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161.
The present experiments were designed to investigate the effects of omeprazole, a H(+)-K+ ATPase inhibitor, on corporal smooth muscle tone in vitro. All spontaneous contractile activity in the corpus cavernosum was blocked following omeprazole (0.1 mM-1 mM) administration. However atropine (1 microM), Nw-nitro L-arginine methyl ester (L-NAME, 30 microM) or indomethacin (10 microM) did not affect the spontaneous contraction. Omeprazole (10 microM-1 mM) concentration-dependently induced relaxation in corporal smooth muscle precontracted with 10 microM phenylephrine or 80 mM KCl. Pretreatment of corporal tissue with L-NAME (30 microM), indomethacin (10 microM), ammonium chloride (7.5 mM), sodium acetate (7.5 mM), tetraethyl ammonium chloride (0.5 mM) or glibenclamide (1 microM) had no effect on the omeprazole induced relaxant responses. Nimodipine, an L-type Ca++ channel blocker, relaxed corporal strips precontracted with 80 mM KCl. Collectively, these results indicate that the inhibition of spontaneous contraction and the relaxation of precontracted corporal smooth muscle by omeprazole is probably mediated by the blockade of calcium channels. Further work is needed to determine the cellular mechanism(s) of action by which omeprazole acts on corpus cavernosum smooth muscle. 相似文献
162.
Lipid A isolated by mild acid hydrolysis from lipopolysaccharides of 22 nontypeable and 2 type f Haemophilus influenzae strains was investigated using electrospray ionization coupled to quadrupole ion trap mass spectrometry. The lengths, positions, and number of acyl chains in the lipid A molecule were determined using multiple-step tandem mass spectrometry (MSn). All of the analyzed strains showed a major lipid A molecule comprising beta-2-amino-2-deoxy-D-glucopyranose-(1-->6)-alpha-2-amino-2-deoxy-D-glucopyranose phosphorylated at the C4' and C1 positions. The C2/C2' and C3/C3' positions were substituted by amide-linked and ester-linked 3-hydroxytetradecanoic acid chains, respectively. The fatty acid chains on C3' and C2' were further esterified by tetradecanoic acid chains. In all strains, minor amounts of lipid A molecules with different acylation patterns were identified. Thus, structures comprising the hexaacylated lipid A with the C2 or C3 position being substituted by 3-hydroxydecanoic acid, and hexaacylated lipid A with the C3 and C3' positions being substituted by 3-hydroxydodecanoic or dodecanoyloxytetradecanoic acid, respectively, were found. In addition, lipid A with an acetyl group attached to the 3-hydroxytetradecanoic acid groups attached to the C2 or C3 position was detected in two nontypeable H. influenzae strains. 相似文献
163.
Acarturk E Attila G Bozkurt A Akpinar O Matyar S Seydaoglu G 《Journal of biochemistry and molecular biology》2005,38(4):486-490
Genetic factors are important in the pathogenesis of coronary artery disease (CAD). Angiotensin converting enzyme (ACE) gene insertion(I)/deletion(D) polymorphism is one of the genetic factor found to be related with CAD. We investigated the association between I/D polymorphism of the ACE gene and the presence of CAD. Three hundred and seven patients (187 males and 120 females, aged between 35-80, mean 54.3 +/-9.8 years) who underwent diagnostic coronary angiography were included in the study. ACE I/D polymorphism was detected by polymerase chain reaction. Of the 307, 176 had CAD. The most frequently observed genotype in all subjects was ID (47.9 %). However, in patients with CAD the frequency of II genotype was lower whereas DD genotype was higher compared to the controls (p < 0.05). The number of D allele carrying subjects were also higher (p < 0.05) in CAD patients. The logistic regression analysis indicated that the ACE D allele is an independent risk factor (odds ratio = 1.48, 95 % CI = 1.01-2.18, p < 0.05). In conclusion, the I/D polymorphism of ACE gene (carrying D allele) is an independent risk factor for CAD in the studied Turkish population. 相似文献
164.
Güntürkün O 《Current opinion in neurobiology》2005,15(6):686-693
Both mammals and birds can flexibly organize their behavior over time. In mammals, the mental operations generating this ability are called executive functions and are associated with the prefrontal cortex. The corresponding structure in birds is the nidopallium caudolaterale. Anatomical, neurochemical, electrophysiological and behavioral studies show these structures to be highly similar. The avian forebrain displays no lamination that corresponds to the mammalian neocortex, hence lamination does not seem to be a requirement for higher cognitive functions. Because all other aspects of the neural architecture of the mammalian and the avian prefrontal areas are extremely comparable, the freedom to create different neural architectures that generate prefrontal functions seems to be very limited. 相似文献
165.
Aygul R Demircan B Erdem F Ulvi H Yildirim A Demirbas F 《Biological trace element research》2005,108(1-3):43-52
The levels of oxidants xanthine oxidase (XO), nitric oxide (NO), and malondialdehyde (MDA) and of the antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione reductase (GRD) were determined in plasma within 24 h after onset of hemorrhagic stroke in 17 patients (9 men and 8 women, aged 60.7+/-11.5 yr) and in 20 healthy controls (12 men and 8 women, aged 62.5+/-8.3 yr). Compared to controls, the plasma SOD and total superoxide scavenger activities (TSSA) were significantly lower and the NO levels were significantly higher among the stroke patients. XO showed a slight, nonsignificant increase in the patients, but the levels of MDA, NSSA, GRD, and GSH-Px did not show any significant differences between the two groups. The hemorrhage volume was negatively correlated with the initial score of the Glasgow Coma Scale and a positive correlation with lethal outcome, but it did not correlate significantly with any of the measured parameters. The results suggest that free radicals might play a role in the development of brain injury following brain hemorrhage. 相似文献
166.
Söğüt S Kotuk M Yilmaz HR Ulu R Ozyurt H Yildirim Z 《Cell biochemistry and function》2004,22(3):157-162
The aim of this experimental study was to investigate the possible role of adenosine deaminase (AD) and xanthine oxidase (XO) in the pathogenesis of cisplatin-induced nephrotoxicity and the effect of erdosteine in decreasing the toxicity. The intraperitoneal injection of cisplatin (7 mg kg(-1) body weight) induced a significant increase in plasma creatinine level and blood urea nitrogen (BUN), and plasma and damaged renal tissue activities of AD and XO in rats. Co-treatment with erdosteine (10 mg kg(-1)day(-1)) attenuated the increase in the plasma creatinine and BUN levels, and significantly prevented the increase in tissue and plasma AD and XO activities (P<0.05). The results of this study revealed that XO and AD may play an important role in the pathogenesis of cisplatin-induced nephrotoxicity. The potent free radical scavenger erdosteine may have protective potential in this process and it will become a promising drug in the prevention of this undesired side-effect of cisplatin, but further studies are needed to illuminate the exact protection mechanism of erdosteine against cisplatin-induced nephrotoxicity. 相似文献
167.
We examined genetic differences of four Vitis vinifera populations (A, B, C, D) including local Kabarcik cultivar grown along an altitude gradient of 800, 900, 1000, and 1150 m above sea level in the Coruh Valley (800 m: A population; 900 m: B population; 1000 m: C population; 1150 m: D population). Leaf samples were used for both RAPD and fatty acid analysis. A total of 60 individuals with 15 individuals per population were included in this study. RAPD analyses showed various band sizes, which ranged from 250 to 3000 bp. Mean polymorphic locus ratios were determined as 96.29% considering four populations. The highest percentage of polymorphic loci (97.8%) was produced by the highest altitude. Thirty-two different fatty acids were found; linoleic acid was the most common in all four populations. According to the dendograms obtained from statistical analyses of RAPD and fatty acid profiles the populations that were close to each other in terms of geographical distance also were similar genetically. 相似文献
168.
Melissa M. Broadway Elizabeth A. Rogers Chungyu Chang I-Hsiu Huang Prabhat Dwivedi Suleyman Yildirim Michael P. Schmitt Asis Das Hung Ton-That 《Journal of bacteriology》2013,195(16):3774-3783
Toxigenic Corynebacterium diphtheriae strains cause diphtheria in humans. The toxigenic C. diphtheriae isolate NCTC13129 produces three distinct heterotrimeric pili that contain SpaA, SpaD, and SpaH, making up the shaft structure. The SpaA pili are known to mediate bacterial adherence to pharyngeal epithelial cells. However, to date little is known about the expression of different pili in various clinical isolates and their importance in bacterial pathogenesis. Here, we characterized a large collection of C. diphtheriae clinical isolates for their pilin gene pool by PCR and for the expression of the respective pilins by immunoblotting with antibodies against Spa pilins. Consistent with the role of a virulence factor, the SpaA-type pili were found to be prevalent among the isolates, and most significantly, corynebacterial adherence to pharyngeal epithelial cells was strictly correlated with isolates that were positive for the SpaA pili. By comparison, the isolates were heterogeneous for the presence of SpaD- and SpaH-type pili. Importantly, using Caenorhabditis elegans as a model host for infection, we show here that strain NCTC13129 rapidly killed the nematodes, the phenotype similar to isolates that were positive for toxin and all pilus types. In contrast, isogenic mutants of NCTC13129 lacking SpaA-type pili or devoid of toxin and SpaA pili exhibited delayed killing of nematodes with similar kinetics. Consistently, nontoxigenic or toxigenic isolates that lack one, two, or all three pilus types were also attenuated in virulence. This work signifies the important role of pili in corynebacterial pathogenesis and provides a simple host model to identify additional virulence factors. 相似文献
169.
Rachel L. Redler ;David Shirvanyants ;Onur Dagliyan ;Feng Ding ;Doo Nam Kim ;Pradeep Kota ;Elizabeth A. Proctor ;Srinivas Ramachandran ;Arpit Tandon ;Nikolay V. Dokholyan 《分子细胞生物学报》2014,(2):104-115
The generation of toxic non-native protein conformers has emerged as a unifying thread among disorders such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Atomic-level detail regarding dynamical changes that facilitate protein aggre- gation, as well as the structural features of large-scale ordered aggregates and soluble non-native oligomers, would contribute signifi- cantly to current understanding of these complex phenomena and offer potential strategies for inhibiting formation of cytotoxic species. However, experimental limitations often preclude the acquisition of high-resolution structural and mechanistic information for aggregating systems. Computational methods, particularly those combine both aU-atom and coarse-grained simulations to cover a wide range of time and length scales, have thus emerged as crucial tools for investigating protein aggregation. Here we review the current state of computational methodology for the study of protein self-assembly, with a focus on the application of these methods toward understanding of protein aggregates in human neurodegenerative disorders. 相似文献
170.