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222. A novel carboxymethylated mercaptotriazinoindole inhibitor of aldose reductase interferes with the polyol pathway in streptozotocin-induced diabetic rats
- Creator:
- Soltesova Prnova, M., Ballekova, J., Alena Gajdošíková, Gajodsik, A., and Stefek, M.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, diabetici, diabetics, carboxymethylated mercaptotriazinoindole, aldose reductase inhibitor, polyol pathway, diabetic complications, 14, and 612
- Language:
- English
- Description:
- The aim of the present work was to study the effect of 3- mercapto-5H-1,2,4-triazino[5,6-b]indole-5-acetic acid (CMTI), an efficient aldose reductase inhibitor, on sorbitol accumulation in selected organs of streptozotocin-induced diabetic rats in vivo . In addition, the effect of CMTI on aldose reductase back reaction and on sorbitol dehydrogenase was determined. The model of experimental diabetes in male Wistar rats induced by streptozotocin was used. Experimental diabetes was induced by triple intraperitoneal doses of streptozotocin on three consecutive days. In diabetic rats, significant elevation of sorbitol concentration in the sciatic nerve and eye lenses was recorded. CMTI administered intragastrically (50 mg/kg/day) for five consecutive days significantly inhibited sorbitol accumulation in the sciatic nerve, yet it was without effect in eye lenses of diabetic animals. For aldose reductase back reaction, the substrate affinity of glycerol to aldose reductase was one order lower than that of glyceraldehyde in forward reaction. In addition, the back reaction was much slower, characterized by Vmax value of about 30 times lower than that of the forward reaction. Inhibition of aldose reductase by CMTI was characterized by closely related IC50 values in submicromolar range for both forward and back reactions. No significant inhibition of the second enzyme of the polyol pathway, sorbitol dehydrogenase, by 100 μM CMTI was recorded (I=0.9±2.7 %, n=3). To conclude, the presented results showed the ability of CMTI to affect the polyol pathway in diabetic rats in vivo and represent thus a further step in a complex preclinical evaluation of CMTI as a potential agent for treatment of chronic diabetic complications., M. Soltesova Prnova, J. Ballekova, A. Gajdosikova, A. Gajdosik, M. Stefek., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
223. A periadventitial sirolimus-releasing mesh decreased intimal hyperplasia in a rabbit model
- Creator:
- Ivo Skalský, Elena Filová, Ondrej Szárszoi, Martin Pařízek, Lytvynets, A., Jana Malušková, Alena Lodererová, Eduard Brynda, Věra Lisá, Burdíková, Z., Martin Čapek, Jan Pirk, and Lucie Bačáková
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, stenózy, hyperplazie, stenoses, hyperplasia, intimal hyperplasia, controlled drug release, perivascular mesh, rapamycin, 14, and 612
- Language:
- English
- Description:
- Autologous vein grafts used as aortocoronary bypasses are often prone to intimal hyperplasia, which results in stenosis and occlusion of the vein. The aim of this study was to prevent intimal hyperplasia using a newly developed perivascular system with sustained release of sirolimus. This system of controlled drug release consists of a polyester mesh coated with a copolymer of L-lactic acid and ε -caprolactone that releases sirolimus. The mesh is intended for wrapping around the vein graft during surgery. The mesh releasing sirolimus was implanted in periadventitial position onto arteria carotis communis of rabbits, and neointimal hyperplasia was then assessed. We found that implanted sirolimus-releasing meshes reduced intima thickness by 47±10 % compared to a vein graft after 3 weeks. The pure polyester mesh decreased vein intima thickness by 35±9 %. Thus, our periadventitial system for controlled release of sirolimus prevented the develo pment of intimal hyperplasia in autologous vein grafts in vivo in rabbits. A perivascularly applied mesh releasing sirolimus is a promising device for preventing stenosis of autologous vein grafts., I. Skalský ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
224. A phylogenetic test of the parasite-host associations between Maculinea butterflies (Lepidoptera: Lycaenidae) and Myrmica ants (Hymenoptera: Formicidae)
- Creator:
- Jansen, Gunther, Vepsäläinen, Kari, and Savolainen, Riitta
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, entomologie, coevolution, host switching, Large blues, local adaptation, Maculinea, Myrmica, Phengaris, 2, and 59
- Language:
- English
- Description:
- The parasitic caterpillars of Maculinea (Lepidoptera: Lycaenidae) need to be adopted and nursed by ants of the genus Myrmica (Hymenoptera: Formicidae). Each Maculinea species is locally associated with one or a few main and often several secondary host species. To determine whether the parasite-host associations bear marks of cophylogenetic constraints, we reconstructed phylogenies of Maculinea and Myrmica using DNA sequence data. We searched for evidence of cospeciation with a tree-independent (ParaFit) and tree-based (TreeFitter) method. This did not reveal any indication of phylogenetic host tracking in Maculinea. This agrees with earlier insights, which emphasise that as most of the potential host ant populations are never infested by Maculinea, the selective pressure of the butterflies on Myrmica is likely to be slight. Each Maculinea species also specialises on one or a few host plant species before adoption by ants. We suggest that Maculinea species have a substantial potential to accommodate evolutionarily to geographically changing ranges of potential Myrmica hosts, available at the oviposition sites of the butterflies. We use recently published evidence on geographically varying host ant species to discuss a suite of plausible scenarios of adaptive shifts to new Myrmica host species. and Gunther Jansen, Kari Vepsäläinen, Riitta Savolainen.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
225. A polymorphism in the cyclooxygenase 2 gene in type 1 diabetic patients with nephropathy
- Creator:
- Hubáček, J. A., Terezie Pelikánová, Věra Lánská, and Radko Komers
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, cyklooxygenáza 2, diabetická nefropatie, polymorfismus, cyclooxygenase 2, diabetic nephropathy, polymorphism, -765G>C polymorphism, 14, and 612
- Language:
- English
- Description:
- Diabetic nephropathy (DN), the most serious complication of Type 1 diabetes (DM1), has a strong genetic component. Cyclooxygenase-2 (COX-2), an in ducible enzyme by a number of stimuli, has been implicated in pathophysiology of cardiovascular and renal disease, including DN. The allele -765C, of the -765G>C polymorphism (rs20417) in the COX-2 promoter has lower promoter activity compared with the -765G allele and protective effects in cardiovascular disease. This polymorphism was not investigated in patients with DM1 and nephropathy. The study was conducted in 779 Caucasian patients with DM1 and compared to a representative sample of healthy Czech population. The patients demonstr ated lower frequencies of the CC genotype (P=0.005). From th e DM1 cohort, 153 patients met the criteria for low risk of the development of DN (LRDN, duration of DM1>10 years, normoalbuminuria, normotension) and 139 patients had manifest DN. There were no differences in -765G>C polymorphisms between LRDN and DN patients. Moreover, the C/G allele frequenc ies did not also differ between the groups. In conclusion, patients with DM1 display lower freqencies of the protective CC genotype as compared to healthy subjects. However, the study did not reveal associations of -765G>C polymorphism with the risk of DN., J. A. Hubáček ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
226. A possible role of the oxidant tissue injury in the development of hypoxic pulmonary hypertension
- Creator:
- Jan Herget, Jiří Wilhelm, Novotná, J., Adam Eckhardt, Richard Vytášek, Mrázková, L., and Ošťádal, M.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, plicní hypertenze, pulmonary hypertension, chronic hypoxia, pulmonary vasculature, structural remodeling, oxygen free radicals, nitrotyrosine, 14, and 612
- Language:
- English
- Description:
- Chronic sojourn in hypoxic environment results in the structural remodeling of peripheral pulmonary arteries and pulmonary hypertension. We hypothesize that the pathogenesis of changes in pulmonary vascular structure is related to the increase of radical production induced by lung tissue hypoxia. Hypoxia primes alveolar macrophages to produce more hydrogen peroxide. Furthermore, the increased release of oxygen radicals by other hypoxic lung cells cannot be excluded. Several recent reports demonstrate the oxidant damage of lungs exposed to chronic hypoxia. The production of nitric oxide is high in animals with hypoxic pulmonary hypertension and the serum concentration of nitrotyrosine (radical product of nitric oxide and superoxide interaction) is also increased in chronically hypoxic rats. Antioxidants were shown to be effective in the prevention of hypoxia induced pulmonary hypertension. We suppose that the mechanism by which the radicals stimulate of the vascular remodeling is due to their effect on the metabolism of vascular wall matrix proteins. Non-enzymatic protein alterations and/or activation of collagenolytic matrix metalloproteinases may also participate. The presence of low-molecular weight cleavage products of matrix proteins stimulates the mesenchymal proliferation in the wall of distal pulmonary arteries. Thickened and less compliant peripheral pulmonary vasculature is then more resistant to the blood flow and the hypoxic pulmonary hypertension is developed., J. Herget, J. Wilhelm, J. Novotná, A. Eckhardt, R. Vytášek, L. Mrázková, M. Ošťádal., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
227. A preliminary study on T-786C endothelial nitric oxide synthase gene and renal hemodynamic and blood pressure responses to dietary sodium
- Creator:
- Dengel, Donald R., Brown, M. D., Ferrell, R. E., Reynolds, T. H., and Supiano, M. A.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, stárnutí, glomerulární filtrace, human physiology, aging, glomerular filtration, renal plasma flow, 14, and 612
- Language:
- English
- Description:
- The purpose of the present study was to examine the role of the T-786C endothelial nitric oxide synthase (eNOS) gene polymorphism on changes in renal hemodynamics and blood pressure due to Na+ loading. Twenty-eight older (63±1 years), moderately obese (39±2 % fat) hypertensives had th eir glomerular filtration rate (GFR), renal plasma flow (RPF), blood pressure (BP) and plasma nitric oxide (NOx) levels determined after eight days of low (20 mEq) and high (200 mEq) Na+ diets. The two Na+ diets were separated by a 1-week washout period. Subjects were genotyped for the eNOS-786 site and were grouped on whether they were homozygous or heterozygous for the C allele (TC+CC, n=13) or only homozygous for the T allele (TT, n=15). The TC+CC genotype group had a significantly greater increase in diastolic (P=0.021) and mean arterial (P=0.018) BP and a significant decline in both RPF (P=0.007) and GFR (P=0.029) compared to the TT genotype group with Na+ loading. Furthermore, Na+ loading resulted in a significant (P=0.036) increase in plasma NOx in the TT, but not in the TC+CC genotype group as well as a trend (P=0.051) for an increase in urine NOx in TC+CC, but not in the TT genotype group. The increase in BP during Na+ loading in older hypertensives was associated with the eNOS genotype and may be related to changes in renal hemodynamics due to changes in NO metabolism., D. R. Dengel, M. D. Brown, R. E. Ferrell, T. H. Reynolds, M. A. Supiano., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
228. A priori a matematika u Berkeleyho
- Creator:
- Marek Tomeček
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Filozofie, Berkeley, George, 1685-1753, filozofie, matematika, empirismus, philosophy, mathematics, empiricism, a priori, 5, and 101
- Language:
- Czech
- Description:
- According to the Oxford English Dictonary George Berkeley introduced the term a priori into English. His inspiration for this was, it seems, to be found partly in the writings of his immediate predecessors, particularly Pierre Bayle, and partly in his pedagogical work where he adjudicated disputations between his pupils. Some of his arguments against the existence of matter Berkeley tells us are a priori, others a posteriori. Even the a priori arguments are underpinned by prior semantic principles of an anti-abstractionist character, which are shown to be important particularly in the immaterialist philosophy of mathematics. Berkeley's courageously unorthodox, and generally unpublished, thoughts about mathematics thus grow from the same soil as his celebrated denial of matter., Marek Tomeček., and Obsahuje poznámky a bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
229. A question of adaptability: climate and habitat change lower trait diversity in butterfly communities in south-western Germany
- Creator:
- Filz, Katharina J., Wiemers, Martin, Herrig, Anne, Weitzel, Matthias, and Schmitt, Thomas
- Type:
- article, články, model:article, and TEXT
- Subject:
- Zoologie, zoologie, entomologie, Lepidoptera, species decline, community composition change, habitat specialisation, functional groups, community temperature index, fallows, south-western Germany, 2, and 59
- Language:
- English
- Description:
- Invertebrate diversity has rapidly declined throughout Europe during the last century. Various reasons for this decrease have been proposed including human induced factors like climate change. Temperature changes alter distributions and occurrences of butterflies by determining habitat conditions at different scales. We evaluated changes in the composition of butterfly communities recorded at nine areas of fallow ground in south-western Germany in 1973, 1986, 2010 and 2012 using Pollard’s transect technique. To demonstrate the importance of climatic changes in affecting butterfly communities, we calculated the community temperature index (CTI) for each butterfly community in each year. Although they increased slightly, the CTI-values did not match the temperature trends recorded in the study region. However, the reduction in the standard deviations of the CTIs over time is reflected in the marked loss of cold- and warm-adapted species due to their inability to cope with temperature and land-use induced habitat changes. Results of our butterfly surveys indicate a marked decline in species richness and striking changes in the composition of the butterfly communities studied. This trend was most pronounced for habitat specialists, thus mirroring a depletion in trait diversity. Our results indicate that, in the course of large-scale anthropogenic changes, habitat degradation at smaller scales will continuously lead to the replacement of habitat specialists by ubiquitous species., Katharina J. Filz ... [et al.]., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
230. A review of the recent seismic activity in the southern part of Egypt (Upper Egypt)
- Creator:
- Haggag, Hamed Mohamed, Gaber, Hassan Hassib, Sayed, Abdalah Dahy, and Ezzat, Mohamed
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, seizmicita, seismicity, Asuán (Egypt), Aswan (Egypt), seismic energy, Upper Egypt, 7, and 551
- Language:
- English
- Description:
- Analyzing the earthquake catalogue of the Upper Egypt area since 1982 revealed some char acteristics of the seismic activity in the area. Construction of a seismicity map according to the seismicity level in the Upper Egypt showed 14 seismic zones and that the seismic activity is intense around the stra it of the Gulf of Suez, along the Red Sea axis, Abu Dabbab and Aswan area. While the detailed study of Aswan zone showed 8 distinct sub-seismic zones and that the activity is concentrated in and around Gable Marawa area. The b-value was calculated for each seismic zone; it is found that the highest value is in Abu Dabbab area followed by Aswan area. A seismic energy rele ased map of the Upper Egypt was constructed for the period from 1982 to 2006; the map reveals the main active zones with high energy values. The study gives new insight for a better understanding of the seismic activity in the Upper Egypt and helps in the seismic hazard assessment., Haggag Hamed Mohamed, Gaber Hassan Hassib, Sayed Abdalah Dahy and Ezzat Mohamed El-Amin., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public