Search PubMed⌕ Search

Biomedical subjects

G Bauer

Publications and source records attributed to G Bauer.

At least 253 records · Page 14Linked to original sources
PubMed1995

Direct transforming activity of TGF-beta on rat fibroblasts.

Treatment of NRK 536 fibroblasts with EGF and transforming growth factor type beta (TGF-beta) is known to lead to the reversible induction of the transformed phenotype in a large percentage of cells. Maintenance of the transformed state is dependent on the continuous presence of the cytokines. Here we show that treatment of these cells with TGF-beta alone leads to the formation of a small percentage of colonies, the majority of which stably retain the transformed phenotype after removal of the cytokine. Colony induction is dependent on the concentration of TGF-beta originally present. Stably transformed cells grow in soft agar without further addition of exogenous TGF-beta, and exhibit criss-cross morphology in monolayer culture and a diffuse actin pattern. Transformation of NRK 536 cells can be demonstrated only for individualized cells treated with TGF-beta in soft agar, as treatment in monolayer leads to the induction of apoptosis in newly transformed cells by neighboring normal cells. Transformation of NRK 536 fibroblasts by TGF-beta is not due to the induction of point mutations by TGF-beta.

Agar↗
PubMed1995

Catechol interferes with TGF-beta-induced elimination of transformed cells by normal cells: implications for the survival of transformed cells during carcinogenesis.

We have recently shown that TGF-beta-treated normal fibroblasts are able to induce apoptosis of transformed fibroblasts, leading to their elimination. Here we describe a test system that allows the quantitative analysis of the elimination of G418-resistant transformed cells by TGF-beta-treated normal cells. This assay system was used to screen for substances that interfere with the elimination of transformed cells. Catechol and hydroquinone, but not resorcinol, were found to represent potent antagonists of TGF-beta-induced elimination of transformed cells by normal cells. Protection of transformed cells from negative effects derived from their cellular environment defines a hitherto unrecognized crucial mechanism for the survival of transformed cells. The protective effect of catechol as seen in this experimental system may act in concert with its co-carcinogenic and promoting activities during carcinogenesis.

Animals↗
PubMed1995

The phenotypic spectrum related to the human epilepsy susceptibility gene "EJM1".

Linkage studies of families ascertained through patients with juvenile myoclonic epilepsy (JME) suggest that an HLA-linked susceptibility gene on chromosome 6, designated "EJM1," predisposes to a group of idiopathic generalized epilepsies (IGEs) comprising JME, juvenile absence epilepsy (JAE), childhood absence epilepsies (CAE), and epilepsies with generalized tonic-clonic seizures (GTCS). To explore the EJM1-related phenotypic spectrum, we conducted linkage studies with HLA-DQ alpha restriction fragment length polymorphisms in 44 families ascertained through patients with CAE or JAE. Our results for the entire group of families provide evidence against a major susceptibility locus for idiopathic absence epilepsies and broader spectra of IGEs in the HLA region. Lod scores less than -2 were obtained for a region from 10 cM up to 23 cM on either side of the HLA-DQ alpha locus, depending on the assumed trait model. Suggestive evidence for linkage was found only for a subgroup of families with JME patients assuming an autosomal dominant mode of inheritance with 70% penetrance. A maximum lod score was obtained when family members with JME, JAE, CAE, and idiopathic GTCS were included into the affection status. Our results demonstrate that (1) the genetic susceptibility to idiopathic absence epilepsies and broader spectra of IGEs is heterogeneous, (2) the gene effect of EJM1 depends on the familial genetic background, and (3) EJM1 confers genetic susceptibility to idiopathic absence epilepsies and broader spectra of IGEs in the presence of family members with JME.

Disease Susceptibility↗
PubMed1995

Clonal analysis of the effect of TGF-beta on the apoptosis-inducing activity of normal cells.

We have recently described induction of apoptosis in transformed fibroblasts by transforming growth factor type beta (TGF-beta)-treated normal fibroblasts, which leads to the specific elimination of transformed cells. Here we investigate whether the ability to eliminate transformed cells is the property of a specialized subpopulation of normal fibroblasts or whether all cells within the population are able to respond to exogenous TGF-beta by induction of elimination of transformed cells. Clonal analysis of the eliminative capacity of normal fibroblasts showed that all cells are able to induce elimination after addition of optimal concentrations of exogenous TGF-beta. In the absence of exogenously added TGF-beta, a minority of clones exhibited complete eliminative activity. Neither the ability nor the inability to perform elimination in the absence of exogenous TGF-beta was a stable characteristic of the respective cell clones. The number of cell clones with the ability to respond to suboptimal concentrations of TGF-beta increased with the passage number of the normal cells, whereas the number of clones inducing apoptosis in the absence of exogenous TGF-beta remained constant.

3T3 Cells↗
PubMed1995

Displaced scapular fractures: indication and long-term results of open reduction and internal fixation.

Displaced scapular fractures are often found in polytraumatized patients. In emergency treatment they assume a minor role. Advances in dealing with severely injured patients in most instances allow us to perform an operation on the fractured scapula within the first 2 weeks after injury. A differentiated approach is necessary as exclusively conservative treatment does not always bring about good results. From 1981-1991 we performed open reduction and internal fixation (ORIF) in 25 patients with displaced fractures of the scapula. The long-term results could be assessed in 20 patients after an average of 6.1 years. The different types of fractures were classified according to Habermeyer/Ideberg, and the Constant score was used in the evaluation of results. Some 64% of patients were involved in road accidents, and 64% suffered concomitant injuries. Articular fractures (n = 6) were the most common ones, followed by fractures of the coracoid process (n = 5) and the neck of the scapula (n = 2). There was no early postoperative complication, and follow-up showed a breakage of K-wires in one patient (fracture of the acromion). Thirteen patients obtained a very good, two patients a good, four a fair and one a poor result (according to the Constant score). Fractures of the scapular neck had the best results in terms of pain, daily activity, range of motion, and strength) as compared with fractures of the glenoid and apophyseal fractures.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗