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71.
Choong Hyun Lee In Koo Hwang Ki-Yeon Yoo Jung Hoon Choi Ok Kyu Park Jae-Chul Lee Young-Gil Jeong In Se Lee Moo-Ho Won 《Cellular and molecular neurobiology》2009,29(5):665-672
The hippocampus is associated with learning and memory function and shows neurochemical changes in aging processes. Calbindin
D-28k (CB) binds calcium ion with a fast association rate. We examined age-related changes in CB immunoreactivity and its
protein level in the gerbil hippocampus during normal aging. In the hippocampal CA1 region (CA1) and CA2, CB immunoreaction
was found in some neurons in the stratum pyramidale (SP) at postnatal month 1 (PM 1). CB immunoreactivity in neurons was markedly
increased at PM 3. Thereafter, CB immunoreactivity was decreased with time: CB-immunoreactive (+) neurons were fewest at PM 24. In the CA3, a few CB+ neurons were found only in the SP at PM 1 and in the stratum radiatum at PM 18 and 24. In addition, mossy fibers were stained
with CB at PM 1. CB immunoreactivity in mossy fibers was markedly increased at PM 3, thereafter it was decreased with time.
In the dentate gyrus, many granule cells (GC) in the granule cell layer were stained with CB at PM 1. CB immunoreactivity
in GC was markedly increased at PM 3, thereafter CB immunoreactivity was decreased with time. In Western blot analysis, CB
protein level in the gerbil hippocampus was highest at PM 3, thereafter CB protein levels were decreased with time. This result
indicates that CB in the gerbil hippocampus is abundant at PM 3 and is decreased with age. 相似文献
72.
Sang Kwang Lee Yongtae Kim Sung‐Soo Kim Jeong Hwa Lee Kun Cho Sang Sook Lee Zee‐Won Lee Kyung‐Hoon Kwon Young Hye Kim Haeyoung Suh‐Kim Jong Shin Yoo Young Mok Park 《Proteomics》2009,9(18):4389-4405
Mesenchymal stem cells (MSCs) are multipotent cells, which have the capability to differentiate into various mesenchymal tissues such as bone, cartilage, fat, tendon, muscle, and marrow stroma. However, they lose the capability of multi‐lineage differentiation after several passages. It is known that basic fibroblast growth factor (bFGF) increases growth rate, differentiation potential, and morphological changes of MSCs in vitro. In this report, we have used 2‐DE coupled to MS to identify differentially expressed proteins at the cell membrane level in MSCs growing in bFGF containing medium. The cell surface proteins isolated by the biotin–avidin affinity column were separated by 2‐DE in triplicate experiments. A total of 15 differentially expressed proteins were identified by quadrupole‐time of flight tandem MS. Nine of the proteins were upregulated and six proteins were downregulated in the MSCs cultured with bFGF containing medium. The expression level of three actin‐related proteins, F‐actin‐capping protein subunit alpha‐1, actin‐related protein 2/3 complex subunit 2, and myosin regulatory light chain 2, was confirmed by Western blot analysis. The results indicate that the expression levels of F‐actin‐capping protein subunit alpha‐1, actin‐related protein 2/3 complex subunit 2, and myosin regulatory light chain 2 are important in bFGF‐induced morphological change of MSCs. 相似文献
73.
Ibrahim M. El-Deeb Byung Sun Park Su Jin Jung Kyung Ho Yoo Chang-Hyun Oh Seung Joo Cho Dong Keun Han Jae Yeol Lee So Ha Lee 《Bioorganic & medicinal chemistry letters》2009,19(19):5622-5626
A series of rationally designed ROS1 tyrosine kinase inhibitors was synthesized and screened. Compound 12b has showed good potency with IC50 value of 209 nM, which is comparable with that of the reference lead compound 1. Molecular modeling studies have been performed, that is, a homology model for ROS1 was built, and the screened inhibitors were docked into its major identified binding site. The docked poses along with the activity data have revealed a group of the essential features for activity. Overall, simplification of the lead compound 1 into compound 12b has maintained the activity, while facilitated the synthetic advantages. A molecular interaction model for ROS1 kinase and inhibitors has been proposed. 相似文献
74.
Ok Tae Kim Nam Hee Yoo Gum Soog Kim Young Chang Kim Kyong Hwan Bang Dong Yun Hyun Seung Hye Kim Min Young Kim 《Plant Cell, Tissue and Organ Culture》2013,112(1):87-93
It has been recognized that ginsenoside Rg3 is not naturally produced in ginseng although this ginsenoside can accumulate in red ginseng as the result of a thermal process. In order to determine whether or not Rg3 is synthesized in ginseng, hairy roots were treated with methyl jasmonate (MJ). From HPLC analysis, no peak for Rg3 was observed in the controls. However, Rg3 did accumulate in hairy roots that were MJ-treated for 7?days. Rg3 content was 0.42?mg/g (dry weight). To gain more insight into the effects of MJ on UDP-glucosyltransferase (UGT) activity, we attempted to evaluate ginsenoside Rg3 biosynthesis by UGT. A new peak for putative Rg3 was observed, which was confirmed by LC-MS/MS analysis. Our findings indicate that the proteins extracted from our hairy root lines can catalyze Rg3 from Rh2. This suggests that our ginseng hairy root lines possess Rg3 biosynthesis capacity. 相似文献
75.
Nam Jin Noh Yowhan Son Jin Woo Koo Kyung Won Seo Rae Hyun Kim Yoon Young Lee Kyung Seun Yoo 《Journal of Plant Biology》2010,53(1):61-69
The nitrogenase activity, root nodule biomass, and rates of nitrogen (N) fixation were measured in 25-year-old pure north-
and south-facing Robinia pseudoacacia stands in an urban forest of Seoul (Kkachisan Mountain) in central Korea. The nitrogenase activity was estimated using an
acetylene reduction (AR) assay, which showed an increasing trend during the early growing season, with sustained high rates
from June through to September with a decrease thereafter. July had the highest nitrogenase activity rate (micromoles C2H4 per gram dry nodule per hour), averaging 95.8 and 115.1 for the north- and south-facing stands, respectively. The maximum
root nodule biomass (kilograms per hectare) was 45.7 and 9.1 for the north- and south-facing stands in July, respectively.
The AR rate appeared to be strongly correlated to the soil temperature (r
2 = 0.68, P < 0.001) and soil pH (r
2 = 0.59, P < 0.001) while root nodule biomass was correlated to the soil temperature (r
2 = 0.36, P < 0.01) and water content (r
2 = 0.35, P < 0.05). The soil temperature showed clear differences between seasons, while there was a significant difference in soil pH,
organic matter, total N concentrations, and available phosphorus between the north- and south-facing stands. The N2 fixation rates during the growing season varied from 0.1 to 37.5 kg N ha−1 month−1 depending on the sampling location and time. The annual N2 fixation rate (kg N per hectare per year) was 112.3 and 23.2 for the north- and south-facing stands, respectively. The differences
in N2 fixation rate between the two stands were due mainly to the differences in total nodule biomass. 相似文献
76.
Lim MY Ryou J Kim SY Shin EH Yoo YJ Yun SM Noh YT Han MG Ju YR 《Journal of vector ecology》2012,37(1):97-101
The seroprevalence of Hantaan virus (HTNV) in wild rodents in South Korea was analyzed. Wild rodents were trapped in 18 cities in eight provinces during 2005-2007 and on three islands and four mountains during 2008-2010. Sera were collected from 629 out of 933 trapped wild animals and examined for immunoglobulin G antibodies to HTNV using indirect immunofluorescence assays. Apodemus agrarius (80.1%) was the most frequently captured species at almost all trapping sites. The overall prevalence of HTNV antibodies was 0.26 (162/629). Seropositive individuals were more frequent in cities (32.2%, n=410) than on islands (14.0%, n=57) or mountains (13.6%, n= 162). HTNV antibody-positive rate was higher in the fall (29.6%, n=253) than in the spring (23.1%, n=376). A. agrarius had the highest prevalence of HTNV antibodies (26.9%, n=561) of all tested species. Considering all the individuals, the prevalence of HTNV antibodies was higher in males (29.2%, n=250) than in females (22.3%, n=305). Our results show that HTNV is widely distributed throughout South Korea, and that HTNV infection of wild rodents is affected by their habitat, species, sex, and season. 相似文献
77.
Kang NS Jeong HJ Yoo YD Yoon EY Lee KH Lee K Kim G 《The Journal of eukaryotic microbiology》2011,58(2):152-170
Woloszynskia species are dinoflagellates in the order Suessiales inhabiting marine or freshwater environments; their ecophysiology has not been well investigated, in particular, their trophic modes have yet to be elucidated. Previous studies have reported that all Woloszynskia species are photosynthetic, although their mixotrophic abilities have not been explored. We isolated a dinoflagellate from coastal waters in western Korea and established clonal cultures of this dinoflagellate. On the basis of morphology and analyses of the small/large subunit rRNA gene (GenBank accession number=FR690459), we identified this dinoflagellate as Woloszynskia cincta. We further established that this dinoflagellate is a mixotrophic species. We found that W. cincta fed on algal prey using a peduncle. Among the diverse prey provided, W. cincta ingested those algal species that had equivalent spherical diameters (ESDs) ≤12.6 μm, exceptions being the diatom Skeletonema costatum and the dinoflagellate Prorocentrum minimum. However, W. cincta did not feed on larger algal species that had ESDs≥15 μm. The specific growth rates for W. cincta increased continuously with increasing mean prey concentration before saturating at a concentration of ca. 134 ng C/ml (1,340 cells/ml) when Heterosigma akashiwo was used as food. The maximum specific growth rate (i.e. mixotrophic growth) of W. cincta feeding on H. akashiwo was 0.499 d(-1) at 20 °C under illumination of 20 μE/m(2) /s on a 14:10 h light-dark cycle, whereas its growth rate (i.e. phototrophic growth) under the same light conditions without added prey was 0.040 d(-1). The maximum ingestion and clearance rates of W. cincta feeding on H. akashiwo were 0.49 ng C/grazer/d (4.9 cells/grazer/d) and 1.9 μl/grazer/h, respectively. The calculated grazing coefficients for W. cincta on co-occurring H. akashiwo were up to 1.1 d(-1). The results of the present study suggest that grazing by W. cincta can have a potentially considerable impact on prey algal populations. 相似文献
78.
The toxicities of the herbicide glufosinate-ammonium to three predatory insect and two predatory mite species of Tetranychus urticae Koch were determined in the laboratory by the direct contact application. At a concentration of 540 ppm (a field application rate for weed control in apple orchards), glufosinate-ammonium was almost nontoxic to eggs of Amblyseius womersleyi Schicha, Phytoseiulus persimilis Athias-Henriot, and T. urticae but highly toxic to nymphs and adults of these three mite species, indicating that a common mode of action between predatory and phytophagous mites might be involved. In tests with predatory insects using 540 ppm, glufosinate-ammonium revealed little or no harm to larvae and pupae of Chrysopa pallens Rambur but was slightly harmful to eggs (71.2% mortality), nymphs (65.0% mortality), and adults (57.7% mortality) of Orius strigicollis Poppius. The herbicide showed no direct effect on eggs and adults of Harmonia axyridis (Pallas) but was harmful, slightly harmful, and harmless to first instars (100% mortality), fourth instars (51.1% mortality), and pupae (24.5% mortality), respectively. The larvae and nymphs of predators died within 12 h after treatment, suggesting that the larvicidal and nymphicidal action may be attributable to a direct effect rather than an inhibitory action of chitin synthesis. On the basis of our data, glufosinate-ammonium caused smaller effects on test predators than on T. urticae with the exception of P. persimilis, although the mechanism or cause of selectivity remains unknown. Glufosinate-ammonium merits further study as a key component of integrated pest management. 相似文献
79.
Culturable Actinobacteria from the Marine Sponge Hymeniacidon perleve: Isolation and Phylogenetic Diversity by 16S rRNA gene-RFLP Analysis 总被引:1,自引:0,他引:1
A total of 106 actinobacteria associated with the marine sponge Hymeniacidon perleve collected from the Yellow Sea, China were isolated using eight different media. The number of species and genera of actinobacteria recovered from the different media varied significantly, underlining the importance of optimizing the isolation conditions. The phylogenetic diversity of the actinobacteria isolates was assessed using 16S rRNA gene amplification–restriction fragment length polymorphism (RFLP) analysis of the 106 strains with different morphologies. The RFLP fingerprinting of selected strains by HhaI-digestion of the 16S rRNA genes resulted in 11 different patterns. The HhaI-RFLP analysis gave good resolution for the identification of the actinobacteria isolates at the genus level. A phylogenetic analysis using 16S rRNA gene sequences revealed that the isolates belonged to seven genera of culturable actinobacteria including Actinoalloteichus, Micromonospora, Nocardia, Nocardiopsis, Pseudonocardia, Rhodococcus, and Streptomyces. The dominant genus was Streptomyces, which represented 74% of the isolates. Three of the strains identified are candidates for new species. 相似文献
80.