Publications by authors named "Hiroko Nishikawa"

PAR1b is a cytoplasmic serine/threonine kinase that controls cell polarity and cell-cell interaction by regulating microtubule stability while mediating cytoplasmic-to-nuclear translocation of BRCA1. PAR1b is also a cellular target of the CagA protein of which leads to chronic infection causatively associated with the development of gastric cancer. The CagA-PAR1b interaction inactivates the kinase activity of PAR1b and thereby dampens PAR1b-mediated BRCA1 phosphorylation, which reduces the level of nuclear BRCA1 and thereby leads to BRCAness and BRCAness-associated genome instability underlying gastric carcinogenesis.

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Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) is performed to distinguish between benign and malignant lesions by evaluating the changes in signal intensity of the acquired image (kinetic curve). This study aimed to verify whether the existing breast DCE-MRI analyzed by the sigmoid model can accurately distinguish between benign and invasive ductal carcinoma (IDC) and predict the subtype. A total of 154 patients who underwent breast MRI for detailed breast mass examinations were included in this study (38 with benign masses and 116 with IDC.

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Purpose: This study investigated the effectiveness of assistive work of radiological technologists (RTs) in conducting computed tomography (CT)/magnetic resonance imaging (MRI) during emergencies.

Methods: In total, 2681 examinations in 2294 patients who underwent CT or MRI during our after-hours clinic hours were conducted. The emergency of the diseases was classified into three categories: emergency diseases, semi-emergency diseases, and non-emergency diseases.

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Mammography after breast-conserving surgery and radiation therapy is an important tool for followup. Early diagnosis of local recurrence enables prompt treatment decisions, which may affect patient prognosis. For complicated post-treatment changes, radiologists sometimes have difficulties in interpreting follow-up mammography.

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Purpose: The purpose of this study is to assess the feasibility and usefulness of time-resolved magnetic resonance angiography (TR-MRA) for follow-up of visceral artery aneurysms (VAAs) after embolotherapy.

Material And Methods: Twenty-one VAAs (11 splenic, six renal, three internal iliac, and one superior pancreaticoduodenal artery aneurysms) in 18 patients (median age, 64 years; range, 36-88 years) previously treated by embolisation with platinum coils, were evaluated. The mean size of the aneurysm was 10.

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Article Synopsis
  • East Asian CagA is linked to a higher risk of gastric cancer compared to Western CagA due to differences in how they interact with the SHP2 phosphatase.
  • The East Asian CagA variant binds much more effectively to SHP2's N-SH2 domain through a specific segment called EPIYA-D, enhancing SHP2's activity significantly.
  • Both East and Western CagA can lead to SHP2 deregulation, but they utilize different mechanisms, with East Asian CagA having stronger and more effective interactions that promote cancerous traits in cells.
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CagA, an oncogenic virulence factor produced by , is causally associated with the development of gastrointestinal diseases such as chronic gastritis, peptic ulcers, and gastric cancer. Upon delivery into gastric epithelial cells via bacterial type IV secretion, CagA interacts with a number of host proteins through the intrinsically disordered C-terminal tail, which contains two repeatable protein-binding motifs, the Glu-Pro-Ile-Tyr-Ala (EPIYA) motif and the CagA multimerization (CM) motif. The EPIYA motif, upon phosphorylation by host kinases, binds and deregulates Src homology 2 domain-containing protein tyrosine phosphatase 2 (SHP2), a oncoprotein, inducing pro-oncogenic mitogenic signaling and abnormal cell morphology.

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Objective: To compare the diagnostic ability of planar images (PI) and images obtained by a computer-aided diagnosis (CAD) system (Viewer for Standardized Bone Scintigraphies; VSBONE) of whole-body bone scintigraphy for detecting bone metastases in breast cancer patients.

Methods: 81 women (median: 56 years; range: 32-79) with a history of breast cancer were included in this study. They underwent whole-body bone scintigraphy after intravenous injection of 740 MBq technetium-99m hydroxymethylene diphosphonate.

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Purpose: To assess the usefulness of transcatheter arterial embolization (TAE) for the hepatic arterial injury related to percutaneous transhepatic portal intervention (PTPI).

Materials And Methods: Fifty-four patients, 32 males and 22 females with a median age of 68 years (range 43-82 years), underwent PTPI. The procedures consisted of 33 percutaneous transhepatic portal vein embolizations, 19 percutaneous transhepatic variceal embolizations, and 2 percutaneous transhepatic portal venous stent placements.

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Chronic infection with cagA-positive Helicobacter pylori is the strongest risk factor for atrophic gastritis, peptic ulcers, and gastric cancer. CagA, the product of the cagA gene, is a bacterial oncoprotein, which, upon delivery into gastric epithelial cells, binds to and inhibits the polarity-regulating kinase, partitioning-defective 1b (PAR1b) [also known as microtubule affinity-regulating kinase 2 (MARK2)], via its CagA multimerization (CM) motif. The inhibition of PAR1b elicits junctional and polarity defects, rendering cells susceptible to oncogenesis.

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Disassembly of the Cdc45-MCM-GINS (CMG) DNA helicase, which unwinds the parental DNA duplex at eukaryotic replication forks, is the key regulated step during replication termination but is poorly understood. In budding yeast, the F-box protein Dia2 drives ubiquitylation of the CMG helicase at the end of replication, leading to a disassembly pathway that requires the Cdc48 segregase. The substrate-binding domain of Dia2 comprises leucine-rich repeats, but Dia2 also has a TPR domain at its amino terminus that interacts with the Ctf4 and Mrc1 subunits of the replisome progression complex, which assembles around the CMG helicase at replication forks.

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Purpose: The aim of this study is to analyze the technical and clinical success rates and safety of transarterial fiducial marker placement for image-guided proton therapy for malignant liver tumors.

Methods And Materials: Fifty-five patients underwent this procedure as an interventional treatment. Five patients had 2 tumors, and 4 tumors required 2 markers each, so the total number of procedures was 64.

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We present a case of acute small-bowel bleeding from the collateral artery of the superior mesenteric-left deep circumflex iliac artery that was successfully managed by transarterial coil embolization.

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DNA polymerases delta and epsilon (pol delta and epsilon) are the major replicative polymerases and possess 3'-5' proofreading exonuclease activities that correct errors arising during DNA replication in the yeast Saccharomyces cerevisiae. This study measures the fidelity of the holoenzyme of wild-type pol epsilon, the 3'-5' exonuclease-deficient pol2-4, a +1 frameshift mutator for homonucleotide runs, pol2C1089Y, and pol2C1089Y pol2-4 enzymes using a synthetic 30-mer primer/100-mer template. The nucleotide substitution rate for wild-type pol epsilon was 0.

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