923 research outputs found

    Identification of a Novel HIF-1α-α_{M}β_{2} Integrin-NET Axis in Fibrotic Interstitial Lung Disease

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    Neutrophilic inflammation correlates with mortality in fibrotic interstitial lung disease (ILD) particularly in the most severe form, idiopathic pulmonary fibrosis (IPF), although the underlying mechanisms remain unclear. Neutrophil function is modulated by numerous factors, including integrin activation, inflammatory cytokines and hypoxia. Hypoxia has an important role in inflammation and may also contribute to pulmonary disease. We aimed to determine how neutrophil activation occurs in ILD and the relative importance of hypoxia. Using lung biopsies and bronchoalveolar lavage (BAL) fluid from ILD patients we investigated the extent of hypoxia and neutrophil activation in ILD lungs. Then we used ex vivo neutrophils isolated from healthy volunteers and BAL from patients with ILD and non-ILD controls to further investigate aberrant neutrophil activation in hypoxia and ILD. We demonstrate for the first time using intracellular staining, HIF-1α stabilization in neutrophils and endothelial cells in ILD lung biopsies. Hypoxia enhanced both spontaneous (+1.31-fold, p < 0.05) and phorbol 12-myristate 13-acetate (PMA)-induced (+1.65-fold, p < 0.001) neutrophil extracellular trap (NET) release, neutrophil adhesion (+8.8-fold, <0.05), and trans-endothelial migration (+1.9-fold, p < 0.05). Hypoxia also increased neutrophil expression of the αM (+3.1-fold, p < 0.001) and αX (+1.6-fold, p < 0.01) integrin subunits. Interestingly, NET formation was induced by αMβ2 integrin activation and prevented by cation chelation. Finally, we observed NET-like structures in IPF lung sections and in the BAL from ILD patients, and quantification showed increased cell-free DNA content (+5.5-fold, p < 0.01) and MPO-citrullinated histone H3 complexes (+21.9-fold, p < 0.01) in BAL from ILD patients compared to non-ILD controls. In conclusion, HIF-1α upregulation may augment neutrophil recruitment and activation within the lung interstitium through activation of β2 integrins. Our results identify a novel HIF-1α- αMβ2 integrin axis in NET formation for future exploration in therapeutic approaches to fibrotic ILD

    Walking through volcanic mud : the 2,100 year-old Acahualina footprints (Nicaragua) II: the Acahualina people, environmental conditions and motivation

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    We analyzed bare human footprints in Holocene tuff preserved in two pits in the Acahualinca barrio in the northern outskirts of Managua (Nicaragua). Lithology, volcanology, and age of the deposits are discussed in a companion paper (Schmincke et al. Bull Volcanol doi: 10.1007/s00445-008-0235-9, 2008). The footprint layer occurs within a series of rapidly accumulated basaltic–andesitic tephra that is regionally correlated to the Masaya Triple Layer Tephra. The people were probably trying to escape from a powerful volcanic eruption at Masaya Caldera 20 km farther south that occurred at 2.1 ka BP. We subdivided the swath of footprints, up to 5.6 m wide, in the northern pit (Pit I) into (1) a central group of footprints made by about six individuals, the total number being difficult to determine because people walked in each other’s footsteps one behind the other and (2) two marginal groups on either side of the central group with more widely spaced tracks. The western band comprises tracks of three adjacent individuals and an isolated single footprint farther out. The eastern marginal area comprises an inner band of deep footprints made by three individuals and, farther out, three clearly separated individuals. We estimate the total number of people as 15–16. In the southern narrow and smaller pit (Pit II), we recognize tracks of ca. 12 individuals, no doubt made by the same group. The group represented in both pits probably comprised male and female adults, teenagers and children based on differences in length of footprints and of strides and depth of footprints made in the soft wet ash. The smallest footprints (probably made by children) occur in the central group, where protection was most effective. The footprint layer is composed of a lower 5–15-cm thick, coarse-grained vesicle tuff capped by a medium to fine-grained tuff up to 3 cm thick. The surface on which the people walked was muddy, and the soft ash was squeezed up on the sides of the foot imprints and between toes. Especially, deep footprints are mainly due to local thickening of the water-rich ash, multiple track use, and differences in weight of individuals. The excellent preservation of the footprints, ubiquitous mudcracks, sharp and well-preserved squeeze-ups along the margins of the tracks and toe imprints, and the absence of raindrop impressions all suggest that the eruption occurred during the dry season. The people walked at a brisk pace, as judged from the tight orientation of the swath and the length of the strides. The directions of a major erosional channel in the overlying deposits that probably debouched into Lake Managua and the band of footprints are strictly parallel, indicating that people walked together in stride along the eastern margin of a channel straight toward the lake shore, possibly a site with huts and/or boats for protection and/or escape

    The leading digit distribution of the worldwide Illicit Financial Flows

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    Benford's law states that in data sets from different phenomena leading digits tend to be distributed logarithmically such that the numbers beginning with smaller digits occur more often than those with larger ones. Particularly, the law is known to hold for different types of financial data. The Illicit Financial Flows (IFFs) exiting the developing countries are frequently discussed as hidden resources which could have been otherwise properly utilized for their development. We investigate here the distribution of the leading digits in the recent data on estimates of IFFs to look for the existence of a pattern as predicted by Benford's law and establish that the frequency of occurrence of the leading digits in these estimates does closely follow the law.Comment: 13 pages, 10 figures, 6 tables, additional data analyi

    A pilot study evaluating the use of ABCD2 score in pre-hospital assessment of patients with suspected transient ischaemic attack: experience and lessons learned

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    Background: Suspected transient ischaemic attack (TIA) is a common presentation to emergency medical services (EMS) in the United Kingdom (UK). Several EMS systems have adopted the ABCD2 score to aid pre-hospital risk stratification and decision-making on patient disposition, such as direct referral to an Emergency Department or specialist TIA clinic. However, the ABCD2 score, developed for hospital use, has not been validated for use in the pre-hospital context of EMS care. Methods: We conducted a pilot study to assess eligibility criteria, recruitment rates, protocol compliance, consent and follow-up procedures to inform the development of a definitive study to validate the ABCD2 tool in pre-hospital evaluation of patients with suspected TIA. Results: From 1st May–1st September 2013, nine patients with an EMS suspected diagnosis of TIA had the TIA diagnosis later confirmed by a specialist from five participating sites. This recruitment rate is comparable to stroke trials in the EMS setting. Bureaucratic obstacles and duplication of approval processes across participating sites took 13 months to resolve before recruitment commenced. Due to the initial difficulty in recruitment, a substantial amendment was approved to modify inclusion criteria, allowing patients with atrial fibrillation and/or taking anticoagulant therapy to participate in the study. Conclusions: It is possible to identify, recruit and follow up patients with suspected TIA in the EMS setting. Training large numbers of EMS staff is required as exposure to TIA patients is infrequent. Significant insight was gained into the complexity of NHS research governance mechanisms in the UK. This knowledge will facilitate the planning of a future adequately powered study to validate the ABCD2 tool in a pre-hospital setting

    Gamma interferon induces different keratinocyte cellular patterns of expression of HLA-DR and DQ and intercellular adhesion molecule-I (ICAM-I) antigens

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    With indirect immunofluorescence techniques we demonstrated that recombinant gamma-interferon induced the expression of the class II antigens HLA-DR and HLA-DQ as well as intercellular adhesion molecule-1 (ICAM-1) on normal, cultured human keratinocytes grown in low-calcium, serum-free medium. Each antigen displayed a distinctive cellular staining pattern. HLA-DR was strongly localized to perinuclear zones with intense cell surface expression; HLA-DQ displayed a perinuclear accentuation, but with minimal cell surface staining, and ICAM-1 was strongly expressed in a diffuse cytoplasmic pattern with intense cell surface expression. Keratinocytes grown in medium supplemented with 10% fetal calf serum underwent differentiation, with a diminished expression of all three antigens as compared to those grown in low-calcium, serum-free medium. These results confirm that gamma interferon can differentially regulate HLA-DR nd HLA-DQ expression; that there are probably different biochemical metabolic pathways by which these three molecules are expressed on keratinocytes, and that the expression is also a function of the degree of keratinocyte differentiation. The strong cell surface expression of ICAM-1 is suggested to be of major importance as the recognition molecule, by which T cells bind to gamma interferon exposed keratinocytes, and suggests and integral role for this molecule in epidermal lymphocyte trafficking.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74686/1/j.1365-2133.1989.tb07759.x.pd

    Longevity and relationships with children: the importance of the parental role

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    <p>Abstract</p> <p>Background</p> <p>Social networks predict longevity across societies but specific mechanisms are largely unknown. The aim of this work was to examine the role of children in the longevity of elderly men and women in a cohort of community dwelling elderly people in Spain.</p> <p>Methods</p> <p>The data were taken from the "Aging in Leganes" cohort study with 15 years of follow-up. The baseline population was an age- and sex-stratified random sample of community dwelling people over 65 living in Leganés (Madrid) in 1993. Poor relationship with at least one child, emotional support and the perceived roles elders play in the lives of their children, extended family, spouse and friends were assessed at baseline. Cox proportional hazards models were fit to investigate the effects of social roles variables on longevity, adjusting for a wide range of socioeconomic, behavioural and health covariates.</p> <p>Results</p> <p>In the fully adjusted model, having a poor relationship with at least one child increased mortality by 30%. Elderly persons who felt their role in their children's lives was important (HR = 0.70; 95% CI 0.54; 0.91) had a lower mortality risk than those who felt they played a small role. Feeling loved and listened to by one's children did not have an effect on survival. Maintaining an important role in the extended family was also significantly associated with survival.</p> <p>Conclusion</p> <p>In this Mediterranean population, maintaining an important role in the lives of one's children is associated with survival. Functions of social networks related to meaning of life and different forms of social support may have important effects on mortality, and these functions may vary across cultures according to family norms and values.</p

    Identification of a novel HIF-1α-αMβ2 integrin-NETosis axis in fibrotic interstitial lung disease

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    Neutrophilic inflammation correlates with mortality in fibrotic interstitial lung disease (ILD) particularly in the most severe form, idiopathic pulmonary fibrosis (IPF), although the underlying mechanisms remain unclear. Neutrophil function is modulated by numerous factors, including integrin activation, inflammatory cytokines and hypoxia. Hypoxia has an important role in inflammation and may also contribute to pulmonary disease. We aimed to determine how neutrophil activation occurs in ILD and the relative importance of hypoxia. Using lung biopsies and bronchoalveolar lavage (BAL) fluid from ILD patients we investigated the extent of hypoxia and neutrophil activation in ILD lungs. Then we used ex vivo neutrophils isolated from healthy volunteers and BAL from patients with ILD and non-ILD controls to further investigate aberrant neutrophil activation in hypoxia and ILD. We demonstrate for the first time using intracellular staining, HIF-1α stabilization in neutrophils and endothelial cells in ILD lung biopsies. Hypoxia enhanced both spontaneous (+1.31-fold, p < 0.05) and phorbol 12-myristate 13-acetate (PMA)-induced (+1.65-fold, p < 0.001) neutrophil extracellular trap (NET) release, neutrophil adhesion (+8.8-fold, <0.05), and trans-endothelial migration (+1.9-fold, p < 0.05). Hypoxia also increased neutrophil expression of the αM (+3.1-fold, p < 0.001) and αX (+1.6-fold, p < 0.01) integrin subunits. Interestingly, NET formation was induced by αMβ2 integrin activation and prevented by cation chelation. Finally, we observed NET-like structures in IPF lung sections and in the BAL from ILD patients, and quantification showed increased cell-free DNA content (+5.5-fold, p < 0.01) and MPO-citrullinated histone H3 complexes (+21.9-fold, p < 0.01) in BAL from ILD patients compared to non-ILD controls. In conclusion, HIF-1α upregulation may augment neutrophil recruitment and activation within the lung interstitium through activation of β2 integrins. Our results identify a novel HIF-1α- αMβ2 integrin axis in NET formation for future exploration in therapeutic approaches to fibrotic ILD

    Do social networks affect the use of residential aged care among older Australians?

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    Background: Older people's social networks with family and friends can affect residential aged care use. It remains unclear if there are differences in the effects of specific (with children, other relatives, friends and confidants) and total social networks upon use of low-level residential care and nursing homes. Methods: Data were drawn from the Australian Longitudinal Study of Ageing. Six waves of data from 1477 people aged ≥ 70 collected over nine years of follow-up were used. Multinomial logistic regressions of the effects of specific and total social networks on residential care use were carried out. Propensity scores were used in the analyses to adjust for differences in participant's health, demographic and lifestyle characteristics with respect to social networks. Results Higher scores for confidant networks were protective against nursing home use (odds ratio [OR] upper versus lower tertile of confidant networks = 0.50; 95%CI 0.33–0.75). Similarly, a significant effect of upper versus lower total network tertile on nursing home use was observed (OR = 0.62; 95%CI 0.43–0.90). Evidence of an effect of children networks on nursing home use was equivocal. Nursing home use was not predicted by other relatives or friends social networks. Use of lower-level residential care was unrelated to social networks of any type. Social networks of any type did not have a significant effect upon low-level residential care use. Discussion: Better confidant and total social networks predict nursing home use in a large cohort of older Australians. Policy needs to reflect the importance of these particular relationships in considering where older people want to live in the later years of life.Lynne C Giles, Gary FV Glonek, Mary A Luszcz and Gary R Andrew
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