[Evaluation of malformations of the fetal central nervous system using fetal MRI]. / Das fetale MRT in der pränatalen Beurteilung von ZNS-Störungen.

PURPOSE: Ultrasound as the primary prenatal screening modality is used to detect fetal anomalies. Aim of the study was to prove the additional value of fetal magnetic resonance imaging (MRI). MATERIALS AND METHODS: In 25 pregnant women (age 30.6 +/- 4.8; 24 single and one twin pregnancy) with pathologic findings of the central nervous system detected by obstetric ultrasound, a fetal MRI was performed. All sequences (T2w-HASTE, TRUEFISP, T 1w-FLASH 2D, DWI) were performed using the breath-hold technique. The results were compared to postnatal MRI or ultrasound scan findings and tested for correlation with the clinical course and development of these children. RESULTS: Three to seven days after ultrasound, an MRI of all 26 fetuses without sedation was performed (26.6 +/- 4.0 GW). One healthy twin was not included in this study. MRI confirmed the ultrasonographic diagnosis in 7 cases. Compared to ultrasound, an additional pathology could be detected by MRI in 8 cases. In 10 cases ultrasound diagnosis was overruled by MRI. Prenatal MRI findings were confirmed by postnatal imaging in 18 children. The clinical course was predictable in 8 of 15 cases, depending on the pathology detected. Three newborns died in the perinatal period. CONCLUSION: Our results showed that fetal MRI has a high impact as an addition to ultrasound in evaluating congenital CNS pathology. Fetal MRI has become a helpful device for advising parents. However, clinical course and development still cannot be predicted based on MRI findings alone.

Needlelike and spherical polyelectrolyte complex nanoparticles of poly(l-lysine) and copolymers of maleic acid.

We report on the bulk and surface properties of dispersions consisting of nonstoichiometric polyelectrolyte complex (PEC) nanoparticles. PEC nanoparticles were prepared by mixing poly(l-lysine) (PLL) or poly(diallyldimethylammonium chloride) (PDADMAC) with poly(maleic acid-co-alpha-methylstyrene) (PMA-MS) or poly(maleic acid-co-propylene) (PMA-P). The monomolar mixing ratio was n-/n+ = 0.6, and the concentration ranged from 1 to 6 mmol/L. Subsequent centrifugation enabled the separation of the excess polycation, resulting in a stable coacervate phase further used in the experiments. The bulk phase parameters turbidity and hydrodynamic radius (R(h)) of the PEC nanoparticles showed a linear dependence on the total polymer content independently of the mixed polyelectrolytes. This can be interpreted by the increased collision probability of the polyelectrolyte chains when the overlap concentration is approached or exceeded. Different morphologies of the cationic PEC nanoparticles, which were solution-cast onto Si supports, were obtained by atomic force microscopy (AFM). The combinations of PLL/PMA-MS and PDADMAC/PMA-MS revealed more or less hemispherical particle shapes, whereas that of PLL/PMA-P revealed an elongated needlelike particle shape. Circular dichroism and attenuated total reflection Fourier transform infrared (ATR-FTIR) measurements proved the alpha-helical conformation for the PEC PLL/PMA-P and the random coil conformation for the PEC PLL/PMA-MS. We conclude that stiff alpha-helical PLL induces anisotropic elongated PEC nanoparticles, whereas randomly coiled PLL forms isotropic spherical PEC nanoparticles.

Preparation and adsorption of refined polyelectrolyte complex nanoparticles.

We report on bulk and surface properties of centrifuged nonstoichiometric polyelectrolyte complex (PEC) dispersions. PECs were prepared by mixing poly(diallyldimethylammonium chloride) (PDADMAC) and sodium poly(maleic acid-co-alpha-methylstyrene) (PMA-MS) at the monomolar mixing ratio of 0.6 and polymer concentration >/=1 mmol/l. Centrifugation of initial PEC dispersions revealed three phases: supernatant (SUP), coacervate (COAC), and an insoluble precipitate. Mass, turbidity, particle hydrodynamic radii (R(h)), and the titratable charge amount were determined for those phases. The turbid COAC phase consisted of 200-nm nanoparticles and carried 60% of the polymer mass and 20% of the titratable charge amount of the initial PEC dispersion. The SUP phase showed no turbidity and no such nanoparticles, but carried 80% of the initial titratable charge amount, presumably caused by excess polycations. Furthermore, linear dependences of turbidity and R(h) on COAC concentration was observed. COAC adsorption was studied at polyelectrolyte multilayer (PEM) modified silicon surfaces in dependence on both adsorption time and concentration using attenuated total-reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. The adsorption data were fitted by the simple Langmuir model. Comparison of COAC particles and polystyrene latices revealed similar adsorption features. SEM and AFM measurements resulted in hemispherically shaped adsorbed COAC particles with coverages >/=25%, whose calculated volumes correlated well with those in dispersion obtained by PCS.

[Measurement of volume flow by "colour velocity imaging (CVI)": technique of measurement in the intrahepatic fetal umbilical vein]. / Volumen-Flussmessung mit "Colour Velocity Imaging (CVI)": Technik der Messung in der intrahepatischen fetalen Vena umbilicalis.

"Colour Velocity Imaging (CVI)" permits acquisition of ultrasound Doppler data for quantitative analysis. CVI can be used to study the fetal circulation. In a pilot study we attempted measuring umbilical venous flow. Data acquisition is simple and fast. In the current implementation, data is sent to a work-station and analysed off-line. There is significant "intra-observer-variability" that could be attributable to true physiological variation or measurement inaccuracies. Measurement of fetal umbilical volume flow by CVI is a new and simple technique. Before its clinical use assumptions about the vessel, flow, variability and normal values must be verified in the fetus.

[Modern documentation in fetomaternal medicine: Classical client-server approach versus browser-based front-end]. / Moderne Dokumentation in der fetomaternalen Medizin: Klassische DB-Lösung versus Browser-basiertes Front-End.

In most areas of medicine electronic documentation today is mandatory. Biometric or longitudinal data and data collected according to quality assessment programs can often only be collected in computer databases. Two different technical realisations in commercial software products for fetomaternal medicine are compared.

Constriction of an extremity after amnioreduction in a TRAP-like sequence.

We present an unusual case of TRAP sequence (twin reversed arterial perfusion) with persistent polyhydramnios despite spontaneous thrombosis of the vena umbilicalis of the acardius. Serial amnioreduction was performed owing to considerable maternal discomfort and preterm labor. After three procedures, spontaneous abortion occurred. Unexpectedly, the normal twin had an apparently recent constriction of the right forearm. We hypothesize that limb constriction could be a rare but specific complication of aggressive amnioreduction.