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6266. Evaluating the link between photosynthetic capacity and leaf vascular organization with principal component analysis

Creator:
Polutchko, S. K., Stewart, J. J., Demmig-Adams, Barbara, and Adams, William W.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, growth temperature, high light, low light, phloem parenchyma cells, xylem, 2, and 581
Language:
Multiple languages
Description:
Significant linear relationships between photosynthetic capacity and principal components loaded by phloem cell numbers and tracheary elements per minor vein as well as the latter two normalized for vein density (proxy for apoplastic phloem loading capacity involving membrane transporters) were revealed for all apoplastic loaders (summer annuals and winter annual Arabidopsis thaliana). In addition, significant linear relationships between photosynthetic capacity and a principal component loaded by tracheary element cross-sectional areas and volumes per unit of leaf area (water flux capacity proxy) was present for symplastic and apoplastic loaders. Lastly, a significant linear relationship between photosynthetic capacity and a principal component loaded by phloem cell cross-sectional areas and volumes per unit of leaf area (proxy for symplastic loading capacity involving cytosolic enzymes for companion cells) was revealed for summer annual symplastic loaders as well as for A. thaliana (in the case of sieve elements, a proxy for sugar export capacity from the leaves)., S. K. Polutchko, J. J. Stewart, B. Demmig-Adams, W. W. Adams., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6267. Evaluating the role of intestinal parasites in the high rates of irritable bowel syndrome in South America: a pilot study

Creator:
Vasquez-Rios, George, Machicado, Jorge D, Gamero, Maria T, Pezua, Adriana, Betancourt, Angel B, Terashima, Angelica, and Marcos, Luis A
Format:
print, počítač, and online zdroj
Type:
model:article and TEXT
Subject:
parazitické organismy, tračník, parasitic organisms, colon, Jižní Amerika, South America, soil-transmitted helminths, Blastocystis sp., functional gastrointestinal diseases, 2, and 59
Language:
English
Description:
There is limited data on the role of intestinal parasites in irritable bowel syndrome (IBS) in South America. We evaluated the association between intestinal parasitism and IBS status in Peru. Intestinal parasites were detected in 43% of the IBS cases and in 51% of the controls (P = 0.4). After excluding those infected by any parasite, the IBS prevalence remained high (22%; P = 0.7). No statistically significant difference was noted between IBS cases and controls in terms of monoparasitism, biparasitism or multiparasitism. Furthermore, the protist Blastocystis sp. was inversely associated with IBS., George Vasquez-Rios, Jorge D. Machicado, Maria T. Gamero, Adriana Pezua, Angel B. Betancourt, Angelica Terashima, Luis A. Marcos., and Obsahuje bibliografii
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

6268. Evaluation of calcium channel blockers as potential hepatoprotective agents in oxidative stress injury of perfused hepatocytes

Creator:
Hassan Farghali, Eva Kmoníčková, Halka Lotková, and Martínek, J.
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, verapamil, diltiazem, Tertbutyl hydroperoxide, hepatoprotection, ATPase, 14, and 612
Language:
English
Description:
The aim of this study was to investigate the effects of calcium channel blockers on tertbutyl hydroperoxide (TBH) induced liver injury using isolated perfused rat hepatocytes. Rat hepatocytes were immobilized in agarose threads and perfused with Williams E medium. Hepatocyte injury was induced by the addition of tertbutyl hydroperoxide (1 mM) to the perfusion medium 30 min after the addition of either verapamil or diltiazim. Hepatocyte injury was observed by monitoring the functional and metabolic competence of hepatocytes or by ultrastructural morphological examination of hepatocytes. Verapamil (0.5 mM) reduced lactate dehydrogenase leakage in TBH-injured hepatocytes as compared to the controls (154± 11 % vs. 247± 30 %). Lipid peroxides production was reduced after verapamil pretreatment as compared to the controls and oxygen consumption was increased by pretreatment of hepatocytes with verapamil. Verapamil pretreatment increased the protein synthesis activity at both levels of granular endoplasmic reticulum and free polysomes in cytoplasm and decreased ATPase activity. Diltiazem was qualitatively effective as verapamil. It is concluded that in hepatocyte oxidative injury, calcium channel blockers exhibited hepatoprotective properties. The hepatoprotective effect of calcium channel blockers was accompanied by a decrease in ATPase activity, which may implicate a normalization of Ca2+i after TBH intoxication., H. Farghali, E. Kmoníčková, H. Lotková, J. Martínek., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6269. Evaluation of cardiac effects of the new antineoplastic drug - dimethoxybenfluron - in the rabbit

Creator:
Jarmila Macháčková, Michaela Adamcová, Yvona Mazurová, Radomír Hrdina, and Milan Nobilis
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, kardiomyopatie, cardiomyopathy, cardiac troponin T, daunorubicin, dimethosybenfluron, antineoplastic drugs, 14, and 612
Language:
English
Description:
Cardiotoxicity ranks among the most serious adverse effects of some cytostatics. The cardiac effects of repeated i.v. administration of a new antineoplastic agent, dimethoxybenfluron (once a week, 10 administrations), were investigated in rabbits with respect to cardiac function and the release of cardiac troponin T (cTnT). Different doses of dimethoxybenfluron were administered to two groups of animals (12 mg/kg; n = 7 and 24 mg/kg; n = 6) and compared with either a control group (saline 1 ml/kg; n = 6) or a group with experimentally induced cardiomyopathy (daunorubicin 50 mg/m2; n = 13). In daunorubicin-induced cardiomyopathy, cTnT levels in animals with premature deaths were significantly higher (0.31±0.11 mg/l) in comparison with the surviving animals (0.04±0.03 mg/l). However, cardiac TnT levels after the administration of dimethoxybenfluron in both doses were within the physiological range (lower than 0.1 mg/l) during the whole experiment as it was in the control group. The lack of cardiotoxicity of this new antineoplastic drug was supported by the absence of alterations in PEP:LVET ratio, left ventricle dP/dtmax or histological heart examination as well as by the fact that no premature death of animals occurred following repeated administration of dimethoxybenfluron. It is possible to conclude that no signs of cardiotoxicity were observed following repeated i.v. administration of dimethoxybenfluron., J. Macháčková, M. Adamcová, Y. Mazurová, R. Hrdina, M. Nobilis., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

6270. Evaluation of ECG time intervals in a rabbit model of anthracycline-induced cardiomyopathy: a useful tool for assessment of cardioprotective agents

Creator:
Anna Potáčová, Michaela Adamcová, Čajnáková, H., Hrbatová, L., Martin Štěrba, Popelová, O., Tomáš Šimůnek, Přemysl Poňka, and Vladimír Geršl
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Fyziologie člověka a srovnávací fyziologie, fyziologie, troponiny, physiology, troponins, chelátor železa, ECG, troponin T, iron chelator, anthracyclines, daunorubicin, dexrazoxane, 14, and 612
Language:
English
Description:
The aim of this study was to analyze the ECG time intervals in the course of the development of chronic anthracycline cardiomyopathy in rabbits. Furthermore, this approach was employed to study the effects of a model cardioprotective drug (dexrazoxane) and two novel iron chelating compounds - salicylaldehyde isonicotinoyl hydrazone (SIH) and pyridoxal 2-chlorobenzoyl hydrazone (o-108). Repeated daunorubicin administration induced a significant and progressive prolongation of the QRS complex commencing with the 8th week of administration. At the end of the study, we identified a significant correlation between QRS duration and the contractility index dP/dtmax (r=-0.81; P<0.001) as well as with the plasma concentrations of cardiac troponin T (r=0.78; P<0.001). In contrast, no alterations in ECG time intervals were revealed in the groups co-treated with either dexrazoxane or both novel cardioprotective drugs (SIH, o-108). Hence, in this study, the QRS duration is for the first time shown as a parameter suitable for the non-invasive evaluation of the anthracycline cardiotoxicity and cardioprotective effects of both well established and investigated drugs. Moreover, our results strongly suggest that novel iron chelators (SIH and o-108) merit further study as promising cardioprotective drugs against anthracycline cardiotoxicity., A. Potáčová, M. Adamcová, H. Čajnáková, L. Hrbatová, M. Štěrba, O. Popelová, T. Šimůnek, P. Poňka, V. Geršl., and Obsahuje bibliografii a bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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