Storage phosphor digital mammography

Digital mammography using storage phosphor CR is still in the investigational stage. It is the only digital mammography system that has been tested in preliminary clinical trials with promising early results. Further clinical studies are needed to assess the impact of the limited spatial resolution of storage phosphor technology on its application as a digital screening mammography system. Further studies also are needed to determine the optimum image processing parameters needed in digital mammography.     

NOD/SCID mice engineered to express human IL-3, GM-CSF and Steel factor constitutively mobilize engrafted human progenitors and compromise human stem cell regeneration.

Transplantation of immunodeficient mice with human hematopoietic cells has greatly facilitated studies of the earliest stages of human hematopoiesis. These include demonstration of the ability of injected 'human-specific' hematopoietic growth factors to enhance the production of human cells at multiple levels of differentiation. In contrast, the effects of continuous exposure to such molecules have not been well investigated. Here, we show that nonobese diabetic severe combined immunodeficiency mice genetically engineered to produce ng/ml serum levels of human interleukin-3 (IL-3), granulocyte/macrophage-stimulating factor (GM-CSF) and Steel factor (SF) display a complex phenotype when transplanted with primitive human bone marrow (BM) or fetal liver cells. This phenotype is characterized by an enhancement of terminal human myelopoiesis and a matched suppression of terminal human erythropoiesis, with a slight reduction in human B-lymphopoiesis in the BM of the engrafted mice. Human clonogenic progenitors are more prevalent in the blood of the transplanted growth factor-producing mice and this is accompanied by a very marked reduction of more primitive human cells in the BM. Our findings suggest that long-term exposure of primitive human hematopoietic cells to elevated levels of human IL-3, GM-CSF and SF in vivo may deleteriously affect the stem cell compartment, while expanding terminal myelopoiesis.     

High-dose therapy and autologous hematopoietic stem-cell transplantation does not increase the risk of second neoplasms for patients with Hodgkin's lymphoma: a comparison of conventional therapy alone versus conventional therapy followed by autologous hematopoietic stem-cell transplantation.

PURPOSE: To determine the incidence of second malignancies among patients with Hodgkin's lymphoma (HL) treated with autologous hematopoietic stem cell transplantation (AHSCT) compared with patients receiving conventional therapy alone and to identify potential risk factors for their occurrence. PATIENTS AND METHODS: We analyzed data on 1,732 consecutive patients with HL treated at the British Columbia Cancer Agency from 1976 to 2001, including 202 patients undergoing AHSCT. The median follow-up duration was 9.8 years for the whole cohort, 9.7 years for those patients treated with conventional therapy, and 7.8 years from AHSCT. RESULTS: The cumulative incidence of developing any second malignancy 15 years after therapy for HL was 9% (risk ratio = 3.5; P < .001); however, the incidence did not differ between those patients receiving conventional therapy alone compared with those undergoing AHSCT (10% and 8%, respectively; P = .48). In multivariate analysis, the only factor significantly associated with an increased risk of developing any second neoplasm or solid tumor was age > or = 35 years (P < .0001). An increased risk of therapy-induced acute myeloid leukemia and therapy-induced myelodysplastic syndrome was seen for patients aged > or = 35 years (P = .03) and stage III/IV (P = .04). CONCLUSION: Patients with HL are at increased risk of developing a second neoplasm. However, those patients undergoing AHSCT do not seem to be at greater risk compared with those patients receiving conventional therapy alone, at least during the first decade after therapy.     

The clinical use of karyotyping spontaneous abortions

OBJECTIVE: The objective of this study was to assess the clinical use of routinely karyotyping spontaneous abortion material. STUDY DESIGN: We retrospectively reviewed the records of the Pittsburgh Cytogenetics Laboratory from January 1, 1998, to December 31, 2001, for all tissues from spontaneous losses at 20 weeks' gestation or less for which complete medical records were available. RESULTS: There were 517 submitted samples of which 28 (5.4%) failed to grow in culture. Overall, 55.8% of samples were abnormal; 52.3% of normal results were male. In samples from pregnancies at 13 weeks or less the rate of abnormality was 69.1%. When analyzed by maternal age, the rate of abnormality for first-trimester losses was 57.2% in women younger than 35 years, and 82.3% in those 35 years or older. There was no difference in the rate of abnormality when comparing first loss with two or more losses, first pregnancy with two or more pregnancies, or the presence or absence of at least one live birth. CONCLUSION: Chromosome abnormalities are the cause for pregnancy loss in 50% to 80% of cases, depending on maternal age and gestational age at time of the loss. Karyotyping of spontaneous losses in the first trimester beginning with the patient's second loss provides clinically important etiologic information and decreases the number of evaluations necessary for recurrent pregnancy loss.     

Variable cytotoxicity of diphtheria toxin 388-granulocyte-macrophage colony-stimulating factor fusion protein for acute myelogenous leukemia stem cells

In this study, the utility of DT388-granulocyte-macrophage colony-stimulating factor (GM-CSF) for the ex vivo purging and direct administration to patients with acute myeloid leukemia (AML) is tested using clonogenic assays, long-term cultures (LTC), and NOD/SCID mice as assays for leukemic progenitors.We compare the ability of 24-hour exposure to 0.3 microg/mL (4 nM) DT388-GM-CSF to kill AML colony forming cells (CFC) and the more primitive AML progenitors detected after 6 weeks in stromal cocultures (AML LTC-initiating cells or AML LTC-IC) and after 8 weeks in NOD/SCID mice.AML samples (n = 10), expressing a mean of 35 to 1466 GM-CSF receptors/blast, showed mean (range) percent kills of AML CFC and LTC-IC of 61 (17-98) and 46 (0-94) respectively with a direct correlation (r = 0.69) between the % kills detected in the in vitro assays. Among 5 evaluable samples the percent reduction in AML cell engraftment in NOD/SCID marrow following ex vivo DT388-GM-CSF treatment varied from 38% to 100%. 40% to 56% of normal bone marrow CFC and 31% to 48% of normal LTC-IC survived the same ex vivo treatment (n = 3). In subsequent experiments, NOD/SCID mice received AML blast cell injections intravenously followed in 24 hours by 1.5 microg DT388-GM-CSF daily intraperitoneally for 5 days. A reduction of marrow blast cells was seen with 7 of 9 samples tested 4 to 12 weeks post one course of toxin. Repeating the 5-day course of toxin 2 or 3 times at 4-week intervals did not improve the response, while delaying administration until 4 to 8 weeks post AML cell injection reduced the toxin's effectiveness (n = 5).This fusion toxin may prove useful for in vitro purging of stem cell harvests from selected AML patients and for direct administration to such patients.     

Gene transfer to primary normal and malignant human hemopoietic progenitors using recombinant retroviruses

To study the feasibility of using retroviruses for gene transfer into human hemopoietic cells, various cell types were exposed to virus carrying the gene for neomycin resistance (neor). In preliminary studies using K562 cells as targets, we found that high viral titer and co-cultivation with viral producer cells rather than incubation in medium exposed to viral producer cells were important variables for achieving high frequencies of G418 resistant (G418r) colonies. The maximum frequency of G418r K562 colonies after co-cultivation with cells producing a neor virus titer of 4 X 10(6) cfu/mL was 60%. When primary human progenitors from normal marrow, fetal liver, or chronic myelogenous leukemia blood were exposed to high titer viral stocks, both with and without helper virus, under conditions optimized for K562 cells, maximum frequencies of G418r colonies were 3% to 16% for granulocyte macrophage progenitors and 2% to 6% for primitive erythroid progenitors. The presence of the neor gene in both G418r K562 and primary hemopoietic colonies was verified by Southern blot. Expression of the neor gene was shown by RNA spot blot. These data demonstrate efficient transfer and expression of the neor gene in both K562 cells and primary human hemopoietic cells from normal and leukemic individuals.     

Allogeneic haematopoietic stem cell transplantation for chronic lymphocytic leukaemia: outcome in a 20-year cohort

The curative potential of allogeneic haematopoietic stem cell transplant (allo HSCT) in chronic lymphocytic leukaemia CLL is established, with a demonstrated role for graft-versus-leukaemia and less certainty for other factors in determining outcome. The first two decades of CLL patients proceeding to allo HSCT at the Leukaemia/Bone Marrow Transplant Program of British Columbia (n = 49 consecutive, 1991-2009) were studied to clarify factors predicting outcome. The donor was related in 29 (59%) and unrelated in 20 (41%). Conditioning was reduced-intensity in 27 (55%) and myeloablative in 22 (45%). Thirty-one of 49 patients survive with median follow-up of 5 years (0·2-15). Cumulative incidence of non-relapse mortality; complete remission (CR); clearance of fluorescence in situ hybridization (FISH) abnormality and progression at 10 years was 36%; 69%; 55% and 22%. Overall survival (OS) was 63% at 2 years; 55% at 5 years and beyond. Factors predicting OS (P value by log rank <0·05) were: comorbidity index <3, FISH rank (Dohner) and 17p deletion, alemtuzumab pre-HSCT, achievement of CR post-HSCT, donor chimerism >90%, clearance of FISH abnormality post-HSCT and absence of high-grade (3-4) graft-versus-host disease. Results from this province-wide, two-decade cohort demonstrated that a substantial proportion of patients with high-risk CLL become long term disease-free survivors.     

Mechanisms that regulate the cell cycle status of very primitive hematopoietic cells in long-term human marrow cultures. II. Analysis of positive and negative regulators produced by stromal cells within the adherent layer.

Numerous factors that can influence the proliferation and differentiation in vitro of cells at various stages of hematopoiesis have been identified, but the mechanisms used by stromal cells to regulate the cycling status of the most primitive human hematopoietic cells are still poorly understood. Previous studies of long-term cultures (LTC) of human marrow have suggested that cytokine-induced variations in stromal cell production of one or more stimulators and inhibitors of hematopoiesis may be important. To identify the specific regulators involved, we performed Northern analyses on RNA extracted from human marrow LTC adherent layers, or stromal cell types derived from or related to those present in the adherent layer. These analyses showed marked increases in interleukin-1 beta (IL-1 beta), IL-6, and granulocyte colony-stimulating factor (G-CSF) mRNA levels within 8 hours after treatments that lead to the activation within 2 days of primitive hematopoietic progenitors in such cultures. Increases in granulocyte-macrophage (GM)-CSF and M-CSF mRNA were also sometimes seen. Bioassays using cell lines responsive to G-CSF, GM-CSF, and IL-6 showed significant elevation in growth factor levels 24 hours after IL-1 beta stimulation. Neither IL-3 nor IL-4 mRNA was detectable at any time. In contrast, transforming growth factor-beta (TGF-beta) mRNA and nanogram levels of TGF-beta bioactivity in the medium were detected at all times in established LTC, and these levels were not consistently altered by any of the manipulations that stimulated hematopoietic growth factor production and primitive progenitor cycling. We also found that addition of anti-TGF-beta antibody could prolong or reactivate primitive progenitor proliferation when added to previously stimulated or quiescent cultures, respectively. Together, these results indicate a dominant negative regulatory role of endogenously produced TGF-beta in unperturbed LTC, with activation of primitive hematopoietic cells being achieved by mechanisms that stimulate stromal cells to produce G-CSF, GM-CSF, and IL-6. Given the similarities between the LTC system and the marrow microenvironment, it seems likely that the control of human stem cell activation in vivo may involve similar variations in the production of these factors by stromal cells.