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R Winston

Publications and source records attributed to R Winston.

At least 55 records · Page 3Linked to original sources

Regulation of insulin-like growth factors by antiestrogen.

Insulin-like growth factors are potent mitogens for breast cancer cell proliferation. This effect is modulated by the circulatory and extracellular IGFBPs as well as by the affinity of ligand binding receptors on the target cells. Antiestrogens have been shown to reduce both circulatory and microenvironmental IGF levels and thus suppress the IGF-I-induced growth of both ER-positive and ER-negative breast cancer cells. However, the effects of antiestrogens in down regulation of type I IGF receptor and in altering the autophosphorylation tyrosine kinase activity of EGF receptors are mainly observed in ER-positive cells. Furthermore, alteration of IGFBP by antiestrogens such as a marked increase of IGFBP-I production have been shown to inhibit the proliferative effect of IGF-I on ER-positive, but stimulate this effect, on ER-negative cells. Such differential effects from IGF receptor and IGFBP may explain the clinical outcome that tumor regression from antiestrogens is mainly observed in ER-positive type. This assumption based on IGF regulation alone is certainly an oversimplistic view amid the complexity of autocrine, paracrine, and endocrine functions.

Breast Neoplasms↗

Human immunodeficiency virus (HIV) Tat-reactive antibodies present in normal HIV-negative sera and depleted in HIV-positive sera. Identification of the epitope.

We have detected, in sera of normal human immunodeficiency virus (HIV)-free subjects, IgM antibodies reactive with the Tat protein of HIV in significant titers and at very high frequency, and, in HIV-positive sera, progressively lower titers as HIV pathogenesis ensues. Epitope analysis indicates that the Tat-reactive antibodies of both HIV-negative and HIV-positive sera are homologous, suggesting, therefore, that their decline in HIV-positive sera may represent attrition of a host defense factor. The identified epitope displays minimal homology with that previously defined for another set of IgM antibodies shown to be present in normal sera, deficient in HIV-positive sera, and postulated to be natural antibodies. We propose that the Tat-reactive antibodies, as well, are a set of natural antibodies and that the normal humoral immune system includes a repertoire of antibodies, nonimmunogenic in origin, that contribute to immune homeostasis and, consequently, to host resistance to HIV pathogenesis.

Amino Acid Sequence↗

BABI in dispute.

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Blastomeres↗