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Comparison of methods for suspectibility testing of pathogens to antiinfective agents and conclusions concerning the further development of these methods
Hübner, Nils-Olaf,Sciermoch, Katharina,Kramer, Axel
GMS Krankenhaushygiene Interdisziplin?r , 2007,
Abstract: The evaluation of microbial resistance is one of the most important and most often performed tests in clinical microbiology and infection control laboratories. We show and compare our own approach to improved methods based on an overview on assets and drawbacks of established methods of resistance testing of pathogens to antimicrobial agents.
Effects of methyl-, phenyl-, ethylmercury and mercurychlorid on immune cells of harbor seals (Phoca vitulina)
Effects of methyl-, phenyl-, ethylmercury and mercurychlorid on immune cells of harbor seals (Phoca vitulina)

Antje Kakuschke,Elizabeth Valentine-Thon,Sonja Fonfar,Katharina Kramer,Andreas Prange,
Antje Kakuschke
,Elizabeth Valentine-Thon,Sonja Fonfar,Katharina Kramer,Andreas Prange

环境科学学报(英文版) , 2009,
Abstract: Mercury (Hg) is present in the marine environment as a natural metal often enhanced through human activities. Depending on its chemical form, Hg can cause a wide range of immunotoxic e ects. In this study, the influence of methyl-, ethyl- and phenylmercury as well as mercurychloride on immune functions was evaluated. Two parameters of cellular immunity, proliferation and mRNA cytokine expression of interleukin-2, -4, and transforming growth factor , were investigated in harbor seal lymphocytes after in vitro exposure to Hg compounds. While all Hg compounds had a suppressive e ect on proliferation, di erences between juvenile and adult seals were found. Lymphocytes from juveniles showed a higher susceptibility to the toxic e ect compared to lymphocytes from adults. Furthermore, the degree of inhibition of proliferation varied among the four Hg compounds. The organic compounds seem to be more immunotoxic than the inorganic compound. Finally, for the cytokine expression of methylmercury-incubated lymphocytes, timedependent changes were observed, but no dose-dependency was found. Marine mammals of the North Sea are burdened with Hg, and lymphocytes of harbor seals may be functionally impaired by this metal. The present in vitro study provides baseline information for future studies on the immunotoxic e ects of Hg on cellular immunity of harbor seals.
Interaction of antiseptics and antibiotics – principles and first in vitro results
Hübner, Nils-Olaf,Assadian, Ojan,Sciermoch, Katharina,Kramer, Axel
GMS Krankenhaushygiene Interdisziplin?r , 2007,
Abstract: While knowledge of possible interactions of antimicrobial substances is limited, combined use of antiseptics and antibiotics is clinical practice. The authors address the basic concepts and problems in interaction testing and show that the combination of microbiocidal substances does not necessarily lead to an synergistic effect in vitro. New approaches to avoid problems of existing methods are shown.
Opinion Leaders and Lead Users in Marketing and Management Accounting and Impact on Small Business Performance  [PDF]
Katharina Simbeck
Social Networking (SN) , 2013, DOI: 10.4236/sn.2013.21002
Abstract: This paper empirically investigates into the business performance benefit that lead users or opinion leaders among small business owners draw from their higher involvement in management accounting or marketing topics. This work also contributes to a better identification of network members’ roles solely through their ties between each other. Indeed, lead users and opinion leaders can be differentiated by a higher degree centrality in comparison to their peers. However, being an opinion leader or a lead user does not yield a measurable business benefit to the small businesses studied in this sample.
Early Childhood Education: Difficulties Creating and Changing Daily Practice  [PDF]
Sonia Kramer
Creative Education (CE) , 2014, DOI: 10.4236/ce.2014.56048

This paper is based on research carried out with children and adults at early childhood education institutions in Rio de Janeiro, Brazil. The research goals were to identify interactions between adults and children and to rethink pedagogical practice. The theoretical-methodological framework was based on language and culture studies, the sociology of childhood and anthropology. After studying children and adults in different contexts and early childhood education public policies and practice, the results present challenges of changing and creating early education practices in difficult contexts, especially with regard to the creation and use of spaces intended for children. This is the focus of the text, which is structured in three sections. Section one presents the theoretical and methodological issues. The second section analyzes three case studies developed in public pre-schools situated in different cities in the state of Rio de Janeiro. Section three presents conclusions and priorities for intervention and change concerning children, adults and their interactions.

Training Needs of International Medical Graduates [IMGs] in Psychiatry  [PDF]
Milton Kramer
Open Journal of Psychiatry (OJPsych) , 2014, DOI: 10.4236/ojpsych.2014.44036
Abstract: The potential shortage of psychiatrists over the next 5 - 10 years has focused attention on the need to recruit more IMGs to fill the needs rather than use nurse practitioners or physician assistants. IMGs make up about 1/3 of first year psychiatry residents. These individuals have been found to provide services to the poor, the elderly and the psychotic. The quality of their medical work has been found to be satisfactory. The training needs of these physicians require an understanding on the part of their teachers that they come from cultures with different values that we have. The extended families of these primarily Asian residents clash with our strong commitment to individualism. It leads to a We-self rather than our I-Self. This difference coupled with the stress of leaving to come to a new culture is a great stress. Their exposure to psychiatry has been limited. They request and need more interview demonstration and practice, ore feedback and examinations. They should have help in accent reduction. They should be exposed to the working of the hospital by sitting on departmental and hospital committees. The faculty should extend their social opportunities and work as mentors on joint projects. Courses on the history of American culture should be taught. Psychotherapy for them should be encouraged as well as teaching medical ethics. They must become the major educational concern for the department that they are in.
Boundaries of Smooth Strictly Convex Sets in the Euclidean Plane R2  [PDF]
Horst Kramer
Open Journal of Discrete Mathematics (OJDM) , 2017, DOI: 10.4236/ojdm.2017.72008
Abstract: We give a characterization of the boundaries of smooth strictly convex sets in the Euclidean plane R2?based on the existence and uniqueness of inscribed triangles.
TNF-Overexpression in Borna Disease Virus-Infected Mouse Brains Triggers Inflammatory Reaction and Epileptic Seizures
Katharina Kramer, Dirk Schaudien, Ulrich L. M. Eisel, Sibylle Herzog, Jürgen A. Richt, Wolfgang Baumg?rtner, Christiane Herden
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0041476
Abstract: Proinflammatory state of the brain increases the risk for seizure development. Neonatal Borna disease virus (BDV)-infection of mice with neuronal overexpression of tumor necrosis factor-α (TNF) was used to investigate the complex relationship between enhanced cytokine levels, neurotropic virus infection and reaction pattern of brain cells focusing on its role for seizure induction. Viral antigen and glial markers were visualized by immunohistochemistry. Different levels of TNF in the CNS were provided by the use of heterozygous and homozygous TNF overexpressing mice. Transgenic TNF, total TNF (native and transgenic), TNF-receptor (TNFR1, TNFR2), IL-1 and N-methyl-D-aspartate (NMDA)-receptor subunit 2B (NR2B) mRNA values were measured by real time RT-PCR. BDV-infection of TNF-transgenic mice resulted in non-purulent meningoencephalitis accompanied by epileptic seizures with a higher frequency in homozygous animals. This correlated with lower weight gain, stronger degree and progression of encephalitis and early, strong microglia activation in the TNF-transgenic mice, most obviously in homozygous animals. Activation of astroglia could be more intense and associated with an unusual hypertrophy in the transgenic mice. BDV-antigen distribution and infectivity in the CNS was comparable in TNF-transgenic and wild-type animals. Transgenic TNF mRNA-expression was restricted to forebrain regions as the transgene construct comprised the promoter of NMDA-receptor subunit2B and induced up-regulation of native TNF mRNA. Total TNF mRNA levels did not increase significantly after BDV-infection in the brain of transgenic mice but TNFR1, TNFR2 and IL-1 mRNA values, mainly in the TNF overexpressing brain areas. NR2B mRNA levels were not influenced by transgene expression or BDV-infection. Neuronal TNF-overexpression combined with BDV-infection leads to cytokine up-regulation, CNS inflammation and glial cell activation and confirmed the presensitizing effect of elevated cytokine levels for the development of spontaneous epileptic seizures when exposed to additional infectious noxi.
Inorganic pyrophosphatase in uncultivable hemotrophic mycoplasmas: identification and properties of the enzyme from Mycoplasma suis
Katharina Hoelzle, Simone Peter, Michele Sidler, Manuela M Kramer, Max M Wittenbrink, Kathrin M Felder, Ludwig E Hoelzle
BMC Microbiology , 2010, DOI: 10.1186/1471-2180-10-194
Abstract: Inorganic pyrophosphatases (PPase) are important enzymes that catalyze the hydrolysis of inorganic pyrophosphate PPi to inorganic phosphate Pi. PPases are essential and ubiquitous metal-dependent enzymes providing a thermodynamic pull for many biosynthetic reactions. Here, we describe the identification, recombinant production and characterization of the soluble (s)PPase of Mycoplasma suis.Screening of genomic M. suis libraries was used to identify a gene encoding the M. suis inorganic pyrophosphatase (sPPase). The M. suis sPPase consists of 164 amino acids with a molecular mass of 20 kDa. The highest identity of 63.7% was found to the M. penetrans sPPase. The typical 13 active site residues as well as the cation binding signature could be also identified in the M. suis sPPase. The activity of the M. suis enzyme was strongly dependent on Mg2+ and significantly lower in the presence of Mn2+ and Zn2+. Addition of Ca2+ and EDTA inhibited the M. suis sPPase activity. These characteristics confirmed the affiliation of the M. suis PPase to family I soluble PPases. The highest activity was determined at pH 9.0. In M. suis the sPPase builds tetramers of 80 kDa which were detected by convalescent sera from experimentally M. suis infected pigs.The identification and characterization of the sPPase of M. suis is an additional step towards the clarification of the metabolism of hemotrophic mycoplasmas and, thus, important for the establishment of an in vitro cultivation system. As an antigenic and conserved protein the M. suis sPPase could in future be further analyzed as a diagnostic antigen.Mycoplasma suis belongs to a group of highly specialized uncultivable hemotrophic bacteria within the family Mycoplasmataceae that attach to the surface of host erythrocytes [1,2]. In the last few years reports on hemotrophic mycoplasmas in various animal species [1] as well as in humans [3,4] continuously increased. Obviously, hemotrophic mycoplasmas are emerging agents with a zoonotic pot
Intense Long-Lived Fluorescence of 1,6-Diphenyl-1,3,5-Hexatriene: Emission from the S1-State Competes with Formation of O2 Contact Charge Transfer Complex  [PDF]
Katharina Hunger, Karl Kleinermanns
Open Journal of Physical Chemistry (OJPC) , 2013, DOI: 10.4236/ojpc.2013.31008

The fluorescence kinetics of 1,6-diphenyl-1,3,5-hexatriene (DPH) dissolved in cyclohexane was investigated as a function of temperature, concentration and 355 nm excitation pulse energy. At concentrations above 2.5 μM and excitation energies above 1 mJ a long-lived, very intense emission, which appears within less than 5 ns and lasts up to 70 ns, is observed. During the first 50 ns the decay does not follow an exponential but rather a linear behaviour. In oxygen saturated solutions the long-lived emission is suppressed and solely short-lived fluorescence with τ < 5 ns can be detected. A kinetic simulation was performed, based on a model whereupon the long-lived emission originates from the S1-state and competes with the formation of DPH-O2 contact charge-transfer complexes and intersystem crossing which both quench the fluorescence. Our investigations show that even the small amount of oxygen dissolved in nitrogen saturated solutions has a distinct influence on the fluorescence kinetics of DPH.

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