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Molecular Imaging and Biology Jun 2011The purpose of this study was to develop a tool for functional phenotyping of the maternal circulation in the mouse placenta.
PURPOSE
The purpose of this study was to develop a tool for functional phenotyping of the maternal circulation in the mouse placenta.
PROCEDURES
In utero macromolecular dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was performed on embryonic day 10.5 (E10.5), E13.5, and E18.5. Fluorescence analysis was also used for validation of the results.
RESULTS
The initial rate of contrast enhancement revealed an increased maternal blood volume fraction as the pregnancy progressed. Serial imaging of E10.5 and E13.5 placentas revealed a loss of contrast enhancement due to phagocytic uptake. A key application of macromolecular DCE-MRI would be to follow mouse pregnancies during fetal and placental manipulation including embryo transfer, tetraploid complementation, and fetal resorptions. We were able to resolve strain differences in ICR outbred mice carrying both ICR and C57Bl/6J embryos and to differentiate in utero resorptions from functional placentas.
CONCLUSIONS
Our results highlight the importance of the functional in utero analysis of placental vascularization in physiological phenotyping of transgenic mice and suggest MRI, particularly macromolecular DCE-MRI, as a non-invasive tool for the analysis of the placenta.
Topics: Albumins; Animals; Blood Circulation; Contrast Media; Embryo, Mammalian; Female; Magnetic Resonance Imaging; Mice; Organ Size; Phenotype; Placenta; Polyploidy; Pregnancy; Species Specificity; Time Factors
PubMed: 20686857
DOI: 10.1007/s11307-010-0390-1 -
Gynecologic and Obstetric Investigation 2007The objective of this study was to determine whether the maternal surface of the placenta is fractal, and whether the mean fractal dimension differs according to the...
AIMS
The objective of this study was to determine whether the maternal surface of the placenta is fractal, and whether the mean fractal dimension differs according to the gestational age and clinically or pathologically different conditions.
METHODS
Using digitized images of the maternal surface of 75 placentas, fractal dimensions were measured with a fractal analysis software.
RESULTS
The mean fractal dimension of the maternal surface of the placentas significantly exceeded the topological dimension of a surface (= 2). This means that the morphological pattern of the maternal surface fulfills the mathematical definition of fractal structures. Among the three different groups of gestational age, the mean fractal dimension in 22-29 weeks was significantly lower than that in 30-36 and 37-41 weeks (p = 0.022 and 0.014, respectively). Although not significantly different (p = 0.149), in 30-36 weeks the mean fractal dimension of the placentas complicated by pregnancy-induced hypertension (PIH) was greater than that without PIH.
CONCLUSION
Fractal geometry, a vocabulary of irregular shapes, can be useful for describing quantitatively the architecture of the maternal surface of the placenta and become a useful tool for analyzing physiological and pathological placental formation mathematically.
Topics: Adolescent; Adult; Female; Fractals; Gestational Age; Humans; Models, Biological; Photography; Placenta; Placenta Diseases; Pregnancy; Pregnancy Complications; Retrospective Studies
PubMed: 17191010
DOI: 10.1159/000098198 -
Acta Diabetologica Latina 1976The morphologic characteristics of the chorial villi from normal full-term placentas and from placentas of different clinical types of diabetic women were studied. The...
The morphologic characteristics of the chorial villi from normal full-term placentas and from placentas of different clinical types of diabetic women were studied. The latter showed early maturation of the trophoblast, higher percentage of villi with stromal edema, and higher percentage of vessels of the villous trunks with lesions causing partial or total obstruction of the vascular lumen. The fact that the diabetic patients were treated suggests that the metabolic correction of diabetes mellitus prevents the occurrence or development of the multiple disturbances which the disease produces in the evolution of human pregnancy.
Topics: Birth Weight; Chorionic Villi; Edema; Endothelium; Female; Humans; Infant, Newborn; Organ Size; Placenta; Pregnancy; Pregnancy Trimester, Third; Pregnancy in Diabetics; Trophoblasts; Umbilical Arteries; Umbilical Veins
PubMed: 1029353
DOI: 10.1007/BF02581119 -
Theriogenology Sep 2010The aim of the study was to compare horse and donkey placentae using stereological techniques. Term placentae were collected at spontaneous foaling from seven... (Comparative Study)
Comparative Study
The aim of the study was to compare horse and donkey placentae using stereological techniques. Term placentae were collected at spontaneous foaling from seven Thoroughbred mares, seven pony mares, and six jenny donkeys. Maternal and foal weights were recorded and the mass, volume, and gross area of each allantochorion was also recorded. Ten random biopsies were recovered and processed for light microscopy from which the surface density of the microcotyledons (S(v)) and the total microscopic area of fetomaternal contact were calculated stereologically. Gestation length was longer in the donkeys than the other two groups (median values: 371 vs. 327 and 341 days, P < 0.05). There were significant correlations between foal birthweight and gross area (rho = 0.89; n = 20; P < 0.05), mass (rho = 0.84; n = 20; P < 0.05) and volume (rho = 0.89; n = 20; P < 0.05) of the allantochorion. S(v) was higher in the donkey placenta than the other groups (median values: 0.05 vs. 0.03 and 0.04 microm(-1), P < 0.05) although placental efficiency was lower in the donkeys (median values: 0.87 vs. 1.33 and 1.32 kg/m2, P < 0.01). The results of the study confirmed that, although strong morphological similarities exist between the allantochorion of the horse and donkey, that of the donkey develops more complex microcotyledons, as judged stereologically, and exhibits a lower placental efficiency. These differences may be related to maternal genotype and/or the longer gestation length shown by the donkey compared to the horse, but a negative correlation (rho = -0.92, P < 0.01) was also found between age and placental efficiency in donkeys.
Topics: Animals; Body Size; Equidae; Female; Placenta; Pregnancy; Pregnancy, Animal
PubMed: 20494422
DOI: 10.1016/j.theriogenology.2010.03.006 -
Romanian Journal of Morphology and... 2013The authors analyze the main histopathological changes of placentas from pregnancies ended with fetal distress at birth and the tasks associated with diabetes. The...
The authors analyze the main histopathological changes of placentas from pregnancies ended with fetal distress at birth and the tasks associated with diabetes. The parallel between the two types of placentas not trying to prove the existence of pathognomonic lesions. Are set out both the similarities between the two titles of placentas lesions (such as changes in microcirculation and so on) as well as particular aspects. The authors analyze a group of 19 pregnant women hospitalized in Obstetrics and Gynecology Clinics of Emergency County Hospital of Craiova, Romania, in September 2010-September 2011, who were born and who were diagnosed with diabetes. In the same period, were studied 21 pregnant women whose pregnancy ended with the birth of a child with fetal distress. Such were identified as placental lesions suggestive of fetal distress as diverse etiology of placental vascular changes and the placenta in pregnancy associated diabetes as immaturity and vascular edema and fibrinoid changes and glycogen stores. The authors have proposed to highlight some lesions suggestive of two groups of diseases but independent groups were analyzed and conclusions were drawn after discussing results. This study is justified by insufficient knowledge of the causes that lead to fetal distress regardless of its etiology. In conclusion, the authors mention both placenta's common changes as specifically changes of the placenta for each type of disorder.
Topics: Diabetes, Gestational; Female; Fetal Distress; Fetal Growth Retardation; Humans; Placenta; Placenta Diseases; Placental Circulation; Pregnancy
PubMed: 24068397
DOI: No ID Found -
Developmental Biology Jan 2016Imprinted genes, which are expressed from a single parental allele in response to epigenetic marks first established in the germline, function in a myriad of processes...
Imprinted genes, which are expressed from a single parental allele in response to epigenetic marks first established in the germline, function in a myriad of processes to regulate mammalian development. Recent work suggests that imprinted genes may regulate the signalling function of the placenta by modulating the size of the endocrine compartment. Here we provide in vivo evidence that this hypothesis is well founded. Elevated expression of the imprinted Pleckstrin homology-like domain, family a, member 2 (Phlda2) gene drives a reduction of the spongiotrophoblast endocrine compartment, diminished placental glycogen and asymmetric foetal growth restriction. Using both loss-of-function and gain-in-expression mouse models, here we further show that Phlda2 exclusively modulates the spongiotrophoblast compartment of the placenta without significantly altering the composition of the trophoblast giant cell endocrine lineages that share a common progenitor with this lineage. Additionally, we show that Phlda2 loss-of-function placentae contain nearly three times more placental glycogen than non-transgenic placentae. Remarkably, relative to a fully wild type scenario, wild type placentae also accumulate excessive glycogen. While loss-of-function of Phlda2 increased both placental weight and placental glycogen, the weight of both mutant and non-transgenic fetuses was lower than that found in a fully wild type scenario indicating that excessive glycogen accumulation comes at the cost of foetal growth. This work firstly highlights a novel signalling function for the spongiotrophoblast in stimulating the global accumulation of placental glycogen. Furthermore, this work suggests that Phlda2 manipulates the placenta's demands for maternal resources, a process that must be tightly regulated by epigenetic marks to ensure optimal foetal growth.
Topics: Animals; Cell Lineage; Cell Proliferation; Endocrine System; Female; Fetal Growth Retardation; Gene Expression Regulation, Developmental; Genomic Imprinting; Genotype; Glycogen; Hormones; Mice; Models, Biological; Nuclear Proteins; Oligonucleotide Array Sequence Analysis; Phenotype; Placenta; Pregnancy; Transcriptome; Trophoblasts
PubMed: 26476147
DOI: 10.1016/j.ydbio.2015.10.015 -
Placenta 2005Based on histology, the placentae of eutherians are currently grouped in epitheliochorial, endotheliochorial and haemochorial placentae. In a haeckelian sense, the... (Review)
Review
Based on histology, the placentae of eutherians are currently grouped in epitheliochorial, endotheliochorial and haemochorial placentae. In a haeckelian sense, the epitheliochorial contact with marked histiotrophic feeding by uterine milk is generally considered as primitive, especially since similar contacts exist in Marsupials. In contrast, the more intimate endotheliochorial and haemochorial contact, facilitating haemotrophic nutrition, is interpreted as a derived state. A cladistic analysis based on the phylogenetic relationships established by molecular analyses reveals that the basic clades are all characterized by an endotheliochorial or haemochorial placenta, and that the epitheliochorial placenta evolved at least three times in a convergent manner. This evolution may be explained by the fact that the epitheliochorial placenta in eutherians is more efficient in nutritional transfer (flow rate by exchange surface). Moreover, this arrangement may confer an advantage to the mother who can probably reduce the degree of manipulation by a genetically imprinted embryo.
Topics: Animals; Evolution, Molecular; Female; Genomic Imprinting; Mammals; Maternal-Fetal Exchange; Phylogeny; Placenta; Pregnancy
PubMed: 16085037
DOI: 10.1016/j.placenta.2004.11.005 -
Acta Endocrinologica. Supplementum 1972
Topics: Abortion, Spontaneous; Abruptio Placentae; Adaptation, Psychological; Animals; Female; Fetal Death; Gestational Age; Haplorhini; Humans; Macaca; Maternal-Fetal Exchange; Placenta; Placenta Diseases; Placenta Previa; Pregnancy; Stress, Physiological; Stress, Psychological; Umbilical Arteries; Umbilical Cord; Umbilical Veins
PubMed: 4627295
DOI: 10.1530/acta.0.071s221 -
Biology of the Neonate 1976Dissection and graphic reconstruction of villous stems of human placentas has shown that the allegedly typical pattern, namely, one single villous stem and one maternal...
Dissection and graphic reconstruction of villous stems of human placentas has shown that the allegedly typical pattern, namely, one single villous stem and one maternal arterial ostium supplying each lobule, is not the usual state. More often, portions of one villous stem supply several lobules, and several stems take part in the formation of one lobule. This, together with the previously demonstrated location of arterial ostia at the interlobular areas, leads to the concept that arterial ostia, usually in close association with large anchoring villi, form a network at the base of the placenta which determines the distribution of the lobules.
Topics: Animals; Chorionic Villi; Female; Haplorhini; Humans; Macaca mulatta; Papio; Placenta; Pregnancy; Pregnancy Trimester, Second; Pregnancy Trimester, Third; Saimiri
PubMed: 813788
DOI: 10.1159/000240812 -
Placenta 1988Several problem areas in morphometry of human and animal placentae are reviewed. Attention is given to methods of tissue processing (handling, mode of fixation,... (Review)
Review
Several problem areas in morphometry of human and animal placentae are reviewed. Attention is given to methods of tissue processing (handling, mode of fixation, embedding, shrinkage) and sampling (of organs, tissue blocks, sections, micrographs). Principal sources of bias and sampling variability are identified and the crucial importance of randomized sampling is emphasized. Methods for obtaining structural quantities from sections are compared. The case is made for estimating absolute values (volumes, surface areas, lengths, numbers, thicknesses) using stereological principles rather than relying on planar data (profile areas, perimeter lengths, numbers, apparent thicknesses). Absolute values may be obtained simply and efficiently without resort to expensive measuring devices. Finally, morphological descriptors suitable for correlating with functional data or for comparing normal and diseased organs are surveyed.
Topics: Delivery, Obstetric; Female; Histological Techniques; Humans; Organ Size; Placenta; Pregnancy; Tissue Survival
PubMed: 3070535
DOI: 10.1016/0143-4004(88)90001-x