464 research outputs found
Mercury, Cadmium and Lead Biogeochemistry in the Soil–Plant–Insect System in Huludao City
Mercury, cadmium, and lead concentrations of ashed plants and insects samples were investigated and compared with those of soil to reveal their biogeochemical processes along food chains in Huludao City, Liaoning Province, China. Concentration factors of each fragments of the soil–plant–the herbivorous insect–the carnivorous insect food chain were 0.18, 6.57, and 7.88 for mercury; 6.82, 2.01, and 0.48 for cadmium; 1.47, 2.24, and 0.57 for lead, respectively. On the whole, mercury was the most largely biomagnified, but cadmium and lead were not greatly accumulated in the carnivorous insects as expected when the food chain extended to the secondary consumers. Results indicated that concentration factors depended on metals and insects species of food chains
Sex-related difference in food-anticipatory activity of mice
The expression of food-anticipatory activity (FAA) is induced by restricted feeding (RF), and its entrainment requires food-entrainable oscillators, the neuroanatomical basis of which is currently unclear. Although RF impacts various hormones, sex-related differences in FAA are unclear. 'Here, we report significantly more food-anticipatory wheel-running activity in male than in female mice during RF. In parallel with the sex-related difference in FAA, male and female mice display different food intake and body weight in response to RF. Since gonadal hormones could be involved in the sex-specific difference in FAA, we compared sham and gonadectomized male and female wild-type mice. In gonadectomized mice, the sex difference in FAA was abolished, indicating a role for gonadal hormones in FAA. Further, plasma concentrations of the hormone ghrelin were higher in female than in male mice during ad libitum (AL) feeding, and RF induced a temporal advance in its peak in both sexes. RF also shifted the expression peak of the circadian gene mPer1 in the hippocampus and liver, although no sex difference was found in either the level or the cyclic phase of its expression. Per1(Brdm1) mutant mice were still sexually dimorphic for FAA, but diminished FAA was noted in both male and female Per2(Brdm1) mutant mice. In summary, our results imply that gonadal hormones contribute to the sex difference in FAA, possibly through modulating ghrelin activity. (C) 2015 Published by Elsevier Inc
Tetraaquabis(2-oxo-1,2-dihydroquinoline-4-carboxylato-κO 4)nickel(II)
In the title compound, [Ni(C10H6NO3)2(H2O)4], the central NiII atom is located on an inversion center and coordinated in a slightly distorted octahedral geometry by two O atoms from two 2-oxo-1,2-dihydroquinoline-4-carboxylate ligands and four water molecules, all of which act as monodentate ligands. The crystal structure features an extensive network of intermolecular hydrogen-bonding interactions (O—H⋯O and N—H⋯O) and offset face-to-face π–π stacking interactions [centroid–centroid distances = 3.525 (3) and 3.281 (5) Å]
The ability of pandemic influenza virus hemagglutinins to induce lower respiratory pathology is associated with decreased surfactant protein D binding
AbstractPandemic influenza viral infections have been associated with viral pneumonia. Chimeric influenza viruses with the hemagglutinin segment of the 1918, 1957, 1968, or 2009 pandemic influenza viruses in the context of a seasonal H1N1 influenza genome were constructed to analyze the role of hemagglutinin (HA) in pathogenesis and cell tropism in a mouse model. We also explored whether there was an association between the ability of lung surfactant protein D (SP-D) to bind to the HA and the ability of the corresponding chimeric virus to infect bronchiolar and alveolar epithelial cells of the lower respiratory tract. Viruses expressing the hemagglutinin of pandemic viruses were associated with significant pathology in the lower respiratory tract, including acute inflammation, and showed low binding activity for SP-D. In contrast, the virus expressing the HA of a seasonal influenza strain induced only mild disease with little lung pathology in infected mice and exhibited strong in vitro binding to SP-D
Anti-tumor activity of N-trimethyl chitosan-encapsulated camptothecin in a mouse melanoma model
<p>Abstract</p> <p>Background</p> <p>Camptothecin (CPT) has recently attracted increasing attention as a promising anticancer agent for a variety of tumors. But the clinical application is largely hampered by its extreme water insolubility and unpredictable side effect. It is essential to establish an efficient and safe protocol for the administration of CPT versus melanoma.</p> <p>Methods</p> <p>Camptothecin was encapsulated with N-trimethyl chitosan (CPT-TMC) through microprecipitation and sonication. Its inhibition effect on B16-F10 cell proliferation and induction of apoptosis was evaluated by MTT assay and flow cytometric analysis in vitro. The anti-tumor activity of CPT-TMC was evaluated in C57BL/6 mice bearing B16-F10 melanoma. Tumor volume, tumor weight and survival time were recorded. Assessment of apoptotic cells within tumor tissue was performed by TUNEL assay. Antiangiogenesis and antiproliferation effects of CPT-TMC in vivo were conducted via CD31 and PCNA immunohistochemistry, respectively.</p> <p>Results</p> <p>CPT-TMC efficiently inhibited B16-F10 cells proliferation and increased apoptosis in vitro. Experiment group showed significant inhibition compared with free CPT-treated group (81.3% vs. 56.9%) in the growth of B16-F10 melanoma xenografts and prolonged the survival time of the treated mice (P < 0.05). Decreased cell proliferation, increased tumor apoptosis as well as a reduction in angiogenesis were observed.</p> <p>Conclusions</p> <p>Our data suggest that N-trimethyl chitosan-encapsulated camptothecin is superior to free CPT by overcoming its insolubility and finally raises the potential of its application in melanoma therapy.</p
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