Identification of Novel Functional Inhibitors of Acid Sphingomyelinase

We describe a hitherto unknown feature for 27 small drug-like molecules, namely functional inhibition of acid sphingomyelinase (ASM). These entities named FIASMAs (Functional Inhibitors of Acid SphingoMyelinAse), therefore, can be potentially used to treat diseases associated with enhanced activity of ASM, such as Alzheimer's disease, major depression, radiation- and chemotherapy-induced apoptosis and endotoxic shock syndrome. Residual activity of ASM measured in the presence of 10 µM drug concentration shows a bimodal distribution; thus the tested drugs can be classified into two groups with lower and higher inhibitory activity. All FIASMAs share distinct physicochemical properties in showing lipophilic and weakly basic properties. Hierarchical clustering of Tanimoto coefficients revealed that FIASMAs occur among drugs of various chemical scaffolds. Moreover, FIASMAs more frequently violate Lipinski's Rule-of-Five than compounds without effect on ASM. Inhibition of ASM appears to be associated with good permeability across the blood-brain barrier. In the present investigation, we developed a novel structure-property-activity relationship by using a random forest-based binary classification learner. Virtual screening revealed that only six out of 768 (0.78%) compounds of natural products functionally inhibit ASM, whereas this inhibitory activity occurs in 135 out of 2028 (6.66%) drugs licensed for medical use in humans

Gold nanoparticles allow detection of early-stage edema in mice via computed tomography imaging

Jenny Domey, Ulf Teichgräber, Ingrid Hilger Institute of Diagnostic and Interventional Radiology, University Hospital Jena, Jena, Germany Abstract: Due to their high X-ray attenuation, gold nanoparticles (GNPs) emerged as preclinical contrast agents by giving high vasculature contrast. For this reason, GNPs are regularly applied for computed tomography (CT) imaging of tumors but not for the visualization of inflammation. The aim of this study was to evaluate the biocompatibility and applicability of preclinical GNPs (AuroVist™) of two different sizes (1.9 nm and 15 nm) for the detection of inflammation-associated phagocytes in early-stage edema. Both GNP variants were stable under in vitro conditions and achieved high micro-CT (mCT) contrast after embedment into agarose. Fifteen-nanometer GNPs were detected after uptake into macrophages via mCT imaging exhibiting higher X-ray contrast than cells treated with 1.9 nm GNPs and untreated ones. Both 1.9 nm and 15 nm GNPs exhibited good biocompatibility on murine macrophages according to ATP and cellular dehydrogenase levels. Reactive oxygen species levels produced by phagocytic cells decreased significantly (P≤0.05) after co-incubation with GNPs regardless of the size of the nanoparticle (NP) in comparison to untreated control cells. In vivo mCT studies of inflammation imaging revealed that GNPs with a diameter of 15 nm accumulated within subcutaneous edema 2 hours after injection with a maximum signaling 8 hours postinjection and could be detected up to 48 hours within the edema region. In contrast, 1.9 nm GNPs were not shown to accumulate at the site of the inflammation region and were mostly excreted via the renal system 2–4 hours after injection. In conclusion, our study demonstrated that both GNP variants (1.9 nm and 15 nm) were stable and biocompatible under in vitro conditions. However, only 15 nm NPs have the potential as contrast agent for phagocyte labeling and applications in CT imaging of inflammation on a cellular level. Keywords: inflammation, GNP, phagocytes, AuroVist™, biocompatibilit

Methotrexate-coupled nanoparticles and magnetic nanochemothermia for the relapse-free treatment of T24 bladder tumors

Marcus Stapf, Ulf Teichgräber, Ingrid Hilger Department of Experimental Radiology, Institute of Diagnostic and Interventional Radiology, Jena University Hospital, Friedrich-Schiller University Jena, Jena, Germany Abstract: Heat-based approaches have been considered as promising tools due to their ability to directly eradicate tumor cells and/or increase the sensitivity of tumors to radiation- or chemotherapy. In particular, the heating of magnetic nanoparticles (MNPs) via an alternating magnetic field can provide a handy alternative for a localized tumor treatment. To amplify the efficacy of magnetically induced thermal treatments, we elucidated the superior tumor-destructive effect of methotrexate-coupled MNPs (MTX/MNPs) in combination with magnetic heating (nanochemothermia) over the thermal treatment alone. Our studies in a murine bladder xenograft model revealed the enormous potential of nanochemothermia for a localized and relapse-free destruction of tumors which was superior to the thermal treatment alone. Nanochemothermia remarkably fostered the reduction of tumor volume. It impaired proapoptotic signaling (eg, p-p53), cell survival (eg, p-ERK1/2), and cell cycle (cyclins) pathways. Additionally, heat shock proteins (eg, HSP70) were remarkably affected. Moreover, nanochemothermia impaired the induction of angiogenic signaling by decreasing, for example, the levels of VEGF-R1 and MMP9, although an increasing tumor hypoxia was indicated by elevated Hif-1α levels. In contrast, tumor cells were able to recover after the thermal treatments alone. In conclusion, nanochemothermia on the basis of MTX/MNPs was superior to the thermal treatment due to a modification of cellular pathways, particularly those associated with the cellular survival and tumor vasculature. This allowed very efficient and relapse-free destruction of tumors. Keywords: bladder cancer, magnetic heating, magnetic nanoparticles, methotrexate, hyperthermia, mouse xenograf

‘Low-dose’ dopamine worsens renal perfusion in patients with acute renal failure

‘Low-dose’ dopamine is frequently used in intensive care units (ICU) for its presumed renoprotective effects, but prospective and retrospective studies have so far not proven prevention or amelioration of renal injury. Data on renal perfusion following dopamine infusion are limited. In order to circumvent the problem of patient heterogeneity in the ICU setting, we used a crossover design in a prospective, double-blind randomized controlled study to investigate the effect of ‘low-dose’ dopamine on renal resistance indices, as determined by Doppler ultrasound. Forty patients, 10 without and 30 with acute renal failure (ARF, defined as doubling of baseline creatinine or an increase above 2 mg/dl), were included. Dopamine (2 μg/kg min) or placebo was given intravenously in alternating sequence for four subsequent periods of 60 min, starting randomly with either dopamine or placebo. Resistive (RI) and pulsatility index (PI) were closely correlated, positively related to serum creatinine values at baseline and highly reproducible during the two paired infusion periods. Dopamine reduced renal vascular resistance in patients without ARF (median RI/PI from 0.70 to 0.65/1.20 to 1.07, P<0.01) but increased resistance indices in patients with ARF (median RI/PI from 0.77 to 0.81/1.64 to 1.79, P<0.01) in the absence of effects on systemic hemodynamics. Subgroup analysis of patients with ARF revealed that dopamine induced renal vasoconstriction above 55 years (n=22) and in patients not receiving norepinephrine (n=20). In conclusion ‘low-dose’ dopamine can worsen renal perfusion in patients with ARF, which adds to the rationale for abandoning the routine use of ‘low-dose’ dopamine in critically ill patients

Heterogeneous response of different tumor cell lines to methotrexate-coupled nanoparticles in presence of hyperthermia

Marcus Stapf,* Nadine P&ouml;mpner,* Ulf Teichgr&auml;ber, Ingrid HilgerInstitute of Diagnostic and Interventional Radiology, Department of Experimental Radiology, Jena University Hospital, Friedrich-Schiller University, Jena, Germany*These authors contributed equally to&nbsp;this workAbstract: Today, the therapeutic efficacy of cancer is restricted by the heterogeneity of the response of tumor cells to chemotherapeutic drugs. Since those therapies are also associated with severe side effects in nontarget organs, the application of drugs in combination with nanocarriers for targeted therapy has been suggested. Here, we sought to assess whether the coupling of methotrexate (MTX) to magnetic nanoparticles (MNP) could serve as a valuable tool to circumvent the heterogeneity of tumor cell response to MTX by the combined treatment with hyperthermia. To this end, we investigated five breast cancer cell lines of different origin and with different mutational statuses, as well as a bladder cancer cell line in terms of their response to exposure to MTX as a free drug or after its coupling to MNP as well as in presence/absence of hyperthermia. We also assessed whether the effects could be connected to the cell line-specific expression of proteins related to the uptake and efflux of MTX and MNP. Our results revealed a very heterogeneous and cell line-dependent response to an exposure with MTX-coupled MNP (MTX&ndash;MNP), which was almost comparable to the efficacy of free MTX in the same cell line. Moreover, a cell line-specific and preferential uptake of MTX&ndash;MNP compared with MNP alone was found (probably by receptor-mediated endocytosis), agreeing with the observed cytotoxic effects. Opposed to this, the expression pattern of several cell membrane transport proteins noted for MTX uptake and efflux was only by tendency in agreement with the cellular toxicity of MTX&ndash;MNP in different cell lines. Higher cytotoxic effects were achieved by exposing cells to a combination of MTX&ndash;MNP and hyperthermal treatment, compared with MTX or thermotherapy alone. However, the heterogeneity in the response of the tumor cell lines to MTX could not be completely abolished &ndash; even after its combination with MNP and/or hyperthermia &ndash; and the application of higher thermal dosages might be necessary.Keywords: magnetic nanoparticles, SPION, in vitro, methotrexate, hyperthermia, breast cancer, bladder cance

Reformierter Regelstudiengang zur Förderung der Neigungsorientierung im Studium der Humanmedizin: JENOS

Introduction: In the last ten years, the medical faculty at Friedrich Schiller University Jena has reformed its traditional curriculum for human medicine. The reformed JENa professional interest-Oriented Studies (JEnaer Neigungs-Orientiertes Studium, JENOS) - with the objective to facilitate career entry through a professional interest-oriented practical approach - emerged due to the stipulation of cost neutrality.Methods: Report on the process sequence of JENOS from the reform idea to implementation: the initial processes, the development and assessment process with accompanying dialogue and dispute of the reform process within the faculty shall be discussed. The 17 objectives of the JENOS reformed traditional curriculum shall be presented and the current level of fulfilment assessed.Results: The structural link of the professional interest-oriented proposals was achieved through the recognition by the "Landesprüfungsamt" (State Examination Board) as elective subjects with 21 semester hours (SH). Feedback and evaluations were conducted using lecturer and student information systems that were implemented in parallel. Eleven of 17 objectives have been achieved, three are still in process and three have not been achieved.Discussion: A professional interest orientation could be achieved through the reform. The weaknesses are found primarily in the links between teaching content. These are currently undergoing a mapping process in order to be optimised. Conclusions: Despite cost neutrality, JENOS is the successful result of reforming the curriculum. The academic reform complied with some requirements for the Master Plan 2020 for Medical Studies in order to be able to implement future changes.Einleitung: Die Medizinische Fakultät der Friedrich-Schiller-Universität Jena hat in den letzten zehn Jahren ihren Regelstudiengang der Humanmedizin reformiert. Unter der Vorgabe der Kostenneutralität ist der reformierte JEnaer NeigungsOrientierte Studiengang (JENOS) - mit der Zielsetzung den Berufseinstieg durch eine neigungsorientierte Praxisorientierung zu erleichtern - entstanden.Methodik: Bericht über den Prozessverlauf von JENOS von der Reformidee zur Umsetzung: Es werden die anfänglichen Prozesse, der Entwicklungs- und Begutachtungsprozess mit dem Dialog und Disput für den Reformprozess in der Fakultät betrachtet. Die 17 Zielsetzungen des reformierten Regelstudiengangs JENOS werden vorgestellt und deren bisheriger Erfüllungsgrad bewertet.Ergebnisse: Die strukturelle Anbindung der neigungsorientierten Angebote erfolgte über die Anerkennung als Wahlfach mit 21 Semesterwochenstunden (SWS) über das Landesprüfungsamt. Feedbacks und Evaluationen wurden über ein zeitgleich eingeführtes Dozenten- und Studierendeninformationssystem durchgeführt. 11 von 17 Zielsetzungen konnten erreicht werden, drei weitere im Ansatz, und drei konnten nicht erreicht werden.Diskussion: Eine Neigungsorientierung konnte mit der Reform realisiert werden. Die Schwächen beziehen sich in erster Linie auf die Verknüpfung der Lehrinhalte, welche aktuell durch einen Mapping-Prozess optimiert werden. Schlussfolgerung: Trotz Kostenneutralität ist es mit JENOS gelungen, eine Studienreform erfolgreich durchzuführen. Die Studienreform hat partielle Voraussetzungen für den Masterplan Medizinstudium 2020 geschaffen, um künftige Veränderungen umsetzen zu können