Amniotic fluid cells; prenatal sex prediction and culture

Placental Tissues as Biomaterials in Regenerative Medicine

Placental tissues encompass all the tissues which support fetal development, including the placenta, placental membrane, umbilical cord, and amniotic fluid. Since the 1990s there has been renewed interest in the use of these tissues as a raw material for regenerative medicine applications. Placental tissues have been extensively studied for their potential contribution to tissue repair applications. Studies have attributed their efficacy in augmenting the healing process to the extracellular matrix scaffolds rich in collagens, glycosaminoglycans, and proteoglycans, as well as the presence of cytokines within the tissues that have been shown to stimulate re-epithelialization, promote angiogenesis, and aid in the reduction of inflammation and scarring. The compositions and properties of all birth tissues give them the potential to be valuable biomaterials for the development of new regenerative therapies. Herein, the development and compositions of each of these tissues are reviewed, with focus on the structural and signaling components that are relevant to medical applications. This review also explores current configurations and recent innovations in the use of placental tissues as biomaterials in regenerative medicine.

Neonatal withdrawal syndrome and behavioral effects produced by maternal drug use

Over the last two decades, drug and alcohol abuse by pregnant women has spread to epidemic proportions. Maternal drug abuse has neurobehavioral and somatic effects which may be long-lasting and devastating to the offspring. Opiates, such as heroin and pain killers that contain a narcotic component, are widely abused today. A prominent manifestation of fetal exposure to these drugs is the neonatal withdrawal syndrome, which typically includes wakefulness, jitteriness and other symptoms of cerebral irritability. These, in turn, may interrupt early mother-infant interaction, affecting the infant's long-term emotional and cognitive development. Fetal cocaine exposure may cause neonatal cerebral irritability, changes in habituation responses, reduced head circumference, poor mental development and long-lasting impairment of the brain. Benzodiazepines can cause fetal dysmorphism (including microcephaly), neurological and behavioral impairments and neonatal withdrawal symptoms. Maternal use of amphetamines may cause neonatal dysphoria and agitation, as well as long-term lassitude and drowsiness that may result in poor feeding. Fetal exposure to alcohol may cause neonatal withdrawal symptoms, maladaptive behavior in childhood and the fetal alcohol syndrome (including microcephaly). Maternal alcohol consumption is also a common cause of mental retardation. Fetal exposure to marijuana may delay maturation of the visual system and impair memory and verbal performance at 2 years of age. The inevitable conclusion is that society must seek ways not only to treat, but also to prevent this epidemic. To this end, a key factor would be to identify potential drug abusing mothers before they reach the stage of prenatal care and educate them regarding the fatal consequences of drug abuse.

Enhancement of amniocyte growth on a precoated surface

This study investigates whether cell-free amniotic fluid facilitates cell attachment to the surface of culture plates and thereby promotes rapid amniocyte growth. Isolated or pooled cell-free amniotic fluid samples at different volumes were added to culture plates. Trypsinized subcultures, grown in Eagle's minimum essential alpha medium supplemented with fetal bovine serum (4-20 per cent), were monitored by cell counts. The results demonstrated growth stimulation on culture plates precoated with amniotic fluid. The minimal time for coating the culture plates was 6 h. Maximal coating was observed after an overnight incubation with 2-3 ml of the fluid per culture vessel. No synergistic effect from addition of fetal bovine serum to amniotic fluid was observed. A freshly coated surface provided the best amniocyte growth. When primary cultures are grown on a precoated surface, there is an increase in colony counts in 80 per cent of the samples tested. This method may be used to improve amniocyte growth, especially in samples with relatively small numbers of cells.

Bovine fetal fluid cells in vitro: fate and fetal sex prediction accuracy

The in vitro fate of bovine fetal fluid cells and the efficiency of fetal sex predication from cultures of these cells are studied using aspirates from live animals and pregnant uteri collected from the slaughterhouse. Over 70 percent of bovine amniotic fluid samples aspirated from pregnant uteri at the time of slaughter yielded cultures adequate for chromosome analysis whereas only 10 percent of allantoic fluid samples produced growth of cells satisfactory for chromosome analysis. Fetal sexing accuracy was 100 percent in all samples studied. Seven readily recognizable cell types were noted in cultures of fetal fluid cells obtained at various stages of gestation. In a majority of cases, the in vitro morphology of cells from both fetal cavities was similar to that observed in primary human amniotic fluid cell cultures.

Amniotic fluid testosterone and follicle-stimulating hormone in the determination of fetal sex

To determine whether hormone analysis could be used for accurate determination of fetal sex, we measured testosterone (T) and follicle-stimulating hormone (FSH) in 130 amniotic fluid samples at midgestation. The mean unconjugated T in amniotic fluid of 73 patients carrying male fetuses was 202 pg. per milliliter (95 per cent confidence limits [CL]: 70 to 580) and all but three had levels higher than 90 pg. per milliliter. The mean amniotic fluid unconjugated T for 49 patients carrying female fetuses of 41 pg. per milliliter (95 per cent CL: 11 TO 125) was fivefold lower than that for the male fetuses and all but three patients carrying female fetuses had amniotic fluid T levels of 90 pg. per milliliter or lower. The mean amniotic fluid FSH of 0.7 ml. U. per milliliter (95 per cent CL: less than 0.5 to 3.4) for subjects with male fetuses was tenfold lower than that for patients with female fetuses. Amniotic fluid FSH levels less than 2.0 ml. U. per milliliter were found in 88 per cent of patients carrying male fetuses and in only one patient with a female fetus, and levels greater than 10 ml. U. per milliliter were found in those with female fetuses only. In eight patients (7 per cent of cases), neither amniotic fluid T nor FSH determinations were indicative of fetal sex. Measurement of unconjugated T and FSH in amniotic fluid may be an adjunct to other methods of determining fetal sex.

Amniotic fluid cell cultures

In an 18-month period, 249 samples of amniotic fluid were used experimentally in attempts to enhance success in cell cultures. None of the experimental situations proved entirely satisfactory in this aim. Emphasis is laid on the quality of serum used in culture. Particularly satisfactory serum should be retained for use in amniotic fluid cell cultures which are dependent on unknown growth stimulating factors present only in certain batches of sera.

Chromosome analysis before birth and its value in genetic counselling

Chromosome analysis of amniotic cell cultures was achieved in 29 out of 30 consecutive patients who were referred for genetic counselling during pregnancy. Amniocentesis was performed without any apparent untoward maternal or fetal complication. The only pregnancy terminated was that of a carrier of X-linked granulomatous disease, in whom the amniotic cells showed that the fetus was male and also had Down's syndrome (trisomy G). Chromosome analysis in the remaining 28 patients showed normal karyotypes. The interval between amniocentesis and a definitive karyotype varied from 7 to 31 (average 18.4) days.The reliability of chromosome analysis from amniotic cell culture and of fetal sex determination by means of the sex chromatin and Y-fluorescence techniques was studied further in amniotic fluid from cases of therapeutic abortion and of rhesus incompatibility. The fetal sex was correctly determined in all cases. It is concluded that antenatal diagnosis of genetic disease by amniocentesis now permits a more practical approach to genetic counselling.