Antilisterial activity of grape juice and grape extracts derived from Vitis vinifera variety Ribier.

Grape juice and skin and seed extracts of Vitis vinifera var. Ribier black table grapes were found to be highly inhibitory towards Listeria monocytogenes. This grape juice was also active against all other Listeria species tested but not against Bacillus cereus, Salmonella Menston, Escherichia coli, Staphylococcus aureus or Yersinia enterocolitica. Fractionation of the extracts showed that the antilisterial activity was strongest in the polymeric phenolic fractions. Two different types of active compounds were identified: the red-pigmented polymeric phenolics from juice and skin showed pH-dependent antilisterial activity, while the unpigmented polymeric phenolics from the seed showed antilisterial activity which was independent of pH.

Differential effects of IL-2 incubation on hematopoietic potential of autologous bone marrow and mobilized PBSC from patients with hematologic malignancies.

Culturing of hematopoietic progenitor cells for 24 h with IL-2 generates cytotoxic effector cells that mediate in vitro and possibly in vivo antitumor activity. We examined the effect of IL-2 incubation on progenitor cells from 24 patients with hematologic malignancies using paired autologous bone marrow (ABM) and PBSC to determine differences in hematopoietic potential. Cells were cryopreserved and stored in liquid nitrogen until conditioning therapy was completed. After thawing, cells were incubated with IL-2 for 24 h at 37 degrees C. Paired samples of ABM and PBSC from the same patient were analyzed for nucleated and mononuclear cell number, CD34 antigen expression, and colony-forming unit (CFU) activity before and after IL-2 incubation. There was a significant decrease in the average number of mononuclear cells (MNC) (x10(8)/kg) (<0.001) and CD34+ cells (x10(6)/kg) (0.006) from both ABM and PBSC after 24 h IL-2 culture (ABM MNC: 0.6+/-0.1 vs. 0.4+/-0.0, p = <0.001; PBSC MNC: 4.4+/-0.5 vs. 3.7+/-0.4, p = 0.03; ABM CD34+: 2.4+/-0.5 vs. 1.3+/-0.3, p = <0.001; PBSC CD34+: 6.6+/-1.8 vs. 5.0+/-1.2, p = 0.05). However, whereas ABM CFU/10(5) MNC plated (269.3+/-47.2 vs. 385.6+/-70.6) were significantly increased (p = 0.005), there was no change in PBSC CFU (271.0+/-47.2 vs. 257.3+/-48.5). The mean plating efficiency (%) of ABM CD34+ cells was markedly increased after IL-2 incubation (10.1+/-3.3 vs. 19.0+/-7.2, p = 0.04), although it was lower than that of PBSC CD34+ cells, which did not change significantly in culture (29.4+/-5.5 vs. 36.0+/-6.5). Additional work is in progress to determine the cause and significance of the enhanced plating efficiency of the ABM progenitor cells.