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Biomedical subjects

W Schempp

Publications and source records attributed to W Schempp.

95 records · Page 6Linked to original sources
PubMed1979

Ellobius lutescens Th. (Rhodentia, Microtinae): Q-, R-, and replication banding patterns. Chromosome 1 polymorphism in the male and presumptive heterogamety in the female.

Five specimens of Ellobius lutescens, four males and one female, were studied by several banding methods. Structural polymorphism occurred in the longest chromosome pair of the karyotype of two males: a pericentric inversion in one animal and a paracentric inversion in the other. In the female studied, one chromosome 1 differs from those of the males by a marked elongation of a proximal euchromatic band in the long arm. Thus, the female seems to represent the heterogametic sex. Chromosome 9 showed the same banding pattern in both sexes. The possible meaning of this chromosome constitution for the sex-determining mechanism of E. lutescens is discussed.

Animals↗
PubMed1978

Comparison of thymidine, fluorodeoxyuridine, hydroxyurea, and methotrexate blocking at the G1/S phase transition of the cell cycle, studied by replication patterns.

Cultures of human amniotic fluid cells and fibroblasts were temporarily blocked by the replication inhibitors thymidine (dT) surplus, fluorodeoxyuridine (FdU), hydroxyurea (HU), or methotrexate uridine (MU). The respective arresting point at G1-S transition and the homogeneity of the blocked cell population were determined by means of BrdU replication patterns. Most variation of patterns were found after HU. After MU, cells were arrested before the onset of replication, while with dT surplus of FdU an arresting point in early S seemed more likely.

Amniotic Fluid↗
PubMed1978

Decrease of DNA synthesis in amniotic fluid cells during the middle part of S-phase revealed by differential chromosome staining after incorporation of BrdU.

The time sequence of DNA replication in partially synchronized human amniotic fluid cells has been analysed, employing BrdU incorporation techniques.--Regardless of the interval between removal of the methotrexate/uridine block and addition of BrdU during S-phase, the treatment results in an R-type replication pattern. Conversely, replacement of BrdU containing medium by another one with thymidine yields G-type replication patterns. A thymidine pulse during the first 4 h of S-phase results in R-type replication patterns; from 7--10 h after block removal it produces G-type pattern. In between, only faint red staining dots can be found indicating a marked decrease of replicational activity during the middle part of the S-phase.

Amniotic Fluid↗
PubMed1978

Silver-staining specificity in metaphases after incorporation of 5-bromodeoxyuridine (BUDR).

Silver staining is reported to be reduced in chromatin substituted by BUDR. This quenching effect allows for the demonstration of replication patterns and differential chromatid staining. Though the differentiation, as compared to other staining techniques, is of inferior quality, it is of theoretical importance concerning the effect of BUDR incorporation into chromatin.

Bromodeoxyuridine↗