Samar N. Roy

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PURPOSE Gemtuzumab ozogamicin (Mylotarg; Wyeth Laboratories, Philadelphia, PA) consists of a semisynthetic derivative of calicheamicin, a cytotoxic antibiotic linked to a recombinant monoclonal antibody directed against the CD33 antigen present on leukemic myeloblasts in most patients with acute myeloid leukemia (AML). In this study, we review the(More)
Human fibrinogen (340 kDa) is a dimer, with each identical half-molecule composed of three different polypeptides (Aalpha, 66 kDa; Bbeta, 55 kDa; and gamma, 48 kDa). To understand the mechanisms of chain assembly, a coupled in vitro transcription translation system capable of assembling fibrinogen chains was developed. Fibrinogen chain assembly was assayed(More)
Taxol is an inhibitor of cell replication that promotes the assembly of microtubules in vitro and in cells. In the murine macrophage-like cell line J774.2, a taxol-resistant subline (J7/TAX-50) has been developed in vitro by growing the cells in increasing drug concentrations. These cells, which are approximately 800-fold resistant to taxol, display some(More)
Previous studies indicated that synthesis of B beta chain may be a rate-limiting factor in the production of human fibrinogen since Hep G2 cells contain surplus pools of A alpha and gamma but not of B beta chains, and fibrinogen assembly commences by the addition of preformed A alpha and gamma chains to nascent B beta chains attached to polysomes. To test(More)
The complete amino acid sequence of rabbit testicular angiotensin-converting enzyme has been deduced from the sequence of the corresponding cDNA clone. A protein of the expected molecular weight of 84,000 was translated in vitro from the mRNA encoded by this cDNA. All of the previously determined sequences of seven tryptic peptides from the enzyme are(More)
To develop procedures for the expression of Rh antigen-containing proteins, we prepared a previously cloned Rh cDNA by isolation from a human bone marrow library using polymerase chain reaction (PCR). The cDNA that encodes either Rh(E) or (e) antigens was inserted into a vector (pGEM7ZRh) and transcription/translation performed in a reticulocyte lysate(More)
The association of [3H]bleomycin A2 and Cu(II):[3H]bleomycin A2 with HeLa cells has been characterized. Under the conditions of our experiments, approximately 0.1% of the total drug in the medium associates with HeLa cells. Both forms of the drug bind to HeLa cells in a specific and saturable manner, with a Km of 20 microM and a Vmax of 2.5 pmol/min/10(6)(More)
Earlier studies showed that overexpression of B beta fibrinogen chains, by transfection of Hep G2 cells with B beta cDNA, specifically enhanced the synthesis of all three fibrinogen chains (Roy, S. N., Mukhopadhyay, G., and Redman, C. M. (1990) J. Biol. Chem. 265, 6389-6393). To determine whether overexpression of any of the three component chains of(More)
A method for the preparation of biologically active [3H]- and [13C]bleomycin A2 is described. Demethyl Cu(II):bleomycin A2, isolated after pyrolysis of Cu(II):bleomycin A2, was methylated with either [3H]-or [13C]methyl iodide, which resulted in Cu(II):bleomycin A2 labeled in the dimethylsulfonium moiety. Copper was removed by treatment with dithizone in(More)