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N Kamada

Publications and source records attributed to N Kamada.

At least 73 records · Page 4Linked to original sources
PubMed1999

Myeloid differentiation antigen and cytokine receptor expression on acute myelocytic leukaemia cells with t(16;21)(p11;q22): frequent expression of CD56 and interleukin-2 receptor alpha chain.

We report the cellular characteristics of cells from three patients with de novo acute myelocytic leukaemia (AML) with t(16;21)(p11;q22), two M4 and one M5a according to the FAB classification, and two permanent cell lines with t(16;21)(p11;q22), TSU1621MT and YNH-1. The FUS/ERG fusion mRNA was demonstrated in all cases by reverse transcriptase-polymerase chain reaction (RT-PCR). The immunophenotypes of the AML cells, and YNH-1 and TSU1621MT cell lines with t(16;21) were characterized as CD34+CD33+CD13+CD11b+CD18+CD56+ HLA-DR-/+. Cells from all samples strongly expressed c-kit, granulocyte colony-stimulating factor receptor (G-CSFR), c-fms (macrophage colony-stimulating factor receptor), interleukin-3 receptor alpha chain (IL-3Ralpha), and granulocyte macrophage colony-stimulating factor receptor alpha chain (GM-CSFRalpha), and these data corresponded well to the growth responsiveness to the cytokines. IL-2Ralpha expression was also found in all t(16;21) samples, but IL-2 did not act on the proliferation of the leukaemic cells in in vitro cultures. G-CSF distinctly promoted the proliferation of leukaemic cells of t(16;21) AML, but did not enhance the expression of MPO and neutrophil differentiation of these cells. Our findings indicate that AML cells with t(16;21) preserve stem cell properties such as CD34 and c-kit expression, and suggest that they have the potential to differentiate into a monocytic lineage. The relationship between the unique cellular characteristics (especially CD56 and IL-2Ralpha expression) and FUS/ERG protein remains undetermined.

Adolescent↗
PubMed1999

Protein expression of cell cycle regulator, p27Kip1, correlates with histopathological grade of non-Hodgkin's lymphoma.

The protein p27Kip1 is one of the cyclin-dependent kinase inhibitors that are known to play important roles in the regulation of cell-cycle progression. Low levels of p27 expression in malignant cells are associated with poor prognosis in patients with breast, lung, colorectal and gastric cancers. To determine the relation of cyclin-dependent kinase inhibitors to histopathological grades of B-cell non-Hodgkin's lymphomas, the expression of p27, cyclin D1 and cyclin E in lymph node tissues was investigated in 56 patients with B-cell non-Hodgkin's lymphomas by western blotting and immunohistochemical techniques. High levels of p27 expression were observed in most lymph node tissue samples (93%) obtained from patients with low grade B-cell non-Hodgkin's lymphomas, while expression was low in lymph node tissue taken from all patients with intermediate and high grade B-cell non-Hodgkin's lymphomas. The difference in p27 expression in lymphoma tissues was significant among the different histopathological grades of B-cell non-Hodgkin's lymphomas (P<0.01). The analysis of the survival time of patients showed that the reduction of p27 expression correlated with poor prognosis. Cyclin D1, showed a high level of expression in mantle cell lymphomas and high grade B-cell non-Hodgkin's lymphomas. Cyclin E showed limited expression in 18 of 31 lymphoma tissues. Both cyclin D1 and E protein expression were not significantly different among the grades of B-cell non-Hodgkin's lymphomas. These results demonstrate that the level of p27 expression in lymphoma tissue is an important parameter in the classification of B-cell non-Hodgkin's lymphomas and in the prediction of prognosis.

Blotting, Western↗
PubMed1999

Chromosomal instability in acute myelocytic leukemia and myelodysplastic syndrome patients among atomic bomb survivors.

To clarify the mechanism of leukemogenesis in atomic bomb survivors, leukemic cells were investigated using fluorescence in situ hybridization (FISH) analysis on the basis of conventional G-banding in patients with a history of radiation exposure and also in de novo patients. Conventional G-banding showed higher incidences (p < 0.005) of structural and numerical abnormalities without any specific types of chromosome aberrations in the group exposed to a dose of more than one Gy, compared to the non-exposed group. FISH analysis revealed significantly higher incidences (P < 0.05) of subclones with monosomy 7 and deletion of the 20q13.2 region, which were not found in conventional cytogenetic analysis in the exposed group (more than one Gy) compared to the non-exposed controls. Furthermore, segmental jumping translocation (SJT) of the c-MYC gene region was observed only in the exposed group. These chromosomal instability suggested that the leukemic cells from the heavily exposed patients contained persistent cellular genetic instability which may strongly influence the development of leukemia in people exposed to radiation.

Adult↗
PubMed1999

High incidence of meningioma among Hiroshima atomic bomb survivors.

Since the atomic bomb explosions in Hiroshima and Nagasaki, high incidences of leukemia, thyroid cancer and other tumors have been reported as atomic bomb-induced tumors. We investigated the incidence of meningioma among Hiroshima atomic bomb survivors. Sixty-eight patients surgically treated for meningioma who had been within 2.0 km of the hypocenter of the explosion were identified. Six hundred and seven non-exposed patients with meningioma were also studied. Treatment dates were from 1975 to 1992. The incidences of meningioma among 68 subjects within 2.0 km and 607 non-exposed patients were 8.7 and 3.0 cases per 10(5) persons per year, respectively. The incidences of meningioma among the survivors of Hiroshima in 5-year intervals since 1975 were 5.3, 7.4, 10.1, and 14.9, respectively. The incidences of meningioma classified by distances from the hypocenter of 1.5-2.0 km, 1.0-1.5 km and less than 1.0 km were 6.3, 7.6 and 20.0, respectively. The incidences of meningioma classified by doses to the brain of 0-0.099 Sv, 0.1-0.99 Sv and more than 1.0 Sv were 7.7, 9.2 and 18.2, respectively. The incidence of meningioma among Hiroshima atomic bomb survivors has increased since 1975. There was a significant correlation between the incidence and the dose of radiation to the brain. The present findings strongly suggest that meningioma is one of the tumors induced by atomic bombing in Hiroshima.

Brain↗
PubMed1999

Biological dosimetry of atomic bomb survivors exposed within 500 meters from the hypocenter and the health consequences.

Seventy-eight atomic bomb survivors were examined for biological dosimetry using chromosome abnormality. They had been exposed within 500 meters from the hypocenter in heavily shielded conditions and were found from NHK-RIRBM joint study carried out from 1966 to 1971. Estimation of the exposure doses for these survivors was made under the following steps; 1) calculation by DS86 system (physically estimated doses) in survivors who had been exposed within 1,500 meters and had precise records of exposure conditions. RBE for the neutron was defined as 10. 2) setting of exposure dose-chromosome aberration curve, and 3) observation of chromosome aberrations in the proximally exposed survivors, for whom biological doses were estimated. Estimation of the exposure doses were possible from the aberration rate of chromosome in the peripheral lymphocytes, even 25-40 years after the exposure. Of the 78 survivors, 96% were estimated to have exposed more than one Sv. Detection of transforming gene(s) of N and K RAS genes in DNAs from non-leukemic survivors was carried out as one of the biological investigations for these heavily exposed survivors. All four survivors examined showed N or K RAS gene mutation. Three of the four healthy survivors had cancer or leukemia 7-10 years after the examination. Further continuous follow-up study of these heavily exposed people will give us more information on the late effects of A-bomb radiation, which may arise in the future.

Animals↗
PubMed1999

Neutron energy-dependent initial DNA damage and chromosomal exchange.

This study was undertaken to investigate the biological effect of monoenergetic neutrons on human lymphocyte DNA and chromosomes. Monoenergetic neutrons of 2.3, 1.0, 0.79, 0.57, 0.37 and 0.186 MeV were generated, and 252Cf neutrons and 60Co gamma-rays were also used for comparison. Biological effect was evaluated two ways. The RBE values with the comet assay were estimated as 6.3 and 5.4 at 0.37 MeV and 0.57 MeV relative to that of 60Co gamma-rays, and chromosome aberration rates were also observed in these different levels of monoenergetic neutrons. The yield of chromosome aberrations per unit dose was high at lower neutron energies with a gradual decline with 0.186 MeV neutron energy. The RBE was increased to 10.7 at 0.57 MeV from 3.9 at 252Cf neutrons and reached 16.4 as the highest RBE at 0.37 MeV, but the value decreased to 11.2 at 0.186 MeV. The response patterns of initial DNA damage and chromosome exchange were quite similar to that of LET. These results show that the intensity of DNA damage and chromosomal exchange is LET dependent. RBE of low energy neutrons is higher than that of fission neutrons. Low energy neutrons containing Hiroshima atomic bomb radiation may have created a significantly higher incidence of biological effect in atomic bomb survivors.

Animals↗
PubMed1999

Molecular analysis of the Corynebacterium glutamicum transketolase gene.

Transketolase is important in production of the aromatic amino acids in Corynebacterium glutamicum. The complete nucleotide sequence of the C. glutamicum transketolase gene has been identified. The DNA-derived protein sequence is highly similar to the transketolase of Mycobacterium tuberculosis, taxonomically related to C. glutamicum. The alignment of the N-terminus regions between both transketolases showed TTG to be the most probable start codon. Potential ribosomal binding and promoter regions were situated upstream from the TTG. The deduced amino acid sequence consists of 700 residues with a calculated molecular mass of 75 kDa, and contains all amino acid residues involved in cofactor and substrate binding in the well-characterized yeast transketolase sequence.

Amino Acid Sequence↗
PubMed1999

Growth inhibition of myeloid leukemia cells by troglitazone, a ligand for peroxisome proliferator activated receptor gamma, and retinoids.

Peroxisome proliferator activated receptor gamma (PPARgamma) plays a central role in the process of adipocyte differentiation. This receptor and its heterodimeric partner, retinoid X receptor alpha (RXRalpha), form a DNA-binding complex that regulates transcription of adipocyte-specific genes. Troglitazone, an antidiabetic drug, has recently been identified as a synthetic ligand for PPARgamma. We studied the effects of troglitazone on proliferation and differentiation of normal and malignant hematopoietic cells. Expression of PPARgamma was easily detectable by Western blot analyses in all five myeloid leukemia cell lines. Troglitazone alone (10-5 M) did not induce differentiation in any of the cell lines; however, this compound suppressed the clonal growth (10-75% of inhibition) of all five myeloid leukemia cell lines. Myelomonocytic U937 cells, which were the most responsive to the growth suppressing effects of troglitazone, were arrested in the G1 phase of the cell cycle when cultured with this compound. Simultaneous treatment of myeloid leukemia cell lines with both troglitazone and a ligand that specifically binds either RXR (LG100268), or retinoic acid receptors (RAR, ATRA, ALART1550), or both (9-cis RA) resulted in additive suppression of clonal growth. In summary, our studies showed that troglitazone when combined with a retinoid was a moderately potent inhibitor of clonogenic growth of acute myeloid leukemia cells.

Alitretinoin↗
PubMed1999

Induction of apoptosis in CD34+ cells by sera from patients with aplastic anemia.

To investigate the pathogenesis of aplastic anemia (AA), the apoptosis of CD34+ cells was assayed with annexin V-fluorescein 24 hr and 48 hr after incubation with the serum of normal controls (n = 10), patients with non severe AA (NSAA, n = 13) and severe AA (SAA, n = 10). The CD34+ progenitors from the bone marrow of normal donors contained a significantly greater proportion of apoptotic cells after incubation with serum from SAA patients than that incubated with serum from normal controls and NSAA. Moreover, the percent apoptosis of CD34+ cells after 24 hr incubation with serum from NSAA was slightly higher than that of normal controls. This appears to be related to clinical severity. No significant difference was found in the percent apoptosis of CD34+ cells between incubation for 24 hr and 48 hr with the same serum. To further explore the mechanism of increased apoptosis induced by the serum of AA patients, the expression of the Fas receptor was measured after incubation with serum from the normal controls and AA patients using flow cytometry. After incubation with serum from the AA patients, the Fas receptor was overexpressed, correlating with the increased apoptosis induced by the same serum from AA patients. In addition, the induction of apoptosis and Fas expression on CD34+ cells by serum from the SAA patients was blocked partly by preincubation of the serum with anti-gamma-IFN neutralizing MoAb. These findings suggested that some aberrant components of the serum in the AA patients, which was confirmed partly to be gamma-IFN, can induce CD34+ progenitors apoptosis through the Fas signaling pathway. This may contribute to understanding the decreased number of stem cells characteristic of aplastic anemia.

Adolescent↗
PubMed1999

Instability of chromosome 7 in colony forming cells of patients with aplastic anemia.

Monosomy 7 in isolated bone marrow mononuclear cells and colony forming cells from patients with aplastic anemia who later developed myelodysplastic syndrome/leukemia with monosomy 7 were examined by fluorescence in situ hybridization. Colonies derived from bone marrow mononuclear cells of the aplastic anemia patients consisted of a mixture of cells of normal karyotype and monosomy 7, ranging from 0 to 97.2%. This result suggests that colony forming cells initially had a normal karyotype but then lost chromosome 7 during growth in the semisolid culture. This finding suggests the genetically unstable condition of chromosome 7 in colony forming cells in aplastic anemia patients. This chromosome instability of colony forming cells may lead to malignant transformation.

Anemia, Aplastic↗
PubMed1998

19-nor vitamin-D analogs: a new class of potent inhibitors of proliferation and inducers of differentiation of human myeloid leukemia cell lines.

We have studied the in vitro biological activities and mechanisms of action of 1,25-dihydroxyvitamin D3 (1,25D3) and nine potent 1,25D3 analogs on proliferation and differentiation of myeloid leukemia cell lines (HL-60, retinoic acid-resistant HL-60 [RA-res HL-60], NB4 and Kasumi-1). The common novel structural motiff for almost all the analogs included removal of C-19 (19-nor); each also had unsaturation of the side chain. All the compounds were potent; for example, the concentration of analogs producing a 50% clonal inhibition (ED50) ranged between 1 x 10(-9) to 4 x 10(-11) mol/L when using the HL-60 cell line. The most active compound [1, 25(OH)2-16,23E-diene-26-trifluoro-19-nor-cholecalciferol (Ro 25-9716)] had an ED50 of 4 x 10(-11) mol/L; in contrast, the 1,25D3 produced an ED50 of 10(-9) mol/L with the HL-60 target cells. Ro 25-9716 (10(-9) mol/L, 3 days) was a strong inducer of myeloid differentiation because it caused 92% of the HL-60 cells to express CD11b and 75% of these cells to reduce nitroblue tetrazolium (NBT). This compound (10(-8) mol/L, 4 days) also caused HL-60 cells to arrest in the G1 phase of the cell cycle (88% cells in G1 v 48% of the untreated control cells). The p27(kip-1), a cyclin-dependent kinase inhibitor which is important in blocking the cell cycle, was induced more quickly and potently by Ro 25-9716 (10(-7) mol/L, 0 to 5 days) than by 1,25D3, suggesting a possible mechanism by which these analogs inhibit proliferation of leukemic growth. The NB4 promyelocytic leukemia cells cultured with the Ro 25-9716 were also inhibited in their clonal proliferation (ED50, 5 x 10(-11) mol/L) and their expression of CD11b was enhanced (80% positive [10(-9) mol/L, 4 days] v 27% untreated NB4 cells). Moreover, the combination of Ro 25-9716 (10(-9) mol/L) and all-trans retinoic acid (ATRA, 10(-7) mol/L) induced 92% of the NB4 cells to reduce NBT, whereas only 26% of the cells became NBT positive after a similar exposure to the combination of 1,25D3 and ATRA. Surprisingly, Ro 25-9716 also inhibited the clonal growth of poorly differentiated leukemia cell lines (RA-res HL-60 [ED50, 4 x 10(-9) mol/L] and Kasumi-1 [ED50, 5 x 10(-10) mol/L]). For HL-60 cells, Ro 25-9716 markedly decreased the percent of the cells in S phase of the cell cycle and increased the expression of the cyclin-dependent kinase inhibitor, p27(kip-1). In summary, 19-nor vitamin D3 compounds strongly induced differentiation and inhibited clonal proliferation of various myeloid leukemia cell lines, suggesting a therapeutic niche for their use in myeloid leukemia.

Cell Cycle↗
PubMed1998

Mechanisms of growth control of Kaposi's sarcoma-associated herpes virus-associated primary effusion lymphoma cells.

Primary effusion lymphoma (PEL) is a distinct clinicopathologic entity associated with Kaposi's sarcoma-associated herpes virus (KSHV). Several cytokines, including interleukin-6 (IL-6), basic fibroblast growth factor (bFGF), and platelet-derived growth factor (PDGF) may be important for survival of KS cells. However, little is known about the interaction of cytokines with KSHV-infected lymphocytes from PEL. Therefore, we investigated what cytokines were produced by KSHV-infected PEL cell lines (KS-1, BC-1, BC-2), what cytokine receptors were expressed by these cells, what response these cells had to selected cytokines, and what was the effect of IL-6 antisense phosphorothioated oligonucleotides. Reverse transcriptase-polymerase chain reaction (RT-PCR) and protein studies showed that these three cell lines produced IL-10, IL-6, and the receptors for IL-6. The granulocyte macrophage colony-stimulating factor (GM-CSF), IL-1beta, IL-8, IL-12, bFGF, PDGF, and c-kit transcripts were not detected in the cell lines. High levels (0.7 to 5 ng/mL/10(6) cells/48 hours) of IL-6 protein were consistently detected in supernatants of the cell lines by enzyme-linked immunosorbent assay (ELISA) tests. In clonogenic assays, interferon-alpha (IFN-alpha) and IFN-gamma suppressed the clonal growth of the PEL cells, but GM-CSF, IL-4, IL-6, IL-8, IL-10, and oncostatin M did not change it. We examined for several autocrine loops that have been suggested to occur in KS. Experiments using antisense oligonucleotides showed that the clonal growth of KS-1 and BC-1 was nearly 100% inhibited by IL-6 antisense oligonucleotides (10 micromol/L), but not at all by either oligonucleotides (</=10 micromol/L) to IL-6 sense, IL-6 scrambled, viral IL-6 (vIL-6) antisense, or IL-10 antisense. Furthermore, the IL-6 antisense oligonucleotides had no effect on two B-cell lymphoma cell lines, which were not infected with KSHV. Addition of IL-6 antibody did not inhibit clonal growth of any of the cell lines. Taken together, we have defined the cytokines and their receptors expressed on PEL cells and have found that these cells synthesized IL-6 and IL-6 receptors; interruption of this pathway by IL-6 antisense oligonucleotides specifically prevented the growth of these cells. These findings will offer potential new therapeutic strategies for PEL.

Cell Division↗
PubMed1998

Technical details for safer venous and biliary anastomoses for liver transplantation in the rat.

Although orthotopic liver transplantation in the rat is a well-established experimental model, no detailed illustrated description of the procedure is available in the literature. As a result, achieving success in the technique without prolonged learning time requires training in specialized centers where the step-by-step details essential to success in the technique can be learnt. The aim of this paper is to provide beginners with the culminative experience of 15 years of improvements made to Kamada's original model, clearly illustrating the necessary steps and fine detail of each anastomosis to help beginners avoid unnecessary complications. We hope that this complete description of orthotopic liver transplantation in the rat, which remains the most difficult rodent transplant model to master, will greatly help microsurgeons acquire this demanding procedure.

Anastomosis, Surgical↗
PubMed1998

New technique of complete thymectomy in adult rats without tracheal intubation.

Adult rat thymectomy is frequently performed as part of the protocol for experiments in transplant immunology. Current methods used are either imprecise (suction methods) or require tracheal intubation (surgical technique) and are thus difficult to master. We have developed a safe technique of surgical removal of the thymus with resolution of any pneumothorax by suction through the xyphoid insertions of the diaphragm. This method is easy to learn and gives a 95% success rate.

Animals↗
PubMed1998

Timing of lymphocyte transfusion and portal clamping for the development of lethal graft-versus-host disease in the rat.

The effects of surgical intervention on the incidence and augmentation of graft-versus-host disease (GVHD) were studied in the rat. To elicit GVHD, splenocytes from parental LEW rats at a dose of 4 x 10(8) or 1.5 x 10(8) cells/350g body weight were injected via the tail vein into (LEW x BN)F1 rats. The injection of 4 x 10(8) of LEW rat splenocytes induced lethal GVHD in all nontreated F1 rats, while 1.5 x 10(8) of LEW splenocytes did not induce any signs of GVHD. However, when the F1 rats had received the same dose of parental LEW lymphocytes in combination with portal clamping, 14 recipients out of the 15 rats (93%) suffered GVHD and 10 rats (67%) died from GVHD. Interestingly, portal clamping 7 days after the injection enhanced the incidence of GVHD, whereas no GVHD was observed in the intervention group either 3 or 7 days prior to the cell transfusion. When 1.5 x 10(8) of allogeneic lymphocytes were injected intravenously together with 0.1-1.0 mg/kg of endotoxin instead of portal clamping, the injection led the early death by GVHD, while the injection of methylpredonisolone did not enhance GVHD. These results thus indicate that either simultaneous or delayed surgical intervention has the potential to trigger a dormant state in transferred alloreactive lymphocytes.

Animals↗
PubMed1998

The differential induction of two immediate early genes, c-fos and c-jun, after systemic hypovolemic shock/resuscitation in the rat liver and kidney.

The aim of this study was to investigate the expression of the immediate early genes (IEGs), c-fos and c-jun, in the rat kidney and liver in two types of hemorrhage shock/resuscitation models. In the first group, hemorrhagic shock was induced by the withdrawal of blood through the carotid artery. A mean arterial blood pressure (MAP) of 40mmHg was maintained for 1h before blood was reperfused. In the second group, the MAP was maintained at the same level for 2h. Animals were resuscitated with Ringer's lactate solution. In the first group, a rapid and transient induction of c-fos and c-jun mRNAs in both the liver and kidney was observed, peaking 0 to 2 h after reperfusion. In the second group, a more protracted pattern of induction was evident in both organs. In both models, the induction of c-fos mRNA was distinctly different in the liver and kidney. These results indicated, first, that with respect to IEG expression, organs respond differently to a systemic shock/resuscitation stimuli, and second, that alterations in the pattern of IEG expression might represent an indication of the degree of organ damage or the repair processes subsequent to hypotension/reperfusion.

Animals↗