Rat visceral yolk sac cells: viability and expression of cell markers during maternal diabetes

The function of the visceral yolk sac (VYS) is critical for embryo organogenesis until final fetal development in rats, and can be affected by conditions such as diabetes. In view of the importance of diabetes during pregnancy for maternal and neonatal health, the objective of this study was to assess fetal weight, VYS cell markers, and viability in female Wistar rats (200-250 g) with induced diabetes (alloxan, 37 mg/kg) on the 8th gestational day (gd 8). At gd 15, rats from control (n=5) and diabetic (n=5) groups were anesthetized and laparotomized to remove the uterine horns for weighing of fetuses and collecting the VYS. Flow cytometry was used for characterizing VYS cells, and for determining mitochondrial activity, cell proliferation, DNA ploidy, cell cycle phases, and caspase-3 activity. Fetal weight was reduced in the diabetic group. Expression of the cell markers CD34, VEGFR1, CD115, CD117, CD14, CCR2, CD90, CD44, STRO-1, OCT3/4, and Nanog was detected in VYS cells in both groups. In the diabetic group, significantly decreased expression of CD34 (P<0.05), CCR2 (P<0.001), and OCT3/4 (P<0.01), and significantly increased expression of CD90 (P<0.05), CD117 (P<0.01), and CD14 (P<0.05) were observed. VYS cells with inactive mitochondria, activated caspase-3, and low proliferation were present in the rats with diabetes. Severe hyperglycemia caused by maternal diabetes had negative effects on pregnancy, VYS cell viability, and the expression of cell markers.

Rat visceral yolk sac cells: viability and expression of cell markers during maternal diabetes.

The function of the visceral yolk sac (VYS) is critical for embryo organogenesis until final fetal development in rats, and can be affected by conditions such as diabetes. In view of the importance of diabetes during pregnancy for maternal and neonatal health, the objective of this study was to assess fetal weight, VYS cell markers, and viability in female Wistar rats (200-250 g) with induced diabetes (alloxan, 37 mg/kg) on the 8th gestational day (gd 8). At gd 15, rats from control (n=5) and diabetic (n=5) groups were anesthetized and laparotomized to remove the uterine horns for weighing of fetuses and collecting the VYS. Flow cytometry was used for characterizing VYS cells, and for determining mitochondrial activity, cell proliferation, DNA ploidy, cell cycle phases, and caspase-3 activity. Fetal weight was reduced in the diabetic group. Expression of the cell markers CD34, VEGFR1, CD115, CD117, CD14, CCR2, CD90, CD44, STRO-1, OCT3/4, and Nanog was detected in VYS cells in both groups. In the diabetic group, significantly decreased expression of CD34 (P<0.05), CCR2 (P<0.001), and OCT3/4 (P<0.01), and significantly increased expression of CD90 (P<0.05), CD117 (P<0.01), and CD14 (P<0.05) were observed. VYS cells with inactive mitochondria, activated caspase-3, and low proliferation were present in the rats with diabetes. Severe hyperglycemia caused by maternal diabetes had negative effects on pregnancy, VYS cell viability, and the expression of cell markers.

Nutritional studies of the embryo during early organogenesis with normal embryos and embryos exhibiting yolk sac dysfunction.

In 1961 we reported that heterologous kidney antiserum when injected into pregnant rats resulted in wide spectrum of congenital malformations. Further studies identified that it was the IgG component of the antiserum that was teratogenic and that complement was not necessary to produce the teratogenic effect. Labeled antibody studies demonstrated that the kidney antiserum localized in the kidney and in the visceral yolk sac (VYS) and parietal yolk sac placentas. Preparation of yolk sac (YS) antiserum proved to be more potent than the kidney antiserum. Adsorption studies with VYS and parietal yolk sac antiserum revealed that the site of the teratogenic process was located in the VYS. In vitro embryo culture experiments demonstrated that direct injection of the teratogenic antibody into the amniotic or YS cavity did not injure the embryo, thus indicating that the teratogenic antibody had to come in contact with the absorptive surface of the VYS. Collaboration with Dr. John Lloyd demonstrated that teratogenic antibody interfered with the process of pinocytosis and the delivery of amino acids (AA) to the developing embryo. Our studies into the nature of the source of AA for the embryo indicated that in some instances > 95% of the AA present in the developing embryo were derived from maternal proteins and the remainder from free AA in the maternal serum. We also demonstrated that embryonic methionine was derived primarily from the digestion of maternal serum proteins but that more of the methionine was diverted from the synthesis of embryonic proteins, supporting the view that it has important functions other than the synthesis of proteins. All these studies focus on the role of the YS in human development and whether human YS dysfunction may play a role in the pathogenesis of congenital malformations. Further studies on the delivery of AA to the embryo are warranted to determine whether certain AA are in short supply in maternal serum and place the embryo at risk if nutritional alterations in the maternal environment occurs. Furthermore, the YS may be an organ whose role might offer opportunities for pregnancy control.

Correlación entre embriocardia, saco vitelino y cuerpo lúteo en embarazo menor de diez semanas para eveluar su viabilidad y evolución

Existen reportes en la literatura mundial que, considerando algunos parámetros de ecografía temprana, hacen predicciones sobre le evolución del embarazo. Se pretendió demostrar estos hallazgos reportados universalmente para su aplicabilidad a la población que consulta al Hospital Militar Central, para la cual se realizaron ecografías transvaginales a 220 pacientes con embarazos menores de 10 semanas, en la Unidad de Ecografía Ginecoobstétrica del Hospital Militar Central o en la Unidad de Diagnóstico obstétrico y Ginecológico, (Obgyn), midiendo el diámetro del saco vitelino, cuantificando la embriocardia y valorando la presencia de cuerpo lúteo. Se realizó el seguimiento de las pacientes al final del período de estudio. Fueron excluidas 56 pacientes y con las 164 restantes no fue posible corroborar lo reportado en la bibliografía. Por tal motivo no podemos hacer ninguna predicción sobre el pronóstico del embarazo basados en las mediciones de ciertos parámetros por ecografía transvaginal en embarazos tempranos