Lee Y.,Niigata University |
Tsai D.-Y.,Niigata University |
Shinohara N.,Gifu University of Medical Science
Medical Physics | Year: 2010
Purpose: The objective was to develop and investigate an automated scoring scheme of the American College of Radiology (ACR) mammographic accreditation phantom (RMI 156, Middleton, WI) images. Methods: The developed method consisted of background subtraction, determination of region of interest, classification of fiber and mass objects by Mahalanobis distance, detection of specks by template matching, and rule-based scoring. Fifty-one phantom images were collected from 51 facilities for this study (one facility provided one image). A medical physicist and two radiologic technologists also scored the images. The human and computerized scores were compared. Results: In terms of meeting the ACR's criteria, the accuracies of the developed method for computerized evaluation of fiber, mass, and speck were 90%, 80%, and 98%, respectively. Contingency table analysis revealed significant association between observer and computer scores for microcalcifications (p<5%) but not for masses and fibers. Conclusions: The developed method may achieve a stable assessment of visibility for test objects in mammographic accreditation phantom image in whether the phantom image meets the ACR's criteria in the evaluation test, although there is room left for improvement in the approach for fiber and mass objects. © 2010 American Association of Physicists in Medicine.
Ogata Y.,Nagoya University |
Miyahara H.,Gifu University of Medical Science |
Ishigure N.,Nagoya University |
Ishihara M.,Nagoya City University |
And 2 more authors.
Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment | Year: 2014
A novel sum-peak method was developed to measure samples containing multiple radionuclides. The conventional sum-peak method is one of the absolute radioactivity measurement methods for radionuclides emitting more than one photon in coincidence. The method requires the knowledge of the total count rate as well as the peak count rates and the sum peak count rate. If there are other radionuclides in a sample, it is fraught with difficulty to estimate the total count rate of the nuclide of interest. To solve the problem, a novel calculation method solely using the peak count rates and the sum peak count rate was developed by modifying the conventional sum-peak method. The new method was theoretically verified and experimentally investigated using 60Co and 22Na, and was successfully confirmed. It was proved that the modified sum-peak method is effective to measure samples with multiple radionuclides and is quite simple and practical. © 2014 Elsevier B.V. All rights reserved.
Mano T.,Gifu University of Medical Science
Acta physiologica Hungarica | Year: 2010
Bone loss is one of the most important complications for astronauts who are exposed to long-term microgravity in space and also for bedridden elderly people. Recent studies have indicated that the sympathetic nervous system plays a role in bone metabolism. This paper reviews findings concerning with sympathetic influences on bone metabolism to hypothesize the mechanism how sympathetic neural functions are related to bone loss in microgravity. Animal studies have suggested that leptin stimulates hypothalamus increasing sympathetic outflow to bone and enhances bone resorption through noradrenaline and β-adrenoreceptors in bone. In humans, even though there have been some controversial findings, use of β-adrenoblockers has been reported to be beneficial for prevention of osteoporosis and bone fracture. On the other hand, microneurographically-recorded sympathetic nerve activity was enhanced by exposure to microgravity in space as well as dry immersion or long-term bed rest to simulate microgravity. The same sympathetic activity became higher in elderly people whose bone mass becomes generally reduced. Our recent findings indicated a significant correlation between muscle sympathetic nerve activity and urinary deoxypyridinoline as a specific marker measuring bone resorption. Based on these findings we would like to propose a following hypothesis concerning the sympathetic involvement in the mechanism of bone loss in microgravity: An exposure to prolonged microgravity may enhance sympathetic neural traffic not only to muscle but also to bone. This sympathetic enhancement increases plasma noradrenaline level and inhibits osteogenesis and facilitates bone resorption through β-adrenoreceptors in bone to facilitate bone resorption to reduce bone mass. The use of β-adrenoblockers to prevent bone loss in microgravity may be reasonable.
Liu J.,Shenyang University |
Wu J.,Harbin Medical University |
Wang B.,U.S. Center for Disease Control and Prevention |
Zeng S.,Shenyang University |
And 4 more authors.
Journal of Medical Virology | Year: 2014
It is well accepted that vaccination by oral administration has many advantages over injected parenteral immunization. The present study focuses on whether oral vaccination with a DNA vaccine could induce protective immunity against respiratory challenge infection. The M1 gene of influenza A virus was used to construct DNA vaccine using pcDNA 3.1(+) plasmid, a eukaryotic expression vector. The cationic liposomes were used to deliver the constructed DNA vaccine. In vitro and in vivo expression of M1 gene was observed in the cell line and in the intestine of orally vaccinated C57BL/6 mice, respectively. It became clear that this type of oral DNA vaccination was capable of inducing both humoral and cellular immune responses, together with an augmentation of IFN-γ production. In addition, oral vaccination with liposome-encapsulated DNA vaccine could protect the mice against respiratory challenge infection. These results suggest that gastrointestinal tract, a constituent member of the common mucosal immune system, is a potent candidate applicable as a DNA vaccine route against virus respiratory diseases. © 2013 Wiley Periodicals, Inc.
Sugiura A.,Gifu University of Medical Science |
Miyao M.,Nagoya University |
Yamamoto T.,Gifu University of Medical Science |
Takada H.,Gifu University of Medical Science
Displays | Year: 2011
The abnormal contraction of ciliary muscles due to the performance of a near visual task for several hours causes various vision problems such as asthenopia and visual loss. However, these problems can be resolved by activating the muscles by alternately repeating negative and positive accommodation. In this study, we have verified the effect of accommodation training that uses the strategy of presenting a stereoscopic movie to myopic youth and measuring the uncorrected distant visual acuity, spherical diopter (SPH), a flicker test and subjective index of asthenopia obtained using a visual analog scale (VAS). Stereoscopic movies are prepared by using the POWER 3D method (Olympus Visual Communications Co., Ltd.), which reduces the inconsistency between the experienced and the actual senses. Thirty-two myopic students aged 20 ± 1 years (16 males and 16 females) were chosen as the subjects. One group performed the accommodation training for 6 min, and the other group underwent a near visual task during the same period as the control group. We concluded that the accommodation training using a stereoscopic movie had temporarily improved visual acuity. This training seemed to lead to a decrease in asthenopia. © 2011 Elsevier B.V. All rights reserved.