Counting of leukocytes in samples from G-CSF mobilized donors, leukapheresis products, and cord blood: the performances of an analyzer with dedicated profiles.

INTRODUCTION: Accurate white blood cell counting (WBC) and differential count by blood analyzers could allow a more informative characterization of granulocyte colony-stimulating factor (G-CSF) mobilized blood (MB), leukapheresis products (LP), and cord blood (CB). However, reliable counting by a blood cell analyzer in this setting is a major challenge owing to quali-quantitative abnormalities of blood cells. METHODS: We evaluated the performances of the analyzer Pentra DX 120 by Horiba ABX working with dedicated cell-gating profiles, which generate three-part differential counts in samples obtained from donors' MB, LP, and CB. The results of the analyzer were compared to counts obtained by flow cytometry and manual counts, the latter performed for reference validation and in the case of discrepant results between study and reference counts. RESULTS: Pentra DX 120 generated highly correlated counts (R > 0.91 in all cases) to those obtained by flow cytometry in all samples (MB, LP, and CB) with high degree of count accuracy in most cases and referred to WBC absolute count and differential count including lymphocytes (LYM) %, monocytes (MON) %, and polymorphonuclear leukocytes (PMN) %. Accuracy, judged by the difference between study and reference counts and expressed as percentage of reference count, ranged from 0.8% to 8.6%, and sporadic loss of accuracy occurred for MON % only in no more than 10% of CB samples. CONCLUSION: The ABX Pentra DX 120 provided accurate WBC count and differential count during MB, LP, and CB analyses and allowed a better characterization of donors' hematologic status and graft composition.

Evaluation of the analytical performances of a portable, 18-parameter hemometric system using capillary blood samples for blood donor enrolment.

BACKGROUND AND OBJECTIVES: Blood donor enrolment process is frequently based on the sole capillary haemoglobin (Hb) evaluation while platelet donors by apheresis also requires platelet (Plt) count. The 'sole Hb' approach prevents a complete donor evaluation and does not allow Plt donor enrolment. To extend blood counts before donations, we evaluated the performances of a multiparametric counter using capillary blood. MATERIALS AND METHODS: The ABX Micros 60 (Micros 60) blood analyzer was employed on capillary blood and compared with venous counts by a reference counter (Coulter AcT 5diff) in a first series of 416 donors and in a second series of 136, after a 3-month period of routine use of this study counter. An average of 50 microl of capillary blood was collected whose 10 microl had been aspirated by Micros 60. RESULTS: High correlations were found between capillary counts using Micros 60 and venous counts using the reference counter. Mean Plt counts differed of 37 x 10(9)/l less for capillary approach in the first series of comparisons, but decreased to 10 x 10(9)/l less in the second series due to a greater expertise of operators in capillary sampling. All other parameters were accurate and never reached clinical relevance albeit they showed statistically significant differences. CONCLUSION: Data on Micros 60 demonstrated that capillary predonation counts may represent a feasible and effective approach to realize an accurate enrolment process of blood and Plt donors.

Parp and cell death or protection in rat primary astroglial cell cultures under LPS/IFNgamma induced proinflammatory conditions.

The enzyme poly(ADP-ribose)polymerase (PARP) has a leader role in the DNA damage survey mechanisms by its nick-sensor function, but it is also involved in the early events of the programmed cell death, particularly during inflammatory injury, as a coactivator of NF-kB. In the present study, we evaluated the PARP involvement in the mechanisms of protection and/or cell death in rat astroglial cell cultures during the early phase of proinflammatory commitment after lipopolysaccharide and interferon gamma treatment. According with the recent findings that PARP-1 phosphorylation by MAPK/ERK-2 pathway seems to modulate PARP activation, in time course experiments we demonstrated that a very early PARP activation and expression is able to trigger a cell death pathway, DNA damage independent, during strong proinflammatory insults, maintaining its role of guardian of the genome stability only during the normal cell cycling.

Effect of antioxidant diets on mitochondrial gene expression in rat brain during aging.

Age-related increase of reactive oxygen species (ROS) is particularly detrimental in postmitotic tissues. Calorie restriction (CR) has been shown to exert beneficial effects, consistent with reduced ROS generation by mitochondria. Many antioxidant compounds also mimic such effects. N-acetyl cysteine (NAC) provides thiol groups to glutathione and to mitochondrial respiratory chain proteins; thus, it may counteract both ROS generation and effects. In the present study we investigated, in different rat brain areas during aging (6, 12, and 28 months), the effect of 1-year treatment with CR and dietary supplementation with NAC on the expression of subunit 39 kDa and ND-1 (mitochondrial respiratory complex I), subunit IV (complex IV), subunit alpha of F0F1-ATP synthase (complex V) and of adenine nucleotide translocator, isoform 1 (ANT-1). The observed age-related changes of expression were prevented by the dietary treatments. The present study provides further evidence for the critical role of mitochondria in the aging process.

The diagnosis of hairy cell leukemia can be established by flow cytometric analysis of peripheral blood, even in patients with low levels of circulating malignant cells.

The diagnosis of hairy cell leukemia (HCL) has traditionally been based on microscopic means. Immunophenotypic analysis of peripheral blood by flow cytometry is not widely recognized as a method for diagnosing HCL, perhaps due to the expectation of low yield of neoplastic cells in patients who are characteristically leukopenic. The abnormal coexpression of CD103, CD25, and intense CD11c and CD20 on monotypic, slightly large B-lymphocytes has previously been shown to be highly characteristic of HCL. We wished to determine if this pattern was valuable in the diagnosis of HCL in leukopenic patients with low levels of neoplastic cells in the peripheral blood. The abnormal immunophenotype above was observed in 25 peripheral blood specimens from patients with unexplained cytopenias or suspected lymphoproliferative processes. Ten of the 25 blood samples exhibited this abnormal phenotype in less than 5% of circulating leukocytes (ranging from <1% to 4%). All 10 patients had other manifestations of HCL, including cytopenias (mean white blood cell count, 1.8 x 10(3)/mm(3); hemoglobin, 11.0 gm/dl; platelets, 74 x 10(3)/mm(3)), splenomegaly, and typical bone marrow morphologic changes. Eight of the 10 patients achieved an excellent response to one course of 2-CDA, with significant improvement of cytopenias (mean white blood cell count: 5.3 x 10(3)/mm(3); hemoglobin: 14.4 g/dl; platelets: 181 x 10(3)/mm(3)) and regression of splenomegaly. One patient had a partial response to alpha interferon and a subsequent complete response to 2-CDA, and one died during treatment. In conclusion, flow cytometric immunophenotyping of peripheral blood is capable of detecting low levels of circulating malignant cells in HCL, even in leukopenic patients. As such, it can be a very useful, non-invasive tool in the diagnosis of this disorder.

Photoexcitation of the methionine-iron bond in iron(III) cytochrome c: bimolecular reaction with NADH.

When iron(III) cytochrome c aqueous solutions containing NADH are irradiated with polychromatic light (wavelength greater than 280 nm), iron(II) cytochrome c and NAD+ in the stoichiometric ratio 2/1 are observed to be the principal reaction products, independently of the presence of oxygen; in addition, a minor process due to direct photodegradation of the nucleotide is observed. The selection of monochromatic 290 nm irradiation light (at which NADH has an absorbance minimum) and an adequate reactant concentration allowed parallel reactions to be minimized and new information to be obtained on the mechanism of the photoredox process. The experimental results are consistent with a reaction mechanism whereby NADH donates one electron to a "reactive intermediate" of the hemoprotein formed from the light-induced methionine-to-iron charge transfer excited state. In this process an NAD. radical is formed which, in deaerated solution, immediately reduces another molecule of the hemoprotein, and is itself oxidized to NAD+. In aerated solution, the NAD. radical rapidly reacts with oxygen to give NAD+ and superoxide O2- anion radical which, in turn, reduces the second iron(III) cytochrome c molecule.