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D Leibowitz

Publications and source records attributed to D Leibowitz.

43 records · Page 3Linked to original sources
PubMed1985

Structure and expression of two beta genes in a beta thalassemia homozygote.

Two beta globin gene alleles have been cloned and characterized from a patient with beta + thalassemia. Both beta genes have single base mutations in the small intervening sequence (IVS 1); one 6 nucleotides and the other 110 nucleotides from the 5' end of IVS 1. Both genes lead to abnormal splicing of beta globin mRNA precursors when expressed in HeLa cells. Despite the fact that both alleles produce some normal beta globin mRNA transcripts, the patient has clinically severe beta + thalassemia (Cooley's anemia).

Base Sequence↗
PubMed1981

Intellect and behaviour in Duchenne muscular dystrophy.

A study was made of intellectual, educational and emotional functioning of 57 boys with Duchenne muscular dystrophy, aged between three and 13 years, using standard intelligence tests, a reading test and the Rutter Behaviour Questionnaires. Their intelligence test scores were about 1 SD below the mean, the majority functioning better on performance than on verbal tasks. Reading levels were variable, but averaged about 1-5 SD below the mean; a large proportion of the boys read at a very low level. Both of the Behaviour Questionnaires showed a high rate of emotional disorder. The cognitive tests showed no change with age and the general pattern of functioning remained constant. This study confirms the view that intellectual impairment, and particularly verbal impairment, is associated with Duchenne muscular dystrophy, but it is non-progressive and does not affect all children. A high rate of emotional disturbance is also associated with the disease.

Adolescent↗
PubMed1981

Isolation and characterization of cloned DNA: the delta and beta globin genes in homozygous beta + thalassemia.

We have isolated and characterized a clone of human DNA from a patient with beta+ thalassemia containing the entire delta and beta structural genes and their flanking sequences. Partial Eco RI digestion of spleen DNA was used to obtain 15 to 20 kilobase (kb) pieces of human DNA that were then ligated to charon 4A lambda phage DNA. The 8 x 10(5) recombinants obtained were grown and screened for their content of beta gene sequences. Four positive clones were found, and one (beta T1-1) has been extensively analyzed. Subclones containing the entire beta gene and the large beta intervening sequence (IVS 2) have been isolated in the plasmid pBR 322. The fragments generated by restriction enzyme digestion in these subclones have been compared to those in similar subclones from normal beta genes. No differences have been found indication no significant rearrangements of deletions of the delta and beta genes. With the enzymes used, 11.2% of IVS 2 have been compared, and thus far no differences between the thalassemic and normal genes have been detected. The 24 enzymes used include Hph I, which recognizes the 5' end of IVS 2, and AIu I that cleaves at the 3' end. Thus, there appears to be conservation of nucleotide sequences at the ends of IVS 2 in this beta + thalassemia patient, although RNA metabolism studies suggest a possible defect in RNA processing.

Adult↗
PubMed1978

Organization of human delta--and beta-globin genes in cellular DNA and the presence of intragenic inserts.

We have analyzed human cellular DNA for its delta--and beta-globin gene sequence content by separation of restriction enzyme fragments by agarose gel electrophoresis; transfer of the DNA fragments to nitrocellulose filters; hybridization of filters with 32P--beta-globin cDNA; and analysis by autoradiography. A short cDNA has been used to identify specifically the 3' end of the genes and to orient the fragments. A comparison of the globin gene fragments generated by normal and Lepore DNA has been used to distinguish fragments representing DNA sequences between the delta and beta genes and those containing sequences flanking either 5' to the delta gene or 3' to the beta gene. The results indicate that unique restriction fragments are presented in normal DNA and absent in Lepore DNA, and allow preliminary ordering of these fragments on a restriction enzyme map. In addition, the Lepore, delta--and beta-globin genes have been found to contain at least one inserted nucleotide sequence of about 1000 bases which is not represented in mature globin mRNA.

Cell Line↗
PubMed1978

Changes in restricted human cellular DNA fragments containing globin gene sequences in thalassemias and related disorders.

Human cellular DNA fragments from cells of normal subjects and patients with thalassemia obtained by restriction enzyme digestion were analyzed for their globin gene content. The fragments were separated on agarose gels, transferred to nitrocellulose filters, hybridized to globin [(32)P]cDNA, and radioautographed. One to ten picograms of globin gene sequences were detectable. With EcoRI digestion, eight to nine cellular DNA fragments were found to contain globin genes. Three of these contained beta-like gene sequences assayed with beta globin cDNA probe. One beta-like fragment was absent in DNA from a homozygous subject for hemoglobin Lepore. Two of the three beta gene-containing fragments present in normal DNA were absent in DNA from a patient with hereditary persistence of fetal hemoglobin. The same two fragments containing beta-like genes were absent from deltabeta thalassemic DNA and one new fragment containing beta-like genes was found. Together with results obtained by hybridization of these DNAs in solution, the data are consistent with deletion of specific restriction human DNA fragments in subjects with these disorders and a greater deletion of beta-like gene sequences in subjects with hereditary persistence of fetal hemoglobin than in those with deltabeta thalassemia.

Base Sequence↗
PubMedDate not supplied

Fertility drug therapies: past, present, and future.

Throughout the last 30 years there has been an evolution of drug therapies aimed at the treatment of infertility. These agents primarily address the induction of ovulation or enhancing ovulation by allowing more oocytes to mature simultaneously. As this evolution has progressed, drugs have moved away from human products to the advent of the recombinant or genetically engineered technology. The drugs have not cured infertility, but they have affected positively the quest of families confronted by infertility.

Adult↗