Osmotic and convective dehydrofreezing were studied to determine sugar concentration, ascorbic acid loss, and texture changes in dried and dehydrofrozen kiwifruit. Two concentrations of sucrose (60Њ and 72Њ Brix) were used as osmotic solutions after convective air drying. Time needed to reach desired moisture was reduced with combined drying compared with osmotic drying. Firmness was evaluated by the maximum force from a back extrusion test. A reduction in maximum force was observed after freezing, as compared with fresh and dried fruit. Addition of ascorbic and citric acid as antioxidants in the osmotic solution prevented browning, and significant loss of ascorbic acid during osmotic drying. Air drying at 30ЊC produced distinguishable color changes.

Depletion of T lymphocytes from allogeneic bone marrow transplants successfully prevents the development of graftversus-host disease (GvHD) but is associated with impaired engraftment, immunosuppression, and abrogation of the graft-versus-leukemia effect. We therefore explored the possibility of selectively eliminating alloreactive T cells by CD95/ CD95L-mediated activation-induced cell death (AICD) in a major histocompatibility complex allogeneic murine model system. Activation of resting or preactivated T lymphocytes from C3H/HeJ (H-2 k ) mice was induced with irradiated BALB/cJ (H- 2 IntroductionGraft-versus-host disease (GvHD) represents a major complication of allogeneic bone marrow transplantation (BMT), which results in significant morbidity and mortality. Donor T lymphocytes present in the BM or peripheral blood stem cell transplant cause GvHD by recognizing major as well as minor histocompatibility antigens (reviewed by Ferrara et al 1 ). Although innovative strategies for the prediction, prevention, or treatment of this caveat in allogeneic BMT have been proposed, 2-9 prophylaxis or treatment of GvHD still remains unsatisfactory. Removal of donor-derived T lymphocytes prior to transplantation efficiently ameliorates GvHD. However, ex vivo depletion of T cells has been associated with an increased risk of viral opportunistic infections, 10 impaired engraftment, 11 and the loss of the graft-versus-leukemia (GvL) effect, resulting in an increased incidence of recurrence of leukemia. 12,13 These observations emphasize the clinical importance of allogeneic T cells in conferring a protective antiviral immunity as well as mediating a GvL effect. Several clinical and experimental studies support the idea that GvHD and GvL are not only mediated by the same (host-specific) T cell but also by distinct (leukemia-specific) alloreactive donor T-cell populations. 14-16 Moreover, allo-major histocompatibility complex (MHC)-restricted cytotoxic T lymphocytes (CTLs) to antigens frequently expressed at elevated levels on leukemic cells can be cloned from an allorestricted T-cell repertoire and used to mediate a GvL reaction without causing GvHD. [17][18][19] However, immunotherapy with ex vivo-generated specific T cells requires the identification and characterization of tumor-specific antigens to be targeted. To circumvent this prerequisite of cloning leukemia-specific T cells, we aimed to develop a complementing strategy that would allow ex vivo elimination of alloreactive T cells responsible for GvHD while preserving an allorestricted T-cell population able to both mediate GvL and antiviral immunity effects. Because the activation-induced cell death (AICD) mediated by CD95/CD95 ligand (CD95L) (reviewed by Lenardo et al 20 ) represents an important physiologic pathway to control the expansion of antigen-activated T cells at the down phase of an immune response, it therefore might provide a means to selectively deplete activated alloreactive T lymphocytes. Induction of AICD triggered by repetitive T-cell receptor (TCR...

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