Biomedical subjects

Susanne König

Publications and source records attributed to Susanne König.

5 recordsLinked to original sources

PubMed2004

Amino acid analysis in mammalian cell culture media containing serum and high glucose concentrations by anion exchange chromatography and integrated pulsed amperometric detection.

The direct separation detection of amino acids by anion exchange chromatography with integrated pulsed amperometric detection was optimized for the analysis of typical mammalian cell culture broth samples. Existing gradient elution conditions were adapted, considering the additions of peptone (2 g/L) and 10 vol% fetal calf serum to the medium as well as changing concentrations of glucose from 5.5 g/L up to complete consumption. Samples had to be analyzed in two dilutions with water (1:33.3 and 1:200) due to the strongly varying amino acid concentrations in the samples as a result of the medium composition and cell metabolism. The method was validated in a linear working range for the most common amino acids (2.5-7.5 and 1.25-3.75 microM for cystine/cysteine with 15 microl injection volume). The relative standard deviation of the method for all amino acids was less than 5%, with detection limits of less than 0.6 microM and quantitation limits of less than 1.6 microM. As an example, data for the amino acid composition of different media used for the production of inactivated influenza vaccines in cell culture are shown.

Amino Acids↗

PubMed2002

[Empirical analysis of transference and relationship patterns--A single case study].

In the present study a psychoanalytic therapy was assessed by the CCRT method for the first time. We used reformulated categories for CCRT scoring. The data analyses were based not only on the most frequent categories but on newly developed alternative strategies. We could determine specific relationship patterns with special objects reflecting aspects of the clinical concept of transference.

Adult↗

PubMed2002

[The connection between affective evaluation of recollected relationship experiences and the severity of the psychic impairment].

This study, carried out at three different university centers contributes to validating the valence dimension of the CCRT-method. Working on the state of the CCRT-research on affective evaluation of relationship narratives, the connection between the valence dimension of the responses from others (RO), responses of the self (RS) and the severity of the psychic disorder has been analysed with the help of two different samples (n = 266 resp. n = 32) taken from female patients. Both, therapists as well as patients themselves, evaluated the severity of the impairment similarly. The more the patients were impaired, the more negatively they describes both their own reactions and those of their interaction partners as shown in the relationship episodes.

Adult↗

PubMed2002

[Connections between attachment prototypes and relationship patterns].

Connections between attachment styles and relationship patterns are studied on 32 female psychotherapy patients. Our study gives first hints to a connection between attachment variables, assessed by the German version of the Adult Attachment Prototype Rating (AAPR) and predominant relationship patterns, assessed by the Core Conflictual Relationship Theme Method (CCRT) developed by Luborsky, if both methods are used independently. Subsamples according to the attachment styles show differences in CCRT variables.

Adult↗

PubMedDate not supplied

Substitution of glutamine by pyruvate to reduce ammonia formation and growth inhibition of mammalian cells.

In mammalian cell culture technology glutamine is required for biomass synthesis and as a major energy source together with glucose. Different pathways for glutamine metabolism are possible, resulting in different energy output and ammonia release. The accumulation of ammonia in the medium can limit cell growth and product formation. Therefore, numerous ideas to reduce ammonia concentration in cultivation broths have been developed. Here we present new aspects on the energy metabolism of mammalian cells. The replacement of glutamine (2 mM) by pyruvate (10 mM) supported cell growth without adaptation for at least 19 passages without reduction in growth rate of different adherent commercial cell lines (MDCK, BHK21, CHO-K1) in serum-containing and serum-free media. The changes in metabolism of MDCK cells due to pyruvate uptake instead of glutamine were investigated in detail (on the amino acid level) for an influenza vaccine production process in large-scale microcarrier culture. In addition, metabolite profiles from variations of this new medium formulation (1-10 mM pyruvate) were compared for MDCK cell growth in roller bottles. Even at very low levels of pyruvate (1 mM) MDCK cells grew to confluency without glutamine and accumulation of ammonia. Also glucose uptake was reduced, which resulted in lower lactate production. However, pyruvate and glutamine were both metabolized when present together. Amino acid profiles from the cell growth phase for pyruvate medium showed a reduced uptake of serine, cysteine, and methionine, an increased uptake of leucine and isoleucine and a higher release of glycine compared to glutamine medium. After virus infection completely different profiles were found for essential and nonessential amino acids.

Ammonia↗