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Biomedical subjects

C J Epstein

Publications and source records attributed to C J Epstein.

At least 235 records · Page 13Linked to original sources

The prenatal diagnosis of genetic disorders.

Prenatal diagnosis has proven highly effective in assessing the status of fetuses at risk of all cytogenetic and of several biochemical and structural disorders with genetic etiologies. The original methodology, based on the cytogenetic and biochemical analysis of cultured amniotic fluid cells, has now been complemented by a wide variety of new techniques. These include several methods for fetal visualization (sonography, fetoscopy, x ray), sampling of fetal blood, and analysis of very small quantities of material. Additional approaches, based on these and other technologies, are likely to permit the prenatal diagnosis of an ever increasing number of genetic disorders. At the same time, the number of pregnancies monitored will increase as greater resources become available and as screening programs identify couples at risk of having genetically abnormal children prior to the birth of an affected child. Prenatal diagnosis is already a powerful means of preventing the birth of individuals with significant genetic defects, thereby sparing both individuals and society from the burdens that such disorders produce. In the future, it is likely to be even more effective.

Amniotic Fluid↗

Severe pulmonary involvement in adult Gaucher's disease. Report of three cases and review of the literature.

Three patients with "adult" Gaucher's disease with severe pulmonary involvement are described. The clinical course of these patients was characterized by hepatosplenomegaly in infancy, followed by the juvenile onset of dyspnea culminating in pulmonary failure and death. Pathologic examination of the lungs in these patients revealed not only massive infiltration of alveolar walls by Gaucher's cells but also clumps of these cells filling alveolar spaces and obliterating functional air exchanging tissue. The lack of neurologic involvement in these cases delineates them from the "juvenile" forms of Gaucher's disease whereas the malignant course and pulmonary involvement were atypical of the "adult" form. The severity of this type of Gaucher's disease makes it a good candidate for prenatal enzymatic diagnosis.

Child↗

DNA cytophotometry in pre-natal cytogenetic diagnosis.

DNA cytophotometry was used to resolve a cytogenetic ambiguity involving a possible deletion of part of the short arm of chromosome 18 in cells obtained by amniocentesis. Measurements of chromosomal DNA content were within normal limits. This is the first time that DNA cytophotometry has been used in cytogenetic diagnosis; it illustrates the potential of this new approach to cytogenetics.

Adult↗

Mild and severe Hunter syndrome (MPS II) within the same sibships.

X-linked Hunter syndrome (MPS II) is presently thought to exist in two clinically and genetically distinct forms, mild and severe, which are biochemically indistinguishable. However, two sibships have been studied in which both mildy and severely affected children are present. Therefore, genetic counseling for families with MPS II should be reconsidered to take into account the possibility of heterogeneity within a family in terms of the degree of psychomotor retardation and potential longevity.

Adolescent↗

Hunter syndrome presenting as macrocephaly and hydrocephalus.

A 2-year-old boy with macrocephaly, communicating hydrocephalus, and mild hepatosplenomegaly was found to have mild Hunter syndrome (MPS II). Establishment of the latter diagnosis was complicated by the paucity of obvious physical findings because of the patient's young age and his ethnic origin.

Child, Preschool↗

Dosage effects for superoxide dismutase-1 in nucleated cells aneuploid for chromosome 21.

Assays of the activity of chromosome 21 determined superoxide dismutase-1 (SOD-1) in lymphocytes and polymorphonuclear granulocytes have demonstrated 38% and 40% increases, respectively, in cells from individuals with trisomy 21. Similarly, SOD-1 activity in trisomic fibroblasts is increased by 81%, while cells monosomic for chromosome 21 have only 60% of normal activity. Taken together with the data on SOD-1 activities in trisomic erythrocytes and platelets, the present results firmly confirm the existence of a true dosage effect for this enzyme in cells aneuploid for chromosome 21. However, the results of assays of the activity of glutathione peroxidase in trisomic fibroblasts did not confirm the possibility previously reported of a chromosome 21 related dosage effect for this enzyme.

Cell Line↗

The Hunter syndrome in females: is there an autosomal recessive form of iduronate sulfatase deficiency?

Profound iduronate sulfatase deficiency, characteristic of the Hunter syndrome, has been found in cultured fibroblasts, serum, lymphocytes, and tissues of two clinically affected girls. The patients are karyotypically normal and have normal fathers; cloning of the mothers' fibroblasts did not reveal the mosaicism expected of carriers of an X-linked disease. Homozygosity for a previously unsuspected autosomal recessive gene for iduronate sulfatase is considered the most likely explanation, although heterozygosity for the X-linked gene and subsequent selection cannot be completely excluded.

Child↗

Localization fo the gene AVG for the antiviral expression of immune and classical interferon to the distal portion of the long arm of chromosome 21.

The responses of normal fibroblasts and of fibroblasts trisomic and monosomic for chromosome 21 to exogenously administered virus-induced (classical) and phytohemagglutinin-induced (immune) human interferon were determined. The virus-induced interferon was obtained from leukocytes treated with Sendai virus and from neonatal foreskin fibroblasts treated with Newcastle disease virus. With both classical and immune interferons, the mean response of the trisomic cell lines was three times that of the normal cells, whereas that of the monosomic lines was half or less that of the normal cells, Furthermore, a line trisomic for only the distal half of the long arm of chromosome 21 (q21 leads to qter) also demonstrated increased sensitivity to virus- and phytohemagglutinin-induced interferons, a fact that indicated that the gene responsible for the antiviral effect of interferon, AVG, is located on this part of chromosome 21. Responses to the two categories of interferon (virus-induced and phytohemagglutinin-induced) of individual cell lines of different degrees of sensitivity were strongly correlated (r=0.79). It is concluded, therefore, that despite their physical and antigenic differences, the antiviral expressions of both classical and immune interferons are ultimately mediated by the same genetic locus, AVG.

Cell Line↗

Lactate dehydrogenase X: effects of antibody on mouse gametes but not on early development.

A rabbit antiserum specific for LDH-X, the spermatozoal form of mouse lactate dehydrogenase, was prepared. This antiserum had no effect on fertility of female mice when injected before or after insemination. Similarly, there was no toxicity to the embryo when high concentrations of the antiserum were added to cultures of 2-cell and 8- to 16-cell embryos. There was, however, a moderate inhibitory effect on fertilization in vitro, which may be attributable to a direct action of antiserum to LDH-X on sperm.

Animals↗

The role of cyclic AMP in myogenesis.

The effect of exogenously administered cyclic AMP derivatives and of endogenously elevated cyclic AMP levels on the spontaneous fusion of skeletal muscle myoblasts has been investigated. Contrary to earlier reports, cAMP does not appear to have a direct inhibitory effect on the fusion of an established line (L8) of rat myoblasts. Similarly, cAMP did not block the fusion of primary chick myoblasts. However, fusion of the rat myoblasts was prevented when the cAMP induced inhibition of growth prevented the cells from reaching the "critical" cell density necessary for fusion.

Bucladesine↗