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排序方式: 共有457条查询结果,搜索用时 187 毫秒
71.
72.
Malek Zihlif Tareq Mahafza Nathir M. Obeidat Tawfiq Froukh Mazen Shaban Fatima M. Al-Akhras Nadwa Zihlif Randa Naffa 《Gene》2013
Allergic rhinitis is a chronic inflammatory disease that is assumed to be due to an interaction between different genetic and/or environmental factors. A disintegrin and metalloprotease domain 33 (ADAM33) has been extensively studied as a susceptibility gene in asthma and has been linked to bronchial hyper-responsiveness. In this study, we investigated the association between ADAM33 single nucleotide polymorphisms and the incidence of allergic rhinitis among the Jordanian population. We conducted a case–control association study on 120 adult individuals diagnosed with allergic rhinitis and 128 normal healthy controls. 8 single-nucleotide polymorphisms in ADAM33 were genotyped using PCR-RFLP method. No significant differences in the allelic frequencies of all SNPs tested between AR patients and the control volunteers were found, although S2 C/G SNP showed a tendency toward significance with P = 0.06. On the genotype level significant association were found in the following genotypes: T1 AA, T1 AG, T2 GG, T2 AG, T + 1 GG, T + 1 AG, V4 CG, S2 CC, S2 CG, Q-1AA. Seven haplotypes were present only within AR patients and eight haplotypes were completely absent from the AR patients. Three haplotypes exhibited significant association with AR P ≤ 0.05, two of them were present only in AR patients. In conclusion, the polymorphisms in the ADAM33 gene are associated with susceptibility to AR in the Jordanian population. Furthermore, the haplotype of the tested SNPs were also associated with the risk of AR. 相似文献
73.
Shovan Mondal Jean‐Valère Naubron Damien Campolo Michel Giorgi Michéle P. Bertrand Malek Nechab 《Chirality》2013,25(12):832-839
The absolute configurations (AC) of azaheterocylic compounds resulting from the cascade rearrangement of enediynes involving only light atoms were unambiguously assigned by the joint use of vibrational circular dichroism (VCD) and copper radiation single crystal X‐ray diffraction (XRD). These AC determinations proved that the rearrangements of enediynes proceeded with memory of chirality and retention of configuration. Chirality 25:832–839, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
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76.
The effect of Tylenchorhynchus nudus on growth of Kentucky bluegrass was investigated under controlled environmental conditions in both a phytotron and a greenhouse. The nematode significantly reduced weights of clippings, crowns and roots. Pathogenicity was greater in sandy loam soil than in loam and was enhanced by submitting plants to nutrient and/or moisture stresses; soil nutrient level was most critical. The results suggest that T. nudus contributes significantly to summer decline of bluegrass lawns in South Dakota. 相似文献
77.
Oxidative stress-induced expression and modulation of Phosphatase of Regenerating Liver-1 (PRL-1) in mammalian retina 总被引:2,自引:0,他引:2
Yu L Kelly U Ebright JN Malek G Saloupis P Rickman DW McKay BS Arshavsky VY Bowes Rickman C 《Biochimica et biophysica acta》2007,1773(9):1473-1482
The phosphatase of regenerating liver-1, PRL-1, gene was detected in a screen for foveal cone photoreceptor-associated genes. It encodes a small protein tyrosine phosphatase that was previously immunolocalized to the photoreceptors in primate retina. Here we report that in cones and cone-derived cultured cells both PRL-1 activity and PRL-1 gene expression are modulated under oxidative stress. Oxidation reversibly inhibited the phosphatase activity of PRL-1 due to the formation of an intramolecular disulfide bridge between Cys104 within the active site and another conserved Cys, Cys49. This modulation was observed in vitro, in cell culture and in isolated retinas exposed to hydrogen peroxide. The same treatment caused a rapid increase in PRL-1 expression levels in cultured cells which could be blocked by the protein translation inhibitor, cycloheximide. Increased PRL-1 expression was also observed in living rats subjected to constant light exposure inducing photooxidative stress. We further demonstrated that both oxidation and overexpression of PRL-1 upon oxidative stress are greatly enhanced by inhibition of the glutathione system responsible for cellular redox regulation. These findings suggest that PRL-1 is a molecular component of the photoreceptor's response to oxidative stress acting upstream of the glutathione system. 相似文献
78.
New insights into porcine-human synteny conservation 总被引:1,自引:0,他引:1
Niels J. Larsen Stefan Marklund Kemba A. Kelly Massoud Malek Christopher K. Tuggle Martine Yerle Max F. Rothschild 《Mammalian genome》1999,10(5):488-491
Eleven genes were mapped to the porcine genome with the aim of improving the human-porcine comparative gene map. Five of
these genes were from regions of the human genome painted by porcine chromosomal probes; of these, two mapped to chromosomes
not expected from the painting results. Among the six genes from human regions not painted by porcine chromosomal probes,
three genes did not map where expected by the principle of parsimony. Several of the gene assignments indicate the existence
of small regions of conserved synteny not detected by heterologous chromosome painting, especially in telomeric regions. We
have also detected new rearrangements in gene order within the regions of correspondence between human Chromosome (HSA) 15
and porcine Chromosome (SSC) 1 as well as between HSA4 and SSC8.
Received: 30 September 1998 / Accepted: 3 December 1998 相似文献
79.
Ana Luisa Kadekaro Renny J. Kavanagh Kazumasa Wakamatsu Shosuke Ito Michelle A. Pipitone Zalfa A. Abdel‐Malek 《Pigment cell & melanoma research》2003,16(5):434-447
Solar ultraviolet radiation (UV) is a major environmental factor that dramatically alters the homeostasis of the skin as an organ by affecting the survival, proliferation and differentiation of various cutaneous cell types. The effects of UV on the skin include direct damage to DNA, apoptosis, growth arrest, and stimulation of melanogenesis. Long‐term effects of UV include photoaging and photocarcinogenesis. Epidermal melanocytes synthesize two main types of melanin: eumelanin and pheomelanin. Melanin, particularly eumelanin, represents the major photoprotective mechanism in the skin. Melanin limits the extent of UV penetration through the epidermal layers, and scavenges reactive oxygen radicals that may lead to oxidative DNA damage. The extent of UV‐induced DNA damage and the incidence of skin cancer are inversely correlated with total melanin content of the skin. Given the importance of the melanocyte in guarding against the adverse effects of UV and the fact that the melanocyte has a low self‐renewal capacity, it is critical to maintain its survival and genomic integrity in order to prevent malignant transformation to melanoma, the most fatal form of skin cancer. Melanocyte transformation to melanoma involves the activation of certain oncogenes and the inactivation of specific tumor suppressor genes. This review summarizes the current state of knowledge about the role of melanin and the melanocyte in photoprotection, the responses of melanocytes to UV, the signaling pathways that mediate the biological effects of UV on melanocytes, and the most common genetic alterations that lead to melanoma. 相似文献
80.
Chemical Composition,Antioxidant Properties, α‐Glucosidase Inhibitory,and Antimicrobial Activity of Essential Oils from Acacia mollissima and Acacia cyclops Cultivated in Tunisia
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The genus Acacia is quite large and can be found in the warm subarid and arid parts, but little is known about its chemistry, especially the volatile parts. The volatile oils from fresh flowers of A. mollissima and A. cyclops (growing in Tunisia) obtained by hydrodistillation were analyzed by GC then GC/MS. Eighteen (94.7% of the total oil composition) and 23 (97.4%) compounds were identified in these oils, respectively. (E,E)‐α‐Farnesene (51.5%) and (E)‐cinnamyl alcohol (10.7%) constituted the major compounds of the flower oil of A. mollissima, while nonadecane (29.6%) and caryophyllene oxide (15.9%) were the main constituents of the essential oil of A. cyclops. Antioxidant activity of the isolated oils was studied by varied assays, i.e., 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2‐azinobis 3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS); the isolated oils showed lowest IC50 (4 – 39 μg/ml) indicating their high antioxidant activity. The α‐glucosidase inhibitor activity was also evaluated and Acacia oils were found to be able to strongly inhibit this enzyme with IC50 values (81 – 89 μg/ml) very close to that of acarbose which was used as positive control. Furthermore, they were tested against five Gram‐positive and Gram‐negative bacteria and one Candida species. Essential oil of A. mollissima was found to be more active than that of A. cyclops, especially against Pseudomonas aeruginosa (MIC = 0.31 mg/ml and MBC = 0.62 mg/ml). 相似文献