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Background: To evaluate drug use (alcohol, tobacco, cannabis and other drugs) and its association with mean CD4/CD8 T cell count ratio, a marker of chronic inflammation, in virally suppressed people living with HIV-1 (PLWH) in Nouvelle Aquitaine, France. Methods: A multi-centric, cross-sectional analysis was conducted in 2018–19 in the QuAliV study—ANRS CO3 AQUIVIH-NA cohort. Tobacco, alcohol, cannabis, and other drug use (poppers, cocaine, amphetamines, synthetic cathinones, GHB/GBL) were self-reported. CD4 and CD8 T cell counts and viral load measures, ± 2 years of self-report, and other characteristics were abstracted from medical records. Univariable and multivariable linear regression models, adjusted for age, sex, HIV risk group, time since HIV diagnosis, and other drug use were fit for each drug and most recent CD4/CD8 ratio. Results: 660 PLWH, aged 54.7 ± 11.2, were included. 47.7% [315/660] had a CD4/CD8 ratio of < 1. Their mean CD4/CD8 ratio was 1.1 ± 0.6. 35% smoked; ~ 40% were considered to be hazardous drinkers or have alcohol use disorder; 19.9% used cannabis and 11.9% other drugs. Chemsex-associated drug users' CD4/CD8 ratio was on average 0.226 (95% confidence interval [95% CI] − 0.383, − 0.070) lower than that of non-users in univariable analysis (p = 0.005) and 0.165 lower [95% CI − 0.343, 0.012] in multivariable analysis (p = 0.068). Conclusions: Mean differences in CD4/CD8 ratio were not significantly different in tobacco, alcohol and cannabis users compared to non-users. However, Chemsex-associated drug users may represent a population at risk of chronic inflammation, the specific determinants of which merit further investigation. Trial registration number: NCT03296202. [ABSTRACT FROM AUTHOR]

Background: Pharmacokinetics data on ceftazidime are sparse for the paediatric population, particularly for children with cystic fibrosis (CF) or severe infections.Objectives: To characterize the population pharmacokinetics of ceftazidime in critically ill children, identify covariates that affect drug disposition and evaluate the current dosing regimens.Methods: The study was registered with Clinicaltrials.gov (NCT01344512). Children receiving ceftazidime were selected in 13 French hospitals. Plasma concentrations were determined by UPLC-MS/MS. Population pharmacokinetic analyses were performed using NONMEN software.Results: One hundred and eight patients, aged 28 days to 12 years, with CF (n = 32), haematology and/or oncology disorders (n = 47) or severe infection (n = 29) were included. Ceftazidime was administered by continuous or intermittent infusions; 271 samples were available for analysis. A two-compartment model with first-order elimination and allometric scaling was developed and covariate analysis showed that ceftazidime pharmacokinetics were also significantly affected by CLCR and CF. Ceftazidime clearance was 82% higher in CF than in non-CF patients. Monte Carlo simulations showed that the percentage of target attainment (PTA) for the target of T>MIC = 65% was (i) lower in CF than in non-CF children with intermittent infusions and (ii) higher with continuous than intermittent infusion in all children.Conclusions: The population pharmacokinetics model for ceftazidime in children was influenced by body weight, CLCR and CF. A higher PTA was obtained with continuous versus intermittent infusions. Further studies should explore the benefits of continuous versus intermittent infusion of ceftazidime, including current versus increased doses in CF children. [ABSTRACT FROM AUTHOR]

Key message: Trait-assisted genomic prediction approach is a way to improve genetic gain by cost unit, by reducing budget allocated to phenotyping or by increasing the program's size for the same budget. This study compares different strategies of genomic prediction to optimize resource allocation in breeding schemes by using information from cheaper correlated traits to predict a more expensive trait of interest. We used bread wheat baking score (BMS) calculated for French registration as a case study. To conduct this project, 398 lines from a public breeding program were genotyped and phenotyped for BMS and correlated traits in 11 locations in France between 2000 and 2016. Single-trait (ST), multi-trait (MT) and trait-assisted (TA) strategies were compared in terms of predictive ability and cost. In MT and TA strategies, information from dough strength (W), a cheaper trait correlated with BMS (r = 0.45), was evaluated in the training population or in both the training and the validation sets, respectively. TA models allowed to reduce the budget allocated to phenotyping by up to 65% while maintaining the predictive ability of BMS. TA models also improved the predictive ability of BMS compared to ST models for a fixed budget (maximum gain: + 0.14 in cross-validation and + 0.21 in forward prediction). We also demonstrated that the budget can be further reduced by approximately one fourth while maintaining the same predictive ability by reducing the number of phenotypic records to estimate BMS adjusted means. In addition, we showed that the choice of the lines to be phenotyped can be optimized to minimize cost or maximize predictive ability. To do so, we extended the mean of the generalized coefficient of determination (CDmean) criterion to the multi-trait context (CDmulti). [ABSTRACT FROM AUTHOR]

Oxygen‐depleted areas are spreading in coastal and offshore waters worldwide, but the implication for production and bioaccumulation of neurotoxic methylmercury (MeHg) is uncertain. We combined observations from six cruises in the Baltic Sea with speciation modeling and incubation experiments to gain insights into mercury (Hg) dynamics in oxygen depleted systems. We then developed a conceptual model describing the main drivers of Hg speciation, fluxes, and transformations in water columns with steep redox gradients. MeHg concentrations were 2–6 and 30–55 times higher in hypoxic and anoxic than in normoxic water, respectively, while only 1–3 and 1–2 times higher for total Hg (THg). We systematically detected divalent inorganic Hg (HgII) methylation in anoxic water but rarely in other waters. In anoxic water, high concentrations of dissolved sulfide cause formation of dissolved species of HgII: HgS2H−(aq) and Hg (SH)20(aq). This prolongs the lifetime and increases the reservoir of HgII readily available for methylation, driving the high MeHg concentrations in anoxic zones. In the hypoxic zone and at the hypoxic‐anoxic interface, Hg concentrations, partitioning, and speciation are all highly dynamic due to processes linked to the iron and sulfur cycles. This causes a large variability in bioavailability of Hg, and thereby MeHg concentrations, in these zones. We find that zooplankton in the summertime are exposed to 2–6 times higher MeHg concentrations in hypoxic than in normoxic water. The current spread of hypoxic zones in coastal systems worldwide could thus cause an increase in the MeHg exposure of food webs. Key Points: Iron and sulfur cycling in the redoxcline explain particulate and dissolved mercury concentration peaks found in the water columnHigh in situ mercury methylation explains elevated methylmercury concentrations in anoxic waterWe present a conceptual model describing cycling and speciation of mercury across the redoxcline [ABSTRACT FROM AUTHOR]

Key message: Genetic and phenotypic analysis of two complementary maize panels revealed an important variation for biomass yield. Flowering and biomass QTL were discovered by association mapping in both panels. Abstract: The high whole plant biomass productivity of maize makes it a potential source of energy in animal feeding and biofuel production. The variability and the genetic determinism of traits related to biomass are poorly known. We analyzed two highly diverse panels of Dent and Flint lines representing complementary heterotic groups for Northern Europe. They were genotyped with the 50 k SNP-array and phenotyped as hybrids (crossed to a tester of the complementary pool) in a western European field trial network for traits related to flowering time, plant height, and biomass. The molecular information revealed to be a powerful tool for discovering different levels of structure and relatedness in both panels. This study revealed important variation and potential genetic progress for biomass production, even at constant precocity. Association mapping was run by combining genotypes and phenotypes in a mixed model with a random polygenic effect. This permitted the detection of significant associations, confirming height and flowering time quantitative trait loci (QTL) found in literature. Biomass yield QTL were detected in both panels but were unstable across the environments. Alternative kinship estimator only based on markers unlinked to the tested SNP increased the number of significant associations by around 40 % with a satisfying control of the false positive rate. This study gave insights into the variability and the genetic architectures of biomass-related traits in Flint and Dent lines and suggests important potential of these two pools for breeding high biomass yielding hybrid varieties. [ABSTRACT FROM AUTHOR]

Data about the patterns of care and the specific outcome of elderly patients with advanced gastrointestinal stromal tumors (GISTs) are almost nonexistent. Between 2001 and 2009, 44 patients ≥75 years old with advanced GISTs started first-line imatinib (400 mg/day) in seven participating institutions. Clinical data were collected by reviewing medical records and were entered in a comprehensive database. During the same period, 160 patients with advanced GIST (136 patients <75 years old, 24 patients ≥75 years old) had access to an imatinib blood level testing program. Imatinib plasma concentration (patient dose 400 mg/day) tests were centralized in a single laboratory. Median age was 78 years old (range 75-86). Thirty-six patients (82 %) experienced at least one adverse event (Table 2). Drug-related adverse events were mainly of grades 1 and 2 and were medically manageable. Permanent dose reduction (200-300 mg/day) was required for 20 patients (45.5 %) and was significantly more frequent for patients with performance status (PS) ≥2: 33.5 versus 8.5 %, p = 0.04. Eight patients (18 %) required imatinib interruption for intolerance. Median PFS was 34.4 months (95 % CI 11.5-57.4) (Fig. 1). Median overall survival (OS) was 50.3 months (95 % CI 37-63.5). Performance status <2 was the sole pre-therapeutic factor associated with improved OS. No correlation was found between comorbidities and tolerance or outcome. Imatinib trough plasma concentrations increase with age, although this correlation did not reach statistical significance. First-line imatinib is a feasible and effective treatment in patients with advanced GISTs ≥75 years. Aging seems to have only a moderate impact on imatinib pharmacokinetics. Overall survival is similar to that of younger patients. Comorbidities did not result in increased incidence of toxicity. Careful follow-up regarding tolerance issues should be considered in elderly patients with poor PS. [ABSTRACT FROM AUTHOR]

Data about the patterns of care and the specific outcome of elderly patients with advanced gastrointestinal stromal tumors (GISTs) are almost nonexistent. Between 2001 and 2009, 44 patients ≥75 years old with advanced GISTs started first-line imatinib (400 mg/day) in seven participating institutions. Clinical data were collected by reviewing medical records and were entered in a comprehensive database. During the same period, 160 patients with advanced GIST (136 patients <75 years old, 24 patients ≥75 years old) had access to an imatinib blood level testing program. Imatinib plasma concentration (patient dose 400 mg/day) tests were centralized in a single laboratory. Median age was 78 years old (range 75–86). Thirty-six patients (82 %) experienced at least one adverse event (Table 2). Drug-related adverse events were mainly of grades 1 and 2 and were medically manageable. Permanent dose reduction (200–300 mg/day) was required for 20 patients (45.5 %) and was significantly more frequent for patients with performance status (PS) ≥2: 33.5 versus 8.5 %, p = 0.04. Eight patients (18 %) required imatinib interruption for intolerance. Median PFS was 34.4 months (95 % CI 11.5–57.4) (Fig. 1). Median overall survival (OS) was 50.3 months (95 % CI 37–63.5). Performance status <2 was the sole pre-therapeutic factor associated with improved OS. No correlation was found between comorbidities and tolerance or outcome. Imatinib trough plasma concentrations increase with age, although this correlation did not reach statistical significance. First-line imatinib is a feasible and effective treatment in patients with advanced GISTs ≥75 years. Aging seems to have only a moderate impact on imatinib pharmacokinetics. Overall survival is similar to that of younger patients. Comorbidities did not result in increased incidence of toxicity. Careful follow-up regarding tolerance issues should be considered in elderly patients with poor PS. [ABSTRACT FROM AUTHOR]

Hg cycling in biologically productive coastal areas is of special importance given the potential for bioaccumulation of monomethylmercury (MMHg) into aquatic organisms. Field experiments were performed during three different seasons in Arcachon Bay, a mesotidal lagoon (SW France), to assess the variability of the water column concentrations, sediment-water exchanges and potential formation and degradation of MMHg. The objectives were to evaluate the contribution of intertidal mudflats to MMHg production and the various pathways of Hg species export. Dissolved and bulk concentrations of Hg species in the water column downstream of tidal flats were measured throughout several tidal cycles. The Hg benthic fluxes at the sediment-water interface were determined by means of benthic chambers for three different stations. Hg methylation and demethylation potentials were determined in surficial sediments and the water column using isotopic tracers. The tidal surveys demonstrated that benthic remobilization of Hg occurs primarily in association with sediment erosion and advection during ebb tide. However, elevated dissolved Hg concentrations observed at low tide were found to be caused by a combination of pore-waters seeping, benthic fluxes and methylation in the water column. Benthic fluxes were more intense during late winter conditions (median MMHg and inorganic Hg (IHg) fluxes: 64 and 179 pmol m h, respectively) and subsequently decreased in spring (median 0.7 and −5 pmol m h, respectively) and fall (median −0.4 and −1.3 pmol m h, respectively). The trends in methylation and demethylation potentials were at the opposite of the fluxes, two times lower during winter than for spring or fall conditions. In this tidal environment, MMHg production in surface sediments and its subsequent release is estimated to be the major source of MMHg to the water column during winter and spring time. However, during the more productive summer period, the Hg methylation extent in the water column may be very significant and equivalent to the sediment contribution. [ABSTRACT FROM AUTHOR]

Tyrosine kinase inhibitors (TKIs) have potent effects on malignant cells, and they also target kinases in normal cells, which may have therapeutic implications. Using a collection of 55 leukemia patients treated with TKI therapy (chronic myeloid leukemia, n=47; acute lymphoblastic leukemia, n=8), we found that dasatinib, a second-generation broad-spectrum TKI, induced a rapid, dose-dependent and substantial mobilization of non-leukemic lymphocytes and monocytes in blood peaking 1-2 h after an oral intake and the blood counts closely mirrored drug plasma concentration. A preferential mobilization was observed for natural killer (NK), NK T, B and γδ+ T cells. Mobilization was coupled with a more effective transmigration of leukocytes through an endothelial cell layer and improved cytotoxicity of NK cells. Platelet numbers decreased markedly after the drug intake in a proportion of patients. Similar effects on blood cell dynamics and function were not observed with any other TKI (imatinib, nilotinib and bosutinib). Thus, dasatinib induces a unique, rapid mobilization and activation of cytotoxic, extravasation-competent lymphocytes, which may not only enhance antileukemia immune responses but can also be causally related to the side-effect profile of the drug (pleural effusions, thrombocytopenia). [ABSTRACT FROM AUTHOR]

Stable isotopic tracer methodologies now allow the evaluation of the reactivity of the endogenous (ambient) and exogenous (added) Hg to further predict the potential effect of Hg inputs in ecosystems. The differential reactivity of endogenous and exogenous Hg was compared in superficial sediments collected in a coastal lagoon (Arcachon Bay) and in an estuary (Adour River) from the Bay of Biscay (SW France). All Hg species (gaseous, aqueous, and solid fraction) and ancillary data were measured during time course slurry experiments under variable redox conditions. The average endogenous methylation yield was higher in the estuarine (1.2 %) than in the lagoonal sediment (0.5 %), although both methylation and demethylation rates were higher in the lagoonal sediment in relation with a higher sulfate-reducing activity. Demethylation was overall more consistent than methylation in both sediments. The endogenous and exogenous Hg behaviors were always correlated but the exogenous inorganic Hg (IHg) partitioning into water was 2.0-4.3 times higher than the endogenous one. Its methylation was just slightly higher (1.4) in the estuarine sediment while the difference in the lagoonal sediment was much larger (3.6). The relative endogenous and exogenous methylation yields were not correlated to IHg partitioning, demonstrating that the bioavailable species distributions were different for the two IHg pools. In both sediments, the exogenous IHg partitioning equaled the endogenous one within a week, while its higher methylation lasted for months. Such results provide an original assessment approach to compare coastal sediment response to Hg inputs. [ABSTRACT FROM AUTHOR]

Background Imatinib mesylate is a potent inhibitor of platelet-derived growth factor and transforming growth factor-β signalling pathways which may play a role in systemic sclerosis (SSc)-associated skin changes. Objectives We aimed primarily at assessing the efficacy of imatinib mesylate in scleroderma skin fibrosis. Methods We performed a phase II double-blinded trial on patients with scleroderma with either morphoea involving > 20% of body surface area or SSc with extensive skin involvement: modified Rodnan Skin Score (mRSS) ≥ 20/51. Each patient was randomized to receive either imatinib mesylate 400 mg or placebo daily for a total of 6 months, and then was followed up 6 months after therapy discontinuation. Skin fibrosis was assessed by mRSS and measurement of the dermal thickness using skin biopsies performed at inclusion and at 6 months of treatment. In addition, quality of life (Dermatology Life Quality Index and modified Health Assessment Questionnaire for Scleroderma) was recorded at each visit, and pulmonary function before and after intervention. Results Twenty-eight patients were included in the study with a mean age of 48·9 years (range 30-71): 25 had a diagnosis of a SSc and three of diffuse cutaneous scleroderma. Demographic data, frequency of organ involvement of SSc and mRSS were comparable between groups. At 6 months, the proportion of variation of mRSS from inclusion was not statistically significantly different between the two groups (median +0·10 in imatinib group vs. −0·16 in placebo group, P = 0·098). Similarly, changes in dermal thickness, quality of life and diffusion capacity for carbon monoxide were not significantly different between groups. Conclusions This study failed to demonstrate the efficacy of imatinib 400 mg daily to improve skin fibrosis of diffuse scleroderma after 6 months of treatment based on validated outcome measurements. [ABSTRACT FROM AUTHOR]

Nasal-type natural killer (NK) cell lymphoma is an infrequent aggressive malignant disease with very poor prognosis. We aimed to explore the possible role of the transcription factor STAT3 in the pathophysiology of this malignancy, as it was involved in oncogenesis and chemoresistance. For this, we established and characterized a continuous interleukin 2-dependent NK cell line (MEC04) from a patient with a fatal nasal-type NK-cell lymphoma. Cells harbored poor cytotoxic activity against K562 cells, and spontaneously secreted interferon-gamma, interleukin-10 and vascular-endothelium growth factor in vitro. STAT3 was phosphorylated in Y705 dimerization residue in MEC04 cells and restricted to the nucleus. Y705 STAT3 phosphorylation involved JAK2, as exposure of cells to AG490 inhibitor inhibited Y705 STAT3 phosphorylation. By using recombinant transducible TAT-STAT3-beta (beta isoform), TAT-STAT3Y705F (a STAT3 protein mutated on Y705 residue, which prevents STAT3 dimerization) and peptides inhibiting specifically STAT3 dimerization, we inhibited STAT3 phosphorylation and cell growth, with cell death induction. Finally, STAT3 was phosphorylated in Y705 residue in the nuclei of lymphoma cells in eight/nine patients with nasal-type NK/T-cell lymphoma and in YT, another NK cell line. Our results suggest that STAT3 protein has a major role in the oncogenic process of nasal-type NK-cell lymphomas, and may represent a promising therapeutical target. [ABSTRACT FROM AUTHOR]

Mesenchymal stem cells (MSCs) have an immunosuppressive effect and can inhibit the proliferation of alloreactive T cells in vitro and in vivo. Cotransplantation of MSCs and hematopoietic stem cells (HSCs) from HLA-identical siblings has been shown to reduce the incidence of acute graft- vs.-host disease. MSCs are heterogeneous and data on the inhibitory effects of different MSC subsets are lacking. The antigen Stro1 is a marker for a pure primitive MSC subset. We investigated whether Stro-1-enriched induce a more significant suppressive effect on lymphocytes in a mixed lymphocyte reaction (MLR), and whether this action is related to a specific gene expression profile in Stro-1-enriched compared to other MSCs. We demonstrated that the Stro-1-enriched population elicits a significantly more profound dose-dependent inhibition of lymphocyte proliferation in a MLR than MSCs. One thousand expanded Stro-1-enriched induced an inhibitory effect comparable to that of 10 times as many MSCs. Inhibition by Stro-1-enriched was more significant in contact-dependent cultures than in noncontact-dependant cultures at higher ratio. The Stro-1-enriched inhibitory effect in both culture types was linked to increased gene expression for soluble inhibitory factors such as interleukin-8 (IL-8), leukemia inhibitory factor (LIF), indoleamine oxidase (IDO), human leukocyte antigen-G (HLA-G), and vascular cell adhesion molecule (VCAM1). However, tumor growth factor-β1 (TGF-β) and IL-10 were only up-regulated in contact-dependant cultures. These results may support using a purified Stro-1-enriched population to augment the suppressive effect in allogeneic transplantation. [ABSTRACT FROM AUTHOR]

Alkylphenols and their derivatives, alkylphenol polyethoxylates (APEs), are synthetic chemicals of concern owing to their endocrine properties. Nonylphenol (NP) is a critical APE metabolite because of its recalcitrance to biodegradation, toxicity, and ability to bio-accumulate in aquatic organisms. Studies of NP effects in vertebrates demonstrated estrogenic disrupting properties in fish, birds, reptiles, and mammal cells in which NP displaces the natural estrogen from its receptor. Less is known on its toxicity toward invertebrates. Effects on reproduction have been reported, but toxicity on development has been poorly documented thus far. We investigated NP toxicity on survival and regeneration of the freshwater coelenterate Hydra attenuata. Hydra is known for its regenerative capacity and its sensitivity to chemical pollution. It has been used for over 20 years to screen for teratogenicity of chemicals (Johnson et al. (1982) Teratog Carcinog Mutagen 2:263–276). Our results showed that hydra appeared as one of the most sensitive species to acute and chronic toxicity of NP compared to several freshwater invertebrates. Regeneration was disrupted at NP concentrations lower than those affecting survival. Toxicity thresholds of NP for aquatic vertebrates and invertebrates are also reported and discussed in the context of environmental risk assessment and of water quality objectives recommended for surface waters in industrialized countries. NP levels have decreased during the last decade because of a voluntary agreement of surfactant producers and users. At present, concentrations of NP found in surface waters are far below 1 μg/L in Europe, but can reach several μg/L when wastewater treatment plant inefficiency occurs. [ABSTRACT FROM AUTHOR]

Resistance based on slow-rusting genes has proven to be a useful strategy to develop wheat cultivars with durable resistance to rust diseases in wheat. However this type of resistance is often difficult to incorporate into a single genetic background due to the polygenic and additive nature of the genes involved. Therefore, markers, both molecular and phenotypic, are useful tools to facilitate the use of this type of resistance in wheat breeding programs. We have used field assays to score for both leaf and yellow rust in an Avocet- YrA × Attila population that segregates for several slow-rusting leaf and yellow rust resistance genes. This population was analyzed with the AFLP technique and the slow-rusting resistance locus Lr46/Yr29 was identified. A common set of AFLP and SSR markers linked to the Lr46/Yr29 locus was identified and validated in other recombinant inbred families developed from single chromosome recombinant populations that segregated for Lr46. These populations segregated for leaf tip necrosis (LTN) in the field, a trait that had previously been associated with Lr34/Yr18. We show that LTN is also pleiotropic or closely linked to the Lr46/Yr29 locus and suggest that a new Ltn gene designation should be given to this locus, in addition to the one that already exists for Lr34/Yr18. Coincidentally, members of a small gene family encoding β-1 proteasome subunits located on group 1L and 7S chromosomes implicated in plant defense were linked to the Lr34/Yr18 and Lr46/Yr29 loci. [ABSTRACT FROM AUTHOR]

The aim of the present study was to evaluate the capacity to expand of hematopoietic stem cell (HSC) samples from eight patients with NHL, and to follow in parallel the fate of tumor cells in four of eight samples still containing bcl2/JH+ tumor cells after CD34+ or CD19-/20-/34+ cell selection. The presence of bcl2/JH+ cells was also investigated after expansion in four of eight samples, two of which were bcl2/JH- at harvesting and two which were initially bcl2/JH+ but became bcl2/JH- (below the level of PCR detection) after cell selection, to assess a possible reappearance of occult tumor cells after expansion culture. We used culture conditions that we previously had established to allow high level expansion of normal precursors, progenitors and LTC-ICs. In this study, particular attention was given to the role of Flt3-ligand, known to favor the growth of B cells. The expansion conditions were: 1.5 × 103 cells/ml in serum-free medium containing stem cell factor (SCF), interleukin-3 (IL-3), IL-6, granulocyte-stimulating factor (G-CSF), erythropoietin (Epo) ± Flt3-ligand (Flt3-L) for 10 days. After culture, total cells, CFU-GMs, BFU-Es and LTC-ICs were expanded to a mean of 833-, 6.6-, 4.6-, and 1.8-fold, respectively with the cocktail of cytokines not including Flt3-L. When Flt3-L was added, the mean expansion values were 1095-, 31-, 15- and three-fold, respectively. Residual bcl2/JH+ cells present in four of eight samples before expansion were not detected after expansion. Similarly, no tumor cells reappeared after expansion of the two samples which had become negative after selection, as well as in the two samples which were bcl2/JH- at harvesting. These results suggest first that ex vivo expansion of hematopoietic stem cells in patients with non-Hodgkin’s lymphoma is feasible without incurring the parallel... [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the ex vivo expansion of normal CD34+ cells in gas-permeable polypropylene bags suitable for clinical use. Cells were cultured for 14 days in serum-free medium supplemented with SCF, IL3, IL6, FLT3-l, G-CSF ± MGDF or Epo. The bags supported the expansion of hematopoietic cells in a similar manner to small scale well or flask systems, allowing mean expansions of up to 2193-fold for total nucleated cells, 140-fold for CFU-GM and 66-fold for LTC-IC. Increasing the initial cell concentration from 5 × 103 to 1 × 105 CD34+ cells/ml induced the production of granulocytic cells with terminal differentiation while simultaneously decreasing the overall extent of expansion of the white blood cells produced. We tested the phagocytic activity and oxidative metabolism of the white blood cells produced. The percentage of phagocytic cells was 39 ± 0.5% in expanded cultures derived from fractions initiated at 5 × 103, 104 or 105 cells/ml and 45 ± 6% in cultured cells obtained from starting fractions containing 5 × 104 cells/ml, as compared to 58 ± 4% in normal controls. A study of the potential for oxygen-dependent microbe killing showed that the expanded cells produced H2O2, although in lesser quantities than control cells. We subsequently investigated the possibility of freezing expanded cells. Total cell recovery after thawing was 45 ± 4%, while recoveries of progenitors and stem cells ranged from 65 to 90%, without any influence of the initial cell concentration. This new approach could be of major interest for clinical practice, as it would allow evaluation of the quality of a graft prior to its infusion and employs experimental conditions which meet the criteria for potential clinical use. [ABSTRACT FROM AUTHOR]

We tested two positive selection techniques for separation of CD34+ cells from bone marrow and analyzed the yields of CD34+ cells, BFU-E, CFU-GM, CFU-MK and LTC-IC after selection and expansion. An immunoadsorption procedure (CellPro) and an immunomagnetic (Baxter) CD34+ cell separation method were employed to purify the same bone marrow samples from seven normal subjects. Mean yields of CFU-GM and CFU-MK and absolute numbers of LTC-ICs were not different in the two purified cell populations. In contrast, the mean recovery of BFU-E was significantly lower for the immunoadsorption (21 ± 14%) than for the immunomagnetic technique (44 ± 27%). After separation, CD34+ cells were evaluated in 10-day liquid cultures for their expansion capacity in terms of total cells and progenitors. The expansion capacity of progenitors such as CFU-GM, CFU-MK and especially BFU-E selected by immunoadsorption was higher than the capacity of progenitors obtained by immunomagnetism, although final total and progenitor cell numbers are similar. Our results suggest that the populations separated by the two techniques differ mainly in the expansion capacity of progenitors and in the recovery of BFUE after the selection procedure. These differences between two methods, which already are widely employed in research and in clinical transplantation, should be taken into account when considering the aims of the experiments. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the association of transport proteins in the cellular intake of imatinib and nilotinib drugs. It says that leukemic K562 cells in bovine serum were used to investigate the impact of transporter inhibitors on intracellular concentrations. Findings reveal that no difference was found between cell lines with or without inhibitors using nilotinib and intracellular therapeutic drug monitoring may be more sensitive compared to plasma concentration.

The article describes the case of a 40-year-old woman with acute myeloid leukemia who received an autologous bone marrow transplantation (ABMT) in complete remission and who was later infused with mesenchymal stem cells (MSC) following graft failure. Infusion was performed three years after ABMT to improve hematopoiesis. MSC were isolated from a mismatched brother bone marrow's leukocyte antigen.