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Biomedical subjects

M Golomb

Publications and source records attributed to M Golomb.

29 records · Page 2Linked to original sources
PubMed1980

Purification of reverse transcriptase from avian retroviruses using affinity chromatography on heparin-sepharose.

Reverse transcriptase from Rous sarcoma virus and avian myeloblastosis virus was purified by a rapid two-step procedure using chromatography on phosphocellulose and heparin-Sepharose. The resulting enzyme was homogeneous, had a high specific activity and was free of contaminating nucleases. This procedure has been adapted to small-scale preparation of enzyme from mutant virus containing thermolabile reverse transcriptase, and is equally suitable for large-scale enzyme purification.

Avian Leukosis Virus↗
PubMed1980

Activation of an Mg2+-dependent DNA endonuclease of avian myeloblastosis virus alpha beta DNA polymerase by in vitro proteolytic cleavage.

Partial chymotryptic digestion of purified avian myeloblastosis virus alpha beta DNA polymerase resulted in the activation of a Mg2+-dependent DNA endonuclease activity. Incubation of the polymerase-protease mixture in the presence of super-coiled DNA and Mg2+ permitted detection of the cleaved polymerase fragment possessing DNA nicking activity. Protease digestion conditions were established permitting selective cleavage of beta to alpha, which contained DNA polymerase and RNase H activity and to a family of polypeptides ranging in size from 30,000 to 34,000 daltons. These latter beta-unique fragments were purified by polyuridylate-Sepharose 4B chromatography and were shown to contain both DNA binding and DNA endonuclease activities. We have demonstrated that this group of polymerase fragments derived by chymotryptic digestion of alpha beta DNA polymerase is similar to the in vivo-isolated avian myeloblastosis virus p32pol in size, sequence, and DNA endonuclease activity.

Avian Leukosis Virus↗
PubMed1979

Endonuclease activity of purified RNA-directed DNA polymerase from avian myeloblastosis virus.

Highly purified preparations of RNA-directed DNA polymerase from avian myeloblastosis virus (AMV) contain a Mn2+-activated endonuclease activity capable of nicking supercoiled DNA. This endonuclease activity co-sediments in glycerol gradients with the alphabeta form of AMV DNA polymerase, and co-chromatographs with DNA polymerase activity on DEAE-cellulose, phosphocellulose, and heparin-Sepharose. It is also present in AMV alphabeta-DNA polymerase purified by electrophoresis through nondenaturing polyacrylamide gels and subsequently chromatographed on poly(C)-agarose. alphabeta-associated endonuclease is co-immunoprecipitated with DNA polymerase activity by antiserum directed against alphabeta holoenzyme. The alpha form of AMV DNA polymerase lacks this activity. In its enzymatic properties, alphabeta-associated endonuclease resembles the endodeoxyribonuclease activity associated with the AMV p32 protein, which has been shown to be structurally related to the beta (but not the alpha) subunit of AMV DNA polymerase.

Avian Leukosis Virus↗
PubMed1979

Response to amitriptyline and urinary MHPG in bipolar depressive patients.

This investigation was done in order to test the hypothesis that urinary MHPG levels provide a predictor of response to therapy in depressed patients. 15 elderly biopolar depressives were included in this study. Their depressive state was estimated by the Hamilton Depressive Scale and their urinary MHPG levels were simultaneously measured before and after 5 weeks of amitriptyline therapy. When comparing amitriptyline responders to nonresponders by parametric techniques, the responders excreted significantly higher mean MHPG levels before the treatment than the nonresponders. During treatment MHPG levels rose significantly in both groups.

Aged↗
PubMed1977

T7- and T3-specific RNA polymerases: characterization and mapping of the in vitro transcripts read from T3 DNA.

The late genetic region of the T3 bacteriophage genome is transcribed by a phage-specified RNA polymerase, the product of T3 gene 1. In vitro, purified T3 RNA polymerase acting with T3 DNA template synthesizes six major RNA products, with molecular weights of 5.5 X 10(6), 4.2 X 10(6), 1.7 X 10(6), 0.87 X 10(6), 0.52 X 10(6), and 0.23 X 10(6). These are designated T3 RNA species I through VI, respectively. These RNAs are formed in equimolar amounts, with the exception of T3 species V, which is made in approximately twice this amount. T3 RNA species I, II, and VI have been mapped by the use of terminally deleted templates and are found to originate from promoters located at 56, 67, and 98% genome length, respectively, and to share a common terminator at approximately 100%. T3 species III, IV, and V must originate from the class III region of the T3 genome between 37.5 and 56%. Although the pattern of transcription by T3 RNA polymerase in vitro closely resembles that of the RNA polymerase from the related phage T7, neither polymerase is able to use major promoter sites for the other enzyme at an appreciable rate.

Coliphages↗
PubMed1977

Isolation of recombinants between T7 and T3 bacteriophages and their use in vitro transcriptional mapping.

A variety of T3 X T7 recombinants were isolated from crosses between T3 and T7 parental phages carrying amber markers in various genes (gene 1 to gene 19). The genetic constitution of these recombinants was determined by reference to the selected markers and also directly by analysis of the proteins translated from the T3 X T7 recombinants in vivo. Although T3 and TM phages are closely related, most T3 and T7 proteins differ slightly in size, and hence the genetic origin of a gene can be determined by protein analysis. The major transcripts read by T3 and T7 RNA polymerases from T3 X T7 recombinant phage DNAs vary, depending on which regions of the T3 or T7 chromosome are present. T7 RNA polymerase is unable to utilize major promoter sites employed by T3 polymerase at an appreciable rate, and the converse is also true. Hence the transcriptional pattern for a recombinant phage DNA obtained with the T3 or T7 polymerase allows a determination of the identity of the different promoter sites on the genome. The transcriptional analysis of T3 X T7 recombinant DNAs together with earlier observations has been used to map the promoter sites for five out of seven major T3 and T7 RNA species on the genetic maps of T3 and T7. The promoter sites for the T7 and T3 RNA species IIIa, IV, and V originate at the beginning of genes 7, 9, and 10, respectively; the promoter sites for the T7 and T3 RNA species I and II are located to the left of gene 11 and gene 13, respectively. No T3 X T7 recombinants were found for which the specificity of the phage RNA polymerase was not correlated with the corresponding promoter sites for species IIIa and I (the transcription of which covers 60% of the genome). That means that the RNA polymerase specified by the recombinant genome is able to read all of the information encoded in sequences read normally from major promoters by the enzyme on the wild-type phage genome. This suggests that the in vitro specificity for promoter site selection by the phage polymerases is also maintained in vivo.

Coliphages↗
PubMed1976

Correlation between anti-DNA antibody titre and psychiatric manifestations in systemic lupus erythematosus.

A patient with systemic lupus erythematosus with predominant psychiatric involvement was followed during two psychotic exacerbations of her disease. A high correlation was found between disease activity and the titre of anti-DNA antibodies. Disease activity was preceded and accompanied by a high titre, while remission was associated with low titre. The significance of this correlation for the pathogenesis, diagnosis and managment of the psychiatric symptoms of systemic lupus erythematosus are discussed.

Adult↗
PubMed1974

A preliminary map of the major transcription units read by T7 RNA polymerase on the T7 and T3 bacteriophage chromosomes.

Transcription of T7 DNA by T7 RNA polymerase in vitro gives rise to six major size classes of RNAs comprising seven major T7 RNA species. These RNAs are all read from the r-strand of T7 DNA and are not derived from the early (leftmost on the conventional genetic map) region of the molecule. When artifically shortened T7 DNA templates are transcribed, four (I, II, IIIb, and VI) of the seven species are found to be truncated or deleted. This indicates that all are terminated near the right end of the T7 DNA molecule, probably at a common termination site near 98.5%. (Map positions are all given in terms of percentage of total length measured from the left end of the molecule.) Since the approximate lengths of the transcripts are known, the promotor sites for T7 RNA species I, II, IIIb, and VI are tentatively mapped at 56, 64, 83, and 97% on the T7 chromosome. Only a single major T3 RNA is transcribed by T7 RNA polymerase; analysis of transcripts directed by shortened T3 DNA templates indicates it is analogous to T7 RNA species IIIb. Hence the promotor and terminator sites for T3 species IIIb are tentatively mapped at 83 and 98.5%, respectively, on the T3 chromosome. The major transcripts read by T7 RNA polymerase from T3-T7 hybrid phage DNAs vary, depending on which regions of the T7 chromosome are present. This provides an alternative method of mapping the strong T7 promotor sites on the T7 chromosome.

Chromosome Mapping↗
PubMedDate not supplied

Behavioral treatment of essential hypertension: a comparison between cognitive therapy and biofeedback of heart rate.

The efficacy and the mechanisms of action of two behavioral treatments for essential hypertension were compared: cognitive group therapy for anger control and biofeedback for heart rate control. The cognitive therapy aimed at lowering the "general anger" level and helping overt expression of "anger out;" heart rate biofeedback aimed at slowing heart rate in stress situations. Ninety-seven essential hypertensive patients were randomly assigned to three groups; after 20 dropouts, 77 patients fully participated in the study: cognitive treatment (N = 30), biofeedback (N = 27), and control (no treatment, N = 20). The treatments were held in 17 weekly sessions; during treatment, blood pressure was measured once a month, and during follow-up after 1 and 6 months. The anger level and heart rate control were assessed at the beginning and the end of treatment. The main results were: 1) a significant decrease of blood pressure for both treatments as compared with control, 2) a significant decrease of blood pressure with heart rate biofeedback as compared with cognitive therapy, and 3) a better control in anger achieved with cognitive therapy and a lesser control in heart rate as compared with biofeedback.

Adaptation, Psychological↗