排序方式： 共有36条查询结果，搜索用时 0 毫秒
31.
Parsons DW Li M Zhang X Jones S Leary RJ Lin JC Boca SM Carter H Samayoa J Bettegowda C Gallia GL Jallo GI Binder ZA Nikolsky Y Hartigan J Smith DR Gerhard DS Fults DW VandenBerg S Berger MS Marie SK Shinjo SM Clara C Phillips PC Minturn JE Biegel JA Judkins AR Resnick AC Storm PB Curran T He Y Rasheed BA Friedman HS Keir ST McLendon R Northcott PA Taylor MD Burger PC Riggins GJ Karchin R Parmigiani G Bigner DD Yan H Papadopoulos N Vogelstein B Kinzler KW Velculescu VE 《Science (New York, N.Y.)》2011,331(6016):435-439
Medulloblastoma (MB) is the most common malignant brain tumor of children. To identify the genetic alterations in this tumor type, we searched for copy number alterations using high-density microarrays and sequenced all known protein-coding genes and microRNA genes using Sanger sequencing in a set of 22 MBs. We found that, on average, each tumor had 11 gene alterations, fewer by a factor of 5 to 10 than in the adult solid tumors that have been sequenced to date. In addition to alterations in the Hedgehog and Wnt pathways, our analysis led to the discovery of genes not previously known to be altered in MBs. Most notably, inactivating mutations of the histone-lysine N-methyltransferase genes MLL2 or MLL3 were identified in 16% of MB patients. These results demonstrate key differences between the genetic landscapes of adult and childhood cancers, highlight dysregulation of developmental pathways as an important mechanism underlying MBs, and identify a role for a specific type of histone methylation in human tumorigenesis. 相似文献
32.
Manmeet Kumar Ausaf Ahmad Preeti Rawat Mohammad Faheem Khan Naila Rasheed Prasoon Gupta B. Sathiamoorthy Gitika Bhatia Gautam Palit Rakesh Maurya 《Fitoterapia》2010
Oxidative damage is an established outcome of chronic stress. Thus, the present study was designed to investigate the modulatory role of ethanolic extract of Evolvulus alsinoides (EA) in terms of oxidative alterations at peripheral and central level in rats subjected to chronic unpredictable stress (CUS). CUS exposure for 7 days reduced Cu, Zn superoxide dismutase and catalase activity with increase in glutathione peroxidase activity and lipid peroxidation, while decrease in reduced glutathione level in blood plasma, frontal cortex and hippocampus regions of brain. Oral administration of EA extract at 200 mg/kg p.o. normalized these stress induced oxidative alterations with an efficacy similar to that of melatonin. Further, EA extract was taken up for detailed chemical investigation. Two new flavonol-4′-glycoside, kaempferol 4′-O-β-d-glucopyranosyl-(1 → 2)-β-d-glucopyranoside (3) and kaempferol 4′-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside (5) were isolated, along with eight known compounds (1, 2, 4 and 6–10). The structures of new compounds were established by detailed spectroscopic studies, while known compounds were characterized by direct comparison of their reported NMR data. All these compounds were evaluated for their in vitro antioxidant activity. Compounds 3, 5, 9 and 10 at 100 and 200 μg/ml showed significant in vitro antioxidant activity. Therefore, EA may hold great potential in preventing clinical deterioration in stress induced oxidative load and related disorders. 相似文献
33.
The nucleotide sequence of the oncogene of the Rasheed strain of rat sarcoma virus was determined. The oncogene (Ra-v-ras) encodes a 29,000-dalton (p29) transforming protein. This protein is distinct from the immunologically related 21,000-dalton protein (p21) of the Harvey murine sarcoma virus in its amino terminus and in having additional mutations in its carboxyl terminus. Although the functional significance of these changes is unknown, they appear to occur only in rat sarcoma virus. 相似文献
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35.
Khurram Bashir Nasir Mahmood Khan Sultana Rasheed Muhammad Salim 《Paddy and Water Environment》2007,5(2):73-81
Pakistan is well known for its basmati rice with long grain and aroma, as well as for non-basmati indica varieties; however
average yield is lower as compared with other countries. Besides, cultural practices, the main reason for low productivity
in Pakistan is that, local varieties are susceptible to different biotic and abiotic factors like insect pests, diseases,
drought, and salinity. Different approaches have been undertaken in Pakistan to tackle these problems through traditional
breeding of selection and crossing, mutation breeding, somaclonal variation as well as plant transformation studies in recent
past. For variety development, the most successful examples arose from traditional breeding that produced famous basmati varieties
like Basmati 370, Basmati 385 and Super basmati, and non-basmati varieties such as IRRI-6, DR-82, DR-83, DR-92, Swat-I and
Swat-II, which earn a significant share of foreign exchange every year. Six varieties have also been developed through mutation
breeding, and one through exploitation of somaclonal variation but their contribution to the national economy is not significant.
On the other hand, no variety has been registered as commercial by plant transformation groups. This review discusses the
problems and prospects of rice breeding with special emphasis on basmati rice in Pakistan particularly in Pakistani Punjab
(a major producing area), as well as focuses on future research programs. 相似文献
36.
Muhammad Imran Muhammad Irfan Muhammad Yaseen Naser Rasheed 《Journal of Crop Science and Biotechnology》2018,21(5):425-434
Low-use efficiency of phosphatic fertilizers in calcareous soils is a serious issue worldwide resulting in sub-optimal phosphorus (P) availability to plants. Polymer-coated fertilizers provide an effective solution to enhance P-use efficiency in such soils by reducing fixation and ensuring slow and consistent phosphate supply to growing plants. The present field experiment was conducted to evaluate the effectiveness of commercial diammonium phosphate (DAP) fertilizer and coated DAP with polymer and/or glycerin to improve plant growth, grain yield, and P-use efficiency of wheat crops. The results revealed that application of 100% recommended rate of glycerin + polymer coated DAP significantly enhanced plant height, number of fertile tillers m-2, 1000-grain weight, grain yield, and P uptake in comparison with commercial DAP fertilizer. Moreover, polymer coated DAP produced comparatively better results than glycerin coated DAP alone. The sustainable yield index, P agronomic and recovery efficiencies were also improved and recorded higher with glycerin + polymer-coated DAP fertilizer at 100% of the recommended rate. Furthermore, higher P uptake, P recovery, and agronomic efficiencies in response to coated DAP were found responsible for sustainable wheat yield. Overall, the glycerin + polymer-coated DAP with 75% recommended rate showed statistically identical results to uncoated DAP with 100% recommended rate. The amount of applied P vulnerable to fixation was significantly reduced with the application of glycerin + polymer-coated DAP thereby resulting in improved plant growth, grain yield, and P-use efficiency of wheat crops. 相似文献