Ultra high frequency (UHF) ultrasound enables the visualization of very small structures that cannot be detected by conventional ultrasound. The utilization of UHF imaging as a new imaging technique for the 3D-in-vivo chorioallantoic membrane (CAM) model can facilitate new insights into tissue perfusion and survival. Therefore, human renal cystic tissue was grafted onto the CAM and examined using UHF ultrasound imaging. Due to the unprecedented resolution of UHF ultrasound, it was possible to visualize microvessels, their development, and the formation of anastomoses. This enabled the observation of anastomoses between human and chicken vessels only 12 h after transplantation. These observations were validated by 3D reconstructions from a light sheet microscopy image stack, indocyanine green angiography, and histological analysis. Contrary to the assumption that the nutrient supply of the human cystic tissue and the gas exchange happens through diffusion from CAM vessels, this study shows that the vasculature of the human cystic tissue is directly connected to the blood vessels of the CAM and perfusion is established within a short period. Therefore, this in-vivo model combined with UHF imaging appears to be the ideal platform for studying the effects of intravenously applied therapeutics to inhibit renal cyst growth.
Adherent cell systems are usually dissociated before being cryopreserved, as standard protocols are established for cells in suspension. The application of standard procedures to more complex systems, sensitive to dissociation, such as adherent monolayers, especially comprising mature cell types or tissues remains unsatisfactory. Uncontrolled cell detachment due to intracellular tensile stress, membrane ruptures and damages of adhesion proteins are common during freezing and thawing of cell monolayers. However, many therapeutically relevant cell systems grow adherently to develop their native morphology and functionality, but lose their integrity after dissociation. The hypothesis is that cells on stretchable substrates have a more adaptable cytoskeleton and membrane, reducing cryopreservation-induced stress. Our studies investigate the influence of stretchable surfaces on the cryopreservation of adherent cells to avoid harmful dissociation and expedite post-thawing cultivation of functional cells. A stretching apparatus for defined radial stretching, consisting of silicone vessels and films with specific surface textures for cell culture, was developed. Adherent human umbilical cord mesenchymal stem cells (hUC-MSCs) were cultivated on a stretched silicone film within the vessel, forming a monolayer that was compressed by relaxation, while remaining attached to the relaxed film. Compressed hUC-MSCs, which were cryopreserved adherently showed higher viability and less detachment after thawing compared to control cells without compression. Within three to seven days post-thawing, the hUC-MSCs recovered, and the monolayer reformed. These experiments support the hypothesis that cryopreservation success of adherent cell systems is enhanced by improved adaptability of the cytoskeleton and cell membrane, opening up new approaches in cryobiotechnology.
PURPOSE:Complete resection of the affected tissue remains the best curative treatment option for liver-derived tumors and colorectal liver metastases. In addition to preoperative cross-sectional imaging, contrast-enhanced intraoperative ultrasound (CE-IOUS) plays a crucial role in the detection and localization of all liver lesions. However, its exact role is unclear. This study was designed to evaluate the clinical and oncological impact of using CE-IOUS in the surgical treatment of these diseases.MATERIALS AND METHODS:Over the three-year study period, 206 patients with primary liver tumors and hepatic metastases were enrolled in this prospective, monocentric study to evaluate the impact of CE-IOUS in liver surgery. Secondary outcomes included comparing the sensitivity and specificity of CE-IOUS with existing preoperative imaging modalities and identifying preoperative parameters that could predict a strategic impact of CE-IOUS. In addition, the oncological significance of CE-IOUS was evaluated using a case-cohort design with a minimum follow-up of 18 months.RESULTS:CE-IOUS findings led to a change in surgical strategy in 34% of cases (n=70/206). The accuracy in cases with a major change could be confirmed histopathologically in 71.4% of cases (n=25/35). The impact could not be predicted using parameters assumed to be clinically relevant. An oncological benefit of a CE-IOUS adapted surgical approach was demonstrated in patients suffering from HCC and colorectal liver metastases.CONCLUSION:CE-IOUS may significantly increase R0 resection rates and should therefore be used routinely as an additional staging method, especially in complex liver surgery.
Krebs cycle activity in the presence of extracellular citrate and absolute citrate levels.
Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer with adverse outcomes that have barely improved over the last decade. About half of all patients present with metastasis at the time of diagnosis, and the 5-year overall survival rate across all stages is only 6%. Innovative in vivo research models are necessary to combat this cancer and to discover novel treatment strategies. The chorioallantoic membrane (CAM) model represents one 3D in vivo methodology that has been used in a large number of studies on different cancer types for over a century. This model is based on a membrane formed within fertilized chicken eggs that contain a dense network of blood vessels. Because of its high cost-efficiency, simplicity, and versatility, the CAM model appears to be a highly valuable research tool in the pursuit of gaining more in-depth insights into PDAC. A summary of the current literature on the usage of the CAM model for the investigation of PDAC was conducted and subdivided into angiogenesis, drug testing, modifications, personalized medicine, and further developments. On this comprehensive basis, further research should be conducted on PDAC in order to improve the abysmal prognosis of this malignant disease.
Synaptic proteins and synaptic transmission are under homeostatic control, but the relationship between these two processes remains enigmatic. Here, we systematically investigated the role of E3 ubiquitin ligases, key regulators of protein degradation-mediated proteostasis, in presynaptic homeostatic plasticity (PHP). An electrophysiology-based genetic screen of 157 E3 ligase-encoding genes at the Drosophila neuromuscular junction identified thin , an ortholog of human tripartite motif-containing 32 ( TRIM32 ), a gene implicated in several neurological disorders, including autism spectrum disorder and schizophrenia. We demonstrate that thin functions presynaptically during rapid and sustained PHP. Presynaptic thin negatively regulates neurotransmitter release under baseline conditions by limiting the number of release-ready vesicles, largely independent of gross morphological defects. We provide genetic evidence that thin controls release through dysbindin , a schizophrenia-susceptibility gene required for PHP. Thin and Dysbindin localize in proximity within presynaptic boutons, and Thin degrades Dysbindin in vitro. Thus, the E3 ligase Thin links protein degradation-dependent proteostasis of Dysbindin to homeostatic regulation of neurotransmitter release.
Hepatocytes are of special interest in biomedical research for disease modelling, drug screening and in vitro toxicology. Human induced pluripotent stem cell (hiPSC)-derived hepatocytes could complement primary human hepatocytes due to their capability for large-scale expansion. In this study, we present an optimized protocol for the generation of hepatocyte-like cells (HLCs) from hiPSC in monolayer (2D) and suspension culture (3D) for production of organoids. A protocol was initially optimized in 2D using a gene edited CYP3A4 Nanoluciferase reporter hiPSC line for monitoring the maturity of HLCs and cryopreservation of definitive endoderm (DE) cells. The protocol was optimized for microwell cultures for high-throughput screening to allow for a sensitive and fast readout of drug toxicity. To meet the increasing demand of hepatic cells in biomedical research, the differentiation process was furthermore translated to scalable suspension-based bioreactors for establishment of hepatic organoids. In pilot studies, the technical settings have been optimized by adjusting the initial seeding density, rotation speed, inoculation time, and medium viscosity to produce homogeneous hepatic organoids and to maximize the biomass yield (230 organoids/ml). To speed up the production process, cryopreservation approaches for the controlled freezing of organoids were analysed with respect to cell recovery and marker expression. The results showed that cryopreserved organoids maintained their phenotype only when derived from hepatocyte progenitors (HPs) at day 8 but not from more mature stages. The establishment of robust protocols for the production of large batches of hepatocytes and hepatic organoids could substantially boost their use in biomedical and toxicology studies.
Background. Pneumonia in liver transplant recipients is one of the most common infections in the early phase after transplantation. The diagnosis is based on clinical signs combined with positive microbiological samples taken from the lower respiratory tract. However, the role of bacterial colonization is not clear, nor is its association with pneumonia or its long-term consequences. The aim of this study was to investigate the association between positive microbiological findings and clinically relevant pneumonia and analyze different clinical and laboratory parameters for their association with pneumonia in liver transplant recipients. Methods. This was a retrospective analysis of 266 adult orthotopic liver transplantations between January 2008 and December 2013. A multidisciplinary in-house specialist panel established and confirmed the diagnosis of clinically relevant pneumonia in microbiologically positive patients. Results. Of the 266 transplantations analyzed, 54 patients (20%) showed microbiologically positive trachea-bronchial cultures during the first 21 days after liver transplantation. Of those 54 patients, 24 (44.4%) had pneumonia as rated by the multidisciplinary specialist panel. Presence of gram-negative Enterobacteriaceae (P =.013) and positive chest radiologic findings (P =.035) were associated with pneumonia in microbiological-positive patients. Although patients with pneumonia had the lowest long-term survival, those without pneumonia but with positive microbiological cultures had still worse survival compared with the Model for End-Stage Liver Disease-matched control group without positive cultures (P =.012). Conclusions. Gram-negative Enterobacteriaceae and positive radiologic findings were associated with pneumonia in liver transplant recipients with positive microbiological trachea-bronchial cultures. Recipients with bacterial colonization without pneumonia also showed decreased long-term survival.
The gold standard in cryopreservation is still conventional slow freezing of single cells or small aggregates in suspension, although major cell loss and limitation to non-specialised cell types in stem cell technology are known drawbacks. The requirement for rapidly available therapeutic and diagnostic cell types is increasing constantly. In the case of human induced pluripotent stem cells (hiPSCs) or their derivates, more sophisticated cryopreservation protocols are needed to address this demand. These should allow a preservation in their physiological, adherent state, an efficient re-cultivation and upscaling upon thawing towards high-throughput applications in cell therapies or disease modelling in drug discovery. Here, we present a novel vitrification-based method for adherent hiPSCs, designed for automated handling by microfluidic approaches and with ready-to-use potential e.g. in suspension-based bioreactors after thawing. Modifiable alginate microcarriers serve as a growth surface for adherent hiPSCs that were cultured in a suspension-based bioreactor and subsequently cryopreserved via droplet-based vitrification in comparison to conventional slow freezing. Soft (0.35%) versus stiff (0.65%) alginate microcarriers in concert with adhesion time variation have been examined. Findings revealed specific optimal conditions leading to an adhesion time and growth surface (matrix) elasticity dependent hypothesis on cryo-induced damaging regimes for adherent cell types. Deviations from the found optimum parameters give rise to membrane ruptures assessed via SEM and major cell loss after adherent vitrification. Applying the optimal conditions, droplet-based vitrification was superior to conventional slow freezing. A decreased microcarrier stiffness was found to outperform stiffer material regarding cell recovery, whereas the stemness characteristics of rewarmed hiPSCs were preserved.
Zusammenfassung Ziel des Verbundprojekts AKTIV-kommunal war die Entwicklung, pilothafte Umsetzung und Evaluierung einer integrierten Toolbox für die digitale Transformation kommunaler Energieversorger. In drei integriert bearbeiteten Teilprojekten standen die Digitalisierung von Arbeitsprozessen, digitale Arbeitsmodelle sowie Digital Leadership im Mittelpunkt der Projektaktivitäten. Dabei bildeten jeweils ein Forschungspartner und ein Anwendungsunternehmen ein Tandem, um zu wissenschaftlich fundierten und praxistauglichen Ergebnissen zu gelangen. Der Projektbeirat, dem namhafte Vertreter/-innen aus Unternehmen, von Verbänden, der Sozialpartner und weitere Wissenschaftler angehörten, gab zusätzliche Impulse für die Projektarbeit. Im vorliegenden Beitrag werden die zentralen Ergebnisse von AKTIV-kommunal vorgestellt. Darüber hinaus werden Hinweise zu den im Projektverlauf erstellten Transfermaterialien gegeben und erfolgt ein Ausblick auf zukünftige Forschungsaktivitäten.
The internal diameter (ID) coating by means of thermal spraying is currently experiencing growing interest in science and industry. In contrast to the well-established plasma- and arc-based spray techniques, there is a lack of knowledge concerning kinetic processes such as HVOF, HVAF and warm spray (WS). A major challenge represents the necessity of short spray distances and the compact design of novel ID spray guns with reduced combustion power. Conventional WC-Co powders (− 45 + 15 µm) are not able to achieve a sufficient heat and momentum transfer. The use of fine powders < 15 µm offers an approach to overcome this drawback as they feature a larger surface-to-volume ratio and a lower mass. However, the processing of fine powders requires suitable spray equipment and a sensitive parameter adjustment. In this study, warm spraying of fine WC-12Co powders (− 10 + 2 µm) with a novel ID spray gun (HVOF + N 2 ) “ID RED” (Thermico Engineering GmbH, Germany) was investigated. First, the flame profile as well as the in-flight behavior of the particles along the spray jet (spray distances SD = 10-80 mm) was analyzed at different nitrogen flows NF = 15-115 L/min to find suitable spray parameter intervals. Subsequently, planar steel samples were coated with SD = 10-50 mm and constant NF = 90 L/min. Analyses regarding the microstructure, the mechanical properties and the phase evolution of the coatings were performed. The aim was to study spraying with the novel ID gun and to scrutinize shortest feasible spray distances. Finally, steel tubes (internal diameter of 81.6 mm and a wall thickness of 10.0 mm) were coated with SD = 20 mm and NF = 90 L/min to investigate in how far the results can be transferred to ID parts. Correlations between the particle behavior, the microstructure and the coating properties were made.
Einleitung Der Einfluss einer SARS-CoV-2-Infektion auf chronisch entzundliche Darmerkrankungen (CED) ist bislang nicht gut charakterisiert, und es ist unklar, ob diese eine Anpassung der immunsuppressiven Therapie erfordert. Methodik Fur die retrospektive Dokumentation klinischer Parameter und Veranderungen einer immunsuppressiven Therapie von mit SARS-CoV-2 infizierten CED-Patienten wurde ein nationales Melderegister etabliert. Ergebnisse Insgesamt wurden nur 3 von 185 CED-Patienten (1,6 %) wegen abdomineller Symptome auf eine SARS-CoV-2-Infektion getestet. Im COVID-19-Krankheitsverlauf entwickelten 43,5 % Durchfall, abdominelle Schmerzen oder Hamatochezie (Hospitalisierungsrisiko mit vs. ohne abdominelle Symptome: 20,0 % vs. 10,6 %, p Diskussion Bei mit SARS-CoV-2 infizierten CED-Patienten traten haufig neue abdominelle Symptome bei Infektion auf. Diese fuhrten aber nur selten zur SARS-CoV-2-Testung. Eine hohe CED-Aktivitat zum Zeitpunkt des SARS-CoV-2-Nachweises war mit einem erhohten Hospitalisierungsrisiko assoziiert.
Introduction Pulmonary rehabilitation (PR) aims to improve disease control in patients with chronic obstructive pulmonary disease (COPD) and asthma. However, the success of PR-programs depends on the patients’ participation and willingness to cooperate. Taking the patients’ preferences into consideration might improve both of these factors. Accordingly, our study aims to analyze patients’ preferences regarding current rehabilitation approaches in order to deduce and discuss possibilities to further optimize pulmonary rehabilitation. Methods and analysis At the end of a 3 weeks in-house PR, patients’ preferences concerning the proposed therapies were assessed during two different time slots (summer 2015 and winter 2015/2016) in three clinics using a choice-based conjoint analysis (CA). Relevant therapy attributes and their levels were identified through literature search and expert interviews. Inclusion criteria were as follows: PR-inpatient with asthma and/or COPD, confirmed diagnosis, age over 18 years, capability to write and read German, written informed consent obtained. The CA analyses comprised a generalized linear mixed-effects model and a latent class mixed logit model. Results A total of 542 persons participated in the survey. The most important attribute was sport and exercise therapy. Rehabilitation preferences hardly differed between asthma and COPD patients. Health-related quality of life (HRQoL) as well as time since diagnosis were found to have a significant influence on patients’ rehabilitation preferences. Conclusions Patients in pulmonary rehabilitation have preferences regarding specific program components. To increase the adherence to, and thus, the effectiveness of rehabilitation programs, these results must be considered when developing or optimizing PR-programs.
Citrate is important for lipid synthesis and epigenetic regulation in addition to ATP production. We have previously reported that cancer cells import extracellular citrate via the pmCiC transporter to support their metabolism. Here, we show for the first time that citrate is supplied to cancer by cancer-associated stroma (CAS) and also that citrate synthesis and release is one of the latter’s major metabolic tasks. Citrate release from CAS is controlled by cancer cells through cross-cellular communication. The availability of citrate from CAS regulated the cytokine profile, metabolism and features of cellular invasion. Moreover, citrate released by CAS is involved in inducing cancer progression especially enhancing invasiveness and organ colonisation. In line with the in vitro observations, we show that depriving cancer cells of citrate using gluconate, a specific inhibitor of pmCiC, significantly reduced the growth and metastatic spread of human pancreatic cancer cells in vivo and muted stromal activation and angiogenesis. We conclude that citrate is supplied to tumour cells by CAS and citrate uptake plays a significant role in cancer metastatic progression.
Einleitung Der Covid-19-Verlauf bei Patienten mit chronisch entzündlichen Darmerkrankungen (CED) war zu Beginn der Pandemie ungewiss. CED-Patienten befürchteten insbesondere einen negativen Einfluss einer immunsuppressiven Therapie auf den Covid-19-Schweregrad.
Because tobacco is a potent carcinogen, secondary causes of lung cancer are often diminished in perceived importance, especially in small cell lung cancer (SCLC), the most lethal lung cancer which is almost exclusively related to tobacco. Inherited susceptibility to SCLC and its association with clinical characteristics remain unknown.
Einleitung Um mit Hilfe eines Sprachtestverfahrens einen Rückschluss auf das Tonaudiogramm (TA) zu erhalten, kann derzeit im deutschsprachigen Raum der Freiburger Sprachtest mit Zahlen (FBZ, HVSprache) und der Göttinger Satztest (GÖSA) in Ruhe verwendet werden. Ist dies im Hinblick auf die Pädaudiologie auch mit anderen Verfahren möglich? Material und Methoden An der Studie nahmen ohrgesunde Probanden (10 ♀, 2 ♂; Alter: 20 – 33 Jahre; Median: 23 Jahre) teil. Der PTA4 bei 0.5, 1, 2, 4 kHz beträgt -2,9 dB HL (Median). Die Sprachaudiometrie fand in Ruhe im normalhörenden Zustand und mit einer künstlich erzeugten einseitigen Schallleitungsschwerhörigkeit (SLSH) (durch Ohrstöpsel, OS) statt. Getestet wurden der FBZ (HVSprache), der Einsilbertest (FBE) und der Oldenburger Satztest (OLSA). Die kinderaudiometrischen Verfahren (Frequency Specific Animal Soundtest (mFast) und der Adaptive Auditive Sprachtest, AAST) wurden analog zum FBZ angewendet. Hier erfolgte die Bestimmung des Pegels für 50 % Verstehen (SRTRuhe).
The locus coeruleus is a pontine nucleus that produces much of the brain's norepinephrine. Despite its small size, the locus coeruleus is critical for a myriad of functions and is involved in many neurodegenerative and neuropsychiatric disorders. In this review, we discuss the physiology and anatomy of the locus coeruleus system and focus on norepinephrine's role in synaptic plasticity. We highlight Parkinson's disease as a disorder with motor and neuropsychiatric symptoms that may be understood as aberrations in the normal functions of locus coeruleus.