Biomedical subjects

R E Kaufman

Publications and source records attributed to R E Kaufman.

48 records · Page 3Linked to original sources

PubMed1980

A family of long reiterated DNA sequences, one copy of which is next to the human beta globin gene.

An unusually long repeated DNA sequence was identified in cloned DNA, three kb 3' to the human beta-globin gene. Other members of this repeated sequence family were isolated from a human genomic DNA library and characterized by Southern blotting techniques, electron microscopy, and solution hybridization. The copy located next to the beta-globin gene was found to be 6.4 +/- 0.2 kb long and continuous over that length. This repeated sequence family comprises about 1% of the human genome and contains 3000-4800 copies of moderate sequence divergence which are interspersed with other less-highly repeated DNA. The 6.4 kb repeated unit does not appear to be composed of any smaller tandemly repeated subunits, nor is it expressed at a high level in bone marrow cell RNA.

Bacteriophage lambda↗

PubMed1980

Hemoglobin switching in sheep. Cloning and characterization of the beta A and beta-like embryonic globin genes from genomic DNA.

Genomic DNA from a fetal sheep homozygous for the beta A gene was used to construct a library of one million cloned DNA fragments using the bacteriophage vector, Charon 4A. Screening of 150,000 plaques from this library using radioactive beta-globin gene sequences resulted in the isolation of two recombinant bacteriophage containing globin genes. One of these, S beta AG-21, contains the complete adult beta A-globin gene as demonstrated by hybridization and restriction endonuclease analysis. In common with adult globin genes from other species, the beta A gene contains small (105 base pairs) and large (900 base pairs) intervening sequences. The second recombinant bacteriophage, SG-4, contains a complete embryonic beta-like globin gene which is expressed in the sheep embryo as demonstrated by hybridization analysis with cDNA made from sheep embryonic globin mRNA. Although differing in its restriction endonuclease map from the adult beta-globin genes, SG-4 appears to contain a large intervening sequence of at least 750 base pairs in length. Finally, preliminary evidence is discussed which indicates that a Pvu II site just 5' to the Cap site may be a common feature of sheep globin genes.

Animals↗

PubMed1980

Cloning and characterization of DNA sequences surrounding the human gamma-, delta-, and beta-globin genes.

The human gamma-, delta-, and beta-globin genes are located within a 30-kilobase (kb) region of DNA, of which only 20% represents the globin genes. We have attempted to define the nature of flanking and intergenic sequences by isolating recombinants containing the human epsilon, both gamma-, or the 3' end of the beta-globin gene from a bacteriophage library of cloned human DNA. Comparison of these recombinants and a recombinant containing the delta- and beta-globin genes (H beta G1) has provided the following results. The epsilon-globin gene is located 14 kb 5' to the G gamma gene. DNA sequence homology between the region containing the two G gamma genes and the delta nd beta gene region is limited to only a few hundred nucleotides which include the globin coding sequences. Repetitive DNA sequences have been found in the region 3' to the beta-globin gene. Sequences located adjacent to the beta-globin gene are repeated in the globin gene region. A repetitive DNA sequence more than 3.2 kb long is repeated frequently in the human genome but is not repeated in the globin gene region in the clones examined.

Bacteriophage lambda↗

PubMed1976

National gonorrhea therapy monitoring study: treatment results.

To monitor the efficacy of the 1972 United States Public Health Service recommended treatment regimens for uncomplicated gonorrhea, we studied 9008 patients who were randomly assigned either to aqueous procaine penicillin G, 4.8 million units intramuscularly plus 1 g of oral probenecid, or to one of the three other recommended regimens. Among the 3871 patients re-examined within three to seven days after therapy, the penicillin-probenecid regimen was successful in 96.8 per cent, whereas the cure rates of the ampicillin-probenecid, tetracycline, and spectinomycin regimens were 92.8, 96.2, and 94.8 per cent, respectively. In clinics comparing the regimens, penicillin G-probenecid was as effective as tetracycline, but more effective than ampicillin-probenecid (P less than 0.05) and spectinomycin (P less than 0.01). However, in patients re-examined three to 14 days after treatment, only the ampicillin-probenecid regimen was significantly less effective than penicillin probenecid (P less than 0.01). Despite these differences in results, all four regimens recommended by the Public Health Service provided effective therapy for uncomplicated gonorrhea.

Administration, Oral↗

PubMed1976

National gonorrhea therapy monitoring study: in vitro antibiotic susceptibility and its correlation with treatment results.

To monitor temporal trends and regional differences in antibiotic susceptibility, we measured the minimum inhibitory concentrations for penicillin G, ampicillin, tetracycline, and spectinomycin of 4405 pre-treatment gonococcal isolates from patients with uncomplicated gonorrhea. As compared to isolates studied in 1970-1971, recent United States isolates appeared equally sensitive to penicillin G and more sensitive to tetracycline. Relatively resistant strains were found throughout the country. We also studied 1974 patients, treated for uncomplicated gonorrhea according to the 1972 regimens recommended by the United States Public Health Service, to determine the relation between pretreatment minimum inhibitory concentrations and treatment results. For patients receiving the procaine penicillin-probenecid and ampicillin-probenecid regimens, minimum inhibitory concentrations to the treatment drugs were significantly higher in patients not cured than in those cured (P less than 0.01 fr penicillin and P less than 0.05 for ampicillin). In contrast, spectinomycin-treatment results appeared to be independent of the isolate's susceptibility to spectinomycin and other antibiotics.

Ampicillin↗

PubMed1974