Ex vivo exposure to titanium dioxide and silver nanoparticles mildly affect sperm of gilthead seabream (Sparus aurata) - A multiparameter spermiotoxicity approach

Nanoparticles (NP) are potentially reprotoxic, which may compromise the success of populations. However, the reprotoxicity of NP is still scarcely addressed in marine fish. Therefore, we evaluated the impacts of environmentally relevant and supra environmental concentrations of titanium dioxide (TiO₂: 10 to 10,000 μg·L^-1) and silver NP (Ag: 0.25 to 250 μg·L^-1) on the sperm of gilthead seabream (Sparus aurata). We performed short-term direct exposures (ex vivo) and evaluated sperm motility, head morphometry, mitochondrial function, antioxidant responses and DNA integrity. No alteration in sperm motility (except for supra environmental Ag NP concentration), head morphometry, mitochondrial function, and DNA integrity occurred. However, depletion of all antioxidants occurred after exposure to TiO₂ NP, whereas SOD decreased after exposure to Ag NP (lowest and intermediate concentration). Considering our results, the decrease in antioxidants did not indicate vulnerability towards oxidative stress. TiO₂ NP and Ag NP induced low spermiotoxicity, without proven relevant ecological impacts.

Mobilization and collection of peripheral blood stem cells in multiple myeloma patients older than 65 years

Over the past 10 years, the incidence of multiple myeloma (MM) has been greater among individuals >65 years old than in younger age groups. This retrospective study of peripheral blood stem cell mobilization and harvesting examined patients of various age groups who were afflicted with this pathology. One group of 17 patients ≥65 years of age with MM (group A) were mobilized between 2002 and 2009 and compared with 33 consecutive patients of younger ages with the same diagnosis treated in 2008 and 2009 (group B). The 2 populations had a similar gender distribution; their median ages were 66 and 52 years, respectively. A successful mobilization was defined as a collection of ≥2.5 × 10(6) CD34+/kg body weight. The mobilization used filgrastim (16 μg/kg/d) with the beginning of the harvest on the fifth day. The median number of outpatient apheresis procedures per patient was 2 in group A and 1 in group B. There were no incidents or serious adverse reactions. Patients in group A collected 4.68 × 10(6) CD34+ cells/kg and for group B 3.30 × 10(6)/kg. The group A patients required a greater number of apheresis procedures to collect the appropriate graft. In conclusion, mobilization with growth factors and PHSP harvest by apheresis was safe with reasonable costs for subjects including those aged ≥65 years, resulting in an option for autologous transplantation.

Ancestim (recombinant human stem cell factor, SCF) in association with filgrastim does not enhance chemotherapy and/or growth factor-induced peripheral blood progenitor cell (PBPC) mobilization in patients with a prior insufficient PBPC collection

Up to a third of autologous transplantation candidates fail to mobilize hematopoietic progenitors into the peripheral blood with chemotherapy and/or growth factor treatment, thus requiring innovative mobilization strategies. In total, 20 cancer patients unable to provide adequate PBPC products after a previous mobilization attempt were treated with ancestim (20 microg/kg/day s.c.) and filgrastim (10 microg/kg/day s.c.). In 16 patients, the pre-study mobilization was with filgrastim alone. Eight patients underwent single large volume leukapheresis (LVL) and 12 multiple standard volume leukaphereses (SVL) in both mobilizations. Pairwise comparison of peripheral blood CD34(+) cell concentrations on the day of first leukapheresis failed to document synergism - median CD34(+)/microl of 3.2 (<0.1 to 15.4) and 4.5 (1-28.56) for the pre-study and on-study mobilizations (P = 0.79, sign test), and 4.2 (<0.1-15.4) and 5 (1-28.56), respectively, for the 16 patients previously mobilized with filgrastim alone (P = 1, sign test). The number of CD34(+) cells/kg collected per unit of blood volume (BV) processed was similar in both mobilizations - median 0.1 x 10(6)/kg/BV and 0.09 x 10(6)/kg/BV, respectively (P = 1, sign test). In this phase II study, the combination of ancestim and filgrastim did not allow adequate PBPC mobilization and collection in patients with a previous suboptimal PBPC collection.

The number of donor CD3(+) cells is the most important factor for graft failure after allogeneic transplantation of CD34(+) selected cells from peripheral blood from HLA-identical siblings

This study analyzed the characteristics of 257 HLA-identical sibling transplants of granulocyte colony-stimulating factor-mobilized peripheral blood progenitor cells depleted of T cells by CD34(+) positive selection (allo-PBT/CD34(+)) for their effect on the incidence of graft failure. Twenty-four patients developed graft failure (actuarial probability, 11%; 95% confidence interval, 7.1-14. 9). Prognostic factors considered were sex and age of donor and recipient, donor-recipient blood group compatibility, diagnosis, disease status at transplant, conditioning regimen, cytomegalovirus serology, number of CD34(+) and CD3(+) cells infused, and cryopreservation. The major factor associated with graft failure was the number of CD3(+) cells in the inoculum. Twenty-three of 155 patients receiving a T-cell dose in the graft less than or equal to 0.2 x 10(6)/kg experienced graft failure, compared with only one of 102 patients receiving more than 0.2 x 10(6)/kg (actuarial probability 18% vs 1%, respectively; P =.0001). The actuarial probability of graft failure progressively increased as the number of CD3(+) cells in the graft decreased, which was determined by grouping the number of CD3(+) cells in quartiles (log-rank P =.03; log-rank for trend P =.003). In the multivariate analysis by the proportional hazard method, 2 covariates entered into regression at a significant level: CD3(+) cells less than or equal to 0.2 x 10(6)/kg (risk ratio = 17; P <.0001), and patients with chronic myelogenous leukemia (CML) conditioned with busulphan-based regimens (risk ratio = 4.8; P =.001). From these results it appears that the number of CD3(+) cells in the inoculum-with a threshold of 0.2 x 10(6)/kg or less-is the most critical factor in maintaining a sustained engraftment in allo-PBT/CD34(+) from HLA-identical siblings. In addition, for patients with CML receiving 0.2 x 10(6)/kg or less CD3(+) cells, total body irradiation might be better than busulphan-based regimens.

Central nervous system (CNS) tuberculosis following allogeneic stem cell transplantation

Tuberculosis is an uncommon infectious complication after stem cell transplantation. We report a patient who presented with a brain mass, 3 months after pulmonary tuberculosis had been diagnosed and while he was receiving triple antituberculous therapy. He had extensive chronic GVHD. The diagnosis was made after biopsy of the lesion. The cerebral mass was excised, antituberculous treatment was maintained and the patient made a complete neurologic recovery. Six months later, he died of gram-negative septic shock. Mycobacterial infections should be considered in allograft recipients with chronic GVHD and solid lesions in the brain. Bone Marrow Transplantation (2000) 25, 567-569.

Umbilical cord blood processing with the Optipress II blood extractor

BACKGROUND

We have previously shown that UC blood (UCB) units can be volume-reduced manually, in a closed system, without major losses of nucleated and CD34(+) cells and without the addition of exogenous material. Our aim was to use an automated method for the separation of the UCB components using the Optipress II, extractor, with the 'buffy-coat' collection in a standardized volume.

METHODS

After centrifugation, the 51 UCB units were separated into the three blood components, plasma, buffy coat (BC) and red cells, using the Optipress II. The final volume of the BC fraction, rich in nucleated and progenitor CD34(+) cells, was set at 30 mL. The nucleated and CD34(+) cell content of the UCB collections and the resulting BC were evaluated.

RESULTS

The UCB units were grouped according to the volume collected: Group I < 80 mL and Group II > or = 80 mL. Standardization of the BC at 30 mL resulted in significant volume reduction for both groups, with median values of 51% in Group I and 70% in Group II. The nucleated and CD34(+) cell recoveries in the BC from Group I were 88% and 99% respectively; for Group II they were 80% and 97%.

DISCUSSION

This semi-automated method of volume reduction efficiently reduces low, as well as high volume UCB units, with good nucleated- and progenitor-cell yields. Being a closed system and free of external material, the risk of contamination is minimized. The resulting fractions are then available for validation studies of the unit, effectively fulfilling the main requisites for UCB banking.

Single- versus dual-platform assays for human CD34+ cell enumeration

We comparatively assessed CD34+ cell quantification by two of the recently available single platform assays, the IMAGN 2000 STELLer (Immucor, Lisbon, Portugal) microvolume fluorimetry and the ProCOUNT (BD-ENZIfarma, Lisbon, Portugal) flow cytometry, with our "in-house" dual-platform flow cytometric assay. The performance of the methods was evaluated by linearity and reproducibility tests. The linearity study, over a range of 0-1,200 CD34+ cell/microl, gave a good linear relationship for the three methods, with R(2) > 0.99. Precision tested at three different concentrations gave coefficients of variation ranging from 3.6-26.4% for the STELLertrade mark, 2.4-13.8% for the ProCOUNT, and 3.2-6.4% for flow cytometry. CD34+ cells were quantified in umbilical cord blood (UCB), UCB enriched-leukocyte buffy-coat (BC), mobilized peripheral blood (PB) and mobilized peripheral blood progenitor cells (PBPC) collected by leucapheresis, from a total of 72 samples. Flow cytometric results showed good linear correlation to the absolute counts obtained by the STELLer and ProCOUNT for all samples (R > 0.90 for all methods), with no differences when compared by paired tests (P > 0.05). Linear correlations between methods were also found when individually looking at the different cell sources: UCB or PB, BC, and PBPC, with low, intermediate and high CD34+ cell concentrations, respectively. Furthermore, with the exception of a significant difference between the ProCOUNT and STELLer results for UCB (P < 0.05), no other difference between methods was found for each of the individual populations (P > 0.05). To our knowledge, this is the first report in which the results are presented and analyzed according to each source of CD34+ cells. Our results show that the STELLer and the ProCOUNT are equally efficient for the dual-platform flow cytometric assay in CD34+ cell quantification.

Analysis of surface markers on CD34+ cells, isolated from cord blood and G-CSF primed peripheral blood

We report a comparative study of the expression of multilineage and adhesion molecules on CD34+ cells isolated from human umbilical cord blood (CB) and G-CSF-mobilized peripheral blood progenitor cells (PBPC) from healthy volunteers. The major difference found between the two sources of CD34+ populations was the expression of CD54 molecule, which was higher in CB in comparison to PBPC.

Umbilical cord blood processing: volume reduction and recovery of CD34+ cells

One of the main problems for the establishment of umbilical cord blood (UCB) banks is the storage space needed for the frozen samples. The aim of this study was to find a method of reducing the volume of UCB units without major losses of the haematopoietic progenitor-CD34+ cells. The UCB was collected into a triple blood bag system, in which the anti-coagulant had been previously adjusted. The blood bag was first centrifuged for red cell depletion followed by a second centrifugation for plasma reduction. At this point, the main bag containing the white blood cell (WBC) rich fraction "buffy coat' (BC) and the "waste bag' were sealed and detached. Haematologic cell counts and CD34+ cell quantification were done in whole blood and in the isolated fractions. The average volume of the 19 UCB samples processed was 103 ml. Separation by centrifugation led to a mean volume reduction of 56% with red cell depletion of 59%. The white blood cell recovery was of 72% with a significant CD34+ cell recovery of 87%. This seems a promising method for cord blood volume reduction and enrichment of CD34+ cells.