PubMed Health⌕ Search

Biomedical subjects

A Ben-Zeev

Publications and source records attributed to A Ben-Zeev.

12 recordsLinked to original sources
PubMed1991

Chloroamphetamine did not prevent the effects of chronic antidepressants on 5-hydroxytryptamine inhibition of forskolin-stimulated adenylate cyclase in rat hippocampus.

Administration of p-chloroamphetamine (PCA, 10 mg/kg i.p. on two occasions) to rats resulted in a severe depletion of [3H]paroxetine binding sites, a measure of presynaptic serotonergic terminals, in both cortex and hippocampus, but did not affect [3H]8-hydroxy-2-(di-n-propylamino)tetralin [( 3H]8-OH-DPAT) binding or 5-hydroxytryptamine (5-HT)-induced inhibition of forskolin-stimulated adenylate cyclase in hippocampal membranes. Administration of either imipramine (15 mg/kg i.p. for 2 weeks) or lithium (0.2% for 2 weeks) to PCA-treated rats did not affect [3H]8-OH-DPAT binding but reduced the degree of inhibition of forskolin-stimulated adenylate cyclase by 5-HT in hippocampal membranes. It is concluded that the effects of imipramine and Li+ on 5-HT1A receptor-mediated responses in the hippocampus are exerted postsynaptically, possibly at a level distal to the receptor.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1978

In vitro RNA synthesis in nuclei from herpes simplex virus infected cells: effects of ultraviolet-irradiated, defective and bromodeoxyuridine-resistant virus preparations.

Transcription of virus DNA was detectable in vitro in nuclei isolated from cells infected with wild type and bromodeoxyuridine (BUdR)-resistant herpes simplex virus type 1 but was suppressed in nuclei of cells infected with ultraviolet irradiated or defective virus or cells treated with BUdR during infection.

Bromodeoxyuridine↗
PubMed1977

Isolation of Marek's disease virus DNA from infected cells by electrophoresis on polyacrylamide gels.

Marek's disease virus DNA isolated from the nuclear fraction of infected chicken embryo fibroblasts and sucrose-purified particles was electrophoresed on 3 per cent polyacrylamide gels and was compared in its electrophoretical behaviour with isolated pseudorabies and herpes simplex DNA, strain HF. The DNA molecules eluted from the gel were identified by their sedimentation coefficient (53--55S) and buoyant density (1.707 g/ml) to be of viral origin. MDV DNA molecules were electrophoretically also detected and identified in DNA preparations of the lymphoblastoid Marek's disease tumour cell line MSB-1 which therefore has to be considered as a producer line. The electrophoresis of DNA preparations from Marek's disease virus-infected cells on polyacrylamide gels provides a semipreparative method for the isolation of MDV DNA.

Animals↗
PubMed1975

Nucleic acid biosynthesis in nuclei of cell infected with herpesviruses (HSV and EBV).

Analysis of nuclei isolated from herpes simplex virus (HSV)-infected cells by electrophoresis in polyacrylamide gels showed that only virion-associated DNA molecules migrated into the gels. The viral DNA molecules, which do not migrate in the gels, are the precursors for the mature viral DNA. Centrifugation of deoxycholate-treated infected nuclei in sucrose gradients revealed that most of the viral DNA co-sedimented with the cellular DNA. The DNA-dependent RNA polymerase activity also co-sedimented with the viral and cellular DNA. Incubation of nuclei isolated from HSV-infected cells, under in vitro conditions that support DNA synthesis, resulted in the synthesis of viral molecules of low molecular weight. Under the same conditions, nuclei from Burkitt lymphoblasts did not synthesize DNA. The nature of the association between cellular DNA and EBV DNA was studied by hybridization with EBV cRNA. EBV-specific sequences were found in the lymphoblast DNA; they banded at a density of 1.707 g/cm3. Some of the viral mRNA transcribed in HSV-infected nuclei is symmetrically transcribed from HSV DNA. The symmetrical portions of the RNA are removed, since poly (A)-containing mRNA molecules lack homologous sequences. Most of the RNA synthesized in HSV-infected nuclei can be released after incubation of the nuclei in vitro in the presence of ATP. The released RNA consists of poly(A)plus and poly (A)-minus molecules. The mechanism of RNA transport from the nuclei still remains to be studied.

Adenosine Triphosphate↗
PubMedDate not supplied

Specific interaction between the p53 cellular tumour antigen and major heat shock proteins.

The protein p53 is capable of participating in neoplastic transformation and can form specific complexes with the large-T antigen of simian virus 40 (SV40). This interaction probably results in the stabilization of p53 (refs 7,8) and may contribute to SV40-mediated transformation. Several non-SV40-transformed cells also exhibit a stabilized p53 which is present in elevated levels. Recently, this stabilization was shown to coincide with the ability to precipitate a polypeptide (p68) of relative molecular mass (Mr) 68,000-70,000 by anti-p53 monoclonal antibodies. We now report that this co-precipitation indeed represents a specific complex between the two proteins; the complex sediments on a sucrose gradient as a relatively broad peak of 10-14S and can be dissociated in vitro. Furthermore, p68 is the HSP70 heat shock protein cognate, found in elevated levels in a p53-overproducing cell line. On heat-shock treatment of such overproducers, p53 also forms a complex with the related highly inducible HSP68.

Animals↗