3,671 research outputs found

    Projected poleward migration of the Southern Ocean CO2 sink region under high emissions

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    The Southern Ocean is a major region of ocean carbon uptake, but its future changes remain uncertain under climate change. Here we show the projected shift in the Southern Ocean CO2 sink using a suite of Earth System Models, revealing changes in the mechanism, position and seasonality of the carbon uptake. The region of dominant CO2 uptake shifts from the Subtropical to the Antarctic region under the high-emission scenario. The warming-driven sea-ice melt, increased ocean stratification, mixed layer shoaling, and a weaker vertical carbon gradient is projected to together reduce the winter de-gassing in the future, which will trigger the switch from mixing-driven outgassing to solubility-driven uptake in the Antarctic region during the winter season. The future Southern Ocean carbon sink will be poleward-shifted, operating in a hybrid mode between biologically-driven summertime and solubility-driven wintertime uptake with further amplification of biologically-driven uptake due to the increasing Revelle Factor

    Isoflurane Preconditioning at Clinically Relevant Doses Induce Protective Effects of Heme Oxygenase-1 on Hepatic Ischemia Reperfusion in Rats

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    <p>Abstract</p> <p>Background</p> <p>Activation of heme oxygenase-1 (HO-1) has been proved to reduce damages to the liver in ischemia reperfusion injury. The objective of present study was to determine whether clinic relevant doses of isoflurane treatment could be sufficient to activate HO-1 inducing, which confers protective effect against hepatic ischemia-reperfusion injury.</p> <p>Methods</p> <p>The hepatic artery and portal vein to the left and the median liver lobes of forty male Sprague-Dawley rats were occluded for 60 minutes. Reperfusion was allowed for 4 hours before the animal subjects were sacrificed. Six groups (n = 12) were included in the study. A negative control group received sham operation and positive control group a standard ischemia-reperfusion regimen. The third group was pretreated with isoflurane prior to the ischemia-reperfusion. The fourth group received an HO-1 inhibitor zinc protoporphyrin (Znpp) prior to the isoflurane pretreatment and the ischemia-reperfusion. The fifth group received Znpp alone before ischemia-reperfusion procedure, and the sixth group was administrated with a HO-1 inducer hemin prior to IR. HO-1 in the liver was measured using an enzymatic activity assay, a Western blot analysis, as well as immunohistochemical method. Extent of liver damage was estimated by determination of the serum transaminases, liver lipid peroxidation and hepatic histology. Infiltration of the liver by neutrophils was measured using a myeloperoxidase activity assay. TNFΞ± mRNA in the liver was measured using RT-PCR.</p> <p>Results</p> <p>Isoflurane pretreatment significantly attenuated the hepatic injuries and inflammatory responses caused by the ischemia reperfusion. Selectively inhibiting HO-1 with ZnPP completed blocked the protective effects of isoflurane. Inducing HO-1 with hemin alone produced protective effects similar in magnitude to that of isoflurane.</p> <p>Conclusions</p> <p>Clinic relevant doses of isoflurane attenuate ischemia reperfusion injury in rats by increasing the HO-1 expression and activity.</p

    Backbone resonance assignments of the monomeric DUF59 domain of human Fam96a

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    Proteins containing a domain of unknown function 59 (DUF59) appear to have a variety of physiological functions, ranging from iron-sulfur cluster assembly to DNA repair. DUF59 proteins have been found in bacteria, archaea and eukaryotes, however Fam96a and Fam96b are the only mammalian proteins predicted to contain a DUF59 domain. Fam96a is an 18 kDa protein comprised primarily of a DUF59 domain (residues 31-157) and an N-terminal signal peptide (residues 1-27). Interestingly, the DUF59 domain of Fam96a exists as monomeric and dimeric forms in solution, and X-ray crystallography studies of both forms unexpectedly revealed two different domain-swapped dimer structures. Here we report the backbone resonance assignments and secondary structure of the monomeric form of the 127 residue DUF59 domain of human Fam96a. This study provides the basis for further understanding the structural variability exhibited by Fam96a and the mechanism for domain swapping

    Simultaneous determination of natural and synthetic steroid estrogens and their conjugates in aqueous matrices by liquid chromatography / mass spectrometry

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    An analytical method for the simultaneous determination of nine free and conjugated steroid estrogens was developed with application to environmental aqueous matrices. Solid phase extraction (SPE) was employed for isolation and concentration, with detection by liquid chromatography/mass spectrometry (LC/MS) using electrospray ionisation (ESI) in the negative mode. Method recoveries for various aqueous matrices (wastewater, lake and drinking water) were determined, recoveries proving to be sample dependent. When spiked at 50 ng/l concentrations in sewage influent, recoveries ranged from 62-89 % with relative standard deviations (RSD) < 8.1 %. In comparison, drinking water spiked at the same concentrations had recoveries between 82-100 % with an RSD < 5%. Ion suppression is a known phenomenon when using ESI; hence its impact on method recovery was elucidated for raw sewage. Both ion suppression from matrix interferences and the extraction procedure has bearing on the overall method recovery. Analysis of municipal raw sewage identified several of the analytes of interest at ng/l concentrations, estriol (E3) being the most abundant. Only one conjugate, estrone 3-sulphate (E1-3S) was observe

    Assessment of low-dose cisplatin as a model of nausea and emesis in beagle dogs, potential for repeated administration

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    Cisplatin is a highly emetogenic cancer chemotherapy agent, which is often used to induce nausea and emesis in animal models. The cytotoxic properties of cisplatin also cause adverse events that negatively impact on animal welfare preventing repeated administration of cisplatin. In this study, we assessed whether a low (subclinical) dose of cisplatin could be utilized as a model of nausea and emesis in the dog while decreasing the severity of adverse events to allow repeated administration. The emetic, nausea-like behavior and potential biomarker response to both the clinical dose (70 mg/m2) and low dose (15 mg/m2) of cisplatin was assessed. Plasma creatinine concentrations and granulocyte counts were used to assess adverse effects on the kidneys and bone marrow, respectively. Nausea-like behavior and emesis was induced by both doses of cisplatin, but the latency to onset was greater in the low-dose group. No significant change in plasma creatinine was detected for either dose groups. Granulocytes were significantly reduced compared with baseline (P = 0.000) following the clinical, but not the low-dose cisplatin group. Tolerability of repeated administration was assessed with 4 administrations of an 18 mg/m2 dose cisplatin. Plasma creatinine did not change significantly. Cumulative effects on the granulocytes occurred, they were significantly decreased (P = 0.03) from baseline at 3 weeks following cisplatin for the 4th administration only. Our results suggest that subclinical doses (15 and 18 mg/m2) of cisplatin induce nausea-like behavior and emesis but have reduced adverse effects compared with the clinical dose allowing for repeated administration in crossover studies

    Human surfactant protein D alters oxidative stress and HMGA1 expression to induce p53 apoptotic pathway in eosinophil leukemic cell line

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    This article is made available through the Brunel Open Access Publishing Fund. Copyright: Β© 2013 Mahajan et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Surfactant protein D (SP-D), an innate immune molecule, has an indispensable role in host defense and regulation of inflammation. Immune related functions regulated by SP-D include agglutination of pathogens, phagocytosis, oxidative burst, antigen presentation, T lymphocyte proliferation, cytokine secretion, induction of apoptosis and clearance of apoptotic cells. The present study unravels a novel ability of SP-D to reduce the viability of leukemic cells (eosinophilic leukemic cell line, AML14.3D10; acute myeloid leukemia cell line, THP-1; acute lymphoid leukemia cell lines, Jurkat, Raji; and human breast epithelial cell line, MCF-7), and explains the underlying mechanisms. SP-D and a recombinant fragment of human SP-D (rhSP-D) induced G2/M phase cell cycle arrest, and dose and timedependent apoptosis in the AML14.3D10 eosinophilic leukemia cell line. Levels of various apoptotic markers viz. activated p53, cleaved caspase-9 and PARP, along with G2/M checkpoints (p21 and Tyr15 phosphorylation of cdc2) showed significant increase in these cells. We further attempted to elucidate the underlying mechanisms of rhSP-D induced apoptosis using proteomic analysis. This approach identified large scale molecular changes initiated by SPD in a human cell for the first time. Among others, the proteomics analysis highlighted a decreased expression of survival related proteins such as HMGA1, overexpression of proteins to protect the cells from oxidative burst, while a drastic decrease in mitochondrial antioxidant defense system. rhSP-D mediated enhanced oxidative burst in AML14.3D10 cells was confirmed, while antioxidant, N-acetyl-L-cysteine, abrogated the rhSP-D induced apoptosis. The rhSP-D mediated reduced viability was specific to the cancer cell lines and viability of human PBMCs from healthy controls was not affected. The study suggests involvement of SP-D in host’s immunosurveillance and therapeutic potential of rhSP-D in the eosinophilic leukemia and cancers of other origins.Department of Biotechnology, Indi

    A Pair of Dopamine Neurons Target the D1-Like Dopamine Receptor DopR in the Central Complex to Promote Ethanol-Stimulated Locomotion in Drosophila

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    Dopamine is a mediator of the stimulant properties of drugs of abuse, including ethanol, in mammals and in the fruit fly Drosophila. The neural substrates for the stimulant actions of ethanol in flies are not known. We show that a subset of dopamine neurons and their targets, through the action of the D1-like dopamine receptor DopR, promote locomotor activation in response to acute ethanol exposure. A bilateral pair of dopaminergic neurons in the fly brain mediates the enhanced locomotor activity induced by ethanol exposure, and promotes locomotion when directly activated. These neurons project to the central complex ellipsoid body, a structure implicated in regulating motor behaviors. Ellipsoid body neurons are required for ethanol-induced locomotor activity and they express DopR. Elimination of DopR blunts the locomotor activating effects of ethanol, and this behavior can be restored by selective expression of DopR in the ellipsoid body. These data tie the activity of defined dopamine neurons to D1-like DopR-expressing neurons to form a neural circuit that governs acute responding to ethanol

    Development of a method to assess alignment of the foot and lower leg

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    ABSTRACT Ito S, Tomita Y, Tanabe S. Development of a method to assess alignment of the foot and lower leg. Jpn J Compr Rehabil Sci 2013; 4: 80-83. Purpose: Three-dimensional analyses of the foot and lower leg have been restricted to large-scale research facilities, since such analyses require a large experimental area and expensive measurement systems. Therefore, we developed a new threedimensional method of analyzing still pictures using commercially available digital cameras, and applied it to clinical use. Methods: We used three digital cameras. One was set 6 m behind the subject, while the other two were placed at 45 degrees to the right and left sides of the first camera, each the same distance from the subject. We used a plaster model of a lower leg and foot, on which several markers were mounted. The positions of the three-dimensional coordinates of the markers were computed by triangulation from the pictures taken with the three cameras, and the accuracy was verified. Results: The average reading error was 0.6 mm, and the average and maximum repetition errors were 1.3 mm and 1.6 mm, respectively. Comparison with direct evaluation was found to be 2.3% at maximum. These results showed that the method is highly reliable. Conclusion: Although a three-dimensional analysis using this method has the limitation of still picture analysis, it may be useful in many clinical applications because it requires only inexpensive apparatus and a small experimental area
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