PMA and doxorubicin decrease viability, MTT activity and expression of CD10 marker on NALM-1 leukemic cells

PMA (10, 20 ng/ml) and doxorubicin (5-20 ng/ml) decreased the viability and MTT-activity of NALM-1 pre-B leukemic cells (3 days' treatment). Further, CD10 was downregulated, suggesting that PMA and doxorubicin induced differentiation of NALM-1 cells. However, PMA did not alter expression of B cell markers CD20 and of mIgM. In contrast to PMA, another differentiation agent ATRA did not alter CD10 expression on NALM-1 cells but affected viability after 6 days (5, 10 ng/ml). The data in this study are the first evidence that PMA and doxorubicin inhibited viability and MTT activity and induced partial differentiation, by decreasing CD10 on NALM-1 cells.

The relevance of multidrug resistance-associated P-glycoprotein expression in the treatment response of B-cell chronic lymphocytic leukemia

BACKGROUND AND OBJECTIVES

The aim of this study was to determine whether expression of P-glycoprotein (Pgp) is an intrinsic feature of B-lymphocytes in B-cell chronic lymphocytic leukemia (B-CLL) and how it correlates with hematologic indices and tumor load in the disease. Furthermore, the change of Pgp expression under cytotoxic treatment and its correlation to treatment outcome were studied.

DESIGN AND METHODS

In 42 B-CLL patients, of whom 13 were sequentially monitored, expression of extracellular (MRK-16) and intracellular (C-219) Pgp epitopes on peripheral blood lymphocytes was determined by flow cytometry analysis and quantified by ratio of the mean fluorescence (RMF) in flow cytometry analysis.

RESULTS

Median RMF values in B-CLL patients were higher than in age-matched controls. Pgp expression did not correlate with any of the hematologic features or clinical stage of the disease. Patients who received some type of cytoreductive treatment prior to the study had lower Pgp values for both measured epitopes (median RMF for C-219 and MRK-16 of 1.99 and 2.03 in comparison to those of non-treated patients: 3.11 and 2.88, respectively). In 13 patients monitored during treatment the decrease in RMF was noted after treatment with chlorambucil, with RMF values for both Pgp epitopes decreasing in responders. This was in contrast to unchanged or even increased RMF values in those patients who did not respond to therapy.

INTERPRETATION AND CONCLUSIONS

Our study confirms the importance of quantitative evaluation of Pgp expression by flow cytometry. At the clinical level, cross-sectional, single test evaluation of Pgp is of limited value whereas sequential follow-up values correlate with treatment response.

[Multiple drug resistance]

The multidrug-resistance (MDR) phenotype expressed in mammalian cell lines is complex. A cell selected with a single agent can acquire cross-resistance to a remarkably wide range of compounds which have no structural or functional similarities. The basis for cross-resistance seems to be a decreased net cellular accumulation of the drugs involved, and has been attributed to alterations in plasma membrane. An over-expressed plasma membrane P glycoprotein of relative molecular mass of 170 kD (Pgp) is consistently found in different MDR human and animal cell lines, and in transplantable tumors. Consequently, it has been postulated that Pgp directly or indirectly mediates MDR. This paper reviews the current knowledge on etiology, pathogenesis, diagnosis and therapy of MDR.

Multiple changes of immunologic parameters in prisoners of war. Assessments after release from a camp in Manjaca, Bosnia

OBJECTIVE

To assess immune reactivity in men just released from a war prisoner camp.

PARTICIPANTS

Random sample of 29 men from a group of 764 liberated detainees in war prisoner camp in Bosnia, 15 matched healthy control subjects, and pre-war historical control subjects.

MAIN OUTCOME MEASURES

Report on immune reactivity parameters, such as lymphocyte immunophenotypes, natural killer cell and phagocyte function, serum cytokines, and hormones.

RESULTS

Compared with control subjects, detainees had significantly lowered red blood cell count, hemoglobin mass concentration, hematocrit, total serum proteins, and albumin level, while the percentage and count of monocytes and non-segmented neutrophils were increased. Flow cytometry revealed a significant increase in percentage of activated lymphocytes, activated T lymphocytes, Tc/s lymphocytes, B lymphocytes, and total HLA-DR lymphocytes. The absolute counts of activated lymphocytes and activated T lymphocytes were also significantly increased. The percentages of naive Th/i lymphocytes and the ratio of CD4:CD8 lymphocytes were decreased. The in vitro natural killer cell cytotoxic activity and phagocytic functions of ingestion and digestion were significantly depressed. Serum interferon, serum cortisol, and prolactin were also significantly lowered. Serum tumor necrosis factor was increased.

CONCLUSIONS

Alterations in the main parameters of the immune system and depression of important immune effector functions may have resulted from the psychological stress, physical deprivation, and malnutrition experienced by these war camp prisoners during their detainment.

Flow cytometric analysis of lymphocytic subsets in haemorrhagic fever with renal syndrome virus infection

Percentage counts of T-lymphocytes (helper and suppressor subpopulation) and B-lymphocytes were performed in the peripheral blood of two confirmed cases of HFRS infection using Coulter Clone monoclonal antibodies and Becton Dickinson flow cytometry. The individual values were compared with those from healthy subjects. HFRS patients had lower total T-cell (CD2) and T-helper (CD4 subset) counts. This seems linked with the role of the CD4 determinant as viral receptor. The measuring of specific lymphocyte helper and suppressor subpopulations might be useful in predicting the course of the disease and in following the effects of therapy.