RESUMEN
The evaluation of urinary albumin excretion (UAE) and estimated glomerular filtration rate (eGFR) is suggested for the assessment of cardiovascular risk. It is unclear whether UAE and eGFR provide complementary information. UAE, eGFR, cardiovascular risk factors, and the incidence of cardiovascular disease were analyzed in 45- to 64-year-old individuals involved in the Gubbio study. UAE in the highest decile was defined as high (microng/min: > or = 18.6 in men and > or = 15.7 in women), eGFR in the lowest decile as low (mL/min/1.73 m(2): <64.2 in men and <57.9 in women). Kidney dysfunction was more frequent when defined by both markers than when defined by one marker only (UAE or eGFR) because high UAE and low eGFR tended to cluster in different individuals. The hazard ratio (HR) for incident cardiovascular disease was 1.85 in individuals with high UAE only (95%CI 1.04-3.25), 1.84 in individuals with low eGFR only (95%CI 1.04-3.26), and 5.93 in individuals with high UAE and low eGFR (95%CI 2.58-13.61). Concomitant evaluation of UAE and eGFR should be considered to adequately assess kidney dysfunction and cardiovascular risk.
Asunto(s)
Enfermedades Cardiovasculares/etiología , Enfermedades Renales/complicaciones , Enfermedades Cardiovasculares/epidemiología , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana EdadRESUMEN
Estimated glomerular filtration rate (eGFR) and urinary albumin (U-Alb) have been suggested as indicators for the early identification of persons with kidney dysfunction. The Gubbio Study collected data on serum creatinine, UAlb, other laboratory indices, blood pressure, and medical history in a population sample of 4574 adults (2083 men and 2491 women, age range 18- 95 years). The study included analyses on six disorders which are commonly associated with kidney disease (hypertension, cardiovascular disease, anemia, high serum uric acid, high serum phosphorus/low serum calcium, and high serum potassium). Low eGFR (<60 mL/min per 1.73 m2) was found in 6.6% of men and 6.2% of women. Low eGFR prevalence varied largely with age (from <1% at 18-24 years up to > 30% at > or =75 years in both sexes, p<0.001). On the basis of these data, it was estimated that the prevalence of low eGFR in the whole Italian population could be 1.3 million among men (95%CI 1.1/1.5) and 1.5 million among women (95%CI 1.3/1.8). Data available only for age 45-64 indicate that 6.4% of men and 3.0% of women have high U-Alb (> or =20 microg/min) in the presence of non-low eGFR. Low eGFR was associated with at least two disorders potentially due to kidney disease in the majority of persons but was rarely associated with a previous diagnosis of kidney disease (<5% of cases). These data support the use of eGFR for the screening of people with or at risk of developing kidney disease. Awareness of kidney disease is very low in the Italian population.
Asunto(s)
Insuficiencia Renal Crónica/diagnóstico , Insuficiencia Renal Crónica/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Diagnóstico Precoz , Femenino , Humanos , Riñón/fisiopatología , Masculino , Persona de Mediana Edad , Insuficiencia Renal Crónica/fisiopatología , Adulto JovenAsunto(s)
Reordenamiento Génico de Linfocito T , Cadenas Pesadas de Inmunoglobulina/genética , Región de Unión de la Inmunoglobulina/genética , Leucemia-Linfoma de Células T del Adulto/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Receptores de Antígenos de Linfocitos T/genética , Niño , Humanos , Región Variable de Inmunoglobulina/genética , Leucemia-Linfoma de Células T del Adulto/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Recurrencia , Análisis de Secuencia de ADN/métodosRESUMEN
Detection of minimal residual disease (MRD), using immunoglobulin (Ig) and T-cell receptor (TCR) gene rearrangements as clone-specific targets, represents the most recent development in diagnosis and treatment of acute lymphoblastic leukaemia (ALL). Nevertheless, risk of false-negative results, due to secondary or ongoing rearrangements of Ig/TCR genes during the disease course, might hamper MRD detection. Therefore, to gain extensive information on clonal stability, we performed PCR-GeneScan analysis of Ig/TCR gene rearrangements at diagnosis and subsequent relapse in bone marrow samples from 53 childhood precursor-B-ALL patients. In addition, sequencing analysis of junctional regions at diagnosis and relapse provided a detailed insight in the stability and changes of Ig/TCR gene rearrangements during the disease course. At least one stable clonal Ig/TCR target was found in 94% of patients. In three patients complete differences in Ig/TCR rearrangements between diagnosis and relapse were observed, suggesting relapse with a new clone. At relapse, 71% of diagnostic clonal PCR targets was conserved. Since the comparison of Ig/TCR gene rearrangements at diagnosis and relapse in our precursor-B-ALL patients did not show significant difference in the stability of different clonal PCR targets (IGH, 70%; IGK, 71%; TCRD, 67%; TCRG, 75%), we conclude that there is no 'preferential' clone-specific target for MRD monitoring.
Asunto(s)
Neoplasia Residual/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Análisis de Secuencia de ADN , Adolescente , Niño , Preescolar , Células Clonales/patología , Femenino , Estudios de Seguimiento , Reordenamiento Génico de Linfocito B , Reordenamiento Génico de Linfocito T , Genes de Inmunoglobulinas , Humanos , Lactante , Masculino , Neoplasia Residual/diagnóstico , Neoplasia Residual/genética , Reacción en Cadena de la Polimerasa , Leucemia-Linfoma Linfoblástico de Células Precursoras B/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Recurrencia , Factores de TiempoRESUMEN
The wild-type yeast Saccharomyces cerevisiae (S. cerevisiae) is able to export less than 1 percent of the protein to be secreted. The reasons for retention of most of the secretory proteins on the cell surface of S. cerevisiae are unknown. Recently, temperature-sensitive (ts) mutants of S. cerevisiae showing an oversecretion phenotype were isolated. In order to study the influence of the mitochondrial genome status on protein export in yeast cells, we have isolated several types of respiratory impaired mitochondrial mutants of either the parental S. cerevisiae strain or their derivative ts protein-overexporting mutants. In this paper we demonstrate by quantitative analyses of exported proteins and by SDS-PAGE analysis that protein overexport in ts mutants requires mitochondrial genome integrity and function.
Asunto(s)
Proteínas Fúngicas/metabolismo , Mitocondrias/fisiología , Saccharomyces cerevisiae/fisiología , Southern Blotting , ADN Mitocondrial/química , ADN Mitocondrial/genética , ADN Mitocondrial/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Mitocondrias/genética , Mutagénesis , Mutación , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismoRESUMEN
In the yeast Saccharomyces cerevisiae, mutants are viable with large deletions (rho-), or even complete loss of the mitochondrial genome (rho0). One class of rho- mutants, which is called hypersuppressive, is characterised by a high transmission of the mutated mitochondrial genome to the diploid progeny when mated to a wild-type (rho+) haploid. The nuclear gene CCE1 encodes a cruciform cutting endonuclease, which is located in the mitochondrion and is responsible for the highly biased transmission of the hypersuppressive rho- genome. CCE1 is a Holliday junction specific endonuclease that resolves recombination intermediates in mitochondrial DNA. The cleavage activity shows a strong preference for cutting after a 5'-CT dinucleotide. In the absence of the CCE1 gene product, the mitochondrial genomes remain interconnected and have difficulty segregating to the daughter cells. As a consequence, there is an increase in the fraction of daughter cells that are rho0. In this paper we demonstrate the usefulness of lycorine, together with staining by 4',6-diamidino-2-phenylindole (DAPI), to assay for the mitotic stability of a variety of mitochondrial genomes. We have found that rho+ and rho- strains that contain CT sequences produce a large fraction of rho0 progeny in the absence of CCE1 activity. Only those rho- mitochondrial genomes lacking the CT recognition sequence are unaffected by the cce1 allele.
Asunto(s)
Alcaloides de Amaryllidaceae , Núcleo Celular/genética , Endodesoxirribonucleasas/genética , Mitocondrias/genética , Fenantridinas/farmacología , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae/genética , Coloración y Etiquetado/métodos , Composición de Base , Cruzamientos Genéticos , ADN Mitocondrial/aislamiento & purificación , Diploidia , Farmacorresistencia Microbiana , Eliminación de Gen , Resolvasas de Unión Holliday , Indoles , Mitocondrias/ultraestructura , Hibridación de Ácido Nucleico , Saccharomyces cerevisiae/ultraestructuraRESUMEN
Purification of a lipoxygenase enzyme from the cultivar Tresor of durum wheat semolina (Triticum turgidum var. durum Desf) was reinvestigated furnishing a new procedure. The 895-fold purified homogeneous enzyme showed a monomeric structure with a molecular mass of 95 +/- 5 kDa. Among the substrates tested, linoleic acid showed the highest k(cat)/K(m) value; a beta-carotene bleaching activity was also detected. The enzyme optimal activity was at pH 6. 8 on linoleic acid as substrate and at pH 5.2 for the bleaching activity on beta-carotene, both assayed at 25 degrees C. The dependence of lipoxygenase activity on temperature showed a maximum at 40 degrees C for linoleic acid and at 60 degrees C for bleaching activity on beta-carotene. The amino acid composition showed the presence of only one tryptophan residue per monomer. Far-UV circular dichroism studies carried out at 25 degrees C in acidic, neutral, and basic regions revealed that the protein possesses a secondary structure content with a high percentage of alpha- and beta-structures. Near-UV circular dichroism, at 25 degrees C and at the same pH values, pointed out a strong perturbation of the tertiary structure in the acidic and basic regions compared to the neutral pH condition. Moreover, far-UV CD spectra studying the effects of the temperature on alpha-helix content revealed that the melting point of the alpha-helix is at 60 degrees C at pH 5.0, whereas it was at 50 degrees C at pH 6.8 and 9.0. The NH(2)-terminal sequence allowed a homology comparison with other lipoxygenase sequences from mammalian and vegetable sources.
Asunto(s)
Lipooxigenasa/química , Lipooxigenasa/metabolismo , Triticum/enzimología , Secuencia de Aminoácidos , Secuencia Conservada , Harina , Cinética , Lipooxigenasa/aislamiento & purificación , Datos de Secuencia Molecular , Peso Molecular , Fragmentos de Péptidos/química , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Especificidad por Sustrato , TermodinámicaRESUMEN
Expression of serogroup B meningococcal capsular polysaccharide undergoes frequent phase variation involving reversible frameshift mutations within a homopolymeric repeat in the siaD gene. A high rate of phase variation is the consequence of a biochemical defect in methyl-directed mismatch repair. The mutator phenotype is associated to the absence of DNA adenine methyltransferase (Dam) activity in all pathogenic isolates and in 50% of commensal strains. Analysis of the meningococcal dam gene region revealed that in all Dam- strains a gene encoding a putative restriction endonuclease (drg) that cleaves only the methylated DNA sequence 5'-GmeATC-3' replaced the dam gene. Insertional inactivation of the dam and/or drg genes indicated that high rates of phase variation and hypermutator phenotype are caused by absence of a functional dam gene.
Asunto(s)
Enzimas de Restricción del ADN/genética , Genes Bacterianos , Neisseria meningitidis/genética , Metiltransferasa de ADN de Sitio Específico (Adenina Especifica)/genética , Secuencia de Aminoácidos , Cápsulas Bacterianas/genética , Cápsulas Bacterianas/inmunología , Secuencia de Bases , Clonación Molecular , Reparación del ADN/genética , Enzimas de Restricción del ADN/química , Regulación Bacteriana de la Expresión Génica/genética , Datos de Secuencia Molecular , Mutación , Neisseria meningitidis/patogenicidad , Fenotipo , ARN Mensajero/análisis , Mapeo Restrictivo , Alineación de Secuencia , Serología , Metiltransferasa de ADN de Sitio Específico (Adenina Especifica)/química , Transformación GenéticaRESUMEN
In previous papers (Del Giudice et al. Curr Genet 8:493-497, 1984; Massardo et al. Curr Genet 17:455-457, 1985) we have shown that strains of Saccharomyces cerevisiae that are devoid of mitochondrial DNA (rhoo) are resistant to the alkaloid lycorine isolated from Amaryllis plants, whereas strains containing mitochondrial DNA (rho-, mit-, or rho+) are sensitive to this drug. In addition, we were able to show that the so-called hypersuppressive petites, whose mitochondrial genomes consist of short regions of DNA containing an ori sequence,show intermediate resistance. In this paper, we demonstrate that the degree of suppressiveness of a rho- mutant correlates with the degree of resistance to lycorine.
Asunto(s)
Alcaloides/farmacología , Alcaloides de Amaryllidaceae , ADN Mitocondrial/genética , Fenantridinas/farmacología , Saccharomyces cerevisiae/genética , Supresión Genética , Farmacorresistencia Microbiana/genética , MutaciónRESUMEN
In vivo analysis of expression of the chloroplast rDNA cluster during somatic embryogenesis of Daucus carota (D.carota) was performed by Northern-blot analysis with different DNA probes, spanning both the 16S rRNA gene, the 16S-23S rRNA spacer, which contains the two mosaic tRNA genes tRNA(Ile) and tRNA(Ala), and the region upstream of the 16S rRNA gene, where a tRNA(Val) maps. We show that expression both of the spacer tRNAs tRNA(Ile) and tRNA(Ala) is not significantly regulated during development whereas the amount of the transcript corresponding to tRNA(Val) is not detectable during early embryonic stages and progressively accumulates during late phases. Multiple transcription start sites have been identified upstream of the tRNA(Val) gene by S1 mapping analysis, which are activated late during the embryogenesis. These data indicate that developmental control mechanisms act on plastid gene expression during embryogenesis in carrot.
Asunto(s)
Cloroplastos/metabolismo , ADN Ribosómico/genética , ARN de Transferencia/genética , Verduras/genética , Secuencia de Bases , Northern Blotting , Células Cultivadas , Mapeo Cromosómico , Clonación Molecular , ARN Polimerasas Dirigidas por ADN/metabolismo , Escherichia coli/enzimología , Regulación de la Expresión Génica , Datos de Secuencia Molecular , ARN de Transferencia de Alanina/genética , ARN de Transferencia de Isoleucina/genética , ARN de Transferencia de Valina/genética , Transcripción Genética , Verduras/crecimiento & desarrolloRESUMEN
The open reading frame in the first intron of the mitochondrial gene encoding subunit I of cytochrome c oxidase encodes a maturase and stimulates homologous recombination in Escherichia coli. In this paper, we demonstrate that this intron is mobile in crosses, indicating that it also encodes an endonuclease. This is the first report on an intron which possesses mobility and acts as a maturase.
Asunto(s)
Cruzamientos Genéticos , ADN Mitocondrial/genética , Endorribonucleasas/genética , Intrones , Nucleotidiltransferasas/genética , Schizosaccharomyces/genética , Clonación Molecular , Elementos Transponibles de ADN/genética , Farmacorresistencia Microbiana/genética , Endonucleasas/genética , Código Genético , Saccharomyces cerevisiae/genéticaRESUMEN
The petite-positive yeast Saccharomyces cerevisiae can be efficiently and completely converted to respiratory-deficient cytoplasmic petite mutants by intercalating drugs. Rho0 petites from Schizosaccharomyces pombe could only be obtained in strains carrying a nuclear mutation. In this paper we report the efficient isolation of rho0 mutants in a Sch. pombe strain containing a mitochondrial mutator mutation. We also show that the alkaloid lycorine is able to differentiate between cells containing defective mitochondrial DNA (mit-) and those lacking mitochondrial DNA completely (rho0). Rho0 cells are resistant to the alkaloid whereas mit- and wild-type cells show the same sensitivity.
Asunto(s)
Alcaloides de Amaryllidaceae , ADN de Hongos/genética , ADN Mitocondrial/genética , Fenantridinas/farmacología , Schizosaccharomyces/efectos de los fármacos , Schizosaccharomyces/genética , Farmacorresistencia Microbiana/genética , Mutación , Schizosaccharomyces/metabolismo , Eliminación de SecuenciaRESUMEN
The open reading frame of the first intron of the mitochondrial cox1 gene (cox1I1) was expressed in Escherichia coli. The putative intron-encoded protein stimulated the formation of intra-chromosomal lac(+)-recombinants about threefold. No stimulation was found when the reading frame was inserted in the opposite direction, or when it was interrupted by a deletion. The intronic open reading frame did not complement recA- or recB- mutants of E. coli. In S. pombe, elimination of this intron did not abolish homologous recombination in mitochondria. A possible role of the recombinase activity in yeast mitochondria will be discussed.
Asunto(s)
ADN Nucleotidiltransferasas/genética , ADN de Hongos/genética , ADN Mitocondrial/genética , Complejo IV de Transporte de Electrones/genética , Endorribonucleasas/genética , Escherichia coli/genética , Proteínas Fúngicas/genética , Integrasas , Intrones , Nucleotidiltransferasas/genética , Recombinación Genética , Schizosaccharomyces/genética , Secuencia de Aminoácidos , Secuencia de Bases , Genes Fúngicos , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Empalme del ARN , Recombinasas , Saccharomyces cerevisiae/genética , Homología de Secuencia de Ácido NucleicoRESUMEN
The galactokinase (GalK) expression plasmid vector system pKO-1 has been used to screen for promoter elements in the maize transposable element Mu1 that function in Escherichia coli. Two transcriptional start points, named S1 and S2, were identified, which are located in the two direct repeats of the transposable element. This paper demonstrates that sequence elements exist in a plant transposable element which function as prokaryotic promotors.
Asunto(s)
Elementos Transponibles de ADN , ARN Polimerasas Dirigidas por ADN/metabolismo , Escherichia coli/genética , Regiones Promotoras Genéticas , Zea mays/genética , Secuencia de Bases , Clonación Molecular , Datos de Secuencia Molecular , Mapeo Restrictivo , Transcripción GenéticaRESUMEN
In a previous paper we have shown that the alkaloid lycorine inhibits growth of rho+, mit- and rho-, strains of Saccharomyces cerevisiae, whereas strains devoid of mitochondrial DNA (rho degrees) are resistant to more than 200 micrograms/ml of the alkaloid. In this report we show that hypersuppressive petites are almost as resistant as rho degrees mutants, whereas isogenic rho- petites, which have retained longer segments of the genome, are sensitive to the drug.
Asunto(s)
Alcaloides de Amaryllidaceae , ADN Mitocondrial/metabolismo , Fenantridinas/farmacología , Saccharomyces cerevisiae/genética , ADN de Hongos/metabolismo , Farmacorresistencia Microbiana/genética , Saccharomyces cerevisiae/crecimiento & desarrollo , Saccharomyces cerevisiae/metabolismoAsunto(s)
Ascomicetos/genética , ADN de Hongos/genética , ADN Mitocondrial/genética , Genes Fúngicos , Animales , ADN Ribosómico/genética , Regulación de la Expresión Génica , Intrones , Mamíferos/genética , Mutación , ARN de Hongos/genética , Saccharomyces cerevisiae/genética , Transcripción GenéticaRESUMEN
Mutants resistant to 200 micrograms/ml of the alkaloid lycorine (LYCR) in non-fermentable substrate were isolated after nitrosoguanidine mutagenesis. Tetrad analysis and growth of heterozygous (LYCR/lycS) diploids from two different mutants revealed that a single nuclear and dominant mutation is responsible for the resistant phenotype. In the wild type total protein synthesis is only slightly inhibited, whereas DNA and RNA synthesis is lowered to about 30% of the control. In the lycorine resistant mutants all macromolecular syntheses are unaffected by the drug.
Asunto(s)
Alcaloides de Amaryllidaceae , Antifúngicos/farmacología , Mutación , Fenantridinas/farmacología , Saccharomyces cerevisiae/genética , Farmacorresistencia Microbiana , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/crecimiento & desarrollo , Especificidad de la EspecieRESUMEN
The alkaloid lycorine inhibits growth of rho (+), mit (-), and rho (-) strains, whereas rho (0) strains (devoid of mitochondrial DNA) of Saccharomyces cerevisiae are resistant to high concentrations of the drug. The inhibitory effect of lycorine on the growth of rho (+) strains can be counteracted by the addition of ascorbic acid to the plating medium. Lycorine induces cytoplasmic respiratory deficient mutants upon growth in glucose complete medium containing the alkaloid. The minimal inhibitory concentration of lycorine in glucose complete medium is ten times higher than in glycerol complete medium, thus demonstrating its preferential action on mitochondrial functions. Total protein synthesis and mitochondrial protein synthesis are only slightly inhibited by lycorine. It has, however, an inhibitory effect on DNA and RNA synthesis.