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Biomedical subjects

A Wirtz

Publications and source records attributed to A Wirtz.

10 recordsLinked to original sources

Trisomy 18 in chorionic villus sampling: problems and consequences.

Among 1547 patients undergoing first-trimester prenatal diagnosis, 100 fetal chromosome aberrations were detected. Thirteen of these involved chromosome 18. In two structural abnormalities of chromosome 18, the aberration could be excluded in amniotic fluid cells and two healthy infants were born. Trisomy 18 was not confirmed in amniotic fluid cells in three trisomy 18 mosaics. In eight non-mosaic trisomy 18 first-trimester diagnoses, the diagnosis was excluded by amniotic fluid cells or fetal cultures in four, and confirmed in the remaining four. Diagnosis of chromosome 18 aberrations in the direct preparation should be confirmed in the long-term culture of the chorionic villus sample or by amniotic fluid cultures.

Amniocentesis

Characteristics of galactokinase and galactose-1-phosphate uridyltransferase in cultivated fibroblasts and amniotic fluid cells.

The kinetic characteristics of galactose-1-phosphate uridyltransferase and galactokinase in cultivated fibroblasts and amniotic fluid cells were investigated. The Km values of galactokinase for galactose at 2.0 mM ATP are 0.34 mM in amniotic fluid cells and 0.48 mM in fibroblasts. The Km values for ATP at 0.5 mM galactose are 1.25 mM and 2.10 mM. Transferase and galactokinase activities and protein content increase logarithmically during the growth of cultivated cells. The specific activity of both enzymes also increases and reaches a maximum level 10--15 days after subculture. The specific activity of transferase increases faster than that of galactokinase in the case of amniotic fluid cells. In the case of fibroblasts the specific activity of galactokinase increases faster than that of transferase.

Amniotic Fluid

[Prenatal diagnosis in pregnancies at advanced maternal age (author's transl)].

Among 113 prenatal diagnoses in pregnancies at advanced maternal age (mothers older than 37 years) 7 aberrant fetal karyotypes were found (6.2%). Detailed reports of one case of trisomy 21, 18 and 13 each, as well as of XXY-, XYY- and XXX gonosomal constitution respectively are presented in the following. The frequency and severity of chromosome aberrations occurring in fetuses from elder women are discussed with respect to data from the literature. It seems that this group bears a higher risk for chromosomally abnormal offspring than has been suggested before.

Abnormalities, Multiple

Cataract in a fetus at risk for oculo-cerebro-renal syndrome (Lowe).

A high-risk pregnancy for X-linked recessive inherited Lowe's syndrome was terminated due to a male karyotype in the cultured amniotic fluid cells. The eyes of the male fetus showed specific cataracteous changes of the lens. A posterior lenticonus was due to a defect of the lens capsule. The lenses were of normal size. Loss of lens material through a lens capsule defect could account for the small discoid lens usually seen in Lowe's syndrome. Amino acids in amniotic fluid had normal concentrations except lysine and proline which were markedly elevated.

Amino Acids

[The chromosome bands. Significance for clinical and cytogenetic research (author's transl)].

The methods of performing chromosomal investigations have been fundamentally changed in the last few years through the discovery of differential staining methods. While only a rough classification of the chromosomes into single groups could be carried out earlier, it is now possible to identify every individual pair of chromosomes on the basis of a typical pattern of bands. By means of these banding techniques smaller chromosomal variations can be recognized which were overlooked earlier and which have led to the delineation of new chromosomal malformation syndromes. In the present work, the modern methods of chromosome analysis are reviewed. Examples from clinical diagnosis show the necessity of using these techniques.

Abnormalities, Multiple