Magdalena Usategui-Gomez

A Comparative Study of Amniotic Fluid, Maternal Sera and Cord Sera by Disc Electrophoresis.∗

Summary 1) Individual amniotic fluid proteins were quantitated by means of disc elec-trophoresis and immunodiffusion techniques, and proteins of the amniotic fluid were compared to those found in maternal and fetal serum. 2) The findings indicate that the proteins of the amniotic fluid originate at least partly from maternal serum. 3) Selective ultrafiltration on the basis of molecular size cannot explain apparent inhibition of the passage of haptoglobins and IgA into the amniotic fluid. Some additional mechanism, other than simple filtration, must be active. The authors would like to thank Dr. William Flood, Dr. Curtis Flory and members of the Putnam Memorial Hospital delivery room staff for their unfailing help and assistance in obtaining specimens for this study. Gratitude is also expressed to Dr. R. Woodworth of the University of Vermont for supplying purified haptoglobin 1-1.

Rh-D antibody titer in amniotic fluids

Abstract A study was made of Rh antibody titers in the amniotic fluids from 42 Rh-sensitized pregnancies. It was learned that the antibody titer of such fluid can be used as a reliable index of the severity of kemolytic disease in the fetus.

In vitro studies of protein transfer across human fetal membranes.

Summary Maternal sera were dialyzed in vitro across individual or combined fetal membranes to elucidate the functions of the membranes in protein transport. Concentration of individual proteins in the dialyzates obtained, closely resembled the composition of amniotic fluid. Results of these in vitro studies indicate that the fetal membranes are able to select protein molecules for passage not only according to size, but also on the basis of their chemical structure.

Viral haemagglutination inhibitory potency of human placental alkaline phosphatase

Abstract Purified preparations of human placental alkaline phosphatase exhibit the ability to inhibit haemagglutination of red blood cells by Toolans 21–29 H-1 virus. The peaks for enzyme activity and haemagglutination inhibitory potency of different column fractions coincide with each other in TEAE-cellulose anion exchange chromatograms. Purified placental enzyme loses virus inhibitory capacity on lyophilization, contamination with bacteria and also on cleavage of terminal sialic acid residues by treatment with influenza virus neuraminidase.

Association of Placental Alkaline Phosphatase Activity with Preparations of the Human Placental Inhibitor to Hemagglutination by H-1 Virus

Summary Purified preparations of the glycoprotein found in human placental fluid that inhibits the hemagglutination of H-1 and HB viruses, have also been shown to contain alkaline phosphatase activity. This phosphatase activity has been identified as a placental phosphatase by comparing its characteristic behavior with that of purified human placental alkaline phosphatase. It is probable that the viral inhibitor and the large molecular-weight variant of placental alkaline phosphatase are the same glycoprotein.

Further purification of a human placental inhibitor to hemagglutination by H-1 virus.

Summary The glycoprotein found in human placental fluids that inhibits the hemagglutination of H-1 and HB viruses has been obtained in a high degree of purity as shown by disc electrophoresis and immunodiffusion. It sediments as a macroglobulin whose biological activity can be destroyed by treatment with trypsin, chymotrypsin, papain, neuraminidase, or sodium metaperiodate. The inhibitor possesses a remarkable capacity for reacting with H-1 virus since it is active in as low a concentration as 0.004 μg/ml.

Purification of a Horse Placental Inhibitor to Hemagglutination by H-1 or HB Viruses∗

Summary The active material found in horse placental fluids which inhibits the hemagglutination of H-1 and HB viruses has been purified, and a homogeneous product obtained as shown by disc electrophoresis. The inhibitor sediments in a sucrose gradient as a macroglobulin that can be rendered inactive by treatment with papain, neuraminidase, or sodium metaperiodate. Though a similar inhibitor is found in human placental fluids, the two substances are not identical. The purified material from the horse placental fluids shows a remarkable capacity for inhibiting hemagglutination by H-1 virus since it is active in concentrations as low as 0.006 μg/ml.

A Human Placental Fluid Inhibitor to Hemagglutination by H-1 and HB Viruses II. Electron Microscope Studies.

Summary Treatment of H-l or HB viruses with a purified hemagglutination inhibitor derived from human placental fluids induces the formation of large three-dimensional aggregates of virus. Fibrils, 10áR or less in diameter, appear to connect the virus though they may not be the cause of the virus clumping. The placental inhibitor does not affect H-3 or RV viruses. When antibody is added to its homologous virus, aggregates are also formed. These are 2-dimensional and much smaller than those formed by the placental fluid fraction. They are characterized by the presence of fibrils, believed to be antibody, which join the individual virus particles.

A Human Placental Fluid Inhibitor to Hemagglutination by H-1 and H-B Viruses I. Purification.

Summary A substance found in human placental fluids that inhibits the hemagglutination of H-1 and HB viruses but not that of H-3 or RV viruses, has been purified and found to be an electrophoretically homogeneous glycoprotein stable to heat and a wide pH range. It also appears to be immunologically homogeneous and occurs in the slow a or fast β region.