TY - JOUR A1 - Zinner, Christoph A1 - Hauser, Anna A1 - Born, Dennis-Peter A1 - Wehrlin, Jon P. A1 - Holmberg, Hans-Christer A1 - Sperlich, Billy T1 - Influence of Hypoxic Interval Training and Hyperoxic Recovery on Muscle Activation and Oxygenation in Connection with Double-Poling Exercise JF - PLoS One N2 - Here, we evaluated the influence of breathing oxygen at different partial pressures during recovery from exercise on performance at sea-level and a simulated altitude of 1800 m, as reflected in activation of different upper body muscles, and oxygenation of the m. triceps brachii. Ten well-trained, male endurance athletes (25.3±4.1 yrs; 179.2±4.5 cm; 74.2±3.4 kg) performed four test trials, each involving three 3-min sessions on a double-poling ergometer with 3-min intervals of recovery. One trial was conducted entirely under normoxic (No) and another under hypoxic conditions \((Ho; F_iO_2 = 0.165)\). In the third and fourth trials, the exercise was performed in normoxia and hypoxia, respectively, with hyperoxic recovery \((HOX; F_iO_2 = 1.00)\) in both cases. Arterial hemoglobin saturation was higher under the two HOX conditions than without HOX (p<0.05). Integrated muscle electrical activity was not influenced by the oxygen content (best d = 0.51). Furthermore, the only difference in tissue saturation index measured via near-infrared spectroscopy observed was between the recovery periods during the NoNo and HoHOX interventions (P<0.05, d = 0.93). In the case of HoHo the athletes’ \(P_{mean}\) declined from the first to the third interval (P < 0.05), whereas Pmean was unaltered under the HoHOX, NoHOX and NoNo conditions. We conclude that the less pronounced decline in \(P_{mean}\) during 3 x 3-min double-poling sprints in normoxia and hypoxia with hyperoxic recovery is not related to changes in muscle activity or oxygenation. Moreover, we conclude that hyperoxia \((F_iO_2 = 1.00)\) used in conjunction with hypoxic or normoxic work intervals may serve as an effective aid when inhaled during the subsequent recovery intervals. KW - triceps KW - bood KW - medical hypoxia KW - blood KW - arms KW - hyperoxia KW - breathing KW - near-infrared spectroscopy Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126299 VL - 10 IS - 10 ER - TY - JOUR A1 - Wang, Huiqiang A1 - Chen, Nanhai G. A1 - Minev, Boris R. A1 - Zimmermann, Martina A1 - Aguilar, Richard J. A1 - Zhang, Qian A1 - Sturm, Julia B. A1 - Fend, Falko A1 - Yu, Yong A. A1 - Cappello, Joseph A1 - Lauer, Ulrich M. A1 - Szalay, Aladar A. T1 - Optical Detection and Virotherapy of Live Metastatic Tumor Cells in Body Fluids with Vaccinia Strains JF - PLoS ONE N2 - Metastatic tumor cells in body fluids are important targets for treatment, and critical surrogate markers for evaluating cancer prognosis and therapeutic response. Here we report, for the first time, that live metastatic tumor cells in blood samples from mice bearing human tumor xenografts and in blood and cerebrospinal fluid samples from patients with cancer were successfully detected using a tumor cell-specific recombinant vaccinia virus (VACV). In contrast to the FDA-approved CellSearch system, VACV detects circulating tumor cells (CTCs) in a cancer biomarker-independent manner, thus, free of any bias related to the use of antibodies, and can be potentially a universal system for detection of live CTCs of any tumor type, not limited to CTCs of epithelial origin. Furthermore, we demonstrate for the first time that VACV was effective in preventing and reducing circulating tumor cells in mice bearing human tumor xenografts. Importantly, a single intra-peritoneal delivery of VACV resulted in a dramatic decline in the number of tumor cells in the ascitic fluid from a patient with gastric cancer. Taken together, these results suggest VACV to be a useful tool for quantitative detection of live tumor cells in liquid biopsies as well as a potentially effective treatment for reducing or eliminating live tumor cells in body fluids of patients with metastatic disease. KW - lymph nodes KW - cancer treatment KW - metastatic tumors KW - breast cancer KW - blood KW - prostate cancer KW - ascites KW - mouse models Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130059 VL - 8 IS - 9 ER - TY - JOUR A1 - Tsoneva, Desislava A1 - Stritzker, Jochen A1 - Bedenk, Kristina A1 - Zhang, Qian A1 - Cappello, Joseph A1 - Fischer, Utz A1 - Szalay, Aladar A. T1 - Drug-encoded Biomarkers for Monitoring Biological Therapies JF - PLoS One N2 - Blood tests are necessary, easy-to-perform and low-cost alternatives for monitoring of oncolytic virotherapy and other biological therapies in translational research. Here we assessed three candidate proteins with the potential to be used as biomarkers in biological fluids: two glucuronidases from E. coli (GusA) and Staphylococcus sp. RLH1 (GusPlus), and the luciferase from Gaussia princeps (GLuc). The three genes encoding these proteins were inserted individually into vaccinia virus GLV-1h68 genome under the control of an identical promoter. The three resulting recombinant viruses were used to infect tumor cells in cultures and human tumor xenografts in nude mice. In contrast to the actively secreted GLuc, the cytoplasmic glucuronidases GusA and GusPlus were released into the supernatants only as a result of virus-mediated oncolysis. GusPlus resulted in the most sensitive detection of enzyme activity under controlled assay conditions in samples containing as little as 1 pg/ml of GusPlus, followed by GusA (25 pg/ml) and GLuc (≥375 pg/ml). Unexpectedly, even though GusA had a lower specific activity compared to GusPlus, the substrate conversion in the serum of tumor-bearing mice injected with the GusA-encoding virus strains was substantially higher than that of GusPlus. This was attributed to a 3.2 fold and 16.2 fold longer half-life of GusA in the blood stream compared to GusPlus and GLuc respectively, thus a more sensitive monitor of virus replication than the other two enzymes. Due to the good correlation between enzymatic activity of expressed marker gene and virus titer, we conclude that the amount of the biomarker protein in the body fluid semiquantitatively represents the amount of virus in the infected tumors which was confirmed by low light imaging. We found GusA to be the most reliable biomarker for monitoring oncolytic virotherapy among the three tested markers. KW - mouse models KW - vaccinia virus KW - luciferase KW - biomarkers KW - cytolysis KW - viral replication KW - cell cultures KW - blood Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125265 VL - 10 IS - 9 ER - TY - JOUR A1 - Thal, Serge C. A1 - Smetak, Manuel A1 - Hayashi, Kentaro A1 - Förster, Carola Y. T1 - Hemorrhagic cerebral insults and secondary Takotsubo syndrome: findings in a novel in vitro model using human blood samples JF - International Journal of Molecular Sciences N2 - Intracranial hemorrhage results in devastating forms of cerebral damage. Frequently, these results also present with cardiac dysfunction ranging from ECG changes to Takotsubo syndrome (TTS). This suggests that intracranial bleeding due to subarachnoid hemorrhage (SAH) disrupts the neuro–cardiac axis leading to neurogenic stress cardiomyopathy (NSC) of different degrees. Following this notion, SAH and secondary TTS could be directly linked, thus contributing to poor outcomes. We set out to test if blood circulation is the driver of the brain–heart axis by investigating serum samples of TTS patients. We present a novel in vitro model combining SAH and secondary TTS to mimic the effects of blood or serum, respectively, on blood–brain barrier (BBB) integrity using in vitro monolayers of an established murine model. We consistently demonstrated decreased monolayer integrity and confirmed reduced Claudin-5 and Occludin levels by RT-qPCR and Western blot and morphological reorganization of actin filaments in endothelial cells. Both tight junction proteins show a time-dependent reduction. Our findings highlight a faster and more prominent disintegration of BBB in the presence of TTS and support the importance of the bloodstream as a causal link between intracerebral bleeding and cardiac dysfunction. This may represent potential targets for future therapeutic inventions in SAH and TTS. KW - Takotsubo syndrome KW - subarachnoid hemorrhage KW - inflammation KW - in vitro KW - blood KW - blood–brain barrier KW - human KW - patient KW - endothelial cells Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-288305 SN - 1422-0067 VL - 23 IS - 19 ER - TY - JOUR A1 - Schumann, Sarah A1 - Eberlein, Uta A1 - Muhtadi, Razan A1 - Lassmann, Michael A1 - Scherthan, Harry T1 - DNA damage in leukocytes after internal ex-vivo irradiation of blood with the α-emitter Ra-223 JF - Scientific Reports N2 - Irradiation with high linear energy transfer α-emitters, like the clinically used Ra-223 dichloride, severely damages cells and induces complex DNA damage including closely spaced double-strand breaks (DSBs). As the hematopoietic system is an organ-at-risk for the treatment, knowledge about Ra-223-induced DNA damage in blood leukocytes is highly desirable. Therefore, 36 blood samples from six healthy volunteers were exposed ex-vivo (in solution) to different concentrations of Ra-223. Absorbed doses to the blood were calculated assuming local energy deposition of all α- and β-particles of the decay, ranging from 0 to 142 mGy. γ-H2AX + 53BP1 co-staining and analysis was performed in leukocytes isolated from the irradiated blood samples. For DNA damage quantification, leukocyte samples were screened for occurrence of α-induced DNA damage tracks and small γ-H2AX + 53BP1 DSB foci. This revealed a linear relationship between the frequency of α-induced γ-H2AX damage tracks and the absorbed dose to the blood, while the frequency of small γ-H2AX + 53BP1 DSB foci indicative of β-irradiation was similar to baseline values, being in agreement with a negligible β-contribution (3.7%) to the total absorbed dose to the blood. Our calibration curve will contribute to the biodosimetry of Ra-223-treated patients and early after incorporation of α-emitters. KW - alpha particles KW - blood KW - DNA Breaks KW - double-stranded KW - gamma rays KW - healthy volunteers KW - humans KW - leukocytes KW - radiation effects KW - radium Y1 - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-175596 VL - 8 IS - 2286 ER - TY - JOUR A1 - Schick, Martin Alexander A1 - Baar, Wolfgang A1 - Bruno, Raphael Romano A1 - Wollborn, Jakob A1 - Held, Christopher A1 - Schneider, Reinhard A1 - Flemming, Sven A1 - Schlegel, Nicolas A1 - Roewer, Norbert A1 - Neuhaus, Winfried A1 - Wunder, Christian T1 - Balanced hydroxyethylstarch (HES 130/0.4) impairs kidney function in-vivo without inflammation JF - PLoS One N2 - Volume therapy is a standard procedure in daily perioperative care, and there is an ongoing discussion about the benefits of colloid resuscitation with hydroxyethylstarch (HES). In sepsis HES should be avoided due to a higher risk for acute kidney injury (AKI). Results of the usage of HES in patients without sepsis are controversial. Therefore we conducted an animal study to evaluate the impact of 6% HES 130/0.4 on kidney integrity with sepsis or under healthy conditions Sepsis was induced by standardized Colon Ascendens Stent Peritonitis (sCASP). sCASP-group as well as control group (C) remained untreated for 24 h. After 18 h sCASP+HES group (sCASP+VOL) and control+HES (C+VOL) received 50 ml/KG balanced 6% HES (VOL) 130/0.4 over 6h. After 24h kidney function was measured via Inulin- and PAH-Clearance in re-anesthetized rats, and serum urea, creatinine (crea), cystatin C and Neutrophil gelatinase-associated lipocalin (NGAL) as well as histopathology were analysed. In vitro human proximal tubule cells (PTC) were cultured +/- lipopolysaccharid (LPS) and with 0.1–4.0% VOL. Cell viability was measured with XTT-, cell toxicity with LDH-test. sCASP induced severe septic AKI demonstrated divergent results regarding renal function by clearance or creatinine measure focusing on VOL. Soleley HES (C+VOL) deteriorated renal function without sCASP. Histopathology revealed significantly derangements in all HES groups compared to control. In vitro LPS did not worsen the HES induced reduction of cell viability in PTC cells. For the first time, we demonstrated, that application of 50 ml/KG 6% HES 130/0.4 over 6 hours induced AKI without inflammation in vivo. Severity of sCASP induced septic AKI might be no longer susceptible to the way of volume expansion KW - colloids KW - kidneys KW - histopathology KW - blood KW - creatinine KW - sepsis KW - urine KW - inflammation Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126068 VL - 10 IS - 9 ER - TY - JOUR A1 - Rudel, Thomas A1 - Prusty, Bhupesh K. A1 - Siegl, Christine A1 - Hauck, Petra A1 - Hain, Johannes A1 - Korhonen, Suvi J. A1 - Hiltunen-Back, Eija A1 - Poulakkainen, Mirja T1 - Chlamydia trachomatis Infection Induces Replication of Latent HHV-6 JF - PLoS ONE N2 - Human herpesvirus-6 (HHV-6) exists in latent form either as a nuclear episome or integrated into human chromosomes in more than 90% of healthy individuals without causing clinical symptoms. Immunosuppression and stress conditions can reactivate HHV-6 replication, associated with clinical complications and even death. We have previously shown that co-infection of Chlamydia trachomatis and HHV-6 promotes chlamydial persistence and increases viral uptake in an in vitro cell culture model. Here we investigated C. trachomatis-induced HHV-6 activation in cell lines and fresh blood samples from patients having Chromosomally integrated HHV-6 (CiHHV-6). We observed activation of latent HHV-6 DNA replication in CiHHV-6 cell lines and fresh blood cells without formation of viral particles. Interestingly, we detected HHV-6 DNA in blood as well as cervical swabs from C. trachomatis-infected women. Low virus titers correlated with high C. trachomatis load and vice versa, demonstrating a potentially significant interaction of these pathogens in blood cells and in the cervix of infected patients. Our data suggest a thus far underestimated interference of HHV-6 and C. trachomatis with a likely impact on the disease outcome as consequence of co-infection. KW - blood KW - chlamydia KW - chlamydia infection KW - chlamydia trachomatis KW - DNA replication KW - macrophages KW - polymerase chain reaction KW - viral load Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-96731 ER - TY - JOUR A1 - Radakovic, D. A1 - Reboredo, J. A1 - Helm, M. A1 - Weigel, T. A1 - Schürlein, S. A1 - Kupczyk, E. A1 - Leyh, R. G. A1 - Walles, H. A1 - Hansmann, J. T1 - A multilayered electrospun graft as vascular access for hemodialysis JF - PLoS ONE N2 - Despite medical achievements, the number of patients with end-stage kidney disease keeps steadily raising, thereby entailing a high number of surgical and interventional procedures to establish and maintain arteriovenous vascular access for hemodialysis. Due to vascular disease, aneurysms or infection, the preferred access—an autogenous arteriovenous fistula—is not always available and appropriate. Moreover, when replacing small diameter blood vessels, synthetic vascular grafts possess well-known disadvantages. A continuous multilayered gradient electrospinning was used to produce vascular grafts made of collagen type I nanofibers on luminal and adventitial graft side, and poly-ɛ-caprolactone as medial layer. Therefore, a custom-made electrospinner with robust environmental control was developed. The morphology of electrospun grafts was characterized by scanning electron microscopy and measurement of mechanical properties. Human microvascular endothelial cells were cultured in the graft under static culture conditions and compared to cultures obtained from dynamic continuous flow bioreactors. Immunofluorescent analysis showed that endothelial cells form a continuous luminal layer and functional characteristics were confirmed by uptake of acetylated low-density-lipoprotein. Incorporation of vancomycin and gentamicin to the medial graft layer allowed antimicrobial inhibition without exhibiting an adverse impact on cell viability. Most striking a physiological hemocompatibility was achieved for the multilayered grafts. KW - collagens KW - polymers KW - vascular surgery KW - endothelial cells KW - cell cultures KW - blood KW - antibiotics KW - scanning electron microscopy Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-159102 VL - 12 IS - 10 ER - TY - JOUR A1 - Popp, Michael A1 - Thielman, Ina A1 - Nieswandt, Bernhard A1 - Stegner, David T1 - Normal Platelet Integrin Function in Mice Lacking Hydrogen Peroxide-Induced Clone-5 (Hic-5) JF - PLoS One N2 - Integrin αIIbβ3 plays a central role in the adhesion and aggregation of platelets and thus is essential for hemostasis and thrombosis. Integrin activation requires the transmission of a signal from the small cytoplasmic tails of the α or β subunit to the large extracellular domains resulting in conformational changes of the extracellular domains to enable ligand binding. Hydrogen peroxide-inducible clone-5 (Hic-5), a member of the paxillin family, serves as a focal adhesion adaptor protein associated with αIIbβ3 at its cytoplasmic tails. Previous studies suggested Hic-5 as a novel regulator of integrin αIIbβ3 activation and platelet aggregation in mice. To assess this in more detail, we generated Hic-5-null mice and analyzed activation and aggregation of their platelets in vitro and in vivo. Surprisingly, lack of Hic-5 had no detectable effect on platelet integrin activation and function in vitro and in vivo under all tested conditions. These results indicate that Hic-5 is dispensable for integrin αIIbβ3 activation and consequently for arterial thrombosis and hemostasis in mice. KW - platelet activation KW - fibrinogen KW - integrins KW - platelets KW - thrombin KW - flow cytometry KW - platelet aggregation KW - blood Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-125724 VL - 10 IS - 7 ER - TY - JOUR A1 - Nordbeck, Peter A1 - Bönhof, Leoni A1 - Hiller, Karl-Heinz A1 - Voll, Sabine A1 - Arias-Loza, Paula A1 - Seidlmaier, Lea A1 - Williams, Tatjana A1 - Ye, Yu-Xiang A1 - Gensler, Daniel A1 - Pelzer, Theo A1 - Ertl, Georg A1 - Jakob, Peter M. A1 - Bauer, Wolfgang R. A1 - Ritter, Oliver T1 - Impact of Thoracic Surgery on Cardiac Morphology and Function in Small Animal Models of Heart Disease: A Cardiac MRI Study in Rats JF - PLoS ONE N2 - Background Surgical procedures in small animal models of heart disease might evoke alterations in cardiac morphology and function. The aim of this study was to reveal and quantify such potential artificial early or long term effects in vivo, which might account for a significant bias in basic cardiovascular research, and, therefore, could potentially question the meaning of respective studies. Methods Female Wistar rats (n = 6 per group) were matched for weight and assorted for sham left coronary artery ligation or control. Cardiac morphology and function was then investigated in vivo by cine magnetic resonance imaging at 7 Tesla 1 and 8 weeks after the surgical procedure. The time course of metabolic and inflammatory blood parameters was determined in addition. Results Compared to healthy controls, rats after sham surgery showed a lower body weight both 1 week (267.5±10.6 vs. 317.0±11.3 g, n<0.05) and 8 weeks (317.0±21.1 vs. 358.7±22.4 g, n<0.05) after the intervention. Left and right ventricular morphology and function were not different in absolute measures in both groups 1 week after surgery. However, there was a confined difference in several cardiac parameters normalized to the body weight (bw), such as myocardial mass (2.19±0.30/0.83±0.13 vs. 1.85±0.22/0.70±0.07 mg left/right per g bw, p<0.05), or enddiastolic ventricular volume (1.31±0.36/1.21±0.31 vs. 1.14±0.20/1.07±0.17 µl left/right per g bw, p<0.05). Vice versa, after 8 weeks, cardiac masses, volumes, and output showed a trend for lower values in sham operated rats compared to controls in absolute measures (782.2±57.2/260.2±33.2 vs. 805.9±84.8/310.4±48.5 mg, p<0.05 for left/right ventricular mass), but not normalized to body weight. Matching these findings, blood testing revealed only minor inflammatory but prolonged metabolic changes after surgery not related to cardiac disease. Conclusion Cardio-thoracic surgical procedures in experimental myocardial infarction cause distinct alterations upon the global integrity of the organism, which in the long term also induce circumscribed repercussions on cardiac morphology and function. This impact has to be considered when analyzing data from respective animal studies and transferring these findings to conditions in patients. KW - heart rate KW - body weight KW - surgical and invasive medical procedures KW - magnetic resonance imaging KW - blood KW - vascular surgery KW - myocardial infarction KW - cardiac ventricles Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-130064 VL - 8 IS - 8 ER - TY - JOUR A1 - Nieswandt, Bernhard A1 - Morowski, Martina A1 - Brachs, Sebastian A1 - Mielenz, Dirk A1 - Dütting, Sebastian T1 - The Adaptor Protein Swiprosin-1/EFhd2 Is Dispensable for Platelet Function in Mice N2 - Background Platelets are anuclear cell fragments derived from bone marrow megakaryocytes that safeguard vascular integrity, but may also cause pathological vessel occlusion. Reorganizations of the platelet cytoskeleton and agonist-induced intracellular Ca2+-mobilization are crucial for platelet hemostatic function. EF-hand domain containing 2 (EFhd2, Swiprosin-1) is a Ca2+-binding cytoskeletal adaptor protein involved in actin remodeling in different cell types, but its function in platelets is unknown. Objective Based on the described functions of EFhd2 in immune cells, we tested the hypothesis that EFhd2 is a crucial adaptor protein for platelet function acting as a regulator of Ca2+-mobilization and cytoskeletal rearrangements. Methods and Results We generated EFhd2-deficient mice and analyzed their platelets in vitro and in vivo. Efhd2-/- mice displayed normal platelet count and size, exhibited an unaltered in vivo life span and showed normal Ca2+-mobilization and activation/aggregation responses to classic agonists. Interestingly, upon stimulation of the immunoreceptor tyrosine-based activation motif-coupled receptor glycoprotein (GP) VI, Efhd2-/- platelets showed a slightly increased coagulant activity. Furthermore, absence of EFhd2 had no significant impact on integrin-mediated clot retraction, actomyosin rearrangements and spreading of activated platelets on fibrinogen. In vivo EFhd2-deficiency resulted in unaltered hemostatic function and unaffected arterial thrombus formation. Conclusion These results show that EFhd2 is not essential for platelet function in mice indicating that other cytoskeletal adaptors may functionally compensate its loss. KW - adaptor protein Swiprosin-1/EFhd2 KW - platelets KW - platelet activation KW - platelet aggregation KW - cytoskeleton KW - thrombin KW - blood KW - actins KW - collagens Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-113316 ER - TY - JOUR A1 - Mueller, A. A1 - Stoetter, L. A1 - Kalluvya, S. A1 - Stich, A. A1 - Majinge, C. A1 - Weissbrich, B. A1 - Kasang, C. T1 - Prevalence of hepatitis B virus infection among health care workers in a tertiary hospital in Tanzania JF - BMC Infectious Diseases N2 - Background: Sub-Saharan Africa has a high prevalence of hepatitis B virus (HBV) infections. Health care workers (HCWs) are at high risk of contracting HBV infection through their occupation. Vaccination of HCWs against HBV is standard practice in many countries, but is often not implemented in resource-poor settings. We aimed with this cross-sectional study to determine HBV prevalence, HCW vaccination status, and the risk factors for HCWs contracting HBV infection in Tanzania. Methods: We enrolled 600 HCWs from a tertiary Tanzanian hospital. Their demographics, medical histories, HBV vaccination details and risk factors for contracting blood-borne infections were collected using a standardized questionnaire. Serum samples were tested for HBV and hepatitis C virus (HCV) markers by ELISA techniques, PCR and an anti-HBs rapid test. HCWs were divided in two subgroups: those at risk of contracting HBV (rHCW 79.2 %) via exposure to potentially infectious materials, and those considered not at risk of contracting HBV (nrHCW, 20.8 %). Results: The overall prevalence of chronic HBV infection (HBsAg+, anti-HBc+, anti-HBs-) was 7.0 % (42/598). Chronic HBV infection was found in 7.4 % of rHCW versus 5.6 % of nrHCW(p-value = 0.484). HCWs susceptible to HBV (HBsAg-, anti-HBc-, anti-HBs-) comprised 31.3 %. HBV immunity achieved either by healed HBV infection (HBsAg-, anti-HBc+, anti-HBs+) or by vaccination (HBsAg-, anti-HBc-, anti-HBs+) comprised 36.5 % and 20.2 %, respectively. 4.8 % of participants had indeterminate results (HBsAg-, anti-HBc+, anti-HBc-IgM-, anti-HBs-). Only 77.1 % of HCWs who received a full vaccination course had an anti-HBs titer > 10 ml/U. An anti-HBs point-of-care test was 80.7 % sensitive and 96.9 % specific. There was a significantly higher risk for contracting HBV (anti-HBc+) among those HCW at occupational risk (rHCW) of older age (odds ratios (OR) in rHCW 3.297, p < 0.0001 vs. nrHCW 1.385, p = 0.606) and among those HCW being employed more than 11 years (OR 2.51, p < 0.0001***). HCV prevalence was low (HCV antibodies 1.2 % and HCV-RNA 0.3 %). Conclusions: Chronic HBV infection is common among Tanzanian HCWs. One third of HCWs were susceptible to HBV infection, highlighting the need for vaccination. Due to high prevalence of naturally acquired immunity against HBV pre-testing might be a useful tool to identify susceptible individuals. KW - hepatitis C virus KW - point-of-care test KW - human-immunodeficiency-virus KW - C virus KW - seroprevalence KW - syphilis KW - vaccine KW - Uganda KW - blood KW - hepatitis B virus KW - health care workers KW - Tanzania Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-141786 VL - 15 IS - 386 ER - TY - JOUR A1 - Køllgaard, Tania A1 - Ugurel-Becker, Selma A1 - Idorn, Manja A1 - Andersen, Mads Hald A1 - Becker, Jürgen C. A1 - Straten, Per thor T1 - Pre-Vaccination Frequencies of Th17 Cells Correlate with Vaccine-Induced T-Cell Responses to Survivin-Derived Peptide Epitopes JF - PLoS One N2 - Various subsets of immune regulatory cells are suggested to influence the outcome of therapeutic antigen-specific anti-tumor vaccinations. We performed an exploratory analysis of a possible correlation of pre-vaccination Th17 cells, MDSCs, and Tregs with both vaccination-induced T-cell responses as well as clinical outcome in metastatic melanoma patients vaccinated with survivin-derived peptides. Notably, we observed dysfunctional Th1 and cytotoxic T cells, i.e. down-regulation of the CD3\(\zeta\)chain (p=0.001) and an impaired IFN\(\gamma\)-production (p=0.001) in patients compared to healthy donors, suggesting an altered activity of immune regulatory cells. Moreover, the frequencies of Th17 cells (p=0.03) and Tregs (p=0.02) were elevated as compared to healthy donors. IL-17-secreting CD4\(^{+}\) T cells displayed an impact on the immunological and clinical effects of vaccination: Patients characterized by high frequencies of Th17 cells at pre-vaccination were more likely to develop survivin-specific T-cell reactivity post-vaccination (p=0.03). Furthermore, the frequency of Th17 (p=0.09) and Th17/IFN\(\gamma\)\(^{+}\) (p=0.19) cells associated with patient survival after vaccination. In summary, our explorative, hypothesis-generating study demonstrated that immune regulatory cells, in particular Th17 cells, play a relevant role for generation of the vaccine-induced anti-tumor immunity in cancer patients, hence warranting further investigation to test for validity as predictive biomarkers. KW - suppressor cells KW - melanoma patients KW - patient survival KW - cancer patients KW - Th17 KW - tumor immunity KW - blood Y1 - 2015 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-151509 VL - 10 IS - 7 ER - TY - JOUR A1 - Kraft, Peter A1 - Drechsler, Christiane A1 - Gunreben, Ignaz A1 - Nieswandt, Bernhard A1 - Stoll, Guido A1 - Heuschmann, Peter Ulrich A1 - Kleinschnitz, Christoph T1 - Von Willebrand Factor Regulation in Patients with Acute and Chronic Cerebrovascular Disease: A Pilot, Case-Control Study JF - PLoS ONE N2 - Background and Purpose In animal models, von Willebrand factor (VWF) is involved in thrombus formation and propagation of ischemic stroke. However, the pathophysiological relevance of this molecule in humans, and its potential use as a biomarker for the risk and severity of ischemic stroke remains unclear. This study had two aims: to identify predictors of altered VWF levels and to examine whether VWF levels differ between acute cerebrovascular events and chronic cerebrovascular disease (CCD). Methods A case–control study was undertaken between 2010 and 2013 at our University clinic. In total, 116 patients with acute ischemic stroke (AIS) or transitory ischemic attack (TIA), 117 patients with CCD, and 104 healthy volunteers (HV) were included. Blood was taken at days 0, 1, and 3 in patients with AIS or TIA, and once in CCD patients and HV. VWF serum levels were measured and correlated with demographic and clinical parameters by multivariate linear regression and ANOVA. Results Patients with CCD (158±46%) had significantly higher VWF levels than HV (113±36%, P<0.001), but lower levels than AIS/TIA patients (200±95%, P<0.001). Age, sex, and stroke severity influenced VWF levels (P<0.05). Conclusions VWF levels differed across disease subtypes and patient characteristics. Our study confirms increased VWF levels as a risk factor for cerebrovascular disease and, moreover, suggests that it may represent a potential biomarker for stroke severity, warranting further investigation. KW - cerebrovascular diseases KW - sex addiction KW - biomarkers KW - ischemic stroke KW - blood KW - stroke KW - platelets KW - demography Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-119588 SN - 1932-6203 VL - 9 IS - 6 ER - TY - JOUR A1 - Koessler, Juergen A1 - Schwarz, Michaela A1 - Weber, Katja A1 - Etzel, Julia A1 - Koessler, Angela A1 - Boeck, Markus A1 - Kobsar, Anna T1 - The role of adenosine diphosphate mediated platelet responsiveness for the stability of platelet integrity in citrated whole blood under ex vivo conditions JF - PLoS ONE N2 - Background: Platelets are important for effective hemostasis and considered to be involved in pathophysiological processes, e.g. in cardiovascular diseases. Platelets provided for research or for therapeutic use are frequently separated from citrated whole blood (WB) stored for different periods of time. Although functionally intact platelets are required, the stability of platelet integrity, e.g. adenosine diphosphate (ADP) mediated responsiveness, has never been thoroughly investigated in citrated WB under ex vivo conditions. Objectives: Platelet integrity was evaluated at different time points in citrated WB units, collected from healthy donors and stored for 5 days at ambient temperature. The analysis included the measurement of activation markers, of induced light transmission aggregometry and of purinergic receptor expression or function. Inhibitory pathways were explored by determination of basal vasodilator-stimulated phosphoprotein (VASP)-phosphorylation, intracellular cyclic nucleotide levels and the content of phosphodiesterase 5A. Fresh peripheral blood (PB) samples served as controls. Results: On day 5 of storage, thrombin receptor activating peptide-6 (TRAP-6) stimulated CD62P expression and fibrinogen binding were comparable to PB samples. ADP induced aggregation continuously decreased during storage. Purinergic receptor expression remained unchanged, whereas the P2Y1 activity progressively declined in contrast to preserved P2Y12 and P2X1 function. Inhibitory pathways were unaffected except for a slight elevation of VASP phosphorylation at Ser\(^{239}\) on day 5. Conclusion: After 5 days of storage in citrated WB, platelet responsiveness to TRAP-6 is sufficiently maintained. However, ADP-mediated platelet integrity is more sensitive to deterioration, especially after storage for more than 2 days. Decreasing ADP-induced aggregation is particularly caused by the impairment of the purinergic receptor P2Y1 activity. These characteristics should be considered in the use of platelets from stored citrated WB for experimental or therapeutic issues. KW - fibrinogen KW - phosphorylation KW - platelets KW - blood KW - specimen storage KW - flow cytometry Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-159879 VL - 12 IS - 11 ER - TY - JOUR A1 - Klughammer, Johanna A1 - Dittrich, Marcus A1 - Blom, Jochen A1 - Mitesser, Vera A1 - Vogel, Ulrich A1 - Frosch, Matthias A1 - Goesmann, Alexander A1 - Müller, Tobias A1 - Schoen, Christoph T1 - Comparative genome sequencing reveals within-host genetic changes in Neisseria meningitidis during invasive disease JF - PLoS ONE N2 - Some members of the physiological human microbiome occasionally cause life-threatening disease even in immunocompetent individuals. A prime example of such a commensal pathogen is Neisseria meningitidis, which normally resides in the human nasopharynx but is also a leading cause of sepsis and epidemic meningitis. Using N. meningitidis as model organism, we tested the hypothesis that virulence of commensal pathogens is a consequence of within host evolution and selection of invasive variants due to mutations at contingency genes, a mechanism called phase variation. In line with the hypothesis that phase variation evolved as an adaptation to colonize diverse hosts, computational comparisons of all 27 to date completely sequenced and annotated meningococcal genomes retrieved from public databases showed that contingency genes are indeed enriched for genes involved in host interactions. To assess within-host genetic changes in meningococci, we further used ultra-deep whole-genome sequencing of throat-blood strain pairs isolated from four patients suffering from invasive meningococcal disease. We detected up to three mutations per strain pair, affecting predominantly contingency genes involved in type IV pilus biogenesis. However, there was not a single (set) of mutation(s) that could invariably be found in all four pairs of strains. Phenotypic assays further showed that these genetic changes were generally not associated with increased serum resistance, higher fitness in human blood ex vivo or differences in the interaction with human epithelial and endothelial cells in vitro. In conclusion, we hypothesize that virulence of meningococci results from accidental emergence of invasive variants during carriage and without within host evolution of invasive phenotypes during disease progression in vivo. KW - blood KW - comparative genomics KW - throat KW - genetic loci KW - Neisseria meningitidis KW - genomic libraries KW - genome sequencing KW - sequence assembly tools Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-159547 VL - 12 IS - 1 ER - TY - JOUR A1 - Ibrahim, Eslam S. A1 - Ohlsen, Knut T1 - The old yellow enzyme OfrA fosters Staphylococcus aureus survival via affecting thiol-dependent redox homeostasis JF - Frontiers in Microbiology N2 - Old yellow enzymes (OYEs) are widely found in the bacterial, fungal, and plant kingdoms but absent in humans and have been used as biocatalysts for decades. However, OYEs’ physiological function in bacterial stress response and infection situations remained enigmatic. As a pathogen, the Gram-positive bacterium Staphylococcus aureus adapts to numerous stress conditions during pathogenesis. Here, we show that in S. aureus genome, two paralogous genes (ofrA and ofrB) encode for two OYEs. We conducted a bioinformatic analysis and found that ofrA is conserved among all publicly available representative staphylococcal genomes and some Firmicutes. Expression of ofrA is induced by electrophilic, oxidative, and hypochlorite stress in S. aureus. Furthermore, ofrA contributes to S. aureus survival against reactive electrophilic, oxygen, and chlorine species (RES, ROS, and RCS) via thiol-dependent redox homeostasis. At the host–pathogen interface, S. aureusΔofrA has defective survival in macrophages and whole human blood and decreased staphyloxanthin production. Overall, our results shed the light onto a novel stress response strategy in the important human pathogen S. aureus. KW - MRSA KW - blood KW - phagocytes KW - quinone KW - ROS KW - stress response KW - electrophilic stress Y1 - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-274381 SN - 1664-302X VL - 13 ER - TY - JOUR A1 - Hofmann, Sebastian A1 - Braun, Attila A1 - Pozgaj, Rastislav A1 - Morowski, Martina A1 - Vögtle, Timo A1 - Nieswandt, Bernhard T1 - Mice lacking the SLAM family member CD84 display unaltered platelet function in hemostasis and thrombosis JF - PLoS One N2 - Background Platelets are anuclear cell fragments derived from bone marrow megakaryocytes that safeguard vascular integrity by forming thrombi at sites of vascular injury. Although the early events of thrombus formation—platelet adhesion and aggregation—have been intensively studied, less is known about the mechanisms and receptors that stabilize platelet-platelet interactions once a thrombus has formed. One receptor that has been implicated in this process is the signaling lymphocyte activation molecule (SLAM) family member CD84, which can undergo homophilic interactions and becomes phosphorylated upon platelet aggregation. Objective The role of CD84 in platelet physiology and thrombus formation was investigated in CD84-deficient mice. Methods and Results We generated CD84-deficient mice and analyzed their platelets in vitro and in vivo. \(Cd84^{−/−}\) platelets exhibited normal activation and aggregation responses to classical platelet agonists. Furthermore, CD84 deficiency did not affect integrin-mediated clot retraction and spreading of activated platelets on fibrinogen. Notably, also the formation of stable three-dimensional thrombi on collagen-coated surfaces under flow ex vivo was unaltered in the blood of \(Cd84^{−/−}\) mice. In vivo, \(Cd84^{−/−}\) mice exhibited unaltered hemostatic function and arterial thrombus formation. Conclusion These results show that CD84 is dispensable for thrombus formation and stabilization, indicating that its deficiency may be functionally compensated by other receptors or that it may be important for platelet functions different from platelet-platelet interactions. KW - flow cytometry KW - CD coreceptors KW - integrins KW - blood KW - platelet aggregation KW - platelet activation KW - cytotoxic T cells KW - platelets Y1 - 2014 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-126477 VL - 9 IS - 12 ER - TY - JOUR A1 - Haertle, Larissa A1 - Maierhofer, Anna A1 - Böck, Julia A1 - Lehnen, Harald A1 - Böttcher, Yvonne A1 - Blüher, Matthias A1 - Schorsch, Martin A1 - Potabattula, Ramya A1 - El Hajj, Nady A1 - Appenzeller, Silke A1 - Haaf, Thomas T1 - Hypermethylation of the non-imprinted maternal MEG3 and paternal MEST alleles is highly variable among normal individuals JF - PLoS ONE N2 - Imprinted genes show parent-specific activity (functional haploidy), which makes them particularly vulnerable to epigenetic dysregulation. Here we studied the methylation profiles of oppositely imprinted genes at single DNA molecule resolution by two independent parental allele-specific deep bisulfite sequencing (DBS) techniques. Using Roche (GSJunior) next generation sequencing technology, we analyzed the maternally imprinted MEST promoter and the paternally imprinted MEG3 intergenic (IG) differentially methylated region (DMR) in fetal cord blood, adult blood, and visceral adipose tissue. Epimutations were defined as paternal or maternal alleles with >50% aberrantly (de)methylated CpG sites, showing the wrong methylation imprint. The epimutation rates (range 2–66%) of the paternal MEST and the maternal MEG3 IG DMR allele, which should be completely unmethylated, were significantly higher than those (0–15%) of the maternal MEST and paternal MEG3 alleles, which are expected to be fully methylated. This hypermethylation of the non-imprinted allele (HNA) was independent of parental origin. Very low epimutation rates in sperm suggest that HNA occurred after fertilization. DBS with Illumina (MiSeq) technology confirmed HNA for the MEST promoter and the MEG3 IG DMR, and to a lesser extent, for the paternally imprinted secondary MEG3 promoter and the maternally imprinted PEG3 promoter. HNA leads to biallelic methylation of imprinted genes in a considerable proportion of normal body cells (somatic mosaicism) and is highly variable between individuals. We propose that during development and differentiation maintenance of differential methylation at most imprinting control regions may become to some extent redundant. The accumulation of stochastic and environmentally-induced methylation errors on the non-imprinted allele may increase epigenetic diversity between cells and individuals. KW - DNA methylation KW - genomic imprinting KW - polymerase chain reaction KW - blood KW - epigenetics KW - sequence alignment KW - sperm Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-170433 VL - 12 IS - 8 ER - TY - JOUR A1 - Boch, Tobias A1 - Spiess, Birgit A1 - Heinz, Werner A1 - Cornely, Oliver A. A1 - Schwerdtfeger, Rainer A1 - Hahn, Joachim A1 - Krause, Stefan W. A1 - Duerken, Matthias A1 - Bertz, Hartmut A1 - Reuter, Stefan A1 - Kiehl, Michael A1 - Claus, Bernd A1 - Deckert, Peter Markus A1 - Hofmann, Wolf‐Karsten A1 - Buchheidt, Dieter A1 - Reinwald, Mark T1 - Aspergillus specific nested PCR from the site of infection is superior to testing concurrent blood samples in immunocompromised patients with suspected invasive aspergillosis JF - Mycoses N2 - Invasive aspergillosis (IA) is a severe complication in immunocompromised patients. Early diagnosis is crucial to decrease its high mortality, yet the diagnostic gold standard (histopathology and culture) is time‐consuming and cannot offer early confirmation of IA. Detection of IA by polymerase chain reaction (PCR) shows promising potential. Various studies have analysed its diagnostic performance in different clinical settings, especially addressing optimal specimen selection. However, direct comparison of different types of specimens in individual patients though essential, is rarely reported. We systematically assessed the diagnostic performance of an Aspergillus‐specific nested PCR by investigating specimens from the site of infection and comparing it with concurrent blood samples in individual patients (pts) with IA. In a retrospective multicenter analysis PCR was performed on clinical specimens (n = 138) of immunocompromised high‐risk pts (n = 133) from the site of infection together with concurrent blood samples. 38 pts were classified as proven/probable, 67 as possible and 28 as no IA according to 2008 European Organization for Research and Treatment of Cancer/Mycoses Study Group consensus definitions. A considerably superior performance of PCR from the site of infection was observed particularly in pts during antifungal prophylaxis (AFP)/antifungal therapy (AFT). Besides a specificity of 85%, sensitivity varied markedly in BAL (64%), CSF (100%), tissue samples (67%) as opposed to concurrent blood samples (8%). Our results further emphasise the need for investigating clinical samples from the site of infection in case of suspected IA to further establish or rule out the diagnosis. KW - antifungal KW - aspergillosis KW - BAL KW - blood KW - cerebrospinal fluid KW - comparison KW - PCR KW - Aspergillus Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-214065 VL - 62 IS - 11 SP - 1035 EP - 1042 ER - TY - JOUR A1 - Bargul, Joel L. A1 - Jung, Jamin A1 - McOdimba, Francis A. A1 - Omogo, Collins O. A1 - Adung'a, Vincent O. A1 - Krüger, Timothy A1 - Masiga, Daniel K. A1 - Engstler, Markus T1 - Species-Specific Adaptations of Trypanosome Morphology and Motility to the Mammalian Host JF - PLoS Pathogens N2 - African trypanosomes thrive in the bloodstream and tissue spaces of a wide range of mammalian hosts. Infections of cattle cause an enormous socio-economic burden in sub-Saharan Africa. A hallmark of the trypanosome lifestyle is the flagellate’s incessant motion. This work details the cell motility behavior of the four livestock-parasites Trypanosoma vivax, T. brucei, T. evansi and T. congolense. The trypanosomes feature distinct swimming patterns, speeds and flagellar wave frequencies, although the basic mechanism of flagellar propulsion is conserved, as is shown by extended single flagellar beat analyses. Three-dimensional analyses of the trypanosomes expose a high degree of dynamic pleomorphism, typified by the ‘cellular waveform’. This is a product of the flagellar oscillation, the chirality of the flagellum attachment and the stiffness of the trypanosome cell body. The waveforms are characteristic for each trypanosome species and are influenced by changes of the microenvironment, such as differences in viscosity and the presence of confining obstacles. The distinct cellular waveforms may be reflective of the actual anatomical niches the parasites populate within their mammalian host. T. vivax displays waveforms optimally aligned to the topology of the bloodstream, while the two subspecies T. brucei and T. evansi feature distinct cellular waveforms, both additionally adapted to motion in more confined environments such as tissue spaces. T. congolense reveals a small and stiff waveform, which makes these parasites weak swimmers and destined for cell adherence in low flow areas of the circulation. Thus, our experiments show that the differential dissemination and annidation of trypanosomes in their mammalian hosts may depend on the distinct swimming capabilities of the parasites. KW - swimming KW - viscosity KW - flagella KW - host-pathogen interactions KW - cell motility KW - blood KW - parasitic diseases KW - trypanosoma brucei gambiense Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-146513 VL - 12 IS - 2 ER -