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PubMedDate not supplied

Purification and partial characterization of peroxidase from human term placenta of non-smokers: metabolism of benzo(a)pyrene-7, 8-dihydrodiol.

Peroxidase (Donor: H(2)O(2)oxidoreductase EC 1.11.1.7) from human term placentae of non-smokers was purified to homogeneity by a combination of NH(4)Cl extraction, affinity chromatography, (NH(4))(2)SO(4)precipitation, ion-exchange and gel filtration chromatography. The homogeneity of purified human placental peroxidase (HTPP) was confirmed by gel filtration, reverse phase high performance liquid chromatography (HPLC) and SDS-PAGE. Peroxidase was found to be a membrane bound enzyme. A high concentration of NH(4)Cl (1.2 m) was needed to extract and solublize the enzyme. Removal of the salt resulted in irreversible precipitation of the enzyme. The protein exhibited a molecular mass of 126 000 kDa according to gel filtration and approximately 60 000 kDa by SDS-PAGE, indicating that the peroxidase is a homodimer. The purified peroxidase showed an optimum pH range of 7 to 8.5 and the K(m)for H(2)O(2)and guaiacol were found to be 0.08 m m and 10.0 m m, respectively. The purified peroxidase oxidized several substrates, namely potassium iodide, tetramethyl benzidine, guaiacol, ortho dianisidne and tyrosine. The enzyme was resistant to thermal denaturation up to 70 degrees C and also to chaotropic agents, guanidinium chloride and urea. Spectral properties indicated the presence of Soret band at 433 which shifted to 451 nm on complexation with cyanide. The circular dichroism studies showed that HTPP has a predominantly helical secondary structure. The enzyme showed similarities to the myeloperoxidase with regard to spectral and catalytical properties but differed significantly in amino acid composition, the R(z)value and molecular mass. Purified HTPP differed from eosinophil peroxidase in all physico-chemical properties indicating that it is not of eosinophil origin, but may represent a distinct, constitutive peroxidase in human placenta. Further, purified peroxidase catalyzed oxidation of benzo(a)pyrene-7, 8-dihydrodiol in presence of tyrosine and hydrogen peroxide to BP-tetrols, the hydrolytic products of BP-diol-epoxides, demonstrating the ability of peroxidase in bioactivation of benzo(a)pyrene in human placenta.

Adult↗
PubMed1983

Vaccine and serum-mediated protection against brucella infection of mouse placenta.

Pregnant mice inoculated i.p. or i.v. with virulent Brucella abortus Strain 544 displayed strong infection, evidenced by brucella enumeration in placentas and dams' spleens. Vaccination 1 month before pregnancy decreased frequency of placental colonization and number of brucella per infected placenta and per spleen. Protein-bound cell wall peptidoglycan (PG) fractions extracted from brucella protected mice as well as H38 killed and B19 attenuated living vaccines. The lipopolysaccharide (LPS) fraction was comparatively less active. Immune serum injected i.v., either 24 h before or just after i.v. challenge of 15-day pregnant mice effectively transferred resistance to placental colonization. Anti LPS, anti PG and anti killed brucella sera protected mice as well as vaccination one month before pregnancy. The immunity transferred persisted for at least 3 days.

Animals↗
PubMed1990

Purification, partial characterization, and development of a specific radioimmunoassay for goat placental lactogen.

Placental lactogen (PL) was isolated from goat cotyledonary tissue by a combination of mild alkaline extraction, anion and cation exchange chromatography, chromatofocussing and molecular filtration. The product, enriched 15,000-fold from the initial extract, was homogeneous when examined by SDS-gel electrophoresis (Mr 22,500) and isoelectricfocussing indicated a pI of 8.35 with a trace contaminant of pI 8.0. When assessed by relative binding activity in radioreceptor assays (RRA), goat PL exhibited somatotropic activity equivalent to 2.2 units/mg dry weight and lactogenic activity equivalent to 28.5 units/mg. A radioimmunoassay (RIA) for goat PL is described that is highly sensitive (190 pg/tube) and has acceptable repeatability within and between assays (6 and 13%, respectively). The assay is not affected by goat pituitary extracts or partly purified goat growth hormone and prolactin. Despite the marked increase in sensitivity of the RIA over that previously available when goat PL was measured by RRA, the hormone was not detected in jugular plasma of goats before Day 44 of pregnancy; concentrations increased thereafter and highest levels were measured during the last third of pregnancy in animals bearing triplets. Measurements by RIA are in general agreement with those obtained earlier in several studies in which RRAs were used. The hormone was detected in amniotic fluid. Maternal concentrations of goat PL declined before parturition and were undetectable by 18 h post partum.

Animals↗
PubMed1998

NO modulates fetoplacental blood flow distribution and whole body oxygen extraction in fetal sheep.

It is unknown if nitric oxide (NO) influences the relative level of the left (LV) and right ventricular (RV) outputs, the blood flow distribution between the body and placenta, or whole body O2 extraction and O2 consumption in the fetus. To address these questions eight fetal lambs were chronically instrumented at 128-134 days gestation (term 147 days), and blood flows were measured with radioactive microspheres 3-4 days later at baseline and after inhibition of NO synthesis with N omega-nitro-L-arginine (L-NNA, 10 and 25 mg/kg i.v.). L-NNA progressively reduced the combined ventricular output (P < 0.005) but did not alter the relative levels of the LV and RV outputs. Fetal body blood flow fell by 31% after 10 mg/kg L-NNA (P < 0.005), but a reduction in placental blood flow (P < 0.005) was smaller (20%) and not observed until 25 mg/kg L-NNA. Whole body O2 extraction increased by 71% after 10 mg/kg L-NNA (P < 0.005) and did change further at 25 mg/kg L-NNA, whereas whole body O2 consumption rose by 15% at 10 mg/kg L-NNA (P < 0.05) and returned to baseline at 25 mg/kg L-NNA. These results suggest that, as well as reducing the combined ventricular output, inhibition of fetal NO synthesis redistributes systemic blood flow toward the placenta and increases fetal body O2 extraction. The latter initially increases whole body O2 consumption and then maintains it at near baseline levels after a fall in placental perfusion.

Animals↗
PubMed1992

Venous drainage of the human uterus: respiratory gas studies in normal and fetal growth-retarded pregnancies.

OBJECTIVE: To determine respiratory gas relationships between the uterine veins and umbilical vein in normal and pregnancies complicated by intrauterine growth retardation. STUDY DESIGN: Respiratory gases were measured in both uterine veins and the umbilical vein in eight normal and 13 pregnancies with intrauterine growth retardation. RESULTS: No significant differences were found in the placental versus nonplacental uterine veins. There was a significant correlation for umbilical and uterine venous values of PO2 (p less than 0.002) and PCO2 (p less than 0.004) in appropriate-for-gestational-age pregnancies, umbilical venous PO2 was always less than uterine venous PO2, and PCO2 always greater than uterine. The transplacental gradient was significantly higher in intrauterine growth retarded than appropriate-for-gestational-age pregnancies for both POC2 and PCO2. There was a lower uterine oxygen extraction in intrauterine growth retarded pregnancies (p less than 0.05). CONCLUSION: There is no consistent relationship between placental venous drainage in each uterine vein and placental location. The human placenta simulates a relatively inefficient venous equilibrator and the larger transplacental gradients in intrauterine growth retarded pregnancies may reflect differences in both perfusion pattern and placental structure.

Blood Gas Analysis↗
PubMed1980

[New placental protein (PP15) with immunosuppressive properties (author's transl)].

The isolation and characterization of a new placental protein (PP15) which has immunosuppressive properties are described. The protein was purified from extracts of human term placentae by rivanol and ammonium sulfate fractionation, gel filtration, ion exchange chromatography, preparative zone electrophoresis, and chromatography on hydroxyapatite. PP15 was found to have a sedimentation coèfficient of 2.9 S and a molecular weight of 30,700 daltons as determined by ultracentrifugation; its molecules apparently are composed of two identical subunits which are held together by non-covalent bonds. The electrophorectic mobility of PP15 corresponds to that of albumin. PP15 is a glycoprotein and contains 3.3% carbohydrates (hexoses 2.8%, hexosamines 0.3%, sialic acid 0.2%). The amino acid composition of this protein was also determined: the most abundant amino acids in the peptide chain were found to be glutamic acid, aspartic acid, isoleucine, and leucine. PP15 has immunosuprressive properties: on testing its effect on the lymphoycte transformation in the MLC-test in vitro a significant inhibitory activity could be demonstrated.

Aspartic Acid↗
PubMed1991

Isolation and characterization of five new soluble placental tissue proteins (PP22, PP23, PP24, PP25, PP26).

Five new soluble placental tissue proteins (PP22, PP23, PP24, PP25, PP26) were isolated to purity from saline extracts of human term placentas and characterized by their physico-chemical properties. Specific antisera to the new proteins were obtained by immunizing animals with the corresponding purified proteins. They were used to detect and quantitate the new proteins in extracts of placentas and other human tissues by immunochemical methods such as gel diffusion tests. The immunohistochemical localization of the new proteins as well as measurement of their concentrations in body fluids by sensitive radioimmunoassays are presently under investigation.

Animals↗
PubMed1990

Partial purification and characterization of a peroxidase activity from human placenta.

Peroxidases can metabolize a variety of xenobiotics to reactive intermediates capable of binding to protein or DNA. The potential role of these enzymes in fetotoxicity has not been explored. In this study, the presence of peroxidase activity was observed in human term and pre-term placenta. Human term placental peroxidase activity (HTPP) was partially purified by concanavalin A affinity chromatography from CaCl2 extracts of the particulate fraction. HTPP appears to be a membrane-bound glycoprotein. Arachidonic acid-dependent oxidation of guaiacol was not observed, suggesting that the peroxidase activity was not due to prostaglandin synthase. Moreover, HTPP preparations were devoid of catalase and spectrally dissimilar from human haemoglobin, cytochrome P-450, eosinophil peroxidase and myloperoxidase, suggesting an endogenous origin. An Mr of approx. 119,000 was determined for HTPP by gel filtration. Cathodic slab-PAGE of cetyltrialkylammonium bromide-solubilized HTPP yielded two peroxidase-staining bands.

Chromatography, Affinity↗
PubMed1987

Measurement of thyroid hormone concentrations in human placenta.

Concentrations of thyroxine (T4), 3,5,3'-triiodothyronine (T3) and 3,3',5'-triiodothyronine (rT3) in the placenta were measured in 7 patients with abortion, in 9 patients with premature delivery, in 16 normal pregnancies and in 4 pregnant women with Graves' disease. The placentas, obtained at delivery, were homogenized and centrifuged at 800 X g. T4, T3 and rT3 concentrations in the supernatants were extracted with 3 vol. of 99% ethanol and measured by RIAs. In normal pregnancy, placental T4, T3 and rT3 concentrations were 18.8 +/- 5.9 (mean +/- SD), 0.026 +/- 0.012, and 1.70 +/- 0.49 ng/g tissue, respectively. Ratios of rT3/T3 and rT3/T4 in the placenta were about 12 and 2.3 times as high as those in the fetal sera, respectively. There was a significant positive correlation between the placental T4 and the maternal or cord serum T4 concentrations. However, no correlation was found between the placental T3 or rT3 concentrations and the maternal or cord T3 or rT3 concentrations. In 4 patients with Graves' disease, the placental T4 concentration was elevated. These results indicate that the placental T4 concentration is influenced by both the maternal and fetal serum T4, and elevated ratios of rT3/T3 and rT3/T4 in the placenta might be due to the active placental 5-monodeiodination.

Abortion, Spontaneous↗
PubMed2003

Antenatal detection of mosaic trisomy 9 by ultrasound: a case report and literature review.

This paper presents a fetus with mosaic trisomy 9 diagnosed by chorionic villus sampling and confirmed by cordocentesis, and compares this case with published cases in order better to define the ultrasound markers confined to trisomy 9 syndrome. Detailed fetal ultrasound examination was carried out, revealing shortened femur, placental cysts and oligohydramnios. All published trisomy 9 cases with abnormal ultrasound findings were extracted from the MEDLINE database in the period from 1973 to 2002. We found 12 non-mosaic and 13 mosaic cases, including our case. The most frequent ultrasound abnormalities included characteristic cardiac, skeletal, craniofacial and central nervous system malformations. Intrauterine growth restriction and single umbilical artery were prevalent non-specific findings in both non-mosaic and mosaic groups. Parental chromosomal variations, as in our case, were not uncommon findings. When a fetus shows structural anomalies suggesting the presence of trisomy 9, karyotyping should be performed on both chorionic villi or amniocytes and fetal blood lymphocytes to enable a correct diagnosis to be made.

Adult↗
PubMedDate not supplied

Heterogeneity of hepatic protein tyrosine phosphatases.

We have identified multiple members of the protein tyrosine phosphatase family in three subcellular compartments from rat liver; membrane, cytoskeleton and cytosol. Characterization based on substrate specificity, size, and reactivity with an anti-peptide antiserum against human placental PTP1B indicate the presence of at least three PTPases in Triton X-100 extracts of particulate membranes. Of these, one of 600 kDa possesses characteristics of a transmembrane, receptor-like enzyme. A fourth particulate PTPase (70 kDa) represents a distinct cytoskeletal PTPase. Cytosol contains one main PTPase species which was detected as a 41 kDa protein in Western immunoblots. These data indicate the existence of multiple hepatic PTPases whose differences in structure and subcellular localization may reflect functional heterogeneity.

Animals↗
PubMed2006

Increased plasma mRNAs of placenta-specific 1 (PLAC1) and glial cells-missing 1 (GCM1) in mothers with pre-eclampsia.

In this study we have investigated whether quantitative analysis of placental mRNAs in maternal plasma provides a way to monitor placental status. We measured plasma concentrations of human chorionic gonadotropin beta-subunit (betahCG) and human placental lactogen (hPL) mRNAs as previously reported mRNAs and pregnancy associated plasma protein A (PAPP-A), placenta-specific 1 (PLAC1) and glial cells-missing 1 (GCM1) mRNAs, which have not been measured during the course of normal pregnancy. Firstly, peripheral blood was obtained at various times from healthy pregnant women to clarify the time course of placental mRNAs. Secondly, blood was obtained from women with pre-eclampsia and gestational age-matched controls to examine whether placental mRNAs change in pre-eclampsia. Plasma was separated from these samples for extraction of RNA, followed by reverse transcription polymerse chain reaction analysis. Median concentrations of PLAC1 and GCM1 mRNA in plasma of pre-eclamptic subjects respectively were 1625 and 2141 copies/ml, significantly higher than 195 and 881 copies/ml, the values for controls (Mann-Whitney test, p<0.001). No significant difference was seen in hPL, betahCG, or PAPP-A mRNA concentration between pre-eclamptic and control groups. Plasma PLAC1 and GCM1 mRNAs appear promising as noninvasively measurable molecular markers for pre-eclampsia.

Adult↗
PubMed1989

[Isolation of calphobindin-II and its mechanism of anticoagulant activity].

In addition to calphobindin-I (a placental coagulation inhibitor), another anticoagulant protein (calphobindin-II) was isolated from the EDTA extract of human placenta. The purified protein had a molecular weight of 68,000 daltons according to sodium dodecyl sulfate polyacrylamide gel electrophoresis under both reduced and non-reduced conditions. This protein prolonged prothrombin time, activated partial thromboplastin time and recalcification time, but did not affect thrombin time. This substance also inhibited both factor X activation by a complex of [factor VII-tissue factor-Ca2+] and factor II activation by a complex of [factor Xa-phospholipid-Ca2+]. This protein was a stronger anticoagulant than calphobindin-I.

Annexins↗
PubMed1984

[The effect of calf blood dialysate on the excretion of estriol in placental insufficiency].

The efficacy of a dialysate of calf blood in the treatment of chronic placental insufficiency is assessed using the urinary oestriol elimination as parameter. Compared with a control group, those cases receiving 2 times 250 ml protein-free dialysate of calf blood (Solcoseryl) in saline solution over 9 days showed a significant increase in the daily quantity of urinary oestriol elimination already from the second day of treatment onwards. Other conventional procedures in the medical treatment of placental insufficiency are discussed. Some of these are known to have secondary effects or must be regarded as invasive.

Actihaemyl↗
PubMed1980

Primary culture of human mammary epithelial cells embedded in collagen gels.

Human mammary epithelial cells were dissociatd from mastectomy tissues. The contaminating fibroblasts were removed by the use of Percoll density-gradient centrifugation, which utilizes the difference in buoyant densities between epithelial cells and fibroblasts. A preparation highly enriched for mammary epithelial cells ws then embedded in collagen gel and cultured in Ham's F12 medium containing 12.5% horse serum, 2.5% fetal calf serum, 0.1 microgram cholera toxin/ml, an extract prepared from human male urine (L microgram protein/ml), and a hormone combination of 10 microgram insulin/ml, 10 microgram human placental lactogen/ml, 1 microgram aldosterone/ml, and 0.5 microgram hydrocortisone/ml. Sustained growth leading to an increase of tenfold to thirtyfold in cell number over the initial value was accomplished in primary culture, and this growth was maintained even after passage to secondary culture. Deletion of either the urine extract or the hormone combination resulted in less than optimal growth. Subsequent studies showed that hydrocortisone alone could replace the hormone combination. In addition, urine extract could be replaced by extracts prepared from human kidneys or brains. The collagen gel system provies a reproducible and consistent method for sustained three-dimensional growth of mammary epithelial cells from human breast tissue in primary as well as passaged cultures.

Aldosterone↗
PubMed1992

The effect of placental management at cesarean delivery on operative blood loss.

OBJECTIVES: The effect of alternative methods of placental delivery at cesarean section on blood loss has not been reported. The hypothesis of this study was that spontaneous expulsion of the placenta would reduce operative blood loss, compared with that of manual extraction during cesarean delivery. STUDY DESIGN: We prospectively randomized and compared outcomes of 62 gravid women with manual (n = 31) or spontaneous (n = 31) placental delivery at cesarean section. Operative blood loss was measured directly. RESULTS: Blood loss measured at cesarean delivery was greater in the manually delivered group (967 +/- 248 ml) than in the spontaneously delivered group (666 +/- 271 ml, p < 0.0001). The incidence of postpartum endometritis was sevenfold greater in the manual than the spontaneous group (23% vs 3%, respectively; p < 0.05). CONCLUSIONS: We conclude that spontaneous expulsion of the placenta at cesarean delivery results in less operative blood loss and a lower incidence of postoperative endometritis.

Adult↗
PubMed1989

Human placental sterylsulfatase: immunocytochemical and biochemical localization.

Human placental sterylsulfatase was localised in situ by light and electron microscope immunocytochemical techniques as well as in homogenate and tissue extract fractions by enzyme assays. Light microscope observations on frozen sections of term and preterm placenta revealed sterylsulfatase immunoactivity primarily in the syncytiotrophoblast. Electron microscope observations confirmed the light microscope findings; in addition, they showed that the sulfatase is present in the endoplasmic reticulum of endothelial cells, too. In the syncytiotrophoblast, the enzyme was detectable in the cytoplasmic membrane of the nuclear evelope, in the membranes of the rough endoplasmic reticulum, in the plasma membrane with predominant localisation in coated pits, and in the membranes of endosomes and multivesicular bodies; little or no reactivity was detectable over the membranes of the Golgi complex and of lysosomes. Sterylsulfatase immunoactivity was absent in placentas with hereditary sterylsulfatase deficiency. The observations indicate that human placental sterylsulfatase is normally present in the membranes of compartments along the secretory pathway and the endocytic route of cells lining the fetal and maternal blood. Homogenates of normal term placenta as well as membrane vesicle preparations obtained by extraction of trophoblast tissue with isotonic saline were fractionated by differential centrifugation; the fractions were assayed for specific activities of sterylsulfatase and several marker enzymes of cellular topography. In agreement with our immunocytochemical findings, the results of these biochemical localisation experiments indicate the repeatedly described association of the placental sterylsulfatase with microsomal membranes but also point to the presence of the enzyme's activity in the microvillous plasma membrane of the syncytiotrophoblast. This localisation of sterylsulfatase may have functional implications in the placental uptake of circulating steroid sulfates.

Arylsulfatases↗