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ABSTRACT: To assess coagulation activation and endothelial cell injury in normotensive and pre-eclamptic pregnant women, a comparison was made of plasma levels of tissue factor, fibronectin, fibrinopeptide A and D-dimer. Samples were taken from 50 nonpregnant women, 40 normotensive pregnant women in the third trimester and 27 women with pre-eclampsia after diagnosis and before treatment. High levels of fibrinopeptide A and D-dimer were found in pre-eclamptic women. Moreover, the ratio fibrinopeptide A:D-dimer was much greater in the pre-eclampsia group than in normotensive pregnant women. The levels of fibronectin and tissue factor were also higher in the pre-eclampsia group. The increase of tissue factor levels suggests an alteration of the extrinsic coagulation pathway in pre-eclampsia. The increase of fibrinopeptide A:D-dimer ratio shows that the activation of coagulation is associated with a relative hypofibrinolysis in pre-eclampsia.
British Journal of Obstetrics and Gynaecology 07/1999; 106(6):594-7.
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ABSTRACT: Pineal cell aggregates in 5, 10 and 15 day-old chick embryos have been studied. Cell aggregates were classified into rosettes or vesicles and spheroid and ellipsoid vesicles distinguished. The number of pineal vesicles per unit of surface (vesicle density) was determined in three pineal portions: apical, anterior and posterior. By day 5, only cellular rosettes were found, mainly in the apical portion. After 10 and 15 days, the presence of rosettes was occasional. The posterior wall showed only small spheroid vesicles, while in the apical and anterior areas ellipsoid vesicles were also observed. Moreover, the spheroid/ellipsoid vesicle ratio increased from the 10th to the 15th day of incubation. The vesicle density decreased between the 10th and 15th day because of the increase in both vesicle and pineal size, without changes in the total number of vesicles. The results suggest that changes in vesicle morphology and density could be related to the functional activity of the pineal gland during embryonic development.
European Journal of Morphology 03/1999; 37(1):29-35.
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ABSTRACT: The effects of static electromagnetic fields on the development of the chick embryo pineal gland were studied. A total of 144 fertilized White Leghorn eggs were sacrificed after 5, 10 and 15 days of incubation. The stage of development was determined in all embryos using the Hamburger and Hamilton method [J Morphol 49: 88-92, 1951]. The various morphometric parameters (diameter and distance of the pineal gland and its lumen) were measured on serial 7-micron-thick sections. The data were obtained in a morphometer and processed statistically. The intensities of the static electromagnetic fields were 18 and 36 mT. Control and exposed embryos were equally distributed and randomly assigned. After 5 days of incubation, 25% of embryos exposed to a static electromagnetic field of 18 mT had a more advanced stage of development than controls and embryos exposed to 36 mT. On the 10th and 15th day, embryos exposed to either 18 or 36 mT tended to be more developed than controls. In the morphometric study, results were similar for the controls and exposed embryos after 5 and 10 days of incubation. However, the values of the 15-day-old embryos exposed to static magnetic fields were lower than the values of the controls (p > 0.01). These differences were more pronounced in the embryos exposed to 36 mT. These results seem to indicate that static electromagnetic fields affect the development and growth of embryos unequally, and that their action can depend not only on the intensity of the static electromagnetic field, but also on the length of exposure and the organ which is developing. It may be interesting to use these data in ultrastructural and physiological studies.
Cells Tissues Organs 02/1999; 165(2):74-80. · 2.20 Impact Factor
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ABSTRACT: Morphofunctional study of umbilical cords from pregnancies complicated by preeclampsia shows both activation and lesion of endothelium. The cellular findings in umbilical cords from pregnancies complicated by preeclampsia can be summarized as: (i) higher number of cells with secretion bladders and increase in the number and size of both secretion bladders and microvilli-like protrusions; (ii) increase in collagen, fibrin, fibronectin and lipidic vesicles in the vessel wall; (iii) vacuolization of endothelial cells; (iv) presence of lipidic vacuoles and lipophages in the vessel wall; (v) erosion and disorganisation of the endothelium that exposes extracellular proteins to the blood flow. Endothelial cell cultures from preeclamptic pregnancies show kinetic disorders and cell detachment. The results confirm that an endothelial cell lesion occurs in preeclampsia and this cellular disorder can be reproduced in vitro.
Gynecologic and Obstetric Investigation 02/1999; 47(2):95-101. · 1.28 Impact Factor
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Laboratory Investigation 05/1998; 78(4):507-8. · 3.64 Impact Factor
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ABSTRACT: Few studies have been performed to evaluate the ultrastructural changes that exposure to static magnetic fields (SMF) can cause to the processes of cell migration and differentiation in the cerebellum during development. Thus, we have studied the development of the cerebellum in the chick embryo (n = 144) under a uniform SMF (20 mT). All of our observations were done on folium VIc of Larsell's classification. The cerebella of chick embryos, which were exposed solely on day 6 of incubation and sacrificed at day 13 of incubation [short exposure (S)1; n = 24], showed an external granular layer (EGL) that was less dense than the EGL in the control group (n = 24). The molecular layer (ML) exhibited a low number of migratory neuroblastic elements. Moreover, the internal granular layer (IGL) was immature, with the cellular elements less abundant and more dispersed than in controls. In chick embryos exposed on day 6 of incubation and sacrificed at day 17 (S2; n = 24), the outstanding feature was the regeneration of the different layers of the cerebellar cortex. The cerebellar cortex of chick embryos exposed continuously to an identical field from the beginning of the incubation up to day 13 [long exposure (L)1; n = 24] or day 17 (L2; n = 24) of incubation showed a higher number of alterations than that of group S1. Electron microscopy confirmed the findings from light microscopy and, at the same time, showed clear signs of cell degeneration and delay in the process of neuronal differentiation. This was more apparent in groups L1 (100%) and L2 (100%) than in groups S1 (95.4%) and S2 (65.2%). In conclusion, the present study showed that SMF can induce irreversible developmental effects on the processes of cell migration and differentiation of the chick cerebellar cortex.
Bioelectromagnetics 02/1997; 18(1):36-46. · 1.84 Impact Factor
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ABSTRACT: The influence of continuous electromagnetic fields (0, 181 or 361 Gs/cm2) on the development of chick embryo (n = 144) was studied. Several parameters were determined at days 5, 10 and 15 of incubation: stage (following Hamburger and Hamilton), vertex-coccyx length (size) and weight. At 5 days of incubation, all embryos showed a similar stage. However, at days 10 and 15, the embryos exposed to 181 Gs/cm2 showed a stage significantly superior to that of the others. There were no differences between the exposed embryos and the control ones with regard to weight and stature, except at 15 days when the embryos exposed to 361 Gs/cm2 showed greater weight and stature than those of the controls.
Acta Anatomica 02/1992; 145(4):302-6.
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ABSTRACT: A silver impregnation method and a morphometric approach were used to define differences existing in the motor nerve terminal branching pattern between a fast-twitch muscle (extensor digitorum longus) and a slow-twitch one (soleus) of the normal adult rat. Because no single measure can describe precisely all geometrical properties (ie both topology and metrics) of the nerve terminals, we evaluated morphologic parameters defining length and angular characteristics in the different terminal segments classified according to their centrifugal order. The main results indicate that the distal free-end segments in the extensor digitorum longus muscle are shorter and less divergent than in the soleus nerve terminals. The endings in the two muscles have different fractal dimensions. Findings are discussed in the context of the hypothetical mechanisms governing motor nerve terminal size and complexity.
Biology of the Cell 02/1992; 74(3):299-305. · 3.60 Impact Factor
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ABSTRACT: meso-2,3-Dimercaptosuccinic acid (DMSA), an antidote for the treatment of experimental and human poisoning by a number of heavy metals, has been reported to reduce the lethality of animals poisoned with arsenic more effectively than 2,3-dimercaptopropanol. In the present study, the effect of DMSA on arsenite-induced embryotoxic and teratogenic effects was evaluated in mice. In a first experiment, a series of four DMSA injections was administered sc to pregnant Swiss mice immediately after a single ip injection of 12 mg/kg of sodium arsenite (NaAsO2) given on Day 10 of gestation, and at 24, 48, and 72 hr thereafter. DMSA effectiveness was assessed at dosage levels of 0, 80, 160, and 320 mg/kg/day. Treatment with DMSA significantly reduced the embryolethality and the incidence of gross external and skeletal malformations and variations provoked by NaAsO2. Based on these findings, the effect of increasing the time interval between acute arsenite exposure and initiation of DMSA therapy was investigated in a second experiment. On Day 10 of gestation, DMSA (320 mg/kg) was administered sc to pregnant mice at 0, 0.25, 0.50, 1, 4, or 12 hr after a 12-mg/kg ip dose of NaAsO2. Embryotoxicity and teratogenicity derived from NaAsO2 exposure were significantly reduced when DMSA was given during the first hour after NaAsO2 injection. According to these results, a delay between acute arsenite intoxication and DMSA treatment should be avoided to have a practical beneficial effect on the arsenite exposed conceptus.
Fundamental and Applied Toxicology 09/1991; 17(2):314-20.
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ABSTRACT: In a series of 215 anteroposterior X-ray films, a study was made of the horizontal distance between the pedicles of each lumbar vertebra, first of all sequentially, describing the morphology adopted by the lateral limits of the canal, and secondly determining the absolute value for each level separately and in relation to the variables of sex and age. The absolute value of this distance at each level is related to the thickness of the pedicles and the width of the vertebral bodies of L3 and L4. The values obtained were tested with the appropriate statistics in each case.
Acta Anatomica 02/1988; 131(1):35-40.
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ABSTRACT: meso-2,3-Dimercaptosuccinic acid (DMSA), an antidote for the treatment of experimental and human poisoning by a number of heavy metals, has been reported to reduce the lethality of animals poisoned with arsenic more effectively than 2,3-dimercaptopropanol. In the present study, the effect of DMSA on arsenite-induced embryotoxic and teratogenic effects was evaluated in mice. In a first experiment, a series of four DMSA injections was administered sc to pregnant Swiss mice immediately after a single ip injection of 12 mg/kg of sodium arsenite (NaAsO2) given on Day 10 of gestation, and at 24, 48, and 72 hr thereafter. DMSA effectiveness was assessed at dosage levels of 0, 80, 160, and 320 mg/kg/day. Treatment with DMSA significantly reduced the embryolethality and the incidence of gross external and skeletal malformations and variations provoked by NaAsO2. Based on these findings, the effect of increasing the time interval between acute arsenite exposure and initiation of DMSA therapy was investigated in a second experiment. On Day 10 of gestation, DMSA (320 mg/kg) was administered sc to pregnant mice at 0, 0.25, 0.50, 1, 4, or 12 hr after a 12-mg/kg ip dose of NaAsO2. Embryotoxicity and teratogenicity derived from NaAsO2 exposure were significantly reduced when DMSA was given during the first hour after NaAsO2 injection. According to these results, a delay between acute arsenite intoxication and DMSA treatment should be avoided to have a practical beneficial effect on the arsenite exposed conceptus.
Fundamental and Applied Toxicology.
