Effects of alveolar surfactant aggregates on T-lymphocyte proliferation

AbstractThe effects of alveolar large aggregate (LA) and small aggregate (SA) surfactant subfractions isolated from healthy adult rats on mitogen-stimulated proliferative responses of human peripheral blood mononuclear cells (PBMC) was examined. Various concentrations of total surfactant suppressed proliferation of stimulated lymphocytes by up to 95% of mitogen-stimulated cells alone. LA subfractions of total surfactant had no effect on proliferation, whereas SA significantly enhanced the lymphocyte proliferation at lower concentrations (7.8 μg/ml) compared to mitogen-stimulated cells alone. Higher concentrations of SA (62.5 μg/ml) inhibited lymphocyte proliferation. This concentration-dependent effect of SA on proliferation of PBMC was also present when cells were stimulated with various lectins including anti-CD3, concanavalin A and phytohemagglutinin. Analysis of the supernatant of mitogen-stimulated cell cultures treated with inhibitory concentrations of SA showed decreased amounts of interleukin (IL)-2, compared to cells alone, which could be reversed by adding exogenous IL-2 to the cell cultures with the SA. These results suggest that alveolar surfactant subfractions have distinct functions within the alveoli, both biophysically and with respect to their effects on the host’s immunomodulatory responses

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

This article is made available through the Brunel Open Access Publishing Fund. Copyright: © 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

Food systems sustainability : an examination of different viewpoints on food system change

Global food insecurity levels remain stubbornly high. One of the surest ways to grasp the scale and consequence of global inequality is through a food systems lens. In a predominantly urban world, urban food systems present a useful lens to engage a wide variety of urban (and global) challenges—so called ‘wicked problems.’ This paper describes a collaborative research project between four urban food system research units, two European and two African. The project purpose was to seek out solutions to what lay between, across and within the different approaches applied in the understanding of each city’s food system challenges. Contextual differences and immediate (perceived) needs resulted in very different views on the nature of the challenge and the solutions required. Value positions of individuals and their disciplinary “enclaves” presented further boundaries. The paper argues that finding consensus provides false solutions. Rather the identification of novel approaches to such wicked problems is contingent of these differences being brought to the fore, being part of the conversation, as devices through which common positions can be discovered, where spaces are created for the realisation of new perspectives, but also, where difference is celebrated as opposed to censored

Development of a method for measuring volatile organic compounds in the blood of fire victims using 'purge and trap' gas chromatography

International audienceSmoke inhalation remains a major cause of morbidity and mortality. Clinical and laboratory studies have revealed numerous potentially toxic components of combustion in the fire environment and in human tissue samples. However, the frequency and importance of the various compounds remains poorly understood. A new simple method to quantitatively measure volatile organic compounds (VOCs) in small samples of the blood of fire victims has been developed utilising the 'purge and trap' method of gas phase chromatography with flame ionisation detection using two columns. Thirty-three compounds were identified on the basis of the retention index method with acceptable repeatability and reproducibility. This method should permit a more complete investigation of the toxic volatile organic compounds found in fire victim

Melanins and melanogenesis: methods, standards, protocols

Despite considerable advances in the past decade, melanin research still suffers from the lack of universally accepted and shared nomenclature, methodologies, and structural models. This paper stems from the joint efforts of chemists, biochemists, physicists, biologists, and physicians with recognized and consolidated expertise in the field of melanins and melanogenesis, who critically reviewed and experimentally revisited methods, standards, and protocols to provide for the first time a consensus set of recommended procedures to be adopted and shared by researchers involved in pigment cell research. The aim of the paper was to define an unprecedented frame of reference built on cutting-edge knowledge and state-of-the-art methodology, to enable reliable comparison of results among laboratories and new progress in the field based on standardized methods and shared information

Family Presence during Resuscitation: A Qualitative Analysis from a National Multicenter Randomized Clinical Trial

<div><p>Background</p><p>The themes of qualitative assessments that characterize the experience of family members offered the choice of observing cardiopulmonary resuscitation (CPR) of a loved one have not been formally identified.</p><p>Methods and Findings</p><p>In the context of a multicenter randomized clinical trial offering family members the choice of observing CPR of a patient with sudden cardiac arrest, a qualitative analysis, with a sequential explanatory design, was conducted. The aim of the study was to understand family members’ experience during CPR. All participants were interviewed by phone at home three months after cardiac arrest. Saturation was reached after analysis of 30 interviews of a randomly selected sample of 75 family members included in the trial. Four themes were identified: 1- choosing to be actively involved in the resuscitation; 2- communication between the relative and the emergency care team; 3- perception of the reality of the death, promoting acceptance of the loss; 4- experience and reactions of the relatives who did or did not witness the CPR, describing their feelings. Twelve sub-themes further defining these four themes were identified. Transferability of our findings should take into account the country-specific medical system.</p><p>Conclusions</p><p>Family presence can help to ameliorate the pain of the death, through the feeling of having helped to support the patient during the passage from life to death and of having participated in this important moment. Our results showed the central role of communication between the family and the emergency care team in facilitating the acceptance of the reality of death.</p></div