A preliminary evaluation of immune stimulation following exposure to metal particles and ions using the mouse popliteal lymph node assay

Highly selective apo-arginase based method for sensitive enzymatic assay of manganese (II) and cobalt (II) ions

A novel enzymatic method of manganese (II) and cobalt (II) ions assay, based on using apo-enzyme of Mn²⁺-dependent recombinant arginase I (arginase) and 2,3-butanedione monoxime (DMO) as a chemical reagent is proposed. The principle of the method is the evaluation of the activity of L-arginine-hydrolyzing of arginase holoenzyme after the specific binding of Mn²⁺ or Co²⁺ with apo-arginase. Urea, which is the product of enzymatic hydrolysis of L-arginine (Arg), reacts with DMO and the resulted compound is detected by both fluorometry and visual spectrophotometry. Thus, the content of metal ions in the tested samples can be determined by measuring the level of urea generated after enzymatic hydrolysis of Arg by reconstructed arginase holoenzyme in the presence of tested metal ions. The linearity range of the fluorometric apo-arginase-DMO method in the case of Mn²⁺ assay is from 4pM to 1.10nM with a limit of detection of 1pM Mn²⁺, whereas the linearity range of the present method in the case of Co²⁺ assay is from 8pM to 45nM with a limit of detection of 2.5pM Co²⁺. The proposed method being highly sensitive, selective, valid and low-cost, may be useful to monitor Mn²⁺ and Co²⁺ content in clinical laboratories, food industry and environmental control service.

Data on the histological and immune cell response in the popliteal lymph node in mice following exposure to metal particles and ions

Hip implants containing cobalt–chromium (CoCr) have been used for over 80 years. In patients with metal-on-metal (MoM) hip implants, it has been suggested that wear debris particles may contribute to metal sensitization in some individuals, leading to adverse reactions. This article presents data from a study in which the popliteal lymph node assay (PLNA) was used to assess immune responses in mice treated with chromium-oxide (Cr₂O₃) particles, metal salts (CoCl₂, CrCl₃, and NiCl₂) or Cr₂O₃ particles with metal salts (“A preliminary evaluation of immune stimulation following exposure to metal particles and ions using the mouse popliteal lymph node assay” (B.E. Tvermoes, K.M. Unice, B. Winans, M. Kovochich, E.S. Fung, W.V. Christian, E. Donovan, B.L. Finley, B.L. Kimber, I. Kimber, D.J. Paustenbach, 2016) [1]). Data are presented on (1) the chemical characterization of TiO₂ particles (used as a particle control), (2) clinical observations in mice treated with Cr₂O₃ particles, metal salts or Cr₂O₃ particles with metal salts, (3) PLN weight and weight index (WI) in mice treated with Cr₂O₃ particles, metal salts or Cr₂O₃ particles with metal salts, (4) histological changes in PLNs of mice treated with Cr₂O₃ particles, metal salts or Cr₂O₃ particles with metal salts, (5) percentages of immune cells in the PLNs of mice treated with Cr₂O₃ particles, metal salts or Cr₂O₃ particles with metal salts, and (6) percentages of proliferating cells in the PLNs of mice treated with Cr₂O₃ particles, metal salts or Cr₂O₃ particles with metal salts.