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Biomedical subjects

C H Rodeck

Publications and source records attributed to C H Rodeck.

At least 73 records · Page 4Linked to original sources
PubMed1995

Fetal haemoglobin concentration and mean red cell volume are not related to the maternal values at 18-25 weeks' gestation.

A cross-sectional study of 64 women and their fetuses undergoing cordocentesis at 18-25 weeks showed no significant correlation between maternal and fetal Hb or MCV and no relationship between these measurements and fetal abdominal circumference. We found no evidence for a nutritional or physiological association between maternal and fetal haematological status.

Cordocentesis↗
PubMed1995

The time of appearance and disappearance of fetal DNA from the maternal circulation.

A single copy Y-chromosome DNA sequence was amplified using the polymerase chain reaction (PCR) from the peripheral blood of 30 women who had achieved a pregnancy through an in vitro fertilization (IVF) programme. The time of conception was known precisely and was confirmed by serial ultrasound scans. Conceptions were dated as the number of weeks after fertilization plus 2, to give a time equivalent to the obstetric menstrual dating of the pregnancy (LMP). Y-chromosome-specific DNA was detected in all pregnancies with a male fetus (18/30). The earliest detection was at 4 weeks and 5 days, and the latest at 7 weeks and 1 day. Y-chromosome-specific sequences were no longer detected in any of the male pregnancies 8 weeks after delivery. No Y-chromosome sequences were detected in any of the pregnancies where only female babies were delivered. This demonstrates that fetal DNA appears in the maternal circulation early in the first trimester, that it can be identified in all pregnancies tested by 7 weeks, that it continues to be present throughout pregnancy, and that it has been cleared from the maternal circulation 2 months after parturition. Early non-invasive prenatal diagnosis for aneuploidies and inherited disorders will be possible in all pregnancies if fetal cells can be isolated free from maternal contamination (or identified accurately in the presence of maternal cells) without problems of contamination from previous pregnancies.

DNA↗
PubMed1995

Genetic basis of lethal junctional epidermolysis bullosa in an affected fetus: implications for prenatal diagnosis in one family.

Fetal skin biopsy at 20 weeks' gestation in a woman at risk for a child with the lethal skin-blistering disorder junctional epidermolysis bullosa (Herlitz) confirmed an affected fetus. Genomic DNA from the aborted fetus was examined for mutations in laminin 5, a macromolecule involved in adhesion at the dermal-epidermal junction, and a candidate protein in this condition. Polymerase chain reaction (PCR) amplification of exon 10 and parts of the flanking introns of the gene encoding the beta 3 chain of laminin 5 (LAMB3) and subsequent analysis by agarose gel electrophoresis showed a more slowly migrating band in the affected fetus compared with the normal control. Nucleotide sequencing of the abnormal PCR product revealed a homozygous 77 bp duplication within the exon, resulting in a premature termination codon 250 bp downstream from the 3' end of the duplication. Maternal DNA was heterozygous for the mutant and wild-type alleles. These findings illustrate the genetic basis of the skin disease in this case and also offer the prospects of a simple, rapid, and reliable first-trimester DNA-based prenatal, or even preimplantation, diagnostic test for future pregnancies in this family.

Adult↗
PubMed1995

Needle modifications for invasive fetal procedures.

OBJECTIVE: To investigate the effect of needle size and siliconization on fetal blood sampling, transfusion, and electrocardiography. METHODS: Standard needles were modified by increasing the internal (but not the external) diameter and either siliconization of the bore or external Teflon coating. The siliconized needles were subjected to a series of flow experiments with either blood or saline at various driving pressures, and assessed in clinical use during fetal transfusion and fetal blood sampling. The Teflon-coated needles were used for fetal transfusion to try and facilitate the fetal electrocardiogram (ECG). RESULTS: Under conditions simulating fetal transfusion, the siliconized needle allowed a 93% increase in flow rate compared to the standard needle (P < .05). Samples obtained after fetal transfusion with the siliconized needles were free of clots, whereas 50% of the post-transfusion samples with the standard needle had clots present. Similarly, samples taken for fetal platelet count were free of platelet clumping and clots with siliconized needles, but not with standard needles. Fetal ECG recordings were recorded successfully when Teflon-coated needles were used to access the fetal circulation via the intrahepatic vein. CONCLUSIONS: Modifications to standard needles improved blood flow and reduced the activation of coagulation during both fetal intravascular transfusion and platelet count measurement. Direct fetal ECG recording was facilitated by Teflon coating the external surface of the needle, insulating the fetal signal from maternal electrical signals.

Blood Transfusion, Intrauterine↗
PubMed1995

A major role of class I Fc gamma receptors in immunoglobulin G anti-D-mediated red blood cell destruction by fetal mononuclear phagocytes.

OBJECTIVE: To examine Fc gamma receptor (Fc gamma R) classes that direct immunoglobulin (Ig) G anti-D-mediated red blood cell interaction with fetal mononuclear phagocytes. METHODS: Mononuclear phagocytes isolated from fetal blood and spleen at 20-35 and 12-15 weeks' gestation, respectively, were tested in a modified mononuclear phagocytosis assay against IgG anti-D-coated red blood cells in the absence and presence of Fc gamma R class-specific monoclonal antibodies as inhibitors. Monocytes from cord and adult blood served as controls. RESULTS: In the absence of any inhibitor, attachment and phagocytosis indices of fetal monocytes were similar to those of their newborn and adult counterparts but markedly less than those of mononuclear phagocytes from fetal spleen. Blockade of the high-affinity Fc gamma RI caused a profound (more than 93%) reduction in red blood cell attachment and phagocytosis indices of fetal as well as newborn and adult monocytes. It also brought about a marked decrease in the attachment and phagocytosis indices of mononuclear phagocytes from fetal spleens (64 and 81%, respectively). With fetal spleen mononuclear phagocytes, anti-Fc gamma RII lacked any significant effect on their interaction with red blood cells, whereas anti-Fc gamma RIII caused a significant (43%) inhibition of their phagocytosis. CONCLUSION: Immunoglobulin G anti-D-mediated attachment to and phagocytosis by fetal mononuclear phagocytes of red blood cells is well developed early during the second trimester. High-affinity Fc gamma RI plays a major role in the effector function of circulating monocytes and splenic mononuclear phagocytes, whereas Fc gamma RIII, expressed strongly on the latter effectors, participates in target ingestion.

Antibodies, Monoclonal↗
PubMed1995

First trimester fetal nuchal translucency: problems with screening the general population. 1.

OBJECTIVE: To evaluate the feasibility of measuring first trimester nuchal translucency in an unselected population, to assess the relationship with gestation and maternal age and to measure reproducibility. DESIGN: A prospective observational study. SETTING: University College Hospital, London. SUBJECTS: One thousand and four women attending for a routine first trimester dating scan between eight and thirteen weeks of gestation. Measurements of nuchal translucency were attempted in 1368 (80.3%) and successful in 1127 (82% of attempts). RESULTS: Nuchal translucency is most easily measured at 11 weeks of gestation. If a cut-off of > or = 3 mm is used, 6% of unselected fetuses between eight and thirteen weeks of gestation are classified as abnormal. Nuchal translucency increases with gestational but not maternal age. Reproducibility is poor: by repeating measurements with a different operator, the same operator using a different still image, or the same operator using the same still image, 18.8%, 17.5% or 12.4% of nuchal translucency measurements, respectively, change their classification as normal or abnormal. CONCLUSIONS: If nuchal translucency > or = 3mm were used as an indication for karyotyping, 6% of the normal pregnant population would be screen positive. However, the percentage will vary greatly depending on the gestational age profile of the screened population. The poor reproducibility of nuchal translucency measurement could diminish its usefulness as a screening test for Down's syndrome.

Adult↗
PubMed1995

First trimester fetal nuchal translucency: problems with screening the general population. 2.

OBJECTIVE: To investigate first trimester nuchal translucency > or = 3 mm as a screening test for aneuploidy in the normal pregnant population. DESIGN: A pilot observational study. SETTING: University College Hospital, London. SUBJECTS: One thousand one hundred and twenty-seven women had measurements of nuchal translucency at the time of their dating scan (8-13 weeks of gestation). RESULTS: Seventy fetuses (6%) had a nuchal translucency > or = 3 mm. Five karyotypically abnormal fetuses were identified by standard routine techniques (three trisomy 21, two trisomy 18), all in high risk mothers (> or = 39 years). Only two had nuchal translucency > or = 3 mm (one trisomy 21, one trisomy 18). CONCLUSIONS: Although nuchal translucency measurement is feasible and promising, there is at present insufficient data to warrant its introduction for screening of the general population, or to replace traditional second trimester screening.

Adult↗
PubMed1995

Analysis of fetal and neonatal urine using proton nuclear magnetic resonance spectroscopy.

AIM: To use high field proton nuclear magnetic resonance spectroscopy (1H NMR) to characterise the low molecular weight metabolite composition of neonatal and fetal urine in relation to gestational age and perinatal outcome. METHODS: The first urine passed by two neonatal groups, six full term and five preterm infants with normal renal function, was analysed by 1H NMR and compared with fetal urine from 14 cases with obstructive uropathy. RESULTS: The mean ratios of taurine, myo-inositol, and trimethylamine-N-oxide (TMAO) to creatinine were 4.3, 10.1, and 14.1 times higher, respectively, in the preterm group when compared with those of the full term group. Fetal obstructive uropathy was characterised by glycosuria, amino and organic aciduria, regardless of gestational age (13-30 weeks). CONCLUSIONS: Samples of the first urine passed--that is, urine produced in fetal life--by normal preterm infants are useful controls for cases of obstructive uropathy detected in the third trimester. 1H NMR will become a clinically useful tool for monitoring renal development and abnormalities in utero.

Fetus↗
PubMed1995

Use of type VII collagen gene (COL7A1) markers in prenatal diagnosis of recessive dystrophic epidermolysis bullosa.

Generalised recessive dystrophic epidermolysis bullosa (EB) is a severe inherited disease in which patients suffer from blistering and scarring of the skin and mucous membranes after minor mechanical trauma. Tight genetic linkage has been established to the type VII collagen gene (COL7A1) at 3p21, with no evidence of locus heterogeneity. Several COL7A1 mutations have now been identified in recessive dystrophic EB patients. Prenatal diagnosis has been performed by examination of a fetal skin biopsy taken at about 16 weeks' gestation, and relies on identification of characteristic ultrastructural and immunohistochemical changes. We have now achieved a first trimester prenatal diagnosis using intragenic and flanking COL7A1 markers in a pregnancy at risk for recessive dystrophic EB. Segregation of the informative markers predicted the baby would be an unaffected carrier. The pregnancy continued to term and a healthy baby was born, confirming this result.

Collagen↗
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↗