RESUMO
We are interested in identifying Drosophila melanogaster RNA-binding proteins involved in important developmental decisions made at the level of mRNA processing, stability, localization or translational control. A large subset of the proteins known to interact with specific RNA sequences shares an evolutionarily conserved 80-90-amino-acid (aa) domain referred to as an RNA-recognition motif (RRM), including two ribonucleoprotein identifier sequences known as RNP-1 and RNP-2. Hence, we have herein applied degenerate polymerase chain reaction (PCR) methodology to clone three additional members (termed rox2, rox8 and rox21) of the D. melanogaster RRM-protein gene superfamily encoding putative trans-acting regulatory factors. Representative cDNA clones were isolated, the conceptual aa sequences of the candidate Rox proteins were inferred from their nucleotide sequences, and database searches were conducted. Rox2 displays extensive aa sequence similarities to putative RNA-binding proteins encoded by the genomes of the plants Oryza sativa and Arabidopsis thaliana; Rox21 resembles essential metazoan pre-mRNA splicing factors; as described elsewhere, Rox8 is likely a fly homolog of the two human TIA-1-type nucleolysins [Brand and Bourbon, Nucleic Acids Res. 21 (1993) 3699-3704].
Assuntos
Proteínas de Drosophila , Drosophila melanogaster/genética , Genes de Insetos/genética , Hormônios de Inseto/genética , Proteínas de Ligação a RNA/genética , Proteínas Repressoras , Sequência de Aminoácidos , Animais , Arabidopsis/genética , Sequência de Bases , Sequência Conservada , Drosophila melanogaster/crescimento & desenvolvimento , Dados de Sequência Molecular , Família Multigênica , Oryza/genética , Filogenia , Proteínas de Plantas/genética , Reação em Cadeia da Polimerase/métodos , Precursores de RNA/metabolismo , Splicing de RNA , Fatores de Processamento de RNA , Proteínas de Ligação a RNA/biossíntese , Proteínas de Ligação a RNA/química , Ribonucleoproteínas/química , Ribonucleoproteínas/genética , Alinhamento de Sequência , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Transativadores/genéticaRESUMO
BACKGROUND: In cases of fetal congenital heart block, the fetal heart rate (FHR) pattern is uninterpretable, often leading to an operative delivery. Reflectance pulse oximetry, a new technique that continuously measures the fetal arterial oxygen saturation (SaO2) during labor, is potentially useful in intrapartum monitoring of fetuses with this condition. CASES: Two fetuses with congenital heart block were monitored with reflectance pulse oximetry and fetal scalp blood sampling. The first patient delivered spontaneously. Adequate signal quality was achieved during 73% of the study time. Mean +/- standard deviation (SD) SaO2 was 53 +/- 14%. Fetal outcome was good. The second patient was delivered by cesarean because of arrest of labor. Oxygen saturation values were obtained during 89% of the study time. The mean SaO2 was 42 +/- 13%. There was a period of 8 minutes with SaO2 values below 20%. Capillary blood pH dropped from 7.33 to 7.25; SaO2 values then returned to levels above 30% and the capillary blood pH normalized. The neonate was born in good condition. CONCLUSION: In fetal congenital heart block, adequate surveillance with FHR monitoring during labor is not possible; therefore, continuous information on fetal oxygenation may be valuable in assessing the fetal condition and may prevent unnecessary obstetric interventions.
Assuntos
Doenças Fetais/fisiopatologia , Monitorização Fetal/métodos , Bloqueio Cardíaco/congênito , Oximetria , Adulto , Feminino , HumanosRESUMO
Four cases of conjoined twins are presented. On the basis of these cases and a review of the literature we present the ultrasonographic features to diagnose this rare condition prenatally in its various forms. Recommendations to avoid misdiagnosis are given. Consequences of this diagnosis and assessment of shared organs are discussed for counselling and obstetrical care.
