Automated enumeration of CD34+ cells in peripheral blood and bone marrow.

We have developed a rapid and accurate method to enumerate the number of CD34+ cells in peripheral blood, bone marrow, and leukopheresis samples. The method consists of a two-tube assay and a dedicated software program for data acquisition and analysis. The first reagent combination consists of (a) a nucleic acid dye to identify nucleated cells, (b) a CD45 monoclonal antibody labeled with PE/CY5 to discriminate progenitor cells from mature lymphoid, neutrophil, erythroid, and monocytic cells, (c) an IgG1 control antibody labeled with PE to establish the boundary between specific and nonspecific staining, and (d) a known number of fluorescent beads to determine an absolute count of cells. In the second reagent combination the IgG1 control antibody is replaced by a CD34 antibody labeled with PE that is used to identify the CD34+ cells in the location established by the control reagent combination. The software program uses the fluorescent beads to adjust the forward light scatter, orthogonal light scatter, and three fluorescence detectors of the flow cytometer. The expected location of the CD34+ cells is then established with the control reagent combination followed by the enumeration of the CD34+ cells per microliter of sample with the reagent combination containing the CD34 antibody. This method is sensitive enough to detect CD34+ cells in peripheral blood of normal donors and can reliably determine an increase in CD34+ cells in the peripheral blood of patients treated with chemotherapy and/or growth factors. The method alleviates some of the difficulties encountered when small numbers of CD34+ cells are enumerated. The system allows for more precise evaluations of the grafts used for bone marrow transplantation.

Directional consistency: Determinant of learned maze performance of five mice strains.

The heterogeneous mouse stocks HS/lbg and SABRA/HUC, and the inbred strains C57B1/6J, CBA/LAC, and BALB/crgl (a total of 88 mice), were employed in an investigation on strain differences in delayed spontaneous alternations (SA), and eight-arm-maze performance (EAM). Intact male mice were tested for SA at age 41 days for two consecutive days, and for EAM at age 50-54 days, under conditions of water deprivation that commenced on day 43. The concept of EAM directional consistency (DC), proposed and defined here, was found highly related to EAM performance, and a better predictor of SA than EAM performance. Faceted smallest space analysis (FSSA), which provides a broad, simultaneous, perspective on the various maze behaviors observed (SA, EAM, DC), indicates that DC is both more closely related to SA and a more coherent concept than performance. The findings suggest that DC is a more elementary behavior, possibly related to different etiology than that of performance. Whilst in some studies EAM performance is viewed as spatial, here DC of mice suggest that, in fact, the animals are learning a set of rules. The results confirmed the superiority of the outbred HS over the inbred CBA, C57 and BALB, with SABRA occupying an intermediate position, and indicate that the medium performance strains rely on DC more than the others.

Restricted expression of p55 interleukin 2 receptor (CD25) on normal T cells.

Using a phycoerythrin-conjugated antibody to the p55 chain of the interleukin 2 receptor, normal blood lymphocytes were found to be on average 30% positive for this marker. Two-thirds of these cells are in the CD4 subset and most are within the CD45RA negative fraction associated with activated or memory T cells.

Achievement Motive: A Faceted Definition And Structural Analysis.

Facet technique is used to analyze contents of achievement motive questionnaire items proposed in recent years and to construct an explicit definition for achievement motive. The theoretical discussion provides the rationale for an hypothesis concerning the structure (i.e. classifications, ordering, dimensionality) of interrelationships among components of achievement motive. Using data from a sample of executive managers, the hypothesis is then tested by means of Guttman's Smallest Space Analysis and found to be correct.

A Smallest Space Analysis (Ssa) Of Potential Work Mobility.

This paper introduces a new methodological approach-smallest space analysis-to the examination of potential work mobility. Operational definition of such mobility is introduced in terms of amounts and kinds of organizational and occupational incentives which might be offered to an employee. Then empirical data on system analysts in Israel are used to test the structure of the definition. The potential mobility with respect to both organization and occupation is found to be structured essentially as expected.