Dynamik der Elektrolytkonzentrationen im Blutplasma von Rindern mit operativ beendeter Torsio uteri intra partum

Gegenstand und Ziel: Es sollte überprüft werden, inwieweit beim Rind die Elektrolyte im Blutplasma durch eine Torsio uteri intra partum einschließlich operativer Behandlung (Gruppe 1) im Vergleich zu mit Sectio caesarea beendeten Dystokien ohne Torsio uteri (Gruppe 2) bzw. Normalgeburten (Gruppe 3) während der ersten 10 Tage post operationem/partum beeinflusst werden. Material und Methoden: In die Studie gingen 45 schwarzbunte Rinder mit chirurgisch therapierter Torsio uteri intra partum ein. Im Abstand von 24 Stunden, beginnend unmittelbar präoperativ, bis 10 Tage post operationem (p. o.) wurden Blutproben aus der Vena jugularis externa entnommen und Gesamtkalzium, anorganisches Phosphat, Mg2+, Na+, und K+ bestimmt. Die Vergleichsgruppen umfassten jeweils 11 Tiere. Ergebnisse: Die Veränderungen der Plasmaspiegel von Gesamtkalzium, anorganischem Phosphat, Na+ und K+ waren bei den 33 überlebenden Rindern mit Torsio uteri und den Tieren der Gruppen 2 und 3 gering. Der Magnesiumplasmaspiegel fiel postoperativ besonders bei Gruppe 1, aber auch bei Gruppe 2 im Vergleich zu Gruppe 3 signifikant ab und verblieb bis zum Ende der Beobachtungszeit unterhalb des Referenzbereichs. Bei den 12 verendeten Patienten mit Torsio uteri traten im Vergleich zu den überlebenden Rindern mit Gebärmutterdrehung eine deutlichere, am vierten postoperativen Tag signifikante Hypomagnesiämie und ein signifikant erniedrigter Plasmakaliumspiegel auf. Schlussfolgerung: Nach geburtshilflich-chirurgischen Eingriffen sollten bei Rindern die Elektrolytplasmaspiegel insbesondere von Magnesium und Kalium überprüft und die Elektrolyte gegebenenfalls substituiert werden. Klinische Relevanz: Ein postoperativ niedriger Plasmakaliumspiegel in Verbindung mit einer Hypomagnesiämie ist bei Rindern, die wegen einer Torsio uteri operiert wurden, ein Hinweis auf eine schlechte Prognose quoad vitam.

Untersuchungen zur Eignung des ultrasonographisch ermittelten Uterusgewichtes und der uterinen Echotextur zur Prognose der Fertilität beim weiblichen Schwein

Gegenstand und Ziel: Es wurde untersucht, ob sich ultrasonographisch ermitteltes Uterusgewicht (UG) und uterine Echotextur (ET) zur Prognose der Fertilität beim weiblichen Schwein eignen. Gleichzeitig sollte eruiert werden, ob ein optimales UG, das für Jung- (JS) und Altsauen (AS) 400-600 bzw. 500-700 g betragen soll, existiert. Material und Methoden: Insgesamt 67 abgesetzte AS (Betrieb A = B-A) sowie 44 JS und 64 AS mit unterschiedlichen Reproduktionsstörungen (Betrieb B = B-B) wurden einen Tag nach dem Absetzen (B-A) oder am Ende einer 15-tägigen Altrenogest- Applikation (B-B) transkutan sonographisch untersucht. Das UG wurde mithilfe der sonographisch ermittelten Querschnittsfläche der Uterushörner (QF) errechnet (UG = 357,6 × QF0,801; beide B), die ET in die Grade 1-4 eingeteilt (homogen bis hochgradig heterogen; nur B-B) und Uteri mit ET-Grad 1 als physiologisch betrachtet. Tiere wurden nur dann berücksichtigt, wenn sie zum Zeitpunkt der Erfassung von UG und ET sonographisch Follikel mit einer Größe von 2-4 mm aufwiesen und im darauf folgenden Östrus zeitgerecht ovuliert hatten. Eine Sau galt als fertil, wenn sie tragend wurde. Ergebnisse: Die UG betrugen 306-1789 g. Tragende und nicht tragende AS (B-A) bzw. JS und AS (B-B) wiesen jeweils ein ähnliches mittleres UG und zu ähnlichen Anteilen UG von < 400 / > 600 g (JS) oder < 500 / > 700 g (AS) auf. Sauen mit ET-Grad 4 wurden seltener (p ≤ 0,05) bzw. tendenziell seltener (p ≤ 0,1) tragend als Tiere mit den ET-Graden 1 und 2 (57,1% vs. 87,0% bzw. 82,2%). Uteri mit dem ET-Grad 4 waren schwerer als die mit den ET-Graden 1-3 (p ≤ 0,05). Schlussfolgerungen: JS und AS werden unabhängig davon tragend, ob die Uteri leicht oder schwer sind. Weisen Sauen kleine Follikel, aber hochgradig heterogen texturierte Uteri auf, sind die Uteri häufig funktionsgestört und überwiegend schwer. Derartige Sauen haben verringerte Trächtigkeitschancen. Klinische Relevanz: Die sonographisch beurteilte ET eignet sich zur Prognose der Fertilität beim weiblichen Schwein, das UG nicht. Optimale UG sind zu bezweifeln.

Immobilization of pH-sensitive CdTe Quantum Dots in a Poly(acrylate) Hydrogel for Microfluidic Applications

Microfluidic devices present the basis of modern life sciences and chemical information processing. To control the flow and to allow optical readout, a reliable sensor material that can be easily utilized for microfluidic systems is in demand. Here, we present a new optical readout system for pH sensing based on pH sensitive, photoluminescent glutathione capped cadmium telluride quantum dots that are covalently immobilized in a poly(acrylate) hydrogel. For an applicable pH sensing the generated hybrid material is integrated in a microfluidic sensor chip setup. The hybrid material not only allows in situ readout, but also possesses valve properties due to the swelling behavior of the poly(acrylate) hydrogel. In this work, the swelling property of the hybrid material is utilized in a microfluidic valve seat, where a valve opening process is demonstrated by a fluid flow change and in situ monitored by photoluminescence quenching. This discrete photoluminescence detection (ON/OFF) of the fluid flow change (OFF/ON) enables upcoming chemical information processing.

[The first biologic for rheumatoid arthritis: factors influencing the therapeutic decision]

BACKGROUND AND AIMS

Biologics (disease modifying antirheumatic drugs, bDMARD) have been in use in Germany for the treatment of rheumatoid arthritis (RA) since 2001, usually after failure of at least one conventional synthetic (cs)DMARD. We analyzed temporal changes in factors that influence the decision for either a first bDMARD or a further csDMARD.

MATERIAL AND METHODS

We analyzed data from 9513 bDMARD-naive RA patients in the German biologics register RABBIT who switched to a new therapy. For three recruitment periods (2001-2003, 2004-2006 and 2009-2015) factors influencing the therapeutic decision were analyzed by means of machine learning methods and logistic regression analysis.

RESULTS

In all recruitment periods the number of previous csDMARDs, high dosages of glucocorticoids (>7.5 mg/day) and a higher DAS28 (>5.1) were significantly associated with the decision for a first bDMARD. Over time, the chance of receiving a bDMARD increased in patients with moderate disease activity, moderate glucocorticoid dosages (5-7.5 mg/day) and those with comorbidities, such as congestive heart failure or prior malignancy. Men had a higher chance of receiving a bDMARD than women only in the first recruitment period. Private health insurance, high education and gainful employment were significantly associated with more frequent prescription of bDMARDs in all recruitment periods.

DISCUSSION

The time-dependent changes in the impact of disease activity, concomitant drugs, gender and comorbidity on the prescription of bDMARDs mirror the increasing therapeutic options and the growing experience in the application of the new substances in patients at higher risk. The influence of demographic and social factors may reflect safety concerns in patients at increased risk of adverse events but also the need to economize drug costs..

Test of the Brink-Axel Hypothesis for the Pygmy Dipole Resonance

The gamma strength function and level density of 1^{-} states in ^{96}Mo have been extracted from a high-resolution study of the (p[over →], p[over →]^{'}) reaction at 295 MeV and extreme forward angles. By comparison with compound nucleus γ decay experiments, this allows a test of the generalized Brink-Axel hypothesis in the energy region of the pygmy dipole resonance. The Brink-Axel hypothesis is commonly assumed in astrophysical reaction network calculations and states that the gamma strength function in nuclei is independent of the structure of the initial and final state. The present results validate the Brink-Axel hypothesis for ^{96}Mo and provide independent confirmation of the methods used to separate gamma strength function and level density in γ decay experiments.

Optimization of first order decay gas generation model parameters for landfills located in cold semi-arid climates

Canada has one of the highest waste generation rates in the world. Because of high land availability, land disposal rates in the province of Saskatchewan are high compared to the rest of the country. In this study, landfill gas data was collected at semi-arid landfills in Regina and Saskatoon, Saskatchewan, and curve fitting was carried out to find optimal k and L_o or DOC values using LandGEM, Afvalzorg Simple, and IPCC first order decay models. Model parameters at each landfill were estimated and compared using default k and L_o or DOC values. Methane generation rates were substantially overestimated using default values (with percentage errors from 55 to 135%). The mean percentage errors for the optimized k and L_o or DOC values ranged from 11.60% to 19.93% at the Regina landfill, and 1.65% to 10.83% at the Saskatoon landfill. Finally, the effect of different iterative methods on the curve fitting process was examined. The residual sum of squares for each model and iterative approaches were similar, with the exception of iterative method 1 for the IPCC model. The default values in these models fail to represent landfills located in cold semi-arid climates. The use of site specific data, provided enough information is available regarding waste mass and composition, can greatly help to improve the accuracy of these first order decay models.

Generic nature of long-range repulsion mechanism on a bulk insulator?

Dynamic atomic force microscopy measurements are reported that provide evidence for the presence of long-range repulsion in molecular self-assembly on a bulk insulator surface. We present the structures formed from four different benzoic acid derivatives on the (10.4) cleavage plane of calcite kept in ultra-high vacuum. These molecules have in common that they self-assemble into molecular stripes when deposited onto the surface held at room temperature. For all molecules tested, a detailed analysis of the stripe-to-stripe distance distribution reveals a clear deviation from what would be expected for randomly placed, non-interacting stripes (i.e., geometric distribution). When excluding kinetic effects during growth, this result gives evidence for a long-range repulsion mechanism acting during the assembly of these stripes. The fact that this finding is robust against changes in the molecular structure indicates a generic nature of the observed mechanism, implying a ubiquitous origin such as electrostatic repulsion. Finally, we discuss parameters that might affect the unambiguous observation of this generic repulsion under specific experimental conditions.

Comprehensive assessment of food and nutrient intake of children and adolescents in Germany: EsKiMo II - the eating study as a KiGGS module

Background

As part of the second wave of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS Wave 2), food and nutrient intake of children and adolescents aged 6–17 years living in Germany is assessed in EsKiMo II – the Eating Study as a KiGGS Module.

Methods

EsKiMo II is a cross-sectional study, conducted from June 2015 until September 2017. The study population comprises 6 to 17-year-old study participants from the cross-sectional sample of KiGGS Wave 2 in 167 KiGGS sample points, which are revisited by trained nutritionists. Dietary intake is assessed by weighted food records during three consecutive days plus one randomly selected day within the following 3 months for children aged 6–11 years. Dietary intake for adolescents aged 12–17 years is assessed by computer-assisted dietary history interviews, reflecting the past four weeks, using the software DISHES. Further information, for example, about specific diets and dietary supplement intake, is reported during a standardised computer assisted interview for all participants. Food items are coded by the German Food Code and Nutrient Database (BLS 3.02).

Discussion

EsKiMo II provides actual data on the dietary behaviour of children and adolescents living in Germany and their determinants. Results of EsKiMo II will be relevant for decision-making, measures, and evaluations within nutrition, consumer and health policy.

Serious adverse events and the risk of stroke in patients with rheumatoid arthritis: results from the German RABBIT cohort

OBJECTIVE

In the general population, the incidence of stroke is increased following other serious events and hospitalisation. We investigated the impact of serious adverse events on the risk of stroke in patients with rheumatoid arthritis (RA), taking risk factors and treatment into account.

METHODS

Using data of the German biologics register RABBIT (Rheumatoid Arthritis: Observation of Biologic Therapy) with 12354 patients with RA, incidence rates (IRs) and risk factors for stroke were investigated using multi-state and Cox proportional hazard models. In addition, in a nested case-control study, all patients with stroke were matched 1:2 to patients with identical baseline risk profile and analysed using a shared frailty model.

RESULTS

During follow-up, 166 strokes were reported. The overall IR was 3.2/1000 patient-years (PY) (95% CI 2.7 to 3.7). It was higher after a serious adverse event (IR: 9.0 (7.3 to 11.0)), particularly within 30 days after the event (IR: 94.9 (72.6 to 121.9)). The adjusted Cox model showed increased risks of age per 5 years (HR: 1.4 (1.3 to 1.5)), hyperlipoproteinaemia (HR: 1.6 (1.0 to 2.5)) and smoking (HR: 1.9 (1.3 to 2.6)). The risk decreased with better physical function (HR: 0.9 (0.8 to 0.96)). In the case-control study, 163 patients were matched to 326 controls. Major risk factors for stroke were untreated cardiovascular disease (HR: 3.3 (1.5 to 7.2)) and serious infections (HR:4.4 (1.6 to 12.5)) or other serious adverse events (HR: 2.6 (1.4 to 4.8)).

CONCLUSIONS

Incident adverse events, in particular serious infections, and insufficient treatment of cardiovascular diseases are independent drivers of the risk of stroke. Physicians should be aware that patients who experience a serious event are at increased risk of subsequent stroke.

Electric Dipole Polarizability of ^{48}Ca and Implications for the Neutron Skin

The electric dipole strength distribution in ^{48}Ca between 5 and 25 MeV has been determined at RCNP, Osaka from proton inelastic scattering experiments at forward angles. Combined with photoabsorption data at higher excitation energy, this enables the first extraction of the electric dipole polarizability α_{D}(^{48}Ca)=2.07(22)  fm^{3}. Remarkably, the dipole response of ^{48}Ca is found to be very similar to that of ^{40}Ca, consistent with a small neutron skin in ^{48}Ca. The experimental results are in good agreement with ab initio calculations based on chiral effective field theory interactions and with state-of-the-art density-functional calculations, implying a neutron skin in ^{48}Ca of 0.14-0.20 fm.

Alternative carbon dioxide modelling approaches accounting for high residual gases in LandGEM

High Canadian waste disposal rates necessitate landfill gas monitoring and accurate forecasting. CO₂ estimates in LandGEM version 3.02 currently rest on the assumptions that CO₂ is a function of CH₄, where the two gases make up nearly 100% of landfill gas content, leading to overestimated CO₂ collection estimates. A total of 25 cases (five formulas, five approaches) compared annual CO₂ collection at four western Canadian landfills. Despite common use in literature, the 1:1 ratio of CH₄ to CO₂ was not recommended to forecast landfill gas collection in cold climates. The existing modelling approach significantly overestimated CO₂ production in three of four sites, resulting in the highest residual sum of squares. Optimization resulted in the most accurate results for all formulas and approaches, which had the greatest reduction in residual sums of squares (RSS) over the default approach (60.1 to 97.7%). The 1.4 Ratio approach for L _o:L _o-CO2 yielded the second most accurate results for CO₂ flow (mean RSS reduction of 50.2% for all sites and subsection models). The annual k-modified LandGEM calculated k's via two empirical formulas (based on precipitation) and yielded the lowest accuracy in 12 of 20 approaches. Unlike other studies, strong relationships between optimized annual k's and precipitation were not observed.

E2 decay strength of the M1 scissors mode of ^{156}Gd and its first excited rotational state

The E2/M1 multipole mixing ratio δ_{1→2} of the 1_{sc}^{+}→2_{1}^{+} γ-ray decay in ^{156}Gd and hence the isovector E2 transition rate of the scissors mode of a well-deformed rotational nucleus has been measured for the first time. It has been obtained from the angular distribution of an artificial quasimonochromatic linearly polarized γ-ray beam of energy 3.07(6) MeV scattered inelastically off an isotopically highly enriched ^{156}Gd target. The data yield first direct support for the deformation dependence of effective proton and neutron quadrupole boson charges in the framework of algebraic nuclear models. First evidence for a low-lying J^{π}=2^{+} member of the rotational band of states on top of the 1^{+} band head is obtained, too, indicating a significant signature splitting in the K=1 scissors mode rotational band.

Global patterns of phosphatase activity in natural soils

Soil phosphatase levels strongly control the biotic pathways of phosphorus (P), an essential element for life, which is often limiting in terrestrial ecosystems. We investigated the influence of climatic and soil traits on phosphatase activity in terrestrial systems using metadata analysis from published studies. This is the first analysis of global measurements of phosphatase in natural soils. Our results suggest that organic P (Porg), rather than available P, is the most important P fraction in predicting phosphatase activity. Structural equation modeling using soil total nitrogen (TN), mean annual precipitation, mean annual temperature, thermal amplitude and total soil carbon as most available predictor variables explained up to 50% of the spatial variance in phosphatase activity. In this analysis, Porg could not be tested and among the rest of available variables, TN was the most important factor explaining the observed spatial gradients in phosphatase activity. On the other hand, phosphatase activity was also found to be associated with climatic conditions and soil type across different biomes worldwide. The close association among different predictors like Porg, TN and precipitation suggest that P recycling is driven by a broad scale pattern of ecosystem productivity capacity.

Chaos and Regularity in the Doubly Magic Nucleus ^{208}Pb

High-resolution experiments have recently lead to a complete identification (energy, spin, and parity) of 151 nuclear levels up to an excitation energy of E_{x}=6.20  MeV in ^{208}Pb [Heusler et al., Phys. Rev. C 93, 054321 (2016)PRVCAN2469-998510.1103/PhysRevC.93.054321]. We present a thorough study of the fluctuation properties in the energy spectra of the unprecedented set of nuclear bound states. In a first approach, we group states with the same spin and parity into 14 subspectra, analyze standard statistical measures for short- and long-range correlations, i.e., the nearest-neighbor spacing distribution, the number variance Σ^{2}, the Dyson-Mehta Δ_{3} statistics, and the novel distribution of the ratios of consecutive spacings of adjacent energy levels in each energy sequence, and then compute their ensemble average. Their comparison with a random matrix ensemble which interpolates between Poisson statistics expected for regular systems and the Gaussian orthogonal ensemble (GOE) predicted for chaotic systems shows that the data are well described by the GOE. In a second approach, following an idea of Rosenzweig and Porter [Phys. Rev. 120, 1698 (1960)PHRVAO0031-899X10.1103/PhysRev.120.1698], we consider the complete spectrum composed of the independent subspectra. We analyze their fluctuation properties using the method of Bayesian inference involving a quantitative measure, called the chaoticity parameter f, which also interpolates between Poisson (f=0) and GOE statistics (f=1). It turns out to be f≈0.9. This is so far the closest agreement with a GOE observed in the spectra of bound states in a nucleus. The same analysis is also performed with spectra computed on the basis of shell model calculations with different interactions (surface-delta interaction, Kuo-Brown, Michigan-three-Yukawa). While the simple surface-delta interaction exhibits features typical for nuclear many-body systems with regular dynamics, the other, more realistic interactions yield chaoticity parameters f close to the experimental values.

Post passivation light trapping back contacts for silicon heterojunction solar cells

Light trapping in crystalline silicon (c-Si) solar cells is an essential building block for high efficiency solar cells targeting low material consumption and low costs. In this study, we present the successful implementation of highly efficient light-trapping back contacts, subsequent to the passivation of Si heterojunction solar cells. The back contacts are realized by texturing an amorphous silicon layer with a refractive index close to the one of crystalline silicon at the back side of the silicon wafer. As a result, decoupling of optically active and electrically active layers is introduced. In the long run, the presented concept has the potential to improve light trapping in monolithic Si multijunction solar cells as well as solar cell configurations where texturing of the Si absorber surfaces usually results in a deterioration of the electrical properties. As part of this study, different light-trapping textures were applied to prototype silicon heterojunction solar cells. The best path length enhancement factors, at high passivation quality, were obtained with light-trapping textures based on randomly distributed craters. Comparing a planar reference solar cell with an absorber thickness of 280 μm and additional anti-reflection coating, the short-circuit current density (J_SC) improves for a similar solar cell with light-trapping back contact. Due to the light trapping back contact, the J_SC is enhanced around 1.8 mA cm^-2 to 38.5 mA cm^-2 due to light trapping in the wavelength range between 1000 nm and 1150 nm.

Arthrodesis for septic arthritis of the ankle: risk factors and complications

INTRODUCTION

Septic ankle joint arthrodesis is a good therapeutic option in cases of infection after trauma or orthopedic surgical procedures. Many different procedures have been described, but external fixation seems to be standard. Aim of this study is to identify risk factors for complications in septic ankle joint arthrodesis with the external AO frame fixator.

MATERIALS AND METHODS

Patients who received septic ankle joint arthrodesis between January 2008 and December 2012 were included in this study. Patients were evaluated clinically and with radiographs or CT scans.

RESULTS

Follow-up of 74 of 79 patients with an external AO frame fixator could be evaluated; follow-up was 411 days (105-991). The mean age at surgery was 57.7 years (19-87). At this time, complications occurred in 41 patients (52 %) with wound healing problems (17 patients, 22 %) and non-union (12 patients, 15 %), and some needed surgical revision. In our collective, men had a significant higher non-union rate (p = 0.031), age or BMI showed no difference. Patients with diabetes and alcohol consumption showed a higher risk for complications (p = 0.049 and p = 0.031, respectively). 62 % of primary arthrodesis showed union, whereas in the case of revision, arthrodesis only 39 % showed union.

CONCLUSIONS

Septic ankle joint arthrodesis with the external AO frame fixator is a probable tool to achieve union. This study showed that there is a high complication rate and some risk factors for complications could be identified. A blinded and prospective study is needed to compare intramedullary nailing and external fixation to evaluate the possible advantage of intramedullary devices in septic ankle arthrodesis.

Risk for lower intestinal perforations in patients with rheumatoid arthritis treated with tocilizumab in comparison to treatment with other biologic or conventional synthetic DMARDs

Objective

To investigate the risk of developing lower intestinal perforations (LIPs) in patients with rheumatoid arthritis (RA) treated with tocilizumab (TCZ).

Methods

In 13 310 patients with RA observed in the German biologics register Rheumatoid Arthritis: Observation of Biologic Therapy, 141 serious gastrointestinal events possibly associated with perforations were reported until 31 October 2015. All events were validated independently by two physicians, blinded for treatment exposure.

Results

37 LIPs (32 in the colon/sigma) were observed in 53 972 patient years (PYs). Only two patients had a history of diverticulitis (one in TCZ). Age, current/cumulative glucocorticoids and non-steroidal anti-inflammatory drugs were significantly associated with the risk of LIP. The crude incidence rate of LIP was significantly increased in TCZ (2.7/1000 PYs) as compared with all other treatments (0.2−0.6/1000 PYs). The adjusted HR (ref: conventional synthetic (cs) disease-modifying anti-rheumatic drugs (DMARDs)) in TCZ was 4.48 (95% CI 2.0 to 10.0), in tumour necrosis factor-α inhibitor (TNFi) 1.04 (0.5 to 2.3) and in other biologic DMARDs 0.33 (0.1 to 1.4). 4/11 patients treated with TCZ presented without typical symptoms of LIP (acute abdomen, severe pain). Only one patient had highly elevated C reactive protein (CRP). One quarter of patients died within 30 days after LIP (9/37), 5/11 under TCZ, 2/13 under TNFi and 2/11 under csDMARD treatment.

Conclusions

The incidence rates of LIP under TCZ found in this real world study are in line with those seen in randomised controlled trials of TCZ and higher than in all other DMARD treatments. To ensure safe use of TCZ in daily practice, physicians and patients should be aware that, under TCZ, LIP may occur with mild symptoms only and without CRP elevation.

Swelling behavior of bisensitive interpenetrating polymer networks for microfluidic applications

Bisensitive interpenetrating polymer network (IPN) hydrogels of temperature sensitive net-poly(N-isopropylacrylamide) and pH sensitive net-poly(acrylic acid-co-acrylamide) for microfluidic applications were prepared via a sequential synthesis using free radical polymerization. The IPN indicated a suitable reversible alteration of swelling in response to the change in pH and temperature. The adequate change of the hydrogel volume is a basic requirement for microfluidic applications. Using the introduced correction factor f, it is possible to determine the cooperative diffusion coefficient (Dcoop) of cylindrical samples at any aspect ratio. The determined cooperative diffusion coefficient allowed the evaluation of varying swelling processes of different network structures. The presence of the second sub-network of the IPN improved the swelling behaviour of the first sub-network compared to the individual networks.

Functional Determination of Plasminin Arginine-stabilized Plasma

Reliable data on plasmin activities in blood of patients during fibrinolytic treatment are lacking. This is due to continuing plasminogen activation by plasminogen activators after blood withdrawal. The purpose of this study was to establish a new method for stabilization of blood and to detect plasmin activity in stabilized plasma. For optimization of plasma stabilization by arginine, 50 μL pooled normal citrated plasma was incubated with 50 μL of 0 to 1500 m M arginine, pH 8.7, and 25 μL 100 IU/mL u-PA, 1250 IU/mL t-PA, 10000 U/mL reteplase, 400 U/mL plasminogen-streptokinase-activator complex, 10 μg/mL tenecteplase in 6% BSA-PBS or 25 μL 25 μg/mL plasmin in 20% glycerol. Twenty-five microliters 3 m M HDVal-Leu-Lys-pNA were added immediately (1 step) or after 90 minutes (room temperature [RT]). The same experiment was performed with pooled normal citrated plasma supplemented with 3.2 mg/mL EDTA, preoxidized with 0 m M or 20 m M chloramine-T for 10 minutes (37°C). For optimization of plasmin activity, the oxidation time of the arginine-stabilized plasma sample containing 0.5 U/mL active plasmin and the chloramine-T amount was varied. Citrated plasma is stabilized against the in vitro action of all six plasminogen activators tested if the final arginine concentration is greater than 500 mM. Neither the addition of EDTA nor the addition of chloramine-T changes this plasma-stabilizing power of arginine. The optimized functional plasmin assay consists of incubation of 10 μL arginine-stabilized plasma with 10 μL 1.5 M arginine, pH 8.7, and 10 μL 100 m MCT in PBS. After 30 minutes (37°C), 75 μL 1.2 M KCl, 1.6 M Arg, 0.75 m M Val-Leu-Lys-pNA (Stop-CS Reagent), and 175 μL 6% BSAPBS are added and the absorbance increase (ΔA) at 405 nm is determined. With the present arginine stabilization procedure of plasma and the determination of plasmin activity in arginine-stabilized plasma as described, it is feasible to determine the activity of plasmin in blood of patients receiving fibrinolytic treatment without artefactual in vitro changes in the samples.

In vitro Simulation of Therapeutic Plasmatic Fibrinolysis

One type of therapy for thromboembolism is plasmatic thrombolysis. Several plasminogen activators (PA) are clinically available, including urokinase (u-PA), tissue plasminogen activator (t-PA), streptokinase (SK), plasminogen-streptokinase-activator-complex (PSAC), or mutants of t-PA such as reteplase (RP) or tenecteplase (TP). Therapeutic plasmatic fibrinolysis was simulated, using the PA at relevant plasma concentrations, and plasmin (Pli) and PA activities were determined. Normal citrated plasma was supplemented with 31 to 1,000 IU/mL u-PA, 0.31 to 20 μg/mL t-PA, 125 to 4,000 IU/mL SK, 12.5 to 400 U/mL PSAC, 125 to 4,000 U/mL RP, or 0.31 to 10,μg/mL TP. Ten IU/mL urokinase was also incubated with pooled plasma of stroke patients, that was previously oxidized with the singlet oxygen (1O2) donor chloramine T® (CT), to destroy plasmatic PAI-1 and a2-antiplasmin. After 0 to 80 minutes (37°C), 50-μL samples were withdrawn and added to 100 μL 1.5 M arginine, pH 8.7, and oxidized with 50 μL of 20 mM CT. For determination of plasmin activity, 10 μL thereof was incubated with 150 μL 1.5 M arginine, pH 8.7, and 100 μL 20 mM CT preoxidized (15 minutes 37°C) pooled normal citrate buffered EDTA-plasma for 30 minutes (37°C). For determination of [PA+Pli]-activity, arginine was added after this incubation. 25-μL 6 mM Val-Leu-Lys-pNA were added and AA/h at room temperature (RT) was monitored, using a microtiterplate reader. [PA+Pli]-Pli = PA. The PA concentration required to induce 25% [ED25] of the maximally inducible Pli-activity in plasma (= 1 U/mL = 45 mg/L = 0.53 Amol/L active Pli; AA = 363 + 8 mA/h RT) after 10 minutes (37°C) were 320 IU/mL u-PA, 8 μg/mL t-PA, 140 U/mL PSAC, 6,000 IU/mL SK, 720 U/mL RP, and approximately 150 μg/mL TP. The approximate activity half-lives of the PA in plasma were 30 minutes for u-PA, 30 minutes for t-PA, greater than 80 minutes for SK, greater than 80 minutes for PSAC, 50 minutes for RP, and 80 minutes for TP. The present study shows-for the first time-a combined kinetic in vitro simulation of the plasmatic activity of six different PAs. At clinically used concentrations, RP induces the highest plasmatic Pli activity. Due to unselective generation of plasmin in plasma, all PA are of some danger in inducing severe hemorrhagias. Clinical thrombolysis might be improved by usage of more physiologic activators of thrombolysis, such as activators of polymorphonuclear neutrophils.

Spectral Properties of Dirac Billiards at the van Hove Singularities

We study distributions of the ratios of level spacings of rectangular and Africa-shaped superconducting microwave resonators containing circular scatterers on a triangular grid, so-called Dirac billiards (DBs). The high-precision measurements allowed the determination of, respectively, all 1651 and 1823 eigenfrequencies in the first two bands. The resonance densities are similar to that of graphene. They exhibit two sharp peaks at the van Hove singularities which separate the band structure into regions with a linear and a quadratic dispersion relation, respectively. In the vicinity of the van Hove singularities we observe rapid changes in, e.g., the wave function structure. Accordingly, we question whether the spectral properties are there still determined by the shapes of the DBs. The commonly used statistical measures are no longer applicable; however, we demonstrate in this Letter that the ratio distributions provide suitable measures.

Congenital hairy polyp of the oropharynx presenting as an esophageal mass in a neonate, a case report and literature review

PURPOSE

To review the literature of congenital hairy polyps and describe the clinical presentation, operative management, and histologic findings of a congenital hairy polyp arising from the palatopharyngeus muscle in a neonate with recurrent choking episodes.

METHODS

Chart review of a 2-month-old male referred to a tertiary care pediatric hospital.

RESULTS

We present a case of a 2-month-old male who presented to the emergency room with recurrent episodes of choking and vomiting. The patient was previously healthy with no prior medical or neonatal history. The parents noted a small fleshy mass in the patient's oropharynx that he would chew on and swallow after several minutes. However, on physical exam, there was no evidence of oropharyngeal mass. The patient did not have respiratory distress. Imaging revealed a 22×7×11mm oblong, fatty mass in the lower cervical and upper thoracic esophagus with a thin stalk extending proximally to the upper collapsed esophagus. Intraoperative recorded laryngoscopy revealed a pedunculated soft palate mass attached to the right superior palatopharyngeus muscle. Histopathology revealed ectodermal and mesodermal elements in a polypoid structure lined by keratinizing squamous epithelium with adnexal structures and central mature adipose tissue, consistent with congenital hairy polyp resembling an accessory tragus of the ear and branchial anomaly. At 6-week follow up, the patient was doing well and gaining weight appropriately with no further choking episodes. There was no evidence of velopharyngeal dysfunction on follow up exam. The surgical site was completely healed and there was no evidence of recurrence.

DISCUSSION

Congenital hairy polyps of the naso- and oropharynx are rare but may present as airway or esophageal masses, causing respiratory distress or choking episodes in a pediatric patient. The pathologic findings of keratinizing squamous epithelium, adnexal structures, adipose and cartilage tissues resemble congenital accessory tragus and may be considered a branchial arch anomaly.

[How do register data support clinical decision-making?]

BACKGROUND

Patients in daily rheumatological care differ in their individual risk profiles from participants in randomized controlled trials (RCT), e.g. due to comorbidities and age. Transferring results from RCTs into routine daily practice is therefore limited.

OBJECTIVE

The aim of this study was to evaluate the contribution of observational studies for decision-making in routine rheumatology practice.

MATERIAL AND METHODS

We used data from the German biologics register RABBIT which includes patients with rheumatoid arthritis (RA) when starting synthetic (s) or biologic (b) disease-modifying antirheumatic drugs (DMARD). They are observed for at least 5 years. Comorbidities and clinically relevant aspects (e.g. history of malignancies) are reported at baseline and adverse events at regular follow-up.

RESULTS

Only one out of three patients treated with bDMARDs in RABBIT would have fulfilled the inclusion criteria of the respective pivotal study. Register data enabled developing a risk scoring model which evaluates the individual risk of a patient for serious infections depending on different risk factors and the respective DMARD treatment. Open online access to the score provides the possibility of risk estimation for all rheumatologists. Further results identified long-standing high disease activity as a dominant risk factor for a worsening of prevalent comorbidities. In patients with heart failure it was shown that effective treatment and control of disease activity with tumor necrosis factor (TNF) inhibitors was more likely to be protective than harmful.

CONCLUSION

Observational studies contribute essentially to the assessment of individual risks of patients. The results provide valuable information to support clinical decision-making and therefore strengthen the evidence when treating patients of higher age or with existing comorbidities.

Impact of treatment with biologic DMARDs on the risk of sepsis or mortality after serious infection in patients with rheumatoid arthritis

Objective

This observational cohort study investigated the impact of biological (b) disease-modifying antirheumatic drugs (DMARDs) on the outcomes of serious infections (SIs) in patients with rheumatoid arthritis.

Methods

We investigated outcomes of SIs observed in 947 patients enrolled in the German biologics register RABBIT(Rheumatoid arthritis: observation of biologic therapy). Outcomes were (1) recovery without complication, (2) sepsis following SI (≤30 days), and (3) death after SI without known sepsis (≤90 days). We applied a multinomial generalised estimating equation model for longitudinal data to evaluate the risks of sepsis and death simultaneously.

Results

Sepsis within 30 days after SI was reported in 135 out of 947 patients, 85 of these had a fatal outcome. Fifty-three patients died within 90 days after SI without known sepsis. The adjusted risk of developing sepsis increased with age and was higher in patients with chronic renal disease. Compared with conventional synthetic (cs)DMARDs, the risk was significantly lower when patients were exposed to bDMARDs at the time of SI (OR: 0.56, 95% CI 0.38 to 0.81). Risk factors of fatal SI were higher age, use of glucocorticoids at higher doses and heart failure. Patients treated with bDMARDs and those with better physical function had a significantly lower mortality risk.

Conclusions

These results suggest a beneficial effect of bDMARDs on the risk of sepsis after SI and the risk of a fatal outcome. Successful immunosuppression may prevent an unregulated host response to SI, that is, the escalation to sepsis. Further investigation is needed to validate these results.

Nonquenched Isoscalar Spin-M1 Excitations in sd-Shell Nuclei

Differential cross sections of isoscalar and isovector spin-M1 (0(+)→1(+)) transitions are measured using high-energy-resolution proton inelastic scattering at E(p)=295  MeV on (24)Mg, (28)Si, (32)S, and (36)Ar at 0°-14°. The squared spin-M1 nuclear transition matrix elements are deduced from the measured differential cross sections by applying empirically determined unit cross sections based on the assumption of isospin symmetry. The ratios of the squared nuclear matrix elements accumulated up to E(x)=16  MeV compared to a shell-model prediction are 1.01(9) for isoscalar and 0.61(6) for isovector spin-M1 transitions, respectively. Thus, no quenching is observed for isoscalar spin-M1 transitions, while the matrix elements for isovector spin-M1 transitions are quenched by an amount comparable with the analogous Gamow-Teller transitions on those target nuclei.

Quantum and wave dynamical chaos in superconducting microwave billiards

Experiments with superconducting microwave cavities have been performed in our laboratory for more than two decades. The purpose of the present article is to recapitulate some of the highlights achieved. We briefly review (i) results obtained with flat, cylindrical microwave resonators, so-called microwave billiards, concerning the universal fluctuation properties of the eigenvalues of classically chaotic systems with no, a threefold and a broken symmetry; (ii) summarize our findings concerning the wave-dynamical chaos in three-dimensional microwave cavities; (iii) present a new approach for the understanding of the phenomenon of dynamical tunneling which was developed on the basis of experiments that were performed recently with unprecedented precision, and finally, (iv) give an insight into an ongoing project, where we investigate universal properties of (artificial) graphene with superconducting microwave photonic crystals that are enclosed in a microwave resonator, i.e., so-called Dirac billiards.

Cross-section fluctuations in open microwave billiards and quantum graphs: The counting-of-maxima method revisited

The fluctuations exhibited by the cross sections generated in a compound-nucleus reaction or, more generally, in a quantum-chaotic scattering process, when varying the excitation energy or another external parameter, are characterized by the width Γcorr of the cross-section correlation function. Brink and Stephen [Phys. Lett. 5, 77 (1963)] proposed a method for its determination by simply counting the number of maxima featured by the cross sections as a function of the parameter under consideration. They stated that the product of the average number of maxima per unit energy range and Γcorr is constant in the Ercison region of strongly overlapping resonances. We use the analogy between the scattering formalism for compound-nucleus reactions and for microwave resonators to test this method experimentally with unprecedented accuracy using large data sets and propose an analytical description for the regions of isolated and overlapping resonances.

Emission of herbivore elicitor-induced sesquiterpenes is regulated by stomatal aperture in maize (Zea mays) seedlings

Maize seedlings emit sesquiterpenes during the day in response to insect herbivory. Parasitoids and predators use induced volatile blends to find their hosts or prey. To investigate the diurnal regulation of biosynthesis and emission of induced sesquiterpenes, we applied linolenoyl-L-glutamine (LG) to maize seedlings in the morning or evening using a cut-stem assay and tracked farnesene emission, in planta accumulation, as well as transcript levels of farnesyl pyrophosphate synthase 3 (ZmFPPS3) and terpene synthase10 (ZmTPS10) throughout the following day. Independent of time of day of LG treatment, maximum transcript levels of ZmFPPS3 and ZmTPS10 occurred within 3-4 h after elicitor application. The similarity between the patterns of farnesene emission and in planta accumulation in light-exposed seedlings in both time courses suggested unobstructed emission in the light. After evening induction, farnesene biosynthesis increased dramatically during early morning hours. Contrary to light-exposed seedlings dark-kept seedlings retained the majority of the synthesized farnesene. Two treatments to reduce stomatal aperture, dark exposure at midday, and abscisic acid treatment before daybreak, resulted in significantly reduced amounts of emitted and significantly increased amounts of in planta accumulating farnesene. Our results suggest that stomata not only play an important role in gas exchange for primary metabolism but also for indirect plant defences.

Dielectric square resonator investigated with microwave experiments

We present a detailed experimental study of the symmetry properties and the momentum space representation of the field distributions of a dielectric square resonator as well as the comparison with a semiclassical model. The experiments have been performed with a flat ceramic microwave resonator. Both the resonance spectra and the field distributions were measured. The momentum space representations of the latter evidenced that the resonant states are each related to a specific classical torus, leading to the regular structure of the spectrum. Furthermore, they allow for a precise determination of the refractive index. Measurements with different arrangements of the emitting and the receiving antennas were performed and their influence on the symmetry properties of the field distributions was investigated in detail, showing that resonances with specific symmetries can be selected purposefully. In addition, the length spectrum deduced from the measured resonance spectra and the trace formula for the dielectric square resonator are discussed in the framework of the semiclassical model.

Spectral properties and dynamical tunneling in constant-width billiards

We determine with unprecedented accuracy the lowest 900 eigenvalues of two quantum constant-width billiards from resonance spectra measured with flat, superconducting microwave resonators. While the classical dynamics of the constant-width billiards is unidirectional, a change of the direction of motion is possible in the corresponding quantum system via dynamical tunneling. This becomes manifest in a splitting of the vast majority of resonances into doublets of nearly degenerate ones. The fluctuation properties of the two respective spectra are demonstrated to coincide with those of a random-matrix model for systems with violated time-reversal invariance and a mixed dynamics. Furthermore, we investigate tunneling in terms of the splittings of the doublet partners. On the basis of the random-matrix model we derive an analytical expression for the splitting distribution which is generally applicable to systems exhibiting dynamical tunneling between two regions with (predominantly) chaotic dynamics.