Transplantation-associated thrombotic microangiopathy (TA-TMA) is a devastating complication of hematopoietic stem cell transplantation. TA-TMA likely represents the final stage of vascular endothelial injury; however, its pathophysiology is largely unknown, making clinical management difficult. Recently, the association of neutrophil extracellular traps (NETs) with the development of thrombotic thrombocytopenic purpura and hemolytic uremic syndrome has been reported. Thus, we explored whether NETs are also relevant to the occurrence of TA-TMA. We retrospectively analyzed post-transplant trends of serum NET levels in 90 patients, 11 of whom developed TA-TMA. Relative to baseline (before the conditioning regimen), elevated serum NET levels either at 4 weeks after transplantation or as early as the day of transplantation were associated with significantly increased risk of TA-TMA. In contrast, thrombomodulin, a potential marker for TA-TMA, was not helpful to predict the occurrence of TA-TMA in our study. In addition, we directly detected glomerular deposition of NETs in 2 TA-TMA patients. Increased NET levels are a significant risk factor for TA-TMA, suggesting that NET level is a useful biomarker for TA-TMA.

Molecularly imprinted polymeric membranes, bearing the tetrapeptide derivative H-Asp-(OcHex)-Ile-Asp(OcHex)-Glu(OBzl)-CH2-, were prepared during the membrane preparation (casting) process in the presence of print molecule Boc-L-Trp. The molecularly imprinted membranes thus obtained showed adsorption selectivity toward a print molecule family, such as L-Trp, L-Phe, L-Ala, L-Arg, and L-Glu. The tetrapeptide derivative in the molecularly imprinted membranes preferentially recognized the L-amino acid from the D-isomer. Enantioselective permeation was attained with the present membrane, and the D-isomer was permeated in preference to the L-isomer by using the concentration difference as a driving force for membrane transport. Electrodialysis of racemic amino acid showed the possibility that permselectivity directly reflects its adsorption selectivity. It was made clear that the optical resolution was attained by the molecularly imprinted polymeric membranes.

Cell proliferation and transformation induced by growth factor stimulation or by carcinogens, viruses, or oncogenes are characterized by an associated increase in polyamine levels, which is mediated by increased polyamine biosynthesis and enhanced uptake of polyamines. Polyamine biosynthesis is catalyzed particularly, in the level of ornithine decarboxylase (ODC). The elevation of cellular polyamine levels on the other hand accelerates the induction of ornithine decarboxylase antizyme (antizyme), which is involved not only in ODC-degradation, but in the negative regulation of polyamine transport. Taking advantage of these characteristics of antizyme, the potential of antizyme as a factor having anti-cell growth and anti-tumor activity was investigated. We show that antizyme can induce cell death associated with a rapid decline of intracellular polyamine contents. The possible anti-tumor activities of ectopically expressed antizyme were tested in p21H-ras (Val 12)-transformed NIH3T3 cells and several human malignant cell lines including a line with loss of p53 expression, and they were shown to be as sensitive as nontransformed NIH3T3 cells in vitro. The in vivo antitumor activity was also tested using nude mice inoculated with H-ras transformed NIH3T3 cells that had been transfected with inducible antizyme expression vector and the results showed that antizyme expression in vivo blocks tumor formation in these mice. These results suggest that ectopic antizyme expression is of possible therapeutic bene®t in the treatment of cancer, which is mediated by ODC inactivation and intracellular polyamine depletion.

A synthetic gene for human epidermal growth factor (hEGF) was joined to a sequence encoding the signal peptide of Escherichia coli alkaline phosphatase. This hybrid gene was placed under the control of the alkaline phosphatase gene (phoA) promoter in a recombinant plasmid, which was used to transfect E. coli. The hybrid protein that was expressed in host cells under conditions of phosphate limitation was processed accurately during the secretion process, and mature hEGF was recovered in the periplasmic fraction. On the other hand, no EGF was detected in the periplasmic space when the synthetic hEGF gene was not accompanied by the phoA signal sequence.

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