Paediatric acute care cardiology collaborative data registry validation.

BACKGROUND: The Pediatric Acute Care Cardiology Collaborative (PAC3) was established to improve acute care cardiology outcomes through the development of an accurate and well-validated clinical registry. We report the validation results of the initial PAC3 registry audits and describe a novel regional audit format developed to accommodate a rapidly expanding membership facilitate collaborative learning and allow for necessary modification due to the COVID-19 pandemic. MATERIALS AND METHODS: Six hospitals were audited using a regional audit format and three hospitals were subsequently audited virtually. Critical and challenging-to-collect data elements were audited among at least 40 randomly selected cases. Discrepancies were categorised as either major or minor depending on their relative importance to patient outcomes and clinical care. Results were tabulated and reported. RESULTS: We audited 386 encounters and 27,086 individual data fields across 9 hospitals. The aggregate overall accuracy rate was 99.27% and the aggregate major discrepancy rate was 0.51%. The overall accuracy rate ranged from 98.77% to 99.59%, and the major discrepancy rate ranged from 0.26% to 0.88% across the cohort. No appreciable difference was seen between audit formats. Both the regional and virtual audit methods were viewed favourably by participants. CONCLUSIONS: A low data discrepancy rate was found demonstrating that the PAC3 registry is a highly accurate data source for use in quality improvement, benchmarking, and research. Regional audits and virtual audits were both successfully implemented.

Blind adaptive filtering for non-invasive extraction of the fetal electrocardiogram and its non-stationarities.

The objective is to extract automatically a beat-to-beat fetal electrocardiogram (fECG) from a maternal electrocardiogram (mECG) using surface electrodes placed on the maternal abdomen and to derive fetal PR, QT, QTc, and QS durations to allow early diagnosis and monitoring treatment of certain fetal cardiac disorders. mECG and abdominal noise in abdominal maternal recordings can be orders of magnitude stronger than the fECG signal and the P and T waves that are embedded in them. A two-stage blind adaptive filtering algorithm was used for fECG extraction, the first stage using frequency-domain electrocardiogram features and the second considering time-domain features. Three channels of abdominal recordings were obtained from 12 patients at 20-40 weeks of gestation. In each case beat-to-beat unaveraged fECGs were isolated. The combined filter allowed identification of diagnostically important PR, QT, and RR durations. Comparison with synthetic data is also included.

Trisomy 21. Second-trimester ultrasound.

Not every aspect of sonographic examination reveals karyotypic abnormalities. Ultrasound examination of a fetus with trisomy 21 generally reveals normal amniotic fluid, normal placentation, and normal fetal growth. In addition, other chromosomal abnormalities have many of the same sonographic findings as Down syndrome, and many findings have a large overlap with phenotypically normal fetuses. The importance of second-trimester ultrasound screening for Down syndrome has remained great because of its ease of use and relative effectiveness. Trained sonographers can adjust the relative risk for trisomy 21 and alter the need for genetic amniocentesis. It is important that parents understand the limitations of a screening test and the risks and benefits of possible subsequent confirmatory testing. If a major structural abnormality is identified on ultrasound, karyotype determination should be considered. Nuchal thickness in the first or second trimester remains the most clinically useful marker for trisomy 21. The predictive value of all the markers depends on the population studied and can be modified by a host of biochemical markers and historical factors. If fetal karyotype analysis could be performed without sampling through the uterus, prenatal diagnosis could be offered to all pregnant women, and screening would be unnecessary. Despite its limitations, ultrasound will have an important role in prenatal diagnosis at least until isolating and testing fetal cells from maternal blood or other sources becomes practical and widely available. Whether used alone or in conjunction with additional biochemical or molecular serum markers, ultrasound is an important and powerful tool in prenatal genetic evaluation.

Force Measurements between Semifluorinated Thiolate Self-Assembled Monolayers: Long-Range Hydrophobic Interactions and Surface Charge.

Long-range interactions between self-assembled monolayers (SAMs) of semifluorinated alkanethiols have been studied by direct force measurements in water and aqueous NaCl solutions. SAMs prepared from three different thiols, with identical fluorinated head groups but varying hydrocarbon spacer lengths, were investigated: CF(3)(CF(2))(9)(CH(2))(x)SH, where x=2, 11, or 17. Force measurements show that the interactions in water and electrolyte solutions are composed of both double-layer interactions emerging from what appears to be charges adsorbed onto the surfaces and long-range "hydrophobic" attractions, in excess of the expected van der Waals forces. The three investigated thiols produce similar results in force measurements, though the contact angles with water are slightly different. The "hydrophobic" attraction has the form of step-like attractive discontinuities in the force profiles at separations ranging from 20 to 40 nm, caused by bridging of microscopic bubbles residing at the surfaces. The shape or range of these discontinuities are not significantly affected by replacement of the water with either 1 mM or 1 M NaCl solutions. The origin of the charges causing the electrostatic double-layer interaction is unclear, but some possible causes are discussed. Copyright 2001 Academic Press.

X-ray structures of isoforms of the actin-binding protein profilin that differ in their affinity for phosphatidylinositol phosphates.

We determined the structures of Acanthamoeba profilin I and profilin II by x-ray crystallography at resolutions of 2.0 and 2.8 A, respectively. The polypeptide folds and the actin-binding surfaces of the amoeba profilins are very similar to those of bovine and human profilins. The electrostatic potential surfaces of the two Acanthamoeba isoforms differ. Two areas of high positive potential on the surface of profilin II are candidate binding sites for phosphatidylinositol phosphates. The proximity of these sites to the actin binding site provides an explanation for the competition between actin and lipids for binding profilin.