A comparison of mass balance, pharmacokinetics and disposition of [14C(U)]- and [125I]recombinant human interleukin-2 in cynomolgus monkeys.

Recombinant human interleukin-2 (rHuIL-2) has been metabolically labeled with 14C amino acids in Escherichia coli and affinity purified on a rHuIL-2 receptor affinity column. The radiolabeled molecule had a specific radioactivity of 238 dpm/unit and the identical amino acid sequence and biological activity as unlabeled rHuIL-2. In this study, we used this labeled [14C(U)]rHuIL-2 and commercially available [125I]rHuIL-2 (identical in sequence to the [14C(U)]rHuIL-2) to compare the mass balance, pharmacokinetics, and disposition in cynomolgus monkeys.

Ultraviolet-B (290-320 nm)-irradiation inhibits epidermal growth-factor binding to mammalian cells.

Mitogens, such as polypeptide growth factors and phorbol ester tumor promoters, act by binding to specific receptors and inducing a pleiotropic response in cultured mammalian cells, which results in the induction of cellular proliferation. An early effect of such agents is the inhibition of binding of epidermal growth factor (EGF) to its receptor. Ultraviolet radiation has also been shown to induce a proliferative response in vivo and in vitro and to act as a tumor promoter in animal skin.

Ultraviolet radiation alters choline phospholipid metabolism in human keratinocytes.

Ultraviolet radiation B (UVB-290-320 nm) induces inflammation and hyperproliferation in human epidermis. This response is associated with the recovery from irradiated skin of inflammatory mediators derived from membrane phospholipids. We have previously reported that UVB stimulates the production of such mediators by human keratinocytes (HK) in culture.

Effect of strategic anthelmintic treatment and pasture management on productivity and control of nematode parasites in weaner-yearling beef cattle.

Three groups of 17 beef calves were used to evaluate effects of strategic anthelmintic treatment on safe (group 1) and contaminated (group 2) pasture in comparison with minimal treatment at weaning and contaminated pasture (group 3). The investigation extended from weaning in November 1982 to the following August. Results of faecal egg counts, herbage larval counts, plasma pepsinogen and tracer calf worm counts in autumn and spring indicated minimal levels of infection on safe pastures provided in November and April (group 1).

Ultraviolet radiation acts as an independent mitogen for normal human melanocytes in culture.

Identification of growth factors for normal human melanocytes has been significantly aided by the recent development of in vitro culture systems for this cell. Utilizing such a system, we studied the effect of ultraviolet radiation (UVR) on both melanocyte growth and melanization by incorporation of 3H-thymidine and 3H-L-dihydroxyphenylalanine (3H-DOPA), respectively. 3H-thymidine incorporation was found to be significantly stimulated during the first 24 h following a single irradiation.