Sterilization and the capital inflow problem in East Asia, 1987-97

노트 : Volume Title: Regional and global capital flows: Macroeconomic causes and consequences Chapter Title: Sterilization and the capital inflow problem in East Asia, 1987-9

Quantitative Estimation of Urate Transport in Nephrons in Relation to Urinary Excretion Employing Benzbromarone-Loading Urate Clearance Tests in Cases of Hyperuricemia

Background: A four-component system for urate transport in nephrons has been proposed and widely investigated by various investigators studying the mechanisms underlying urinary urate excretion. However, quantitative determinations of urate transport have not been clearly elucidated yet. Methods: The equation Cua = {Ccr(1 – R1) + TSR}(1 – R2) was designed to approximate mathematically urate transport in nephrons, where R1 = urate reabsorption ratio; R2 = urate postsecretory reabsorption ratio; TSR = tubular secretion rate; Cua = urate clearance, and Ccr = creatinine clearance . To investigate relationships between the three unknown variables (R1, R2, and TSR), this equation was expressed as contour lines of one unknown on a graph of the other two unknowns. Points at regular intervals on each contour line for the equation were projected onto a coordinate axis and the high-density regions corresponding to high-density intervals of a coordinate were investigated for three graph types. For benzbromarone (BBR)-loading Cua tests, Cua was determined before and after oral administration of 100 mg of BBR and CuaBBR(∞) was calculated from the ratio of CuaBBR(100)/Cua. Results: Before BBR administration, points satisfying the equation on the contour line for R1 = 0.99 were highly dense in the region R2 = 0.87–0.92 on all three graphs, corresponding to a TSR of 40–60 ml/min in hyperuricemia cases (HU). After BBR administration, the dense region was shifted in the direction of reductions in both R1 and R2, but TSR was unchanged. Under the condition that R1 = 1 and R2 = 0, urate tubular secretion (UTS) was considered equivalent to calculated urinary urate excretion (Uex) in a model of intratubular urate flow with excess BBR; CuaBBR(∞) = TSR was deduced from the equation at R1 = 1 and R2 = 0. In addition, TSR of the point under the condition that R1 = 1 and R2 = 0 on the graph agreed with TSR for the dense region at excess BBR. TSR was thus considered approximately equivalent to CuaBBR(∞), which could be determined from a BBR-loading Cua test. Approximate values for urate glomerular filtration, urate reabsorption, UTS, urate postsecretory reabsorption (UR2), and Uex were calculated as 9,610; 9,510; 4,490; 4,150, and 440 µg/min for HU and 6,890; 6,820; 4,060; 3,610, and 520 µg/min for normal controls (NC), respectively. The most marked change in HU was the decrease in TSR (32.0%) compared to that in NC, but UTS did not decrease. Calculated intratubular urate contents were reduced more by higher UR2 in HU than in NC. This enhanced difference resulted in a 15.4% decrease in Uex for HU. Conclusion: Increased UR2 may represent the main cause of urate underexcretion in HU

Phased Array with Surface Acoustic Wave (SAWPA) for Screening and Sizing of Surface Defects

Nondestructive inspection of whole structures is important for the safety and reliability. For the inspection of internal defects, ultrasonic testing (UT) with bulk waves has been widely used, whereas such UT cannot inspect surface due to a dead zone. To this end, we proposed a phased array with surface acoustic wave (SAW PA) [1,2] for rapidly inspecting surface defects with a high sensitivity. However, the performance has yet to be fully educed because it was not optimized in terms of the wedge and imaging region. The objective of this study is to improve SAW PA and to demonstrate the wide-range and detailed imaging capabilities for screening and sizing, respectively. The schematic of SAWPA is illustrated in Fig. 1. An array transducer is set on a wedge with a critical angle of Rayleigh wave. Following a delay law, SAWis focused on multiple focal points on the surface, providing an image over the scan area. Note that SAWPA has a capability of a real-time imaging. In this study, the wedge for SAW generation was improved. In the previous study [1], the wedge was made of acrylic resin that is inexpensive and has good workability. It is however relatively attenuative, so that the incident wave was significantly attenuated during the propagation in the wedge. Therefore, it was changed to polystyrene that is less attenuative. The polystyrene has smaller critical angle than acrylic resin, thus also shortening the propagation distance in the wedge. This is useful for both screening and sizing. To show the wide-range imaging capability, a hole specimen (A6063) was imaged with varying the propagation distance of Rayleigh wave. As a result, a sufficient signal-to-noise ratio was obtained even in a far distance of 400 mm (Fig. 2). Subsequently, it was applied to the crack specimen, where the imaging area was set beneath the wedge to attain high resolution and sensitivity, although the region outside the wedge was selected for screening and in Ref. [1]. As a result, the crack was clearly imaged with a high resolution. These results show that the improved SAWPA is useful for both screening and sizing

Sulfate transporters involved in sulfate secretion in the kidney are localized in the renal proximal tubule II of the elephant fish (Callorhinchus milii)

Most vertebrates, including cartilaginous fishes, maintain their plasma SO4 (2-) concentration ([SO4 (2-)]) within a narrow range of 0.2-1 mM. As seawater has a [SO4 (2-)] about 40 times higher than that of the plasma, SO4 (2-) excretion is the major role of kidneys in marine teleost fishes. It has been suggested that cartilaginous fishes also excrete excess SO4 (2-) via the kidney. However, little is known about the underlying mechanisms for SO4 (2-) transport in cartilaginous fish, largely due to the extraordinarily elaborate four-loop configuration of the nephron, which consists of at least 10 morphologically distinguishable segments. In the present study, we determined cDNA sequences from the kidney of holocephalan elephant fish (Callorhinchus milii) that encoded solute carrier family 26 member 1 (Slc26a1) and member 6 (Slc26a6), which are SO4 (2-) transporters that are expressed in mammalian and teleost kidneys. Elephant fish Slc26a1 (cmSlc26a1) and cmSlc26a6 mRNAs were coexpressed in the proximal II (PII) segment of the nephron, which comprises the second loop in the sinus zone. Functional analyses using Xenopus oocytes and the results of immunohistochemistry revealed that cmSlc26a1 is a basolaterally located electroneutral SO4 (2-) transporter, while cmSlc26a6 is an apically located, electrogenic Cl(-)/SO4 (2-) exchanger. In addition, we found that both cmSlc26a1 and cmSlc26a6 were abundantly expressed in the kidney of embryos; SO4 (2-) was concentrated in a bladder-like structure of elephant fish embryos. Our results demonstrated that the PII segment of the nephron contributes to the secretion of excess SO4 (2-) by the kidney of elephant fish. Possible mechanisms for SO4 (2-) secretion in the PII segment are discussed

First-in-human phase 1 trial of hemoglobin vesicles as artificial red blood cells developed for use as a transfusion alternative

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Quantitation of the neural silencing activity of anion channelrhodopsins in Caenorhabditis elegans and their applicability for long-term illumination

Ion pumps and channels are responsible for a wide variety of biological functions. Ion pumps transport only one ion during each stimulus-dependent reaction cycle, whereas ion channels conduct a large number of ions during each cycle. Ion pumping rhodopsins such as archaerhodopsin-3 (Arch) are often utilized as light-dependent neural silencers in animals, but they require a high-density light illumination of around 1 mW/mm2. Recently, anion channelrhodopsins -1 and -2 (GtACR1 and GtACR2) were discovered as light-gated anion channels from the cryptophyte algae Guillardia theta. GtACRs are therefore expected to silence neural activity much more efficiently than Arch. In this study, we successfully expressed GtACRs in neurons of the nematode Caenorhabditis elegans (C. elegans) and quantitatively evaluated how potently GtACRs can silence neurons in freely moving C. elegans. The results showed that the light intensity required for GtACRs to cause locomotion paralysis was around 1 µW/mm2, which is three orders of magnitude smaller than the light intensity required for Arch. As attractive features, GtACRs are less harmfulness to worms and allow stable neural silencing effects under long-term illumination. Our findings thus demonstrate that GtACRs possess a hypersensitive neural silencing activity in C. elegans and are promising tools for long-term neural silencing

Quantitation of the neural silencing activity of anion channelrhodopsins in Caenorhabditis elegans and their applicability for long-term illumination

Ion pumps and channels are responsible for a wide variety of biological functions. Ion pumps transport only one ion during each stimulus-dependent reaction cycle, whereas ion channels conduct a large number of ions during each cycle. Ion pumping rhodopsins such as archaerhodopsin-3 (Arch) are often utilized as light-dependent neural silencers in animals, but they require a high-density light illumination of around 1 mW/mm2. Recently, anion channelrhodopsins -1 and -2 (GtACR1 and GtACR2) were discovered as light-gated anion channels from the cryptophyte algae Guillardia theta. GtACRs are therefore expected to silence neural activity much more efficiently than Arch. In this study, we successfully expressed GtACRs in neurons of the nematode Caenorhabditis elegans (C. elegans) and quantitatively evaluated how potently GtACRs can silence neurons in freely moving C. elegans. The results showed that the light intensity required for GtACRs to cause locomotion paralysis was around 1 µW/mm2, which is three orders of magnitude smaller than the light intensity required for Arch. As attractive features, GtACRs are less harmfulness to worms and allow stable neural silencing effects under long-term illumination. Our findings thus demonstrate that GtACRs possess a hypersensitive neural silencing activity in C. elegans and are promising tools for long-term neural silencing