De novo synthesis of placental protein-14 (PP14) and not PP12 by monolayer cultures of glandular epithelium of gestational endometrium.

Nine monolayer cell cultures of glandular epithelium from gestational endometrium were established from six apparently healthy women undergoing elective termination of pregnancy (7-11 weeks gestation). Radiolabel incorporation studies showed increasing incorporation of [35S]methionine into proteins present in supernatant and cytosol fractions over 48 h. The secreted proteins represented approximately 20% of the total incorporation of methionine into cytosolic proteins. De novo synthesis and secretion of placental protein-14 (PP14) and not PP12 was identified by a novel combination of line immunoelectrophoresis and autoradiography. All monolayer cultures demonstrated the presence of radiolabeled PP14, but not PP12, in the culture supernatants. These observations suggest that the glandular epithelial cells are the major site of synthesis and secretion of PP14 in human gestational endometrium.

The selection of antibodies with defined desorption properties from precipitated immune complexes for use in immunoadsorption procedures.

A general method for preparing immunosorbents with preselected antibody avidity is described. The method, which is a modification of a method described previously, also includes immunospecific purification of the ligand prior to coupling on the gel matrix. Polyclonal anti-alpha-1-fetoprotein antibodies in precipitated immune complexes were separated according to their avidity (low, intermediate and high) by dissociation with agents of increasing efficiency. After solid-phase coupling the antigen binding activity of the separated antibody preparations was examined according to recovery, capacity and binding strength. Antibodies of intermediate avidity derived from the immune complexes demonstrated optimal properties for preparative affinity chromatography.

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.

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.

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.

Localization and significance of urokinase plasminogen activator and its receptor in placental tissue from intrauterine, ectopic and molar pregnancies.

Urokinase plasminogen activator receptor (uPAR) is a membrane-anchored protein with urokinase plasminogen activator (uPA) as the ligand. This complex induces proteolysis and remodelling of maternal decidua during placental implantation. The presence of uPAR on trophoblasts is supposed to promote adhesion, migration and invasion. In cancer tissue, high levels of uPAR are correlated with a poor prognosis. This immunohistochemical study shows the localization of uPA and uPAR in a prospective design with stereological sampling of fetal and maternal tissue from normal, ectopic and hydatidiform molar (HM) pregnancies. Cytokeratin and Ki67 were used as markers for trophoblasts and proliferating cells. Membrane-bound uPAR was observed on villous non-proliferating intermediate trophoblasts (IT) within cell columns in intrauterine and ectopic pregnancies. The corresponding proliferating IT with cytological atypia sprouting from the chorionic villi in HM was uPAR-negative. uPA but not uPAR was observed in anchoring distal IT at the attachment-point to the basal plate. In the placental bed, extravillous interstitial trophoblasts were uPA-positive but uPAR-negative. The trophoblast giant cells were both uPA- and uPAR-negative. In relation to the maternal vessels, a focal distribution for uPA and uPAR was present in the endovascular and perivascular trophoblasts. The intraluminal trophoblasts overlying endothelial cells were uPAR-positive only. In maternal tissue from intrauterine and molar pregnancies, uPAR was seen in the decidual cells in a zone facing the anchoring villi and the fibrinoid lesions with embedded trophoblasts. In contrast, the stromal cells of the fallopian tube without a decidual reaction facing the implanted gestation were uPAR-negative. Non-invaded decidual, myometrial and muscular tissue of the pregnant uterus and fallopian tube was extensively positive for uPA whereas 'pseudodecidual' cells from the intrauterine evacuate in patients with an ectopic pregnancy only showed a focal and scanty reaction for uPA. When trophoblast invasion of the decidua was present, the decidual cells were uPA-negative. A semi-quantitative assessment of the receptor was estimated in villous IT within cell columns in normal and molar pregnancies but, in conclusion, quantitative evaluation of uPAR cannot be used to predict development of post-molar persistent trophoblastic disease (PTD).

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.

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).

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.

Comparison of pregnancy-associated murine protein-1 and human pregnancy zone protein.

Immunological cross-reaction between human pregnancy zone protein (PZP, SP-3, alpha 2-PAG) and pregnancy-associated murine protein-1 (PAMP-1) was demonstrated by countercurrent line immunoelectrophoresis using antibodies against the proteins raised in hens. The levels of PZP and PAMP-1 were measured during pregnancy and found to be very similar in the first half of pregnancy. Both proteins were found to be heterogeneous and separable according to surface properties. It is suggested that the murine PAMP-1 can be used to study the physiology of human PZP.

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.

Prelabor evaluation of inducibility.

Data were collected prospectively on 381 patients admitted for stimulation of labor because of premature rupture of the membranes and 808 patients for induction of labor. The induction was by primary amniotomy in 337 cases, and the remaining 471 cases, because of relatively unfavorable cervical conditions, were treated without primary amniotomy. Induction of labor failed on the first day in 181 of the cases with an unfavorable cervix. All patients were delivered vaginally of one living infant in cephalic presentation. The predictive value of the Bishop pelvic score and other factors regarding the duration of labor (induction-delivery time) and the inducibility of labor (latency period) were evaluated by multiple regression analyses. The influence of parity on duration of labor was found to be very constant and highly significant, whereas it seemed to have only little influence on inducibility. The only factor of significant importance to inducibility thus seems to be the prelabor cervical condition. Of the 5 components in the Bishop score, dilatation was found to be most important and should be weighted at least twice the value given it by Bishop. A new pelvic score for prelabor evaluation of inducibility is proposed on the basis of these results.

Placental function studies in low birth weight infants with and without dysmaturity.

Maternal blood levels of human placental lactogen and schwangerschaftsprotein 1 were measured in 51 women who delivered a growth-retarded infant. The levels were substantially lower in the 27 women whose infants were clinically dysmature than in the 24 women whose infants were small but of normal appearance. About one-half (44%) the cases of true dysmaturity had abnormal concentrations of human placental lactogen (less than 4 mg/L), whereas none of the small but normal group had values in this zone. It is concluded that biochemical tests of this type reflect dynamic aspects of placental function and not simply the overall size of the fetus and placenta.

Maternal serum levels of placental protein 5 in complications of late pregnancy.

Maternal serum levels of placental protein 5 (PP5) were measured during the third trimester in women with normal and abnormal pregnancies. PP5 levels were significantly elevated in patients with preeclampsia, diabetes, intrauterine growth retardation associated with preeclampsia, and twin pregnancy.

The prediction of pregnancy failure by measurement of pregnancy-associated plasma protein A (PAPP-A) following in vitro fertilization and embryo transfer.

Circulating PAPP-A was measured serially in five patients following successful IVF-ET. PAPP-A concentrations were consistently normal in all three patients in whom pregnancies progressed normally to term. Depressed levels of PAPP-A were observed in one patient who miscarried spontaneously at 17 weeks' gestation despite ultrasound evidence of normal fetal development. Circulating PAPP-A was not detected in the fifth patient, whose tubal pregnancy ruptured at 8 weeks. These data are discussed in relation to surveillance of pregnancies following IVF-ET.

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.

Immunochemical and biological studies on two molecular variants of pregnancy specific beta 1 glycoprotein (SP1) SP1 alpha and SP1 beta.

Analytical crossed immunoelectrophoresis was performed to examine the relationship of a high molecular mass alpha 2 mobile glycoprotein (SP1 alpha) which is immunochemically identifiable with pregnancy specific beta 1 glycoprotein (SP1 beta). There was no evidence for any reaction of SP1 alpha with antisera to normal human serum protein, nor for complex formation following incubation with normal serum proteins. The half-life of SP1 alpha was apparently shorter than that of SP1 beta after delivery of the placenta.

Circulating levels of pregnancy zone protein: normal range and the influence of age and gender.

Serum levels of pregnancy zone protein (PZP) were measured in 506 apparently normal males and 329 normal non-pregnant females, the age range being 18 to 70 years. The estimations of PZP were performed by sensitive radio-rocket-line immunoelectrophoresis. The distribution of the data had a marked positive skew in both sexes which was reduced following logarithmic transformation. Serum concentrations in both men and women were found to increase significantly with advancing age. This increase and the mean concentrations were significantly higher in females.

Circulating levels of relaxin are normal in pregnant women with pelvic pain.

OBJECTIVE: The hormone relaxin induces loosening of the pelvic ligaments and joints in several species. Previous studies have suggested a similar role for relaxin during human pregnancy. Furthermore, a correlation has been noted between high circulating levels of this hormone and severe pelvic pain in pregnant women. The present study was designed to evaluate whether serum relaxin concentrations were elevated in pregnant women with clear subjective and objective evidence of pain attributable to relaxation of the pelvic ligaments. STUDY DESIGN: Serum relaxin was measured at week 33 of gestation in 455 pregnant women with clearly defined pain in their pelvic joints and 455 normal pregnant controls matched for age and parity. All participants underwent an examination consisting of a structured questionnaire and fifteen specific tests for pelvic joint pain. The group with pain was further subdivided into four subgroups with different levels of disability and prognosis. Relaxin concentrations were measured using enzyme-linked immunoassay. RESULTS: There was no difference in serum relaxin concentration between the control and study group, nor between the subgroups of women with pelvic pain. CONCLUSION: We failed to confirm an earlier claim that circulating relaxin levels are related to pelvic girdle pain in pregnant women.