Placental villi-decidua interactions in normal and hypertensive pregnancies: a morphological quantitative study.

The decidual response to the implantation of the embryo is characterized by physical modifications to the uterine wall, with proliferation of the stromal cells which later change into decidual cells. We performed associated morphological and morphometrical studies to assess how the placental villi and decidua intersect, both in normal terminal pregnancy and in hypertensive patients in whom microenvironmental modifications induced by hypertension may cause significant alterations in mother-fetus relationships. In placentas of hypertensive women our morphometric analyses showed a higher number of chorionic villi-decidua interactions (p less than 0.05) with a more clumped distribution (p less than 0.05) and a smaller surface area of single interaction (p less than 0.001), in association with a higher number (p less than 0.005), and greater areas (p less than 0.01) of decidual cells. These data demonstrate how the placenta can enhance mother-fetus contacts impaired as the result of a hypertensive condition.     

In vitro effect of magnesium on the Na/K-ATPase isolated from human placenta.

Magnesium (Mg) is an activator of many cellular processes, among which is cation transport. An imbalance of cation transport may be involved in several diseases, as well as during pregnancy. Since the action of Mg in vivo in preventing gestational diseases is known, as well as its role in vitro on some cation transport activities, we studied the action of increasing concentrations of Mg on the activity of the enzyme Na/K-ATPase isolated from placental tissue of six normotensive women, at term. Incubation in a medium with increasing concentrations of Mg resulted in a significant activation of the enzyme, which was related to Mg concentration. The study demonstrates the action of Mg in vitro on isolated enzymes, and suggests the use of enzyme purification as a model for the study of cation transport in pregnancy.     

Effect of magnesium-deficient diet on cation transport in pregnant rabbits.

The imbalance of cation transport is considered to play an important role in the development of hypertension, and this also applies to hypertension during pregnancy. Magnesium (Mg) is one of the factors that regulate cation transport across the cell membrane. We therefore studied the effect of a magnesium-deficient diet on the activity of erythrocyte Na/K-ATPase and Mg-ATPase from six pregnant rabbits and compared the results to those obtained from six controls on a normal diet. None of the rabbits on the deficient diet developed hypertension or intrauterine growth retardation; nevertheless the activity of both enzymes was significantly reduced compared to the group on the normal diet. Since the reduced activity of these enzymes can determine sodium or calcium retention in the cell, Mg deficiency could be the basis of the onset of some forms of hypertension in pregnancy.     

Effect of sexual steroid hormones on spiramycin disposition in genital tract secretions of the ewe.

The present work investigated the influence of sexual steroid compounds (estradiol 17 beta and fluorogestone) on antibiotic passage across the uterine barrier. Five healthy and mature ewes, with controlled hormonal impregnation, were given a single iv injection of spiramycin, a macrolide antibiotic, at a dose of 64,000 IU/kg. Plasma and uterine secretions were regularly sampled before the injection and for 30 h post-injection. Blood was collected from the jugular vein and uterine secretions were obtained by uterine flushing with a sterile saline solution containing 0.2% inulin. Spiramycin was concentrated in the uterine secretions, whatever the hormonal status; the secretions-to-plasma ratio was 4.68 +/- 1.88 under estrogen priming and 2.68 +/- 0.91 under progestagen priming. The area under the concentration-time curve (AUC) and the mean residence time (MRT) were significantly higher (p less than 0.001) in uterine secretions than in plasma. The AUC in uterine secretions was significantly higher (p less than 0.05) under estrogen priming (439.07 +/- 241.25 IU.h/mL) than under progestagen priming (141.41 +/- 89.37 IU.h/mL). The spiramycin MRTs in uterine secretions were 11.92 +/- 4.08 and 12.06 +/- 3.35 h for both estrogens and progestagen treatment, respectively. These experiments demonstrate that estrogens increase uterine bioavailability, but not the residence time, of spiramycin when administered by a systemic route.     

Modifications induced by LDL from type 1 diabetic patients on endothelial cells obtained from human umbilical vein.

The aim of the present work was to analyze the effect of LDL obtained from type 1 diabetic patients in good metabolic control on human umbilical vein endothelial cells (HUVECs) after a short incubation period to detect possible atherogenic modifications of endothelial properties. Cultured HUVECs were incubated for 3 h with culture medium alone (control HUVEC), with native LDL from 12 healthy men (control LDL), or with native LDL from 12 type 1 diabetic men (type 1 LDL) (100 pg/ml). After the incubation, the following parameters were evaluated: nitric oxide synthase (NOS) activity, cytoplasmic Ca2+ levels, Na+-K+-ATPase activity, plasma membrane fluidity determined by means of 1,6-diphenyl-1,3,5-hexatriene (DPH) and 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH), and plasma membrane conjugated diene (CD) content. The same experiments were repeated after bradykinin stimulation or in the presence of the antioxidant butylated hydroxytoluene (BHT), and nitric oxide (NO) production in intact HUVECs was also evaluated. HUVECs incubated with control LDL in comparison with control HUVECs showed a decreased fluidity of the membrane surface evaluated by TMA-DPH and a higher CD content. These alterations were prevented by the presence of BHT. HUVECs incubated with type 1 LDL in comparison with both control HUVECs and cells incubated with control LDL showed 1) increased NOS and Na+-K+-ATPase activity, cytoplasmic Ca2+ levels, and CD content, and 2) decreased fluidity of the membrane surface evaluated by TMA-DPH. These modifications were blunted--but not abolished--by the presence of BHT. After bradykinin stimulation either in the absence or in the presence of BHT, both cytoplasmic Ca2+ levels and NO production were increased in control HUVECs and in HUVECs incubated with control LDL, while a reduced response was observed in HUVECs incubated with type 1 LDL. The alterations observed in the endothelial function after the cell-LDL interaction might play a central role in the atherogenic process in diabetes.     

A study on human umbilical cord endothelial cells: functional modifications induced by plasma from insulin-dependent diabetes mellitus patients.

The aim of the present study was to evaluate the action of plasma from insulin-dependent diabetic (IDDM) pregnant women on nitric oxide synthase (NOS) activity in cultured human umbilical vein endothelial cells (HUVECs). We also studied the effect of the plasma on cytosolic calcium and on Na+/K+-adenosine triphosphatase (ATPase) activity. Dynamic fluorescence studies of membrane fluidity were contemporarily performed to detect a direct effect of plasma on the endothelial cell membrane. We observed a significant increase in NOS activity, intracellular calcium, and Na+/K+-ATPase activity in cultured HUVECs exposed to IDDM plasma. Our dynamic fluorescence study showed a different microenvironmental organization of the cellular membrane after incubation with plasma from IDDM pregnant women, with a marked decrease in microheterogeneity as evaluated in terms of 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) lifetime distribution width. The present investigation suggests that plasma from IDDM pregnant women can cause a generalized disturbance in the function of endothelial cells cultured from healthy subjects. Such a modification might play a central role in the pathogenesis of the vascular complications of the disease.     

The management of feto-maternal alloimmune thrombocytopenia: Report of three cases

We report herein three cases of severe fetal thrombocytopenia due to anti-human platelet antigen (HPA)- 1a maternal antibodies. The first and the third cases were diagnosed on the basis of previously affected siblings and treated successfully by maternal intravenous human immunoglobulins and corticosteroids. In the second case an unexpected neonatal thrombocytopenia was found after birth without previously affected siblings and treated subsequently with intravenous immunoglobulins. Our experience supports a switch from an invasive management, including early FBS (fetal blood sampling) and platelet transfusions, to a more cautious approach. Also in severe HPA-1a alloimmunization and in ‘high risk’ fetuses, prenatal maternal treatment could be performed, without previous FBS, only on the basis of a risk score defined by sibling history and parents' genotypes.