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R Truitt

Publications and source records attributed to R Truitt.

3 recordsLinked to original sources

Role of K+ ion channels in lymphokine-activated killer (LAK) cell lytic function.

Cells of the immune system possess K+ ion channels which have been implicated in various cellular functions including activation, differentiation and cytolytic function. To define the role of K+ ion channels in the lytic function of lymphokine-activated killer (LAK) cells, we investigated the effects of K+ channel blockers on their cytolytic activity. Results show that when LAK cell mediated cytolysis of AKIL-20 tumor cells was carried out in the presence of: a) the K+ channel blocker, 4-aminopyridine (4-AP); b) the monoamine, serotonin (5-hydroxytryptamine; 5-HT); c) the serotonin agonist, quipazine; d) or the Ca++ dependent K+ channel blocker, quinidine, the cytolytic activity of the LAK cells was inhibited in a dose-dependent manner. Preincubation of LAK effector cells also inhibited lysis in a dose-dependent manner, whereas preincubation of the AKIL-20 tumor target cells produced no inhibitory effects. This study demonstrates that K+ ion channels are involved in the LAK cell cytolytic process and that compounds, including neuroendocrine products, which modulate K+ ion channel function are capable of modulating the lytic activity of these effector cells.

4-Aminopyridine

Partially matched bone marrow transplantation in patients with myelodysplastic syndromes.

Six patients with a myelodysplastic syndrome (MDS) were treated with bone marrow transplantation (BMT) using partially-matched related (3) or unrelated (3) donors. Patients' ages ranged from 7 to 31 years (median, 10 years). Bone marrow karyotype abnormalities were present in five patients included four with monosomy 7 and one with trisomy 8. One patient was in complete remission before transplant; the remaining five had excess of blasts or were undergoing leukemic transformation. Donor, and recipient were mismatched at the DR locus (2), A locus (2), B locus (1), or A and B loci (1). Conditioning included busulfan, cytarabine, cyclophosphamide, methylprednisolone, and total body irradiation. Cyclosporine was started on day -1. Marrows were T-cell depleted using a monoclonal antibody (MoAb) (CD3) and normal rabbit serum. Four patients engrafted routinely. One patient died of aspergillosis before engraftment (day 12) and one patient failed to engraft on first attempt, but engrafted following additional preparation. Median time to neutrophils greater than 500/microL and platelets greater than 25,000/microL were 16 and 19 days, respectively. Acute graft-v-host disease (GVHD) was less than or equal to grade II in all patients. One patient died with recurrent disease (day 257). One patient died at day 515 of pancreatitis and respiratory failure. Three patients are alive and disease-free at 240, 395, and 560 days post-BMT including two patients with unrelated donors. Partially matched T-depleted bone marrow from related or unrelated donors may be effective, and possibly curative therapy for patients with MDS who lack a histocompatibility locus antigen (HLA)-identical sibling donor.

Adolescent