Development of the conducting airway epithelium in fetal Syrian golden hamsters during normal and diabetic pregnancies

The conducting airway epithelium of fetal Syrian golden hamsters was studied from gestational day 12 to day 15, during normal and uncontrolled diabetic pregnancies. Diabetes was induced in the pregnant hamsters by injecting streptozotocin at 60 mg/kg body weight, subcutaneously, early on gestational day 10. Cells in S-phase were labelled immunochemically with bromodeoxyuridine (BrdU), and the day on which endocrine cells and ciliated cells first appeared was determined. In control fetuses, the BrdU-labelling indices (LI's) of different anatomical airway levels were significantly different from one gestational day to the next. For example, the LI of the lobar bronchus was significantly different on each gestational day (P less than .0001), and the same was true of the bronchioles. Moreover, the difference between LI's of the lobar bronchus and bronchioles-terminal buds was highly significant on day 12 (P less than .0001), and on day 13 the differences between lobar bronchus and bronchioles, lobar bronchus and terminal buds, and bronchioles and terminal buds were also highly significant (P less than .0001). However, on gestational days 14 and 15, the LI's were reduced and were comparable at different airway levels. The BrdU-labelling indices were very consistent among fetuses of the same age, and the differences between the average LI's for pups of different litters was numerically very small. Hyperglycemia (mild, moderate, severe) did not alter LI's in the fetal airway epithelial cells. Furthermore, although glycogen was not depleted from the airway epithelium of the hyperglycemic fetuses as it was in the controls, the endocrine cells first appeared on gestational days 12, 13, and 14, respectively, in the trachea, lobar bronchus and bronchioles, followed 1 day later by the ciliated cells, in the fetuses of control and diabetic mothers. In our experimental model, induction of diabetes in the pregnant hamsters on gestational day 10 did not appear to alter development or differentiation of the fetal conducting airway epithelium.     

Placental pathology in fetal thrombophilia

The aim of this study was to test the hypothesis that placental vascular lesions of the fetal circulation are caused by fetal thrombophilic mutations. The study included 64 newborns of women with one or more of the following pregnancy complications: preeclampsia, placental abruption, and intrauterine growth restriction. The most prevalent inherited thrombophilias--factor V Leiden, factor II (prothrombin) G20210A, and homozygosity for methyltetrahydrofolate reductase C677T--were examined in maternal blood and fetal umbilical cord blood. One pathologist reviewed all of the slides for fetal vascular lesions. Associations between fetal thrombotic vasculopathy and fetal thrombophilia were tested for using Fisher's exact test; Z scores and gestational age were compared using the Student t-test. Fetal thrombophilic mutations were diagnosed in 19 of 64 newborns, 15 of whom had coexistent maternal thrombophilia. There was no statistical difference in the prevalence of thrombotic lesions of the fetal circulation between newborns with and without thrombophilia. The combination of maternal and fetal thrombophilia was also not associated with increased fetal vascular lesions. The results indicate that fetal thrombophilia alone, even in the context of maternal underperfusion, is not associated with fetal vascular lesions of the placenta, although it may represent an underlying risk factor for lesions triggered by other process(es).     

Insulin and the IGF system in the human placenta of normal and diabetic pregnancies

The insulin/insulin-like growth factor (IGF) system regulates fetal and placental growth and development. In maternal diabetes, components of this system including insulin, IGF1, IGF2 and various IGF-binding proteins are deregulated in the maternal or fetal circulation, or in the placenta. The placenta expresses considerable amounts of insulin and IGF1 receptors at distinct locations on both placental surfaces. This makes the insulin and the IGF1 receptor accessible to fetal and/or maternal insulin, IGF1 and IGF2. Unlike the receptor for IGF1, the insulin receptor undergoes a gestational change in expression site from the trophoblast at the beginning of pregnancy to the endothelium at term. Insulin and IGFs are implicated in the receptor-mediated regulation of placental growth and transport, trophoblast invasion and placental angiogenesis. The dysregulation of the growth factors and their receptors may be involved in placental and fetal changes observed in diabetes, i.e. enhanced placental and fetal growth, placental hypervascularization and higher levels of fetal plasma amino acids.     

Placental adaptive responses and fetal programming

Fetal programming occurs when the normal pattern of fetal development is disrupted by an abnormal stimulus or 'insult' applied at a critical point in in utero development. This then leads to an effect, for example diabetes or hypertension, which manifests itself in adult life. As the placenta is the regulator of nutrient composition and supply from mother to fetus and the source of hormonal signals that affect maternal and fetal metabolism, appropriate development of the placenta is crucial to normal fetal development. Placental function evolves in a carefully orchestrated developmental cascade throughout gestation. Disruption of this cascade can lead to abnormal development of the placental vasculature or of the trophoblast. Timing of a developmental 'insult' will be critical in consequent placental function and hence programming of the fetus. The 'insults' that alter placental development include hypoxia and abnormal maternal nutrient status, to which the placenta may adapt by alterations in transporter expression and activity to maintain fetal growth or by epigenetic regulation of placental gene expression. Hypoxia is physiological for organogenesis and placental tissue normally exists in a relatively hypoxic environment, but intrauterine growth restriction (IUGR) and pre-eclampsia are associated with a greater degree of trophoblast hypoxia. The metabolic activity of placental mitochondria leads to oxidative stress even in normal pregnancy which is exacerbated further in IUGR, diabetic and pre-eclamptic pregnancies and may also give nitrative stress known to lead to covalent modification and hence altered activity of proteins. Hypoxia, oxidative and nitrative stress all alter placenta development and may be a general underlying mechanism that links altered placental function to fetal programming.     

Comparison of disaturated phosphatidylcholine and fetal lung maturity surfactant/albumin ratio in diabetic and nondiabetic pregnancies

We studied fetal lung maturity (FLM) by the amniotic fluid surfactant/albumin (FLM S/A) ratio and the disaturated phosphatidylcholine (DSPC) amniotic fluid levels at different gestational ages in diabetic (179 women with type 1 diabetes mellitus antedating pregnancy; infants delivered within 72 hours after amniotic fluid testing for DSPC level and FLM S/A ratio) and nondiabetic pregnancies (2 independent nondiabetic groups, 300 for FLM S/A ratio and 1,231 for DSPC level). The degree of maternal glycemia during gestation was estimated by serial measurements of hemoglobin A1. Multiple regression analyses, including gestational age (GAs) and diabetic status as independent variables and FLM S/A ratio and DSPC level as dependent variables, revealed significant effect from diabetic status and GA for FLM S/A ratio and a significant effect from GA but not from diabetic status for DSPC level. Glucose levels were controlled adequately throughout gestation as reflected by mean total glycated hemoglobin levels. Amniotic fluid levels of DSPC, the major surface tension-lowering component of pulmonary surfactant, are not significantly different between diabetic and nondiabetic pregnancies at different GAs.     

Temporal organization of fetal behavior from 24-weeks gestation onwards in normal and complicated pregnancies.

Developmental aspects of behavioral organization were investigated in 29 healthy fetuses from 24-weeks gestation onwards: (a) short-term association between body (GM) and eye (EM) movements; (b) linkage of pairs of the three state variables [fetal heart rate pattern (FHRP), GM, and EM]; and (c) sequence of change of state variables during transitions. Linkage and sequence were also studied in complicated pregnancies. Short-term association between GM and EM was well established after 28 weeks. Linkage of state variables improved considerably after 32-34 weeks. FHRP was the first variable to change during synchronized transitions from 1F to 2F between 28-39 weeks, and the last variable during 2F to 1F transitions between 32-39 weeks. Although clear developmental patterns could be recognized, the interfetal variability was such that identification of the abnormal fetus is still difficult. Only transitions were significantly different in growth-restricted fetuses, as they showed no specific sequence of change. Assessing the temporal organization of fetal behavior seems, therefore, until now, not of great clinical value.     

Placental expression of ceruloplasmin in pregnancies complicated by severe preeclampsia

There is consensus that ischemia/reperfusion injury associated with preeclampsia (PE) promotes both placental damage and the release of factors leading to maternal endothelium dysfunction, a hallmark of this potentially life-threatening syndrome. These factors include plasminogen activator inhibitor-1 (PAI-1) and soluble fms-like tyrosine kinase-1 (sFlt-1). The goal of this study was to further characterize placental factors involved in the pathophysiology of PE. Thus, DNA microarray gene profiling was utilized to identify mRNA differentially regulated in placentas from women with severe PE compared to both preterm (PC) and term control (TC) groups. Microarray studies detected an upregulation of mRNA for ceruloplasmin, a copper-containing iron transport protein with antioxidant ferroxidase properties, in PE compared to PC and TC placentas, respectively. Quantitative real-time PCR confirmed these results by demonstrating significant increases in ceruloplasmin mRNA in PE vs PC and TC placentas. Supporting previous reports, the expression of sFlt-1 and PAI-1 were also upregulated in PE placentas. Immunohistochemistry localized ceruloplasmin to the intervillous space in PE and PC placentas, whereas stronger syncytial staining was noted in PE. Western blotting confirmed a significant increase in ceruloplasmin levels in placental tissue in PE compared to PC groups. PCR identified the presence of mRNA for ceruloplasmin in primary cultures of syncytiotrophoblasts, but not villous-derived fibroblasts, suggesting that syncytium is the site of ceruloplasmin synthesis in placenta. Hypoxic treatment (1% O(2)) of syncytiotrophoblasts enhanced levels of ceruloplasmin mRNA approximately 25-fold, a significantly greater upregulation than that noted for PAI-1 and sFlt-1, suggesting that enhanced ceruloplasmin expression is a sensitive marker of syncytial hypoxia. We suggest that syncytial ceruloplasmin and its associated ferroxidase activity, induced by the hypoxia accompanying severe PE, is important in an endogenous cellular program to mitigate the damaging effects of subsequent reperfusion injury at this site.     

Placental protein 14 in human in-vitro fertilization early pregnancies.

Placental protein 14 (PP14) and human chorionic gonadotrophin (HCG) were analysed in patients participating in an in-vitro fertilization-embryo transfer programme which did not include any kind of luteal support. Women with normal pregnancies, spontaneous abortions, ectopic pregnancies, biochemical pregnancies and non-pregnant women were compared. A combination of HCG and PP14 analyses distinguished between normal and abnormal implantation as early as 15 days after oocyte retrieval. The product of HCG (IU/l) and PP14 (micrograms/l) concentrations differed significantly between normal pregnancy, spontaneous abortion and ectopic pregnancy (P = 0.0248). It is concluded that both endometrial (PP14) and trophoblastic (HCG) markers, when used in combination, exhibit changes in abnormal implantation which may be clinically useful.     

Comparison of fetal growth in singleton, twin, and triplet pregnancies.

The objective of this longitudinal retrospective study was to evaluate differences of the fetal growth and fetal organ growth among singleton small for gestational age (S-SGA), singleton appropriate for gestational age (S-AGA), twin (Tw-AGA), and triplet (Tri-AGA) infants. Ultrasonographic examinations were performed on 35 S-AGA, 18 S-SGA, 52 Tw-AGA and 12 Tri-AGA fetuses. Circumferences of head (HC), abdomen (AC), spleen (SC) and adrenal gland (AGC) and lengths of femur diaphysis (FDL), liver (LL), estimated weight (EWT) were measured every 2 weeks after 15 weeks of menstrual age until delivery. There was no significant difference in predicted HC values in S-AGA, Tw-AGA and Tri-AGA fetuses; these values were lowest in S-SGA fetuses. As the number of fetuses in the uterus increased with advancing menstrual age, the slope of the growth curve for predicted AC value became lower, but there was no significant difference between Tri-AGA and S-SGA fetuses. There was no significant difference in predicted FDL values among Tw-AGA, Tri-AGA and S-SGA fetuses; those values were significantly lower than that in S-AGA fetuses. There was no significant difference in predicted EWT value between Tw-AGA and Tri-AGA fetuses, which were intermediate between those for S-AGA and S-SGA fetuses. There were no significant differences in predicted SC and AGC values between S-AGA and Tw-AGA fetuses, respectively. However, in S-SGA fetuses, the slopes of the growth curve for SC and AGC were lower than those in the other two groups with advancing menstrual age. There were slight differences in predicted LL values between S-AGA, S-SGA and Tw-AGA fetuses. These results suggest that in AGA fetuses, there was a slight difference in growth pattern among singleton, twin, and triplet pregnancies.     

瘦素、脂联素与TNF-α在子痫前期胎盘中的表达及相关性研究

目的检测子痫前期胎盘中瘦素、脂联素及TNF-α的表达并探讨TNF-α与另两个因子的相关性。方法采用免疫组化方法检测55例子痫前期患者及21例正常对照组胎盘瘦素、脂联素及TNF-α的表达水平。结果重度子痫前期组胎盘瘦素表达水平显著高于正常组(P<0.01),轻度组与正常组无统计学差异(P>0.05);重度组胎盘脂联素表达水平显著低于正常组(P<0.01),轻度组与正常组无统计学差异(P>0.05);子痫前期胎盘TNF-α表达水平显著高于正常组(P<0.05及P<0.01);重度组瘦素与TNF-α成正相关(r=0.536),而正常组与病例组中脂联素与TNF-α均无相关性(r=0.416r、=0.398及r=0.254)。结论脂联素、瘦素及TNF-α参与子痫前期的发病,且TNF-α可调节瘦素的水平,但对脂联素的调节不明显。