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101.
Methotrexate (MTX), a folic acid antagonist, is widely used as a cytotoxic chemotherapeutic agent. MTX-associated neurotoxicity is an important clinical problem. The aim of this study was to investigate the role of caffeic acid phenethyl ester (CAPE) on cerebellar oxidative stress induced by MTX in rats. A total of 19 adult male rats were divided into three experimental groups as follows: MTX group (MTX treated), MTX+CAPE group (MTX+CAPE treated), and control group. MTX was administered intraperitoneally (i.p.) with a single dose of 20 mg kg−1 on the second day of experiment. CAPE was administered i.p. with a dose of 10 μmol kg−1 day−1 for 7 days. Malondialdehyde (MDA) levels and activities of superoxide dismutase (SOD) and catalase (CAT) were determined in cerebellar tissue of rats. MTX caused to significant increase in MDA levels (an important marker of lipid peroxidation) in the MTX group compared with the controls (p = 0.006). CAPE significantly reduced the MTX induced lipid peroxidation in the MTX+CAPE group compared to the MTX (p = 0.007). The activities of SOD and CAT were significantly increased in the MTX group when compared with the control group (p = 0.0001, p = 0.004, respectively). The increased activities of these enzymes were significantly reduced by CAPE treatment (p = 0.004, p = 0.034, respectively). As a result, CAPE may protect from oxidative damage caused by MTX treatment in rat cerebellum.  相似文献   
102.
The present study was set to identify the members of An. maculipennis complex, which includes effective malaria vectors, throughout the Mediterranean region of Turkey using the second internal transcribed spacer of ribosomal DNA (rDNA-ITS2) sequences from 200 specimens. Resulting sequences of this complex from the Mediterranean region revealed the presence of three species belonging to the An. maculipennis complex, namely An. sacharovi, An. maculipennis s.s. and An. melanoon. The lengths of ITS2 region were 284, 294 and 306 bp in length for An. maculipennis s.s., An. melanoon and An. sacharovi respectively. While no sequence divergence was observed within any species, An. sacharovi was the most distantly related species from An. maculipennis s.s. and An. melanoon with a sequence divergence of 15.1% and 15.4%, respectively. While An. melanoon was the rare species, An. maculipennis s.s., was the most abundant and An. sacharovi was the most wide spread one.  相似文献   
103.
The objective of this study was to evaluate the long-term stability of the antiretroviral spermicide WHI-07 (5-bromo-6-methoxy-5,6-dihydro-3′-azidothymidine-5′-(p-bromophenyl)-methoxyalaninyl phosphate) in a polymer-based microemulsion. The recovery and stability of WHI-07 in gelmicroemulsion was examined by a validated high-performance liquid chromatography (HPLC) method. The stability was examined over a period of 24 weeks at 3 controlled temperatures (4°C, 25°C, and 40°C). The recovery of the prodrug from 0.5% to 2.0% WHI-07-loaded gel-microemulsion was 99.8%. HPLC analysis revealed that a 2% WHI-07-loaded gel-microemulsion stored at room temperature and cold temperatures for 24 weeks retained >90% of the prodrug, whereas those stored at 40°C maintained 90% of initial WHI-07 for at least 10 weeks. The observed stability of WHI-07 in gel-microemulsion is of great importance for its widespread utility in various climatological conditions. Published: September 1, 2006  相似文献   
104.
Wnt pathway deregulation is a common characteristic of many cancers. Only colorectal cancer predominantly harbours mutations in APC, whereas other cancer types (hepatocellular carcinoma, solid pseudopapillary tumours of the pancreas) have activating mutations in β‐catenin (CTNNB1). We have compared the dynamics and the potency of β‐catenin mutations in vivo. Within the murine small intestine (SI), an activating mutation of β‐catenin took much longer to achieve Wnt deregulation and acquire a crypt‐progenitor cell (CPC) phenotype than Apc or Gsk3 loss. Within the colon, a single activating mutation of β‐catenin was unable to drive Wnt deregulation or induce the CPC phenotype. This ability of β‐catenin mutation to differentially transform the SI versus the colon correlated with higher expression of E‐cadherin and a higher number of E‐cadherin:β‐catenin complexes at the membrane. Reduction in E‐cadherin synergised with an activating mutation of β‐catenin resulting in a rapid CPC phenotype within the SI and colon. Thus, there is a threshold of β‐catenin that is required to drive transformation, and E‐cadherin can act as a buffer to sequester mutated β‐catenin.  相似文献   
105.
The aim of the study was to investigate simultaneously serum and milk malondialdehyde (MDA) levels, superoxide dismutase (SOD), glutathione peroxidase (GPx) activities, and antioxidant potential (AOP) in active-smoking, passive-smoking, and nonsmoking mothers and to search if there is any difference between serum and milk oxidant/ antioxidant status caused by smoking. According to their smoking status, 60 mothers (age range: 20–35 yr) were classified into one of three groups: the active-smoking mothers (n=15), the passive-smoking mothers (n=22), and the nonsmoking mothers (n=23). Serum and milk MDA, SOD, GPx, and AOP values were determined in mothers on the postpartum seventh day by the spectrophotometric method. Serum Zn and Cu concentrations were determined by atomic absorption spectrophotometry (AAS). There was no significant difference in serum samples with respect to MDA (p=0.17), SOD (p=0.51) and AOP (p=0.36) levels, but there was a significant difference in serum GPx (p=0.002) levels among the study groups. The significant differences were also found in milk samples in terms of MDA (p=0.002) and SOD (p=0.011), but not in GPx (p=0.11) and AOP (p=0.29) levels among the study groups. No significant difference was seen in serum zinc concentration (p=0.49), but copper concentration differed significantly among the groups (p=0.005). These observations suggest that human milk is more vulnerable to oxidative stress and lipid peroxidation than serum samples in smoking mothers, even if they are passive smokers.  相似文献   
106.
107.
Self-organized flocking in mobile robot swarms   总被引:1,自引:0,他引:1  
In this paper, we study self-organized flocking in a swarm of mobile robots. We present Kobot, a mobile robot platform developed specifically for swarm robotic studies. We describe its infrared-based short range sensing system, capable of measuring the distance from obstacles and detecting kin robots, and a novel sensing system called the virtual heading system (VHS) which uses a digital compass and a wireless communication module for sensing the relative headings of neighboring robots. We propose a behavior based on heading alignment and proximal control that is capable of generating self-organized flocking in a swarm of Kobots. By self-organized flocking we mean that a swarm of mobile robots, initially connected via proximal sensing, is able to wander in an environment by moving as a coherent group in open space and to avoid obstacles as if it were a “super-organism”. We propose a number of metrics to evaluate the quality of flocking. We use a default set of behavioral parameter values that can generate acceptable flocking in robots, and analyze the sensitivity of the flocking behavior against changes in each of the parameters using the metrics that were proposed. We show that the proposed behavior can generate flocking in a small group of physical robots in a closed arena as well as in a swarm of 1000 simulated robots in open space. We vary the three main characteristics of the VHS, namely: (1) the amount and nature of noise in the measurement of heading, (2) the number of VHS neighbors, and (3) the range of wireless communication. Our experiments show that the range of communication is the main factor that determines the maximum number of robots that can flock together and that the behavior is highly robust against the other two VHS characteristics. We conclude by discussing this result in the light of related theoretical studies in statistical physics.  相似文献   
108.
The therapeutic effects of poly(adenosine diphosphate-ribose) polymerase inhibition by 3-aminobenzamide (3-AB) were investigated in testicular ischemia-reperfusion (I/R) injury, using sperm analysis and histopathological and biochemical examinations, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities and reduced glutathione (GSH) levels. Male rats were divided into 3 groups: sham (n = 12), I/R (n = 12), and I/R with 3-AB (I/R-3-AB) (n = 12). The left testicular artery was occluded for 1 h, followed by 24 h (for biochemical and histopathological examinations) and 30 days (for sperm analysis) of reperfusion. 3-AB treatment intraperitoneally 10 min prior to and 1 h after reperfusion increased the I/R-induced decrease in sperm motility in both testes and reduced the increased abnormal sperm rates in the ipsilateral testis. However, 3-AB treatment failed to prevent the I/R-induced decrease in sperm concentration in both testes. SOD and CAT activities did not change in any group. GSH-Px activity and GSH levels were increased by I/R. 3-AB treatment reversed the I/R-induced increase in GSH-Px activity, similar to the level in sham rats, but did not alter GSH levels. 3-AB treatment significantly increased the I/R-induced decrease in histopathologic score. In conclusion, 3-AB treatment has potential biochemical and histopathological benefits beyond improving sperm quality and may have the potential to decrease damage from testicular torsion.  相似文献   
109.
An efficient and modular one-pot synthesis of polysubstituted aromatic amines by a mild reductive amination procedure is described and the biological potential of these nitrogen-centered compounds is demonstrated by growth inhibition of murine connective tissue cells and microscopy-based morphological studies.  相似文献   
110.
Oxidative stress occurs during maximal exercise, perhaps as a result of increased consumption of oxygen. Vitamins C and E can overcome the effects of antioxidants in exercise. We investigated the effects of supplementation with a combination of vitamin C and E (VCE) on blood lipid peroxidation (LP) and antioxidant levels following maximal training in basketball players. Blood samples were taken from 14 players (group A) and divided into two subgroups namely maximal training (group B) and maximal training plus VCE groups (group C). Group B maximally exercised for 35 days. VCE was supplemented to group C for 35 days and blood samples were taken from group B and C. Plasma and hemolyzed erythrocyte samples were obtained from the players. Erythrocyte glutathione peroxidase (GSH‐Px) activity and plasma vitamin E concentration were lower in group B than in group A, whereas plasma and erythrocyte LP levels were higher in group B than in group A. Plasma vitamin A, vitamin E, erythrocyte GSH‐Px, and reduced glutathione (GSH) values were higher in group C than in groups A and B although LP levels in plasma and erythrocytes were lower in group C than in group A and B. β‐Carotene values did not change in the three groups. In conclusion, VCE supplementation in maximal exercising basketball players may strengthen the antioxidant defense system by decreasing reactive oxygen species (ROS). Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   
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