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Latest Paper:
Department of Radiology, Shiga University of Medical Science, Seta Tsukinowa-cho, Otsu, Shiga 520-2192, Japan. matsuo@belle.shiga-med.ac.jp
With use of the phase shift of X-rays that occurs when they pass through an object, phase-contrast imaging (herein referred to as "phase imaging") can produce images different from those of conventional contact imaging (herein referred to as "conventional imaging"). For this reason, assessment of the image quality based on noise-equivalent quanta (NEQ) and detective quantum efficiency (DQE) which does not include object-based information may not be appropriate for comparison of image quality between phase and conventional images. As an alternative method, we conceived a new image-quality assessment method with images that contain information about an object. First, we constructed images with an object and without an object under the same imaging parameters; then, we obtained two-dimensional power spectra by Fourier transform of those images. Second, we calculated the radial direction distribution function with the power spectra, and the distribution of signal intensity, which we defined as a signal intensity distribution function (SIDF). In this way, differences in image quality were evaluated relatively based on the SIDF of the imaged object. In our study, we first confirmed that phase-imaging evaluation was not appropriate by comparing NEQ and DQE of conventional, magnification, and phase imaging. Further, comparing the image quality of projected plant seeds by employing conventional, magnification, and phase imaging, we found that the phase-imaging method provided a higher image quality regarding edge sharpness than did conventional and magnification imaging. Therefore, based on these results, our image assessment method is considered useful for evaluation of images which include object-based information.
Department of Physical Chemistry, Showa Pharmaceutical University, Higashi-Tamagawagakuen 3-3165, Machida, Tokyo 194-8543, Japan. matsuoka@ac.shoyaku.ac.jp
We used a model intestinal solution to understand the mechanisms of cholesterol lowering by the addition of plant sterols. The experimental results of the competitive solubilization of cholesterol and β-sitosterol in vitro give useful information about these mechanisms. The states of the model intestinal solution as a solubilizer were analyzed by transmission electron microscopy (TEM) and dynamic light scattering (DLS) by changing the number of components, and the bile salt and phosphatidylcholine concentrations. There were aggregates of different sizes: liposomes and mixed micelles depending on their components and concentrations. The maximum solubilization of cholesterol increased from 0.2mM to 1.3mM when adding fatty compounds in the pure bile salts system, which is almost the same as the full components model intestinal solution. Therefore, an excessive intake of fatty compounds may also increase cholesterol absorption in vivo. Even if the components of the model intestinal solution were modified from the standard condition, there were not remarkable differences in the selectivity of cholesterol and β-sitosterol in competitive solubilization. With the addition of β-sitosterol, the maximum solubilization of cholesterol decreases to almost half of that in the system with only cholesterol, except for PC-rich systems. In general, the different structures of aggregates considerably influence the maximum solubilization of sterols but not the selectivity of cholesterol and β-sitosterol in the competitive solubilization. The Gibbs energy change (ΔG°) of the solubilization of β-sitosterol showed a more negative value than cholesterol by -4 to -6kJmol(-1), which indicates that β-sitosterol is energetically favored relative to cholesterol in the model intestinal solution, regardless of the different systems.
EnteroMedics Inc., St Paul, MN, USA.
High-frequency alternating current (HFAC) is known to disrupt axonal conduction in peripheral nerves, and HFAC has much potential as a therapeutic approach for a number of pathological conditions. Many previous studies have utilized motor output as a bioassay of effects of HFAC on conduction through medium- to large-diameter motor axons. However, little is known about the effectiveness of HFAC on smaller, more slowly conducting nerve fibres. The present study tested whether HFAC influences axonal conduction through sub-diaphragmatic levels of the rat vagus nerve, which consists almost entirely of small calibre axons. Using an isolated nerve preparation, we tested the effects of HFAC on electrically evoked compound action potentials (CAPs). We found that delivery of charge-balanced HFAC at 5000 Hz for 1 min was effective in producing reversible blockade of axonal conduction. Both Aδ and C components of the vagus CAP were attenuated, and the degree of blockade as well as time to recovery was proportional to the amount of HFAC current delivered. The Aδ waves were more sensitive than C waves to HFAC blockade, but they required more time to recover.
Anal Bioanal Chem. 2011 Aug 26;:
21870070
Kosuke Yamasaki,
Yasunobu Sakuma,
Junya Sasaki,
Ken-Ichiro Matsumoto,
Kazunori Anzai,
Keisuke Matsuoka,
Chikako Honda,
Masamichi Tsukada,
Kazutoyo Endo,
Shuichi Enomoto
School of Agriculture, Meiji University, 1-1-1 Higashi-Mita, Tama-ku, Kawasaki, Kanagawa, 214-8571, Japan.
The excretion of essential trace elements, namely, Se, Sr, As, Mn, Co, V, Fe, and Zn into the bile of Se-deficient (SeD) Wistar male rats was studied using the multitracer (MT) technique, and instrumental neutron activation analysis (INAA). Normal and Se-control (SeC) rat groups were used as reference groups to compare the effects of Se levels on the behaviors of the essential trace elements. The excretion (% dose) of Se, Sr, As, Mn, Co, and V increased with Se levels in the liver. The biliary excretion of Mn and As dramatically enhanced for SeC rats compared with SeD rats, while that of V accelerated a little for SeC rats. The radioactivity levels of (59)Fe and (65)Zn in the MT tracer solution were insufficient to measure their excretion into bile. The role of glutathione and bilirubin for biliary excretion of the metals was discussed in relation to Se levels in rat liver.
Takatoshi Nakagawa,
Yuki Nishi,
Akihiro Kondo,
Yuko Shirai,
Chie Honda,
Michio Asahi,
Toshiko Tanimoto
Department of Pharmacology, Osaka Medical College, Takatsuki 569-8686, Japan.
6(I),6(IV)-Di-O-[α-l-fucopyranosyl-(1→6)-2-acetamido-2-deoxy-β-d-glucopyranosyl]-cyclomaltoheptaose (βCD){6(I),6(IV)-di-O-[α-l-Fuc-(1→6)-β-d-GlcNAc]-βCD (5)} and 6-O-[α-l-fucopyranosyl-(1→6)-2-acetamido-2-deoxy-β-d-glucopyranosyl]-βCD {6-O-[α-l-Fuc-(1→6)-β-d-GlcNAc]-βCD (6)} were chemically synthesized using the corresponding authentic compounds, bis(2,3-di-O-acetyl)-pentakis(2,3,6-tri-O-acetyl)-βCD as the glycosyl acceptor and 2,3,4-tri-O-benzyl-α-l-fucopyranosyl-(1→6)-3,4-di-O-acetyl-2-deoxy-2-(2,2,2-trichloroethoxycarbonylamino)-d-glucopyranosyl trichloroacetimidate as the fuco-glucosaminyl donor. NMR confirmed that α-l-Fuc-(1→6)-d-GlcNAc was bonded by β-linking to the βCD ring. To evaluate biological efficiency, the biological activities of the new branched βCDs were examined. The cell detachment activity of 5 was lower than that of 6 in real-time cell sensing (RT-CES) assay, indicating that 5 has lower toxicity. In SPR analysis, 5 had a higher special binding with AAL, a fucose-recognizing lectin. These results suggest that 5 could be an efficient drug carrier directed at cells expressing fucose-binding proteins.
Naozumi Mimida,
Ayano Ureshino,
Norimitsu Tanaka,
Narumi Shigeta,
Noriko Sato,
Yuki Moriya-Tanaka,
Hiroshi Iwanami,
Chikako Honda,
Akira Suzuki,
Sadao Komori,
Masato Wada
Faculty of Agriculture, Iwate University, Morioka, Iwate, 020-8550, Japan.
The apple (Malus × domestica Borkh.) is one of the commercially important fruit crops in the worldwide. The apple has a relatively long juvenile period (up to 4 years) and a long reproductive period between the flower initiation and the mature fruit (14-16 months), which prevent the fruit breeding. Therefore, the understanding of the flowering system is important to improve breeding efficiency in the apple. In this study, to examine the temporal and spatial expression patterns of the floral genes, MdTFL1, MdAP1 (MdMASD5), AFL2, and MdFT, we conducted in situ hybridization analysis in the apple shoot apex. In vegetative phase, MdTFL1 was expressed on the rib meristem zone. When vegetative meristem began converting into inflorescence meristem, the expression level of MdTFL1 was drastically decreased. At the early stage of inflorescence meristem, the expression levels of AFL2, MdFT, and MdAP1 were up-regulated in the leaf primordia and the upper region of cell layers on the shoot apex. In late stage, the expression levels of AFL2 and MdAP1 were up-regulated in the young floral primordia. At a more advanced stage, high expression of MdAP1 was observed in the inflorescence primordium through the inner layer of sepal primordia and the outer layer of receptacle primordia and floral axis. Our results suggest that AFL2, MdFT, and MdAP1 affect to convert from the vegetative meristem into the inflorescence meristem after the decline of MdTFL1 expression. After that, AFL2 and MdAP1 promote the formation of the floral primordia and floral organs.
Chem Phys Lipids. 2010 Mar 24;:
20346931
Cit:3
Department of Physical Chemistry, Showa Pharmaceutical University, Higashi-Tamagawagakuen 3-3165, Machida, Tokyo 194-8543, Japan.
Slight differences in the molecular structures of a category of sterol/stanol species affect the solubility of cholesterol in a bile salt solution. We systematically studied the preferential solubilization of cholesterol and sterol/stanol in sodium taurodeoxycholate solutions using relatively minor plant species of sterol/stanol (brassicasterol and stigmasterol) and a non-plant sterol (cholestanol). As relatively major sterol/stanol species (beta-sitosterol, beta-sitostanol, and campesterol) have already been examined using nearly identical procedures to that used in our system, we were able to sufficiently discuss the cholesterol-lowering effects resulting from the molecular structures of six sterol/stanol species. The results of competitive solubilization revealed that cholestanol has the largest cholesterol-lowering effect, decreasing cholesterol solubility to 33% of that in a single solubilizate system. The molecular structure of cholestanol is also most similar to that of cholesterol. In contrast, brassicasterol and stigmasterol have little ability to decrease cholesterol solubility in a mixed binary system. Both have an unsaturated double bond at the side chain of the steroid ring. By applying thermodynamic analyses to these results, we found that the Gibbs energy changes (DeltaG( degrees )) of solubilization for sterol/stanol species with cholesterol-lowering effects show larger negative values than that for cholesterol.
Junji Tanaka,
Hiromi Oda,
Toshihide Mimura,
Chika Honda,
Hiromu Oohara,
Hiroaki Kawasaki,
Atsushi Kondo,
Yukihito Wada
Department of Diagnostic Radiology, Saitama Medical University Hospital, 38 Morohongo, Moroyamamachi, Irumagun, Saitama, 350-0495, Japan, jtanaka@saitama-med.ac.jp.
PURPOSE: The aim of this study was to determine whether a high-resolution digital radiography system that was originally developed for mammography could be used for general radiographic purposes by means of a phantom test. MATERIALS AND METHODS: This system includes an X-ray tube with a smaller focal point than is generally used for general radiography, and a computed radiography (CR) system to provide the highest spatial resolution. The imaging object and CR plate are intentionally separated to capture an edge-enhancing effect that is the result of a phase-shift (phase contrast) of the X-rays. RESULTS: This system showed greater sharpness and spatial resolution, as well as an equal level of contrast resolution compared to a conventional X-ray system. The image sharpness in this system appears to be at least partially attributable to an edge-enhancing effect produced by the phase-contrast effect, which occurs when X-rays pass the surfaces of objects. CONCLUSION: This technique may be suitable for clinical use and may contribute to improved image-quality in general radiography.
Shizuyo Horiyama,
Chie Honda,
Kiyoko Suwa,
Yasuyo Okada,
Masanori Semma,
Atsushi Ichikawa,
Mitsuo Takayama
School of Pharmacy and Pharmaceutical Sciences, Mukogawa Women's University, Hyogo, Japan. horiyama@mukogawa-u.ac.jp
Sorbic acid (SA: CH(3)-CH=CH-CH=CH-COOH) is one of the widely used food preservatives, although there have been some reports of its toxic activity, for example, on DNA and skin cells. In order to examine the effects of SA on mammalian tissues, we have developed a highly sensitive analytical method using LC/MS/MS with positive and negative ion mode electrospray ionization (ESI). In a previous study, we found that a nonacidic eluent offers better ionization efficiency than acids or their ammoniun salts. However, optimal results could not be obtained because the anion form of SA is poorly retained on a conventional reversed phase column. To resolve this problem, we chose a new type of column and used high-resolution mass spectrometry and positive ion mode analysis. There have only been a few reports using these methods in the positive mode, for example derivatized SA, because acid compounds such as SA are usually used in the negative ion mode. However, a new type of low-carbon-content and polar-endcapped C18 phase column was developed for better separation of SA from the matrix. High-resolution selected reaction monitoring (SRM) gave the best signal to noise ratio in normal-resolution SRM. In the positive ion mode, the CH(3)OH-0.05% HCOOH/0.1% CH(3)COOH eluent system yielded the best ionization efficiency. We propose a highly sensitive and simple analysis using a two-ion-mode ESI SRM method. Such systems should allow quantification of the amount of SA in or around the cells, without the need for pretreatment such as solid phase extraction.
Manabu Aoki,
Kenta Miki,
Hiroshi Sasaki,
Masato Kido,
Jun Shirahama,
Sayako Takagi,
Masao Kobayashi,
Chikara Honda,
Chihiro Kanehira
Department of Radiology, Jikei University School of Medicine, Tokyo, Japan. maoki@jikei.ac.jp
PURPOSE: To analyze rectal bleeding prognostic factors associated with prostate brachytherapy (PB) or in combination with external-beam radiation therapy (EBRT) and to examine dosimetric indications associated with rectal bleeding. MATERIALS AND METHODS: The study included 296 patients followed up for >36 months (median, 48 months). PB was performed alone in 252 patients and in combination with EBRT in 44 patients. PB combined with EBRT is indicated for patients with a Gleason score >6. The prescribed dose was 144 Gy for monotherapy and 110 Gy for PB + EBRT (44-46 Gy). RESULTS: Although 9.1% who received monotherapy had 2.3% grade 2 rectal bleeding, 36.3% who received combined therapy had 15.9% grade 2 rectal bleeding. Combined therapy was associated with higher incidence of rectal bleeding (P = 0.0049) and higher percentage of grade 2 bleeding (P = 0.0005). Multivariate analysis revealed that R-150 was the only significant factor for rectal bleeding, and modified Radiation Therapy Oncology Group (RTOG) grade in monotherapy and biologically equivalent dose (BED) were significant for combined therapy. Moreover, grade 2 rectal bleeding increased significantly at D90 > 130 Gy. CONCLUSION: Although R-150 was the significant prognostic factor for rectal bleeding and modified RTOG rectal toxicity grade, BED was the significant prognostic factor for modified RTOG rectal toxicity grade.
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