RESUMEN
Endocrine disruptive chemicals (EDCs) cause adverse health effects through interaction with endocrine systems. They are classified by chemical structure, effects on specific endocrine systems, bioaccumulation, persistence in the environment, or clinically observable effects. For research of the complex mechanisms of action in the human body, only in vitro model systems have so far been available, that have insufficient high-throughput capacity, which makes risk evaluation more difficult. In addition, in industrial nations, living people are often exposed to mixtures of substances, with various effects. The clinical importance of epigenetic changes caused by the action of EDCs during vulnerable phases of development is currently unclear. Epidemiological studies are criticized because reproducibility is not always guaranteed. Nevertheless, they remain the method of choice for the development and analysis of suitable model systems. Positive associations, in spite of sometimes conflicting results, are key in the selection of factors that can then be analysed in model systems in an unbiased way. This article depicts the mainly positive epidemiological findings for EDC-caused effects in the fields of growth and metabolism, neurocognitive development and sexual development and reproduction. As a result, there is a need for closer linkage between epidemiological studies and mechanistic research into model systems, especially focusing on the interaction of different EDCs and the consequences of prenatal and early life exposure.
Asunto(s)
Trastornos del Desarrollo Sexual/epidemiología , Disruptores Endocrinos/envenenamiento , Exposición a Riesgos Ambientales/estadística & datos numéricos , Trastornos del Crecimiento/epidemiología , Enfermedades Metabólicas/epidemiología , Trastornos Neurocognitivos/epidemiología , Contaminación Química del Agua/estadística & datos numéricos , Comorbilidad , Estudios Epidemiológicos , Medicina Basada en la Evidencia , Humanos , Incidencia , Modelos Biológicos , Factores de RiesgoRESUMEN
BACKGROUND: Genome-wide association studies (GWAS) have identified many risk loci for asthma, but effect sizes are small, and in most cases, the biological mechanisms are unclear. Targeted metabolite quantification that provides information about a whole range of pathways of intermediary metabolism can help to identify biomarkers and investigate disease mechanisms. Combining genetic and metabolic information can aid in characterizing genetic association signals with high resolution. This work aimed to investigate the interrelation of current asthma, candidate asthma risk alleles and a panel of metabolites. METHODS: We investigated 151 metabolites, quantified by targeted mass spectrometry, in fasting serum of asthmatic and nonasthmatic individuals from the population-based KORA F4 study (N = 2925). In addition, we analysed effects of single-nucleotide polymorphisms (SNPs) at 24 asthma risk loci on these metabolites. RESULTS: Increased levels of various phosphatidylcholines and decreased levels of various lyso-phosphatidylcholines were associated with asthma. Likewise, asthma risk alleles from the PDED3 and MED24 genes at the asthma susceptibility locus 17q21 were associated with increased concentrations of various phosphatidylcholines with consistent effect directions. CONCLUSIONS: Our study demonstrated the potential of metabolomics to infer asthma-related biomarkers by the identification of potentially deregulated phospholipids that associate with asthma and asthma risk alleles.
Asunto(s)
Asma/genética , Asma/metabolismo , Perfilación de la Expresión Génica , Metaboloma , Fosfatidilcolinas/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Estudios Transversales , Femenino , Sitios Genéticos , Genotipo , Humanos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Polimorfismo de Nucleótido SimpleRESUMEN
Considering obesity as an example, the present study has developed an ethical, legal and psychological understanding of personal responsibility, which aims at enabling and activating health promoting behaviour. Enhancing individual capabilities and modifying social and political factors that have an effect on individual behaviour are highlighted as a promising, appropriate and ethically sound strategy of prevention.
Asunto(s)
Conducta Cooperativa , Conductas Relacionadas con la Salud , Comunicación Interdisciplinaria , Estilo de Vida , Obesidad/prevención & control , Responsabilidad Social , Estudios Transversales , Ética Médica , Conducta Alimentaria/ética , Alemania , Promoción de la Salud/ética , Humanos , Programas Nacionales de Salud , Obesidad/epidemiología , Poder Psicológico , Autocuidado/ética , Autocuidado/métodosRESUMEN
Dormant seeds and young seedlings of wheat (Triticum aestivum L.) tolerate desiccation. A transcript expressed in this desiccation-tolerant tissue has been cloned and sequenced (J. Curry, C.F. Morris, M.K. Walker-Simmons [1991] Plant Mol Biol 16: 1073-1076). This wheat cDNA clone encodes a protein that is homologous to other group 3 late embryogenesis abundant (LEA) proteins. In this report, we describe the production of polyclonal antibodies to the protein product of the cDNA clone and assess group 3 LEA protein levels in desiccation-tolerant tissue. The group 3 LEA antibodies detected four major proteins in wheat with molecular masses from 27 to 30.5 kD. The genes for these proteins mapped to wheat chromosomes 1A, 1B, and 1D. The group 3 LEA proteins were present in mature seed embryos and were maintained when growth-arrested, dormant seeds were hydrated for 111 h. However, in germinating seeds the group 3 LEA proteins declined and were no longer detectable by 111 h. We severely dehydrated seedlings (more than 90% water loss) to assess group 3 LEA transcript and protein accumulation in tissues of these desiccation-tolerant plants. In response to dehydration, abscisic acid (ABA) levels increased dramatically and group 3 LEA mRNAs were induced in root, shoot, and scutellar tissue. However, group 3 LEA proteins were detected only in shoot and scutellar tissue and not in root tissue. Treatment of nonstressed seedlings with 20 [mu]M ABA resulted in low levels of group 3 LEA proteins in the roots, whereas higher levels were found in the shoot and scutellar tissue. When dehydrated seedlings were rehydrated, shoot and scutellar tissue resumed growth. The roots did not resume growth and subsequently died. New roots developed later from the scutellar tissue. Thus, in severely dehydrated wheat seedlings, the accumulation of high levels of group 3 LEA proteins is correlated with tissue dehydration tolerance.
RESUMEN
A technique for marker exchange-eviction mutagenesis that enables the construction of directed, unmarked mutations in Gram-negative bacteria was demonstrated in Erwinia chrysanthemi. The technique employs an nptI-sacB-sacR cartridge that is carried on a 3.8-kb BamHI fragment and confers kanamycin (Km) resistance and sucrose sensitivity (due to the production of levansucrase by sacB) in E. chrysanthemi. The cartridge was inserted into a Sau3A site in a cloned E. chrysanthemi pelC gene (encoding pectate lyase isozyme PLc) and then introduced into the Erwinia genome by gene exchange recombination. The resulting mutant was KmR, sucrose-sensitive, and PLc-deficient. The cartridge was then excised from the plasmid-borne pelC gene by PstI cleavage to leave a 28-bp frame-shifting insertion. The pelC allele containing the 28-bp insertion was exchanged for the chromosomal allele containing the nptI-sacB-sacR cartridge by selection for sucrose tolerance. The resulting E. chrysanthemi mutant was Kms and PLc-deficient. The technique permits the construction of complex strains with many directed mutations without the introduction of a corresponding number of antibiotic resistance markers and should prove useful, for example, in exploring the role of the multiple pel genes in E. chrysanthemi.
Asunto(s)
Bacterias Gramnegativas/genética , Mutación , Erwinia/genética , Escherichia coli/genética , Genes Bacterianos , Marcadores Genéticos , Resistencia a la Kanamicina , PlásmidosRESUMEN
Production of polyclonal antibodies in the lumen of a perforated golf ball implanted surgically under the skin of a rabbit offers advantages over conventional techniques. Less stress is placed on the rabbit because bleeding is eliminated, complete adjuvants are not used and animal handling is minimized. The technique also offers the advantage that large amounts of antibody-containing fluid can be removed easily from the ball. In this report we describe the surgical protocol and demonstrate use of this technique to produce high-titered antibodies to plant and plant viral proteins.
Asunto(s)
Formación de Anticuerpos , Técnicas Inmunológicas , Plásticos , Animales , Femenino , Virus del Mosaico/inmunología , Proteínas de Plantas/inmunología , Prótesis e Implantes , Conejos , Deshidrogenasas del Alcohol de Azúcar/inmunologíaRESUMEN
The notions 'common good' and 'public good' are mostly used as synonyms in bioethical discussion of biobanks, but have different origins. As a consequence, they should be applied differently. In this article, the respective characteristics are worked out and then subsequently examined which consent models emerge from them. Distinguishing normative and descriptive traits of both concepts, it turns out that one concept is unjustly used, and that the other one fits better to the context of a plural society. A reflected use of these differing concepts may help to choose an appropriate form of consent and allows public trust in biobank research to deepen.
Asunto(s)
Bancos de Muestras Biológicas/ética , Investigación Biomédica/ética , Confidencialidad/ética , Consentimiento Informado/ética , Participación del Paciente , Salud Pública/normas , Justicia Social , Humanos , ConfianzaAsunto(s)
Investigación Biomédica , Mala Conducta Científica , Humanos , Edición , Sociedades CientíficasRESUMEN
One of the greatest challenges our health care system has recently been faced, namely obesity, a matter which also raises questions of social ethics. Including genetic predispositions as well as environmental and behavioral factors, the etiology of extreme overweight is complex and this which predetermines multiple responsibilities in prevention. Against the background of our knowledge about genetics the particular problem of individual responsibility must be reconsidered. Prevention aims at changing and then sustaining specific patterns of behavior and thus addresses the individual acting as an autonomous, responsible person. For this purpose the preconditions of autonomy and individual responsibility must be examined and formulated. On the one hand, the capacities of the individual must not be overstrained but, and on the other, he or she should be able to act autonomously within the scope of his or her capabilities. Because of this, the enhancement of individual capabilities can be set as a leading criterion of the ethical considerations on strategies of prevention, which may help to put such a concept of individual responsibility into practice.
Asunto(s)
Ética Médica , Conductas Relacionadas con la Salud , Promoción de la Salud/ética , Obesidad/prevención & control , Cultura , Predisposición Genética a la Enfermedad , Alemania , Humanos , Estilo de Vida , Obesidad/etiología , Obesidad/genética , Autonomía Personal , Salud Pública/éticaRESUMEN
A system was developed for the rapid characterization of microbial pectic enzyme complexes and then tested on Erwinia chrysanthemi and Sclerotium rolfsii. Pectic enzymes in minute samples of crude culture filtrates were resolved by ultrathin-layer polyacrylamide gel isoelectric focusing and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and then assayed with an ultrathin pectate-agarose overlay stained with ruthenium red. The simple procedure can be completed within 30 min after isoelectric focusing, can detect extremely low levels of pectate lyase (6.4 x 10 mumol of product per min), and is sufficiently sensitive to determine the pectate lyase isozyme profile of a single bacterial colony with a diameter of 4 mm. Pectate lyases and polygalacturonases can be distinguished by altering buffer conditions in the overlays. The assay system revealed additional isozymes not resolved by classical techniques and generally corroborated the previously published isoelectric points and molecular weights of the pectate lyase isozymes and exo-poly-alpha-d-galacturonosidase produced by E. chrysanthemi and the endopolygalacturonase and exopolygalacturonase produced by S. rolfsii.
RESUMEN
Erwinia spp. that cause soft-rot diseases in plants produce a variety of extracellular pectic enzymes. To assess the correlation between patterns of pectic enzyme production and taxonomic classification, we compared the enzymes from representative strains. Supernatants obtained from polygalacturonate-grown cultures of nine strains of Erwinia chrysanthemi, three strains of E. carotovora subsp. carotovora, and three strains of E. carotovora subsp. atroseptica were concentrated and subjected to ultrathin-layer polyacrylamide gel isoelectric focusing. Pectate lyase, polygalacturonase, and exo-poly-alpha-D-galacturonosidase activities were visualized by staining diagnostically buffered pectate-agarose overlays with ruthenium red after incubation of the overlays with the isoelectric focusing gels. The isoelectric focusing profiles of pectate lyase and polygalacturonase were nearly identical for strains of E. carotovora subsp. carotovora and E. carotovora subsp. atroseptica, showing three pectate lyase isozymes with isoelectric points higher than 8.7 and a polygalacturonase with pI of ca. 10.2. Isoelectric focusing profiles of the E. chrysanthemi pectic enzymes were substantially different. Although there was considerable intraspecific heterogeneity, all strains produced at least four isozymes of pectate lyase, which could be divided into three groups: basic (pI, ca. 9.0 to 10.0), slightly basic (pI, ca. 7.0 to 8.5), and acidic (pI, ca. 4.0 to 5.0). Several strains of E. chrysanthemi also produced a single form of exo-poly-alpha-D-galacturonosidase (pI, ca. 8.0).(ABSTRACT TRUNCATED AT 250 WORDS)
Asunto(s)
Erwinia/enzimología , Isoenzimas/metabolismo , Polisacárido Liasas/metabolismo , Focalización Isoeléctrica , Isoenzimas/aislamiento & purificación , Pectinas , Plantas , Polisacárido Liasas/aislamiento & purificación , Especificidad de la EspecieRESUMEN
Germination of embryonic axes from dormant grain is inhibited by low concentrations of abscisic acid (ABA) compared with axes from nondormant grain. Incubation of dormant grain axes in 0.05 to 50 micromolar ABA caused the prolonged synthesis of a set of heat-stable proteins. Two of these proteins were identified as dehydrins. In nondormant grain axes, 100- to 1000-fold greater ABA concentrations were required to produce similar results. When embryonic axes of dormant wheat (Triticum aestivum) grain were imbibed without ABA, endogenous ABA levels increased 2.5-fold by 4 hours and then gradually declined. Heat-stable proteins were continuously synthesized for at least 18 hours. No increase in endogenous ABA was observed when nondormant grain axes were imbibed. Endogenous ABA levels in nondormant grain axes remained constant at 4 hours and then declined. The nondormant grain axes initially synthesized the heat-stable proteins, but that synthesis disappeared between 8 and 12 hours. These results showing the prolonged synthesis of ABA-responsive, heat-stable proteins by dormant grain axes, demonstrate that biochemical differences occur when axes from dormant compared with nondormant grains are imbibed.
RESUMEN
The phytopathogenic enterobacterium Erwinia chrysanthemi excretes multiple isozymes of the plant tissue-disintegrating enzyme, pectate lyase (PL). Genes encoding PL were cloned from E. chrysanthemi CUCPB 1237 into Escherichia coli HB101 by inserting Sau3A-generated DNA fragments into the BamHI site of pBR322 and then screening recombinant transformants for the ability to sink into pectate semisolid agar. Restriction mapping of the cloned DNA in eight pectolytic transformants revealed overlapping portions of a 9.8-kilobase region of the E. chrysanthemi genome. Deletion derivatives of these plasmids were used to localize the pectolytic genotype to a 2.5-kilobase region of the cloned DNA. PL gene expression in E. coli was independent of vector promoters, repressed by glucose, and not induced by galacturonan. PL accumulated largely in the periplasmic space of E. coli. An activity stain used in conjunction with ultrathin-layer isoelectric focusing resolved the PL in E. chrysanthemi culture supernatants and shock fluids of E. coli clones into multiple forms. One isozyme with an apparent pI of 7.8 was produced at a far higher level in E. coli and was common to all of the pectolytic clones. Activity staining of renatured PL in sodium dodecyl sulfate-polyacrylamide gels revealed that this isozyme comigrated with the corresponding isozyme produced by E. chrysanthemi. The PL isozyme profiles produced by different clones and deletion derivative subclones suggest that the cloned region contains at least two PL isozyme structural genes. Pectolytic E. coli clones possessed a limited ability to macerate potato tuber tissues.