Fetal Cord Serum Research Articles

288. Somatomedin a in maternal serum during pregnancy and postpartum period and fetal cord serum: Relationship to the various hormones and cystine aminopeptidase during pregnancy

288. Somatomedin a in maternal serum during pregnancy and postpartum period and fetal cord serum: Relationship to the various hormones and cystine aminopeptidase during pregnancy

Inhibitory effect of alpha-fetoprotein on protein synthesis in a reticulocyte lysate cell-free system.

The inhibitory effect of human alpha-fetoprotein on the protein synthesis (incorporation of [3H]leucine into the total protein fraction) weas observed in a rabbit reticulocyte lysate cell-free system. The incorporation was inhibited to 50% of the control level by 14-16 microM alpha-fetoprotein, and decreased to about 15% at a concentration higher than 40 microM. An almost identical dose dependence was obtained between fetal alpha-fetoprotein and hepatoma-derived alpha-fetoprotein. This inhibitory effect on the protein synthesis was due to the interference of alpha-fetoprotein to the 40 S initiation complex formation from the ternary complex (eukaryotic initiation factor 2.GTP.Met-tRNAfMet). In contrast human serum albumin purified from fetal cord sera did not exhibit this inhibition under the same conditions. These results indicate that alpha-fetoprotein may function as a regulator of the protein synthesis in the fetal stage.

Humoral immunity in myasthenia gravis: Biochemical characterization of acquired antireceptor antibodies and clinical correlations

The titer and characteristics of antiacetylcholine receptor antibody (AChR-Ab) were investigated in 184 patients with myasthenia gravis. Mean AChR-Ab titers of each clinical grade increased with the severity of the disease. AChR-Ab was always of an IgG class. IgM (5 of 92) and IgA (2 of 48) class AChR-Ab were detected, but only concurrently with IgG and in low concentrations. IgG subclass 3 was not prominent. In 3 patients with AChR-Ab titers in the normal range, blockade of bungarotoxin binding to receptor could still be demonstrated. AChR-Ab from 6 patients was heterogeneous in affinity for receptor, reactivity from human ocular and gastrocnemius muscle, and blockade ot toxin binding. AChR-Ab was oligoclonal in 4 of 6 patients, as shown by concurrent production of AChR-Ab IgG of both kappa and lambda types. Amniotic fluid and fetal cord serum did not interfere with antibody-receptor interaction. Variation in the pattern of weakness among patients was a function of both the heterogeneity of AChR antibodies and the antigenic uniqueness of receptor complexes from different human muscles.

Antisperm antibody inhibition of sperm penetration of zona-free hamster eggs

Serum samples with sperm-immobilizing antibody activity from six women were examined for ability to block sperm-egg interaction by a zona penetration test where human follicular ova matured in vitro were used. Exposure of spermatozoa from a fertile healthy donor to the sera impaired binding to and penetration through the zona pellucida of the spermatozoa completely in five cases and incompletely in one case. Successful fertilization in vitro was achieved by using fetal cord serum instead of autoserum of the patient included in the in vitro fertilization and embryo transfer program. These results suggest that interference with sperm-egg interaction may be an additional mechanism of infertility that is caused by antisperm antibodies.

POLYAMINE INTERACTION WITH PREGNANCY SERUM IN SUPPRESSION OF LYMPHOCYTE TRANSFORMATION

Biogenic polyamines interacting with pregnancy serum elicit potent suppression of lymphocyte transformation in vitro. Within the assay limits, activity was first shown after about 15 weeks' gestation and reached its highest level at about 28 weeks. This level was maintained until term. It is thought that specific humoral amine oxidases were the cause. Fetal-cord serum and non-pregnancy serum were inactive. This system may have an immunoregulatory function in pregnancy.

Purification and identification of a human-serum DNA-binding protein associated with malignant diseases.

A malignancy-associated human serum DNA-binding protein (C3DP protein), which was previously detected using dodecylsulfate gel electrophoresis, has been purified and characterized. This protein was isolated from human fetal cord serum by DNA-cellulose affinity chromatography, ammonium sulfate fractionations, DEAE-cellulose chromatography, and Sephadex gel filtration. The molecular weight of purified C3DP protein has been shown to be 135000 by ultracentrifugation, gel filtration, and dodecylsulfate gel electrophoresis. Dodecylsulfate gel electrophoresis following disulfide bond reduction has revealed that this protein is composed of three subunits having molecular weights of 74000, 40000 and 22000. Carbohydrate has been demonstrated to be attached to the 74000 and 22000 molecular weight components. Immunochemical studies have revealed that the C3DP protein is a fragment of human complement component C3, which closely resembles C3c.

Somatomedin-C Receptor Ontogeny and Levels in Porcine Fetal and Human Cord Serum

The ontogeny of somatomedin receptors in tissues of fetal pigs and levels of somatomedin-C in fetal pig serum at various gestational ages and in human cord serum was investigated. Specific binding of 125I somatomedin-C by particulate membranes prepared from fetal organs from a variety of gestational ages almost always exceeds specific 125I insulin binding. In liver, kidney, heart and the maternal portion of the placenta, apparent binding affinity for somatomedin is relatively constant throughout gestation and is the same for membranes from fetal and adult animals. In contrast, in the fetal portion of the placenta, specific somatomedin-C binding and apparent binding affinity increases as gestation progresses. The changes in this tissue correlate temporally with the acceleration of growth of the pig fetus. Membranes prepared from fetal lungs exhibit higher specific binding of somatomedin and higher affinity constants than adult lung membranes. Somatomedin levels in fetal pig serum are about 25% of those observed in the sow and are constant throughout fetal life. Somatomedin in human cord serum is likewise low compared to adult levels. Small-for-gestational age infants and large, postmature infants have lower mean somatomedin levels than normal weight, full-term infants. The identification of specific somatomedin receptors in fetal tissues opens the possibility that somatomedin-C stimulates growth of the fetus. Although not resolved, the relatively low levels of somatomedin in fetal serum may reflect low levels of the somatomedin binding protein rather than an absolute deficiency of biologically active somatomedin.

Primary culture and maintenance of steroid-secreting human placenatal monolayers.

A simple method is described for primary culture and for maintenance of hormone-producing cells from normal human placenta. A consistent yield of cells was obtained and an average survival of 3 to 4 months in culture using 1 mm3 explants from the most vascular area of the placentas. These explants were placed in a variety of culture media in 30 ml flasks and incubated at 37 degrees C in an atmosphere of 5% CO2 and 95% air. The best yields in terms of cell growth were observed with Eagle's MEM (minimum essential medium) with supplements of horse serum and fetal calf serum or human cord serum. (Ham's F-10 with supplement of horse serum and fetal calf serum supports growth for the longest period and media containing human cord serum had the best yield of steroids.

The Zn-α 2 -glycoprotein level in human serum during ontogenesis

Using electrophoresis in antibody-containing agarose gel with planimetric evaluation of antigen—antibody precipitation peak area, Zn-α 2 -glycoprotein was quantitatively estimated in normal human serum at different ages. Quantitative differences were found between the main Zn-α 2 -glycoprotein concentration in fetal serum (2.5 ± 1.8 mg/100 ml), cord serum (4.8 ± 1.6 mg/100 ml) and serum of infants, children, adolescents and adults (8.9 ± 2.2 mg/100 ml 10.4 ± 4.0 mg/100 ml). The Zn-α 2 -glycoprotein concentration in serum increases already during the first few days after birth as compared with its concentration in cord serum, to reach the mean values representative for postnatal age approximately between the first and second week after birth. Differences from normal human serum Zn-α 2 -glycoprotein concentration during ontogenesis may be expected in pathological conditions. At present this phenomenon is being studied in detail, especially in nephropathies and autoimmune diseases.

Antenatal diagnosis of argininosuccinic aciduria.

Argininosuccinic aciduria (ASAuria) is an inherited disorder of ureogensis characterized by periodic hyperammonemia, seizures, and mental retardation. Transabdominal amniocentesis was performed at 16 weeks' gestation on a 31‐year‐old female whose one previous child had this disease. ASA concentration in the amniotic fluid was 0.073 μmoles/ml (normal = 0). Cultured amniotic cells incubated with L‐citrulline‐ureido‐11C accumulated ASA‐14C as did cultured fibroblasts of patients with ASAuria; normal cells (including those from subjects heterozygous for argininosuc‐cinasc deficiency) do not accumulate this metabolic intermediate.Pregnancy was terminated at 22 weeks by hysterotomy. Fetal liver ASase was 3–5 percent of normal, and liver ASA concentration was 9.36 μmoles/g wet wt. (normal = 0), confirming the prediction of an affected fetus. Fetal cord serum ASA and citrulline concentrations were 0.098 and 0.071 μmoles/ml, respectively; simultaneous maternal concentrations were 0 and 0.014. Maternal urine ASA concentrations during pregnancy were 0.15.5 and 0.166 μmoles/mg crmtinine; 10 weeks after tcrmination, ASA was present in only trace amounts.Current emphasis is on development of techniques to minimize the delay between amniocentesis and intrauterine diagnosis. It is possible that this and some other no‐threshold aminoacidurias may be diagnosed on the basis of amniotic fluid amino acids alone.