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151.

Background

Many studies associated the main polyphenolic constituent of green tea, (-)-Epigallocatechin-3-gallate (EGCG), with inhibition of cancers, invasion and metastasis. To date, most of the studies have focused on the effect of EGCG on cell proliferation or death. Since cell migration is an important mechanism involved in tumor invasion, the aim of the present work was to target another approach of the therapeutic effect of EGCG, by investigating its effect on the cell migratory behavior.

Methods

The effect of EGCG (at concentrations lower than 10 μg/ml) on the migration speed of invasive cells was assessed by using 2D and 3D models of cell culture. We also studied the effects of EGCG on proteinases expression by RT-PCR analysis. By immunocytochemistry, we analyzed alterations of vimentin organization in presence of different concentrations of EGCG.

Results

We observed that EGCG had an inhibitory effect of cell migration in 2D and 3D cell culture models. EGCG also inhibited MMP-2 mRNA and protein expression and altered the intermediate filaments of vimentin.

Conclusion

Taken together, our results demonstrate that EGCG is able to inhibit the migration of bronchial tumor cells and could therefore be an attractive candidate to treat tumor invasion and cell migration.  相似文献   
152.
153.
Rats are known to emit ultrasonic vocalizations (USVs). These USVs have been hypothesized to hold biological meaning, and the relationship between USVs and behavior has been extensively studied. However, most of these studies looked at specific conditions, such as fear-inducing situations and sexual encounters. In the present experiment, the USVs of pairs of rats in ordinary housing conditions were recorded and their features were examined. Three clusters of USVs in the 25-, 40-, and 60-kHz range were detected, which roughly corresponded to fighting, feeding, and moving, respectively. We analyzed sequential combinations of two or more clusters using a state transition model. The results revealed a more specific correspondence between the USVs and behaviors, suggesting that rat USV may work as a type of communication tool.  相似文献   
154.
Air-breathing divers are assumed to have evolved to apportion their time between surface and underwater periods to maximize the benefit gained from diving activities. However, whether they change their time allocation depending on the aim of the dive is still unknown. This may be particularly crucial for ‘surfacers’ because they dive for various purposes in addition to foraging. In this study, we counted breath events at the surface and estimated oxygen consumption during resting, foraging and other dives in 11 green turtles (Chelonia mydas) in the wild. Breath events were counted by a head-mounted acceleration logger or direct observation based on an animal-borne video logger, and oxygen consumption was estimated by measuring overall dynamic body acceleration. Our results indicate that green turtles maximized their submerged time, following this with five to seven breaths to replenish oxygen for resting dives. However, they changed their dive tactic during foraging and other dives; they surfaced without depleting their estimated stores of oxygen, followed by only a few breaths for effective foraging and locomotion. These dichotomous surfacing tactics would be the result of behavioural modifications by turtles depending on the aim of each dive.  相似文献   
155.
Three species of Ophiostoma possessing Pesotum anamorphs isolated from bark beetles and their galleries infesting Abies species in Nikko, Japan, are described as new species. Ophiostoma nikkoense is characterized by brush-shaped synnemata producing long septate clavate conidia, perithecia with neck, and allantoid ascospores. Ophiostoma microcarpum has smaller perithecia with hyphoid ostiolar hyphae on the neck, and the ascospores are cylindrical or ossiform in side and face views. Ophiostoma abieticola has perithecia without ostiolar hyphae on the neck and produces orange-section-shaped or reniform ascospores.Contribution no. 187, Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba  相似文献   
156.

Background

Dendritic cells (DCs) are the most potent antigen-presenting cells in the mammalian immune system. In the skin, epidermal Langerhans cells (LCs) and dermal dendritic cells (DDCs) survey for invasive pathogens and present antigens to T cells after migration to the cutaneous lymph nodes (LNs). So far, functional and phenotypic differences between these two DC subsets remain unclear due to lack of markers to identify DDCs.

Methodology/Principal Findings

In the present report, we demonstrated that macrophage galactose-type C-type lectin (MGL) 2 was exclusively expressed in the DDC subset in the skin-to-LN immune system. In the skin, MGL2 was expressed on the majority (about 88%) of MHCII+CD11c+ cells in the dermis. In the cutaneous LN, MGL2 expression was restricted to B220CD8αloCD11b+CD11c+MHCIIhi tissue-derived DC. MGL2+DDC migrated from the dermis into the draining LNs within 24 h after skin sensitization with FITC. Distinct from LCs, MGL2+DDCs localized near the high endothelial venules in the outer T cell cortex. In FITC-induced contact hypersensitivity (CHS), adoptive transfer of FITC+MGL2+DDCs, but not FITC+MGL2DCs into naive mice resulted in the induction of FITC-specific ear swelling, indicating that DDCs played a key role in initiation of immune responses in the skin.

Conclusions/Significance

These results demonstrated the availability of MGL2 as a novel marker for DDCs and suggested the contribution of MGL2+ DDCs for initiating CHS.  相似文献   
157.
The semi-pilot scale of continuous flow type hydrothermal reactor has been investigated to separate hemicellulose fraction from corncob. We obtained the effective recovery of hemicellulose using tubular type reactor at 200 °C for 10 min. From constituent sugar analysis of corncob, 82.2% of xylan fraction was recovered as mixture of xylose, xylooligosaccharides and higher-xylooligosaccharide which has more than DP 10. During purification of solubilized fraction by hydrothermal reaction such as ultrafiltration and ion exchange resin, higher-xylooligosaccharide was recovered as the precipitate. This precipitate was identified as non-blanched xylan fraction which has from DP 11 to DP 21 mainly. In this system, only a small amount of furfural has been generated. This tubular reactor has a characteristic controllability of thermal history, and seems to be effective for sugar recovery from soft biomass like corncob.  相似文献   
158.
Termites are major decomposers in terrestrial ecosystems and the second most diverse lineage of social insects. The Kalotermitidae form the second-largest termite family and are distributed across tropical and subtropical ecosystems, where they typically live in small colonies confined to single wood items inhabited by individuals with no foraging abilities. How the Kalotermitidae have acquired their global distribution patterns remains unresolved. Similarly, it is unclear whether foraging is ancestral to Kalotermitidae or was secondarily acquired in a few species. These questions can be addressed in a phylogenetic framework. We inferred time-calibrated phylogenetic trees of Kalotermitidae using mitochondrial genomes of ∼120 species, about 27% of kalotermitid diversity, including representatives of 21 of the 23 kalotermitid genera. Our mitochondrial genome phylogenetic trees were corroborated by phylogenies inferred from nuclear ultraconserved elements derived from a subset of 28 species. We found that extant kalotermitids shared a common ancestor 84 Ma (75–93 Ma 95% highest posterior density), indicating that a few disjunctions among early-diverging kalotermitid lineages may predate Gondwana breakup. However, most of the ∼40 disjunctions among biogeographic realms were dated at <50 Ma, indicating that transoceanic dispersals, and more recently human-mediated dispersals, have been the major drivers of the global distribution of Kalotermitidae. Our phylogeny also revealed that the capacity to forage is often found in early-diverging kalotermitid lineages, implying the ancestors of Kalotermitidae were able to forage among multiple wood pieces. Our phylogenetic estimates provide a platform for critical taxonomic revision and future comparative analyses of Kalotermitidae.  相似文献   
159.
Cyclins B1 and B2 are subtypes of cyclin B, a regulatory subunit of a maturation/M-phase promoting factor, and they are also highly conserved in many vertebrate species. Cyclin B1 is essential for mitosis, whereas cyclin B2 is regarded as dispensable. However, the overexpression of the cyclin B2 N-terminus containing the cytoplasmic retention signal, but not cyclin B1, inhibits bipolar spindle formation in Xenopus oocytes and embryos. Here we show that endogenous cyclin B2 was localized in and around the germinal vesicle. The perinuclear localization of cyclin B2 was perturbed by the overexpression of its N-terminus containing the cytoplasmic retention signal, which resulted in a spindle defect. This spindle defect was rescued by the overexpression of bipolar kinesin Eg5, which is located at the perinuclear region in the proximity of endogenous cyclin B2. These results demonstrate that the proper localization of cyclin B2 is essential for bipolar spindle formation in Xenopus oocytes.  相似文献   
160.
Five independent mutations in the hypoxanthine guanine phosphoribosyltransferase (HPRT) gene were identified in a partially HPRT deficient patient with gout and in four Lesch-Nyhan patients. Using the polymerase chain reaction (PCR) technique coupled with direct sequencing, the nucleotide sequences of the entire HPRT coding region amplified from the cDNA and also of each exon amplified form the genomic DNA were analyzed. Three independent point mutations in the coding region were detected in the partially HPRT deficient patient (Case 1) and in two Lesch-Nyhan patients (Case 2 and 3), resulting in single amino acid substitutions. The family study of Case 3, utilizing a PvuII restriction site created in the mutant gene, indicated that the mother was a heterozygote, and a sister and a fetal brother had inherited the normal HPRT gene from the mother. In two other mutants causing Lesch-Nyhan syndrome, a portion of the HPRT gene was deleted, and RNA splicing was missing in both mutants. A 4-bp deletion at the 5 end of exon 4 resulted in formation of three different types of abnormal mRNA (Case 4). The other mutant (Case 5) produced abnormal mRNA including 26bp of intron 8 instead of the deleted 58bp at the 5 end of exon 9, because of a 74-bp deletion from intron 8 to exon 9.  相似文献   
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