Publications by authors named "Masahiro Tokunaga"

Article Synopsis
  • Ahed is a newly identified gene in haematopoiesis that plays a crucial role in blood cell development, discovered through screening mutant embryonic stem cells.
  • Conditional knockout of Ahed leads to severe anemia and prenatal death, as its absence hampers the ability of haematopoietic cells to regenerate in living organisms.
  • Deletion of Ahed disrupts multiple biological pathways in adult mice and is linked to mutations found in cancer patients, highlighting its importance in both normal blood development and potential involvement in cancers.
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Article Synopsis
  • - The study focuses on a rare case of a 74-year-old woman diagnosed with both multiple myeloma (MM) and colon cancer, highlighting the limited discussion on treatment outcomes for such patients.
  • - The patient underwent palliative surgery due to widespread peritoneal dissemination of the cancer and continued treatment with lenalidomide for MM instead of systemic chemotherapy.
  • - Remarkably, the patient survived for over 36 months without any signs of tumor progression, suggesting that lenalidomide may have some benefits in managing concurrent malignancies.
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A 34-year-old man with no medical history presented with fever 4 days after receiving the first dose of mRNA-1273 coronavirus disease 2019 (COVID-19) vaccine. He had no prior clinical evidence of severe acute respiratory syndrome coronavirus 2 infection and was negative for serial polymerase chain reaction testing. Ten days after vaccination, he was referred to our hospital because of no response to antibiotics and the emergence of neutropenia, thrombocytopenia, and liver dysfunction.

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A 71-year-old man with stage IIB (Union for International Cancer Control, 8 edition) non-small cell lung cancer underwent intensity-modulated radiation therapy with a dose of 66 Gy administered in 33 fractions concomitant with carboplatin and paclitaxel therapy. On computed tomography after completion of radiation therapy, ground-glass opacity, which was larger on the contralateral side, was observed, but it was not observed in the high-dose area on the ipsilateral side. Although the adverse event theoretically shows dose dependency, it was finally diagnosed as radiation pneumonitis.

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A 23-year-old woman was admitted to our hospital because of rapidly developing lower abdominal pain. Computed tomography revealed ascites, splenomegaly, and a huge mass that occupied the pouch of Douglas and surrounded her uterus. A markedly elevated white blood cell count of 495×10/l and the identification of the BCR-ABL1 fusion gene led to the diagnosis of chronic myeloid leukemia (CML).

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A 68-year-old female was diagnosed with follicular lymphoma (FL) grade 2, based on the excisional biopsy of her enlarged left cervical lymph node. Positron-emission tomography/computed tomography (PET/CT) revealed the F-fluoro-deoxyglucose-avid lesions in the sigmoid colon and at the fundus of the gallbladder, besides those in the left neck. A sigmoid colon polyp, which was endoscopically resected, proved histologically to be a well- to moderately-differentiated tubular adenocarcinoma with deep invasion into the submucosa.

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A 76-year-old woman was referred to our hospital because of fever, hemorrhagic skin lesion with pruritus, and severe thrombocytopenia. Anemia; marked eosinophilia; and elevated ALP, CRP, and soluble IL-2 receptor levels were observed on admission. Both anti-nuclear antibody and Coombs tests were positive.

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Article Synopsis
  • Hematopoietic stem cells (HSCs) are diverse and can both self-renew and differentiate, but the factors keeping this diversity are not fully understood.
  • Research indicates that the protein SATB1 plays a crucial role in regulating this heterogeneity, as studies on mice with conditional knockout of Satb1 show its importance for adult HSC self-renewal and lymphocyte formation.
  • Experiments revealed that HSCs with high SATB1 levels tend to differentiate into lymphocytes, while those with lower levels follow a myeloid pathway, demonstrating that SATB1 influences the multipotency of HSCs and their varied functionalities.
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Adult-onset autoimmune neutropenia (AIN) is rarely self-limiting, unlike infant-onset AIN. Although several therapeutic agents have been reported, including corticosteroids, more effective treatment options may exist. Here, we describe neutrophil recovery by eltrombopag in a 52-year-old male AIN patient with immune thrombocytopenia (ITP) who was referred to our hospital with severe neutropenia.

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Haploid mouse embryonic stem cells (ESCs), in which a single hit mutation is sufficient to produce loss-of-function phenotypes, have provided a powerful tool for forward genetic screening. This strategy, however, can be hampered by undesired autodiploidization of haploid ESCs. To overcome this obstacle, we designed a new methodology that facilitates enrichment of homozygous mutant ESC clones arising from autodiploidization during haploid gene trap mutagenesis.

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Disseminated carcinomatosis of the bone marrow (DCBM) is diffusely invasive bone metastasis resulting from solid tumors. DCBM is often associated with disseminated intravascular coagulation (DIC) or hemolytic anemia. Generally, DCBM treatment includes cytotoxic chemotherapy for underlying solid tumors and management of hematological conditions if present.

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Malignant psoas syndrome is a rare malignant condition presenting as lumbosacral plexopathy and painful fixed flexion of the hip. Metastasis to the psoas muscle is observed, which damages the nerve bundles in the lumbosacral plexuses. The syndrome presents as refractory lower back pain with several other neurological symptoms.

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Proanthocyanidins, which are composed of oligomeric flavan-3-ol units, are contained in various foodstuffs (e.g., fruits, vegetables, and drinks) and are strongly biologically active compounds.

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Osteoporosis involves hyperactive osteoclasts. A large number of current drugs result in side effects affecting their efficacy in the clinic. Polyphosphoesters are unique polymeric biomaterials because of their biocompatibility, biodegradability, and bone affinity.

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A 6-field technique using lateral beams in conformal radiotherapy was developed for patients with bilateral supraclavicular lymph node metastasis of lung cancer. The possibility of using this technique in practice was evaluated. Six fields with the same isocenter point (IP) were arranged.

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Background: Genome-wide saturation mutagenesis and subsequent phenotype-driven screening has been central to a comprehensive understanding of complex biological processes in classical model organisms such as flies, nematodes, and plants. The degree of "saturation" (i.e.

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Purpose: Balloon-occluded retrograde transvenous obliteration (B-RTO) has shown great potential in controlling acute gastric variceal hemorrhage, although rebleeding related to the procedure may occur in a small percentage of patients. The purpose of this study was to identify risk factors of perioperative rebleeding and prognostic factors of postoperative survival in B-RTO performed for acute episodes of gastric variceal hemorrhage.

Methods: We retrospectively analyzed 39 consecutive patients who underwent B-RTO for gastric variceal rupture at our hospital between June 2003 and May 2011.

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Bloom syndrome, an autosomal recessive disorder of the BLM gene, confers predisposition to a broad spectrum of early-onset cancers in multiple tissue types. Loss of genomic integrity is a primary hallmark of such human malignancies, but many studies using disease-affected specimens are limited in that they are retrospective and devoid of an appropriate experimental control. To overcome this, we devised an experimental system to recapitulate the early molecular events in genetically engineered mouse embryonic stem cells, in which cells undergoing loss of heterozygosity (LOH) can be enriched after inducible down-regulation of Blm expression, with or without site-directed DNA double-strand break (DSB) induction.

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Sir2 has been shown to be essential for transcriptional silencing and longevity provided by calorie restriction in Saccharomyces cerevisiae and Caenorhabditis elegans. In this study, we investigated the role for its mammalian homologue, SIRT1, in hematopoietic cells. SIRT1 inhibitor, nicotinamide (NA), promoted and its activator, resveratrol, inhibited the differentiation of murine bone marrow c-Kit(high)Sca-1(+)Lineage(-) (KSL) cells during the culture system ex vivo.

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It would be of great value to predict the efficacy of tyrosine kinase inhibitors (TKIs) in the treatment of individual CML patients. We propose an immunoblot system for detecting the phosphorylation of Crkl, a major target of Bcr-Abl, in blood samples after in vitro incubation with TKIs. When the remaining phosphorylated Crkl after treatment with imatinib was evaluated as the "residual index (RI)", high values were found in accordance with imatinib resistance.

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Dendritic cells (DCs) play important roles in tumor immunology. Leukemic cells in patients with myeloid neoplasms can differentiate into DCs in vivo (referred to as in vivo leukemic DCs), which are postulated to affect anti-leukemia immune responses. We established a reproducible culture system of in vitro FLT3 ligand-mediated DC (FL-DC) differentiation from murine lineage(-) Sca-1(+) c-Kit(high) cells (LSKs), which made it possible to analyse the effects of target genes on steady-state DC differentiation from hematopoietic stem/progenitor cells.

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BCR-ABL is a causative tyrosine kinase (TK) of chronic myelogenous leukemia (CML). In CML patients, although myeloid cells are remarkably proliferating, erythroid cells are rather decreased and anemia is commonly observed. This phenotype is quite different from that observed in polycythemia vera (PV) caused by JAK2 V617F, whereas both oncogenic TKs activate common downstream molecules at the level of hematopoietic stem cells (HSCs).

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Synopsis of recent research by authors named "Masahiro Tokunaga"

  • - Masahiro Tokunaga's research primarily focuses on the role of specific genes in haematopoiesis and their implications in various hematological malignancies, as highlighted in his recent work identifying the gene Ahed and its essential function in murine blood cell development.
  • - His studies also encompass clinical cases that examine complex interactions of multiple malignancies, such as the treatment outcomes of patients with concomitant multiple myeloma and adenocarcinoma, showcasing a blend of laboratory and clinical investigation.
  • - Additionally, Tokunaga's contributions include insights into adverse effects of COVID-19 vaccinations related to hematological conditions and investigations into radiation-induced complications in lung cancer treatment, further underlining the multifaceted approach of his research in both basic and applied medical sciences.