Development of a purification procedure for the placental protein 14 involving metal-chelate affinity chromatography and hydrophobic interaction chromatography

Placental protein 14 was isolated from the biological material of patients undergoing legal abortions. The major part of ballast protein was removed by ion-exchange chromatography on DEAE-Sepharose and CM-Sepharose. Albumin was separated by chromatography on Blue-Sepharose. Complete purification was obtained by metal-chelate affinity chromatography on Nickel-Chelate Sepharose and hydrophobic interaction chromatography on Phenyl-Sepharose and Octyl-Sepharose. The protein was not exposed to denaturing agents or extreme pH.     

Microtubule organization in the differentiating transfer cells of the placenta inLilium spp.

Summary Placental cells in the ovarian transmitting tissue ofLilium spp. are organized as transfer cells with inbuddings facing the ovarian locule. A detailed analysis of microtubule (MT) organization during development of these polarized cells is reported here. Formation of wall projections occurs at the apical part of the cell starting on the day of anthesis, and a fully mature secretion zone is found four days after anthesis. MTs are organized into distinct cortical and central arrays. The cortical array undergoes a unique transition at anthesis. MTs in the basal half of the cell remain in longitudinal bundles while in the apical half of the cell their longitudinal orientation is replaced by a transverse alignment. One day after anthesis, these transverse bundles become a meshwork of short, randomly organized MTs, while MTs in the basal half of the cell retain their longitudinal alignment. The realignment of MTs in the apical half of the cell coincides with the deposition of the secondary cell wall. The central array is composed of short, randomly arranged strands of MTs in the cytoplasm between the nucleus and the apical and basal periclinal walls of the cell. This array first appears as solitary strands in the apical part of the cell one day before anthesis. The central array extends during development and is eventually seen in the basal half of the cell. We propose that MTs in the cortical region near the apical wall act as templates for the deposition of cellulose microfibrils in the secondary cell wall. MTs in the central array in these transfer cells may be involved in the trafficking of vesicles and/or positioning of organelles near the secretion zone.Abbreviations MT microtubule - daa day after anthesis - dba day before anthesis     

Remarkably high rate of molecular evolution of ruminant placental lactogens

The sequences of ovine and bovine placental lactogens (based on published cDNA sequences) are remarkably different, indicating a very rapid rate of evolution. Analysis of the cDNA sequences indicates that the rate of nonsynonymous substitution in these proteins is considerably greater than the rate of synonymous substitution. This is an unusual situation, which suggests that the observed rapid rate of evolution is due to incorporation of adaptive rather than neutral mutations.     

In vivo development of vitrified rabbit embryos: Effects on prenatal survival and placental development

The aim of this work is to study the effect of the vitrification procedure on prenatal survival and on placental development at the end of gestation in rabbits (Oryctolagus cuniculus). One hundred eighty-one females were slaughtered at 72 h of gestation. Morphologically normal embryos recovered at 72 h of gestation were kept at room temperature until transfer or vitrification. Vitrified embryos (320 embryos) were transferred into a total of 24 does and fresh embryos (712 embryos) were transferred into a total of 43 does. Females were induced to ovulate 72 h before transfer when fresh embryos were transferred and 60 to 63 h before transfer when vitrified embryos were transferred. Each recipient doe received eight embryos into the left oviduct and eight embryos into the right oviduct. The number of implanted embryos was estimated by laparoscopy as number of implantation sites at Day 14 of gestation. Recipient females were slaughtered by stunning and exsanguination 25 d after the transfer, and fetuses were classified according to their status. Live fetuses and fetal and maternal placenta were weighed Pregnancy rate was defined as the total number of females having at least one live fetus at Day 28 of gestation divided by the total number of females. Prenatal survival was estimated as live fetuses at Day 28 of gestation divided by the number of transferred embryos. The pregnancy rate after transfer of vitrified embryos (92%) was similar to that achieved with fresh embryos (86%), but prenatal survival was lower for vitrified than for fresh embryos (53% vs. 34%). We did not find differences in embryo survival from 72 h to implantation. Transfer of vitrified embryos reduced fetal survival from implantation to Day 28 (57% vs. 82%). Differences in the number of live fetuses at Day 28 of gestation were mainly due to the higher fetal mortality observed soon after implantation in pregnancies resulting from the transfer of vitrified embryos. A higher percentage of decidual reactions and atrophic maternal placentas (27.5% vs. 8.3%) and also of atrophic fetal and maternal placentas (12.1% vs. 5.3%) were observed after transfer of vitrified embryos. Both treatments showed similar percentage of dead fetuses (3.3% vs. 4%). Maternal placenta of the fetuses from fresh embryos was 15% heavier than maternal placenta of fetuses from vitrified embryos.     

P16抑癌基因在人完全性葡萄胎和正常胎盘组织中的表达

目的研究P16抑癌基因与葡萄胎发生的关系。方法分别取完全性葡萄胎和正常早孕流产标本各30例,用SABC免疫组织化学染色方法,检测P16抑癌基因在两种组织中的表达,并采用图像分析技术,对正常早孕绒毛组和葡萄胎组P16抑癌基因的表达情况进行对比分析。结果与正常绒毛相比,P16抑癌基因在完全性葡萄胎组织中的表达部位和表达量有显著性差异。结论P16抑癌基因与人完全性葡萄胎发生密切相关。     

Use of phospholipid transfer protein as a probe to study the lipid dynamics and alkaline phosphatase activity in the brush border membrane of human term placenta

Incubation of placental brush border membrane (BBM) along with sonicated vesicles of exogenous lipids (egg yolk PC) in the presence of phospholipid-transfer protein (PL-TP) showed a decrease in the alkaline phosphatase activity due to the change in the membrane micro-environment, such as fluidity. Effect of substrate concentration was tested by Lineweaver-Burk plot, which showed decreased V(max) and K(M). The effect of temperature was probed by the Arrhenius plot, which showed no change in transition temperature, but a decline in the energy of activation both below and above the transition temperature. The protein-catalyzed transfer of phospholipid from the donor unilamellar vesicles resulted in a substantial increase in the BBM phospholipid and a net decrease in cholesterol/phospholipid molar ratio. The change in membrane fluidity was assessed by translational as well as rotational diffusion of membrane extrinsic fluorescent probes, pyrene and diphenyl-hexatriene. An increased lateral mobility was recorded by the increased pyrene excimer formation. A decrease in fluorescent polarization of diphenyl-hexatriene was observed, which led to the decrease in fluorescence anisotropy and order parameter, and therefore, an increase in membrane fluidity (rotational diffusion). Mean anisotropy parameter was also decreased in the presence of PL-TP. Thus, the placental BBM alkaline phosphatase activity showed a distinct lipid dependence which may have important physiological consequences.     

Dynamic tensile properties of human placenta

Automobile crashes are the largest cause of injury death for pregnant females and the leading cause of traumatic fetal injury mortality in the United States. Computational models, useful tools to evaluate the risk of fetal loss in motor vehicle crashes, are based on a limited number of quasi-static material tests of the placenta. This study presents a total of 20 dynamic uniaxial tensile tests on the maternal side of the placenta and 10 dynamic uniaxial tensile tests on the chorion layer of the placenta. These tests were completed from 6 human placentas to determine material properties at a strain rate of 7.0 strains/s. The results show that the average peak strain at failure for both the maternal portion and the chorion layer of the placenta are similar with a value of 0.56 and 0.61, respectively. However, the average failure stress for the chorion layer, 167.8 kPa, is much higher than the average failure stress for the placenta with the chorionic plate removed, 18.6 kPa. This is due to differences in the structure and function of these layers in the placenta. In summary, dynamic loading data for the placenta have been determined for use in computational modeling of pregnant occupant kinematics in motor vehicle crashes. Moreover the computational model should utilize the material properties for the placenta without the chorion layer.     

78例胎盘早剥临床分析

目的：探讨胎盘早剥的诱发因素、手术方式和临床处理方法。方法：采用回顾性病例分析的方法,对2010年6月至2012年1月在我院妇产科接受治疗的78例胎盘早剥患者的临床资料进行统计,分析胎盘早剥的诱因、临床分度及处置原则。结果：诱发因素：妊娠期高血压病占第1位,胎膜早破为第2位,妊娠期合并糖尿病为第3位。此外,羊水过多、妊娠合并子宫肌瘤、外伤等也是引起胎盘早剥的因素。在78例胎盘早剥患者中,重度的有18例,中度的有32例,这50例患者全用采取剖宫产进行处置。另有28例为轻度胎盘早剥,其中6例采用阴道分娩。结论：胎盘早剥以妊娠期高血压、胎膜早破、妊娠期糖尿病为主要发病诱因,中重度胎盘早剥一般用剖宫产终止妊娠,轻度胎盘早剥可部分用阴道分娩。     

Chitosan coating does not prevent the effect of the transfer of green silver nanoparticles biosynthesized by Streptomyces malachitus into fetuses via the placenta

Green synthesized nanoparticles are more advantageous over conventionally prepared ones due to less toxicity, production cost, and environmental hazards. With the widespread of the utilization of nanoparticles, little is known about the maternal-fetal transplacental transfer of green nanoparticles. We have biosynthesized silver nanoparticles using metabolites of Streptomyces malachitus and sunlight then coated them with chitosan. These nanoparticles have been characterized and intraperitoneally administered at doses of 100 mg/kg on the 6^th, 8^th, and 10^th gestational days. On the 18^th day of pregnancy, both coated and non-coted NPs were detected in different maternal tissues, placenta, and in fetuses, as determined by estimation of silver content and observation by electron microscopy. Chitosan coating decreased the silver content in different tissues, maybe due to the larger size of coated nanoparticles that retards the transfer. The toxic effects on maternal and fetal tissues were proportional to their silver content, as determined by the liver and kidney functional analysis of pregnant rats and the ultrastructural and histopathological examination of the maternal liver, placenta and fetal liver. The present data suggest that green silver nanoparticles biosynthesized by Streptomyces malachitus cross the placenta and have toxic effects on maternal tissues, placenta, and fetus. Chitosan coating of these nanoparticles decreases the transfer, and consequently, the toxicity. However, it does not prevent this toxicity.