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Biomedical subjects

C Romanini

Publications and source records attributed to C Romanini.

At least 181 records · Page 10Linked to original sources
PubMed1991

Modifications induced by gestational hypertension on platelet calcium transport.

Several studies have recently demonstrated that the platelets of subjects affected by essential hypertension have, in their basal state, an elevated cellular calcium content. Such data appear particularly interesting with regard to gestational hypertension (GH). Supposing that the intracellular calcium may be involved in the regulation of blood pressure we have studied the cytosolic calcium concentration, Na+/K(+)-ATPase activity, Ca(2+)-ATPase activity, fluidity, and the cholesterol/phospholipid (C/P) molar ratio of the plasma membranes in platelets from 20 normotensive pregnant women and 20 women affected by mild gestational hypertension without pharmacological treatment, near term. We observed an increased Ca(2+)-ATPase activity and a decreased Na(+)K(+)-ATPase activity in GH compared to the controls, accompanied by an increased Ca2+ intraplatelet concentration in the same patients. The fluidity and the C/P molar ratio were also increased. Our study gives indirect support to the hypothesis, supposing a reduced Na+/K(+)-ATPase activity which might cause increased intracellular Na+ content and decreased Ca2+ efflux through the Na+/Ca2+ exchange. However, out data can not rule out the other hypotheses explaining the increased cellular Ca2+ content. The present data indicate that GH is accompanied by a membrane structural abnormality that alters its physical state and modifies the membrane-related cellular functions.

Biological Transport, Active↗
PubMed1991

Longitudinal assessment of behavioural transitions in healthy human fetuses during the third trimester of pregnancy.

A longitudinal study was performed on 35 healthy fetuses in order to evaluate the developmental course of behavioural transitions during the last trimester of pregnancy. A progressive decrease in the duration of transitions as a function of gestational age was evidenced for both transitions from 1F to 2F and transitions from 2F to 1F. Concerning the sequence in change of behavioural variables (fetal heart rate, fetal eye movements and fetal gross body movements) a random distribution was found until 30 weeks for 1F to 2F transitions and until 34 weeks for 2F-1F transitions. After these gestational ages fetal heart rate and fetal gross body movements respectively become the first variable to change during 1F-2F and 2F-1F transitions. Reference values for these parameters are calculated in order to provide a basis for the diagnosis of behavioural abnormalities in high risk fetuses.

Analysis of Variance↗
PubMed1991

Modifications induced by gestational diabetes mellitus on cellular membrane properties.

Alterations in erythrocyte plasma membrane properties (enzymatic activities and membrane fluidity) have been observed in patients affected by insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM). In order to verify whether these alterations are present also in gestational diabetes mellitus (GDM) we studied the plasma membranes obtained from two different cellular types (erythrocyte from both mother and cord blood and placenta syncytiothrophoblast cell) of 16 healthy pregnant women and 15 women affected by GDM. The following determinations were performed on the membrane preparations: Na+/K(+)-ATPase activity, acetyl-cholinesterase (AchE) activity, membrane fluidity and cholesterol:phospholipid ratio. We observed a reduction of both enzymatic activities and a decrease of membrane fluidity in maternal and cord blood erythrocytes and in syncytiotrophoblast plasma membranes in GDM pregnant women in comparison with controls. The cholesterol to phospholipid ratio was significantly lower in the erythrocyte membranes of women affected by GDM than in normal pregnant women, while it was increased in the cord blood erythrocyte membranes and in placental membranes in GDM in comparison with controls. The present study found, in GDM patients, a membrane alteration similar to the abnormality reported in IDDM and NIDDM (i.e. decreased Na+/K(+)-ATPase activity), while opposite modifications were observed with regard to other membrane activities and properties. The different membrane alterations observed in GDM with respect to IDDM and NIDDM might be linked to the different degree of metabolic control, on the contrary the reduced Na+/K(+)-ATPase activity might be a primary event in the pathogenesis of diabetes mellitus per se and might constitute a signal of high risk of developing the disease later in the women affected by GDM during pregnancy.

Acetylcholinesterase↗
PubMed1991

Doppler velocimetry versus nonstress test in the antepartum monitoring of low-risk pregnancies.

One thousand singleton low-risk pregnancies were cross-sectionally studied at 36-40 weeks gestation with continuous-wave Doppler ultrasonography in order to assess its usefulness as an antepartum monitoring technique for the identification of fetuses at risk of developing an adverse outcome. Uterine artery and umbilical artery S/D values were measured and related to fetal outcome. Results were compared with those of the nonstress test. No significant differences in fetal outcome, with the exception of birth weight, were found between patients with normal and abnormal uterine S/D values. In pregnancies with abnormal umbilical S/D values, a higher incidence of cesarean section for fetal distress and lower birth weight were observed. Moreover, those newborns more frequently had complications such as low 5-minute Apgar score, requiring resuscitation and admission to the intensive care unit. When compared to nonstress test, umbilical velocimetry showed a higher efficiency in identifying fetuses at risk for adverse outcome.

Arteries↗
PubMed1991

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.

Dose-Response Relationship, Drug↗
PubMed1991

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.

Animals↗
PubMed1991

Telephonic transmission of cardiotocographic recordings from a remote facility to an obstetric unit.

The Authors describe their experience in telephonic transmission of cardiotocographic recordings. With a Corometrics 116 and 410 unit installed in a remote facility, 61 CTG recordings were tele-transmitted and received by a Toshiba personal computer. The concordance between original and transmitted CTG record was excellent and a very low percentage of signal loss during transmission (3.2%) was found. The advantages of telephone transmission of CTG in peripheral areas are stressed.

Cardiotocography↗
PubMed1990

Effects of behavioural states on cardiac output in the healthy human fetus at 36-38 weeks of gestation.

Doppler velocity waveforms from atrioventricular valves were recorded in 20 healthy fetuses at 36--38 weeks of gestation during both behavioural states 1F (quiet sleep) and 2F (active sleep). No significant changes were found in the ratios between the velocities during early passive ventricular filling and active ventricular filling (E/A ratios) at the level of both mitral and tricuspid valves when the measurements obtained during states 1F and 2F were compared. Moreover, during state 2F the left ventricular output increased and the right ventricular output decreased, resulting in a marked modification of the right to left cardiac output ratio. Our data suggest a redistribution of cardiac output in favour of the left side of the heart during state 2F.

Blood Circulation↗
PubMed1990

Doppler assessment of fetal blood flow velocity waveforms during acute maternal oxygen administration as predictor of fetal outcome in post-term pregnancy.

The changes in fetal blood flow velocity waveforms during maternal administration of 60% humidified oxygen were assessed by Doppler ultrasonography in 45 post-term fetuses. During oxygen treatment, nine fetuses exhibited temporary increases (24.3 +/- 2.0% [1 standard deviation] above pretreatment values) in the pulsatility index at the level of internal carotid artery. Although no significant changes (2.9 +/- 5.1%) were found in the remaining 36 fetuses. In this former group a higher incidence of emergency cesarean delivery due to fetal distress and more neonatal complications were observed. Also, meconium staining of the amniotic fluid and low 1- and 5-minute Apgar scores occurred more frequently in the group of fetuses who responded to maternal oxygen administration. An increase of at least 20% in the pulsatility index of internal carotid artery during maternal hyperoxygenation may be a useful marker of adverse outcome in post-term fetuses.

Adolescent↗
PubMed1990

Doppler echocardiographic assessment of time to peak velocity in the aorta and pulmonary artery of small for gestational age fetuses.

The time to peak velocity was measured at the level of the ascending aorta and pulmonary artery by Doppler echocardiography in 38 small-for-gestational age (SGA) fetuses before and during maternal hyperoxygenation. The values were compared to a reference range derived from the study of 142 appropriate-for-gestational age (AGA) fetuses. In the SGA fetuses the time to peak velocity at the level of pulmonary artery was significantly lower and at the level of the aorta significantly higher than in AGA fetuses. During maternal hyperoxygenation the aortic time to peak velocity decreased towards normal range but there was no significant change at the level of the pulmonary artery. These results may indicate variations of aortic and pulmonary pressures in SGA fetuses that can be partially modified by maternal hyperoxygenation and which may be associated with changes in the peripheral resistance of the cerebral circulation.

Aorta, Thoracic↗
PubMed1990

Effects of maternal hyperoxygenation on atrioventricular velocity waveforms in healthy and growth-retarded fetuses.

In order to assess whether maternal hyperoxygenation induces modifications of Doppler-measured velocity waveforms across atrioventricular valves, 15 healthy and 15 growth-retarded fetuses were studied in basal conditions and during the maternal administration of 60% humidified oxygen. Recordings were performed at 5-min intervals before, during and after maternal oxygen administration. In basal conditions, growth-retarded fetuses exhibited significantly lower ratios between the velocities during early passive ventricular filling and active ventricular filling (E/A ratio) at the level of both mitral and tricuspid valves when compared to healthy fetuses. Furthermore in healthy fetuses the velocity time integral across the tricuspid valve always slightly exceeded that across the mitral valve, whilst growth-retarded fetuses showed an inversed ratio between these velocities. During oxygen administration no changes were found between the two groups of fetuses with regard to the E/A ratios. Similarly the velocity time integrals were unaffected by oxygen administration in the healthy fetuses. Besides growth-retarded fetuses exhibited significant temporary modifications during oxygen administration as expressed by an increase in the velocity time integral across the mitral valve associated with a decrease of that across the tricuspid. These changes result in an inversion of the ratio between transtricuspid and transmitral velocity time integrals reaching values similar to those of healthy fetuses. Short-term oxygen administration affects the intracardiac flow redistribution present in growth-retarded fetuses bringing it to a pattern similar to that of healthy fetuses whereas the E/A ratios were not affected by the treatment.

Blood Circulation↗
PubMed1990

Functional assessment of uteroplacental and fetal circulations by means of color Doppler ultrasonography.

A study was made in order to assess whether the combined use of color flow mapping and conventional pulsed Doppler could improve the accuracy of blood flow velocity waveform analysis in fetal and placental circulations. Fifty patients were studied at 18 to 20 or 26 to 28 weeks of gestation by two trained investigators by means of either conventional Doppler or conventional Doppler plus color flow mapping. Recordings were performed at the level of the uterine arteries, umbilical artery, descending aorta, and internal carotid artery. The experimental procedure was repeated the following day with the patients undergoing the alternate technique of recording. In all the vascular districts investigated, color flow mapping allowed us to obtain a higher number of reliable recordings, to shorten the observation time, and to reduce the intra- and interobserver coefficient of variations.

Aorta, Thoracic↗
PubMed1990

[In vitro structural aspects of the human trophoblastic cell].

Maternal- fetal exchanges are mainly regulated by trophoblast, which displays an active role during embryo growth. Trophoblast organization into a syncytial layer involves structural and functional steps that may be monitored and better elucidated by "in vitro" studies. In light of this, we have carried out morphological and biochemical analyses in order to evaluate 1) the syncytiotrophoblast formation in culture (48 h, 5-30 days) the Na+/K+ATPase activity and 3) the plasmalemmal microviscosity changes occurring during "in vitro" trophoblast production. Morphological and biochemical modulations have been pointed out.

Cells, Cultured↗
PubMed1990

Natural killer cells and Tac antigen in the hypertension of pregnancy.

Of the immunological alterations in pregnancy hypertension were studied peripheral blood lymphocyte subpopulation in normal and hypertensive pregnancies by means of monoclonal antibodies. In pregnant women with hypertension an increase was found in NK activity. It was also shown that an increase in circulating T cells expressing Tac antigen occurred in women with pregnancy hypertension. These preliminary data on Tac antigen suggest that there is an activation of Leu 3 cells; which may introduce the concept of Leu 3 activity like NK activity. Further studies on this subject could explain that the concept of Leu 3 activity is correct.

Female↗
PubMed1990

Improvement of decreased natural killer cell activity in cervical cancer patients by active lipids (AL 721).

In the present study we observed the absolute number of NK cells and the NK activity in 10 patients with cervical cancer. NK activity was determined before and after stimulation with Active Lipids. We reported a significant decrease of basal NK activity, but after AL stimulation NK activity was increased with statistical significance. Therefore our findings show that the reduction of NK activity in neoplastic patients is not an irreversible phenomenon since it can be restored by "in vitro" AL administration. This is important for the adoptive immunotherapy by which we could give LAK cells to the patients.

Drug Combinations↗
PubMed1989

Calcium and sodium transport in gestational hypertension.

The enzymatic activities of Na+/K+ ATPase and Ca2+ ATPase were determined on erythrocyte membranes from 9 normotensive and 9 gestational hypertensive pregnant women near term. A reduction in the activity of the Na+/K+ ATPase and a relative increase in the activity of the Ca2+ ATPase were found in the hypertensive patients, possibly due to a conformational alteration of erythrocyte membranes. This observation supports the possible role of the transmembrane cation transport in the pathogenesis of gestational hypertension.

Adult↗
PubMed1989

Behavioural state transitions in healthy and growth retarded fetuses.

The transitions, i.e. time intervals between two different behavioural states, were studied in 10 healthy and 10 growth retarded fetuses (IUGR) in near term pregnancies. In healthy fetuses, transitions usually lasted less than 3 min whereas IUGR fetuses showed a longer duration when compared to healthy fetuses. Moreover, a significant trend in the change of state variables (fetal heart rate, fetal eye movements and fetal gross body movements) was evident in healthy fetuses: fetal heart rate was the first variable to change in transitions from 1F to 2F and the last variable to change in transitions from 2F to 1F. On the other hand IUGR fetuses showed a random sequence in order of change. These findings were substantiated by the intraindividual consistency evidenced in repeated recordings. In conclusion the analysis of transitions differentiates between healthy fetuses and those affected by IUGR.

Blood Flow Velocity↗