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D Gurari-Rotman

Publications and source records attributed to D Gurari-Rotman.

13 recordsLinked to original sources
PubMed1989

Cell receptor assays.

There are four general assay methods used to quantify a drug/biologic in a preparation, including: (1) in vivo bioassays; (2) in vitro bioassays; (3) immunoassays; and (4) receptor assays. The cell receptor assay is used to evaluate the first step in the molecular action of the drug biologic, its interaction with a specific cellular receptor. Subsequently, the drug biologic must initiate other events, such as internalisation, signal transduction, and/or alterations of one or more cellular constituents in order to elicit its biological effect. Major factors to consider in cell receptor assay development include: (1) establishment of a reference standard preparation; (2) labelling; purifying and characterisation of the biologic drug; (3) cell receptor source; (4) methodology, e.g. separation of bound and free, and other factors affecting accuracy and reproducibility; (5) ligand specificity; and (6) correlation with bioactivity. It should be emphasised that cell receptor binding cannot be assumed to correlate with biological activity because of the requirement that subsequent steps must take place prior to achieving the final response. Chemically altered drugs biologics may bind to a specific cell receptor without eliciting a biological activity. Thus, utilisation of a cell receptor assay requires careful evaluation at both the chemical and biological levels prior to its acceptance as a measure of potency.

Animals↗
PubMed1982

Inhibition by glucocorticosteroid hormones of interferon and prostaglandin E induction by poly(rI). Poly(rC).

We have examined the relationship between induction of interferon (IFN) and prostaglandin E (PGE) production by poly(rI).poly(rC) in cultured human foreskin fibroblasts (FS11). Hydrocortisone and dexamethasone (2 . 5 x 10(-7) M), which are known inhibitors of PGE synthesis, significantly decreased the induction of both IFN and PGE in IFN-pretreated (primed) cells. Desoxycorticosterone, progesterone and estradiol were devoid of this activity. Hydrocortisone also blocked the induction of IFN by double-stranded RNA (dsRNA), cycloheximide and actinomycin D in FS11 cells. Arachidonic acid overcame the inhibitory effect of hydrocortisone on PGE production, but failed to restore IFN production in the presence of the steroid. Moreover, the prostaglandin synthetase inhibitors, indomethacin, aspirin and flufenamic acid, did not change IFN production by dsRNA in primed FS11 cells, although prostaglandin synthesis was abolished. Although the induction of IFN and PGE by poly(rI).poly(rC) might be consequences of the same initial event in the cell, the accumulation of PGE does not seem to have a regulatory effect on the synthesis of IFN in this system.

Cells, Cultured↗
PubMed1979

Monkey interferon: activity on human cells and chromatographic properties. Brief report.

Monkey interferon (MKIF) produced in monkey BSC-1 cells infected with Newcastle disease virus showed antiviral activity on human foreskin fibroblasts and RD114cells--a human line transformed by feline sarcoma virus. The titer of the monkey interferon in human cells was 10--30 fold greater than that found in several normal monkey (BSC-1, CV-1 or SV 40 transformed (C2, C6, T-22) monkey cell lines tested. Ten to fifteen-fold purification of MKIF without loss of activity could be achieved by chromatography on Phenyl-Sepharose CL-4B. Antiviral activity of MKIF was fully resistant to treatment with 1 per cent sodium dodecyl sulfate (SDS).

Animals↗
PubMed1978

Production of human lymphoblastoid interferon by Namalva cells.

Optimum conditions for growth and interferon production by a human lymphoblastoid cell line, Namalva, have been studied. Adaptation to large-scale production is possible utilizing either Sendai virus or Newcastle disease virus. Priming of cultures before induction is unnecessary. The interferon produced has properties similar to human leukocyte interferon. The production of lymphoblastoid interferon per cell is increased two- to fourfold after dilution with serum-free medium of a saturation-density culture of Namalva induced with Newcastle disease virus. Maximum interferon yields were obtained 27 h after the addition of virus, using cultures diluted to 4 X 10(5) to 9 X 10(5) cells per ml. The presence of glutamine in the dilution medium was required for maximum interferon production. Newcastle disease virus appeared to inhibit the rates of RNA and protein synthesis more effectively in the diluted cultures.

Animals↗
PubMed1976

Apparent dispensability of the carbohydrate moiety of human interferon for antiviral activity.

Human leukocyte and tritium-labeled fibroblast interferons, prepared by induction with Sendai virus and with double-stranded polyinosinic acid.polycytidylic acid respectively, have been studied in relation to the carbohydrate moieties attached to them. These interferons were partially purified by immunoabsorbance and by gel filtration. On treatment with glycosidases, about 80% of the 3H-labeled sugar moieties in this glycoprotein-containing fraction was removed without detectable alteration of the antiviral activity or antibody-binding properties characteristic of interferon. The molecular weight of leukocyte interferon was reduced by about 4000. As others have reported, the heterogeneous character of interferon revealed by isoelectric focusing was greatly reduced by the enzyme treatment.

Carbohydrates↗
PubMed1974

Partial purification of human interferon by affinity chromatography.

Human interferon prepared by challenge of leukocytes with Sendai virus, or of fibroblasts with double-stranded poly(inosinic acid).poly(cytidylic acid), has been studied with respect to purification by affinity chromatography. Both leukocyte and fibroblast interferons are removed from crude tissue culture fluids by means of columns of antibody to leukocyte interferon attached to Sepharose-4B. The antibody was prepared in sheep using, as antigen, material that had been partially purified by gel filtration through Sephadex G-100 columns. Many of the impurities in the crude fibroblast interferon were presumably not recognized by the sheep antibodies induced by leukocyte interferon. Fibroblast interferon was, therefore, much more effectively purified as the result of this "common denominator" approach. The fibroblast product, in contrast to interferon from leukocytes, could only be harvested efficiently from the crude starting material when a carrier protein (bovine-serum albumin, and later, cytochrome c) was added to the eluting buffers to counteract losses, presumably due to adsorption on purification and assay equipment. Both varieties of interferon exhibit molecular weights of approximately 20,000-25,000, although association with higher molecular weight proteins occurs.

Adsorption↗