Damage and protection of UC blood cells during cryopreservation.

BACKGROUND: Current procedures for the cryopreservation of umbilical cord blood (UCB) progenitor cells, which are based on techniques used for BM, have had varying degrees of success (survival 9-118%). Improving the effectiveness of UCB cell therapies demands a more comprehensive understanding of freezing injury during cryopreservation. METHODS: Leukocyte concentrates from UCB, with or without 10% DMSO were cooled at 1 degrees C/min to different subzero temperatures (-5 to -50 degrees C), then either thawed directly (thaw) or plunged into liquid nitrogen before thawing (plunge). Single-platform flow cytometry with 7-amino-actinomycin D was used to directly quantify survival of CD34(+) cells. Fluorescent microscopy was used to examine plasma membrane integrity of nucleated cells. RESULTS: Without DMSO, recovery of nucleated cells was approximately 80% for both thaw and plunge. Survival was 9%, indicating damage to the plasma membrane. With 10% DMSO, nucleated cell recovery was also approximately 80%, indicating that DMSO does not improve recovery of nucleated cells. Survival, however, was much higher with DMSO, > 60% for nucleated cells thawed directly, and 30-55% for cells thawed from plunge, demonstrating cryoprotection conferred by DMSO. With DMSO, survival of CD34(+) cells was higher than that of nucleated cells, indicating that CD34(+) cells with 10% DMSO are more tolerant to cryopreservation than the total nucleated cell population. DISCUSSION: This study provides the necessary data on the low temperature response of UCB progenitor cells that are critical for the development of standards for the cryopreservation of UCB.

Translocations involving chromosome 12p11-13, methotrexate metabolism, and outcome in childhood B-progenitor cell acute lymphoblastic leukemia: a Pediatric Oncology Group study.

Children with B-progenitor cell acute lymphoblastic leukemia whose lymphoblasts at diagnosis accumulate high levels of methotrexate (MTX) and MTX polyglutamates (MTXPGs) appear to have a good prognosis. This has been attributed to increased sensitivity of their blast cells to MTX. However, the proportion of children who are cured of B-progenitor cell acute lymphoblastic leukemia exceeds the number whose lymphoblasts accumulate high MTXPG levels. We report that lymphoblasts from patients with < 50 chromosomes who have translocations that involve the short arm of chromosome 12 accumulate low levels of MTXPGs. These patients appear to have an excellent survival because none of 14 patients with translocations affecting 12p has relapsed, 26-79 months following diagnosis.

Accumulation of methotrexate polyglutamates, ploidy and trisomies of both chromosomes 4 and 10 in lymphoblasts from children with B-progenitor cell acute lymphoblastic leukemia: a Pediatric Oncology Group Study.

Levels of accumulation of methotrexate polyglutamates were measured in vitro in lymphoblasts obtained at diagnosis from children with B-progenitor cell acute lymphoblastic leukemia (pro-B ALL). They were compared to numerical and structural chromosomal abnormalities present in these leukemic cells. In a series of 95 patients, the percent with high lymphoblast methotrexate polyglutamate levels increased with the increase in modal number of total chromosomes (p<0.001). Thus, lymphoblast methotrexate polyglutamate accumulation appeared to be closely linked to the extent of hyperdiploidy in childhood pro-B ALL. Lymphoblasts from 35 (88%) of the 40 children with hyperdiploid (>50 chromosomes) and 23 (88%) of 26 with hyperdiploid (DNA Index >1.16) pro-B ALL accumulated high levels of methotrexate polyglutamate, suggesting that they were more sensitive to methotrexate cytotoxicity. While children with hyperdiploid (DNA Index >1.16) pro-B ALL have a good prognosis, those with trisomies of both chromosomes 4 and 10, almost all of whom are hyperdiploid, have an even better outcome. There was no significant difference in methotrexate polyglutamate levels in lymphoblasts from 19 children with and 21 without trisomies of both chromosomes 4 and 10 (p = 0.25). The improved response to multi-agent chemotherapy conferred by the presence of trisomies of both chromosomes 4 and 10 in such patients may be due to increased sensitivity of their lymphoblasts to one or more anti-leukemic agents in addition to methotrexate.

Ibogaine and a total alkaloidal extract of Voacanga africana modulate neuronal excitability and synaptic transmission in the rat parabrachial nucleus in vitro.

Ibogaine is a natural alkaloid of Voacanga africana that is effective in the treatment of withdrawal symptoms and craving in drug addicts. As the synaptic and cellular basis of ibogaine's actions are not well understood, this study tested the hypothesis that ibogaine and Voacanga africana extract modulate neuronal excitability and synaptic transmission in the parabrachial nucleus using the nystatin perforated patch-recording technique. Ibogaine and Voacanga africana extract dose dependently, reversibly, and consistently attenuate evoked excitatory synaptic currents recorded in parabrachial neurons. The ED50 of ibogaine's effect is 5 microM, while that of Voacanga africana extract is 170 micrograms/ml. At higher concentrations, ibogaine and Voacanga africana extract induce inward currents or depolarization that are accompanied by increases in evoked and spontaneous firing rate. The depolarization or inward current is also accompanied by an increase in input resistance and reverses polarity around 0 mV. The depolarization and synaptic depression were blocked by the dopamine receptor antagonist haloperidol. These results indicate that ibogaine and Voacanga africana extract 1) depolarize parabrachial neurons with increased excitability and firing rate; 2) depress non-NMDA receptor-mediated fast synaptic transmission; 3) involve dopamine receptor activation in their actions. These results further reveal that the Voacanga africana extract has one-hundredth the activity of ibogaine in depressing synaptic responses. Thus, ibogaine and Voacanga africana extract may produce their central effects by altering dopaminergic and glutamatergic processes.

Successful reversal of neutropenia in Felty's syndrome with recombinant granulocyte colony stimulating factor.

We report two patients with Felty's syndrome and chronic skin ulcers treated successfully with recombinant granulocyte colony stimulating factor (GCSF). In both cases granulocytes returned to the normal range within days of starting treatment, and their cutaneous ulcers improved. In one patient granulocytes were maintained at normal levels with a regimen of GCSF 3 micrograms/kg twice weekly for 14 months.

Bone marrow granulocyte reserve in chronic benign idiopathic neutropenia.

Fifteen patients with chronic benign idiopathic neutropenia (CBIN) with neutrophil counts less than 1.0 X 10(9)/1 have been studied. The mean age was 33 years (range 23-50) comprising 11 females and 4 males. Bone marrow cellularity was normal except in two patients who showed slight reduction and one who had a slight increase. Bone marrow differential counts were normal apart from a small increase in the percentage of promyelocytes and reduction in the myeloid/erythroid ratio in some patients. Peripheral blood counts showed no 'compensatory' monocytosis. Epinephrine stimulation tests showed no evidence of excess neutrophil margination. After endotoxin administration there was a one- to two-fold increase in neutrophil counts in three patients, a three-fold increase in three patients and a greater than four-fold increase in the remaining nine patients. The findings suggest that the benign course of CBIN is not due to excess neutrophil margination nor to compensatory monocytosis, but that at least one mechanism includes a functionally adequate release of neutrophils to the peripheral blood under conditions of stress with subnormal delivery of neutrophils under basal conditions. The variability in responses to endotoxin suggests that CBIN is not entirely homogeneous with respect to mechanism. The findings of relatively normal bone marrow cellularity and differential counts and a normal or substantial neutrophil response to endotoxin appear characteristic. They may help predict a benign clinical course in neutropenic patients and assist diagnosis of the CBIN variant of idiopathic neutropenia.

Lithium carbonate therapy in severe Felty's syndrome. Benefits, toxicity, and granulocyte function.

Lithium carbonate was administered to six patients with severe Felty's syndrome, five of whom had problems with infection. Two patients had granulocyte increments that persisted after therapy was discontinued; in one of them problems with infections resolved. In another patient a transient granulocyte rise accompanied treatment. There was no response in three patients. Granulocyte function was measured in three patients during treatment. It was normal except for subnormal hexose monophosphate shunt activity in two patients. Although serum lithium levels were less than 1.5 mmole/L, serious toxic effect occurred in one patient and significant side effects in the other five. These results support a short trial of lithium carbonate therapy in patients with severe symptomatic Felty's syndrome. Potentially beneficial granulocyte increases occur in a minority of patients only, however, and side effects and toxic effects are common.

Transient anti-D in an Rh-positive patient with congenital dyserythropoietic anemia type II.

A multiply transfused Rh-positive patient with congenital dyserythropoietic anemia type II or hereditary erythroblastic multinuclearity with a positive acidified serum test is described in whom a transient anti-D was accompanied by a positive direct antiglobulin test. A brief review of the literature and possible mechanisms for this observation are presented.

Preference of the early murine immune response for polymorphic determinants on human lymphoid-leukemia cells and the potential use of monoclonal antibodies to these determinants in leukemia-typing panel.

28 monoclonal antibodies (MCAs) which were produced following immunization of mice with human lymphoid leukemia or lymphoma cells were subjected to extensive specificity testing using immunofluorescence and complement-mediated cytotoxicity assays. All except one of the MCAs reacted with lymphocytes from at least one normal donor, but only 36% reacted with at least one subpopulation of lymphocytes from every normal donor tested. 60% of the MCAs detected polymorphic determinants, the frequency of polymorphism ranging from 27 to 91%, 50% of these MCAs reacting with B lymphocytes but not T lymphocytes. The marked heterogeneity observed when testing human lymphoid leukemias with these MCAs could be explained by both polymorphism and heterogeneity in lymphocyte differentiation marker expression. An awareness of the preferential murine immune response to polymorphic determinants on human lymphoid leukemia cells is essential when interpreting unexpected positive or negative results when testing with MCAs. An MCA believed to be detecting a monomorphic determinant may be detecting a high-frequency (supratypic) polymorphic determinant, and a putative leukemia-specific MCA may be detecting a low-frequency polymorphic determinant. Our panel, which includes MCAs which detect polymorphic determinants, appears useful in following the course of leukemia and may be useful for leukemia classification.