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Search Results: 1 - 10 of 375 matches for " Karolin Thiel "
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Standardized intensive care unit management in an anhepatic pig model: new standards for analyzing liver support systems
Christian Thiel, Karolin Thiel, Alexander Etspueler, Thomas Schenk, Matthias H Morgalla, Alfred Koenigsrainer, Martin Schenk
Critical Care , 2010, DOI: 10.1186/cc9196
Abstract: Eight pigs underwent total hepatectomy after Y-graft interposition between the infrahepatic vena cava and the portal vein to the suprahepatic vena cava. An intracranial probe was inserted for intracranial pressure (ICP) monitoring. Animals received pressure-controlled ventilation under deep narcosis. Vital parameters were continuously recorded. Urinary output, blood gas analysis, haemoglobin, hematocrit, serum electrolytes, lactate, and glucose were monitored hourly, and creatinine, prothrombin time, international normalised ratio, and serum albumin were monitored every 8 hours. Sodium chloride solution 0.9%, hydroxyethyl starch 6%, fresh frozen plasma, and erythrocyte units were used for volume substitution, and norepinephrine was used to prevent severe hypotension. Serum electrolytes and acid-base balance were corrected as required. Antibiotic prophylaxis with ceftriaxon was given daily, as well as furosemide, to maintain diuresis.Postoperative survival was 100% after 24 hours, with a maximum survival of 73 (mean, 58 ± 4) hours. Haemodynamic parameters such as heart rate, mean arterial pressure, and pulse oximetry remained stable during surgical procedures and following anhepatic status due to ICU therapy until escalating at time of death. Deteriorating pulmonary function could be stabilized by increasing oxygen concentration, positive end-expiratory pressure, and maximal airway pressure. Furosemide was used to maintain diuresis until renal failure occurred. ICP started at 15-17 mmHg and increased continuously up to levels of 41-43 mmHg at time of death. All animals died as a result of multiple-organ failure.Using standardized intensive care management after total hepatectomy, we were able to prolong anhepatic survival over 58 hours without the use of liver support systems. The survival benefit of liver support systems in previous animal studies should be reevaluated against our model.Several models of acute hepatic failure have been investigated in animal studies
A simple dummy liver assist device prolongs anhepatic survival in a porcine model of total hepatectomy by slight hypothermia
Karolin Thiel, Martin Schenk, Alexander Etspüler, Thomas Schenk, Matthias H Morgalla, Alfred K?nigsrainer, Christian Thiel
BMC Gastroenterology , 2011, DOI: 10.1186/1471-230x-11-79
Abstract: Total hepatectomy was performed in ten female pigs followed by standardized intensive care support until death. Five animals (dummy group, n = 5) underwent additional cyclic connection to an extracorporeal dummy device which consisted of a plasma separation unit. The separated undetoxified plasma was completely returned to the pigs circulation without any plasma substitution or exchange in contrast to animals receiving intensive care support alone (control group, n = 5). All physiological parameters such as vital and ventilation parameters were monitored electronically; laboratory values and endotoxin levels were measured every 8 hours.Survival of the dummy device group was 74 ± 6 hours in contrast to 53 ± 5 hours of the control group which was statistically significant (p < 0.05). Body temperature 24 hours after hepatectomy was significantly lower (36.5 ± 0.5°C vs. 38.2 ± 0.7°C) in the dummy device group. Significant lower values were measured for blood lactate (1.9 ± 0.2 vs. 2.5 ± 0.5 mM/L) from 16 hours, creatinine (1.5 ± 0.2 vs. 2.0 ± 0.3 mg/dL) from 40 hours and ammonia (273 ± 122 vs. 1345 ± 700 μg/dL) from 48 hours after hepatectomy until death. A significant rise of endotoxin levels indicated the onset of sepsis at time of death in 60% (3/5) of the dummy device group animals surviving beyond 60 hours from hepatectomy.Episodes of slight hypothermia induced by cyclic connection to the extracorporeal dummy device produced a significant survival benefit of more than 20 hours through organ protection and hemodynamic stabilisation. Animal studies which focus on a survival benefit generated by liver assist devices should especially address the aspect of slight transient hypothermia by extracorporeal cooling.Acute liver failure (ALF) is defined as rapid and progressive development of severe acute liver injury with impaired liver synthetic function without a previous history of liver disease. Worsening encephalopathy and cerebral edema escalating in brain stem herniat
Comparative Evaluation of the Anti-ulcer Activity of Curcumin and Omeprazole during the Acute Phase of Gastric Ulcer—Efficacy of Curcumin in Gastric Ulcer Prevention against Omeprazole  [PDF]
Karolin Kamel Abdul-Aziz
Food and Nutrition Sciences (FNS) , 2011, DOI: 10.4236/fns.2011.26088
Abstract: We have confirmed in our laboratory the antiulcer activity of curcumin during the acute chronic phase of gastric ulcer disease at doses of 20, 40 and 80 mg/kg (dissolved in saline solution). In the previous study, the potent effective dose of curcumin was 80 mg/kg that appears a propitious protective effect against gastric ulcer development. Therefore, the comparison between such recommended dose of curcumin and one of the proton pump inhibitors (PPIs) staff is worth-while. Since, the pharmacological control of gastric acid secretion is the main desired goal for gastro-cytoprotection, particularly, the H+/K+-ATPase (acid proton pump) inhibitors. Nevertheless, several studies have indicated that long-term inhibition of gastric acid secretion results in mucosal hyperplasia and carcinoid tumor development, due to increase circulating gastrin levels. Ulcer and the preventive indexes were scored, mucin, juice volume, total acidity, luminal haemoglobin, total antioxidant and total peroxide were evaluated. The pro-inflammatory cytokine IL-6 and the major angiogenic growth factor VEGF levels were measured. Conclusion, curcumin and omeprazole are potentially preventing gastric lesions development in the gastric wall during the acute phase of gastric ulcer diseases, but curcumin was more potent in its effect. Curcumin promotes gastric ulcer prevention/healing by induction of angiogenesis in the granular tissue of ulcers. That may be via upregulation of VEGF expression as reflected from VEGF level in serum and gastric juice, however, omeprazole might be has no role in this story.
Current Perspectives on Sunitinib Targeted Therapy for Tumors  [PDF]
Karolin Kamel Abdel-Aziz
Journal of Cancer Therapy (JCT) , 2011, DOI: 10.4236/jct.2011.24073
Abstract: This review highlights therapeutic agents from recent cancer therapeutic trials showing the greatest potential for further clinical use for sunitinib in the near future. In fact, sunitinib is one of multi-tyrosine kinase inhibitors; tyrosine kinases are enzymes, which transfer phosphate groups from ATP to the hydroxyl group of tyrosine residues on signal transduction molecules. Phosphorylation of signal transduction molecules, in turn, induces dramatic changes in tumor growth, including activation of angiogenesis and DNA synthesis. Therefore, sustain efforts have been directed for developing inhibitors for angiogenesis, which is the marginal process for tumor growth and development through targeting TKs. Almost if not all angiogenesis inhibitors target the vascular endothelial growth factor (VEGF) signaling pathway.
A Methodology to Assess the Safety of Aircraft Operations When Aerodrome Obstacle Standards Cannot Be Met  [PDF]
Hartmut Fricke, Christoph Thiel
Open Journal of Applied Sciences (OJAppS) , 2015, DOI: 10.4236/ojapps.2015.52007
Abstract: When Aerodrome Obstacle Standards cannot be met as a result of urban or technical development, an aeronautical study can be carried out with the permission of EASA, in conjunction with ICAO, to prove how aircrafts can achieve an equivalent level of safety. However currently, no detailed guidance for this procedure exists. This paper proposes such a safety assessment methodology in order to value obstacle clearance violations around airports. This method has already been applied to a safety case at Frankfurt Airport where a tower elevating 4 km out of threshold 25R severely violates obstacle limitation surfaces. The model data refers to a take-off and landing performance model (TLPM) computing precisely aircraft trajectories for both standard and engine out conditions at ground proximity. The generated tracks are used to estimate collision risk incrementally considering EASA/FAA, EU-OPS & ICAO clearance criteria. Normal operations are assessed with a probabilistic analysis of empirical take-off/landing track data generating the local actual navigation performance (ANP) on site. The ANP shows integration to collision risk for an aircraft with any obstacle. The obstacle is tested for clearance within a “5-step-plan” against all performance requirements for landing climb and take-off climb. The methodology thereby delivers a comprehensive risk picture: The presented safety case for Frankfurt Airport showed an equivalent safety level despite the violation of standards. The collision risk during both normal and degraded performance operations was still found to be within ICAO Collision Risk Model (CRM) limits, requiring only limited risk mitigation measures. The presented work should complement ICAO Doc 9774 Appendix 3.
Cationic polypeptides in a concept of oppositely charged polypeptides as prevention of postsurgical intraabdominal adhesions  [PDF]
Karolin Isaksson, Daniel ?kerberg, Katarzyna Said, Bobby Tingstedt
Journal of Biomedical Science and Engineering (JBiSE) , 2011, DOI: 10.4236/jbise.2011.43028
Abstract: Background: Two differently charged polypeptides, α-poly-L-lysine and poly-L-glutamate, have previously been shown to effectively reduce postoperative intraabdominal adhesions. Though α-poly-L-lysine showed toxicity in doses too close to the lowest therapeutic dose, the aim in the present study was to investigate the possible antiadhesive effect of another four cationic polypeptides. Materials/Methods: 125 mice were studied with a standardized and reproducible adhesion model and given epsilon poly-L-lysine, lactoferrin, lysozyme and polyarginine respectively in a combination with poly-L-glutamate. Epsilon poly-L-lysine was also tested in different concentrations and as single treatment. Results: All four cationic polypeptides above showed a significantly better anti-adhesive effect than the controls receiving saline (p<0.05). Epsilon poly-L-lysine had the best antiadhesive effect of the new substances tested in the experiment. Single treatment with the epsilon poly-L-lysine showed toxic side effects. Discussion: We have shown that epsilon poly-L-lysine, polyarginine, lysozyme and lactoferrin, in descending order, all can reduce postoperative intraabdominal adhesions in mice when combined with poly-L-glutamate. There were side effects of epsilon poly-L-lysine resembling those of α-poly-L-lysine, although less toxic. The antiadhesive effect of epsilon poly-L-lysine did not reach the level of α-poly-L-lysine. Further studies will concentrate on additional investigation, trying to modify the α-poly-L-lysine to lower its toxicity. The less toxic epsilon poly-L-lysine also needs further attention in our research of antiadhesive bioactive polypeptides.
Alternative Nitrogenases in Anabaena variabilis: The Role of Molybdate and Vanadate in Nitrogenase Gene  [PDF]
Teresa Thiel, Brenda S. Pratte
Advances in Microbiology (AiM) , 2013, DOI: 10.4236/aim.2013.36A011
Abstract: Anabaena variabilis ATCC 29413 has two distinct nitrogenases that function in heterocysts, a conventional Mo-nitrogenase and an alternative V-nitrogenase. Synthesis of these two enzymes was repressed in cells growing with a source of fixed nitrogen, such as ammonium; however, the V-nitrogenase was also repressed by Mo. Expression of the V-nitrogenase which was not affected by V and expression of the Mo-nitrogenase was not affected by the presence or absence of either Mo or V. In the absence of both Mo and V in an environment lacking fixed nitrogen, cells became starved for both metals; however, low levels of nitrogen fixation and slow growth persisted. A mutant lacking the V-nitrogenase was still able to grow very slowly in Mo-and V-free medium; however, loss of the Mo-nitrogenase in a nifDK1 mutant abolished the residual growth, suggesting that only the Mo-nitrogenase functioned under these conditions to support slow growth. The addition of vanadate, molybdate, or tungstate, which is transported by the molybdate transporter, to cells starved for these metals resulted in an increase in nitrogenase activity within two hours after the addition of the metal and this increase required new protein synthesis. While tungstate functioned about as well as vanadate in supporting acetylene reduction, the cells were not able to grow any better with tungstate than with no added metal. A mutant lacking the V-nitrogenase showed no increase in nitrogenase activity upon addition of tungstate, suggesting that the V-nitrogenase was able to incorporate tungstate. Tungstate was able to substitute for molybdate in repressing transcription of a Mo-transport gene, but it did not repress transcription of the vnfH gene, which was repressed by Mo. The availability of Mo and V plays an important role in controlling whether the Mo-or the V-nitrogenase is used for nitrogen fixation.
The Power Laws of Violence against Women: Rescaling Research and Policies
Karolin E. Kappler, Andreas Kaltenbrunner
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0040289
Abstract: Background Violence against Women –despite its perpetuation over centuries and its omnipresence at all social levels– entered into social consciousness and the general agenda of Social Sciences only recently, mainly thanks to feminist research, campaigns, and general social awareness. The present article analyzes in a secondary analysis of German prevalence data on Violence against Women, whether the frequency and severity of Violence against Women can be described with power laws. Principal Findings Although the investigated distributions all resemble power-law distributions, a rigorous statistical analysis accepts this hypothesis at a significance level of 0.1 only for 1 of 5 cases of the tested frequency distributions and with some restrictions for the severity of physical violence. Lowering the significance level to 0.01 leads to the acceptance of the power-law hypothesis in 2 of the 5 tested frequency distributions and as well for the severity of domestic violence. The rejections might be mainly due to the noise in the data, with biases caused by self-reporting, errors through rounding, desirability response bias, and selection bias. Conclusion Future victimological surveys should be designed explicitly to avoid these deficiencies in the data to be able to clearly answer the question whether Violence against Women follows a power-law pattern. This finding would not only have statistical implications for the processing and presentation of the data, but also groundbreaking consequences on the general understanding of Violence against Women and policy modeling, as the skewed nature of the underlying distributions makes evident that Violence against Women is a highly disparate and unequal social problem. This opens new questions for interdisciplinary research, regarding the interplay between environmental, experimental, and social factors on victimization.
Extended parental care in crustaceans: an update
THIEL,MARTIN;
Revista chilena de historia natural , 2003, DOI: 10.4067/S0716-078X2003000200007
Abstract: many crustacean species show extended parental care (xpc) for fully developed juvenile offspring. herein, the present state of knowledge of the major patterns and consequences of xpc is reviewed, and furthermore important future research topics are identified. crustaceans with xpc are found in marine, freshwater and terrestrial environments, but care for late juvenile stages appears to be more common in terrestrial environments. in all species, females participate or even take the main share of xpc activities. crustaceans that carry their offspring during xpc commonly release early juvenile stages, while species inhabiting particular microhabitats may host offspring until these have reached subadult or adult stages. apart from providing a suitable and safe microhabitat to small offspring, parents share food with, groom or actively defend their juveniles. some of the most important benefits of xpc include improved juvenile growth and survival. xpc may also lead to conflicts among developing offspring or between parents and offspring, especially during later phases of xpc when resources (food and space) become increasingly limiting. similarly, during long-lasting cohabitation, epibionts (e.g., parasites) may be transferred from parents to offspring, as is indicated by observational evidence. for several species, local recruitment, where juveniles recruit in the immediate vicinity of their parents, has been observed. under these conditions, local populations may rapidly increase, potentially leading to intra-specific competition for space, thereby possibly causing a decrease in reproductive activity or a reduction in length of xpc. another consequence of xpc and local recruitment could be limited dispersal potential, but some marine crustaceans with xpc and local recruitment nevertheless have a wide geographic distribution. it is hypothesized that the existence of suitable dispersal vectors such as floating macroalgae or wood can lead to a substantial increase in dispe
Extended parental care in crustaceans: an update Cuidado parental extendido en crustáceos: conocimiento actual
MARTIN THIEL
Revista chilena de historia natural , 2003,
Abstract: Many crustacean species show extended parental care (XPC) for fully developed juvenile offspring. Herein, the present state of knowledge of the major patterns and consequences of XPC is reviewed, and furthermore important future research topics are identified. Crustaceans with XPC are found in marine, freshwater and terrestrial environments, but care for late juvenile stages appears to be more common in terrestrial environments. In all species, females participate or even take the main share of XPC activities. Crustaceans that carry their offspring during XPC commonly release early juvenile stages, while species inhabiting particular microhabitats may host offspring until these have reached subadult or adult stages. Apart from providing a suitable and safe microhabitat to small offspring, parents share food with, groom or actively defend their juveniles. Some of the most important benefits of XPC include improved juvenile growth and survival. XPC may also lead to conflicts among developing offspring or between parents and offspring, especially during later phases of XPC when resources (food and space) become increasingly limiting. Similarly, during long-lasting cohabitation, epibionts (e.g., parasites) may be transferred from parents to offspring, as is indicated by observational evidence. For several species, local recruitment, where juveniles recruit in the immediate vicinity of their parents, has been observed. Under these conditions, local populations may rapidly increase, potentially leading to intra-specific competition for space, thereby possibly causing a decrease in reproductive activity or a reduction in length of XPC. Another consequence of XPC and local recruitment could be limited dispersal potential, but some marine crustaceans with XPC and local recruitment nevertheless have a wide geographic distribution. It is hypothesized that the existence of suitable dispersal vectors such as floating macroalgae or wood can lead to a substantial increase in dispersal distances of crustaceans with XPC via rafting, surpassing that of crustaceans with pelagic larvae. Since crustaceans with XPC may be particularly susceptible to changing environmental conditions, especially in the terrestrial environment where populations are often small and locally restricted, conservation of biodiversity should focus on these (and other invertebrate) species with XPC Muchas especies de crustáceos presentan cuidado parental extendido (XPC), donde individuos juveniles completamente desarrollados son cuidados por los padres. En la presente contribución se revisa el conocim
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