Publications by authors named "Ikuo Kobayashi"

72 Publications

Activity-Integrated Hidden Markov Model to Predict Calving Time.

Animals (Basel) 2021 Feb 3;11(2). Epub 2021 Feb 3.

Center for Animal Disease Control, University of Miyazaki, Miyazaki 889-2192, Japan.

Accurately predicting when calving will occur can provide great value in managing a dairy farm since it provides personnel with the ability to determine whether assistance is necessary. Not providing such assistance when necessary could prolong the calving process, negatively affecting the health of both mother cow and calf. Such prolongation could lead to multiple illnesses. Calving is one of the most critical situations for cows during the production cycle. A precise video-monitoring system for cows can provide early detection of difficulties or health problems, and facilitates timely and appropriate human intervention. In this paper, we propose an integrated approach for predicting when calving will occur by combining behavioral activities extracted from recorded video sequences with a Hidden Markov Model. Specifically, two sub-systems comprise our proposed system: (i) Behaviors extraction such as lying, standing, number of changing positions between lying down and standing up, and other significant activities, such as holding up the tail, and turning the head to the side; and, (ii) using an integrated Hidden Markov Model to predict when calving will occur. The experiments using our proposed system were conducted at a large dairy farm in Oita Prefecture in Japan. Experimental results show that the proposed method has promise in practical applications. In particular, we found that the high frequency of posture changes has played a central role in accurately predicting the time of calving.
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http://dx.doi.org/10.3390/ani11020385DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7913511PMC
February 2021

Prostatic Pharmacokinetic/Pharmacodynamic Evaluation of Ampicillin-Sulbactam for Bacterial Prostatitis and Preoperative Prophylaxis.

J Clin Pharmacol 2021 Jun 12;61(6):820-831. Epub 2021 Jan 12.

Department of Clinical Pharmacotherapy, Hiroshima University, Minami-ku, Hiroshima, Japan.

This study aims to define the penetration of ampicillin and sulbactam into prostate tissue, develop a prostatic pharmacokinetic model of each drug, and assess the appropriateness of ampicillin-sulbactam regimens for the treatment of prostatitis and the prophylaxis of postoperative infection, based on a pharmacokinetic and pharmacodynamic simulation. Subjects were prostatic hyperplasia patients prophylactically receiving a 0.5-hour infusion of 1.5 g (1:0.5 g) or 3 g (2:1 g) ampicillin-sulbactam before transurethral resection of the prostate. Ampicillin and sulbactam concentrations in plasma and prostate tissue were measured. The prostate tissue/plasma ratios of both ampicillin and sulbactam were approximately 0.37 (area under the drug concentration-time curve), and penetration was similar. The prostatic population pharmacokinetic model, which included a covariate analysis, adequately predicted prostate tissue concentrations in our patient population. For therapeutic use, aiming for a bactericidal target of 50% of time above minimum inhibitory concentration (T > MIC) in prostate tissue, 3 g ampicillin-sulbactam 4 times daily achieved ≥90% expected probability against only Enterococcus faecalis in typical patients with a creatinine clearance (CL ) of 30 mL/min. For prophylactic use, aiming for a bacteriostatic target of 30% T > MIC, 3 g ampicillin-sulbactam 4 times daily achieved ≥90% expected probability of attaining the bacteriostatic target against E. faecalis and Proteus species when CL was 30 mL/min. Based on prostatic simulations, the present study provides helpful recommendations for the treatment of bacterial prostatitis and preoperative prophylaxis in prostatectomy.
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http://dx.doi.org/10.1002/jcph.1800DOI Listing
June 2021

Effect of protective glasses on radiation dose to eye lenses during whole breast irradiation.

J Appl Clin Med Phys 2020 Nov 30;21(11):272-277. Epub 2020 Oct 30.

Department of Radiology, Juntendo University Shizuoka Hospital, Shizuoka, Japan.

Objectives: The efficacy of radiotherapy for breast cancer has greatly improved owing to better irradiation methods. Radiotherapy aims to deliver therapeutic doses to predetermined target volumes while sparing surrounding healthy tissues. However, there are few reports on radiation exposure to eye lenses, and the recommended exposure limits to ocular lens have been substantially reduced in recent years. This study aimed to investigate the amount of radiation exposure to eye lenses using optically stimulated luminescence dosimeters (OSLDs) and determine whether wearing special protective devices to protect the eyes, as an organ at risk, during whole breast irradiation, is necessary.

Methods: This experiment used OSLDs on water-equivalent phantom to measure the change in scattered radiation dose due to the difference of irradiation field while using 4- and 6-MV photons of TrueBeam linear accelerator. Using a total treatment dose of 50 Gy, a target was positioned to approximate the breast, and a plan was formulated to deliver 2 Gy per treatment by tangential irradiation. The mean (SD) irradiation dose at the lens position outside the irradiation field was reported.

Results: The scattered radiation dose outside the irradiation field was more affected by the irradiation field size than by the radiation energy. The out-of-field irradiation dose with a larger field of view was higher than that with a smaller field of view. The use of 0.07- and 0.83-mm-thick lead shield protective glasses reduced the radiation dose by 56.1% (P < .001) and 55.6% (P < .001), respectively.

Conclusions: In this experimental model, the amount of radiation the eye was exposed to during whole breast irradiation was determined by the distance of the eye from the radiation field edge and by wearing protective glasses. In clinical practice, the protection offered by eyeglasses may reduce the risk of long-term side effects and allow the use of higher intensive radiotherapy.
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http://dx.doi.org/10.1002/acm2.13073DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7700920PMC
November 2020

Dorsal Vein Complex Preserving Technique During Robot-Assisted Radical Prostatectomy.

J Endourol Case Rep 2020 17;6(3):220-223. Epub 2020 Sep 17.

Department of Urology, Aichi Medical University, Nagakute, Japan.

Recently, two techniques of robot-assisted radical prostatectomy (RARP), which preserve dorsal vein complex (DVC), endopelvic fascia, and full neurovascular bundle (NVB), through anterior approach were reported. The techniques in a relatively large workspace seem less technically demanding than Retzius-sparing RARP. In this case report, we present a further modified technique of transperitoneal-anterior-antegrade approach with a division of the endopelvic fascia to reduce the technical demands. In a routine evaluation, a 65-year-old man was shown to have a prostate-specific antigen level of 5.07 ng/mL. Prostatic biopsy revealed a Gleason score of 6 (3 + 3) adenocarcinoma in 2 of the 12 specimens, and the clinical stage was diagnosed as cT2aN0M0. RARP was performed including transperitoneal full NVB sparing, antegrade preservation of DVC, and division of endopelvic fascia to increase the prostate mobility and reduce technical demands. The patient completely gained continence on the day after removal of the catheter, and potency was recovered 30 days after surgery. Our DVC preservation technique in the transperitoneal-anterior-antegrade approach with a division of the endopelvic fascia during RARP may be safe, reduce technical demands, and facilitate early recovery of continence and sexual function after surgery.
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http://dx.doi.org/10.1089/cren.2020.0021DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7580670PMC
September 2020

Discontinuation of first-line molecular-targeted therapy and prognosis in patients with metastatic renal cell carcinoma: Impact of disease progression vs. adverse events.

Urol Oncol 2020 12 18;38(12):937.e19-937.e25. Epub 2020 Jul 18.

Department of Nephro-urology, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan.

Objectives: We evaluated the impact of discontinuation of first-line (1L) molecular-targeted therapy on prognostic outcomes among patients with metastatic renal cell carcinoma (mRCC).

Methods: Study patients with mRCC were treated with 1L molecular-targeted agents at 4 separate institutions. Prognostic outcomes in this patient cohort were analyzed retrospectively based on whether discontinuation of 1L therapy was related to adverse events (AEs) or progression of disease (PD).

Results: Of the 201 patients enrolled, 117 patients (58%) and 84 patients (42%) discontinued 1L targeted therapy due to PD and AEs, respectively. Second-line therapy was subsequently provided to 101 (86%) and 66 (79%) of the patients who discontinued 1L therapy secondary to PD or AEs, respectively. Patients who discontinued 1L therapy due to AEs were significantly older than those with PD. The progression-free survival and overall survival from the initiation of 1L targeted therapy were significantly longer in patients who discontinued 1L therapy due to AE than in those who discontinued 1L therapy due to PD. The OS from the initiation of second-line targeted therapy was significantly longer in patients who discontinued 1L therapy due to AE than those with PD. Furthermore, AE as a reason for discontinuation of 1L targeted therapy as opposed to PD was independently associated with longer progression-free survival and OS as determined by multivariate analysis.

Conclusions: Our findings suggest that mRCC patients who discontinue 1L therapy due to AEs have a more favorable prognosis than those who discontinue therapy due to PD.
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http://dx.doi.org/10.1016/j.urolonc.2020.06.023DOI Listing
December 2020

Body Condition Score Estimation Based on Regression Analysis Using a 3D Camera.

Sensors (Basel) 2020 Jul 2;20(13). Epub 2020 Jul 2.

Field Science Center, Faculty of Agriculture, University of Miyazaki, 1 Chome-1 Gakuenkibanadainishi, Miyazaki 889-2192, Japan.

The Body Condition Score (BCS) for cows indicates their energy reserves, the scoring for which ranges from very thin to overweight. These measurements are especially useful during calving, as well as early lactation. Achieving a correct BCS helps avoid calving difficulties, losses and other health problems. Although BCS can be rated by experts, it is time-consuming and often inconsistent when performed by different experts. Therefore, the aim of our system is to develop a computerized system to reduce inconsistencies and to provide a time-saving solution. In our proposed system, the automatic body condition scoring system is introduced by using a 3D camera, image processing techniques and regression models. The experimental data were collected on a rotary parlor milking station on a large-scale dairy farm in Japan. The system includes an application platform for automatic image selection as a primary step, which was developed for smart monitoring of individual cows on large-scale farms. Moreover, two analytical models are proposed in two regions of interest (ROI) by extracting 3D surface roughness parameters. By applying the extracted parameters in mathematical equations, the BCS is automatically evaluated based on measurements of model accuracy, with one of the two models achieving a mean absolute percentage error () of 3.9%, and a mean absolute error () of 0.13.
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http://dx.doi.org/10.3390/s20133705DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7374283PMC
July 2020

A multicenter study of radiation doses to the eye lenses of medical staff performing non-vascular imaging and interventional radiology procedures in Japan.

Phys Med 2020 Jun 20;74:83-91. Epub 2020 May 20.

Human Resources Development Center, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage, Chiba 263-8555, Japan.

Purpose: This study aimed to measure the eye lens doses received by physicians and other medical staff participating in non-vascular imaging and interventional radiology procedures in Japan.

Material And Methods: From October 2014 to March 2017, 34 physicians and 29 other medical staff engaged in non-vascular imaging and interventional radiology procedures at 18 Japanese medical facilities. These professionals wore radioprotective lead glasses equipped with small, optically stimulated luminescence dosimeters and additional personal dosimeters at the neck during a 1-month monitoring period. The H(3) and the H(10) and H(0.07) were obtained from these devices, respectively. The monthly H(3), H(10), and H(0.07) for each physician and other medical staff member were then rescaled to a 12-month period to enable comparisons with the revised occupational equivalent dose limit for the eye lens.

Results: Among physicians, the average annual H(3) values measured by the small luminescence dosimeters on radioprotective glasses were 25.5 ± 38.3 mSv/y (range: 0.4-166.8 mSv/y) and 9.3 ± 16.6 mSv/y (range: 0.3-82.4 mSv/y) on the left and right sides, respectively. The corresponding values for other medical staff were 3.7 ± 3.1 mSv/y (range: 0.4-10.4 mSv/y) and 3.2 ± 2.7 mSv/y (range: 0.5-11.5 mSv/y), respectively.

Conclusions: The eye lens doses incurred by physicians and other medical staff who engaged in non-vascular imaging and interventional radiology procedures in Japan were provided. Physicians should wear radioprotective glasses and use additional radioprotective devices to reduce the amount of eye lens doses they receive.
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http://dx.doi.org/10.1016/j.ejmp.2020.05.004DOI Listing
June 2020

Molecular epidemiological survey and phylogenetic analysis of bovine respiratory coronavirus in Japan from 2016 to 2018.

J Vet Med Sci 2020 Jun 9;82(6):726-730. Epub 2020 Apr 9.

Center for Animal Disease Control, University of Miyazaki, Miyazaki 889-2192, Japan.

Bovine coronavirus (BCoV) is an etiological agent of bovine respiratory disease (BRD). BRD is a costly illness worldwide; thus, epidemiological surveys of BCoV are important. Here, we conducted a molecular epidemiological survey of BCoV in respiratory-diseased and healthy cattle in Japan from 2016 to 2018. We found that 21.2% (58/273) of the respiratory-diseased cattle were infected with BCoV. The respiratory-diseased cattle had virus amounts 4.7 times higher than those in the asymptomatic cattle. Phylogenetic analyses showed that the BCoV identified in Japan after 2005 formed an individual lineage that was distinct from the strains found in other countries. These results suggest that BCoV is epidemic and has evolved uniquely in Japan.
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http://dx.doi.org/10.1292/jvms.19-0587DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7324836PMC
June 2020

[Reduction of Radiation Exposure to Operator with Radiation Protective Device in ERCP Procedure Using Over-coach X-ray TV System].

Nihon Hoshasen Gijutsu Gakkai Zasshi 2020 ;76(1):54-63

Research Institute of Nuclear Engineering, University of Fukui.

It is important to reduce the dose received by medical staffs. The purpose of this study was to evaluate the effect of protective curtain and the property of small optically stimulated luminescence (OSL) dosimeters used for ambient dose measurement in fluoroscopy. The property of small OSL dosimeters was investigated in terms of uniformity, changing fluoroscopy time and polymethyl methacrylate (PMMA) thickness, and angular dependence. Paper pipes were assembled in glid shape and ambient dose was investigated by using small OSL dosimeters that were put on them with and without protective curtain. Air kerma was investigated by small OSL dosimeters that were put on a head phantom at the position of eyes. Dose response of small OSL dosimeters was independent of fluoroscopy time and PMMA thickness, so it is appropriate to measure ambient dose by small OSL dosimeters. In relation to ambient dose, there was significant difference with and without protective curtain (p<0.001, paired-t-test). These air kerma on the head phantom were reduced to approximately 20% by attaching protective curtain. In order to reduce the dose received by operators, it is desirable to use protective curtain.
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http://dx.doi.org/10.6009/jjrt.2020_JSRT_76.1.54DOI Listing
February 2020

A more accurate and safer method for the measurement of scattered radiation in X-ray examination rooms.

Radiol Phys Technol 2020 Mar 23;13(1):69-75. Epub 2019 Dec 23.

Showa University Graduate School of Health Sciences, Tokyo, Japan.

Advancements in and increasing usage of complex diagnostic examinations with interventional procedures and surgeries has led to an increase in the occupational radiation doses received by physicians and other medical staff. Measuring the scattered radiation doses received by these staff is vital for the development-effective radiation protection programs. In this study, we measured scattered doses during angiography and digital breast tomosynthesis examinations with small-type dosimeters using our jungle gym (JG) method with measurement points at 50-cm intervals. The results were compared with measurements taken using the conventional ion chamber method. The JG method uses paper pipe tubes and a plastic joint structure and allows measurements at different points inside an examination room. The difference between measurements can be attributed to the radiation absorption characteristics of the components used in the JG method. A maximum radiation dose reduction of 20% was observed due to absorption by the JG components. This effect was smaller than the measurement error produced because of reproducibility issues and other limitations of the conventional method. The conventional measurement has disadvantages that are associated with the reproducibility of measurement points, equipment load, and the radiation exposure experienced by the measurer. The proposed JG method exhibits significant improvements in all these aspects. Furthermore, the measurer does not have to be present in the measurement room; therefore, the JG method is extremely safe and useful for radiation protection.
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http://dx.doi.org/10.1007/s12194-019-00550-6DOI Listing
March 2020

Clinical pharmacokinetics of flomoxef in prostate tissue and dosing considerations for prostatitis based on site-specific pharmacodynamic target attainment.

J Infect Chemother 2020 Feb 9;26(2):236-241. Epub 2019 Dec 9.

Department of Clinical Pharmacotherapy, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.

Flomoxef is used to treat bacterial prostatitis; however, its prostatic pharmacokinetics have not been fully clarified. Flomoxef (500 or 1000 mg) was administered to patients with benign prostatic hypertrophy (n = 54). After a 0.5-h infusion, venous blood samples were drawn at time points of 0.5-5 h, and prostate tissue samples were collected at time points of 0.5-1.5 h during transurethral resection of the prostate. The drug concentrations in plasma and prostate tissue were analyzed pharmacokinetically and used for a stochastic simulation to predict the probability of attaining pharmacodynamic target in prostate tissue. Showing dose linearity in the prostatic pharmacokinetics, flomoxef rapidly penetrated into prostate tissue, with a prostate/plasma ratio of 0.48-0.50 (maximum drug concentration) and 0.42-0.55 (area under the drug concentration-time curve). Against the tested populations of Escherichia coli, Klebsiella and Proteus species isolates, 0.5-h infusion of 1000 mg three times daily achieved a ≥90% expected probability of attaining the bactericidal target (70% of the time above the minimum inhibitory concentration [MIC]) in prostate tissue. The site-specific pharmacodynamic-based breakpoint (the highest MIC at which the target-attainment probability in prostate tissue was >90%) values were 0.25 mg/L (MIC for 90th percentile of E. coli and Klebsiella species) for 500 mg four times daily and 0.5 mg/L (MIC of Proteus species) for 1000 mg four times daily. These results help to fully characterize the prostatic pharmacokinetics of flomoxef, while also helping to rationalize and optimize the dosing regimens for prostatitis based on site-specific pharmacodynamic target attainment.
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http://dx.doi.org/10.1016/j.jiac.2019.08.019DOI Listing
February 2020

Evaluation of scattered radiation from fluoroscopy using small OSL dosimeters.

Radiol Phys Technol 2019 Dec 6;12(4):393-400. Epub 2019 Nov 6.

Department of Radiology, Eastern Chiba Medical Center, 3-6-2, Okayamadai, Togane, Chiba, 283-8686, Japan.

Recently, there has been a significant amount of interest in studying the importance of radiation doses to the eye lens during endoscopic retrograde cholangiopancreatography (ERCP). A study that focused on measuring the scattered radiation using an ionization chamber survey meter reported that a lead curtain was useful in reducing the scattered radiation. The over-couch X-ray tube system tends to deliver higher doses to the head and neck of the staff involved in the procedure than the under-couch X-ray tube position. In this study, a small optically stimulated luminescence (OSL) dosimeter called the nanoDot was used to evaluate and measure the amount of radiation; this dosimeter was developed by Landauer Ltd. and was specifically designed for point measurements. There are numerous studies that have reported the usefulness of personal OSL dosimeters other than the nanoDot to measure scattered radiation. Here, we evaluated the amount of scattered radiation, along with the degree of reduction achieved with the use of a protective curtain, while employing a personal OSL dosimeter and nanoDot. When the scattered radiation dose was measured using the nanoDot, the maximum recorded value without a protective curtain was 0.363 mGy and that with a protective curtain was 0.026 mGy, both at the height of 100 cm. The maximum reduction rate of scattered radiation while using a protective curtain was approximately 93% and 97% at 100 cm and 150 cm, respectively. The measured values recorded using both personal OSL dosimeters and nanoDot machine were strongly correlated.
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http://dx.doi.org/10.1007/s12194-019-00536-4DOI Listing
December 2019

Effects of live yeast supplementation on serum oxidative stress biomarkers and lactation performance in dairy cows during summer.

J Vet Med Sci 2019 Dec 9;81(12):1705-1712. Epub 2019 Oct 9.

Laboratory of Veterinary Internal Medicine, Faculty of Agriculture, University of Miyazaki, 1-1, Gakuen Kibanadai-nishi, Miyazaki 889-2192, Japan.

This study aimed to evaluate the effects of live yeast (Saccharomyces cerevisiae) (LY) supplementation on serum oxidative stress biomarkers, antioxidant vitamin levels, and lactation performance in dairy cows during summer. A total of 16 lactating cows weighing 707.5 ± 13.1 kg (mean ± standard error) were enrolled and randomly assigned to either supplemented (n=8) or control group (n=8). In the supplemented group, the cows were administered with LY product at 10 g/day per cow from mid-July to mid-September for 8 weeks. The serum levels of derivatives of reactive oxygen metabolites in the supplemented group were lower (P<0.05) at week 6. The serum retinol and blood glucose concentrations in the supplemented group were higher (P<0.01) at week 8. LY supplementation did not affect physiological responses, such as rectal temperature, respiratory rate, protein and cholesterol metabolism, and lactation performance. During the study period, daily average milk yield decreased in both groups. The reduction rates of milk yield in the supplemented and control groups were 17.6 and 20.0%, respectively. These results suggest that LY supplementation may reduce oxidative stress and improve carbohydrate metabolism in lactating dairy cows during summer.
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http://dx.doi.org/10.1292/jvms.19-0328DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6943311PMC
December 2019

Response of a nanoDot OSLD system in megavoltage photon beams.

Phys Med 2019 Aug 28;64:74-80. Epub 2019 Jun 28.

Nagase Landauer Ltd., Block C22-1, Suwa, Tsukuba, Ibaraki 300-2686, Japan.

Purpose: The aim of this study was to investigate the response of a nanoDot optically stimulated luminescence dosimeter (OSLD) system in megavoltage photon beams.

Methods: The nanoDot response was compared with the ionization chamber measurements for 4-18-MV photons in a plastic water phantom. The response was also calculated by the Monte Carlo method. In addition, the perturbation correction factor, P, in the nanoDot cavity was calculated according to the Burlin's cavity theory. The angular dependence of the nanoDot was evaluated using a spherical phantom.

Results: The calculated and measured nanoDot responses at a 10-cm depth and 10 × 10-cm field were in agreement within 1% for 4-18-MV. The response increased by 3% at a 20 × 20-cm field for the lower energy of 4 MV; however, it was constant within ±1% for 6-18 MV. The response was in a range from 1.0 to 0.99 for mean photon energy of more than 1.0 MeV but it increased with less than the 1.0 MeV. P for the nanoDot cavity was approximately constant at 0.96-0.97 for greater than and equal to 10 MV. The angular dependence decreased by 5% and 3% for 6 and 15 MV, respectively.

Conclusions: The nanoDot was energy-independent in megavoltage photon beams.
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http://dx.doi.org/10.1016/j.ejmp.2019.06.014DOI Listing
August 2019

Increased infiltration of CCR4-positive regulatory T cells in prostate cancer tissue is associated with a poor prognosis.

Prostate 2019 10 7;79(14):1658-1665. Epub 2019 Aug 7.

Department of Urology, Aichi Medical University School of Medicine, Nagakute, Japan.

Background: Regulatory T cells (Tregs) play important roles in the suppression of immune responses, including antitumor immune responses. C-C chemokine receptor 4 (CCR4) is highly expressed on effector Tregs, and anti-CCR4 antibody is attracting attention as a novel immunotherapeutic agent for solid tumors. This study aimed to evaluate the expression of CCR4-positive Tregs (CCR4+Tregs) in prostate cancer and estimate the clinical potential of CCR4-targeting therapy for prostate cancer.

Methods: A total of 15 radical prostatectomy (RP) specimens and 60 biopsy specimens from individuals diagnosed with prostate cancer were analyzed to evaluate the infiltration of CCR4+Tregs in prostate cancer. The relationships between the number of CCR4+Tregs and clinical parameters were investigated in RP and biopsy specimens. Moreover, the total number of Tregs, CCR4+Tregs, and T cells and the ratio of CCR4+Tregs to Tregs and T cells in biopsy specimens were compared between patients with poor prognosis who progressed to castration-resistant prostate cancer (CRPC) within 12 months (n = 13) and those with good prognosis who were stable with hormone-sensitive prostate cancer over 12 months (n = 47). Furthermore, biopsy specimens were divided into two groups: low and high CCR4+Treg expression groups and the prognosis was compared between them.

Results: There was a higher expression of CCR4+Tregs in RP specimens with a higher (≥8) Gleason score than in those with a lower (<8) Gleason score (P = .041). In biopsy specimens, 65.9% Tregs were positive for CCR4. The number of CCR4+Tregs positively correlated with clinical stage (P < .001) and Gleason score (P = .006). The total number of Tregs and CCR4+Tregs significantly increased in the poor prognosis group compared with that in the good prognosis group (P = .024 and .01, respectively). Furthermore, patients with lower CCR4+Treg expression levels showed a significantly longer time to progression to CRPC (not reached vs 27.3 months; P < .001) and median survival time (not reached vs 69.0 months; P = .014) than those with higher expression levels.

Conclusions: CCR4+Tregs are highly infiltrated in the prostate tissue of patients with poor prognosis with potential to progress to CRPC. Furthermore, the degree of infiltration of CCR4+Tregs is related to the prognosis of prostate cancer.
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http://dx.doi.org/10.1002/pros.23890DOI Listing
October 2019

Targeting lactate dehydrogenase‑A promotes docetaxel‑induced cytotoxicity predominantly in castration‑resistant prostate cancer cells.

Oncol Rep 2019 Jul 24;42(1):224-230. Epub 2019 May 24.

Division of Research Creation, Research Creation Support Center, Aichi Medical University, Nagakute 480‑1195, Japan.

Docetaxel (DOC) is one of the most effective chemotherapeutic agents against castration‑resistant prostate cancer (CRPC). Despite an impressive initial clinical response, the majority of patients eventually develop resistance to DOC. In tumor metabolism, where tumors preferentially utilize anaerobic metabolism, lactate dehydrogenase (LDH) serves an important role. LDH controls the conversion of pyruvate to lactate, with LDH‑A, one of the predominant isoforms of LDH, controlling this metabolic process. In the present study, the role of LDH‑A in drug resistance of human prostate cancer (PC) was examined by analyzing 4 PC cell lines, including castration‑providing strains PC3, DU145, LNCaP and LN‑CSS (which is a hormone refractory cell line established from LNCaP). Sodium oxamate (SO) was used as a specific LDH‑A inhibitor. Changes in the expression level of LDH‑A were analyzed by western blotting. Cell growth and survival were evaluated with a WST‑1 assay. Cell cycle progression and apoptotic inducibility were evaluated by flow cytometry using propidium iodide and Annexin V staining. LDH expression was strongly associated with DOC sensitivity in PC cells. SO inhibited growth of PC cells, which was considered to be caused by the inhibition of LDH‑A expression. Synergistic cytotoxicity was observed by combining DOC and SO in LN‑CSS cells, but not in LNCaP cells. This combination treatment induced additive cytotoxic effects in PC‑3 and DU145 cells, caused cell cycle arrest in G2‑M phase and increased the number of cells in the sub‑G1 phase of cell cycle in LN‑CSS cells. SO promoted DOC induced apoptosis in LN‑CSS cells, which was partially caused by the inhibition of DOC‑induced increase in LDH‑A expression. The results strongly indicated that LDH‑A serves an important role in DOC resistance in advanced PC cells and inhibition of LDH‑A expression promotes susceptibility to DOC, particularly in CRPC cells. The present study may provide valuable information for developing targeted therapies for CRPC in the future.
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http://dx.doi.org/10.3892/or.2019.7171DOI Listing
July 2019

Genetic characteristics of feral Misaki horses based on polymorphisms of microsatellites and mitochondrial DNA.

J Vet Med Sci 2019 May 12;81(5):707-711. Epub 2019 Mar 12.

Department of Veterinary Medicine, Faculty of Agriculture, University of Miyazaki, 1-1 Gakuen Kibanadai Nishi, Miyazaki 889-2192, Japan.

The Misaki horse is a Japanese native horse, known as the "feral horse of Cape Toi". In this study, we acquired the genetic information to establish their studbook, and analyzed their genetic characteristics for conservation. We genotyped 32 microsatellites and a mitochondrial D-loop region in 77 Misaki horses (80.2% of the population). The average number of alleles, observed heterozygosity, and expected heterozygosity were 3.4, 0.509, and 0.497, respectively. A neighbor-joining phylogenetic tree of individuals was constructed. Moreover, the results suggested that Misaki horses experienced a bottleneck, but it was neither severe nor recent. In addition, three mitochondrial haplotypes were confirmed. Consequently, we clarified the genetic background of Misaki horses that have been resident at Cape Toi for a long time.
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http://dx.doi.org/10.1292/jvms.18-0565DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6541847PMC
May 2019

Changes in expression of the autophagy-related genes microtubule-associated protein 1 light chain 3β and autophagy related 7 in skeletal muscle of fattening Japanese Black cattle: a pilot study.

Asian-Australas J Anim Sci 2019 Apr 13;32(4):592-598. Epub 2018 Sep 13.

Department of Biochemistry and Applied Biosciences, Faculty of Agriculture, University of Miyazaki, Miyazaki 889-2192, Japan.

Objective: Autophagy is a bulk degradation system for intracellular proteins which contributes to skeletal muscle homeostasis, according to previous studies in humans and rodents. However, there is a lack of information on the physiological role of autophagy in the skeletal muscle of meat animals. This study was planned as a pilot study to investigate changes in expression of two major autophagy-related genes, microtubule-associated protein 1 light chain 3β (MAP1LC3B) and autophagy related 7 (ATG7) in fattening beef cattle, and to compare them with skeletal muscle growth.

Methods: Six castrated Japanese Black cattle (initial body weight: 503±20 kg) were enrolled in this study and fattened for 7 months. Three skeletal muscles, M. longissimus, M. gluteus medius, and M. semimembranosus, were collected by needle biopsy three times during the observation period, and mRNA levels of MAP1LC3B and ATG7 were determined by quantitative reverse-transcription polymerase chain reaction. The expression levels of genes associated with the ubiquitin-proteasome system, another proteolytic mechanism, were also analyzed for comparison with autophagy-related genes. In addition, ultrasonic scanning was repeatedly performed to measure M. longissimus area as an index of muscle growth.

Results: Our results showed that both MAP1LC3B and ATG7 expression increased over the observation period in all three skeletal muscles. Interestingly, the increase in expression of these two genes in M. longissimus was highly correlated with ultrasonic M. longissimus area and body weight. On the other hand, the expression of genes associated with the ubiquitin-proteasome system was unchanged during the same period.

Conclusion: These findings suggest that autophagy plays an important role in the growth of skeletal muscle of fattening beef cattle and imply that autophagic activity affects meat productivity.
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http://dx.doi.org/10.5713/ajas.18.0370DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6409458PMC
April 2019

Impact of a novel biopsy instrument with a 25-mm side-notch needle on the detection of prostate cancer in transrectal biopsy.

Int J Urol 2018 08 18;25(8):746-751. Epub 2018 Jul 18.

Department of Urology, Aichi Medical University, Nagakute, Aichi, Japan.

Objectives: To evaluate the impact of a novel biopsy instrument that extends the length of the side-notch on the detection of prostate cancer in transrectal needle biopsy.

Methods: We collaborated with a biopsy needle manufacturer and developed a novel biopsy instrument (PRIMECUT II long-notch type) with a 25-mm side-notch length and 28-mm stroke length to take longer tissue cores. The sampled core length, cancer detection rate, pain and complications of 489 patients who underwent transrectal biopsy using the long-notch needle were compared with those of 469 patients who underwent biopsy using a normal instrument with a 19-mm side-notch length and 22-mm stroke length.

Results: The mean length of tissue taken by the long-notch needle was significantly longer than that of tissue taken by the normal-notch needle (16.3 vs 22.4 mm, P < 0.001). The overall cancer detection rate was 42.0% for the normal-notch needle and 51.1% for the long-notch needle (P = 0.005). In patients with a prostate volume of 20-40 mL, the cancer detection rate for the long-notch needle was especially higher than that for the normal-notch needle (74.2% vs 47.5%, P < 0.001). Multivariate analysis showed that the long-notch needle improved cancer detection significantly (odds ratio 1.702, P < 0.001). There were no differences of pain during biopsy and complication between the two groups.

Conclusions: The novel biopsy instrument with a 25-mm side-notch can take longer tissue samples safely and has a significantly higher rate of prostate cancer detection in transrectal biopsy.
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http://dx.doi.org/10.1111/iju.13722DOI Listing
August 2018

Bovine respiratory syncytial virus infection enhances Pasteurella multocida adherence on respiratory epithelial cells.

Vet Microbiol 2018 Jul 30;220:33-38. Epub 2018 Apr 30.

Department of Veterinary Science, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan; Center for Animal Disease Control, University of Miyazaki, Miyazaki, Japan. Electronic address:

Primary infection with bovine respiratory syncytial virus (BRSV) predisposes cattle to secondary infection with bacteria that cause bovine respiratory disease complex (BRDC). However, the interaction between BRSV and bacteria is unclear. This in vitro study examined the adherence of Pasteurella multocida (PM) to BRSV-infected cells was assessed in colony forming unit assays, by flow cytometry analysis, and by indirect immunofluorescence analysis (IFA) of epithelial cells (A549, HEp-2, and MDBK). An in vitro model based on infection of BRSV-infected epithelial cells revealed that PM adherence to BRSV-infected cells was 2- to 8-fold higher than uninfected cells. This was confirmed by flow cytometry analysis and IFA. Epithelial cell expression of mRNA encoding cytokines and chemokines increased after exposure to PM, but increased further after co-infection with BRSV and PM. BRSV-mediated adherence of PM to epithelial cells may underlie the serious symptoms of BRDC.
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http://dx.doi.org/10.1016/j.vetmic.2018.04.031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7117154PMC
July 2018

Evaluation of surface dose and image quality using the half-scan mode in chest computed tomography-guided interventional radiology: a phantom study.

Radiol Phys Technol 2018 Jun 27;11(2):138-148. Epub 2018 Feb 27.

Nagase-Landauer, Ltd., Block C22-1, Suwa, Tsukuba, Ibaraki, 300-2686, Japan.

The authors aimed to evaluate the effects of the half-scan mode on image quality and physician exposure to radiation in computed tomography (CT)-guided interventional radiology (IVR) to the right lung using an intermittent CT fluoroscopy technique for measuring phantom surface dose distribution and image noise. For the half-scan mode, settings at 0°, 90°, 180°, and 270° were used as the central axis of the X-ray exposure range on the chest phantom. With the center of the ventral side in the chest phantom defined as 0°, optically stimulated luminescent dosimeters were attached at five positions at 30° intervals on the right side of the phantom surface. Securing a space for device operation during the procedure is necessary. The couch was shifted downward by 50 mm to reproduce the conditions used for measurement in clinical settings. Image noise and contrast-to-noise ratio were measured to assess image quality; subjective evaluation was performed using simulated lung nodules placed in the phantom. The phantom surface dose distribution in the measured half-scan mode depended on the angle setting. Additionally, the phantom surface dose in the half-scan mode at the 90° setting was reduced by approximately 50%; however, image quality was clearly decreased. In CT-guided IVR to the right lung, using a lead drape and half-scan mode according to the procedural situation is important.
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http://dx.doi.org/10.1007/s12194-018-0445-6DOI Listing
June 2018

Seasonal changes in serum oxidative stress biomarkers in dairy and beef cows in a daytime grazing system.

J Vet Med Sci 2018 Jan 14;80(1):20-27. Epub 2017 Nov 14.

Laboratory of Veterinary Internal Medicine, Faculty of Agriculture, University of Miyazaki, 1-1, Gakuen Kibanadai-nishi, Miyazaki 889-2192, Japan.

This study aims to evaluate the oxidative stress during hot summer season using serum oxidative stress biomarkers and elucidate the effects of serum antioxidant vitamin levels in dairy and beef cows in a daytime grazing system. Blood samples were collected once a month from eight Holstein Friesian (HF) and 10 Japanese Black (JB) cows from November 2013 to October 2014. Serum values of derivatives of reactive oxygen metabolites (d-ROMs) tended to be higher in March in both breeds and those in HF cows were kept at higher (P<0.001) levels than those in JB cows during the study period. Serum levels of biological antioxidant potential (BAP) in both breeds were maintained at almost the same values during study period. The OSI [(d-ROMs/BAP) × 100] values in both breeds showed similar seasonal changes, i. e. increase from December to March and decrease from March to August or September. In addition, the OSI values in HF cows were kept at higher (P<0.01) levels than those in JB cows during the study period. Serum concentrations of α-tocopherol, β-carotene, blood urea nitrogen and total cholesterol showed similar seasonal changes in both breeds, low in the winter and high from spring to summer, which may be attributed to the pasture grass intake. Opposite changes in OSI values and serum concentrations of α-tocopherol and β-carotene indicated that antioxidant vitamin levels could affect oxidative stress status.
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http://dx.doi.org/10.1292/jvms.17-0321DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5797854PMC
January 2018

Short-term grazing behavior of cattle under indoor housing for a new-bred tetraploid ruzigrass ( Germain et Everard).

Asian-Australas J Anim Sci 2018 May 20;31(5):748-754. Epub 2017 Oct 20.

Faculty of Agriculture, University of Miyazaki, Miyazaki 8892192, Japan.

Objective: The preference evaluation of cattle is an important factor for estimation and improvement of the grazing amounts of newly introduced or bred grasses or cultivars in barn. This study was performed to assess the grazing behavior (the amount of grazing and/or the grazing speed) of cattle as indirect method using newly bred tetraploid strain 'OKI-1'(BR) hay as treatment group and 'Callide' (CG) hay as control group. It also compared the feasibility of using behavioral differences between two groups as one criteria for evaluating preference by Japanese black cattle in barn.

Methods: Three experiments were carried out using 12 growing Japanese Black cattle including 6 males and 6 females. In each experiment, the four Japanese Black cattle (2 males and 2 females) were placed in separated stall and allowed to graze BR and CG in manger that was separated into two portions for about 30 min. The position and behavior of the cattle were recorded, and weighed the residual of each gay at 15 and 30 minutes after experiment start.

Results: The BR was superior to CG in chemical composition such as protein, fibers and non-fibrous carbohydrate. The cattle, over all, tended to prefer BR over CG in the first half 15 minutes in terms of the time spent and amount of grazing. Additionally, growing cattle exhibited neophilia for BR bred newly.

Conclusion: These findings indicated the current approach could be applied for one of criteria to evaluate the preference of hay by Japanese black cattle under indoor housing environment.
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http://dx.doi.org/10.5713/ajas.17.0543DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5930286PMC
May 2018

Clinical pharmacokinetics and pharmacodynamic target attainment of pazufloxacin in prostate tissue: Dosing considerations for prostatitis.

J Infect Chemother 2017 Dec 12;23(12):809-813. Epub 2017 Oct 12.

Department of Urology, Aichi Medical University School of Medicine, Nagakute, Aichi, 480-1195, Japan.

The present study examined the clinical pharmacokinetics of pazufloxacin in prostate tissue and estimated the probability of target attainment for tissue-specific pharmacodynamic goals related to treating prostatitis using various intravenous dosing regimens. Patients with prostatic hypertrophy received prophylactic infusions of pazufloxacin (500 mg, n = 23; 1000 mg, n = 25) for 0.5 h prior to transurethral prostate resection. Drug concentrations in plasma (0.5-5 h) and prostate tissue (0.5-1.5 h) were measured by high-performance liquid chromatography and used for subsequent noncompartmental and three-compartmental analysis. Monte Carlo simulation was performed to evaluate the probability of target attainment of a specific minimum inhibitory concentration (MIC) in prostate tissue: the proportion that achieved both area under the drug concentration over time curve (AUC)/MIC = 100 and maximum concentration (C)/MIC = 8. Prostatic penetration of pazufloxacin was good with mean C ratios (prostate tissue/plasma) of 0.82-0.99 and for AUC, 0.80-0.98. The probability of reaching target MIC concentrations in prostate tissue was more than 90% for dosing schedules of 0.25 mg/L for 500 mg every 24 h (500 mg daily), 0.5 mg/L for 500 mg every 12 h (1000 mg daily), 1 mg/L for 1000 mg every 24 h (1000 mg daily), and 2 mg/L for 1000 mg every 12 h (2000 mg daily). Importantly, the 2000 mg daily regimen of pazufloxacin produced a profile sufficient to have an antibacterial effect in prostate tissue against clinical isolates of Escherichia coli and Klebsiella pneumonia with MIC values less than 2 mg/L.
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http://dx.doi.org/10.1016/j.jiac.2017.08.005DOI Listing
December 2017

Plasma anti-Müllerian hormone profile in heifers from birth through puberty and relationship with puberty onset.

Biol Reprod 2017 Jul;97(1):153-161

Laboratory of Theriogenology, Faculty of Agriculture, University of Miyazaki, Miyazaki, Japan.

The current study aimed to define the plasma profile of anti-Müllerian hormone (AMH) and follicle stimulating hormone (FSH) in heifers during postnatal life until achieving puberty, as defined by plasma progesterone (P4) profile, to demonstrate a relationship between AMH and age of puberty onset. Blood samples collected from 11 Japanese Black female calves within 1 week after birth (W 0) and then biweekly until the sixth week after puberty (WP 6) were assayed for AMH, FSH, and P4. The heifers were classified into two groups based on age of puberty onset: ≤42 weeks (early puberty group; EP, n = 4) and ≥44 weeks (late puberty group; LP, n = 7). Minimal plasma AMH concentration occurring at W 0 gradually increased to its peak level by W 10 (fourfold higher than W 0; P < 0.01) before gradually declining to a steady plateau 6 weeks before puberty (WP -6). The AMH peak was preceded by a significant rise in plasma FSH at W 4, W 6, and W 8 compared with W 0. Plasma AMH at W 16 positively correlated with WP 4 and WP 6 (r = 0.69 and 0.71, respectively; P < 0.05). Overall plasma AMH and FSH was significantly higher and lower in EP compared with LP, respectively. In conclusion, heifers exhibit a characteristic plasma AMH profile during postnatal life, such that plasma AMH at an early prepubertal age could be a biomarker for precocious puberty and postpubertal AMH levels.
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http://dx.doi.org/10.1093/biolre/iox069DOI Listing
July 2017

Axitinib-induced reversible posterior leukoencephalopathy syndrome in a patient with metastatic renal cell carcinoma.

Int Cancer Conf J 2017 Oct 2;6(4):197-199. Epub 2017 Aug 2.

Department of Urology, Aichi Medical University School of Medicine, 1-1 Karimata, Yazako, Nagakute, Aichi 480-1195 Japan.

A 61-year-old woman with metastatic renal carcinoma was treated with axitinib as a second-line tyrosine kinase inhibitor. Thirteen days after the treatment, the patient developed reversible posterior leukoencephalopathy syndrome (RPLS). Her symptoms and imaging findings resolved after withdrawal of axitinib, blood pressure control, and administration of glycerin and levetiracetam. RPLS should be kept in mind as a possible rare adverse event after axitinib administration.
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http://dx.doi.org/10.1007/s13691-017-0306-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6498335PMC
October 2017

EVALUATION OF EYE LENS DOSES OF INTERVENTIONAL CARDIOLOGISTS.

Radiat Prot Dosimetry 2017 Apr;173(1-3):218-222

Nagase Landauer, LTD., Suwa, Tsukuba, Ibaraki 300-2686, Japan.

The effective dose of medical staff members, especially interventional radiologists and cardiologists, is classified as a relatively high level. We measured the dose for interventional cardiologists by using optically stimulated luminescence dosimeters (OSLDs). However, this quantity is not the same as Hp (3). In experiments, the dose at the eye-lens position of a phantom were measured using OSLDs and thermoluminescence dosimeters (TLDs). A conversion factor from dose measured by using TLDs to OSLDs was estimated from these results. In addition, the eye doses of interventional cardiologists in clinical situations were measured, and the effect of eyewear on the eye-lens dose was discussed.
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http://dx.doi.org/10.1093/rpd/ncw321DOI Listing
April 2017

Entrance surface dose measurements using a small OSL dosimeter with a computed tomography scanner having 320 rows of detectors.

Radiol Phys Technol 2017 Mar 24;10(1):49-59. Epub 2016 Jun 24.

Nagase-Landauer, Ltd., C22-1 Suwa, Tsukuba, Ibaraki, 300-2686, Japan.

Entrance surface dose (ESD) measurements are important in X-ray computed tomography (CT) for examination, but in clinical settings it is difficult to measure ESDs because of a lack of suitable dosimeters. We focus on the capability of a small optically stimulated luminescence (OSL) dosimeter. The aim of this study is to propose a practical method for using an OSL dosimeter to measure the ESD when performing a CT examination. The small OSL dosimeter has an outer width of 10 mm; it is assumed that a partial dose may be measured because the slice thickness and helical pitch can be set to various values. To verify our method, we used a CT scanner having 320 rows of detectors and checked the consistencies of the ESDs measured using OSL dosimeters by comparing them with those measured using Gafchromic™ films. The films were calibrated using an ionization chamber on the basis of half-value layer estimation. On the other hand, the OSL dosimeter was appropriately calibrated using a practical calibration curve previously proposed by our group. The ESDs measured using the OSL dosimeters were in good agreement with the reference ESDs from the Gafchromic™ films. Using these data, we also estimated the uncertainty of ESDs measured with small OSL dosimeters. We concluded that a small OSL dosimeter can be considered suitable for measuring the ESD with an uncertainty of 30 % during CT examinations in which pitch factors below 1.000 are applied.
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http://dx.doi.org/10.1007/s12194-016-0366-1DOI Listing
March 2017

Estimation of identification limit for a small-type OSL dosimeter on the medical images by measurement of X-ray spectra.

Radiol Phys Technol 2016 Jul 3;9(2):286-92. Epub 2016 Jun 3.

Nagase Landauer, LTD., C22-1 Suwa, Tsukuba, Ibaraki, 300-2686, Japan.

Our aim in this study is to derive an identification limit on a dosimeter for not disturbing a medical image when patients wear a small-type optically stimulated luminescence (OSL) dosimeter on their bodies during X-ray diagnostic imaging. For evaluation of the detection limit based on an analysis of X-ray spectra, we propose a new quantitative identification method. We performed experiments for which we used diagnostic X-ray equipment, a soft-tissue-equivalent phantom (1-20 cm), and a CdTe X-ray spectrometer assuming one pixel of the X-ray imaging detector. Then, with the following two experimental settings, corresponding X-ray spectra were measured with 40-120 kVp and 0.5-1000 mAs at a source-to-detector distance of 100 cm: (1) X-rays penetrating a soft-tissue-equivalent phantom with the OSL dosimeter attached directly on the phantom, and (2) X-rays penetrating only the soft-tissue-equivalent phantom. Next, the energy fluence and errors in the fluence were calculated from the spectra. When the energy fluence with errors concerning these two experimental conditions was estimated to be indistinctive, we defined the condition as the OSL dosimeter not being identified on the X-ray image. Based on our analysis, we determined the identification limit of the dosimeter. We then compared our results with those for the general irradiation conditions used in clinics. We found that the OSL dosimeter could not be identified under the irradiation conditions of abdominal and chest radiography, namely, one can apply the OSL dosimeter to measurement of the exposure dose in the irradiation field of X-rays without disturbing medical images.
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http://dx.doi.org/10.1007/s12194-016-0362-5DOI Listing
July 2016

Energy dependence measurement of small-type optically stimulated luminescence (OSL) dosimeter by means of characteristic X-rays induced with general diagnostic X-ray equipment.

Radiol Phys Technol 2016 Jan 20;9(1):99-108. Epub 2015 Nov 20.

Nagase Landauer, LTD, C22-1 Suwa, Tsukuba, Ibaraki, 300-2686, Japan.

For X-ray inspections by way of general X-ray equipment, it is important to measure an entrance-skin dose. Recently, a small optically stimulated luminescence (OSL) dosimeter was made commercially available by Landauer, Inc. The dosimeter does not interfere with the medical images; therefore, it is expected to be a convenient detector for measuring personal exposure doses. In an actual clinical situation, it is assumed that X-rays of different energies will be detected by a dosimeter. For evaluation of the exposure dose measured by a dosimeter, it is necessary to know the energy dependence of the dosimeter. Our aim in this study was to measure the energy dependence of the OSL dosimeter experimentally in the diagnostic X-ray region. Metal samples weighing several grams were irradiated and, in this way, characteristic X-rays having energies ranging from 8 to 85 keV were generated. Using these mono-energetic X-rays, the dosimeter was irradiated. Simultaneously, the fluence of the X-rays was determined with a CdTe detector. The energy-dependent efficiency of the dosimeter was derived from the measured value of the dosimeter and the fluence. Moreover, the energy-dependent efficiency was calculated by Monte-Carlo simulation. The efficiency obtained in the experiment was in good agreement with that of the simulation. In conclusion, our proposed method, in which characteristic X-rays are used, is valuable for measurement of the energy dependence of a small OSL dosimeter in the diagnostic X-ray region.
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http://dx.doi.org/10.1007/s12194-015-0339-9DOI Listing
January 2016