Intrapartum sonographic weight estimation

PURPOSE

To evaluate the accuracy of intrapartum sonographic weight estimation (WE).

MATERIALS AND METHODS

This retrospective, cross-sectional study included 1958 singleton pregnancies. Inclusion criteria were singleton pregnancy with cephalic presentation, vaginal delivery and ultrasound examination with complete biometric parameters performed on the day of delivery during the latent or active phase of labor, and absence of chromosomal or structural anomalies. The accuracy of intrapartum WE was compared to a control group of fetuses delivered by primary cesarean section at our perinatal center and an ultrasound examination with complete biometric parameters performed within 3 days before delivery (n = 392). Otherwise, the same inclusion criteria as in the study group were applied. The accuracy of WE was compared between five commonly applied formulas using means of percentage errors (MPE), medians of absolute percentage errors (MAPE), and proportions of estimates within 10 % of actual birth weight.

RESULTS

In the whole study group, all equations showed a systematic underestimation of fetal weight (negative MPEs). Overall, best MAPE and MPE values were found with the Hadlock II formula, using BPD, AC and FL as biometric parameters (Hadlock II, MPE: -1.28; MAPE: 6.52). MPEs differed significantly between WE in the study and control group for all evaluated formulas: in the control group, either no systematic error (Hadlock III, IV and V) or a significant overestimation (Hadlock I, II) was found. Regarding MAPEs, application of the Hadlock III (HC, AC, FL) and V (AC) formula resulted in significant lower values in the control group (Hadlock III, MAPE: 7.48 vs. 5.95, p = 0.0008 and Hadlock V, MAPE: 8.79 vs. 7.52, p = 0.0085). No significant differences were found for the other equations.

CONCLUSIONS

A systematic underestimation of fetal weight has to be taken into account in sonographic WE performed intrapartum. Overall, the best results can be achieved with WE formulas using the BPD as the only head measurement.

Screening Performance and Costs of Different Strategies in Prenatal Screening for Trisomy 21

Objective: Cell-free fetal DNA (cffDNA) testing has opened new options in prenatal screening for trisomy 21. Due to the higher costs of cffDNA testing there is an ongoing debate on how to combine different screening strategies. Methods: For this study, a model-based approach was used to evaluate all births in Germany in 2012 together with the percentage of euploid and trisomic pregnancies. Detection rates (DR), false positive rates (FPR), the costs of different screening strategies for trisomy 21 and combinations of these strategies were compared. The number of fetuses with trisomy 21 at 12 + 0 weeks of gestation was estimated based on maternal age distribution. We examined the screening performance of a screening strategy based on maternal age, first trimester screening (FTS) and cffDNA testing as well as the combinations "maternal age and cffDNA" and "FTS and cffDNA". Results: In 2012 673 544 children were born. Median maternal age at delivery was 30.2 years (25th-75th quartile: 27.0-34.0). Based on maternal age distribution the expected number of fetuses with trisomy 21 at 12 weeks' gestation was 1788. Our study population therefore consisted of 675 332 pregnancies. Screening based only on maternal age or FTS or cffDNA resulted in detection rates of 63.3 %, 92.2 % and 99.0 % and false positive rates of 21.8 %, 8.0 % and 0.1 %, respectively. When maternal age was combined with cffDNA, cffDNA testing was only offered to women over a certain age; if a cut-off of 30 years was used, this resulted in a DR of 85.2 % and a FPR of 1.7 %. If primary screening consisted of FTS with cffDNA testing only done when the risk was between 1 : 10 and 1 : 1000, the detection rate was 96.7 % and the false positive rate was 1.2 %. Conclusion: In this model-based study we showed that prenatal screening for trisomy 21 can be improved even more by combining FTS and cffDNA. Further studies are necessary to examine whether these results can be reproduced in reality.

The Cause of Acute Respiratory Failure Predicts the Outcome of Noninvasive Ventilation in Immunocompromised Children

BACKGROUND

Noninvasive ventilation (NIV) may be superior to conventional therapy in immunocompromised children with respiratory failure.

METHODS

Mortality, success rate, prognostic factors and side effects of NIV for acute respiratory failure (ARF) were investigated retrospectively in 41 in children with primary immunodeficiency, after stem cell transplantation or chemotherapy for oncologic disease.

RESULTS

In 11/41 (27%) children invasive ventilation was avoided and patients were discharged from ICU. In children with NIV failure ICU-mortality was 19/30 (63%). 8/11 (72%) children with NIV success had recurrence of ARF after 27 days. Only 4/11 (36%) children with first episode NIV success and 8/30 (27%) with NIV failure survived to hospital discharge. Lower FiO2, SpO2/FiO2 and blood culture positive bacterial sepsis were predictive for NIV success, while fungal sepsis or culture negative ARF were predictive for NIV failure. We observed catecholamine treatment in 14/41 (34%), pneumothorax in 2/41 (5%), mediastinal emphysema in 3/41 (7%), a life threatening nasopharyngeal hemorrhage and need for resuscitation during intubation in 5/41 (12%) NIV-episodes.

CONCLUSIONS

The prognosis of ARF in immunocompromised children remains guarded independent of initial success or failure of NIV due to a high rate of recurrent ARF. Reversible causes like bacterial sepsis had a higher NIV response rate. Relevant side effects of NIV were observed.

Subsurface cation vacancy stabilization of the magnetite (001) surface

Iron oxides play an increasingly prominent role in heterogeneous catalysis, hydrogen production, spintronics, and drug delivery. The surface or material interface can be performance-limiting in these applications, so it is vital to determine accurate atomic-scale structures for iron oxides and understand why they form. Using a combination of quantitative low-energy electron diffraction, scanning tunneling microscopy, and density functional theory calculations, we show that an ordered array of subsurface iron vacancies and interstitials underlies the well-known (√2 × √2)R45° reconstruction of Fe3O4(001). This hitherto unobserved stabilization mechanism occurs because the iron oxides prefer to redistribute cations in the lattice in response to oxidizing or reducing environments. Many other metal oxides also achieve stoichiometry variation in this way, so such surface structures are likely commonplace.

Cone beam computed tomography and low-dose multislice computed tomography in orthodontics and dentistry: a comparative evaluation on image quality and radiation exposure

OBJECTIVES

The goal of the present work was to assess various computed tomography (CT) systems in term of image quality and organ doses, namely five cone-beam CT (CBCT) scanners operated at standard settings and three multislice CT (MSCT) scanners operated at greatly dose-reduced settings.

MATERIALS AND METHODS

Radiographic volume scans were taken on a complete human cadaveric head specimen and the image quality of each was rated by four experienced examiners according to specific skeletal structures and bone-soft tissue interfaces. Radiation doses were captured by a head-and-neck phantom (Rando; Alderson Research Laboratories). Standard protocols were used for the CBCT scans. For the MSCT scans, tube voltage and current were adjusted to minimize radiation without compromising image quality.

RESULTS

Interobserver agreement was close to perfect, with iota coefficients of 0.931 (95% CI 0.807-0.978) between groups 1 and 2 and 0.959 (95% CI 0.869-1.000) between groups 1 and 3. Ratings of image quality in terms of skeletal-structure representation were slightly better for the CBCT than the MSCT scanners, although these differences were not statistically significant. The two groups of scanners applied considerably different organ doses: the lowest dose (0.03 mSv) was measured on the bone surface with a CBCT unit (Picasso Trio® from Vatech) and the highest dose (8.30 mSv) in the vicinity of the eye lens with another CBCT unit (3D Accuitomo 170® from J. Morita).

CONCLUSION

The various systems tested offer similar imaging quality but demonstrated distinct differences in organ dose levels. The decision on which approach to take is not between CBCT and MSCT but rather between specific models and parameter settings. If these are optimized, MSCT images providing useful clinical information can be obtained at much reduced levels of radiation. Depending on the model and setting used, MSCT radiation levels may even be lower than during CBCT scans.

The evolution of boosting algorithms. From machine learning to statistical modelling

BACKGROUND

The concept of boosting emerged from the field of machine learning. The basic idea is to boost the accuracy of a weak classifying tool by combining various instances into a more accurate prediction. This general concept was later adapted to the field of statistical modelling. Nowadays, boosting algorithms are often applied to estimate and select predictor effects in statistical regression models.

OBJECTIVES

This review article attempts to highlight the evolution of boosting algorithms from machine learning to statistical modelling.

METHODS

We describe the AdaBoost algorithm for classification as well as the two most prominent statistical boosting approaches, gradient boosting and likelihood-based boosting for statistical modelling. We highlight the methodological background and present the most common software implementations.

RESULTS

Although gradient boosting and likelihood-based boosting are typically treated separately in the literature, they share the same methodological roots and follow the same fundamental concepts. Compared to the initial machine learning algorithms, which must be seen as black-box prediction schemes, they result in statistical models with a straight-forward interpretation.

CONCLUSIONS

Statistical boosting algorithms have gained substantial interest during the last decade and offer a variety of options to address important research questions in modern biomedicine.

Gene expression profiles induced by growth factors in in vitro cultured osteoblasts

Objectives

Effects of insulin-like growth factor 1 (IGF1), fibroblast growth factor 2 (FGF2) and bone morphogenetic protein 2 (BMP2) on the expression of genes involved in the proliferation and differentiation of osteoblasts in culture were analysed. The best sequence of growth factor addition that induces expansion of cells before their differentiation was sought.

Methods

Primary human osteoblasts in in vitro culture were treated with IGF1, BMP2 or FGF2 (10 ng/ml) for 24 hours (IGF1) or 48 hours (BMP2 and FGF2). Experiments were performed during the exponential growth phase with approximately 1e7 cells per 75 cm² flask. mRNA was reverse transcribed directly and analysed using RT-PCR Taqman assays. Expression levels of key genes involved in cell growth and differentiation (CDH11, TNFRSF11B, RUNX2, POSTN, ALP, WNT5A, LEF1, HSPA5, FOS, p21) were monitored using RT-PCR with gene-specific Taqman probes.

Results

Autocrine expression of BMP2 is stimulated by FGF2 and BMP2 itself. BMP2 and FGF2 act as proliferative factors as indicated by reduced expression of ALP and POSTN, whereas IGF1 exhibits a more subtle picture: the Wingless und Int-1 (Wnt) signalling pathway and the Smad pathway, but not p38 mitogen-activated protein (MAP) kinase signalling, were shown to be activated by IGF1, leading to proliferation and differentiation of the cells.

Conclusions

For future use of autologous bone cells in the management of bony defects, new treatment options take advantage of growth factors and differentiation factors. Thus, our results might help to guide the timely application of these factors for the expansion and subsequent differentiation of osteoblastic cells in culture.

Cite this article: Bone Joint Res 2014;3:236–40.

Automated adjustments of inspired fraction of oxygen to avoid hypoxemia and hyperoxemia in neonates - a systematic review on clinical studies

Supplemental oxygen is commonly provided during transition of neonates immediately after birth. Whereas an initial FiO2 of 0.21 is now recommended to stabilize full-term infants in the delivery room, the best FiO2 to start resuscitation of the very low birth weight infant (VLBWI) immediately after delivery is currently not known. Recent recommendations include the use of pulse oximetry to titrate the use of supplemental oxygen. As reference values for pulse oximetry during the first minutes of life have become available, automated FiO2-adjustments are feasible and may be very useful for delivery room care to limit oxygen exposure. Beyond neonatal transition, preterm infants in the neonatal intensive care unit (NICU) commonly require supplemental oxygen to avoid hypoxemia, especially VLBWI receiving respiratory support because of poor respiratory drive and/or lung disease. For respiratory care of newborn infants in the NICU automated FiO2-adjustment systems have been developed and have been studied in preterm infants for limited time frames using short-term physiological outcomes. These studies could demonstrate short-term benefits such as more stable arterial oxygen saturation. Recent clinical trials have shown that oxygen targeting may significantly affect mortality and morbidity. Therefore, randomized controlled trials are needed to study the effects of automated FiO2-adjustment on long-term outcomes to prove possible benefits on survival, the rate of retino-pathy of prematurity and on neuro-development-al outcome.

The growth of ultra-thin zirconia films on Pd(3)Zr(0 0 0 1)

Despite its importance in many areas of industry, such as catalysis, fuel cell technology and microelectronics, the surface structure and physical properties of ZrO2 are not well understood. Following the successful growth of ultra-thin zirconia on Pt3Zr(0 0 0 1) (Antlanger et al 2012 Phys. Rev. B 86 035451), we report on recent progress into ZrO2 thin films, which were prepared by oxidation of a Pd3Zr(0 0 0 1) crystal. Results from scanning tunneling microscopy (STM), Auger electron spectroscopy (AES), x-ray photoelectron spectroscopy (XPS) as well as density-functional theory (DFT) are presented. Many sputter-annealing cycles are required for preparation of the clean Pd3Zr alloy surface, because oxygen easily dissolves in the bulk. By oxidation and post-annealing, a homogeneous ultra-thin ZrO2 film was obtained. This is an O-Zr-O trilayer based on cubic ZrO2(1 1 1). Using STM images corrected for distortion and creep of the piezo scanner the in-plane lattice parameter was determined as (351.2 ± 0.4) pm, slightly contracted with respect to the cubic ZrO2 bulk phase. The oxide forms an overlayer that is either incommensurate or has a very large superstructure cell (a = 8.3 nm); nevertheless its rotational orientation is always the same. In contrast to ultra-thin zirconia on Pt3Zr(0 0 0 1), where the uppermost substrate layer is pure (but reconstructed) Pt, STM and XPS suggest a stoichiometric Pd3Zr below the oxide. The oxide film binds to the substrate mainly via bonds between oxygen and the Zr atoms in the substrate. The ultra-thin oxide shows large buckling in STM, confirmed by DFT calculations, where the buckling of the Zr layer can exceed 100 pm. Compared to the ZrO2 film on Pt3Zr(0 0 0 1), the oxide on Pd3Zr(0 0 0 1) has the advantage that the substrate below does not reconstruct, leading to a homogeneous oxide film.

Botulinum toxin A and lidocaine have an impact on adipose-derived stem cells, fibroblasts, and mature adipocytes in vitro

Lipofilling with autologous fat tissue is widely used in plastic and reconstructive surgery to treat soft-tissue deficiency. Unfortunately, implanted cells disappear gradually and make it difficult to predict the resorption rate. Several adjuvants are used to improve the success of fat tissue grafting. In this study, the effect of botulinum toxin (BoNT) on mature adipocytes, as well as adipose-derived stem cells (ASC) and fibroblasts was evaluated. As lidocaine is the most prevalent drug to anesthetize the donor site as well as the area to be treated with autologous fat, this local anesthetic was examined too. Primary ASCs, fibroblasts, and mature adipocytes were exposed to 1, 10, and 20 IU/ml BoNT A and 1% lidocaine. Cells were tested on proliferation, viability, and LDH release. Adipogenic differentiation potential was evaluated by quantitative real-time PCR analyzing the expression of FABP4. BoNT had no significant influence on the proliferation or viability of tested cells. By trend, low concentrations of BoNT improved adipogenic potential of ASCs. Lidocaine had a strong diminishing effect on the proliferation of ASCs and fibroblasts and on the viability of these cells. Mature adipocytes show no significant inferior viability after BoNT or lidocaine treatment. BoNT has no negative effect on ASCs, mature adipocytes, or fibroblasts in vitro. Lidocaine (1%) negatively influences the proliferation and viability of fibroblasts and partly of ASCs but not of mature adipocytes.

A Boy with an LCR3/4-Flanked 10q22.3q23.2 Microdeletion and Uncommon Phenotypic Features

The recurrent 10q22.3q23.2 deletion with breakpoints within low copy repeats 3 and 4 is a rare genomic disorder, reported in only 13 patients to date. The phenotype is rather uncharacteristic, which makes a clinical diagnosis difficult. A phenotypic feature described in almost all patients is a delay in speech development, albeit systematic studies are still pending. In this study, we report on a boy with an LCR3/4-flanked 10q22.3q23.2 deletion exhibiting an age-appropriate language development evaluated by a standardized test at an age of 2 years and 3 months. The boy was born with a cleft palate - a feature not present in any of the patients described before. Previously reported cases are reviewed, and the role of the BMPR1A gene is discussed. The phenotype of patients with an LCR3/4-flanked 10q22.3q23.2 deletion can be rather variable, so counseling the families regarding the prognosis of an affected child should be done with caution. Long-term studies of affected children are needed to delineate the natural history of this rare disorder.

Tick-borne pathogens in the blood of wild and domestic ungulates in South Africa: interplay of game and livestock

We screened for tick-borne pathogens blood samples from 181 wild and domestic ungulates belonging to 18 host species in 4 South African Provinces. Polymerase chain reaction followed by reverse line blotting and sequencing allowed detecting 16 tick-borne pathogen species belonging to the genera Babesia, Theileria, Anaplasma, and Ehrlichia. Ten pathogen species were involved in 29 new host-pathogen combinations. Most infections (77.9%) involved more than one pathogen species. Principal component analysis (PCA) assigned the 163 infections, identified to species level, to 4 groups. Three groups were associated with sheep, cattle, and horse and their respective wild counterparts. Each group was characterised by high homogeneity in pathogen assemblage and host phylogenetic status. These groups characterised the most privileged transmission routes between and among wild and domestic ungulates. The 4th group showed high heterogeneity in pathogen assemblage and host phylogenetic status. This group seems to indicate frequent spill over events in impala of pathogens that usually circulate among cattle- or sheep-related species. Within 6 localities, we sampled an equal number of wild and domestic animals (n=128). On this dataset once having controlled for the significant variation among localities, the infection prevalence and intensity of infection did not differ significantly between wild and domestic hosts. This suggests that both animal types, domestic and wild hosts, could act as evenly efficient sources of infection for themselves and for each other. Overall, this study shed new light on the pathogen circulation naturally achieved at the interplay between wild and domestic ungulates.