Biomedical subjects

U Nicolini

Publications and source records attributed to U Nicolini.

At least 55 records · Page 3Linked to original sources

PubMed1994

Measurements of fetal limb bones in early pregnancy.

The fetal humerus, radius/ulna, femur, tibia/fibula and foot were measured in 296 pregnant women at 64-108 days' menstrual age, using vaginal sonography. All limb measurements correlated significantly with gestational age and biparietal diameter independently. Ratios of limb segment lengths did not change with gestation. Reference ranges (mean and 95% data intervals) were constructed for each limb segment. These data may prove useful in prenatal diagnosis of skeletal dysplasias and in the antenatal assessment of patients at risk of chromosomal abnormalities.

Journal Article↗

PubMed1994

Prenatal diagnosis of congenital human cytomegalovirus infection.

Fifteen fetuses at risk of congenital human cytomegalovirus (HCMV) infection underwent prenatal diagnosis at 16-30 weeks' gestation by a combination of amniocentesis and fetal blood sampling. HCMV was isolated from the amniotic fluid in six patients, but HCMV-specific IgM was detected in only three of them. Two of the nine neonates, who were delivered following a negative prenatal diagnosis, had congenital HCMV infection diagnosed by virus isolation in the urine. The interval from infection to prenatal testing was 3 and 4 weeks in the two false-negative cases and > or = 7 weeks in the true-positive cases. Although timely testing for HCMV infection allows the option of termination of pregnancy, it may be flawed by false-negative results.

Amniocentesis↗

PubMed1994

Erythropoietic suppression in fetal anemia because of Kell alloimmunization.

OBJECTIVE: Our purpose was to test the hypothesis that maternal anti-Kell alloimmunization produces fetal anemia by erythroid suppression. STUDY DESIGN: Erythropoiesis in 11 anemic fetuses from maternal anti-Kell alloimmunization was compared with that in 11 fetuses where the mother was alloimmunized to RhD; each was matched for hematocrit, gestational age, hydrops, and perinatal outcome. Comparisons of the difference were performed by either paired t or Wilcoxon tests. RESULTS: The anti-Kell group had reduced reticulocytosis (p = 0.007) and erythroblastosis (p = 0.045) and lower amniotic fluid bilirubin concentrations (p = 0.02) in comparison with the anti-D group. No correlation was found between hematocrit and reticulocytosis in the anti-Kell group, whereas the anti-D group had a significant linear relationship (r = 0.63, p < 0.05), indicating a progressive reticulocytosis in response to the degree of anemia. CONCLUSION: These findings suggest that erythroid suppression, rather than hemolysis, is the predominant mechanism in producing fetal anemia related to maternal Kell alloimmunization. Fetal blood sampling is the investigation of choice in the evaluation of anemia related to maternal Kell alloimmunization, because reduced hemolysis means amniotic fluid bilirubin concentrations correlate poorly with anemia.

Erythroblastosis, Fetal↗

PubMed1994

Transplacental IgG subclass concentrations in pregnancies at risk of haemolytic disease of the newborn.

The relationship of haemolytic disease of the newborn (HDN) to the transplacental passage of the four IgG subclasses was assessed at various gestational ages by comparing the maternal and fetal IgG subclass concentrations in 34 pregnancies at risk of HDN with those in 30 pregnancies not at risk. Higher maternal and fetal IgG1 levels were attained in pregnancies at risk of HDN than in pregnancies not at risk. In contrast, a slight decrease in maternal IgG2 and IgG4 levels occurred in pregnancies at risk of HDN, as compared with a slight rise in maternal IgG2 and IgG4 levels in pregnancies not at risk of HDN. Changes in fetal IgG2 and 4 concentrations in either type of pregnancy were very similar, showing only slight increases between the 19th and 34th week of gestation. A slight decrease in maternal IgG3 occurred in both types of pregnancy. In contrast, higher and fairly steady levels of fetal IgG3 were observed in fetuses not at risk of HDN throughout gestation, when compared with those in 'at risk' pregnancies. However, the statistical reliability of these results is not clear since only small numbers of samples were tested and because wide variations in IgG concentrations were observed. The IgG subclass concentrations in 50 paired maternal and cord blood samples were also measured and revealed that IgG1 levels were substantially higher in cord rather than maternal blood; cord and maternal IgG2, 3 and 4 levels, on the other hand, were fairly similar.

Erythroblastosis, Fetal↗

PubMed1994

The effect of neuromuscular blockade on human fetal heart rate and its variation.

OBJECTIVE: To determine the effect of neuromuscular blockade on fetal heart rate and its variation. DESIGN: Case control study. SETTING: Tertiary referral fetal medicine unit in a London teaching hospital. SUBJECTS: Forty women with rhesus iso-immunisation requiring an intravascular fetal blood transfusion between 28 and 34 weeks gestation. INTERVENTION: Intravascular injection of pancuronium to the fetus prior to fetal blood transfusion in 20 cases. MAIN OUTCOME MEASURES: Comparison between the group receiving pancuronium and the control group with regard to differences in perceived fetal activity and computer derived numerical indices of fetal heart rate and fetal heart rate variation after fetal blood transfusion. RESULTS: After transfusion in the control group, there were fewer perceived fetal movements, a small reduction in fetal heart rate but no differences in number of fetal heart rate accelerations or measures of fetal heart rate variation. In the study group, pancuronium produced no change in fetal heart rate despite a virtual abolition of perceived fetal movements and fetal heart rate accelerations. Measures of fetal heart rate variation were reduced by 60%. Comparison of the pre- to post-transfusion changes between the two groups showed significant differences for all fetal heart rate indices. CONCLUSION: Fetal activity accounts for more than half the measured variation of the human fetal heart rate.

Blood Transfusion, Intrauterine↗

PubMed1994

Cervical changes throughout pregnancy as assessed by transvaginal sonography.

OBJECTIVE: To evaluate changes in cervical dimensions by transvaginal ultrasound in non-randomly selected pregnant women. METHODS: This longitudinal study included 154 pregnant women undergoing transvaginal ultrasound assessment of the cervix at a mean gestational age of 12, 16, 20, 25, and 31 weeks. On each occasion, the longitudinal and anteroposterior diameters of the cervix were measured. The rate of prematurity in the series was 1.9%, and the mean gestational age at delivery was 38.7 weeks. RESULTS: Overall, cervical length (mean 4.3 cm; 95% confidence interval 4.1-4.3) did not change significantly (P = .06), whereas the anteroposterior diameter of the cervix at its midportion shortened throughout the investigated period of gestation. Multiparous women had longer and thicker cervices than primigravidas or women with previous cesareans or first-trimester abortions. Gestational age at delivery did not correlate with cervical dimensions at any stage of pregnancy. CONCLUSIONS: The cervix undergoes a change in shape from cylindrical to conic, more marked in primigravidas than in parous women. Women who had previous cesarean deliveries had cervical characteristics similar to primigravidas; therefore, it appears that mechanical, rather than hormonal, factors have a greater effect in determining changes of cervical dimensions throughout pregnancy.

Adult↗

PubMed1994

Maternal and fetal platelet activation in normal pregnancy.

OBJECTIVE: To study the platelet activation phase in normal pregnant women and their fetuses, both in vivo under basal conditions and in vitro after stimulation by adenosine diphosphate (ADP), a weak agonist, and U46619, a strong one. METHODS: Platelet function was investigated in 39 normal pregnant women and their fetuses undergoing fetal blood sampling at 18-37 weeks' gestation, using flow cytometry and the anti-GMP140 monoclonal antibody. This combined technique allows platelets to be investigated in small aliquots of whole blood, and it detects platelet secretion regardless of aggregation. In all cases, the percentage of activated platelets was determined under basal conditions and after addition of platelet agonists: ADP at concentrations of 10 and 50 mumol/L, and U46619, a stable analogue of thromboxane A2, at 1 mumol/L. RESULTS: Compared to nonpregnant controls, pregnant women had a significantly lower percentage of activated platelets after addition of U46619 (P = .02). Compared to their mothers, fetuses had significantly inferior platelet activation after addition of both platelet-activating factors at all concentrations used (ADP 10 mumol/L, P < .0001 and ADP 50 mumol/L, P < .0001; U46619, P < .0001). Maternal and fetal platelet activation did not change with duration of gestation. In the fetus, the percentage of activated platelets did not correlate with hematocrit, pH, or oxygen pressure, but it correlated significantly with platelet count after addition of U46619 (r = 0.45, P = .006). CONCLUSIONS: Decreased platelet activation in both pregnant women and fetuses suggests the action of a plasma factor that selectively inhibits prostaglandin-dependent activation. Prostacyclin, which is known to decrease platelet aggregation and release reactions caused by agonists, might have a greater inhibitory effect in the fetus than in the mother, or be present in larger amounts in the fetus.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

PubMed1993

46,XY/47,XY, + 17p + mosaicism in amniocytes associated with fetal abnormalities despite normal fetal blood karyotype.

46,XY/47,XY, + 17p + mosaicism was found in two primary amniotic fluid cultures (AFCs). Fetal blood karyotype was normal, but ultrasonography revealed Dandy-Walker malformation and bilateral choroid plexus cysts. Following termination of pregnancy, fetal examination revealed post-axial polydactyly and neuroblastoma-in-situ affecting both adrenals in addition to the cerebellar abnormalities. Mosaicism for the aberrant cell line was confirmed in all fetal tissues sampled and in the placenta.

Abnormalities, Multiple↗

PubMed1993

Prenatal diagnosis of anatomical connections in conjoined twins by use of contrast magnetic resonance imaging.

Omphalopagus conjoined twins were diagnosed by ultrasonography in a pregnant woman at 21 weeks' gestation. In order to clarify the anatomical connections, magnetic resonance imaging (MRI) was performed, having achieved fetal paralysis by intravascular injection of 100 mg of pancuronium into each twin. Prior to MRI, 2 ml of a 0.0001 mmol/ml solution of gadolinium DTPA was also injected into the stomach of one twin. The contrast agent opacified the bowel loops of both twins, indicating bowel to bowel anastomosis. Following pregnancy termination, autopsy confirmed the prenatal diagnosis.

Abortion, Therapeutic↗

PubMed1993

Prenatal confirmation of trisomy 12 mosaicism by fetal skin biopsy.

Trisomy 12 mosaicism diagnosed at 16 weeks' amniocentesis in a 42-year-old woman was not confirmed at 18 weeks' gestational age in amniotic fluid or fetal blood. Fetal skin biopsy performed at the same time did, however, allow the detection of trisomy 12 in 1 of 14 fibroblasts analysed. Fetal skin biopsy can be included within the diagnostic procedures to be performed when a level III mosaicism is found in the amniotic fluid.

Adult↗

PubMed1993

Prenatal treatment of congenital human cytomegalovirus infection by fetal intravascular administration of ganciclovir.

Ganciclovir was administered 'in utero' for 12 days in a 29-week-old fetus with ascertained congenital human cytomegalovirus (HCMV) infection, thrombocytopenia and elevated gamma-glutamyl transferase (gammaGT) value. Efficacy of therapy was shown by reduction in virus titer of amniotic fluid and fetal urine, disappearance of viral DNA in fetal blood, and normalization of platelet count and gammaGT value. However, stillbirth occurred at 32 weeks of gestation and HCMV inclusion bodies were detected in kidneys, lungs, heart and pancreas at autopsy. During therapy, side-effects,possibly related to ganciclovir administration, were observed.

Journal Article↗

PubMed1993

Fetal urine analysis for the assessment of renal function in obstructive uropathy.

OBJECTIVES: The assessment of fetal renal function plays a key role in the evaluation of posterior urethral valve obstruction cases. The aim of our study was to determine the value of several urinary compounds, including beta 2-microglobulin, N-acetyl-beta-D-glucosaminidase, and microalbumin in the assessment of prenatal renal function in cases of posterior urethral valve and their potential role in the selection of such cases for in utero shunting. STUDY DESIGN: A range of urinary compounds was measured, including beta 2-microglobulin, N-acetyl-beta-D-glucosaminidase, and microalbumin in 25 cases of posterior urethral valve obstruction. These cases were divided into four groups based on outcome. The Mann-Whitney test and analysis of covariance were used. RESULTS: Sodium, calcium, and beta 2-microglobulin were the best predictors for fetal survival. beta 2-Microglobulin values > 13 mg/L were almost invariably associated with fatal outcome. CONCLUSION: The estimation of beta 2-microglobulin may help in counseling parents and in selecting cases for in utero shunting.

Acetylglucosaminidase↗

PubMed1993

Prenatal diagnosis and fetal therapy.

The protective effect of folic acid supplementation has been demonstrated in patients at risk of neural tube defects by a large, randomized double-blind study. The feasibility of second-trimester screening for Down syndrome, based on the combination of maternal and biochemical markers on maternal blood, has also been verified in two large series from both the United Kingdom and the United States. These results represent major advances in the field of prenatal diagnosis, which, in the future, is likely to rely more and more on better selection by noninvasive testing of high-risk patients. The emphasis has moved away from very early invasive testing due to concerns related to the safety of both early chorionic villus sampling and amniocentesis. Evaluation of renal damage in fetuses with obstructive uropathy by analysis of urinary biochemistry may constitute the basis for more efficient selection of cases amenable to antenatal treatment. Twin-to-twin transfusion syndrome remains a challenge for the future.

Congenital Abnormalities↗

PubMed1993

Acid-base and hematologic values at blood sampling in the evaluation of trisomic fetuses: a case-control study.

OBJECTIVE: To investigate whether nonhydropic trisomic fetuses display specific alterations of acid-base and/or hematologic values. METHODS: Acid-base and hematologic variables were analyzed in 28 trisomic fetuses (12 with trisomy 21 and 16 with trisomy 18) and 28 chromosomally normal controls matched for gestational age and fetal size undergoing fetal blood sampling at 18-36 weeks' gestation. RESULTS: There were no differences between the groups in pH, oxygen pressure, carbon dioxide pressure, and base excess. Compared with matched controls, hematocrit, hemoglobin, and red blood cell counts were significantly higher in fetuses with trisomy 21 and significantly lower in those with trisomy 18. All other hematologic variables were similar in trisomic fetuses and their controls. CONCLUSIONS: Growth retardation in trisomic fetuses is associated with decreased oxygen supply, as it is in chromosomally normal growth-retarded fetuses. The higher perinatal mortality that occurs with trisomies 21 and 18 is not explained by more pronounced hypoxemia for a given degree of growth retardation. There is no specific association of acid-base and hematologic values that is diagnostic of chromosomal abnormality at fetal blood sampling.

Acid-Base Imbalance↗

PubMed1992

Cystic lesions of the fetal kidney: diagnosis and prediction of postnatal function by fetal urine biochemistry.

Fetal urine was aspirated under ultrasound control from 21 large cystic renal masses in 18 pregnancies of 20 to 35 weeks gestation. None were associated with bladder or ureteric dilatation. At postnatal investigation, 12 kidneys were demonstrated to be hydronephrotic (5 with no or poor function) and 9 multicystic. Urinary concentrations of sodium (Na+), calcium (Ca++), and phosphate (PO4--) were significantly higher in the multicystic group than in the hydronephrotic, whereas urea and creatinine levels were lower. Determination of urinary PO4-- enabled differential diagnosis with no false-positive or false-negative cases. Among hydronephrotic kidneys, no biochemical parameter accurately predicted postnatal function, although creatinine was increased in all three nonfunctioning kidneys. In hydronephrotic kidneys, urinary Na+ concentration increased with advancing gestational age (r = .66; P < .02), suggesting that the duration of hydronephrosis has a negative effect on renal function.

Calcium↗

PubMed1992

Mononuclear phagocyte assays, autoanalyzer quantitation and IgG subclasses of maternal anti-RhD in the prediction of the severity of haemolytic disease in the fetus before 32 weeks gestation.

In 40 cases of haemolytic disease of the fetus due to RhD immunization where the fetus required intrauterine transfusion, fetal packed cell volume was compared with the following parameters of maternal anti-D: (a) concentration, (b) IgG subclass, (c) activity in a macrophage binding assay, and (d) activity in a monocyte antibody-dependent cell mediated cytotoxicity (ADCC) assay. The anti-D concentration exceeded 4 iu/ml in all cases, correctly indicating the risk of haemolytic disease. A relationship between IgG subclass composition of the anti-D and severity of anaemia was not observed; IgG1, IgG3 and IgG1 + 3 antibodies were all detected. The ADCC assay gave the best correlation between assay results and fetal packed cell volume; high results correctly indicated fetal anaemia in 95% of cases. Macrophage binding assay results were only considered as high in 70% of cases. Overall, these results indicate that serological tests and bioassays in highly immunized mothers may not generate any information that proves more useful than ultrasonography and their previous obstetric history.

Antibody-Dependent Cell Cytotoxicity↗

PubMed1992

Fetal breathing movements in oligohydramnios are not increased by aminoinfusion.

OBJECTIVE: To determine whether fetal breathing movements (FBM) in pregnancies with oligohydramnios change with restoration of amniotic fluid volume. DESIGN: A prospective experimental study. SETTING: Fetal Medicine Unit, tertiary referral hospital. SUBJECTS: 16 women with singleton pregnancies complicated by severe oligohydramnios. INTERVENTIONS: Restoration of amniotic fluid volume by transabdominal amnioinfusion. Controls comprised pregnancies in which infused fluid leaked vaginally, so that oligohydramnios was not corrected. MAIN OUTCOME MEASURES: Change in total breathing movements, change in FBM incidence derived from 40 min recordings immediately before and after amnioinfusion. RESULTS: There was no significant difference in the change in total breathing movements or in the change in incidence of FBM between the 10 pregnancies in which amniotic fluid volume was restored, and the other six in which fluid leaked after infusion and volume was not restored. In both groups, there was no significant change with infusion in number of FBM (mean change -72, 95% CI -218 to +74 in the fluid-retained group and -64, 95% CI -273 to +145 in the fluid-leaked group) and incidence of FBM (median change -2.5%, range -27 to +10 in the fluid retained group and -4.5%, range -34 to +15 in the fluid-leaked group). CONCLUSIONS: This study suggests that restitution of amniotic fluid volume in human pregnancies complicated by severe oligohydramnios does not acutely alter the incidence of FBM. These data support an increasing literature suggesting that impairment of fetal breathing is not the mechanism for oligohydramnios-related pulmonary hypoplasia.

Amnion↗

PubMed1992

Midpregnancy plasma zinc in normal and growth retarded fetuses--a preliminary study.

OBJECTIVE: To determine plasma zinc concentrations in normally and abnormally growing fetuses. DESIGN: Prospective observational study. SETTING: Fetal Medicine Unit, Queen Charlotte's Maternity Hospital. SUBJECTS: 53 pregnant women attending for fetal blood sampling at between 18 and 40 weeks gestation. 27 fetuses were normal (central group), 11 fetuses were growth retarded and 15 were malformed. MAIN OUTCOME MEASURES: Plasma zinc concentrations in maternal and fetal blood at time of fetal blood sampling. RESULTS: In normally growing fetuses, between 18 and 40 weeks gestation, there was no fall in maternal plasma zinc concentration; the fetal level fell by 36%. In 10 fetuses with symmetrical growth retardation, plasma zinc concentration tended to be low, but was not significantly different from that in the normal control fetuses. CONCLUSION: The results suggest that (i) placental transfer of zinc is an uphill secretory process and that it is a rate-limiting step in the accumulation of zinc by the fetus and (ii) in fetuses with symmetrical intrauterine growth retardation, a low plasma zinc is probably a parallel phenomenon and not necessarily an aetiological factor.

Female↗