排序方式: 共有138条查询结果,搜索用时 15 毫秒
61.
Tasdemir E Maiuri MC Galluzzi L Vitale I Djavaheri-Mergny M D'Amelio M Criollo A Morselli E Zhu C Harper F Nannmark U Samara C Pinton P Vicencio JM Carnuccio R Moll UM Madeo F Paterlini-Brechot P Rizzuto R Szabadkai G Pierron G Blomgren K Tavernarakis N Codogno P Cecconi F Kroemer G 《Nature cell biology》2008,10(6):676-687
Multiple cellular stressors, including activation of the tumour suppressor p53, can stimulate autophagy. Here we show that deletion, depletion or inhibition of p53 can induce autophagy in human, mouse and nematode cells subjected to knockout, knockdown or pharmacological inhibition of p53. Enhanced autophagy improved the survival of p53-deficient cancer cells under conditions of hypoxia and nutrient depletion, allowing them to maintain high ATP levels. Inhibition of p53 led to autophagy in enucleated cells, and cytoplasmic, not nuclear, p53 was able to repress the enhanced autophagy of p53(-/-) cells. Many different inducers of autophagy (for example, starvation, rapamycin and toxins affecting the endoplasmic reticulum) stimulated proteasome-mediated degradation of p53 through a pathway relying on the E3 ubiquitin ligase HDM2. Inhibition of p53 degradation prevented the activation of autophagy in several cell lines, in response to several distinct stimuli. These results provide evidence of a key signalling pathway that links autophagy to the cancer-associated dysregulation of p53. 相似文献
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63.
Objective: Using data from many countries in the world combined with in‐depth U.S. dietary data, we explored trends in caloric sweetener intake, the role of urbanization and income changes in explaining these trends, and the contribution of specific foods to these changes. Research Methods and Procedures: Food disappearance data from 103 countries in 1962 and 127 in 2000 were coupled with urbanization and gross national income per capita data in pooled regression analysis to examine associations between these factors and caloric sweetener intake. Three nationally representative surveys from 1977 to 1978, 1989 to 1991, and 1994 to 1996 plus 1998 are used to examine caloric sweetener intake trends in the United States and the foods responsible for these changes. Results: Increased consumption of caloric sweetener is one element in the world's dietary changes, represented by a 74‐kcal/d increase between 1962 and 2000. Urbanization and income growth represent 82% of the change. U.S. data show an 83‐kcal/d increase of caloric sweetener consumed—a 22% increase in the proportion of energy from caloric sweetener. Of this increase, 80% comes from sugared beverages; restaurant and fast food sources are represented in greater proportions. Discussion: Caloric sweetener use has increased considerably around the world. Beverage intake seems to be a major contributor. 相似文献
64.
Domingos PM Brown S Barrio R Ratnakumar K Frankfort BJ Mardon G Steller H Mollereau B 《Developmental biology》2004,273(1):121-133
Photoreceptor development begins in the larval eye imaginal disc, where eight distinct photoreceptor cells (R1-R8) are sequentially recruited into each of the developing ommatidial clusters. Final photoreceptor differentiation, including rhabdomere formation and rhodopsin expression, is completed during pupal life. During pupation, spalt was previously proposed to promote R7 and R8 terminal differentiation. Here we show that spalt is required for proper R7 differentiation during the third instar larval stage since the expression of several R7 larval markers (prospero, enhancer of split mdelta0.5, and runt) is lost in spalt mutant clones. In R8, spalt is not required for cell specification or differentiation in the larval disc but promotes terminal differentiation during pupation. We show that spalt is necessary for senseless expression in R8 and sufficient to induce ectopic senseless in R1-R6 during pupation. Moreover, misexpression of spalt or senseless is sufficient to induce ectopic rhodopsin 6 expression and partial suppression of rhodopsin 1. We demonstrate that spalt and senseless are part of a genetic network, which regulates rhodopsin 6 and rhodopsin 1. Taken together, our results suggest that while spalt is required for R7 differentiation during larval stages, spalt and senseless promote terminal R8 differentiation during pupal stages, including the regulation of rhodopsin expression. 相似文献
65.
Katerina D Samara Dimitrios Tsetis Katerina M Antoniou Charalambos Protopapadakis George Maltezakis Nikolaos M Siafakas 《Journal of medical case reports》2011,5(1):58
Introduction
Hemoptysis constitutes a common and urgent medical problem. Swift and effective management is of crucial importance, especially in severe, life-threatening cases. In cases of idiopathic hemoptysis, in which no underlying pulmonary pathology can be identified, treatment is challenging. We report our experience with bronchial artery embolization in the treatment of massive idiopathic hemoptysis.Cases presentation
We report three consecutive cases of acute severe idiopathic hemoptysis. Our patients (two men aged 51 and 56 years and one woman aged 46 years), were of Caucasian ethnicity. We discuss the results and management of the patients, and review the literature. All three patients were treated safely and successfully with transcatheter embolization of the bronchial arteries using tris-acryl gelatin microspheres. Hemoptysis was controlled. All cases were followed up for 12 months, and there was no recurrence of bleeding.Conclusion
Bronchial artery embolization is an effective tool for the evaluation and treatment of massive idiopathic hemoptysis.66.
Ronaldo Souza Lopes Maria Alice Freitas Queiroz Samara Tatielle Monteiro Gomes Antonio Carlos Rosário Vallinoto Luiz Ricardo Goulart Ricardo Ishak 《Biotechnology advances》2018,36(7):1847-1854
Human immunodeficiency virus (HIV) remains a worldwide health problem despite huge investments and research breakthroughs, and no single drug is effective in killing the virus yet. Among new strategies to control HIV infection, the phage display (PD) technology has become a promising tool in the discovery of peptides that can be used as new drugs, or also as possible vaccine candidates. This review discusses basic aspects of PD and its use to advance two main objectives related to combating HIV-1 infection: the identification of peptides that inhibit virus replication and the identification of peptides that induce the production of neutralizing antibodies. We will cover the different approaches used for mapping and selection of mimotopes, and discuss the promising results of these biologicals as antiviral agents. 相似文献
67.
Ioannis Spanos Yannis Raftoyannis Gerasimos Goudelis Eleni Xanthopoulou Theano Samara Alexandros Tsiontsis 《Plant and Soil》2005,278(1-2):171-179
After a wildfire in a Pinus halepensis Mill. forest, in northern Greece, the burned trees were logged and the logs were removed either by mechanical or animal traction.
The effects of logging and log removal methods on soil and vegetation recovery were evaluated comparing the logged sites with
a burned but unlogged site and the unburned forest. Fire and logging did not affect the soil pH and caused only a short-term
reduction in organic matter content. Two years after the fire, the highest rates of soil loss were observed in the logged
area where mules were used for log removal. Soil moisture showed some differences between treatments during the first year
after fire but then values were similar. Logging and particularly the use of skidders for log removal caused an initial increase
in the amount of exposed bare ground but later when vegetation cover increased differences were minimized. The main woody
species showed a species specific response to the treatments and while seeder species were favoured in the unlogged sites
the same was not true for the respouters. In general, the growth and survival of pine seedlings was not affected by treatments. 相似文献
68.
Ninonuevo MR Ward RE LoCascio RG German JB Freeman SL Barboza M Mills DA Lebrilla CB 《Analytical biochemistry》2007,361(1):15-23
Oligosaccharides are the third most abundant component in human milk. In the past decades, it became apparent that they would be able to protect against pathogens and participate in the development of the gut microflora for infants. However, their role in infants' nutrition and development remains poorly understood. To better understand this function, it is extremely important to have a quantitative tool for profiling oligosaccharides. In this article, we show the development of a method to quantitatively differentiate the relative amounts of oligosaccharides fermented by different intestinal bacteria. To determine the oligosaccharide consumption, bacteria were grown in a medium using human milk oligosaccharides (HMOs) as the only carbon source purified from breast milk and further analyzed by matrix-assisted laser desorption/ionization-Fourier transform ion cyclotron resonance mass spectrometry (MALDI-FTICR MS). A method using an internal deuterium-labeled standard was developed and compared with an external standard method, with the internal standard method giving better precision and unambiguous measurements than the external standard method and providing to be a novel and robust tool for following bacterial fermentation of milk oligosaccharides. 相似文献
69.
Samara R.B. Damasceno Francisco Rodrigo A.M. Oliveira Nathalia S. Carvalho Camila F.C. Brito Irismara S. Silva Francisca Beatriz M. Sousa Renan O. Silva Damião P. Sousa André Luiz R. Barbosa Rivelilson M. Freitas Jand-Venes R. Medeiros 《Life sciences》2014
Aims
The present study aimed to investigate the potential anti-inflammatory and anti-nociceptive effects of carvacryl acetate, a derivative of carvacrol, in mice.Main methods
The anti-inflammatory activity was evaluated using various phlogistic agents that induce paw edema, peritonitis model, myeloperoxidase (MPO) activity, pro and anti-inflammatory cytokine levels. Evaluation of antinociceptive activity was conducted through acetic acid-induced writhing, hot plate test, formalin test, capsaicin and glutamate tests, as well as evaluation of motor performance on rotarod test.Key findings
Pretreatment of mice with carvacryl acetate (75 mg/kg) significantly reduced carrageenan-induced paw edema (P < 0.05) when compared to vehicle-treated group. Likewise, carvacryl acetate (75 mg/kg) strongly inhibited edema induced by histamine, serotonin, prostaglandin E2 and compound 48/80. In the peritonitis model, carvacryl acetate significantly decreased total and differential leukocyte counts, and reduced levels of myeloperoxidase and interleukin-1 beta (IL-1β) in the peritoneal exudate. The levels of IL-10, an anti-inflammatory cytokine, were enhanced by carvacryl acetate. Pretreatment with carvacryl acetate also decreased the number of acetic acid-induced writhing, increased the latency time of the animals on the hot plate and decreased paw licking time in the formalin, capsaicin and glutamate tests. The pretreatment with naloxone did not reverse the carvacryl acetate-mediated nociceptive effect.Significance
In conclusion, the current study demonstrated that carvacryl acetate exhibited anti-inflammatory activity in mice by reducing inflammatory mediators, neutrophil migration and cytokine concentration, and anti-nociceptive activity due to the involvement of capsaicin and glutamate pathways. 相似文献70.
Gokcumen O Dulik MC Pai AA Zhadanov SI Rubinstein S Osipova LP Andreenkov OV Tabikhanova LE Gubina MA Labuda D Schurr TG 《American journal of physical anthropology》2008,136(3):278-293
The Altaian Kazakhs, a Turkic speaking group, now reside in the southern part of the Altai Republic in south-central Russia. According to historical accounts, they are one of several ethnic and geographical subdivisions of the Kazakh nomadic group that migrated from China and Western Mongolia into the Altai region during the 19th Century. However, their population history of the Altaian Kazakhs and the genetic relationships with other Kazakh groups and neighboring Turkic-speaking populations is not well understood. To begin elucidating their genetic history, we analyzed the mtDNAs from 237 Altaian Kazakhs through a combination of SNP analysis and HVS1 sequencing. This analysis revealed that their mtDNA gene pool was comprised of roughly equal proportions of East (A-G, M7, M13, Y and Z) and West (H, HV, pre-HV, R, IK, JT, X, U) Eurasian haplogroups, with the haplotypic diversity within haplogroups C, D, H, and U being particularly high. This pattern of diversity likely reflects the complex interactions of the Kazakhs with other Turkic groups, Mongolians, and indigenous Altaians. Overall, these data have important implications for Kazakh population history, the genetic prehistory of the Altai-Sayan region, and the phylogeography of major mitochondrial lineages in Eurasia. 相似文献