RESUMEN
BACKGROUND: The Alzheimer's disease (AD) brain displays atrophy with amyloid-ß (Aß) and tau deposition, whereas decreased Aß42 and increased tau are measured in cerebrospinal fluid (CSF). The aim of this study was to relate cognitive performance to the degree of brain atrophy, CSF biomarker levels and neuropathology in a cohort of aged men. METHODS: Fifty-eight 86-92-year-old men from the Uppsala Longitudinal Study of Adult Men (ULSAM) cohort underwent cognitive testing, brain computed tomography and lumbar puncture. Atrophy was graded with established scales. Concentrations of CSF Aß42, t-tau and p-tau were measured by ELISA. Thirteen brains were examined post mortem. RESULTS: Forty-six of the individuals were considered non-demented, whereas twelve were diagnosed with dementia, either at baseline (n = 4) or during follow-up (n = 8). When comparing subjects with and without dementia, there were no differences in the degree of atrophy, although the mini mental state examination (MMSE) scoring correlated weakly with the degree of medial temporal atrophy (MTA) (p = 0.04). Moreover, the CSF biomarker levels did not differ significantly between healthy (n = 27) and demented (n = 8) subjects (median values 715 vs 472 pg/ml for Aß42, 414 vs 427 pg/ml for t-tau and 63 vs 60 pg/ml for p-tau). Similarly, there were no differences in the biomarker levels between individuals with mild (n = 24) and severe (n = 11) MTA (median values 643 vs 715 pg/ml for Aß42, 441 vs 401 pg/ml for t-tau and 64 vs 53 pg/ml for p-tau). Finally, the neuropathological changes did not correlate with any of the other measures. CONCLUSION: In this cohort of aged men only a weak correlation could be seen between cognitive performance and MTA, whereas the various neuroradiological, biochemical and neuropathological measures did not correlate with each other. Thus, AD biomarkers seem to be less informative in subjects of an advanced age.
Asunto(s)
Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/metabolismo , Encéfalo/patología , Cognición/fisiología , Proteínas tau/metabolismo , Anciano de 80 o más Años , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/metabolismo , Biomarcadores/metabolismo , Líquido Cefalorraquídeo/metabolismo , Ensayo de Inmunoadsorción Enzimática , Humanos , Estudios Longitudinales , MasculinoRESUMEN
BACKGROUND: Family history is one of the most consistent risk factors for dementia. Therefore, analysis of families with a distinct inheritance pattern of disease can be a powerful approach for the identification of previously unknown disease genes. OBJECTIVE: To map susceptibility regions for Alzheimer's disease. METHODS: A complete genome scan with 369 microsatellite markers was carried out in 12 extended families collected in Sweden. Age at disease onset ranged from 53 to 78 years, but in 10 of the families there was at least one member with age at onset of < or =65 years. Mutations in known early-onset Alzheimer's disease susceptibility genes have been excluded. All people were genotyped for APOE, but no clear linkage with the epsilon4 allele was observed. RESULTS: Although no common disease locus could be found in all families, in two families an extended haplotype was identified on chromosome 8q shared by all affected members. In one of the families, a non-parametric multimarker logarithm of the odds (LOD) score of 4.2 (p = 0.004) was obtained and analysis based on a dominant model showed a parametric LOD score of 2.4 for this region. All six affected members of this family shared a haplotype of 10 markers spanning about 40 cM. Three affected members in another family also shared a haplotype in the same region. CONCLUSION: On the basis of our data, we propose the existence of a dominantly acting Alzheimer's disease susceptibility locus on chromosome 8.
Asunto(s)
Enfermedad de Alzheimer/genética , Cromosomas Humanos Par 8/genética , Predisposición Genética a la Enfermedad/genética , Anciano , Apolipoproteínas E/genética , Análisis Mutacional de ADN , Salud de la Familia , Femenino , Ligamiento Genético/genética , Genoma Humano/genética , Genotipo , Haplotipos/genética , Humanos , Escala de Lod , Masculino , Repeticiones de Microsatélite , Persona de Mediana Edad , Linaje , Polimorfismo Conformacional Retorcido-Simple , SueciaRESUMEN
Interleukin-18 is a proinflammatory cytokine, which strongly induces IFN-gamma production. We have cloned the human IL-18 promoter and screened for possible polymorphisms. Three single nucleotide polymorphisms were detected in the promoter and two polymorphisms in the 5'-nontranslated region of the gene. Three combinations of these polymorphisms were observed in the Swedish population. All IL-18 promoter alleles were found to have clear promoter activity when inserted into a luciferase reporter vector. There were no significant differences in promoter activity between alleles without stimulation, but after stimulation with PMA/ionomicin one of the alleles had clearly lower activity than the other (P<0.01). Measurement of IL-18 and IFN-gamma production in 48 multiple sclerosis patients by RT-PCR showed slightly higher expression of IL-18 in individuals homozygous for the most frequent haplotype. Two IL-18 promoter polymorphisms were analyzed by sequence specific PCR in 208 multiple sclerosis patients and 139 healthy controls, however, no significant differences were found. In summary, our data indicate that common IL-18 promoter polymorphisms influence the expression of IL-18 and potentially also of IFN-gamma.
Asunto(s)
Regulación de la Expresión Génica , Interleucina-18/genética , Esclerosis Múltiple/genética , Polimorfismo Genético , Regiones Promotoras Genéticas , Alelos , Secuencia de Bases , Clonación Molecular , Células HeLa , Humanos , Interferón gamma/genética , Datos de Secuencia MolecularRESUMEN
To investigate whether arbitrarily primed (AP)-PCR and/or 16S rDNA sequencing could be used as rapid methods for epidemiological typing and species identification of clinical Burkholderia isolates from patients with cystic fibrosis (CF), a total of 39 clinical B. cepacia isolates, including 33 isolates from 14 CF patients, were fingerprinted. ERIC-2 primer was used for AP-PCR. The AP-PCR clustering analysis resulted in 14 different clusters at a 70% similarity level. The AP-PRC patterns were individual despite considerable similarities. To sequence rDNA, a broad-range PCR was applied. The PCR product included four variable loops (V8, V3, V4 and V9) of the 16S ribosomal small subunit RNA gene. The multiple sequence alignment produced 12 different patterns, 5 of them including more than one isolate. Heterogeneity of the bases in the V3 region, indicating the simultaneous presence of at least two different types of 16S rRNA genes in the same cell, was revealed in 10 isolates. Most of the CF patients were adults who had advanced disease at follow-up. Both the sequencing and the AP-PCR patterns revealed genetic heterogeneity of isolates between patients. According to the results obtained, AP-PCR could advantageously be used for epidemiological typing of Burkholderia, whereas partial species identification could effectively be obtained by sequencing of the V3 region of the 16S RNA gene.
Asunto(s)
Infecciones por Burkholderia/epidemiología , Burkholderia cepacia/genética , Fibrosis Quística/complicaciones , ADN Ribosómico/genética , Filogenia , Reacción en Cadena de la Polimerasa/métodos , ARN Ribosómico 16S/genética , Adolescente , Adulto , Secuencia de Bases , Burkholderia/clasificación , Burkholderia/genética , Burkholderia/aislamiento & purificación , Infecciones por Burkholderia/complicaciones , Burkholderia cepacia/clasificación , Burkholderia cepacia/aislamiento & purificación , Fibrosis Quística/genética , Cartilla de ADN , ADN Ribosómico/análisis , Femenino , Genes Bacterianos/genética , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Epidemiología Molecular/métodos , Datos de Secuencia Molecular , Prevalencia , Esputo/microbiología , Suecia/epidemiologíaRESUMEN
BACKGROUND: Multiple lines of research suggest that increased cystatin C activity in the brain protects against the development of Alzheimer disease (AD). METHODS: Serum cystatin C levels were analyzed at two examinations of the Uppsala Longitudinal Study of Adult Men, a longitudinal, community-based study of elderly men (age 70 years, n = 1,153 and age 77 years, n = 761, a subset of the age 70 examination). Cox regressions were used to examine associations between serum cystatin C and incident AD. AD cases were identified by cognitive screening and comprehensive medical chart review in all subjects. RESULTS: On follow-up (median 11.3 years), 82 subjects developed AD. At age 70 years, lower cystatin C was associated with higher risk of AD independently of age, APOE4 genotype, glomerular filtration rate, diabetes, hypertension, stroke, cholesterol, body mass index, smoking, education level, and plasma amyloid-beta protein 40 and 42 levels (hazard ratio [HR] for lowest [<1.12 micromol/L] vs highest [>1.30 micromol/L] tertile = 2.67, 95% CI 1.22-5.83, p < 0.02). The results were similar at age 77 years (43 participants developed AD during follow-up). Furthermore, a 0.1-mumol/L decrease of cystatin C between ages 70 and 77 years was associated with a 29% higher risk of incident AD (HR 1.29, 95% CI 1.03-1.63, p < 0.03). CONCLUSIONS: Low levels of serum cystatin C precede clinically manifest Alzheimer disease (AD) in elderly men free of dementia at baseline and may be a marker of future risk of AD. These findings strengthen the evidence for a role for cystatin C in the development of clinical AD.
Asunto(s)
Envejecimiento/sangre , Enfermedad de Alzheimer/sangre , Enfermedad de Alzheimer/epidemiología , Cistatinas/sangre , Citoprotección/fisiología , Anciano , Enfermedad de Alzheimer/fisiopatología , Biomarcadores/análisis , Biomarcadores/sangre , Encéfalo/metabolismo , Encéfalo/fisiopatología , Causalidad , Estudios de Cohortes , Cistatina C , Cistatinas/análisis , Regulación hacia Abajo/fisiología , Humanos , Hiperlipidemias/epidemiología , Enfermedades Renales/epidemiología , Estudios Longitudinales , Masculino , Obesidad/epidemiología , Valor Predictivo de las Pruebas , Modelos de Riesgos Proporcionales , Factores de Riesgo , Fumar/epidemiología , Suecia/epidemiologíaRESUMEN
Interferon-gamma (IFN-gamma) plays a crucial role in the regulation of the immune response. Alterations in IFN-gamma production have been found in several diseases including multiple sclerosis (MS). Such alterations could be caused by the action of different factors on cytokine production, or, theoretically, by mutations in the gene. We screened the IFN-gamma gene promoter and part of the first intron, known to contain a c-Rel specific enhancer, for possible mutations by sequencing. We found a C to T substitution in the IFN-gamma promoter at position -333. Screening for this mutation by sequence-specific PCR in 214 MS patients and 164 controls identified two patients, both heterozygous, but no controls with this mutation. No mutations were found in the first intron. The interferon-gamma gene is highly conserved and changes in IFN-gamma expression are probably due to the influence of regulatory factors on gene transcription, rather than gene polymorphisms.
Asunto(s)
Interferón gamma/genética , Esclerosis Múltiple/genética , Mutación , Polimorfismo Genético , Estudios de Casos y Controles , Análisis Mutacional de ADN , Regulación de la Expresión Génica , Humanos , Intrones , Regiones Promotoras Genéticas , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas c-rel , Secuencias Reguladoras de Ácidos Nucleicos , Transcripción GenéticaRESUMEN
A rapid ELISA test for detection, characterization and quantification of human paraproteins was developed. The proposed method is a sandwich ELISA, where the capture antibody is specific for a given heavy chain (gamma, alpha or mu) and the labelled antibody is specific either for kappa or for lambda light chain. Both standard and patient sera are tested with all six possible antibody combinations. Each paraprotein produces a significant increase in titre (as compared with standard) only when tested with the relevant pair of antibodies. This enables the determination of the isotype and light chain type of the paraprotein and the evaluation of its relative quantity in patient serum. The accuracy of the assay (relative deviation) varies from 0.04 for gamma lambda to 0.19 for alpha kappa. The cut-off values for each type of polyclonal immunoglobulin were determined with 200 healthy donor sera. 103 patient sera were analysed. ELISA data are in good agreement with M-component and other clinical data.
Asunto(s)
Ensayo de Inmunoadsorción Enzimática , Paraproteinemias/diagnóstico , Paraproteínas/análisis , Anticuerpos Monoclonales/inmunología , Enfermedades Autoinmunes/diagnóstico , Enfermedades Hematológicas/diagnóstico , Humanos , Inmunoglobulinas/sangre , Proteínas de Mieloma/análisis , Proteínas de Mieloma/inmunología , Neoplasias/diagnóstico , Paraproteínas/clasificación , Paraproteínas/inmunología , Reproducibilidad de los ResultadosRESUMEN
Multiple sclerosis (MS) is an inflammatory, demyelinating disease of the central nervous system (CNS) characterized by blood-brain barrier (BBB) breakdown. Disruptions of BBB continuity result in an influx of activated T cells and monocytes, and could contribute to lesion formation in the CNS. Matrix metalloproteinases (MMP) are enzymes implicated in BBB disruption, and in degradation of extracellular matrix proteins and myelin components. An imbalance in levels of MMP and tissue inhibitors of MMP (TIMP) has been implicated in the pathogenesis of MS. Since monocytes form a major cell population in acute MS lesions and may facilitate their entrance into the CNS by secretion of MMP, knowledge on MMP expression by blood monocytes could be useful to improve our understanding of the pathogenesis of MS. In the present study, we examined the expression of MMP-1, -3, -7, -9, -14 and TIMP-1 mRNA by blood monocytes in patients with MS using in situ hybridization. Levels of MMP-1, -3, -7, -9 and of TIMP-1 mRNA expressing monocytes were elevated in MS compared to controls, while those of MMP-14 did not differ. We therefore conclude that MS is associated with elevated levels of MMP and TIMP expressing blood monocytes that may contribute to MS pathogenesis.
Asunto(s)
Expresión Génica , Metaloproteinasas de la Matriz/genética , Monocitos/enzimología , Esclerosis Múltiple/enzimología , Inhibidor Tisular de Metaloproteinasa-1/genética , Femenino , Humanos , Masculino , Metaloproteinasa 1 de la Matriz/genética , Metaloproteinasa 1 de la Matriz/metabolismo , Metaloproteinasa 3 de la Matriz/genética , Metaloproteinasa 3 de la Matriz/metabolismo , Metaloproteinasa 7 de la Matriz/genética , Metaloproteinasa 7 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Metaloproteinasas de la Matriz/metabolismo , Metaloproteinasas de la Matriz Asociadas a la Membrana , Metaloendopeptidasas/genética , Metaloendopeptidasas/metabolismo , Persona de Mediana Edad , Esclerosis Múltiple/genética , ARN Mensajero , Inhibidor Tisular de Metaloproteinasa-1/metabolismoRESUMEN
Epidemiological studies show that susceptibility to multiple sclerosis (MS) has a strong genetic component, but apart from the HLA gene complex, additional genetic factors have proven difficult to map in the general population. Thus, localized populations, where MS patients are assumed to be more closely related, may offer a better opportunity to identify shared chromosomal regions. We have performed a genome-wide scan with 834 microsatellite markers in a data set consisting of 54 MS patients and 114 healthy family members. A group of families from a small village were possible to track back to common ancestors living in the 17th century. We used single marker- and haplotype-based transmission disequilibrium test (TDT) analysis and nonparametric linkage analysis to analyze genotyping data. Regions on chromosomes 2q23-31, 6p24-21, 6q25-27, 14q24-32, 16p13-12 and 17q12-24 were found to be in transmission disequilibrium with MS. Strong transmission disequilibrium was detected in 14q24-32, where several dimarker haplotypes were in transmission disequilibrium in affected individuals. Several regions showed modest evidence for linkage, but linkage and TDT were both clearly positive only for 17q12-24. All patients and controls were also typed for HLA class II genes; however, no evidence for a gene-gene interaction was observed.
Asunto(s)
Cromosomas Humanos Par 14/genética , Predisposición Genética a la Enfermedad , Genoma Humano , Desequilibrio de Ligamiento , Esclerosis Múltiple/genética , Marcadores Genéticos/genética , Haplotipos/genética , Humanos , Repeticiones de Microsatélite/genética , Linaje , SueciaRESUMEN
Interferon gamma (IFN gamma) and interleukin 4, 10 and 12 (IL-4, -10, -12) production was measured in whole peripheral blood (WPB) and peripheral blood mononuclear cells (PBMC) of 10 chronic hepatitis C (CHC) patients. The level of IFN gamma in supernatants in mitogen-activated WPB was lower than in healthy donors. IL-10 served as a possible downregulative factor for IFN gamma, since its spontaneous IL-10 production was enhanced in CHC. Neutralization of IL-10 partly restored IFN gamma response in CHC patients. Recombinant IL-12 (rIL-12) also enhanced IFN gamma of CHC patients, but IL-12 production was decreased in CHC. Thus, IFN gamma production deficiency in CHC patients is secondary to blockage by high levels of IL-10-impaired IL-12 production.