Amniotic Fluid Cell Cultures Research Articles

Polyploidy in prenatal genetic diagnosis

Summary Facilities for the prenatal diagnosis of chromosomal anomalies using cultured amniotic fluid cells are becoming widely available. In 24 consecutive pregnancies studied for diagnostic purposes, polyploidy up to 83.3 per cent was found in amniotic fluid cell cultures. Nonetheless, 14 clinically normal infants have been delivered to date. Extensive polyploidy in amniotic fluid cell cultures appears to be quite compatible with the birth of a clinically normal child. In view of the increasing number of hospitals providing prenatal diagnostic facilities, this phenomenon needs wide appreciation.

α-1,4 Glucosidase activity in Pompe's disease

α-1,4 Glucosidase (α-glu) has been shown to be absent in cultivated amniotic fluid cells (AFC), fibroblasts (FIB) and liver (LIV) of patients with Pompe's disease. In contrast, α-glu is present in the kidney (KID) and amniotic fluid (AF) of these patients. In an attempt to explain these differences, properties of α-glu including pH optima, turanose inhibition and heat inactivation were studied in controls (C) and Pompe's (P). The results are as follows: No α-glu activity could be demonstrated in urine or maternal serum. α-glu in amnion had properties identical with FIB and LIV enzyme. Upon differential centrifugation of the cell-free amniotic fluid, cells and tissues, α-glu was found primarily in the 25,000 × g fraction. These data clearly indicate that the α-glu present in AFC, FIB and LIV have identical properties which are distinctly different from the α-glu in AF and KID. The α-glu in AF differs from that found in KID in its greater heat lability. These studies fail to identify the origin of the α-glu in amniotic fluid. The diagnosis of Pompe's disease in utero must rest on the demonstration of the α-glu deficiency in amniotic fluid cells.

A simplified technique for the culture of amniotic fluid cells

<h2>Summary</h2> Based on studies of 40 consecutive amnioticfluid specimens, it was concluded that the most reliable and efficient technique for the culture of amniotic fluid cells is to utilize the amniotic fluid itself as the culture medium. Neither additives nor manipulation of the fluid are necessary; even gentle centrifugation and resuspension may destroy viable cells.

Amylo-1, 6-glucosidase in human fibroblasts: Studies in Type III glycogen storage disease

Using the assay system which measures the incorporation of U-C 14 glucose into new branch points in the glycogen molecule, it has been possible to show the presence of amylo-1,6-glucosidase in human fibroblasts derived from skin biopsies and in cultivated amniotic fluid cells. The marked decrease of this enzyme in cultured fibroblasts from a child with Type III glycogen storage disease indicate the usefulness of this technique not only in establishing the diagnosis among patients, but opens up the possibility of prenatal detection of debrancher enzyme deficiency.

Study of hereditary metabolic diseases using in vitro techniques

Some 50 hereditary metabolic diseases can now be identified by means of white blood cells, somatic cell cultures, and in some instances by culture of amniotic fluid cells as shown in Table 5. These new developments are of obvious importance to the clinician because they offer simplified approaches to the detection of some difficult syndromes and obviate the necessity of having to do surgical biopsies under general anesthesia to establish the diagnosis.

Prenatal chromosome analysis.

CHROMOSOME analysis can be performed on fibroblasts cultured from amniotic fluid1–3. This is the basis of a technique for the intrauterine detection of chromosomal aberrations in the foetuses of women who are known to have a high risk of producing abnormal offspring. Valenti et al.1, for example, reported the intrauterine detection of trisomy 21 in amniotic fluid cell cultures and they subsequently performed a therapeutic abortion. The pathological findings on the foetus confirmed the diagnosis.

Ornithine-ketoacid transaminase activity in human skin and amniotic fluid cell culture

l-Ornithine-2-oxoacid aminotransferase activity was detected in human diploid cells cultured from control skin biopsies, from amniotic fluids, and from the skin biopsy of a patient with the type of hyherornithinemia associated with homocitrullinuria and hyperammonemia. The potential usefulness of finding this enzyme activity in cultured human cells is discussed.

CULTIVATED AMNIOTIC-FLUID CELLS AND FIBROBLASTS DERIVED FROM FAMILIES WITH CYSTIC FIBROSIS

An earlier report that cultivated fibroblasts from children with cystic fibrosis and their parents contain metachromatic granules was confirmed in 38 out of 45 cases. However, the presence or absence of such granules in cultivated amniotic-fluid cells does not seem to be a reliable test for cystic fibrosis in utero. Amniotic-fluid cells from 6 women who had previously given birth to a child with cystic fibrosis were cultivated. Metachromatic granules were seen in 4: 2 of the children had cystic fibrosis. In 2 cases metachromasia was not seen, but 1 child was normal while the other had cystic fibrosis.