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Biomedical subjects

A Tojo

Publications and source records attributed to A Tojo.

At least 19 recordsLinked to original sources
PubMed2003

Effective transduction and stable transgene expression in human blood cells by a third-generation lentiviral vector.

Difficulty in gene transduction of human blood cells, including hematopoietic stem cells, has hampered the development of gene therapy applications for hematological disorders, encouraging the development and use of new gene delivery systems. In this study, we used a third-generation self-inactivating (SIN) lentiviral vector system based on human immunodeficiency virus type 1 (HIV-1) to improve transduction efficiency and prevent vector-related toxicity. The transduction efficiency of the HIV-1-based vector was compared directly with the Moloney murine leukemia virus (MLV) SIN vector in human leukemia cell lines. Initial transduction efficiencies were almost 100% for the HIV and less than 50% for the MLV vectors. Similar results were observed in 11 types of primary cells obtained from leukemia or myeloma patients. Transgene expression persisted for 8 weeks in cells transduced with the HIV vector, but declined with the MLV vector. In addition, resting peripheral blood lymphocytes and CD34(+) hematopoietic cells were transduced successfully with the HIV vector, but not with the MLV vector. Finally, we confirmed vector gene integration in almost all colony-forming cells transduced with the HIV vector, but not with the MLV vector. In conclusion, this lentiviral vector is an excellent gene transduction system for human blood cells because of its high gene transduction and host chromosome integration efficiency.

Cells, Cultured↗
PubMed2003

Primary amyloidosis with multiple pulmonary nodular lesions and IgA nephropathy-like renal involvement.

A 66-year-old woman demonstrated multiple nodular lesions in the lungs without symptoms, and laboratory tests and transbronchial lung biopsy (TBLB) had been negative for malignancy, tuberculosis and sarcoidosis 15 years ago. She developed proteinuria and hematuria 10 years later. Renal biopsy revealed focal segmental mesangial proliferation with predominant IgA deposition in the paramesangium, suggesting IgA nephropathy. However, electron-microscopic observation revealed 8-12 nm fibril deposits in the interstitium and few in the mesangium that were positively stained with amyloid P protein and negative for amyloid A protein. Re-evaluation of previous TBLB samples showed apple-green birefringence with Congo-red staining that was resistant to potassium permanganate reaction. Electron-microscopic observation with high magnification and immunostaining for amyloid components led to a diagnosis of AL amyloidosis in this patient with predominant mesangial IgA deposition and slowly progressive nodular lesions in the lungs.

Aged↗
PubMed2002

Acute disseminated encephalomyelitis (ADEM) after allogeneic bone marrow transplantation for acute myeloid leukemia.

Acute disseminated encephalomyelitis (ADEM) is a rare inflammatory demyelinating disease of the central nervous system. We describe here a patient who developed ADEM after allogeneic bone marrow transplantation (BMT). A 48-year-old woman with acute myeloid leukemia (M2) underwent allogeneic BMT from her HLA-identical sister. Cyclosporin for prophylaxis of acute graft-versus-host disease (GVHD) was discontinued from day 15 because of its toxicity. She was relatively well after the resolution of cytomegalovirus reactivation and chronic GVHD. Nine months after BMT, she suddenly developed diplopia, dysarthria, and gait disturbance. Computed tomography of the brain at that time revealed no abnormal findings. Leukemia recurrence was not revealed. The neurological symptoms were very mild without further deterioration. Her clinical course was carefully watched without therapy. Two weeks after onset, fluid attenuated inversion recovery magnetic resonance imaging (MRI) revealed multifocal abnormal high-signal intensity mainly in the white matter of the cerebrum as well as in the cerebellum and brainstem. Cerebrospinal fluid examination showed no abnormal findings. No laboratory findings suggested the presence of infectious agents. The typical MRI findings and an acute monophasic clinical course of this patient led to a diagnosis of ADEM. Twelve weeks after onset, the symptoms had almost resolved. Follow-up MRI showed a substantial improvement of the previous lesions without any new lesions. The symptoms had completely resolved 5 months after onset. This is a rare case of ADEM developing after allogeneic BMT.

Acute Disease↗
PubMed2002

Transient hematopoietic stem cell rescue using umbilical cord blood for a lethally irradiated nuclear accident victim.

We performed stem cell rescue and allogeneic skin transplantation on a lethally neutron-irradiated nuclear accident victim. HLA-DRB1 mismatched unrelated umbilical cord blood cells (2.08 x 10(7)/kg recipient body weight) were transplanted to an 8-10 Gy equivalent neutron-irradiated patient because of a lack of a suitable bone marrow or peripheral blood donor. Pre-transplant conditioning consisted of anti-thymocyte gamma-globulin alone, and GVHD prophylaxis was a combination of cyclosporine (CYA) and methylprednisolone (mPSL). Granulocyte colony-stimulating factor (G-CSF), erythropoietin (EPO), and thrombopoietin (TPO) were concurrently administered after transplantation. The absolute neutrophil count reached 0.5 x 10(9)/l on day 15, the reticulocyte count rose above 1% on day 23, and the platelet count was over 50 x 10(9)/l on day 27, respectively. Cytogenetic studies of blood and marrow showed donor/recipient mixed chimerism. Rapid autologous hematopoietic recovery was recognized after withdrawal of CYA and mPSL. Repeated pathological examinations of the skin revealed no evidence of acute GVHD. Eighty-two days after the irradiation, skin transplantation was performed to treat radiation burns. Almost 90% of the transplanted skin engrafted. Immunological examination after autologous hematopoietic recovery revealed an almost normal T cell count. However, immune functions were severely impaired. The patient died from infectious complication 210 days after the accident.

Adult↗
PubMed2001

Characterization of ochratoxin A transport by human organic anion transporters.

The purpose of this study was to investigate the characteristics of ochratoxin A (OTA) transport by multispecific human organic anion transporters (hOAT1 and hOAT3, respectively) using the second segment of proximal tubule (S2) cells from mice stably expressing hOAT1 and hOAT3 (S2 hOAT1 and S2 hOAT3). S2 hOAT1 and S2 hOAT3 exhibited a time- and dose-dependent, and a saturable increase in uptake of [3H]-OTA, with apparent Km values of 0.42 microM (hOAT1) and 0.75 microM (hOAT3). These OTA uptakes were inhibited by several substrates for the OATs. Para-aminohippuric acid (PAH), probenecid, piroxicam, octanoate and citrinin inhibited [3H]-OTA uptake by hOAT1 and hOAT3 in a competitive manner (Ki = 4.29-3080 microM), with the following order of potency: probenecid > octanoate > PAH > piroxicam > citrinin for hOAT1; probenecid > piroxicam > octanoate> citrinin > PAH for hOAT3. These results indicate that hOAT1, as well as hOAT3, mediates a high-affinity transport of OTA on the basolateral side of the proximal tubule, but hOAT1- and hOAT3-mediated OTA transport are differently influenced by the substrates for the OATs. These pharmacological characteristics of hOAT1 and hOAT3 may be significantly related with the events in the development of OTA-induced nephrotoxicity in the human kidney.

Animals↗
PubMed2001

Severe autoimmune thrombocytopenia after allogeneic bone marrow transplantation for aplastic anemia.

Autoimmune thrombocytopenia (AITP) after bone marrow transplantation (BMT) was suggested to occur by immune dysregulation mainly in association with graft-versus-host disease (GVHD). Here we present a patient who developed severe AITP after BMT. A 40-year-old woman with severe aplastic anemia received a BMT from a partially HLA-matched brother. Despite myeloid and erythroid engraftments, platelet recovery was delayed. All bone marrow cells were 46,XY and were derived from the donor. Grade I acute GVHD involving skin developed from day 34 posttransplantation, but promptly responded to prednisolone in addition to a prophylactic dose of tacrolimus. With the tapering of prednisolone, thrombocytopenia progressed without substantial changes in the white blood cell count, hemoglobin concentration, or reticulocyte count. On day 188, the patient developed chronic GVHD involving skin and liver, which promptly responded to the readministration of prednisolone and increased tacrolimus. However, the patient's platelet count decreased to 9 x 10(9) cells/L on day 222. The platelet-associated immunoglobulin G (PAIgG) values were elevated. Bone marrow examination showed hypercellularity with plentiful megakaryocytes. The number of colony-forming units-megakaryocyte was within the normal range. The elevated PAIgG values and a correlation between thrombocytopenia and the intensity of the immunosuppressive agents strongly suggested a causative role of the autoimmune mechanisms for thrombocytopenia in this patient.

Adult↗
PubMed2001

Reduced albumin reabsorption in the proximal tubule of early-stage diabetic rats.

The aim of this study is to investigate the role of the proximal tubule in microalbuminuria in the early stage of diabetic nephropathy. Diabetes was induced in male Sprague-Dawley rats by an injection of streptozotocin (50 mg/kg, i.v.). After 2 weeks, albumin delivery in the proximal tubule was measured using micropuncture and the endocytosis process of FITC-labeled albumin was evaluated with immunoelectron microscopy. Albumin was significantly reabsorbed in the proximal convoluted tubule (PCT) of controls (0.39+/-0.05 ng/min at early PCT to 0.17+/-0.08 at late PCT, P<0.05), whereas albumin reabsorption was inhibited in diabetic rats (0.27+/-0.05 to 0.21+/-0.08). Immunogold study revealed that FITC-albumin was significantly less reabsorbed in endosomes and lysosomes of S1 segments in diabetic rats than in controls (endosome: 1.20+/-0.10 vs 2.16+/-0.15 microm-1, P<0.0001; lysosome: 0.26+/-0.03 vs 0.83+/-0.07, P<0.0001). The expression of megalin, an endocytosis receptor, was decreased at the apical membrane of PCT in diabetic rats. The lipid peroxidation production in the proximal tubule was significantly increased in diabetic rats. In conclusion, albuminuria in early-stage diabetic rats can be partly explained by a decreased albumin endocytosis with reduced megalin expression and with increased lipid peroxidation in the proximal tubule.

Albumins↗
PubMed2001

Haematopoietic progenitor cells from the common marmoset as targets of gene transduction by retroviral and adenoviral vectors.

To establish a new non-human primate model for human cytokine and gene therapy, we characterized lymphocytes and haematopoietic progenitor cells of the small New World monkey, the common marmoset. We first assessed the reactions of marmoset bone marrow (BM) and peripheral blood (PB) cells to mouse anti-human monoclonal antibodies (mAbs) for the purpose of isolating marmoset lymphocytes and haematopoietic progenitor cells. Both cell fractions stained with CD4 and CD8 mAbs were identified as lymphocytes by cell proliferation assay and morphological examination. Myeloid-specific mAbs such as CD14 and CD33 did not react with marmoset BM and PB cells. No available CD34 and c-kit mAbs could be used to purify the marmoset haematopoietic progenitor cells. Furthermore, we studied the in vitro transduction of the bacterial beta-galactosidase (LacZ) gene into CFU-GM derived from marmoset BM using retroviral and adenoviral vectors. The transduction efficiency was increased by using a mixed culture system consisting of marmoset BM stromal cells and retroviral producer cells. It was also possible to transduce LacZ gene into marmoset haematopoietic progenitor cells with adenoviral vectors as well as retroviral vectors. The percentage of adenovirally transduced LacZ-positive clusters was 15% at day 4 (multiplicity of infection=200), but only 1-2% at day 14. The differential use of viral vector systems is to be recommended in targeting different diseases. Our results suggested that marmoset BM progenitor cells were available to examine the transduction efficiency of various viral vectors in vitro.

Adenoviridae↗
PubMed2001

Unrelated cord blood transplantation for adult patients with myelodysplastic syndrome-related secondary acute myeloid leukaemia.

Seven adult patients with myelodysplastic syndrome (MDS)-related secondary acute myeloid leukaemia (AML) were treated with total body irradiation (TBI), cytosine arabinoside (Ara-C) and cyclophosphamide (CY), followed by unrelated human leucocyte antigen (HLA)-mismatched cord blood transplantation (CBT). Granulocyte colony-stimulating factor (G-CSF) was infused continuously from 12 h before until the end of Ara-C therapy to enhance the antileukaemia effect of Ara-C. Five patients are alive and free of disease at 7-31 months after transplantation. These preliminary results suggest that adult MDS-related secondary AML patients without suitable related or unrelated bone marrow donors should be considered as candidates for CBT.

Acute Disease↗
PubMed2001

Tissue-specific induction of E-selectin in glomeruli is augmented following diabetes mellitus.

We recently demonstrated that induction of adhesion molecules is tissue, cell type, and blood vessel size specific. We examined here whether the glomeruli, a peculiar vascular system, express adhesion molecules in a specific manner in the murine kidney. In addition, since serum levels of soluble adhesion molecules have been reported to be elevated in diabetic patients, we examined the influence of diabetes mellitus on the induction of adhesion molecules in the kidney. Analysis of E-selectin mRNA expression by in situ hybridization indicated that it was selectively induced in glomeruli by intravenous administration of interleukin-1beta, while ICAM-1 mRNA expression was seen diffusely in endothelium lining the small arteries and capillaries or in glomeruli, and VCAM-1 mRNA expression was most prominent in endothelial cells of larger blood vessels. Induction of E-selectin mRNA expression in glomeruli by proinflammatory stimuli was augmented in streptozotocin-induced diabetic mice as compared with control mice, while ICAM-1 or VCAM-1 mRNA induction was only slightly influenced. Furthermore, immunohistochemical analysis showed that selective expression of E-selectin in glomeruli was augmented predominantly in epithelial cells, depending on the duration of diabetes mellitus, in KK-Ay mice. These findings suggest that glomerulus-specific expression of E-selectin is related to the development of diabetic nephropathy.

Animals↗
PubMed2001

Distribution of stanniocalcin 1 in rat kidney and its regulation by vitamin D3.

Stanniocalcin is a glycoprotein hormone first described in fish as a hypocalcemic factor, and recently its mammalian counterpart has been identified. Localization of stanniocalcin 1 and its regulation of expression were determined in control and 1alpha,25-dihydroxyvitamin D3-treated rats. Immunoreactivity for stanniocalcin 1 was detected in the loop of Henle, macula densa cells, distal convoluted tubule (DCT), and cortical collecting duct (CCD), and also faintly in the medullary collecting ducts. Pre-embedding electron-microscopic immunocytochemistry revealed stanniocalcin 1 in the apical membrane of cells of loop of Henle, DCT, and principal cells of CCD. The expression of stanniocalcin 1 was increased by elevated plasma calcium via 1alpha,25-dihydroxyvitamin D3 treatment. In conclusion, stanniocalcin 1 was expressed in the apical membrane of distal nephron segments and enhanced by vitamin D3.

Animals↗
PubMed2001

Tubulointerstitial nephritis associated with acute intermittent porphyria.

Progressive renal impairment associated with acute intermittent porphyria is not well recognized and the mechanism of renal damage remains unclear. We report a case of a 51-year-old female with acute intermittent porphyria and long-term follow-up who developed proteinuria and renal insufficiency. Her biopsy showed marked tubulointerstitial damage with mitochondrial abnormalities. Urinary excretion of lipid peroxidation was increased compared to healthy controls. The porphyrin precursors may increase lipid peroxidation products and damage mitochondria leading to tubulointerstitial nephritis.

Acute Disease↗
PubMed2001

[Interferon-alpha therapy].

Interferon-alpha (IFN alpha) with or without Ara-C is a choice of therapy for patients with CML who cannot receive allogeneic stem cell transplantation and gives those better prognosis than a conventional chemotherapy, although it has a variety of adverse effects. Especially, in a certain population(about 20%) of CML patients, IFN alpha can induce complete cytogenetic response in spite of persistant minimal residual disease. The basis of IFN alpha activity against CML is still unknown, but the contribution of immune-mediated mechanism is expected.

Antimetabolites, Antineoplastic↗
PubMed2000

Hyperfunction of neutrophils in a patient with BCR/ABL negative chronic myeloid leukemia: a case report with in vitro studies.

BACKGROUND: Among patients diagnosed with chronic myeloid leukemia (CML), a small percentage lack a BCR/ABL fusion gene, a landmark of CML. Their clinical features are distinct from patients with BCR/ABL positive CML, although to the authors' knowledge the pathogenesis to date has been unknown. METHODS: A 50-year-old female patient with BCR/ABL negative CML and multiple complications of Graves disease, Sweet syndrome, and a fatal pulmonary alveolar proteinosis (PAP) is described in the current study. To show a clonal origin of her myeloid cells, hypoxanthine phosphoribosyltransferase (HPRT) assay was applied. Because the patient developed a progressive and fatal neutrophilia, a screening of cell functions in neutrophilic lineage, including in vitro colony assay of her bone marrow cells and production of superoxide and interleukin-8 (IL-8) by blood neutrophils was performed. RESULTS: Southern blot analysis based on the polymorphism of the HPRT gene was compatible with monoclonality of her neutrophils. The patient had an increased amount of bone marrow granulocyte-macrophage progenitor cells, which formed colonies in response to a very low dose (0.1 ng/mL) of granulocyte-colony stimulating factor. In vitro production of superoxide and IL-8, which is an inducer of positive chemotaxis of neutrophils, by her peripheral neutrophils was markedly augmented. Her bronchoalveolar lavage fluid also contained a significant amount of IL-8 as well as an unusual infiltration of neutrophils. CONCLUSIONS: In the patient in the current study, hyperfunction of the neutrophils might have contributed to the onset of PAP as well as Sweet syndrome and to the pathogenesis of BCR/ABL negative CML.

Bone Marrow↗
PubMed2000

Identification of a melanoma antigen, PRAME, as a BCR/ABL-inducible gene.

In order to elucidate molecular events in BCR/ABL-induced transformation, we adopted a polymerase chain reaction (PCR)-based technique of differential display and compared mRNA expression in human factor-dependent cells, TF-1, with that in factor-independent cells, ID-1, which were established from TF-1 cells by transfection of BCR/ABL. Cloning and sequencing of a gene which was upregulated in ID-1 cells revealed that the gene was identical to a melanoma antigen, PRAME. Our present study demonstrated that PRAME was markedly expressed in primary leukemic cells with chronic myeloid leukemia (CML) in blastic crisis and Philadelphia (Ph)+-acute lymphoblastic leukemia (ALL), in which BCR/ABL played an important role as a pathogenic gene. Moreover, comparison of PRAME expression among CD34+ cells with CML in blastic, accelerated, and chronic phases revealed a higher expression in CML in advanced phases. Thus PRAME was considered to be a good candidate for a marker of Ph+-leukemic blast cells as well as a new target antigen of leukemic blast cells that cytotoxic T cells can recognize.

Antigens, Neoplasm↗
PubMed2000

Biological activity of human granulocyte colony stimulating factor with a modified C-terminus.

Granulocyte colony-stimulating factor (G-CSF) undergoes receptor-mediated internalization into target cells which are normally restricted to neutrophilic granulocytes and their committed progenitor cells, suggesting that it may be applicable as a myeloid cell-targeting vehicle. To test this notion, we constructed a cDNA encoding a human G-CSF/murine stem cell factor (mSCF) chimeric molecule in a mammalian expression vector and transfected NIH3T3 cells with this plasmid. The resulting chimeric cytokine consisted of the entire G-CSF sequences fused to Lys148 of mSCF. It can be released from the surface membrane of NIH3T3 transformants through proteolytic cleavage at Ala164 of mSCF. The culture media conditioned by a number of stable transformants, which were confirmed by an enzyme-linked immunosorbent assay (ELISA) to secrete an hG-CSF derivative, were examined for their ability to stimulate CFU-G-derived colony formation as well as the proliferation of G-CSF-dependent NFS-60 cells. The results indicated that this C-terminus modified version of hG-CSF is as potent as recombinant hG-CSF in both assays.

3T3 Cells↗