Leukocyte Alkaline Phosphatase in Hematological Disorders

Leukocyte alkaline phosphatase activity was studied biochemically and histochemically in various blood diseases. 1) N-APA is preferable to LAPA as a unit of biochemical measurement. 2) The low content of leukocyte AP in CGL was confirmed. The determination of leukocyte AP is useful in the diagnosis and treatment of CGL. 3) The low N-APA in CGL rises to normal as a rule after successful treatment and this normalization is consistent with the double cell population theory in leukemic processes. 4) The high content of leukocyte AP in acute leukemia, aplastic anemia, leukemoid reaction, idiopathic eosinophilia, myelosclerosis and infection may be explained by the hypothesis that it represents increased neutropoiesis. 5) A close correlation was confirmed between biochemical and histochemical results, indicating that histochemical methods are reliable and suitable for adoption as a routine test

Six Cases of Leukemia Discovered at Mass Surveys of Nagasaki Atomic Bomb Survivors

1) Mass screening examinations were conducted on atomic bomb survivors in Nagasaki from 1954 to 1957. We found six cases of leukemia . 2) Five cases out of these six were chronic granulocytic leukemia and one was acute myeloblastic leukemia. 3) Three cases out of five chronic granulocytic leukemia are considered to have been in an early stage of this disease. Each of these cases showed leukocytosis, increase of basophils and a small number of immature cells in the peripheral blood. Decreased leueocyte alkaline phospatase and increased leukocyte catalase activity and increased basophils are important findings to be emphasized

Studies on Recovery from Radiation Injury.

Lethally irradiated adult CF#1 mice received intraperitoneal implants of two sliced spleens taken from adult CF#1 mice at various intervals after lethal irradiation with the spleen-shielding procedure. The following results were obtained : the survival of mice implanted with shielded spleens removed three hours, one, ten and fourteen days after irradiation was enhanced significantly, whereas, the survival of mice implanted with spleens removed four and seven days after irradiation failed to increase survival rate

Distamycin A Inhibits HMGA1-Binding to the P-Selectin Promoter and Attenuates Lung and Liver Inflammation during Murine Endotoxemia

Background: The architectural transcription factor High Mobility Group-A1 (HMGA1) binds to the minor groove of AT-rich DNA and forms transcription factor complexes (“enhanceosomes”) that upregulate expression of select genes within the inflammatory cascade during critical illness syndromes such as acute lung injury (ALI). AT-rich regions of DNA surround transcription factor binding sites in genes critical for the inflammatory response. Minor groove binding drugs (MGBs), such as Distamycin A (Dist A), interfere with AT-rich region DNA binding in a sequence and conformation-specific manner, and HMGA1 is one of the few transcription factors whose binding is inhibited by MGBs. Objectives: To determine whether MGBs exert beneficial effects during endotoxemia through attenuating tissue inflammation via interfering with HMGA1-DNA binding and modulating expression of adhesion molecules. Methodology/Principal Findings: Administration of Dist A significantly decreased lung and liver inflammation during murine endotoxemia. In intravital microscopy studies, Dist A attenuated neutrophil-endothelial interactions in vivo following an inflammatory stimulus. Endotoxin induction of P-selectin expression in lung and liver tissue and promoter activity in endothelial cells was significantly reduced by Dist A, while E-selectin induction was not significantly affected. Moreover, Dist A disrupted formation of an inducible complex containing NF-κB that binds an AT-rich region of the P-selectin promoter. Transfection studies demonstrated a critical role for HMGA1 in facilitating cytokine and NF-κB induction of P-selectin promoter activity, and Dist A inhibited binding of HMGA1 to this AT-rich region of the P-selectin promoter in vivo. Conclusions/Significance: We describe a novel targeted approach in modulating lung and liver inflammation in vivo during murine endotoxemia through decreasing binding of HMGA1 to a distinct AT-rich region of the P-selectin promoter. These studies highlight the ability of MGBs to function as molecular tools for dissecting transcriptional mechanisms in vivo and suggest alternative treatment approaches for critical illness

Two mechanisms of the enhanced antibody-dependent cellular cytotoxicity (ADCC) efficacy of non-fucosylated therapeutic antibodies in human blood

<p>Abstract</p> <p>Background</p> <p>Antibody-dependent cellular cytotoxicity (ADCC) has recently been identified as one of the critical mechanisms underlying the clinical efficacy of therapeutic antibodies, especially anticancer antibodies. Therapeutic antibodies fully lacking the core fucose of the Fc oligosaccharides have been found to exhibit much higher ADCC in humans than their fucosylated counterparts. However, data which show how fully non-fucosylated antibodies achieve such a high ADCC in human whole blood have not yet been disclosed. The precise mechanisms responsible for the high ADCC mediated by fully non-fucosylated therapeutic antibodies, even in the presence of human plasma, should be explained based on direct evidence of non-fucosylated antibody action in human blood.</p> <p>Methods</p> <p>Using a human <it>ex vivo </it>B-cell depletion assay with non-fucosylated and fucosylated anti-CD20 IgG1s rituximab, we monitored the binding of the therapeutic agents both to antigens on target cells (target side interaction) and to leukocyte receptors (FcγR) on effector cells (effector side interaction), comparing the intensities of ADCC in human blood.</p> <p>Results</p> <p>In the target side interaction, down-modulation of CD20 on B cells mediated by anti-CD20 was not observed. Simple competition for binding to the antigens on target B cells between fucosylated and non-fucosylated anti-CD20s was detected in human blood to cause inhibition of the enhanced ADCC of non-fucosylated anti-CD20 by fucosylated anti-CD20. In the effector side interaction, non-fucosylated anti-CD20 showed sufficiently high FcγRIIIa binding activity to overcome competition from plasma IgG for binding to FcγRIIIa on natural killer (NK) cells, whereas the binding of fucosylated anti-CD20 to FcγRIIIa was almost abolished in the presence of human plasma and failed to recruit NK cells effectively. The core fucosylation levels of individual serum IgG1 from healthy donors was found to be so slightly different that it did not affect the inhibitory effect on the ADCC of fucosylated anti-CD20.</p> <p>Conclusion</p> <p>Our results demonstrate that removal of fucosylated antibody ingredients from antibody therapeutics elicits high ADCC in human blood by two mechanisms: namely, by evading the inhibitory effects both of plasma IgG on FcγRIIIa binding (effector side interaction) and of fucosylated antibodies on antigen binding (target side interaction).</p