Adrenomedullin production is increased in normal human pregnancy.
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OBJECTIVE: Adrenomedullin, a recently discovered vasoactive peptide originally identified in pheochromocytoma, has been found to be increased in the plasma of pregnant women at term. This study was designed to elucidate whether adrenomedullin secretion is dependent on gestational age and the possible source and function of this peptide in human pregnancy. STUDY DESIGN: Adrenomedullin concentrations were determined by RIA in amniotic fluid and maternal plasma obtained from 110 pregnant women between 8 and 40 weeks of gestation. Subjects were stratified into five groups according to gestational age. In term patients (n = 15), adrenomedullin was also measured in the umbilical artery and vein separately. RESULTS: High concentrations of adrenomedullin were present in plasma and amniotic fluid samples from patients in the first, second and third trimester. There was no significant difference in mean maternal plasma concentration of adrenomedullin between the five patient groupings. Amniotic fluid adrenomedullin concentrations decreased from 81.2 +/- 11.7 pg/ml at 8-12 weeks of gestation to 63.7 +/- 6.0 pg/ml at 13-20 weeks of gestation and then increased at 21-28 weeks of gestation to 99.1 +/- 10.4 pg/ml. A further increase was found in samples collected after 37 weeks of gestation (132.6 +/- 10.1 pg/ml). In the umbilical vein, adrenomedullin concentration was higher (P < 0.05) than in the artery (65.7 +/- 6.1 pg/ml and 48.5 +/- 5.2 pg/ml respectively), suggesting that adrenomedullin in the fetal circulation derives from the placenta. CONCLUSIONS: Our results demonstrate the presence of adrenomedullin in maternal plasma and amniotic fluid throughout gestation, and show that its production starts very early in gestation, suggesting that this hormone may have an important role in human reproduction, from implantation to delivery. (+info)
Mosaic trisomy 17 in amniocytes: phenotypic outcome, tissue distribution, and uniparental disomy studies.
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Mosaicism for trisomy 17 in amniocyte cultures is a rare finding, whilst postnatal cases are exceptional. In order to gain insight into the possible effects of the distribution of the trisomic line and of uniparental disomy (UPD) on embryofoetal development, we have performed follow-up clinical, cytogenetic and molecular investigations into three newly detected prenatal cases of trisomy 17 mosaicism identified in cultured amniotic fluid. In the first case, the pregnancy ended normally with the birth of a healthy girl, and analysis of newborn lymphocytes and of multiple extra-embryonic tissues was indicative of confined placental mosaicism. The second case was also associated with a normal pregnancy outcome and postnatal development, and only euploid cells were found in peripheral blood after birth. However, maternal isodisomy 17 consequent to a meiosis II error and loss of a chromosome 17 homologue was detected in peripheral lymphocytes postnatally. In the third case, pathological examination after termination of pregnancy showed growth retardation and minor dysmorphisms, and the trisomic line was detected in foetal skin fibroblasts. In addition, biparental derivation of chromosome 17 was demonstrated in the euploid lineage. These results, together with previously reported data, indicate that true amniotic trisomy 17 mosaicism is more commonly of extra-embryonic origin and associated with normal foetal development. Phenotypic consequences may arise when the trisomic line is present in foetal tissues. Case 2 also represents the first observation of maternal UPD involving chromosome 17; the absence of phenotypic anomalies in the child suggests that chromosome 17 is not likely to be subject to imprinting in maternal gametes. (+info)
Collagenous constituents of amniotic fluid.
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The amniotic fluid (AF) was fractionated by dialysis, gel filtration and SDS/PAGE, and submitted to the assay of collagenous constituents. The collagenous character of peptides and proteins of amniotic fluid was confirmed by hydroxyproline (Hyp) assay and treatment with bacterial collagenase followed by electrophoresis and gel filtration of the digestion products. It was found that AF contains collagen degradation products but the classical method of Hyp determination described by Woessner (Arch. Biochem. Biophys., 1961, 93, 440-447) gives overestimated values due to the interference with other AF components. Fractionation of AF on Sephadex G-100 column allowed to remove the interfering material and to estimate the actual Hyp content which equals to approx. 6.2 microg/ml. About 70% of Hyp was found in low molecular dialyzable products and the rest (about 30%) appears to be a constituent of nondialyzable collagenous polypeptides of the molecular mass of about 7.9-26.3 kDa. It is suggested that such collagenous polypeptides may be the products of proteolytic conversion of collagen precursor (procollagen) into the monomeric form of this protein. No high molecular forms of collagen, corresponding to alpha-subunits, were found. (+info)
Prenatal diagnosis of spinal muscular atrophy type I (Werdnig- hoffmann) by DNA deletion analysis of cultivated amniocytes.
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AIM: Presentation of a prenatally diagnosed case of Werdnig-Hoffmann disease, the most severe type of spinal muscular atrophy. METHODS: DNA obtained from cultivated amniocytes was analyzed for deletions in the survival motor neuron gene and neuronal apoptosis inhibitory protein gene. RESULTS: The fetus was diagnosed as an affected homozygote for deletions in exon 7 and exon 8 of the survival motor neuron gene. No deletions of exon 5 in the neuronal apoptosis inhibitory protein gene were found. CONCLUSION: Direct DNA deletion analysis of the survival motor neuron gene and neuronal apoptosis inhibitory protein gene in affected families represents a highly reliable and fast method for prenatal diagnosis of Werdnig-Hoffmann disease. (+info)
Prenatal confirmation of the translocation between chromosome 15 and Y-chromosome by fluorescence in situ hybridization.
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A 30-year-old woman and her husband visited our hospital with habitual abortion as the complaint. Chromosome examination revealed a normal 46, XX for her and 46, XY, 15, der (15) t (Y; 15) (q12; p12) for him. After her pregnancy amniocentesis was performed. The karyotype was 46, XX, 15, der (15) t (Y; 15) (q12; p12) pat. ish der (15) (DYZ1+). A female baby was delivered. The growth of the baby was normal at 12 months of age. (+info)
Second-trimester maternal urine human chorionic gonadotrophin beta-core fragment concentrations in Asian pregnancies with fetal chromosomal abnormalities.
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The aim of this study was to investigate the second trimester concentrations of maternal urine human chorionic gonadotrophin beta-core fragment (HCGbetacf) in Asian pregnanci2es with fetal chromosomal abnormalities. HCGbetacf concentrations were analysed from 34 urine samples in chromosomally abnormal pregnancies, including 28 cases of Down's syndrome, one case of trisomy 18, and five cases of other chromosomal abnormalities (one mosaic deletion and four translocations), and in a cohort of 268 normal pregnancies receiving second trimester amniocentesis. Results were normalized to urine creatinine (Cr) concentration and converted to the multiple of the median (MOM) concentration for the appropriate gestation. The median HCGbetacf MOM concentrations of Down's syndrome pregnancies (12.89) was significantly higher than that of normal pregnancies (1. 06) (P < 0.00001). Wide variations of HCGbetacf concentrations were observed in other chromosomally abnormal pregnancies. There were 18 of 28 (64%) Down's syndrome cases but one of five (20%) other chromosomally abnormal cases with HCGbetacf concentrations above the 95th centile of the control values (8.22 MOM cut-off). These findings suggest that HCGbetacf could be a potential marker in urine screening for fetal Down's syndrome in Asians. (+info)
Prenatal diagnostic and prognostic value of human cytomegalovirus load and IgM antibody response in blood of congenitally infected fetuses.
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Human cytomegalovirus (HCMV) load and virus-specific IgM were quantified in blood of 36 fetuses from mothers with primary HCMV infection. Nineteen fetuses were congenitally infected and 17 were uninfected as diagnosed by virus isolation from and DNA detection in amniotic fluid. Sensitivity of antigenemia was 57.9%; of viremia, 55. 5%; of leukoDNAemia, 82.3%; and of IgM, 57.9%; specificity was 100% for all assays. When amniocentesis was performed, 4 HCMV-infected fetuses (group A) showed abnormal ultrasound and biochemical/hematologic findings, 8 (group B) had elevated gamma-glutamyl transferase values, and 7 (group C) had normal ultrasound and biochemical findings. Virus loads were higher in groups A and B than in group C. In group A, no pregnancy went to term, in group B, 3 of 6 newborns were symptomatic at birth, and in group C, the 6 newborns were subclinically infected. Taken together, virologic, laboratory, and ultrasound findings may contribute to a better prognostic definition of fetal HCMV infection. (+info)
Role of multicolor fluorescence in situ hybridization (FISH) in simultaneous detection of probe sets for chromosome 18, X and Y in uncultured amniotic fluid cells.
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Major aneuploidies diagnosed prenatally involve the autosomes 13, 18, and 21, and sex chromosomes. Fluorescence in situ hybridization (FISH) allows rapid analysis of chromosome copy number in interphase cells. The purpose of this study was to evaluate the role of multicolor fluorescence in situ hybridization in simultaneous detection of probe sets for chromosome 18, X, and Y in uncultured amniotic fluid cells as a safer alternative method for aneuploidy detection prenatally. Fifty amniotic fluid samples were analyzed by FISH and standard cytogenetics. Mean time to obtain results was three days for fluorescence in situ hybridization and 20 days for karyotype. Fluorescence in situ hybridization was informative in 43 samples (86%), and within this group, two aneuploidies were correctly identified. This evaluation demonstrates that FISH with X, Y, and 18 alpha satellite DNA probes could accurately and rapidly detect aneuploidies involving these chromosomes and could be used in any prenatal clinical laboratory. (+info)