Publications by authors named "Katoh F"

Diamond-Blackfan anemia (DBA) is a rare congenital disease caused by mutations in ribosomal protein genes and is characterized by pure red cell aplasia. While the prognosis is relatively favorable, quality of life (QOL) among DBA patients is negatively impacted by the adverse effects of long-term prednisolone (PSL) therapy and blood transfusions. We describe a 43-year-old man who was diagnosed with DBA (Hb of 2.

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X-linked lymphoproliferative syndrome (XLP) is a rare primary immunodeficiency characterized by increased vulnerability to Epstein-Barr virus infection. XLP type 1 is caused by mutations in SH2D1A, whereas X-linked inhibitor of apoptosis (XIAP) encoded by XIAP/BIRC4 is mutated in XLP type 2. In XIAP deficiency, hemophagocytic lymphohistiocytosis (HLH) occurs more frequently and recurrence is common.

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Purpose: The purpose of the study was to evaluate the clinical relationship between cervical spinal canal stenosis (CSCS) and incidence of traumatic cervical spinal cord injury (CSCI) without major fracture or dislocation, and to discuss the clinical management of traumatic CSCI.

Methods: Forty-seven patients with traumatic CSCI without major fracture or dislocation (30 out of 47 subjects; 63.83 %, had an injury at the C3-4 segment) and 607 healthy volunteers were measured the sagittal cerebrospinal fluid (CSF) column diameter at five pedicle and five intervertebral disc levels using T2-weighted midsagittal magnetic resonance imaging.

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Inhibitors of phosphodiesterase 4 (PDE4) are an important class of anti-inflammatory drug that act by inhibiting the production of proinflammatory cytokines, including tumor necrosis factor-alpha (TNF-alpha). We have synthesized and evaluated a series of 2-substituted phthalazinone derivatives as PDE4 inhibitors. Structure-activity relationship studies led to the identification of benzylamine-substituted phthalazinones as potent PDE4 inhibitors that also suppressed TNF-alpha production by whole rat blood cells.

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Cystic fibrosis transmembrane conductance regulator (CFTR) anion channels are the regulated exit pathway in Cl(-) secretion by teleost mitochondria rich salt secreting (MR) cells of the gill and opercular epithelia of euryhaline teleosts. By confocal light immunocytochemistry, immunogold transmission electron microscopy (TEM), and co-immunoprecipitation, using regular and phospho-antibodies directed against conserved sites, we found that killifish CFTR (kfCFTR) and the tyrosine kinase focal adhesion kinase (FAK) phosphorylated at Y407 (FAK pY407) are colocalized in the apical membrane and in subjacent membrane vesicles of MR cells. We showed previously that basolateral FAK pY407, unlike other FAK phosphorylation sites, is osmosensitive and dephosphorylates during hypotonic shock of epithelial cells (Marshall et al.

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The kidney is an organ playing an important role in ion regulation in both freshwater (FW) and seawater (SW) fish. The mechanisms of ion regulation in the fish kidney are less well studied than that of their gills, especially at the level of transporter proteins. We have found striking differences in the pattern of Na(+)/K(+)/2Cl(-) cotransporter (NKCC) expression between species.

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The shift of chloride cell distribution was investigated during early life stages of seawater-adapted killifish (Fundulus heteroclitus). Chloride cells were detected by immunocytochemistry with an an-tiserum specific for Na(+), K(+)-ATPase in whole-mount preparations and paraffin sections. Chloride cells first appeared in the yolk-sac membrane in the early embryonic stage, followed by their appearance in the body skin in the late embryonic stage.

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Focal adhesion kinase (FAK), also known as PYK2, is a tyrosine kinase that functions in integrin-mediated signaling in mechanosensitive cells but its role in osmosensing cells is unknown. Antibodies directed against phosphorylated FAK, whose epitopes are conserved among vertebrates, were used to follow phosphorylation patterns in an osmosensing ion secreting epithelium, the killifish (Fundulus heteroclitus) opercular membrane. At the electron microscopic level, a unique combination of integrin beta1, the phosphorylated form of FAK at tyrosine 407 (pY407) and Na(+), K(+), 2Cl(-) cotransporter (NKCC1) were all colocalized only on the basolateral membrane in chloride cells.

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Purpose: To evaluate the three-dimensional intrafraction motion of the breast during tangential breast irradiation using a real-time tracking radiotherapy (RT) system with a high-sampling frequency.

Methods And Materials: A total of 17 patients with breast cancer who had received breast conservation RT were included in this study. A 2.

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Article Synopsis
  • The estuarine fish Fundulus heteroclitus serves as a valuable model for studying interactions between individuals and their environment, due to extensive research on their adaptive responses to different conditions.
  • This body of work has significantly enhanced our knowledge in areas like physiology, gene regulation, toxicology, and genetics, not only for Fundulus but also for other vertebrates.
  • The current research is limited by a lack of genomic resources, and creating a more comprehensive genomics toolbox for these species could lead to major advances in understanding biological mechanisms and ecological strategies across vertebrates.
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Article Synopsis
  • A modified version of tamoxifen, known as tamoxifen hemicitrate hydrate, was developed and characterized using various analytical techniques like X-ray diffraction and thermal analysis.
  • The results indicated that the compound exists in a specific molar ratio (2:1:3 for tamoxifen:citric acid:water) and revealed the presence of multiple forms during heating, including sesquihydrate and hemihydrate.
  • Additionally, the stability tests showed that tamoxifen citrate can transform into tamoxifen hemicitrate hydrate in water within 24 hours, which suggests adjustments in the manufacturing process to account for this transformation.
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Background: In an attempt to develop effective and non-cytotoxic cancer chemopreventive derivatives of retinoids, a novel acyclic retinoid has previously been synthesized. This acyclic retinoid, NIK-333, had been reported to suppress recurrence of primary hepatocellular carcinomas. We explored the molecular mechanisms by which NIK-333 exerts anti-proliferative effects.

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Background: Connexins form the intercellular channels of the gap junction and play an integral part in a variety of biological functions, such as maintaining tissue homeostasis, cell growth control, and development. Previously it was demonstrated that the expression of connexin 26 (Cx26) can increase the metastatic potential of mouse melanoma cells. The objective of the study was to investigate the role Cx26 plays in the metastasis of human melanoma cells, focusing on the communication between melanoma cells and endothelial cells.

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In the skin of zebrafish embryo, the vacuolar H(+)-ATPase (V-ATPase, H(+) pump) distributed mainly in the apical membrane of H(+)-pump-rich cells, which pump internal acid out of the embryo and function similarly to acid-secreting intercalated cells in mammalian kidney. In addition to acid excretion, the electrogenic H(+) efflux via the H(+)-ATPases in the gill apical membrane of freshwater fish was proposed to act as a driving force for Na(+) entry through the apical Na(+) channels. However, convincing molecular physiological evidence in vivo for this model is still lacking.

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Article Synopsis
  • The study examined the photostability of tamoxifen citrate forms A and B using various analytical techniques, including HPLC and UV/vis spectroscopy.
  • Form A was found to be chemically unstable when exposed to light, showing more significant color changes compared to stable form B.
  • Form A absorbed UVA light at a longer wavelength than form B, leading to degradation and color changes likely due to its selective absorption of photoenergy.
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Despite all the efforts and technological advances during the last few decades, the cellular mechanisms for branchial chloride uptake in freshwater (FW) fish are still unclear. Although a tight 1 : 1 link with HCO-3 secretion has been established, not much is known about the identity of the ion-transporting proteins involved or the energizing steps that allow for the inward transport of Cl- against the concentration gradient. We propose a new model for Cl- uptake in FW fish whereby the combined action of an apical anion exchanger, cytoplasmic carbonic anhydrase, and basolateral V-type H+ -ATPase creates a local [HCO-3] high enough to energize Cl- uptake.

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To evaluate a possible involvement of prolactin (PRL) in low-salinity tolerance of a marine pufferfish Takifugu rubripes, or fugu, gene-expression profiles of PRL in the pituitary and PRL receptor (PRLR) in the osmoregulatory organs were investigated in fish exposed to 25%-dilute seawater (SW). Following transfer from full-strength (100%) SW to 25% SW, plasma osmolality and Na(+) and Cl(-) levels were slightly decreased on day 1, which were restored on days 3 and 7. Expression levels of PRL mRNA in the pituitary was significantly increased in response to 25% SW transfer, which was in sharp contrast with a remarkable decrease in growth hormone (GH) mRNA levels.

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Purpose: The purpose of this study was to establish a useful methodology, possibly providing information on the stoichiometry of pharmaceutical drug salts obtained from salt screening by using a multiwell plate and a Raman microscope.

Methods: Tamoxifen salt screening was conducted with monobasic and polybasic acids on 96-well quartz plates with a Raman microscope. Appearance and crystalline forms of salts prepared on 96-well plates were observed by polarizing light microscope and Raman microscope, respectively.

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We have previously shown that continuous intravenous infusion of NaHCO3 for 24 h ( approximately 1000 micromol kg(-1) h(-1)) results in the relocation of V-H+-ATPase from the cytoplasm to the basolateral membrane in the gills of the Pacific dogfish. To further investigate this putative base-secretive process we performed similar experiments with the addition of colchicine, an inhibitor of cytoskeleton-dependent cellular trafficking processes. Blood pH and plasma total CO2 were significantly higher in the colchicines-treated, HCO3- -infused fish compared with fish infused with HCO3- alone.

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The kidney plays an important role in ion regulation in both freshwater and seawater fish. However, ion transport mechanisms in the teleost kidney are poorly understood, especially at the molecular level. We have cloned a kidney-specific SLC26 sulfate/anion exchanger from rainbow trout (Oncorhynchus mykiss) that is homologous to the mammalian SLC26A1 (Sat-1).

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Glucagon, a polypeptide hormone consisting of 29 amino acid residues, tends to form gel-like fibrillar aggregates, and the glucagon fibril, as well as other pathologically related fibrils including prion, amylin, and beta-amyloid, have been found to be cytotoxic through the activation of apoptotic signaling pathways. To understand the aggregation properties of glucagon fibril, we have characterized and compared the physicochemical properties of glucagon, secretin, a member of the glucagon superfamily, and amylin using analytical techniques including capillary electrophoresis (CE), circular dichroism (CD), FT-IR, FT-Raman, transmission electron microscopy (TEM), and beta-sheet-imaging probe. Aging treatment of glucagon resulted in the formation of fibrillar aggregates in time- and concentration-dependent manner, and FT-IR and FT-Raman analyses showed the spectral shift of amide I band, suggesting the conformational changes from alpha-helix to beta-sheet structure.

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We have recently established a unique in vitro experimental model for mitochondrion-rich cell (MRC) research, a ;yolk-ball' incubation system, in which the yolk sac is separated from the embryonic body of Mozambique tilapia embryos and subjected to in vitro incubation. To evaluate the ion-transporting property of the yolk balls, we examined Cl- content and turnover in yolk balls incubated in freshwater and seawater for 48 h, and distribution patterns of three ion transporters, Na+/K+-ATPase, Na+/K+/2Cl- cotransporter (NKCC) and cystic fibrosis transmembrane conductance regulator (CFTR), in MRCs in the yolk-sac membrane. The Cl- turnover rate measured by whole-body influx of 36Cl- was about 60 times higher in yolk balls in seawater than in freshwater, while there was no essential difference in Cl- content between them.

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To study the mechanisms of branchial acid-base regulation, Pacific spiny dogfish were infused intravenously for 24 h with either HCl (495+/- 79 micromol kg(-1) h(-1)) or NaHCO(3) (981+/-235 micromol kg(-1) h(-1)). Infusion of HCl produced a transient reduction in blood pH. Despite continued infusion of acid, pH returned to normal by 12 h.

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In contrast to findings in vitro, the clinical response to anticancer chemotherapy is not simply associated with the p53 mutation status. To analyze the relationship between the actual response of solid tumors with p53 mutation and other biological characteristics, we used a human cancer-nude mouse panel of 21 lines derived from stomach, colorectal, breast, lung, and liver cancers for experimental chemotherapy. We examined the tumor growth rates of the cancer lines and the effects of nine drugs in clinical use, namely, mitomycin C (MMC), cisplatin (CDDP), nimustine hydrochloride (ACNU), irinotecan (CPT-11), cyclophosphamide (CPA), 1-(2-tetrahydrofuryl)-5-fluorouracil (FT-207), a 4:1 mixture of uracil and FT-207 (UFT), 5'-deoxy-5-fluorouridine (5'-DFUR), and adriamycin (ADM), on these tumors.

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Reabsorption of filtered urea by the kidney tubule is essential for retaining high levels of urea in body fluids of marine elasmobranchs. To elucidate the mechanisms of urea reabsorption, we examined the distribution of a facilitative urea transporter (UT) in the kidney of the dogfish Triakis scyllia. We isolated a cDNA encoding a UT that is homologous to the facilitative UT cloned from another dogfish species, Squalus acanthias.

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