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41.
JMJD3 is a histone H3K27 demethylase 总被引:2,自引:0,他引:2
Histone methylation is an important epigenetic phenomenon that participates in a diverse array of cellular processes and has been found to be associated with cancer. Recent identification of several histone demethylases has proved that histone methylation is a reversible process. Through a candidate approach, we have biochemically identified JMJD3 as an H3K27 demethylase. Transfection of JMJD3 into HeLa cells caused a specific reduction oftrimethyl H3K27, but had no effect on di-and monomethyl H3K27, or histone lysine methylations on H3K4 and H3K9. The enzymatic activity requires the JmjC domain and the conserved histidine that has been suggested to be important for a cofactor binding. In vitro biochemical experiments demonstrated that JMJD3 directly catalyzes the demethylation. In addition, we found that JMJD3 is upregulated in prostate cancer, and its expression is higher in metastatic prostate cancer. Thus, we identified JMJD3 as a demethylase capable of removing the trimethyl group from histone H3 lysine 27 and upregulated in prostate cancer. 相似文献
42.
Hawksbill sea turtles: can phylogenetics inform harvesting? 总被引:2,自引:2,他引:0
43.
Experimental evidence that female ornamentation increases the acquisition of sperm and signals fecundity 总被引:3,自引:0,他引:3
Cornwallis CK Birkhead TR 《Proceedings. Biological sciences / The Royal Society》2007,274(1609):583-590
Mate choice can lead to the evolution of sexual ornamentation. This idea rests on the assumption that individuals with more elaborate ornaments than competitors have higher reproductive success due to gaining greater control over mating decisions and resources provided by partners. Nevertheless, how the resources and quality of sexual partners that individuals gain access to are influenced by the ornamentation of rival individuals remains unclear. By experimentally concealing and subsequently revealing female ornaments to males, we confirm in the fowl, Gallus gallus, that female ornamentation influences male mating decisions. We further show, by manipulating the relative ornament size of females, that when females had larger ornaments than competitors they were more often preferred by males and obtained more sperm, especially from higher quality males, as measured by social status. Males may benefit by investing more sperm in females with larger ornaments as they were in better condition and produced heavier eggs. Female ornament size also decreased during incubation, providing a cue for males to avoid sexually unreceptive females. This study reveals how inter-sexual selection can lead to the evolution of female ornaments and highlights how the reproductive benefits gained from mate choice and bearing ornaments can be dependent upon social context. 相似文献
44.
Charlie Strange Felix JF Herth Kevin L Kovitz Geoffrey McLennan Armin Ernst Jonathan Goldin Marc Noppen Gerard J Criner Frank C Sciurba 《BMC pulmonary medicine》2007,7(1):1-12
Background
Lung volume reduction surgery is effective at improving lung function, quality of life, and mortality in carefully selected individuals with advanced emphysema. Recently, less invasive bronchoscopic approaches have been designed to utilize these principles while avoiding the associated perioperative risks. The Endobronchial Valve for Emphysema PalliatioN Trial (VENT) posits that occlusion of a single pulmonary lobe through bronchoscopically placed Zephyr® endobronchial valves will effect significant improvements in lung function and exercise tolerance with an acceptable risk profile in advanced emphysema.Methods
The trial design posted on Clinical trials.gov, on August 10, 2005 proposed an enrollment of 270 subjects. Inclusion criteria included: diagnosis of emphysema with forced expiratory volume in one second (FEV1) < 45% of predicted, hyperinflation (total lung capacity measured by body plethysmography > 100%; residual volume > 150% predicted), and heterogeneous emphysema defined using a quantitative chest computed tomography algorithm. Following standardized pulmonary rehabilitation, patients were randomized 2:1 to receive unilateral lobar placement of endobronchial valves plus optimal medical management or optimal medical management alone. The co-primary endpoint was the mean percent change in FEV1 and six minute walk distance at 180 days. Secondary end-points included mean percent change in St. George's Respiratory Questionnaire score and the mean absolute changes in the maximal work load measured by cycle ergometry, dyspnea (mMRC) score, and total oxygen use per day. Per patient response rates in clinically significant improvement/maintenance of FEV1 and six minute walk distance and technical success rates of valve placement were recorded. Apriori response predictors based on quantitative CT and lung physiology were defined.Conclusion
If endobronchial valves improve FEV1 and health status with an acceptable safety profile in advanced emphysema, they would offer a novel intervention for this progressive and debilitating disease.Trial Registration
ClinicalTrials.gov: NCT00129584 相似文献45.
46.
Steven P. Cohen Charlie Brown Connie Kurihara Anthony Plunkett Conner Nguyen Scott A. Strassels 《CMAJ》2011,183(5):E289-E295
Background
Nonmilitary personnel play an increasingly critical role in modern wars. Stark differences exist between the demographic characteristics, training and missions of military and nonmilitary members. We examined the differences in types of injury and rates of returning to duty among nonmilitary and military personnel participating in military operations in Iraq and Afghanistan.Methods
We collected data for nonmilitary personnel medically evacuated from military operations in Iraq and Afghanistan between 2004 and 2007. We compared injury categories and return-to-duty rates in this group with previously published data for military personnel and identified factors associated with return to duty.Results
Of the 2155 medically evacuated nonmilitary personnel, 74.7% did not return to duty. War-related injuries in this group accounted for 25.6% of the evacuations, the most common causes being combat-related injuries (55.4%) and musculoskeletal/spinal injuries (22.9%). Among individuals with non–war-related injuries, musculoskeletal injuries accounted for 17.8% of evacuations. Diagnoses associated with the highest return-to-duty rates in the group of nonmilitary personnel were psychiatric diagnoses (15.6%) among those with war-related injuries and noncardiac chest or abdominal pain (44.0%) among those with non–war-related injuries. Compared with military personnel, nonmilitary personnel with war-related injuries were less likely to return to duty (4.4% v. 5.9%, p = 0.001) but more likely to return to duty after non–war-related injuries (32.5% v. 30.7%, p = 0.001).Interpretation
Compared with military personnel, nonmilitary personnel were more likely to be evacuated with non–war-related injuries but more likely to return to duty after such injuries. For evacuations because of war-related injuries, this trend was reversed.In modern warfare, injuries sustained in combat have never been the leading source of attrition among soldiers. In World War I, World War II and the Korean War, respiratory and infectious diseases were the top reasons for hospital admissions among service members. By the Vietnam Conflict, non-battle injuries had supplanted respiratory illness as the leading cause of hospital admissions and have remained the leading cause ever since.1,2The principal causes for medical evacuation of military personnel from US operations in Iraq and Afghanistan were recently described in a large four-year epidemiologic study.3 In descending order, the leading reasons were musculoskeletal conditions, combat-related injuries, neurologic symptoms and psychiatric disorders; the last category surpassed combat-related injuries as the number two reason in the latter half of both engagements. However, nonmilitary personnel were not included in that study. Over the past three years, nonmilitary members, including US Department of Defense civilians, private contractors and diplomats, have comprised about 50% of personnel serving in Iraq and about two-thirds of those serving in Afghanistan.4,5Several reasons may explain why the types of injury and the return-to-duty rates differ between military and nonmilitary personnel. First, the motivations for overseas deployment might differ between the groups. Whereas some civilian personnel (e.g., diplomats) may be assigned to positions in Iraq and Afghanistan, virtually all private contractors volunteer for their jobs. In contrast, most military members have little choice in their deployment. Second, military and nonmilitary members assigned to war zones have different occupational specialties, living conditions and regulations to which they must adhere. Especially for junior military personnel, jobs tend to be more dangerous, living environments more austere and regulations more stringent. Finally, unlike military personnel, who are paid regardless of deployment status, most contractors’ pay is contingent upon continued employment in theatres of operation. In addition, nonmilitary personnel are generally compensated with higher salaries than service members in comparable occupational specialties.In civilian cohorts, many of these factors have been shown to influence return-to-work rates in a variety of contexts. Studies of the effect of financial compensation on work status after injury have generally shown a direct correlation between return-to-work rates and higher income levels.6,7 Similar associations have also been found between return-to-work rates and job satisfaction and coping mechanisms, factors that may be influenced by work conditions and perceived control over one’s environment.8–10The objectives of our study were threefold: to ascertain whether the reasons for medical evacuation from military operations differed between military and nonmilitary personnel; to determine whether return-to-duty rates differed between the two groups; and to identify factors that influence return-to-duty rates among nonmilitary members. 相似文献47.
Washington J. Gapare Brian S. Baltunis Milo? Ivkovi? Charlie B. Low Paul Jefferson Harry X. Wu 《Tree Genetics & Genomes》2011,7(2):409-419
Growth and form traits from a series of three provenance trials of Pinus radiata D. Don planted in New Zealand and Australia were analysed at age 9 years from planting. The trials included selections from
three mainland California natural populations—A?o Nuevo, Monterey and Cambria. Monterey and Cambria performed better than
A?o Nuevo at two New Zealand sites, but Monterey and A?o Nuevo were almost identical in growth, whereas Cambria grew less
vigorously at the Australian site. We detected significant provenance differences for diameter at breast height (DBH) growth
and stem straightness across countries (p < 0.001). Estimated heritability for DBH ranged from 0.19 to 0.26 within sites, while heritability estimates for stem straightness
and branching frequency ranged from 0.10 to 0.24. Estimated type B genetic correlations for DBH were always higher between
the two trials in New Zealand trials than between pairs of trials in New Zealand and the Australian site. The genetic coefficient
of variation (CVA) for DBH was around 8–10% compared to ca. 5% for the current breeding population. These results suggested that there is appreciable
genetic variation in the native populations, and infusion of these materials would increase the genetic variation in current
breeding populations. Ten unrelated parents ranked above control seedlots from the older open-pollinated seed orchard stock
for DBH growth and would be potential candidates for infusion. The promising performance of the Cambria material is an important
result because the genetic base of the present Australian and New Zealand plantations is principally derived from A?o Nuevo
and Monterey. 相似文献
48.
49.
As more information becomes available regarding the role of inflammation following stroke, it is apparent that some inflammatory
mediators are detrimental and others are beneficial to the progression of ischemic injury. Cortical spreading depression (CSD)
is known to impart some degree of ischemic tolerance to the brain and to influence the expression of many genes. Many of the
genes whose expression is altered by CSD are associated with inflammation, and it appears likely that modulation of the inflammatory
response to ischemia by CSD contributes to ischemic tolerance. Understanding which inflammatory processes are influenced by
CSD may lead to the identification of novel targets in the effort to develop an acute treatment for stroke. 相似文献
50.
Rangel-Castro JI Prosser JI Ostle N Scrimgeour CM Killham K Meharg AA 《Environmental microbiology》2005,7(4):544-552
The influence of liming on rhizosphere microbial biomass C and incorporation of root exudates was studied in the field by in situ pulse labelling of temperate grassland vegetation with (13)CO(2) for a 3-day period. In plots that had been limed (CaCO(3) amended) annually for 3 years, incorporation into shoots and roots was, respectively, greater and lower than in unlimed plots. Analysis of chloroform-labile C demonstrated lower levels of (13)C incorporation into microbial biomass in limed soils compared to unlimed soils. The turnover of the recently assimilated (13)C compounds was faster in microbial biomass from limed than that from unlimed soils, suggesting that liming increases incorporation by microbial communities of root exudates. An exponential decay model of (13)C in total microbial biomass in limed soils indicated that the half-life of the tracer within this carbon pool was 4.7 days. Results are presented and discussed in relation to the absolute values of (13)C fixed and allocated within the plant-soil system. 相似文献