RESUMEN
OBJECTIVE: To evaluate the obstetrical outcome of pregnancies obtained after assisted reproductive technology (ART).in women with unexplained infertility. MATERIALS AND METHODS: We conducted a retrospective observational case - control cohort study between January 2011 and May 2017. All pregnancies obtained after ART (Intra uterine insemination, In Vitro Fertilization, Intra Cytoplasmic Sperm Injection) were included. The ART pregnancy outcome of women with unexplained infertility was compared to ART pregnancies obtained in a context of male infertility. Cases were matched to controls (1:2) for age, Body Mass Index (BMI), and smoking status. RESULTS: After exclusion of twins, we studied 67 singleton pregnancies in the case group, matched with 129 singleton pregnancies in the control group. The first-trimester complications (miscarriage before 12 weeks gestation (WG), ectopic pregnancy) were similar in the two groups. Concerning the 2nd and the 3rd trimester, the incidence of gestational diabetes mellitus, pre-eclampsia, placenta previa, preterm labor was comparable between the two groups. In singletons, we found a non-significant increase of post-partum hemorrhage (OR=5.5, IC 0.5-50, p=0.13) and small for gestational age new-borns (OR=3.45, IC 0.65-18.1, p=0.14) in women with unexplained infertility. CONCLUSION: More adverse obstetrical outcome are commonly reported after ART, even in singleton pregnancies. Little is known for explaining it and to distingue the own contributions of ART techniques and of the infertility etiology. In our study, we didn't observe a significant negative impact of a history of unexplained infertility on pregnancy. However, further large studies are needed to evaluate more accurately the possible liabilities of the infertility etiology on obstetrical and perinatal outcome.
Asunto(s)
Infertilidad Femenina/terapia , Resultado del Embarazo , Técnicas Reproductivas Asistidas , Aborto Espontáneo/epidemiología , Adulto , Factores de Edad , Índice de Masa Corporal , Estudios de Casos y Controles , Distribución de Chi-Cuadrado , Diabetes Gestacional/epidemiología , Femenino , Fertilización In Vitro , Humanos , Infertilidad Femenina/diagnóstico , Infertilidad Masculina , Masculino , Trabajo de Parto Prematuro/epidemiología , Placenta Previa/epidemiología , Preeclampsia/epidemiología , Embarazo , Embarazo Ectópico/epidemiología , Técnicas Reproductivas Asistidas/estadística & datos numéricos , Estudios Retrospectivos , Fumar , Estadísticas no Paramétricas , Adulto JovenRESUMEN
Among the Escherichia coli operons repressed from multiple sites on DNA, the galactose operon is unique: its repression requires an auxiliary protein, HU, to assist cooperative repressor binding to two distant DNA sites. Here we show that GalR can still mediate repression from distant sites in an artificial and simplified regulatory region which totally disturbs the organisation of the natural interactions. This simple and unexpected cooperation of a protein incapable of self-association in solution might be involved in regulation of the gal operon. Furthermore, the assay may be generalised to detection of rather weak cooperative interactions between DNA-bound proteins.
Asunto(s)
Escherichia coli/genética , Regulación Bacteriana de la Expresión Génica , Proteínas Represoras/metabolismo , Proteínas Bacterianas/metabolismo , ADN Bacteriano/química , ADN Bacteriano/metabolismo , Proteínas de Unión al ADN/metabolismo , Proteínas de Escherichia coli , Conformación de Ácido Nucleico , Regiones Operadoras Genéticas , Factores de Transcripción/metabolismoRESUMEN
The Région Languedoc Roussillon is the umbrella organisation for an interconnected and integrated project on active and healthy ageing (AHA). It covers the 3 pillars of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA): (A) Prevention and health promotion, (B) Care and cure, (C) and (D) Active and independent living of elderly people. All sub-activities (poly-pharmacy, falls prevention initiative, prevention of frailty, chronic respiratory diseases, chronic diseases with multimorbidities, chronic infectious diseases, active and independent living and disability) have been included in MACVIA-LR which has a strong political commitment and involves all stakeholders (public, private, patients, policy makers) including CARSAT-LR and the Eurobiomed cluster. It is a Reference Site of the EIP on AHA. The framework of MACVIA-LR has the vision that the prevention and management of chronic diseases is essential for the promotion of AHA and for the reduction of handicap. The main objectives of MACVIA-LR are: (i) to develop innovative solutions for a network of Living labs in order to reduce avoidable hospitalisations and loss of autonomy while improving quality of life, (ii) to disseminate the innovation. The three years of MACVIA-LR activities are reported in this paper.
Asunto(s)
Envejecimiento , Política de Salud , Promoción de la Salud , Vida Independiente , Medicina Preventiva , Accidentes por Caídas/prevención & control , Anciano , Anciano de 80 o más Años , Enfermedad Crónica , Comorbilidad , Unión Europea , Francia , Hospitalización , Humanos , Afecciones Crónicas Múltiples , Salud Bucal , Autonomía Personal , Polifarmacia , Calidad de Vida , Enfermedades RespiratoriasRESUMEN
Two Escherichia coli control regions have been compared in their ability to be unwound by RNA polymerase during formation of the transcriptionally active ("open") complex: the wild-type control region, consisting of two overlapping binding sites P1 and P2, both weakly transcribed, and an "up" P1 mutant, the strong lac L8UV5 promoter. The final complexes were characterized by their topological unwinding, by DNase I and orthophenanthroline footprints, as well as by methylation of unpaired cytosine residues. At the wild-type control region, the RNA polymerase footprint is weak, and single-strand formation is incomplete and slow. The same signals are strong, complete and quickly established at lac L8UV5; yet the final complexes were found to be equally unwound (by 1.7 turns) in the absence of nucleotide substrates as well as during an abortive initiation cycle. At the lac wild-type region, open complex formation occurs slowly enough to permit the measurement of the extent of a single-stranded region and of topological unwinding during the latency period. Not all the final species are active and unwinding appears to precede, in time, full open-complex formation. At the lac UV5 promoter the same conclusion was reached by a different method involving those changes in the various parameters that characterize open-complex formation monitored by an abortive initiation assay, conducted at increasing levels of template superhelicity. From both approaches we conclude that, at these promoters, the formation of the single-stranded region occurs at the expense of a negative change in linking number, initially stored in a closed intermediate, perhaps as negative writhing. Furthermore, abortive transcription assays indicate that the specific initiation efficiency of the species stored at both promoters, P1 and P2, on the wild-type template is increased as a whole with increasing superhelicity (conversion of inactive species to active ones, increased efficiency of active ones). We conclude that negative supercoiling is not an extra-regulatory element of the lactose system, allowing modulation of expression of the wild-type promoter to the profit of P1. Instead, P2 and P1, in the absence of active catabolite receptor protein (CRP-cAMP), appear to be equally weak and to be equally affected by negative supercoiling in the range of superhelical densities examined. The physiological importance of the P1-P2 competition in the regulation of expression in this region is thus questioned. The major effect of CRP-cAMP stimulation appears to be the direct activation at the P1 promoter.
Asunto(s)
ARN Polimerasas Dirigidas por ADN/genética , Escherichia coli/genética , Regiones Promotoras Genéticas , Secuencia de Bases , ADN Bacteriano/metabolismo , ADN Superhelicoidal/metabolismo , ARN Polimerasas Dirigidas por ADN/metabolismo , Cinética , Datos de Secuencia Molecular , Moldes GenéticosRESUMEN
mRNA synthesis can be controlled at some distance from the start of transcription in eukaryotes and prokaryotes. It is generally assumed that the distal elements of the transcriptional machinery directly interact with the proximal elements, forcing the DNA to bend in a loop. DNA loop formation and transcription can be affected by the distance between the sites, their helical positioning, their orientation, their concentration (responsible for a cis- or a trans-effect of the DNA sequences), and DNA compaction in chromatin. The corresponding in vitro and in vivo situations have been critically examined for a number of systems, mostly prokaryotic.
Asunto(s)
ADN/ultraestructura , Transcripción Genética , Sitios de Unión , ADN/genética , ADN/metabolismo , Elementos de Facilitación Genéticos , Conformación de Ácido Nucleico , Unión ProteicaRESUMEN
BACKGROUND/OBJECTIVES: An imbalance between Th1 and Th2 cells is involved in allergic rhinitis (AR) that may be improved by probiotics. To test the efficacy of the probiotic Lactobacillus paracasei subsp. paracasei LP-33, a double-blind, placebo-controlled, randomized trial was carried out in patients with AR to grass pollen treated with loratadine and presenting altered quality of life. SUBJECTS/METHODS: Subjects with persistent AR, symptomatic during the grass pollen season, and a positive skin test or specific immunoglobulin E to grass pollens were included by general practitioners (GPs). All received loratadine for 5 weeks. The primary end point was the improvement in Rhinitis Quality of Life (RQLQ) global score at the fifth week of LP-33 consumption compared with placebo (in addition to loratadine). Secondary end points included nasal and ocular symptoms (individual and total symptom scores), visual analogue scale and time of first exacerbation of the symptoms when loratadine was stopped. RESULTS: A total of 425 subjects were included. Using intent-to-treat analysis, the RQLQ global score decreased significantly more in the LP-33 group than in the placebo group (P=0.0255, difference=-0.286 (95% confidence interval (CI): -0.536; -0.035)). No significant differences were noted for the change of the rhinitis total symptom score 5 global score between groups (P=0.1288, difference=-0.452 (95% CI: -1.036; 0.132)). Significant differences in ocular symptoms (RQLQ) were observed between groups (P=0.0029, difference=-0.4087 (95% CI: -0.6768; -0.1407)). CONCLUSIONS: This study performed by GPs shows that LP-33 improves the quality of life of subjects with persistent AR who are currently being treated with an oral H1-antihistamine. Whereas nasal symptoms had not changed, ocular symptoms had consistently improved.
Asunto(s)
Suplementos Dietéticos , Lactobacillus , Probióticos/administración & dosificación , Rinitis Alérgica Estacional/terapia , Adulto , Método Doble Ciego , Determinación de Punto Final , Femenino , Antagonistas de los Receptores Histamínicos/farmacología , Humanos , Loratadina/uso terapéutico , Masculino , Persona de Mediana Edad , Cooperación del Paciente , Polen/efectos adversos , Polen/inmunología , Calidad de Vida , Rinitis Alérgica Estacional/tratamiento farmacológico , Rinitis Alérgica Estacional/inmunología , Estaciones del Año , Resultado del TratamientoRESUMEN
The onset of puberty is the sum of complex and multifactorial mechanisms resulting from the action of both activating and inhibiting factors, leading to the maturation of the gonads and the ability to reproduce. Many contributors to pubertal development are involved in fat mass acquisition and their action is relayed through the hypothalamus. It is therefore easy to understand how chronic diseases can affect the development of puberty and fertility apart from the specific impact of their molecular alteration. We have chosen cystic fibrosis and chronic renal disease as examples of chronic disorders affecting puberty through distinct mechanisms. As drugs are undistinguishable from chronic diseases, we also describe the impact of corticosteroids and chemotherapy on reproductive function. Last, we describe the surveillance and care of pubertal delay and its consequences (growth and bone mineralization) of patients affected with chronic disorders during adolescence.
Asunto(s)
Enfermedad Crónica , Fertilidad/fisiología , Pubertad/fisiología , Corticoesteroides/efectos adversos , Fibrosis Quística/complicaciones , Fibrosis Quística/fisiopatología , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Trastornos Gonadales/etiología , Humanos , Hipotálamo/fisiopatología , Pubertad Tardía/complicaciones , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/fisiopatologíaAsunto(s)
Accidentes por Caídas/prevención & control , Promoción de la Salud , Equilibrio Postural/fisiología , Centros Médicos Académicos , Accidentes por Caídas/economía , Anciano , Anciano de 80 o más Años , Envejecimiento/fisiología , Investigación Biomédica , Costo de Enfermedad , Femenino , Fracturas Óseas/economía , Fracturas Óseas/etiología , Francia , Geriatría/educación , Humanos , Vida Independiente , Difusión de la Información , Masculino , Salud Pública , Factores de RiesgoRESUMEN
The bacteriophage T3 promoter can be selectively transcribed by the corresponding RNA polymerase in eukaryotic cells. A toxic gene can in principle be linked to this promoter in a "dormant" and innocuous transgene in a transgenic animal. In this scheme, the activating strain expresses the RNA polymerase. When expression of the gene is needed in the progeny, the 2 lines are crossed. However, when a single molecule is sufficient to kill the cell--as with the diphtheria toxin--transcriptional "leakage" from the promoter may not be tolerated by the cell, even when extremely weak. Therefore, prior to more elaborate studies, diphtheria toxin, as a prototype of a gene toxic to the organism, has been linked to the bacteriophage T3 promoter in a T3-E-DTA construct. The T3-E-DTA plasmid has been transiently transfected into human embryonic kidney derived cells together with a lacZ plasmid. By co-transfection, the T3-E-DTA cells can be readily identified as lacZ positive, and their fate followed by the production of beta-galactosidase at the single cell or overall population level. In spite of the extreme toxicity of the toxin, the cells tolerate the presence of the T3-E-DTA construct, and are only killed--with a high efficiency--when the T3 RNA polymerase is present. Transactivation is usually restricted to the auxiliary factors of transcription. With this study, the promoter and the polymerase are revealed as potential and efficient inducible and activating elements of a very simple binary system.
Asunto(s)
Bacteriófago T3/genética , Genes Letales/genética , Riñón/citología , Regiones Promotoras Genéticas/genética , Transfección , Bacteriófago T3/enzimología , ARN Polimerasas Dirigidas por ADN/metabolismo , Toxina Diftérica/genética , Humanos , Plásmidos/genéticaRESUMEN
Two remote and weak lac regressor binding sites can be used jointly to repress the synthesis of beta-galactosidase in E. coli, while they cannot separately. When this result is discussed in reference to the various modes of cooperation between the sites, it supports with a new approach a model implying the simultaneous binding of lac repressor to both sites with the formation of a DNA loop. In connection with this point, we present a new strategy to detect cooperative interactions in vivo, based on the asymmetry of the DNA binding site, formally equivalent here to a half-site, heterodimerization of the protein, and influence of orientation of the sites on repression at short and long distance.
Asunto(s)
ADN Bacteriano/genética , Escherichia coli/genética , Operón Lac/genética , Regiones Operadoras Genéticas/genética , Escherichia coli/enzimología , Expresión Génica/genética , Genética Microbiana , Factores de Transcripción/genética , beta-Galactosidasa/genéticaRESUMEN
The cI repressor of bacteriophage lambda is better-fitted to the proximal interactions in which it naturally takes part than to the long-distance cooperative interactions on DNA for which it has become representative. The first observation in support of this statement is the ambiguity of an untypical DNAase I footprint which has become a diagnostic for DNA circularisation (and thus for the capacity of the protein to control expression at a distance). However, it was also observed without effective DNA looping when lac repressor binds to nearly contiguous sites. Additionally, the surface of interaction between the two dimers seems to be more important than the one commonly admitted (via some contacts between the flexible arms), the biological function of the repressor is lost when the sites are separated and loops have not been observed for large separation of the sites. In fact, naturally distant interactions can conform to shorter distances, as an intrinsic property of DNA looping. On the contrary, interactions which are naturally optimised for contiguity are generally constrained to proximity. Alternative protein-protein contacts are generally responsible for this situation (cf. CRP versus NRI in Escherichia coli).
Asunto(s)
Bacteriófago lambda/química , Proteínas de Unión al ADN/metabolismo , Proteínas Represoras/metabolismo , Proteínas Virales/metabolismo , Huella de ADN , ADN Circular/química , Elementos de Facilitación Genéticos , Conformación de Ácido NucleicoRESUMEN
We have used a gel retardation assay to investigate the influence of DNA supercoiling on loop formation between lac repressor and two lac operators. A series of 15 DNA minicircles of identical size (452 bp) was constructed carrying two lac operators at distances ranging from 153 to 168 bp. Low positive or negative supercoiling (sigma = +/- 0.023) changed the spacing between the two lac operators required for the formation of the most stable loops. This reveals the presence of altered double helical repeats (ranging from 10.3 to 10.7 bp) in supercoiled DNA minicircles. At elevated negative supercoiling (sigma = -0.046) extremely stable loops were formed at all operator distances tested, with a slight spacing periodicity remaining. After relaxation of minicircle-repressor complexes with topoisomerase I one superhelical turn was found to be constrained in those minicircles which carry operators at distances corresponding to a non-integral number of helical turns. This indicates that DNA loop formation can define local DNA domains with altered topological properties of the DNA helix.
Asunto(s)
ADN Superhelicoidal/genética , Operón Lac , Proteínas Represoras/metabolismo , Factores de Transcripción/metabolismo , Secuencia de Bases , Enzimas de Restricción del ADN , ADN Superhelicoidal/metabolismo , Escherichia coli/genética , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , PlásmidosRESUMEN
Distal effects on the in vivo repression of the deo operon are thought to be mediated by the deoR repressor with DNA loop formation. Such loops are easily observed by electron microscopy when the oligomeric deoR repressor is added to a DNA fragment carrying the three genetically defined operators at their chromosomal distances. Upon binding of deoR to any two operators, single loops are formed, 280, 600, and 880 bp in size. With the deo operon, double loops are also formed, which are the combination of the 280 bp and 600 bp loops and the result of simultaneous binding of the protein to its three sites. The formation of both single and double loops is consistent with the long-range effects observed in vivo and with the cooperative involvement of all three operator sites in the repression.
Asunto(s)
ADN Bacteriano/genética , Escherichia coli/genética , Regulación de la Expresión Génica , Regiones Operadoras Genéticas , Proteínas Represoras/fisiología , Factores de Transcripción/fisiología , Sitios de Unión , ADN Bacteriano/ultraestructura , Desoxirribonucleótidos , Microscopía Electrónica , Conformación de Ácido Nucleico , Operón , Regiones Promotoras Genéticas , Secuencias Reguladoras de Ácidos NucleicosRESUMEN
Repression of the lac promoter may be achieved in two different ways: either by interference with the action of RNA polymerase or by interference with CAP activation. We investigated cooperative repression of the Escherichia coli lac operon by systematic conversion of its three natural operators (O1, O2 and O3) on the chromosome. We find that cooperative repression by tetrameric Lac repressor increases with both quality and proximity of the interacting operators. A short distance of 92 bp allows effective repression by two very weak operators (O3, O3). The cooperativity of lac operators is discussed in terms of a local increase of repressor concentration. This increase in concentration depends on flexible DNA which allows loop formation.
Asunto(s)
Represión Enzimática , Escherichia coli/genética , Operón Lac/genética , Regiones Operadoras Genéticas/genética , Proteínas Represoras/metabolismo , Secuencia de Bases , ADN Bacteriano/genética , Regulación Bacteriana de la Expresión Génica , Modelos Genéticos , Datos de Secuencia Molecular , Conformación de Ácido Nucleico , Unión Proteica , Relación Estructura-ActividadRESUMEN
Tetrameric lac repressor may bind to two lac operators on one DNA fragment and induce the intervening DNA to form a loop. Electron microscopy, non-denaturing polyacrylamide gel electrophoresis, and DNase I protection experiments were used to demonstrate such DNA loops, where the distance between the centres of symmetry of the two lac operators varies between 63 and 535 bp. Formation of a DNA loop is favoured by correct phasing of the two lac operators and a low concentration of both components of the reaction. When a large excess of lac repressor over DNA is used, a 'tandem' structure is observed, in which both lac operators are occupied independently by two repressor tetramers. When the concentrations of both lac repressor and lac operator are high, a 'sandwich' structure is observed, in which two DNA molecules are connected by two lac repressor tetramers in trans.