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Biomedical subjects

Małgorzata Srebniak

Publications and source records attributed to Małgorzata Srebniak.

5 recordsLinked to original sources

Cellular toxicity of oxycholesterols.

Oxycholesterols (OS) are formed from cholesterol or its immediate precursors by enzymatic or free radical action in vivo, or they may be derived from food. OS exhibit a wide spectrum of biological activities. In OS cytotoxicity, several mechanisms seem to be involved: e.g. inhibition of HMG-CoA reductase activity, antiproliferative action, apoptosis induction, replacement of cholesterol by OS in membranes followed by changes in cellular membrane structure and functionality, and immune system functions alteration. Furthermore, OS may be mutagenic and carcinogenic and may serve as intracellular signaling or regulatory molecules. Here we review OS cellular activities with special attention to the cytotoxic action in vivo and in vitro using experimental models.

Animals↗

[Chromosome instability syndromes].

Defects of DNA repair underlie genetic syndromes. Chromosomal aberrations and mutations might cause specific inborn defects. There are several syndromes with characteristic clinical features, which appear to be caused by chromosome instability which is a consequence of DNA repair defects. This article describe syndromes where hereditary mutations are the reason of chromosomal instability and cause serious clinical results: ataxia-telangiectasia, Nijmegen breakage syndrome, Bloom syndrome, Fanconi's anemia, ICF syndrome, Roberts syndrome, dominantly inherited--PCD, Werner syndrome, xeroderma pigmentosum, Cockayne syndrome, trichothiodystrophy (TTD) and Rothmund-Thomson syndrome (RTS).

DNA Repair-Deficiency Disorders↗

Subfertile couple with t(4;22)(q23;q11.2).

A couple was referred for cytogenetic examination due to idiopathic miscarriages. The proband proved to be a carrier of chromosomal translocation and her partner's karyotype was found to be normal. The karyotype of the proband is 46,XX,t(4;22)(q23;q11.2) and can be regarded as a reason of fertility problems in the investigated couple. The risk of further miscarriages is high, but the risk of a progeny with abnormal karyotype is rather low, as the progeny would probably have lethal imbalances.

Abortion, Spontaneous↗

The influence of calyculin A on lymphocytes in vitro.

Human lymphocytes were cultured in vitro and treated with calyculin A. The aim of this work was to estimate the influence of calyculin A on chromosome morphology and banding patterns. It was also interesting whether calyculin A treatment is useful in cytogenetic analysis of human karyotype. We proved that calyculin A induces chromosome condensation in lymphocytes and raises the mitotic index significantly. Moreover, calyculin A does not influence the banding patterns. Therefore it is concluded that calyculin A can be clinically useful for human karyotyping.

Chromosome Banding↗

Cytogenetic analysis of an asymmetric potato hybrid.

An asymmetric potato hybrid and its parental lines were cytogenetically examined. DAPI (4'-6-diamidino-2-phenylindole) staining was used to count chromosomes in all analysed lines and revealed the presence of minichromosomes in the hybrid genome. Fluorescent in situ hybridization (FISH) with rDNA sequence as a probe helped to determine the ploidy level of analysed lines and revealed that none of the minichromosomes contains rDNA repeats. CMA (chromomycin A3) band occurred to be a new chromosome marker that identifies potato chromosome No.1. It was possible to detect a deletion in one of four chromosomes No. 1 of the asymmetric potato hybrid. On the basis of these analyses a karyotype of the asymmetric hybrid was constructed.

DNA, Ribosomal↗