Tetrathiomolybdate is effective in a mouse model of arthritis.

OBJECTIVE: To test for protective effects of therapy with tetrathiomolybdate, a copper-lowering drug, against collagen-induced arthritis in mice. METHODS: Mice were injected with bovine collagen II, and limb joint swelling and erythema were scored. Tetrathiomolybdate treated mice received drug by oral gavage or in drinking water. Plasma ceruloplasmin was followed as a measure of body copper status, and maintained between 20 and 60% of baseline. Urine for isoprostane studies was collected in metabolic cages. At sacrifice, blood was collected for cytokine assays, and hind limbs fixed in formalin. RESULTS: Tetrathiomolybdate strongly protected against the collagen-induced arthritis as reflected in scores of swelling and erythema, and as seen histologically. Further, tetrathiomolybdate strongly protected against the increase in urine isoprostanes (a marker of oxidant damage) seen in collagen treated controls. The drug also protected against the increase in interleukin 2, interleukin 1beta, and tumor necrosis factor-a levels seen in collagen treated controls. CONCLUSION: Based on the positive results reported here, and the good safety profile of tetrathiomolybdate in human studies so far, a trial of tetrathiomolybdate in arthritis syndromes seems warranted.

Evaluation of ultrasound tissue damage based on changes in image echogenicity in canine kidney.

Sufficiently high intensity ultrasound can create hyperechoic regions in an ultrasound image due to local bubble generation. We explore the link between the temporal extent of these hyperechoic regions and tissue damage caused by ultrasound therapy. The decay rate of increased echogenicity from the focal zone in insonated live exteriorized canine kidney was quantified and correlated to the spatial extent of tissue damage. The decay half-time, t(half), defined as the time for echogenicity enhancement to decay by a factor of 2, was observed in all cases to be greater than 41 s in spatial zones in which extensive histological damage was observed. In cases in which the measured thalf was less than 11 s, the damage was limited to minor hemorrhage, or it was not detected. These t(half) discrimination boundaries of 41 and 11 s were not statistically different for cases in which contrast agent was used to enhance therapeutic efficiency. This was true even though contrast agent infusion significantly reduced the therapy pulse duration threshold for damage production.

Tetrathiomolybdate protects against cardiac damage by doxorubicin in mice.

Cardiac toxicity is the limiting factor in therapy with doxorubicin, an otherwise useful cancer drug. In this article we detail our study of a mouse model of doxorubicin-induced cardiac toxicity in which, after 4 days' treatment, doxorubicin caused marked increases in plasma concentrations of creatine kinase, lactic dehydrogenase, and troponin I, indicators of cardiac injury; marked increases in the plasma concentrations of tumor necrosis factor-alpha and interleukin-1(beta), both inflammatory cytokines; and a marked increase in the plasma concentration of interleukin-2, an indicator of cytotoxic T-cell activation. Therapy with tetrathiomolybdate, designed to limit copper availability, eliminated almost all of the increases of these six parameters in plasma. The marked protection against cardiac injury by doxorubicin in tetrathiomolybdate-treated animals suggests that tetrathiomolybdate would be of use clinically in helping prevent doxorubicin toxicity in patients. In other preclinical work, it has been shown that tetrathiomolybdate potentiates the chemotherapeutic effect of doxorubicin in cancer, so a double benefit might accrue clinically from the combined use of tetrathiomolybdate and doxorubicin. The mechanism by which tetrathiomolybdate protects against doxorubicin toxicity is of considerable interest. Our working hypothesis, based on the inhibition of interleukin-2 by tetrathiomolybdate as shown here, is that tetrathiomolybdate interrupts the inflammatory cascade at the activated-T-lymphocyte stage.