[Psammomatous melanotic schwannoma as indicator of a Carney complex]

Within a few months a 31-year-old female patient was diagnosed with a psammomatous melanotic schwannoma, an atrial myxoma and microfollicular adenomas in both thyroid lobes. Therefore, sufficient diagnostic criteria of a Carney complex were fulfilled. The Carney complex is an inherited autosomal dominant disorder with highly variable phenotypes, which was initially described by Carney in 1985 as a complex of myxomas, spotty skin pigmentation and endocrine overactivity. Pathologists should consider this differential diagnosis in reports when confronted with a psammomatous melanotic schwannoma.

A prospective randomized trial on preventative methods for positional head deformity: physiotherapy versus a positioning pillow

OBJECTIVE

To evaluate the impact of stretching exercises versus available bedding pillows on positional head deformities.

STUDY DESIGN

Fifty children aged 5 months or younger with positional head deformity were included in this prospective clinical trial (n=20 plagiocephaly, n=10 brachycephaly, n=20 combination). A random distribution was performed for treatment with the bedding pillow alone (n=25) or with stretching exercises (n=25) for 6 weeks. Anthropometric caliper measurements were done before and after that interval. Cranial vault asymmetry index (CVAI) and cranial index (CI) were calculated and analyzed using a descriptive statistical general linear model.

RESULTS

ΔCVAI in the stretching group was 2.09% for plagiocephaly and 2.34% for combined head deformities. Using the bedding pillow, ΔCVAI was 3.01% in plagiocephal children and 2.86% for combined head deformity. The ΔCI in the stretching group was 0.94% for isolated brachycephal children and 2.24% for combined head deformity. ΔCI in the pillow group was 3.63% for brachycephaly and 3.23% in children with combined head deformities, respectively.

CONCLUSIONS

Bedding pillows and stretching exercises both resulted in improvements in positional cranial deformation. For children with combined plagiocephaly and brachycephaly, improvement in cranial asymmetry was slightly greater when using bedding pillows versus stretching.

Structural study of low concentration LiCl aqueous solutions in the liquid, supercooled, and hyperquenched glassy states

Neutron diffraction experiments on a solution of LiCl in water (R = 40) at ambient conditions and in the supercooled and hyperquenched states are reported and analyzed within the empirical potential structure refinement framework. Evidence for the modifications of the microscopic structure of the solvent in the presence of such a small amount of salt is found at all investigated thermodynamic states. On the other hand, it is evident that the structure of the hyperquenched salty sample is similar to that of pure low density amorphous water, although all the peaks of the radial distribution functions are broader in the present case. Changes upon supercooling or hyperquenching of the ion's hydration shells and contacts are of limited size and evidence for segregation phenomena at these states does not clearly show up, although the presence of water separated contacts between ion of the same sign is intriguing.

High-density amorphous ice: Molecular dynamics simulations of the glass transition at 0.3 GPa

Based on several force fields (COMPASS, modified TIP3P and SPC/E) high-density amorphous ice is simulated by use of isothermal-isobaric molecular dynamics at a pressure of p approximately 0.3 GPa in the temperature range from 70 to 300 K. Starting at low temperature a large number of heating/cooling cycles are performed and several characteristic properties (density, total energy, and mobility) are traced as functions of temperature. While the first cycles are showing irreversible structural relaxation effects data points from further cycles are reproducible and give clear evidence for the existence of a glass-to-liquid transition. Although, the observed transition temperatures T(g) are dependent on the actual force field used and slightly dependent on the method adopted the results indicate that high-density amorphous ices may indeed be low-temperature structural proxies of ultraviscous high-density liquids.

An error model for protein quantification

MOTIVATION

Quantitative experimental data is the critical bottleneck in the modeling of dynamic cellular processes in systems biology. Here, we present statistical approaches improving reproducibility of protein quantification by immunoprecipitation and immunoblotting.

RESULTS

Based on a large data set with more than 3600 data points, we unravel that the main sources of biological variability and experimental noise are multiplicative and log-normally distributed. Therefore, we suggest a log-transformation of the data to obtain additive normally distributed noise. After this transformation, common statistical procedures can be applied to analyze the data. An error model is introduced to account for technical as well as biological variability. Elimination of these systematic errors decrease variability of measurements and allow for a more precise estimation of underlying dynamics of protein concentrations in cellular signaling. The proposed error model is relevant for simulation studies, parameter estimation and model selection, basic tools of systems biology.

AVAILABILITY

Matlab and R code is available from the authors on request. The data can be downloaded from our website www.fdm.uni-freiburg.de/~ckreutz/data.

Impact of the AEP-Monitor/2-derived composite auditory-evoked potential index on propofol consumption and emergence times during total intravenous anaesthesia with propofol and remifentanil in children

BACKGROUND

The composite auditory evoked potential index (cAAI), derived from the AEP Monitor/2 (version 1.6; Danmeter A/S, Odense, Denmark) is a measure of the hypnotic component of general anaesthesia. The purpose of this study was to evaluate the impact of cAAI guidance on propofol consumption and emergence times in children receiving total intravenous anaesthesia (TIVA) with propofol and remifentanil.

METHODS

Twenty children, aged 3-11 years, scheduled for strabismus repair under TIVA with propofol and remifentanil were enrolled. Remifentanil was given to all patients at a constant infusion rate of 0.3 microg kg(-1) min(-1) throughout the anaesthesia. Patients were randomly allocated to receive a continuous propofol infusion adjusted either according to a conventional clinical practice (Group C, n = 10) or guided by cAAI-monitoring (Group G, n = 10, target cAAI 25-35). All patients were connected to the AEP Monitor/2, but in group C the anaesthetist was blinded to cAAI values. Propofol consumption (mgkg(-1)h(-1)) and emergence times (min) were the primary and secondary outcome measures.

RESULTS

Propofol consumption and emergence times (mean +/- SD) were significantly lower in group G compared to group C (Propofol: G: 4.2 +/- 1.7 vs. C 6.4 +/- 1.3 mg kg(-1) h(-1); P < 0.01; emergence times: G: 5.1 +/- 3.7 vs. C 13.2 +/- 8.2 min; P < 0.01). Intraoperative cAAI values (median [interquartile range]) were significantly higher in group G (23.9 [18-29.7]) than in group C (18.4 [16.0-22.1]; P < 0.01). Haemodynamic variables remained stable within age-related limits, and there were no observations of adverse events, especially no clinical signs of intraoperative awareness in any patient.

CONCLUSION

Composite auditory evoked potential index monitoring during propofol/remifentanil-TIVA in children results in reduced propofol consumption and faster emergence.

Control of oxygen transport in the microcrustacean Daphnia: regulation of haemoglobin expression as central mechanism of adaptation to different oxygen and temperature conditions

The pathway for oxygen, the control of oxygen transport and the role of haemoglobin expression for the physiological adaptation to different oxygen and temperature conditions were studied in the ecological model organism Daphnia magna. Ventilation of the inner walls of the carapace as the main gas exchange area as well as of the embryos in the brood pouch are controlled, oxygen-dependent processes. The P(O2)-dependent increase of heart rate as well as perfusion rate during short-term, progressive hypoxia improves the circulatory oxygen transport within the body. The regulation of haemoglobin (Hb) expression is the central mechanism for a medium-term adaptation to hypoxia. Genetic control elements and oxygen conditions near the two Hb synthesis sites (fat cells, epipodite epithelial cells) determine, which types of Hb subunits and, accordingly, hetero-multimeric Hb macromolecules are produced. One synthesis site may respond mainly to internal, the other one to external oxygen conditions. Depending on environmental condition, either higher quantities of macromolecules of unchanged functionality (P50) or increasing amounts of macromolecules with higher oxygen affinity are synthesized. The Hb subunit DmHbA is probably of considerable importance for this functional change. The physiological benefits of haemoglobin in Daphnia are discussed. Physiological adaptation of Daphnia to different temperatures is also related to the control of oxygen transport processes with the regulation of haemoglobin expression again as a central mechanism.

Simulation of all-order density-functional perturbation theory, using the second order and the strong-correlation limit

To boost the accuracy of electronic structure calculations, the exchange-correlation energy may be constructed from the Kohn-Sham orbitals. A formally exact construction is the density-functional perturbation series, which appears to diverge for many real systems. We predict the radius of convergence and resum this series, using only exact exchange and second-order correlation plus explicit density functionals for the strong-interaction limit. Our new correlation functional, along with exact exchange, predicts atomization energies with competitive accuracy and without the usual error cancellation.

Toxicity of combined sewer overflows on river phytoplankton: the role of heavy metals

The toxic effect of a combined sewer overflow (CSO) on the phytoplankton community of the river Seine has been studied by means of short-term primary production measurements. As the discharged solids usually do not remain in the water column, only filtered or centrifugated fractions were tested. The collected phytoplankton were grown in the laboratory for 2 days, after addition of N, P and EDTA. Stock cultures in exponential growth were directly tested with heavy metals, but resuspended algal cells were used for effluent testing. The results show an increase of EC50 value for the single metal species in the order Cu<<Zn</=Pb. Free metal contents were calculated with the chemical speciation model Mineql+. The EC50 dilution of the tested CSOs effluent was 50%. This value increased by 30% after addition of 5 10(-6) M EDTA, indicating that the effluent toxicity is only partially due to its metallic compounds.

1H, 51V and 15N nuclear magnetic resonance studies of structure and properties of vanadia supported on TiO chi/SiO2

1H magic-angle spinning nuclear magnetic resonance (MAS NMR) spectra of TiO chi/SiO2 catalysts suggest the interaction of surface TiO chi species with Si-OH groups of the silica. Simultaneously, Ti-OH groups from surface titania species appear. The distribution of TiO chi species over SiO2 is non-uniform, since a considerable part of surface OH groups remains unreacted with supported titania. Supported vanadia species interact both with Si-OH and Ti-OH groups. 51V NMR spectra suggest the interaction of vanadia with supported titania species and show the non-uniform distribution of titania over the SiO2 surface. Deposition of titania as well as vanadia produces strong electron-accepting (Lewis) sites which interact with the terminal N atom of adsorbed N2O molecules, resulting in a downfield shift of the resonance in 15N NMR spectra. The acid strength of electron-accepting sites is similar in both cases. Only about 10% of the total amount of supported titania and vanadia create Lewis sites.

Induction of stress fibres and intercellular gaps in human vascular endothelium by shock-waves

Human umbilical cords were exposed to high amplitude focussed ultrasonic pulses with focal energy densities 0.6 and 0.4 mJ mm-2. The endothelium of the exposed vessel (vein) was examined by means of confocal laser scanning microscopy and scanning electron microscopy. The degree of tissue change ranged from the induction of stress fibres and intercellular gaps to the complete detachment of endothelial cells combined with damage of the basement membrane. An increased number of stress fibres may indicate an increased vessel wall permeability. This might explain the enhanced effects in experimental tumour therapy that have been found by other authors when combining shock-waves with drugs.

Shock wave induced endothelial damage--in situ analysis by confocal laser scanning microscopy

For more than a decade, extracorporal shock wave lithotripsy has been a standard clinical method for the treatment of urinary stones. However, side effects that are likely to be correlated to vessel damage can often be observed using noninvasive diagnostic techniques, e.g., magnetic resonance imaging. To avoid side effects it is useful to understand the interaction between shock waves and the vascular system. In particular, this is important in view of new applications like gallstone lithothripsy. In the present study, we exposed human umbilical vessels to electromagnetically generated ultrasound shock waves to analyze subsequent alterations of their endothelial layer. Following en face preparation and fluorescent staining, the endothelium was examined in a confocal laser scanning microscope. Endothelial cells of the shock wave exposed vessels revealed permeabilization of plasma membranes and mitochondrial alterations as potentially lethal damage. An increase in the number of stress fibres may indicate functional changes possibly influencing vessel wall permeability.