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511.
Phosphatidylinositol phosphates (PIPs) function as important second messengers in many cellular events. In the human intestinal protist Entamoeba histolytica, where phagocytosis/trogocytosis plays an indispensable role in proliferation and pathophysiology during infection, various PIPs are involved in multiple steps of phago/trogocytosis. PI3‐phosphate (PI3P) plays a pivotal role in the biogenesis of phagosome/trogosomes via recruitment of PI3P effectors. Because no known PI3P downstream effectors are conserved in E. histolytica, we exploited a unique method to identify the proteins PI3P dependently recruited to phagosomes. We rationalised that overexpression of PI3P‐binding GFP‐HrsFYVE competes for PI3P on phagosomal membranes and results in dissociation of PI3P effectors from phagosomes. EhVps26 and EhVps35, but not sorting nexins (SNXs), of the retromer complex were detected from phagosomes only without GFP‐HrsFYVE overexpression. Two potential SNXs, EhSNX1 and EhSNX2, identified in the genome, possess only phox homology domain and specifically bound to PI3P, but retromer components, EhVps26 and EhVps35, did not bind to PI3P. Live and immunofluorescence imaging showed that EhSNX1 was recruited to the trogocytic cup and tunnel‐like structures, and subsequently, EhSNX2 was recruited to trogosomes. Furthermore, EhSNX1, but not EhSNX2, specifically bound to Arp2/3 and EhVps26, which were localised to the tunnel‐like structures and the trogosomes, respectively. EhSNX2 gene silencing increased trogocytosis, suggesting that EhSNX2 plays an inhibitory role in trogocytosis. 相似文献
512.
Tomoyoshi Iwatsubo Hiroki Nakagawa Nagao Ogura Hidetaro Takehana 《Bioscience, biotechnology, and biochemistry》2013,77(4):907-908
Optically active trisubstituted and tetrasubstituted cyclopentanes, with proper functional groups of proper stereochemistry as precursors for chiral synthesis of brefeldin A and prostaglandins, were prepared stereoselectively from carbohydrate. 相似文献
513.
Pleomorphic adenoma of rat salivary gland is extremely rare, and culture of cells obtained from rat salivary gland tumors has not been reported. We have established a long-term cell line from a pleomorphic adenoma of a Sprague-Dawley rat submaxillary gland. The pleomorphic adenoma was composed of oval or spindle-shaped cells occasionally forming a small duct. Alcian blue-positive intercellular matrices, consisting mainly of glycosaminoglycans, were abundant. The cultured cells showed characteristics similar to those of the original tumor. This cell line should be useful for biological and biochemical studies of glycosaminoglycan-synthesis of pleomorphic adenoma cells. 相似文献
514.
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516.
Snow cover manipulation in agricultural fields: as an option for mitigating greenhouse gas emissions
Yosuke Yanai Tomoyoshi Hirota Yukiyoshi Iwata Manabu Nemoto Nobuhisa Koga Osamu Nagata Shinjiro Ohkubo 《Ecological Research》2014,29(4):535-545
Short-term N2O emission occurs in relation to snowmelt within seasonally frozen soil. To understand the effects of changing winter climates on the N2O flux, snow cover manipulation experiments are useful. In Japan, snow cover manipulation is practiced by farmers to improve agricultural yield and is executed either by applying a broadcast of blackish agent onto the snow cover, which leads to faster snow-melting thereby extending the crop-growing season, or by snow cover removal/re-accumulation, leading to an enhanced soil frost depth for weed management. Implementation of these practices involves using an amount of fossil fuel, in addition to influencing soil-derived N2O emissions, therefore, the load factors of snow cover management practices per unit area of agricultural field were estimated in this study. Field data including micrometeorological conditions, ground surface flux of N2O, and amount of fossil fuel consumed during machinery operation for management practices, were obtained at two sites in Hokkaido over 2 years (2008–2010). Fuel consumption for the field spreading was found to be unexpectedly small (0.017 Mg CO2 eq ha?1). It was therefore suggested that acceleration of snowmelt may have the potential to reduce net greenhouse gas emissions if the agent used is a low-degradable C-rich material, such as charcoal. For soil frost control, the fossil fuel consumption during a set of snow cover removal/re-accumulation (estimated as 0.052 Mg CO2 eq ha?1) is discussed, together with the relationship between possible mechanisms causing stimulation of N2O production in frozen soil and inherent large differences in N2O flux among sites. 相似文献
517.
Terada Tomoyoshi Morisaka Tadamichi Wakabayashi Ikuo Yoshioka Motoi 《Journal of Ethology》2022,40(3):245-256
Journal of Ethology - Toothed whales are the ideal model to validate the hypothesis that the complexity of sound communication relates to sociality. Compared to the numerous studies on several... 相似文献
518.
Kenji Sobue Yoshihiko Muramoto Masataka Fujita Shiro Kakiuchi 《Biochemical and biophysical research communications》1981,100(3):1063-1070
Previously we have shown that purified spectrin binds calmodulin in the presence of Ca2+ with a Kd value of 3 μM (Sobue, K. et al. (1980) Biochemistry International 1, 561–566). We now provide evidence that the calmodulin-binding activity found in the human erythrocyte cytoskeleton is indeed due to spectrin and no other binding proteins are involved, i.e. the binding activity was purified from the erythrocyte cytoskeleton quantitatively and the purified peak contained spectrin as the only protein constituent. Moreover, Kd value (2.8 μM) and the maximum binding capacity (160,000 – 200,000 calmodulin per cell) obtained from the kinetic analysis of the binding activity in the crude cytoskeleton agreed with the corresponding values reported for purified spectrin. Since the concentration of calmodulin in the erythrocyte cell, which was 2.5 μM or 1.6 × 105 molecules per cell, is close to both the Kd value and the number of the binding sites in the cell, respectively, free calmodulin in the erythrocyte cell may be in a dynamic equilibrium with the spectrin-bound form in vivo depending upon the intracellular concentration of Ca2+. 相似文献
519.
Histochemical studies on pseudocysts in adenoid cystic carcinoma of the human salivary gland 总被引:1,自引:0,他引:1
M. Toida J. Takeuchi M. Sobue K. Tsukidate S. Akao T. Fukatsu N. Nakashima 《The Histochemical journal》1985,17(8):913-924
Summary Pseudocysts are unique structures found in adenoid cystic carcinomata of human salivary glands. They were studied in 13 such cases by histochemical and immunohistochemical means. The pseudocysts contained an abundance of mucoid materials which reacted strongly with both Alcian Blue and dialysed iron ferrocyanide. The mucoid material was digested with chondroitinase ABC and heparitinase, but was resistant toStreptomyces hyaluronidase. The inner surfaces of the pseudocysts were strongly reactive for laminin, whereas the interface between the tumour cell nests and the outer stromal area was intensely reactive for fibronectin. Numerous fibronectin-reactive fibrils and blood coagulation factor XIII (F-XIII)-positive cells were distributed extensively in the outer stromal area. The F-XIII-positive cells were also found within some pseudocysts. The results obtained in the present study have shown that the pseudocysts represent a peculiar structure consisting of basement membrane components; laminin, fibronectin, heparan sulphate and chondroitin sulphate. 相似文献
520.
Epigastrius with omphalocele--report of a case 总被引:1,自引:0,他引:1
An epigastrius (parasitic twinning in the epigastrium) was delivered via the vaginal route spontaneously and died 37 days later. The autosite had cardiac hypertrophy with VSD, PDA, and PFO and an omphalocele. The liver was partly conjoined. There was a small swelling at the lower part of the autosite's bifurcated sternum to which the parasitic left pelvis and lower extremity were attached. On the second day after birth, parasitectomy was performed. The amputated specimens consisted of a small left pelvic girdle with a free extremity, a scrotal mass, nipplelike structures and two small protuberances externally. The liver, intestines, two testes, one kidney, one ureter, and the bladder were contained within the omphalocele. Although all of the organs and external structures of the parasite had abnormal histopathological findings, differentiated muscle fibers and submucous and/or myenteric plexus were observed. 相似文献