Hypofractionated radiation therapy in the treatment of canine thymoma: Retrospective study of eight cases          下载免费PDF全文

Sho Goto  Mami Murakami  Mifumi Kawabe  Ryota Iwasaki  Kazuki Heishima  Hiroki Sakai  Takashi Mori 《Veterinary radiology & ultrasound》2017,58(5):613-620

Thymomas are one of the most common tumors of the cranial mediastinum in dogs; however there is limited information available on the use of radiation therapy for treating this neoplasm. Objectives of the current retrospective observational study were to describe outcomes and side effects of a hypofractionated radiation therapy protocol in a group of dogs with confirmed thymoma. A total of eight dogs were included. To generate individualized treatment plans, we designed the planning target volume according to the limits on mean lung dose and the percentage of the total lung volume exceeding 20 Gy (V20). The total administered dose was 48–49 Gy, with one fraction per week for a total of six to seven fractions. After therapy, two dogs achieved complete responses, two achieved partial responses, and the disease remained stable in two. Two dogs died during the radiation therapy protocol and were not classified. The median mean lung dose and V20 were 6.0 Gy (range: 3.1–15.0 Gy) and 12.4% (range: 2.3–27.5%), respectively. The overall response rate was 50.0%, and the median time to response following treatment initiation was 22 days (range: 14–115 days). Acute and late side effects were common in the skin and/or lung and were self‐limiting or asymptomatic. The median survival time was not reached (range: 8–1128 days) and the 1 year survival rate was 75.0%. Hypofractionated radiation therapy was well tolerated in this sample of dogs with thymoma and may be considered when owners decline surgical treatment or the tumor is deemed unresectable.  相似文献   

Simulation of the effects of genotype and N availability on rice growth and yield response to an elevated atmospheric CO₂ concentration     

Hiroe YoshidaTakeshi Horie  Kou NakazonoHiroyuki Ohno  Hiroshi Nakagawa 《Field Crops Research》2011,124(3):433-440

The objective of this study was to identify physiological processes that result in genotypic and N fertilization effects on rice yield response to elevated atmospheric CO₂ concentrations ([CO₂]). This study conducted growth and yield simulations for 9 rice genotypes grown at 4 climatically different sites in Asia, assuming the current atmospheric [CO₂] (360 ppm) and elevated [CO₂] (700 ppm) using 5 levels of N fertilizer (4, 8, 12, 16, 20 g m⁻² N fertilizer). A rice growth model that was developed and already validated for 9 different genotypes grown under 7 sites in Asia was used for the simulation, integrating additional components into the model to explain the direct effect of [CO₂] on several physiological processes. The model predicted that the relative yield response to elevated [CO₂] (RY, the ratio of yield under 700 ppm [CO₂] to that under 360 ppm [CO₂]) increased with increasing N fertilizer, ranging from 1.12 at 4 g m⁻² N fertilizer to 1.22 at 20 g m⁻² N fertilizer, averaged overall genotypes and locations. The model also predicted a large genotypic variation in RY at the 20 g N treatment, ranging from 1.08 for ‘WAB450-I-B-P-38-HB’ to 1.41 for ‘Takanari’ averaged overall locations. Combining all genotypes grown at the 5N fertilization conditions, a close 1:1 relationship was predicted between RY and the relative [CO₂] response in spikelet number for crops with a small number of spikelets (less than 30,000 m⁻²) under the current atmospheric [CO₂] (n = 18, r = 0.89^***). In contrast, crops with a large number of spikelets under the current atmospheric [CO₂] showed a significantly larger RY than the relative [CO₂] response for spikelet number per unit area. The model predicted that crops with a larger number of spikelets under the current atmospheric [CO₂] derived great benefit from elevated [CO₂] by directly allocating increased carbohydrate to their large, vacant sink, whereas crops with a smaller number of spikelets primarily required an increased spikelet number to use the increased carbohydrate to fill grains. The simulation analyses suggested that rice with a larger sink capacity relative to source availability under the current atmospheric [CO₂] showed a larger yield response to elevated [CO₂], irrespective of whether genotype or N availability was the major factor for the large sink capacity under the current [CO₂]. The model predicted that the RY response to nitrogen was brought about through the N effects on spikelet number and non-structural carbohydrate accumulation. The genotypic variation in RY was related to differences in spikelet differentiation efficiency per unit plant N content. Further model validation about the effects of [CO₂] on growth processes is required to confirm these findings considering data from experimental studies.  相似文献   

A model for simulating plant N accumulation,growth and yield of diverse rice genotypes grown under different soil and climatic conditions     

Hiroe Yoshida  Takeshi Horie 《Field Crops Research》2010

The objective of this study was to develop a whole-process model for explaining genotypic and environmental variations in the growth and yield of irrigated rice by incorporating a newly developed sub-model for plant nitrogen (N) uptake into a previously reported model for simulating growth and yield based on measured plant N. The N-uptake process model was developed based on two hypotheses: (1) the rate of root system development in the horizontal direction is proportional to the rate of leaf area index (LAI) development, and (2) root N-absorption activity depends on the amount of carbohydrate allocated to roots. The model employed two empirical soil parameters characterizing indigenous N supply and N loss. Calibration of the N-uptake process sub-model and validation of the whole-process model were made using plant N accumulation, and growth and yield data obtained from a cross-locational experiment on nine rice genotypes at seven locations in Asia, respectively. Calibration of the N-uptake process sub-model indicated that a large genotypic difference exists in the proportionality constant between rate of root system development and that of LAI development during early growth stages. The whole-process model simultaneously explained the observed genotypic and environmental variation in the dynamics of plant N accumulation (R² = 0.91 for the entire dataset), above-ground biomass growth (R² = 0.94), LAI development (R² = 0.78) and leaf N content (R² = 0.79), and spikelet number per unit area (R² = 0.78) and rough grain yield (R² = 0.81). The estimated value of the site (field)-specific soil parameter representing the rate of N loss was negatively correlated with cation exchange capacity of the soil and was approximated by a logarithmic function of cation exchange capacity for seven sites (R² = 0.95). Large yearly and locational variations were estimated in the soil parameter for representing the rate of indigenous N supply at 25 °C. With the use of these two soil parameters, the whole-system model explained the observed genotypic and environmental variations in plant N accumulation, growth and yield of rice in Asia.  相似文献   

Metabolic conversion of dietary quercetin from its conjugate to active aglycone following the induction of hepatocarcinogenesis in fisher 344 rats     

Oi N  Hashimoto T  Kanazawa K 《Journal of agricultural and food chemistry》2008,56(2):577-583

Quercetin exhibits a potent anticarcinogenic activity. However, ingested quercetin circulates as the glucuronide/sulfate conjugates, which are less active compared to the aglycone in healthy individuals. This study aimed to develop further understandings of the cancer-preventing mechanism with dietary quercetin. According to a two-stage hepatocarcinogenesis model with N-diethylnitrosamine (DEN) and phenobarbital (PB), preneoplasms were induced specifically in the liver of Fisher 344 rats. In the liver, glutathione S-transferase placental form (GST-P) positive foci were produced 14 weeks later. beta-Glucuronidase activity increased significantly in the liver by 1.2-fold in the DEN/PB group compared to the activity in a saline group. In the kidney, thymus, lung, heart, and plasma, the activities were similar between both groups. When quercetin was dosed intragastrically 15 min before sacrifice, the aglycone level of quercetin in liver was significantly 1.9-fold higher in the DEN/PB group than in the saline group. On the other hand, quercetin was dosed to rats 3 times a week for 14 weeks. The treatment kept the aglycone level of quercetin at a significantly higher level and tended to suppress the formation of GST-P positive foci. The increase in beta-glucuronidase activity with carcinogenesis induction became insignificant following the frequent doses of quercetin. It was considered that quercetin aglycone played a preventative role and, thus, the conjugates were converted to the active aglycone by beta-glucuronidase that was induced by the generation of preneoplasms.  相似文献   

The high yield of irrigated rice in Yunnan,China: ‘A cross-location analysis’     

Keisuke Katsura  Shuhei Maeda  Iskandar Lubis  Takeshi Horie  Weixing Cao  Tatsuhiko Shiraiwa 《Field Crops Research》2008

A number of field trials on rice productivity have demonstrated very high yield, but reported limited information on environmental factors. The objective of this study was to reveal the environmental factors associated with high rice productivity in the subtropical environment of Yunnan, China. We conducted cross-locational field experiments using widely different rice varieties in Yunnan and in temperate environments of Kyoto, Japan in 2002 and 2003. The average daily radiation throughout the growing season was greater at Yunnan (17.1 MJ m⁻² day⁻¹ average over 2 years) relative to Kyoto (13.2 MJ m⁻² day⁻¹). The average daily temperature throughout the growing season was 24.7 °C at Yunnan, and 23.8 °C at Kyoto. The highest yield (16.5 tonnes ha⁻¹) was achieved by the F1 variety Liangyoupeijiu at Yunnan in 2003, and average yield of all varieties was 33% and 39% higher at Yunnan relative to Kyoto in 2002 and 2003, respectively. There was a close correlation between grain yield and aboveground biomass at maturity, while there was little variation in the harvest index among environments. Large biomass accumulation was mainly caused by intense incident radiation at Yunnan, as there was little difference in crop radiation use efficiency (RUE) between locations. Large leaf area index (LAI) was also suggested to be an important factor. Average nitrogen (N) accumulation over 2 years was 49% higher at Yunnan than at Kyoto, and also contributed to the large biomass accumulation at Yunnan. The treatments of varied N application for Takanari revealed that the ratio of N accumulated at maturity to the amount of fertilized N was significantly higher at Yunnan than at Kyoto, even though there was no great difference in soil fertility. The Takanari plot with high N application showed a N saturation in plant growth at Kyoto, which might be related to low radiation and relatively high temperatures during the mid-growth stage. These results indicate that the high potential yield of irrigated rice in Yunnan is achieved mainly by intense incident solar radiation, which caused the large biomass and the N accumulation. The low nighttime temperature during the mid-growth stage was also suggested to be an important factor for large biomass accumulation and high grain yield at Yunnan.  相似文献   

Growth and survival of eel leptocephali (Anguilla japonica) in low-salinity water     

Akihiro Okamura  Yoshiaki Yamada  Naomi Mikawa  Noriyuki Horie  Tomoko Utoh  Toyoji Kaneko  Satoru Tanaka  Katsumi Tsukamoto   《Aquaculture (Amsterdam, Netherlands)》2009,296(3-4):367-372

We investigated the effects of low-salinity water on the growth, survival, and activity of artificially reared Japanese eel larvae (Anguilla japonica), proceeding from the assumption that such water quality saves energy due to lower cost for osmoregulation. We reared 5-day-old larvae in 0%, 10%, 30%, 50%, 70%, and 100% seawater (SW) with or without diet for 13 days. All larvae reared in 0% and 10% SW died within 6 days, while larvae in 70% and 100% SW survived until 9 days. Larvae in 30% and 50% SW further survived until 13 days without diet. Significant growth in body depth was observed in 30% and 50% SW after 7 days rearing with diet (0.65 ± 0.02 and 0.62 ± 0.02 mm, respectively) as compared with the initial size (0.49 ± 0.03 mm), while no significant growth was observed under the other salinity conditions examined. Larvae swam actively in the light (about 2000 lx) in 50%, 70%, and 100% SW, while they were apparently inactive in 0%, 10%, and 30% SW. The long-term rearing trial showed a 2.2-fold higher 2-month cumulative survival rate in 50% SW (18.2%) than in 100% SW (8.2%). The body depth of larvae in 50% SW (1.58 ± 0.47 mm) was also significantly larger than in 100% SW (1.32 ± 0.35 mm). These findings indicate that the intermediate salinity can result in better growth and survival performance in Japanese eel larvae.  相似文献   

Effect of temperature decrease on oocyte development,sex steroids,and gonadotropin β-subunit mRNA expression levels in female Japanese eel <Emphasis Type="Italic">Anguilla japonica</Emphasis>     

Ryusuke Sudo  Ryota Tosaka  Shigeho Ijiri  Shinji Adachi  Hiroaki Suetake  Yuzuru Suzuki  Noriyuki Horie  Satoru Tanaka  Jun Aoyama  Katsumi Tsukamoto 《Fisheries Science》2011,77(4):575-582

To improve understanding of the mechanism of early ovarian development in eels, the effects of water temperature decrease on oocyte development, plasma levels of sex steroids [estradiol 17β (E2), testosterone (T), 11-ketotestosterone (11-KT)], and gonadotropin β-subunit [follicle-stimulating hormone (FSHβ), luteinizing hormone (LHβ)] messenger RNA (mRNA) expression levels were investigated. A total of 27 female Japanese eels Anguilla japonica were divided into initial, control, and test (water temperature decrease) groups. Starting on 22 September 2009, eels in the test group were reared in a tank with gradual temperature decrease from 25°C to 15°C over 39 days, while the control group was maintained at 25°C. The test group accumulated more oil droplets in their oocytes than did the other groups. Levels of sex steroids, especially 11-KT, were higher in the test group. In contrast, FSHβ and LHβ mRNA expression levels were lower in the test group. These results suggest that water temperature decrease only induced an early stage of ovarian development that was partly affected by an 11-KT increase. For further maturation, other environmental factors related to induction of gonadotropin increase appear to be needed.  相似文献   

Soil management: The key factors for higher productivity in the fields utilizing the system of rice intensification (SRI) in the central highland of Madagascar   总被引：1，自引：0，他引：1  

Yasuhiro Tsujimoto  Takeshi Horie  Hamon Randriamihary  Tatsuhiko Shiraiwa  Koki Homma   《Agricultural Systems》2009,100(1-3):61-71

The system of rice intensification (SRI) developed in Madagascar in the 1980s has been promoted as an integrated crop and resource management approach to rice-cultivation, especially for resource-limited smallholder farms. While advocates have claimed that SRI could boost rice yields with less external input, many criticisms have challenged its effectiveness regarding yields and applicability to larger-scale rice farming systems. In this study, we conducted a field survey and on-farm experiments to assess rice yield performance and key management practices on a few of the early SRI-practicing smallholder farms in the central highland of Madagascar.Rice grain yields at the survey fields were 9.9 t ha⁻¹ maximum without using mineral fertilizer. Deep plowing to the depth of 25–30 cm as well as SRI practices have been conducted continuously since the early 1990s. In addition, an effective drainage system facilitated intensive water management at these high-yielding fields. On-farm experiments demonstrated some yield increases with no interaction for the examined SRI practices, though the effects were not great enough to explain the high yields at these fields. The soils of these high-yielding fields contained relatively large amounts of soil organic carbon (SOC) from the surface to the deep soil layers, and the soil mineralizable nitrogen was closely correlated with rice grain yields.The results indicated that the high yields at the fields of those who were early to adopt SRI were mainly due to the soil fertility associated with great nitrogen-supplying ability, rather than ‘synergetic effects’ of the SRI components. This high N-supplying ability of the soil and accumulated SOC from surface to deep soil layers were attributable to the long-term combined practices of extensive organic applications and deep plowing. Soil hydrology could be another key factor stimulating high rates of soil N-mineralization.These management practices were, however, only applied to the limited numbers of fields within less than 1.0 ha of total landholdings of these farmers due to the great demand in labor and organic resources and the difficulty in controlling irrigation water. Intensive weeding and widely spaced transplanting of young seedlings were also performed in the fields with irrigation and drainage systems sufficient to avoid yield losses from flooding and drought. Although extensive and long-term systematic research is further required to fully assess the benefits of this sort of intensive management as opposed to conventional methods, the preferential allocation of intensive management by the successful SRI-adopters might be the implication of its location-specificity and difficulty in scaling up even within the resource-limited smallholder farms.  相似文献   

Immunological studies on Metastrongylus apri infection. IV. Influence of whole body X-irradiation or anti-guinea pig thymocyte serum injection on acquired immunity in thymectomized guinea pigs.     

M Koga  M Yamada  T Onishi  M Horie  S Noda 《Nippon juigaku zasshi. The Japanese journal of veterinary science》1976,38(6):611-618

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Congenital mesoblastic nephroma in a dog: a benign variant of nephroblastoma     

T Takeda  T Makita  N Nakamura  H Horie 《Veterinary pathology》1989,26(3):281-282

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