Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
Más filtros

Banco de datos
Tipo del documento
Intervalo de año de publicación
1.
Clin Exp Allergy ; 43(4): 463-74, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23517042

RESUMEN

BACKGROUND: Both asthma and obesity are complex disorders that are influenced by environmental and genetic factors. Shared genetic factors between asthma and obesity have been proposed to partly explain epidemiological findings of co-morbidity between these conditions. OBJECTIVE: To identify genetic variants that are associated with body mass index (BMI) in asthmatic children and adults, and to evaluate if there are differences between the genetics of BMI in asthmatics and healthy individuals. METHODS: In total, 19 studies contributed with genome-wide analysis study (GWAS) data from more than 23 000 individuals with predominantly European descent, of whom 8165 are asthmatics. RESULTS: We report associations between several DENND1B variants (P = 2.2 × 10(-7) for rs4915551) on chromosome 1q31 and BMI from a meta-analysis of GWAS data using 2691 asthmatic children (screening data). The top DENND1B single nucleotide polymorphisms(SNPs) were next evaluated in seven independent replication data sets comprising 2014 asthmatics, and rs4915551 was nominally replicated (P < 0.05) in two of the seven studies and of borderline significance in one (P = 0.059). However, strong evidence of effect heterogeneity was observed and overall, the association between rs4915551 and BMI was not significant in the total replication data set, P = 0.71. Using a random effects model, BMI was overall estimated to increase by 0.30 kg/m(2) (P = 0.01 for combined screening and replication data sets, N = 4705) per additional G allele of this DENND1BSNP. FTO was confirmed as an important gene for adult and childhood BMI regardless of asthma status. CONCLUSIONS AND CLINICAL RELEVANCE: DENND1B was recently identified as an asthma susceptibility gene in a GWAS on children, and here, we find evidence that DENND1B variants may also be associated with BMI in asthmatic children. However, the association was overall not replicated in the independent data sets and the heterogeneous effect of DENND1B points to complex associations with the studied diseases that deserve further study.


Asunto(s)
Índice de Masa Corporal , Estudio de Asociación del Genoma Completo , Adolescente , Adulto , Anciano , Alelos , Asma/complicaciones , Niño , Preescolar , Femenino , Humanos , Masculino , Persona de Mediana Edad , Obesidad/complicaciones , Obesidad/genética , Polimorfismo de Nucleótido Simple , Adulto Joven
2.
Sci Total Environ ; 890: 164293, 2023 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-37216983

RESUMEN

Microplastic (MP) is potentially harmful to lake ecosystems, with its uptake into the food web largely controlled by its residence time in the lake water column. Here we combine laboratory and virtual experiments to quantify residence times of small MP (<15 µm) in two contrasting model lakes; Lake Constance (large lake) and Esthwaite Water (a small lake). We compare MP residence times in a purely physical system with MP transport controlled by sinking and mixing to a model where, in addition to physical processes, zooplankton package MP into faecal pellets that are then egested into the water column. The laboratory experiments showed that MP settling velocities increased from ~5 × 10-6-10-3 mm s-1 for pristine MP to ~1 mm s-1 for MP embedded faeces. Modeled lake residence times for the 0.5 and 5 µm particles were >15 years in the abiotic models, while in the biotic simulations they were reduced to ~1 year. There was little difference between abiotic and biotic simulations for the 15 µm particles. The ratio of the MP zooplankton uptake velocity to the sinking velocity (v_up/vs_epi) was used to classify biological vs. physical transport pathways. For the 0.5 and 5 µm particles v_up/vs_epi was ≫1 in all cases for both lakes, while for the 15 µm MP there was a transition between biological and physical processes dominating residence times depending on zooplankton numbers. Our results suggest that packaging of small MP in faecal pellets by zooplankton will control its residence time in lakes. Moreover, the majority of small MP will cycle through organisms before reaching the sediment, increasing the likelihood of negative ecological effects and transfer in the food web.


Asunto(s)
Lagos , Contaminantes Químicos del Agua , Animales , Microplásticos , Plásticos , Ecosistema , Zooplancton , Agua
3.
Transl Med UniSa ; 19: 66-81, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31360670

RESUMEN

Seventy four Reference Sites of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) have been recognised by the European Commission in 2016 for their commitment to excellence in investing and scaling up innovative solutions for active and healthy ageing. The Reference Site Collaborative Network (RSCN) brings together the EIP on AHA Reference Sites awarded by the European Commission, and Candidate Reference Sites into a single forum. The overarching goals are to promote cooperation, share and transfer good practice and solutions in the development and scaling up of health and care strategies, policies and service delivery models, while at the same time supporting the action groups in their work. The RSCN aspires to be recognized by the EU Commission as the principal forum and authority representing all EIP on AHA Reference Sites. The RSCN will contribute to achieve the goals of the EIP on AHA by improving health and care outcomes for citizens across Europe, and the development of sustainable economic growth and the creation of jobs.

4.
FEMS Microbiol Rev ; 17(3): 357-64, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7576773

RESUMEN

The toxicity associated with conventional cancer chemotherapy is primarily due to a lack of specificity for tumour cells. In contrast, intravenously injected clostridial spores exhibit a remarkable specificity for tumours. This is because, following their administration, clostridial spores become exclusively localised to, and germinate in, the hypoxic/necrotic tissue of tumours. This unique property could be exploited to deliver therapeutic agents to tumours. In particular, genetic engineering could be used to endow a suitable clostridial host with the capacity to produce an enzyme within the tumour which can metabolise a systemically introduced, non-toxic prodrug into a toxic metabolite. The feasibility of this strategy (clostridial-directed enzyme prodrug therapy, CDEPT) has been demonstrated by cloning the Escherichia coli B gene encoding nitroreductase (an enzyme which converts the prodrug CB1954 to a highly toxic bifunctional alkylating agent) into a clostridial expression vector and introducing the resultant plasmid into Clostridium beijerinckii (formerly C. acetobutylicum) NCIMB 8052. The gene was efficiently expressed, with recombinant nitroreductase representing 8% of the cell soluble protein. Following the intravenous injection of the recombinant spores into mice, tumour lysates have been shown, by Western blots, to contain the E. coli-derived enzyme.


Asunto(s)
Antineoplásicos/administración & dosificación , Clostridium/genética , Sistemas de Liberación de Medicamentos/métodos , Neoplasias/tratamiento farmacológico , Nitrorreductasas/genética , Esporas Bacterianas , Animales , Antineoplásicos/metabolismo , Antineoplásicos/uso terapéutico , Aziridinas/administración & dosificación , Aziridinas/metabolismo , Aziridinas/uso terapéutico , Biotransformación , ADN Recombinante , Ratones , Nitrorreductasas/metabolismo , Nitrorreductasas/uso terapéutico , Profármacos/uso terapéutico
5.
Gene ; 87(1): 79-90, 1990 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-2110101

RESUMEN

The complete nucleotide (nt) sequence of a 5.1-kb EcoRI DNA restriction fragment carrying the replication region of the Streptococcus faecalis plasmid pAM beta 1 has been determined. Of the seven major open reading frames (ORF A-G) identified within this fragment, two (C and E) were shown to be encoding by in vitro transcription/translation assays. Evidence was obtained that synthesis of the polypeptide (Mr 57,380) encoded by the largest ORF (E) was essential for replication. Deletion analysis indicated that the minimum unit of DNA required for replication resided on a 2.59-kb AccI-HpaI subfragment. ORF C resided outside of this fragment and encompassed an extensive region of directly repeated nt sequence. The encoded polypeptide (Mr 30,471) was therefore composed of large tracts of reiterated amino acid sequence (11 x VDP and 35 x TEP tripeptides) which probably caused the observed anomalous electrophoretic mobility of the synthesised protein (equivalent to 61 kDa). Deletion of a 416-bp segment of DNA between unique KpnI and StyI sites caused an increase in copy number, which correlated with the in vitro production of higher levels of ORF E polypeptide. Although homology was detected between the sequenced DNA, and the replicon of a closely related streptococcal plasmid (pSM19035), none was evident to any other characterised Gram+ plasmid.


Asunto(s)
Replicación del ADN , Enterococcus faecalis/genética , Plásmidos , Secuencia de Aminoácidos , Bacillus subtilis/genética , Secuencia de Bases , Deleción Cromosómica , Clonación Molecular , Desoxirribonucleasa EcoRI , Escherichia coli/genética , Variación Genética , Vectores Genéticos , Datos de Secuencia Molecular , Secuencias Repetitivas de Ácidos Nucleicos , Mapeo Restrictivo , Homología de Secuencia de Ácido Nucleico
6.
FEMS Microbiol Lett ; 124(2): 195-202, 1994 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-7813889

RESUMEN

The Escherichia coli B gene (nfnB) encoding nitroreductase has been cloned in Escherichia coli K-12 and its nucleotide sequence determined. The translated amino acid sequence was found to share substantial identity (88.5%) with the equivalent proteins of Enterobacter cloacae and Salmonella typhimurium. When the structural gene was placed under the transcriptional control of either the trp or lac promoter, recombinant nitroreductase was accumulated to 33% and 25% of the cell's soluble protein, respectively. Substitution of the nfrB ribosome binding site with that of the E. coli lacZ gene reduced production levels of nitroreductase. The sequenced region also contained two incomplete open reading frames of unknown function.


Asunto(s)
Escherichia coli/genética , Nitrorreductasas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , Escherichia coli/enzimología , Datos de Secuencia Molecular , Nitrorreductasas/biosíntesis , Plásmidos , Proteínas Recombinantes/biosíntesis
7.
FEMS Microbiol Lett ; 70(3): 277-84, 1992 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-1624106

RESUMEN

The gene (sod) encoding Bacillus caldotenax (BC) Mn-superoxide dismutase (MnSOD) has been cloned in Escherichia coli and its entire nucleotide sequence determined. Within the coding region of the gene there were 21 nucleotide differences to the previously sequenced sod of Bacillus stearothermophilus (BS). The predicted amino acid sequence of BCMnSOD had two amino acid dissimilarities to the BSMnSOD, containing Asp and Val at positions 13 and 188, respectively, compared to Glu and Ile at the respective equivalent positions of BSMnSOD. Recombinant BCMnSOD was shown to be functionally active in E. coli, both in vitro and in vivo, and was produced at levels representing over 40% of the cells' soluble protein by coupling sod transcription to the E. coli trp promoter. The sequenced region of DNA was also found to encompass part of a second open-reading frame, of unknown function, previously noted 3' to the B. stearothermophilus gene.


Asunto(s)
Bacillus/genética , Superóxido Dismutasa/genética , Secuencia de Aminoácidos , Bacillus/enzimología , Secuencia de Bases , Clonación Molecular , Escherichia coli/genética , Datos de Secuencia Molecular , Homología de Secuencia de Ácido Nucleico , Superóxido Dismutasa/biosíntesis
8.
Science ; 204(4394): 728-9, 1979 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-17840228
9.
Science ; 197(4311): 1355-6, 1977 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-17747001
10.
Ann N Y Acad Sci ; 193: 189-93, 1972 Aug 25.
Artículo en Inglés | MEDLINE | ID: mdl-4506965
16.
J Nurs Educ ; 7(2): 2, 1968 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-4171239
17.
Pers Soc Psychol Rev ; 3(1): 2-22, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-15647145

RESUMEN

A theory is outlined that assumes that emotions are motivational states with the special function of producing adaptation to situational conditions. The theory assumes that the emotional system lies in the central nervous system, that it is fast to react, able to change quickly from one emotional state to another, produces only one emotion at a time, and that the intensity of that emotion is a nonmonotonic function of deterrence to the aim of the emotion. Supporting data from several experimental tests are reported, and selected theoretical problems are discussed.

18.
J Pers ; 43(3): 421-33, 1975 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1185488

RESUMEN

Half of the subjects, college students, were insulted by the experimenter while half were not. Within each of these conditions, half of the subjects were led to believe they would have an opportunity to administer electric shock to the experimenter, while the other half were not. A measure of hostility toward the experimenter was taken before there was any actual opportunity to shock him. As predicted from reactance theory, it was found that the mere opportunity to shock the experimenter reduced hostility that was produced by his insulting behavior. Alternative interpretations and implications were discussed.


Asunto(s)
Agresión , Hostilidad , Adolescente , Adulto , Electrochoque , Femenino , Humanos , Relaciones Interpersonales
19.
J Mol Microbiol Biotechnol ; 2(1): 59-69, 2000 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-10937489

RESUMEN

Non-proteolytic, Group II strains of Clostridium botulinum are of particular concern to the food industry because of their ability to survive and grow in REPFEDs (refrigerated processed foods of extended durability). Their analysis would benefit from the availability of a gene transfer system. In the present study we have been able, for the first time, to demonstrate transformation in a representative Group II strain, ATCC 25765. Initial attempts to transform ATCC 25765 with existing clostridial cloning vectors (pMTL540E and pMTL500E) were, however, prevented by a restriction barrier. Through a combination of classical and molecular approaches we were able to show that strain ATCC 25765 possesses a restriction endonuclease (Cbol) and a methylase activity (M. Cbol) which have the same specificity as Mspl and M.Mspl, respectively. Cbol cleaves the palindrome 5'-CCGG-3' to generate a 3'-GC sticky end, whilst M.Cbol specifically methylates the external C residue. An E. coli host was generated which expressed a Bacillus subtilis methylase enzyme (M.BsuF1) with equivalent specificity to M.Cbol. Plasmids (pMTL540E and pMTL500E) prepared in this strain were subsequently shown to be capable of transforming ATCC 25765. The highest frequencies (0.8 X 10(4) transformants per microg of DNA) were obtained when cells were cultivated in media supplemented with 1% (w/v) glycine, and when the electroporation was undertaken at 10 kV/cm, 25 microF and at 400 ohms. Having developed an effective transformation procedure, we went on to construct reporter cassettes based on the Thermanaerobacterium sulfurigenes lacZ and the Vibrio fischeri luxAB genes. Using the former, and promoter regions isolated from the botulinum toxin genes, we have obtained preliminary evidence that reporter genes may be used to evaluate the physiological factors that affect toxin production in the food environment.


Asunto(s)
Clostridium botulinum/genética , Genes Reporteros , Transformación Bacteriana , Clostridium botulinum/metabolismo , Metilación de ADN , ADN-Citosina Metilasas/metabolismo , Desoxirribonucleasas de Localización Especificada Tipo II/metabolismo , Regulación Bacteriana de la Expresión Génica , Luciferasas/genética , Luciferasas/metabolismo , Mapeo Restrictivo , Especificidad por Sustrato , beta-Galactosidasa/genética , beta-Galactosidasa/metabolismo
20.
Appl Environ Microbiol ; 64(5): 1612-9, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9572925

RESUMEN

The gutD gene of Clostridium beijerinckii NCIMB 8052 encoding glucitol 6-phosphate dehydrogenase was cloned on a 5.7-kbp chromosomal DNA fragment by complementing an Escherichia coli gutD mutant strain and selecting for growth on glucitol. Five open reading frames (ORFs) in the order gutA1 gutA2 orfX gutB gutD were identified in a 4.0-kbp region of the cloned DNA. The deduced products of four of these ORFs were homologous to components of the glucitol phosphotransferase system (PTS) and glucitol 6-phosphate dehydrogenase from E. coli, while the remaining ORF (orfX) encoded an enzyme which had similarities to members of a family of transaldolases. A strain in which gutD was inactivated by targeted integration lacked glucitol 6-phosphate dehydrogenase activity. The gutA1 and gutA2 genes encoded two polypeptides forming enzyme IIBC of the glucitol PTS comprising three domains in the order CBC. Domain IIA of the glucitol PTS was encoded by gutB. Glucitol phosphorylation assays in which soluble and membrane fractions of cells grown on glucose (which did not synthesize the glucitol PTS) or cells grown on glucitol were used confirmed that there is a separate, soluble, glucitol-specific PTS component, which is the product of the gutB gene. The gut genes were regulated at the level of transcription and were induced in the presence of glucitol. Cells grown in the presence of glucose and glucitol utilized glucose preferentially. Following depletion of glucose, the glucitol PTS and glucitol 6-phosphate dehydrogenase were synthesized, and glucitol was removed from the culture medium. RNA analysis showed that the gut genes were not expressed until glucose was depleted.


Asunto(s)
Clostridium/metabolismo , Genes Bacterianos , Sorbitol/metabolismo , Deshidrogenasas del Alcohol de Azúcar/genética , Secuencia de Aminoácidos , Secuencia de Bases , Transporte Biológico , Clonación Molecular , Clostridium/genética , Escherichia coli/genética , Datos de Secuencia Molecular , Sistemas de Lectura Abierta
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA