Prenatal diagnosis of congenital cytomegalovirus infection in 115 cases: a 5 years' single center experience.

OBJECTIVE: The objective of this study is to investigate the diagnostic value of invasive prenatal diagnosis (PD) of congenital cytomegalovirus (CMV) infection from amniotic fluid (AF) and fetal blood (FB). METHODS: A retrospective study was conducted on 115 pregnancies with CMV primary infection. A total of 111 AF and 106 FB samples were investigated for various virological and non-virological markers. Detailed ultrasound examinations were performed at time of PD. RESULTS: Overall sensitivity of CMV PCR in FB (75.6%; 95%CI 60-87) and AF (72.7%; 95%CI 57-85) was comparable. In women with amniocentesis >8 weeks between seroconversion and PD, we did not observe significant differences between amniocentesis performed ≥17 + 0 (sensitivity 90.9%; 95%CI 71-99) and ≥20 + 0 gestational weeks (sensitivity 90.0%; 95%CI 68-99). Virological markers in FB were higher in symptomatic compared with asymptomatic fetuses (p < 0.05). No significant differences were observed for non-virological markers. However, platelet counts <120 × 10e9/L and beta-2 microglobulin values >14 mg/L were more frequently found in fetuses with severe ultrasound abnormalities compared with fetuses with no or mild abnormalities (p < 0.001). CONCLUSION: Optimal timing of amniocentesis in women with primary infection in early gestation should be reevaluated in a prospective study. Analysis of FB markers may be beneficial in the individual management of pregnant women with confirmed congenital CMV infection. © 2017 John Wiley & Sons, Ltd.

Successful treatment of an infant with CDA type II by intrauterine transfusions and postnatal stem cell transplantation.

Congenital dyserythropoietic anemias are rare hematological disorders leading to ineffective erythropoiesis with chronic anemia, complicated by iron overload. Here we present a remarkable clinical course of an infant with CDA type II who first presented as a severe fetal hydrops, requiring serial intrauterine red cell transfusions. While postnatal transfusion dependency persisted, the patient was successfully transplanted with a myeloablative conditioning regimen and peripheral blood stem cells of a matched donor. We believe that allogeneic HSCT is a reasonable therapeutic approach for patients with very severe CDA, even if only a matched unrelated donor is available.

[Chemotherapy-induced fetal anemia in maternal acute myelocytic leukemia]. / Chemotherapieinduzierte fetale Anämie bei akuter myeloischer Leukämie der Mutter.

This article discusses the management of a pregnancy of a 32-year-old primigravida with acute myelocytic leukemia treated with induction chemotherapy starting in the 20 + 5 week of gestation. Sonographic monitoring showed evidence of fetal ascites and anemia that could be treated with an intrauterine fetal transfusion. After maternal recovery, a caesarean section was performed in the 27 + 5 week of gestation. We delivered a vivid eutrophic female prematurely. The infant showed persisting signs of myelosuppression. Two further transfusions had to be performed. The present report describes the interdisciplinary therapeutic management when polychemotherapy during pregnancy is necessary for the mother. Cases of acute leukemia in pregnancy are complicated by severe prenatal risks caused by the hematologic illness and by the immediate beginning of chemotherapy. In the third trimester premature delivery is preferable to intrauterine exposition to cytostatic agents. In the second trimester the pregnancy has to be monitored for the typical risks and complications of chemotherapy. Fetal cytotoxic myelosuppression is detectable by prenatal observation so that interventional strategies are feasible.

Mirror-image RNA that binds D-adenosine.

A 58-mer L-RNA ligand that binds to naturally occurring D-adenosine with a dissociation constant of 1.7 microM in solution was identified from a combinatorial library employing mirror-design. The corresponding D-RNA ligand shows identical binding affinity to L-adenosine. Reciprocal chiral specificity was also evident from ligand discrimination; the binding affinity of the L-RNA ligand for D-adenosine was 9000-fold greater than its affinity for L-adenosine and vice versa. While the D-RNA ligand was rapidly degraded in human serum, the L-RNA ligand displayed an extraordinary stability. This indicates the potential application of specifically designed L-RNA ligands as stable monoclonal antibody analogues and the development of highly stable L-ribozymes.

Mirror-design of L-oligonucleotide ligands binding to L-arginine.

The high affinity and selectivity of nucleic acid ligands have clearly demonstrated that RNA can be targeted to a variety of molecules. In practice, however, the use of unmodified aptamers is impeded by the low stability of RNA in biological fluids. Here we describe the mirror-design of a stable 38-mer L-oligoribonucleotide ligand that binds to L-arginine. This L-RNA ligand was also able to bind to a short peptide containing the basic region of the human immunodeficiency virus type-1 Tat-protein. The L-RNA ligand displayed the expected stability in human serum. These findings may contribute to the identification of novel diagnostics and pharmaceuticals.

Crystal structure of an RNA dodecamer containing the Escherichia coli Shine-Dalgarno sequence.

The synthetic dodecameric RNA fragment rUAAGGAGGUGAU resembles a region upstream of the initiation site in prokaryotic mRNAs whereas the pyrimidine-rich complementary strand is identical to the last 12 nucleotides of Escherichia coli 16 S rRNA. The complex thus serves as a model for the Shine-Dalgarno interaction which is required for proper initiation of translation. The crystal structure of rUAAGGAGGUGUA.rAUCACCUCCUUA has been determined at 2.6 A resolution and refined against 2957 1 sigma(F) structure amplitudes to an R-value of 0.195. The unit cell of the triclinic crystals contains two double-stranded RNA molecules. The conformation of the two duplexes is similar, with a root-mean-square deviation of 0.683 A between equivalent atoms, and resembles calf thymus A-DNA as determined by X-ray fiber diffraction methods. Both molecules from continuous helices that penetrate the entire crystal, but the dinucleotide step in between dodecameric duplexes has an unusual geometry with a negative twist angle. The long helices cross over each other in a characteristic manner by inserting the backbone of one molecule into the minor groove of another. These contacts are stabilized by several direct intermolecular hydrogen bonds most of which are mediated by 2'-hydroxyl groups of the ribose sugars suggesting a general mode for the interaction between RNA molecules which is different from DNA-DNA interactions.

Crystal structure of domain E of Thermus flavus 5S rRNA: a helical RNA structure including a hairpin loop.

The synthetic RNA fragment 5'-CUGGGCGG(GCGA)CCGCCUGG (nucleotides in parentheses indicate the loop region) corresponds to the natural sequence of domain E from nucleotides 79-97 of the Thermus flavus 5S rRNA including a hairpin loop. The RNA structure determined at 3.0 A and refined to an R-value of 24.1% also represents the first X-ray structure GNRA tetraloop. The loop is in distinctly different conformation from other GNRA tetraloops analyzed by NMR. The conformation of the two molecules in the asymmetric unit is influenced and stabilized by specific intermolecular contacts. The structural features presented here give evidence for the ability of RNA molecules to adapt to specific environments.

Crystal structure of domain A of Thermus flavus 5S rRNA and the contribution of water molecules to its structure.

This is the first high resolution crystal structure of an RNA molecule made by solid phase chemical synthesis and representing a natural RNA. The structure of the domain A of Thermus flavus ribosomal 5S RNA is refined to R = 18% at 2.4 A including 159 solvent molecules. Most of the 2'-hydroxyl groups as well as the phosphate oxygens are involved either in specific hydrogen bonds in intermolecular contacts or to solvent molecules. The two U-G and G-U base-pairs are stabilized by H-bonds supplied via three water molecules to compensate for the lack of base-pair hydrogen bonds. The structure shows for the first time in detail the importance of highly ordered internal water in stabilizing an RNA structure.

Crystallization and preliminary diffraction studies of the structural domain E of Thermus flavus 5S rRNA.

The ribosomal 5S RNA is an essential constituent of the large ribosomal subunit. To overcome the difficulties of crystallizing large RNA molecules such as 5S rRNAs, we decided to divide the 5S rRNA in five domains A through E to determine their structure. Recently we determined the crystal structural of the helical domain A. Here we report the crystallization of the chemically synthesized domain E of the Thermus flavus 5S rRNA. The crystal form is trigonal with unit cell dimensions: a = b = 42.80 A and c = 162.20 A. Diffraction-data to 2.8 A have been recorded and the structure solution is currently underway by means of MIR and MAD techniques.

Initial analysis of 750 MHz NMR spectra of selective 15N-G,U labelled E. coli 5S rRNA.

The overall folding of an RNA molecule is reflected in its base pairing pattern. The identification of that pattern provides a first step towards the determination of the structure of an RNA molecule. We show that the application of heteronuclear NMR methods at 750 MHz to E. coli 5S rRNA (120 nucleotides) selectively labelled with 15N in guanine and uridine allows observation of base pairing patterns for a larger RNA molecule. We also present evidence that the fold of the E-domain of the 5S rRNA (nt 79-97) as a contiguous part of the 5S rRNA and as an isolated molecule is virtually the same.

First-trimester diagnosis of fetal congenital heart disease by transvaginal two-dimensional and Doppler echocardiography.

Until recently, prenatal diagnosis of fetal cardiac malformations was restricted to the second and third trimesters. With the advent of high-frequency transvaginal probes, earlier detection of such malformations is possible. We present a case of nonimmune hydrops fetalis with complete atrioventricular canal defect, insufficiency of atrioventricular valves, and complete heart block at 11 weeks' gestation diagnosed by transvaginal two-dimensional and Doppler echocardiography.

Fetal complete heart block: antenatal diagnosis, significance and management.

Complete heart block was diagnosed prenatally in 21 fetuses. Associated structural cardiac defects were present in 18 fetuses, in particular complete atrioventricular canal with atrial isomerism (5 cases), and 'corrected' transposition of the great arteries (4 cases). Maternal systemic lupus erythematosus was proved in only one case. In 11 fetuses, intra-uterine congestive heart failure with the signs of non-immune hydrops fetalis occurred. In all 11 fetuses, the hydrops was associated with a cardiac defect, in particular complete atrioventricular canal with atrial isomerism in 5 cases. A review of the literature confirms that only the association of complete heart block and cardiac malformation can cause intra-uterine congestive heart failure, whereas in the case of fetal complete heart block without cardiac malformation or with prenatally hemodynamically insignificant cardiac malformation, congestive heart failure is rare. Only 30% of newborns with complete heart block have associated cardiac malformations. In our series, however, 86% of the fetuses with complete heart block had cardiac malformations. The most important reason for this percentage discrepancy is that almost all fetuses with associated severe cardiac defects, in particular atrioventricular canal defects, develop heart failure which frequently results in prenatal death. Thus, fetal deaths are not included in pediatric statistics. Nevertheless, fetuses with isolated complete heart block generally do not develop heart failure and in almost all of the cases are born alive.

Prenatal diagnosis and management in fetuses with cystic hygromata colli.

We report on 45 fetuses with prenatally diagnosed bilateral cystic hygromata colli by ultrasound. Two of the 45 cases involved a twin pregnancy with only one fetus showing hygromata colli. In 2 cases there was only isolated hygromata colli. The other 43 cases showed the signs of non-immune hydrops fetalis. The cytogenetic findings were: 9 fetuses with Turner syndrome, 1 fetus with Turner mosaicism, 1 fetus with trisomy 18, 6 fetuses with trisomy 21, 12 fetuses with normal karyotype, and 16 fetuses with a failed chromosome culture. In fetuses with Turner syndrome and normal karyotype the sonographic findings were similar: massive bilateral hygromata colli, substantial fluid accumulations in skin and body cavities, oligohydramnios and intra-uterine growth retardation. In the cases with trisomy 21, the relative size of the hygromata colli was smaller. Intra-uterine growth retardation and oligohydramnios were not observed. The sole survivor of our group (elective pregnancy interruption: 30 cases; intra-uterine death: 14 cases) (karyotype: 46,XY) presented sonographically with massive ascites, a moderate cystic hygroma, and appropriate fetal development, and a normal amniotic fluid quantity. These findings are analysed in order to provide recommendations for prenatal diagnosis, prenatal management and genetic counselling of the couples concerned.

Flow analysis in the pulmonary trunc in fetuses with tetralogy of Fallot by colour Doppler flow mapping; two case reports.

Prenatal diagnosis of tetralogy of Fallot by two-dimensional echocardiography, which is based on demonstration of a ventricular septal defect and a large overriding aorta, is difficult. In the majority of cases the main pulmonary artery is small. In utero, there is no pathologically increased degree of the physiological right-ventricular hypertrophy. Colour Doppler flow mapping of reverse flow from the descending aorta via the ductus arteriosus into the main pulmonary artery is easily demonstrated, and provides an indirect sign of severe right-ventricular outlet obstruction. The technique also differentiates between pulmonary stenosis and atresia; the stenotic jet, even small, is identified by demonstration of high velocities and turbulences in the main pulmonary artery.

A-Z-RNA conformational changes effected by high pressure.

This paper reports evidence obtained by circular dichroism (CD) spectroscopy measurements indicating that two oligoribonucleotide duplexes with the alternating purine-pyrimidine sequences r(GC)6 or r(AU)6 change their A-RNA conformation under high pressure. Under the high-pressure conditions at which B-Z-DNA transition easily occurs, RNA acquires a conformation which only differs slightly from that of A-RNA. However, exposure of r(GC)6 or r(AU)6 to high pressure (6 kbar) in the presence of 5 M NaCl causes a conformation change of both oligoribonucleotide duplexes from their A- to their Z-RNA form. The departure of RNA or DNA duplexes from their original conformations under high pressure depends on the water structure itself and involves displacing an active (structural) water molecule outside the nucleic acid molecules. Experiments carried out until now in many laboratories have shown that B-Z or A-Z transitions of DNA or RNA, respectively, do not depend on the conditions applied, but the common mechanism for these processes seems to be dehydration. This same effect can be observed either at high salt concentrations or in the presence of an alcohol or at high pressure. Our results also support the view that the higher stability of RNA compared with DNA duplexes is due to the strong interaction of the 2'-hydroxyl groups of RNA with water molecules.

The specific hydrolysis of HIV-1 TAR RNA element with the anti-TAR hammerhead ribozyme: structural and functional implications.

The main transcriptional regulator of the human immunodeficiency virus is the Tat protein, which recognises and binds to a fragment RNA at the 5' end of viral mRNA, named transactivation response element (TAR) RNA. Extensive mutagenesis studies have shown that a region of TAR RNA important for Tat binding involves a set of nucleotides surrounding a characteristic UCU nucleotide bulge. The specific Tat-TAR complex formation enhances the rate of transcription elongation but inhibition of that interaction prevents the human immunodeficiency virus type 1 (HIV-1) replication. If so, a possibility of virus inactivation would be a site specific degradation of the TAR RNA element. To break down and inactivate TAR RNA, we designated the anti-hammerhead (HH) ribozyme to cleave nucleosides within the bulge. We showed for the first time the new type of the AUC hammerhead ribozyme, which hydrolyses specifically the TAR RNA element at C8 nucleotide in the bulge (C24 in the standard TAR RNA numbering). The cleavage reaction has broad magnesium requirements. Mn and particularly Ca are less efficient. Argininamide interferes with the cleavage of TAR RNA induced by the ribozyme. These results have two implications; (i) structural, where the HIV-1 TAR RNA element in solution occurs in equilibrium of only two forms, one of which, a double stranded RNA, meets structural requirements for ribozyme pairing and cleavage, and (ii) functional, the HH ribozyme can be explored for an inactivation of HIV-1 through the TAR RNA element deintegration.

Antepartum fetal blood sampling with cordocentesis. Comparison with chorionic villus sampling and amniocentesis in diagnosing karyotype anomalies.

Cordocentesis under ultrasound guidance, or percutaneous umbilical blood sampling, was first reported in 1983 by Daffos et al. Since then the method has gained importance in prenatal diagnosis. In 1,011 cases at a women's clinic in Bonn, Federal Republic of Germany, 35% of the cordocentesis cases were done for blood group incompatibilities plus intravascular transfusion in most of the cases. In the remaining 65% the indications for cordocentesis were a rapid karyotype analysis, diagnosis of fetal infections and determination of fetal acid-base status in severe intrauterine growth retardation. Chorionic villus sampling (CVS) and amniocentesis were also performed to detect karyotype anomalies. Amniocentesis constituted 78.8% of the procedures and detected 50% of the karyotype abnormalities. Cordocentesis and CVS constituted 17.3% and 3.9%, respectively, of all the procedures and diagnosed 39% and 11%, respectively, of the abnormalities. Different forms of trisomy were the most common karyotype anomaly. Translocation was noted in 22 cases. Turner's, Klinefelter and triple X syndromes and triploidy were the next major forms.

Multiple antepartum amnioinfusions in selected cases of oligohydramnios.

In general the perinatal outcome of oligohydramnios is poor. The diverse etiology of the entity is difficult to pinpoint. Multiple antepartum amnioinfusions can be beneficial in selected cases not associated with malformations, abnormal karyotypes or premature rupture of the membranes. We treated 38 patients with 105 such instillations.