Inactivation of ricin by constituents present in a skin decontamination lotion.

Ricin is a proteinaceous toxin, listed on the schedules of both the chemical and biological weapons conventions. The ease of accessibility to the Ricinus communis plant and toxin extraction makes ricin a viable concern for use of intentional release and causal effects. The adverse effects following exposure to the toxin are caused by the bipartite molecular structure of ricin which allows binding to the mammalian cell surface, enter via endocytic uptake, and deliver the catalytically active polypeptide into the cell cytosol where it irreversibly inhibits protein synthesis, causing cell death. In the present study, the inactivation effectiveness of RSDL® (Reactive Skin Decontamination Lotion) and its individual inactivating constituents (Potassium 2,3-butanedione monoximate (KBDO) and 2,3-butanedione (DAM)) was evaluated for ricin using a number of read out systems including a cytotoxicity assay, quantitative sandwich ELISA test, and a mass spectrometry-based assay. The results demonstrate that RSDL is able to abolish ricin activity after an incubation time of 30 min as determined in the cytotoxicity assay, and after 2 min as determined in the ELISA assay. Mass spectrometric analysis provided evidence that RSDL is able to induce cleavage of the disulfide linkage between the A- and B- polypeptide chain of ricin which is crucial to the inactivation of the toxin, but this seems not the only mechanism of inactivation. Follow on studies would assist to elucidate the details of the toxin inactivation because it is possible that additional generic mechanisms are in place for denaturation with the RSDL lotion components. This may also provide a promise for testing and inactivation with RSDL of other protein toxins.

Role of the T-cell receptor in kidney ischemia-reperfusion injury.

T cells have been demonstrated to modulate ischemia-reperfusion injury (IRI) in kidney, lung, liver and intestine. The underlying mechanisms for T-cell engagement in IRI are unknown. We hypothesized that the T-cell receptor (TCR) plays a role in renal IRI, and examined the effects of TCR alpha/beta (alphabeta) and gamma/delta (gammadelta) deficiency on ischemic acute renal failure (ARF). TCR-specific deficiency in specific mice was confirmed by fluorescence-activated cell sorting analysis using monoclonal antibodies (Abs). IRI was induced by bilateral clamping of kidney pedicles for 30 min, followed by reperfusion. Serum creatinine and kidney histopathology were used to assess the severity of experimental ARF. TCR alphabeta-deficient mice were significantly protected from kidney dysfunction compared to wild-type (WT) littermates after IRI (P<0.05). Histologic analysis demonstrated a significant reduction in renal tubular injury in both TCR alphabeta- and gammadelta-deficient mice compared to WT mice postischemia. TCR alphabeta-deficient mice had reduced tumor necrosis factor-alpha and interleukin-6 protein expression in kidney tissue compared to WT mice at 24 h postischemia using a microbead-based protein detection platform. Relative protection from kidney IRI did not correlate with neutrophil and macrophage infiltration of kidney tissue. Thus, the TCR plays a direct but modest pathophysiological role in kidney IRI. These data suggest that alloantigen-independent activation in IRI can lead to engagement of antigen-specific molecules on T cells. Furthermore, given that the TCR is already a target for diagnostics and therapeutic strategies in immune diseases, these approaches can now be harnessed for IRI.

Projection system with brightness amplifier for biology and medicine.

Some results of investigation of biological systems using laser projection microscope is given. The scheme permitted to work both in reflected and transmitting light. The image of a living cell on a large screen was observed.