Prevalence and prognostic impact of dynamic atrial functional mitral regurgitation assessed by isometric handgrip exercise

AIMS

In atrial functional mitral regurgitation (aFMR), a considerable proportion of patients displays a discrepancy between symptoms and echocardiographic findings at rest. Exercise testing plays a substantial role in assessing the haemodynamic relevance of mitral regurgitation (MR) and is recommended by current guidelines. Here, we aimed to assess the prevalence, extent, and prognostic impact of exercise-induced changes in patients with aFMR.

METHODS AND RESULTS

Patients with at least mild MR who underwent handgrip exercise echocardiography at the University Hospital Duesseldorf between January 2019 and September 2021 were enrolled. Patients were followed up for 1 year to assess clinical outcomes. Eighty patients with aFMR were included [median age: 80 (77-83) years; 53.8% female]. The median N-terminal pro-brain natriuretic peptide level was 1756 (1034-3340) ng/L. At rest, half of the patients (53.8%) had mild MR, 20 patients (25.0%) had moderate MR, and 17 patients (21.2%) had severe MR. In approximately every fifth patient (17.5%) with non-severe MR at rest, the MR became severe during exercise. Handgrip exercise led to a reclassification of MR severity in 28 patients (35.0%). At 1-year follow-up, adverse events occurred more often in patients with severe MR at rest (76.5%) and exercise-induced dynamic severe MR (66.7%) than in those with non-severe MR (28.6%; P < 0.001).

CONCLUSION

Handgrip exercise during echocardiography revealed exercise-induced changes in aFMR in every third patient. These data may have implications for therapeutic decision-making in symptomatic patients with non-severe aFMR at rest.

Skin dysbiosis and loss of microbiome site specificity in critically ill patients

An increasing amount of evidence has linked critical illness with dysbiotic microbiome signatures in different body sites. The disturbance of the indigenous microbiota structures has been further associated with disease severity and outcome and has been suggested to pose an additional risk for complications in intensive care units (ICUs), including hospital-acquired infections. A better understanding of the microbial dysbiosis in critical illness might thus help to develop strategies for the prevention of such complications. While most of the studies addressing microbiome changes in ICU patients have focused on the gut, the lung, or the oral cavity, little is known about the microbial communities on the skin of ICU patients. Since the skin is the outermost organ and the first immune barrier against pathogens, its microbiome might play an important role in the risk management for critically ill patients. This observational study characterizes the skin microbiome in ICU patients covering five different body sites at the time of admission. Our results show a profound dysbiosis on the skin of critically ill patients, which is characterized by a loss of site specificity and an overrepresentation of gut bacteria on all skin sites when compared to a healthy group. This study opens a new avenue for further investigations on the effect of skin dysbiosis in the ICU setting and points out the need of strategies for the management of dysbiosis in critically ill patients.IMPORTANCEUnbalanced gut microbiota in critically ill patients has been associated with poor outcome and complications during the intensive care unit (ICU) stay. Whether the disturbance of the microbial communities in these patients is extensive for other body sites, such as the skin, is largely unknown. The skin not only is the largest organ of the body but also serves as the first immune barrier against potential pathogens. This study characterized the skin microbiota on five different body sites in ICU patients at the time of admission. The observed disturbance of the bacterial communities might help to develop new strategies in the risk management of critically ill patients.

Dimerization and Crowding in the Binding of Interleukin 8 to Dendritic Glycosaminoglycans as Artificial Proteoglycans

The interactions of glycosaminoglycans (GAG) with proteins of the extracellular matrix govern and regulate complex physiological functions including cellular growth, immune response, and inflammation. Repetitive presentation of GAG binding motifs, as found in native proteoglycans, might enhance GAG-protein binding through multivalent interactions. Here, we report the chemical synthesis of dendritic GAG oligomers constructed of nonasulfated hyaluronan tetrasaccharides for investigating the binding of the protein chemokine interleukin 8 (IL-8) to artificial, well-defined proteoglycan architectures. Binding of mutant monomeric and native dimerizable IL-8 was investigated by NMR spectroscopy and isothermal titration calorimetry. Dendritic oligomerization of GAG increased the binding affinity of both monomeric and dimeric IL-8. Monomeric IL-8 bound to monomeric and dimeric GAG with KD values of 7.3 and 0.108 μM, respectively. The effect was less pronounced for dimerizable wild-type IL-8, for which GAG dimerization improved the affinity from 34 to 5 nM. Binding of dimeric IL-8 to oligomeric GAG was limited by steric crowding effects, strongly reducing the affinity of subsequent binding events. In conclusion, the strongest effect of GAG oligomerization was the amplified binding of IL-8 monomers, which might concentrate monomeric protein in the extracellular matrix and thus promote protein dimerization under physiological conditions.

Genotyping of European Toxoplasma gondii strains by a new high-resolution next-generation sequencing-based method

PURPOSE

A new high-resolution next-generation sequencing (NGS)-based method was established to type closely related European type II Toxoplasma gondii strains.

METHODS

T. gondii field isolates were collected from different parts of Europe and assessed by whole genome sequencing (WGS). In comparison to ME49 (a type II reference strain), highly polymorphic regions (HPRs) were identified, showing a considerable number of single nucleotide polymorphisms (SNPs). After confirmation by Sanger sequencing, 18 HPRs were used to design a primer panel for multiplex PCR to establish a multilocus Ion AmpliSeq typing method. Toxoplasma gondii isolates and T. gondii present in clinical samples were typed with the new method. The sensitivity of the method was tested with serially diluted reference DNA samples.

RESULTS

Among type II specimens, the method could differentiate the same number of haplotypes as the reference standard, microsatellite (MS) typing. Passages of the same isolates and specimens originating from abortion outbreaks were identified as identical. In addition, seven different genotypes, two atypical and two recombinant specimens were clearly distinguished from each other by the method. Furthermore, almost all SNPs detected by the Ion AmpliSeq method corresponded to those expected based on WGS. By testing serially diluted DNA samples, the method exhibited a similar analytical sensitivity as MS typing.

CONCLUSION

The new method can distinguish different T. gondii genotypes and detect intra-genotype variability among European type II T. gondii strains. Furthermore, with WGS data additional target regions can be added to the method to potentially increase typing resolution.

Quality parameters for the medicinal plant Drosera rotundifolia L.: A new approach with established techniques

Monographs of the European Pharmacopoeia (Ph. Eur.) are the basis for quality control of medicinal plants and therefore important to ensure the consistency, quality, safety, and efficacy of phytopharmaceuticals. The traditional medicinal plant sundew (Drosera sp.) has disappeared from therapy due to nature conservation, but can now be cultivated sustainably on rewetted peatland. However, currently there is no valid Ph. Eur. monograph for the quality control of Droserae herba. In this study, sundew material from different species and sources was investigated with the aim of developing quality control methods based on the Ph. Eur. and defining a uniform quality standard for Droserae herba. It was possible to distinguish between sundew species of different quality, using macroscopic, microscopic, and chromatographic methods. Special emphasis was laid on the content of flavonoids and naphthoquinones as important quality parameters as their content differed between the sundew species. The differences in content and toxicity result in the recommendation that only round-leaved sundew (Drosera rotundifolia L.) should be used as a medicinal plant for the production of phytopharmaceuticals in the future.

Invasive electrical stimulation in the treatment of avascular osteonecrosis of the femoral head - mid-term results

The study aimed to evaluate the outcomes of osteonecrosis of the femoral head (ONFH) in adults after surgical treatment including invasive electromagnetic osteostimulation (E-Stim). Further, the influence of disease stage and several comorbidities on the joint preservation rate should be examined. Sixty patients (66 hip joints) with ONFH were included in this retrospective cross-sectional analysis (mean follow-up: 58 months, 19-110 months). Potential ONFH risk factors and comorbidities (ONFH stage, age, sex, alcohol, smoking, cortisone medication, chemotherapy) were recorded. The influence of specific parameters on the joint preservation rates was evaluated by a multivariate logistic regression analysis. Finally, patients with preserved hip joints underwent an assessment of their last available X-rays. The joint preservation rate depended on the initial ONFH Steinberg stage (I+II: 82.8%, III: 70.8%, ≥ IVa: 38.5%). Initially collapsed ONFH (p ≤ 0.001) and cortisone therapy (p = 0.004) significantly decreased the joint preservation rates. In case of progressed ONFH, the presence of ≥ 2 risk factors resulted in higher THA conversion rates (stage III: OR 18.8; stage ≥IVa: OR 12). In 94% of the available X-rays, the ONFH stage improved or did not progress. No complications could be attributed to the E-Stim device or procedure. The present surgical protocol including minimally invasive E-Stim revealed high joint preservation rates for non-collapsed ONFH after mid-term postoperative follow-up. Especially in progressed ONFH, the-risk profile seems to be crucial and hence, for joint preserving surgery, careful patient selection is recommended.

Do hip resurfacing and short hip stem arthroplasties differ from conventional hip stem replacement regarding impingement-free range of motion?

Total hip joint replacement (THR) is clinically well-established. In this context, the resulting range of motion (ROM) is crucial for patient satisfaction when performing joint movements. However, the ROM for THR with different bone preserving strategies (short hip stem and hip resurfacing) raises the question of whether the ROM is comparable with conventional hip stems. Therefore, this computer-based study aimed to investigate the ROM and type of impingement for different implant systems. An established framework with computer-aided design 3D models based on magnetic resonance imaging data of 19 patients with hip osteoarthritis was used to analyse the ROM for three different implant systems (conventional hip stem vs. short hip stem vs. hip resurfacing) during typical joint movements. Our results revealed that all three designs led to mean maximum flexion higher than 110°. However, hip resurfacing showed less ROM (-5% against conventional and -6% against short hip stem). No significant differences were observed between the conventional and short hip stem during maximum flexion and internal rotation. Contrarily, a significant difference was detected between the conventional hip stem and hip resurfacing during internal rotation (p = 0.003). The ROM of the hip resurfacing was lower than the conventional and short hip stem during all three movements. Furthermore, hip resurfacing shifted the impingement type to implant-to-bone impingement compared with the other implant designs. The calculated ROMs of the implant systems achieved physiological levels during maximum flexion and internal rotation. However, bone impingement was more likely during internal rotation with increasing bone preservation. Despite the larger head diameter of hip resurfacing, the ROM examined was substantially lower than that of conventional and short hip stem.

Ligand binding of interleukin-8: a comparison of glycosaminoglycans and acidic peptides

Recognition and binding of regulatory proteins to glycosaminoglycans (GAGs) from the extracellular matrix is a process of high biological importance. The interaction between negatively charged sulfate or carboxyl groups of the GAGs and clusters of basic amino acids on the protein is crucial in this binding process and it is believed that electrostatics represent the key factor for this interaction. However, given the rather undirected nature of electrostatics, it is important to achieve a clear understanding of its role in protein-GAG interactions and how specificity and selectivity in these systems can be achieved, when the classical key-lock binding motif is not applicable. Here, we compare protein binding of a highly charged heparin (HP) hexasaccharide with four de novo designed decapeptides of varying negative net charge. The charge density of these peptides was comparable to typical GAGs of the extracellular matrix. We used the regulatory protein interleukin-8 (IL-8) because its interactions with GAGs are well described. All four peptide ligands bind to the same epitope of IL-8 but show much weaker binding affinity as revealed in 1H-15N HSQC NMR titration experiments. Complementary molecular docking and molecular dynamics simulations revealed further atomistic details of the interaction mode of GAG versus peptide ligands. Overall, similar contributions to the binding energy and hydrogen bond formation are determined for HP and the highly charged peptides, suggesting that the entropic loss of the peptides upon binding likely account for the remarkably different affinity of GAG versus peptide ligands to IL-8.

Chaperone-mediated autophagy in neuronal dendrites utilizes activity-dependent lysosomal exocytosis for protein disposal

The complex morphology of neurons poses a challenge for proteostasis because the majority of lysosomal degradation machinery is present in the cell soma. In recent years, however, mature lysosomes were identified in dendrites, and a fraction of those appear to fuse with the plasma membrane and release their content to the extracellular space. Here, we report that dendritic lysosomes are heterogeneous in their composition and that only those containing lysosome-associated membrane protein (LAMP) 2A and 2B fuse with the membrane and exhibit activity-dependent motility. Exocytotic lysosomes dock in close proximity to GluN2B-containing N-methyl-D-aspartate-receptors (NMDAR) via an association of LAMP2B to the membrane-associated guanylate kinase family member SAP102/Dlg3. NMDAR-activation decreases lysosome motility and promotes membrane fusion. We find that chaperone-mediated autophagy is a supplier of content that is released to the extracellular space via lysosome exocytosis. This mechanism enables local disposal of aggregation-prone proteins like TDP-43 and huntingtin.

A Hybrid AI-Based Method for ICD Classification of Medical Documents

Automatic document classification is a common problem that has successfully been addressed with machine learning methods. However, these methods require extensive training data, which is not always readily available. Additionally, in privacy-sensitive settings, transfer and reuse of trained machine learning models is not an option because sensitive information could potentially be reconstructed from the model. Therefore, we propose a transfer learning method that uses ontologies to normalize the feature space of text classifiers to create a controlled vocabulary. This ensures that the trained models do not contain personal data, and can be widely reused without violating the GDPR. Furthermore, the ontologies can be enriched so that the classifiers can be transferred to contexts with different terminology without additional training. Applying classifiers trained on medical documents to medical texts written in colloquial language shows promising results and highlights the potential of the approach. The compliance with GDPR by design opens many further application domains for transfer learning based solutions.

Crystalline sirolimus-coated balloon (cSCB) angioplasty in an all-comers, patient population with stable and unstable coronary artery disease including chronic total occlusions: rationale, methodology and design of the SCORE trial

BACKGROUND

A decade ago, the iopromide-paclitaxel coated balloon (iPCB) was added to the cardiologist's toolbox to initially treat in-stent restenosis followed by the treatment of de novo coronary lesions. In the meantime, DES technologies have been substantially improved to address in-stent restenosis and thrombosis, and shortened anti-platelet therapy. Recently, sirolimus-coated balloon catheters (SCB) have emerged to provide an alternative drug to combat restenosis.

METHODS

The objective of this study is to determine the safety and efficacy of a novel crystalline sirolimus-coated balloon (cSCB) technology in an unselective, international, large-scale patient population. Percutaneous coronary interventions of native stenosis, in-stent stenosis, and chronic total occlusions with the SCB in patients with stable coronary artery disease or acute coronary syndrome were included. The primary outcome variable is the target lesion failure (TLF) rate at 12 months, defined as the composite rate of target vessel myocardial infarction (TV-MI), cardiac death or ischemia-driven target lesion revascularization (TLR). The secondary outcome variables include TLF at 24 months, ischemia driven TLR at 12 and 24 months and all-cause death, cardiac death at 12 and 24 months.

DISCUSSION

Since there is a wealth of patient-based all-comers data for iPCB available for this study, a propensity-score matched analysis is planned to compare cSCB and iPCB for the treatment of de novo and different types of ISR. In addition, pre-specified analyses in challenging lesion subsets such as chronic total occlusions will provide evidence whether the two balloon coating technologies differ in their clinical benefit for the patient.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier: NCT04470934.

Metal-coated concave cone in a fused-silica rod as a multi-function plasmonic element

A collimated light beam parallel to the axis of a fused-quartz cylinder impinging on a 90° apex angle concave cone cut in a quartz rod is transformed into a cylindrical wave by total internal reflection. A thin metal film at the quartz-air interface enables excitation of the plasmon mode at the air side that can polarize the cylindrical wave and/or has the potential to monitor physical, chemical, or biological quantities or events at the inner wall of the cone. The present Letter first analyzes the plasmon coupling mechanism and conditions. It then describes the diamond-grinding technique achieving a smooth cone wall and the finest possible tip. The experimental evidence of the polarization conversion is brought on a diamond-grinded section of fused-silica rod and gold coating of the concave wall.

Subintimal shift as mechanism for side-branch occlusion in percutaneous treatment of chronic total occlusions with bifurcation lesions

BACKGROUND

The aim of this study was to describe the mechanism of subintimal shift (SIS), standardise diagnostic criteria and sensitise the interventional community to this phenomenon. The treatment of chronic total occlusions (CTO) by means of percutaneous coronary intervention (PCI) is complicated by bifurcation lesions involved in the CTO segment or adjacent to it. Extraplaque expansion of intracoronary devices during CTO PCI may extend the dissection plane over the bifurcation with the consequential side or main branch compression by an intimo-medial flap. This phenomenon is hereby described for the first time and named subintimal shift.

METHODS

Experienced CTO operators from 3 international high volume centers for CTO PCI retrospectively searched their personal records for paradigmatic cases of SIS, summarising key features and proposing diagnostic criteria.

RESULTS

The series comprised 7 demonstrative cases, illustrating SIS by intravascular imaging (2 cases) or indirect angiographic signs during CTO PCI (5 cases). Five cases were triggered by stent expansion, 1 by balloon inflation and 1 case was aborted after angiographic warning signs. In 4 cases, SIS resulted in total occlusion of a branch, refractory to ballooning whenever attempted. Four cases required bailout intervention and in 2 cases the branch was left occluded, resulting in a rise of cardiac markers.

CONCLUSIONS

Subintimal shift is a noteworthy complication in CTO bifurcations, potentially resulting in occlusion of the relevant side or even the main branch. Intracoronary imaging prior to stenting is recommended to understand the tissue planes. Some counterintuitive peculiarities of this phenomenon, like its refractoriness to ballooning, must be known by CTO operators for its efficient resolution.

Hemodynamic markers of pulmonary vasculopathy for prediction of early right heart failure and mortality after heart transplantation

BACKGROUND

Elevated pulmonary vascular resistance (PVR) is broadly accepted as an imminent risk factor for mortality after heart transplantation (HTx). However, no current HTx recipient risk score includes PVR or other hemodynamic parameters. This study examined the utility of various hemodynamic parameters for risk stratification in a contemporary HTx population.

METHODS

Patients from seven German HTx centers undergoing HTx between 2011 and 2015 were included retrospectively. Established risk factors and complete hemodynamic datasets before HTx were analyzed. Outcome measures were overall all-cause mortality, 12-month mortality, and right heart failure (RHF) after HTx.

RESULTS

The final analysis included 333 patients (28% female) with a median age of 54 (IQR 46-60) years. The median mean pulmonary artery pressure was 30 (IQR 23-38) mm Hg, transpulmonary gradient 8 (IQR 5-10) mm Hg, and PVR 2.1 (IQR 1.5-2.9) Wood units. Overall mortality was 35.7%, 12-month mortality was 23.7%, and the incidence of early RHF was 22.8%, which was significantly associated with overall mortality (log-rank HR 4.11, 95% CI 2.47-6.84; log-rank p < .0001). Pulmonary arterial elastance (Ea) was associated with overall mortality (HR 1.74, 95% CI 1.25-2.30; p < .001) independent of other non-hemodynamic risk factors. Ea values below a calculated cutoff represented a significantly reduced mortality risk (HR 0.38, 95% CI 0.19-0.76; p < .0001). PVR with the established cutoff of 3.0 WU was not significant. Ea was also significantly associated with 12-month mortality and RHF.

CONCLUSIONS

Ea showed a strong impact on post-transplant mortality and RHF and should become part of the routine hemodynamic evaluation in HTx candidates.

Metabolomic Profiling in Patients with Heart Failure and Exercise Intolerance: Kynurenine as a Potential Biomarker

Aims: Metabolic and structural perturbations in skeletal muscle have been found in patients with heart failure (HF) both with preserved (HFpEF) and reduced (HFrEF) ejection fraction in association with reduced muscle endurance (RME). We aimed in the current study to create phenotypes for patients with RME and HFpEF compared to RME HFrEF according to their metabolomic profiles and to test the potential of Kynurenine (Kyn) as a marker for RME. Methods: Altogether, 18 HFrEF, 17 HFpEF, and 20 healthy controls (HC) were prospectively included in the current study. The following tests were performed on all participants: isokinetic muscle function tests, echocardiography, spiroergometry, and varied blood tests. Liquid chromatography tandem mass spectrometry was used to quantify metabolites in serum. Results: Except for aromatic and branched amino acids (AA), patients with HF showed reduced AAs compared to HC. Further perturbations were elevated concentrations of Kyn and acylcarnitines (ACs) in HFpEF and HFrEF patients (p < 0.05). While patients with HFpEF and RME presented with reduced concentrations of ACs (long- and medium-chains), those with HFrEF and RME had distorted AAs metabolism (p < 0.05). With an area under the curve (AUC) of 0.83, Kyn shows potential as a marker in HF and RME (specificity 70%, sensitivity 83%). In a multiple regression model consisting of short-chain-ACs, spermine, ornithine, glutamate, and Kyn, the latest was an independent predictor for RME (95% CI: −13.01, −3.30, B: −8.2 per 1 µM increase, p = 0.001). Conclusions: RME in patients with HFpEF vs. HFrEF proved to have different metabolomic profiles suggesting varied pathophysiology. Kyn might be a promising biomarker for patients with HF and RME.

Evaluating Tannins and Flavonoids from Traditionally Used Medicinal Plants with Biofilm Inhibitory Effects against MRGN E. coli

In the search for alternative treatment options for infections with multi-resistant germs, traditionally used medicinal plants are currently being examined more intensively. In this study, the antimicrobial and anti-biofilm activities of 14 herbal drugs were investigated. Nine of the tested drugs were traditionally used in Europe for treatment of local infections. For comparison, another five drugs monographed in the European Pharmacopoeia were used. Additionally, the total tannin and flavonoid contents of all tested drugs were analyzed. HPLC fingerprints were recorded to obtain further insights into the components of the extracts. The aim of the study was to identify herbal drugs that might be useable for treatment of infectious diseases, even with multidrug resistant E. coli, and to correlate the antimicrobial activity with the total content of tannins and flavonoids. The agar diffusion test and anti-biofilm assay were used to evaluate the antimicrobial potential of different extracts from the plants. Colorimetric methods (from European Pharmacopeia) were used for determination of total tannins and flavonoids. The direct antimicrobial activity of most of the tested extracts was low to moderate. The anti-biofilm activity was found to be down to 10 µg mL−1 for some extracts. Tannin contents between 2.2% and 10.4% of dry weight and total flavonoid contents between 0.1% and 1.6% were found. Correlation analysis indicates that the antimicrobial and the anti-biofilm activity is significantly (p < 0.05) dependent on tannin content, but not on flavonoid content. The data analysis revealed that tannin-rich herbal drugs inhibit pathogens in different ways. Thus, some of the tested herbal drugs might be useable for local infections with multi-resistant biofilm-forming pathogens. For some of the tested drugs, this is the first report about anti-biofilm activity, as well as total tannin and flavonoid content.

Investigations on the production of optical freeforms applying the advanced wheel polishing process

The growing interest in providing additional degrees of freedom to the design of high-end optical systems has led to an increased demand for freeform optical elements. The efficient fabrication of such elements requires a polishing process that provides high removal rates and a stable removal function while working with a relatively small spot size. Taking these constraints into consideration this paper focuses on the successful implementation of polishing processes applying the A-WPT (Advanced Wheel Polishing Tool) technology. Addressing the requirements regarding its removal characteristics as mentioned before, it represents an appropriate choice for providing an efficient pre-polishing as well as corrective polishing technique. In order to maintain perpendicularity towards the freeform surface to be polished, the A-WPT is run on a 5-axis simultaneous machining system. First investigations of the achieved surface accuracy after pre-polishing were carried out as well as an assessment of residual surface features within different spatial frequency regions. In addition, the polished surface is being checked for remaining SSD using an OCT technique.

Investigations on a novel process chain for manufacturing of freeform surfaces

Freeform optical surfaces have become increasingly important in recent years, as they can be used to construct optical assemblies with a reduced number of optical surfaces compared to systems without freeform surfaces, and thus optical systems can get more compact and lighter. However, the flexible and efficient production of precise optical freeform surfaces poses a major problem. This manifests itself in insufficient precision of the optics, long delivery times and high prices. It is shown, that ultrasonic grinding processes, combined with an ultra-fine grinding process and subsequent plasma jet polishing, are very well suited for the production of freeform optics and have a high technical and economic potential. Therefore, the aim is to validate an industrially suitable process chain based on this combination, in order to produce freeform optics of high accuracy (shape deviations <100 nm RMS) that can be manufactured in significantly fewer steps than before.

Influence of X-rays and gamma-rays on the mechanical performance of human bone factoring out intraindividual bone structure and composition indices

Doses of irradiation above 25 ​kGy are known to cause irreversible mechanical decay in bone tissue. However, the impact of irradiation doses absorbed in a clinical setting on the mechanical properties of bone remains unclear. In daily clinical practice and research, patients and specimens are exposed to irradiation due to diagnostic imaging tools, with doses ranging from milligray to Gray. The aim of this study was to investigate the influence of irradiation at these doses ranges on the mechanical performance of bone independent of inter-individual bone quality indices.

Therefore, cortical bone specimens (n ​= ​10 per group) from a selected organ donor were irradiated at doses of milligray, Gray and kilogray (graft tissue sterilization) at five different irradiation doses. Three-point bending was performed to assess mechanical properties in the study groups.

Our results show a severe reduction in mechanical performance (work to fracture: 50.29 ​± ​11.49 Nmm in control, 14.73 ​± ​1.84 Nmm at 31.2 ​kGy p ​≤ ​0.05) at high irradiation doses of 31.2 ​kGy, which correspond to graft tissue sterilization or synchrotron imaging. In contrast, no reduction in mechanical properties were detected for doses below 30 ​Gy. These findings are further supported by fracture surface texture imaging (i.e. more brittle fracture textures above 31.2 ​kGy).

Our findings show that high radiation doses (≥31.2 ​kGy) severely alter the mechanical properties of bone. Thus, irradiation of this order of magnitude should be taken into account when mechanical analyses are planned after irradiation. However, doses of 30 ​Gy and below, which are common for clinical and experimental imaging (e.g., radiation therapy, DVT imaging, CT imaging, HR-pQCT imaging, DXA measurements, etc.), do not alter the mechanical bending-behavior of bone.

Inhibition of ceramide synthesis improves the outcome in ischemia/reperfusion injury using human-induced pluripotent stem cell derived cardiomyocyte

Introduction and aim

Ceramides are proven to be biologically active in apoptosis, inflammation, mitochondrial dysfunction, and as a second messenger in various signaling pathways1. However, the data linking the role of ceramides in ischemia/reperfusion injury (I/R injury) are lacking. We aimed to establish an I/R injury model using human-induced pluripotent stem cell (hiPSC)-derived cardiomyocyte (CM) and to evaluate ceramide levels, ceramide synthesis pathway, and outcome of CM with inhibition of ceramide synthesis during I/R injury.

Methods

HiPSC technology has been used to generate functional human CMs to elucidate the underlying mechanisms of the pathophysiology of the human heart.

Results

In our model, we observed an increase of mRNA levels of genes regulating ceramide synthesis after 6 h of ischemia followed by 16 h reperfusion, such as SPTLC1 (1.1±0.08 vs 1.0, p=0.2), CerS2 (1.6±0.3 vs 1.0, p&lt;0.001), CerS4 (1.3±0.1 vs 1.0, p=0.02), CerS5 (1.3±0.1 vs 1.0, p=0.03), and SMPD (1.6±0.1 vs 1.0, p=0.008) compared to control. Also, both long- and very long-chain ceramide species levels measured with mass spectrometry were increased significantly after 6 h ischemia followed by 16 h reperfusion compared to control (C14:0: 1,1±0.3 pmol/million cells vs 0,3±0,2 pmol/ million cells, p=0.02 and C24:1: 26,3±7,1 pmol/ million cells vs 9,6±3,4 pmol/ million cells, p=0.02).

Inhibition of ceramide synthesis with Fumonisin B1 (FB1) significantly increased the viability after 6h of ischemia followed by 16 h of reperfusion compared to CMs incubated without inhibitors (32.2%±1.5% vs 26.9%±2.6%, p=0.04). Interestingly, we identified two mechanisms with which the viability improves after incubation with ceramide inhibitor. The first mechanism observed could be the restoration of both intracellular calcium baseline (control 29±1.2, I/R 55±5.7 and I/R with FB1 35.6±2.5, p&lt;0,001) and peak (control 45.1±5.6, I/R 94.3±5.7 and I/R with FB1 56.5±7.5, p&lt;0,001) levels to nearly the same levels as observed in control samples. A possible cause of increased calcium oscillations after 6 h of ischemia followed by 3 h of reperfusion in the first place could be an upregulation of the RyR2 levels detected by qPCR (2.5±0.4 vs control 1.0, p=0.008). The second mechanism of improving viability in I/R injury could be a decrease of generation of reactive oxygen species (ROS) detected by MitoSOX dye after incubation with FB1 inhibitor to nearly the same levels as observed in control (control 22±5.1, I/R 33.8±5.8 and I/R with FB1 30.7±5.9, p=0,06).

Conclusion

We conclude that ceramides have important implications in either mediating or causing injury and their inhibition improves the outcome of I/R injury by decreasing ROS generation and improving calcium oscillations.

Funding Acknowledgement

Type of funding sources: Public hospital(s). Main funding source(s): Jena University Hospital, Clinic for Internal Medicine 1Interdisciplinary Center for Clinical Research Jena

Remote monitoring of cardiac implanted electronic devices: legal requirements and ethical principles - ESC Regulatory Affairs Committee/EHRA joint task force report

The European Union (EU) General Data Protection Regulation (GDPR) imposes legal responsibilities concerning the collection and processing of personal information from individuals who live in the EU. It has particular implications for the remote monitoring of cardiac implantable electronic devices (CIEDs). This report from a joint Task Force of the European Heart Rhythm Association and the Regulatory Affairs Committee of the European Society of Cardiology (ESC) recommends a common legal interpretation of the GDPR. Manufacturers and hospitals should be designated as joint controllers of the data collected by remote monitoring (depending upon the system architecture) and they should have a mutual contract in place that defines their respective roles; a generic template is proposed. Alternatively, they may be two independent controllers. Self-employed cardiologists also are data controllers. Third-party providers of monitoring platforms may act as data processors. Manufacturers should always collect and process the minimum amount of identifiable data necessary, and wherever feasible have access only to pseudonymized data. Cybersecurity vulnerabilities have been reported concerning the security of transmission of data between a patient's device and the transceiver, so manufacturers should use secure communication protocols. Patients need to be informed how their remotely monitored data will be handled and used, and their informed consent should be sought before their device is implanted. Review of consent forms in current use revealed great variability in length and content, and sometimes very technical language; therefore, a standard information sheet and generic consent form are proposed. Cardiologists who care for patients with CIEDs that are remotely monitored should be aware of these issues.

Ethiopian Medicinal Plants Traditionally Used for the Treatment of Cancer; Part 3: Selective Cytotoxic Activity of 22 Plants against Human Cancer Cell Lines

Medicinal plants have been traditionally used to treat cancer in Ethiopia. However, very few studies have reported the in vitro anticancer activities of medicinal plants that are collected from different agro-ecological zones of Ethiopia. Hence, the main aim of this study was to screen the cytotoxic activities of 80% methanol extracts of 22 plants against human peripheral blood mononuclear cells (PBMCs), as well as human breast (MCF-7), lung (A427), bladder (RT-4), and cervical (SiSo) cancer cell lines. Active extracts were further screened against human large cell lung carcinoma (LCLC-103H), pancreatic cancer (DAN-G), ovarian cancer (A2780), and squamous cell carcinoma of the esophagus (KYSE-70) by using the crystal violet cell proliferation assay, while the vitality of the acute myeloid leukemia (HL-60) and histiocytic lymphoma (U-937) cell lines was monitored in the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) microtiter assay. Euphorbia schimperiana, Acokanthera schimperi, Kniphofia foliosa, and Kalanchoe petitiana exhibited potent antiproliferative activity against A427, RT-4, MCF-7, and SiSo cell lines, with IC₅₀ values ranging from 1.85 ± 0.44 to 17.8 ± 2.31 µg/mL. Furthermore, these four extracts also showed potent antiproliferative activities against LCLC-103H, DAN-G, A2780, KYSE-70, HL-60, and U-937 cell lines, with IC₅₀ values ranging from 0.086 to 27.06 ± 10.8 µg/mL. Hence, further studies focusing on bio-assay-guided isolation and structural elucidation of active cytotoxic compounds from these plants are warranted.

Establishment of a quantification method for β-glucans and their immune activity potential for quality control of β-glucan containing products

Beta glucans are complex glucose polymers well known for their immune modulatory properties. Therefore they are used and advertised in dietary supplements. Unfortunately there is no standardized test system for quality control of such health-related foods. This approach combined wet chemical and enzyme-based quantification methods (e.g. aniline blue, Glucatell®) with a cytokine secretion assay as parameter for immune activation to resolve this problem and to establish a quality control system for β-glucan containing products and extracts. Commercially available pure β-glucans with different origin and structure were used in this study. None of the methods allowed an accurate β-glucan quantification. Most promising was the test kit K-EBHLG (Megazyme). However, cytokine secretion from whole blood was detectable under the influence of β-glucans, but there was no correlation with the quantification results using the commercially available kits. Therefore, the quality control of β-glucan containing products needs further efforts.

Primary stability of a cementless modular revision hip stem in relation with the femoral defect size: A biomechanical study

PURPOSE

Cementless modular fluted hip stems are commonly used in revision arthroplasty. Nevertheless, there is a wide spectrum of recommendations concerning the minimum bone stock required to enable osseous ingrowth and implant-bone micromotions <100 µm. This experimental study investigated the primary stability of a tapered cementless fluted revision stem depending on different types of bone defects.

METHODS

Implant-bone interface movements with a bimodular stem were examined under cyclic axial and torsional loading using composite femora. In four degrees of freedom, the implant subsidence and micromotions were captured with linear variable differential transformers for the intact femora and seven different defects ranging from Paprosky type I to type IIIB.

RESULTS

With a 7-cm length of intact diaphysis proximal to the isthmus (Paprosky IIIA), mean implant-bone micromotions of 66 µm occurred. An implant-bone contact zone of only 5 cm (Paprosky IIIA) resulted in micromotions notably over 100 µm and significantly increased subsidence (p < 0.05). With a Paprosky IIIB defect (3 cm of intact diaphysis) rotational instability occurred in all specimens.

CONCLUSIONS

Aside from critically increased interfacial micromotions (>100 µm), rotational instability emerged as a mechanism of fixation failure when the implant-bone contact zone was only 5 cm or less. Hence, future studies investigating the implant fixation in the case of femoral bone defects should consider both axial and torsional loading. With regard to the clinical application, our data suggest maintaining 7 cm of diaphyseal implant-bone contact for a safe anchorage of cementless fluted hip revision stems.

No impact of weather conditions on the outcome of intensive care unit patients

Global warming leads to increased exposure of humankind to meteorological variation, including short-term weather changes. Weather conditions involve changes in temperature, heat and cold, in air pressure and in air humidity. Every single condition influences the incidence and mortality of different diseases such as myocardial infarction and stroke. This study investigated the impact of weather conditions on short- and long-term mortality of 4321 critically ill patients (66 ± 14 years, 2638 men) admitted to an intensive care unit (ICU) over a period of 5 years. Meteorological information (air temperature, air pressure and humidity) for the same period was retrieved. The influence of absolute weather parameters, different seasons, sudden weather changes including "warm" and "cold" spells on ICU and long-term mortality was analyzed. After correction for Simplified Acute Physiology Score (SAPS-2), no impact of meteorological conditions on mortality was found. Different seasons, sudden weather changes, "warm spells" or "cold spells" did not affect the outcome of critically ill patients.

The role of microglia membrane potential in chemotaxis

Microglia react to danger signals by rapid and targeted extension of cellular processes towards the source of the signal. This positive chemotactic response is accompanied by a hyperpolarization of the microglia membrane. Here, we show that optogenetic depolarization of microglia has little effect on baseline motility, but significantly slows down the chemotactic response. Reducing the extracellular Ca2+ concentration mimics the effect of optogenetic depolarization. As the membrane potential sets the driving force for Ca2+ entry, hyperpolarization is an integral part of rapid stimulus-response coupling in microglia. Compared to typical excitable cells such as neurons, the sign of the activating response is inverted in microglia, leading to inhibition by depolarizing channelrhodopsins.

Experimental results from face and lateral fine grinding of fused silica and BK7 using metal and resin bonded tools

The experimental setup shall compare face grinding with lateral grinding in a single processing step using fused silica and BK7 as materials. Resin and metal bonded tools are used in face and lateral grinding strategies. The paper presents the results in order to deepen the knowledge about those grinding technologies and to further improve the properties of fabricated components. Furthermore, the results confirm, that ultra-fine grinding is a technology, which can be used to process inorganic non-metallic materials with high quality surfaces with a low roughness and high flatness in a low processing time.

Micromotion and subsidence of a cementless conical fluted stem depending on femoral defect size - A human cadaveric study

BACKGROUND

Cementless modular endoprostheses with tapered fluted stems cover a wide spectrum of femoral defects in reconstructive surgery of the hip. Nevertheless, for these hip stems the recommendations concerning the minimum diaphyseal anchorage distance differ widely. The present experimental study investigated the primary stability of a conical fluted revision stem depending on different types of femoral bone defects.

METHODS

Using six fresh frozen human femora, the relative movement of a bi-modular revision stem within the implant-bone interface was examined under cyclic loading conditions. Implant subsidence as well as micromotions at the bone-implant interface were captured with linear variable differential transformers for the intact femora and three different defects ranging from Paprosky type II to type IIIB.

FINDINGS

Compared to the intact femur, the infliction of a Paprosky type IIIB defect (3 cm of intact diaphysis) notably increased mean stem subsidence (13-389 μm per 500 load cycles; P = 0.116) but the mean interface micromotion vector sum remained unchanged (50 μm vs. 53 μm). In Paprosky IIIB defects the subsidence component resulting from rotation (horizontal plane) was significantly higher than with the intact femur and a Paprosky II defect (P ≤ 0.041).

INTERPRETATION

With optimal bone quality and ideal femur preparation a 3 cm conical fixation was sufficient to meet the set criteria of bony ingrowth in vitro. A conical fixation of 7 cm should be recommended to limit rotational subsidence, especially in case of impaired diaphyseal bone quality or expected difficulties with partial weight-bearing.

A novel echocardiographic-derived classification after LAA closure can accurately predict incomplete ostial closure and significant peri-device leaks

Background

The assessment of residual peri-device leaks (PDL) after percutaneous left atrial appendage closure (LAAC) remains crucial in the post-procedural management. Clinical significance of PDL is still poorly understood and echocardiographic recognition of PDL remains challenging. This study aimed to verify a novel proposed echocardiographic classification for prediction of clinically significant PDL following LAAC.

Methods

We retrospectively evaluated our echocardiographic data of 72 patients who underwent percutaneous LAAC at the University Hospital Jena between September 2015 - 2018. All echo images were transferred to a workstation for offline analysis by two independent investigators. Total number of studies was 127. We proposed a morphological classification of LAA devices (Fig. 1A-C) based on the amount of echodensity and luceny inside the devices into three types: type A: homogenous echodensity in 0, 45, 90 and 135°; indicating completely thrombosed device, type B with inhomogeneous echo-lucencies (&lt;50% of device) and type C: partially thrombosed device with echo-lucencies &gt;50% of total, which we labeled “ice-cream cone” sign. Each type was then matched to the degree of PDL and other clinical and paraclinical parameters.

Results

Tab.1 shows patient's characteristics. PDL was found in 21% of patients. Four patients showed regression of PDL after 160 days. Patients with type C had the most percentage of PDL in three types at 6 months follow-up (type A: 7%, type B: 33%, type C 100%, p&lt;0.001). Device size in patients with type C was largest in three types (type A: 25.9±3.6mm, type B: 25.8±3.4mm, type C 29.8±3.0mm, type A vs. B, p=0.018; type B vs. C, p=0.007). Mean compression rate after 45 days was 21±9.3% in type A vs. 14±7.4% in type C (p=0.022). Ice cream sign showed a sensitivity of 53.1%, specificity of 100% and positive predictive value of 100% for prediction of PDL.

Conclusion

Our data demonstrate that: 1) This novel classification irrespective of anticoagulation regimen, can accurately discriminate among various degrees of PDL, in such that type C or “ice cream sign” has a very high positive predictive value for PDL (100%). 2) Type A, the ideal type, is associated with smaller landing zones and a higher compression rate.

Funding Acknowledgement

Type of funding source: None

Relevant correlation of Galectin-3 with a novel morphological classification system for LAA closure – the end of echocardiographic follow up after occluder implantation?

Introduction

Echocardiographic detection of residual peri-device leakage (PDL) after percutaneous left atrial appendage closure (LAAC) remains crucial. Significance of PDL and cardiac tissue remodeling after LAAC are still poorly understood but might have diagnostic implications. This study aims to characterize and verify if a novel echocardiographic classification system to asses the success of LAAC in combination with quantifiable biomarkers of cardiovascular tissue remodeling can help in the prediction of PDL.

Methods

Patients eligible for LAAC were included. Serum levels of the cardiac remodeling marker Galectin-3 were determined before device implantation (baseline), 45 days (45d) and 6 months (6M) after LAAC using ELISAs. Transesophageal echocardiography (TEE) was carried out to assess success of the LAAC procedure. All echo images were retrospectively evaluated by two independent investigators. Based on the amount of echodensity and luceny inside the devices after LAAC, three types can be distinguished that grade the degree of closure of the LAA. Type A has complete homogenous echodensity in 0, 45, 90 and 135°, indicating completely thrombosed device. Type B shows inhomogeneous echo-lucencies (&lt;50% of device). Type C describes a partially thrombosed device with echo-lucencies &gt;50%. Novel classification according to Hamadanchi, Jena, Germany (Fig. 1).

Results

We included 44 patients (characteristics listed in Table 1). Complete LAAC (without any residual flow) was achieved in 64% (28 patients) after 45 days and in 80% (35 patients) after 6 months. Mean PDL diameter was 3.5±1.5mm. Type A showed the lowest rate of PDL after 45d (Type A: 22% vs. Type B: 33% vs. Type C: 88%; p=0.007) and after 6M (Type A: 12% vs. Type B: 28% vs. Type C: 100%; p=0.002). Galectin-3 levels did not show a relevant difference regarding the type of AF at baseline (paroxysmal AF: 11.7±5.4 ng/ml vs. permanent AF: 12.1±6.3 ng/ml; p=0.45). We observed a significant increase and distribution of serum levels of Galectin-3 [ng/ml] after 45 days among the three types (Baseline: 13.1±5.8; 45d: 16.3±7.2 (Type A) vs. 19.2±8.6 (Type B) vs. 25.8±9.4 (Type C); p=0.031) followed after 6 months by a drop of Galectin-3 for type A and B toward and below baseline levels (6M: 8.9±3.1 (Type A) vs. 12.4±5.5 (Type B)) whereas type C persisted in showing elevated Galectin-3 levels compared to all other types (6M: 17.5±4.5 (Type C); p&lt;0.001), Fig. 2. Correlation analysis shows a significant negative correlation trend between Galectin-3 and mean PDL diameter (−0.51; p=0.016) after 45 days and a relevant positive correlation after 6 months (0.58; p=0.017).

Conclusion

After LAAC, Galectin-3 levels are elevated, as a marker of myocardial fibrosis in the LAA. Depending on the degree of closure of the LAA, Galectin-3 decreases to the baseline level or stays elevated in case of relevant PDL and could therefore be considered as a new biomarker for closure success.

Funding Acknowledgement

Type of funding source: None

Dynamics of Galectin-3 serum levels after percutaneous occlusion of the left atrial appendage: a new surrogate parameter for successful LAA closure?

Introduction

Left atrial cardiac tissue remodeling following left atrial appendage closure (LAAC) is a scientifically neglected phenomenon until now but might have impact on functional outcome of patients suffering from atrial fibrillation (AF). Thus, our study is focused on quantification of key biomarkers reflecting fibrosis development as a major component within cardiovascular tissue remodeling.

Methods

Patients (CHA2DS2VASC score ≥1, HASBLED score ≥3) with bleeding complications under anticoagulation therapy and therefore eligible for LAAC were included in the present study. Serum levels of biomarkers of cardiac fibrosis and remodeling (Galectin-3, ST2/IL-2, ST2/IL-1, B domain containing Tenascin-C (B+ Tn-C), C domain containing Tenascin- C (C+ Tn-C)) were determined before device implantation (baseline), 45 days (45d) and 6 months (6M) after LAAC using commercially available ELISAs. To quantify functional outcome, all patients performed a 6-minutes walk test (6- MWT). Transesophageal echocardiography (TEE) was carried out to assess success of the LAAC procedure regarding peri-device leakage (PDL).

Results

We included 33 patients (age: 73.5±6.7 years; 21 men (64%) and 12 women (36%); BMI: 29.1±5.1 kg/m2; CHA2DS2VASC score: 4.2±1.2; left ventricular ejection fraction: 61.1±9.3%; mean occluder size: 25.9±3.9 mm; type of AF: 46% paroxysmal (15 patients), 55% permanent (18 patients)). Complete LAAC (without any residual low) was achieved in 60% (19 patients) after 45 days and in 87% (29 patients) after 6 months. At baseline, Galectin-3 levels did not show a relevant difference regarding the type of AF (paroxysmal AF: 14.7±5.4 ng/ml vs. permanent AF: 13.1±6.3 ng/ml; p=0.45). We observed a significant increase of serum levels of Galectin-3 [ng/ml] after 45 days vs. baseline (baseline: 13.3±5.8 vs. 45d: 18.3±10.6; p=0.005) with a return to baseline levels after 6 months (baseline: 13.3±5.8 vs. 6M: 12.5±5.4; p=0.28). Compared to patients with successful LAAC, patients with PDL had a trend towards higher levels of Galectin-3 after 6 months (11.3±5.5 ng/ml vs. 16.1±4.1 ng/ml, p=0.09). Measurements of other fibrosis markers were statistically not significantly different. The walking distance measured by the 6-MWT increased significantly from 298.5±89.5 meters at baseline to 335.5±95.1 meters (p=0.04) after 45d and remained significantly elevated after 6M (346.7±122.7 meters; p=0.02).

Conclusion

The implantation of an LAA occluder device is accompanied by significantly increased circulating levels of the fibrosis biomarker Galectin-3 after 45 days in patients with AF. The regression in serum levels after 6 months probably reflects a successful fibrotic remodeling in the left atrial appendage over time and might be used as surrogate parameter for LAAC success. Increased and stable exercise tolerance after 45 days can be observed.

Funding Acknowledgement

Type of funding source: None

Influence of Macitentan on the Vascular Tone and Recruitment of Finger Capillaries Under Hypobaric Hypoxia in High Altitude

Betge, Stefan, Stefan Drinda, Thomas Neumann, Laura Bäz, Alexander Pfeil, Christian Schulze, Ralf Mrowka, Christian Jung, and Marcus Franz. Influence of macitentan on the vascular tone and recruitment of finger capillaries under hypobaric hypoxia in high altitude. High Alt Med Biol. 21:336-345, 2020. Introduction: Acute normobaric (NH) and hypobaric hypoxia (HH) has effects on the vascular tone of larger arteries and may have effects on the microcirculation. These effects may be noninvasively detectable by automated devices. A part of these effects may be mediated by endothelin (ET) and should be influenced by macitentan (MAC), a dual endothelin receptor antagonist (ERA). Methods: We used photoplethysmographic sensors, fingertip volume sensors, nailfold capillaroscopy, and laser Doppler probes at rest and after a 5-minute forearm ischemia in healthy study subjects under NH, under HH, and under HH plus a single dose of MAC. Results: NH at simulated 4000 m led to increased heart rates (HR) and pulse wave velocities (PWV) and reduced augmentation index (AIX). The values for the AIX showed a high SD and differed between the used devices. At simulated 5500 m, only baseline mean value (BMV; EndoPAT) showed a further change, indicating less filled capillaries of the fingertips. HH (2978 m) increased HR, blood pressure values, and PWV. Focusing on the microcirculation of the fingertips, HH reduced the BMV and the nailfold capillary density and the postischemic capillary recruitment. MAC had no effect on the BMV, but antagonized the effects of HH on the nailfold capillaries and led to a strongly increased postischemic diameter of the arterial limbs. Concordantly, the postischemic blood flow velocity increment, measured through ultrasound Doppler, was increased at ALT+MAC. Conclusions: The BMV may be a parameter for changes of the microcirculation of the finger tips. A single dose of MAC blocked hypoxia-induced capillary rarefaction and enhanced postischemic hyperemia of the fingertips. These results indicate the importance of ET-1 for the regulation of the microcirculation under hypoxia. The German Registry of Clinical Studies (DRKS) ID: 00005459.

Freeze-frame imaging of synaptic activity using SynTagMA

Information within the brain travels from neuron to neuron across billions of synapses. At any given moment, only a small subset of neurons and synapses are active, but finding the active synapses in brain tissue has been a technical challenge. Here we introduce SynTagMA to tag active synapses in a user-defined time window. Upon 395-405 nm illumination, this genetically encoded marker of activity converts from green to red fluorescence if, and only if, it is bound to calcium. Targeted to presynaptic terminals, preSynTagMA allows discrimination between active and silent axons. Targeted to excitatory postsynapses, postSynTagMA creates a snapshot of synapses active just before photoconversion. To analyze large datasets, we show how to identify and track the fluorescence of thousands of individual synapses in an automated fashion. Together, these tools provide an efficient method for repeatedly mapping active neurons and synapses in cell culture, slice preparations, and in vivo during behavior.

Determination of Ethoxyquin in Feeds by Liquid Chromatography: Collaborative Study

Ethoxyquin is a chemical antioxidant used in feeds, ingredients, fats, and oils. A liquid chromatographic (LC) method for determination of ethoxyquin was developed. The method involves acetonitrile extraction of the sample and isocratic Cis reversed-phase chromatography with ammonium acetate buffer-acetonitrile as mobile phase and fluorescence detection. A collaborative study of the determination of ethoxyquin in various meals and extruded pet foods was conducted by The lams Company Research Laboratory. Eleven laboratories analyzed 16 samples (including 2 blind duplicates) consisting of 7 meat meals and 9 extruded pet foods. Sample means ranged from 0.25 to 289 ppm. Repeatability standard deviations ranged from 0.08 to 3.2 ppm, and repeatability relative standard deviations ranged from 4.5 to 32%. Reproducibility standard deviations ranged from 0.12 to 13 ppm, and reproducibility relative standard deviations ranged from 4.5 to 55%. The LC method for determination of ethoxyquin in feeds has been adopted first action by AOAC INTERNATIONAL.

Outcome of Surgical and Conservative Treatment of Patients with Shoulder Impingement Syndrome - a Prospective Comparative Clinical Study

PURPOSE OF THE STUDY Subacromial impingement is one of the most common reasons for shoulder pain. The surgical management of this condition has recently become the focus of criticism because of the rising number of surgical procedures and the lack of superiority of surgical over conservative treatment. In this prospective comparative study, we compared standardised conservative care with surgical treatment and placed special emphasis on the patients' ability to work. MATERIAL AND METHODS A total of 106 patients (25 women, 81 men; mean age: 45.4 12.3 years) were included in this prospective comparative clinical study. Patients in the non-operative arm (n = 42) received standardised physiotherapy. Patients in the surgical arm (n = 38) underwent arthroscopic subacromial decompression. All patients were followed up at 3, 6 and 12 months. Shoulder function (Constant score), pain (Numerical Rating Scale), and the duration of inability to work were assessed. RESULTS Shoulder function and pain improved significantly with both kinds of treatment. At no time of follow up we detected significant differences between the two treatment options. An analysis of the patients' ability to work showed that conservative treatment was superior to surgical treatment at 3-month follow-up (0.3 versus 5.0 weeks; p < 0.001) and between 4 and 6-month after intervention (0.2 versus 1.6 weeks; p = 0.032). DISCUSSION In the study presented here, significant improvements in function (Constant score) and pain (NRS) were achieved in both the non-operative and the surgical arm. There were no significant differences between the two groups at any time point. These results are similar to those reported by other authors in recent studies. Unlike other research work, however, our study demonstrated a major difference in the development and duration of inability to work. CONCLUSIONS Conservative and surgical treatment of subacromial impingement syndrome led to similar outcomes for shoulder pain and function at 3, 6 and 12 months after intervention. However, patients who were managed conservatively returned to work significantly earlier than patients who underwent surgery. Key words: subacromial impingement, shoulder, constant score, pain, ability to work.

Ultra-fine grinding of inorganic non-metallic materials using various types of bonds and processing strategies

Ultra-fine grinding is a technology, which can be used to process inorganic non-metallic materials. High quality surfaces with a low roughness, and high flatness are achievable in a low processing time. The experimental setup which is described shall compare face grinding with lateral grinding in a single processing step using various materials, bonds and processing parameters. The results are supposed to deepen the knowledge about this grinding technology to further improve the properties of fabricated components.

Functional impairment assessed by the Barthel Index influenced outcomes after transcatheter aortic valve implantation

Objective. We investigated the influence of functional impairment assessed by the Barthel index (BI) on the three-month outcomes after transfemoral-transcatheter aortic valve intervention (TF-TAVI) under general anesthesia. Design. We included retrospectively analyzed 336 patients undergoing TAVI between January 2017 and January 2018 in central hospital, Bad Berka, Germany. All patients were followed up at three-month in our center's outpatient clinic. We stratified the patients according to the BI. Results. At baseline, 76 patients had a BI <80. Patients with a BI <80 were characterized by advanced age (80.6 ± 5.6 vs. 83 ± 4.1 years. p = .027), diabetes mellitus on insulin and higher surgical risk scores. A prior cerebral ischemic event was recorded more in patients with a BI ≥80. Regarding intermediate outcomes, three-month mortality was significantly higher in patients with a BI <80. Patients with a BI <80 developed significantly more postoperative cardiac decompensation, delirium and strokes. Patients with BI <80 had lower hemoglobin level preoperative and needed more blood transfusion postoperative. Other valve academic research consortiums (VARCs) complications were equally distributed in both groups. A BI <80 was associated with prolonged postoperative hospital stay and was an independent predictor of FT protocol failure (OR 4; CI 95% 1.3-11. p .02). Conclusions. A BI <80 is associated with increased mortality and risk of neurological events and cardiac decompensations after TF TAVI. A BI <80 is an independent predictor of failure in fast track TAVI.

P3731The improvement in left atrial strain among patients undergoing percutaneous left atrial appendage closure

Background

Percutaneous left atrial appendage closure (LAAC) is being established as an alternative option for atrial fibrillation (AF) patients with high bleeding risk. Few studies reported the influence of percutaneous LAAC on left atrial (LA) performance, but most of the studies demonstrated no remarkable changes in their parameters after the procedure.

Method

The study included 95 patients (age: 75±6.7 years, 67% male) whom underwent percutaneous LAAC in a single center between September 2012 and November 2018. LA strain was evaluated at three different time intervals by transesophageal echocardiography (baseline, 45 days and 180 days after procedure). All data were analyzed using a dedicated. 70 patients had atrial fibrillation whereas 25 were in sinus rhythm. Analysis was performed for peak atrial longitudinal strain (PALS) and peak atrial contraction strain (PACS) from segment of lateral wall in mid-esophageal 4 chamber view. The validity of lateral wall left atrial analysis was recently shown by our group. PACS was obtained in patients with sinus rhythm during exams.

Results

Compared to baseline, PALS was significantly increased after 45 days (12.4±8.4% vs 16.0±10.7%, p=0.001) and remained stable after 180 days (13.8±9.0% vs 17.0±12.4%, p=0.098). Even in only patients with atrial fibrillation during exams, it was increased (10.8±7.7% vs 13.4±7.1%, p=0.012 and 8.5±5.1% vs 13.9±8.1%, p=0.014). Similarly, compared with the baseline, PACS was significantly increased after 45 days and 180 days (5.8±3.9% vs 10.6±7.6%, p=0.001 and 4.5±2.6% vs 7.9±3.1%, p=0.036).

The Changes in PALS and PACS

Conclusion

Our study has demonstrated for the first time the improvement in LA strain following LAAC within 45 days of implantation by transesophageal echocardiography and these values were maintained at least for 6 months. Further appraisal is warranted for confirmation of these preliminary findings.

Influence of Synthetic Bone Substitutes on the Anchorage Behavior of Open-Porous Acetabular Cup

BACKGROUND

The development in implants such as acetabular cups using additive manufacturing techniques is playing an increasingly important role in the healthcare industry.

METHOD

This study compared the primary stability of four selectively laser-melted press-fit cups (Ti6Al4V) with open-porous, load-bearing structural elements on the surface. The aim was to assess whether the material of the artificial bone stock affects the primary stability of the acetabular cup. The surface structures consist of repeated open-porous, load-bearing elements orthogonal to the acetabular surface. Experimental pull-out and lever-out tests were performed on exact-fit and press-fit cups to evaluate the primary stability of the cups in different synthetic bone substitutes. The acetabular components were placed in three different commercially available synthetic materials (ROHACELL-IGF 110, SikaBlock M330, Sawbones Solid Rigid). Results & conclusions: Within the scope of the study, it was possible to show the differences in fixation strength between the tested acetabular cups depending on their design, the structural elements used, and the different bone substitute material. In addition, functional correlations could be found which provide a qualitative reference to the material density of the bone stock and the press-fit volume of the acetabular cups.

Myocardial Inflammation, Measured Using 18-Fluorodeoxyglucose Positron Emission Tomography With Computed Tomography, Is Associated With Disease Activity in Rheumatoid Arthritis

OBJECTIVE

To determine the prevalence and correlates of subclinical myocardial inflammation in patients with rheumatoid arthritis (RA).

METHODS

RA patients (n = 119) without known cardiovascular disease underwent cardiac 18-fluorodeoxyglucose (FDG) positron emission tomography with computed tomography (PET-CT). Myocardial FDG uptake was assessed visually and measured quantitatively as the standardized uptake value (SUV). Multivariable linear regression was used to assess the associations of patient characteristics with myocardial SUVs. A subset of RA patients who had to escalate their disease-modifying antirheumatic drug (DMARD) therapy (n = 8) underwent a second FDG PET-CT scan after 6 months, to assess treatment-associated changes in myocardial FDG uptake.

RESULTS

Visually assessed FDG uptake was observed in 46 (39%) of the 119 RA patients, and 21 patients (18%) had abnormal quantitatively assessed myocardial FDG uptake (i.e., mean of the mean SUV [SUV_mean ] ≥3.10 units; defined as 2 SD above the value in a reference group of 27 non-RA subjects). The SUV_mean was 31% higher in patients with a Clinical Disease Activity Index (CDAI) score of ≥10 (moderate-to-high disease activity) as compared with those with lower CDAI scores (low disease activity or remission) (P = 0.005), after adjustment for potential confounders. The adjusted SUV_mean was 26% lower among those treated with a non-tumor necrosis factor-targeted biologic agent compared with those treated with conventional (nonbiologic) DMARDs (P = 0.029). In the longitudinal substudy, the myocardial SUV_mean decreased from 4.50 units to 2.30 units over 6 months, which paralleled the decrease in the mean CDAI from a score of 23 to a score of 12.

CONCLUSION

Subclinical myocardial inflammation is frequent in patients with RA, is associated with RA disease activity, and may decrease with RA therapy. Future longitudinal studies will be required to assess whether reduction in myocardial inflammation will reduce heart failure risk in RA.