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22763. The pore architecture of the cystic fibrosis transmembrane conductance regulator channel revealed by co-mutation in pore-forming transmembrane regions

Creator:
Qian, Feng, Liu, Lian, Liu, Zhenzhen, and Lu, Chengbiao
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, cystic fibrosis transmembrane conductance regulator, patch clamp, site-directed mutagenesis, 14, and 612
Language:
English
Description:
The cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel contains 12 transmembrane (TM) regions that are presumed to form the channel pore. However, t here is no direct evidence clearly illustrating the involvement of these transmembr ane regions in the actual CFTR pore structure. To obtain insight into the architecture of the CFTR channel pore, we used patch clamp recording techniques and a strategy of comutagenesis of two potential pore-forming transmembrane regions (TM1 and TM6) to investigate the collaboration of these two TM regions. We performed a range of specific functional assays comparing the single channel conductance, anion binding, and anion selectivity properties of the co -mutated CFTR variants, and the results indicated that TM1 and TM6 play vital roles in forming the channel pore and, thus, determine the functional properties of the channel. Furthermore, we provide d functional evidence that the amino acid threonine (T338) in TM6 has synergic effects with lysine (K95) in TM1. Therefore, we propose that these two residues have functional collaboration in the CFTR channel pore and may collectively form a selective filter ., F. Qian, L. Liu, Z. Liu, C. Lu., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

22764. The positive roles of exogenous putrescine on chlorophyll metabolism and xanthophyll cycle in salt-stressed cucumber seedlings

Creator:
Yuan, R. N., Shu, S., Guo, S. R., Sun, J., and Wu, J. Q.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
pigmenty, pigments, biosyntéza chlorofylu, degradace chlorofylu, deepoxidace, ztráta energie, chlorophyll biosynthesis, chlorophyll degradation, de-epoxidation, energy dissipation, light-harvesting complex, 2, and 581
Language:
Multiple languages
Description:
The effects of foliar spray of putrescine (Put; 8 mM) on chlorophyll (Chl) metabolism and xanthophyll cycle in cucumber seedlings were investigated under saline conditions of 75 mM NaCl. Exogenous Put promoted the conversion of uroporhyrinogen III to protoporphyrin IX and alleviated decreases in Chl contents and in a size of the xanthophyll cycle pool under salt stress. Moreover, the Put treatment reduced the activities of uroporphyrinogen III synthase, chlorophyllase, and Mg-dechelatase and downregulated the transcriptional levels of glutamyl-tRNA reductase, 5-aminolevulinate dehydratase, uroporphyrinogen III synthase, uroporphyrinogen III decarboxylase, and chlorophyllide a oxygenase, but significantly increased the expression levels of non-yellow coloring 1-like, pheide a oxygenase, red chlorophyll catabolite reductase, and violaxanthin de-epoxidase. Taken together, these results suggest that Put might improve Chl metabolism and xanthophyll cycle by regulating enzyme activities and mRNA transcription levels in a way that improved the salt tolerance of cucumber plants., R. N. Yuan, S. Shu, S. R. Guo, J. Sun, J. Q. Wu., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

22765. The possibility of using clos e-range mono-photogrammetry in measuring relative displacements of rock blocks

Creator:
Gołuch, Piotr, Ćmielewski, Kazimierz, Kuchmistera, Janusz, and Kowalski, Krzysztof
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, geodezie, geodesy, close-range mono-photogrammetry, deformation measurement, plate target, rock block, 7, and 551
Language:
English
Description:
The paper presents a method for measuring relative displacements of rock blocks on the basis of recorded images of prototype plate targets measurement. The developed measuring targets, after deposition on the surveyed object (for example rock blocks) act as control points, which represent the behavior of the object over time. Two types of targets ware constructed: passive (appropriately chosen figure) and active (respectively arranged fiber targets). The paper presents preliminary results of work in the laboratory using a calibrated semi-metric camera (Canon D5 Mark II - SLR camera with a CMOS 21 million pixels sensor), two passive targets, geodetic engineering tripod, micrometric simulator of shifts and Leica TC1800 total station. During the experimental work one of the targets was set on a tripod, and the other placed on the total station telescope set on the observation pillar. While taking a series of images the first target was fixed, while the other was moved and rotated. The displacements were made with a micrometric table in two mutually perpendicular directions XY in the horizontal plane, and by simulated rotation of the horizontal wheel and vertical wheel of the total station (rotation of the instrument by the adjusting screws). Using the principles of close-range mono-photogra mmetry from automatic measurement of the recorded images of both plate targets, the values of displacements and rotations were compared with the references., Piotr Gołuch, Kazimierz Ćmielewski, Janusz Kuchmistera and Krzysztof Kowalski., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

22766. The possible role of mRNA expression changes of GH/IGF-1/insulin axis components in subcutaneous adipose tissue in metabolic disturbances of patients with acromegaly

Creator:
Touskova, V., Klouckova, J., Viktória Ďurovcová, Zdeňka Lacinová, Petra Kaválková, Trachta, P., Mikuláš Kosák, Mraz, M., Marek, J., Krsek, M., and Martin Haluzík
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, tuková tkáň, inzulinová rezistence, adipose tissue, insulin resistance, acromegaly, 14, and 612
Language:
English
Description:
We explored the effect of chronically elevated circulating levels of growth hormone (GH)/insulin -like -growth- factor-1 (IGF-1) on mRNA expression of GH/IGF-1/insulin axis components and p85alpha subunit of phosphoinositide -3-kinase (p85alpha) in subcutaneous adipose tissue (SCAT) of patients with active acromegaly and compared these findings with healthy control subjects in order to find its possible relationships with insulin resistance and body composition changes. Acromegaly group had significantly decreased percenta ge of truncal and whole body fat and increased homeostasis model assessment-insulin resistance (HOMA -IR). In SCAT, patients with acromegaly had significantly increased IGF-1 and IGF -binding protein-3 (IGFBP-3) expression that both positively correlated wit h serum GH. P85alpha expression in SCAT did not differ from control group. IGF-1 and IGFBP-3 expression in SCAT were not independently associated with percentage of truncal and whole body fat or with HOMA -IR while IGFBP -3 expression in SCAT was an independ ent predictor of insulin receptor as well as of p85alpha expression in SCAT. Our data suggest that GH overproduction in acromegaly group increases IGF-1 and IGFBP-3 expression in SCAT while it does not affect SCAT p85alpha expression. Increased IGF-1 or IGFBP-3 in SCAT of acromegaly group do not appear to contribute to systemic differences in insulin sensitivity but may have local regulatory effects in SCAT of patients with acromegaly., V. Touskova, J. Klouckova, V. Durovcova, Z. Lacinova, P. Kavalkova, P. Trachta, M. Kosak, M. Mraz, D. Haluzikova, V. Hana, J. Marek, M. Krsek, M. Haluzik., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

22767. The potential of leaf chlorophyll content to screen bread-wheat genotypes in saline condition

Creator:
Kiani-Pouya, A. and Rasouli, F.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, biomasa, chlorid sodný, chlorofyl, pšenice, photosynthesis, biomass, sodium chloride, chlorophyll, wheat, NaCl, SPAD, Triticum aestivum L, 2, and 581
Language:
Multiple languages
Description:
Physiological traits, which are positively associated with yield under salt-stress conditions, can be useful selection criteria in screening for salt tolerance. We examined whether chlorophyll (Chl) content can be used as screening criterion in wheat. Our study involved 5 wheat genotypes under both saline and nonsaline field conditions as well as in a sand-culture experiment. Salt stress reduced significantly biomass, grain yield, total Chl and both Chl a and b in all genotypes. In the sand-culture experiment, Chl accumulation was higher in PF70354/BOW, Ghods, and H499.71A/JUP genotypes at nonsaline control, moderate, and high salt concentrations, respectively. In the field experiment, genotype H499.71A/JUP belonged to those with the highest Chl density. The SPAD (Soil Plant Analysis Development) meter readings were linearly related to Chl content both in the sand-culture and in the field experiment. However, salt stress affected the calibration of SPAD meter. Therefore, separate Chl-SPAD equations were suggested for saline and nonsaline conditions. The correlation coefficients between the grain yield and SPAD were positive and significant both in the sand culture and in the field experiment. These findings suggested that SPAD readings could be used as a tool for rapid assessment of relative Chl content in wheat genotypes. It could be used for the indirect selection of high-yielding genotypes of wheat under saline condition in sand-culture and field experiments., A. Kiani-Pouya, F. Rasouli., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

22768. The potential role of nitric oxide in the hypertrophic growth of the left ventricle

Creator:
Fedor Šimko and Šimko, J.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, oxid dusnatý, nitric oxide, cardiac hypertrophy, angiotensin II, L-NAME, 14, and 612
Language:
English
Description:
Left ventricular hypertrophy (LVH) is the result of interaction between a chronic hemodynamic overload and non-hemodynamic factors. There are several lines of evidence presented in this work suggesting that nitric oxide (NO) may participate in the hypertrophic growth of the myocardium. First, endothelial NO production was shown to be decreased in several types of hemodynamically overloaded circulation both in animals and humans. Second, compounds stimulating NO production were able to diminish the extent or modify the nature of LVH in some models of myocardial hypertrophic growth. Third, arterial hypertension can be induced by inhibition of nitric oxide synthase activity. This NO-deficient hypertension is associated with the development of concentric LVH, myocardial fibrosis and protein remodeling of the left ventricle. The mechanism of LVH development in NO-deficient hypertension is complex and involves decreased NO production and increased activation of the renin-angiotensin-aldosterone system. Cardiovascular protection via ACE inhibition in NO-deficient hypertension may be induced by mechanisms not involving an improvement of NO production. In conclusion, the hypertrophic growth of the LV appears to be the result of interaction of vasoconstrictive and growth stimulating effects of angiotensin II on the one hand and of vasodilating and antiproliferative effects of nitric oxide on the other., F. Šimko, J. Šimko., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

22769. The potential use of fly ash with a high content of unburned carbon in geopolymers

Creator:
Jiří Škvarla, Jiří Botula, Martin Sisol, Krinická, Ivana, and Kolesárová, Miroslava
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, 7, and 551
Language:
English
Description:
Jiří Škvarla, Martin Sisol, Jiří Botula, Miroslava Kolesárová and Ivana Krinická. and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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