Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 28
Filtrar
1.
Ultrasound Obstet Gynecol ; 49(4): 460-464, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27981672

RESUMEN

OBJECTIVE: To assess the performance of screening for fetal trisomies 21, 18 and 13 by cell-free (cf) DNA analysis of maternal blood using a new method based on paired-end massively parallel shotgun sequencing (MPSS). METHODS: This was a blinded study of plasma samples (1mL) obtained from 1000 women undergoing screening for fetal trisomies 21, 18 and 13 at 11-13 weeks' gestation. The study included 50 cases with confirmed fetal trisomy 21, 30 with trisomy 18, 10 with trisomy 13 and 910 unaffected pregnancies. Paired-end MPSS with the neoBona® test allowed simultaneous assessment of fetal fraction, cfDNA fragment size distribution and chromosome counting, which were integrated into a new analysis algorithm to calculate trisomy likelihood ratios (t-score) for each chromosome of interest. Each sample was classified as trisomic or unaffected using chromosome-specific cut-offs set at t-score values of 1.5 for trisomy 21 and 3.0 for trisomies 18 and 13. RESULTS: Valid results were provided for 988 (98.8%) cases; 12 (1.2%) samples, from nine euploid and three trisomy 21 pregnancies, did not pass quality-control criteria and were excluded from further analysis. All 47 cases of trisomy 21, all 10 of trisomy 13, 29 of 30 with trisomy 18 and all 901 unaffected cases were classified correctly. Median fetal fraction was 10.5% (range, 0.3-33.8%) and trisomic and unaffected cases with low fetal fractions of < 1% were identified correctly. CONCLUSIONS: This novel method for cfDNA analysis of maternal plasma, which utilizes paired-end MPSS, can provide accurate prediction of fetal trisomies. Use of a new multicomponent t-score removes the need to reject samples with fetal fraction < 4%, which potentially extends the benefits of non-invasive prenatal cfDNA analysis to a larger proportion of pregnancies. © 2016 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Asunto(s)
Trastornos de los Cromosomas/diagnóstico , Síndrome de Down/diagnóstico , Secuenciación de Nucleótidos de Alto Rendimiento/métodos , Trisomía/diagnóstico , Adulto , Sistema Libre de Células , Cromosomas Humanos Par 13 , Cromosomas Humanos Par 18 , ADN/sangre , Femenino , Humanos , Edad Materna , Embarazo , Diagnóstico Prenatal , Sensibilidad y Especificidad , Síndrome de la Trisomía 13 , Síndrome de la Trisomía 18
2.
Ultrasound Obstet Gynecol ; 45(1): 61-6, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25297464

RESUMEN

OBJECTIVES: To report clinical implementation of cell-free DNA (cfDNA) analysis of maternal blood in screening for trisomies 21, 18 and 13 in twin pregnancies and examine variables that could influence the failure rate of the test. METHODS: cfDNA testing was performed in 515 twin pregnancies at 10-28 weeks' gestation. The failure rate of the test to provide results was compared with that in 1847 singleton pregnancies, and logistic regression analysis was used to determine which factors among maternal and pregnancy characteristics were significant predictors of test failure. RESULTS: Failure rate of the cfDNA test at first sampling was 1.7% in singletons and 5.6% in twins. Of those with a test result, the median fetal fraction in twins was 8.7% (range, 4.1-30.0%), which was lower than that in singletons (11.7% (range, 4.0-38.9%)). Multivariable regression analysis demonstrated that twin pregnancy, higher maternal weight and conception by in-vitro fertilization provided significant independent prediction of test failure. Follow-up was available in 351 (68.2%) of the twin pregnancies and comprised 334 with euploid fetuses, 12 discordant for trisomy 21 and five discordant for trisomy 18. In all 323 euploid cases with a result, the risk score for each trisomy was < 1:10 000. In 11 of the 12 cases with trisomy 21 and in the five with trisomy 18, the cfDNA test gave a high-risk result, but in one case of trisomy 21, the score was < 1:10 000. CONCLUSION: In twin pregnancies screening by cfDNA testing is feasible, but the failure rate is higher and detection rate may be lower than in singletons.


Asunto(s)
Gonadotropina Coriónica Humana de Subunidad beta/sangre , ADN/sangre , Embarazo Gemelar/sangre , Proteína Plasmática A Asociada al Embarazo/metabolismo , Diagnóstico Prenatal , Trisomía/diagnóstico , Adulto , Sistema Libre de Células , Reacciones Falso Positivas , Femenino , Edad Gestacional , Humanos , Recién Nacido , Masculino , Edad Materna , Embarazo , Estudios Prospectivos , Medición de Riesgo , Sensibilidad y Especificidad
4.
Cir. plást. ibero-latinoam ; 39(4): 321-326, oct.-dic. 2013. ilus
Artículo en Español | IBECS | ID: ibc-121508

RESUMEN

Distinguimos en las fosas nasales la presencia de un estrecho o válvula y, de ella, investigamos específicamente su porción anterior conocida en Cirugía Plástica como válvula nasal interna (VNI). Analizamos en este artículo las características, disposición y relaciones de sus distintos componentes, puntualizando específicamente el singular comportamiento del mucoepitelio valvular con respecto a los cartílagos triangulares y cuadrangular. Advertimos sobre la posibilidad de complicaciones postoperatorias en el caso de indebido trato valvular durante la cirugía y adjuntamos preparados y sus correspondientes dibujos con el propósito de facilitar la comprensión de los hechos observados (AU)


In this paper, we sand out the presence of a strait or valve in the nostrils, and about it, it's specifically investigated it's anterior portion known in Plastic Surgery as internal nasal valve (INV). Characteristics, provision and relations of its individual components are discussed, specifically pointing out the ubique behavior of the valvular mucosal epithelium in connection with the triangular and quadrangular cartilage. We warn out the possibility of postoperative complications in case of improper surgical valvular treatment and we attach preparations and their corresponding drawings in order to make easy the understanding of the observed facts (AU)


Asunto(s)
Humanos , Rinoplastia/métodos , Cavidad Nasal/anatomía & histología , Cartílagos Nasales/anatomía & histología , Procedimientos de Cirugía Plástica/métodos , Complicaciones Posoperatorias/prevención & control
5.
Fetal Diagn Ther ; 34(3): 172-5, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23485930

RESUMEN

Characterization of marker chromosomes before the introduction of array CGH (aCGH) assays was only based on their banding patterns (G, C, and NOR staining) and fluorescent in situ hybridization techniques. The use of aCGH greatly improves the identification of marker chromosomes in some cases. We describe an atypical case of Pallister-Killian syndrome (PKS) detected at prenatal diagnosis with a very unusual cytogenetic presentation: a supernumerary ring chromosome including two copies of 12p. A similar anomaly described in a postnatal patient suggests ring chromosome as a possible cause of PKS. Extra ring chromosomes might be a more common etiology for PKS than previously thought, given the difficulty in their characterization before the advent of aCGH.


Asunto(s)
Trastornos de los Cromosomas/genética , Isocromosomas , Adulto , Cromosomas Humanos Par 12/genética , Hibridación Genómica Comparativa , Femenino , Humanos , Cariotipo , Mosaicismo , Embarazo , Diagnóstico Prenatal
6.
Prenat Diagn ; 33(2): 173-8, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23280558

RESUMEN

OBJECTIVE: This study aims to assess the suitability of non-invasive prenatal RHD genotyping in non-immunized midtrimester pregnant women from a mixed ethnic population, to prevent unnecessary anti-D immunoglobulin prophylaxis and to identify RHD variants METHODS: Rhesus D-negative pregnant women were offered fetal RHD genotyping at 24 gestational weeks. A total of 284 samples were tested for RHD status using multiplex rt-PCR amplification of exons 5 and 7 of the RHD gene and exons 6 and 10 in selected cases. Women carrying RHD-negative fetuses were counseled about their option to avoid routine antenatal anti-D immunoglobulin administration. Diagnostic accuracy of RHD genotyping was compared with postnatal Rhesus D serotyping. RESULTS: A total of 184 positives (65%), 91 negatives (32%) and 7 cases (2.5%) compatibles with RHD variants were detected by RHD genotyping. No false negative results were found, and a single false positive was observed in a twin pregnancy. Genotyping was accepted when offered by 94% of women (284/302), and anti-D immunoglobulin was avoided in 95% (90/95) of RHD-negative fetuses. CONCLUSIONS: Non-invasive routine antenatal RHD genotyping at 24 weeks of pregnancy is a highly accurate method, resulting in the avoidance of 95% of unnecessary administrations of anti-D immunoglobulin, with no false negative results.


Asunto(s)
Técnicas de Genotipaje , Diagnóstico Prenatal , Sistema del Grupo Sanguíneo Rh-Hr/genética , Exones , Femenino , Sangre Fetal , Humanos , Recién Nacido , Masculino , Embarazo , Segundo Trimestre del Embarazo , Grupos Raciales/genética , España
8.
Rev. argent. cir. plást ; 19(4): 97-102, 20130000. fig
Artículo en Español | LILACS, BINACIS | ID: biblio-1553866

RESUMEN

Se distingue en las fosas nasales la presencia de un estrecho o válvula y, de ella, se investiga específi camente su porción anterior conocida en la Especialidad de Cirugía Plástica como válvula nasal interna (VNI). Las características, disposición y relaciones de sus distintos componentes son analizados en esta presentación, puntualizando específi camente el singular comportamiento del mucoepitelio valvular con respecto a los cartílagos triangulares y cuadrangular. Se advierte sobre la posibilidad de complicaciones posoperatorias en el caso de indebido trato valvular. Se adjuntan preparados y sus correspondientes dibujos con el propósito de facilitar la comprensión de los hechos observados


Stands out the presence of a strait or valve in the nostrils, and about it, it's specifi cally investigated it's anterior portion known in the fi eld as internal nasal valve (INV). Characteristics, provision and relations of its individual components are discussed in this presentation, specifi cally pointing out the ubique behavior of the valvular mucosal epithelium in connection with the triangular and quadrangular cartilage. It warns out the possibility of post operative complications in case of improper valvular treatment. Attached preparations and their corresponding drawings in orden te facilitate the understanding of the observed facts.


Asunto(s)
Humanos , Masculino , Femenino , Rinoplastia/métodos , Constricción Patológica/cirugía , Cavidad Nasal/anatomía & histología
9.
Phys Rev Lett ; 108(6): 061103, 2012 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-22401050

RESUMEN

We model neutrino emission from a newly born neutron star subsequent to a supernova explosion to study its sensitivity to the equation of state, neutrino opacities, and convective instabilities at high baryon density. We find the time period and spatial extent over which convection operates is sensitive to the behavior of the nuclear symmetry energy at and above nuclear density. When convection ends within the protoneutron star, there is a break in the predicted neutrino emission that may be clearly observable.

11.
Clin Microbiol Infect ; 16(7): 836-42, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19840031

RESUMEN

Human papillomavirus (HPV) infection is the cause of cervical cancer. Integration of HPV-16 DNA in cervical cells is considered to be a key event in the progression towards invasive cancer, but little is known about this event in anal carcinogenesis. The integration could be a useful biomarker for cancer progression. Optimized assays are needed to determine the value of real-time detection of HPV integration in longitudinal studies, and this approach is only possible with a high-throughput assay. The aim of this study was to develop a new multiplex real-time PCR assay based on simultaneous amplification of the E2 and E6 HPV open reading frames (ORFs) in order to assess the physical status (episomal and/or integrated) of HPV-16 in anal cells of HIV-positive men. The comparative threshold (Ct) cycle values for E2 and E6 obtained for SiHA cells and artificial mixtures of episomal and integrated DNA were as expected: similar Ct for episomal forms and absence of E2 amplification for integrated forms. The multiplex real-time PCR was tested in 77 consecutive samples from individual HIV-infected patients with HPV-16 anal infection. The integration of HPV-16 was detected in 25 (32%) patients: 23 as mixed (episomal and integrated) and two as completed integrated forms. The integration occurs in the early stage of anal lesions and was associated with the severity of the lesions (p 0.004). The multiplex real-time PCR assay developed in the course of this study was shown to be a simple, sensitive, specific and inexpensive technique which may be applied routinely to detect HPV-16 integration.


Asunto(s)
Canal Anal/virología , Enfermedades del Ano/virología , Papillomavirus Humano 16/genética , Papillomavirus Humano 16/fisiología , Infecciones por Papillomavirus/virología , Reacción en Cadena de la Polimerasa , Integración Viral , Canal Anal/patología , Enfermedades del Ano/complicaciones , Enfermedades del Ano/patología , Línea Celular Tumoral , ADN Viral/análisis , ADN Viral/genética , Proteínas de Unión al ADN/genética , Femenino , Infecciones por VIH/complicaciones , Papillomavirus Humano 16/aislamiento & purificación , Humanos , Masculino , Proteínas Oncogénicas Virales/genética , Sistemas de Lectura Abierta , Infecciones por Papillomavirus/complicaciones , Infecciones por Papillomavirus/patología , Proteínas Represoras/genética
14.
J Med Genet ; 43(4): 353-61, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16199537

RESUMEN

BACKGROUND: Karyotype analysis has been the standard method for prenatal cytogenetic diagnosis since the 1970s. Although highly reliable, the major limitation remains the requirement for cell culture, resulting in a delay of as much as 14 days to obtaining test results. Fluorescent in situ hybridisation (FISH) and quantitative fluorescent PCR (QF-PCR) rapidly detect common chromosomal abnormalities but do not provide a genome wide screen for unexpected imbalances. Array comparative genomic hybridisation (CGH) has the potential to combine the speed of DNA analysis with a large capacity to scan for genomic abnormalities. We have developed a genomic microarray of approximately 600 large insert clones designed to detect aneuploidy, known microdeletion syndromes, and large unbalanced chromosomal rearrangements. METHODS: This array was tested alongside an array with an approximate resolution of 1 Mb in a blind study of 30 cultured prenatal and postnatal samples with microscopically confirmed unbalanced rearrangements. RESULTS: At 1 Mb resolution, 22/30 rearrangements were identified, whereas 29/30 aberrations were detected using the custom designed array, owing to the inclusion of specifically chosen clones to give increased resolution at genomic loci clinically implicated in known microdeletion syndromes. Both arrays failed to identify a triploid karyotype. Thirty normal control samples produced no false positive results. CONCLUSIONS: Analysis of 30 uncultured prenatal samples showed that array CGH is capable of detecting aneuploidy in DNA isolated from as little as 1 ml of uncultured amniotic fluid; 29/30 samples were correctly diagnosed, the exception being another case of triploidy. These studies demonstrate the potential for array CGH to replace conventional cytogenetics in the great majority of prenatal diagnosis cases.


Asunto(s)
Aberraciones Cromosómicas , Enfermedades Fetales/diagnóstico , Análisis de Secuencia por Matrices de Oligonucleótidos/métodos , Diagnóstico Prenatal/métodos , Femenino , Enfermedades Fetales/genética , Genoma Humano , Humanos , Embarazo , Sensibilidad y Especificidad
15.
Phys Rev Lett ; 95(15): 151802, 2005 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-16241715

RESUMEN

We derive model-independent, "naturalness" upper bounds on the magnetic moments munu of Dirac neutrinos generated by physics above the scale of electroweak symmetry breaking. In the absence of fine-tuning of effective operator coefficients, we find that current information on neutrino mass implies that[EQUATION: SEE TEXT] bohr magnetons. This bound is several orders of magnitude stronger than those obtained from analyses of solar and reactor neutrino data and astrophysical observations.

16.
Phys Rev Lett ; 93(23): 231802, 2004 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-15601143

RESUMEN

We point out that extensions of the standard model with low scale (approximately TeV) lepton number violation (LNV) generally lead to a pattern of lepton flavor violation (LFV) experimentally distinguishable from the one implied by models with grand unified theory scale LNV. As a consequence, muon LFV processes provide a powerful diagnostic tool to determine whether or not the effective neutrino mass can be deduced from the rate of neutrinoless double beta decay. We discuss the role of mu-->egamma and mu-->e conversion in nuclei, which will be studied with high sensitivity in forthcoming experiments.

17.
Mol Hum Reprod ; 10(11): 839-46, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15361554

RESUMEN

The quantitative fluorescent PCR (QF-PCR) assay, introduced during the last few years, allows prenatal diagnoses of common chromosome aneuploidies in a few hours after sampling. We report the first assessment of QF-PCR performed on a large cohort of 18,000 consecutive clinical specimens analysed in two different Centres. All samples were analysed by QF-PCR using several selected STR markers together with amelogenin and, occasionally, SRY for fetal sexing. Results were compared with those obtained by conventional cytogenetic analysis. In 17,129 tests, normal fetuses were detected by QF-PCR. No false positives were observed. All 732 cases of trisomy 21, 18, 13, triploidies, double trisomies as well as all but one fetuses with X and Y aneuploidies were correctly diagnosed. Chromosome mosaicism could also be suspected in several samples. In some cases of in vitro culture failures, QF-PCR was the only evidence of fetal X, Y, 21, 18 and 13 chromosome complement. QF-PCR proved to be efficient and reliable in detecting major numerical chromosome disorders. The main advantages of the molecular assay are its very low cost, speed and automation enabling a single operator to perform up to 40 assays per day. QF-PCR relieves anxiety of most parents within 24 h from sampling and accelerates therapeutic interventions in the case of an abnormal result. In countries where large scale conventional cytogenetics is hampered by its high cost and lack of technical expertise, QF-PCR may be used as the only prenatal diagnostic test.


Asunto(s)
Aneuploidia , Cromosomas Humanos/genética , Reacción en Cadena de la Polimerasa , Diagnóstico Prenatal/métodos , Femenino , Humanos , Repeticiones de Minisatélite/genética , Embarazo
18.
Ann Genet ; 47(2): 177-9, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15183750

RESUMEN

Rearrangements involving long arm of chromosome 12 are rare events. To our knowledge, we present the first case of an interstitial deletion of the long arm of chromosome 12 in a prenatal diagnosis. A review of the literature is included in our report.


Asunto(s)
Deleción Cromosómica , Cromosomas Humanos Par 12/genética , Diagnóstico Prenatal , Anomalías Múltiples/diagnóstico , Amniocentesis , Femenino , Humanos , Masculino , Embarazo , Tercer Trimestre del Embarazo
19.
Phys Rev Lett ; 91(16): 162001, 2003 Oct 17.
Artículo en Inglés | MEDLINE | ID: mdl-14611393

RESUMEN

On the basis of a next-to-leading-order calculation in chiral perturbation theory, the first complete analysis of isospin breaking for direct CP violation in K0-->2 pi decays is performed. We find a destructive interference between three different sources of isospin violation in the CP violation parameter epsilon'. Within the uncertainties of large-N(c) estimates for the low-energy constants, the isospin violating correction for epsilon' is below 15%.

20.
Mol Hum Reprod ; 7(10): 1001-6, 2001 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11574670

RESUMEN

The clinical application of quantitative fluorescent polymerase chain reaction (QF-PCR) for rapid prenatal detection of chromosome aneuploidies has been limited in most studies to the detection of autosomal trisomies. Recently it has been shown that a newly identified highly polymorphic marker, termed X22, which maps to the Xq/Yq pseudoautosomal region of the sex chromosomes, used together with the X-linked short tandem repeat (STR) HPRT, allows the accurate detection of gonosome aneuploidies. We have developed a rapid assay, which includes these STR markers together with a sequence of the amelogenin region of the sex chromosomes and selected highly polymorphic autosomal STR. Two more X chromosome markers, as yet not used in previous QF-PCR applications, were also included in the assay. The molecular test was then used in a clinical trial on 551 uncultured amniotic fluid samples, allowing the assessment of copy number for chromosomes X, Y and 21 in 100% of cases. In the course of this study, two fetuses with Turner's syndrome and one with Klinefelter's syndrome were identified along with 17 autosomal trisomies. The assay proved to be so efficient and reliable that in most aneuploidy cases, in which ultrasound findings were in agreement with the molecular result, therapeutical interventions were possible without waiting for the result of cytogenetic analysis.


Asunto(s)
Amniocentesis , Trastornos de los Cromosomas/diagnóstico , Reacción en Cadena de la Polimerasa/métodos , Adulto , Amelogenina , Aneuploidia , Trastornos de los Cromosomas/genética , Proteínas del Esmalte Dental/genética , Femenino , Fluorescencia , Marcadores Genéticos , Humanos , Masculino , Embarazo , Procesos de Determinación del Sexo , Secuencias Repetidas en Tándem
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...