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The Impact of Experimental Preconditioning Using Vascular Endothelial Growth Factor in Stroke and Subarachnoid Hemorrhage
Sven Oliver Eicker,Moritz Hoppe,Nima Etminan,Stephan Macht
Stroke Research and Treatment , 2013, DOI: 10.1155/2013/948783
An emboligenic pulmonary abscess leading to ischemic stroke and secondary brain abscess
Albrecht Philipp,Stettner Mark,Husseini Leila,Macht Stephan
BMC Neurology , 2012, DOI: 10.1186/1471-2377-12-133
Abstract: Background Ischemic stroke by septic embolism occurs primarily in the context of infective endocarditis or in patients with a right-to-left shunt and formation of a secondary cerebral abscess is a rare event. Erosion of pulmonary veins by a pulmonary abscess can lead to transcardiac septic embolism but to our knowledge no case of septic embolic ischemic stroke from a pulmonary abscess with secondary transformation into a brain abscess has been reported to date. Case presentation We report the case of a patient with a pulmonary abscess causing a septic embolic cerebral infarction which then transformed into a cerebral abscess. After antibiotic therapy and drainage of the abscess the patient could be rehabilitated and presented an impressive improvement of symptoms. Conclusion Septic embolism should be considered as cause of ischemic stroke in patients with pulmonary abscess and can be followed by formation of a secondary cerebral abscess. Early antibiotic treatment and repeated cranial CT-scans for detection of a secondary abscess should be performed.
The Impact of Experimental Preconditioning Using Vascular Endothelial Growth Factor in Stroke and Subarachnoid Hemorrhage
Sven Oliver Eicker,Moritz Hoppe,Nima Etminan,Stephan Macht,Jason Perrin,Hans-Jakob Steiger,Daniel H?nggi
Stroke Research and Treatment , 2013, DOI: 10.1155/2013/948783
Abstract: Vascular endothelial growth factor (VEGF) stimulating angiogenesis was shown to be a potential novel therapeutic approach for the treatment of ischemic vascular diseases. The goal of the present study was to examine whether transfection of VEGF before occurrence of major stroke (part I) and cerebral vasospasm after experimental subarachnoid hemorrhage (SAH; part II) develops neuroprotective qualities. A total of 25 (part I) and 26 (part II) brains were analyzed, respectively. In part one, a significant reduction of infarct volume in the VEGF-treated stroke animals (43% reduction, ) could be detected. In part two, significant vasospasm was induced in all hemorrhage groups . Analyzing microperfusion, a significant higher amount of perfused vessels could be detected , whereas no significant effect could be detected towards macroperfusion. Histologically, no infarctions were observed in the VEGF-treated SAH group and the sham-operated group. Minor infarction in terms of vasospasm-induced small lesions could be detected in the control vector transduced group and saline-treated group . The present study demonstrates the preconditioning impact of systemic intramuscular VEGF injection in animals after major stroke and induced severe vasospasm after SAH. 1. Introduction Cerebral vasospasm and delayed cerebral ischemia contribute the major part of secondary morbidity and mortality after severe subarachnoid hemorrhage (SAH) [1–5]. Despite the current treatment strategies, the rate of related permanent disability is estimated at 10% to 20% [6–9]. Vascular endothelial growth factor (VEGF) is involved in neurogenesis, inhibition of apoptosis, learning, and memory [10]. It can directly promote neuroprotection, but first of all VEGF is the main factor responsible for angiogenesis whereby an indirect neuroprotection is discussed. VEGF expression is increased during cerebral ischemia in humans and animals [11]. However, endogenous VEGF seems to be insufficient to protect the brain from ischemic injury completely. Interestingly, it could be shown that exogenous administrated VEGF induces angiogenic changes that result in a reduction of cerebral ischemic injury [12, 13]. For this reason VEGF was adopted as a potential novel therapeutic approach for the treatment of ischemic vascular disease, particularly in ischemic stroke [14–18]. The aim of the present experimental study was to examine the effect of systemic overexpression of VEGF prior to stroke and SAH with regard to cerebral infarction, vasospasm, and perfusion. 2. Material and Methods This study was carried out in
Local Delivery of Nimodipine by Prolonged-Release Microparticles—Feasibility, Effectiveness and Dose-Finding in Experimental Subarachnoid Hemorrhage
Daniel H?nggi, Jason Perrin, Sven Eicker, Kerim Beseoglu, Nima Etminan, Marcel Alexander Kamp, Hi-Jae Heiroth, Nadia Bege, Stephan Macht, Katrin Frauenknecht, Clemens Sommer, Thomas Kissel, Hans-Jakob Steiger
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0042597
Abstract: Background and Purpose To investigate the effect of locally applied nimodipine prolonged-release microparticles on angiographic vasospasm and secondary brain injury after experimental subarachnoid hemorrhage (SAH). Methods 70 male Wistar rats were categorized into three groups: 1) sham operated animals (control), 2) animals with SAH only (control) and the 3) treatment group. SAH was induced using the double hemorrhage model. The treatment group received different concentrations (20%, 30% or 40%) of nimodipine microparticles. Angiographic vasospasm was assessed 5 days later using digital subtraction angiography (DSA). Histological analysis of frozen sections was performed using H&E-staining as well as Iba1 and MAP2 immunohistochemistry. Results DSA images were sufficient for assessment in 42 animals. Severe angiographic vasospasm was present in group 2 (SAH only), as compared to the sham operated group (p<0.001). Only animals within group 3 and the highest nimodipine microparticles concentration (40%) as well as group 1 (sham) demonstrated the largest intracranial artery diameters. Variation in vessel calibers, however, did not result in differences in Iba-1 or MAP2 expression, i.e. in histological findings for secondary brain injury. Conclusions Local delivery of high-dose nimodipine prolonged-release microparticles at high concentration resulted in significant reduction in angiographic vasospasm after experimental SAH and with no histological signs for matrix toxicity.
How accurately do instructors judge students' attitudes online? A measurement of expectations and level of satisfaction with an Online Information Systems masters program
Lauren-Nicole Macht,Jenny Preece
Research in Learning Technology , 2002, DOI: 10.3402/rlt.v10i3.11412
Abstract: In order to run a successful educational program, instructors as well as staff members must constantly review and adapt to the expectations, concerns, demographics and satisfaction level of their student consumers. This study was conducted in order to examine these issues in an online educational setting. First, interviews were given to the program instructors in order to determine their opinions about the students' expectations and satisfaction levels. This information was then used to create a student survey that assessed the students' expectations and level of satisfaction. These two sets of results were then compared This comparison revealed that the online instructors did have a good grasp of the online students' expectations, concerns, demographics and satisfaction level. The only areas where the instructors' concepts of student views were slightly less accurate was student concerns and student feelings about the program administration, where the instructors overestimated the level of concern the students had about successfully returning to the learning environment and underestimated the students' satisfaction with the program's administration. This leads us to conclude that, even with the added online factor, instructors strongly understand student expectations, satisfaction levels, demographics and concerns.
The Function of with Respect to Sensitizer Stability in Nanocrystalline Dye Solar Cells
A. Barkschat,T. Moehl,B. Macht,H. Tributsch
International Journal of Photoenergy , 2008, DOI: 10.1155/2008/814951
Abstract: Dyes of characteristically different composition have been tested with respect to long-term stability in operating standardized dye sensitized cells during a time period of up to 3600 hours. Selective solar illumination, the use of graded filters, and imaging of photocurrents revealed that degradation is linked to the density of photocurrent passed. Photoelectrochemical degradation was observed with all sensitizers investigated. Sensitization was less efficient and sensitizers were less photostable with nanostructured ZnO compared to nanostructured TiO2. The best performance was confirmed for cis-RuII(dcbpyH2)2(NCS)2 on TiO2. However, it was 7–10 times less stable under other identical conditions on ZnO. Stability is favored by carboxylate anchoring and metal-centred electron transfer. In presence of TiO2, it is enhanced by formation of a stabilizing charge-transfer complex between oxidized Ru dye and back-bonding interfacial Ti3
Informationsbedürfnisse lterer Menschen mit Parkinson-Syndrom: Eine qualitative Studie Information Needs in Older Persons with Parkinson's Disease in Germany: A Qualitative Study Necesidades de información en personas mayores con la enfermedad de Parkinson en Alemania: un estudio cualitativo
Michael Macht,Christian Gerlich,Heiner Ellgring,The Infopark Collaboration
Forum : Qualitative Social Research , 2003,
Abstract: Die Fragen der qualitativen Studie waren: (1) Welche Informationsbedürfnisse u ern ltere Personen mit Parkinsonsyndrom und wie lassen sich diese Informationsbedürfnisse klassifizieren? (2) Wie erleben sie die Informationen und die Kommunikation professioneller Personen? (3) Ver ndern sich die Informationsbedürfnisse im Verlauf der Erkrankung? Die Daten wurden in halbstrukturierten Interviews in drei Fachkliniken und im Wohnbereich der Teilnehmer in l ndlichen und st dtischen Gebieten in Deutschland erhoben. 33 Personen im Alter von über 65 Jahren mit schwacher, mittlerer und stark ausgepr gter Parkinson-Symptomatik nahmen freiwillig an der Untersuchung teil. Die qualitative Analyse der Interviews zeigte: (1) Die Informationsbedürfnisse lterer Parkinson-Patienten beziehen sich auf identifizierbare Themen und Zusammenh nge. Aufgrund verschiedener Motive u erte eine Minderheit der Teilnehmer keine Informationsbedürfnisse. (2) Die Teilnehmer sch tzen verschiedene Informationsquellen als nützlich ein (Gespr ch mit Professionellen, audiovisuelles und schriftliches Material, Informationen von Familienangeh rigen, Freunden und anderen Patienten). (3) Die Informationsbedürfnisse ver ndern sich im Verlauf der Erkrankung. (4) Die Teilnehmer beschrieben positive und negative Erfahrungen in der Kommunikation mit Professionellen und gaben verschiedene Empfehlungen zur Verbesserung der Information von Parkinson-Patienten. Aufgrund der Interviews lassen sich Ma nahmen zur Verbesserung der Information für ltere Personen mit Parkinsonsyndrom und zur Verbesserung der Kommunikation von Professionellen ableiten. Erstens sollten die momentanen Informationsbedürfnisse einer Person erfasst werden, bevor Informationen vermittelt werden. Zweites kann es für einige Personen günstiger sein, Informationen an einem sp teren Zeitpunkt zu erhalten. Drittens sollten die jeweils geeigneten Informationen aus verschiedenen Quellen stammen. Viertens sollten Professionelle die aktive Suche nach Informationen und Kontakte zwischen Patienten f rdern. Fünftens ist die Informationsvermittlung am wirksamsten, (1) wenn sich Patienten und Professionelle regelm ig treffen, (2) wenn Professionelle eine Atmosph re des Vertrauens, der Offenheit und der Ermutigung f rdern, (3) wenn sie ihre Kommunikation an die individuellen Merkmale des Patienten anpassen und (4) wenn die gegebenen Informationen verst ndlich sind. URN: urn:nbn:de:0114-fqs0301176 The study addressed the following questions: (1) What are the information needs of older people with Parkinson's disease (PD) and how can these needs be
Association between Magnetic Resonance Imaging and the Result of Medial Branch Blocks  [PDF]
Stephan Klessinger, Wolfgang Freund
Pain Studies and Treatment (PST) , 2017, DOI: 10.4236/pst.2017.51001
Abstract: The aim of this retrospective practice audit was to assess the correlation between painful zygapophysial joints and changes seen in magnetic resonance imaging (MRI). Patients with unilateral pain were tested with controlled medial branch blocks. The MRI scans of patients with a positive response were compared blinded with normal MRI scans. The dimensions of the joint were assessed and osteoarthritis was graded. Fifteen symptomatic patients and 15 asymptomatic patients were included and evaluated. Comparison of the joints showed that the maximum diameter of symptomatic joints was significantly larger, and the grading of osteoarthritis was significantly higher for symptomatic joints. No healthy patient was assigned a grade 3. Grades 2 and 3 were found significantly more often in symptomatic patients. Only one symptomatic joint was assigned grade 0. Grade 0 was found significantly more often in asympto-matic patients. The presented MRI technique has limited value as a diagnostic test for lumbar zygapophysial joint pain. It is not possible to detect a single symptomatic joint. However, the osteoarthritis grading for the lumbar zyg-apophysial joints might be helpful for finding predictors for negative response if the results of the rating are grade zero. Therefore, unnecessary medial branch blocks might be avoided.
Thinking and acting strategically: promoting integrated solid waste management and corporate responsibility through a public private partnership; the case of Altamira, Tamaulipas, Mexico
Bernhard B?sl,Alejandro von Bertrab,Juan David Hernández,Axel Macht
Field Actions Science Reports , 2010,
Abstract: This article provides an assessment of a public private partnerships (PPP) among the German Technical Cooperation (GTZ), the Municipality of Altamira, Tamaulipas, Mexico and private counterparts BASF Mexicana and Terminal de LNG de Altamira (TLA). The municipality of Altamira, located in the urban-industrial hub of southern Tamaulipas, Mexico, faces important challenges in the field of urban public service delivery, particularly waste management, due to a high demographic growth rate and chronic budgetary constraints. The partnership was formed as a means to develop and implement the Municipal Program for the Prevention and Integrated Management of Solid and Special Wastes. The paper discusses the efficacy of the PPP as a policy instrument for the implementation of integrated solid waste management. As an assessment method, the authors draw on GTZ’s success criteria for the cooperation with the private sector. Criteria include the degree of complementarity, subsidiarity, neutrality and quality of private sector contributions. We argue that this PPP displays a pioneering alliance structure, since the private sector becomes a direct ally in creating strategies for the promotion sustainable development and not simply an exclusive contractor for urban public services delivery or a recipient of incentives from international development cooperation. The PPP provides a means to reach corporate social and environmental responsibility goals while at the same time it promotes development-related policy goals enshrined in the bilateral cooperation agreement between Germany and Mexico. However, the alliance faces important challenges related to different organizational cultures, electoral times and citizen participation. Cet article évalue un partenariat public-privé (PPP) entre GTZ (société allemande de coopération technique), la municipalité d’Altamira, dans l’état du Tamaulipas au Mexique et deux homologues privés : BASF Mexicana et Terminal de LNG de Altamira (TLA). La municipalité d’Altamira, située dans le centre industriel urbain du sud du Tamaulipas, est confrontée à d’importantes difficultés dans le domaine de la prestation de services publics urbains, en particulier la gestion des déchets, en raison d’une croissance démographique élevée et de contraintes budgétaires chroniques. Le partenariat a été constitué en vue de développer et de mettre en uvre le Programme municipal pour la prévention et la gestion intégrée des déchets solides et spéciaux. Cet article discute de l’efficacité du PPP comme instrument de mise en uvre d’une gestion intégrée des déchets
Self-diffusion and Interdiffusion in Al80Ni20 Melts: Simulation and Experiment
Juergen Horbach,Subir K. Das,Axel Griesche,Michael-Peter Macht,Guenter Frohberg,Andreas Meyer
Physics , 2007, DOI: 10.1103/PhysRevB.75.174304
Abstract: A combination of experimental techniques and molecular dynamics (MD) computer simulation is used to investigate the diffusion dynamics in Al80Ni20 melts. Experimentally, the self-diffusion coefficient of Ni is measured by the long-capillary (LC) method and by quasielastic neutron scattering. The LC method yields also the interdiffusion coefficient. Whereas the experiments were done in the normal liquid state, the simulations provided the determination of both self-diffusion and interdiffusion constants in the undercooled regime as well. The simulation results show good agreement with the experimental data. In the temperature range 3000 K >= T >= 715 K, the interdiffusion coefficient is larger than the self-diffusion constants. Furthermore the simulation shows that this difference becomes larger in the undercooled regime. This result can be refered to a relatively strong temperature dependence of the thermodynamic factor \Phi, which describes the thermodynamic driving force for interdiffusion. The simulations also indicate that the Darken equation is a good approximation, even in the undercooled regime. This implies that dynamic cross correlations play a minor role for the temperature range under consideration.
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