Launching the dialogue: Safety and innovation as partners for success in advanced manufacturing.

Emerging and novel technologies, materials, and information integrated into increasingly automated and networked manufacturing processes or into traditional manufacturing settings are enhancing the efficiency and productivity of manufacturing. Globally, there is a move toward a new era in manufacturing that is characterized by: (1) the ability to create and deliver more complex designs of products; (2) the creation and use of materials with new properties that meet a design need; (3) the employment of new technologies, such as additive and digital techniques that improve on conventional manufacturing processes; and (4) a compression of the time from initial design concept to the creation of a final product. Globally, this movement has many names, but "advanced manufacturing" has become the shorthand for this complex integration of material and technology elements that enable new ways to manufacture existing products, as well as new products emerging from new technologies and new design methods. As the breadth of activities associated with advanced manufacturing suggests, there is no single advanced manufacturing industry. Instead, aspects of advanced manufacturing can be identified across a diverse set of business sectors that use manufacturing technologies, ranging from the semiconductors and electronics to the automotive and pharmaceutical industries. The breadth and diversity of advanced manufacturing may change the occupational and environmental risk profile, challenge the basic elements of comprehensive health and safety (material, process, worker, environment, product, and general public health and safety), and provide an opportunity for development and dissemination of occupational and environmental health and safety (OEHS) guidance and best practices. It is unknown how much the risk profile of different elements of OEHS will change, thus requiring an evolution of health and safety practices. These changes may be accomplished most effectively through multi-disciplinary, multi-sector, public-private dialogue that identifies issues and offers solutions.

C57BL/6 mice are resistant to acute restraint modulation of cutaneous hypersensitivity.

C57BL/6 mice, in contrast to BALB/c mice, display minimal behavioral changes in response to environmental stressors and are considered relatively stress-resistant. We have shown that application of acute restraint prior to chemical challenge enhanced cutaneous hypersensitivity (CHS) in BALB/c mice and that this enhanced response is partially glucocorticoid dependent. Due to strain differences in the immune response and in the response to environmental stressors, we hypothesized that acute restraint would not enhance CHS in the less stress-sensitive C57BL/6 mice. We sensitized and challenged C57BL/6 mice with the contact sensitizer, 2, 4-dinitrofluorobenzene (DNFB) in the presence and absence of restraint. Acute restraint, applied prior to chemical challenge, significantly increased serum corticosterone, but to concentrations approximately 60% of those reported for BALB/c mice. Neither restraint nor the exogenous administration of corticosterone enhanced chemical-induced ear swelling in C57BL/6 mice. Pharmacological interruption of the hypothalamic pituitary adrenal axis (HPAA) with the glucocorticoid type II receptor antagonist, RU486, did not alter the development of CHS, however, adrenalectomized (ADX) mice exhibited decreased ear swelling, a measurement that was decreased further by restraint. Combined application of acute restraint and corticosterone prior to chemical challenge significantly enhanced the ear swelling response in C57BL/6 wild-type mice. These data confirm that C57BL/6 mice have a blunted corticosterone response to restraint and that acute restraint does not modulate cutaneous hypersensitivity. Furthermore, our data demonstrate that stress-resistance is not conferred exclusively through the glucocorticoid pathways.

IL-4 fails to regulate in vitro beryllium-induced cytokines in berylliosis.

Bronchoalveolar lavage (BAL) cells from patients with chronic beryllium disease (CBD) have been used to evaluate the beryllium-specific immune response and potential immunotherapeutics. Beryllium induces interferon-gamma (IFN-gamma), interleukin-2 (IL-2), tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-10 (IL-10) from BAL cells. An antibody to IL-2 and recombinant human (rHu) IL-10 is able to partially suppress the beryllium-stimulated immune response. To obtain BAL cells, bronchoscopy is required, providing risk to the patient and a limited number of cells to study the immune response. As a result, the objectives of the study were to determine 1) whether CBD peripheral blood mononuclear cells (PBMNs) stimulated with beryllium would produce a similar cytokine pattern as BAL cells, and 2) whether this response could be modulated by interleukin-4 (IL-4), an immunomodulatory cytokine. CBD and normal individuals' PBMN and BAL cells were stimulated with and without beryllium sulfate. To modulate this antigen-stimulated response, we added rHu IL-4 to the unstimulated and beryllium-stimulated cells. IFN-gamma, IL-2, TNF-alpha, IL-6 and IL-10 cytokine concentrations were determined from cell supernatants by enzyme-linked immunosorbent assays (ELISA), while IL-4 messenger ribonucleic acid (mRNA) was assessed using polymerase chain reaction (PCR). Beryllium did not stimulate any of these cytokines from normal PBMNs. Increasing levels of IL-6 and TNF-alpha were produced constituitively by CBD PBMNs over time. Compared to the unstimulated CBD PBMNs, beryllium stimulated significant IFN-gamma, TNF-alpha, IL-2, IL-6 and IL-10 production. This response was similar to that stimulated from CBD BAL cells, although of a much lower magnitude. Low levels of IL-4 mRNA were found in CBD and control PBMNs, which were not increased with beryllium stimulation. The beryllium-stimulated cytokine levels were not decreased by the addition of IL-4. IL-4 was unable to downregulate any of these beryllium-stimulated cytokines from CBD BAL cells or increase IL-4 mRNA from either CBD PBMN or BAL cells, and thus is an unlikely immunomodulatory agent in CBD. From the data, it was concluded that chronic beryllium disease peripheral blood mononuclear cells provide a model to study the beryllium-stimulated immune response. Interleukin-4's inability to downregulate any of the beryllium-stimulated cytokines makes it an unlikely therapeutic candidate in chronic beryllium disease.

Restraint stress applied prior to chemical sensitization modulates the development of allergic contact dermatitis differently than restraint prior to challenge.

BALB/c mice were sensitized and challenged on the skin with the contact sensitizer, dinitroflourobenzene. Acute restraint applied before sensitization diminished, whereas restraint administered before challenge enhanced, chemical-induced ear swelling and leukocytic infiltration in the dermis. Administration of RU486, a glucocorticoid receptor antagonist, partially reversed restraint modulation of the ear swelling response in both restraint paradigms. Restraint did not modulate significantly the concentration of TNF-alpha and IL-1 beta in ear tissue homogenates. These data show that acute restraint modulates cutaneous sensitization differently than challenge, but the changes are not reflected in TNF-alpha or IL-l beta production.

Restraint-induced modulation of allergic and irritant contact dermatitis in male and female B6.129 mice.

Recent studies in rats have indicated that acute restraint enhances cutaneous hypersensitivity. We hypothesized that acute restraint would also modulate the development of allergic and irritant dermatitis in mice and that these restraint-induced changes would be reflected in the cutaneous cytokine profile and be gender-specific. For these studies, male and female B6.129 mice were sensitized and challenged with the contact sensitizer dinitrofluorobenzene or challenged with the irritant croton oil. Two-hour restraint was applied prior to chemical challenge. Restraint combined with chemical increased ear swelling in both genders in ACD, a change that was blocked by administration of RU-486 prior to restraint. Neither restraint nor RU-486 administration modulated development of ICD; however, IL-1beta was decreased by restraint in females only. TNF-alpha and IFN-gamma production were modified in ACD; TNF-alpha in both genders and IFN-gamma in female mice only. Our data demonstrate that acute restraint increases serum corticosterone in B6.129 male and female mice to comparable levels. Restraint modulated the murine ear swelling in ACD, but not ICD, in both genders, and the change in the ear swelling response and cytokine production were, at least in part, corticosterone-dependent.

Chemical activation of innate and specific immunity in contact dermatitis.

Recent reports have suggested that chemical-induced allergic contact dermatitis may not be a traditional type IV hypersensitivity, in part due to the dual irritant and antigenic properties of sensitizing chemicals. In order to investigate the contribution of these properties to the molecular and cellular mechanism underlying allergic contact dermatitis, we evaluated oxazolone-induced changes in cell populations and cytokine production in the dermis of transgenic mice with impaired innate immunity (the FcgammaR subunit knockout mouse), and absent specific immunity (the athymic mouse), and the appropriate B6,129F2 and C57BL/6 control mice. Oxazolone and croton oil were applied in a single sensitizing dose, or in sensitizing and challenge doses, and the dermal response was evaluated by immunohistochemistry. In the wild type mice, with or without sensitization to oxazolone or croton oil, we observed mixed Th1/Th2 cytokine production and both CD4+ and CD8+ T lymphocytes; however, the neutrophil was the predominant cell in the dermis, even 72 h after final chemical application. Athymic mice displayed a similar neutrophil response with moderate Th1/Th2 cytokine production, and FcgammaR subunit knockout mice exhibited very mild dermatitis when treated with either oxazolone or croton oil. These results provide support for the hypothesis that allergic contact dermatitis is not a classic delayed type hypersensitivity, demonstrate the importance of the interaction between the irritant and antigenic properties of sensitizing chemicals in the development of allergic contact dermatitis, and suggest that the irritant effect of chemicals may be mediated through the cutaneous innate immune system.

Partial IL-10 inhibition of the cell-mediated immune response in chronic beryllium disease.

Chronic beryllium disease (CBD) provides a human disorder in which to study the delayed type IV hypersensitivity response to persistent Ag that leads to noncaseating pulmonary granuloma formation. We hypothesized that, in CBD, failure of IL-10 to modulate the beryllium-specific, cell-mediated immune response would result in persistent, maximal cytokine production and T lymphocyte proliferation, thus contributing to the development of granulomatous lung disease. To test this hypothesis, we used bronchoalveolar lavage cells from control and CBD subjects to evaluate the beryllium salt-specific production of endogenous IL-10 and the effects of exogenous human rIL-10 (rhIL-10) on HLA expression, on the production of IL-2, IFN-gamma, and TNF-alpha, and on T lymphocyte proliferation. Our data demonstrate that beryllium-stimulated bronchoalveolar lavage cells produce IL-10, and the neutralization of endogenous IL-10 does not increase significantly cytokine production, HLA expression, or T lymphocyte proliferation. Second, the addition of excess exogenous rhIL-10 partially inhibited the beryllium-stimulated production of IL-2, IFN-gamma, and TNF-alpha; however, we measured no change in T lymphocyte proliferation or in the percentage of alveolar macrophages expressing HLA-DP. Interestingly, beryllium salts interfered with an IL-10-stimulated decrease in the percentage of alveolar macrophages expressing HLA-DR. We conclude that, in the CBD-derived, beryllium-stimulated cell-mediated immune response, low levels of endogenous IL-10 have no appreciable effect; exogenous rhIL-10 has a limited effect on cytokine production and no effect on T lymphocyte proliferation or HLA expression.

Beryllium-stimulated release of tumor necrosis factor-alpha, interleukin-6, and their soluble receptors in chronic beryllium disease.

Chronic beryllium disease (CBD) provides a model system in which to evaluate the antigen-stimulated, cell-mediated, immune response that leads to granulomatous lung disease. We hypothesized that beryllium salts would stimulate bronchoalveolar lavage (BAL) cell release of tumor necrosis factor-alpha (TNF-alpha) and lnterleukin-6 (IL-6), and their soluble receptors, soluble TNF receptor I (sTNF RI), sTNF RII, and sIL-6R and that chronic exposure to antigen would increase production of soluble receptors in the serum and BAL fluid (BALF) of beryllium-sensitized and CBD patients. We have demonstrated (1) similar constitutive TNF-alpha, IL-6, and soluble receptor production by control subjects and CBD patients, (2) a BeSO4-stimulated increase in TNF-alpha and IL-6 production by CBD-derived BAL cells, and (3) a BeSO4-induced decrease in sTNF RII production by BAL cells from control subjects. We measured increased serum sTNF RI and serum and BALF sIL-6R in beryllium-sensitized subjects and increased sTNF RI and RII in serum and sIL-6R and sTNF RII and BALF in CBD patients. These changes correlated with pulmonary lymphocytosis and clinical measures of disease severity, indicating that soluble receptors may reflect disease status.

Contribution of sialic acid to the voltage dependence of sodium channel gating. A possible electrostatic mechanism.

A potential role for sialic acid in the voltage-dependent gating of rat skeletal muscle sodium channels (rSkM1) was investigated using Chinese hamster ovary (CHO) cells stably transfected with rSkM1. Changes in the voltage dependence of channel gating were observed after enzymatic (neuraminidase) removal of sialic acid from cells expressing rSkM1 and through the expression of rSkM1 in a sialylation-deficient cell line (lec2). The steady-state half-activation voltages (Va) of channels under each condition of reduced sialylation were approximately 10 mV more depolarized than control channels. The voltage dependence of the time constants of channel activation and inactivation were also shifted in the same direction and by a similar magnitude. In addition, recombinant deletion of likely glycosylation sites from the rSkM1 sequence resulted in mutant channels that gated at voltages up to 10mV more positive than wild-type channels. Thus three independent means of reducing channel sialylation show very similar effects on the voltage dependence of channel gating. Finally, steady-state activation voltages for channels subjected to reduced sialylation conditions were much less sensitive to the effects of external calcium than those measured under control conditions, indicating that sialic acid directly contributes to the negative surface potential. These results are consistent with an electrostatic mechanism by which external, negatively charged sialic acid residues on rSkM1 alter the electric field sensed by channel gating elements.

Beryllium induces IL-2 and IFN-gamma in berylliosis.

Chronic beryllium disease (CBD) provides a model for study of the Ag-stimulated, cell-mediated immune response that, over time, progresses to granulomatous lung disease. Using cells obtained with bronchoalveolar lavage from patients with CBD and normal individuals, we evaluated beryllium salt-stimulated T lymphocyte proliferation and production of proinflammatory cytokines. Our findings demonstrate that beryllium sulfate stimulates production of both IL-2 and IFN-gamma, not IL-4 and IL-7. We observed a brief time course for IL-2 protein (6-48 h after BeSO4 stimulation) and mRNA production (3-6 h) and a protracted time course for IFN-gamma protein (24-168 h) and mRNA (0.25-168 h). Beryllium-stimulated T lymphocyte proliferation and IFN-gamma release were only partially inhibited by neutralization of IL-2. On the basis of these findings, we hypothesized that IFN-gamma and the IL-2/IFN-gamma-inducible alpha subunit of the soluble IL-2 receptor were elevated in serum and bronchoalveolar lavage fluid of individuals with disease and were molecular markers of granulomatous disease. The data demonstrate that levels of the alpha subunit of the soluble IL-2 receptor, but not IFN-gamma, are elevated in the serum (median = 1428 U/ml; interquartile range = 823-2137 U/ml) and bronchoalveolar lavage fluid (median = 1.56 U/ml, interquartile range = 1.04-4.22 U/ml) of patients with CBD and correlate with the degree of pulmonary lymphocytosis and clinical measures of disease severity. We conclude that IL-2 and IFN-gamma are produced in the beryllium-stimulated, cell-mediated immune response with different time courses and that the alpha subunit of the soluble IL-2 receptor may serve as a biomarker of disease progression.

Human mast cell basic fibroblast growth factor in pulmonary fibrotic disorders.

Mast cells (MCs) are abundant in fibrotic tissue, although their role in fibrogenesis remains obscure. Recent studies suggest MCs may produce basic fibroblast growth factor (bFGF). To evaluate the hypothesis that MC bFGF contributes to the fibrotic response in human interstitial lung disease, we studied lung tissue, bronchoalveolar lavage fluid and serum in 1) idiopathic pulmonary fibrosis, 2) chronic beryllium disease and sarcoidosis, 3) control subjects with no disease or who were beryllium sensitized with normal lung histology. Diseased subjects underwent clinical assessments to stage disease severity. We determined that most bFGF+ cells in lung interstitium are MCs and are most abundant in idiopathic pulmonary fibrosis. Distribution of bFGF+ MCs matched that of extracellular matrix deposition and correlated with the extent of fibrosis morphometrically. Only one bFGF isoform (17.8 kd) was found in idiopathic pulmonary fibrosis and chronic beryllium disease lung tissues and interacted with heparin-like molecules in the lung. Using a human MC line, we verified that MCs express bFGF mRNA and protein that localizes to cytoplasmic granules. Clinically, bFGF concentrations in bronchoalveolar lavage fluid and serum were highest in disease states and correlated with bronchoalveolar lavage cellularity and severity of gas exchange abnormalities, supporting a role for MC bFGF in the pulmonary fibrotic response and its clinical consequence.

Cytokine production by bronchoalveolar lavage cells in chronic beryllium disease.

Chronic beryllium disease (CBD) begins as a sensitizing cell-mediated immune response to beryllium antigen that progresses to granulomatous lung disease. Previous studies demonstrated the involvement of proinflammatory cytokines in the disease process, but the pattern and regulation of cytokine release is unknown. Using bronchoalveolar lavage (BAL) cells from CBD patients in short-term tissue culture, we evaluated cytokine protein levels by enzyme-linked immunosorbent assay and T-lymphocyte proliferation by tritiated thymidine incorporation. We observed the beryllium-stimulated release of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-2 (IL-2), and interferon-gamma (IFN-gamma) but not interleukin-4 (IL-4). Beryllium-stimulated IFN-gamma release was sustained to 168 hr in culture, whereas IL-2 concentrations returned to baseline after 24 hr. Neutralization of IL-2 decreased beryllium-stimulated T-lymphocyte proliferation, but the level of proliferation remained elevated in comparison to unstimulated BAL cells. These data suggest that T helper 1 (Th1) lymphocytes participate in the beryllium disease process; that IFN-gamma levels remain elevated after IL-2 levels return to baseline; and that IL-2 participates directly in beryllium-stimulated T-cell proliferation, but other T-lymphocyte mitogenic cytokines may be involved.