Search PubMed⌕ Search

Biomedical subjects

B Modell

Publications and source records attributed to B Modell.

At least 91 records · Page 5Linked to original sources
PubMed1983

Method of sampling chorionic villi in first trimester of pregnancy under guidance of real time ultrasound.

Samples of chorionic villi were obtained in the first trimester by aspiration using a cannula passed transcervically under the guidance of real time ultrasound. In initial studies in 47 anaesthetised patients immediately before therapeutic abortion a method was developed giving a success rate of 89%. In 10 patients successful sampling was performed as an outpatient procedure without anaesthesia. In all, seven diagnostic procedures were undertaken and four of the five unaffected pregnancies continued. The technique of chorionic villous sampling using real time ultrasound is simple to learn and yields material for biochemical analysis and chromosomal study without the need for tissue culture. The exact obstetric risk, however, remains to be defined.

Catheterization↗
PubMed1982

Survival and desferrioxamine in thalassaemia major.

A small randomised trial and observation of all patients homozygous for beta-thalassaemia in Britain born in or before 1963 indicated that those patients who had received average weekly doses of more than 4 g of desferrioxamine over the previous few years were less likely to die in the near future than were patients of similar ages who had received less, or no, desferrioxamine.

Adolescent↗
PubMed1981

Ineffective erythropoiesis in haemoglobin E beta -thalassaemia: an electron microscope study.

Electron microscope studies have been performed on the bone marrow cells of two non-splenectomized patients and the circulating erythroblasts and reticulocytes of three splenectomized patients with HbE/beta-thalassaemia. Some intracellular precipitates (probably consisting of alpha-chains) and mild dyserythropoietic changes were found in the early polychromatic erythroblasts within the bone marrow. Larger quantities of precipitate and more marked dyserythropoietic changes were found in the late polychromatic erythroblasts and reticulocytes both within the marrow and within the circulation. The bone marrow macrophages contained phagocytosed erythroblasts within their cytoplasm. These data indicate that the anaemia in HbE/beta-thalassaemia results largely from dyserythropoiesis and ineffective erythropoiesis. The ultrastructural abnormalities encountered in the cases of HbE/beta-thalassaemia were qualitatively and quantitatively similar to those seen in homozygous beta-thalassaemia.

Adult↗
PubMed1981

Obstetric outcome and problems of mid-trimester fetal blood sampling for antenatal diagnosis.

Detailed follow-up is presented of 335 pregnancies in which mid-trimester fetal blood sampling was performed for the diagnosis of a haemoglobinopathy, mostly beta-thalassemia. There were three twin pregnancies. Thirty-eight fetuses were lost including four in whom a diagnosis of thalassemia major was made. Placentacentesis was particularly associated with fetal vessel trauma, exsanguination and early intrauterine fetal death, while late complications associated with fetoscopy or failed fetoscopy necessitating subsequent placentacentesis included spontaneous abortion, leakage of amniotic fluid and premature onset of labour.

Abortion, Spontaneous↗
PubMed1980

Thalassaemia as a model of recessive genetic disease in the community.

In order to gain understanding of some of the problems of genetic counseling for a severe recessive disease in England, a Greek Cypriot extended family including 87 living members and known to be transmitting a beta-thalassaemia gene was investigated for the extent and the sources of their knowledge about thalassaemia. 42% of members tested carried beta-thalassaemia trait: nearly half were already aware of this, but only 10% of the non-carriers were aware of their status. The study illustrated many of the difficulties in conveying accurate counselling to a whole community and the need for active involvement of all health workers, especially general practitioners. This study is also relevant to the approaching possibility of genetic counseling for cystic fibrosis.

Cyprus↗
PubMed1980

Effect of introducing antenatal diagnosis on reproductive behaviour of families at risk for thalassaemia major.

Families who were at risk of producing a child with thalassaemia major were studied to determine the sequential effects on their reproductive behaviour of knowing the risk and, subsequently, of knowing that antenatal diagnosis was available. Knowing the risk caused them virtually to stop reproduction and to seek termination of 70% of pregnancies, most of which were accidental. The introduction of antenatal diagnosis in 1975 permitted the resumption of nearly normal reproduction by at-risk families, with fewer than 30% of pregnancies being terminated for thalassaemia major. All couples at risk for thalassaemia major should be detected and counselled before they produce an affected child; responsibility for either choosing or refusing antenatal diagnosis should be theirs alone.

Abortion, Induced↗
PubMed1980

Model for antenatal diagnosis of beta-thalassaemia and other monogenic disorders by molecular analysis of linked DNA polymorphisms.

Polymorphisms of DNA restriction sites within the human fetal globin genes have been used to identify chromosomes that carry beta-thalassaemia genes in individuals heterozygous for this disease. This has allowed an antenatal diagnosis for beta-thalassaemia to be carried out by observation of the pattern of the inherited polymorphism of a linked DNA sequence not involved in the genetic pathogenesis of the disease. In the populations we have investigated there is no constant pattern of polymorphism that segregates with the beta-thalassaemia gene. The use of linked polymorphisms should, therefore, be applicable to antenatal diagnosis both of beta-thalassaemia and of any other single-gene defect for which there is a DNA probe specific for a sequence linked to the affected locus.

DNA↗
PubMed1980

Haematological aspects of antenatal diagnosis for thalassaemia in Britain.

The results are described of 200 antenatal diagnostic tests for haemoglobinopathies performed on samples of fetal blood obtained during the second trimester of pregnancy. Haemoglobin A synthesis in the fetus was measured by incorporation of tritiated leucine in vitro and separation of the globin chains on CM23 columns. The range of HbA synthesis detected was 3.5-8.0% in normal fetuses, 2.0-5.0% in fetuses with thalassaemia trait, and less than 1.6% in fetuses with thalassaemia major. There were eight cases in which other haemoglobinopathies were diagnosed. 29% of the pregnancies were terminated because thalassaemia major was diagnosed, and 9.5% of the remaining healthy fetuses were lost for obstetric reasons. Follow up has been possible for 96% of the 124 surviving babies and three misdiagnoses have come to light; one false positive (0.5%) and two false negatives (1%). These figures represent a first effort at antenatal diagnosis for haemoglobinopathies and it is likely that they will improve with the passage of time.

Chromatography, Ion Exchange↗