Biomedical subjects

K K Vernof

Publications and source records attributed to K K Vernof.

4 recordsLinked to original sources

PubMed1994

Expression of eosinophil-granule major basic protein messenger ribonucleic acid in placental X cells.

BACKGROUND: The human eosinophil-granule major basic protein (MBP) is a 13.8-kilodalton cationic polypeptide constituting the core of the eosinophil granule. MBP is cytotoxic to parasites and numerous mammalian cells and is a potent secretagogue for platelets, basophils, mast cells, and neutrophils. Concentrations of a molecule immunochemically similar to eosinophil granule MBP are present in maternal plasma, and MBP has been localized by immunofluorescence to placental X cells. EXPERIMENTAL DESIGN: To determine whether X cells produce MBP, the expression of MBP messenger RNA (mRNA) was investigated in placentas by Northern blot analyses and by in situ hybridization with 35S-labeled RNA probes. RESULTS: Northern blot analyses of RNA from placental septa and villi showed the existence of a 1.0-kb RNA band that hybridized with the MBP anti-sense probe; no MBP mRNA was detected in whole blood of normal or pregnant women or in cord blood. Analyses of placentas by in situ hybridization showed MBP mRNA in X cells of placental septa and anchoring villi, but not in other cellular elements such as syncytiotrophoblasts, cytotrophoblasts, villous stromal cells, and fetal endothelial cells. RNase pretreatment abolished X-cell hybridization signals; treatment of sections with an excess of nonradiolabeled anti-sense RNA also blocked binding of the 35S-labeled anti-sense RNA probe. Additional evidence supporting the production of MBP by X cells was obtained using a combination of in situ hybridization and immunofluorescence, which showed colocalization of MBP and its mRNA. CONCLUSIONS: The presence of MBP mRNA and MBP protein in placental X cells indicates that X cells synthesize this biologically active molecule.

Blood Proteins↗

PubMed1992

Pregnancy-associated major basic protein in amniotic fluid.

The pregnancy-associated major basic protein, a protein elevated in the sera of all pregnant women, is virtually identical to the eosinophil granule major basic protein. To determine whether pregnancy-associated major basic protein is present in amniotic fluid, we examined samples from both early and late gestation by a double antibody radioimmunoassay. A total of 112 amniotic fluids were tested and all but three contained levels of pregnancy-associated major basic protein greater than 400 ng/ml. Amniotic fluid pregnancy-associated major basic protein antigenic activity was immunochemically identical to that of the eosinophil granule major basic protein and also had identical physicochemical properties such as heat stability and the need for reduction and alkylation. Although the majority of amniotic fluid samples (90 of 112) were obtained from healthy women with normal gestations, the remaining 21 amniotic fluid samples were from women with Rh sensitization and from one gestation complicated by intrauterine growth retardation.

Amniotic Fluid↗

PubMed1992

Maternal floor infarction: relationship to X cells, major basic protein, and adverse perinatal outcome.

OBJECTIVE: Maternal floor infarction of the placenta is characterized by gross placental abnormalities and histologic evidence of X-cell proliferation. Previously, pregnancy-associated major basic protein has been localized to the placental X cell and identified at elevated levels in serum and amniotic fluid in all normal pregnancies. Here we test the hypothesis that pregnancy-associated major basic protein is localized to the X cells in maternal floor infarction and that it contributes to the pathophysiologic features of pregnancies complicated by maternal floor infarction. STUDY DESIGN: Seven patients with eight pregnancies complicated by maternal floor infarction were evaluated. We analyzed placental tissue, serum, amniotic fluid, and placental cyst fluid for pregnancy-associated major basic protein. RESULTS: Placental tissue from pregnancies complicated by maternal floor infarction had increased numbers of X cells and fibrinoid material that occupied or surrounded degenerating villi and that stained intensely for pregnancy-associated major basic protein. Serum pregnancy-associated major basic protein levels were variable and likely cannot be used to predict the occurrence of maternal floor infarction. CONCLUSION: Pregnancy-associated major basic protein, a potent cytotoxin, is localized to X cells and is deposited in close proximity to chorionic villi in maternal floor infarction and may contribute to the pathophysiology of this disorder.

Adult↗

PubMedDate not supplied

Analysis of pregnancy-associated major basic protein levels throughout gestation.

Previous studies have shown that MBP levels rise before labour and have suggested the use of pMBP levels as a predictor of labour. We hypothesize that pMBP levels show a common pattern in pregnant women including a late third trimester rise in pMBP which predicts the onset of labour. Serum pMBP levels were measured throughout gestation in 112 pregnant women. We then analysed the relationship of pMBP levels to the time of labour onset, and to other features of pregnancy. An exponential increase in pMBP levels was seen early in gestation from weeks 5 to 21 in all pregnant women. In total, 79 per cent of the women showed rises in pMBP of > or = 25 per cent above baseline during the third trimester. pMBP levels were shown to be associated with placental weight, multiple gestation, and parity. pMBP levels could not, however, be used to form a precise model for the prediction of labour. The role of pMBP in pregnancy remains unclear.

Blood Proteins↗