308 research outputs found

    Differential regulation of C-C chemokines during fibroblast-monocyte interactions: adhesion vs. inflammatory cytokine pathways.

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    The cell-to-cell interactions during chronic inflammatory diseases likely contribute to leukocyte accumulation leading to increased pathology and organ dysfunction. In particular, there is a paucity of information relating to the maintenance of chronic fibrotic diseases. Using a lung fibroblast line and enriched monocyte populations, we have investigated the activational events which contribute to the production of two C-C chemokines, macrophage inflammatory protein-1 alpha (MIP-1alpha) and monocyte chemoattractant protein-1 (MCP-1), during fibroblast-monocyte interactions. Neither the fibroblast cell line (16lu) nor isolated monocytes alone produced significant levels of MIP-1alpha or MCP-1. However, when isolated monocytes were layered onto 16 lu fibroblast monolayers a significant increase in MIP-1alpha and MCP-1 production was observed. The use of fixed cell populations indicated that the MIP-1alpha was derived from monocytes and MCP-1 from both cell populations. To examine the molecules which were required for chemokine production during the interaction, specific antibodies were used in the co-cultures. Blocking beta3-integrin interactions significantly inhibited MIP-1alpha production. In contrast, beta-integrin interactions had no effect on the MCP-1 production, while, neutralization of TNF significantly decreased MCP-1 production during the co-culture. These data indicate that fibroblast-monocyte interactions induce chemokine production through different mechanisms and a combination of these responses may contribute to the maintenance of the mononuclear cell accumulation during disease progression

    Inhalation developmental toxicology studies: Teratology study of acetone in mice and rats: Final report

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    Acetone, an aliphatic ketone, is a ubiquitous industrial solvent and chemical intermediate; consequently, the opportunity for human exposure is high. The potential for acetone to cause developmental toxicity was assessed in Sprague-Dawley rats exposed to 0, 440, 2200, or 11000 ppm, and in Swiss (CD-1) mice exposed to 0, 440, 2200, and 6600 ppm acetone vapors, 6 h/day, 7 days/week. Each of the four treatment groups consisted of 10 virgin females (for comparison), and approx.32 positively mated rats or mice. Positively mated mice were exposed on days 6-17 of gestation (dg), and rats on 6-19 dg. The day of plug or sperm detection was designated as 0 dg. Body weights were obtained throughout the study period, and uterine and fetal body weights were obtained at sacrifice (rats, 20 dg; mice, 18 dg). Implants were enumerated and their status recorded. Live fetuses were sexed and examined for gross, visceral, skeletal, and soft-tissue craniofacial defects. 46 refs., 6 figs., 27 tabs

    Elastic and inelastic light scattering from single bacterial spores in an optical trap allows the monitoring of spore germination dynamics

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    Raman scattering spectroscopy and elastic light scattering intensity (ESLI) were used to simultaneously measure levels of Ca-dipicolinic acid (CaDPA) and changes in spore morphology and refractive index during germination of individual B. subtilis spores with and without the two redundant enzymes (CLEs), CwlJ and SleB, that degrade sporesâ peptidoglycan cortex. Conclusions from these measurements include: 1) CaDPA release from individual wild-type germinating spores was biphasic; in a first heterogeneous slow phase, Tlag, CaDPA levels decreased â ¼15% and in the second phase ending at Trelease, remaining CaDPA was released rapidly; 2) in L-alanine germination of wild-type spores and spores lacking SleB: a) the ESLI rose â ¼2-fold shortly before Tlag at T1; b) following Tlag, the ESLI again rose â ¼2-fold at T2 when CaDPA levels had decreased â ¼50%; and c) the ESLI reached its maximum value at â ¼Trelease and then decreased; 3) in CaDPA germination of wild-type spores: a) Tlag increased and the first increase in ESLI occurred well before Tlag, consistent with different pathways for CaDPA and L-alanine germination; b) at Trelease the ESLI again reached its maximum value; 4) in L-alanine germination of spores lacking both CLEs and unable to degrade their cortex, the time Î Trelease (Treleaseâ Tlag) for excretion of â ¥75% of CaDPA was â ¼15-fold higher than that for wild-type or sleB spores; and 5) spores lacking only CwlJ exhibited a similar, but not identical ESLI pattern during L-alanine germination to that seen with cwlJ sleB spores, and the high value for Î Trelease. Originally published Analytical Chemistry, Vol. 81, No. 10, May 200

    Process evaluation of a participatory ergonomics programme to prevent low back pain and neck pain among workers

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    Background: Both low back pain (LBP) and neck pain (NP) are major occupational health problems. In the workplace, participatory ergonomics (PE) is frequently used on musculoskeletal disorders. However, evidence on the effectiveness of PE to prevent LBP and NP obtained from randomised controlled trials (RCTs) is scarce. This study evaluates the process of the Stay@Work participatory ergonomics programme, including the perceived implementation of the prioritised ergonomic measures.Methods: This cluster-RCT was conducted at the departments of four Dutch companies (a railway transportation company, an airline company, a steel company, and a university including its university medical hospital). Directly after the randomisation outcome, intervention departments formed a working group that followed the steps of PE during a six-hour working group meeting. Guided by an ergonomist, working groups identified and prioritised risk factors for LBP and NP, and composed and prioritised ergonomic measures. Within three months after the meeting, working groups had to implement the prioritised ergonomic measures at their department. Data on various process components (recruitment, reach, fidelity, satisfaction, and implementation components, i.e., dose delivered and dose received) were collected and analysed on two levels: department (i.e., working group members from intervention departments) and participant (i.e., workers from intervention departments).Results: A total of 19 intervention departments (n = 10 with mental workloads, n = 1 with a light physical workload, n = 4 departments with physical and mental workloads, and n = 4 with heavy physical workloads) were recruited for participation, and the reach among working group members who participated was high (87%). Fidelity and satisfaction towards the PE programme rated by the working group members was good (7.3 or higher). The same was found for the Stay@Work ergocoach training (7.5 or higher). In total, 66 ergonomic measures were prioritised by the working groups. Altogether, 34% of all prioritised ergonomic measures were perceived as implemented (dose delivered), while the workers at the intervention departments perceived 26% as implemented (dose received).Conclusions: PE can be a successful method to develop and to prioritise ergonomic measures to prevent LBP and NP. Despite the positive rating of the PE programme the implementation of the prioritised ergonomic measures was lower than expected. © 2010 Driessen et al; licensee BioMed Central Ltd
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