Antiapoptotic function of 17AA(+)WT1 (Wilms' tumor gene) isoforms on the intrinsic apoptosis pathway.

The WT1 gene is overexpressed in human primary leukemia and a wide variety of solid cancers. The WT1 gene is alternatively spliced at two sites, yielding four isoforms: 17AA(+)KTS(+), 17AA(+)KTS(-), 17AA(-)KTS(+), and 17AA(-)KTS(-). Here, we showed that 17AA(+)WT1-specific siRNA induced apoptosis in three WT1-expressing leukemia cell lines (K562, HL-60, and Kasumi-1), but not in WT1-non-expressing lymphoma cell line (Daudi). 17AA(+)WT1-specific siRNA activated caspase-3 and -9 in the intrinsic apoptosis pathway but not caspase-8 in the extrinsic one. On the other hand, 17AA(-)WT1-specific siRNA did not induce apoptosis in the three WT1-expressing cell lines. The apoptosis was associated with activation of proapoptotic Bax, which was activated upstream of the mitochondria. Constitutive expression of 17AA(+)WT1 isoforms inhibited apoptosis of K562 leukemia cells induced by apoptosis-inducing agents, etoposide and doxorubicin, through the protection of mitochondrial membrane damages, and DNA-binding zinc-finger region of 17AA(+)WT1 isoform was essential for the antiapoptotic functions. We further studied the gene(s) whose expression was altered by the expression of 17AA(+)WT1 isoforms and showed that the expression of proapoptotic Bak was decreased by the expression of 17AA(+)KTS(-)WT1 isoform. Taken together, these results indicated that 17AA(+)WT1 isoforms played antiapoptotic roles at some points upstream of the mitochondria in the intrinsic apoptosis pathway.

Deficiency in WT1-targeting microRNA-125a leads to myeloid malignancies and urogenital abnormalities.

The Wilms' tumor gene WT1 is overexpressed in leukemia and solid tumors and has an oncogenic role in leukemogenesis and tumorigenesis. However, precise regulatory mechanisms of WT1 overexpression remain undetermined. In the present study, microRNA-125a (miR-125a) was identified as a miRNA that suppressed WT1 expression via binding to the WT1-3'UTR. MiR-125a knockout mice overexpressed WT1, developed myeloproliferative disorder (MPD) characterized by expansion of myeloid cells in bone marrow (BM), spleen and peripheral blood, and displayed urogenital abnormalities. Silencing of WT1 expression in hematopoietic stem/progenitor cells of miR-125a knockout MPD mice by short-hairpin RNA inhibited myeloid colony formation in vitro. Furthermore, the incidence and severity of MPD were lower in miR-125a (-/-) mice than in miR-125a (+/-) mice, indicating the operation of compensatory mechanisms for the complete loss of miR-125a. To elucidate the compensatory mechanisms, miRNA array was performed. MiR-486 was occasionally induced in compete loss of miR-125a and inhibited WT1 expression instead of miR-125a, resulting in the cancellation of MPD occurrence. These results showed for the first time the post-transcriptional regulatory mechanisms of WT1 by both miR-125a and miR-486 and should contribute to the elucidation of mechanisms of normal hematopoiesis and kidney development.

The size of erythrocyte ghosts.

The volume of resealed erythrocyte ghosts formed during hypotonic hemolysis of normal human erythrocytes was measured by means of a continuous mean corpuscular volume analyzer. The final volume of resealed ghosts was 140.6 +/- 15.2 fl. Strong correlations exist between the volume of ghosts and the initial mean corpuscular volume and mean corpuscular hemoglobin of the erythrocyte, and between the enlargement ratio and the mean corpuscular volume or mean corpuscular hemoglobin of the erythrocyte.

Leucocyte myosin and its location in the cell.

The intracellular location of the binding site of antibody against purified myosin prepared from equine leucocytes was investigated in neutrophils and lymphocytes by electron microscopy using peroxidase-labelled antibody method. The myosin extracted from equine leucocytes could bind skeletal muscle F-actin and the formed complex showed the biophysical and biochemical properties and electron microscopic appearance of actomyosin. On immunodiffusion, the leucocyte myosin formed a single precipitin line with its antibody prepared in rabbits. The antibody also formed single precipitin lines with myosins from lymphocytes and thrombocytes, fusing with each other. The antibody against the leucocyte myosin did not react with myosins from skeletal or arterial smooth muscle. The specificity of the antibody was further established by determination of K+-EDTA-activated ATPase activity remained in the supernate of antigen-antibody mixture. Under electron microscope, the intracellular immunoreactive products of peroxidase labelled antibody were found in cytoplasm of neutrophils and lymphocytes incubated with antibody against leucocyte myosin, but not in neutrophils or lymphocytes treated with IgG from normal rabbits.

Human galactocerebrosidase gene: promoter analysis of the 5'-flanking region and structural organization.

Galactocerebrosidase (GALC; EC 3.2.1.46) is a lysosomal enzyme which hydrolyzes several galactolipids and the deficiency of GALC is responsible for Krabbe disease. Recently, we cloned cDNAs for human and murine GALC. In this study we characterized the genomic organization and the promoter of the human gene. The gene was about 60 kb in length and consisted of 17 exons as reported by Luzi et al. DNA sequence analysis showed that the 5'-flanking region of the first exon was GC-rich and had not typical TATA-box but ten GC-box-like sequences within a 200 bp sequence upstream from the initiation codon. Another inframe ATG, which has better Kozak consensus sequence, was found at 48 bp upstream to the first ATG reported]. Promoter analysis using a luciferase assay in COS 7 cells showed that the -149 to -112 nucleotide (from the initiation codon A) region has dominant promoter activity. In this region three GC-box-like sequence and one YY1 binding site were detected. Primer extension revealed several transcription start sites within the region of -146 to -103 nucleotide. In this study we firstly demonstrated that the YY1 binding site and subsequent GC-box-like sequences could be a promoter in a housekeeping gene.

Thrombopoietin inhibits in vitro osteoclastogenesis from murine bone marrow cells.

To determine whether thrombopoietin (TPO) can modulate the osteoclastic differentiation from hematopoietic stem cells, we investigated the effect of TPO on in vitro osteoclastogenesis by using the coculture of murine bone marrow cells with the stromal cell line (ST2) in the presence of 1alpha,25-dihydroxyvitamin D3 and dexamethasone. Recombinant human TPO inhibited the formation of tartrate-resistant acid phosphatase-positive multinucleated cells in a dose-dependent manner (0.02-200 ng/ml). The effect of TPO on differentiation of bone-resorbing capacity was investigated by pit assay. TPO dose dependently decreased the areas oftoluidine blue-stained resorption pits (2.0-200 ng/ml). To identify the cellular target of TPO, we used a variety of bone marrow/stromal cell coculture methods. Initially, we found that TPO mainly exerted its effect on the early stage of osteoclastic differentiation in delayed addition experiments. Consequently, the majority of TPO's inhibition of osteoclastic cell formation was due to its effect on bone marrow cells. Finally, we examined whether transforming growth factor-beta (TGFbeta) and platelet-derived growth factor (PDGF), major cytokines produced by megakaryocytes, mediate the inhibitory effect of TPO. The addition of either anti-TGFbeta or anti-PDGF antibody to bone marrow cell culture completely antagonized the effect of TPO on osteoclastogenesis. Furthermore, treatment of bone marrow cells with TGFbeta or PDGF mimicked the inhibitory effect of TPO. These data suggest that TPO inhibits osteoclastogenesis through stimulating thrombopoiesis and that TGFbeta and PDGF mediate the effect of TPO by impacting on macrophage-lineage cells as osteoclast precursors.

Nitric oxide production by cultured rat Leydig cells.

Nitric oxide (NO) has emerged as an intracellular and intercellular messenger in a number of biological systems. In the present study, we demonstrated that NO was produced by cultured rat Leydig cells, and that inducible nitric oxide synthase (iNOS) messenger RNA (mRNA) was expressed in Leydig cells. NO was measured as nitrite with the method of Griess. Although unstimulated Leydig cells produce little NO, interleukin-1 beta (IL-1 beta) markedly increased NO production. NO production was inhibited by the NOS inhibitor, NG-monomethyl-L-arginine. Northern blot analysis showed that iNOS mRNA was little expressed in freshly isolated immature Leydig cells, but that iNOS mRNA levels were increased by the addition of IL-1 beta in a dose-dependent manner at the concentration up to 10 ng/ml. The levels of iNOS mRNA were increased as early as 3 h after the addition of IL-1 beta and persisted for up to 24 h. In adult Leydig cells, IL-1 beta stimulated iNOS mRNA expression. Immunocytochemical analysis demonstrated iNOS-like immunoreactivity in the cytoplasm of Leydig cells. These results indicate that NO is produced in Leydig cells and suggest that NO might be involved in the physiological function of Leydig cells.

Down-modulation of c-kit mRNA and protein expression by erythroid differentiation factor/activin A.

We examined the effects of erythroid differentiation factor (EDF)/activin A on the expression of c-kit mRNA and protein in murine erythroleukemia (MEL) cells. EDF/activin A induced MEL cells to benzidine positive cells. Northern blot analysis showed that the c-kit mRNA expression was reduced synchronously with increase of beta-globin and uroporphyrinogen decarboxylase gene expression during EDF/activin A induced erythroid differentiation. Scatchard analysis indicated that the cell surface receptor number was reduced without change of affinity during differentiation. Our results suggest that EDF/activin A may act as a natural regulator of erythropoiesis with modulation of c-kit gene expression.

Nitric oxide production of rat Leydig and Sertoli cells is stimulated by round spermatid factor(s).

In this study, we provide evidence of cell-to-cell interaction between rat germ cells and Leydig or Sertoli cells in relation to nitric oxide (NO) production and inducible nitric oxide synthase (iNOS) messenger RNA (mRNA) expression. As a result of being cultured in a round spermatid-conditioned medium (RSd-CM), NO production in both Leydig and Sertoli cells increased in proportion to the length of the culture period. iNOS mRNA expression in both types of cells also increased in a dose-dependent manner as a result of being cultured with RSd-CM. This increase was detected as early as 3 h and was maintained up to 24 h. In contrast, neither NO production nor iNOS mRNA increased in either type of cell following culture in a pachytene spermatocyte-conditioned medium (PS-CM). Our findings suggest that RSd may control NO production of Leydig and Sertoli cells. This cell-to-cell interaction may be an important mechanism of regulation of testicular function.

Electrocardiogram is very useful for predicting acute heart failure following myeloablative chemotherapy with hematopoietic stem cell transplantation rescue.

A prospective study was conducted in 71 evaluable patients who received myeloablative hematopoietic stem cell transplantation (HSCT) at our facility from 1995 to 2002, to find a sensitive marker for post-transplant heart failure, including echocardiographic systolic and diastolic markers and QTc interval. QTc was found to be an independent and significant risk factor for acute heart failure (AHF) on multivariate logistic regression analysis (OR 1.5, P=0.01, 95% confidence interval (CI) 1.1-2.0), while no significant differences between patients with AHF and those without AHF were found in age, sex, treatment history, type of conditioning regimen, and echocardiographic systolic and diastolic markers. On further analysis, post-transplant risk of AHF appeared to be increased as QTc was prolonged. The post-transplant risk of AHF in the group with longest QTc on multivariate logistic regression analysis was found to be 9.8 times that in the group with shortest QTc (P=0.04, 95% CI 1.0-100). These results suggest that echocardiographic markers are less valuable predictors of post-transplant AHF, but that prolongation of the QTc, an ECG marker, before HSCT is strongly associated with onset of AHF after HSCT.

Reticulocytes in human preserved blood as control material for automated reticulocyte counters.

The authors studied the changes in the percentage of reticulocytes in blood preserved for three weeks. The samples were obtained from healthy adults and stored at 4 degrees C. An automated reticulocyte counter was used for measurements. After one week, the relative percentage of reticulocytes had decreased to around 80% of the initial value, and it reached 60% after three weeks of storage. When the y-axis of plots of the change against time was converted to a log scale, negative correlation was strong (r = -0.9972), and the curve was useful for estimation of the reticulocyte count in preserved blood. Stored blood might be used as a control material for reticulocyte counting by automated methods.

Counting and differential of bone marrow cells by an electronic method.

The authors studied the cell count and size distribution curves of nucleated cells in bone marrow aspirate, using a fully automatic blood cell counter, and compared the results with those of the traditional manual method. The cell count by the electronic method correlated well with that by the manual method when the cell concentration was 100 X 10(9)/L or less. The size distribution curve had two peaks. The small cell fraction found electronically correlated well with the lymphocyte and erythroblast fractions found manually on Giemsa-stained smears. The method was highly reproducible, and technical problems did not arise, so the authors think it can be used in routine clinical testing.

Leukemic blasts detected by the Technicon H-1 blood cell counter.

The authors studied the usefulness of the flagging system of the Technicon H-1 Cell Counter using samples from 45 patients with acute leukemia, 24 with acute lymphoblastic leukemia (ALL), and 21 with acute nonlymphoblastic leukemia (ANLL). Results by the automated method were compared with those by the eye-count method. Four out of 24 specimens were falsely negative; no false positive results were found. For ANLL specimens, there were no false positives or negatives. When 1% or more of the cells were blasts by the eye-count method, the automated system almost always flagged the sample. The results suggested that the flagging system programmed in the H-1 is useful for the diagnosis and follow-up of leukemia.

An automated optoelectronic reticulocyte counter.

Microscopic reticulocyte counting is time consuming and imprecise. A new reticulocyte counter has been developed, and the authors evaluated its utility for laboratory use. The counter, R-1000 of Sysmex-TOA Medical Electronics Company, Kobe, Japan, is based on the principles of flow cytometry. Reticulocytes are detected as fluorescent cells stained with a basic dye, auramine O, under argon-laser light. The automated count had high correlation to the manual count (r = 0.941). Linearity and reproducibility were both high. About 60 specimens were tested in one hour. Not only the reticulocyte percentage and count but also the maturity of reticulocytes was found from the intensity of the fluorescence, whether high, moderate, or slight. Normal reference values were 0.007 +/- 0.0055 (0.70 +/- 0.55%) for the reticulocytes, (4.63 +/- 1.09) X 10(9)/L for the reticulocyte count, 2.3 +/- 1.9% for highly fluorescent cells, 18.7 +/- 5.1% for moderately fluorescent cells, and 78.8 +/- 6.6% for cells with slight fluorescence. In patients with suppressed bone marrow function, such as is caused by chemotherapy, the reticulocyte fraction and count were low, and cells with slight fluorescence increased. In patients in whom bone marrow function was stimulated, such as with hemolytic anemia, the reticulocyte percentage, reticulocyte count, and highly fluorescent cells were high. Patients with chronic renal failure being treated by hemodialysis had a similar reticulocyte pattern to that in hemolytic anemia except that the reticulocyte count was decreased. Results for elderly patients were not different from those of healthy young controls. Some patients with a normal reticulocyte count and percentage had numerous highly fluorescent cells, perhaps because of hemolytic anemia not yet identified. Automated reticulocyte counting provides reliable data, so such measurement should be useful for analysis of the kinetics of red blood cells and for the study of the pathogenesis of anemia.

Restructuring of international council for standardization in haematology (ICSH) in Asia.

Standardization and harmonization in Laboratory testing are a key issue in the midst of globalization era, because most of laboratory testing has been currently achieved with various kinds of automated systems. In the developed countries, automated systems with highly-regulated principles are commonly used in the routine laboratory. However, there are so many undeveloped and developing countries in Asia that diversity of testing levels can be observed in the area. Some laboratories use glass chamber method for blood cell counting, while other laboratory use semi-automated or fully automated analyzers for complete blood count. International standardization on Hematology is focused on the developed system but not for the developing system. Established standardized documents therefore whould not be unsuitable for Asian societies. In the context, International Council for Standardization in Hematology (ICSH) changed its rules to adjust our Asian Societies and ICSH started to restructure the body. International ICSH society is divided into 5 region sub-groups. Asian area is able to possess one new sub-society, ICSH-Asia. Its reconstruction work has been just started with Asain colleagues, and we are now extending the new societies to discuss Asian problems on the quality of hematology testing.

Treatment with cytosine arabinoside and granulocyte colony-stimulating factor in patients with myelodysplastic syndrome and its leukemic phase.

Twenty-one patients with myelodysplastic syndrome (MDS) or overt leukemia resulting from MDS were treated with recombinant human granulocyte colony-stimulating factor (rhG-CSF) and cytosine arabinoside (Ara-C). Ara-C was administered in a dose of 20 mg/m2 every 12 h for 5 days and after 2 days 125 micrograms of rhG-CSF was administered for 10 days. After recovery of the leukocyte count the therapy was repeated, doubling the dose of Ara-C serially when possible. Of 13 patients with MDS, four achieved complete remission (CR), two good response (GR), two minor response (MR), and five no response (NR). Of eight patients with overt leukemia from MDS, only one with hyperplastic bone marrow achieved a partial response (PR) and the remaining seven achieved NR. The efficacy of the combination of rhG-CSF and Ara-C in the treatment of MDS and its leukemic phase is discussed, including at which time rhG-CSF should be administered: before, after or concomitantly with Ara-C. Multicenter randomized studies are needed in the evaluation of this combination therapy.

Successful treatment of pustulosis palmaris et plantaris with granulocyte colony stimulating factor in a patient with hereditary neutropenia.

A 26-year-old female with hereditary neutropenia had Pustulosis Palmaris et Plantaris. Drug administration did not improve her symptoms. Following administration of granulocyte colony stimulating factor (G-CSF; filgrastim), her neutrophil count increased from 300 to 58,000/microliters, and her dermatosis improved. Pustulosis Palmaris et Plantaris has been described as a representative second lesion of focal infection. Neutropenia may be one cause of Pustulosis Palmaris et Plantaris due to refractory focal infection. In the present case, increase in neutrophils with G-CSF may have improved focal infection, resulting in improvement in refractory Pustulosis Palmaris et Plantaris.

Guidelines for organisation and management of external quality assessment using proficiency testing. Expert Panel on Cytometry of the International Council for Standardization in Haematology.

This document is intended to assist towards the WHO objective that external quality assessment (EQA) schemes be established at national and/or regional levels world-wide. Quality assurance is defined as all steps taken by the director of a laboratory to ensure reliability of laboratory results and to increase accuracy, reproducibility and between-laboratory comparability. This includes the use of internal quality control procedures and participation in external quality assessment. Internal quality control provides the means for evaluation of analytic test results at the time of testing in order to decide whether they are reliable enough to be released to the requesting clinicians. EQA, on the other hand, refers to a system of retrospective and objective comparison of results from different laboratories by means of proficiency testing (PT) organised by an external agency. The main purpose is to establish between-laboratory and between-method (including between-instrument) comparability, and agreement with a reference standard where one exists. Internal quality control and EQA complement each other and must never be considered as alternatives.

A comparative study of administration methods of granisetron injection used to treat nausea/vomiting induced by cancer chemotherapy without cisplatin in tumors of hematopoietic organs. Keihanshin Study Group of Hematological Malignancies.

PURPOSE: The antiemetic effect of granisetron injection at a dose of 40 microg/kg used in the treatment of nausea/vomiting induced by multidrug combined cancer chemotherapy excluding cisplatin in patients with tumors of hematopoietic organs was evaluated by comparing a 30-min infusion and a slow intravenous injection given over 30 s. METHODS: A two-group random-allocation comparative study was performed with the cooperation of multiple institutions using a central registration system. RESULTS: In the treatment of acute clinical symptoms, appetite was described as "similar to that during good health" by 61.1% of patients (55/93) in the instillation group and by 47.3% (44/93) in the slow injection group, a significant advantage in the infusion group. However, no significant differences in the number of episodes of vomiting, the severity of nausea or clinical efficacy were found. In the final clinical evaluation and assessment of usefulness based on the subjective judgement of physicians throughout the entire therapeutic period, no differences were discernible. No side effects were reported for either method and there was no indication of a sex difference concerning efficacy. However, the efficacy in patients with an anemic tendency was slightly inferior. CONCLUSIONS: The maintenance of appetite during the administration of anticancer drugs is very important to maintain patients' daily activities and quality of life. The present results support the usefulness of infusion of granisetron as an administration method during chemotherapy for malignant hemopathy.

Leptin receptor and leukemia.

The receptor for leptin, the gene product of the obese gene, is expressed in hematopoietic stem cells. Leptin stimulates normal myeloid and erythroid development, and is secreted from bone marrow adipocytes, which occupy most of the marrow cavity in humans. Leptin might thus play an important role in the control of the expansion and differentiation of primitive hematopoietic cells through paracrine interaction in the bone marrow microenvironment. Leukemic cells of some patients with acute myeloblastic leukemia, acute lymphoblastic leukemia, and chronic myeloid leukemia (CML) also express the leptin receptor. In cases of CML, higher expression of leptin receptor is observed during blast crisis than in chronic phase. Leptin alone and in combination with other cytokines has stimulative effects on proliferation of leukemia cells as well as anti-apoptotic effects. These findings suggest the possibility that leptin plays roles in the pathophysiology of leukemia.