Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “BERYLLIUM”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources
PubMed1979

Relative toxicities of particulate and soluble forms of beryllium to a rat liver parenchymal cell line in culture and possible mechanisms of uptake.

The relative toxicities of particulate beryllium phosphate, soluble beryllium sulphate and a beryllium sulphosalicylate complex to a rat liver parencymal derived cell line have been examined in culture. Due to the propensity of beryllium salts to form beryllium phosphate in solution the incubation medium used was free of inorganic phosphate. Cell death measured by the loss of cellular lactate dehydrogenase into the medium can be produced within 76 h from beryllium phosphate and beryllium sulphosalicylate or 48 h from beryllium sulphate provided the cells have, irrespective of the form of added beryllium, taken up a minimum of 2--5 nmol Be/10(6) cells. Whilst beryllium phosphate was readily taken up as a particle, beryllium complexed with excess sulphosalicylate was not so markedly accumulated by the cells except possibly by formation of small amounts of beryllium phosphate in the medium as a result of inorganic phosphate lost from the cells. The extent of beryllium uptake from beryllium sulphate quantitatively most resembled that observed for beryllium phosphate but was largely independent of beryllium phosphate formation in the medium and not accompanied by the uptake of the SO42- anion. However, the accumulation of beryllium derived from beryllium sulphate did appear to be associated with the production of a sedimentable from believed most probably to be colloidal beryllium hydroxide. The uptake of all forms of beryllium was temperature sensitive and metabolic inhibitor studies and treatment of the cells with trypsin or neuraminidase supported the view that the distinct behaviour of beryllium derived from beryllium sulphate may be related to the enhanced toxicity of this form both under the conditions used and when administered to experimental animals.

Animals↗
PubMed2001

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.

Adult↗
PubMed2002

Potential exposures and risks from beryllium-containing products.

Beryllium is the strongest of the lightweight metals. Used primarily in military applications prior to the end of the Cold War, beryllium is finding new applications in many commercial products, including computers, telecommunication equipment, and consumer and automotive electronics. The use of beryllium in nondefense consumer applications is of concern because beryllium is toxic. Inhalation of beryllium dust or vapor causes a chronic lung disease in some individuals at concentrations as low as 0.01 microg/m3 in air. As beryllium enters wider commerce, it is prudent to ask what risks this might present to the general public and to workers downstream of the beryllium materials industry. We address this question by evaluating the potential for beryllium exposure from the manufacturing, use, recycle, and disposal of beryllium-containing products. Combining a market study with a qualitative exposure analysis, we determine which beryllium applications and life cycle phases have the largest exposure potential. Our analysis suggests that use and maintenance of the most common types of beryllium-containing products do not result in any obvious exposures of concern, and that maintenance activities result in greater exposures than product use. Product disposal has potential to present significant individual risks, but uncertainties concerning current and future routes of product disposal make it difficult to be definitive. Overall, additional exposure and dose-response data are needed to evaluate both the health significance of many exposure scenarios, and the adequacy of existing regulations to protect workers and the public. Although public exposures to beryllium and public awareness and concern regarding beryllium risks are currently low, beryllium risks have psychometric qualities that may lead to rapidly heightened public concern.

Air Pollutants↗
PubMed1997

Risks of beryllium disease related to work processes at a metal, alloy, and oxide production plant.

OBJECTIVES: To describe relative hazards in sectors of the beryllium industry, risk factors of beryllium disease and sensitisation related to work process were sought in a beryllium manufacturing plant producing pure metal, oxide, alloys, and ceramics. METHODS: All 646 active employees were interviewed; beryllium sensitisation was ascertained with the beryllium lymphocyte proliferation blood test on 627 employees; clinical evaluation and bronchoscopy were offered to people with abnormal test results; and industrial hygiene measurements related to work processes taken in 1984-93 were reviewed. RESULTS: 59 employees (9.4%) had abnormal blood tests, 47 of whom underwent bronchoscopy. 24 new cases of beryllium disease were identified, resulting in a beryllium disease prevalence of 4.6%, including five known cases (29/632). Employees who had worked in ceramics had the highest prevalence of beryllium disease (9.0%). Employees in the pebble plant (producing beryllium metal) who had been employed after 1983 also had increased risk, with a prevalence of beryllium disease of 6.4%, compared with 1.3% of other workers hired in the same period, and a prevalence of abnormal blood tests of 19.2%. Logistic regression modelling confirmed these two risk factors for beryllium disease related to work processes and the dependence on time of the risk at the pebble plant. The pebble plant was not associated with the highest gravimetric industrial hygiene measurements available since 1984. CONCLUSION: Further characterisation of exposures in beryllium metal production may be important to understanding how beryllium exposures confer high contemporary risk of beryllium disease.

Adult↗
PubMed2005

Bioavailability of beryllium oxide particles: an in vitro study in the murine J774A.1 macrophage cell line model.

Beryllium metal and its oxide and alloys are materials of industrial significance with recognized adverse effects on worker health. Currently, the degree of risk associated with exposure to these materials in the workplace is assessed through measurement of beryllium aerosol mass concentration. Compliance with the current mass-based occupational exposure limit has proven ineffective at eliminating the occurrence of chronic beryllium disease (CBD). The rationale for this research was to examine the mechanism of beryllium bioavailability, which may be pertinent to risk. The authors tested the hypothesis in vitro that dissolution of particles engulfed by macrophages is greater than dissolution in cellular medium alone. Physicochemical changes were evaluated in vitro for well-characterized high-purity beryllium oxide (BeO) particles in cell-free media alone and engulfed by and retained within murine J774A.1 monocyte-macrophage cells. The BeO particles were from a commercially available powder and consisted of diffuse clusters (aerodynamic diameter range 1.5 to 2.5 microm) of 200-nm diameter primary particles. Following incubation for 124 to 144 hours, particles were recovered and recharacterized. Recovered particles were similar in morphology, chemical composition, and size relative to the original material, confirming the relatively insoluble nature of the BeO particles. Measurable levels of dissolved beryllium, representing 0.3% to 4.8% of the estimated total beryllium mass added, were measured in the recovered intracellular fluid. Dissolved beryllium was not detected in the extracellular media. The BeO chemical dissolution rate constant in the J774A. 1 cells was 2.1 +/- 1.7 x 10(-8)g/(cm2 . day). In contrast, the BeO chemical dissolution rate constant in cell-free media was < 8.1 x 10(-9)g/(cm2 . day). In vivo, beryllium dissolved by macrophages may be released in the pulmonary alveolar environment, in the lymphatic system after transport of beryllium by macrophages, or in the alveolar interstitium after migration and dissolution of beryllium particles in tissue. These findings demonstrate a mechanism of bioavailability for beryllium, are consistent with previously observed results in canine alveolar macrophages, and provide insights into additional research needs to understand and prevent beryllium sensitization and CBD.

Animals↗