Biomedical subjects

M Mucha

Publications and source records attributed to M Mucha.

11 recordsLinked to original sources

PubMed2003

Mapping candidate hotspots of meiotic recombination in segments of human DNA cloned in the yeast Saccharomyces cerevisiae.

The hotspots of meiotic recombination in the human genome can be localized by genetic techniques. The resolution of these techniques is in the range of kilobases and depends on the density of the physical markers identifying allelic variants of the chromosomal loci. We thought it would be interesting to localize these sites with higher resolution. Assuming that some human chromosomal sites conserve their propensity for recombination when cloned in yeast, we localized the hotspots of recombination in several yeast artificial chromosomes (YACs) carrying human DNA. A number of potential recombination hotspots could be identified in the clones studied. Among them there are two classes of sites that are particularly recombination prone also in human meiotic cells: sites associated with CpG islands and sites located in the vicinity of long minisatellite sequences.

Base Sequence↗

PubMed2000

Nuclease-hypersensitive chromatin formed by a CpG island in human DNA cloned as an artificial chromosome in yeast.

CpG islands are mostly unmethylated GC-, and CpG-rich chromosomal segments overlapping promoter sequences in all housekeeping and many tissue-specific genes in vertebrates. Typically, these islands show an open chromatin structure, low in histone H1 and rich in acetylated histones. We have previously found that the island-like CGCG-rich sites in human DNA are hypersensitive to DNase I upon cloning in Saccharomyces cerevisiae. Here we studied, with a higher resolution, the chromatin formed in yeast by one such site, the CpG island accompanying the human glucose-6-phosphate dehydrogenase gene. We have found two strong hypersensitive sites and several positioned nucleosomes flanking the island despite the absence in yeast of such chromatin fiber-shaping factors as histone H1, methyltransferase, and the tissue-specific transcription factors. This finding, together with similar observations from our laboratories and others supports the idea that variations in GC and/or CpG content substantially contribute to the DNA sequence features modulating the structure of the chromatin. The composition-dependent fluctuations in the accessibility of DNA in the chromatin may constitute an evolutionary advantage and may explain the surprising compositional selection that acts in both the coding and non-coding segments of some genes during mammalian evolution.

Chromatin↗

PubMed1984

Marfan syndrome and medullary sponge kidney: case report and speculation on pathogenesis.

The case of a 16 year old boy with Marfan syndrome, recurrent nephrolithiasis, and bilateral Medullary Sponge Kidney (MSKD) is described. This association was not previously described.

Adolescent↗

PubMed1980

[Incidence of spontaneous arteriosclerosis in Lowland Black-and-White (LBW) and Simentaler cows from selected regions of Poland].

Studies on the occurrence of spontaneous arteriosclerosis in the arteries of the uterus were conducted on Lowland Black-and-White (LBW) and Simentaler (S) cows. The material studied had been collected from the genital organs of heifers and cows slaughtered in the abattoirs of Gdańsk (LBW) and Rzeszów (S). The animals had been found free from disease, both clinically and on post-mortem examination. Pathological changes in the arteries of the uterus were diagnosed by post-mortem angiography, and identified histologically and histochemically. In both breeds studied, high intensity of the occurrence of arteriosclerotic changes was found, both in heifers and in multiparae cows (LBW 81.9%, S 33.3%). Histochemical examination of the walls of pathologically changed vessels failed to reveal any accumulation of fatty bodies.

Angiography↗

PubMed1980