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131.
132.
Niels Jessen Ho-Jin Koh Clifford D. Folmes Cory Wagg Nobuharu Fujii Bo Løfgren Cordula M. Wolf Charles I. Berul Michael F. Hirshman Gary D. Lopaschuk Laurie J. Goodyear 《生物化学与生物物理学报:疾病的分子基础》2010,1802(7-8):593-600
Energy deprivation in the myocardium is associated with impaired heart function and increased morbidity. LKB1 is a kinase that is required for activation of AMP-activated protein kinase (AMPK) as well as 13 AMPK-related protein kinases. AMPK stimulates ATP production during ischemia and prevents post-ischemic dysfunction. We used the Cre–Lox system to generate mice where LKB1 was selectively knocked out in cardiomyocytes and muscle cells (LKB1-KO) to assess the role of LKB1 on cardiac function in these mice.Heart rates of LKB1-KO mice were reduced and ventricle diameter was increased. Ex vivo, cardiac function was impaired during aerobic perfusion of isolated working hearts, and recovery of function after ischemia was reduced. Although oxidative metabolism and mitochondrial function were normal, the AMP/ATP ratio was increased in LKB1-KO hearts. This was associated with a complete ablation of AMPKα2 activity, and a stimulation of signaling through the mammalian target of rapamycin. Our results establish a critical role for LKB1 for normal cardiac function under both aerobic conditions and during recovery after ischemia. Ablation of LKB1 leads to a decreased cardiac efficiency despite normal mitochondrial oxidative metabolism. 相似文献
133.
Navjot S. Sodhi Mary Rose C. Posa Tien Ming Lee David Bickford Lian Pin Koh Barry W. Brook 《Biodiversity and Conservation》2010,19(2):317-328
Southeast Asia is a region of conservation concern due to heavy losses of its native habitats. In this overview, we highlight
the conservation importance of Southeast Asia by comparing its degree of species endemism and endangerment, and its rate of
deforestation with other tropical regions (i.e., Meso-America, South America, and Sub-Saharan Africa). Southeast Asia contains
the highest mean proportion of country-endemic bird (9%) and mammal species (11%). This region also has the highest proportion
of threatened vascular plant, reptile, bird, and mammal species. Furthermore, not only is Southeast Asia’s annual deforestation
rate the highest in the tropics, but it has also increased between the periods 1990–2000 and 2000–2005. This could result
in projected losses of 13–85% of biodiversity in the region by 2100. Secondary habitat restoration, at least in certain countries,
would allow for some amelioration of biodiversity loss and thus potentially lower the currently predicted extinction rates.
Nonetheless, urgent conservation actions are needed. Conservation initiatives should include public education, sustaining
livelihoods, and ways to enhance the sustainability of agriculture and increase the capacity of conservation institutions.
Furthermore, these actions should be country-specific and not ignore areas heavily populated by humans, as they can also harbour
high numbers of threatened species. We urge that cooperative conservation initiatives be undertaken and support (e.g., capacity-building)
be given by more developed countries in the region and beyond. 相似文献
134.
? Premise of the study: The development of compound microsatellite markers was conducted in Neolitsea sericea to investigate genetic diversity and population genetic structure of this endangered insular species. ? Methods and Results: Using the compound microsatellite marker technique, 10 compound microsatellite markers that were successfully amplified showed polymorphism when assessed in 55 individuals from two populations in East China and Japan. Overall, the number of alleles ranged from 3 to 17, with an average of 7.9 alleles per locus. In addition, these primers could be easily amplified in Neolitsea aurata var. paraciculata and N. aurata var. chekiangensis. ? Conclusions: The highly polymorphic markers developed and characterized in this study will be useful for population genetic studies of N. sericea. 相似文献
135.
Nobuhiro Kokubo Manami Matsuura Koh Onimaru Eva Tiecke Shigehiro Kuraku Shigeru Kuratani Mikiko Tanaka 《Evolution & development》2010,12(1):34-44
SUMMARY Vertebrate hearts have evolved from undivided tubular hearts of chordate ancestors. One of the most intriguing issues in heart evolution is the abrupt appearance of multichambered hearts in the agnathan vertebrates. To explore the developmental mechanisms behind the drastic morphological changes that led to complex vertebrate hearts, we examined the developmental patterning of the agnathan lamprey Lethenteron japonicum . We isolated lamprey orthologs of genes thought to be essential for heart development in chicken and mouse embryos, including genes responsible for differentiation and proliferation of the myocardium ( LjTbx20, LjTbx4/5 , and LjIsl1/2A ), establishment of left–right heart asymmetry ( LjPitxA ), and partitioning of the heart tube ( LjTbx2/3A ), and studied their expression patterns during lamprey cardiogenesis. We confirmed the presence of the cardiac progenitors expressing LjIsl1/2A in the pharyngeal and splanchnic mesoderm and the heart tube of the lamprey. The presence of LjIsl1/2A -positive cardiac progenitor cells in cardiogenesis may have permitted an increase of myocardial size in vertebrates. We also observed LjPitxA expression in the left side of lamprey cardiac mesoderm, suggesting that asymmetric expression of Pitx in the heart has been acquired in the vertebrate lineage. Additionally, we observed LjTbx2/3A expression in the nonchambered myocardium, supporting the view that acquisition of Tbx2/3 expression may have allowed primitive tubular hearts to partition, giving rise to multichambered hearts. 相似文献
136.
We have developed a new NIR fluorescent probe based on an ytterbium(III) (E)‐1‐(pyridin‐2‐yl‐diazenyl)naphthalen‐2‐ol (PAN) complex. This probe emits near‐infrared luminescence derived from the Yb ion through excitation of the PAN moiety with visible light (λex = 530 nm, λem = 975 nm). The results support the possible utility of the probe for in vivo fluorescence molecular imaging. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
137.
Junichi Matsubara Masaya Ono Kazufumi Honda Ayako Negishi Hideki Ueno Takuji Okusaka Junji Furuse Koh Furuta Emiko Sugiyama Yoshiro Saito Nahoko Kaniwa Junichi Sawada Ayako Shoji Tomohiro Sakuma Tsutomu Chiba Nagahiro Saijo Setsuo Hirohashi Tesshi Yamada 《Molecular & cellular proteomics : MCP》2010,9(4):695-704
138.
Brian Koh 《The Yale journal of biology and medicine》2003,76(4-6):201-202
139.
140.
T-DNA-tagged rice plants were screened under cold- or salt-stress conditions to determine the genes involved in the molecular
mechanism for their abiotic-stress response. Line 0-165-65 was identified as a salt-responsive line. The gene responsible
for this GUS-positive phenotype was revealed by inverse PCR as OsGSK1 (O
ryza
s
ativa
g
lycogen
s
ynthase
k
inase3-like gene
1), a member of the plant GSK3/SHAGGY-like protein kinase genes and an orthologue of the Arabidopsis
b
rassinosteroid
in
sensitive
2
(BIN2), AtSK21. Northern blot analysis showed that OsGSK1 was most highly detected in the developing panicles, suggesting that its expression is developmental stage specific. Knockout
(KO) mutants of OsGSK1 showed enhanced tolerance to cold, heat, salt, and drought stresses when compared with non-transgenic segregants (NT). Overexpression
of the full-length OsGSK1 led to a stunted growth phenotype similar to the one observed with the gain-of-function BIN/AtSK21 mutant. This suggests that OsGSK1 might be a functional rice orthologue that serves as a negative regulator of brassinosteroid (BR)-signaling. Therefore, we
propose that stress-responsive OsGSK1 may have physiological roles in stress signal-transduction pathways and floral developmental processes.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Serry Koh and Sang-Choon Lee are co-first authors. 相似文献