Robert T. Dorr

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Verapamil reversed resistance to doxorubicin in a human multiple myeloma cell line selected for multiple drug resistance. The drug-resistant cell line 8226/DOX40 is known to have reduced intracellular drug accu mulation associated with the overexpression of P-glycoprotein when compared to the sensitive parent cell line 8226/S. Verapamil alone was minimally(More)
The melanocortins (MCs) are a family of multifunctional peptidergic hormones. Several superpotent, prolonged acting, enzymatically resistant, MC analogs have been designed and synthesized to help clarify the nature and role of MCs and their receptors (MCRs) in physiological functions. Two of these analogs, a linear peptide, melanotan I, and a cyclic(More)
Male DBA2 mice were given 10(6) P-388 leukaemic cells i.p. and cimetidine (CMT) at 100 mg/kg 1 day for 10 days, or as a single 100 mg/kg injection 30 min before cyclophosphamide (CTX). CMT significantly prolonged the survival of groups of mice receiving 50, 100 and 200 mg/kg of CTX 3 days after tumour inoculation. Median survival increased by 5.5 days (P(More)
Induction of oxidative stress is a key component of cancer therapy. Pro-oxidant drugs have been demonstrated to enhance the efficacy of radiotherapy and chemotherapy. An emerging concept is that therapeutic outcomes are dictated by the differential redox buffering reserve in subpopulations of malignant cells, indicating the need for noninvasive biomarkers(More)
To define the effects of chronic spinal exposure to a highly selective ٢ opioid agonist c[DPen 2 ,DPen 5 ]enkephalin (DPDPE), adult beagles were prepared with chronic lumbar intrathecal cath-eters. Groups of dogs received intrathecal infusions (100 ␮l/h) of saline (vehicle), DPDPE 3 mg/ml or 6 mg/ml for 28 days. Over the 28-day period, saline or 3 mg/ml(More)
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