[Sickle cell anemia in perinatal placental diagnostics]. / Sichelzellenanämien in der perinatalen Plazentadiagnostik.

Hereditary hemoglobinopathies should be considered as differential diagnosis when examining placental specimens for fetal growth retardation and spontaneous abortion. They can cause various macroscopic and microscopic changes in the placenta that are relevant for routine pathology examination. The importance of interdisciplinary co-operation between obstetrics and pathology to achieve optimum diagnostics and therapy planning is demonstrated using the case of a pregnant woman with heterozygous genotype and her child with homozygous genotype. Within this context, the influence of hemoglobinopathies on placental pathology and fetal development are summarized and exemplified.

Luminescence, structural, and bonding trends upon varying the halogen in isostructural aurophilic dimers.

The preparation of three isonitrile complexes (p-tosyl)CH(2)NCAu(I)X (X = Cl, Br, and I) along with their structural, spectral, and computational characterization are reported. X-Ray crystallography reveals that these complexes all crystallize in the same space group, C2/c, and have closely related supramolecular structures. The three complexes exhibit crossed-dimer structures with short Au...Au aurophilic distances of 3.0634(4) A, 3.1044(7) A, and 3.1083(5) A, for X = Cl, Br, and I, respectively. These distances are among the shortest ligand-unassisted Au...Au interactions reported. While RNCAuX complexes that we reported earlier associate as anti-parallel, one-dimensional aurophilic polymers with long Au...Au distances (approximately 3.6 A) and exhibit orange-red phosphorescence, the analogous aurophilic dimers herein show seemingly counter-intuitive blue-green emissions despite having much shorter Au...Au distances. DFT computations are used to augment experiment and study the T(1) phosphorescent excited state of [RNCAuX](n) in parallel, anti-parallel, and staggered conformations. Excimeric bonding and large Stokes shifts are predicted for all models, the extent of which is sensitive to both "n" and conformation with trends commensurate with experimental luminescence data. Calculations for the three [MeNCAuX](2) dimeric complexes reveal blue-green phosphorescence with a red shift as a function of increasing halide softness, consistent with experimental data for (p-tosyl)CH(2)NCAu(I)X (Cl > Br > I). The overall experimental and theoretical work signifies the central role of ground-state aurophilic bonding and excited-state excimeric bonding on the electronic structure, hence facilitating development of structure-luminescence relations that may assist in the rational design of novel optoelectronic devices.

[Comments on a report by the BQS on obstetric quality indicators]. / Stellungnahme zu einem Gutachten der BQS über geburtshilfliche Qualitätsindikatoren.

When re-evaluating an epidemiologically oriented BQS expertise concerning the quality indicators in obstetrics, we examined three essential methods in obstetrics to verify their scientific evidence and their clinical relevance. In doing so we ascertained that recording the fetal heart rate sub part, analysing fetal blood and determining the blood gas of the umbilical blood are entirely appropriate quality indicators during delivery from a clinical and medical point of view -- although to varying extents. Above all, these three indicators prove to be essentially better evidence-based than described in the BQS expertise. The search for an optimum of evidence-based data in medicine ends in certain fields such as, for example, in obstetrics there where no further randomized studies can be carried out for methodological or ethical reasons. This lack of evidence for the optimum grade I which can clearly be understood from an epidemiological point of view, however, should not lead to an evidence nihilism that fails to accept or admit existing evidence of the weaker grades II and III.

Metal effect on the supramolecular structure, photophysics, and acid-base character of trinuclear pyrazolato coinage metal complexes.

Varying the coinage metal in cyclic trinuclear pyrazolate complexes is found to significantly affect the solid-state packing, photophysics, and acid-base properties. The three isoleptic compounds used in this study are [[3,5-(CF3)2Pz]M]3 with M = Cu, Ag, and Au (i.e., Cu3, Ag3, and Au3, respectively). They form isomorphous crystals and exist as trimers featuring nine-membered M3N6 rings with linear two-coordinate metal sites. On the basis of the M-N distances, the covalent radii of two-coordinate Cu(I), Ag(I), and Au(I) were estimated as 1.11, 1.34, and 1.25 angstroms, respectively. The cyclic [[3,5-(CF3)2Pz]M]3 complexes pack as infinite chains of trimers with a greater number of pairwise intertrimer M...M interactions upon proceeding to heavier coinage metals. However, the intertrimer distances are conspicuously short in Ag3 (3.204 angstroms) versus Au3 (3.885 angstroms) or Cu3 (3.813 angstroms) despite the significantly larger covalent radius of Ag(I). Remarkable luminescence properties are found for the three M3 complexes, as manifested by the appearance of multiple unstructured phosphorescence bands whose colors and lifetimes change qualitatively upon varying the coinage metal and temperature. The multiple emissions are assigned to different phosphorescent excimeric states that exhibit enhanced M...M bonding relative to the ground state. The startling luminescence thermochromic changes in crystals of each compound are related to relaxation between the different phosphorescent excimers. The trend in the lowest energy phosphorescence band follows the relative triplet energy of the three M(I) atomic ions. DFT calculations indicate that [[3,5-(R)2Pz]M]3 trimers with R = H or Me are bases with the relative basicity order Ag << Cu < Au while fluorination (R = CF3) renders even the Au trimer acidic. These predictions were substantiated experimentally by the isolation of the first acid-base adduct, [[Au3]2:toluene]infinity, in which a trinuclear Au(I) complex acts as an acid.

Competing reactions of secondary alcohols with sodium hypochlorite promoted by phase-transfer catalysis.

With aqueous hypochlorite and a phase transfer catalyst, secondary alcohols undergo hitherto unreported free radical reactions that compete with and effectively limit traditional ketone syntheses. Product mixture profiles are determined by reactant ratios, organic cosolvent, and availability of oxygen to the system. Under argon, over half of substrate alcohols, PhCH(OH)R, are converted to benzaldehyde and free radical products through beta-scission of intermediate alkyl hypochlorites. Secondary alcohols with R containing three or more carbons also may undergo delta chlorination.

Labor induction and augmentation with oxytocin: pharmacokinetic considerations.

Traditional protocols for oxytocin infusion regimens recommend increases of infusion rate at 15-20 min intervals. However recent clinical studies agree that prolonged intervals of 30-40 or even 60 minutes are superior to shorter dosage intervals in terms of safety and efficacy. These results are in good agreement with recent pharmacologic data on oxytocin in pregnant women, showing a half-life of about 15 minutes, and of current pharmacokinetic principles, which indicate that at least 3 half-lives of constant infusion will elapse before the corresponding clinical effect may be established. Increasing the oxytocin infusion earlier, could cause excessive uterine contractions and fetal distress.

[Effect of Doppler ultrasound on perinatal mortality of high risk pregnancies: required patient sample?]. / Effekt der Dopplersonographie auf die perinatale Mortalität von Risikoschwangerschaften: erforderliche Patientenzahl?

The clinical value of Doppler ultrasound in obstetrics is related to the question whether pregnancy course and outcome will be improved when this method is introduced into obstetrical management. Recently a couple of randomized controlled management studies have been published and the majority of these trials showed significant beneficial effects. Even perinatal mortality may possibly be reduced, but none of these trials was large enough to achieve a significant reduction. Giles and Bisits [12] performed a metaanalysis by combining evidence from 6 of these trials in high risk pregnancies and could demonstrate a 50% reduction in perinatal mortality at a significance of 5%. But they did not report whether the sample size was large enough to detect this difference with the usually required power of at least 80%. Therefore the question remains whether obstetrical management should be changed in view of these results. Additionally, a clinically useful estimate is needed to determine the chance to reproduce the assumed beneficial effect. The present paper describes the statistical method for calculating the appropriate sample size needed in each group of a trial to detect a predefined treatment difference with specified significance and power. This method is applied in detail to the results of the meta-analysis of Giles and Bisits [12] and a minimal sample size of 1458 high risk pregnancies in each group is calculated. As the Doppler and the control groups actually contained 2102 and 2133 high risk patients respectively, these sample sizes proved to be large enough to detect a 50% reduction in perinatal mortality with a power of at least 80%. Furthermore, 59 high risk pregnancies would need to be managed by Doppler in order to prevent 1 case of perinatal death. In other words, it should be possible to prevent 4 perinatal death cases per 1000 total births when the high risk proportion is 25%.

[Development of a plastic capillary tube for Saling fetal blood analysis. Evaluation of pH-metry with standard references]. / Entwicklung einer Kunststoffkapillar für die Fetalblutanalyse nach Saling. Prüfung der pH-Metrie auf Vergleichbarkeit.

In order to avoid mouth suction and danger of glass breakage during collection and to avoid mixing of the sample with a piece of wire and an external magnet immediately after collection, an unbreakable plastic capillary tube was designed with increased heparin coating and surface and reduced diffusion distance. For assessing agreement between pH measurements of blood samples obtained with the new plastic capillary tube and a commercial glass capillary tube, umbilical blood pH-values of 41 births were analyzed simultaneously by both methods. The mean difference between paired pH-values, the corresponding 95%-confidence interval and the true limits of agreement were calculated. The pH-values obtained with the plastic capillary tube are systematically lower, with a mean pH decrease of 0.009 units, and there is an additional random variation with a standard deviation of 0.009 pH units. The true limits of agreement: [-0.031, 0.013] represent the interval of the worst expected pH difference. The increased heparin availability in the plastic capillary tube may be the reason for the systematic pH deviation of -0.009 units. However this difference does not seem to be clinically relevant and the statistical evaluation shows a sufficiently good agreement between the pH measurements.

[Diagnostic and clinical value of Doppler ultrasound in obstetrics]. / Diagnostische und klinische Wertigkeit der Dopplersonographie in der Geburtshilfe.

The diagnostic value (efficiency) of Doppler ultrasound in obstetrics is assessed by studying the association or correlation between Doppler measurement parameters and pregnancy outcome parameters, without influencing the clinical management. The clinical value (efficacy) is however assessed by studying the ability to improve the outcome of pregnancy if Doppler ultrasound is used in obstetrical management for the purpose of possible intervention. The accepted method for assessment of the diagnostic value is the observational study, and the best method for the assessment of the clinical value is the randomised controlled management study (clinical trial). Observational studies concerning the diagnostic value have been widely reported in the literature. According to these studies significant relationships between abnormal Doppler findings and the following obstetrical problems were found: intrauterine growth retardation, preterm delivery, acidosis determined by fetal blood sampling, abnormal intrapartum fetal heart rate, neonatal depression and acidosis, and admission to neonatal intensive care unit. However from these studies it cannot be concluded that pregnancy outcome will be improved by using this information clinically. This problem can only be properly addressed by appropriate clinical management studies. The majority of the published randomised controlled trials showed beneficial effect from Doppler ultrasound application in high-risk pregnancy management. These effects included a significant decrease in the duration of antenatal and neonatal hospital stay, the rate of labour induction, and the rate of emergency Caesarean section. At the same time there was no difference in the gestational age at delivery or in the total Caesarean section rate. None of these trials alone was large enough to demonstrate a statistically significant reduction in perinatal mortality. However cumulative meta-analysis allows pooling to evaluate the results from separate but similar studies. The results from such an analysis showed that in high-risk pregnancies managed with Doppler there is a significant decrease of 50 per cent in perinatal mortality and in stillbirths of anatomically normal fetuses. It is important to note that there was no increase in neonatal or maternal morbidity associated with the use of Doppler ultrasound, and that the reduction in perinatal mortality was not the result of a delay in timing fetal death.

[Doppler ultrasound of the middle cerebral artery: pre-final normalization of cerebrovascular circulation?]. / Dopplersonographie der fetalen Arteria cerebri media: Präfinale Normalisierung des zerebralen Blutflusses?

We report on the circulatory changes of a severely growth-retarded fetus at 26 weeks of gestation with intrauterine death after 6 days of observation and a birth weight of 480 g. On admission the fetus already showed signs of circulatory centralisation; furthermore, we found pulsation in the umbilical vein and diastolic reverse flow in the umbilical artery. During the days of observation this reverse flow increased and the compensatory phase of fetal circulatory centralisation was followed on the last day by a phase of circulatory decompensation with an apparently normal middle cerebral artery waveform, mimicking preterminal normalisation of fetal cerebral blood flow.