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41.
In the present study, we investigated whether the polymorphisms of glutathione S-transferase M1 (GSTM1) and T1 (GSTT1) genes are risk factors of cataract among Iranian population in a molecular epidemiological way. Blood samples from 150 subjects with cataract (72 male; 78 female) and 150 age- and sex-matched healthy persons were collected. Both patient and control groups were unrelated Iranian Muslims. Using PCR-based method, the genotypes were determined. The null GSTM1 genotype was associated with a 2.38-fold increase in the risk of developing cataract (OR=2.38; 95% CI=1.46-3.89; P = 0.0003). After stratification by sex of subjects, the association was apparent only among women (OR=3.20; 95% CI=1.58-6.52; P = 0.0007). The GSTT1 null genotype was associated with a 1.10-fold increased risk of developing cataract, but this association was not statistically significant. After stratification by sex of subjects, same results were obtained. Female patients with null genotype for GSTM1 and no history of smoking had a 3.45-fold increased cataract risk (P < 0.05), whereas females who were null for GSTM1 and having history of smoking were not at increased risk of cataract.  相似文献   
42.
We present a complete yet computationally simple model for the dielectric response function of liquid water over the energy-momentum plane, which, in contrast to earlier models, is consistent with the recent inelastic X-ray scattering spectroscopy data at both zero and finite momentum transfer values. The model follows Ritchie's extended-Drude algorithm and is particularly effective at the region of the Bethe ridge, substantially improving previous models. The present development allows for a more accurate simulation of the inelastic scattering and energy deposition process of low-energy electrons in liquid water and other biomaterials. As an example, we calculate the stopping power of liquid water for electrons over the 0.1-10 keV range where direct experimental measurements are still impractical and the Bethe stopping formula is inaccurate. The new stopping power values are up to 30-40% lower than previous calculations. Within the range of validity of the first Born approximation, the new values are accurate to within the experimental uncertainties (a few percent). At the low end, the introduction of Born corrections raises the uncertainty to perhaps approximately 10%. Thus the present model helps extend the ICRU electron stopping power database for liquid water down to about two orders of magnitude with a comparable level of uncertainty.  相似文献   
43.
Persson  Hans  Von Fircks  Yuehua  Majdi  Hooshang  Nilsson  Lars Owe 《Plant and Soil》1995,168(1):161-165
Results of the spatial distribution of fine roots are reported from a Norway spruce (Picea abies (L.) Karst.) in SW Sweden stand subjected to drought (D) and ammonium-sulphate application (NS). The sampling was carried out by excavating monoliths in segments of 0.5 × 0.5 × 0.1 m to a depth of one meter. Root data also included in the study were obtained by excavating whole trees and soil coring.The data suggest a fairly deep distribution pattern of fine roots (< 1 mm in diameter) in the study area compared with other forest sites in SW Sweden. The weight fraction of living fine roots in the LFH-horizon amounted to 53, 36 and 55% of the total fine-root biomass and 12, 30 and 32% of the total fine-root necromass (dead fine roots) in the control, D and NS-treatment areas respectively. Drought seemed to result in a redistribution of fine roots to deeper mineral soil horizons. Ammonium sulphate application led to the reverse, viz, a concentration of fine roots to the LFH-horizon. A significantly smaller fine-root necromass was indicated in the LFH-horizon of the control areas compared with both the D and NS-treatment areas, suggesting a high mortality of fine roots in these areas. A heavy dry matter fraction accumulates in roots > 1 mm in diameter and in stumps. These root fraction, were frequently found between the trees, although the stump constitutes an important fraction in terms of dry weight.  相似文献   
44.
Carbon monoxide (CO) produced by incomplete combustion of hydrocarbons, has many toxic effects on different organs, especially the heart and brain that have greater demands for oxygen. The present study aimed to evaluate the protective effects of granulocyte colony stimulating factor (G-CSF) on apoptosis after CO poisoning in rats. Male Wistar rats were exposed to CO 1500 or 3000 ppm for 60 min. Single and multiple doses of G-CSF (10, 50, and 100 μg/kg) were administered to animals. After CO poisoning, carboxyhemoglobin concentration was measured, apoptotic cells were evaluated by TUNEL assay and caspase 3 activity was determined by immunofluorescence. Blood levels of carboxyhemoglobin significantly increased following exposure to both 1500 and 3000 ppm concentrations of CO. However, carboxyhemoglobin levels were significantly higher following exposure to CO 3000 ppm compared to CO 1500 ppm (p?<?0.05). Differences in caspase 3 activity between G-CSF and control groups were significant and G-CSF could decrease apoptosis following CO 3000 ppm poisoning (p?<?0.001). TUNEL assay showed that in rats treat with 5 doses of G-CSF 100 μg/kg, apoptosis was significantly ameliorated compared to control rats and sham (rats that were not exposed to CO) group (p?<?0.05). Concerning caspase 3 activity and apoptosis rate, the best results were found in rats exposed to 3000 ppm and treated with G-CSF 100 μg/kg. In this study, we confirmed that CO poisoning leads to cardiomyocytes apoptosis which could be significantly reduced by G-CSF treatment.  相似文献   
45.
Cardiac complications including arrhythmia and especially atrial fibrillation (AF) are common causes of death in β-thalassemia patients. The main factor in the etiopathogenesis of these complications is iron overload, which results in increased oxidative stress. Although there is a known association between cardiac complications and iron overload in β-thalassemia patients, there is no comprehensive review on AF and excessive iron with a focus on oxidative stress in these patients. The aim of this article was to review the different aspects of AF in β-thalassemia patients with a focus on the prevention and treatment of AF by using iron chelators and/or anti-oxidants. AF in β-thalassemia patients is more common than in the general population. One of the most important causes of AF is cardiac iron overload and the harmful effects of increased oxidative stress. Iron-induced AF can be reversed by using an intensive iron chelation regimen. Based on a few experimental studies, the combination of iron chelators with some anti-oxidants, including NAC, vitamin C, and acetaminophen, can lead to improved cardiac protection. However, the effect of such combinations on cardiac arrhythmias should be further evaluated with animal and human studies.  相似文献   
46.
β-Thalassemia is the most common single gene disorder in Iran and more than 25,000 affected individuals have been reported. It has been reported that in patients with β-thalassemia in the presence of Xmn1 polymorphic site the level of Hb F and Gγ: Aγ ratio is increased. The prevalence of Xmn1 polymorphic site, Gγ: Aγ ratio and Hb F in 197 β-thalassemia major patients from the Kermanshah Province of Iran were studied. The Xmn1 polymorphic site was determined by PCR-RFLP procedure. The levels of Gγ and Aγ chains were detected by HPLC. The percent of Hb F was determined using electrophoresis method. In β-thalassemia major patients the frequency of presence Xmn1 was 0.39. The mean of Gγ: Aγ ratio was found to be 2.5. In the present study it was found that in the presence of Xmn1 polymorphic site Gγ percent and Gγ: Aγ ratio were significantly increased (P = 0.01) and the clinical features such as splenomegaly and bone marrow expansion were significantly improved (P = 0.01). We found that in the presence of Xmn1 polymorphic site on both chromosomes (+/+) the level of Hb F tended to be increased compared to the absence of Xmn1 (−/−). The present investigation has studied the frequency of Xmn1 polymorphic site in β-thalassemia major patients from Western Iran and has revealed that the presence of this polymorphic site caused a positive influence on Hb F production and the Gγ percent which could improve the clinical symptoms of β-thalassemia patients.  相似文献   
47.
Increased level of inflammatory mediators plays a central role in the features of coronary artery diseases. As pentoxifylline could suppress the inflammatory process and has shown some promising beneficial effects in inflammatory diseases, we evaluated the effect of two months pentoxifylline administration in proteome of PBMCs of patients with coronary artery disease (CAD). A randomized placebo-controlled study was used. Fourteen CAD patients were randomized to 2 months of pentoxifyline treatment (1200 mg/day) (n = 7) or placebo treatment (n = 7). Blood samples were obtained before and after treatment. A comparative 2 dimensional gel electrophoresis was performed, and gels were silver-stained. Differentially expressed protein spots were detected and were identified by MALDI-TOF spectrometry. Six differentially expressed proteins were identified as HSP70, PPIA and α-Enolase, (all up-regulated) S100-A9, PIMT and β-5 tubulin (all down-regulated), most of which had previously been shown to play a potential role in the pathogenesis of atherosclerosis. As the blood mononuclear cell proteome responds to pentoxifylline with changes in a number of atherosclerosis-relevant proteins, it seems that pentoxifylline could be a good choice for future studies for prevention of cardiovascular events.  相似文献   
48.
Applications and limitations of the minirhizotron technique (non-destructive) in relation to two frequently used destructive methods (soil coreing and ingrowth cores) is discussed. Sequential coreing provides data on standing crop but it is difficult to obtain data on root biomass production. Ingrowth cores can provide a quick estimate of relative fine-root growth when root growth is rapid. One limitation of the ingrowth core is that no information on the time of ingrowth and mortality is obtained.The minirhizotron method, in contrast to the destructive methods permits simultaneous calculation of fine-root length production and mortality and turnover. The same fine-root segment in the same soil space can be monitored for its life time, and stored in a database for processing. The methodological difficulties of separating excavated fine roots into living and dead vitality classes are avoided, since it is possible to judge directly the successive ageing of individual roots from the images. It is concluded that the minirhizotron technique is capable of quantifying root dynamics (root-length production, mortality and longevity) and fine-root decomposition. Additionally, by combining soil core data (biomass, root length and nutrient content) and minirhizotron data (length production and mortality), biomass production and nutrient input into the soil via root mortality and decomposition can be estimated.  相似文献   
49.
The purpose of this work is to present a method for the calculation of secondary electron spectra generated by photons in water vapour in the energy region from 10 eV to 10 MeV. The cross sections below and above 1 keV have been treated separately. Examples are given for secondary electron spectra for low-energy photons, <100 eV, in which all electrons are photoelectrons, and at higher energy regions, such as for 60Co photons. The spectrum of the first generation of secondary electrons, produced by 60Co photons, which are mainly due to incoherent scattering, was fitted with a set of polynomial functions which can be used as input for electron radiation action calculations.  相似文献   
50.

Depression and Anxiety are two important public health problems that are known to be associated with viral infections. The association between the intake of nutrients such as zinc and copper with symptoms of depression has been studied previously. The aim of the current study was to investigate the association between depression with human T cell lymphotropic virus type 1 (HTLV-1) infection and serum content of zinc and copper in a large Iranian population cohort. The study population consisted of 279 HTLV-1-positive patients who were identified after recruitment as part of a large cohort study: the Mashhad Stroke and Heart Association Disorder (MASHAD) study. They were divided into two groups of diagnosed with or without depression based on their symptoms. Serum zinc and copper levels of all subjects were measured using the flame atomic absorption spectrometry. The population sample comprised of 279 individuals infected with HTLV-1 of whom 192 (68.8%) were women. The mean serum zinc in the group with and without depression was 78.69 ± 13.79 μg/dl and 86.87 ± 19.44 μg/dl, respectively (p < 0.001). Also, the serum copper level was higher in the depressive group (116.75 ± 39.56) than in the non-depressive group (104.76 ± 30.77) (p 0.004). The association between serum zinc and copper with depression in HTLV-1-infected patients which was shown in this study could be considered in the treatment strategies in these patients.

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