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291.
Recent studies report a link between common environmental exposures, such as particulate matter air pollution and tobacco smoke, and decline in cognitive function. The purpose of this study was to assess the association between exposure to polycyclic aromatic hydrocarbons (PAHs), a selected group of chemicals present in particulate matter and tobacco smoke, and measures of cognitive performance among elderly in the general population. This cross-sectional analysis involved data from 454 individuals aged 60 years and older from the 2001–2002 National Health and Nutrition Examination Survey. The association between PAH exposures (as measured by urinary biomarkers) and cognitive function (digit symbol substitution test (DSST)) was assessed using multiple linear regression analyses. After adjusting for age, socio-economic status and diabetes we observed a negative association between urinary 1-hydroxypyrene, the gold standard of PAH exposure biomarkers, and DSST score. A one percent increase in urinary 1-hydroxypyrene resulted in approximately a 1.8 percent poorer performance on the digit symbol substitution test. Our findings are consistent with previous publications and further suggest that PAHs, at least in part may be responsible for the adverse cognitive effects linked to tobacco smoke and particulate matter air pollution.  相似文献   
292.
In a search for novel compounds with analgesic and anti-inflammatory activity, a series of regioisomeric 1-(3-pyridazinyl)-3-arylpyrazole (5a-f, 6a-f) and 1-(3-pyridazinyl)-5-arylpyrazole (7a-f, 8a-f) derivatives were synthesized. The structure of these regioisomers was confirmed by spectral techniques. The compounds were preliminarily screened at 8 microM concentration for their inhibitory activity against cyclooxygenase enzymes, COX-1 and COX-2, using a human whole blood test. The tested derivatives showed inhibitory activity for both enzymes and are worthy of further investigation for developing better leads.  相似文献   
293.
The survival and persistence of Mycobacterium tuberculosis depends on its capacity to manipulate multiple host defense pathways, including the ability to actively inhibit the death by apoptosis of infected host cells. The genetic basis for this anti-apoptotic activity and its implication for mycobacterial virulence have not been demonstrated or elucidated. Using a novel gain-of-function genetic screen, we demonstrated that inhibition of infection-induced apoptosis of macrophages is controlled by multiple genetic loci in M. tuberculosis. Characterization of one of these loci in detail revealed that the anti-apoptosis activity was attributable to the type I NADH-dehydrogenase of M. tuberculosis, and was mainly due to the subunit of this multicomponent complex encoded by the nuoG gene. Expression of M. tuberculosis nuoG in nonpathogenic mycobacteria endowed them with the ability to inhibit apoptosis of infected human or mouse macrophages, and increased their virulence in a SCID mouse model. Conversely, deletion of nuoG in M. tuberculosis ablated its ability to inhibit macrophage apoptosis and significantly reduced its virulence in mice. These results identify a key component of the genetic basis for an important virulence trait of M. tuberculosis and support a direct causal relationship between virulence of pathogenic mycobacteria and their ability to inhibit macrophage apoptosis.  相似文献   
294.
A conceptual neural fuzzy model based on adaptive-network based fuzzy inference system, ANFIS, was proposed using available input on-line and off-line operational variables for a sugar factory anaerobic wastewater treatment plant operating under unsteady state to estimate the effluent chemical oxygen demand, COD. The predictive power of the developed model was improved as a new approach by adding the phase vector and the recent values of COD up to 5–10 days, longer than overall retention time of wastewater in the system. History of last 10 days for COD effluent with two-valued phase vector in the input variable matrix including all parameters had more predictive power. History of 7 days with two-valued phase vector in the matrix comprised of only on-line variables yielded fairly well estimations. The developed ANFIS model with phase vector and history extension has been able to adequately represent the behavior of the treatment system.  相似文献   
295.
A total of 22 motile Aeromonas strains were detected in 48 (18.53%) of 259 fish and 6 (10.71%) of 56 water samples obtained from seven commercial rainbow trout ( Oncorhynchus mykiss , Walbaum) farms in the province of Mersin, Turkey. These strains were identified by conventional microbiological techniques and by using an ID32GN system. Of these isolates 20 (91.3%) were identified as Aeromonas hydrophila and 2 (8.7%) as Aeromonas sobria . While 8 of the A. hydrophila strains were isolated from water samples, 12 isolates were from fish samples. Whereas A. hydrophila strains were found in all farms, A. sobria was detected in only two farms. Genetic diversity by arbitrarily primed polymerase chain reaction (AP-PCR) and antimicrobial sensitivity tests were carried out on eight A. hydrophila isolates obtained from water samples, and isolates from seven A. hydrophila and one A. sobria from fish samples. The AP-PCR band patterns of motile aeromonads demonstrated weak similarity to the A. hydrophila reference strain ATCC 7966. Five A. hydrophila strains in the water samples displayed genetic similarity, but three others were different. Aeromonas hydrophila isolates from fish samples possessed slight similarities, and A. sobria was genetically distant to all A. hydrophila strains. An antimicrobial sensitivity test of 16 isolates revealed that 100% were sensitive to gentamicin, 87.5% to sulphamethoxazole–trimethoprim, 62.5% to enrofloxacin, 43.8% to oxytetracycline, 37.5% to neomycin, 18.75% to streptomycin and 6.25% to erythromycin. All isolates were resistant to novobiocin.  相似文献   
296.
Background: It has been difficult to determine, from the published literature, whether men or women have higher levels of exercise-induced oxidative stress.Objective: The aim of this study was to compare variations between the sexes in lipid hydroperoxide (LPO), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and lactate dehydrogenase (LDH) after 3 different running exercises performed at the same speed.Methods: Eligible participants were healthy university students of both sexes. The participants performed running exercise tests at distances of 800, 1500, and 3000 m at a speed of 10 km/h. Blood samples were taken from the participants just before and immediately after the running activities to determine LPO, SOD, CAT, GR, and LDH, and these measures were compared both before and after exercise and between the sexes.Results: A total of 17 young and healthy, but not physically trained, students (n = 8 men; mean age, 22.00 years; n = 9 women; mean age, 21.78 years) participated in this study. Height, weight, and maximum oxygen consumption values were significantly higher in men than in women (P = 0.01). Significant gender effects were found in LPO levels at 3000 m (F = 5.51; P = 0.03) and in SOD activity at 800 m (F = 7.92; P = 0.01) and 3000 m (F = 6.05; P = 0.03). CAT activity also differed between the sexes at 800 m (F = 15.67; P = 0.01) and 1500 m (F = 6.55; P = 0.02). However, no significant gender-time interaction effect was observed for any measurement at the 800-, 1500-, and 3000-m distances.Conclusions: Changes in LPO, SOD, and CAT activities at different running distances were not different between men and women over time because of a nonsignificant gender-time interaction. With regard to changes in oxidative stress, men and women had similar responses to exercise at the same absolute workload, despite significant differences in physical characteristics.  相似文献   
297.
We compared the effects of early and late stage hypothermia treatment after spinal cord injury. Five groups each consisting of seven rats were included in this study. In Group 1a (Clip applied-non-treatment group) and Group 1b (Clip applied-treated group) the spinal cords were harvested 1 h after the injury. In Group 2a (clip applied, non-treated group) and Group 2b (clip applied-treated group) the injured segments were harvested 24 h after injury. Group 3 was designed as the sham-operated group. The significantly lower levels of TBARS and GSH-Px in Group 2a, as compared with Group 1b suggests that the hypothermia was effective in the early stage of treatment (P < 0.05). In contrast, TBARS and GSH-Px levels were significantly increased at the 24 h timepoint following treatment (P < 0.05).Short-term systemic hypothermia reduces lipid peroxidation in the early stages after spinal cord injury. This beneficial effect disappears 24 h following systemic hypothermic treatment.  相似文献   
298.
Chaenorhinum semispeluncarum H. Y?ld?r?m, Kit Tan, S. ?enol & A. Pirhan sp. nov. and C. yildirimlii Kit Tan, H. Y?ld?r?m, S. ?enol & A. Pirhan sp. nov. (Scrophulariaceae, C. sect. Microrrhinum) from east Anatolia are described and illustrated. They are both narrow endemics related to the rare C. cryptarum, also from east Anatolia. Chaenorhinum semispeluncarum occurs on calcareous marl rich in potassium nitrate at the entrance of wet caves in Malatya and differs from C. cryptarum by its erect habit, smaller corollas, shallowly ribbed and tuberculate, bicoloured seeds. Chaenorhinum yildirimlii from the neighbouring province of Erzincan was found on alluvial soil of stream banks and differs from C. semispeluncarum by its seed characters which are similar to those of C. cryptarum. Chaenorhinum yildirimlii differs from C. cryptarum, most conspicuously by the violet lower corolla lip spotted dark purple at the apex.  相似文献   
299.
Griscelli syndrome is a rare autosomal recessive disease characterized by pigment dilution, variable cellular immunodeficiency, and an acute phase of uncontrolled T lymphocyte and macrophage activation. We previously mapped the disease locus to 15q21 and showed that a MyoVa gene (HGMW-approved symbol MYO5A) defect leads to Griscelli syndrome. We report a second MyoVa mutation in a new patient, confirming this first finding. However, in four other Griscelli syndrome patients analyzed, the MYOVA protein is expressed, and no mutation can be detected in the MyoVa gene coding sequence, even in the alternatively spliced region for which exon-intron boundaries were characterized. Linkage analysis performed in 15 Griscelli families thus far studied confirms the first localization. However, fine haplotype analysis in three families strongly suggests the existence of a second gene at the same locus for Griscelli syndrome less than 7.3 cM distant from the MyoVa gene.  相似文献   
300.
Toluene dioxygenase oxidizes toluene to (+)-cis-1(S),2(R)-dihydroxy-3-methylcyclohexa-3,5-diene. This reaction is catalyzed by a multienzyme system that is induced in cells of Pseudomonas putida F1 during growth on toluene. One of the components of toluene dioxygenase has been purified to homogeneity and shown to be an iron-sulfur protein that has been designated ferredoxinTOL. The molecular weight of ferredoxinTOL was calculated to be 15,300, and the purified protein was shown to contain 2 g of atoms each of iron- and acid-labile sulfur which appear to be organized as a single [2Fe-2S]cluster. Solutions of ferredoxinTOL were brown in color and showed absorption maxima at 277, 327, and 460 nm. A shoulder in the spectrum of the oxidized protein was discernible at 575 nm. Reduction with sodium dithionite or NADH and ferredoxinTOL reductase resulted in a decrease in visible absorbance at 460 and 575 nm, with a concomitant shift in absorption maxima to 382 and 438 nm. The redox potential of ferredoxinTOL was estimated to be -109 mV. In the oxidized state, the protein is diamagnetic. However, upon reduction it exhibited prominent electron paramagnetic resonance signals with anisotropy in g values (gx = 1.81, gy = 1.86, and gz = 2.01). Anaerobic reductive titrations revealed that ferredoxinTOL is a one-electron carrier that accepts electrons from NADH in a reaction that is mediated by a flavoprotein (ferredoxinTOL reductase). The latter is the first component in the toluene dioxygenase system. Reduced ferredoxinTOL can transfer electrons to cytochrome c or to a terminal iron-sulfur dioxygenase (ISP-TOL) which catalyzes the incorporation of molecular oxygen into toluene and related aromatic substrates.  相似文献   
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