Publications by authors named "Takuya Chiba"

Background: The aim of this study to compare of the image quality of calcified lesions in coronary artery disease between deep learning reconstruction (DLR) and model-based iterative reconstruction (MBIR) on energy-integrating detector (EID) based ultra-high-resolution CT (UHRCT).

Methods: We performed a phantom study on EID-based UHRCT using a dedicated insert for calcifications and obtained the derivative values for DLR and MBIR. In the clinical study, the derivative values were compared between DLR and MBIR across 73 calcified lesions in 62 patients.

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This case report shows unique aneurysm at the left ventricular apex associated with a double-chambered left ventricle (DCLV) in asymptomatic 69-year-old female. The aneurysm was located at the apex of an accessory chamber, which was formed by hypertrophied muscle band and the interventricular septum, along with a pronounced jet flow directed towards the apex aneurysm. These finding suggests that the obstruction at the base of the accessory chamber caused a pressure overload at the apex, ultimately leading to the development of the aneurysm.

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A super-resolution deep learning reconstruction (SR-DLR) algorithm trained using data acquired on the ultrahigh spatial resolution computed tomography (UHRCT) has the potential to provide better image quality of coronary arteries on the whole-heart, single-rotation cardiac coverage on a 320-detector row CT scanner. However, the advantages of SR-DLR at coronary computed tomography angiography (CCTA) have not been fully investigated. The present study aimed to compare the image quality of the coronary arteries and in-stent lumen between SR-DLR and model-based iterative reconstruction (MBIR).

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The best cardiac phases in retrospective ECG-gated CT for detecting an intimal tear (IT) in aortic dissection (AD) and an ulcer-like projection (ULP) in an intramural hematoma (IMH) have not been established. This study aimed to compare the detection accuracy of diastolic-phase and systolic-phase ECG-gated CT for IT in AD and ULP in IMH, with subsequent surgical or angiographical confirmation as the reference standard.In total, 81 patients (67.

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Interactions between different animal species are a critical determinant of each species' evolution and range expansion. Chemical, visual, and mechanical interactions have been abundantly reported, but the importance of electric interactions is not well understood. Here, we report the discovery that the nematode Caenorhabditis elegans transfers across electric fields to achieve phoretic attachment to insects.

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Article Synopsis
  • Nutritional needs for metabolic health change across different life stages, with a focus on how protein intake affects health as mice age.
  • A study examined young and middle-aged mice on diets with varying protein levels, revealing that low protein diets led to fatty liver, particularly in older mice.
  • Moderate protein intake (25% and 35%) helped maintain metabolic health by reducing harmful lipid levels and is necessary for both young and middle-aged mice.
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Purpose: Dark band (DB) artifact in head and neck computed tomography (CT) is caused by beam hardening (BH), and decreased CT values in the X-ray target become a problem. Therefore, we investigated whether it is possible to reduce DB artifact in the head and neck with a compensation filter.

Methods: We made 2 types of filters with alcohol and water.

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Bicuspid aortic valve (BAV) patients with aortic stenosis (AS) are known to develop dilatation of the ascending aorta at a younger age, but the morphology of the aorta in these patients is yet to be investigated. Thus, in this study, we aim to evaluate the aortic morphology of BAV patients with severe AS using thin-slice electrocardiogram (ECG) -gated computed tomography (CT) and identify the possible contributing effect of age.In this retrospective study, 122 BAV and 154 tricuspid aortic valve (TAV) patients who received aortic valve replacement for severe AS were assessed by thin-slice ECG-gated CT and three-dimensional reconstruction.

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Many studies have shown the beneficial effects of calorie restriction (CR) on rodents' aging; however, the molecular mechanism explaining these beneficial effects is still not fully understood. Previously, we conducted transcriptomic analysis on rat liver with short-term and mild-to-moderate CR to elucidate its early response to such diet. Here, we expanded transcriptome analysis to muscle, adipose tissue, intestine, and brain and compared the gene expression profiles of these multiple organs and of our previous dataset.

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Purpose: To develop and validate a CT diagnostic algorithm for bicuspid aortic valve (BAV) classification.

Materials And Methods: This retrospective study included 212 consecutive patients with severe aortic stenosis who underwent CT followed by aortic valve replacement (mean age, 71 years [range, 27-93 years]; 125 women; 37% with a BAV) from 2012 to 2017. BAV diagnosis and BAV category were determined by using the CT diagnostic algorithm developed and were compared with those attained through surgical diagnosis.

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Break-induced replication (BIR) is a specialized homologous-recombination pathway for DNA double-strand break (DSB) repair, which often induces genome instability. In this study, we establish EGFP-based recombination reporters to systematically study BIR in mammalian cells and demonstrate an important role of human PIF1 helicase in promoting BIR. We show that at endonuclease cleavage sites, PIF1-dependent BIR is used for homology-initiated recombination requiring long track DNA synthesis, but not short track gene conversion (STGC).

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A fungal metabolite, diatretol, has shown to be a promising antimalarial agent. Diatretol displayed potent in vitro antiparasitic activity against the Plasmodium falciparum K1 strain, with an IC value of 378 ng ml, as well as in vivo efficacy in a Plasmodium berghei-infected mice model, with ca. 50% inhibition at 30 mg/kg (p.

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Calorie restriction (CR) by 30-40% decreases morbidity of age-related diseases and prolongs the lifespan of various laboratory animal species. Taurine (2-aminoethanesulfonic acid) is an important nutrient for lipid metabolism as it conjugates bile acids. Here, we investigated how taurine supplementation induces effects similar to the CR beneficial effects.

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Aim: Caloric restriction (CR), which limits the caloric intake to 60-70% of ad libitum (AL) amounts in various experimental animals, delays aging and extends the lifespan. We previously showed that neuropeptide Y (NPY), an appetite-stimulating peptide, is essential for the anti-oxidative and life-extending effects of CR. Here, we investigated whether a Japanese traditional herbal medicine, rikkunshito (RKT), which induces NPY activation, has CR-like life-extending effects.

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The structure-specific endonuclease ERCC1/XPF plays an important role in nucleotide excision repair and interstrand cross-link repair. In this study, we identified new functions of ERCC1/XPF in DNA double-strand break (DSB) repair. We found that the conserved function of ERCC1/XPF to remove non-homologous sequences at DSBs is a rate-limiting step for homologous recombination in mammalian cells, and more importantly, we uncovered an indispensable role of ERCC1/XPF in repair of DSBs containing DNA secondary structures, including the structure-prone AT-rich DNA sequences derived from common fragile sites and G-quadruplexes (G4s).

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DNA polymerase θ () plays an important role in alternative nonhomologous end joining or microhomology-mediated end joining (alt-NHEJ/MMEJ). Here, we show that POLQ is not only required for MMEJ to repair DNA double-strand breaks (DSBs) generated by endonucleases such as I-SceI or Cas9, but is also needed for repair of DSBs derived from DNA nicks generated by Cas9 nickase. Consistently, we found that POLQ deficiency leads to sensitivity to topoisomerase inhibitors that cause DNA single-strand break (SSB) accumulation at replication forks and to ATR inhibitors that induce replication fork collapse.

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Background: Radical esophagectomy remains the primary treatment option for resectable esophageal cancer. However, it sometimes induces postoperative complications due to its invasive nature. Recently, the impact of loss of muscle mass on postoperative complications and survival among cancer patients has been highlighted.

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Proteasome inhibitors (PI), mainly targeting the β5 subunit of the 20S proteasome, are widely used in the treatment of multiple myeloma (MM). However, PI resistance remains an unresolved problem in the therapy of relapsed and refractory MM. To develop a new PI that targets other proteasome subunits, we examined the anti-MM activity of a novel syringolin analog, syringolog-1, which inhibits the activity of both the β5 and β2 subunits.

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Objectives: Preoperative identification of the artery of Adamkiewicz can help prevent postoperative spinal cord injury in patients undergoing thoracic and thoraco-abdominal aortic aneurysm repair. Although several studies have shown the feasibility of evaluating the artery of Adamkiewicz using multidetector row computed tomography (MDCT), no detailed investigations regarding the collateral circulation to the artery of Adamkiewicz have been performed. The purpose of this study was to investigate the collateral circulation to the artery of Adamkiewicz using MDCT in patients with thoracic and thoraco-abdominal aortic aneurysms.

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Purpose: Preoperative identification of the artery of Adamkiewicz can help prevent postoperative spinal cord injury following thoracic and thoracoabdominal aortic repair. Several studies have demonstrated the feasibility of evaluating the artery of Adamkiewicz using multi-detector row computed tomography (CT), but precise visualization remains a challenge. The present study was conducted to evaluate the usefulness of ultra-high-resolution CT for visualizing the artery of Adamkiewicz with a slice thickness of 0.

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Objective: To explore the feasibility and diagnostic accuracy of modified subtraction coronary CT angiography (CCTA) with short breath-holding time in patients who have limited breath-hold capability and severe coronary artery calcification.

Methods: 11 patients with a coronary calcium score >400 underwent CCTA using a modified subtraction protocol. All patients were unable to hold their breath for more than 20 s.

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Rationale And Objectives: Severe calcifications of the coronary arteries are still a major challenge in coronary computed tomography (CT) angiography (CCTA). Subtraction CCTA using a 320-detector row CT scanner has recently been introduced for patients with severe calcifications. However, the conventional subtraction CCTA method requires a long breath-holding time of approximately 20-40 seconds.

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In this study, we designed and synthesized a structurally simplified syringolin A analogue 4, which could have a switched hydrogen bonding interaction with the β5 subunit of 20S proteasome. This analogue exhibits potent β5 proteasome inhibitory activity with an IC50 value of 107 nM. It also shows cytotoxicity against a range of human cancer cells at submicromolar level (109-254 nM).

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Isosyringolin A, which is an isomer of the proteasome-inhibiting natural product syringolin A, was designed and synthesized to develop analogues that are step economical and synthetically accessible in a practical manner. It was revealed that isosyringolin A exhibited proteasome-inhibitory activity comparable to that of syringolin A and that its derivatization leads to great enhancement in its proteasome inhibitory activity as well as its cytotoxicity against human myeloma cells.

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