Biomedical subjects

J G Westergaard

Publications and source records attributed to J G Westergaard.

85 records · Page 5Linked to original sources

PubMed1980

Comparison of the pregnancy-associated murine protein-2 and human pregnancy-specific beta 1-glycoprotein.

Immunological cross-reaction between human pregnancy-specific beta 1-glycoprotein (SP-1) and pregnancy-associated murine protein-2 (alpha 2-PAMP, PAMP-2) was demonstrated by line immunoelectrophoresis using antibodies against the proteins raised in hens. The pattern of change of PAMP-2 and SP-1 values in serum during pregnancy was very similar. The murine placental growth-rate corresponded to PAMP-2 levels in maternal serum during pregnancy, indicating placental origin. We suggest that the mouse and its PAMP-2 can be used to study human SP-1.

Animals↗

PubMed1979

Pregnancy-specific beta 1-glycoprotein (SP1) determined by means of electroimmunoassay, radial immunodiffusion and nephelometry.

A comparison has been made between rocket-immunoelectrophoresis (RIE), radial immunodiffusion (RID) and automated immunonephelometry (AIP) in the assay of pregnancy-specific beta 1-glycoprotein (SP1) in serum from pregnant women. Using RIE an interaction was demonstrated between the various SP1-reactive molecular populations causing a bias of up to 10%. An interaction corresponding to this phenomenon cannot be demonstrated when using RID and AIP. When correlating the serum-SP1 concentration of samples containing various ratios of SP1-reactive molecules by means of RIE, RID and AIP, it was demonstrated that there was no correlation between the results achieved using one method compared to the results achieved by either of the other methods. The results achieved using one method can therefore exclusively be judged from reference values determined using the same method. The analysis time is essentially shorter with AIP than with RIE and RID.

Female↗

PubMed1979

Molecular heterogeneity of pregnancy specific beta 1 glycoprotein: the effect on measurement by radioimmunoassay and electroimmunoassay.

A comparison of methods for the quantification of circulating pregnancy specific beta 1 glycoprotein in late pregnancy was performed to assess the influence of the presence of a high molecular weight glycoprotein with alpha 2 electrophoretic mobility (SP1 alpha) which is immunochemically identifiable with pregnancy-specific PBETA 1 glycoprotein (SP1 beta). Serum samples from 47 volunteers in the 3rd trimester of pregnancy were subjected to measurements of pregnancy specific beta 1 glycoprotein in rocket immunoelectrophoresis, quantitative crossed-immunoelectrophoresis and radioimmunoassay. Rocket immunoelectrophoresis gives a result which reflects the total SP1 content, i.e. SP1 alpha and SP1 beta while quantitative crossed-immunoelectrophoresis permits differentiation between the two molecules. Radioimmunoassay predominantly measures authenic SP1, i.e. SP1 beta in the presence of physiological amounts of SP1 alpha.

Chromatography, Gel↗

PubMed1979

Specific assay for pregnancy-specific-beta 1-glycoprotein (Sp1-beta). Preparation of antiserum specific for SP1-beta by absorption with a crossreacting high molecular weight serum protein.

Two pregnancy-associated proteins reacting with antibody against pregnancy-specific beta 1-glycoprotein (PS beta G or SP1) were separated by means of ammonium sulphate precipitation, size chromatography and preparative zone electrophoresis. The antibody preparation was made monospecific to the beta-mobile protein by liquid phase cross-absorption of anti-SP1 immunoglobulin preparation with the isolated alpha2-mobile high molecular weight protein. The specificity of the absorbed antibody was tested in line immunoelectrophoresis, rocket immunoelectrophoresis and crossed immunoelectrophoresis.

Absorption↗

PubMed1979

Quantification of the pregnancy-specific beta1-glycoprotein (SP1) by immunoprecipitation techniques: the influence of a cross-reacting high molecular weight alpha2-protein.

Two serum proteins with SP1 determinants were separated by means of size chromatography and preparative zone electrophoresis. One of the proteins had beta1 electrophoretic mobility and an estimated molecular weight of 90,000, and the other had alpha2-mobility and a molecular weight around 400,000. When available antibody preparations to SP1 were used, the high molecular weight protein formed immunoprecipitates only when polyethyleneglycol (PEG) was added to the agarose. It is shown that the high molecular weight protein has a pronounced effect on quantification of SP1 by rocket immunoelectrophoresis, whereas the effect was less pronounced but still considerable when quantification was performed by radial immunodiffusion.

Antigens↗

PubMed1979

Characterization of two pregnancy associated serum proteins with pregnancy specific beta 1-glycoprotein (PS-beta-G)-determinants.

The existence of two pregnancy associated, partially identical glycoproteins with PS-beta-G determinants were demonstrated in serum from pregnant women. Crossed and crossed-line immunoelectrophoretic analysis of pregnancy sera revealed two precipitates with alpha- and beta-mobility, respectively. The ratio between the precipitation areas in various samples could be related to three different types of precipitation patterns observed in rocket immunoelectrophoresis. This variation in precipitation pattern could so far not be related to the progression of any obstetric parameters. The diphasic shape of the precipitate in crossed immunoelectrophoresis was not changed by incubation with normal human male serum or antibody to normal human serum. Incorporation of 4% PEG in the gels enhanced the precipitate in the alpha-region. The cross-reactive glycoproteins were detected in all pregnant women examined. These results point to the need for specific antibody preparations permitting separate quantitation of the two antigen populations with PS-beta-G determinants.

Chemical Precipitation↗

PubMed1978

Two pregnancy-associated serum proteins with pregnancy-specific beta1-glycoprotein determinants.

A protein showing strong antigenic cross-reactivity with the "pregnancy-specific" beta1-glycoprotein (PSbetaG) was demonstrated in serum of pregnant women during the second and third trimesters, but not in sera from normal men and nonpregnant women. The described protein had alpha2-electrophoretic mobility and its molecular weight was estimated to be around 200,000 as compared to 80,000 for PSbetaG. Crossed immunoelectrophoretic analysis, using antiserum to PSbetaG, indicated the presence of additional antigenic determinants in PSbetaG not demonstrable in the cross-reacting alpha2-protein. The PSbetaG/alpha2-protein ratio was rather constant in consecutive serum samples from one woman during pregnancy, but showed a marked variation when sera from different women were compared. Results of rocket immunoelectrophoresis gave a rough estimate of the ratio between these two proteins in a sample of pregnancy serum. The reported findings point to the need for development of specific methods for quantitation of the two proteins and the necessity to re-evaluate earlier quantitative PSbetaG data.

Blood Protein Electrophoresis↗

PubMedDate not supplied

Investigations into the molecular heterogeneity of pregnancy-specific beta 1-glycoprotein (SP1).

The molecular heterogeneity of pregnancy-specific beta 1-glycoprotein (SP1) was examined by analytical immunoelectrophoresis and a radioimmunostaining technique of immunoelectrophoretic plates. Analytical crossed immunoelectrophoretic analysis and radioimmunostaining of these plates demonstrated the presence of normal human serum components in the alpha-mobile precipitate previously considered to be exclusively the high molecular pregnancy-specific protein, SP1 alpha. This observation suggested that two molecular populations were contributing to the alpha-mobile precipitate. Following fractionation of late-pregnancy serum by size chromatography, the radioimmunostaining technique further demonstrated the presence of normal serum components in the intermediate fraction but not in authentic SP1 (i.e., SP1 beta) or the high molecular weight form (SP1 alpha). We suggest that SP1 antigenic determinants are distributed in three different fractions of pregnancy serum, one of which (intermediate fraction) is a complex of authentic SP1 (SP1 beta) and a normal serum protein, whereas non-pregnancy serum components were not demonstrable in the remaining two (i.e., SP1 beta or SP1 alpha).

Female↗

PubMedDate not supplied

Purification of pregnancy-associated plasma protein-A by a two step affinity chromatographic procedure.

A high molecular weight pregnancy specific protein (PAPP-A) was purified by immunospecific affinity chromatography. The purification procedure was based on a new method for affinity chromatography using direct coupling of precipitable immune complexes to the gel matrix. The procedure was performed in two steps: a positive immunospecific affinity chromatography followed by a negative affinity chromatography in which balanced amounts of anti-contaminant antibodies were used as ligant. The purified material at a concentration of 300 microgram/ml was tested by immunoelectrophoretic methods and no contaminants were detectable. WHO beta-1 SP1 reference material 78610 contained 45 microgram PAPP-A/ml.

Antibody Formation↗

PubMedDate not supplied

Specific and reversible interaction between pregnancy-associated plasma protein A and heparin.

An interaction between heparin and circulating pregnancy-associated plasma protein A (PAPP-A) has been observed. This interaction could be reversed by the addition of the specific heparin antagonist protamine sulphate. In the presence of heparin, crossed immunoelectrophoretic analysis revealed an alteration in the electrophoretic mobility of PAPP-A, while a significant increase (22 to 64 per cent, P less than 0.02) in measured levels of PAPP-A was seen in electroimmunoassays. These findings are discussed in relation to the optimal conditions for the precise measurement of PAPP-A.

Anticoagulants↗

PubMedDate not supplied

The localization of pregnancy proteins (hPL, SP1 and PAPP-A) in intra- and extrauterine pregnancies.

The localization of human placental lactogen (hPL), pregnancy-specific beta-1 glycoprotein (Schwangerschaftsprotein 1, SP1) and pregnancy-associated protein A (PAPP-A) was examined in intrauterine and tubal ectopic gestation (n = 5) by the immunoperoxidase technique. The distribution of hPL and SP1 was identical in placental tissues obtained from intra- and extrauterine pregnancies, being uniformly seen throughout the syncytiotrophoblast. hPL and SP1 were not demonstrated in uterine decidual tissue from ectopic pregnancies. During early (week 8) intrauterine pregnancy, PAPP-A was not restricted to the mature syncytiotrophoblast, being observed also in some trophoblast-like cells adjacent to islands of syncytiotrophoblast. In contrast, in ectopic gestation, PAPP-A was observed in these cells at six weeks' gestation only. We were unable to detect PAPP-A in trophoblastic tissue of chorionic villi and uterine decidual tissue from ectopic gestation.

Decidua↗

PubMedDate not supplied

Immunohistochemical demonstration of pregnancy-associated plasma protein A (PAPP-A) in the syncytiotrophoblast of the normal placenta at different gestational ages.

The immunoperoxidase technique was used to study the localization of pregnancy-associated plasma protein A (PAPP-A) in formaldehyde-fixed paraffin-embedded tissue from normal human placentae at the gestational age of 8, 15 and 40 weeks. Sections of formaldehyde-fixed tissue treated with a proteolytic enzyme and incubated in antiserum against PAPP-A either raised in goats or rabbits showed that PAPP-A was distributed in the cytoplasm of the syncytiotrophoblast. The protein was not found in the cytotrophoblast. Sections without pretreatment with trypsin and incubation in goat anti-PAPP-A showed no staining reaction, whereas incubation in rabbit anti-PAPP-A revealed a staining of the syncytiotrophoblast surface. The results indicate that PAPP-A is probably synthesized in the syncytiotrophoblast.

Cytoplasm↗

PubMedDate not supplied

An animal model for the study of the function of pregnancy-specific beta 1-glycoprotein and pregnancy zone protein: a review.

Two pregnancy-associated murine proteins, PAMP-1 and PAMP-2, have been found to be immunologically cross-reacting analogues to the human proteins pregnancy zone protein (PZP) and pregnancy-specific beta 1-glycoprotein (SP-1), respectively. In this study, the physiochemical and biological properties of the proteins are compared and the effect on pregnancy of administration of monospecific antibodies against the proteins is reported.

Abortion, Induced↗