Transfer of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 across the perfused human placenta

The rates of placental transfer of 25-hydroxyvitamin D3 [25-(OH)D3] and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] were determined in an in vitro perfusion system. Antipyrine was included in each perfusion, and the data are expressed as clearance index, the ratio of hydroxyvitamin D3 to antipyrine clearance. In most experiments, serum, 0.2%, was added to the perfusates as a source of vitamin D3-binding protein. Binding as measured by dextran-coated charcoal assay for 25-(OH)D3 was over 90%, for 1,25-(OH)2D3, only 25% to 50%. The clearance index from the maternal to fetal circulation averaged 0.02 and 0.26 for 25-(OH)D3 and 1,25-(OH)2D3, respectively. When vitamin D3-binding protein was omitted from the perfusate, the clearance indices of 25-(OH)D3 were 0.12 and 0.46 in two experiments. Binding to vitamin D3-binding protein is a major determining factor for the transfer rates of 25-(OH)D3 and 1,25-(OH)2D3.     

3D打印模型在复杂型胎盘植入患者子宫切除术中的应用价值

目的 探讨个体化3D打印模型在复杂型胎盘植入患者子宫切除术中的应用方法及意义。方法 2014年1月广州医科大学附属第三医院产科收治复杂性胎盘植入1例,患者在术前行盆腔MRI扫描,获取原始图像后利用数字化医疗三维设计软件对其子宫、胎盘、膀胱进行三维重建。将构建的胎盘植入数字化三维模型行体外手术设计用于指导手术。结果 手术过程中根据术前3D模型预演指示,采用经后路子宫切除术,精确完整的将子宫切除,手术过程顺利。结论 构建的个体化3D打印模型、开展手术前手术方式设计对胎盘植入的手术治疗具有较大的术前和术中指导意义,可使手术过程更加精确化。     

Characterization of 1,25-dihydroxyvitamin D3 receptors and in vivo targeting of [3H]-1,25(OH)2D3 in the sheep placenta

We sought to detect the presence of receptors for 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] in placental tissues of five late gestational pregnant sheep and to quantitate their biochemical properties and abundance. Cytosol prepared from cotyledonary tissue was found to contain two [3H]-1,25(OH)2D3 binding macromolecules that sedimented at 3.2 S and 4.1 S, respectively, on linear (4-20 per cent) hypertonic sucrose gradients. The 4.1 S component cosedimented with serum that had been prelabelled with [3H]-25-hydroxyvitamin D3 (25-OHD3) and was present in cytosols despite extensive washing of the tissue prior to homogenization. Concurrent incubation of the cytosol with [3H]-1,25(OH)2D3 and a tenfold molar excess of radioinert 25-OHD3 resulted in complete resolution of the 3.2 S macromolecule and disappearance of the 4.1 S binding component. The binding of [3H]-1,25(OH)2D3 to the 3.2 S component was completely abolished by coincubation with a 100-fold molar excess of radioinert 1,25(OH)2D3 and was replaced by a well resolved peak in the 4.1 S region. Scatchard analysis of cytosol binding to [3H]-1,25(OH)2D3 in the presence of a tenfold molar excess of radioinert 25OHD3 revealed a single class of non-interacting saturable binding site in the cotyledon and the endometrium of high affinity and low capacity. The mean +/- s.e. of the dissociation constant of the cotyledonary receptor of 0.21 +/- 0.06 nM was not different from that of 0.16 +/- 0.03 nM for the endometrial receptor. However, the abundance of the cotyledonary receptor was fourfold higher than that in the endometrium (110 +/- 20 versus 28 +/- 7 fmol/mg protein). Since it is not possible to completely separate endometrial tissue from cotyledonary tissue, the low abundance of receptor in endometrial cytosols may merely represent contamination of endometrial tissue with cotyledonary tissue. Further analysis of the [3H]-1,25(OH)2D3 occupied receptor in cotyledonary cytosols showed that it bound to DNA cellulose and was eluted with 0.16 M KCl. This in vitro binding of [3H]-1,25(OH)2D3 to DNA was confirmed in vivo by the finding of preferential nuclear targetting of [3H]-1,25(OH)2D3 (56 per cent of total cellular activity), 4 h after fetal intravenous administration of [3H]-1,25(OH)2D3 to five chronically catheterized fetal sheep. Total placental uptake of [3H]-1,25(OH)2D3 at this time amounted to 3.7 +/- 0.9 per cent of the injected dose. Preliminary analysis of ovine placental cytosols revealed a calcium binding protein of similar molecular weight to that found in the ovine intestine and in the intestine and placenta of rodents.(ABSTRACT TRUNCATED AT 400 WORDS)     

Diagnosis of Apert syndrome in the second-trimester using 2D and 3D ultrasound

OBJECTIVES: To illustrate how Apert syndrome, a rare autosomal dominant genetic syndrome, can be detected in the second-trimester of pregnancy using 2D ultrasound, and how 3D ultrasound examination may provide parents with a better understanding of the structural defects affecting their baby. METHODS: Fetal Medicine Unit database searches to identify Apert syndrome cases. RESULTS: Five cases of Apert syndrome were suspected in the second-trimester when sonography showed abnormal extremities including syndactyly, and an abnormal skull shape. In 1 case there was increased nuchal translucency with a normal fetal karyotype in the first-trimester. In all cases, a mutation of the FGFR2 gene confirmed the diagnosis of Apert syndrome. 3D ultrasound was used to show parents the extent of the abnormalities of the skull, face and extremities. Parents were counseled by craniofacial surgeons and geneticists. CONCLUSION: Apert syndrome can be accurately suspected in the second-trimester by careful ultrasound examination of the fetus including the extremities and skull shape. 3D ultrasound can be a useful adjunct to 2D examination for parental counseling.     

Vitamin D3 metabolites stimulate prostaglandin production by human fetal membranes and placenta in vitro

In the present study we examined whether the vitamin D3 metabolites, 25-hydroxyvitamin D and 1-25-dihydroxycholecalciferol affected the production of the prostaglandins PGE2 and PGF2 alpha in human fetal membranes and placenta in vitro. Human amnion, chorion, decidual, and placental cells were maintained in primary monolayer culture. Treatment with the vitamin D3 metabolites resulted in an increase in PGE2 and PGF2 alpha production by amnion, decidua, and placental cells; however, these effects varied with time and were different between tissues. Although there was no significant increase in the production of PGE2 and PGF2 alpha by chorion cells in vitro, there was a significant increase in the production of prostaglandin F metabolites after treatment with the vitamin D3 metabolites. The data suggest that the vitamin D3 metabolites may increase free calcium availability and the conversion of arachidonic acid to the prostaglandins. The data do not, however, exclude the possibility that the vitamin D3 metabolites act at other points of arachidonic acid metabolism. These findings raise the possibility of a paracrine role for the vitamin D3 metabolites in the modulation of prostaglandin production within the human fetal membranes and placenta.     

Determination of the copper content in healthy placenta and placenta in gestosis using atomic absorption spectrophotometry]

Several complications in pregnancy seem to be related to the fluctuations of serum copper. In particular, values of serum copper over the normal range, have been associated to pregnancies complicated by EPH-gestosis. In this study we have evaluated the copper concentration in samples of placenta from 15 gravidas affected by EPH-gestosis and from 15 healthy gravidas with atom absorption spectrophotometry. The results of our study confirm the presence of an elevated copper concentration in the EPH-gestosis patients group (mean value: 196 micrograms/100 g of placental tissue). We can hypothesize that the result is due to a reduced copper uptake from the fetus.     

D2-40/podoplanin expression in the human placenta

Placental tissue expresses many lymphatic markers. The current study was undertaken to examine if D2-40/podoplanin, a lymphatic endothelial marker, was expressed in the human placenta, and how it is altered developmentally and pathologically. We examined D2-40/podoplanin and VEGFR-3 expressions in placentas from normotensive pregnancies at different gestational ages and in placentas from women with clinically defined preeclampsia. D2-40 expression in systemic lymphatic vessel endothelium served as a positive control. Protein expression for D2-40, VEGFR-3, and β-actin was determined by Western blot in placentas from normotensive (n = 6) and preeclamptic (n = 5) pregnancies. Our results show that D2-40/podoplanin was strongly expressed in the placenta, mainly as a network plexus pattern in the villous stroma throughout gestation. CD31 was limited to villous core fetal vessel endothelium and VEGFR-3 was found in both villous core fetal vessel endothelium and trophoblasts. D2-40/podoplanin expression was significantly decreased, and VEGFR-3 significantly increased in preeclamptic placental tissues compared to normotensive placental controls. Placental villous stroma is a reticular-like structure, and the localization of D2-40 to the stroma suggests that a lymphatic-like conductive network may exist in the human placenta. D2-40/podoplanin is an O-linked sialoglycoprotein. Although little is known regarding biological functions of sialylated glycoproteins within the placenta, placental D2-40/podoplanin may support fetal vessel angiogenesis during placenta development and reduced D2-40/podoplanin expression in preeclamptic placenta may contribute to altered interstitial fluid homeostasis and impaired angiogenesis in this pregnancy disorder.     

Management of retained placenta using intraumbilical oxytocin injection

Manual removal of the placenta carries significant risk of hemorrhage and infection plus the risks associated with general anesthesia, if used. Transporting the patient from home or birthing center to hospital or from birthing room to delivery room or operating room is also disruptive to the patient and the initial parent-infant attachment process. The injection of oxytocin into the umbilical vein is a safe procedure that can cause placental separation and delivery, thus preventing the need for manual removal for some women. This technique can be useful in a nurse-midwifery practice in the management of a retained placenta or prolonged third stage of labor. The following review of current research and example of a protocol used in a nurse-midwifery service will provide guidance for incorporating this procedure into practice. As with any new technique, the need to continue to collect and publish outcome data is important.     

Prenatal diagnosis of structural fetal anomalies using 3D/4D ultrasound evaluation

The aim of the study is to investigate the possibilities of three- and four-dimensional ultrasound in the prenatal diagnosis of structural fetal anomalies. We present our first experience with this relatively new diagnostic modality and discuss its implementation into clinical practice.     

Avoiding manual removal of placenta: evaluation of intra-umbilical injection of uterotonics using the Pipingas technique for management of adherent placenta

BACKGROUND: Manual removal of placenta is performed in 1-3% of cases, and whilst a well established and relatively safe procedure, it is not without complications, which include infection, hemorrhage, uterine rupture, and occasional maternal death. METHODS: A three-arm randomized controlled trial of 50 IU Syntocinon (in 30 ml N saline) versus 800 mcg misoprostol (in 30 ml N saline) versus 30 ml N saline alone (control), injected into the placental bed via the umbilical vein using the Pipingas method. A group sequential research model (triangular test: PEST4) was adopted to minimize the sample size, as retained placenta is a relatively uncommon condition. RESULTS: No significant difference in the rate of manual removal was observed between the control and Syntocinon groups. On triggering the automatic stopping rule for this arm of the trial all subsequent cases recruited were allocated to receive either Syntocinon or misoprostol. After a total of 54 cases a significant reduction in manual removal of placenta was observed in the misoprostol group, triggering the automatic stopping rule and terminating the trial. CONCLUSION: Misoprostol (800 mcg) dissolved in 30 ml N saline and administered by intraumbilical injection using the Pipingas technique significantly reduces the need for manual removal for retained adherent placenta, whereas Syntocinon has similar effectiveness to injection of N saline alone.