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Retinopathy, one of the microvascular complications in diabetes, can cause blindness. Salt-loading is known to exacerbate microvascular damage and may affect retinopathy. In this study, we investigated the effect of salt loading on early lesions of diabetic retinopathy. Male C57BL/6 and KK-Ay mice were salt-loaded with 1% sodium chloride (NaCl)-containing drinking water for 12 weeks. In addition, to determine the effects of high fat and high sucrose, a high fat/high sucrose diet was also fed to the 1% NaCl-loaded group of mice of both strains. Retinal thickness was measured at an arbitrary location from the optic nerve disc, and thinning of the retina was observed in KK-Ay mice compared to C57BL/6 mice. Salt-loading caused retinal thinning in C57BL/6 mice, but not in KK-Ay mice. In KK-Ay mice, the effect of salt-loading may have been masked by the effects of obesity and diabetic status during this experimental period. There was also a small effect of QF on the retina, suggesting that dietary components other than salt loading may affect retinopathy.

Glucose is the most abundant monosaccharide, and an essential source of energy for most living cells. Glucose transport across the cell membrane is mediated by two types of transporters: facilitative glucose transporters (gene name: solute carrier 2A) and sodium–glucose cotransporters (SGLTs; gene name: solute carrier 5A). Each transporter has its own substrate specificity, distribution, and regulatory mechanisms. Recently, SGLT1 and SGLT2 have attracted much attention as therapeutic targets for various diseases. This review addresses the basal and functional properties of glucose transporters and SGLTs, and describes the pharmaceutical potential of SGLT1 and SGLT2.

Peripheral artery disease (PAD) is defined as peripheral blood flow impairment, especially in the legs, caused by atherosclerotic stenosis. The disease decreases quality of life because of intermittent claudication or necrosis of the leg. The hindlimb ischaemia model, in which ischaemia is induced by femoral artery ligation, is often utilized as a PAD model. In the hindlimb ischaemia model, nonmetabolic syndrome animals are mainly used. In this study, we investigated the usefulness of Spontaneously Diabetic Torii Leprfa (SDT fatty) rats, a new model for obese type 2 diabetes, as a new PAD animal model. We found that hindlimb blood flow in SDT fatty rats was significantly lower than that in Sprague–Dawley (SD) rats under nonischaemic conditions. Furthermore, SDT fatty rats showed a significantly higher plasma nitrogen oxide level, shorter prothrombin time, and shorter activated partial thromboplastin time than SD rats. In addition, we found that the change in blood flow 7 days after induction of hindlimb ischaemia and the number of Von Willebrand factor‐positive vessels in gastrocnemius muscles were significantly lower in SDT fatty rats than in SD rats. These results suggest that excess production of reactive oxygen species and coagulation activation could be involved in lower blood flow in non‐ischaemic rats and that decreased angiogenesis could be involved in the poor recovery of blood flow in SDT fatty rats with hindlimb ischaemia. Taken together, our results suggest that SDT fatty rats might be useful as a new model for PAD with metabolic syndrome.

Diabetes mellitus (DM) and obesity are associated with neurodegenerative diseases such as Alzheimer’s disease and psychiatric disorders such as major depression. In this study, we investigated pathophysiological changes in the brains of female Spontaneously Diabetic Torii (SDT) fatty rats with diabetes and obesity. Brains of Sprague-Dawley (SD), SDT and SDT fatty rats were collected at 58 weeks of age. The parietal cortical thickness was measured and the number of pyramidal cells in the hippocampal cornu ammonis 1 and 3 (CA1 and CA3) and the number of granule cells in the dentate gyrus (DG) regions were counted. The area of glial fibrillary acidic protein (GFAP) positivity in CA1, CA3 and DG regions were measured. The parietal cortical thickness and the number of cells in CA3 and DG regions of SDT and SDT fatty rats did not show obvious changes. On the other hand, in the CA1 region, the number of cells in SDT rats and SDT fatty rats was significantly lower than that in SD rats, and that in SDT fatty rats was significantly lower than that in SDT rats. The GFAP-positive area in SDT fatty rats was significantly reduced compared to that in SD rats only in the DG region. Preliminarily result showed that the expression of S100a9, an inflammation-related gene, was increased in the brains of SDT fatty rats. These results suggest that female SDT fatty rat may exhibit central nervous system diseases due to obesity and DM.

G‐protein coupled receptor 119 (GPR119) expression in pancreatic β‐cells and intestinal L cells is a potential therapeutic target for treating type 2 diabetes. A natural GPR119 agonist oleoylethanolamide is well known to enhance a glucose‐stimulated insulin secretion (GSIS) and glucagon‐like peptide‐1 (GLP‐1) secretion by elevating intracellular cAMP levels. In the present study, a glucose lowering effect of the GPR119 agonist, JTP‐109192 leading to improvement of insulin sensitivity was examined in Zucker Fatty (ZF) rats. We investigated the in vitro effects of JTP‐109192 on GSIS in the rat pancreatic β‐cell line (INS1E) cells and on GLP‐1 secretion in the murine enteroendocrine cell line (GLUTag) cells. We also investigated the effect of JTP‐109192 on GSIS in Sprague‐Dawley (SD) rats with single administration and its effect on glucose metabolism in ZF rats with repeated administration once daily for about 6 weeks. After repeated administration, the hyperinsulinaemic euglycaemic glucose clamp test was performed to evaluate insulin sensitivity. JTP‐109192 increased intracellular cAMP levels (EC₅₀ value: 3.6 nmol/L) and enhanced GSIS in the INS1E cells and GLP‐1 secretion in GLUTag cells. In SD rats, a single administration of JTP‐109192 enhanced GSIS at high blood glucose levels. The repeated administrations in ZF rats improved glucose metabolism without lack of drug efficacy (tachyphylaxis) and increased glucose infusion rates due to improvement of insulin sensitivity.

A core observatory satellite of the Global Precipitation Measurement (GPM) has been launched by the Japan Aerospace Exploration Agency (JAXA) in February 2014. The satellite can newly observe both liquid and solid precipitation in the high latitude region. Verification of this data is indispensable for improving observation accuracy toward utilization for hydrological cycle and water resource researches in the land area of cold region. This research project “NEPTUNE” aims for comprehensive validation of summer precipitation (rain), winter precipitation (snow fall) and their spatial distribution based on ground truth data obtained by our observation network which we will improve in Northeast Eurasia (Hokkaido, Mongolia and East Siberia), and combining other satellite data analyses. In addition, the project extends to clarify possibilities of GPM data for future applied research using modelling techniques of land surface processes, distributed river runoff, and regional climate., 宇宙航空研究開発機構によって2014 年2 月に打ち上げられた全球降水観測計画（GPM: Global Precipitation Measurement）の主衛星は高緯度地域の降水量が新規に得られる。このデータの検証は，今後の寒冷圏陸域の水循環・水資源研究等への利用促進に向けた観測精度の向上を図るうえで必要不可欠である。本研究プロジェクトでは，観測研究を実施してきた国内外の機関が協働して，北東ユーラシア（主としてモンゴル・東シベリア）で既設の観測システムを改良し，他の衛星データ解析と合わせて，夏季降水（降雨），冬季降水（降積雪）およびそれらの空間分布に関する地上検証を行う。また，今後の応用研究に向けて，陸面モデル・分布型河川流出モデル，メソ気象モデルを利用した，地域規模のGPM 観測データの利用可能性を検討する。

Cesium tin halide based perovskite Cs2SnI6 has been subjected to in-depth investigations owing to its potentiality toward the realization of environment benign Pb free and stable solar cells. In spite of the fact that Cs2SnI6 has been successfully utilized as an efficient hole transport material owing to its p-type semiconducting nature, however, the nature of the majority carrier is still under debate. Therefore, intrinsic properties of Cs2SnI6 have been investigated in detail to explore its potentiality as light absorber along with facile electron and hole transport. A high absorption coefficient (5 × 104 cm–1) at 700 nm indicates the penetration depth of 700 nm light to be 0.2 μm, which is comparable to conventional Pb based solar cells. Preparation of pure and CsI impurity free dense thin films with controllable thicknesses of Cs2SnI6 by the solution processable method has been reported to be difficult owing to its poor solubility. An amicable solution to circumvent such problems of Cs2SnI6 has been provided utilizing spray-coating in combination with spin-coating. The presence of two emission peaks at 710 and 885 nm in the prepared Cs2SnI6 thin films indicated coexistence of quantum dot and bulk parts which were further supported by transmission electron microscopy (TEM) investigations. Time-resolved photoluminescence (PL) and transient absorption spectroscopy (TAS) were employed to investigate the excitation carrier lifetime, which revealed fast decay kinetics in the picoseconds (ps) to nanoseconds (ns) time domains. Time-resolved microwave photoconductivity decay (MPCD) measurement provided the mobile charge carrier lifetime exceeding 300 ns, which was also in agreement with the nanosecond transient absorption spectroscopy (ns-TAS) indicating slow charge decay lasting up to 20 μs. TA assisted interfacial charge transfer investigations utilizing Cs2SnI6 in combination with n-type PCBM and p-type P3HT exhibited both intrinsic electron and hole transport.

Statistical iterative reconstruction is expected to improve the image quality of megavoltage computed tomography (MVCT). However, one of the challenges of iterative reconstruction is its large computational cost. The purpose of this work is to develop a fast iterative reconstruction algorithm by combining several iterative techniques and by optimizing reconstruction parameters. Megavolt projection data was acquired from a TomoTherapy system and reconstructed using our statistical iterative reconstruction. Total variation was used as the regularization term and the weight of the regularization term was determined by evaluating signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and visual assessment of spatial resolution using Gammex and Cheese phantoms. Gradient decent with an adaptive convergence parameter, ordered subset expectation maximization (OSEM), and CPU/GPU parallelization were applied in order to accelerate the present reconstruction algorithm. The SNR and CNR of the iterative reconstruction were several times better than that of filtered back projection (FBP). The GPU parallelization code combined with the OSEM algorithm reconstructed an image several hundred times faster than a CPU calculation. With 500 iterations, which provided good convergence, our method produced a 512$\times$512 pixel image within a few seconds. The image quality of the present algorithm was much better than that of FBP for patient data. An image from the iterative reconstruction in TomoTherapy can be obtained within few seconds by fine-tuning the parameters. The iterative reconstruction with GPU was fast enough for clinical use, and largely improve the MVCT images., 11 pages, 4 figures

第8回極域科学シンポジウム/横断セッション：[IA] 北極国際連携拠点の新展開12月8日（金）国立極地研究所 2階大会議室The Eighth Symposium on Polar Science/Interdisciplinary sessions: [IA] New insights of overseas research stations in the ArcticFri. 8 Dec./2F Auditorium, National Institute of Polar Research

This study investigated evapotranspiration and CO2 exchange, observed by the eddy covariance method, over two larch-dominated forests, in the middle part of the Lena basin, eastern Siberia. Compared with the Spasskaya Pad (SP) forest, the Elgeeii (EG) forest had more plant biomass and a soil texture that allowed for larger water retention. Observations in three growing seasons revealed that the two sites had similar seasonal patterns of meteorological conditions and almost the same total evapotranspiration; however, the net and gross uptakes of CO2 at the EG forest were 1·61 and 1·31 times those at the SP forest, respectively. The difference in aboveground biomass was probably responsible for the higher productivity at EG. Less aboveground biomass would result in less transpiration by trees at SP, which would be compensated for in total evapotranspiration by soil evaporation and transpiration by the forest floor vegetation. It is likely that forest transpiration is commonly optimized to the same level of evapotranspiration under similar meteorological conditions through differences in the contributions of evapotranspiration from the forest floor vegetation and the soil water availability. Water use efficiency (WUE) displayed different patterns, reflecting the seasonal variations in each flux. Seasonal sequences in the WUE at EG indicated a midsummer depletion, which is commonly observed in forest ecosystems under a broad climate. Daily variation corresponding to the vapour pressure deficit and the cloud cover conditions (reduced solar radiation) was also observed. In contrast, WUE was relatively invariable at the seasonal and daily scales at SP. Copyright © 2013 John Wiley & Sons, Ltd.

第7回極域科学シンポジウム/横断セッション:[IA] ニーオルスン観測拠点設立25周年記念横断セッション—北極域の科学（ニーオルスン、GRENE、ArCS)—12月2日（金）国立極地研究所1階交流アトリウム

This study was conducted to determine the impact of fire on the physical and chemical characteristics of soil as well as on the distribution of soil organic and black carbon stocks in ice-rich permafrost regions in eastern Siberia. Three intact and four burnt forest sites with different ignition years were selected. Volumetric water content did not increase in any of the burnt forests in the top soil layer but moisture accumulated at the bottom of the active layer of older burnt sites. Salt content increased in the active layer following forest fires, but a decade later, the salt increase disappeared, indicating the temporal characteristic of this change. The concentration of Na+ and SO_[4]^[2-] in the active layer of the 4-year-old burnt forest site increased 70% and 49% respectively, while other salts (Mg2+ and Ca2+) did not show any variation in the other burnt forest sites compared to the intact forest sites. The organic carbon stock in the top 200 cm of soil in the intact forest site (44.0 kg m^[-2]) was similar to that in burnt forest sites (41.4-43.7 kg m^[-2]). On average, 37% of organic carbon was found in the upper 30 cm of the soil profile for intact and burnt forests. The organic carbon distribution in the top 200 cm soil layer in Central Yakutia was higher than previously reported for other Siberian sites. The highest concentrations of black carbon were found in the upper soil layers (20-40 mg g^[-1] organic carbon) but concentrations of 10-20 mg g^[-1] organic carbon were also found in the permafrost (120-200 cm depth) of the intact and burnt forests. There was no variation in black carbon concentration among the sites. The presence of black carbon in the permafrost suggests that the active layer was deeper before and that black carbon accumulated because of fires that occurred at that time.

Soil moisture plays an important role in hydrology. Understanding factors (such as topography, vegetation, and meteorological conditions) that influence spatio-temporal variability in soil moisture, and how this influence is manifested, is important for understanding hydrological processes. A number of distributed (quasi-)physical hydrological models have been developed to investigate this subject. Previous studies have shown that the spatial differences in the distribution of soil types (residual and colluvial soils) dominantly reflect spatio-temporal fluctuations in soil moisture and runoff. We present a methodology for assessing the spatial distribution of residual and colluvial soils, which differ with respect to their physical characteristics, in a 0·88 km2 forested catchment with complex topography and a complex land-use history. Our method is based on penetration resistance profile data; in this data set, each data point represents soil physical characteristics within an area of about 25 m2. If the spatial distribution of soils under similar meteorological, geological, historical land use, and other conditions could be characterized on the basis of similarity in topographic features, then the spatial distribution of soil could be predicted based on relationships between various topographic indices (e.g. topographic index and local slope). We tested whether our model correctly assessed the reference data. The model's results were 90·5% correct for residual soils and 87·3% correct for colluvial soils. Further studies will quantify the relationships between topographic features of land covered by residual and colluvial soils and changes in spatio-temporal variations in the catchment (e.g. vegetation and land use) as a function of geology or meteorology. Copyright © 2007 John Wiley & Sons, Ltd.

第6回極域科学シンポジウム分野横断セッション：[IA] 急変する北極気候システム及びその全球的な影響の総合的解明―GRENE北極気候変動研究事業研究成果報告2015―11月19日（木） 国立極地研究所 2階 大会議室

第6回極域科学シンポジウム分野横断セッション：[IA] 急変する北極気候システム及びその全球的な影響の総合的解明―GRENE北極気候変動研究事業研究成果報告2015―11月19日（木） 国立極地研究所１階交流アトリウム

第6回極域科学シンポジウム分野横断セッション：[IA] 急変する北極気候システム及びその全球的な影響の総合的解明―GRENE北極気候変動研究事業研究成果報告2015―11月19日（木） 国立極地研究所１階交流アトリウム

主催：JST/CREST，Vrije University, ALTERRA, IBPC

主催：JST/CREST，Vrije University, ALTERRA, IBPC

主催：JST/CREST，Vrije University, ALTERRA, IBPC

主催：JST/CREST，Vrije University, ALTERRA, IBPC

主催：JST/CREST，Vrije University, ALTERRA, IBPC

Seasonal changes in the water and energy exchanges over a pine forest in eastern Siberia were investigated and compared with published data from a nearby larch forest. Continuous observations (April to August 2000) were made of the eddy-correlation sensible heat flux and latent heat flux above the canopy. The energy balance was almost closed, while the sum of the turbulent fluxes sometimes exceeded the available energy flux (Rn-G) when the latent heat flux was large; this was related to the wind direction. We examined the seasonal variation in energy balance components at this site. The seasonal variation and magnitude of the sensible heat flux (H) was similar to that of the latent heat flux (λE), with maximum values occurring in mid-June. Consequently, the Bowen ratio was around 1.0 on many days during the study period. On some clear days just after rainfall, λE was very large, and the sum of H and λE exceeded Rn-G. The evapotranspiration rate above the dry canopy from May to August was 2.2 mm・day^-1. The contributions of understory evapotranspiration (Eu) and overstory transpiration (Eo) to the evapotranspiration of the entire ecosystem (Et) were both from 25 to 50% throughout the period analyzed. These results suggest that Eu plays a very important role in the water cycle at this site. From snowmelt through the tree growth season (23 April to 19 August 2000), the total incoming water, comprised of the sum of precipitation and the water equivalent of the snow at the beginning of the melt season, was 228 mm. Total evapotranspiration from the forest, including interception loss and evaporation from the soil when the canopy was wet, was 208-254 mm. The difference between the incoming and outgoing amounts in the water balance was from +20 to -26 mm. The water and energy exchanges of the pine and larch forest differed in that λE and H increased slowly in the pine forest, while λE increased rapidly in the larch forest and H decreased sharply after the melting season. Consequently, the shape of the Bowen ratio curves at the two sites differed over the period analyzed, as a result of the differences in the species in each forest and in soil thawing.

To understand the effects of climate change on the growing season of plants in Japan, we conducted trend analysis of phenological phases and examined the relationship between phenology and air temperatures. We used phenological data for Ginkgo biloba L., collected from 1953 to 2000. We defined the beginning and the end of the growing season (BGS and EGS) as the dates of budding and leaf fall, respectively. Changes in the air temperature in the 45 days before the date of BGS affected annual variation in BGS. Annual variation in air temperature over the 85 days before EGS affected the date of EGS. The average annual air temperature in Japan has increased by 1.3℃ over the last four decades (1961-2000), and this increase has caused changes in ginkgo phenology. In the last five decades (1953-2000), BGS has occurred approximately 4 days earlier than previously, and EGS has occurred about 8 days later. Consequently, since 1953 the length of the growing season (LGS) has been extended by 12 days. Since around 1970, LGS and air temperatures have shown increasing trends. Although many researchers have stated 2 that phenological events are not affected by the air temperature in the fall, we found high correlations not only between budding dates and air temperatures in spring but also between leaf-fall dates and air temperatures in autumn. If the mean annual air temperature increases by 1℃, LGS could be extended by 10 days. We also examined the spatial distribution of the rate of LGS extension, but we did not find an obvious relationship between LGS extension and latitude., The definitive version is available at www.blackwell-synergy.com

The Spontaneously Diabetic Torii Leprfa (SDT fatty) rat is a novel type 2 diabetic model wherein both male and female rats develop glucose and lipid abnormalities from a young age. In this study, we investigated gender differences in abnormalities and related complications in SDT fatty rats. Food intake was higher in males compared to female rats; however, body weight was not different between genders. Progression of diabetes, including increases in blood glucose and declines in blood insulin, was observed earlier in male rats than in females, and diabetic grade was more critical in male rats. Blood lipids tended to increase in female rats. Gonadal dysfunction was observed in both male and female rats with aging. Microangiopathies, such as nephropathy, retinopathy, neuropathy, and osteoporosis, were seen in both genders, and pathological grade and progression were more significant in males. Qualitative and quantitative changes were observed for metabolic disease gender differences in SDT fatty rats. The SDT fatty rat is a useful model for researching gender differences in metabolic disorders and related diseases in diabetes with obesity.

The water and energy exchanges in forests form one of the most important hydro-meteorological systems. There have been far fewer investigations of the water and heat exchange in high latitude forests than of those in warm, humid regions. There have been few observations of this system in Siberia for an entire growing season, including the snowmelt and leaf fall seasons. In this study, the characteristics of the energy and water budgets in an eastern Siberian larch forest were investigated from the snowmelt season to the leaf fall season. The latent heat flux was strongly affected by the transpiration activity of the larch trees and increased quickly as the larch stand began to foliate. The sensible heat dropped at that time, although the net all-wave radiation increased. Consequently, the seasonal variation in the Bowen ratio was clearly “U”-shaped, and the minimum value (1.0) occurred in June and July. The Bowen ratio was very high (10 - 25) in early spring, just before leaf opening. The canopy resistance for a big leaf model far exceeded the aerodynamic resistance and fluctuated over a much wider range. The canopy resistance was strongly restricted by the saturation deficit, and its minimum value was 100 sec m^-1 (10 mm sec^-1 in conductance). This minimum canopy resistance is higher than values obtained for forests in warm, humid regions, but is similar to those measured in other boreal conifer forests. It has been suggested that the senescence of leaves also affects the canopy resistance, which was higher in the leaf fall season than in the foliated season. The mean evapotranspiration rate from 21 April 1998 to 7 September 1998 was 1.16 mm day^-1, and the maximum rate, 2.9 mm day^-1, occurred at the beginning of July. For the growing season from 1 June - 31 August, this rate was 1.5 mm day^-1. The total evapotranspiration from the forest (151 mm) exceeded the amount of precipitation (106 mm) and was equal to 73% of the total water input (211 mm), including the snow water equivalent. The understory evapotranspiration reached 35% of the total evapotranspiration, and the interception evaporation was 15% of the gross precipitation. The understory evapotranspiration was high and the interception evaporation was low because the canopy was sparse and the LAI was low.

第4回極域科学シンポジウム横断セッション：[IA] 「急変する北極気候システム及びその全球的な影響の総合的解明」―GRENE北極気候変動研究事業研究成果報告2013―11月12日（火） 国立極地研究所 ２階大会議室

第4回極域科学シンポジウム横断セッション：[IA] 「急変する北極気候システム及びその全球的な影響の総合的解明」―GRENE北極気候変動研究事業研究成果報告2013―11月12日（火） 国立極地研究所 ２階大会議室

第4回極域科学シンポジウム横断セッション：[IA] 「急変する北極気候システム及びその全球的な影響の総合的解明」―GRENE北極気候変動研究事業研究成果報告2013―11月12日（火） 国立極地研究所 ２階大会議室

Spontaneously Diabetic Torii Leprfa (SDT fatty) rat, established by introducing the fa allele of the Zucker fatty rat into SDT rat genome, is a new model of obese type 2 diabetes. Both male and female SDT fatty rats show overt obesity, and hyperglycemia and hyperlipidemia are observed at a young age as compared with SDT rats. With early incidence of diabetes mellitus, diabetic complications, such as nephropathy, retinopathy, and neuropathy, in SDT fatty rats were seen at younger ages compared to those in the SDT rats. In this paper, we overview pathophysiological features in SDT fatty rats and also describe new insights regarding the hematology, blood pressure, renal complications, and sexual dysfunction. The SDT fatty rats showed an increase of leukocytes, especially the monocyte count, prominent hypertension associated with salt drinking, end-stage renal disease with aging, and hypogonadism. Unlike other diabetic models, the characteristic of SDT fatty rat is to present an incidence of diabetes in females, hypertension, and retinopathy. SDT fatty rat is a useful model for analysis of various metabolic disorders and the evaluation of drugs related to metabolic disease.

The Spontaneously Diabetic Torii (SDT) rat is an inbred strain of Sprague-Dawley rat and recently is established as a nonobese model of type 2 diabetes (T2D). Male SDT rats show high plasma glucose levels (over 700 mg/dL) by 20 weeks. Male SDT rats show pancreatic islet histopathology, including hemorrhage in pancreatic islets and inflammatory cell infiltration with fibroblasts. Prior to the onset of diabetes, glucose intolerance with hypoinsulinemia is also observed. As a result of chronic severe hyperglycemia, the SDT rats develop profound complications. In eyes, retinopathy, cataract, and neovascular glaucoma are observed. Proliferative retinopathy, especially, resulting from retinal neovascular vessels is a unique characteristic of this model. In kidney, mesangial proliferation and nodular lesion are observed. Both peripheral neuropathy such as decreased nerve conduction velocity and thermal hypoalgesia and autonomic neuropathy such as diabetic diarrhea and voiding dysfunction have been reported. Osteoporosis is another complication characterized in SDT rat. Decreased bone density and low-turnover bone lesions are observed. Taking advantage of these features, SDT rat has been used for evaluating antidiabetic drugs and drugs/gene therapy for diabetic complications. In conclusion, the SDT rat is potentially a useful T2D model for studies on pathogenesis and treatment of diabetic complications in humans.

The Otsuka Long-Evans Tokushima Fatty (OLETF) rat is an animal model for obese-type, noninsulin-dependent diabetes mellitus (NIDDM) in humans. NIDDM in this rat model was shown to be regulated by multiple genes. We have identified 14 quantitative trait loci (QTLs) responsible for NIDDM (Nidd1-14/of) on chromosomes 1, 5, 7, 8, 9, 11, 12, 14, 16, and 17 by a whole genome search in 160 F2 progenies obtained by mating the OLETF and the F344 rats. Among these loci, two QTLs, Nidd1 and 2/of, were declared significant loci at a genome-wide level. Nidd3, 8, 9, and 13/of exhibited heterosis: heterozygotes showing significantly higher glucose levels than OLETF or F344 homozygotes. We also found evidence for interaction (epistasis) between Nidd1/of and Nidd2/of, between Nidd1/of and Nidd10/of, between Nidd2/of and Nidd8/of, and between Nidd2/of and Nidd14/of. Furthermore, Nidd6 and 11/of showed linkage with body weight, and Nidd1, 2, 8, 9, 10, and 12/of had an interaction with body weight. These indicated that NIDDM in the OLETF would have a higher degree of genetic complexity. We suggest several interesting candidate genes located in rat genomic regions for Nidd1-14/of or the syntenic regions in human genome.

text, ナノダイナミクス国際シンポジウム 平成22年1月21日(木) 於長崎大学, Nagasaki Symposium on Nano-Dynamics 2010 (NSND2010), January 21, 2010, Nagasaki University, Nagasaki, Japan, Invited Lecture, Nagasaki Symposium on Nano-Dynamics 2010 (NSND2010), p.76; 2010

We examined the effects of the novel hypoglycaemic agent JTT-608 [trans-4-(4-methylcyclohexyl)-4-oxobutyric acid] on insulin secretion using rat pancreatic islets, and analysed the mechanism of its effect. JTT-608 augmented 8.3 mM glucose-induced insulin secretion dose-dependently, and there was a stimulatory effect of 100 microM JTT-608 at both moderate and high concentrations (8.3, 11. 1 and 16.7 mM) of glucose, but not at low concentrations (3.3 and 5. 5 mM). In perifusion experiments, both phases of insulin release were enhanced, and the effect was eliminated 10 min after withdrawal of the agent. In the presence of 200 microM diazoxide and a depolarizing concentration (30 mM) of K(+), there was an augmentation of insulin secretion by 100 microM JTT-608, not only under high levels of glucose but also under low levels, and the effects were abolished by 10 microM nitrendipine. JTT-608 augmented insulin secretion from electrically permeabilized islets in the presence of stimulatory concentrations (0.3 and 1.0 microM) of Ca(2+), and the intracellular Ca(2+) concentration ([Ca(2+)](i)) response under 16.7 mM glucose, 200 microM diazoxide, and 30 mM K(+) was also increased. The cyclic AMP content in the islets was increased by 100 microM JTT-608, and an additive effect to 1 microM forskolin was observed, but not to 50 microM 3-isobutyl-1-methylxanthine (IBMX). JTT-608 inhibited phosphodiesterase (PDE) activity dose-dependently. We conclude that JTT-608 augments insulin secretion by enhancing Ca(2+) efficacy and by increasing Ca(2+) influx. This appears to be a result of the increased intracellular cyclic AMP concentration due to PDE inhibition.

主催：JST/CREST，Vrije University, ALTERRA, IBPC

Background Marbling defined by the amount and distribution of intramuscular fat, so-called Shimofuri, is an economically important trait of beef cattle in Japan. The c17-25 expressed sequence tag (EST) has been previously shown to possess expression difference in musculus longissimus muscle between low-marbled and high-marbled steer groups, and to be located within genomic region of a quantitative trait locus for marbling. Thus, the akirin 2 (AKIRIN2) gene containing the c17-25 EST sequence was considered as a positional functional candidate for the gene responsible for marbling. In this study, we explored single nucleotide polymorphism (SNP) in the AKIRIN2 and analyzed association of the SNP with marbling. Findings A SNP in the 3' untranslated region of the AKIRIN2, referred to as c.*188G>A, was the only difference detected between high- and low-marbled steer groups. The SNP was associated with marbling in 3 experiments using 100 sires (P = 0.041), 753 paternal half-sib progeny steers from 4 sires heterozygous for the c.*188G>A (P = 0.005), and 730 paternal half-sib progeny steers from 3 sires homozygous for the A allele at the c.*188G>A (P = 0.047), in Japanese Black beef cattle. The effect of genotypes of the SNP on subcutaneous fat thickness was not statistically significant (P > 0.05). Conclusion These findings suggest that the AKIRIN2 SNP polymorphism is associated with marbling and may be useful for effective marker-assisted selection to increase the levels of marbling in Japanese Black beef cattle.

application/pdf, text, Nagasaki Symposium on Nano-Dynamics 2008 (NSND2008) 平成20年1月29日(火)於長崎大学 Poster Presentation, Nagasaki Symposium on Nano-Dynamics 2008 (NSND2008), pp.91

古生層山地における雨水流出特性を解明するために, 京都大学芦生演習林内に2つの小試験流域を設けた。ヤヨイ谷 (10. 5ha) とトヒノ谷 (2. 5ha) である。両流域は距離的には約1. 3km離れている。また両流域ともスギを主とする森林に被覆されている。観測は1977年7月に始まった。雨量は転倒マス型雨量計で測られ, また流量は直角Vノッチの量水堰で測られた水位から算出される。それぞれの記録は自記々録されている。花崗岩山地の小流域で作成したタンクモデルを使って, 本流域で得られた数個の流出例について, それぞれ同一降雨に対する流出曲線を比較した。観測された中小規模の出水では, 古生層地域の2流域の流出曲線は花崗岩地域の2流域のそれとほぼ同様であった。また, 雨水の到達時間は, 花崗岩山地において, 有効降雨強度と流域面積から求める推定式にほぼ適合し, これによって求めた到達時間内の平均降雨強度とピーク流出量あるいは有効降雨強度の関係は, ピーク流出量が花崗岩山地の結果と大きく異なるものではないことを示す。