kurz und kn@pp news : Nr. 33
Interplay between endothelin and erythropoietin in astroglia: the role in protection against hypoxia
Christoph H. Gleiter
- We show that, under in vitro conditions, the vulnerability of astroglia to hypoxia is reflected by alterations in endothelin (ET)-1 release and capacity of erythropoietin (EPO) to regulate ET-1 levels. Exposure of cells to 24 h hypoxia did not induce changes in ET-1 release, while 48–72 h hypoxia resulted in increase of ET-1 release from astrocytes that could be abolished by EPO. The endothelin receptor type A (ETA) antagonist BQ123 increased extracellular levels of ET-1 in human fetal astroglial cell line (SV-FHAS). The survival and proliferation of rat primary astrocytes, neural precursors, and neurons upon hypoxic conditions were increased upon administration of BQ123. Hypoxic injury and aging affected the interaction between the EPO and ET systems. Under hypoxia EPO decreased ET-1 release from astrocytes, while ETA receptor blockade enhanced the expression of EPO mRNA and EPO receptor in culture-aged rat astroglia. The blockade of ETA receptor can increase the availability of ET-1 to the ETB receptor and can potentiate the neuroprotective effects of EPO. Thus, the new therapeutic use of combined administration of EPO and ETA receptor antagonists during hypoxia-associated neurodegenerative disorders of the central nervous system (CNS) can be suggested.
Indication for 'Over the Scope' (OTS)-Clip vs. Covered Self-Expanding Metal Stent (cSEMS) Is Unequal in Upper Gastrointestinal Leakage: Results from a Retrospective Head-to-Head Comparison
Wolf O. Bechstein
Jörg G. Albert
- Background: Intestinal perforation or leakage increases morbidity and mortality of surgical and endoscopic interventions. We identified criteria for use of full-covered, extractable self-expanding metal stents (cSEMS) vs. ‘Over the scope’-clips (OTSC) for leak closure.
Methods: Patients who underwent endoscopic treatment for postoperative leakage, endoscopic perforation, or spontaneous rupture of the upper gastrointestinal tract between 2006 and 2013 were identified at four tertiary endoscopic centers. Technical success, outcome (e.g. duration of hospitalization, in-hospital mortality), and complications were assessed and analyzed with respect to etiology, size and location of leakage.
Results: Of 106 patients (male: 75 (71%), female: 31 (29%); age (mean ± SD): 62.5 ± 1.3 years, 72 (69%) were treated by cSEMS and 34 (31%) by OTSC. For cSEMS vs. OTSC, mean treatment duration was 41.1 vs. 25 days, p<0.001, leakage size 10 (1-50) vs. 5 (1-30) mm (median (range)), and complications were observed in 68% vs. 8.8%, p<0.001, respectively. Clinical success for primary interventional treatment was observed in 29/72 (40%) vs. 24/34 (70%, p = 0.006), and clinical success at the end of follow-up was 46/72 (64%) vs. 29/34 (85%) for patients treated by cSEMS vs. OTSC; p = 0.04.
Conclusion: OTSC is preferred in small-sized lesions and in perforation caused by endoscopic interventions, cSEMS in patients with concomitant local infection or abscess. cSEMS is associated with a higher frequency of complications. Therefore, OTSC might be preferred if technically feasible. Indication criteria for cSEMS vs. OTSC vary and might impede design of randomized studies.
Primary Biliary Acids Inhibit Hepatitis D Virus (HDV) Entry into Human Hepatoma Cells Expressing the Sodium-Taurocholate Cotransporting Polypeptide (NTCP)
Isabel Veloso Alves Pereira
Michael P. Manns
Cláudia Pinto Marques Souza de Oliveira
Thomas von Hahn
- Background: The sodium-taurocholate cotransporting polypeptide (NTCP) is both a key bile acid (BA) transporter mediating uptake of BA into hepatocytes and an essential receptor for hepatitis B virus (HBV) and hepatitis D virus (HDV). In this study we aimed to characterize to what extent and through what mechanism BA affect HDV cell entry.
Methods: HuH-7 cells stably expressing NTCP (HuH-7/NTCP) and primary human hepatocytes (PHH) were infected with in vitro generated HDV particles. Infectivity in the absence or presence of compounds was assessed using immunofluorescence staining for HDV antigen, standard 50% tissue culture infectious dose (TCID50) assays and quantitative PCR.
Results: Addition of primary conjugated and unconjugated BA resulted in a dose dependent reduction in the number of infected cells while secondary, tertiary and synthetic BA had a lesser effect. This effect was observed both in HuH-7/NTCP and in PHH. Other replication cycle steps such as replication and particle assembly and release were unaffected. Moreover, inhibitory BA competed with a fragment from the large HBV envelope protein for binding to NTCP-expressing cells. Conversely, the sodium/BA-cotransporter function of NTCP seemed not to be required for HDV infection since infection was similar in the presence or absence of a sodium gradient across the plasma membrane. When chenodeoxycolic acid (15 mg per kg body weight) was administered to three chronically HDV infected individuals over a period of up to 16 days there was no change in serum HDV RNA.
Conclusions: Primary BA inhibit NTCP-mediated HDV entry into hepatocytes suggesting that modulation of the BA pool may affect HDV infection of hepatocytes.
Der vergessene Retter : Philipp Schwartz – Organisator der Wissenschaftsemigration während des Nationalsozialismus
- Eine Liste mit den Namen von 1.794 Wissenschaftlern, die in Nazideutschland entlassen wurden, steht seit 30 Jahren im Regal des Frankfurter Neurologischen Instituts. Von dort geht die Initiative aus, ihren Urheber wiederzuentdecken: den zu Unrecht in Vergessenheit geratenen Neuropathologen Philipp Schwartz.
Implementation of chronic illness care in German primary care practices - how do multimorbid older patients view routine care? A cross-sectional study using multilevel hierarchical modeling
Juliana J. Petersen
Michael A. Paulitsch
Steffi Gerlinde Riedel-Heller
Hendrik van den Bussche
- Background: In primary care, patients with multiple chronic conditions are the rule rather than the exception. The Chronic Care Model (CCM) is an evidence-based framework for improving chronic illness care, but little is known about the extent to which it has been implemented in routine primary care. The aim of this study was to describe how multimorbid older patients assess the routine chronic care they receive in primary care practices in Germany, and to explore the extent to which factors at both the practice and patient level determine their views.
Methods: This cross-sectional study used baseline data from an observational cohort study involving 158 general practitioners (GP) and 3189 multimorbid patients. Standardized questionnaires were employed to collect data, and the Patient Assessment of Chronic Illness Care (PACIC) questionnaire used to assess the quality of care received. Multilevel hierarchical modeling was used to identify any existing association between the dependent variable, PACIC, and independent variables at the patient level (socio-economic factors, weighted count of chronic conditions, instrumental activities of daily living, health-related quality of life, graded chronic pain, no. of contacts with GP, existence of a disease management program (DMP) disease, self-efficacy, and social support) and the practice level (age and sex of GP, years in current practice, size and type of practice).
Results: The overall mean PACIC score was 2.4 (SD 0.8), with the mean subscale scores ranging from 2.0 (SD 1.0, subscale goal setting/tailoring) to 3.5 (SD 0.7, delivery system design). At the patient level, higher PACIC scores were associated with a DMP disease, more frequent GP contacts, higher social support, and higher autonomy of past occupation. At the practice level, solo practices were associated with higher PACIC values than other types of practice.
Conclusions: This study shows that from the perspective of multimorbid patients receiving care in German primary care practices, the implementation of structured care and counseling could be improved, particularly by helping patients set specific goals, coordinating care, and arranging follow-up contacts. Studies evaluating chronic care should take into consideration that a patient’s assessment is associated not only with practice-level factors, but also with individual, patient-level factors.
Trial registration: Current Controlled Trials ISRCTN89818205.
Is contrast medium osmolality a causal factor for contrast-induced nephropathy?
Andreas M. Bucher
Carlo N. De Cecco
U. Joseph Schoepf
Felix G. Meinel
Aleksander W. Krazinski
James V. Spearman
Andrew D. McQuiston
Thomas J. Vogl
Richard W. Katzberg
- The exact pathophysiology of contrast-induced nephropathy (CIN) is not fully clarified, yet the osmotic characteristics of contrast media (CM) have been a significant focus in many investigations of CIN. Osmotic effects of CM specific to the kidney include transient decreases in blood flow, filtration fraction, and glomerular filtration rate. Potentially significant secondary effects include an osmotically induced diuresis with a concomitant dehydrating effect. Clinical experiences that have compared the occurrence of CIN between the various classes of CM based on osmolality have suggested a much less than anticipated advantage, if any, with a lower osmolality. Recent animal experiments actually suggest that induction of a mild osmotic diuresis in association with iso-osmolar agents tends to offset potentially deleterious renal effects of high viscosity-mediated intratubular CM stagnation.
Neurokognitives Enhancement und Hirndoping bei Medizinstudenten in Deutschland : eine quantitative und qualitative Erhebung zum Umgang mit Leistungsdruck
- Der Begriff Hirndoping beschreibt die Einnahme von Medikamenten mit dem Ziel der geistigen Leistungssteigerung. Diese Medikamente sind verschreibungspflichtig und bei den Konsumenten medizinisch nicht indiziert, werden also zweckentfremdet. Mittlerweile ist aus dem Thema Hirndoping ein Thema geworden, welches öffentlich diskutiert wird. Zeitung, Presse und sogar die Film- und Fernsehindustrie beschäftigen sich mit diesem Thema. So nimmt unter anderem die gestresste Mutter Lynette aus der US-Serie «Desperate Housewives» die Ritalin-Tablette ihres Sohnes ein, um so den anstrengenden Alltag besser meistern zu können. In dem US-Film «Ohne Limit - Die Droge für Reichtum und Macht» dreht sich alles um eine Droge, welche die Leistungsfähigkeit ins unermessliche steigern kann.
In der aktuellen Presse findet man immer öfter Schlagzeilen wie beispielsweise Folgendes: „Studenten unter Druck: Hirndoping kein Massenphänomen“.
Doch auch die Lebensmittel- und Pharmaindustrie ist beim Thema Leistungssteigerung in der Ideenfindung sehr kreativ. Manche Substanzen „verleihen einem Flügel“ (Red Bull®), andere sind lecker in Schokolade eingepackt (Pocket Coffee®) und wieder andere sollen die Menschen geistig aktiver machen (Gingium®).
Der Großteil der bisherigen Studien zum Thema Hirndoping stammt aus den Vereinigten Staaten von Amerika. Erst seit kurzer Zeit wird auch die Prävalenz von Hirndoping in Deutschland untersucht. Wie viele Schülerinnen und Schüler sowie Studentinnen und Studenten Substanzen zur geistigen Leistungssteigerung einnehmen, wurde teils schon für bestimmte Regionen und bestimmte Fachrichtungen stichprobenartig ermittelt. Bisher liegen allerdings noch keine umfangreichen Daten zur Prävalenz von Hirndoping bei Medizinstudenten vor. Daher untersuchte diese Studie die Einnahme von Leistungssteigernden Substanzen bei Medizinstudenten in Frankfurt am Main.
Sphingosine-1-phosphate modulates dendritic cell function: focus on non-migratory effects in vitro and in vivo
Heinfried Hermann Radeke
- Dendritic cells (DCs) are the cutting edge in innate and adaptive immunity. The major functions of these antigen-presenting cells are the capture, endosomal processing and presentation of antigens, providing them an exclusive ability to provoke adaptive immune responses and to induce and control tolerance. Immature DCs capture and process antigens, migrate towards secondary lymphoid organs where they present antigens to naive T cells in a well-synchronized sequence of procedures referred to as maturation. Indeed, recent research indicated that sphingolipids are modulators of essential steps in DC homeostasis. It has been recognized that sphingolipids not only modulate the development of DC subtypes from precursor cells but also influence functional activities of DCs such as antigen capture, and cytokine profiling. Thus, it is not astonishing that sphingolipids and sphingolipid metabolism play a substantial role in inflammatory diseases that are modulated by DCs. Here we highlight the function of sphingosine 1-phosphate (S1P) on DC homeostasis and the role of S1P and S1P metabolism in inflammatory diseases.
Controlled intramyocardial release of engineered chemokines by biodegradable hydrogels as a treatment approach of myocardial infarction
Birgit K. Kramp
Tilman M. Hackeng
Elisa A. Liehn
Rory R. Koenen
- Myocardial infarction (MI) induces a complex inflammatory immune response, followed by the remodelling of the heart muscle and scar formation. The rapid regeneration of the blood vessel network system by the attraction of hematopoietic stem cells is beneficial for heart function. Despite the important role of chemokines in these processes, their use in clinical practice has so far been limited by their limited availability over a long time-span in vivo. Here, a method is presented to increase physiological availability of chemokines at the site of injury over a defined time-span and simultaneously control their release using biodegradable hydrogels. Two different biodegradable hydrogels were implemented, a fast degradable hydrogel (FDH) for delivering Met-CCL5 over 24 hrs and a slow degradable hydrogel (SDH) for a gradual release of protease-resistant CXCL12 (S4V) over 4 weeks. We demonstrate that the time-controlled release using Met-CCL5-FDH and CXCL12 (S4V)-SDH suppressed initial neutrophil infiltration, promoted neovascularization and reduced apoptosis in the infarcted myocardium. Thus, we were able to significantly preserve the cardiac function after MI. This study demonstrates that time-controlled, biopolymer-mediated delivery of chemokines represents a novel and feasible strategy to support the endogenous reparatory mechanisms after MI and may compliment cell-based therapies.