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Biomedical subjects

C H Rodeck

Publications and source records attributed to C H Rodeck.

At least 199 records · Page 11Linked to original sources
PubMed1987

Human fetal lymphocytes require T cell growth factors for cytotoxic responses.

Lymphocytes isolated from the blood of 17 human fetuses, varying in gestational age between 16 and 26 weeks, were tested for their capacity to generate specific cytotoxic cells after mixed lymphocyte culture (MLC) with allogeneic cells in the presence or absence of exogenous T cell growth factor (TCGF). Blood cells from seven fetuses, distributed throughout the age range, failed to generate cytotoxic cells even when TCGF was added in MLC, whereas six others gave positive responses but only when exogenous TCGF was present during the sensitisation phase. The maturation induced in the latter was not caused solely by a direct, non-specific effect of the TCGF, for control responder cells incubated with TCGF in the absence of allogeneic stimulator cells always responded less strongly or not at all. Fetal blood lymphocytes from the remaining four fetuses gave significant cytotoxic responses that were not augmented by TCGF. It is concluded that there can be a clear dichotomy between proliferative and cytotoxic responses to alloantigens and that the inability of human fetal blood lymphocytes to mount cytotoxic responses at this stage of development might be due to deficiencies in helper cells, cytotoxic precursors or both. For three fetuses it was possible to study, additionally, cytotoxic responses of spleen, liver and thymus with and without TCGF. None of them made specific responses even when TCGF was added, though cells from two spleens and one thymus responded directly to TCGF. To ascertain whether the absence of cytotoxic responses might have been caused by a failure of blood, spleen, thymus or liver cells to proliferate, their mixed lymphocyte reactivity, as detected by the uptake of 3H-thymidine, was studied without exogenous TCGF. Whereas thymus cells from only one of five fetuses responded, cells from all other tissues (including blood) responded consistently.

Adult↗
PubMed1987

Relationship of fetal hemoglobin and oxygen content to lactate concentration in Rh isoimmunized pregnancies.

Fetal blood samples were obtained fetoscopically from 32 Rh isoimmunized pregnancies at 18-32 weeks' gestation, and the hemoglobin concentration, plasma lactate concentration, and oxygen content were measured. When the hemoglobin concentration was more than 8 g/dL, the umbilical arterial and venous lactate concentrations were equal. Abnormal elevations of lactate were found in the umbilical artery at hemoglobin concentrations below 8 g/dL (oxygen content 2 mmol/L) and in the umbilical vein at hemoglobin concentrations below 4 g/dL (oxygen content 2 mmol/L); the arterial lactate values were higher than the venous. These results show that lactate is produced by the human fetus stressed by anemic hypoxia and suggest that compensatory cardiovascular mechanisms are unable to maintain adequate oxygenation to all tissues when the umbilical venous oxygen content falls below 2 mmol/L.

Anemia↗
PubMed1986

First-trimester fetal diagnosis for haemoglobinopathies: report on 200 cases.

First-trimester prenatal diagnosis by DNA analysis was found to be possible in 224 (80%) of 281 families at risk of having a child with beta-thalassaemia major. 200 prenatal diagnoses, mainly for beta-thalassaemia or sickle-cell anaemia, were made by means of chorionic villus sampling and fetal DNA analysis. The overall fetal loss rate was 6.7%, the majority being in the first half of the programme. There was one misdiagnosis. Prenatal diagnosis was also carried out successfully for both pairs of twins in two pregnancies. Comparison of these results with 53 prenatal diagnoses made with DNA prepared from amniotic fluid suggests that the first-trimester procedure is more reliable. If further experience confirms that chorionic villus sampling has an acceptably low risk for both mother and fetus it will largely replace other methods for prenatal diagnosis of the haemoglobin disorders and other single-gene conditions.

Amniotic Fluid↗
PubMed1986

First-trimester prenatal diagnosis of cystic fibrosis with linked DNA probes.

Linkage analysis with cloned gene probes has shown that the mutation causing cystic fibrosis is located in the middle of the long arm of chromosome 7. First-trimester diagnosis of cystic fibrosis is reported in four informative families and second-trimester diagnosis in one family with fetal DNA prepared from chorionic villi, hybridised with the tightly linked DNA probes, pJ3.11 and met. Risk calculations show that the expected false-negative and false-positive rates are approximately 2% and 6%, respectively, for typical nuclear families with one affected living child. Existing probes are sufficiently informative to allow full diagnosis in about two-thirds of couples presenting with at least one affected child. In half of the remainder, the inheritance of one parental mutant chromosome can be deduced.

Biopsy↗
PubMed1986

Ultrasound-guided sampling of umbilical cord and placental blood to assess fetal wellbeing.

Fetal and maternal placental (intervillous) blood samples were obtained by means of an outpatient ultrasound-guided technique from a 33-week pregnancy with symmetrical intrauterine growth retardation. The baby was delivered by emergency caesarean section because blood gas, pH, and lactate measurements showed severe hypoxic acidosis, due to inadequate placental transfer.

Acidosis↗
PubMed1986

First trimester prenatal diagnosis of congenital rubella: a laboratory investigation.

Acute primary maternal infection with rubella virus during pregnancy often, but not invariably, leads to the congenital rubella syndrome. Diagnosis by detection of virus specific IgM in the mother is not always possible, and in those cases in which IgM is detected the fetus has not necessarily also been infected. A method for direct, prenatal detection of fetal infection would allow more accurate early diagnosis of congenital rubella syndrome. In this study a case of suspected preconception rubella infection that was not referred until 14 weeks after the appearance of a rash was studied to determine whether a retrospective serological diagnosis of primary rubella could be made, and whether direct evidence of fetal infection could be obtained from a chorionic villus biopsy specimen by detecting virus specific antigens or ribonucleic acid (RNA) sequences. Monoclonal antibodies and a cloned complementary deoxyribonucleic acid probe were used successfully to detect antigens to rubella virus antigens and RNA sequences in the chorionic villus biopsy specimen, which was taken at 15 weeks' gestation. This method should serve as a new approach to the diagnosis of congenital rubella syndrome in utero.

Adult↗
PubMed1986

Rapid karyotyping in non-lethal fetal malformations.

Pure fetal blood samples were obtained fetoscopically, at 16-36 weeks' gestation, from 118 pregnancies complicated by ultrasonographically demonstrable fetal anomalies. Cytogenetic analysis of fetal lymphocytes yielded results within two to four days. Chromosomal abnormalities were found in 12 of 37 fetuses with non-haemolytic hydrops fetalis, 8 of 12 with exomphalos, 1 of 3 with duodenal atresia, 9 of 39 with obstructive uropathy, 1 of 3 with unilateral pleural effusion, 2 of 10 with severe growth retardation and oligohydramnios, 2 of 9 with isolated hydrocephalus, and 3 of 4 with choroid plexus cysts (of the last 4, 1 also had obstructive uropathy and 1 exomphalos). 3 fetuses with gastroschisis were cytogenetically normal. The results suggest that rapid fetal karyotyping is advisable in all cases of non-lethal or potentially correctable fetal malformations detected sonographically during the second or third trimester of pregnancy.

Chromosome Aberrations↗
PubMed1986

Have Liley charts outlived their usefulness?

Fetal blood and amniotic fluid samples were obtained fetoscopically from 59 rhesus-isoimmunized pregnancies at 18 to 25 weeks' gestation. Fetal hemoglobin was measured and amniotic fluid optical density deviation at a wavelength of 450 nm determined. Two sets of normal reference values for optical density at 450 nm and fetal hemoglobin at 16 to 36 and 16 to 25 weeks were established from 475 amniotic fluid and 153 fetal blood samples obtained from pregnancies not complicated by fetal hemolysis. As expected, there was a significant linear correlation between the degree of fetal anemia and the amniotic fluid optical density at 450 nm in rhesus-isoimmunized pregnancies. However, the values of optical density at 450 nm were widely scattered, thereby limiting their ability to predict accurately the severity of disease in these second-trimester pregnancies. In 25 of the patients, the value of optical density at 450 nm was determined at 6 to 16 days before fetoscopy. The severity of fetal anemia could not be predicted by the trend in optical density at 450 nm. These data suggest that the only reliable method to determine the severity of rhesus isoimmunization in the second trimester of pregnancy is the direct measurement of fetal hemoglobin.

Amniotic Fluid↗
PubMed1986

Fetoscopy.

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Female↗
PubMed1986

Prenatal diagnosis of hereditary red cell membrane defect.

The red cells of a severely anaemic 2-year-old child of a white British family showed high haemolytic fragility with poikilocytosis. The cells showed markedly impaired thermal stability. The mother was phenotypically normal, but the father's red cells showed mild elliptocytosis. The spectrin from the latter, extracted at low temperature, was 30% dimeric (cf. 5-10% in normals). Tryptic digests of the spectrin from both father and daughter showed a reduction in the fragment of 80,000 molecular weight, derived from the terminus of the alpha-chain, and the elevation of a fragment of molecular weight 46,000, as well as one of 53,000. These characteristics and the autosomal recessive inheritance lead to a diagnosis of type II hereditary pyropoikilocytosis, so far reported only in two black American families (Lawler et al, 1983). The spectrin from the father was examined with respect to thermal conformational stability, and was found to be normal. The spectrin from the cells of the daughter gave evidence of the presence of oxidative (disulphide) cross-links, as well as of extensive noncovalent aggregation. Blood was obtained from the umbilical cord vein of the 19-week fetus of the pregnant mother: 250 microliters of blood was used for preparation of red cell membranes for SDS-gel electrophoresis and for extraction of spectrin. Analysis of the spectrin by gel electrophoresis in the native state revealed that the proportion of dimer was within the normal range, and the fetus therefore did not possess the hereditary pyropoikilocytosis phenotype. It is suggested that the procedures described could be generally applied to the prenatal identification of phenotypes associated with severe haemolytic anaemias.

Anemia, Hemolytic, Congenital↗
PubMed1986

Normal levels of ATP, total nucleotides and activities of three enzymes related to nucleotide metabolism in fetal erythrocytes.

Pure fetal blood was obtained by direct-vision fetoscopy from 30 fetuses at 17-23 weeks gestation. The erythrocyte concentrations of ATP and total nucleotides and the activities of the enzymes pyrimidine-5'-nucleotide nucleosidase (Pyr5N), phosphoribosylpyrophosphate (PRPP) synthetase and adenylate kinase (AK) were analysed by established techniques to find the normal ranges for this gestational age. The ranges were relatively narrow and could serve as reference values for the prenatal diagnosis of defects in nucleotide metabolism. The results from the fetal erythrocytes were compared with the corresponding values from the maternal blood collected and analysed concurrently. The ATP and total nucleotide concentrations and the activity of Pyr5N in the fetal cells were substantially higher than those of the maternal blood. The activities of PRPP synthetase and AK were much lower. The significance of these findings is discussed.

5'-Nucleotidase↗
PubMed1986

The arylsulphatases of chorionic villi: potential problems in the first-trimester diagnosis of metachromatic leucodystrophy and Maroteaux-Lamy disease.

Three pregnancies at risk for late infantile metachromatic leucodystrophy have been monitored using chorionic villus biopsies. In the first of these a false negative diagnosis was made following assay of arylsulphatase A in villi. Subsequent studies have shown that this error was probably due to interference from another sulphatase in the villi, although the possibility that maternal contamination was also partly responsible could not be excluded. For reliable prenatal diagnosis of metachromatic leucodystrophy using chorionic villi it is advisable that studies with the nitrocatechol substrate are carried out on fractionated homogenates, or that the natural substrate is used. Problems may also occur when chorionic villi are used for assay of arylsulphatase B for first trimester diagnosis of Maroteaux-Lamy disease.

Arylsulfatases↗
PubMed1986

Calcium homeostasis in second trimester fetuses.

The concentrations of ionised calcium ions (Ca++), total calcium, parathyroid hormone, pH, total protein, albumin, sodium, and potassium were measured in paired fetal and maternal blood from pregnancies at 15 to 24 weeks' gestation. Pure fetal blood samples were obtained fetoscopically. The concentrations of fetal ionised calcium ions (n = 26); mean (SD) 1.33 (0.12) mmol/l (5.32 (0.48) mg/100 ml) and those of parathyroid hormone (n = 9); 68 (19) pmol/l (58 (16) micrograms/100 ml) were significantly higher than those of the mothers: 1.18 (0.09) mmol/l (4.7 (0.4) mg/100 ml), and 40 pmol/l (less than 34 micrograms/100 ml), respectively. There was no difference between measured fetal and maternal total calcium, pH, and electrolytes. The fetal total protein and albumin concentrations increased with gestation but were always lower than the equivalent maternal values. The calculated total calcium was 0.23-0.45 mmol/l (0.9-1.8 mg/100 ml) higher in the fetal than in maternal blood from the same pregnancy. There were no fetal arteriovenous differences in ionised calcium ions despite higher venous pH.

Blood Proteins↗
PubMed1986

Prenatal diagnosis of bullous ichthyosiform erythroderma: detection of tonofilament clumps in fetal epidermal and amniotic fluid cells.

The prenatal diagnosis of bullous ichthyosiform erythroderma (BIE) has been achieved at 20 weeks' gestation by electron microscopic identification of a pathognomonic cytoskeletal abnormality within fetal epidermal cells obtained by fetoscopic skin biopsy. The same abnormality was also observed in skin derived amniotic fluid cells. The question whether amniocentesis might be used instead of fetoscopy for future prenatal detection of BIE is discussed.

Actin Cytoskeleton↗
PubMed1986

Fetal tissue biopsy: techniques and indications.

A considerable variety of invasive intrauterine procedures has been developed in the last 15 years. This article describes techniques for obtaining fetal blood, skin, liver, tumour specimens and chorionic villi, and discusses their indications and risks.

Biopsy↗