Yuki Koike
The University of Tokyo, Department of Physics, Undergraduate
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Diseases associated with the Eustachian tube include Eustachian tube stenosis, Eustachian tube opening, and otitis media with effusion. The Eustachian tube insufflation method is used both for examining and treating Eustachian tubes and... more
Diseases associated with the Eustachian tube include Eustachian tube stenosis, Eustachian tube opening, and otitis media with effusion. The Eustachian tube insufflation method is used both for examining and treating Eustachian tubes and is clinically performed on patients with Eustachian tube diseases. However, the Eustachian tube insufflation sounds that are produced by this method are only auscultated by the doctor. Therefore, there is a disadvantage that the sound is not saved as data, and diagnosis is based on the auditory judgment of doctors, leading to weak objectivity. The purpose of this study is to improve the objectivity of diagnosis by developing a system that quantitatively evaluates the severity of the Eustachian tube insufflation sounds. We collected Eustachian tube insufflation sounds from patients with the Eustachian tube disease. The acoustic characteristics of the collected data were analyzed in order to quantify the difference in the Eustachian tube insufflation sound, depending on the degree of the Eustachian tube disease. In addition, spectrum analysis was performed using the maximum entropy method (MEM), and the abnormal sound was extracted from the cross-correlation function with the template of the abnormal sound. The change of the frequency spectrum with time was expressed. As a result, the time taken to open the Eustachian tube was recorded and an index indicating the severity of normal and stenotic sounds was proposed.
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Purpose This study aimed to evaluate prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia (CDH). Methods A systematic literature search was performed to identify relevant observational studies that evaluated... more
Purpose This study aimed to evaluate prenatal predictors of mortality in fetuses with congenital diaphragmatic hernia (CDH). Methods A systematic literature search was performed to identify relevant observational studies that evaluated the ability of lung-to-head ratio (LHR), observed-to-expected LHR (o/e-LHR), observed-to-expected total fetal lung volume (o/e-TFLV), lung-to-thorax transverse area ratio (L/T ratio), intrathoracic herniation of the liver and the stomach, and side of diaphragmatic hernia, using a threshold for the prediction of mortality in fetuses with CDH. Study quality was assessed using the QUADAS-2 tool. Hierarchical summary receiver operating characteristic curves were constructed. Results A total of 50 articles were included in this meta-analysis. The QUADAS-2 tool identified a high risk of bias in more than one domain scored in all parameters. Among those parameters, the diagnostic odds ratio of mortality with o/e-LHR < 25%, o/e-TFLV < 25%, and L/T ratio...
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Blood-feeding arthropods, particularly ticks and mosquitoes are considered the most important vectors of arthropod-borne diseases affecting humans and animals. While feeding on blood meals, arthropods are exposed to high levels of... more
Blood-feeding arthropods, particularly ticks and mosquitoes are considered the most important vectors of arthropod-borne diseases affecting humans and animals. While feeding on blood meals, arthropods are exposed to high levels of reactive oxygen species (ROS) since heme and other blood components can induce oxidative stress. Different ROS have important roles in interactions among the pathogens, vectors, and hosts. ROS influence various metabolic processes of the arthropods and some have detrimental effects. In this review, we investigate the various roles of ROS in these arthropods, including their innate immunity and the homeostasis of their microbiomes, that is, how ROS are utilized to maintain the balance between the natural microbiota and potential pathogens. We elucidate the mechanism of how ROS are utilized to fight off invading pathogens and how the arthropod-borne pathogens use the arthropods’ antioxidant mechanism to defend against these ROS attacks and their possible imp...
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Recently, many researches on autostereoscopic displays have been carried out. In this work, we propose a new display configuration using the Pepper's ghost effect and a dynamic image adjustment method for a large scale... more
Recently, many researches on autostereoscopic displays have been carried out. In this work, we propose a new display configuration using the Pepper's ghost effect and a dynamic image adjustment method for a large scale autostereoscopic display. We also propose a method for extending the number of viewpoints for simultaneous viewing by multiple people. In the experiment, after constructing the device, we acquired the light transport matrix using two cameras and dynamically adjusted the video images. We observed parallax in the adjusted images, and we confirmed that the images were stereoscopic. At present, only one person can view the stereoscopic images at the same time because only two parallax images are presented. However, when acquiring the light transport matrix, we can create the video from multiple viewpoints by increasing the number of cameras. In the future, we will experiment using three cameras and confirm that the three-dimensional image presentation is possible by three parallaxes.
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Pulsed electric current bonding condition for Sapphire/Nd:YAG composite was studied to improve optical and laser quality. Further, bonding of a sapphire-sandwich structure was demonstrated.
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Positron emission tomography (PET) images are often used clinically as they can non-invasively show the accumulation of cancer cells. The standardized uptake value (SUV) is the most common semi-quantitative measurement derived from PET... more
Positron emission tomography (PET) images are often used clinically as they can non-invasively show the accumulation of cancer cells. The standardized uptake value (SUV) is the most common semi-quantitative measurement derived from PET images. However, SUV have some limitations, such as the difficulty of expressing temporal change quantitatively and unifying imaging conditions such as uptake time after medicine administration. Also, the textural features obtained from PET images show the presence of tumors represented by a vague shadow. Although feature analysis of tumors by using SUV have been widely studied, numerical information obtained on tumors from PET images is limited, and thus the wealth of information cannot be utilized. So, parameter to evaluate quantitatively the state of tumor within PET images called texture should be more established. Texture analysis involves various mathematical methods that are applied to quantify the relationships between the grey level intensity value of pixels or voxels and their spatial pattern within PET images, and are used for classification and discrimination. In this study, we propose texture analysis statistically, specifically by using Shannon’s information entropy and KullbackLeibler divergence. We verified our method by using a simulation, and quantified the distribution inside a tumor. We also examined clinical data in the same way; however, as no appropriate evaluation result was obtained, there is room for further improvement of this system.
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Research Interests: Oncology, Molecular Medicine, Cancer, Cell Cycle, Metastasis, and 8 moreApoptosis, Medicine, Colorectal cancer, Oncogene, Cell, Gene, stroma, and VCAM
Geodetic experiments and diving surveys of the outer rise of the Japan Trench off Northeastern Japan were carried out during the Kairei KR07-07 cruise in June 2007 using the ROV KAIKO 7000 II. The cruise aimed at three objectives. The... more
Geodetic experiments and diving surveys of the outer rise of the Japan Trench off Northeastern Japan were carried out during the Kairei KR07-07 cruise in June 2007 using the ROV KAIKO 7000 II. The cruise aimed at three objectives. The first was diving surveys of small seamounts on the outer rise. A new type of seafloor volcanism called 'petit spot' was recently found near the Japan Trench (Hirano et al., 2006). Since each of diving surveys to three seamounts found fresh basalts, the survey area can be a potential locality for another petit spot volcanic field (Abe et al., this meeting). The second objective was diving surveys of the seafloor in the source region of the 2005 M7.1 outer rise earthquake. It was the largest outer rise earthquake recorded off the Japan Trench since the 1933 M8.4 Sanriku- oki tsunami earthquake. Although we could not find any indication of deformation on the seafloor during the survey, we are interested in the observation that the aftershock distr...
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Polyethylene Terephthalate (PET) is a polar polymer and is best known as the material that constitutes a soft drink bottle. PET has excellent physical properties, such as, high heat resistance, low cold resistance, high transparency, good... more
Polyethylene Terephthalate (PET) is a polar polymer and is best known as the material that constitutes a soft drink bottle. PET has excellent physical properties, such as, high heat resistance, low cold resistance, high transparency, good electrical insulation, good chemical resistance, solvent resistance, and so on. It is also used as electrical insulation or a dielectric material, such as, insulation tape, condenser, flat cable, and so on. So far, the high field dielectric properties of a nonpolar polymer, such as LDPE and PP, were reported from the results of dissipation current waveform and electroluminescence (EL) simultaneous observation. It was reported that in high field, charge injection from the electrode will dominant. In this paper, in order to grasp the specific dielectric properties of polar polymers like dipole polarization phenomenon, by using PET film, the simultaneous observations of dissipation current and EL were carried out at the frequencies 50 and 400 Hz. As the result of experiments, it was found that the electric field dependence of power loss density at 50 Hz is saturating above 24 kV/mm and is not saturating at 400 Hz.
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Lymph node status is the most significant prognostic factor of colorectal cancer. However, there is a risk of disease understaging if the extent of lymph node assessment is sub-optimal. Preoperative C-reactive protein (CRP) is known to be... more
Lymph node status is the most significant prognostic factor of colorectal cancer. However, there is a risk of disease understaging if the extent of lymph node assessment is sub-optimal. Preoperative C-reactive protein (CRP) is known to be a useful tool in predicting postoperative outcomes in patients with colorectal cancer. We retrospectively evaluated whether CRP adds to prognosis information in stage I-III colorectal cancer patients with poor lymph node assessment. In stages I-III, multivariate analysis revealed that CRP-positive status and advanced T-stage were factors that independently affected survival. In stage III, univariate analysis revealed that lymph node number retrieval and lymph node ratio were factors that affected survival. However, CRP positivity was the only independent factor for survival. CRP positivity did not predict poor prognosis in stage II or III patients with adequate lymph node retrieval. By contrast, the prognosis of CRP-positive patients was poorer tha...
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The aim of the present study was to evaluate the efficacy and safety of double balloon enteroscopy (DBE) in children with inflammatory bowel disease (IBD). A total of 106 DBE procedures in 67 patients were performed at Mie University... more
The aim of the present study was to evaluate the efficacy and safety of double balloon enteroscopy (DBE) in children with inflammatory bowel disease (IBD). A total of 106 DBE procedures in 67 patients were performed at Mie University Hospital from January 2008 to June 2011. Of these, 17 procedures in 12 children and adolescents with established or suspected Crohn's disease (CD) were included in the present study. The procedure, sedation, efficacy, and safety of DBE were evaluated. Mean patient age was 12.9 years (range, 3-19 years). Patients ≤ 15 years old had general anesthesia. The procedures included the oral approach (n= 9), the anal approach (n= 4), and the ileostomal approach (n= 4). The mean procedure duration was 60 min. Accurate diagnosis was obtained in 7/8 cases (88%) of suspected CD. Only one case was diagnosed as indeterminate colitis, although the total small and large bowel was examined on DBE and pathology. Procedure tolerance was acceptable and recovery was unev...
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AimsImmunosuppressive acidic protein (IAP) is a potent biological marker for immunological surveillance in patients with malignant tumors. This study aimed to investigate the significance of serum IAP as an index of disease status,... more
AimsImmunosuppressive acidic protein (IAP) is a potent biological marker for immunological surveillance in patients with malignant tumors. This study aimed to investigate the significance of serum IAP as an index of disease status, clinicopathological findings and prognosis in colorectal cancer.MethodsA total of 101 patients with colorectal cancer and 80 normal volunteers were included in this retrospective trial. Preoperative serum IAP was assayed using a commercially available enzyme‐linked immunosorbent assay kit.ResultsThe serum IAP level in the patients, which was not associated with clinicopathological features except for tumor size, was significantly higher than that in controls. The serum IAP level was closely correlated with percent body weight loss, serum albumin and cholinesterase, and percentage of circulating lymphocytes reflecting the host's nutritional and immunological conditions. Interestingly, these parameters were not associated with factors reflecting disease...
Research Interests: Gastroenterology, Cancer, Medicine, Colorectal cancer, Humans, and 15 moreInternal Medicine, Female, Male, Cholinesterases, Aged, Middle Aged, Adult, Prognosis, Biological markers, Disease Progression, Enzyme Linked Immunosorbent Assay, Case Control Studies, Colorectal Neoplasms, Neoplasm metastasis, and Lymphocyte Count
Research Interests: Survival Analysis, Immunohistochemistry, Treatment Outcome, Enzyme Inhibitors, Cancer Research, and 15 moreMedicine, Humans, Child, Female, Male, Pediatric Surgery, Infant, Glycolysis, Neuroblastoma, Antineoplastic Agents, GLUT, Adjuvant Chemotherapy, Child preschool, real time polymerase chain reaction, and Paediatrics and reproductive medicine
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Research Interests: Radiology, Magnetic Resonance Imaging, Risk assessment, Medicine, Clinical Practice, and 15 moreHumans, Child, Male, Pediatric Surgery, Embryonic Development, Internal medicine Doppler ultrasonography, Risk Assessment, Sclerotherapy, Congenital abnormalities, Abdominal Pain, Laparotomy, Combined Modality Therapy, Severity of Illness Index, Paediatrics and reproductive medicine, and Retroperitoneal space
The mechanism of distant recurrence in rectal cancer after preoperative chemoradiotherapy (CRT) has yet to be fully elucidated. Further improvements in survival rates cannot be achieved without decreasing distant recurrence after... more
The mechanism of distant recurrence in rectal cancer after preoperative chemoradiotherapy (CRT) has yet to be fully elucidated. Further improvements in survival rates cannot be achieved without decreasing distant recurrence after preoperative CRT. Recently, it was reported that hypoxic conditions were correlated with cancer stem cell generation. Therefore, we investigated the correlation between the expression of CD133 and hypoxia inducible factor-1α (HIF-1α), and their association with clinical outcome. Fifty-two patients with rectal cancer underwent preoperative CRT. Residual cancer cells after CRT were obtained from formalin-fixed paraffin-embedded specimens using micro-dissection. The expression levels of CD133 (PROM1) and HIF-1α genes were measured using real-time reverse transcription polymerase chain reaction. The correlation between expression and irradiation was evaluated using colon cancer cell lines. Immunohistochemical staining of these proteins after CRT was also investigated. We observed a significant inverse correlation between the gene expression of CD133 (PROM1) and HIF-1α genes in residual cancer cells after CRT. Elevated CD133 gene expression was associated with distant recurrence and poor recurrence-free survival. Elevated HIF-1α gene expression was associated with poor overall survival. In vitro, the change in gene expression levels after irradiation showed inverse patterns. Immunohistochemical analyses showed that residual cancer cells strongly expressed CD133 and lacked HIF-1α expression. Our results suggest that CD133 and HIF-1α expression is associated with tumour re-growth and distant recurrence after CRT. These results may assist in clarifying the development of future cancer therapeutics in rectal cancer patients undergoing preoperative CRT.
Research Interests: Cancer, Immunohistochemistry, Medicine, Gene expression, Colorectal cancer, and 14 moreHumans, Male, Clinical oncology, Peptides, Glycoproteins, Cancer Stem Cell, Aged, Middle Aged, Survival Rate, Chemoradiotherapy, Rectal Cancer, Combined Modality Therapy, Hypoxia inducible factor, and Rectal neoplasms
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Inflammation plays an important role in acute coronary syndromes, and some evidence indicates that patients with a more pronounced vascular inflammatory response have a poorer outcome. Soluble intercellular adhesion molecule-1 (sICAM-1)... more
Inflammation plays an important role in acute coronary syndromes, and some evidence indicates that patients with a more pronounced vascular inflammatory response have a poorer outcome. Soluble intercellular adhesion molecule-1 (sICAM-1) is a specific marker for vascular endothelial cell activation. The aim of this study was to investigate the prognostic value of plasma sICAM-1 levels in patients with acute chest pain compatible with myocardial ischemia. This prospective study was conducted at 2 urban university medical centers. The study cohort consisted of 119 consecutive patients with chest pain in whom myocardial ischemia was suspected clinically at presentation. Patients with conditions that affect sICAM-1 levels were ineligible. Cardiac troponin I (cTnI), C-reactive protein, and sICAM-1 levels were assayed at presentation to the emergency department. The primary end point was the occurrence of a serious cardiac event (death, nonfatal acute myocardial infarction, coronary revascularization) in the hospital. Although sICAM-1 levels tended to be higher in patients with a serious cardiac event, there was no significant association. In contrast, a cTnI level greater than 0.2 ng/mL was a powerful predictor of an in-hospital serious cardiac event (odds ratio 16.3, 95% confidence interval [CI] 4.7 to 55.9; P &lt;.0001). Soluble ICAM-1 levels of more than 260 ng/mL at presentation had a sensitivity for predicting a serious cardiac event of 63% (95% CI 46% to 81%) but a specificity of only 47% (95% CI 38% to 57%). In a heterogeneous population of patients with chest pain compatible with myocardial ischemia, elevated sICAM-1 levels are poor predictors of an individual patient suffering a serious cardiac event in the hospital.