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991.
Several mechanisms regarding the adverse health effects of nanomaterials have been proposed. Among them, oxidative stress is considered to be one of the most important. Many in vitro studies have shown that nanoparticles generate reactive oxygen species, deplete endogenous antioxidants, alter mitochondrial function and produce oxidative damage in DNA. 8-Hydroxy-2''-deoxyguanosine is a major type of oxidative DNA damage, and is often analyzed as a marker of oxidative stress in human and animal studies. In this study, we focused on the in vivo toxicity of metal oxide and silver nanoparticles. In particular, we analyzed the induction of micronucleated reticulocyte formation and oxidative stress in mice treated with nanoparticles (CuO, Fe3O4, Fe2O3, TiO2, Ag). For the micronucleus assay, peripheral blood was collected from the tail at 0, 24, 48 and 72 h after an i.p. injection of nanoparticles. Following the administration of nanoparticles by i.p. injection to mice, the urinary 8-hydroxy-2''-deoxyguanosine levels were analyzed by the HPLC-ECD method, to monitor the oxidative stress. The levels of 8-hydroxy-2''-deoxyguanosine in liver DNA were also measured. The results showed increases in the reticulocyte micronuclei formation in all nanoparticle-treated groups and in the urinary 8-hydroxy-2''-deoxyguanosine levels. The 8-hydroxy-2''-deoxyguanosine levels in the liver DNA of the CuO-treated group increased in a dose-dependent manner. In conclusion, the metal nanoparticles caused genotoxicity, and oxidative stress may be responsible for the toxicity of these metal nanoparticles. 相似文献
992.
Makoto Takahashi Zhen Ni Takamasa Yamashita Nan Liang Kenichi Sugawara Susumu Yahagi Tatsuya Kasai 《Clinical neurophysiology》2005,116(12):2757-2764
OBJECTIVE: To investigate whether the intracortical inhibitory (ICI) and facilitatory (ICF) circuits in the primary motor cortex between the first dorsal interosseous (FDI) and abductor digiti minimi (ADM) muscles are modulated differently. METHODS: We conducted paired-pulse transcranial magnetic stimulation in combination with different current directions (anterior-medially: AM, and posterior-laterally: PL) under relaxed and active muscle conditions with interstimulus intervals (ISIs) between 2 and 16 ms. RESULTS: In both muscle conditions, the conditioned motor-evoked potential (MEP) responses obtained with the AM current direction (preferentially eliciting early I-waves) were similar between the two muscles at all ISIs, but the MEP responses obtained with the PL current direction (preferentially eliciting late I-waves) were different between FDI and ADM muscles, in that the conditioned MEP responses in FDI muscle were inhibited at all ISIs under both muscle conditions, whereas those in ADM muscle were suppressed at only short ISIs (2-4 ms). CONCLUSIONS: These results indicate that the inhibitory connections operating for the corticospinal tract neurons in FDI muscle are more potent, and, conversely, that those in ADM muscle are weaker. SIGNIFICANCE: The different modulations of ICI circuits between FDI and ADM muscles is an important neural mechanism which may contribute to different functional demands (finger dexterity). 相似文献
993.
Heart failure (HF) is a life-threatening disease and is a growing public health concern. Despite recent advances in pharmacological management for HF, the morbidity and mortality from HF remain high. Therefore, non-pharmacological approaches for HF are being developed. However, most non-pharmacological approaches are invasive, have limited indication and are considered only for advanced HF. Accordingly, the development of less invasive, non-pharmacological approaches that improve outcomes for patients with HF is important. One such approach may include positive airway pressure (PAP) therapy. In this review, the role of PAP therapy applied through mask interfaces in the wide spectrum of HF care is discussed. 相似文献
994.
Very few reports have described giant pseudomeningoceles ≥ 8 cm in diameter. We report this case of the biggest giant pseudomeningocele at the unusual cervicothoracic level. A 59 year old man who underwent cervicothoracic laminectomy had a giant pseudomeningocele detected and the lesion gradually grew to about 15 cm in diameter by 2 years postoperatively. Cerebrospinal fluid leak closure was performed and the postoperative course was favorable. We present this case, review the literature and discuss the size and portion, mechanism of formation, symptoms and treatments of giant pseudomeningocele. 相似文献
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997.
Takeuchi T Sugiura K Nishiyama K Takahashi H Natsugari H Arata Y Kasai K 《Biological & pharmaceutical bulletin》2011,34(7):1134-1138
Galβ1-4Fuc disaccharide unit was recently reported to be the endogenous structure recognized by the galectin LEC-6 isolated from the nematode Caenorhabditis elegans. LEC-1, which is another major galectin from this organism, is a tandem repeat-type galectin that contains two carbohydrate recognition domains, the N-terminal lectin domain (LEC-1Nh) and the C-terminal lectin domain (LEC-1Ch), and was also found to have an affinity for the Galβ1-4Fuc disaccharide unit. In the present study, we compared the binding strengths of LEC-1, LEC-1Nh, and LEC-1Ch to Galβ1-4Fuc, Galβ1-3Fuc, and Galβ1-4GlcNAc units as well as to LEC-6-ligand N-glycans by using frontal affinity chromatography (FAC) analysis. The two lectin domains of LEC-1 exhibited the highest affinity for Galβ1-4Fuc, though sugar-binding properties differed somewhat between LEC-1Nh and LEC-1Ch. Furthermore, these two domains had significantly lower affinities for the LEC-6-binding glycans. These results suggest that the endogenous recognition unit of LEC-1 is likely to be Galβ1-4Fuc, and that the endogenous ligands for LEC-1 are different from those for LEC-6. 相似文献
998.
Tamura M Takeuchi T Nonaka T Kasai K Arata Y 《Biological & pharmaceutical bulletin》2011,34(6):929-932
LEC-1 is the first tandem repeat-type galectin isolated from an animal system; this galectin has two carbohydrate recognition domains in a single polypeptide chain. Because its two lectin domains have different sugar-binding profiles, these domains are thought to interact with different carbohydrate ligands. In our previous study, we showed that a mutant of LEC-1 in which a cysteine residue was introduced at a unique position in the N-terminal lectin domain (Nh) can be cross-linked with a model glycoprotein ligand, bovine asialofetuin, by using a bifunctional photoactivatable cross-linking reagent, benzophenone-4-maleimide. In the present work, we applied the same procedure to the C-terminal lectin domain (Ch) of LEC-1. Cross-linked products were formed in the cases of two mutants in which a cysteine residue was introduced at Lys1?? and Ser2??, respectively. This method is very useful for capturing and assigning endogenous ligand glycoconjugates with relatively low affinities to each carbohydrate recognition domain of the whole tandem repeat-type galectin molecule. 相似文献
999.
Wataru Gonoi Osamu Abe Hidenori Yamasue Haruyasu Yamada Yoshitaka Masutani Hidemasa Takao Kiyoto Kasai Shigeki Aoki Kuni Ohtomo 《Neuroradiology》2010,52(10):865-873
Introduction
The effects of aging on brain volume are generally investigated using voxel-based morphometry (VBM) or the manually traced region-of-interest (ROI) method. We introduce an atlas-based method as a methodological alternative that calculates absolute volume as a non-biased and semi-automatic whole-brain technique. 相似文献1000.
Hidemasa Takao MD Osamu Abe MD DMSc Hidenori Yamasue MD DMSc Shigeki Aoki MD DMSc Kiyoto Kasai MD DMSc Kuni Ohtomo MD DMSc 《Journal of magnetic resonance imaging : JMRI》2010,31(1):221-226