Mauro Buscaglia

Venous drainage of the human uterus: Respiratory gas studiesin normal and fetal growth-retarded pregnancies

OBJECTIVE To determine respiratory gas relationships between the uterine veins and umbilical vein in normal and pregnancies complicated by intrauterine growth retardation. STUDY DESIGN Respiratory gases were measured in both uterine veins and the umbilical vein in eight normal and 13 pregnancies with intrauterine growth retardation. RESULTS No significant differences were found in the placental versus nonplacental uterine veins. There was a significant correlation for umbilical and uterine venous values of PO2 (p less than 0.002) and PCO2 (p less than 0.004) in appropriate-for-gestational-age pregnancies, umbilical venous PO2 was always less than uterine venous PO2, and PCO2 always greater than uterine. The transplacental gradient was significantly higher in intrauterine growth retarded than appropriate-for-gestational-age pregnancies for both POC2 and PCO2. There was a lower uterine oxygen extraction in intrauterine growth retarded pregnancies (p less than 0.05). CONCLUSION There is no consistent relationship between placental venous drainage in each uterine vein and placental location. The human placenta simulates a relatively inefficient venous equilibrator and the larger transplacental gradients in intrauterine growth retarded pregnancies may reflect differences in both perfusion pattern and placental structure.

In Vivo Placental Transport of Glycine and Leucine in Human Pregnancies

ABSTRACT: L-[1-13C]Glycine and L-[l-13C]leucine were infused as a bolus into 12 pregnant patients carrying normal fetuses before fetal blood sampling at gestational ages ranging from 20 to 37 wk. Maternal venous samples were obtained every 2-3 min for 15 min after the bolus infusion. Fetal samples were obtained from the umbilical vein within 15 min of the bolus. Amino acid plasma enrichments (molar percent enrichment) were determined by gas chromatography-mass spectroscopy and their concentrations by ion exchange chromatography. The ratios of glycine and leucine transfer were assessed from fetal/maternal enrichment ratios for each amino acid. We now report that over the gestational age range of 20-37 wk, under relatively undisturbed fetomaternal conditions (fetal blood sampling), human placental glycine transfer is limited, with a glycine/leucine ratio = 0.16 ± 0.02. We hypothesize that, in human pregnancies, the relative rates of in vivo transplancental transport of amino acids can be assessed indirectly utilizing fetal blood sampling and stable isotope methodology. The application of this approach to leucine and glycine demonstrates that the transfer of leucine is rapid (demonstrable in seconds), whereas that of glycine is more limited.

Cord sampling for the evaluation of oxygenation and acid-base balance in growth-retarded human fetuses

In 14 pregnancies complicated by intrauterine growth retardation, the umbilical cord was sampled before delivery under ultrasonic guidance for rapid fetal karyotyping. Fetal blood was analyzed for respiratory gases, acid-base balance, and lactate concentrations. Two patients were excluded from the study because cord samples were diluted with amniotic fluid. In six patients (group 1), the clinical assessment warranted continuation of pregnancy. Cesarean sections were performed in the remaining eight patients (group 2) within 8 hours of cord sampling. The data from the two groups were compared with those obtained from umbilical venous blood at the time of elective repeat cesarean section in term appropriate for gestational age infants (controls). No significant difference in PO2 was found between groups 1 and 2 and controls. In contrast, there were significant differences in oxygen saturation and acid-base balance between groups 1 and 2. Lactate concentration was inversely correlated with pH and was elevated in five of six fetuses requiring a prompt cesarean section: In two of these five fetuses, nonstress fetal heart rate tracings were reactive. The results suggest that fetal blood biochemistry, and particularly lactate concentration, may represent an additional indicator of fetal well-being in pregnancies complicated by intrauterine growth retardation.

Human neuronal cell viability demonstrated in culture after cryopreservation

A human neuronal cell freezing technique has been developed. The results indicate that human fetal neuronal cells can be frozen with 7%-10% dimethyl sulfoxide (DMSO) as cryoprotectant. The survival of isolated thawed cells has been evaluated in culture. Cells have been frozen at -196 degrees C for 370 days without loss of viability. Average recovery rate of frozen cells was 62% of the recovery rate of cultured unfrozen controls. Thawed cells show neurite outgrowth and maintain both cellular markers such as neuron specific enolase (NSE) and neurochemical characteristics (GABA synthesis). Morphological integrity of cryopreserved neurons has been confirmed at ultrastructural level.

Correlation between Fetal and Maternal Serum Bile Acid Concentrations

ABSTRACT: Serum concentrations of different bile acids (BA) were determined by radioimmunoassay in 56 human fetuses and mothers. Serum was obtained immediately after legal abortion, performed between the 14th and the 21st wk of gestation. Conjugated cholic (CCA) and chenodeoxycholic acid (CCDCA) concentrations were determined in 33 cases, conjugated lithocholic (CLCA) and deoxycholic acid (CDCA) in 20, and sulfolithocholyglycine (SLCG) in 15. In fetal blood, mean concentrations of CCA (0.80 ± 0.40 μmol/liter), CCDCA (4.50 ± 2.70 μmol/liter), and CLCA (1.70 ± 1.04 μmol/liter) were significantly higher than those in the mother (CCA 0.34 ± 0.17 μmol/liter; CCDCA 0.79 ± 0.34 μmol/liter; CLCA: 0.70 ± 0.30 μmol/liter; p < 0.001); fetal serum levels of CDCA (0.46 ± 0.32 μmol/liter) and SLCG (0.15 ± 0.09 μmol/liter) were lower than in the mothers (CDCA 1.20 ± 0.80 μmol/liter, p < 0.001; SLCG 0.40 ± 0.30 μmol/liter, p < 0.01). There was no correlation between levels of BA and gestational age. Serum total protein and albumin concentrations were both reduced in 10 fetuses as compared with the mothers. These data support the concept of a state of physiologic cholestasis during development and suggest that placental transfer of primary BA occurs mostly in the fetal to maternal direction. This transfer could be facilitated by the reduced fetal plasma albumin concentration, since BA in free solution diffuse more easily through the placenta. There is evidence of lithocholic acid synthesis in the fetal liver, while deoxycholic acid appears to be mostly of maternal origin. Finally, sulfation of BA is poorly developed at this age of gestation.

Development of Dopaminergic Neurons in the Human Mesencephalon and in Vitro Effects of Basic Fibroblast Growth Factor Treatment

The origin and development of the mesencephalic dopaminergic (mesDA) neurons within the substantia nigra were characterized in human embryos from Postconception (PC) Week 5.0 to 12.0. Tyrosine hydroxylase (TH) immunoreactive cells were first demonstrated in the ventral mesencephalon at PC Week 5.5 next to the ventricular zone. Cell migration and neurite outgrowth of TH-positive neurons were timed. Early expression of ganglioside GM1 was demonstrated in developing neurons. Glial fibrillary acidic protein (GFAP) was first observed at PC Week 10.0 instead, after the dopaminergic neurotransmitter phenotype expression. In vitro complementary information was obtained: TH-positive cells represented about 3% of the total cell population after a week in culture, based upon accurate anatomical dissection. They tended to form microaggregates and to grow in close contact with glial cells. MesDA neuronal expression of TH activity was measured by a biochemical microassay. TH-positive cells responded to basic fibroblast growth factor (bFGF) both with increased TH activity and neuronal survival. bFGF effects were mediated by the proliferative action on glial cells. Astroglial GFAP-positive cells express nerve growth factor-low-affinity receptor in culture. Information on in vitro and in vivo sequences of mesDA neuronal development and their response to identified neurotrophic molecules may be invaluable for selection of the most appropriate tissue donor age for brain grafting and development of alternative treatment strategies for Parkinsons disease.

Chromosome 14 maternal uniparental disomy in the euploid cell line of a fetus with mosaic 46,XX/47,XX,+14 karyotype

We investigated the parental origin of the extra chromosome 14 and of the two chromosomes 14 of the euploid cell line, in a case of fetal mosaicism 46,XX/47,XX+14 diagnosed at amniocentesis. Molecular analysis of five polymorphic loci of the short tandem repeat type was performed. Markers D14S43 and D14S49 showed the presence of maternal uniparental disomy of chromosome 14 in the apparently normal cell line. The distribution of the markers analysed along the chromosome suggests maternal heterodisomy with a large isodisomic segment in the telomeric region, possibly caused by meiotic crossing-over.

B and T Lymphocyte Subsets in Fetal and Cord Blood: Age-Related Modulation of CD1c Expression

Peripheral blood lymphocytes from fetal, term and adult subjects were analyzed with a panel of B- and T-lymphoid differentiation markers. CD1c +ve and CD5 +ve B cell (IgM +ve) percentage in fetal, cord and adult blood decreased significantly. Fetal and cord blood contained less CD2+ and CD3+ T lymphocytes and a higher percentage of CD38 +ve cells than adult blood. The phenotypic changes occurring during perinatal age in humans relate to the changes in the functional activities of the B and T lymphoid subsets from fetal to postnatal age.

Soluble transferrin receptor in the study of fetal erythropoietic activity

In order to evaluate fetal erythropoiesis we measured red blood cells, hemoglobin, hematocrit, serum transferrin receptor (sTfR), and iron status parameters in fetuses undergoing percutaneous umbilical blood sampling, and in normal newborns at term. We found high levels of sTfR in fetuses and newborns as compared with normal adults (3,149 ± 181 vs. 1,881 ± 137 ng/ml, P < 0.00001). Concentrations of sTfR correlate with gestational age and red blood cell numbers (r = 0.441, P < 0.001; r = 0.366, P = 0.06). sTfR concentrations do not show correlation with iron status parameters. The increased sTfR concentration is consistent with the fact that fetal life is characterized by cell proliferation and tissue growth. sTfR concentration correlates with gestational age and numbers of red blood cells, and can therefore be considered a good indicator of fetal erythropoiesis. It is conceivable that, during intrauterine life, sTfR expression is independent from iron status. sTfR determination will help in reaching a better understanding of some aspects of fetal physiology, and will help elucidate the physiopathology of fetal hematological diseases.

Respiratory gases, acid-base balance and lactate concentrations of the midterm human fetus

Respiratory gases, acid-base balance, and lactate and hemoglobin concentrations were measured in 14 fetal blood samples between 17 and 21 weeks of gestation. The samples were obtained at the time of fetoscopy performed for prenatal diagnosis. Results have been compared with two reference groups: (a) 4 patients in whom fetal cord blood sampling was performed at 32-36 weeks of gestation, and (b) 10 patients at the time of elective cesarean section, 35-39 weeks. PO2 and oxygen saturations were significantly higher and hemoglobin concentration lower in the mid-gestation fetus. Acid-base balance was not significantly different. There was a significant correlation between maternal and fetal hemoglobin concentrations. The oxygen affinity of fetal blood was not significantly different from that described for term fetuses with a oxygen saturation of less than 90%.