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E Engel

Publications and source records attributed to E Engel.

At least 163 records · Page 9Linked to original sources
PubMed1980

[The problem of sex chromosome aneuploidy in genetic counseling using amniocentesis].

The identification of chromosomal alterations remains, undeniably, one of the major objectives of prenatal diagnosis by amniocentesis. A series of 500 cases personally tested by the authors confirms entirely the validity of the principal indication for, and the benefit of, this modern method for the intrauterine detection and prevention of many severe congenital chromosome defects. In our experience, the cases of genetic counselling following detection of sex chromosome anomalies have proven to be particularly difficult. In two of three situations where such a diagnosis was revealed (an XYY and XXY fetus), after hours of discussion and reflection, the parents opted to pursue the pregnancies to term. In the third case (an XYY fetus), an abortion was requested. Certain aspects of these decisions are discussed and the opinions of participants solicited.

Abortion Applicants↗
PubMed1979

[Prenatal diagnosis. Review, personal and prospective studies].

1. In a review of methods developed for the identification of fetal malformations, the technique, risks and results of amniocentesis are presented. 2. Large series already published have demonstrated the relative simplicity and feasibility of the procedure as well as current indications for its utilization. These include the detection of chromosomal anomalies, the determination of sex (in certain sex-linked disorders), documentation of enzymatic and metabolic deficiencies, and the demonstration of open lesions of the neural tube by appropriate techniques. 3. Experience with over 500 cases personally tested by the authors entirely confirms the major indications for and benefits of this modern method for the detection and prevention of severe congenital anomalies during early pregnancy. 4. The identification of chromosomal alterations is currently the major objective of the method. Increased risks are associated with pregnancies involving a maternal age of 35 years or older (which account for 1-3% of aneuploidies), the birth of a previous infant with free trisomy 21 (1% recurrence risk) or secondary to a parental chromosome translocation (as much as 10% risk of aneuploidy). Fetal karyotyping for determination of sex, in cases where the mother is a carrier of an X-linked recessive gene (on average, 50% of male offspring will be affected), is an inadequate method of diagnosis to be utilized only until alternative techniques render possible specific diagnosis of the anomalies under consideration (hemophilias A and B, muscular dystrophy, etc). 5. Several of these techniques are now nearing development through the advent of fetoscopy and advanced ultrasound methodology, and have already been applied to the detection of certain sex-linked disorders and also for diagnosis of hemoglobinopathies (thalassemias, sickel cell anemia) and other conditions requiring the obtaining of fetal blood for diagnosis. Technology allowing direct examination of fetal parts by means of optical instruments is particularly useful in cases where a severe fetal morphologic malformation cannot currently be identified by indirect visualization (ultrasound) or by analysis of cytogenetic or molecular markers. 6. Pathological accumulations of alpha-fetoprotein which are associated with diverse feto-placental abnormalities (particularly open malformations of the neural tube) can be detected in the amniotic fluid and/or maternal blood. In extension of this approach, it is foreseeable that conditions existing prenatally will be diagnosed in a growing number of cases from the study of fetal cells and molecules which can be isolated from the venous blood of pregnant women. This will become feasible as a result of some well-developed techniques which allow separation of fetal from maternal cells and metabolites, and also to some extremely fine analytic techniques, notably examination of the DNA itself by means of restriction enzymes.

Adult↗
PubMed1979

Is there an embryo-fetal exogenous sex steroid exposure syndrome (EFESSES)?

A survey of all outpatient cases referred for genetic counseling during a 10-month period has revealed a history of preconceptional and early gestational exposure to maternally administerd sex hormones in 16 of 91 instances. Particular interest was aroused by 9 of these 16 cases, all of whom were children with dysmorphic features, no cytogenetic anomalies by Giemsa banding studies, and no recognizable clinical diagnosis. Similarities among them were striking and consisted of varying combinations of the following features: moderate growth retardation; mild to severe mental retardation; facial elongation with frontal bossing; primary telecanthus and downward-slanting palpebral fissures; broad, flat, nose bridge and pug nose; pouting lower lip and blunt, square chin; umbilical eversion; deep sacral pit; and, in males, moderate to severe external genital anomalies ranging from mild hypospadias to genital ambiguity. This may suggest the existence of an embryo-fetal exogenous sex steroid exposure syndrome.

Abnormalities, Drug-Induced↗
PubMed1979

Hemophilia and the female: considerations for the radiologist.

Hemophilia A and B are commonly considered male diseases because of their X-linked recessive inheritance, but clinical hemophilia is occasionally seen in females. This may represent an extreme example of the Lyon hypothesis in which a heterozygous female has only the one X chromosome bearing the aberrant gene in the active state.

Bone and Bones↗
PubMed1979

Extent and rate of chromosome segregation in two intraspecific mouse cell hybrids: A9 x diploid foetal erythrocyte and A9 x B82.

Patterns of chromosome segregation were studied in 2 different intraspecific mouse cell hybrids: (1) A9 x B82, formed by fusing 2 cell lines of heteroploid fibroblasts, and (2) UWE, originating from the fusion of A9 cells with euploid foetal erythrocytes. Detailed analyses of Giemsa (G)-banded chromosomes and chromosome arms of both parental and hybrid cells were made for each hybrid type, in order to determine the specificity of the losses and to assess the influence of ploidy and cell differentiation. Unlike the A9 x B82 hybrids, which revealed a significant chromosome loss under selective tissue culture pressures only after 9 months, the UWE hybrids showed a sharp reduction in the total chromosome number during the initial 2 months under similar pressures. However, with no additional cloning, UWE remained karyotypically stable after that time. This rapid chromosomal segregation in UWE hybrids may be caused by properties of the parental foetal erythrocytes. In UWE cells, the majority of the chromosome arms were retained or duplicated. Less than a quarter of the total number of chromosome arms were segregated or lost, and these were all chromosome arms with abnormal mouse G-banding patterns, present only in the heteroploid A9 parental cells. In two of the four A9 x B82 hybrid lines, there was marked segregation of chromosome arms whose banding patterns were identical to those of wild type mouse telocentric chromosomes. For both types of intraspecific cell hybrids, two thirds or more of the chromosome arms had banding patterns which were the same as those of the wild type genome.

Animals↗
PubMed1978

Expression of HLA-A, but not of HLA-B, in mouse-human somatic cell hybrids carrying the region p21 leads to pter of human chromosome 6.

Mouse-human somatic cell hybrids containing human chromosome 17 carrying the region p21 leads to pter of human chromosome 6 and no other human chromosomes, were found to express HLA-A but not HLA-B. Counterselection of the hybrid cells in medium containing 5-bromodeoxyuridine resulted in the growth of hybrid cells that have concordantly lost the expression of HLA-A and the human translocation chromosome.

Animals↗
PubMed1978

HLA frequencies, diabetes mellitus and autoimmunity in Turner's patients and their relatives.

In a preliminary study of twenty-three patients with gonadal dysgenesis (Turner's syndrome) and their families, correlation was sought between their serum defined HLA allele frequencies and their known tendencies toward abnormal immune responses and diabetes mellitus, since individuals with the latter disorders have been shown to have an increased frequency of certain HLA types. We were unable to demonstrate an association between these major serum-defined histocompatibility antigens, immune homeostasis disturbances and sex chromosome aneuploidy in this group. It is felt, however, that testing involving the patterns of HLA-D and "HLA-D related" antigen frequencies should be obtained to further evaluate the possibility of such an association.

Alleles↗
PubMed1977

Assignment of the structural genes for the alpha subunit of hexosaminidase A, mannosephosphate isomerase, and pyruvate kinase to the region q22-qter of human chromosome 15.

Concordant segregation of the expression of the alpha subunit of human hexosaminidase A, human mannosephosphate isomerase, and pyruvate kinase was observed in somatic cell hybrids between either thymidine kinase-deficient mouse cells or thymidine kinase-deficient Chinese hamster cells and human white blood cells carrying a translocation of the distal half (q 22-qter) of the long arm of chromosome 15 to chromosome 17. A positive correlation was established between the expression of these human phenotypes and the presence of the distal half of the long arm of human chromosome 15.

Carbohydrate Epimerases↗
PubMed1977

The chromosome 2 distal short arm trisomy syndrome.

A trisomy for the distal short arm of chromosome 2 (2p23 leads to 2pter) resulted in similar phenotypic and developmental abnormalities in three related males. The cytogenetic defect was traced to a familial balanced 2;3 translocation [t(2;3) (p23;27)]. Comparison of these patients with the seven previously published cases of 2p partial trisomy reveals a pattern of common features including severe mental and growth retardation, a characteristics facial dysmorphism particularly affecting the eyes, abnormalities of the sternum, spine, and digits, a heart defect, and, in males, cryptorchidism and a striking genital anomaly consisting of a very small penis buried in dorsally fused scrotal skin.

Adult↗
PubMed1977

Assignment of the gene for glyoxalase I to region p21 leads to pter of human chromosome 6.

Using somatic cell hybrids between TK-deficient mouse cells and white blood cells derived from a patient with a translocation of the region p21 leads to pter of chromosome 17, we have assigned the gene for human GLO, to region p21 leads to pter of chromosome 6. Since the HLA region is only 10 cM distant from GLO, these results also confirm that the HLA region is located on the short arm of human chromosome 6.

Animals↗
PubMed1977

Karyotypic analyses of parental and hybrid intraspecific mouse cells, A9/B82, by giemsa- and centromeric-banding.

Hybrids between A9 (HGPRT-) and B82 (TK-), mouse heteroploid fibroblast lines, were obtained through continuous cultivation and clonal selection; such hybrids showed marked segregation and by conventional stains displayed chromosome numbers and distribution similar to that of either parental type. Detailed analyses by Giemsa (G)- and centromeric-banding of these parental lines, and of 4 of the reduced hybrids, maintained in culture for up to 5 years, revealed the following points: (1) The distribution of the majority of individual chromosomal classes was similar for 3 of the hybrid cell lines. (2) Over two-thirds of the chromosomal arms in both the parental lines and hybrid lines were identical to normal mouse telocentric chromosomes. (3) For 2 of the hybrid lines, segregation was particularly marked with respect to those chromosomal arms whose G-banding patterns were identical to the wild-type genome; this indicated that segregation had occurred at the expense of redundant chromosomal material introduced by cell fusion. These banded studies demonstrated that segregation chiefly accounted for the sharp reduction in chromosome numbers while recombination accounted for the chromosome heterogeneity of the hybrid cells as compared to the parental genomes.

Animals↗