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Biomedical subjects

G Bauer

Publications and source records attributed to G Bauer.

At least 19 recordsLinked to original sources
PubMed1992

Transformation of rodent fibroblasts by herpes simplex virus: presence of morphological transforming region 1 (MTR 1) is not required for the maintenance of the transformed state.

Studies on the mechanisms of transformation of mammalian cells by herpes simplex virus (HSV) in vitro have been prevented so far by the extremely low transformation frequencies obtained in monolayer culture. Here we present a transformation system that relies on the direct seeding in soft agar of infected single cells, thus avoiding negative interactions between normal and transformed cells. We took advantage of HSV-I temperature-sensitive mutants at the UL9 locus, which codes for a DNA-binding protein necessary for viral DNA replication. At the non-permissive temperature, viral DNA synthesis and late gene expression are prevented. Viral gene expression is restricted to immediate early and early genes. Induction of transformation was highly efficient in our one-step transformation system. It depended on intact viral particles and viral DNA. Immediate early and/or early viral gene expression was sufficient to induce transformation. Colonies were stably transformed and did not show any rescue of viable virus after temperature downshift and co-cultivation with susceptible cells. Transformed cells maintained the transformed state in the absence of viral DNA. Our data therefore support the "hit-and-run" hypothesis for the transforming effect of HSV.

Animals↗
PubMed1992

Reactivity to TGF-beta is one step towards transformation in a murine fibroblast cell line.

High doses of TGF-beta induce reactivity to TGF-beta in a distinct number of C3H10T1/2 fibroblasts suspended in soft agar. Reactive cells can be isolated and stably maintain this property. In the absence of exogenously added TGF-beta, these cells do not form colonies, but show distinct changes in their morphology and cytoskeleton. In contrast to normal C3H10T1/2 cells, they are able to form colonies when low doses of TGF-beta are added. TGF-beta-reactive cells are more easily transformed by UV light than normal C3H10T1/2 cells, and so maintain their transformed phenotype in the absence of added TGF-beta. Reactivity for TGF-beta, therefore, represents one step towards transformation.

Animals↗
PubMed1992

Microbial metabolism of quinoline and related compounds. XV. Quinoline-4-carboxylic acid oxidoreductase from Agrobacterium spec.1B: a molybdenum-containing enzyme.

The quinoline-4-carboxylic acid oxidoreductase from Agrobacterium spec.1B was purified 84-fold to apparent homogeneity with 15% recovery, using ammonium sulphate precipitation, heat precipitation, hydrophobic interaction, anion exchange- and gel chromatography. The molecular mass of the native enzyme was estimated to be 320 kDa by gel filtration. SDS-polyacrylamide gel electrophoresis of the enzyme revealed three protein bands corresponding to 85, 35 and 21 kDa. Per molecule the enzyme contains 8 atoms of iron, 8 atoms of acid-labile sulphur, 2 atoms of molybdenum, 2 molecules of FAD and as molybdenum cofactor, molybdopterin cytosine dinucleotide. Besides quinoline-4-carboxylic acid the enzyme also catalysed the conversion of quinoline, 4-chloroquinoline and 4-methylquinoline to the corresponding 2-oxo-1,2-dihydroderivatives. Cyanide, methanol, 4-chloromercuribenzoate and acriflavin were effective inhibitors.

Chromatography, Gel↗
PubMed1992

Laminar heterotopic grey matter (double cortex) in a patient with late onset Lennox-Gastaut syndrome.

The Lennox-Gastaut syndrome (LGS) is a severe epileptic disorder, characterized by developmental delay, typical electroencephalographic pattern and poor control of seizures. This epileptic syndrome generally presents in early childhood but exceptionally starts at the age of 5 years or later. We describe a patient who was classified as late-onset LGS, with evidence of mild hydrocephalus on CT. MRI added new diagnostic information by demonstrating laminar heterotopic grey matter.

Adult↗
PubMed1992

[The value of breath alcohol determination in street traffic].

436 cases were collected, in which both breath alcohol (AAK) as well as blood ethanol levels (BAK) were determined. We studied the correlation between AAK and BAK. Furthermore, the duration between event, breath alcohol analysis and the consecutive blood sampling was investigated.

Adolescent↗
PubMed1992

[False positive radiographic findings in expert assessment of whiplash trauma of the cervical spine].

It is reported about a possible misdiagnosis after whiplash injuries. Calcifications of the nuchal ligament have been interpreted as fractures. The inappropriate radiological diagnosis has been corrected within the criminal procedure. Prolonged complaints as possible consequences of information about the false positive radiological diagnosis to the patient are discussed.

Accidents, Traffic↗
PubMed1992

[Computerized tomography of intra-articular calcaneus fracture. Comparison: radiomorphologic result--clinical result].

In 55 patients with intraarticular fracture of the calcaneus computed tomography of the fractured bone was performed immediately after the accident and 6-12 months later. We recorded the fracture type according to the classification established by Essex-Lopresti. We evaluated the degree of bony destruction, deformation of the calcaneus and the extent of articular bursting. We recorded the severity of the fracture with reference to a 10-point scale and compared this with the clinical outcome after surgery or conservative therapy. The clinical results were according to a 18-point scale devised by Merle d'Aubigne. Changes between the initial and follow-up CT were also recorded. There was a good correlation between radiological findings and clinical results.

Adolescent↗
PubMed1992

Agenesis of the corpus callosum and epilepsy in two brothers. Neurophysiological and MRI features.

We report on two brothers with partial agenesis of the corpus callosum and seizure disorder presumably related to ectopic grey matter. Development of both patients was characterized by psychomotor retardation and focal epileptic seizures. Genetic examination revealed normal karyotypes. One brother showed a remarkable focal miniature spike and wave periodicity constantly observed on sequential EEG records. Magnetic resonance imaging revealed partial agenesis of the corpus callosum and ectopic grey matter. Prior computerized tomography failed to visualize ectopic grey matter and overestimated corpus callosum agenesis. The heterotopic grey matter, isolated from the surrounding inhibiting influences, is the most probable source of focal seizures and the partial connection of both hemispheres may explain secondary generalization of seizures.

Adult↗
PubMed1991

Inhibition of HIV-1 IIIb replication in AA-2 and MT-2 cells in culture by two ligands of poly (ADP-ribose) polymerase: 6-amino-1,2-benzopyrone and 5-iodo-6-amino-1,2-benzopyrone.

The effects of two adenosine diphosphoribose transferase (ADPRT) enzyme inhibitory ligands, 6-amino-1,2-benzopyrone and its 5-iodo-derivative, were determined in AA-2 and MT-2 cell cultures on the replication of HIV-1 IIIb, assayed by an immunochemical test for the HIV protein p24, and syncytium formation, characteristic of HIV-infected cells. Intracellular concentrations of both drugs were sufficient to inhibit poly(ADP-ribose) polymerase activity within the intact cell. Both drugs inhibited HIV replication parallel to their inhibitory potency on ADPRT, but distinct differences were ascertained between the two cell lines. In AA-2 cells both p24 and syncytium formation were depressed simultaneously, whereas in MT-2 cells only syncytium formation was inhibited by the drugs, and the p24 production, which remained unchanged during viral growth, was unaffected. Both drugs only moderately depressed the growth rate of the AA-2 and MT-2 cells and there was no detectable cellular toxicity. Results suggest the feasibility of the development of a new line of ADPRT ligand anti-HIV drugs that fundamentally differ in their mode of action from currently used chemotherapeutics.

Antiviral Agents↗