Anterior Spinal Artery Syndrome Due to Fibrocartilaginous Embolism-Case Report and Treatment Options

Acute occlusion of the anterior spinal artery and subsequent spinal ischemic infarction leads to anterior spinal artery syndrome characterized by back pain and bilateral flaccid paresis with loss of protopathic sensibility. As a rare cause fibrocartilaginous embolism has been described and is associated with sports or unusual strain.Following gymnastic exercise the day before symptom-onset, a 11 years old girl presented with neck pain, paresis of arms and legs, and impaired deep tendon reflexes. She was unable to lift her arms, grasp, stand, walk and had urinary incontinence. Magnetic resonance imaging revealed a longitudinal T2 hyperintense signal in the anterior spinal cord from C3 to C6 with accompanying bilateral diffusion restriction involving gray matter bilaterally at the level of C4 and C5 and unilaterally at the level of C3/4. The adjacent annulus fibrosus of the intervertebral disc showed a fissure without disc protrusion. Treatment with prednisolone and enoxaparin was started within 12 hours of symptom-onset and continued over 6 days and 8 weeks, respectively. After 2 months, her motor function gradually improved, spinal imaging showed persistent T2 signal hyperintense defects at the level of C4/5. After 5 months, there was only slight impairment affecting elevation and abduction of the right arm.Following physical exercise, the patient suffered from acute anterior spinal cord ischemia with imaging findings in line with a presumed fibrocartilaginous embolism. Unlike most cases, our patient showed almost complete recovery following treatment with prednisolone and enoxaparin. We speculate that the positive outcome is related to rapid treatment initiation.

On the reproducibility of extrusion-based bioprinting: round robin study on standardization in the field

The outcome of three-dimensional (3D) bioprinting heavily depends, amongst others, on the interaction between the developed bioink, the printing process, and the printing equipment. However, if this interplay is ensured, bioprinting promises unmatched possibilities in the health care area. To pave the way for comparing newly developed biomaterials, clinical studies, and medical applications (i.e. printed organs, patient-specific tissues), there is a great need for standardization of manufacturing methods in order to enable technology transfers. Despite the importance of such standardization, there is currently a tremendous lack of empirical data that examines the reproducibility and robustness of production in more than one location at a time. In this work, we present data derived from a round robin test for extrusion-based 3D printing performance comprising 12 different academic laboratories throughout Germany and analyze the respective prints using automated image analysis (IA) in three independent academic groups. The fabrication of objects from polymer solutions was standardized as much as currently possible to allow studying the comparability of results from different laboratories. This study has led to the conclusion that current standardization conditions still leave room for the intervention of operators due to missing automation of the equipment. This affects significantly the reproducibility and comparability of bioprinting experiments in multiple laboratories. Nevertheless, automated IA proved to be a suitable methodology for quality assurance as three independently developed workflows achieved similar results. Moreover, the extracted data describing geometric features showed how the function of printers affects the quality of the printed object. A significant step toward standardization of the process was made as an infrastructure for distribution of material and methods, as well as for data transfer and storage was successfully established.

Electrospinning of collagen: enzymatic and spectroscopic analyses reveal solvent-independent disruption of the triple-helical structure

Electrospinning has become a well-established method for creating nanofibrous meshes for tissue-engineering applications. The incorporation of natural extracellular components, such as electrospun pure collagen nanofibers, has proven to be particularly challenging, as electrospun collagen nanofibers do not constitute native collagen fibers anymore. In this study, we show that this detrimental effect is not only limited to fluorinated solvents, as previously thought. Rat tail collagen was dissolved in acetic acid and ethanol and electrospun at various temperatures. Electrospun collagen mats were analyzed using circular dichroism, enzymatic digestion, SDS-PAGE, western blotting, and Raman spectroscopy and compared to heat-denaturated and electrospun collagen in HFIP. Our data suggest that even non-fluorinated electrospinning solvents, such as acid-based solvents, do not yield structurally intact fibers. Interestingly, neither epithelial cells nor fibroblasts displayed a different cellular response to electrospun collagen compared to collagen-coated polyurethane scaffolds in F-actin staining and metabolic analysis using fluorescent lifetime imaging. The disruption of the structural integrity of collagen might therefore be underestimated based on the cell-material interactions alone. These observations expose the larger than anticipated vulnerability of collagen in the electrospinning process. Based on these findings, the influence of the electrospinning process on the distinct biochemical properties of collagen should always be considered, when ECM-mimicking fibrous constructs are manufactured.

Lead-binding biogenic polyelectrolyte multilayer coating for lead retention in perovskite solar cells

Perovskite solar cells promise to deliver high efficiencies at low manufacturing costs. Yet on their way towards commercialization, they have to face the associated risk of potential lead leakage into the environment after damage to the cell's encapsulation. Here we present a new approach to generate a lead binding coating, based on a layer-by-layer deposition of biopolymers. A lead-adsorbing functionality was shown after subsequent crosslinking, demonstrating a high binding capacity. The lead binding capabilities could be further enhanced by increasing the thickness of the coatings, analyzed both in the supernatant and on the surface of the coated material. The thin-layered coating had a thickness of less than one micrometer, was stable even under low pH conditions and could successfully be transferred onto different substrates, ranging from silicon, gold and glass substrates to polymeric nonwoven materials with high surface areas, further increasing its lead binding capacity. This newly described coating was applied within perovskite solar cell stacks without impeding the overall efficiency but strongly reducing the amount of lead released after simulated rain tests on devices with damaged encapsulation. Accordingly, incorporation of lead-binding polyelectrolyte multilayers inside the encapsulation of perovskite solar cells shows great potential to limit the perovskite solar cells inherent risk of lead leakage in a sustainable manner.

Green Chemistry for Biomimetic Materials: Synthesis and Electrospinning of High-Molecular-Weight Polycarbonate-Based Nonisocyanate Polyurethanes

Conventional synthesis routes for thermoplastic polyurethanes (TPUs) still require the use of isocyanates and tin-based catalysts, which pose considerable safety and environmental hazards. To reduce both the ecological footprint and human health dangers for nonwoven TPU scaffolds, it is key to establish a green synthesis route, which eliminates the use of these toxic compounds and results in biocompatible TPUs with facile processability. In this study, we developed high-molecular-weight nonisocyanate polyurethanes (NIPUs) through transurethanization of 1,6-hexanedicarbamate with polycarbonate diols (PCDLs). Various molecular weights of PCDL were employed to maximize the molecular weight of NIPUs and consequently facilitate their electrospinnability. The synthesized NIPUs were characterized by nuclear magnetic resonance, Fourier-transform infrared spectroscopy, gel permeation chromatography, and differential scanning calorimetry. The highest achieved molecular weight (M _w) was 58,600 g/mol. The NIPUs were consecutively electrospun into fibrous scaffolds with fiber diameters in the submicron range, as shown by scanning electron microscopy (SEM). To assess the suitability of electrospun NIPU mats as a possible biomimetic load-bearing pericardial substitute in cardiac tissue engineering, their cytotoxicity was investigated in vitro using primary human fibroblasts and a human epithelial cell line. The bare NIPU mats did not need further biofunctionalization to enhance cell adhesion, as it was not outperformed by collagen-functionalized NIPU mats and hence showed that the NIPU mats possess a great potential for use in biomimetic scaffolds.

Non-Invasive Three-Dimensional Cell Analysis in Bioinks by Raman Imaging

3D bioprinting is an emerging biofabrication strategy using bioinks, comprising cells and biocompatible materials, to produce functional tissue models. Despite progress in building increasingly complex objects, biological analyses in printed constructs remain challenging. Especially, methods that allow non-invasive and non-destructive evaluation of embedded cells are largely missing. Here, we implemented Raman imaging for molecular-sensitive investigations on bioprinted objects. Different aspects such as culture formats (2D, 3D-cast, and 3D-printed), cell types (endothelial cells and fibroblasts), and the selection of the biopolymer (alginate, alginate/nanofibrillated cellulose, alginate/gelatin) were considered and evaluated. Raman imaging allowed for marker-independent identification and localization of subcellular components against the surrounding biomaterial background. Furthermore, single-cell analysis of spectral signatures, performed by multivariate analysis, demonstrated discrimination between endothelial cells and fibroblasts and identified cellular features influenced by the bioprinting process. In summary, Raman imaging was successfully established to analyze cells in 3D culture in situ and evaluate them with regard to the localization of different cell types and their molecular phenotype as a valuable tool for quality control of bioprinted objects.

Altered Proinflammatory Responses to Polyelectrolyte Multilayer Coatings Are Associated with Differences in Protein Adsorption and Wettability

A full understanding of the relationship between surface properties, protein adsorption, and immune responses is lacking but is of great interest for the design of biomaterials with desired biological profiles. In this study, polyelectrolyte multilayer (PEM) coatings with gradient changes in surface wettability were developed to shed light on how this impacts protein adsorption and immune response in the context of material biocompatibility. The analysis of immune responses by peripheral blood mononuclear cells to PEM coatings revealed an increased expression of proinflammatory cytokines tumor necrosis factor (TNF)-α, macrophage inflammatory protein (MIP)-1β, monocyte chemoattractant protein (MCP)-1, and interleukin (IL)-6 and the surface marker CD86 in response to the most hydrophobic coating, whereas the most hydrophilic coating resulted in a comparatively mild immune response. These findings were subsequently confirmed in a cohort of 24 donors. Cytokines were produced predominantly by monocytes with a peak after 24 h. Experiments conducted in the absence of serum indicated a contributing role of the adsorbed protein layer in the observed immune response. Mass spectrometry analysis revealed distinct protein adsorption patterns, with more inflammation-related proteins (e.g., apolipoprotein A-II) present on the most hydrophobic PEM surface, while the most abundant protein on the hydrophilic PEM (apolipoprotein A-I) was related to anti-inflammatory roles. The pathway analysis revealed alterations in the mitogen-activated protein kinase (MAPK)-signaling pathway between the most hydrophilic and the most hydrophobic coating. The results show that the acute proinflammatory response to the more hydrophobic PEM surface is associated with the adsorption of inflammation-related proteins. Thus, this study provides insights into the interplay between material wettability, protein adsorption, and inflammatory response and may act as a basis for the rational design of biomaterials.

Effect of exercise training on vascular function and endothelial repair in heart failure with preserved ejection fraction: results from the OptimEx trial

Background

Exercise training improves peak oxygen uptake (VO2) in heart failure with preserved ejection fraction (HFpEF), but the underlying mechanisms are unknown. In other cardiovascular diseases, exercise training improves vascular function and increases levels of circulating endothelium-repairing cells. We aimed to investigate the effects of moderate continuous training (MCT) and high intensity interval training (HIIT) on vascular function and cellular endothelial repair in HFpEF.

Methods

This was a prespecified subanalysis of the Optimizing Exercise Training in Prevention and Treatment of Diastolic Heart Failure randomized trial. HFpEF patients (n=180) were randomized to HIIT, MCT or attention control. At baseline and after 12 weeks, we measured peak VO2, fingertip arterial tonometry (n=109), brachial artery flow-mediated dilation (n=59), aortic pulse wave velocity (n=94), and flow cytometry (n=136) for endothelial progenitor cells (CD45dimCD34+VEGFR2+) and angiogenic T cells (CD3+CD31+CD184+). Changes in these parameters were compared between groups using linear mixed models. Parameters were correlated using Spearman's rho.

Results

At 3 months, we did not observe significant differences between HIIT, MCT and control group regarding changes in vascular function throughout the vascular tree (fingertip arterial tonometry, brachial artery flow-mediated dilation and central arterial stiffness, Table 1) or levels of circulating endothelium-repairing cells (endothelial progenitor cells and angiogenic T cells, Table 1). Results were similar at 12 months and when restricting analysis to patients with at least 70% adherence to training sessions. Patients with higher peak VO2 at baseline had lower numbers of circulating endothelial progenitor cells (rho=−0.22, p=0.011).

Conclusions

In patients with HFpEF, exercise training did not change vascular function or levels of endothelium-repairing cells. Thus, improved vascular function likely does not contribute to the change in peak VO2 after training. These findings are in contrast with the benefits of exercise on vascular function in heart failure with reduced ejection fraction and coronary artery disease.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): EU Framework Programme 7 Table 1

The Impact of Biomaterial Cell Contact on the Immunopeptidome

Biomaterials play an increasing role in clinical applications and regenerative medicine. A perfectly designed biomaterial should restore the function of damaged tissue without triggering an undesirable immune response, initiate self-regeneration of the surrounding tissue and gradually degrade after implantation. The immune system is well recognized to play a major role in influencing the biocompatibility of implanted medical devices. To obtain a better understanding of the effects of biomaterials on the immune response, we have developed a highly sensitive novel test system capable of examining changes in the immune system by biomaterial. Here, we evaluated for the first time the immunopeptidome, a highly sensitive system that reflects cancer transformation, virus or drug influences and passes these cellular changes directly to T cells, as a test system to examine the effects of contact with materials. Since monocytes are one of the first immune cells reacting to biomaterials, we have tested the influence of different materials on the immunopeptidome of the monocytic THP-1 cell line. The tested materials included stainless steel, aluminum, zinc, high-density polyethylene, polyurethane films containing zinc diethyldithiocarbamate, copper, and zinc sulfate. The incubation with all material types resulted in significantly modulated peptides in the immunopeptidome, which were material-associated. The magnitude of induced changes in the immunopeptidome after the stimulation appeared comparable to that of bacterial lipopolysaccharides (LPS). The source proteins of many detected peptides are associated with cytotoxicity, fibrosis, autoimmunity, inflammation, and cellular stress. Considering all tested materials, it was found that the LPS-induced cytotoxicity-, inflammation- and cellular stress-associated HLA class I peptides were mainly induced by aluminum, whereas HLA class II peptides were mainly induced by stainless steel. These findings provide the first insights into the effects of biomaterials on the immunopeptidome. A more thorough understanding of these effects may enable the design of more biocompatible implant materials using in vitro models in future. Such efforts will provide a deeper understanding of possible immune responses induced by biomaterials such as fibrosis, inflammation, cytotoxicity, and autoimmune reactions.

Systematic Investigation of Polyurethane Biomaterial Surface Roughness on Human Immune Responses in vitro

It has been widely shown that biomaterial surface topography can modulate host immune response, but a fundamental understanding of how different topographies contribute to pro-inflammatory or anti-inflammatory responses is still lacking. To investigate the impact of surface topography on immune response, we undertook a systematic approach by analyzing immune response to eight grades of medical grade polyurethane of increasing surface roughness in three in vitro models of the human immune system. Polyurethane specimens were produced with defined roughness values by injection molding according to the VDI 3400 industrial standard. Specimens ranged from 0.1 μm to 18 μm in average roughness (Ra), which was confirmed by confocal scanning microscopy. Immunological responses were assessed with THP-1-derived macrophages, human peripheral blood mononuclear cells (PBMCs), and whole blood following culture on polyurethane specimens. As shown by the release of pro-inflammatory and anti-inflammatory cytokines in all three models, a mild immune response to polyurethane was observed, however, this was not associated with the degree of surface roughness. Likewise, the cell morphology (cell spreading, circularity, and elongation) in THP-1-derived macrophages and the expression of CD molecules in the PBMC model on T cells (HLA-DR and CD16), NK cells (HLA-DR), and monocytes (HLA-DR, CD16, CD86, and CD163) showed no influence of surface roughness. In summary, this study shows that modifying surface roughness in the micrometer range on polyurethane has no impact on the pro-inflammatory immune response. Therefore, we propose that such modifications do not affect the immunocompatibility of polyurethane, thereby supporting the notion of polyurethane as a biocompatible material.

Active matrix metalloproteinase-8 and periodontal bacteria-interlink between periodontitis and inflammatory bowel disease?

BACKGROUND

The aim of this study was the investigation of concentration and prevalence of selected periodontal pathogenic bacteria and concentration of active matrix metalloproteinase-8 (aMMP-8) within a group of patients with inflammatory bowel diseases (IBD) and to compare the results with a group of healthy control subjects (HC).

METHODS

Fifty-nine IBD patients with Crohn`s disease (CD, n = 30) or ulcerative colitis (UC, n = 29) and 59 HC were included in this cross-sectional study. Based on periodontal probing depth (PD) and clinical attachment level (CAL), periodontitis was classified as healthy/mild, moderate, or severe. aMMP-8 was analyzed from gingival crevicular fluid using enzyme linked immunosorbent assay. Eleven selected periodontal pathogenic bacteria were analyzed in subgingival plaque samples using polymerase chain reaction.

RESULTS

IBD patients showed higher CAL (P < 0.01), more severe periodontitis (P = 0.04), gingival bleeding (P < 0.01) and aMMP-8 concentration (P < 0.01) than HC. Only in CD, increasing severity of periodontitis was associated with an increase in aMMP-8 concentration (P = 0.02). The prevalences of Eubacterium nodatum and Eikenella corrodens were significantly lower in IBD compared to HC (P = 0.01). Additionally, the prevalence of Eikenella corrodens was significantly higher in CD compared to the UC group (P = 0.04). Further statistically significant differences in selected bacteria between IBD and HC or CD and UC groups could not be found (P > 0.05).

CONCLUSIONS

The results reveal changes in host immune response of IBD patients in terms of aMMP-8. Only in CD increasing aMMP-8 was associated with severity of periodontal disease. The role of periodontal pathogenic bacteria in the interrelationship between IBD and periodontitis remains unclear.

Polyelectrolyte Coatings for Surface Modification of Medical Implants

Polyelectrolyte multi-layer (PEM) coatings are prepared by alternative deposition of single polyelectrolyte monolayers on charged surfaces using the Layer-by-Layer (LbL) dip coating procedure. These are nanometre scaled coatings which allow fulfilling of different technical or biological requirements. The build-up process is based on selfassembly and self-organization of polycations and polyanions on different substrates including complex geometrical structures and even closed volumes, forming homogeneous layer without defects. Depending on the proper selection of the applied polyelectrolytes, coatings with different stabilities can be prepared. Some of the coatings are stable and cannot be removed from the surface. Others are degradable and can be used as systems for controlled local drug delivery. Here we summarise the results of our experience in preparation of PEM coatings with different functionalities. PEM coatings can be used as controllable delivery system for siRNA polyplexes. They can be used to control the adhesion of different cell types on the surfaces and support e.g. the endothelialisation process on cardio-vascular medical devices as e.g. stents or reduce the immunological response of the tissue after implantation. We summarise results from physical characterisation of the coatings (e.g. film thickness, roughness, electrical charge and hydrophilicity) combined with in-vitro biological studies on adhesion of HUVEC cells.

Radiation exposure of patients during 68Ga-DOTATOC PET/CT examinations

Aim: Investigation of the biodistribution and calculation of dosimetry of Ga-68-DOTATOCfor patients imaged in the routine clinical setting for diagnosis or exclusion of neuroendocrine tumours. Patients, methods: Dynamic PET/CT-imaging (Biograph 16) was performed over 20 min in 14 patients (8 men, 6 women) after injection of (112 ± 22) MBq 68Ga-DOTATOC followed by whole body 3D-acquisition (8 bed positions, 3 or 4 min each) 30 min p.i. and 120 min p.i. Urinary tracer elimination was measured and blood activity was derived non-invasively from the blood pool of the heart. The relevant organs for dosimetry were spleen, kidneys, liver, adrenals, urinary bladder and pituitary gland. Dosimetry was performed using OLINDA/ EXM 1.0 software and specific organ uptake was expressed as standardized uptake values (SUVs). Results: Rapid physiological uptake of the radiotracer could be demonstrated in liver, spleen and kidneys, adrenals and pituitary gland (mean SUVs were 6, 20, 16, 10, and 4, respectively). Radiotracer elimination was exclusively via urine (16% of injected dose within 2h); no redistribution could be observed. The spleen and the kidneys received the highest radiation exposure (0.24 mSv/MBq, 0.22 mSv/MBq resp.), mean effective dose yielded 0.023 mSv/MBq. Conclusion: 68Ga-DOTATOC is used extensively for diagnosis of somatostatin receptor positive tumours because it has several advantages over the 111In-labelled ligand. The derived dosimetric values are lower than first approximations from the biological data of OctreoScan. The use of CT for transmission correction of the PET data delivers radiation exposure up to 1 mSv (low dose).

Wirkung von Milch und Diättränken mit und ohne HCO3 –-Ionen auf den intraluminalen pH-Wert im Labmagen und den systemischen Säuren-Basen-Status beim Kalb

Problemstellung: Bei Kälbern wird nach Zufuhrvon Diättränken mit Bikarbonat-Ionen eine besonders ausgeprägte Alkalisierung der Labmageningesta erwartet. Nachfolgend könnten die an saure pH-Werte gebundene abomasale Verdauung sowie unspezifische Infektabwehr beeinträchtigt sein. Material und Methode: Bei acht klinisch gesunden Kälbern wurde operativ eine Plastkanüle in den Labmagen eingesetzt. Danach erhielten die Tiere über sieben bisneun Tage als Nahrung alternierend 1) Kuhmilch, 2) bikarbonatfreie oder 3) bikarbonathaltige Diättränke. Außerdem wurde 4) das Gemisch aus gleichen Teilen bikarbo- nathaltige Diättränke und Milch verabreicht. In den über die Kanüle entnommenen Labmageningesta bestimmten wir dieWertefür pH, Fläche unter der pH-Wert-Kurve (AUC) und [SID3]. Weiterhin wurde vergleichend im arteriellen und venösen Blut der systemische Säuren-Basen-Status anhand traditioneller Hen- derson-Hasselbalch-Parameter sowie der Stewart-Variablen ermittelt. Ergebnisse: Die Fütterung von Milch bewirkte beiden Kälbern einen Anstieg des Labmagen-pH von Nüchternbefunden mit 2,00 ± 0,44 auf Werte bis 4,70 ± 0,41 über zwei Stunden. Die AUC-Werte bis vier Stunden postprandial betrugen 898 ± 87 (= 100%). Die in Milch zubereitete bikarbonatfreie Diättränke führte zur signifikant basischeren Auslenkung desabomasalen pH mit Werten bis 5,35 ± 0,31 sowieAUC = 1084 ± 89 (= 121%). Die mit Wasser hergestellte bikarbonathaltige Diättränke allein und ebenso ihr Gemisch mit Milch verursachten dentransient stärksten Anstieg des Labmagen-pH für 1,5 bzw. 0,5 Stunden auf Werte bis 6,59 ± 0,28 bzw. 6,22 ± 0,12. Die AUC- Werte unterschieden sich mit 1119 ± 45 (= 125%) und 1126 ± 44 (= 125%) signifikant von den Befunden nach Milchtränke, jedoch nichtvon den Resultaten nach Gabe der bikarbonatfreien Diättränke. Systemisch bewirkten die Fütterungen zum Zeitpunkt zwei Stunden postprandial eine im arteriellen und venösen Blut gleichermaßen nachweisbare geringe, teilweise signifikante basische Reaktion, wie ↑ pH, ↑ [HCO3 –, ↑ [BE], ↑ [SID3] und ↓ [Atot] bei unveränderten Werten für PCO2. Die postprandial im Blut der Kälber festgestellte “basische Flut” war nach Gabe der bikarbonathaltigen Diättränken relativ am deutlichsten ausgeprägt. Schlussfolgerung: Im Vergleich zur üblichen Milchfütterung verursachte die in Milch zubereitete bikarbonatfreie Diättränke postprandial signifikant stärkere basische Auslenkungen des Labmagen-pH. Mit Wasser hergestellte bikarbonathaltige Elektrolyttränken führten kurzfristig (≤ 2 h) zu noch stärkerem Anstieg des Labmagen-pH. Die AUC der pH-Wert-Kurve bisvierStunden postprandial (= zeitabhängige “Wirksamkeit”) differierte jedoch nicht signifikant von der nach Gabe der bikarbonatfreien Diättränken.

Stewart-Variablen des Säuren-Basen-Status bei Kälbern

Gegenstand und Ziel: Bisher wird das Stewart-Modell des Säuren-Basen- Status in der klinischen Veterinärmedizin kaum genutzt. Eine Ursache dafür ist der Mangel an Kenntnissen über anerkannte Referenzbereiche der Stewart-Variablen [strong ion difference = SID] und [Acid total = Atot] bei den verschiedenen Tierarten. Außerdem ist bisher wenig über den Einfluss wichtiger Erkrankungen auf die Stewart-Parameter bekannt. Material und Methode: Bei 17 Kälbern (Alter: 1–28 d) wurden statistisch begründete Referenzdaten für Serum-[SID3, 4] und -[Atot- Pro/-Alb] ermittelt. Außerdem wurde retrospektiv der Einfluss von Kälberdiarrhö auf die Stewart-Variablen im Experiment (39 Kälber; Alter: 5,3 ± 2,5 d) und in der klinischen Praxis (36 Kälber; Alter: 8,7 ± 5,0 d) untersucht. Ergebnisse: Gesunde Kälber besitzen in der ersten Lebenswoche mit der Serum-[SID3/4] von etwa 51/48 mmol/l um 2–3 mmol/l signifikant höhere Werte als ältere Tiere. Infolge des postnatalen Anstiegs der Serumalbuminkonzentration erhöhen sich die Serum-[Atot-Alb] von etwa 15 mmol/l (1. Tag) auf Werte von 22 mmol/l (28. Tag). Aus den Stewart-Variablen PvCO2, Serum-[SID4] und -[Atot-Pro] ließ sich der BlutpH mit der Differenz von 0,063 ± 0,0336 gegenüber den gemessenen Werten vorhersagen. Spontan auftretender Durchfall senkt bei Kälbern die Serum-[SID3, 4] auf etwa 40 mmol/l (überlebende Tiere) oder ante mortem auf noch niedrigere Werte. Schlussfolgerung: Die metabolische Azidose durchfallkranker Kälber ist nach dem Stewart-Modell auf die Imbalancen der starken Elektrolyte Na+ und Cl– (SID3↓), die Anhäufung von Blut-Laktat– (SID4↓) sowie die Dehydratation (Atot↑) zurückzuführen. Eine erfolgreiche Therapie der Azidose muss die erniedrigten Serum-[SID] anheben und durch Flüssigkeitszufuhr die Euhydratation mit physiologischer Serum-[Atot] herbeiführen. Klinische Relevanz: In oralen und parenteralen Rehydratationslösungen lassen sich die Werte für [SID] und [Atot] leicht ermitteln und zur prospektiven Wirksamkeitsbeurteilung der Lösungen gegen die Azidose bei durchfallkranken Kälbern nutzen.

Biofunctionalization of surfaces using polyelectrolyte multilayers

Biomaterials play a central role in modern strategies in regenerative medicine and tissue engineering to restore the structure and function of damaged or dysfunctional tissue and to direct cellular behavior. Both biologically derived and synthetic materials have been extensively explored in this context. However, most materials when implanted into living tissue initiate a host response. Modern implant design therefore aims to improve implant integration while avoiding chronic inflammation and foreign body reactions, and thus loss of the intended implant function. Directing these processes requires an in-depth understanding of the immunological processes that take place at the interface between biomaterials and the host tissue. The physicochemical properties of biomaterial surfaces (charge, charge density, hydrophilicity, functional molecular domains, etc.) are decisive, as are their stiffness, roughness and topography. This review outlines specific strategies, using polyelectrolyte multilayers to modulate the interactions between biomaterial surfaces and biological systems. The described coatings have the potential to control the adhesion of proteins, bacteria and mammalian cells. They can be used to decrease the risk of bacterial infections occurring after implantation and to achieve better contact between biological tissue and implants. In summary, these results are important for further development and modification of surfaces from different medical implants.

CpG oligodeoxynucleotides stimulate IFN-γ-inducible protein-10 production in human B cells

Several classes of CpG oligodeoxynucleotides (ODNs) with different immune stimulatory profiles were recently identified: the A-, B- and C-classes. In this study, we investigated the CpG-dependent stimulation of IFN-γ-inducible protein 10 (IP-10 or CXCL10) in different human immune cell types. CpG ODNs induced IP-10 in monocytes, pDCs and in B cells. Purified B cells as well as RPMI 8226 cells responded to CpG stimulation by IP-10 production. Treatment with exogenous IFN-α2b sensitized PBMCs, purified B cells as well as RPMI 8226 cells to respond more efficiently to stimulation with CpG ODNs by IP-10 production. IP-10 signaling could be directly stimulated via TLR9 in CpG-unresponsive HEK293 cells transfected with human TLR9 and an IP-10 reporter construct. Therefore, CpG-mediated IP-10 production is stimulated through IFN-α in cells that express the IFN-α receptor, a second pathway for IP-10 induction exists in TLR9-expressing B cells and pDCs where IP-10 is stimulated directly upon CpG-mediated TLR9 signaling. Our data provide a better understanding of the mechanisms through which CpG ODNs induce efficient Th1 responses.

Fine-tuned PEGylation of chitosan to maintain optimal siRNA-nanoplex bioactivity

Polyethylene glycol (PEG) is a widely used modification for drug delivery systems. It reduces undesired interaction with biological components, aggregation of complexes and serves as a hydrophilic linker of ligands for targeted drug delivery. However, PEGylation can also lead to undesired changes in physicochemical characteristics of chitosan/siRNA nanoplexes and hamper gene silencing. To address this conflicting issue, PEG-chitosan copolymers were synthesized with stepwise increasing degrees of PEG substitution (1.5% to 8.0%). Subsequently formed PEG-chitosan/siRNA nanoplexes were characterized physicochemically and biologically. The results showed that small ratios of chitosan PEGylation did not affect nanoplex stability and density. However, higher PEGylation ratios reduced nanoplex size and charge, as well as cell uptake and final siRNA knockdown efficiency. Therefore, we recommend fine-tuning of PEGylation ratios to generate PEG-chitosan/siRNA delivery systems with maximum bioactivity. The degree of PEGylation for chitosan/siRNA nanoplexes should be kept low in order to maintain optimal nanoplex efficiency.

Regulation of the growth, morphology, mechanical properties and biocompatibility of natural polysaccharide-based multilayers by Hofmeister anions

Herein the optimization of the physicochemical properties and surface biocompatibility of polyelectrolyte multilayers of the natural, biocompatible and biodegradable, linear polysaccharides hyaluronan and chitosan by Hofmeister anions was systematically investigated.

Multivalency of PEG-thiol ligands affects the stability of NIR-absorbing hollow gold nanospheres and gold nanorods

In this work the effect of multivalency on the stability of NIR-absorbing HAuNSs and AuNRs functionalized by mono-, bi- and tridentate polyethyleneglycol (PEG) thiol ligands is reported.

Influence of central nervous system-acting drugs on results of cognitive testing in geriatric inpatients

INTRODUCTION

Growing evidence shows a high correlation between extensive use of central nervous system-acting drugs (CNSADs) in elderly patients and adverse drug reactions (ADRs) such as falls, fractures, and mortality.

RESEARCH QUESTION

Are results of cognitive testing with the Mini Mental Status Examination (MMSE) influenced by use of CNSADs?

SETTING

Geriatric inpatient service for acute, subacute, and rehabilitation care.

METHODS

Secondary combined analysis of two prospective, single-center study cohorts (PROPSYC, 2011 and AGE OUT, 2012) with identical procedure for the MMSE at a tertiary hospital.

RESULTS

Overall, 395 patients were included, 144 male (M) and 251 female (F). Mean age was 80.0 ± 8.4 years (M 76.7 ± 9.1, F 81.9 ± 7.3, p = 0.0000). Mean MMSE points were 22.9 ± 4.8 (M 23.2 ± 4.6, F 22.6 ± 5.0, p = 0.211). In total, 258 patients (65.3 %) used drugs with potential adverse cognitive properties. Analgesics with central activity were given to 117 of 395 patients (29.6 %). Low-potency opioids (tramadol hydrochloride, tilidine) were identified in 60 patients and high-potency opioids in 57 patients. Antidepressants were used in 66 patients, benzodiazepines in 26, and hypnotics in 11, while 38 patients received other CNSADs. We only found significant correlations with the results of cognitive testing for sedatives (diazepam and oxazepam, Pearson's r - 0.79, p = 0.05), but not for lorazepam.

CONCLUSION

Our analysis shows an influence of sedatives (diazepam and oxazepam, but not lorazepam) on cognitive testing with the MMSE in users of CNSADs.

Measurement of pion, kaon and proton production in proton-proton collisions at [Formula: see text] TeV

The measurement of primary [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] production at mid-rapidity ([Formula: see text] 0.5) in proton-proton collisions at [Formula: see text][Formula: see text] 7 TeV performed with a large ion collider experiment at the large hadron collider (LHC) is reported. Particle identification is performed using the specific ionisation energy-loss and time-of-flight information, the ring-imaging Cherenkov technique and the kink-topology identification of weak decays of charged kaons. Transverse momentum spectra are measured from 0.1 up to 3 GeV/[Formula: see text] for pions, from 0.2 up to 6 GeV/[Formula: see text] for kaons and from 0.3 up to 6 GeV/[Formula: see text] for protons. The measured spectra and particle ratios are compared with quantum chromodynamics-inspired models, tuned to reproduce also the earlier measurements performed at the LHC. Furthermore, the integrated particle yields and ratios as well as the average transverse momenta are compared with results at lower collision energies.

Production of [Formula: see text] and [Formula: see text] in proton-proton collisions at [Formula: see text] 7 TeV

The production of the strange and double-strange baryon resonances ([Formula: see text], [Formula: see text]) has been measured at mid-rapidity ([Formula: see text][Formula: see text]) in proton-proton collisions at [Formula: see text] [Formula: see text] 7 TeV with the ALICE detector at the LHC. Transverse momentum spectra for inelastic collisions are compared to QCD-inspired models, which in general underpredict the data. A search for the [Formula: see text] pentaquark, decaying in the [Formula: see text] channel, has been carried out but no evidence is seen.

Exclusive J/ψ photoproduction off protons in ultraperipheral p-Pb collisions at √(s(NN))=5.02 TeV

We present the first measurement at the LHC of exclusive J/ψ photoproduction off protons, in ultraperipheral proton-lead collisions at sqrt[s_{NN}]=5.02  TeV. Events are selected with a dimuon pair produced either in the rapidity interval, in the laboratory frame, 2.5<y<4 (p-Pb) or -3.6<y<-2.6 (Pb-p), and no other particles observed in the ALICE acceptance. The measured cross sections σ(γ+p→J/ψ+p) are 33.2±2.2(stat)±3.2(syst)±0.7(theor)  nb in p-Pb and 284±36(stat)_{-32}^{+27}(syst)±26(theor)  nb in Pb-p collisions. We measure this process up to about 700 GeV in the γp center of mass, which is a factor of two larger than the highest energy studied at HERA. The data are consistent with a power law dependence of the J/ψ photoproduction cross section in γp energies from about 20 to 700 GeV, or equivalently, from Bjorken x scaling variable between ∼2×10^{-2} and ∼2×10^{-5}, thus indicating no significant change in the gluon density behavior of the proton between HERA and LHC energies.

Measurement of prompt D-meson production in p-Pb collisions at √(s(NN))=5.02 TeV

The p_{T}-differential production cross sections of the prompt charmed mesons D^{0}, D^{+}, D^{*+}, and D_{s}^{+} and their charge conjugate in the rapidity interval -0.96<y_{cms}<0.04 were measured in p-Pb collisions at a center-of-mass energy sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The nuclear modification factor R_{pPb}, quantifying the D-meson yield in p-Pb collisions relative to the yield in pp collisions scaled by the number of binary nucleon-nucleon collisions, is compatible within the 15%-20% uncertainties with unity in the transverse momentum interval 1<p_{T}<24  GeV/c. No significant difference among the R_{pPb} of the four D-meson species is observed. The results are described within uncertainties by theoretical calculations that include initial-state effects. The measurement adds experimental evidence that the modification of the momentum spectrum of D mesons observed in Pb-Pb collisions with respect to pp collisions is due to strong final-state effects induced by hot partonic matter.

Measurement of quarkonium production at forward rapidity in [Formula: see text] collisions at [Formula: see text]TeV

The inclusive production cross sections at forward rapidity of [Formula: see text], [Formula: see text], [Formula: see text](1S) and [Formula: see text](2S) are measured in [Formula: see text] collisions at [Formula: see text] with the ALICE detector at the LHC. The analysis is based on a data sample corresponding to an integrated luminosity of 1.35 pb[Formula: see text]. Quarkonia are reconstructed in the dimuon-decay channel and the signal yields are evaluated by fitting the [Formula: see text] invariant mass distributions. The differential production cross sections are measured as a function of the transverse momentum [Formula: see text] and rapidity [Formula: see text], over the ranges [Formula: see text] GeV/c for [Formula: see text], [Formula: see text] GeV/c for all other resonances and for [Formula: see text]. The measured cross sections integrated over [Formula: see text] and [Formula: see text], and assuming unpolarized quarkonia, are: [Formula: see text] [Formula: see text]b, [Formula: see text] [Formula: see text]b, [Formula: see text] nb and [Formula: see text] nb, where the first uncertainty is statistical and the second one is systematic. The results are compared to measurements performed by other LHC experiments and to theoretical models.

Dosimetric measurements of (68)Ga-high affinity DOTATATE: twins in spirit - part III

PURPOSE

68Ga-labelled compounds are increasingly used for somatostatin-receptor scintigraphy because of their favourable biokinetic properties, a higher tumour-to-background contrast and higher diagnostic accuracy compared to the gamma-emitting tracer 111In-DTPA-octreotide. Recently, we have introduced the new tracer 68Ga-DOTA-3-iodo-Tyr3-Thr8-octreotide (68Ga-HA-DOTATATE). The present study demonstrates the biodistribution and radiation dosimetry of this tracer in humans.

PATIENTS, METHODS

Seven men were enrolled in this analysis. Every patient underwent a 20 min dynamic PET scan after intravenous injection of about 114 ± 9 MBq of 68Ga-HA-DOTATATE. This was followed by two whole-body scans at 30 min p. i. and 120 min p. i. Blood radioactivity concentration was determined non-invasively from a ROI drawn over the aorta. Urine was collected until the time of the last scan. Liver, spleen, kidneys and urinary bladder wall were included in the dosimetric estimation that was carried out with the software package OLINDA 1.0.

RESULTS

Physiological 68Ga-HA-DOTATATE uptake was observed in the pituitary gland, thyroid, salivary glands, liver, spleen, kidneys, urinary bladder, adrenals and intestine. Organs with the highest absorbed dose were spleen (0.26 ± 0.11 mSv/MBq), kidneys (0.14 ± 0.03 mSv/MBq) and liver (0.12 ± 0.02 mSv/MBq).The estimated effective dose was 0.024 ± 0.001 mSv/MBq.

CONCLUSION

Our study demonstrates biokinetics and radiation exposure of the 68Ga-labelled tracer HA-DOTATATE to be comparable to other 68Ga-labelled SSR analogues in clinical use.

Untersuchungen über die Kinetik der Spaltung von Di- und Tripeptiden

Für eine Gruppe von Di- und Tripeptiden wurden die Geschwindigkeitskonstanten sowie die Arrhenius schen Aktivierungsenergien und Aktionskonstanten der sauren Hydrolyse der einzelnen Peptidbindungen gemessen. Zeitgesetz und Abstufungen der Aktivierungsenergien lassen sich nur unter bestimmten Annahmen über die Solvatation der Reaktionsteilnehmer auf der Grundlage des Ingold- Benderschen Mechanismus interpretieren. Aktionskonstante und Aktivierungsenergien weisen einen symbaten Gang auf.

1H-NMR-Spektren von 2- und 3-Aminothiophenen

Die chemischen Verschiebungen der Thiophenprotonen werden von der Art des Aminsubstituenten (Dialkylamino-, Pyrrolidino-, Piperidino- usw.) stark beeinflußt. Diese Verschiebungseffekte können auf sterische Hinderung zwischen dem Thiophenring und den α-ständigen Methylengruppen des Amins zurückgeführt werden, wodurch die Wechselwirkung des freien Elektronenpaares des Stickstoffs mit dem π-Elektronengerüst des Thiophens beeinflußt wird. Durch HMO-Modellrechnungen wird gezeigt, daß die π-Elektronendichten in den einzelnen Positionen des Thiophenringes unterschiedlich stark vom C -N-Austauschintegral abhängen. Die Rechenergebnisse befinden sich in Übereinstimmung mit der Substituenten-Abhängigkeit der chemischen Verschiebungen der Thiophenprotonen.

Ressecção de cisto e abscesso renais por laparoscopia em um cão

Cistos renais podem formar-se em qualquer parte do néfron e dos ductos coletores. Alguns são hereditários, originando-se durante a organogênese, e outros se desenvolvem no tecido renal normal, depois que os rins estão completamente formados. No presente relato, descreve-se a ressecção de cisto e abscesso renais, por cirurgia laparoscópica em um cão. Para o acesso, foram utilizados três portais, dois de 10mm de diâmetro e um de 5mm, dispostos na parede abdominal lateral direita e, num segundo momento, na parede abdominal lateral esquerda. Conclui-se, portanto, que a técnica laparoscópica com três portais permite a realização de ressecção de cisto e abscesso renais em cães, sem a ocorrência de recidivas em curto prazo.

K(S)0 and Λ production in Pb-Pb collisions at √(s(NN))=2.76 TeV

The ALICE measurement of K(S)(0) and Λ production at midrapidity in Pb-Pb collisions at √(s(NN))=2.76 TeV is presented. The transverse momentum (p(T)) spectra are shown for several collision centrality intervals and in the p(T) range from 0.4 GeV/c (0.6 GeV/c for Λ) to 12 GeV/c. The p(T) dependence of the Λ/K(S)(0) ratios exhibits maxima in the vicinity of 3 GeV/c, and the positions of the maxima shift towards higher p(T) with increasing collision centrality. The magnitude of these maxima increases by almost a factor of three between most peripheral and most central Pb-Pb collisions. This baryon excess at intermediate p(T) is not observed in pp interactions at √s=0.9 TeV and at √s=7 TeV. Qualitatively, the baryon enhancement in heavy-ion collisions is expected from radial flow. However, the measured p(T) spectra above 2 GeV/c progressively decouple from hydrodynamical-model calculations. For higher values of p(T), models that incorporate the influence of the medium on the fragmentation and hadronization processes describe qualitatively the p(T) dependence of the Λ/K(S)(0) ratio.

Dietary habits and metabolic control in adolescents and young adults with phenylketonuria: self-imposed protein restriction may be harmful

BACKGROUND

In untreated patients, phenylketonuria (PKU) results in severe encephalopathy with mental retardation. A protein-restricted diet is recommended which can be relaxed in adolescence/adulthood.

METHODS

We contacted all 72 adult/adolescent PKU patients who had been treated in our center during early childhood. Some still regularly attended our outpatient clinics, while others were lost for follow-up, giving 51 patients in our study. We asked all patients to complete a dietary protocol as well as a questionnaire on quality of life. Blood and urine were analyzed and body impedance plethysmography and cerebral MRI were performed.

RESULTS

42 % of the patients followed protein restriction supplemented with amino acid mixtures (AAM), others had a vegan diet with (8 %) or without (14 %) AAM; 36 % said they were eating normally and did not need any AAM. However, based on dietary protocols and blood urea levels, protein intake was restricted in this patient group. None of the patients examined had serious nutritional deficits. Phenylalanine levels were higher in patients not taking AAM. MRI of the brain was not different from those following protein restriction and taking AAM. The lesions score and mood correlated best with the cumulative phenylalanine values during the first 10 years of life.

CONCLUSION

In summary, 50 % of adult/adolescent patients from our center did not take AAM at the start of our survey although they unknowingly followed self-imposed protein restriction. They had no overt nutritional deficits; however, long-term brain function may be compromised. Our study emphasizes the need for specialized metabolic care in PKU during adulthood.

[Determination of radioactivity by smartphones]

The interest in the detection of radioactive materials has strongly increased after the accident in the nuclear power plant Fukushima and has led to a bottleneck of suitable measuring instruments. Smartphones equipped with a commercially available software tool could be used for dose rate measurements following a calibration according to the specific camera module.

AIM

We examined whether such measurements provide reliable data for typical activities and radionuclides in nuclear medicine.

METHODS

For the nuclides 99mTc (10 - 1000 MBq), 131I (3.7 - 1800 MBq, therapy capsule) and 68Ga (50 - 600 MBq) radioactivity with defined geometry in different distances was measured. The smartphones Milestone Droid 1 (Motorola) and HTC Desire (HTC Corporation) were compared with the standard instruments AD6 (automess) and DoseGUARD (AEA Technology).

RESULTS

Measurements with the smartphones and the other devices show a good agreement: linear signal increase with rising activity and dose rate. The long time measurement (131I, 729 MBq, 0.5 m, 60 min) demonstrates a considerably higher variation (by 20%) of the measured smartphone data values compared with the AD6. For low dose rates (< 1 µGy/h), the sensitivity decreases so that measurements of e. g. the natural radiation exposure do not lead to valid results. The calibration of the camera responsivity for the smartphone has a big influence on the results caused by the small detector surface of the camera semiconductor.

CONCLUSIONS

With commercial software the camera module of a smartphone can be used for the measurement of radioactivity. Dose rates resulting from typical nuclear medicine procedures can be measured reliably (e. g., dismissal dose after radioiodine therapy). The signal shows a high correlation to measured values of conventional dose measurement devices.

Efficacy, safety and tolerability of vidofludimus in patients with inflammatory bowel disease: the ENTRANCE study

BACKGROUND

Vidofludimus (SC12267) is a novel oral immunomodulator inhibiting dihydroorotate dehydrogenase (DHODH) and the expression of proinflammatory cytokines including interleukin-17 (IL17A and IL17F) and interferon-gamma. The objective of the study was to explore the efficacy, safety and tolerability of vidofludimus in steroid-dependent inflammatory bowel disease (IBD).

METHODS

The open label uncontrolled ENTRANCE study (ClinicalTrials.gov NCT00820365) has been conducted at 13 study centers in Germany, Bulgaria and Romania. Thirty-four steroid-dependent patients with a confirmed diagnosis of Crohn's disease (CD) or ulcerative colitis (UC) were treated with a once daily 35mg oral dose of vidofludimus over 12weeks. Steroids were tapered during the first 8weeks followed by a steroid-free treatment period of 4weeks. Complete response was defined as steroid-free clinical remission at week 12; partial response was defined as being in remission at steroid dose equal or lower than the individual patient's threshold dose for relapse.

RESULTS

Of the thirty-four patients enrolled in this trial 26 were evaluable for primary efficacy assessment. After completion of the 12weeks treatment phase 8 out of 14 (57.1%) patients with CD and 6 out of 12 (50.0%) patients with UC were in steroid-free remission (complete responders). Another 4 (28.6%) patients in CD and 5 (41.7%) patients in UC were partial responders. Vidofludimus was well tolerated, no drug-related serious adverse events were observed.

CONCLUSIONS

This trial provides first evidence of clinical efficacy of vidofludimus in IBD. Although the safety and tolerability profile seems favorable, long-term controlled studies are needed to further investigate its potential as novel IBD therapy.