Blood
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Because of continuous blood transfusions, thalassemia patients are subjected to peroxidative tissue injury by the secondary iron overload. In accordance, analysis of serum from 42 beta-thalassemia patients, aged 4 to 40 years, showed that the mean concentrations of conjugated diene lipid hydroperoxides (CD), lipoperoxides evaluated as malondialdehyde/ thiobarbituric acid (MDA/TBA) adducts, and protein carbonyls increased about twofold with respect to control. Ferritin levels were positively correlated with the amount of MDA (r = .41; P = .007) and showed a positive trend with CD (r = .31; P = .07) and protein carbonyls (r = .35; P = .054), as further evidence of the deleterious effects of high tissue iron levels. ⋯ These results point out that the iron-induced liver damage in thalassemia may play a major role in the depletion of lipid-soluble antioxidants. The variations of the parameters evaluated in the present study were not correlated with the age of the patients. Our results suggest that the measurement of peroxidation products, matched with evaluation of antioxidants, may be a simple measure of iron toxicity in thalessemia, in addition to the conventional indices of iron status.
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
A randomized investigation of high-dose versus standard-dose cytosine arabinoside with daunorubicin in patients with previously untreated acute myeloid leukemia: a Southwest Oncology Group study.
Interest in high-dose cytarabine (HDAC) for both induction and postremission therapy for acute myeloid leukemia (AML) prompted the Southwest Oncology Group (SWOG) to initiate a randomized trial comparing HDAC with standard-dose cytarabine (SDAC) for remission induction of previously untreated AML and to compare high-dose treatment versus conventional doses for consolidation therapy. Patients less than 65 years of age with de novo or secondary AML were randomized for induction between SDAC 200 mg/ m2/d for 7 days by continuous infusion or HDAC at 2 g/ m2 intravenously every 12 hours for 12 doses; both groups received daunorubicin (DNR) at 45 mg/m2/d intravenously for 3 days. Complete responders to SDAC were randomized to receive either two additional courses of SDAC plus DNR or one course of HDAC plus DNR. ⋯ Induction therapy with HDAC plus DNR was associated with greater toxicity than SDAC plus DNR, but with no improvement in CR rate or survival. Following CR induction with SDAC, consolidation with HDAC increased toxicity but not survival or DFS. In a nonrandomized comparison, patients who received both HDAC induction and consolidation had superior survival and DFS compared with those who received SDAC induction with either SDAC or HDAC consolidation.
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Chronic myelogenous leukemia (CML) is a clonal disorder of the hematopoietic stem cell characterized by a chimeric BCR/ABL gene giving rise to a 210-kD fusion protein with dysregulated tyrosine kinase activity. We investigated the effect of genistein, a protein tyrosine kinase inhibitor, on the in vitro growth of CML and normal marrow-derived multi-potent (colony-forming unit-mix [CFU-Mix]), erythroid (burst-forming unit-erythroid [BFU-E]), and granulocyte-macrophage (colony-forming unit-granulocyte-macrophage [CFU-GM]) hematopoietic progenitors. Continuous exposure of CML and normal marrow to genistein induced a statistically significant and dose-dependent suppression of colony formation. ⋯ Analysis of individual colonies by cytogenetics and RT-PCR confirmed that genistein-induced increase in the percentage of nonleukemic progenitors was not due to suppression of BCR/ABL transcription. Analysis of nuclear DNA fragmentation by DNA gel electrophoresis and terminal deoxynucleotidyl transferase assay showed that preincubation of CML mononuclear and CD34+ cells with genistein induced significant evidence of apoptosis. These observations show that genistein is capable of (1) exerting a strong antiproliferative effect on CFU-Mix, BFU-E, and CFU-GM while sparing the more primitive LTC-IC and (2) selecting benign hematopoietic progenitors from CML marrow, probably through an apoptotic mechanism.
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Multicenter Study Clinical Trial
Successful transplantation of HLA-matched and HLA-mismatched umbilical cord blood from unrelated donors: analysis of engraftment and acute graft-versus-host disease.
To reduce the morbidity and mortality associated with unrelated donor bone marrow (BM) transplantation and potentially extend the pool of suitable donors, cryopreserved unrelated donor umbilical cord blood was considered as an alternate source of hematopoietic stem cells for transplantation. Patients with leukemia, BM failure syndrome, or inborn error of metabolism were eligible for a phase I clinical trial designed to estimate the risk of graft failure and severe acute graft-versus-host disease after transplantation of umbilical cord blood from unrelated donors. As of December 21, 1995, unrelated donor umbilical cord blood was used to reconstitute hematopoiesis in eighteen patients aged 0.1 to 21.3 years weighing 3.3 to 78.8 kg with acquired or congenital lympho-hematopoietic disorders or metabolic disease. ⋯ With a median follow-up of 6 months (range, 1.6 to 17 months); the probability of survival at 6 months is 65% in this high risk patient population. We conclude that cryopreserved umbilical cord blood from HLA-matched and mismatched unrelated donors is a sufficient source of transplantable hematopoietic stem cells with high probability of donor derived engraftment and low risk of refractory severe acute graft-versus-host disease. Limitations with regard to recipient size and degree of donor HLA disparity remain to be determined.
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Septic shock and multiple organ failure may be associated with coagulation activation, disseminated fibrin formation, and consumption of coagulation inhibitors such as antithrombin III. We have evaluated prospectively coagulation measurements in patients with severe chemotherapy-induced neutropenia. This group of patients was chosen because of their high risk of developing severe septic complications, thus allowing serial prospective coagulation testing before and during evolving sepsis or septic shock. ⋯ In contrast, FXIIa-alpha antigen levels were not different between groups at onset of fever but increased modestly during the course of septic shock (P = .001). Thus, septic shock in neutropenic patients is associated with increased thrombin generation. Furthermore, both FVIIa and AT III measurements are sensitive markers of an unfavorable prognosis.