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
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
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
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
The Australian species of the genus Coelioxys Latreille are revised. Six species are recognized: Coelioxys albolineata Cockerell, 1905; Coelioxys froggatti Cockerell, 1911; Coelioxys reginae Cockerell, 1905; Coelioxys weinlandi Schulz, 1904 and two new species: Coelioxys julia sp. n. and Coelioxys tasmaniana sp. n. Three names are synonymized: Coelioxys biroi Friese, 1909 syn. n. and Coelioxys albolineata darwiniensis Cockerell, 1929 syn. n. under Coelioxys albolineata, and Coelioxys victoriae Rayment, 1935 syn. n. under Coelioxys froggatti. Species descriptions and redescriptions, illustrations, distribution maps, floral records and a key to both sexes of all species are provided., Léo Correia da Rocha-Filho., and Obsahuje bibliografii
Hypoxic pulmonary vasoconstric tion (HPV) is an important homeostatic mechanism in which increases of [Ca2+] i are primary events. In this study, primary cultured, human pulmonary artery smooth muscle cells (hPASMC) were used to examine the role of TRPC channels in mediating [Ca2+] i elevations during hypoxia. Hypoxia (PO2 about 20 mm Hg) evoked a transient [Ca2+] i elevation that was reduced by removal of extracellular calcium. Nifedipine and verapamil, blockers of vo ltage-gated calcium channels (VGCCs), attenuated th e hypoxia-induced [Ca2+] i elevation by about 30 %, suggesting the presence of alternate Ca2+ entry pathways. Expression of TRPC1 an d TRPC6 in hPASMC were found by RT-PCR and confirmed by Western blot analysis. Antagonists for TRPC, 2APB and SKF96365, significantly reduced hypoxia-induced [Ca2+] i elevation by almost 60 %. Both TRPC6 and TRPC1 were knocked down by siRNA, the loss of TRPC6 decreased hypoxic response down to 21 % of control, whereas the knockdown of TRPC1 reduced the hypoxia respon se to 85 %, suggesting that TRPC6 might play a central role in mediating hypoxia response in hPASMC. However, blockade of PLC pathway caused only small inhibition of the hypoxia response. In contrast, AICAR, the agonist of AMP-activated kinase (AMPK), induced a gradual [Ca2+] i elevation, whereas compound C, an antagonist of AMPK, almost abolished the hypoxia response. Ho wever, co-immunoprecipitation revealed that AMPK α was not colocalized with TRPC6. Our data supports a role for TRPC6 in mediation of the [Ca2+] i elevation in response to hypoxia in hPASMC and suggests that this response may be linked to cellular energy status via an activation of AMPK., C. Tang, W. K To, F. Meng, Y. Wang, Y. Gu., and Obsahuje bibliografii
The classification scheme for micaceous minerals is described. According to the size of mineral particles micas are divided into macrocrystalline compounds and microcrystalline clay micas. Macroc rystalline micas are differentiated into (a) Mg-Fe-Al micas, (b) Li-micas, (c) micas with other cations. Vertical boundary in the suggested scheme divides micas into trioctahedral and dioctahedral members. Additional subdivision is carried out on the basis of the extent of Si substitution in tetrahedral positions of their crystal lattice. Microcrystalline (<4μm) micas are subordinate to the crystallochemical scheme for macrocrystalline micas. List of mica species together with their varieties and synonyms is in Table 2., Karel Melka., and Obsahuje bibliografické odkazy
Oxidative stress is an imbalance between free radicals and antioxidants, and is an important etiological factor in the development of hypertension. Recent experimental evidence suggests that subpressor doses of angiotensin II elevate oxidative stress and blood pressure. We aimed to investigate the oxidative stress related mechanism by which a subpressor dose of angiotensin II induces hypertension in a normotensive rat model. Normotensive male Wistar rats were infused with a subpressor dose of angiotensin II for 28 days. The control group was sham operated and infused with saline only. Plasma angiotensin II and H2O2 levels, whole-blood glutathione peroxidase, and AT-1a, Cu/Zn SOD, and p22phox mRNA expression in the aorta was assessed. Systolic and diastolic blood pressures were elevated in the experimental group. There was no change in angiotensin II levels, but a significant increase in AT-1a mRNA expression was found in the experimental group. mRNA expression of p22phox was increased significantly and Cu/Zn SOD decreased significantly in the experimental group. There was no significant change to the H2O2 and GPx levels. Angiotensin II manipulates the free radical-antioxidant balance in the vasculature by selectively increasing O2 - production and decreasing SOD activity and causes an oxidative stress induced elevation in blood pressure in the Wistar rat., M. M. Govender, A. Nadar., and Obsahuje bibliografii
Many species of carabid beetles are important pre- and post-dispersal seed feeders of herbaceous plants. Here we summarise data from dissections, field observations, rearing and "cafeteria" experiments on 55 granivorous and 188 omnivorous species that occur in Italy. We tested the hypothesis that seed feeding carabids are restricted to taxa with pronounced morphological adaptations for manipulating and crushing seeds in both the larval and adult stages. The feeding guilds of carabids were rearranged into the following groups: (i) strict predators with long mandibles and predaceous larvae, often depending also on non-prey food; (ii) omnivorous species with stout mandibles and larvae of a seed-eating morphotype; (iii) granivorous species, feeding only on seeds with larvae sometimes of the scarabeoid c-form type. The seed feeding carabids in the Italian fauna belong to the tribe Zabrini (Amara and Zabrus genera) and to all the Harpalinae (sub)tribes, from Anisodactylini to Ditomina. The time of reproduction seems to be associated with habitat preference; wetland or dry open land, rather than true granivorous versus omnivorous habits, but in stenophagous seed feeders, a phenological coincidence with particular plants is sometimes recorded., Federica Talarico, Anita Giglio, Roberto Pizzolotto, Pietro Brandmayr., and Obsahuje bibliografii
The purpose of this study was to determine if there is flowmediated vasodilation of the femoral artery in response to progressive increases in flow within a physiological range observed in the in vivo experiments. Femoral artery blood flow was determined in conscious rabbits (n=5) using chronically implanted flowprobes. Resting blood flow was 8.3±0.6 ml/min and increased to 39.9±5.4 ml/min during high intensity exercise. Femoral arteries (n=12, 1705±43 μm outer diameter) harvested from a separate group of rabbits were mounted on cannulas and diameter was continuously monitored by video system. Functional integrity of the endothelium was tested with acetylcholine. The arteries were set at a transmural pressure of 100 mm Hg and preconstricted with phenylephrine to 73±3 % of initial diameter. Using a roller pump with pressure held constant, the arteries were perfused intraluminally with warmed, oxygenated Krebs' solution (pH=7.4) over a physiological range of flows up to 35 ml/min. As flow increased from 5 ml/min to 35 ml/min, diameter decreased significantly (p<0.05) from 1285±58 μm to 1100±49 μm. Thus, in vessels with a functional endothelium, increasing intraluminal flow over a physiological range of flows produced constriction, not dilation. Based on these results, it seems unlikely that flow-mediated vasodilation in the rabbit femoral artery contributes to exercise hyperemia., P. S. Clifford ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy