Publications by authors named "Kana Matsubara"

Background: Complex anatomical features are challenging for minimally invasive intradiscal therapy owing to insufficient visualization for accurate needle advancement. We report the case of a patient with dysraphic vertebral pathologies who presented with L5/S1 degeneration and was successfully treated with annuloplasty using the cone-beam computed tomography (CBCT)-assisted radiofrequency thermocoagulation system.

Case Presentation: A 34-year-old woman presented with a lower back and left radicular pain of L5/S1 discogenic origin, accompanied by spina bifida occulta and lumbosacral transitional vertebra.

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Many concerns have been expressed regarding the possible adverse effects of thyroid hormone-disrupting chemicals in the environment. The disruption of thyroid hormones in the neonatal period may lead to permanent effects on thyroid hormone homeostasis as well as related developmental disorders, as thyroid hormones are essential for regulating the growth and differentiation of many tissues. To understand the long-term alteration in gene expressions by neonatal administration of thyroid hormone-like chemicals in general, we identified genes whose expression was altered in the liver, an important component of the thyroid hormone axis, by neonatal exposure to triiodothyronine (T3).

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Radiation therapy in patients is planned by using computed tomography (CT) images acquired before start of the treatment course. Here, tumor shrinkage or weight loss or both, which are common during the treatment course for patients with head-and-neck (H&N) cancer, causes unexpected differences from the plan, as well as dose uncertainty with the daily positional error of patients. For accurate clinical evaluation, it is essential to identify these anatomical changes and daily positional errors, as well as consequent dosimetric changes.

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Exposure of the fetal brain to ionizing radiation causes congenital brain abnormalities. Normal brain formation requires regionally and temporally appropriate proliferation and differentiation of neural stem cells (NSCs) into neurons and glia. Here, we investigated the effects of X-irradiation on proliferating homogenous NSCs prepared from mouse ES cells.

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When in vivo proton dosimetry is performed with a metal-oxide semiconductor field-effect transistor (MOSFET) detector, the response of the detector depends strongly on the linear energy transfer. The present study reports a practical method to correct the MOSFET response for linear energy transfer dependence by using a simplified Monte Carlo dose calculation method (SMC). A depth-output curve for a mono-energetic proton beam in polyethylene was measured with the MOSFET detector.

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A number of environmental chemicals have been reported to exhibit thyroid hormone-like activity. Since thyroid hormones play a crucial role in development, it is important to identify chemicals in the environment that are capable of endocrine disruption of thyroid hormone homeostasis. In order to detect thyroid hormone-like activity, the growth of pituitary cell lines has been commonly used as a sensitive marker, albeit with limited specificity to thyroid hormones.

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We experimentally evaluated the proton beam dose reproducibility, sensitivity, angular dependence and depth-dose relationships for a new Metal Oxide Semiconductor Field Effect Transistor (MOSFET) detector. The detector was fabricated with a thinner oxide layer and was operated at high-bias voltages. In order to accurately measure dose distributions, we developed a practical method for correcting the MOSFET response to proton beams.

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In order to evaluate the usefulness of a metal oxide-silicon field-effect transistor (MOSFET) detector as a in vivo dosimeter, we performed in vivo dosimetry using the MOSFET detector with an anthropomorphic phantom. We used the RANDO phantom as an anthropomorphic phantom, and dose measurements were carried out in the abdominal, thoracic, and head and neck regions for simple square field sizes of 10 x 10, 5 x 5, and 3 x 3 cm(2) with a 6-MV photon beam. The dose measured by the MOSFET detector was verified by the dose calculations of the superposition (SP) algorithm in the XiO radiotherapy treatment-planning system.

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Background: The aim of this study is to compare the efficacy of stellate ganglion block, performed by ultrasound guided technique and blind technique, and ultrasound guided T2 intercostal nerve block.

Methods: In the present study, we evaluated the changes in upper arm skin temperature, and the development of Horner syndrome after stellate ganglion block (blind technique and ultrasound guided technique) and ultrasound guided T2 intercostal nerve block in 12, 11 and 10 patients scheduled for each block. Stellate ganglion blocks (blind technique) were performed via an anterior paratracheal approach at C6 using 1% mepivacaine 5 ml.

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Article Synopsis
  • The study aimed to verify a strategy for reducing systematic errors in prostate cancer treatment using a computer simulation of position errors during IMRT with a prone fixation device.
  • Researchers simulated an off-line correction method, analyzing portal images from early treatment sessions to determine the optimal number of images needed to minimize setup errors.
  • Results showed that increasing the number of images significantly reduced systematic errors, highlighting a notable impact when random errors were substantial.
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Purpose: Positional reproducibility in patients with prostate cancer fixed in the prone position with a set of immobilization devices for external-beam intensity-modulated radiation therapy (IMRT) was evaluated. In addition, the adequacy of our positional error reduction strategy and current planning target volume (PTV) margins was also evaluated.

Results: Systematic error was corrected by the positional correction that we executed at the first stage of irradiation.

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Objective: It is necessary to reduce the exposure doses from both fluoroscopy and angiocardiography. Pulsed fluoroscopy clearly reduces patients' exposure. By contrast, whether digital acquisition reduces patients' exposure is not clear.

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