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K Simola

Publications and source records attributed to K Simola.

8 recordsLinked to original sources
PubMed1993

Molecular cytogenetic study of patients with Pallister-Killian syndrome.

The Pallister-Killian syndrome (PKS) is characterized by tissue limited chromosomal mosaicism, i.e. the presence of a supernumerary metacentric chromosome [i(12p)] often confined to skin fibroblasts while the karyotype of cultured lymphocytes is normal. In the present study, chromosome painting by chromosomal in situ suppression (CISS) hybridization and interphase cytogenetic procedures employing biotinylated or digoxigenin labelled probes was carried out. These probes comprised a chromosome 12 specific library (LA 12NS01) and chromosome 12 centromere specific alpha-satellite (pSP12-1). They were used to analyse and quantify the presence of i(12p) in lymphocytes, granulocytes/monocytes, skin fibroblasts and buccal mucosal cells from five patients and one aborted fetus with PKS, and ten normal donors. CISS hybridization on mitotic skin fibroblasts reliably indicated the presence of i(12p) cells, even when metaphases of poor quality were included in the analysis. Two of the five patients showed i(12p) in a small proportion (< or = 0.5%) of the cultured lymphocytes too. The interphase cytogenetics procedure did not reveal the isochromosome in lymphocytes or granulocytes/monocytes in any of the patients. Two of the six patients had a twofold increase in the number of buccal mucosal cells with three hybridization signals over control values. However, for mucosal cells, methodological improvements are required. For cytogenetic diagnosis of PKS, cultured fibroblasts subjected to chromosome painting by CISS hybridization with a chromosome 12 specific library probe are recommended.

Adolescent↗
PubMed1979

Heteromorphic X chromosomes in 46,XX males?

This paper reports an attempt to determine whether the short arm of one of the X chromosomes in XX males is longer than normal. In a blind study comparing coded photomicrographs of 15 G-banded mitoses from each of five XX males and five control females, the results were ambiguous and somewhat contradictory, but gave the impression of, or were compatible with, an XXp+ phenomenon in at least two of the five XX males. Measurements of the X chromosomes from the above cells and, in addition, from 15 mitoses from each of six XXY males, failed to disclose any XXp+ phenomenon. Statistical analysis indicated that in the five XX males there was no difference in the lengths of the two Xp arms. The reasons for the apparent discrepancy between the results of ocular inspection and measurement are discussed. The putative heteromorphism might be an alteration in shape, staining intensity, or position of bands, neither of which necessarily leads to an increase in length. We conclude that our results do not indicate any XXp+ phenomenon in the five XX males tested. However, the presence or absence of XXp+ is not in itself evidence for or against interchange betweenthe X and Y in the paternal meiosis. Our results emphasize that the etiology of XX males is likely to be heterogeneous.

Female↗
PubMed1978

Incomplete prenatal diagnosis of G-trisomy mosaicism.

Chromosomal mosaicism is difficult to detect in prenatal diagnosis, and it seems even more difficult to predict its significance correctly. We present a case, in which G-trisomy mosaicism was diagnosed prenatally but was not verified in the aborted fetus. A practical approach to suspected fetal mosaicism in prenatal diagnosis is proposed.

Adult↗
PubMed1977

Two pericentric inversions of human chromosome 11.

A pericentric inv(11) (pl5q23) detectable by G-, Q-, and R-banding and occuring in 1 member of each of 3 generations of a family is described. In another family studied by several banding methods in search of chromosomal markers, a pericentric inv(11) (p11q11) was found. It was detectable only by C-banding, the darkly staining band being located on the short-arm side of the centromere. The reasons for defining this aberration as an inversion rather than a location variant are outlined. This inversion occurred in 9 members of 3 generations of a large family. There was no clear-cut evidence of any clinical consequences of these inversions either in heterozygotes or their offspring.

Azure Stains↗
PubMed1975

Molecular basis of chromosome banding. I. The effect of mouse DNA fractions on two fluorescent dyes in vitro.

The effects of mouse satellite, main band and total DNA on the fluorescence intensity of quinacrine and of the bibenzimidazole derivative Hoechst 33258 were tested in solution. No significant differences were noticed between the double-stranded DNAs in spite of the 5% difference in AT-content between satellite and main band DNA. Single-stranded DNAs enhanced the fluorescence intensity of Hoechst 33258 far less than double-stranded DNAs. Having been denaturated and then reassociated the DNA fractions were intermediate in their enhancing effects on the fluorescence intensity of Hoechst 33258, the differences presumably being due to different degrees of reassociation. The effect of denatured and subsequently reassociated satellite DNA on the fluorescence intensity of quinacrine was similar to that of the native DNAs. Main band and total DNA quenched the fluorescence intensity of quinacrine more after denaturation-reassociation than it did when native. In the discussion the results are related to known cytological data.

Animals↗
PubMed1975

Molecular basis of chromosome banding. II. The effect of silver and mercury ions on the fluorescence intensity of acranil-DNA complexes.

Silver and mercury ions are known to react with the bases of nucleic acids in solution. At low cation/base ratios Ag+ has an affinity for GC pairs in DNA, whereas Hg++ is preferentially bound to AT-rich nucleic acids. We have used fluorometry to measure the effect of these cations on the fluorescence intensity of preformed complexes of acranil and DNA in solution. The results are: 1) Ag+ enhances the fluorescence intensity presumably by affecting the dye intercalated in the vicinity of GC-pairs. 2) The addition of Hg++ leads to a quenching of the fluorescence intensity of the complex at low ion/base ratios, suggesting an effect on the dye molecules bound to AT pairs. At high GC-content of the nucleic acid, slight enhancement of the fluorescence intensity occurs with Hg++. 3) With both metals there is a correlation between base content of DNA and effect on the intensity of fluorescence indicating base specificity of the dye-polymer interaction.

Acridines↗