Amniotic cells

Restriction analysis can be used to detect sickle cell disease prenatally, since the DNA of all cells, including amniotic cells, carries the mutant DNA. It is much more difficult to obtain fetal blood for the analysis of the mutant hemoglobin A P-chain. Furthermore, fetal blood is composed mostly of fetal hemoglobin, sinee-hemoglobin A is made later in development. 

Patients sustain convulsions and neurological deterioration. The urine contains low levels of the metabolites of serotonin, norepinephrine and dopamine. The reductase also plays a role in the maintenance of tetrahydrofolate levels in brain, and some patients have had low folate levels in the serum and CNS. Treatment has been attempted with tryptophan and carbidopa to improve serotonin homeostasis and with folinic acid to replete diminished stores of reduced folic acid. This therapy is sometimes effective. Diagnosis involves assay of DHPR in skin fibroblasts or amniotic cells. Phenylalanine hydroxylase activity is normal. 

In-vitro exposure to resorcinol did not induce sister chromatid exchanges either in Chinese hamster ovary CHO cells or in human lymphocytes. Chromosomal aberrations were induced in vitro in human lymphocytes and amniotic cells but not in CHO cells or human fibroblasts. 

Fig. 5. The effects of cis-dichlorodiammineplatinum(II) on macromolecular syntheses in human amniotic cells in tissue culture at a concentration (5 pM = 1 ppm) similar to that found in tumor cells in animals treated with a therapeutic dose of the drug. DNA Synthesis is measured by the incorporation of radioactively labeled thymidine and is severely and persistently inhibited. The synthesis of RNA, measured by radioactive uridine, and protein, measured by radioactive leucine is not significantly different from control (nontreated) cells represented by the horizontal bar at 1.00.

Although the (3-glucosidase assay can be performed on any tissue, the tissues of choice are peripheral blood leukocytes or cultured fibroblasts grown from a punch biopsy of the skin. Antenatal diagnosis can be made using extracts of cultured amniotic cells obtained from amniocentesis. There are several different (3-glucoside substrates that can be used in the assay the natural substrate glucocerebroside or structurally similar, artificial substrates. 

Enzyme activities may also be measured in urine, cerebrospinal fluid, bone marrow cells or fluid, amniotic cells or fluid, red blood cells, leukocytes, and tissue cells. Cytochemical localization is possible in leukocytes and biopsy specimens (e.g., from liver and muscle). Under ideal conditions, both the concentration of the enzyme and its activity would be measured. Radioimmunoassay (RIA) and its alternative modes such as fluorescence immunoassay (FIA), fluorescence polarization immunoassay (FPIA), and chemiluminescence immunoassay (CLIA) (discussed later), can be used to measure enzyme concentration as well as other clinically important parameters. 

It has been reported [20] that a mixture of A A and A G dimers, or the individual G G dimer, produce effects on the mitotic activity of a human amniotic cell line, and a transient effect on the reproduction of the RNA viruses, polio virus and vesicular stomatitis virus, grown on these cells. These effects may be attributable to the utilisation of the dimers in RNA synthesis of the cells and the viruses. A similar effect on RNA synthesis may also be produced in experiments [20] demonstrating a cytotoxic... 

Prenatal monitoring of a maternal aunt of D.D. was recently accomplished. The fetus was male and his amniotic cells were normal by radioautography with H-hypoxanthine. Amniotic cell lysates also had normal HPRT activity with 583 nm/mg/hr as compared to the normal range of 528-583 nmole/mg/hr. The normal prenatal diagnosis was confirmed by demonstrating a normal HPRT activity of 59 nmole/ mg/hr in an erythrocyte lysate of cord blood obtained at delivery. 

Human amniotic cells were considered as an alternative source of enzyme replacement. They do not express HLA antigens or microglobulin and consequently are not rejected when transplanted (5) They secrete many lysosomal storage enzymes and in addition appear to express significant adenosine deaminase activity. However, very little immune function was restored in S.Y. and none at all in K.A. after enzyme replacement therapy by red cell transfusions, and it was thought unlikely that they would have provided any further benefit. All three children have... 

Zhang HL, Iwama M, Akaike T, Uny DW, Pattanaik A, Parker TM, Konishi I, Nikaido T (2006) Human amniotic cell sheet harvest using a novel temperature-responsive culture surface coated with protein-based polymer. Tissue Eng 12 391 401... 

CBS deficiency Chorionic villi, cultured amniotic cells I, II... 

As neuraminidase activity is readily detectable in amniotic cells, a prenatal diagnosis should be possible in a fetus at risk for sialidosis. Indeed, prenatal diagnosis has been performed in a pregnancy at risk for combined p-galactosidase/neuraminidase deficiency, and the diagnosis of an affected fetus was confirmed by assays of neuraminidase and p-galactosidase in tissues from the aborted fetus Kleuer etal. 1979). 

The prenatal diagnosis of the organic acidurias by enzyme assay on cultured amniotic cells is outside the scope of the present book and will not be discussed further however, attention will be given to an alternative approach to the prenatal diagnosis of the organic acidurias, that of direct chemical analysis of the cell-free amniotic fluid supernatant for accumulating metabolites excreted by the foetus into the fluid. 

The disorder is of autosomal recessive inheritance and may probably be diagnosed in utero by enzymology on cultured amniotic cells or by direct chemical analysis. Treatment reducing the acidosis and preventing the severe hypoglycaemia may be effective. 

Propionyl-CoA carboxylase is expressed in both fibroblasts and cultured amniotic cells, and this has enabled prenatal diagnosis of the condition to be undertaken. Gompertz et al (1973, 1975) reported the detection of a foetus affected with propionic acidaemia in a mother in whom amniocentesis was performed at about 26 weeks gestation. Because of the time of amniocentesis, pregnancy proceeded and the affected infant was born at 38 weeks. Despite therapy with biotin and a low-protein (MSUD) diet the child died at 1 year of age. 

Hsia et al (1976) reported the prenatal detection of two foetuses at risk for propionic acidaemia, but who showed partially reduced activities of propionyl-CoA carboxylase in cultured amniotic cells, consistent with heterogeneity, confirmed at term, and this has also been the experience of the authors. 

Prenatal diagnosis of the disorder should be possible using cultured amniotic cells or foetal blood samples, but caution would be required before diagnosis by amniotic fluid pyroglutamate levels because of the relatively large amounts of this acid present in normal fluid (see Section 8.1 and Chapter 9). 

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