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Biomedical subjects

M Papke

Publications and source records attributed to M Papke.

7 recordsLinked to original sources
PubMed2001

Female sex pheromone of a wandering spider (Cupiennius salei): identification and sensory reception.

Females of the wandering spider Cupiennius salei attach a sex pheromone to their dragline. Males encountering the female dragline examine the silk thread with their pedipalps and then typically initiate reciprocal vibratory courtship with the sexual partner. The female pheromone was identified as (S)-1,1'-dimethyl citrate. The male pheromone receptive sensory cells are located in tip pore sensilla and respond to touching the sensillum tip with female silk or pieces of filter paper containing the synthetic pheromone.

Animal Communication↗
PubMed1997

Cis-regulatory sequences from the first intron of the rat glutamine synthetase gene are involved in hepatocyte specific expression of the enzyme.

In order to identify regulatory elements involved in the hepatocyte specific expression of the enzyme glutamine synthetase [GS (E.C. 6.3.1.2)] we analyzed the first intron of the rat GS gene. A sequence analysis detected clusters of potential transcription factor binding sites in regions that are hypersensitive for DNase I, including sites for Sp1, HNF3 and elements related to binding of members from the C/EBP family. By use of DNA fragments with putative regulatory elements, reporter genes have been constructed that were transfected into isolated hepatocytes in primary culture and into HepG2 hepatoblastoma cells. By these experiments we cold show that sequences from the first intron are able to enhance transcription specifically in hepatocytes but not in cells from the hepatoblastoma cell line. The existence of enhancer effects in the first intron of the GS gene and their restriction to hepatocytes demonstrates that aside from regulatory regions upstream of the transcription start point, there are also downstream regions involved in the specific expression of the gene. We conclude that intronic elements are involved in the pretranslational regulation of the expression of the GS as part of a complex interplay between different regions of the gene.

Animals↗
PubMed1996

Transient transfection of primary cultured hepatocytes using CaPO4/DNA precipitation.

We present a detailed protocol for the transient transfection of non-proliferating primary cultured hepatocytes that is easily reproducible. Using a modification of the classical CaPO4/DNA precipitation method, this protocol is an inexpensive alternative to other methods that are often cumbersome, expensive, difficult to reproduce or harmful to primary hepatocytes. Because only 0.5 x 10(6) cells are needed for a single transfection experiment, several reporter genes can be introduced into hepatocytes of a single liver preparation. With our protocol, different plasmids can be introduced into one cell. In this way, cis-trans interactions can be examined and reporter gene expression can be normalized for transfection efficiency. Furthermore, we describe details of a transfection experiment with two different reporter gene vectors using a luciferase gene and a lacZ gene. The results presented may be helpful to other groups concerned with improved timing of transfection experiments.

Animals↗
PubMed1979

[Myelography with metrizamide (author's transl)].

Metrizamide is a non-ionised, water soluble, and completely absorbable contrast medium which can be used to demonstrate all sections of the spinal canal. The previous strict separation between water soluble, ionised media for the lumbal canal and oily media for the lumbosacral junction as well as the thoracic and cervical canal is no longer necessary. Experience in 110 patients shows that if a suitable concentration is chosen all segments of the spinal canal can be adequately investigated using the lumbal route. The application of contrast media via a lateral cervical entry or suboccipital puncture was not necessary in a single case. Side effects in the form of adhesive arachnoiditis were not observed.

Arachnoiditis↗