27 research outputs found

    Competitiveness of Four Rice Cultivars against Barnyardgrass, Echinochloa oryzicola Vasing, with Reference to Root and Shoot Competition

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    Four cultivars of rice (Oryza sativa L.) different in plant stature were grown on a paddy field, fairly fertile without nitrogen application, with or without barnyard grass, Echinochloa oryzicola Vasing, in the middle of the rice rows. The reduction of the growth variables of the four cultivars by competition with E. oryzicola was examined. The effect of a veneer board inserted in the soil between the rice and barnyardgrass rows was also examined to evaluate the growth reduction by shoot competition (WCS) and root competition (WCr) separately. On the average, the reduction of top dry weight (DWtop) by competition with weed (full competition, WCf) and by WCr increased with the time during the early growth period. Thereafter, the reduction of DWtop by WCr decreased steeply and instead the reduction by WCS increased and became a primary factor of the reduction by WCf in the late growth period. Nitrogen accumulation in the top (Ntop) tended to be reduced at a higher rate than DWtop by WCr. The cultivar difference in the rate of DWt0P reduction by WCf was largest at maturity ranging from 0.22 in Ch86 (very tall indica) to 0.45 in Taichung65d47 (short japonica), and was intermediate in Taichung65 (moderately tall japonica) and Takanari (moderately short indica). The reduction of DWtop and Ntop by WCS in all cultivars almost fully accounted for that by WCf at maturity and closely correlated with the height of rice plant. Although the rate of DWt0P reduction by WCr before heading significantly differed among cultivars (0.13 - 0.28), it did not contribute to the rate of DWtop reduction by WCf at maturity (0.01 - 0.06). These results indicated that shoot competition was a more important factor to cause cultivar difference in the reduction of final biomass by competition with E. oryzicola. Considering its great contribution to WCf during the early growth period especially for Ntop, WCr might be an important factor in the competition with weed of rice cultivars under crucially nitrogen-limited conditions

    Stealth-nanoparticle strategy for enhancing the efficacy of steroids in mice with noise-induced hearing loss.

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    This study aimed to investigate the efficacy of encapsulating steroids, which is a primary choice for the treatment of sensorineural hearing loss, in polyethylene glycol-coated polylactic acid nanoparticles for drug delivery to the cochlea

    Power Doppler signal calibration in the finger joint between two models of ultrasound machine: a pilot study using a phantom and joints in patients with rheumatoid arthritis

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    Background: Despite the advantages of ultrasound (US) in the management of rheumatoid arthritis (RA) patients, power Doppler (PD) US may be highly dependent on the type of US machine used. Purpose: To present a method to calibrate the PD signal of two models of US machines by use of a flow phantom and finger joints of patients with RA. Material and Methods: For the phantom study, the PD signal count was measured in the flow phantom perfusing blood mimicking fluid at various injection rates and pulse repetition frequencies (PRFs). The quantitative PD index was calculated with ImageJ. For the clinical study, the second and third metacarpophalangeal joints of five consecutive patients with RA were examined. The quantitative PD index was measured at various PRFs by use of two models of machine (the same models as the phantom study). Results: For the phantom and clinical studies, negative correlations were found between the PRF and the quantitative PD index when the flow velocity was constant and positive correlations between flow velocity and the quantitative PD index at constant PRF. There was a significant difference in the depiction performance of synovial blood flow between the two models, which can be calibrated by adjusting the PRF values derived from the phantom study in each model. Conclusion: Signal calibration of pannus vascularity between US machines may be possible by adjusting the PRF value according to flow phantom data. Different US machines can thus provide equivalent examination results concerning the pannus vascularity

    Sonographic findings of immunoglobulin G4-related sclerosing sialadenitis

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    Purpose: We evaluated the sonographic findings of immunoglobulin G4-related sclerosing sialadenitis (IgG4-SS). Methods: Nineteen patients with IgG4-SS and 12 healthy volunteers (controls) were enrolled. The following sonographic features were evaluated: (1) enlargement of the submandibular gland by measurement of the longitudinal diameter and thickness; (2) the contour texture of the submandibular gland (smooth or rough); (3) the internal echo texture, categorized into three sonographic patterns (homogeneous, multiple hypoechoic nodule, and diffuse hypoechoic); and (4) quantitative color Doppler signaling. Results: The longitudinal diameter and the thickness (mean ± SD) of the submandibular gland were significantly greater in patients than in controls (p = 0.005 and p < 0.001, respectively). Contour roughness was seen in 62.9 and 8.3 % of patients and controls (p < 0.001), respectively. Homogeneous echo textures alone were seen in controls, whereas multiple hypoechoic nodule patterns were seen in 60 % of the patients, and diffuse hypoechoic patterns were seen in 40 %. Color Doppler signaling (mean ± SD) was significantly higher in patients as compared with controls (p < 0.001). Conclusion: Patients could be distinguished from healthy volunteers using four distinctive sonographic findings, suggesting that ultrasonography would be a useful diagnostic tool for IgG4-SS

    Fluvastatin prevents the development of arthritis in env-pX rats via up-regulation of Rho GTPase-activating protein 12

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    The pleiotropic effects of statins, including an antiarthritic potential, have been noted. This study aimed to determine the efficacy of statins on rheumatoid arthritis (RA) and clarify how statins affect its pathogenesis. Fluvastatin (500 μg/kg/day) or vehicle was given per os to env-pX rats, which carry the human T-cell leukemia virus type I env-pX gene and spontaneously develop destructive arthritis mimicking RA, for 30 days. Blood sampling and ultrasonography (US) of the ankle joints were conducted on days 0, 10, 20, and 30. On day 30, all rats were euthanized, and the ankle joints were subjected to histological analysis. To clarify how fluvastatin affects the pathogenesis of RA, comprehensive serum exosomal microRNA (miRNA) analysis was performed. Gene expression in the primary culture of synovial fibroblasts derived from arthritic rat and human and non-arthritic rat periarticular tissues was determined quantitatively by real-time reverse transcription-polymerase chain reaction (RT-PCR). As a result, the development of arthritis in env-pX rats was significantly suppressed by fluvastatin, which was evident from the viewpoints of serology, US imaging, and histology. Comprehensive serum exosomal miRNA analysis suggested that the expression of Rho GTPase-activating protein 12 (Arhgap12) was decreased in arthritic env-pX rats but increased with the administration of fluvastatin. Corresponding results were obtained by quantitative RT- PCR using primary culture of synovial fibroblasts. The collective findings suggest that fluvastatin prevents the development of arthritis in env-pX rats via the up-regulation of ARHGAP12. This study suggests that ARHGAP12 can be a possible therapeutic target of RA

    Detection of Increased Vascular Signal in Arthritis-Prone Rats Without Joint Swelling Using Superb Microvascular Imaging Ultrasonography

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    This study aimed to determine whether ultrasonography (US) can detect increased vascular signal in the synovial tissue before overt synovitis in rheumatoid arthritis (RA). Env-pX rats that spontaneously develop RA-like synovitis were used. Ankle joints of 15 pre-morbid env-pX rats were observed with power Doppler and superb microvascular imaging (SMI) using an ultrahigh-frequency (8-24 MHz) probe. Signal values were counted as the number of pixels. The total number of vessels and vessel area in the synovial tissue were histologically evaluated. Dilated vessels were determined from the mean value of synovial vessels in three wild-type rats. In all env-pX rats, apparent synovial proliferation was not observed. However, vasodilation was evident. Only SMI values were significantly correlated with the number of dilated vessels (r = 0.585, p = 0.022) but not with the total number of vessels. US with SMI using ultrahigh-frequency probe can detect increased vascular signal in the synovial tissue of arthritis-prone rats

    Refined ultrasonographic criteria for sinusoidal obstruction syndrome after hematopoietic stem cell transplantation

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    Hepatic sinusoidal obstruction syndrome (SOS)/veno-occlusive disease is a life-threatening complication after hematopoietic stem cell transplantation (HSCT). We previously reported the efficacy of the Hokkaido Ultrasonography (US)-based scoring system (HokUS-10) for US findings. To establish easier-to-use criteria, we retrospectively evaluated US findings from 441 patients, including 30 patients with SOS using the HokUS-10 scoring system. Using logistic regression analysis, we established the novel diagnostic criteria HokUS-6. In the presence of ascites, US diagnosis was made in the presence of two of the following 6 parameters: moderate amount of ascites, the appearance of a paraumbilical vein blood flow signal, gallbladder wall thickening, portal vein dilatation, portal vein velocity decrease, and hepatic artery resistive index increase. The AUC, sensitivity, and specificity of HokUS-6 were 0.974 (95% confidence interval 0.962-0.990), 95.2%, and 96.9%, respectively. The scores were significantly higher in patients with severe SOS than in those with non-severe SOS (p = 0.013). Furthermore, the scores before HSCT were significantly higher in patients who developed SOS than in controls (p = 0.001). The HokUS-6 is an easy and useful way to diagnose and identify the risk of SOS
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