182 research outputs found
Hepatocyte transplantation-induced liver inflammation is driven by cytokines-chemokines associated with neutrophils and Kupffer cells
No full textBACKGROUND & AIMS:
Hepatocyte transplantation-induced liver inflammation impairs cell engraftment. We defined whether proinflammatory cytokines and chemokines played roles in regulation of hepatocyte engraftment in the liver.
METHODS:
We performed studies over up to 3 weeks in rat hepatocyte transplantation systems. Expression of 84 cytokine-chemokine genes was studied by quantitative real-time polymerase chain reactions. Expression of selected up-regulated genes was verified by immunohistochemistry. Hepatic recruitment of neutrophils was demonstrated by myeloperoxidase activity assays, and Kupffer cell activation was established by carbon phagocytosis assays. The role of neutrophils and Kupffer cells in regulating expression of cytokine-chemokine genes as well as cell engraftment was determined by cell depletion studies.
RESULTS:
Within 6 hours after syngeneic cell transplantation, expression of 25 cytokine-chemokine genes increased by 2- to 123-fold, P < .05. These genes were largely associated with activated neutrophils and macrophages, including chemokine ligands, CXCL1, CXCL2, CCL3, CCL4; chemokine receptors, CXCR1 or CXCR2, CCR1, CCR2; and regulatory cytokines tumor necrosis factor alpha and interleukin-6. Inflammatory cells in the liver immunostained for CCR1, CCR2, CXCR1, and CXCR2, which indicated that up-regulated messenger RNA was appropriately translated. When neutrophils and Kupffer cells were depleted with neutrophil antiserum and gadolinium chloride, respectively, before transplanting cells, cell transplantation-induced cytokine-chemokine responses were attenuated. Virtually all abnormalities subsided in animals treated with neutrophil antiserum plus gadolinium chloride. Moreover, depletion of neutrophils or Kupffer cells improved engraftment of transplanted cells.
CONCLUSIONS:
Cell transplantation-induced liver inflammation involves proinflammatory cytokine-chemokine systems capable of modulation by neutrophils and Kupffer cells. This offers new directions for optimizing cell therapy strategies
Fenton oxidation of gaseous isoprene on aqueous surfaces
No full textWe report that gaseous isoprene ISO(g) is oxidized into soluble species on the surface of aqueous acidic FeCl2 solutions simultaneously exposed to H2O2(g). In our experiments, ISO(g) and/or H2O2(g) streams intersect aqueous pH ∼ 2 FeCl2 microjets for ∼10 μs. The products formed in these reactive encounters are identified in situ via online electrospray ionization mass spectrometry. We found that the (ISO)nH+ oligomers generated from ISO(g) on the surface of pH < 4 water are oxidized into myriad products whose combined yields exceed 5%. MS2 analysis reveals that the positive ions derived from the protonation of neutral products split H2O and O neutrals, whereas the less abundant negative carboxylate ion products undergo CO, H2O, and CO2 losses. Significantly, all products are fully quenched by ·OH scavenger tert-butyl alcohol. These results are consistent with an oxidation process initiated by the addition of ·OH from (Fe2+(aq) + H2O2(g)) to (ISO)nH+, followed by fast reactions involving dissolved H2O2, HO2·, and O2 that lead to polyols; carbonyls; and, to a lesser extent, carboxylic acids. Our experiments demonstrate that gas-phase olefins are oxidized upon colliding on the surface of Fe-containing acidic aqueous media under typical tropospheric conditions
Reply to the ‘Comment on “The chemical reactions in electrosprays of water do not always correspond to those at the pristine air–water interface”’ by A. J. Colussi and S. Enami, Chem. Sci., 2019, 10, DOI: 10.1039/c9sc00991d
No full textThe air–water interface serves as a crucial site for numerous chemical and physical processes in environmental science and engineering, such as cloud chemistry, ocean-atmosphere exchange, and wastewater treatment. The development of “surface-selective” techniques for probing interfacial properties of water therefore lies at the forefront of research in chemical science. Recently, researchers have adapted electrospray ionization mass spectrometry (ESIMS) to generate microdroplets of water to investigate interfacial phenomena at thermodynamic equilibrium. In contrast, using a broad set of experimental and theoretical techniques, we found that electrosprays of water could facilitate partially hydrated (gas-phase) ions (e.g., H3O+·(H2O)2) to drive/catalyze chemical reactions that are otherwise not possible to accomplish by purely interfacial effects (e.g., enhanced water–hydrophobe surface area) (Chem. Sci., 2019, 10, 2566). Thus, techniques exploiting electrosprays of water cannot be relied upon as generalized surface-selective platforms. Here, we respond to the comments raised by Colussi & Enami (Chem. Sci., 2019, 10, DOI: 10.1039/c9sc00991d) on our paper.The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (#OSR-2016-CRG5-2992). The co-authors thank Dr Mahmoud Ibrahim (KAUST) for his assistance with the 1H-NMR experiments, Professor Richard Saykally and Professor Evan Williams (University of California Berkeley) for fruitful discussions, and Dr Virginia Unkefer (KAUST) for her assistance in editing the manuscript
Growth of normal and neoplastic mouse mammary epithelial cells in primary culture: stimulation by conditioned medium from mouse mammary fibroblasts.
No full textInhibitory effect of human chorionic gonadotropin (hCG) on HIV-1 transmission from lymphocytes to trophoblasts
No full textAbstractIt has been demonstrated that human chorionic gonadotropin (hCG) inhibits HIV production in vitro, suggesting that this soluble placental glycoprotein can control viral replication and spread in vivo, hCG - the major product of fetal trophoblasts - was tested on an in vitro model consisting of choriocarcinoma-derived ENAMI trophoblasts exposed to HIV-infected MOLT-4 lymphocytes. The results show a U-shaped antiviral dose- effect and suggest that hCG may contribute to protection against intrauterine transmission of HIV-1
Green fluorescent protein-doped sol-gel silica planar waveguide to detect organophosphorus compound
No full textOn the Origins of the Monument Dedicated to Mong Gong
No full textThis article examines the process through which a monument was built dedicated to Mong Gong 孟珙, who was active during the middle and late Southern Song 南宋 period in defending China against the Mongols as a spokesman and military chief of staff.The author investigates the reason why, according to the testimony of Liu Kezhuang 劉克莊, no one in the academy of scholarship bothered to implement the imperial edict ordering an inscription be etched into the monument and why it took over three years for the edict to be issued, by basing on the political situation at the time.In answering the first question, the author tums to the relationship between Mong and Chancellor Shi Songzhi 史嵩之, who was dismissed from that post due to public outcry, an event which also influenced the commemoration of Mong, one of his supportcrs. The author also points to the return to power of Mong’s political enemies, Zheng Qingzhi 鄭清之 and Zhao Kui 趙葵, after the fall of Shi.Regarding the second question, the author states that the edict was issued after the collapse of the Zheng-Zhao regime, and as a gesture by Emperor Li to enlist the help of the gentry of Hubei in defending China against the Mongols. As to the focus on the role played by Liu Kezhuang, the author cites such facts as Liu’s high academic esteem, his relationship to the brother-in-law of Gong’s son Zhijin 之縉 and his relationship to Zheng Qingzhi, concluding that Liu was the most qualified person to write a tribute to the Mong’s achievements.The facts about the process of Shi’s fall from power and Zheng’s ascendency were covered up by Liu’s political views and thus a gap was created in the sources. This article attempts to fill that gap by explaining why it existed and describing a political process that occurred at the time, but does not appear in the extant source materials related to the period.journal articl
Public Mining Governance for Sustainable Artisanal Gold Mining: Preventing Mercury Pollution in South America
No full textArtisanal and small-scale gold mining (ASGM) constitutes an essential livelihood strategy for marginalized communities, yet it is also associated with severe environmental and social challenges. Persistent inequality and poverty underpin miners’ dependence on informal practices, where access to safer technologies is limited. Mercury use remains critical in ASGM, often mismanaged in processing, applied in amalgamation, and released into air, water, and soils. An estimated 1000–2000 tonnes are emitted annually despite Minamata Convention commitments. This paper examines how mining governance can foster sustainable transitions in ASGM, focusing on the Chilean National Mining Company (ENAMI) as a case study. ENAMI’s model—combining regulatory oversight, institutional support, and inclusive decision-making—shows how public governance can reduce mercury reliance, mitigate environmental degradation, and enhance social inclusion. Findings highlight the importance of regulation, community participation, capacity-building, and addressing structural inequalities as integral components of sustainability. The study argues that sustainable ASGM requires not only technical innovation but also culturally sensitive institutional reforms capable of overcoming resistance and promoting long-term behavioral change. By situating ASGM within the broader framework of sustainable rural development, this research provides insights for policymakers, practitioners, and scholars seeking to reconcile economic inclusion with environmental stewardship in vulnerable contexts
A Cost-Benefit Analysis of Wisconsin's Screening, Brief Intervention, and Referral to Treatment Program: Adding the Employer's Perspective
No full textAbstract Objective-A previous cost-benefit analysis found Screening, Brief Intervention, and Referral to Treatment (SBIRT) to be cost-beneficial from a societal perspective. This paper develops a costbenefit model that includes the employer's perspective by considering the costs of absenteeism and impaired presenteeism due to problem drinking. Methods-We developed a Monte Carlo simulation model to estimate the costs and benefits of SBIRT implementation to an employer. We first presented the likely costs of problem drinking to a theoretical Wisconsin firm that does not currently provide SBIRT services. We then constructed a cost-benefit model in which the firm funds SBIRT for its employees. The net present value of SBIRT adoption was computed by comparing costs due to problem drinking both with and without the program. Results-When absenteeism and impaired presenteeism costs were considered from the employer's perspective, the net present value of SBIRT adoption was $771 per employee. Conclusions-We concluded that implementing SBIRT is cost-beneficial from the employer's perspective and recommend that Wisconsin employers consider covering SBIRT services for their employees
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