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1.
In this prospective randomized multicenter trial 93 patients, median age 72 years, with RAEB-t (n=25) and myelodysplastic syndrome (MDS)-AML (n=68) were allocated to a standard induction chemotherapy regimen (TAD 2+7) with or without addition of granulocyte-macrophage-CSF (GM-CSF). The overall complete remission (CR) rate was 43% with no difference between the arms. Median survival times for all patients, CR patients, and non-CR patients were 280, 550, and 100 days, respectively, with no difference between the arms. Response rates were significantly better in patients with serum lactate dehydrogenase (S-LDH) levels 相似文献   
2.
Dybedal  I; Jacobsen  SE 《Blood》1995,86(3):949-957
Transforming growth factor beta (TGF-beta) is a bifunctional regulator of the growth of myeloid progenitors and is here demonstrated to directly inhibit the growth of primitive erythroid progenitors by 95% to 100% regardless of the cytokines stimulating growth. Autocrine TGF- beta production of primitive hematopoietic progenitors has previously been reported. In the present study, a neutralizing TGF-beta antibody (anti-TGF-beta) added to serum-containing cultures, resulted in a 3-, 4- , and 25-fold increase in burst-forming unit erythroid (BFU-E) colony formation in response to interleukin-4 (IL-4) plus erythropoietin (Epo), SCF plus Epo, and IL-11 plus Epo, respectively. The growth of BFU-E progenitors has been suggested to require a burst-promoting activity in addition to Epo. Accordingly, we observed no BFU-E colony formation in serum-containing cultures in response to Epo alone. In contrast, 50 BFU-E colonies were formed when anti-TGF-beta was included in the culture. In serum-free cultures, Epo also stimulated BFU-E colony formation in the absence of other cytokines, whereas anti-TGF- beta had no effect on the number of colonies formed. Quantitation of TGF-beta 1 in serum by an enzyme-linked immunosorbent assay method showed predominantly the presence of precursor (latent) TGF-beta 1, but also showed active TGF-beta 1 at a concentration sufficient to potently inhibit erythroid colony formation. Thus, neutralization of active TGF- beta 1 in serum shows that Epo alone is sufficient to stimulate the growth of murine BFU-E progenitors.  相似文献   
3.
Multipotent self-renewing hematopoietic stem cells (HSCs) are responsible for reconstitution of all blood cell lineages. Whereas growth stimulatory cytokines have been demonstrated to promote HSC self-renewal, the potential role of negative regulators remains elusive. Receptors for tumor necrosis factor (TNF) and Fas ligand have been implicated as regulators of steady-state hematopoiesis, and if overexpressed mediate bone marrow failure. However, it has been proposed that hematopoietic progenitors rather than stem cells might be targeted by Fas activation. Here, murine Lin(-)Sca1(+)c-kit(+) stem cells revealed little or no constitutive expression of Fas and failed to respond to an agonistic anti-Fas antibody. However, if induced to undergo self-renewal in the presence of TNF-alpha, the entire short and long-term repopulating HSC pool acquired Fas expression at high levels and concomitant activation of Fas suppressed in vitro growth of Lin(-)Sca1(+)c-kit(+) cells cultured at the single cell level. Moreover, Lin(-)Sca1(+)c-kit(+) stem cells undergoing self-renewal divisions in vitro were severely and irreversibly compromised in their short- and long-term multilineage reconstituting ability if activated by TNF-alpha or through Fas, providing the first evidence for negative regulators of HSC self-renewal.  相似文献   
4.
63 evaluable patients with myelodysplastic syndromes (MDS) and 15 with acute myelogenous leukemia (AML) were randomized between low-dose ara-C (arm A) and low dose ara-C in combination with 13-cis-retinoic acid (13-CRA) and 1 alpha-hydroxy-vitamin D3 (1 alpha D3) (arm B). 69 patients were evaluable and 18 (26.1%) responded to therapy. The addition of 13-CRA and 1 alpha D3 had no positive influence on survival of the patients, remission rates or duration of remissions. 12/27 patients in arm A and 6/29 patients in arm B progressed from MDS to AML during the course of the study (p = 0.0527). Arm B gave significantly more side-effects than arm A (p = 0.005). Therapeutic effects of 13-CRA and 1 alpha D3 on MDS is not supported by this study. However, an inhibiting effect on AML development in some MDS subgroups cannot be excluded.  相似文献   
5.
Previous studies have shown that retinoic acid (RA), similar to tumor necrosis factor-alpha (TNF-alpha), can act as a bifunctional regulator of the growth of bone marrow progenitors, in that it can stimulate granulocyte-macrophage colony-stimulating factor (GM-CSF)- or interleukin-3 (IL-3)-induced GM colony formation, but potently inhibit G-CSF-induced growth. The present study, using highly enriched human CD34+ as well as Lin- murine bone marrow progenitor cells, demonstrates a potent inhibitory effect of 9-cis-RA on burst-forming unit-erythroid (BFU-E) colony formation regardless of the cytokine stimulating growth. Specifically, 9-cis-RA potently inhibited the growth of BFU-E response to erythropoietin (Epo) (100%), stem cell factor (SCF) + Epo (92%), IL- 3 + Epo (97%), IL-4 + Epo (88%), and IL-9 + Epo (100%). Erythroid colony growth was also inhibited when CD34+ progenitors were seeded at one cell per well, suggesting a direct action of RA. Using synthetic ligands to retinoic acid receptors (RARs) and retinoid X receptors (RXRs) that selectively bind and activate RAR-RXR or RXR-RXR dimers, respectively, we dissected the involvement of the two retinoid response pathways in the regulation of normal myeloid and erythroid progenitor cell growth. Transactivation studies showed that both the RAR (Ro 13- 7410) and RXR (Ro 25-6603 and Ro 25-7386) ligands were highly selective at 100 nmol/L. At this concentration, Ro 13-7410 potently inhibited G- CSF-stimulated myeloid as well as SCF + Epo-induced erythroid colony growth. At the same concentration, Ro 25-6603 and Ro 25-7386 had little or no effect on G-CSF-induced colony formation, whereas they inhibited 75% and 53%, respectively, of SCF + Epo-stimulated BFU-E colony growth. Thus, the RAR-RXR response pathway can signal growth inhibition of normal bone marrow myeloid and erythroid progenitor cells. In addition, we demonstrate a unique involvement of the RXR-RXR pathway in mediating growth inhibition of erythroid but not myeloid progenitor cells.  相似文献   
6.
We have published previously a prototype of a decision model for anaemic patients with myelodysplastic syndromes (MDS), in which transfusion need and serum erythropoietin (S-Epo) were used to define three groups with different probabilities of erythroid response to treatment with granulocyte colony-stimulating factor (G-CSF) + Epo. S-Epo 500 U/l and >/= 2 units/month for a poor response, whereas the presence of only one negative prognostic marker predicted an intermediate response. A total of 53 patients from a prospective study were included in our evaluation sample. Patients with good or intermediate probability of response were treated with G-CSF + Epo. The overall response rate was 42% with 28.3% achieving a complete and 13.2% a partial response to treatment. The response rates were 61% and 14% in the good and intermediate predictive groups respectively. The model retained a significant predictive value in the evaluation sample (P < 0.001). Median duration of response was 23 months. Scores for global health and quality of life (QOL) were significantly lower in MDS patients than in a reference population, and fatigue and dyspnoea was significantly more prominent. Global QOL improved in patients responding to treatment (P = 0.01). The validated decision model defined a subgroup of patients with a response rate of 61% (95% confidence interval 48-74%) to treatment with G-CSF + Epo. The majority of these patients have shown complete and durable responses.  相似文献   
7.
Knowledge about cognitive side-effects induced by electroconvulsive therapy (ECT) in depressed elderly patients is sparse. In this study we investigated changes in the cognitive functioning of non-demented elderly depressed patients receiving ECT (n = 62) compared with healthy elderly people (n = 17). Neuropsychological tests were administered at the start of treatment and again within 1 week after treatment. We computed reliable change indices (RCIs) using simple regression methods. RCIs are statistical methods for analyzing change in individuals that have not yet been used in studies of the acute cognitive side-effects of ECT. At the group level, only letter fluency performance was found to be significantly reduced in the ECT group compared with the controls, whereas both groups demonstrated stable or improved performance on all other measures. At the individual level, however, 11% of patients showed retrograde amnesia for public facts post-ECT and 40% of the patients showed a significant decline in neuropsychological functioning. Decline on a measure of delayed verbal anterograde memory was most common. Our findings indicate that there are mild neurocognitive impairments in the acute phase for a substantial minority of elderly patients receiving ECT. Analysis of reliable change facilitated the illumination of cognitive side-effects in our sample.  相似文献   
8.
The Fas receptor and its ligand have been implicated in mediating the bone marrow (BM) suppression observed in graft-versus-host disease and a number of other BM-failure syndromes. However, previous studies have suggested that Fas is probably not expressed on human hematopoietic stem cells (HSCs), but up-regulated as a consequence of their commitment and differentiation, suggesting that progenitors or differentiated blood cells, rather than HSCs, are the targets of Fas-mediated suppression. The present studies confirm that candidate HSCs in human cord blood and BM lack constitutive expression of Fas, but demonstrate that Fas expression on CD34+ progenitor and stem cells is correlated to their cell cycle and activation status. With the use of recently developed in vitro conditions promoting HSC self-renewing divisions, Fas was up-regulated on virtually all HSCs capable of multilineage reconstituting nonobese diabetic/severe combined immunodeficiency (NOD-SCID) mice in vivo, as well as on long-term culture-initiating cells (LTC-ICs). Similarly, in vivo cycling of NOD-SCID repopulating cells upon transplantation, resulted in up-regulation of Fas expression. However, repopulating HSCs expressing high levels of Fas remained highly resistant to Fas-mediated suppression, and HSC function was compromised only upon coactivation with tumor necrosis factor. Thus, reconstituting human HSCs up-regulate Fas expression upon active cycling, demonstrating that HSCs could be targets for Fas-mediated BM suppression.  相似文献   
9.
We report long-term results of treatment of myelodysplastic syndrome (MDS) with erythropoietin and granulocyte colony-stimulating factor (G-CSF). A total of 129 patients were followed up 45 months after last inclusion in the Nordic MDS Group studies. Erythroid response rate was 39% and median response duration 23 months (range, 3-116 months or more). Complete responders showed longer response duration than partial responders (29 versus 12 months, P = .006). The International Prognostic Scoring System (IPSS) groups Low/Intermediate-1 (Low/Int-1) had longer response duration than Int-2/High (25 versus 7 months, P = .002). The time until 25% developed acute myeloid leukemia (AML) was longer in the good and intermediate predictive groups for erythroid response compared with the poor predictive group (52 versus 13 months, P = .008). Only 1 of 20 long-term responders developed AML. We assessed the effect on long-term outcome by comparing treated patients with untreated patients selected from the IPSS database using multivariate Cox regression, adjusting for major prognostic variables. There was no difference in survival (odds ratio [OR], 0.9; 95% confidence interval [CI], 0.7-1.2; P = .55) or risk of AML evolution (OR, 1.3; 95% CI, 0.7-2.2; P = .40) between treated and untreated patients. Patients with high/intermediate probability of response and with IPSS Low/Int-1 show frequent and durable responses without adverse effects on outcome, while other patients should not be considered candidates for this treatment.  相似文献   
10.
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