Cantharidin increases the force of contraction and protein phosphorylation in isolated human atria

Cantharidin, an inhibitor of protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A), is known to increase the force of contraction and shorten the time to relaxation in human ventricular preparations. We hypothesized that cantharidin has similar positive inotropic effects in human right atrial appendage (RAA) preparations. RAA were obtained during bypass surgery performed on human patients. These trabeculae were mounted in organ baths and electrically stimulated at 1 Hz. For comparison, we studied isolated electrically stimulated left atrial (LA) preparations and isolated spontaneously beating right atrial (RA) preparations from wild-type mice. Cumulatively applied (starting at 10 to 30 µM), cantharidin exerted a positive concentration-dependent inotropic effect that plateaued at 300 µM in the RAA, LA, and RA preparations. This positive inotropic effect was accompanied by a shortening of the time to relaxation in human atrial preparations (HAPs). Notably, cantharidin did not alter the beating rate in the RA preparations. Furthermore, cantharidin (100 µM) increased the phosphorylation state of phospholamban and the inhibitory subunit of troponin I in RAA preparations, which may account for the faster relaxation observed. The generated data indicate that PP1 and/or PP2A play a functional role in human atrial contractility.

High-performance cavity-dumped Q-switched Alexandrite laser CW diode-pumped in double-pass configuration

We present a high-performance Alexandrite laser for LIDAR applications with repetition rates up to 20 kHz in cavity-dumped Q-switched operation continuous-wave diode-pumped in the red spectral region. With a double-pass pump configuration, short pulses with 2.8 ns duration at repetition frequencies ranging from 1 kHz to 20 kHz could be demonstrated. At 5 kHz a - to our knowledge - record pulse energy of over 500 µJ could be achieved at 755 nm in TEM₀₀. Furthermore, a stability measurement at an energy of around 350 µJ with 5 kHz showed no degradation over 150 Mega-shots. The influence of the crystal temperature on the laser performance is also investigated, first in continuous-wave and secondly in cavity-dumped Q-switched operation.

Three-dimensional nanothermometry below the diffraction limit

Lanthanide-doped nanothermometers are used to measure temperature through changes in their emission characteristic with sensitivities of up to a few %/K. In contrast to their sensitivity, their spatial resolution, which is of critical importance for various applications, has not been thoroughly studied and optimized. We numerically investigated the improvement in spatial resolution of nanothermometers with a stimulated emission depletion microscopy approach. Fundamental relationships between spatial and temperature resolution were identified by using different beam parameters for the excitation and depletion beams. Our simulations predict contactless temperature measurement below the diffraction limit with temperature resolution of ±1.25K. We further studied the influence of sample thickness and position on both temperature and spatial resolution and showed the potential of three-dimensional measurements.

Role of Cardiac A2A Receptors Under Normal and Pathophysiological Conditions

This review presents an overview of cardiac A2A-adenosine receptors The localization of A2A-AR in the various cell types that encompass the heart and the role they play in force regulation in various mammalian species are depicted. The putative signal transduction systems of A2A-AR in cells in the living heart, as well as the known interactions of A2A-AR with membrane-bound receptors, will be addressed. The possible role that the receptors play in some relevant cardiac pathologies, such as persistent or transient ischemia, hypoxia, sepsis, hypertension, cardiac hypertrophy, and arrhythmias, will be reviewed. Moreover, the cardiac utility of A2A-AR as therapeutic targets for agonistic and antagonistic drugs will be discussed. Gaps in our knowledge about the cardiac function of A2A-AR and future research needs will be identified and formulated.

A comprehensive study of the sorption mechanism and thermodynamics of f-element sorption onto K-feldspar

The mobility of heavy metal contaminants and radionuclides in the environment is directly controlled by their interactions with charged mineral surfaces, hence an assessment of their potential toxicity, e.g. in the context of radioactive waste disposal sites, requires understanding of sorption processes on the molecular level. Here, we investigate the sorption of a variety of rare earth elements (REE) and trivalent actinides (Am, Cm) on K-feldspar using batch sorption, time-resolved laser-induced fluorescence spectroscopy (TRLFS), and a surface complexation model. Initially, a reliable pK_a for K-feldspar's surface deprotonation reaction was determined as 2.5 ± 0.02 by column titration experiments, in excellent agreement with a measured pH_IEP of 2.8. Batch sorption experiments over a broad range of experimental conditions in terms of mineral grain size, pH, [M³⁺], ionic radius, solid/liquid ratio, ionic strength, and equilibration procedures were carried out to quantify macroscopic retention. The trivalent d-block element Y, early, mid, and late lanthanides (La, Eu, Nd, Lu), as well as two minor actinides (Am, Cm) were used for batch sorption experiments and showed similar pH dependent uptake behavior, underlining their chemical analogy. In parallel, spectroscopic investigations provided insight into surface speciation. Cm TRLFS spectra indicate the formation of three inner-sphere sorption complexes with increasing hydrolysis. Additionally, a ternary K-feldspar/Cm/silicate complex was found for pH > 10, and batch and spectroscopic data at low pH (<4) point to small amounts of outer sphere sorption complexes. Based on TRLFS data, batch sorption, and titration data, a generic geochemical sorption model was developed, that describes sorption edges for all investigated M³⁺/K-feldspar systems satisfactorily. The derived stability constants for the binary sorption complexes (logK_1-4 = -3.6, -7.7, -11.5, and -17.4, respectively) could successfully be used to reproduce literature data. The stability constants obtained for the surface complexes were included into the database for the Smart K_d-concept, which will further improve the safety assessment of potential repositories for radioactive waste.

Multibiomarker model to discriminate Type 1 and Type 2 myocardial infarction

Background

The discrimination of patients with type 1 myocardial infarction (T1MI) from patients with type 2 MI (T2MI) is often challenging in the emergency department. Earlier we presented a discrimination model, which based on clinical variables, as well as on troponin concentrations. In the present analyses we sought to investigate the discriminative power of 28 biomarkers in patients with T1MI and T2MI.

Methods

Patients presenting to the emergency department with symptoms suggestive of MI were recruited. The final diagnosis of all patients was adjudicated by two physicians in a blinded fashion and based on the fourth universal definition of MI. For the present analyses only patients with T1MI and T2MI were used. In total 28 biomarkers were measured in blood samples collected directly at admission. A multivariable logistic regression model for T1MI vs T2MI as the dependent variable was used and the predictors were chosen via backward step-down selection.

Results

In total 138 patients (107 T1MI and 31 T2MI) were available for the analyses. The median age of the study population was 65 years and 66.7% were males. Hypertension was present in 77.4% and dyslipidemia in 41.3%. In the multivariable model four biomarkers (apolipoprotein A-II, n-terminal prohormone of brain natriuretic peptide, copeptin and high-sensitivity troponin I) were significant discriminators between T1MI and T2MI (Table 1). Internal validation of the model via bootstrap shows a for overoptimism corrected area under the curve of 0.82.

Conclusion

Using a multibiomarker approach discrimination between T1MI and T2MI could be improved. External validation of our findings is warranted.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Research fellowship by the Deutsche Forschungsgemeinschaft

Usefulness of troponin in selecting patients for invasive coronary angiography after cardiac surgery

Background

Great uncertainty exists about the indication for invasive coronary angiography (ICA) in patients with suspected acute coronary syndrome following cardiac surgery.

Aim

The aim of this study was to define clinical criteria that best identify patients who benefit from ICA after cardiac surgery.

Methods

We performed a retrospective analysis of all patients who underwent cardiac surgery between January 2009 and May 2019 at our center. Exclusion criteria included pediatric patients as well as pacemaker, TAVR and LVAD implantation and heart transplantation procedures. The primary outcome was usefulness of ICA as defined by consequent PCI or re-operation due to ICA findings. ECG changes (ST-elevations) and high-sensitivity Troponin I (hsTrop I) were analyzed.

Results

48,136 patients were screened and after applying exclusion criteria 29,359 patients were finally included in the analysis (mean age 67.8±11.0 years, 31.1% females, Euroscore II 5.14±8.9%). A total of 1,171 patients (4%) underwent post-op ICA. The primary outcome occurred in 440 patients (1.5%) of which 290 underwent consequent PCI and 214 underwent consequent re-operation. Baseline characteristics are shown in table 1. Unadjusted analyses did not identify significant differences in the level of cardiac biomarkers between useful-ICA and unuseful-ICA groups.

In multivariate regression analysis, only ST-elevation on ECG predicted the primary outcome (OR 1.33, 95% CI 1.003–1.76).

Dichotomizing hsTrop I concentrations by applying the guideline-specified cut-off (&gt;70x URL) resulted in correct classification of useful-ICA patients in 95.7%. However, the false-positive rate was also extremely high (83.6%) with a positive predictive value (PPV) of 1.6% and a negative predictive value (NPV) of 99.6% (accuracy 17.5%).

Using area under the curve (ROC) analysis following optimal cut-off values for hsTrop I were identified: in CABG patients a cut-off value of &gt;650x URL (corresponding absolute value 17000 ng/L) was defined with a corresponding sensitivity of 83.3%, specificity of 83.6%, PPV of 8.9% and NPV of 99.6% (accuracy 83.6%). In non-CABG patients (i.e. valve or aortic procedures), the cut-off was about twice as high as that for CABG patients (1,350x URL or 35,000 ng/L) with a corresponding sensitivity of 84.1%, specificity of 89.2%, PPV of 5.9% and NPV of 99.9% (accuracy 89.1%).

Conclusion

Our study demonstrates that currently recommended cut-off concentrations of high-sensitivity troponin are not useful for guiding clinical decision-making in patients with suspected acute coronary syndrome following cardiac surgery, while substantially higher cut-off values might be useful. Those cut-off values critically depend on the type of cardiac surgery performed (CABG vs. non-CABG).

Troponin_Curves post-op

Funding Acknowledgement

Type of funding source: None

Discrimination of myocardial infarction and myocardial injury using a multibiomarker approach

Background

In the Universal Definition of Myocardial Infarction (MI) myocardial injury was introduced as a specific diagnosis in patients with elevated troponin concentrations, but without evidence of acute myocardial ischemia. However, their differentiation within the acute setting might be challenging. Therefore, we sought to investigate a multibiomarker panel in these patients and determine the discriminative capacity to differentiation MI from myocardial injury.

Methods

We use a cohorts of acute patients presenting to the emergency department. All final diagnoses were adjudicated by two physicians in a blinded fashion and based on the fourth universal definition of MI. In case of disagreement a third physician referred. For the present analyses only patients diagnosed with MI or myocardial injury were used. A panel of 28 biomarkers was measured in blood samples collected directly at admission. Spearman correlations were calculated. A multivariable logistic regression model using MI as the dependent variable was used and the predictors were chosen via backward step-back selection. Odds ratios (OR) were calculated for each predictor.

Results

We included 359 patients; 138 were diagnosed as having MI and 221 has having myocardial injury. The median age of the study population was 73 years and 59.1% were males. Hypertension was diagnosed in 80.4%, dyslipidemia in 45.4% and diabetes in 19.0%.The biomarker panel showed a wide range of correlations (Figure 1). In the multivariable model five logarithmized biomarkers (N-terminal prohormone of brain natriuretic peptide [OR 0.62], pulmonary and activation-regulated chemokine [OR 0.51], tumor-necrosis-factor-receptor 2 [OR 2.22], copeptin [OR 1.59] and high-sensitivity troponin I [OR 1.80]) were significant discriminators between MI and myocardial injury. Internal validation of the model via bootstrap shows a for overoptimism corrected area under the curve of 0.84.

Conclusion

In the multivariable model five biomarkers were discriminators between MI and myocardial injury.

Spearman correlations

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Research fellowship by the Deutsche Forschungsgemeinschaft

Experimental and numerical study of interlock requirements for high-power EYDFAs

In this work, we studied the interlock requirements in a seed failure scenario for Er³⁺:Yb³⁺ doped fiber amplifiers (EYDFAs) pumped with high intensities in the MWcm^-2 range at 9XX nm. We fed a time-dependent FEM-tool with the data from backwards directed amplified spontaneous emission (ASE) transients of different commercially available core-pumped single-mode fibers. In the FEM-tool, the Er³⁺:Yb³⁺ system is defined as a bi-directional energy transfer process and described by the corresponding rate equations. The power evolution of the pump, seed, and ASE signal is computed by differential equations taking into account the transient population densities of the relevant energy levels. With the model, we computed the temporal evolution of the corresponding energy levels after a seeder failure to take place within tens to hundreds of µs and calculated the associated gain. The fibers under test provide a critical total gain of 30 dB after ∼ 80 µs within the Yb³⁺ band and after ∼300 µs within the Er³⁺ band. This time decreases with increasing pump power and doping concentration. The results can be extrapolated to high-power cladding-pumped EYDFAs to meet the challenging requirements of engineering-level systems.

THU0053 CONTRIBUTION OF DEFECTIVE NON-APOPTOTIC FAS SIGNALING TO IMMUNE DYSREGULATION IN AUTOIMMUNE LYMPHOPROLIFERATIVE SYNDROME (ALPS)

Background:

ALPS patients show impaired generation of humoral memory for T independent antigens whereas they generate memory for self-antigens due to impaired FAS-dependent removal of autoreactive germinal center B cells. It is known that FAS signaling via caspase activation results in cell apoptosis. However, FAS ligation may also initiate or modulate non-apoptotic signaling as shown for example by its ability to activate NF-κB. Recent data implicate a regulatory role of FAS in the modulation of mTOR signaling in ALPS double-negative T cells. Moreover, a recently described C194V FAS mutation disturbs its post-translational modification leading to impaired apoptosis induction while non-apoptotic signalling is still intact. Consequently, C194V FAS protects from the autoimmune phenotype in the murine ALPS system. This supports the view that FAS may prevent autoimmunity with other mechanisms than inducing apoptosis.

Objectives:

We hypothesize that FAS mutations impair this modulatory signaling, leading to hyper-activation of B cells. Therefore we aim to investigate non apoptotic FAS signaling in B cells derived from healthy individuals and ALPS patients.

Methods:

We studied resting and activated B cells in ALPS patients in presence or absence of FAS ligand by flow cytometry analysing relevant molecules to the CD40 signaling pathway. We used mass cytometry to perform functional phenotyping of B cells isolated from secondary lymphoid organs. Proteomic studies were performed to identify potential signaling circuits and RNA sequencing to study the consequences of FAS signaling on B cell fate.

Results:

In CD40L activated B cells, FAS signaling results in specific modulation of the mTOR signaling pathway. This modulation is absent in ALPS derived B cells. In line with these data germinal center B cells and plasmablast from secondary lymphoid organs of ALPS patients show hyperactive mTOR signaling pathway. Proteomic studies identify a circuit that links FAS to the phosphatase PTEN via DAXX and the deubiquitinase USP7.

Conclusion:

We describe a new role of FAS in the regulation of B cell activation. Defects in FAS signaling in ALPS contribute to dysregulation of the mTOR signaling pathway and disturbed B cell development.

Disclosure of Interests:

None declared

[Malignant tumors of the skull base]

Malignant skull base tumors consist of a heterogeneous group of malignancies that can be divided into primary and secondary (metastatic) skull base tumors. In addition, according their anatomical location, they can be further divided into tumors of the anterior, middle, or posterior cranial fossa. Although malignant skull base tumors do not rigorously respect anatomical borders, their anatomical occurrence can potentially be helpful for possible differential diagnosis. This article is focused on the most common malignant tumors of the skull base and their imaging and clinical presentations.

Ribosome-Associated Chloroplast SRP54 Enables Efficient Cotranslational Membrane Insertion of Key Photosynthetic Proteins

Key proteins of the photosynthetic complexes are encoded in the chloroplast genome and cotranslationally inserted into the thylakoid membrane. However, the molecular details of this process are largely unknown. Here, we demonstrate by ribosome profiling that the conserved chloroplast signal recognition particle subunit (cpSRP54) is required for efficient cotranslational targeting of several central photosynthetic proteins, such as the PSII PsbA (D1) subunit, in Arabidopsis (Arabidopsis thaliana). High-resolution analysis of membrane-associated and soluble ribosome footprints revealed that the SRP-dependent membrane targeting of PsbA is already initiated at an early translation step before exposure of the nascent chain from the ribosome. In contrast to cytosolic SRP, which contacts the ribosome close to the peptide tunnel exit site, analysis of the cpSRP54/ribosome binding interface revealed a direct interaction of cpSRP54 and the ribosomal subunit uL4, which is not located at the tunnel exit site but forms a part of the internal peptide tunnel wall by a loop domain. The plastid-specific C-terminal tail region of cpSRP54 plays a crucial role in uL4 binding. Our data indicate a novel mechanism of SRP-dependent membrane protein transport with the cpSRP54/uL4 interaction as a central element in early initiation of cotranslational membrane targeting.

P4576Prognostic value of high-sensitivity troponin I measured by two assays in patients presenting with suspected myocardial infarction

Background

Troponin is the gold-standard biomarker for diagnosing acute myocardial infarction (AMI). High-sensitivity assayed troponin has furthermore proven to be a promising biomarker for the prediction of future adverse cardiovascular events.

Objective

Aim of the current study was to assess and compare the prognostic value of a single troponin I measurement in patients with suspected AMI analysed by a novel high-sensitive Troponin I (hs-TnI) assay, promising detection of very low troponin I plasma levels, as well as by a well-established hs-TnI assay.

Methods

Data was derived from two prospective studies of patients presenting with suspected AMI to the emergency department. Hs-TnI was measured in a total of 2,312 patients using both a novel hs-TnI assay (1; Singulex Clarity cTnI) and a widely applied and approved hs-TnI assay (2; Abbott Diagnostics, ARCHITECT i1000SR). The prognostic impact for overall mortality of both hs-TnI assays was assessed in the total patient cohort as well as in the subgroups of patients with AMI (n=498) and without AMI (n=1,813). Kaplan-Meier analyses stratified by hs-TnI tertiles in each subgroup were performed. Moreover, prognostic impacts of both hs-TnI assays were analysed in a multiple adjusted cox regression model. We compared the performance of both hs-TnI assays in predicting adverse outcome using c-statistics. Median follow up time was 2.4 years.

Results

Patients with AMI presented with significantly higher hs-TnI values on admission. Unadjusted Kaplan-Meier analysis survival curves in the entire study population (Figure 1) as well as in the non-AMI subgroup indicated a significantly higher event-rate in the third tertiles of both hs-TnI assays for overall mortality. In contrast, irrespective of the used assay we found no association between troponin I plasma levels and overall mortality in the AMI group. Cox regression models revealed significant associations between hs-TnI and overall mortality in the entire study cohort (1: HR 1.17 [1.10–1.25], p<0.001; 2: HR 1.18 [1.11–1.26], p<0.001) and in the non-AMI subgroup (1: HR 1.39 [1.21–1.6], p<0.001; 2: 1.49 [1.28–1.74], p<0.001), but no significant association in the AMI subgroup (1: HR 1.02 [0.91–1.13], p=0.79; 2: 1.03 [0.93–1.3], p=0.55). The addition of hs-TnI to cardiovascular risk factors for the prediction of overall mortality led to a similar increment in the c-index by both hs-TnI assays of 0.014; p=0.034 (1) and 0.015; p=0.037 (2), respectively.

Figure 1. Overall mortality

Conclusion

Hs-TnI assayed on admission is an independent predictor of adverse outcome beyond conventional risk factors in patients presenting to the emergency department with suspected but ruled-out diagnosis of AMI. In patients with the established diagnosis of AMI hs-TnI is not predictive for adverse outcome. Our findings demonstrate the potential role of hs-TnI as a biomarker for risk prediction. Both assessed hs-TnI assays performed equally in predicting adverse events.

P1642High-sensitivity cardiac troponin I and NT-proBNP and their relationship to heart failure in the European BiomarCaRE population

Aims

Heart failure (HF) is an increasingly important contributor to the overall burden of cardiovascular disease in the population. We aimed to determine the distribution of the cardiac biomarkers high-sensitivity cardiac troponin I (hs-cTnI) and N-terminal prohormone of brain natriuretic peptide (NT-proBNP) concentrations across the European population to characterize the association with incident HF.

Methods and results

Based on the Biomarkers for Cardiovascular Risk Assessment in Europe (BiomarCaRE)-project, we analysed data of 48,455 individuals from four prospective population-based cohort studies (DanMONICA, FINRISK, Moli-Sani, Northern Sweden MONICA study) across Europe with a maximum follow-up of 27 years. The median age of the participants was 50.7 years (25th percentile: 40.0 years, 75th percentile: 61.7 years) and 49.1% (25,146) were men. Considered endpoints were incident HF and all-cause mortality. The median follow-up time for occurrence of HF was 6.61 (6.55; 6.66) years. We found that cardiovascular risk factors (CVRFs), especially diabetes with HR of 2.11 (95% CI 1.8, 2.5) and smoking status with HR of 1.79 (95% CI 1.59, 2.1) (Figure 1) were associated with incident HF. Furthermore, beyond the CVRFs, elevated hs-cTnI and NT-proBNP concentrations contributed to risk of HF in the general population with HR of 1.49 (95% CI 1.21, 1.9) and HR of 2.37 (95% CI 1.97, 3.0) respectively. As a cut-off value to select individuals, who would benefit most from preventive strategies, a hs-cTnI concentration of 2.8 ng/L was calculated using the optimal cut-off methodology by Contal and O'Quigley in CSDA 1999.

Hazard ratio for incident HF

Conclusion

In our large population-based cohort, hs-cTnI and NT-proBNP were independently associated with incident HF. Use of biomarkers for HF screening thus may help to select those individuals in the general population who would benefit most from preventive strategies. Based on the cut-off value future studies are needed to evaluate therapeutic options.

On inotropic effects of UTP in the human heart

Uridine 5'-triphosphate (UTP) exerts a positive inotropic effect (PIE) in isolated electrically driven isolated right atrial trabeculae carneae from patients undergoing heart surgery. This review discusses some aspects of the current knowledge on the putative receptor(s) involved and the potential biochemical transduction steps leading to the PIE.

Initial Characterization of Transgenic Mice Overexpressing Human Histamine H2 Receptors

In an integrative approach, we studied the role of histamine H₂ receptors in the mouse heart. We noted that histamine, added cumulatively to the organ bath, failed to affect the force of contraction in left atrial preparations and did not change spontaneous heart rate in right atrial preparations from wild-type mice. By contrast, in the same preparations from mice that overexpressed the human H₂ receptor in a cardiac-specific way, histamine exerted concentration- and time-dependent positive inotropic and positive chronotropic effects. Messenger RNA of the human H₂ receptor was only detected in transgenic mice. Likewise, immunohistology and autoradiography only gave signals in transgenic but not in wild-type cardiac preparations. Similarly, a positive inotropic and positive chronotropic effect was observed with histamine in echocardiography of living transgenic mice and isolated perfused hearts (Langendorff preparation). Phosphorylation of phospholamban was increased in atrial and ventricular preparations from transgenic mice, but not in wild-type animals. The effects of histamine were mimicked by dimaprit and amthamine and antagonized by cimetidine. In summary, we generated a new model to study the physiologic and pathophysiologic cardiac role of the human H₂ receptor.

High non-specific binding of the β1-selective radioligand 2-125I-ICI-H

Aim: As results of cardiac biopsies suggest, myocardial β1-adrenoceptor density is reduced in patients with chronic heart failure. However, changes in cardiac β2-adrenoceptors vary. With suitable radiopharmaceuticals single photon emission computed tomography (SPECT) and positron emission tomography (PET) offer the opportunity to assess β-adrenoceptors non-invasively. Among the novel racemic analogues of the established β1-selective adrenoceptor antagonist ICI 89.406 the iodinated 2-I-ICI-H showed high affinity and selectivity to β1-adrenoceptors in murine ventricular membranes. The aim of this study was its evaluation as a putative sub-type selective β1-adrenergic radioligand in cardiac imaging. Methods: Competition studies in vitro and in vivo were used to investigate the kinetics of 2-I-ICI-H binding to cardiac β-adrenoceptors in mice and rats. In addition, the radiosynthesis of 2-125I-ICI-H from the silylated precursor 2-SiMe3-ICI-H was established. The specific activity was 80 GBq/µmol, the radiochemical yield ranged from 70 to 80%.

Results: The unlabelled compound 2-I-ICI-H showed high β1-selectivity and -affinity in the in vitro competition studies. In vivo biodistribution studies apparently showed low affinity to cardiac β-adrenoceptors. The radiolabelled counterpart 2-125I-ICI-H showed a high degree of non-specific binding in vitro and no specific binding to cardiac β1-adrenoceptors in vivo. Conclusion: Because of its high non-specific binding 2-125I-ICI-H is no suitable radiotracer for imaging in vivo.

Myopathie der Labrador Retriever: neuromuskuläre Veränderungen bei kranken und klinisch gesunden Hunden

Gegenstand und Ziel: Die erbliche Myopathie der Labrador Retriever (LM) ist eine autosomal rezessive Krankheit, die bei schwarzen und gelben Tieren beiderlei Geschlechts und unterschiedlichen Alters vorkommt. Um der Frage nachzugehen, welche Rolle die LM in der hiesigen Labradorpopulation spielt, wurden seit 1998 am Institut für Neuropathologie der Universität Düsseldorf Muskel-und Nervenbiopsien von 121 Labrador Retrievern untersucht. Hunde: Die Tiere gehörten zu zwei Untersuchungsgruppen. Gruppe I (Einsendungen) umfasste 63 Labrador Retriever unterschiedlicher Herkunft aus Deutschland, Schweiz, Italien und Portugal mit Symptomen einer Myopathie. Gruppe II (Zuchttiere): Im Rahmen einer genetischen Studie wurden 58 miteinander verwandte Labrador Retriever aus einer Zucht in der Schweiz untersucht, nachdem dort bei zwei Welpen LM nachgewiesen worden war. Ergebnisse: Gruppe I: 17/63 (27%) hatten eine degenerative Myopathie vom Typ der Labrador-Myopathie, 8/63 (13%) metabolisch-mitochondriale Veränderungen, 33/63 (52%) andere (überwiegend neurogene oder entzündliche) Myopathien und bei 5/63 (8%) wurden keine pathologischen Veränderungen in Muskel und/oder Nerv nachgewiesen. Gruppe II: Zwar hatten nur sieben Tiere der Zucht klinische Symptome, doch wies die Mehrzahl morphologisch und histochemisch nachweisbare neuromuskuläre Veränderungen auf, nämlich 37/58 (64%) solche vom Typ der LM, darunter auch die Eltern und die sieben Geschwister der beiden Welpen, und 11/58 (19%) vorherrschend metabolisch-mitochondriale Veränderungen. Schlußfolgerungen: Die vorliegende Untersuchung zeigt, dass (a) die Verbreitung der erblichen Myopathie und deren Erfassung ein ernst zu nehmendes Problem beim Labrador Retriever darstellt und (b) neben der »klassischen« erblichen Typ-2-Myopathie der Labrador Retriever möglicherweise noch eine zweite, metabolisch-mitochondriale Form der Myopathie besteht, die Ähnlichkeiten mit einer anstrengungsabhängigen Myopathie bei Labrador Retrievern in den USA aufweist.

Current treatment procedures for civilian gunshot wounds

INTRODUCTION

This work provides an overview of the incidence of gunshot wounds during peace conditions in a civilian population and aims to assess the principles of their treatment.

METHOD

We evaluated a total of 104 patients with gunshot wounds with an average age of 38.7 years (range 1871). 84 men (80.8%) and 20 women (19.2%) were involved. The head was affected 7 times (6.7%). Out of those, penetrating injury occurred only once (1.0%). The throat was hit three times (2.9%). The chest was injured 15 times (14.4%), penetrating injury at this site was observed in 10 cases (9.6%). In five cases the lungs were affected and the heart once. Gastric injury occurred 13 times, penetration into the peritoneal cavity occurred seven times (6.7%). The intestine was injured five times, the liver three times and the gall-bladder once. Limb injury was present in 66 (63.5%) cases and in 19 of those, the injury was associated with a fracture. In 50 cases (48.1%), the patient was attacked by another person. 45 patients (43.3%) injured themselves unintentionally, five patients (4.8%) were injured in a suicidal attempt and four (3.8%) were accidentally shot by someone else. The weapons used were: pistol in 57 (54.8%) cases, air rifle in 20 cases (19.2%), a rifle in 10 cases (9.6%), two patients (1.9%) were injured with a detonator and one (1.0%) with an assault rifle. In 14 cases (13.5%), the type of firearm used was not established.

RESULTS

Surgical treatment was indicated in all cases. The first step was always a thorough wound irrigation. Single surgical treatment was performed in 48 cases (46.2%) while the other 56 patients (53.8%) required multiple surgeries. Specialized surgical procedures were performed in a total of 30 cases: seven laparotomies, five thoracotomies, five fracture stabilizations using external fixator, four amputations of limbs, two intramedullary osteosyntheses, two stabilizations with the use of Kirchner wires, two vascular surgeries, one craniotomy and one suture of a peripheral nerve. Complications of healing were not frequent: wound infection was observed in two cases (1.9%), wound dehiscence in one case (1.0%), osteomyelitis in two cases (1.9%), nonunion of the fracture (1.0 %) occurred once and in one case (1.0%), pulmonary embolism was diagnosed which was not fatal.

CONCLUSION

Consistent debridement, fasciotomy, and complete drainage of the wound are only indicated in deep gunshot wounds. A surgical revision of the abdominal cavity is indicated for all penetrating abdominal gunshot injuries. The watch-and-wait approach with surgical wound management and hospitalization is only allowed for unambiguously non-penetrating abdominal injuries. Complications of gunshot wound healing in civilian settings are not common and are most often infectious. Key words: gunshot wound - civilian settings surgical treatment.

Application fields for the new Object Management Group (OMG) Standards Case Management Model and Notation (CMMN) and Decision Management Notation (DMN) in the perioperative field

PURPOSE

Medical processes can be modeled using different methods and notations. Currently used modeling systems like Business Process Model and Notation (BPMN) are not capable of describing the highly flexible and variable medical processes in sufficient detail.

METHODS

We combined two modeling systems, Business Process Management (BPM) and Adaptive Case Management (ACM), to be able to model non-deterministic medical processes. We used the new Standards Case Management Model and Notation (CMMN) and Decision Management Notation (DMN).

RESULTS

First, we explain how CMMN, DMN and BPMN could be used to model non-deterministic medical processes. We applied this methodology to model 79 cataract operations provided by University Hospital Leipzig, Germany, and four cataract operations provided by University Eye Hospital Tuebingen, Germany. Our model consists of 85 tasks and about 20 decisions in BPMN. We were able to expand the system with more complex situations that might appear during an intervention.

CONCLUSION

An effective modeling of the cataract intervention is possible using the combination of BPM and ACM. The combination gives the possibility to depict complex processes with complex decisions. This combination allows a significant advantage for modeling perioperative processes.

Evidence for a functional role of calsequestrin 2 in mouse atrium

AIM

Several genetically modified mice models were studied so far to investigate the role of cardiac calsequestrin (CSQ2) for the contractile function of the ventricle and for the occurrence of ventricular tachycardia. Using a CSQ2 knockout mouse, we wanted to study also the atrial function of CSQ2.

METHODS

The influence of CSQ2 on atrial function and, for comparison, ventricular function was studied in isolated cardiac preparations and by echocardiography as well as electrocardiography in mice with deletion of CSQ2.

RESULTS

Using deletion of exon 1, we have successfully generated a constitutive knockout mouse of the calsequestrin 2 gene (CSQ2^-/- ). CSQ2 protein was absent in the heart (atrium, ventricle), but also in oesophagus and skeletal muscle of homozygous knockout mice. In 6-month-old CSQ2^-/- mice, relative left atrial weight was increased, whereas relative heart weight was unchanged. The staircase phenomena in paced left atrial preparations on force of contraction and the post-rest potentiation were different between wild type and CSQ2^-/- indicative for a decreased sarcoplasmic Ca²⁺ load and supporting an important role of CSQ2 also in the atrium. The incidence of arrhythmias was increased in CSQ2^-/- . In 2-year-old CSQ2^-/- mice, cardiac hypertrophy and heart failure were noted possibly as a result of chronically increased cytosolic Ca²⁺ levels.

CONCLUSION

These data suggest a functional role of CSQ2 not only in the ventricle but also in the atrium of mammalian hearts. Loss of CSQ2 function can cause not only arrhythmias, but also cardiac hypertrophy and heart failure.

Diverse relations between ABC transporters and lipids: An overview

It was first discovered in 1992 that P-glycoprotein (Pgp, ABCB1), an ATP binding cassette (ABC) transporter, can transport phospholipids such as phosphatidylcholine, -ethanolamine and -serine as well as glucosylceramide and glycosphingolipids. Subsequently, many other ABC transporters were identified to act as lipid transporters. For substrate transport by ABC transporters, typically a classic, alternating access model with an ATP-dependent conformational switch between a high and a low affinity substrate binding site is evoked. Transport of small hydrophilic substrates can easily be imagined this way, as the molecule can in principle enter and exit the transporter in the same orientation. Lipids on the other hand need to undergo a 180° degree turn as they translocate from one membrane leaflet to the other. Lipids and lipidated molecules are highly diverse, so there may be various ways how to achieve their flipping and flopping. Nonetheless, an increase in biophysical, biochemical and structural data is beginning to shed some light on specific aspects of lipid transport by ABC transporters. In addition, there is now abundant evidence that lipids affect ABC transporter conformation, dynamics as well as transport and ATPase activity in general. In this review, we will discuss different ways in which lipids and ABC transporters interact and how lipid translocation may be achieved with a focus on the techniques used to investigate these processes. This article is part of a Special Issue entitled: Lipid order/lipid defects and lipid-control of protein activity edited by Dirk Schneider.

Rapid Identification of the Foodborne Pathogen Trichinella spp. by Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

Human trichinellosis occurs through consumption of raw or inadequately processed meat or meat products containing larvae of the parasitic nematodes of the genus Trichinella. Currently, nine species and three genotypes are recognized, of which T. spiralis, T. britovi and T. pseudospiralis have the highest public health relevance. To date, the differentiation of the larvae to the species and genotype level is based primarily on molecular methods, which can be relatively time consuming and labor intensive. Due to its rapidness and ease of use a matrix assisted laser desorption / ionization time of flight mass spectrometry (MALDI-TOF MS) reference spectra database using Trichinella strains of all known species and genotypes was created. A formicacid/acetonitrile protein extraction was carried out after pooling 10 larvae of each Trichinella species and genotype. Each sample was spotted 9 times using α-cyano 4-hydoxy cinnamic acid matrix and a MicroFlex LT mass spectrometer was used to acquire 3 spectra (m/z 2000 to 20000 Da) from each spot resulting in 27 spectra/species or genotype. Following the spectra quality assessment, Biotyper software was used to create a main spectra library (MSP) representing nine species and three genotypes of Trichinella. The evaluation of the spectra generated by MALDI-TOF MS revealed a classification which was comparable to the results obtained by molecular methods. Also, each Trichinella species utilized in this study was distinct and distinguishable with a high confidence level. Further, different conservation methods such as freezing and conservation in alcohol and the host species origin of the isolated larvae did not have a significant influence on the generated spectra. Therefore, the described MALDI-TOF MS can successfully be implemented for both genus and species level identification and represents a major step forward in the use of this technique in foodborne parasitology.