the screening of their beneficial properties to select those that could be used as probiotics in the prevention of bovine metritis were performed. METHODS AND RESULTS: Out of 76 Lactobacillus sp. and seven Streptococcus sp. strains, a small number showed high- and medium hydrophobicity when the microbial adhesion to hydrocarbons method (MATH) was applied. In the agar plate diffusion test, a large number of strains inhibited vaginal bovine Escherichia coli 99/14 and human E. coli. This inhibition was due to acid. Only a few strains inhibited Actinomyces pyogenes 96/393, a pathogen isolated from bovine metritis. This inhibition remained after neutralization. The taxonomic identification of the selected strains was carried out by an amplified ribosomal DNA restriction analysis (ARDRA). Most of the strains were identified as Lactobacillus fermentum, a few as Lactobacillus gasseri and one as Lactobacillus rhamnosus. CONCLUSIONS: Bovine vaginal lactobacilli strains have differential surface properties. The strains selected are capable of inhibiting specific metritis pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: Our results can be applied for future studies to design a probiotic product to prevent metritis in dairy postpartum cows.
Assuntos
Doenças dos Bovinos/prevenção & controle , Endometrite/veterinária , Lactobacillus/crescimento & desenvolvimento , Probióticos/farmacologia , Vagina/microbiologia , Actinomyces/crescimento & desenvolvimento , Actinomyces/isolamento & purificação , Actinomicose/microbiologia , Actinomicose/prevenção & controle , Actinomicose/veterinária , Animais , Antibiose , Bovinos , Doenças dos Bovinos/microbiologia , DNA Ribossômico/análise , Endometrite/microbiologia , Endometrite/prevenção & controle , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/prevenção & controle , Infecções por Escherichia coli/veterinária , Feminino , Genes de RNAr , Lactobacillus/classificação , Lactobacillus/genética , Lactobacillus/isolamento & purificação , RNA Ribossômico 16S/genética , Mapeamento por Restrição , Streptococcus/classificação , Streptococcus/genética , Streptococcus/crescimento & desenvolvimento , Streptococcus/isolamento & purificaçãoRESUMO
This study aims to evaluate potentially beneficial properties of 20 strains of vaginal lactobacilli isolated from women in Tucumán, Argentina, by determining acid and hydrogen peroxide production and auto-aggregation ability. The microorganisms were characterised genetically by amplified ribosomal 16S-DNA restriction analysis (ARDRA). Lactobacillus gasseri and L. rhamnosus were the predominant species identified among the 20 vaginal lactobacilli strains. Most achieved low pH values after 12 h incubation at 37 degrees C and produced hydrogen peroxide in static culture. However, pH decrease and semi-quantitative hydrogen peroxide production of most homofermentative lactobacilli were significantly higher than those of heterofermentative lactobacilli. Of the 20 strains studied, only three demonstrated remarkable auto-aggregation patterns. Four strains were selected for possible use in a probiotic product for vaginal application; however, further in vitro study of other potentially probiotic characteristics is required before attempting clinical trials.
Assuntos
Lactobacillus/isolamento & purificação , Probióticos , Vagina/microbiologia , DNA Bacteriano/genética , Feminino , Humanos , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Lactobacillus/classificação , Lactobacillus/metabolismo , RNA Ribossômico 16S/genéticaRESUMO
We analyzed the influence of presenilins on the genetic cascades that control neuronal differentiation in Xenopus embryos. Resembling sonic hedgehog (shh) overexpression, presenilin mRNA injection reduced the number of N-tubulin+ primary neurons and modulated Gli3 and Zic2 according to their roles in activating and repressing primary neurogenesis, respectively. Presenilin increased shh expression within its normal domain, mainly in the floor plate, whereas an antisense X-presenilin-alpha morpholino oligonucleotide reduced shh expression. Both shh and presenilin promoted cell proliferation and apoptosis, but the effects of shh were widely distributed, while those resulting from presenilin injection coincided with the range of shh signaling. We suggest that presenilin may modulate primary neurogenesis, proliferation, and apoptosis in the neural plate, through the enhancement of shh signaling.
Assuntos
Proteínas de Membrana/genética , Proteínas do Tecido Nervoso , Neurônios/citologia , Proteínas Repressoras , Transativadores/genética , Proteínas de Xenopus , Xenopus laevis/embriologia , Secretases da Proteína Precursora do Amiloide , Animais , Apoptose , Ácido Aspártico Endopeptidases , Diferenciação Celular , Divisão Celular , Sistema Nervoso Central/embriologia , Proteínas de Ligação a DNA/genética , Regulação para Baixo , Embrião não Mamífero/citologia , Embrião não Mamífero/metabolismo , Endopeptidases/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas Hedgehog , Hibridização In Situ , Fatores de Transcrição Kruppel-Like , Proteínas de Membrana/fisiologia , Mutagênese Sítio-Dirigida , Oligonucleotídeos Antissenso , Presenilina-1 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais , Transativadores/fisiologia , Fatores de Transcrição/genética , Tretinoína/farmacologia , Tubulina (Proteína)/genética , Tubulina (Proteína)/metabolismo , Xenopus laevis/genética , Xenopus laevis/metabolismo , Proteína Gli3 com Dedos de ZincoRESUMO
We analyze the synchronization transition for a pair of coupled identical Kauffman networks in the chaotic phase. The annealed model for Kauffman networks shows that synchronization appears through a transcritical bifurcation and provides an approximate description for the whole dynamics of the coupled networks. We show that these analytical predictions are in good agreement with numerical results for sufficiently large networks and study finite-size effects in detail. Preliminary analytical and numerical results for partially disordered networks are also presented.
RESUMO
Alzheimer's disease (AD) is characterized by the presence of neurofibrillary tangles (NFT), senile plaques, and cerebrovascular deposits of amyloid-beta. Ubiquitin has also been shown to be present in some of the inclusions characteristic of this disease. To obtain further insight into the role played by the ubiquitin pathway in AD, we investigated the capacity of postmortem samples of cerebral cortex from normal and AD patients to form high-molecular-weight ubiquitin-protein conjugates. Activity of the ubiquitin-activating enzyme (E1) and ubiquitin-conjugating enzymes (E2) involved in the ubiquitin pathway was also determined. In normal samples, the amount of high-molecular-weight ubiquitin-protein conjugates (HMW-UbPC) in cytosol increased with incubation time, whereas, in samples of AD cases, these were almost undetectable. The addition of an adult rat fraction, enriched in ubiquitinating enzymes, restored the capacity of AD brain cytosolic fraction to form conjugates. The trypsin-like proteolytic activity of the 26S proteasome was found to be decreased in AD cytosol brain. Assay of the activity of E1 and E2 by thiol-ester formation revealed a significant decrease in AD samples. Moreover, Western blotting using a specific antibody against E1 showed a dramatic drop of this enzyme in the cytosolic fraction, whereas normal levels were found in the particulate fraction, suggesting a possible delocalization of the enzyme. Our results suggest that a failure in the ubiquitination enzymatic system in brain cytosol may contribute to fibrillar pathology in AD.
Assuntos
Doença de Alzheimer/enzimologia , Córtex Cerebral/enzimologia , Citosol/enzimologia , Ubiquitinas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Cisteína Endopeptidases/metabolismo , Humanos , Pessoa de Meia-Idade , Complexos Multienzimáticos/metabolismo , Complexo de Endopeptidases do Proteassoma , Proteínas/metabolismo , RatosRESUMO
Insulin degrading enzyme (IDE) is a metalloprotease that has been involved in amyloid beta peptide (A(beta)) degradation in the brain. We analyzed the ability of human brain soluble fraction to degrade A(beta) analogs 1-40, 1-42 and the Dutch variant 1-40Q at physiological concentrations (1 nM). The rate of synthetic 125I-A(beta) degradation was similar among the A(beta) analogs, as demonstrated by trichloroacetic acid precipitation and SDS-PAGE. A 110 kDa protein, corresponding to the molecular mass of IDE, was affinity labeled with either 125I-insulin, 125I-Abeta 1-40 or 125I-A(beta) 1-42 and both A(beta) degradation and cross-linking were specifically inhibited by an excess of each peptide. Sensitivity to inhibitors was consistent with the reported inhibitor profile of IDE. Taken together, these results suggested that the degradation of A(beta) analogs was due to IDE or a closely related protease. The apparent Km, as determined using partially purified IDE from rat liver, were 2.2 +/- 0.4, 2.0 +/- 0.1 and 2.3 +/- 0.3 microM for A(beta) 1-40, A(beta) 1-42 and A(beta) 1-40Q, respectively. Comparison of IDE activity from seven AD brain cytosolic fractions and six age-matched controls revealed a significant decrease in A(beta) degrading activity in the first group, supporting the hypothesis that a reduced IDE activity may contribute to A(beta) accumulation in the brain.
Assuntos
Doença de Alzheimer/enzimologia , Peptídeos beta-Amiloides/metabolismo , Encéfalo/enzimologia , Insulisina/metabolismo , Fragmentos de Peptídeos/metabolismo , Animais , Western Blotting , Estudos de Casos e Controles , Eletroforese em Gel de Poliacrilamida , Humanos , Hidrólise , Ratos , Ratos Wistar , Especificidade por SubstratoRESUMO
Alzheimer's disease (AD) is characterized by the massive deposition in the brain of the 40-42-residue amyloid beta protein (A(beta)). While A(beta)1-40 predominates in the vascular system, A(beta)1-42 is the major component of the senile plaques in the neuropil. The concentration of both A(beta) species required to form amyloid fibrils in vitro is micromolar, yet soluble A(betas) found in normal and AD brains are in the low nanomolar range. It has been recently proposed that the levels of A(beta) sufficient to trigger amyloidogenesis may be reached intracellularly. To study the internalization and intracellular accumulation of the major isoforms of A(beta), we used THP-1 and IMR-32 neuroblastoma cells as models of human monocytic and/or macrophagic and neuronal lineages, respectively. We tested whether these cells were able to internalize and accumulate 125I-A(beta)1-40 and 125I-A(beta)1-42 differentially when offered at nanomolar concentrations and free of large aggregates, conditions that mimic a prefibrillar stage of A(beta) in AD brain. Our results showed that THP-1 monocytic cells internalized at least 10 times more 125I-A(betas) than IMR-32 neuroblastoma cells, either isolated or in a coculture system. Moreover, 125I-A(beta)1-42 presented a higher adsorption, internalization, and accumulation of undigested peptide inside cells, as opposed to 125I-A(beta)1-40. These results support that A(beta)1-42, the major pathogenic form in AD, may reach supersaturation and generate competent nuclei for amyloid fibril formation intracellularly. In light of the recently reported strong neurotoxicity of soluble, nonfibrillar A(beta)1-42, we propose that intracellular amyloidogenesis in microglia is a protective mechanism that may delay neurodegeneration at early stages of the disease.
Assuntos
Peptídeos beta-Amiloides/metabolismo , Monócitos/metabolismo , Neuroblastoma/metabolismo , Fragmentos de Peptídeos/metabolismo , Adsorção , Doença de Alzheimer/metabolismo , Neuropatias Amiloides/metabolismo , Linhagem Celular , Técnicas de Cocultura , Humanos , Radioisótopos do Iodo/análise , Isoformas de Proteínas , Células Tumorais CultivadasRESUMO
Microglial cell involvement in Alzheimer's disease has been related to amyloid beta (A beta) internalization, the release of inflammatory cytokines and the development of neuritic plaques. The human monocyte/macrophage THP-1 cell line has been widely used as a model of human microglial cells. We used THP-1 cells to study the adsorption, internalization and resistance to degradation of A beta1-40 and A beta1-42 isoforms offered at nanomolar concentrations and free of large aggregates, conditions that may mimic a pre-fibrillar stage of A beta in the brain. Under these conditions, A betas did not induce THP-1 activation, as assessed by interleukin-1beta expression. A beta1-42 showed a preferential adsorption and intracellular accumulation as compared to A beta1-40, supporting that competent nuclei for A beta1-42 ordered aggregation may be formed inside microglial cells. In light of the possible neurotoxicity of soluble A beta1-42, we propose that amyloid formation within brain phagocytic cells may be a protective mechanism in early stages of the disease.
Assuntos
Peptídeos beta-Amiloides/metabolismo , Monócitos/metabolismo , Fragmentos de Peptídeos/metabolismo , Linhagem Celular , Humanos , Microglia/metabolismo , Placa Amiloide/metabolismoRESUMO
Most of the cases of early-onset familial Alzheimer's disease (FAD) are related to missense mutations in the presenilin 1 (PS-1) gene on chromosome 14. Although PS-1 mutations are distributed throughout the entire open reading frame, most mutations are found in transmembrane region II and hydrophilic loop VI encoded by exons 5 and 8, respectively. These two groups of substitutions are associated with an age of onset of 40-43 years for exon 5 and 45-55 years for exon 8, respectively. We have previously described a South American pedigree from Argentina with early-onset FAD (mean age of onset 38.9 +/- 3.9 years) with no mutations in exons 16 and 17 of the beta-protein precursor gene (betaPP770 transcript). Here we report the identification of an A --> T transversion at the first position of codon 146 of PS-1 in these patients. This missense mutation results in a Met --> Leu substitution, as reported for the Italian pedigrees Tor1.1 and FAD4. The significant differences in ages of onset and death among members of generations II-III and IV suggest that other genetic and/or environmental factors may influence disease phenotype in this pedigree.
Assuntos
Adenina , Doença de Alzheimer/genética , Variação Genética , Leucina/genética , Proteínas de Membrana/genética , Metionina/genética , Timina , Adulto , Idade de Início , Substituição de Aminoácidos , Argentina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem , Presenilina-1RESUMO
This paper presents allele frequencies of two short tandem repeats (CD4 and F13A1) in three anthropologically defined populations: Sardinians (Italy), Corsicans (France) and Piaroa Indians (Venezuela). The comparison shows some relevant differences both in number and distribution of the CD4 and F13A1 alleles.
Assuntos
Antígenos CD4/genética , Fator XIII/genética , Variação Genética , Indígenas Sul-Americanos/genética , Repetições de Microssatélites , Cromossomos Humanos Par 12 , Cromossomos Humanos Par 6 , França , Humanos , Itália , VenezuelaRESUMO
In order to analyse the humoral immune response to the commensal yeast Pityrosporum ovale, we developed a western immunoblot technique with a salt soluble extract of P. ovale cytoplasm. In the present study, we tested sera from patients with psoriasis (n = 15), seborrhoeic dermatitis (n = 10), pityriasis versicolor (n = 8), and normal controls (n = 10). Seventy-three per cent (11/15) of the patients with psoriasis showed specific reactivity with a protein derived from P. ovale of estimated molecular mass 120 kDa, and 46% (7/15) of the cases recognized a 100-kDa protein. Sera from pityriasis versicolor and normal donors showed nonspecific reactivity with several bands of lower molecular weight. To characterize the location of the 100 and 120-kDa proteins, we performed a lyticase digestion of the cell wall, and analysed the soluble digested products by western blotting. The sera from psoriasis patients detected several bands in the range 100-120 kDa. The finding of the immunoreactive 120-kDa protein in this fraction suggests its location at the space between cell wall and membrane (periplasmic space). As a control, we performed an extraction of the cytoplasmic proteins of the dimorphic yeast Candida albicans. C. albicans showed a different pattern of banding in SDS-PAGE. Immunoblots with C. albicans did not allow the detection of any related band. A smear was observed in the high molecular weight range consistent with the presence of lipopolysaccharides. The role of the immune response in infection by P. ovale has not yet been fully explored.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Anticorpos Antifúngicos/sangue , Proteínas Fúngicas/imunologia , Malassezia/imunologia , Psoríase/imunologia , Biomarcadores/sangue , Western Blotting , Dermatite Seborreica/imunologia , Humanos , Psoríase/microbiologia , Tinha Versicolor/imunologiaRESUMO
The aim of this study is to identify the oligosaccharide residues involved in the asymmetric glycosylation of immunoglobulins. We have studied two anti-DNP monoclonal antibodies of the IgG1 isotype. Results show both qualitative and quantitative differences in the carbohydrates of both monoclonal antibodies and their fragments F(ab')2, Fab' and Fd. One of the antibodies -112D5-, which appears to be homogeneous in the Scatchard plot, has oligosaccharide residues in the L chain and in the Fd of one of the Fab'. On the other hand, 112B2 mAb, which also appears to be asymmetrically glycosylated, shows the bimodal curve characteristic of antibodies with different combining site affinities.
Assuntos
Anticorpos Monoclonais/metabolismo , Imunoglobulina G/metabolismo , Oligossacarídeos/metabolismo , Animais , Afinidade de Anticorpos , Western Blotting , Glicosilação , Fragmentos Fab das Imunoglobulinas/metabolismo , Técnicas In Vitro , Lectinas/metabolismo , Camundongos , Relação Estrutura-AtividadeRESUMO
Se presentan resultados que muestan que el análisis por immunoblotting de la respuesta inmune humoral de pacientes brucelosos permite la caracterización de componentes antigénicso de posible utilidad para el diagnóstico de la enfermedad. Se analizó el suero de 90 pacientes: 20 brucelosos agudos, 23 crónicos y 47 individuos serológicamente positivos sin evidencias clínicas de infección activa al momento del examen (SPI); se utilizó además el suero de 35 personas sanas como control. Todos los sueros fueron ensayados frente a tres fracciones antigéneticas: citoplasmáticas (CYT), membrana externa (OM) y membrana interna (IM). Dichas fracciones, que incluyen virtualmente todas las proteínas bacterianas, fueron preparadas a partir de Brucella abortus 1119/3 por solubilización con detergentes, digestión enzimática y ultracentrifugación. Los resultados obtenidos revelan la existencia de antígenos que permiten detectar a pacientes brucelosos con alta sensibilidad, y diferenciar a éstos del grupo SPI (AU)
Assuntos
Brucelose/diagnóstico , Brucella abortus/imunologia , Antígenos de Bactérias/análise , Immunoblotting , Testes Sorológicos , Epitopos , Sensibilidade e EspecificidadeRESUMO
Se presentan resultados que muestan que el análisis por immunoblotting de la respuesta inmune humoral de pacientes brucelosos permite la caracterización de componentes antigénicso de posible utilidad para el diagnóstico de la enfermedad. Se analizó el suero de 90 pacientes: 20 brucelosos agudos, 23 crónicos y 47 individuos serológicamente positivos sin evidencias clínicas de infección activa al momento del examen (SPI); se utilizó además el suero de 35 personas sanas como control. Todos los sueros fueron ensayados frente a tres fracciones antigéneticas: citoplasmáticas (CYT), membrana externa (OM) y membrana interna (IM). Dichas fracciones, que incluyen virtualmente todas las proteínas bacterianas, fueron preparadas a partir de Brucella abortus 1119/3 por solubilización con detergentes, digestión enzimática y ultracentrifugación. Los resultados obtenidos revelan la existencia de antígenos que permiten detectar a pacientes brucelosos con alta sensibilidad, y diferenciar a éstos del grupo SPI
Assuntos
Antígenos de Bactérias/análise , Brucella abortus/imunologia , Brucelose/diagnóstico , Epitopos , Immunoblotting , Sensibilidade e Especificidade , Testes SorológicosRESUMO
Results indicating that analysis of the immune humoral response of brucellosis patients by immunoblotting provides useful information for the characterization of antigenic fractions of possible diagnostic importance in human brucellosis are presented. Sera of 90 patients were obtained: 23 suffering from chronic brucellosis, 20 from acute brucellosis and 47 belonging to the group of serologically positive individuals (SPI) without clinical evidence of active infection at the time of examination, and 35 healthy volunteers. They were tested against three antigenic fractions: cytoplasmic (CYT), outer membrane (OM) and inner membrane (IM). These fractions, which include virtually all the bacterial protein components, were prepared from Brucella abortus 1119/3 strain by detergent solubilization, enzymatic digestion and ultracentrifugation. Results obtained with these fractions showed the existence of antigens that permit the detection of brucellosis patients and their differentiation from SPI patients, with very high sensitivity.
Assuntos
Antígenos de Bactérias/análise , Brucella abortus/imunologia , Brucelose/diagnóstico , Epitopos , Humanos , Immunoblotting , Sensibilidade e Especificidade , Testes SorológicosRESUMO
Results indicating that analysis of the immune humoral response of brucellosis patients by immunoblotting provides useful information for the characterization of antigenic fractions of possible diagnostic importance in human brucellosis are presented. Sera of 90 patients were obtained: 23 suffering from chronic brucellosis, 20 from acute brucellosis and 47 belonging to the group of serologically positive individuals (SPI) without clinical evidence of active infection at the time of examination, and 35 healthy volunteers. They were tested against three antigenic fractions: cytoplasmic (CYT), outer membrane (OM) and inner membrane (IM). These fractions, which include virtually all the bacterial protein components, were prepared from Brucella abortus 1119/3 strain by detergent solubilization, enzymatic digestion and ultracentrifugation. Results obtained with these fractions showed the existence of antigens that permit the detection of brucellosis patients and their differentiation from SPI patients, with very high sensitivity.