Rescue by Birth

Stallmach, Thomas; Hebisch, Gundula; Meier, Karin; Dudenhausen, Joachim W.; Vogel, Martin

doi:10.1097/00006250-200104000-00005

Cited by 7 publications

(6 citation statements)

References 13 publications

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“…Here K 1 = c mat B/R and K 2 = αc mat (D 2 BL 2 /R) 1/3 . A correction to Eq (15) to account for the effect of the surrounding villous volume can be calculated by considering the diffusion of oxygen between a cylindrical villous surface of radius R 0 + d surrounding a cylindrical capillary of radius R 0 , with both cylinders of equal length. The oxygen concentration is fixed on the surface of the outer cylinder, so that…”

Section: Regression Equation For the Total Oxygen Transfer Ratementioning

confidence: 99%

“…where N flow is given by Eq (15) and N max is the upper bound on the oxygen transfer rate, calculated numerically. It is simple to adapt the regression Eq (19) to plot N versus another quantity such as the flow rate Q or the effective Péclet number Pe eff .…”

Section: Regression Equation For the Total Oxygen Transfer Ratementioning

confidence: 99%

“…Second, a lack of terminal villi and vasculo-synyctial membranes, amongst other markers, characterizes a pathology known as delayed villous maturation, also known as defective villous maturation or distal villous immaturity [9][10][11][12][13][14]. There is an increased prevalence of delayed villous maturation in stillbirths where the autopsy findings were consistent with fetal hypoxia [10,15]; it is also associated with poor neurologic outcomes due to hypoxia [9,13]. There is thought to be an approximately 5% risk of delayed villous maturation recurring in subsequent pregnancies [15].…”

Section: Introductionmentioning

confidence: 99%

“…There is an increased prevalence of delayed villous maturation in stillbirths where the autopsy findings were consistent with fetal hypoxia [10,15]; it is also associated with poor neurologic outcomes due to hypoxia [9,13]. There is thought to be an approximately 5% risk of delayed villous maturation recurring in subsequent pregnancies [15]. Past efforts to model the placenta theoretically can generally be split into those that model the maternal side with assumptions about the fetal side, and vice versa; extensive reviews of the historical literature are available in [16,17].…”

Section: Introductionmentioning

confidence: 99%

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Image-Based Modeling of Blood Flow and Oxygen Transfer in Feto-Placental Capillaries

et al. 2016

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During pregnancy, oxygen diffuses from maternal to fetal blood through villous trees in the placenta. In this paper, we simulate blood flow and oxygen transfer in feto-placental capillaries by converting three-dimensional representations of villous and capillary surfaces, reconstructed from confocal laser scanning microscopy, to finite-element meshes, and calculating values of vascular flow resistance and total oxygen transfer. The relationship between the total oxygen transfer rate and the pressure drop through the capillary is shown to be captured across a wide range of pressure drops by physical scaling laws and an upper bound on the oxygen transfer rate. A regression equation is introduced that can be used to estimate the oxygen transfer in a capillary using the vascular resistance. Two techniques for quantifying the effects of statistical variability, experimental uncertainty and pathological placental structure on the calculated properties are then introduced. First, scaling arguments are used to quantify the sensitivity of the model to uncertainties in the geometry and the parameters. Second, the effects of localized dilations in fetal capillaries are investigated using an idealized axisymmetric model, to quantify the possible effect of pathological placental structure on oxygen transfer. The model predicts how, for a fixed pressure drop through a capillary, oxygen transfer is maximized by an optimal width of the dilation. The results could explain the prevalence of fetal hypoxia in cases of delayed villous maturation, a pathology characterized by a lack of the vasculo-syncytial membranes often seen in conjunction with localized capillary dilations.

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Section: Regression Equation For the Total Oxygen Transfer Ratementioning

confidence: 99%

Section: Regression Equation For the Total Oxygen Transfer Ratementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Image-Based Modeling of Blood Flow and Oxygen Transfer in Feto-Placental Capillaries

et al. 2016

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“…In humans, prenatal fetal death, which accounts for 50% of all in utero death, has been reported to be attributable to hypoxia caused by a maturation defect of placental blood capillaries and reduction in placental blood flow . As it was hypothesized that a reduction of umbilical cord blood flow occurs in umbilical cords with preterm delivery, in the present study we have analyzed the proteins of human preterm‐derived umbilical cord and compared them with the proteins isolated from umbilical cord with term delivery.…”

Section: Resultsmentioning

confidence: 99%

Altered protein profiles in human umbilical cords with preterm and full‐term delivery

Park

Kwon

et al. 2013

Electrophoresis

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Several biomarkers are routinely used clinically for predicting preterm labor; however, these factors are either nonspecific or detected too late. Here, we performed protein profiles in preterm- and term-derived human umbilical cord by using 2DE. Approximately 200 different proteins were identified between preterm- and term-delivered umbilical cords. Among them, 48 proteins were identified. A comparison of preterm proteome to that of term proteome revealed potential candidates for biomarkers, such as hypoxia-inducible proteins, phosphorylated heat-shock protein 27 (HSP27), transgelin, vimentin, and transferrin that are specific to preterm umbilical cords. Especially, HSP27 in preterm-derived umbilical cords shows a significant increase in the mono- and tetra-phosphorylation. The real importance of all of HSP27 phosphorylation as well as hypoxia-inducible factor 1alpha, and glyceraldehyde 3-phosphate dehydrogenase require further validation in vitro and in vivo; nevertheless, we believe that they could represent promising diagnostic targets for detection of sudden early delivery. In conclusion, the results of the current study may provide important insights into the molecular mechanisms underlying umbilical cord development.

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