ABSTRACT The mechanism of diabetic embryopathy was investigated using in vitro experiments in a rat embryo culture system and in streptozotocin-induced diabetic pregnant rats. The energy metabolism in embryos during early organogenesis was characterized by a high rate of glucose utilization and lactic acid production (anaerobic glycolysis). Embryos uninterruptedly underwent glycolysis. When embryos were cultured with hypoglycemic serum, such embryos showed malformations in association with a significant reduction in glycolysis.
In a diabetic environment, hyperglycemia caused an increased glucose flux into embryonic cells without a down-regulation of GLUT1 and an increased metabolic overload on mitochondria, leading to an increased formation of reactive oxygen species (ROS). Activation of the hexamine pathway, subsequently occurring with increased protein carbonylation and increased lipid peroxidation, also contributed to the increased generation of ROS. Hyperglycemia also caused a myo-inositol deficiency with a competitive inhibition of ambient glucose, which might have been associated with a diminished phosphoinositide signal transduction. In the presence of low activity of the mitochondrial oxidative glucose metabolism, the ROS scavenging system in the embryo was not sufficiently developed. Diabetes further weakened the antioxidant system, especially, the enzyme for GSH synthesis, γ-GCS, thereby reducing the GSH concentration. GSH depletion also disturbed prostaglandin biosynthesis. An increased formation of ROS in a diminished GSH-dependent antioxidant system may, therefore, play an important role in the development of embryonic malformations in diabetes.
ABSTRACT Type 1 diabetes results from the destruction of pancreatic b-cells (insulitis). It is a multifactorial disease involving genetic and environmental factors, including the maternal environment. Viruses have also been implicated in the pathogenesis of human type 1 diabetes as well as in its model non-obese diabetic (NOD) mice during the perinatal period, as endogenous viruses and/or as infectious agents vertically transmitted from mothers. However, the role of virus as genetic or environmental factor and its interaction with other maternal factors remain unclear. In a series of experiments, we transplanted preimplantation-stage NOD embryos into the uterus of recipient Institute of Cancer Research (ICR) mice, which are without diabetic genetic predisposition, and NOD mice, which did not exhibit overt diabetes during the experiment, and designated offspring as NOD/ICR and NOD/NOD, respectively. We previously observed that NOD/ICR offspring developed insulitis significantly earlier than NOD/NOD offspring. To assess the role of viruses in the development of insulitis, we examined the appearance of viral particles and expression of retroviruses between NOD/ICR and NOD/NOD. NOD/ICR showed earlier expression of env region of the xenotropic type C retrovirus by polymerase chain reaction analysis than NOD/NOD, while the retrovirus-like particles were observed in the islet b-cells similarly in both groups by electron microscopy. Serum corticosterone level, which is suggested to enhance retroviral induction, was significantly higher in the ICR than in the NOD surrogate mothers. These findings suggest that the observed virus is endogenous and that maternal environmental factors, including hormone levels, affect the induction of endogenous viruses and cause the earlier onset of insulitis.
ABSTRACT The objectives of the study was to check the embryotoxic-teratogenic and fetotoxic effect of mebendazole (Vermox; Richter, Budapest, Hungary) treatment during pregnancy. Mebendazole use during pregnancy was evaluated in mothers of babies born with congenital abnormalities and in matched control mothers of babies born without congenital abnormalities in the population-based data set of the Hungarian Case–Control Surveillance of Congenital Abnormalities between 1980 and 1996.
Of 22 843 women who had newborns or fetuses with congenital abnormalities, 14 were found to have been treated with mebendazole for intestinal nematoda infections/diseases during pregnancy (crude POR: 1.8 with 95% CI: 0.7–4.2). Of 38 151 women who had newborns without any defects (controls), the same number (14) were found to have been treated with mebendazole during pregnancy. Six different congenital abnormality groups were evaluated and a higher prevalence of mebendazole use in these mothers throughout pregnancy was not found. Gestational age and birth weight were analyzed in control infants born to mothers with or without mebendazole treatment. The mean gestational age was somewhat longer and mean birth weight was larger in newborn infants born to mothers with mebendazole treatment. Thus, treatment with mebendazole during pregnancy did not indicate a teratogenic and fetotoxic risk to the embryo or fetus, though the numbers of treated cases and controls in this study were limited.
ABSTRACT Growth-retarded (grt/grt) mice are congenitally primary hypothyroid. Our previous study indicated that thyroid-stimulating hormone (TSH) responsiveness was defective in the grt/grt thyroid gland. We now report additional studies of impaired grt/grt thyroid function. Semiquantitative RT-PCR confirmed that TSH receptor (TSHR) mRNA expression in the grt/grt thyroid was significantly decreased compared with +/+ thyroids. Scatchard analysis revealed that grt/grt and +/+ mice have only one type of TSH binding site. grt/grt thyroids had fewer TSH binding sites, although this did not apparently affect the affinity of TSH for its receptor. The present data suggest that reduced TSHR levels or defects in TSHR signaling could be one of the possible defective sites in the grt/grt thyroid gland.
ABSTRACT We report two cases of a fetus with sirenomelia sequence which showed oligohydramnios and a single umbilical artery. The first case was of a single fetus with symelia apus and only one leg. Prenatal diagnosis of this case was possible. The second case was of a dichorionic-diamniotic twin pregnancy in which one fetus had symelia dipus with two fused lower extremities. Prenatal diagnosis of the condition was not made. In both cases, the fetuses died shortly after birth from respiratory distress due to severe pulmonary hypoplasia. Absence of urinary tract, imperforate anus, and spine deformity were confirmed in both cases.
Although prenatal diagnosis of symelia dipus seems difficult, this condition must be considered in a fetus with severe oligohydramnios.
ABSTRACT We herein report a case of type I congenital cystic adenomatoid malformation of the lung (CCAML) with non-immune hydrops fetalis (NIHF), a mediastinal shift and polyhydramnios diagnosed at 24 weeks’ gestation by ultrasonography. The fetus was treated with a cyst-amniotic shunt at 29 weeks’ gestation. Following a postnatal whole resection of the right lung, postpneumonectomy syndrome appeared and, as a result, the infant died 13 months after delivery due to respiratory failure. Only 19 cases demonstrating CCAML associated with NIHF have been reported previously in Japan. Four cases showed a spontaneous resolution of NIHF, while 5 cases with type I CCAML, which all underwent fetal intervention, demonstrated an excellent outcome.
ABSTRACT We report here two iniencephaly fetuses with chromosome mosaicism. The first fetus (22 weeks) was male with mosaic trisomy 13, and the second fetus (24 weeks) was female with mosaic monosomy X. The first fetus had anencephaly, facial clefting, left-sided rocker bottom foot, equinovarous deformity, bilateral simian crease of hands and horseshoe kidney in addition to iniencephaly. The second fetus had hydrops fetalis with cystic hygroma in addition to iniencephaly. Because the fetuses were sent in formalin, conventional chromosomal analysis was not possible in spite of strong indication. Interphase fluorescence in situ hybridization (FISH) was carried out for targeted aneuploidy analysis. This is fourth published report of chromosomal abnormality in iniencephaly.