Zebrafish models for cancer Liu, Shu; Leach, Steven D
Annual review of pathology,
01/2011, Letnik:
6
Journal Article
Recenzirano
First established as a valuable vertebrate model system for studying development, zebrafish have emerged as an attractive animal system for modeling human cancers. Major technical advances have been ...essential for the generation of zebrafish cancer models relevant to human diseases. These models develop tumors in various organ sites that bear striking resemblance to human malignances, both histologically and genetically. Thus, the focus of cancer research in zebrafish has transcended the need to validate zebrafish as a viable model organism to study cancer biology. With the significant advantages of in vivo imaging, the power of forward genetics, well-established high efficiency for transgenesis, and ease of transplantation, further exploration of the zebrafish cancer models not only will generate unique insights into underlying mechanisms of cancer but will also provide platforms useful for drug discovery.
Olfactory sense remains elusive regarding the primary reception mechanism. Some studies suggest that olfaction is a spectral sense, the olfactory event is triggered by electron transfer (ET) across ...the odorants at the active sites of odorant receptors (ORs). Herein we present a Donor-Bridge-Acceptor model, proposing that the ET process can be viewed as an electron hopping from the donor molecule to the odorant molecule (Bridge), then hopping off to the acceptor molecule, making the electronic state of the odorant molecule change along with vibrations (vibronic transition). The odorant specific parameter, Huang-Rhys factor can be derived from ab initio calculations, which make the simulation of ET spectra achievable. In this study, we revealed that the emission spectra (after Gaussian convolution) can be acted as odor characteristic spectra. Using the emission spectrum of ET, we were able to reasonably interpret the similar bitter-almond odors among hydrogen cyanide, benzaldehyde and nitrobenzene. In terms of isotope effects, we succeeded in explaining why subjects can easily distinguish cyclopentadecanone from its fully deuterated analogue cyclopentadecanone-d28 but not distinguishing acetophenone from acetophenone-d8.
In order to study the molecular mechanisms of green tea polyphenols (GTPs) in treatment or prevention of breast cancer, the cytotoxic effects of GTPs on five human cell lines (MCF-7, A549, Hela, PC3, ...and HepG2 cells) were determined and the antitumor mechanisms of GTPs in MCF-7 cells were analyzed. The results showed that GTPs exhibited a broad spectrum of inhibition against the detected cancer cell lines, particularly the MCF-7 cells. Studies on the mechanisms revealed that the main modes of cell death induced by GTPs were cell cycle arrest and mitochondrialmediated apoptosis. Flow cytometric analysis showed that GTPs mediated cell cycle arrest at both G1/M and G2/M transitions. GTP dose dependently led to apoptosis of MCF-7 cells via the mitochondrial pathways, as evidenced by induction of chromatin condensation, reduction of mitochondrial membrane potential (ΔΨm), improvement in the generation of reactive oxygen species (ROS), induction of DNA fragmentation, and activations of caspase-3 and caspase-9 in the present paper.
We examined the intrinsic relation between two interdependent and interacted processes, namely, chemiosmotic energy coupling partition and redox signaling involved in mitochondrial respiration. The ...following aspects of research were conducted and discussed: generation sites and release sidedness of superoxide from the Q cycle of complex III of the mitochondrial respiratory chain; the different physiological roles of PMF components, ΔΨ and ΔpH (ΔpHS), of the Q cycle in mitochondrial superoxide generating and partitioning; and direct feedback effects of Q cycle–derived O2•− on PMF energy partition through its interaction with protons in ΔpHS to form HO2•, leading to decreasing ΔpHS and ATP synthesis due to its increasing effects of basic proton leak of mitochondria. The present experimental data give new evidence for our hypothesis of reactive oxygen species cycle cooperation with Q cycle and H+ cycle in respiratory chain in keeping PMF energy partition and its equilibrium with redox signaling regulation of mitochondrial respiration.
Industrialization has caused a significant global issue with cadmium (Cd) pollution. In this study, Biochar (Bc), generated through initial pyrolysis of rice straw, underwent thorough mixing with ...magnetized bentonite clay, followed by activation with KOH and subsequent pyrolysis. Consequently, a magnetized bentonite modified rice straw biochar (Fe3O4@B-Bc) was successfully synthesized for effective treatment and remediation of this problem. Fe3O4@B-Bc not only overcomes the challenges associated with the difficult separation of individual bentonite or biochar from water, but also exhibited a maximum adsorption capacity of Cd(II) up to 241.52 mg g−1. The characterization of Fe3O4@B-Bc revealed that its surface was rich in C, O and Fe functional groups, which enable efficient adsorption. The quantitative calculation of the contribution to the adsorption mechanism indicates that cation exchange and physical adsorption accounted for 65.87% of the total adsorption capacity. In conclusion, Fe3O4@B-Bc can be considered a low-cost and recyclable green adsorbent, with broad potential for treating cadmium-polluted water.
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•Magnetized bentonite/biochar composites were prepared for Cd(II) removal.•The maximum adsorption capacity of Fe3O4@B-Bc is 241.52 mg g−1.•Cation exchange and physical adsorption contributed 65.87% of the total capacity.
Seed vigor is a complex property that determines the seed's potential for rapid uniform emergence and subsequent growth. However, the mechanism for change in seed vigor is poorly understood. The ...seeds of poplar (Populus × Canadensis Moench), which are short-lived, were stored at 30 °C and 75 ± 5% relative humidity for different periods of time (0-90 days) to obtain different vigor seeds (from 95 to 0% germination). With decreasing seed vigor, the temperature range of seed germination became narrower; the respiration rate of the seeds decreased markedly, while the relative electrolyte leakage increased markedly, both levelling off after 45 days. A total of 81 protein spots showed a significant change in abundance (≥ 1.5-fold, P < 0.05) when comparing the proteomes among seeds with different vigor. Of the identified 65 proteins, most belonged to the groups involved in metabolism (23%), protein synthesis and destination (22%), energy (18%), cell defense and rescue (17%), and storage protein (15%). These proteins accounted for 95% of all the identified proteins. During seed aging, 53 and 6 identified proteins consistently increased and decreased in abundance, respectively, and they were associated with metabolism (22%), protein synthesis and destination (22%), energy (19%), cell defense and rescue (19%), storage proteins (15%), and cell growth and structure (3%). These data show that the decrease in seed vigor (aging) is an energy-dependent process, which requires protein synthesis and degradation as well as cellular defense and rescue.
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•A novel microbial fuel cell (MFC) was developed to improve the pollutant removal.•The unique design of the air cathode increased water absorption and the retention.•Gas flowrate and ...bed volume can be adjusted to find a best load for MFC operation.•Increasing the inlet loading inhibited microbial growth and reduced output voltage.
This work develops a novel hollow air-cathode biotrickling filter (BTF) microbial fuel cell (MFC) to treat ethyl acetate (EA) in a waste air stream. A BTF was combined with an MFC to form a BTF-MFC, which was effective in controlling volatile organic compounds (VOCs) emission and generating power. The BTF-MFC has an air cathode in its center, increasing the absorption and retention of water by the proton exchange membrane (PEM) to improve its ability to receive protons and oxygen and thereby accelerating the reduction reaction in the cathode. The EA removal efficiency was 17% higher under the close-circuit condition than the open-circuit condition, revealing the potential of the BTF-MFC for VOC control. Under optimum condition, a removal efficiency, maximum power density (PD), and maximum current density (CD) of 92.1%, 146.8 mW/m2, and 500.6 mA/m2, respectively, were obtained. The PD and CD were approximately five times, and the closed-circuit voltage (CCV) was 1.3 times, those obtained in the literature. Furthermore, MFC exhibited a linear increase in elimination capacity (EC) from 35.5 g/m3/h to 66.3 g/m3/h as the EA concentration under organic loading was increased from 36 to 72 g/m3/h under the critical load of about 70 g/m3/h and the maximum EC of 81 g/m3/h. This work establishes the feasibility of using both the improved PEM and a hollow air cathode to increase substantially the generation of electricity by an MFC and to remove EA with a relatively high efficiency.
Abstract The aims of this study were: (1) to examine the prevalence of symptoms of problematic cellular phone use (CPU); (2) to examine the associations between the symptoms of problematic CPU, ...functional impairment caused by CPU and the characteristics of CPU; (3) to establish the optimal cut-off point of the number of symptoms for functional impairment caused by CPU; and (4) to examine the association between problematic CPU and depression in adolescents. A total of 10,191 adolescent students in Southern Taiwan were recruited into this study. Participants' self-reported symptoms of problematic CPU and functional impairments caused by CPU were collected. The associations of symptoms of problematic CPU with functional impairments and with the characteristics of CPU were examined. The cut-off point of the number of symptoms for functional impairment was also determined. The association between problematic CPU and depression was examined by logistic regression analysis. The results indicated that the symptoms of problematic CPU were prevalent in adolescents. The adolescents who had any one of the symptoms of problematic CPU were more likely to report at least one dimension of functional impairment caused by CPU, called more on cellular phones, sent more text messages, or spent more time and higher fees on CPU. Having four or more symptoms of problematic CPU had the highest potential to differentiate between the adolescents with and without functional impairment caused by CPU. Adolescents who had significant depression were more likely to have four or more symptoms of problematic CPU. The results of this study may provide a basis for detecting symptoms of problematic CPU in adolescents.
Endosymbionts are important components of arthropod biology. The white- fly Bemisia tabaci （Gennadius） （Hemiptera： Aleyrodidae） is a cryptic species complex composed of 〉28 putative species. In ...addition to the primary endosymbiont Portiera aley- rodidarum, six secondary endosymbionts （S-endosymbionts）, Hamiltonella, Rickettsia, Wolbachia, Cardinium, Arsenophonus and Fritschea, have been identified in B. tabaci thus far. Here, we tested five of the six S-endosymbiont lineages （excluding Fritschea） from 340 whitely individuals representing six putative species from China. Harniltonella was detected only in the two exotic invaders, Middle East-Asia Minor 1 （MEAM 1） and Mediter- ranean （MED）. Rickettsia was absent in Asia II 1 and MED, scarce in Asia II 3 （13%）, but abundant in Asia II 7 （63.2%）, China 1 （84.7%） and MEAM1 （100%）. Wolbachia, Cardinium and Arsenophonus were absent in the invasive MEAM1 and MED but mostly abundant in the native putative species. Furthermore, phylogenetic analyses revealed that some S-endosymbionts have several clades and different B. tabaci putative species can harbor different clades of a given S-endosymbiont, demonstrating further the complexity of S-endosymbionts in B. tabaci. All together, our results demonstrate the variation and diversity of S-endosymbionts in different putative species ofB. tabaci, especially between invasive and native whiteflies.
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