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Budapest, Hungary

Szittner Z.,EotvosLorand University | Szittner Z.,Diagnosticum Co. | Papp K.,Hungarian Academy of Sciences | Papp K.,Diagnosticum Co. | And 4 more authors.
PLoS ONE | Year: 2013

Microarrayed antigens are used for identifying serum antibodies with given specificities and for generating binding profiles. Antibodies bind to these arrayed antigens forming immune complexes and are conventionally identified by secondary labelled antibodies.In the body immune complexes are identified by bone marrow derived phagocytic cells, such as monocytes. In our work we were looking into the possibility of replacing secondary antibodies with monocytoid cells for the generation of antibody profiles. Using the human monocytoid cell line U937, which expresses cell surface receptors for immune complex components, we show that cell adhesion is completely dependent on the interaction of IgG heavy chains and Fcγ receptors, and this recognition is susceptible to differences between heavy chain structures and their glycosylation. We also report data on a possible application of this system in autoimmune diagnostics.Compared to secondary antibodies, fluorescent monocytesas biosensors are superior in reflecting biological functions of microarray-bound antibodies and represent an easy and robust alternative for profiling interactions between serum proteins and antigens. © 2013 Szittner et al.

Peter P.,EotvosLorand University | Eva S.,EotvosLorand University | Anna K.,EotvosLorand University | Anna K.,Hungarian Academy of Sciences | And 3 more authors.
Applied Animal Behaviour Science | Year: 2014

Besides being a widely investigated behavioural phenomenon, barks of dogs often represent a factor of nuisance for people. Although some argue that dog barking has no or only minimal communicative function, it was shown recently that these acoustic signals carry various information that humans can decipher. However, apart from a few laboratory studies, until now no targeted research has been done about the communicative role of barks in the intraspecific domain. In this field experiment companion dogs were tested with bark playbacks at home, in a suburban environment. From a hidden sound system, placed near to the gate outside of the property, each subject was exposed to pre-recorded barks of an unfamiliar and a familiar dog. Barks for the playbacks were recorded in two different contexts: when the dog was either left alone or when it was barking at a stranger at the fence. We found differences in the behaviour of dogs depending on both the familiarity and context of the playback barks. The position of the dogs (near the house or near the gate) was mainly influenced by the context of the barks (p=0.011), in a significant interaction with the familiarity of the barking dog (p=0.020). Subjects stayed at the gate (nearest to the source of the sound) the longest when they heard an unfamiliar dog barking at a stranger (padj=0.012). Meanwhile they stayed at the house mostly during the barks of a lonely unfamiliar dog (padj=0.001). Dogs oriented more towards the house (where the familiar dog stayed during the experiment) when they heard the familiar dog's barking (p=0.019). Subjects barked more often when they heard the 'stranger' barks, independently of the familiarity of the caller (p=0.035). As a conclusion, dogs seemingly distinguished among the callers based on familiarity and between the contexts of the barks. This is the first study on companion dogs in their natural environment that found evidence that dogs are able to extract detailed information from the barks. The relevance of our findings for the management of excessive bark is discussed. © 2014 Elsevier B.V.

Armatys K.,Clausthal University of Technology | Bencze L.,EotvosLorand University | Miller M.,International Laboratory of High Magnetic Felds and Low Temperatures | Wolter A.,Clausthal University of Technology
Thermochimica Acta | Year: 2014

Vaporisation studies of pure K2SO4 and mixtures of K2SO4 and CaSO4 in the quasi-binary K 2SO4-CaSO4 system using Knudsen effusion mass spectrometry resulted in the determination of thermodynamic data. From the partial pressures of the gaseous species over the condensed phases it was possible to determine the sublimation enthalpyΔsubH and the thermodynamic activities of the components. The sublimation enthalpy of K 2SO4 agrees very well with that of two literature sources. For the first time the experimental data of activities of K2SO 4 and CaSO4 in the binary system could confirm the theoretical studies. © 2013 Elsevier B.V. All rights reserved.

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