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Summary: In the Austrian biodatabase for chronic myelomonocytic leukemia (ABCMML) clinicolaboratory real-life data have been captured from 606 CMML patients from 14 different hospitals over the last 30 years. It is the only large biodatabase worldwide in which functional methods such as semisolid in vitro cultures complement modern molecular methods such as next generation sequencing. This provides the possibility to comprehensively study the biology of CMML. The aim of this study was to compare patient characteristics with published CMML cohorts and to validate established prognostic parameters in order to examine if this real-life database can serve as a representative and useful data source for further research. After exclusion of patients in transformation characteristics of 531 patients were compared with published CMML cohorts. Median values for age, leukocytes, hemoglobin, platelets, lactate dehydrogenase (LDH) and circulating blasts were within the ranges of reported CMML series. Established prognostic parameters including leukocytes, hemoglobin, blasts and adverse cytogenetics were able to discriminate patients with different outcome. Myeloproliferative (MP) as compared to myelodysplastic (MD)-CMML patients had higher values for circulating blasts, LDH, RAS-pathway mutations and for spontaneous myelomonocytic colony growth in vitro as well as more often splenomegaly. This study demonstrates that the patient cohort of the ABCMML shares clinicolaboratory characteristics with reported CMML cohorts from other countries and confirms phenotypic and genotypic differences between MP-CMML and MD-CMML. Therefore, results obtained from molecular and biological analyses using material from the national cohort will also be applicable to other CMML series and thus may have a more general significance. [ABSTRACT FROM AUTHOR]

Abstract: Iron and vitamin B12 deficiencies are two of the most common diseases in the childhood group. Deficiencies of iron and vitamin B12 affect many systems in the body. In this study, to discover the effects of iron and vitamin B12 deficiencies on the hematopoietic stem cells, we studied CFU assay from peripheral blood. One hundred and two children were included in our study and were evaluated in five categories: iron deficiency, iron deficiency anemia, vitamin B12 deficiency, iron and vitamin B12 deficiency, and controls. As a result of statistical analysis, no significant difference was detected between five groups in terms of CFU assays. The results of our study suggest that, in emergent situations, stem cell samples can be collected before treatment with B12 or iron which are common deficiencies in donors of hematopoietic stem cell transplantation. We conclude that we could reach more accurate results by designing a study which contains more patients and includes in vivo results. [ABSTRACT FROM AUTHOR]

Recent insights into the pathophysiology of chronic myelomonocytic leukemia (CMML) have been obtained by the molecular and biological characterization of primary leukemic cells from patients and from animal models. Almost 3 decades ago extensive myeloid colony growth in semisolid cultures without exogenous growth factors was observed as an in vitro characteristic of a subgroup of CMML patients. Recent data suggest that this phenomenon was probably the first indication of an hyperactive RAS signaling pathway in these patients. Although the mutation landscape in CMML is heterogeneous and molecular aberrations in other signaling components can be found in some patients, the RAS pathway seems to play the major pathophysiological role in the majority of CMML patients with myeloproliferation (MP), disease progression and transformation into secondary acute myeloid leukemia (AML). There is also increasing evidence indicating that the MP-CMML is a RAS pathway driven disease which is superimposed onto age-related clonal hematopoiesis. [ABSTRACT FROM AUTHOR]

Purpose: Infected, long bone non-unions present a significant clinical challenge. New and alternative therapies are needed to address this problem. The purposes of this study were to compare the number of circulating granulocyte-macrophage colony-forming units (CFU-GM) in the peripheral blood of polytraumatic patients with infected tibial non-unions and in the peripheral blood of control patients with the hypothesis that their number was decreased in polytraumatic patients; and to treat their infection without antibiotics and with local transplantation of bone marrow concentrated granulocytes precursors.Methods: Thirty (18 atrophic and 12 hyperthrophic ) infected tibial non-unions (without bone defect) that occurred after open fractures in polytraumatic patients were treated without antibiotics and with percutaneous injection of autologous bone marrow concentrate (BMC) containing granulocytes precursors (CFU-GM). CFU-GM progenitors were assessed in the bone marrow aspirate, peripheral blood, and fracture site of these patients. The number of these progenitors was compared with the CFU-GM progenitors of control patient samples (healthy donors matched for age and gender). Outcome measures were: timing of union, callus formation (radiographs and CT scan), and recurrence of clinical infection.Results: As compared to control patients, the number of CFU GM derived colonies was lower at peripheral blood in patients with infected nonunions. The bone marrow graft injected in nonunions contained after concentration 42 621 ± 20 350 CFU-GM-derived colonies/cc. Healing and cure of infection was observed at six months for 25 patients and at one year follow up for 30 patients. At the median ten year follow-up (range: 5 to 15), only one patient had clinical recurrent infection after healing (between 6 months and last follow-up).Conclusion: The peripheral blood of these polytraumatic patients with infected nonunions had a remarkable decrease in CFU-GM-derived colonies as compared with normal controls. Local transplantation of concentrated CFU-GM-derived colonies aspirated from bone marrow allowed cure of infection and healing without antibiotics. [ABSTRACT FROM AUTHOR]

Our previous studies showed that UTL-5g, a novel anti-inflammatory TNF-a inhibitor, enhanced the chemotherapeutic efficacy of cisplatin against HCT-15 human colon cancer cells in an animal tumor model. To extend the study, we set out to investigate 3 newly synthesized analogs of UTL-5g (UTLOH-4a, -4b, and -4c) on whether they are associated with similar biological effects. Chemosensitizing effects of UTL-5g and its 3 analogs were investigated using HCT-15 cells in vitro with increasing doses of cisplatin, carboplatin, or oxaliplatin. IC50 of each drug was determined from the dose-response surviving curves. The antiinflammatory effects were examined by their ability to inhibit PGE2 production in mouse RAW cells stimulated with LPS. Myelotoxicity induced by cisplatin was examined with human CFU-GM clonogenic assay. All 4 compounds significantly potentiated the cytotoxic effect of cisplatin against HCT-15 cancer cells by lowering the IC50 values. Among them, UTL-5g appeared to be the most promising sensitizer of cisplatin and UTLOH-4b was the most potent sensitizer of carboplatin. Anti-inflammatory study showed that UTL-5g, UTLOH-4a, and -4c inhibited PGE2 production in LPS-stimulated RAW cells. In addition, UTL-5g and UTLOH-4a enhanced the survival of CFU-GM colony counts in cultures containing cisplatin, carboplatin and oxaliplatin respectively. [ABSTRACT FROM AUTHOR]

In the last 20 years, one of the main goals in the drug discovery field has been the development of reliable in vitro models. In particular, in 2006 the European Centre for the Validation of Alternative Methods has approved the colony-forming unit granulocytes-macrophages test, which is the first and currently unique test applied to evaluate the myelotoxicity of xenobiotics in vitro. The present work aimed at miniaturizing this in vitro assay by developing and validating a Lab-on-Chip platform consisting of a high number of bioreactor chambers with screening capabilities in a high-throughput regime. [ABSTRACT FROM AUTHOR]

The pteridine neopterin (NP) was shown to be produced by monocytes and has been known as a useful maker of immunological activation, although, the biological activity of this agent is still unclear. To elucidate the biological function of NP, the changes in the number of blood leukocyte, bone marrow and spleen hemopoietic progenitor cells after intraperitoneal administration of NP into mice were investigated. Administration of NP increased the number of blood leukocytes about 2 fold higher than that of the control at days 7 and 14. Blood films, made by smearing samples of peripheral blood, showed the increment of granulocytes in blood of NP treated animals. The number of granulocyte-macrophage progenitor cells (CFU-GM) was also increased in both bone marrow and spleen in mice with NP administration. Extensive study showed that NP stimulated the hematological recovery in bone marrow transplanted animals. All these findings suggest that NP has a stimulating activity on hemopoiesis by affecting the proliferation and differentiation of hemopoietic progenitor cells in vivo.

Abstract: JAK2/STAT signaling promotes survival and expansion of myelodysplastic syndrome (MDS) clones, but little is known about the potential of JAK2/STAT as a therapeutic target in MDS. We investigated the effect of NS-018, a novel antagonist for JAK2, on the colony-forming ability of bone marrow mononuclear cells (BMMNCs) from high-risk MDS patients. NS-018 decreased colony-forming unit-granulocyte/macrophage (CFU-GM) colony numbers from MDS-derived BMMNCs in a dose-dependent manner, and this effect was significantly more potent than against normal BMMNCs. In addition, NS-018 suppressed the phosphorylation of STAT3 in colony-forming cells from MDS patients. Collectively, NS-018 could be a new therapeutic option for high-risk MDS. [Copyright &y& Elsevier]

Abstract: Unstimulated methylcellulose cultures in 25 myelofibrosis (MF) patients were performed to better understand the role of cytokines in the proliferation of MF cells. Compared to controls MF patients show a variable but highly increased spontaneous CFU-GM formation (66 vs 4.8/105 PBMNC). There was a marked reduction of autonomous CFU-GM growth by the cytokine-synthesis-inhibiting molecule IL-10 as well as by antibodies against GM-CSF whereas antibodies against IL-3, G-CSF, M-CSF and IL-1β showed heterogeneous effects. Spontaneous CFU-GM growth >100/105 PBMNC predicted shorter survival. Constitutive release of GM-CSF seems to contribute to proliferation of MF cells in vitro and possibly in vivo. [Copyright &y& Elsevier]

Abstract: In patients with myelodysplastic syndromes (MDS) iron overload caused by long-term red blood cell transfusions is an important factor for comorbidity especially in low-risk MDS. In this report we present the results of a comparative study based on colony formation assays of hematopoietic cells in MDS patients with and without iron overload. We demonstrate that iron overload suppresses the proliferation of erythroid progenitors cells (BFU-E), while the myeloid compartment (CFU-GM) was not found to be affected. Even patients with slightly elevated ferritin values show an impaired proliferation capacity in comparison to patients with normal ferritin levels. Furthermore, we show that this negative impact is reversible by sufficient iron chelation therapy. [Copyright &y& Elsevier]

Abstract: The reports regarding the mutual influence between the central nervous system and the immune system constitute a vast and somewhat controversial body of literature. Stress is known to disturb homeostasis, impairing immunological functions. In this study, we investigated the hematopoietic response of Chlorella vulgaris (CV)-treated mice exposed to single (SST) and repeated stress (RST). We observed a reduction in the numbers of hematopoietic progenitors (HP) in the bone marrow and long-term bone marrow cultures (LTBMC) using flow cytometry and a coinciding decrease in the number of granulocyte–macrophage colonies (CFU-GM) after treatment with both stressors, but SST caused a more profound suppression. We observed a proportional increase in the colony-stimulating activity (CSA) of the serum of animals subjected to SST or RST. In the bone marrow, SST and RST induced a decrease in both mature myeloid and lymphoid populations but did not affect pluripotent hematopoietic progenitors (Lin− Sca-1+c-kit+, LSK), and again, a more profound suppression was observed after SST. We further quantified the levels of interleukin-1α (IL-1α) and interleukin-6 (IL-6) and the number of myeloid cells in LTBMC. Both SST and RST reduced the levels of these cytokines to similar degrees. The myeloid population was also reduced in LTBMC, and SST induced a more intense suppression. Importantly, CV treatment prevented the changes produced by SST and RST in all of the parameters evaluated. Together, our results suggest that CV treatment is an effective tool for the prophylaxis of myelosuppression caused by single or repeated stressors. [Copyright &y& Elsevier]

Transplantation of CD34+ hematopoietic reconstituting cells (HRC) is an important treatment modality. The cells needed for clinical hematopoietic reconstitution after myeloablation most commonly derive from bone marrow which have been mobilized into the peripheral blood. The number of CD34+ cells in mobilized blood samples is used to indicate the appropriateness of transplantation although it does not evaluate the two necessary functions for successful transplantation: long-term reconstitution mediated by cells with self-renewing proliferation and short-term hematopoietic differentiation mediated by progenitor cells. Using a novel high-resolution immunophenotyping technology on a flow cytometric platform, we have assessed uniformly mobilized CD34+ cells for expression levels of 16 molecules previously associated with HRC function and sought correlations of these expression data with functional short-term assays for colony formation that do predict successful transplantation. We found that colony-forming units were significantly correlated with HoxB4 expression, which was explained by the number of CD34+ cells in the samples. However, analysis of colony-forming units normalized to the CD34+ cell count revealed a significant negative correlation with HoxB4 expression. Thus, increased levels of HoxB4 enhance CD34+ cell number via self-renewing expansion but concomitantly depreciate the capacity for short-term differentiation per cell. Our findings demonstrate the translation of experimental findings into a clinical setting and suggest that the expression level of HoxB4 in CD34+ cells can be used as a measure of a sample's appropriateness for transplantation. © 2012 International Society for Advancement of Cytometry [ABSTRACT FROM AUTHOR]

Background Overnight (ON) storage of peripheral blood stem cell (PBSC) occurs frequently in clinical settings. However, there are no standard guidelines for optimal storage conditions of freshly harvested PBSC. The aim of this study was to investigate the influence of storage temperatures on the quality of autologous PBSC and establish optimal storage conditions before cryopreservation. Methods A retrospective analysis was performed on 260 PBSC harvests according to pre-cryopreservation conditions: immediate processing or ON storage at room temperature (RT). For direct comparison, 30 autologous PBSC products were collected prospectively and prepared under three different pre-cryopreservation conditions: immediate processing, ON storage at 4°C and ON storage at RT. The recovery of CD34+ cells, post-thaw CFU-GM count and viability were analysed. Results Retrospective analysis revealed that post-thaw CFU-GM count was significantly lower when PBSC were stored ON at RT compared to when immediately processed (136·4 vs. 409·6/μl). Prospective analysis showed a mean recovery of CD34+ cells of 65·5 ± 25·1%, 70·5 ± 27·4% and 35·9 ± 25·1% for immediate processing, ON storage at 4°C and ON storage at RT, respectively. Similarly, mean viability and CFU-GM counts were significantly reduced when stored ON at RT compared to when immediately processed or stored ON at 4°C (60·4 ± 25·6 vs. 84·1 ± 12·9 vs. 82·7 ± 12·6%, 15·7 ± 25·7 vs. 398·5 ± 906·2 vs. 350·0 ± 847·9/μl, respectively). Conclusions ON storage of autologous PBSC at RT significantly decreased the quality of HPCs. These data indicate that ON storage of autologous PBSC at 4°C would be the most reasonable approach for maintaining the quality of HPCs when immediate processing is not possible. [ABSTRACT FROM AUTHOR]

Abstract: Ethnopharmacological relevance: The Asháninkas, indigenous people of Peru, use cat''s claw (Uncaria tomentosa) to restore health. Uncaria tomentosa has antioxidant activity and works as an agent to repair DNA damage. It causes different effects on cell proliferation depending on the cell type involved; specifically, it can stimulate the proliferation of myeloid progenitors and cause apoptosis of neoplastic cells. Neutropenia is the most common collateral effect of chemotherapy. For patients undergoing cancer treatment, the administration of a drug that stimulates the proliferation of healthy hematopoietic tissue cells is very desirable. It is important to assess the acute effects of Uncaria tomentosa on granulocyte-macrophage colony-forming cells (CFU-GM) and in the recovery of neutrophils after chemotherapy-induced neutropenia, by establishing the correlation with filgrastim (rhG-CSF) treatment to evaluate its possible use in clinical oncology. Materials and methods: The in vivo assay was performed in ifosfamide-treated mice receiving oral doses of 5 and 15mg of Uncaria tomentosa and intraperitoneal doses of 3 and 9μg of filgrastim, respectively, for four days. Colony-forming cell (CFC) assays were performed with human hematopoietic stem/precursor cells (hHSPCs) obtained from umbilical cord blood (UCB). Results: Bioassays showed that treatment with Uncaria tomentosa significantly increased the neutrophil count, and a potency of 85.2% was calculated in relation to filgrastim at the corresponding doses tested. An in vitro CFC assay showed an increase in CFU-GM size and mixed colonies (CFU-GEMM) size at the final concentrations of 100 and 200μg extract/mL. Conclusions: At the tested doses, Uncaria tomentosa had a positive effect on myeloid progenitor number and is promising for use with chemotherapy to minimize the adverse effects of this treatment. These results support the belief of the Asháninkas, who have classified Uncaria tomentosa as a ‘powerful plant’. [Copyright &y& Elsevier]

Abstract: Bone homeostasis is maintained through the balanced action of bone-forming osteoblasts and bone-resorbing osteoclasts. Under pathological conditions or with age, excessive bone loss is often observed due to increased bone resorption. Since osteoclasts are the primary cells in the body that can resorb bone, molecular understanding of osteoclast fate has important clinical implications. Over the past 20years, many molecular players that govern osteoclast differentiation during normal development have been identified. However, whether the same molecules regulate bone loss occurring under pathological conditions remains largely unknown. We report here that although ATP6v0d2-deficient (ATP6v0d2 KO) mice exhibit an osteopetrotic phenotype due to inefficient osteoclast maturation, this deficiency fails to protect mice from ovariectomy (OVX)-induced bone loss, a model for post-menopause-associated osteoporosis. Moreover, we show that an OVX-induced increase in the number of colony forming unit-granulocyte/macrophage (CFU-GM) in bone marrow cells and subsequent osteoclast formation in vitro was not affected in the absence of ATP6v0d2. However, even after OVX, formation of large osteoclasts (>100μm in diameter) with actin rings was still reduced in the absence of ATP6v0d2. Taken together, these findings suggest that the critical role of ATP6v0d2 may be limited to the control of bone homeostasis under normal development, and that OVX-induced bone loss is likely to be governed mostly by the increase in osteoclast precursors rather than increased efficiency of osteoclast maturation. [ABSTRACT FROM AUTHOR]

Abstract: One of the most common dose limiting adverse effects in cancer treatment is myelotoxicity. The aim of this study was to develop an in vitro method for measuring potential myelotoxic properties of a drug candidate in a high throughput setting. Human CD34+ progenitor cells from umbilical cord blood were plated in 384-well microplates with drugs in liquid culture, supplemented with specific cytokines for the granulocytopoietic-macrophage lineage. After 7 or 14 days of proliferation and differentiation the cells were analyzed using the automated non-clonogenic fluorometric microculture cytotoxicity assay (FMCA). Two types of assays setups were evaluated, the FMCA-GM7 where cells were exposed to drugs directly after thawing and cytotoxicity measured on day 7 in contrast to the FMCA-GM14 where the cells were cultured 7 days prior to plating and drug exposure, with viability analysis on day 14 of differentiation. Drug sensitivity was similar in both assays and method validation was performed using 24 drugs with known myelotoxic profile (acyclovir, bortezomib, busulfan, carboplatin, chloramphenicol, chlorpromazine, cisplatin, cytarabine, clozapine, doxorubicin, erlotinib, etoposide, 5-fluorouracil, fludarabine, gefitinib, gemcitabine, hydroxyurea, imatinib, lomustine, melphalan, sorafenib, sunitinib, taxol and 6-thioguanine). The 50% inhibitory concentrations (IC50) from the FMCA-GM7 and the FMCA-GM14 correlated highly (r =0.83) and (r =0.82), respectively, with IC50 from the established clonogenic assay (CFU-GM), obtained from the literature. The current data suggests that the FMCA-GM could offer a simple and robust alternative to the CFU-GM assay in preclinical hematotoxicity studies. [Copyright &y& Elsevier]

2-Amino-O4-benzylpteridine derivatives inactivate the human DNA repair protein O6-alkylguanine-DNA alkyltransferase and have been tested as modulators of alkylating agent chemotherapy. Recently, the therapeutic potential of O4-benzylfolate (O4BF) in modulating bis-chloroethylnitrosourea (BCNU) toxicity was demonstrated in vitro using human HT29 and KB tumor lines. The current studies replicated the previous findings in HT29 and KB cells using ATP as an endpoint. However, the effective treatment conditions were severely toxic to human neutrophil progenitors called CFU-granulocyte/macrophage (CFU-GM), which could not tolerate ≥40 μM BCNU at any O4BF concentration. A lower BCNU concentration (10 μM) in combination with O4BF (2–100 μM) was only moderately tumoricidal. To screen for conditions tolerated by CFU-GM, bone marrow (BM) cells were pre-incubated (5 h) with O4BF, co-treated with O4BF and BCNU (42 h), washed, and plated to quantify CFU-GM survival. O4BF at 2 or 5 μM progressively lowered the inhibitory concentrations (ICs) for BCNU, but further increases in O4BF concentrations did not. Increasing O4BF concentrations with constant BCNU (10 μM) under the same prolonged exposure as in the human marrow study achieved only modest tumoricidal effects. In summary, the unexpected finding that normal BM cells are impacted by an agent developed to target malignant tissue refutes speculation that normal β-folate receptor expressing hematopoietic cells will be spared. Further, the validated IC90 endpoint from the huCFU-GM assay has provided a reference point for judging the potential therapeutic effectiveness of this investigational combination in man using in vitro assays. [ABSTRACT FROM AUTHOR]

Abstract: The ACuteTox Project (part of the EU 6th Framework Programme) was started up in January 2005. The aim of this project is to develop a simple and robust in vitro strategy for prediction of human acute systemic toxicity, which could replace animal tests used for regulatory purposes. Our group is responsible for the characterization of the effect of the reference chemicals on the hematopoietic tissue. CFU-GM assay based on the culture of human mononuclear cord blood cells has been used to characterize the effects of the selected compounds on the myeloid progenitors. Previous results have shown the relevance of the CFU-GM assay for the prediction of human acute neutropenia after treatment of antitumoral compounds, and this assay has been recently approved by the ECVAM''s Scientific Advisory Committee. Among the compounds included in the study there were pharmaceuticals, environmental pollutants and industrial chemicals. Eleven out of 55 chemicals did not show any cytotoxic effect at the maximum concentration tested. The correlation coefficients of CFU-GM IC50, IC70 and IC90 values with human LC50 values (50% lethal concentration calculated from time-related sublethal and lethal human blood concentrations) were 0.4965, 0.5106 and 0.5142 respectively. Although this correlation is not improve respect to classical in vitro basal cytotoxicity tests such as 3T3 Neutral Red Uptake, chemicals which deviate substantially in the correlation with these assays (colchicine, digoxin, 5-Fluorouracil and thallium sulfate) fitted very well in the linear regression analysis of the CFU-GM progenitors. The results shown in the present study indicate that the sensitivity of CFU-GM progenitors correlates better than the sensitivity of HL-60 cells with human LC50 values and could help to refine the predictability for human acute systemic toxicity when a given chemical may affect to the hematopoietic myeloid system. [Copyright &y& Elsevier]

The effects of the composition of PBPC grafts from matched related donors (MRDs) and matched unrelated donors (MUDs) have not been compared. In a single-center study, the compositions of 55 MRD PBPC grafts and 33 MUD grafts were studied for their effect on the rate of engraftment in patients who had evidence of donor cell engraftment on day +28. The MUD grafts came more frequently from young male donors and contained more CD34+ cells but similar numbers of colony-forming units granulocyte-macrophage (CFU-GM) and burst forming units-erythroid. The recovery of neutrophils to >500/mm3 was equally fast in both groups, but recovery of platelets to >20 000/mm3 was significantly delayed in the MUD group (P<0.001). The MUD group also required more transfusions of platelets and red cells. Patients receiving grafts containing low numbers of CFU-GM had markedly delayed platelet recovery. The patients with the slowest engraftment tended to have prolonged transportation times. Storage experiments suggested a major loss of viable CD34+ cells and CFU-GM when undiluted PBPC products are stored at room temperature. The data suggest that a fraction of the MUD grafts suffer during transportation. In vitro proliferation assays should be part of the validation and auditing of transportation of MUD grafts.Bone Marrow Transplantation (2009) 43, 499–505; doi:10.1038/bmt.2008.346; published online 10 November 2008 [ABSTRACT FROM AUTHOR]

Abstract: In this study, we investigated the hematopoietic response of rats pretreated with CV and exposed to the impact of acute escapable, inescapable or psychogenical stress on responsiveness to an in vivo challenge with Listeria monocytogenes. No consistent changes were observed after exposure to escapable footshock. Conversely, the impact of uncontrollable stress (inescapable and psychogenical) was manifested by an early onset and increased severity and duration of myelossuppression produced by the infection. Small size CFU-GM colonies and increased numbers of clusters were observed, concurrently to a greater expansion in the more mature population of bone marrow granulocytes. No differences were observed between the responses of both uncontrollable stress regimens. CV prevented the myelossuppression caused by stress/infection due to increased numbers of CFU-GM in the bone marrow. Colonies of cells tightly packed, with a very condensed nucleus; in association with a greater expansion in the more immature population of bone marrow granulocytes were observed. Investigation of the production of colony-stimulating factors revealed increased colony-stimulating activity (CSA) in the serum of normal and infected/stressed rats treated with the algae. CV treatment restored/enhanced the changes produced by stress/infection in total and differential bone marrow and peripheral cells counts. Further studies demonstrated that INF-γ is significantly reduced, whereas IL-10 is significantly increased after exposure to uncontrollable stress. Treatment with CV significantly increased INF-γ levels and diminished the levels of IL-10. Uncontrollable stress reduced the protection afforded by CV to a lethal dose of L. monocytogenes, with survival rates being reduced from (50%) in infected rats to 20% in infected/stressed rats. All together, our results suggest Chlorella treatment as an effective tool for the prophylaxis of post-stress myelossupression, including the detrimental effect of stress on the course and outcome of infections. [Copyright &y& Elsevier]

Abstract: In animal models, naphthalene toxicity has been studied in different target organs and has been shown to be gender-dependent and metabolism related. In humans, it is readily absorbed and is metabolised by several cytochrome P450’s. Naphthalene and its metabolites can cross the placental barrier and consequently may affect foetal tissues. The aim of this study was to compare the in vitro toxicity of naphthalene and its metabolites, 1-naphthol, 2-naphthol and 1,4-naphthoquinone, on human haematopoietic foetal progenitors (CFU-GM) derived from newborn male and female donors. The mRNA expression of Cyp1A2 and Cyp3A4 was also evaluated. Naphthalene did not affect CFU-GM proliferation, while 1-naphthol, 2-naphthol and particularly 1,4-naphthoquinone strongly inhibited the clonogenicity of progenitors, from both male and female donors. mRNA of Cyp1A2 and Cyp3A4 was not expressed neither at the basal level, nor after naphthalene treatment, while treatment with 1,4-naphthoquinone induced expression of both enzymes in both genders, with Cyp1A2 being expressed four times more than Cyp3A4. Female CFU-GM was significantly more sensitive to 1,4-naphthoquinone than male and after treatment both enzymes were expressed twice as much as in the male precursors. These results suggest that a gender-specific 1,4-naphthoquinone metabolic pathway may exist, which gives rise to unknown toxic metabolites. [Copyright &y& Elsevier]

Abstract: In this study, Chlorella vulgaris (CV) was examined for its chelating effects on the ability of bone marrow stromal cell layer to display myeloid progenitor cells in vitro in lead-exposed mice, using the long-term bone marrow culture (LTBMC). In addition, the levels of interleukin (IL)-6, an important hematopoietic stimulator, as well as the numbers of adherent and non-adherent cells were also investigated. Mice were gavage treated daily with a single 50mg/kg dose of CV for 10 days, concomitant to continuous offering of 1300ppm lead acetate in drinking water. We found that CV up-modulates the reduced ability of stromal cell layer to display myeloid progenitor cells in vitro in lead-exposed mice and restores both the reduced number of non-adherent cells and the ability of stromal cells from these mice to produce IL-6. Monitoring of lead poisoning demonstrated that CV treatment significantly reduced lead levels in blood and tissues, completely restored the normal hepatic ALA levels, decreased the abnormally high plasma ALA and partly recovered the liver capacity to produce porphyrins. These findings provide evidence for a beneficial use of CV for combination or alternative chelating therapy to protect the host from the damage induced by lead poisoning. [Copyright &y& Elsevier]

Abstract: Inorganic arsenic (iAs) and its metabolites are transferred to the foetus through the placental barrier and this exposure can compromise the normal development of the unborn. For this reason, we assessed the toxicity of sodium arsenite (iAsIII) and its metabolites dimethylarsinic acid (DMAV), monomethylarsonic acid (MMAV) and monomethylarsonous acid (MMAIII) on human haematopoietic cord blood cells and murine bone marrow progenitors in vitro, looking at the effects induced at different concentrations in the two genders. The expression of two enzymes responsible for arsenic biotransformation arsenic methyltranferase (AS3MT) and glutathione S-transferase omega 1 (GSTO1) was evaluated in human cord blood cells. Cord blood and bone marrow cells were exposed in vitro to iAsIII at a wide range of concentrations: from 0.0001μM to 10μM. The methylated arsenic metabolites were tested only on human cord blood cells at concentrations ranging from 0.00064μM to 50μM. The results showed that iAsIII was toxic on male and female colony forming units to about the same extent both in human and in mouse. Surprisingly, very low concentrations of iAsIII increased the proliferation rate of both human and murine female cells, while male cells showed no significant modulation. MMAV and DMAV did not exert detectable toxicity on the cord blood cells, while MMAIII had a marked toxic effect both in male and female human progenitors. AS3MT mRNA expression was not induced in human cord blood cells after iAsIII exposure. GSTO1 expression decreased after MMAIII treatment. This study provides evidence that exposure to iAsIII and MMAIII at μM concentrations is associated with immunosuppression in vitro. [Copyright &y& Elsevier]

Abstract: The effects of arsenate (As) and atrazine (Atr) on myeloid progenitors (colony-forming unit-granulocyte/macrophage, CFU-GM) cells derived from bone marrow were studied in male and female mice after combined in utero and juvenile exposure. Female adult mice were treated with arsenate in drinking water during gestation. Then, separate groups of males and females’ offspring were exposed for 4 months to atrazine, to additional arsenate or to co-exposure of atrazine and arsenate together in drinking water. In male mice, arsenate and the combined exposure did not modulate the percentage of CFU-GM progenitors, whereas atrazine significantly decreases the clonogenicity of myeloid cells. In females, the percentage of CFU-GM significantly decreased after atrazine exposure did not change with arsenate treatment, but dramatically increased after the combined exposure. The expression of estrogen receptors alpha (ERα) and beta (ERβ) in bone marrow cells was investigated, and an up-regulation of receptor beta was observed in both genders. A gene expression profile was generated using nylon membranes spotted with 1185 cancer-related genes. Results from microarrays indicate that atrazine alone did not stimulate the expression of any of the genes analysed in both male and female. Arsenic induced gene expression modulation only in female. Major significant changes on the gene expression resulted following the co-exposure to arsenic and atrazine in both male and female. [Copyright &y& Elsevier]

Background Opioid agonists have been shown to exert an inhibitory action on a number of malignant and non-malignant cell types. However, there are no reports dealing with their effect on hemopoietic progenitors. Based upon our previous experience of opioid agonists we examined whether opioids could interfere with the growth of CFU-GM from CD133 + cord blood cells. Methods Cord blood samples were subjected to CD133 + column selection, with subsequent exposure to opioid agonists and antagonists or both, in semi-solid cultures for CFU-GM growth. Colonies of day 7 of culture were replated in fresh medium in the absence of opioids. The colonies were evaluated at 7 and 14 days of culture. RT-PCR was performed for the detection of opioid and somatostatin receptors. Apoptosis tests and immunophenotypic evaluations were employed in liquid cultures in conditions identical to those of the semi-solid ones. Results and discussion Our results suggest that opioids can induce a significant inhibition of CFU-GM growth, which is reversible and not mediated through opioid or somatostatin receptors, while apoptosis is not implicated. Whether this finding could be used for clinical intervention remains to be examined. [ABSTRACT FROM AUTHOR]

Abstract: Haematopoietic colony-stimulating factors are used frequently to moderate myelotoxicity, but administration of granulocyte-colony-stimulating factor (G-CSF) prior to chemotherapy actually may worsen the toxic effects on bone marrow. This is important in the design of clinical cancer treatment protocols. Previously, we found that rosiglitazone may protect granulocyte-macrophage progenitor cells (CFU-GM) against damage caused by a single dose of 5-fluorouracil (5-FU). Our new studies are designed to evaluate whether rosiglitazone has similar beneficial effects on bone marrow preservation when administered concurrently with repeated, daily doses of 5-FU while restricting regeneration time. Myelotoxicity characterized by the decrease in cellularity, frequency of granulocyte-macrophage progenitor cells and CFU-GM content of femoral bone marrow in mice. Five-day oral rosiglitazone pre-treatment decreased the susceptibility of granulocyte-macrophage progenitors to 5-FU damage. Significantly, more CFU-GM cells survived after the single intraperitoneal dose of 5-FU (100mgkg−1). The increased frequency of CFU-GM cells with their intensive proliferation allowed faster restoration of the damaged CFU-GM compartment than was seen in the case of repeated daily administration of the cytostatic drug (25 or 50mgkg−1) together with rosiglitazone for 7 consecutive days. The expansion of the CFU-GM compartment was 3 times and 50 times greater in the combined-treated mice than in their counterparts treated with repeated doses of 5-FU alone, although differences in absolute neutrophil counts were not significant. In conclusion, our results indicated that rosiglitazone has protective effects on bone marrow progenitor cells even after daily 5-FU treatment but further studies are warranted to evaluate the optimal treatment schedules. [Copyright &y& Elsevier]

Abstract: In this study, we show that dexamethasone treatment increases ionizing radiation-induced cell death by inducing the inhibitory κBα (IκBα) pathway in mice. The effect of dexamethasone on radiation-induced cell death was assessed by changes in total spleen cellularity and bone marrow colony-forming unit–granulocyte–macrophage (CFU–GM) contents after total body irradiation. While in vivo treatment of mice with dexamethasone alone (1mg/kg/day, for 2 days) failed to elicit cell death in spleen cells, the combined treatment with dexamethasone (1mg/kg/day, for 2 days) and γ-rays (1 or 5Gy) caused a 50–80% reduction in total cellularity in spleen and CFU–GM contents in bone marrow. These results demonstrate that dexamethasone has a synergistic effect on radiation-induced cellular damages in vivo. Immunoblot analysis showed that dexamethasone treatment significantly increases IκBα expression in the spleens of irradiated mice. In addition, the dexamethasone treatment significantly reduced radiation-induced nuclear translocation of the nucleus factor-κB in the spleens of irradiated mice. These results indicate that dexamethasone treatment in vivo may increase radiation-induced cell damages by increasing IκBα expression in hematopoietic organs such as spleen and bone marrow. [Copyright &y& Elsevier]

As part of the early preclinical development of a new antipsychotic compound, Wistar rats of both sexes were dosed orally for upto 7 days. At high doses, expected changes in appearance and behavior, decreases in bodyweight gain and feed intake but also a fluid and pale bone marrow (BM) were observed. Blood cell counts were normal as were clinical chemical values. BM sections showed a red cell hypoplasia. Circulating reticulocytes and erythroblasts on BM smears were decreased suggesting that the compound might have a selective toxicity for the erythroid lineage. In a mechanistic experiment, rats were dosed for 9 days and phlebotomized after 7 days of exposure to stimulate erythroid regeneration. Red-blood cell mass, reticulocytes and erythropoietin (EPO) levels were monitored before and upto 48 h after bleeding. Results showed that an EPO-mediated pathogenesis could be excluded. The effect of the drug on the formation of Colony-forming units (CFU)-E and CFU-GM was then quantitatively measured in vitro after direct exposure to the compound. In two successive assays, rat or human BM cells were incubated with the drug dissolved in the collection medium at final concentrations of 0.3×10−7 –3×10−5 M. In the presence of adequate growth factors, CFU-E and CFU-GM were cultured and cell proliferation was compared between treated and control groups. Our results showed an expected inhibition by the drug of the growth of erythroid progenitors associated to a similar effect on myeloid progenitors. The CFU-E and CFU-GM of both human and rat sources were totally inhibited from the concentration of 3×10−5 M. The IC50 values were consistent with rat peak plasma levels reached in vivo by the drug. Therefore, the short-term cloning assays performed on rat BM cells were sensitive indicators of the hematotoxicity of the compound and were considered as predictive for human toxicity. [ABSTRACT FROM AUTHOR]

Abstract: In this study, we demonstrated that Uncaria tomentosa extract (UTE) protects mice from a lethal dose of Listeria monocytogenes when administered prophylactically at 50, 100, 150 and 200 mg/kg for 7 days, with survival rates up to 35%. These doses also prevented the myelosuppression and the splenomegaly caused by a sublethal infection with L. monocytogenes, due to increased numbers of granulocyte-macrophage progenitors (CFU-GM) in the bone marrow. Non-infected mice treated with 100 mg/kg UTE also presented higher numbers of CFU-GM in the bone marrow than the controls. Investigation of the production of colony-stimulating factors revealed increased colony-stimulating activity (CSA) in the serum of normal and infected mice pre-treated with UTE. Moreover, stimulation of myelopoiesis and CSA occurred in a dose-dependent manner, a plateaux being reached with the dose of 100 mg/kg. Further studies to investigate the levels of factors such as IL-1 and IL-6 were undertaken. We observed increases in the levels of IL-1 and IL-6 in mice infected with L. monocytogenes and treated with 100 mg/kg of UTE. White blood cells (WBC) and differential counting were also performed, and our results demonstrated no significant changes in these data, when infected mice were pre-treated with 100 mg/kg of UTE. All together, our results suggest that UTE indirectly modulates immune activity and probably disengages Listeria-induced supression of these responses by inducing a higher reserve of myeloid progenitors in the bone marrow in consequence of biologically active cytokine release (CSFs, IL-1 and IL-6). [Copyright &y& Elsevier]

Abstract: Recent studies conducted in our laboratory have demonstrated marked increases in both serum leptin levels and colony numbers in bone marrow progenitor cells following long-term kindled seizures in rats. The present study sought to determine whether such changes in hematopoietic functions following kindling are linked to increased serum leptin levels. Kindled stage V seizures were induced for 30 days in Sprague–Dawley rats by stimulation of the basal complex of amygdala. The results revealed colony numbers in colony forming units-granulocyte/macrophage (CFU-GM) cultures from kindled rats increased significantly, an effect that was blocked by the presence of an anti-leptin antibody. The results further demonstrated that the addition of serum obtained from kindled rats to CFU-GM cultures from control rats significantly increased the numbers of colonies relative to non-serum added cultures. Moreover, the proliferative effects of serum from kindled rats were also blocked by adding an anti-leptin antibody. These findings were confirmed from the observations that the long isoform of the leptin receptor, which is capable of signal transduction, was present only in kindled, but not in control rats. Thus, the results provide evidence that the hematopoietic changes observed following long-term kindling are directly associated with elevated serum leptin levels. [Copyright &y& Elsevier]

Summary:In all, 78 peripheral hematopoietic progenitor cell collections from 52 patients were evaluated using our previously published validated post-thaw assays at the time of collection and following transplantation by assessment of viable CD34+ cells, and granulocyte-macrophage colony-forming units (CFU-GM) cryopreserved in quality control vials. The median (range) post-thaw recovery of viable CD34+ cells and CFU-GM was 66.4%(36.1-93.6%) and 63.0%(28.6-85.7%), respectively, which did not show significant correlation with the engraftment of either neutrophils (P=0.136 and 0.417, respectively) or platelets (P=0.88 and 0.126, respectively). However, the reinfused viable CD34+ cells/kg of patient weight pre- or post-cryopreservation showed significant correlation to engraftment of neutrophils (P=0.0001 and 0.001, respectively) and platelets (P=0.023 and 0.010, respectively), whereas CFU-GM pre- or post-cryopreservation was significantly correlated to neutrophils (P=0.011 and 0.007, respectively) but not to platelets (P=0.112 and 0.100, respectively). The results show that post-cryopreservation assessment of viable CD34+ cells or CFU-GM is as reliable a predictor of rapid engraftment as that of pre-cryopreservation measures. Therefore, the post-cryopreservation number of viable CD34+ cells or CFU-GM should be used to eliminate the risks of unforeseen cell loss that could occur during cryopreservation or long-term storage.Bone Marrow Transplantation (2005) 35, 881-887. doi:10.1038/sj.bmt.1704926 Published online 21 March 2005 [ABSTRACT FROM AUTHOR]

Abstract: The acute rejection of bone marrow (BM) allografts by host effectors can occur within a short period after BM transplantation (BMT) in lethally irradiated mice. Common assays used to ascertain engraftment/resistance involve measuring the growth of granulocyte/monocyte progenitors (colony-forming unit-granulocyte-macrophage) in vitro or splenocyte proliferation assessed by radioisotope incorporation in vivo 5 to 8 days after BMT. However, the correlation of the long-term outcome of BMT with the kinetics of recovery by using the dose of allogeneic BM cells (BMCs) that leads to early rejection as determined by the in vitro assessment has not been extensively studied. Thus, to investigate whether the early rejection of donor BMCs is an indication of a long-term engraftment failure, C57BL/6 (H2b) mice were lethally irradiated and transplanted with various doses of BALB/c (H2d) BMCs. The short-term engraftment of donor precursors (colony-forming unit-granulocyte-macrophage), the kinetics of hematopoietic cell recovery, the extent of donor chimerism, and the proportion of the recipients with long-term survival were determined. The results show that the kinetics and extent of hematopoietic cell recovery were significantly delayed in mice receiving limiting doses of BMCs that were rejected or severely resisted at day 8 after BMT. However, a proportion of these mice survived up to 98 days after BMT with mixed chimerism or donor chimerism. This study demonstrates that early rejection of BM precursors, as assessed by measurement of myeloid progenitors in the spleen after BMT, does not always correlate with the long-term outcome of the marrow allograft and that significant variability is inherent in the extent of chimerism when threshold amounts of BMCs are used. [Copyright &y& Elsevier]

In previous works, we have demonstrated that the myeloprotective properties of several natural and synthetic compounds are partly responsible for their antitumor activity in the Ehrlich ascites tumor(EAT) model. In this work, we present information that may be useful to the study of pharmacological and toxicological properties of compounds that affect the hematological compartment. Clonogenic studies in EAT-inoculated mice demonstrated a rapid decrease in bone marrow CFU-GM, whereas a progressive increase in splenic CFU-GM and cellularity was observed, followed by splenomegaly. Bone marrow cellularity declined on the third day after tumor challenge, returning to normal values thereafter. Serum from EAT-bearing mice produced detectable colony-stimulating activity in vitro. Similar results were observed with the conditioned medium from Ehrlich tumor cell cultures, but not with the cell-free Ehrlich tumor ascitic fluid. Tumor inoculation also resulted in a more striking depletion in the number of non-adherent cells in long-term bone marrow cell cultures(LTBMCs) with no bone marrow stroma formation. We speculate that the physiological alterations induced by the EAT growth can be used to assess the ability of compounds to modulate the hematopoietic response. [ABSTRACT FROM AUTHOR]

Background: A new antipsychotic compound induced unexpected red cell hypoplasia (reticulocytopenia, red marrow hypoplasia) in rats dosed orally for 7 days. Materials and methods: Since an erythropoietin-mediated pathogenesis was excluded, In Vitro tests on rat and human bone marrow cells were performed with measurement of formation of late erythroid (CFU-E) and granulocyte-macrophage (CFU-GM) colony-forming units after incubation with the drug. CFU-E together with growth factors were cultured for 2 days (rat) or 7 days (human) and CFU-GM was cultured for 7 days (rat) or 10 days (human). Results: The drug induced inhibition of erythroid progenitors and myeloid progenitors for both species from 3 × 10-5 mol/L, with the concentration inhibiting the growth of 50% (IC50) consistent with drug plasma levels measured in rats. Conclusion: These cloning assays on rat bone-marrow cells were shown to be adequate models for determining the haematotoxicity of the agent and to be predictive of human toxicity. With only a small amount of compound required, they can be used as screening tools to detect haematotoxic potential of candidate drugs. Keywords: haematotoxicity, clonogenic assays, CFU-E, CFU-GM, screening, In Vitro model Résumé Contexte : Un nouvel antipsychotique induit une hypoplasie érythroïde (réticulocytopénie, hypoplasie de moelle rouge) chez le rat après administration orale pendant 7 jours. Matériels et méthodes : Un mécanisme érythropoïétine-dépendant étant écarté, des tests In Vitro sur cellules de moelle osseuse de rat et d’homme sont effectués, en évaluant la formation CFU-E (colony-forming units-erythrocyte) et CFU-GM (colony-forming units-granulocyte-macrophage) après incubation avec le produit. En présence de facteurs de croissance adéquats, les CFU-E sont cultivés pendant 2 (rat) ou 7 (homme) jours et les CFU-GM pendant 7 (rat) ou 10 (homme) jours. Résultats : Le produit inhibe la croissance des progéniteurs érythroïdes et myéloïdes dans les deux espèces à partir de 3 × 10-5 mol/L, avec des CI50 (concentration inhibant la croissance cellulaire de 50 %) cohérentes avec les taux plasmatiques mesurés chez le rat. Conclusion : Ces essais clonogéniques sur les cellules de moelle osseuse de rat sont donc des modèles adéquats pour l’hématotoxicité du produit et prédictifs pour l’homme. Consommant une faible quantité de produit, ils peuvent être utilisés pour sélectionner de futurs médicaments sur leur potentiel hématotoxique. Mots clés : hématotoxicité, essais clonogéniques, CFU-E, CFU-GM, screening, modèle In Vitro [ABSTRACT FROM AUTHOR]

Previous studies have indicated that MD-fraction (MDF), in which the active component is beta 1,6-glucan with beta 1,3-branches, has anti-tumor activity as an oral agent and acts as an immune adjuvant. Since some other beta glucans appear to promote mobilization of hematopoietic stem cells, the effects of a beta glucan extract from the Maitake mushroom “MD-fraction” on hematopoietic stem cells were examined in a colony forming assay. Here we report for the first time that MDF has a dose response effect on mouse bone marrow cells (BMC) hematopoiesis in vitro. Using the Colony Forming Unit (CFU) assay to detect formation of granulocyte-macrophage (CFU-GM) colonies, and the XTT cytotoxicitiy assay to measure BMC viability, the data showed that the addition of MDF significantly enhanced the development of CFU-GM in a dose range of 50–100 μg/ml (p<0.004). The mechanism of action included significant increase of nonadherent BMC viability, which was observed at MDF doses of 12.5–100 μg/ml (p<0.005). In the presence of Doxorubicin (DOX), MDF promoted BMC viability and protected CFU-GM from DOX induced toxicity. In addition, MDF treatment promoted the recovery of CFU-GM colony formation after BMC were pretreated with DOX. These studies provided the first evidence that MDF acts directly in a dose dependent manner on hematopoietic BMC and enhances BMC growth and differentiation into colony forming cells. [Copyright &y& Elsevier]

Insulin promotes survival of haemopoietic progenitors. We investigated if rosiglitazone, an insulin sensitizer, could confer protection against 5-fluorouracil (5-FU)-induced myelotoxicity in mice. The decrease in bone marrow cellularity, frequency and content of granulocyte–macrophage progenitors (CFU-GM) characterized myelotoxicity in mice, while insulin sensitivity was determined by hyperinsulinaemic euglycaemic glucose clamping. CFU-GM colony numbers increased in groups pre-treated with rosiglitazone (1.5–6 mg/kg, 5 days), compared to that in mice treated with 5-fluorouracil alone. Since rosiglitazone pre-treatment significantly promoted the clonal expansion of CFU-GM when given in the insulin sensitizing dose, we conclude that rosiglitazone had myeloprotective effects possibly by amplifying endogenous insulin action. [Copyright &y& Elsevier]

Summary. T-large granular lymphocyte lymphoproliferative disorder (T-LGL LPD) is an indolent disease characterized by prolonged cytopenia and the presence of circulating large granular lymphocytes in the patient's peripheral blood. Although the disease is commonly thought of as indolent, most patients eventually require therapy because of recurrent infections secondary to neutropenia as well as a need for frequent blood product transfusions. CD26 is a 110-kDa surface glycoprotein with an essential role in T-cell function, including being a marker of T-cell activation and a mediator of T-cell activating signals. In this study, we evaluated CD26 expression in T-LGL patients and correlate CD26 expression with clinical behaviour. In addition, we examined the potential mechanism of cytopenia that is associated with this disorder. Our findings suggest that CD26 is a marker of aggressive T-LGL LPD and that CD26-related signalling may be aberrant in T-LGL LPD. Furthermore, inhibition of granulocyte–macrophage colony-forming units may be mediated by CD8+ cells of T-LGL LPD patients and is major histocompatibility complex class I-restricted. [ABSTRACT FROM AUTHOR]

Coexistence of Philadelphia chromosome-negative (Ph-) progenitors with the Ph+ clone in the early chronic phase of chronic myeloid leukemia (CML) has been documented in previous reports. A different evaluation of methods is needed to justify the clonality of the residual Ph- progenitors. Therefore, the X chromosome inactivation patterns in individual granulocyte-monocyte colony-forming unit (CFU-GM) colonies were studied with the clonality assay for the human androgen receptor gene. A prerequisite for this evaluation was the validation of T-lymphocytes and buccal cells as control cells representing the constitutional lyonization. The percentages of polyclonal CFU-GM cells were determined in 9 Ph+ women with CML and in 5 healthy women. Results of the clonal analysis of CFU-GM colonies were compared with those from reverse transcriptase-polymerase chain reaction analysis of single colonies for BCR/ABL transcripts. Both methods of CFU-GM cell analysis were in agreement regarding the presence of variable proportions (0%-94%) of normal cells in CML. Our results suggest that (a) T-cells and buccal cells have potential for use as controls for the clonal analysis of CML cases and (b) this method can evaluate the frequency of polyclonal/clonal CFU-GM cells in CML cases and is applicable to the analysis of myeloid clonal disorders that lack specific molecular markers. [ABSTRACT FROM AUTHOR]

We prospectively evaluated whether peripheral blood progenitor cells (PBPC) yield from a single leukapheresis could be predicted by measurement of circulating highly fluorescent reticulocytes (HFR). PBPC were collected from 46 leukaphereses in 15 patients with gynecological cancer following platinum-based chemotherapy. Once a level of at least 5.0% HFR was achieved, sufficient PBPC were collected in a single harvest in 71% of the procedures. Whereas, failure to mobilize sufficient PBPC occurred in 24 of 28 leukaphereses when the percentage of circulating HFR was less than 5.0%. In conclusion, circulating HFR may aid in the efficiency of PBPC collections in platinum-based chemotherapy. [Copyright &y& Elsevier]

Summary Enumeration of CD34 + cells is the standard assay procedure for optimization of peripheral blood stem cell harvesting. High fluorescence reticulocytes (HFR) have been shown to signal a rebound in haematopoiesis after chemotherapy. The aim of this study was to evaluate HFR determination, as compared to CD34 + cell counts and CFU-GM, as a potential predictor of PBSC counts after recovery from chemotherapy and/or bone marrow transplantation. Twenty-five paediatric patients undergoing intensive courses of chemotherapy and 9 undergoing bone marrow auto or allografts were investigated. In most of our cases, HFR recovered at the same time or earlier than CD34 + cells. Similarly, the rise in HFR preceeded the CFU-GM peak in most of these cases. In no case did we observe a CFU-GM peak without a rise in HFR%. In our experience, the daily relative HFR increase may be used to predict the optimal time for mobilization of stem cells and was therefore of value clinically to confirm the timing of apheresis. [ABSTRACT FROM AUTHOR]