Determinación temprana del sexo fetal en plasma materno mediante PCR en tiempo real / Early fetal sex determination in maternal plasma by real-time PCR / Determinação precoce do sexo fetal em plasma materno por PCR em tempo real

El análisis de ADN fetal libre en plasma ,materno permite estudiar material genético del feto sin realizar procedimientos invasivos sobre el embarazo. La identificación del sexo fetal mediante la detección de ADN del cromosoma masculino Y, en el plasma de mujeres embarazadas, es de gran utilidad en embarazos con riesgos para hiperplasia suprarrenal congénita o para enfermedades ligadas al cromosoma X. El presente estudio tuvo objetivo evaluar la factibilidad y desempeño diagnostico de la determinación del sexo fetal a través del análisis por PCR en tiempo real de ADN fetal libre en plasma de embarazadas . Se extrajeron 10 mL de sangre periférica a 134 pacientes embrazadas entre las 5 y 32 semanas de gestación, se separó el plasma y se efectuó extracción de ADN. Las muestras se analizaron mediante PCR en tiempo real amplificando el marcador DYS 14 presente en el cromosoma Y. El sexo fetal se confirmo mediante ecografia realizada entre las semanas 20 y 32. la sensibilidad y especificidad de la técnica para detectar el sexo fetal fue 98.5%y del 80,7% respectivamente. La menor edad gestacional de diagnóstico fue 5 semanas. La técnica implementada ha mostrado un desempeño diagnostico similar al descrito en la bibliografía...

Determinación temprana del sexo fetal en plasma materno mediante PCR en tiempo real / Early fetal sex determination in maternal plasma by real-time PCR / DeterminaþÒo precoce do sexo fetal em plasma materno por PCR em tempo real

El análisis de ADN fetal libre en plasma materno permite estudiar material genético del feto sin realizar procedimientos invasivos sobre el embarazo. La identificación del sexo fetal mediante la detección de ADN del cromosoma masculino Y, en el plasma de mujeres embarazadas, es de gran utilidad en embarazos con riesgo para hiperplasia suprarrenal congénita o para enfermedades ligadas al cromosoma X. El presente estudio tuvo como objetivo evaluar la factibilidad y desempeño diagnóstico de la determinación del sexo fetal a través del análisis por PCR en tiempo real de ADN fetal libre en plasma de embarazadas. Se extrajeron 10 mL de sangre periférica a 134 pacientes embarazadas entre las semanas 5 y 32 de gestación, se separó el plasma y se efectuó extracción de ADN. Las muestras se analizaron mediante PCR en tiempo real amplificando el marcador DYS14 presente en el cromosoma Y. El sexo fetal se confirmó mediante ecografía realizada entre las semanas 20 y 32. La sensibilidad y especificidad de la técnica para detectar el sexo fetal fue del 98,5% y del 80,7% respectivamente. La menor edad gestacional de diagnóstico fue 5 semanas. La técnica implementada ha mostrado un desempeño diagnóstico similar al descripto en la bibliografía.(AU)

Free fetal DNA analysis in maternal plasma permits the study of fetal genetic material without performing invasive procedures at pregnancy. The identification of fetal sex by detecting the male Y chromosome DNA in the plasma of pregnant women is very useful in pregnancies at risk for congenital adrenal hyperplasia or X-linked diseases. The present study aimed at evaluating the feasibility and the diagnostic performance of the determination of fetal sex analyzing free fetal DNA by real-time PCR in maternal plasma. A total of 10 mL of peripheral blood was taken from 134 pregnant patients undergoing between 5 and 32 weeks of gestation; the plasma was separated and DNA extraction was performed. Samples were analyzed by real-time PCR amplifying the marker DYS14 present in the Y chromosome. Fetal sex was confirmed by ultrasound performed between weeks 20 and 32. Sensitivity and specificity of the technique to detect the fetal sex were 98.5% and 80.7% respectively. The earliest gestational age at diagnosis was 5 weeks. The implemented technique has shown similar diagnostic performance to that described in the literature.(AU)

A análise do DNA fetal livre no plasma materno permite o estudo do material genético fetal sem a realizaþÒo de procedimentos invasivos na gravidez. A identificaþÒo do sexo fetal através da detecþÒo do DNA do cromossomo masculino Y, no plasma de mulheres grávidas, é muito útil em gestaþ§es com risco de hiperplasia adrenal congÛnita ou para doenþas ligadas ao cromossomo X. O presente estudo teve como objetivo avaliar a factibilidade e desempenho diagnóstico da determinaþÒo do sexo fetal através da análise por PCR em tempo real de DNA fetal livre no plasma de grávidas. 10 mL de sangue periférico foi extraído a partir de 134 pacientes grávidas entre 5 e 32 semanas de gestaþÒo, o plasma foi separado e foi feita a extraþÒo de DNA. As amostras foram analisadas por PCR em tempo real amplificando marcador de DYS14 presente no cromossomo Y. O sexo fetal foi confirmado por ultrassonografia realizada entre as semanas 20 e 32. A sensibilidade e a especificidade da técnica para detectar o sexo fetal foram de 98,5% e 80,7%, respectivamente. A menor idade gestacional de diagnóstico foi de 5 semanas. A técnica utilizada demonstrou um desempenho de diagnóstico semelhante ao descrito na literatura.(AU)

The effect of seasonality on oxidative metabolism in Nacella (Patinigera) magellanica.

We studied the seasonal variation on aerobic metabolism and the response of oxidative stress parameters in the digestive glands of the subpolar limpet Nacella (P.) magellanica. Sampling was carried out from July (winter) 2002 to July 2003 in Beagle Channel, Tierra del Fuego, Argentina. Whole animal respiration rates increased in early spring as the animals spawned and remained elevated throughout summer and fall (winter: 0.09+/-0.02 micromol O2 h-1 g-1; summer: 0.31+/-0.06 micromol O2 h-1 g-1). Oxidative stress was assessed at the hydrophilic level as the ascorbyl radical content/ascorbate content ratio (A./AH-). The A./AH- ratio showed minimum values in winter (3.7+/-0.2 10(-5)AU) and increased in summer (18+/-5 10(-5) AU). A similar pattern was observed for lipid radical content (122+/-29 pmol mg-1 fresh mass [FW] in winter and 314+/-45 pmol mg-1 FW in summer), iron content (0.99+/-0.07 and 2.7+/-0.6 nmol mg-1 FW in winter and summer, respectively) and catalase activity (2.9+/-0.2 and 7+/-1 U mg-1 FW in winter and summer, respectively). Since nitrogen derived radicals are thought to be critically involved in oxidative metabolism in cells, nitric oxide content was measured and a significant difference in the content of the Fe-MGD-NO adduct in digestive glands from winter and summer animals was observed. Together, the data indicate that both oxygen and nitrogen radical generation rates in N. (P.) magellanica are strongly dependent on season.

Oxidative stress in limpets exposed to different environmental conditions in the Beagle Channel.

The aim of this work was to study the oxidative profile of digestive glands of two limpets species (Nacella (Patinigera) magellanica and Nacella (Patinigera) deaurata) exposed to different environmental conditions. The intertidal population of N. (P.) magellanica is subjected to a wide variety of stresses not experienced by N. (P.) deaurata. Although a typical electron paramagnetic resonance (EPR) spectrum of ascorbyl radical in digestive gland from both limpets was observed, neither ascorbyl radical content nor the ascorbyl radical content/ascorbate content ratio was significantly different, suggesting that the difference in the environmental conditions did not appear to be responsible for developing alterations in the oxidative status of both organisms at the hydrophilic level (e.g. cytosol). Lipid peroxidation in the digestive glands was estimated, both as the content of thiobarbituric acid reactive substances (TBARS) and as the content of lipid radicals assessed by EPR, in both organisms. TBARS and lipid radical content were 34.8 and 36.5%, respectively, lower in N. (P.) magellanica as compared to N. (P.) deaurata. On the other hand, total iron content and the rate of generation of superoxide anion were 47.9 and 51.4%, respectively, lower in N. (P.) magellanica as compared to N. (P.) deaurata. The activity of catalase and superoxide dismutase (SOD) was 35.3 and 128.6% higher in N. (P.) magellanica as compared to N. (P.) deaurata, respectively. No significant differences were determined between the digestive glands of both molluscs regarding the content of total thiols. alpha-Tocopherol and beta-carotene content were significantly lower in N. (P.) magellanica as compared to N. (P.) deaurata. A distinctive EPR signal for the adduct Fe--MGD--NO (g = 2.03 and a(N) = 12.5 G) was detected in the homogenates of digestive glands of both limpets. A significant difference in the content of the Fe-MGD-NO adduct in digestive glands from N. (P.) magellanica and N. (P.) deaurata (491 +/- 137 and 839 +/- 63 pmol/g FW, respectively) was observed. Taken as a whole, the data presented here indicated that coping with environmental stressing conditions requires a complex adjustment of the physiological metabolic pathways to ensure survival by minimizing intracellular damage. It is likely that N. (P.) magellanica has a particular evolutionary adaptation to extreme environmental conditions by keeping iron content low and antioxidant activities high.