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Search Results: 1 - 10 of 32286 matches for " Peter Kienbaum "
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In Vitro impairment of whole blood coagulation and platelet function by hypertonic saline hydroxyethyl starch
Alexander A Hanke, Stephanie Maschler, Herbert Sch?chl, Felix Fl?ricke, Klaus G?rlinger, Klaus Zanger, Peter Kienbaum
Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine , 2011, DOI: 10.1186/1757-7241-19-12
Abstract: The study was designed as experimental non-randomized comparative in vitro study. Following institutional review board approval and informed consent blood samples were taken from 10 healthy volunteers and diluted in vitro with either HH (HyperHaes?, Fresenius Kabi, Germany), hypertonic saline (HT, 7.2% NaCl), hydroxyethylstarch (HS, HAES6%, Fresenius Kabi, Germany) or NaCl 0.9% (ISO) in a proportion of 5%, 10%, 20% and 40%. Coagulation was studied in whole blood by rotation thrombelastometry (ROTEM) after thromboplastin activation without (ExTEM) and with inhibition of thrombocyte function by cytochalasin D (FibTEM), the latter was performed to determine fibrin polymerisation alone. Values are expressed as maximal clot firmness (MCF, [mm]) and clotting time (CT, [s]). Platelet aggregation was determined by impedance aggregrometry (Multiplate) after activation with thrombin receptor-activating peptide 6 (TRAP) and quantified by the area under the aggregation curve (AUC [aggregation units (AU)/min]). Scanning electron microscopy was performed to evaluate HyperHaes induced cell shape changes of thrombocytes.Statistics: 2-way ANOVA for repeated measurements, Bonferroni post hoc test, p < 0.01.Dilution impaired whole blood coagulation and thrombocyte aggregation in all dilutions in a dose dependent fashion. In contrast to dilution with ISO and HS, respectively, dilution with HH as well as HT almost abolished coagulation (MCFExTEM from 57.3 ± 4.9 mm (native) to 1.7 ± 2.2 mm (HH 40% dilution; p < 0.0001) and to 6.6 ± 3.4 mm (HT 40% dilution; p < 0.0001) and thrombocyte aggregation (AUC from 1067 ± 234 AU/mm (native) to 14.5 ± 12.5 AU/mm (HH 40% dilution; p < 0.0001) and to 20.4 ± 10.4 AU/min (HT 40% dilution; p < 0.0001) without differences between HH and HT (MCF: p = 0.452; AUC: p = 0.449).HH impairs platelet function during in vitro dilution already at 5% dilution. Impairment of whole blood coagulation is significant after 10% dilution or more. This effect can be pinpoin
Monitoring of the Membrane Potential in Proteoliposomes with Incorporated Cytochrome-c Oxidase Using the Fluorescent Dye Indocyanine
Yu. A. Ivashchuk-Kienbaum
Physics , 2002,
Abstract: A method has been developed to monitor changes of the membrane potential across vesicle membranes in real time. Using the potential-sensitive fluorescent dye indocyanine and on the basis of water/lipid redistribution model, a calculation procedure has been introduced to estimate the membrane potential in vesicles with incorporated cytochrome-c oxidase. Physical parameters, such as vesicle size distribution and density of the lipid bilayer were estimated and used as calculation parameters. By extrapolation of transient potential change to zero time, the initial rate of the potential change (dU/dt) has been calculated. It is also shown, that the initial potential change (dU/dt) may be used to study the proton/electron stoichiometry of cytochrome-c oxidase incorporated in the vesicles.
Whole blood coagulation and platelet activation in the athlete: A comparison of marathon, triathlon and long distance cycling
AA Hanke, A Staib, K G?rlinger, M Perrey, D Dirkmann, P Kienbaum
European Journal of Medical Research , 2010, DOI: 10.1186/2047-783x-15-2-59
Abstract: 68 healthy athletes participating in marathon (MAR, running 42 km, n = 24), triathlon (TRI, swimming 2.5 km + cycling 90 km + running 21 km, n = 22), and long distance cycling (CYC, 151 km, n = 22) were included in the study. Blood samples were taken before and immediately after completion of competition to perform rotational thrombelastometry. We assessed coagulation time (CT), maximum clot firmness (MCF) after intrinsically activation and fibrin polymerization (FIBTEM). Furthermore, platelet aggregation was tested after activation with ADP and thrombin activating peptide 6 (TRAP) by using multiple platelet function analyzer.Complete data sets were obtained in 58 athletes (MAR: n = 20, TRI: n = 19, CYC: n = 19). CT significantly decreased in all groups (MAR -9.9%, TRI -8.3%, CYC -7.4%) without differences between groups. In parallel, MCF (MAR +7.4%, TRI +6.1%, CYC +8.3%) and fibrin polymerization (MAR +14.7%, TRI +6.1%, CYC +8.3%) were significantly increased in all groups. However, platelets were only activated during MAR and TRI as indicated by increased AUC during TRAP-activation (MAR +15.8%) and increased AUC during ADP-activation in MAR (+50.3%) and TRI (+57.5%).While coagulation is activated during physical activity irrespective of type we observed significant platelet activation only during marathon and to a lesser extent during triathlon. We speculate that prolonged running may increase platelet activity, possibly, due to mechanical alteration. Thus, particularly prolonged running may increase the risk of thrombembolic incidents in running athletes.Popularity of marathon running has increased during the last decade. Today, out of 17 million non professional runners in Germany, 100.000 runners participate in marathon competitions. Thrombembolic events have been reported in marathon athletes during competition accounting for considerable morbidity and mortality in otherwise healthy subjects even in the most experienced runners [1-7]. In previous studies, acti
Prospective observational study for perioperative volume replacement with 6% HES 130/0,42, 4% gelatin and 6% HES 200/0,5 in cardiac surgery
M Winterhalter, P Malinski, O Danzeisen, S Sixt, E Monaca, T Jüttner, M Peiper, P Kienbaum, A Koester, N Rahe-Meyer
European Journal of Medical Research , 2010, DOI: 10.1186/2047-783x-15-9-383
Abstract: We included 90 patients undergoing an elective open-heart surgery with the use of the heart-lung machine and observed them consecutively. Group 1 [gelatin 4% (n = 30)], Group 2 [HES 200/0,5 (n = 30)] and Group 3 [HES 130/0,42 (n = 30)]. We measured the perioperative volume replacement, the administration of blood- and coagulation-products, the application of catecholamines, the renal function, blood gas and the platelet aggregation using multiplate electrode analyzer (Multiplate?, Dynabyte medical, Munich, Germany).The gelatin-group needed significantly more norepinephrine than the HES 130/0.42 group. The responsible surgeon considered the blood coagulation in the HES 200/0.5 group most frequently as impaired. Furthermore we saw a significant decrease in platelet function in the HES 200/0.5 group when performing the multiplate?-analysis (ADP-and COL-test). HES 130/0.4 as well as gelatin 4% showed no significant change in platelet function. The gelatin-group and the HES 200/0.5 needed significantly more aprotinine than the HES 130/0.4 group. We saw no significant difference with regards to administration of blood and coagulation products between the three groups. The urinary excretion during the intervention was significantly higher in the HES 200/0.5 group and in the gelatin group than in the HES 130/0.4 group.Our results confirm the lower stabilizing effect of gelatin on circulation during fluid resuscitation. The blood coagulation was mostly impaired due to HES 200/0.5 confirmed by the multiplate?-analysis as well as by different clinical findings.Cardiac surgery is associated with extended blood loss resulting in hypovolemia, circulatory dysregulation and deficient tissue perfusion. Therefore an urgent adequate intravascular volume therapy is essential for the management of these patients and in avoiding organ dysfunction. The advantage of colloids over crystalloids in effective volume replacement and improving haemodynamics has been confirmed and reviewed in sev
Prospective study comparing skin impedance with EEG parameters during the induction of anaesthesia with fentanyl and etomidate
M Winterhalter, S Münte, M Gerhard, O Danzeisen, T Jüttner, E Monaca, L Hoy, N Rahe-Meyer, P Kienbaum
European Journal of Medical Research , 2010, DOI: 10.1186/2047-783x-15-2-47
Abstract: The electrical skin impedance was measured with the help of an electro-sympathicograph (ESG). In 47 patients scheduled for elective cardiac surgery, anaesthesia was induced with intravenous fentanyl 10 μg/kg and etomidate 0.3 mg/kg. During induction, the ESG (Electrosympathicograph), BIS (Bispectral IndeX), BP (arterial blood pressure) and HR (heart rate) values of each patient were recorded every 20 seconds. The observation period from administration of fentanyl to intubation for surgery lasted 4 min.The ESG recorded significant changes in the electrical skin impedance after administration of fentanyl and etomidate(p < 0.05). During induction of anaesthesia, significant changes of BIS, HR and blood pressure were observed as well (p < 0.05).The electrical skin impedance measurement may be used to monitor the effects of anesthetics during general anaesthesia.Clinical assessment uses parameters such as heart rate and blood pressure to determine anaesthetic depth. Administration of etomidate in combination with fentanyl has been suggested for induction of anaesthesia in high-risk patients for cardiac surgery, because of their minor cardiovascular effects [1]. The partly opposed effects of etomidate and fentanyl on heart rate and blood pressure do not allow to predict the adequacy of anaesthesia on the basis of these parameters [2-4]. This is particularly the case in cardiac high-risk patients, whose heart rate and blood pressure behaviour are often dictated by the underlying heart impairment and by heart medication. Cardiosurgical operations are considered to bear a higher risk of unintended intraoperative awareness compared to general surgical operations [5].A previous study addressing EEG changes during a cardiosurgical operation with postoperative recall found no relationship between the time spent awake and EEG changes [6]. In addition, Barr and colleagues observed an insufficient correlation between bispectral index and intraoperatively measured plasma midazolam a
Natural Rights, Morality, and the Law  [PDF]
Drum Peter
Beijing Law Review (BLR) , 2011, DOI: 10.4236/blr.2011.21004
Abstract: It is argued that despite attempts to discount the importance of natural rights for morality, they are fundamental to it; therefore, so too are natural rights to the legitimacy of the law.
Price Stability and the Growth Maximizing Rate of Inflation for Ghana  [PDF]
Peter Quartey
Modern Economy (ME) , 2010, DOI: 10.4236/me.2010.13021
Abstract: Monetary policy in Ghana, which is typical of many central banks, over the years, has focused on ensuring price stability or low inflation. The aim of the policy of price stability is to provide a stable environment for real sector activities to flourish. However, the outcome of the policy on real sector activities has not been subjected to any empirical investigation and this forms the focus of the study. For instance, the Central Bank has focused on single digit inflation and whether such a low rate is growth maximizing is yet to be ascertained. The study therefore investigates the revenue maximizing and the ‘growth maximizing’ rate of inflation for Ghana using data from Bank of Ghana and WDI. The study finds that economic performance is higher under low inflation era than when inflation is high. It also established the revenue maximizing rate of inflation using the Laffer curve approach is lower than the growth maximizing rate of inflation. Also, from the results, it can be deduced that the single digit inflation target set by the Central bank is not growth maximizing.
Aristotle’s Definition of Place and of Matter  [PDF]
Peter Drum
Open Journal of Philosophy (OJPP) , 2011, DOI: 10.4236/ojpp.2011.11006
Abstract: The accuracy of Aristotle’s definition of place is defended in terms of his form-matter theory. This theory is in turn defended against the objectionable notion that it entails matter is ultimately characterless.
Adapted Caussinus-Mestre Algorithm for Networks of Temperature series (ACMANT)  [PDF]
Peter Domonkos
International Journal of Geosciences (IJG) , 2011, DOI: 10.4236/ijg.2011.23032
Abstract: Any change in technical or environmental conditions of observations may result in bias from the precise values of observed climatic variables. The common name of these biases is inhomogeneity (IH). IHs usually appear in a form of sudden shift or gradual trends in the time series of any variable, and the timing of the shift indicates the date of change in the conditions of observation. The seasonal cycle of radiation intensity often causes marked seasonal cycle in the IHs of observed temperature time series, since a substantial portion of them has direct or indirect connection to radiation changes in the micro-environment of the thermometer. Therefore the magnitudes of temperature IHs tend to be larger in summer than in winter. A new homogenisation method (ACMANT) has recently been developed which treats in a special way the seasonal changes of IH-sizes in temperature time series. The ACMANT is a further development of the Caussinus-Mestre method, that is one of the most effective tool among the known homogenising methods. The ACMANT applies a bivariate test for searching the timings of IHs, the two variables are the annual mean temperature and the amplitude of seasonal temperature-cycle. The ACMANT contains several further innovations whose efficiencies are tested with the benchmark of the COST ES0601 project. The paper describes the properties and the operation of ACMANT and presents some verification results. The results show that the ACMANT has outstandingly high performance. The ACMANT is a recommended method for homogenising networks of monthly temperature time series that observed in mid- or high geographical latitudes, because the harmonic seasonal cycle of IH-size is valid for these time series only.
Random but System-Wide Unique Unlinkable Parameters  [PDF]
Peter Schartner
Journal of Information Security (JIS) , 2012, DOI: 10.4236/jis.2012.31001
Abstract: When initializing cryptographic systems or running cryptographic protocols, the randomness of critical parameters, like keys or key components, is one of the most crucial aspects. But, randomly chosen parameters come with the intrinsic chance of duplicates, which finally may cause cryptographic systems including RSA, ElGamal and Zero-Knowledge proofs to become insecure. When concerning digital identifiers, we need uniqueness in order to correctly identify a specific action or object. Unfortunately we also need randomness here. Without randomness, actions become linkable to each other or to their initiator’s digital identity. So ideally the employed (cryptographic) parameters should fulfill two potentially conflicting requirements simultaneously: randomness and uniqueness. This article proposes an efficient mechanism to provide both attributes at the same time without highly constraining the first one and never violating the second one. After defining five requirements on random number generators and discussing related work, we will describe the core concept of the generation mechanism. Subsequently we will prove the postulated properties (security, randomness, uniqueness, efficiency and privacy protection) and present some application scenarios including system-wide unique parameters, cryptographic keys and components, identifiers and digital pseudonyms.
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