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排序方式: 共有192条查询结果,搜索用时 15 毫秒
1.
Excessive intake of essential elements agitates elemental homeostasis resulting in their heterogeneous distribution. Distraction
of these elements in central nervous system (CNS) have been demonstrated in many neurological disorders, which are vital in
generating free radicals, causing oxidative stress, and contributing to neuronal maladies. The developing CNS is highly vulnerable
to environmental agents, including fluoride. Fluorosis is one such disorder ensued from excessive consumption of fluoride
containing water and/or foods that poses a greater threat to the life. Present study offers perturbations caused by fluoride
toxicity on the level of biometal and antioxidant homeostasis and their interactions. Pregnant Wistar rats were exposed to
100- and 200-ppm fluoride (F−) in drinking water and controls with tap water. The pups born to them were used for the study. On 21st postnatal day, the
concentration of fluoride, biometals, and oxidative stress markers were determined in discrete regions of CNS. The levels
of fluoride, copper, and iron increased whereas manganese and zinc were decreased considerably. Among antioxidant enzymes,
catalase, superoxide dismutase, and glutathione peroxidase were decreased and lipid peroxidation was increased with regional
alterations. The correlation coefficient values among oxidative stress markers and biometals were either positive or negative
and showed less significance during correlation. The results confirm that the fluoride provoked oxidative stress and biometal
deformations are synergistic that successively governs the neuronal damage and developing CNS no longer prevents exacerbations
of fluoride. 相似文献
2.
Xuan Pan Madhusudhan Papasani Yi Hao Marco Calamito Fang Wei William J Quinn Arindam Basu Junwen Wang Suchita Hodawadekar Kristina Zaprazna Huifei Liu Yang Shi David Allman Michael Cancro Michael L Atchison 《The EMBO journal》2013,32(8):1168-1182
Conditional knock‐out (KO) of Polycomb Group (PcG) protein YY1 results in pro‐B cell arrest and reduced immunoglobulin locus contraction needed for distal variable gene rearrangement. The mechanisms that control these crucial functions are unknown. We deleted the 25 amino‐acid YY1 REPO domain necessary for YY1 PcG function, and used this mutant (YY1ΔREPO), to transduce bone marrow from YY1 conditional KO mice. While wild‐type YY1 rescued B‐cell development, YY1ΔREPO failed to rescue the B‐cell lineage yielding reduced numbers of B lineage cells. Although the IgH rearrangement pattern was normal, there was a selective impact at the Igκ locus that showed a dramatic skewing of the expressed Igκ repertoire. We found that the REPO domain interacts with proteins from the condensin and cohesin complexes, and that YY1, EZH2 and condensin proteins co‐localize at numerous sites across the Ig kappa locus. Knock‐down of a condensin subunit protein or YY1 reduced rearrangement of Igκ Vκ genes suggesting a direct role for YY1‐condensin complexes in Igκ locus structure and rearrangement. 相似文献
3.
Patterns of Root Colonization in Epacridaceous Plants Collected from Different Sites 总被引:2,自引:0,他引:2
Root colonization was studied in ten species of the Epacridaceaeat three sites in Victoria by morphological and cross-inoculationexperiments. The sites and genera chosen were Cranbourne [Epacrisimpressa Labill. andLeucopogon ericoides(Smith) R. Br.] andRye [L. parviflorus(Andrews) Lindley] on the Mornington Peninsula,and the Grampians[Astroloma conostephioides(Sond.) Benth.,A.humifusum(Cav.) R. Br.,A pinifolium(R. Br.) Benth,Brachylomadaphnoides(Smith) Benth.,E. impressa, E. impressavar.grandifloraBenth.andStyphelia adscendensR. Br.] in western Victoria. For morphologicalstudies, samples of roots from each species at each site werecleared and stained and examined microscopically. For cross-inoculationstudies, cuttings from each site were struck in potting mediuminoculated with soil from the same and other sites. The ericoidmycorrhizae in the roots of plants found at or grown in Cranbourneand Rye soils were similar. Both were significantly differentfrom the internal hyphae found in the roots of plants foundat or grown in Grampians soils, which were three times largerin diameter and formed dense coils which filled the host celland invaded adjacent epidermal cells. This suggests that morethan one fungus is involved in the relationships, that the MorningtonPeninsula sites had a different fungus from the Grampians siteand that host specificity is low. Vesicular structures werealso found commonly on plants at the Grampians site, in contrastwith other sites. Epacridaceae; root; fungus; mycorrhiza; morphology; inoculation 相似文献
4.
Valero-Cuevas FJ Smaby N Venkadesan M Peterson M Wright T 《Journal of biomechanics》2003,36(2):265-270
We have developed a method to quantify the dynamic interaction between fingertip force magnitude (strength) and directional control (dexterity) during pinch with a novel strength-dexterity (S-D) test based on the principle of buckling of compression springs. The test consists of asking participants to use key and opposition pinch to attempt to fully compress springs, in random order, with a wide range of combinations of strength and dexterity requirements. The minimum force required to fully compress the spring and the propensity of the spring to buckle define the strength and dexterity requirements, respectively. The S-D score for each pinch style was the sum of the strength values of all springs successfully compressed fully. We tested 3 participant groups: 18 unimpaired young adults (40yr), and 14 adults diagnosed with carpo-metacarpal osteoarthritis (CMC OA) (>or = 36yr). We investigated the repeatability of the S-D test with 74 springs by testing 14 young adults twice on different days. The per-spring repeatability across subjects was >or = 94%. A minimum performance score for young adults was found as they all could compress a subset of 39 springs. Using this subset of springs, we compared the ability of the S-D score vs. maximal pinch force values to distinguish unimpaired hands from those with CMC OA of the thumb. The score for this 39-spring S-D test distinguished between CMC OA and asymptomatic older adults, whereas pinch meter readings did not (p<0.05). We conclude that the S-D test is repeatable and applicable to clinical research. We propose including the S-D test in studies aiming to quantify impairment and compare treatment outcomes in orthopaedic and neurological afflictions that degrade dynamic manipulation. 相似文献
5.
Structures of substrate bound human angiogenin complexes have been obtained for the first time by computer modeling. The dinucleotides CpA and UpA have been docked onto human angiogenin using a systematic grid search procedure in torsion and Eulerian angle space. The docking was guided throughout by the similarity of angiogenin-substrate interactions with interactions of RNase A and its substrate. The models were subjected to 1 nanosecond of molecular dynamics to access their stability. Structures extracted from MD simulations were refined by simulated annealing. Stable hydrogen bonds that bridged protein and ligand residues during the MD simulations were taken as restraints for simulated annealing. Our analysis on the MD structures and annealed models explains the substrate specificity of human angiogenin and is in agreement with experimental results. This study also predicts the B2 binding site residues of angiogenin, for which no experimental information is available so far. In the case of one of the substrates, CpA, we have also identified the presence of a water molecule that invariantly bridges the B2 base with the protein. We have compared our results to the RNase A-substrate complex and highlight the similarities and differences. 相似文献
6.
We have undertaken the modeling of substrate-bound structures of angiogenin. In our recent study, we modeled the dinucleotide ligand binding to human angiogenin. In the present study, the substrates CpG, UpG, and CpA were docked onto bovine angiogenin. This was achieved by overcoming the problem of an obstruction to the B1 site by the C-terminus and identifying residues that bind to the second base. The modeled complexes retain biochemically important interactions. The docked models were subjected to 1 ns of molecular dynamics, and structures from the simulation were refined by using simulated annealing. Our models explained the enzyme's specificity for both B1 and B2 bases as observed experimentally. The nature of binding of the dinucleotide substrate was compared with that of the mononucleotide product. The models of these complexes were also compared with those obtained earlier with human angiogenin. On the basis of the simulations and annealed structures, we came up with a consensus topology of dinucleotide ligands that binds to human and bovine angiogenins. This dinucleotide conformation can serve as a starting model for ligand-bound complex structures for RNase A family of proteins. We demonstrated this capability by generating the complex structure of CpA bound to eosinophil-derived neurotoxin (EDN) by fitting the consensus topology of CpA to the crystal structure of native EDN. 相似文献
7.
Subramanian S Madgula VM George R Mishra RK Pandit MW Kumar CS Singh L 《Genome biology》2002,3(12):preprint00-13
MRD is a database system to access the microsatellite repeats information of genomes such as archea, eubacteria, and other eukaryotic genomes whose sequence information is available in public domains. MRD stores information about simple tandemly repeated k-mer sequences where k= 1 to 6, i.e. monomer to hexamer. The web interface allows the users to search for the repeat of their interest and to know about the association of the repeat with genes and genomic regions in the specific organism. The data contains the abundance and distribution of microsatellites in the coding and non-coding regions of the genome. The exact location of repeats with respect to genomic regions of interest (such as UTR, exon, intron or intergenic regions) whichever is applicable to organism is highlighted. MRD is available on the World Wide Web at and/or . The database is designed as an open-ended system to accommodate the microsatellite repeats information of other genomes whose complete sequences will be available in future through public domain. 相似文献
8.
Suryanaryana Murty Upadhyayula Srinivasa Rao Mutheneni Sumana Chenna Vaideesh Parasaram Madhusudhan Rao Kadiri 《PloS one》2015,10(3)
The present study was conducted during the years 2006 to 2012 and provides information on prevalence of malaria and its regulation with effect to various climatic factors in East Siang district of Arunachal Pradesh, India. Correlation analysis, Principal Component Analysis and Hotelling’s T2 statistics models are adopted to understand the effect of weather variables on malaria transmission. The epidemiological study shows that the prevalence of malaria is mostly caused by the parasite Plasmodium vivax followed by Plasmodium falciparum. It is noted that, the intensity of malaria cases declined gradually from the year 2006 to 2012. The transmission of malaria observed was more during the rainy season, as compared to summer and winter seasons. Further, the data analysis study with Principal Component Analysis and Hotelling’s T2 statistic has revealed that the climatic variables such as temperature and rainfall are the most influencing factors for the high rate of malaria transmission in East Siang district of Arunachal Pradesh. 相似文献
9.
Andréia S Lessa Bruno D Paredes Juliana V Dias Adriana B Carvalho Luiz Fernando Quintanilha Christina M Takiya Bernardo R Tura Guilherme FM Rezende Antonio C Campos de Carvalho Célia MC Resende Regina CS Goldenberg 《BMC veterinary research》2010,6(1):1-10
Background
Atypical scrapie was first identified in Norwegian sheep in 1998 and has subsequently been identified in many countries. Retrospective studies have identified cases predating the initial identification of this form of scrapie, and epidemiological studies have indicated that it does not conform to the behaviour of an infectious disease, giving rise to the hypothesis that it represents spontaneous disease. However, atypical scrapie isolates have been shown to be infectious experimentally, through intracerebral inoculation in transgenic mice and sheep. The first successful challenge of a sheep with 'field' atypical scrapie from an homologous donor sheep was reported in 2007.Results
This study demonstrates that atypical scrapie has distinct clinical, pathological and biochemical characteristics which are maintained on transmission and sub-passage, and which are distinct from other strains of transmissible spongiform encephalopathies in the same host genotype.Conclusions
Atypical scrapie is consistently transmissible within AHQ homozygous sheep, and the disease phenotype is preserved on sub-passage. 相似文献10.
van Beers JJ Raijmakers R Alexander LE Stammen-Vogelzangs J Lokate AM Heck AJ Schasfoort RB Pruijn GJ 《Arthritis research & therapy》2010,12(6):R219