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PubMed2003

Differential expression of placenta growth factors and their receptors in the normal and pregnancy-induced hypertensive human placentas.

Placental development requires extensive angiogenesis and the invasion of the maternal decidua by the trophoblasts. Adequate and organized interaction of vascular endothelial growth factors (VEGF), placenta growth factors (PlGF), and their receptors are essential for a normal development and function of the placenta. In this study, we evaluated the expressions of PlGFs and their receptors, mRNAs by Northern blotting, in situ hybridization and RT-PCR in the normal and pregnancy-induced hypertensive (PIH) placentas. The expression level of PlGF-2 mRNA was lower in the PIH placentas compared to control as assessed by Northern blotting and in situ hybridization. PlGF mRNA was mainly localized to the vasculosyncytial membrane of placental villi and villous stroma. The expression of PlGF receptor-1 (PlGFR-1) was significantly increased in the PIH placentas compared to the normal ones. These results suggest that the alteration of PlGF-2 and PlGFR-1 mRNA expressions in the placenta are related to the pathogenesis of PIH.

Female↗
PubMed1990

[Continuous ultrasonic observation on the change of location of placenta in placenta previa].

Placenta previa was studied in 50 cases during 20-28 weeks of gestation by ultrasonic scanning. The change of location of placenta was monitored continuously for these cases. The rates of change of location to normal sites were 90% for low-lying placenta, 65% for marginal implantation, 13% for partial placenta previa and 11% for central placenta previa. It is suggested that partial or central placenta previa observed during mid-trimester should be categorized as a high risk state.

Female↗
PubMed1980

Abruptio placentae and placenta previa: frequency, perinatal mortality, and cigarette smoking.

Abruptio placentae and placenta previa are responsible for at least half the excessive fetal and neonatal death associated with maternal smoking during pregnancy. Data from a large prospective study were analyzed to determine if stopping smoking reduced the frequency of these disorders. Mothers who stopped smoking had a 23% lower frequency of abruptio placentae and a 33% lower frequency of placenta previa than women who continued to smoke during pregnancy. The mothers who stopped smoking had only about half as many fetal and neonatal deaths due to abruptio placentae and one third fewer losses to placenta previa than did nothers who continued to smoke. These seeming benefits of stopping smoking were greatest in mothers 30 years of age and older.

Abruptio Placentae↗
PubMed1977

[Quantitative investigations of the human placenta under normal conditions and in case of preeclampsia correlated to the human placenta-lactogen blood-level in the last third of pregnancy (author's transl)].

Thirty-two human placentas from normal and from pregnancies complicated by preeclampsia in last third of gestation were morphologically and morphometrically examined and correlated with human placenta-lactogen blood-level. HPL was determined by the radio-immunoassay (Carbon-Dextran-method). HPL-values, placenta villous surface, the weight of the newborn and placenta showed significant correlation. The placentas were classified according to the morphologic degree of severity (placenta-morphological-index) and compared to preeclamptic index (Goecke) and HPL-values. The results showed correlation between the studied datas according to the severity of preeclampsia. The significance of these results is discussed.

Birth Weight↗
PubMed1983

Placenta flow index in posterior wall placentas measured with 99mtechnetium-labelled human serum albumin.

Measurement of the perfusion of posterior wall placentas with the isotope technique may pose a problem owing to attenuation of the gamma radiation. The present investigation compares the placenta flow index (PFI) in 34 pregnant women with anterior wall placenta and 13 with posterior wall placenta. We found no difference in the shortest skin-to-placenta distance on ultrasound scanning and no difference in PFI between the anterior and the posterior wall placentas.

Adult↗
PubMed1976

Monoamine oxidase in rat placenta, human placenta, and cultured choriocarcinoma.

The activity of monoamine oxidase (MAO), an enzyme which metabolized catecholamines and indoleamines, was determined in rat placenta at various stages of gestation, in human term placenta, and in choriocarcinoma grown in culture. From Day 15 to Day 20 of gestation the specific activity (units/mg protein) of MAO in rat placenta increased at least 3-fold; from Day 20 to the time of parturition, it decreased about 50%. The specific activity of MAO in human placenta at term was about 50%. The specific activity of MAO in human placenta at term was about 8 times higher than that of rat placenta at term. No MAO activity was found in choriocarcinoma grown in culture.

Animals↗
PubMed1975

Relationship of the sex of the foetus to the amount of human chorionic gonadotrophin in placentae; single and dizygotic twin placentae compared.

Human chorionic gonadotrophin (HCG) was assayed by biological and radioimmunological methods in placentae from 16 women with a normal twin pregnancy. When the concentration and total amount of HCG in placentae was related to the sex of the twin foetus, no significant difference between 'male' and 'female' placentae was found. This is contrary to findings that there is a significant (P less than 0-005) difference in the concentration of HCG per g and per placenta of singletons at term. A comparison between the grouped geometric mean data from bioassays shows that the amount of HCG per g and per placenta falls between the geometric mean values for 'male' and 'female' singleton placentae.

Adult↗
PubMed1983

Biochemical studies on collagen in human placenta--relation of collagen to the construction and function of human placenta.

Contents and relating biosynthetic enzyme activities of collagen in human placenta were studied, and its characteristics and possible role were discussed. Main results were as follows. Hydroxyproline contents of the normal placenta in the 1st, 2nd and 3rd trimester were 7.2 +/- 1.1, 14.6 +/- 4.4 and 23.4 +/- 4.8 micrograms/mg protein, respectively, and increased linearly as the pregnancy progressed (p less than 0.01, r = 0.8753). Among cases of abnormal pregnancy, one of three cases of intrauterine stillbirth and cases of light-for-date baby pregnancy with severe toxemia showed significantly higher hydroxyproline content than those of others. Prolyl hydroxylase activities of the normal placenta in the 1st, 2nd and 3rd trimester were 1048.2 +/- 174.0, 381.2 +/- 76.7 and 277.9 +/- 103.7 c.p.m/mg protein, respectively. Significantly higher activities were found in the 1st trimester than in the 2nd and 3rd trimesters (p less than 0.01). In abnormal pregnancy, the activities of the light-for-date baby with severe toxemia were significantly higher levels than those of others (p less than 0.05). These results may suggest that the collagen in the human placenta is not only concerned with developmental construction of the placenta, but also associated with complicated metabolic function of the placenta as well.

Collagen↗
PubMed2006

Differential expression of angiopoietin-1, angiopoietin-2, and Tie receptors in placentas from pregnancies complicated by placenta accreta.

OBJECTIVE: The purpose of this study was to investigate the differential expression of angiopoietin-1, angiopoietin-2, and Tie receptors (Tie-1 and Tie-2) in placentas from pregnancies complicated by placenta accreta. STUDY DESIGN: Paraffin sections of 46 placental specimens with (cases) and 46 without (controls) placenta accreta were studied immunohistochemically for the expression of Tie receptors and angiopoietin-2 in trophoblast populations. Protein levels of Tie receptors and angiopoietins were also examined by Western blot analysis and/or enzyme-linked immunosorbent assay. Controls were matched for gestational age in this case-control study. RESULTS: In both second and third trimesters, the percentage of intermediate/strong immunoreactivity of Tie-2 in the syncytiotrophoblast was significantly lower in cases than controls (P = .015 and .025, respectively). However, Tie-2 expression in the cytotrophoblastic and extravillous trophoblastic cells and Tie-1 in all trophoblast subpopulations were not significantly different between cases and controls (P > .05). The majority of Tie-2 expression, as demonstrated by Western blots, was consistent with the trends of immunohistochemical findings in the syncytiotrophoblast. Enzyme-linked immunosorbent assay in the placental lysates showed that women with placenta accreta demonstrated significantly higher angiopoietin-2 and lower Tie-2 concentrations than did women with normal pregnancies (P = .026 and .003, respectively). Placental angiopoietin-1 levels did not have any significance (P > .05). Also, angiopoietin-2 immunoreactivity in the syncytiotrophoblast was compatible with the finding demonstrated by enzyme-linked immunosorbent assay (P = .005 and .012, respectively). CONCLUSION: These observations suggest that the participation of up-regulated angiopoietin-2 and down-regulated Tie-2 in the placental tissues may indicate a role for these angiogenic factors in the development of placenta accreta.

Angiopoietin-1↗
PubMed1994

Autologous blood transfusion for the patient with placenta previa complicated by placenta increta: a case report.

The patient, who was 34 years of age, had previously had a transverse incision of the lower uterine segment cesarean section because of placenta previa. She was admitted to the hospital due to placenta previa again at 27 weeks of gestation in the current pregnancy. Ultrasound examination revealed placenta increta as well as placenta previa. In an attempt to avoid homologous blood transfusion at the time of profuse hemorrhage anticipated to occur during cesarean section, an autologous blood transfusion was planned. Fifteen hundred ml of autologous blood was collected by a leap-frog method during the 8 weeks prior to cesarean section. A cesarean hysterectomy was performed at 37 weeks of gestation because of placenta increta. Blood loss was estimated at 1,830 ml, and 1,500 ml of autologous blood was transfused. A leap-frog method of autologous blood collection for this pregnant woman with risk of massive hemorrhage was simple and beneficial, resulting in the preservation of more than 1,500 ml of autologous blood for transfusion.

Adult↗
PubMed1992

Placenta accreta: prospective sonographic diagnosis in patients with placenta previa and prior cesarean section.

A prospective evaluation for possible placenta accreta was performed in 34 patients with placenta previa and a history of one or more cesarean sections. Sonographic criteria used included (1) loss of the normal hypoechoic retroplacental myometrial zone, (2) thinning or disruption of the hyperechoic uterine serosa-bladder interface, and (3) presence of focal exophytic masses. Of 18 patients with positive sonographic results, 14 had proof of placenta accreta and 16 of the patients underwent hysterectomy. Of 16 patients with negative sonographic results, only one had placenta accreta, and two patients required hysterectomy. Presence of numerous intraplacental vascular lacunae appears to be an additional risk criterion for placenta accreta, separate from the other criteria listed above.

Cesarean Section↗
PubMed2005

Expression of placenta growth factor mRNA in the rat placenta during mid-late pregnancy.

The placenta is an essential organ that synthesizes several growth and angiogenic factors for its own growth as well as fetal development. It is known that the placenta growth factor (PlGF)is a member of the vascular endothelial growth factor family and is critical for placental growth and fetal development. However, there is little information regarding the expression pattern and cellular localization of PlGF mRNA in rat placenta during pregnancy. The aim of this study was to define the distribution of PlGF mRNA in rat placenta at various gestations. RT-PCR analysis showed that the expression level of PlGF mRNA increased as gestation advanced. Using in situ hybridization histochemistry, positive cells of PlGF mRNA were detected in chorionic villi. PlGF mRNA was expressed in the trophoblast cells and stroma cells surrounding the blood vessels within chorionic villi on day 13 and 15. Also, positive signals of PlGF mRNA were strongly detected in stroma cells of chorionic villi on day 17, 19, and 21. In particular, the density and number of positive signals of PlGF mRNA was significantly increased as gestation advanced. The expression pattern of PlGF mRNA in rat placenta during pregnancy demonstrates that PlGF plays a functional role for placental growth and fetal development during mid-late pregnancy.

Animals↗
PubMed1991

A normal 46,XX infant with a 46,XX/69,XXY placenta: a major contribution to the placenta is from a resorbed twin.

A predominantly triploid 69,XXY placenta was found associated with a normal 46,XX infant. Therefore, a triploid placenta is apparently capable of supporting normal fetal development. The chromosome and pathological results support the conclusion that the triploid placenta originates from a 'vanishing twin' pregnancy. This case is unusual in that persistence of the placenta from the vanished twin has virtually replaced most of the normal placenta.

Amniocentesis↗
PubMedDate not supplied

Serum- and cell-mediated immune protection of mouse placenta and fetus against a Brucella abortus challenge: expression of barrier effect of placenta.

When mice are intravenously inoculated with a virulent Brucella abortus strain at day 12 to 14 of pregnancy and killed three to five days later, colonization of placentae, fetuses and spleens can be estimated by the frequency and level (bacterial count) of infection and by linkage between individual placental and paired fetal infections. This linkage indicates the placental barrier effect, defined as the number of non-infected fetuses linked to 100 colonized placentae. Immune mice serum raised against two Brucella fractions injected one day before challenge (1) restricted the placental colonization (the dose required to infect 50 per cent placentae was increased by 50 to 70 times compared to controls), (2) decreased the level of splenic and placental infection, and (3) increased the barrier effect so that most fetuses were protected even when linked to a heavily infected placenta. Immune (B + T) spleen cells from mice vaccinated with a Brucella cell-wall fraction transferred to recipients seven to eight days before mating, that is, 22 days before challenge (1) restricted the frequency of placental and fetal colonization, (2) decreased the level of splenic, placental and fetal infections, and (3) increased the barrier effect. However, separated B- and T-cells were less active, in particular on the level of fetal infection. In contrast with serum, the cells did not decrease infection of the fetuses linked to heavily infected placentae.

Animals↗
PubMed2004

Elective non-removal of the placenta and prophylactic uterine artery embolization postpartum as a diagnostic imaging approach for the management of placenta percreta: a case report.

BACKGROUND: Placenta percreta, invasion of placental tissue through the uterine wall, is a rare but potentially fatal complication of pregnancy. Historically, the diagnosis was made at laparotomy, usually during Caesarean hysterectomy. CASE: We describe a case of placenta percreta, in which the placenta was allowed to remain fixed to the uterine wall. Antenatal ultrasound and magnetic resonance imaging techniques were used to establish the diagnosis and guide clinical management. Elective postoperative uterine artery embolization down balloon catheters was used to prevent postpartum hemorrhage and to promote involution and shedding of the placenta. After 6 months, the uterus had involuted to the nonpregnant state. CONCLUSION: New diagnostic imaging techniques may be used to guide conservative management of placenta percreta, thereby maintaining fertility and avoiding hemorrhage, blood transfusion, and hysterectomy.

Adult↗
PubMed2000

Characterization of proteoglycans of human placenta and identification of unique chondroitin sulfate proteoglycans of the intervillous spaces that mediate the adherence of Plasmodium falciparum-infected erythrocytes to the placenta.

In pregnant women infected with Plasmodium falciparum, the infected red blood cells (IRBCs) selectively accumulate in the intervillous spaces of placenta, leading to poor fetal outcome and severe health complications in the mother. Although chondroitin 4-sulfate is known to mediate IRBC adherence to placenta, the natural receptor has not been identified. In the present study, the chondroitin sulfate proteoglycans (CSPGs) of human placenta were purified and structurally characterized, and adherence of IRBCs to these CSPGs investigated. The data indicate that the placenta contains three distinct types of CSPGs: significant quantities of uniquely low sulfated, extracellular CSPGs localized in the intervillous spaces, minor amounts of two cell-associated CSPGs, and major amounts of dermatan sulfate-like CSPGs of the fibrous tissue. Of the various CSPGs isolated from the placenta, the low sulfated CSPGs of the intervillous spaces most efficiently bind IRBCs. Based on IRBC adherence capacities and localization patterns of various CSPGs, we conclude that the CSPGs of the intervillous spaces are the receptors for placental IRBC adherence. The identification and characterization of these CSPGs provide a valuable tool for understanding the precise molecular interactions involved in placental IRBC adherence and for the development of therapeutic strategies for maternal malaria. In the accompanying paper (Alkhalil, A., Achur, R. N., Valiyaveettil, M., Ockenhouse, C. F., and Gowda, D. C. (2000) J. Biol. Chem. 275, 40357-40364), we report the structural requirements for the IRBC adherence.

Amino Acids↗
PubMed1996

Expression of insulin-like growth factor-II and IGF-binding protein-1 mRNAs in term rhesus monkey placenta: comparison with human placenta.

The patterns of expression insulin-like growth factor-II (IGF-II) and IGF-binding protein-1 (IGFBP-1) mRNAs were compared between term human and rhesus monkey placenta using in situ hybridization histochemistry. Since IGFs and IGFBPs are paracrine factors, the identification of the sites of synthesis of the IGFs and their binding proteins indicate the potential sites of biological action. In both species, IGF-II mRNA was found in highest abundance in the extravillous cytotrophoblasts. The major difference was observed in placental villi. In the human placenta, IGF-II mRNA was expressed in the chorionic mesoderm of the placental villi, whereas, in the rhesus placenta, it was expressed in the syncytiotrophoblasts and not in the chorionic mesoderm. In both species, IGFBP-1 mRNA was expressed only in the decidua. Therefore, the pattern of expression of IGFBP-1 mRNA in the maternal decidua is similar between rhesus monkey and human placenta, but that of IGF-II mRNA in the fetal placental villi is different. These data suggest that the IGF-II-IGFBP-1 interaction in the paracrine regulation of placental growth and/or function in the rhesus monkey and human placentae may have similarities and differences.

Animals↗
PubMed1998

Comparison of expression patterns for placenta growth factor, vascular endothelial growth factor (VEGF), VEGF-B and VEGF-C in the human placenta throughout gestation.

Angiogenesis and vascular transformation are important processes in the normal development of the placenta. Vascular endothelial growth factor (VEGF) is a potent angiogenic growth factor and is thought to be important for placental development. Recently several new members of this family have been described. In this study we used in situ hybridisation to localise which cells in the placenta expressed mRNA for VEGF, placenta growth factor (PlGF), VEGF-B and VEGF-C. We were unable to find any message for either VEGF-B or VEGF-C in the placenta, suggesting that only low levels are produced which this method was unable to detect. The mRNA encoding VEGF was found to be produced by cells within the villous mesenchyme, decidual macrophages and decidual glands but, in contrast to our previous findings, not by trophoblast. The mRNA encoding PlGF was produced in large amounts by villous cytotrophoblast, syncytiotrophoblast and extravillous trophoblast. The mRNAs encoding VEGF and PlGF were thus not co-localised and it appears that there is unlikely to be any significant production of VEGF/PlGF heterodimer in the placenta.

Blotting, Northern↗