Search PubMed⌕ Search

Biomedical subjects

A Wirtz

Publications and source records attributed to A Wirtz.

At least 37 records · Page 2Linked to original sources
PubMed1983

Specific translocation t(4;11) in an infant with acute lymphoblastic leukaemia of null cell type.

A case of acute lymphoblastic leukaemia of null cell type in infancy showed the specific reciprocal translocation t(4;11) (q21;q23) reported 16 times so far in the world literature. The proportions of abnormal and normal metaphases throughout the course of the illness correlated well with the clinical picture, but even during the short term remission metaphases expressing the translocation were still identifiable in appreciable numbers. Comparison between cytogenetic analyses of cultured and native bone marrow, PHA-stimulated and non-stimulated peripheral blood demonstrated the gradual conquest of the periphery by the abnormal clone. The importance of chromosomal changes and their interpretation for diagnosis, classification and prognostic judgment in haemotologic neoplasms is discussed in the light of the reported case.

Bone Marrow Cells↗
PubMed1980

[Prenatal diagnosis in parents with a balanced structural chromosome aberration (author's transl)].

By means of 10 case reports, the significance of prenatal diagnosis and the risk for the progeny of parents with a balanced structural chromosomal aberration are demonstrated. The aberrations were ascertained through: a previous malformed child, previous miscarriages or stillbirths or through fetal cell analysis during prenatal diagnosis performed for independent reasons. Theoretical considerations concerning the estimates of risk figures in these families are presented and the currently available risk values which are the basis of the indication for prenatal diagnosis, given.

Adult↗
PubMed1980

Prenatal diagnosis of Lesch-Nyhan syndrome and some characteristics of hypoxanthine-guanine phosphoribosyltransferase and adenine phosphoribosyltransferase in human tissues and cultivated cells.

Activities of phosphoribosyltransferase for hypoxanthine and adenine were investigated in erythrocytes and human tissues of fetuses and adults as well as in cultivated fibroblasts and amniotic fluid cells. Kinetic characteristics of these enzymes were also studied in patients with the Lesch-Nyhan syndrome and with partial deficiency for hypoxanthine phosphoribosyltransferase (HGPRTase), and their obligate heterozygotes. The affinity of HGPRTase for both substrates in partial deficiency decreased to 13 to 20% of normal and by a less degree in its heterozygotes (50 to 65% of normal). A slight decrease in the Km for phosphoribosylpyrophosphate was observed in the case of heterozygotes for the Lesch-Nyhan syndrome. Elevated erythrocytic adenine phosphoribosyltransferase (APRTase) activity was found in fetuses, patients with the Lesch-Nyhan syndrome or with partial deficiency, and in some heterozygotes as well. However, the Km of APRTase for hypoxanthine in these subjects was the same as that in the normal adults. The HGPRTase activity in liver increased almost 4 times during the developmental period, whereas the APRTase activity remained approximately the same. In fetal liver, the APRTase activity was almost two times higher than the HGPRTase activity, whereas in fetal brain the HGPRTase activity was higher. The Km of HGPRTase for hypoxanthine in cultivated cells and human tissues were similar to that in erythrocytes and leukocytes. On the other hand, the HGPRTase affinity for phosphoribosylpyrophosphate in these cells was cconsiderably larger than in erythrocytes or in leukocytes.

Adenine Phosphoribosyltransferase↗
PubMed1980

[Interruption of pregnancy based on prenatal diagnosis].

Prenatal examination is indicated when there is a risk of hereditary disease causing alterations in the amnion cells, the amnion fluid, in the blood or the morphology of the fetus. Routine screening is performed in four groups: suspected chromosomalaberration, x-chromosomal heredopathy, metabolic defect or neural tube defect. Dermatologists have special interest in the second and third groups (Fabry disease, Xeroderma pigmentosum and recently Ichthyosis vulgaris). An interruption was proposed in 2,9% of all examinations performed up to now. On the other hand, most of pregnant women whose child was prenatally diagnosed to be healthy, had planned their pregnancy only with respect to the possibility of prenatal examination.

Abortion, Therapeutic↗
PubMed1979

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↗
PubMed1978

[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↗
PubMed1977

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↗
PubMed1976

[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↗