Expression of NK cells activation receptors after occupational exposure to toxics

Elevated lead levels and adverse effects on natural killer cells in children from an electronic waste recycling area

Lead (Pb) has been proved to exert immunotoxicity to influence immune homeostasis in humans. To monitor the internal Pb level and evaluate its effect on natural killer (NK) cells and cytokine/chemokine concentrations, we recruited 285 preschool children from Guiyu, one of the largest electronic waste (e-waste) destinations and recycling areas in the world, and known to have high concentrations of Pb in the air, soil, water, sediment and plants. A total of 126 preschool children were selected from Haojiang as a reference group. Results showed that children in Guiyu, the exposed area, had higher blood Pb levels and lower percentages of NK cells than children from the reference area. A significantly negative association was found between the percentage of NK cells and increasing Pb levels. Moreover, children in Guiyu area had higher platelet counts and IL-1β concentrations, and lower levels of IL-2, IL-27, MIP-1α and MIP-1β were observed in the exposed children. These changes might not be conducive to the development and differentiation of NK cells. Taken together, the elevated Pb levels result in the lower percentages of NK cells, but also alter the levels of platelets, IL-1β and IL-27, which might be unconducive to the activity and function of NK cells.

Endocrine and immunological parameters in individuals involved in Prestige spill cleanup tasks seven years after the exposure

In November 2002 the oil tanker Prestige spilled 63,000tonnes of heavy oil off the northwest coast of Spain, impacting more than 1000km of coastline. A general concern led to a huge mobilization of human and technical resources, and more than 300,000 people participated in cleanup activities, which lasted up to 10months. Some endocrine and immunological alterations were reported in Prestige oil exposed subjects for several months. Therefore, the objective of this study was to evaluate if these alterations are still present seven years after the exposure. Fifty-four individuals exposed for at least 2months were compared to 50 matched referents. Prolactin and cortisol plasma concentrations, percentages of lymphocyte subsets (CD3(+), CD4(+), CD8(+), CD19(+), and CD56(+)16(+)), plasma levels of circulating cytokines (interleukin (IL) 2, IL4, IL6, IL10, tumour necrosis factor α, and interferon γ), and serum concentrations of neopterin, tryptophan and kynurenine were determined in peripheral blood samples. Results showed significant differences in exposed individuals vs. referents only in cortisol (increase), kynurenine and %CD16(+)56(+) lymphocytes (both decrease). Time of exposure to the oil or using protective clothes did not influence the results, but effect of using protective mask was observed on neopterin, %CD8(+), CD4(+)/CD8(+) ratio and IL4. Surveillance of the exposed individuals for early detection of possible health problems related to the endocrine or immunological systems is recommended.

Stimulation of natural killer cells by homoeopathic complexes: an in vitro and in vivo pilot study in advanced cancer patients

The present study was designed in order to evaluate the effects of five homoeopathic complex preparations on functional activity natural killer cells (NKCs) in advanced cancer patients. We examined the effects of Coenzyme Compositum®, Ubichinon Compositum®, Glyoxal Compositum®, Katalysatoren® and Traumeel® on the functional activity of NKCs. Experimental procedures included in vitro and in vivo trials. The in vitro trials were performed in NKCs isolated from 12 healthy volunteers (aged 44 ± 4 years) and incubated with the five homoeopathic complex preparations. The in vivo trials were performed in 15 advanced cancer patients (aged 55 ± 12 years) supplemented for 3 months with the homoeopathic preparations. All five homoeopathic preparations significantly increased the cytotoxic activity of the NKCs at the lowest NKCs/target cell ratio 12:1 (p < 0·05). The order of activity was: Ubichinon Compositum® > Glyoxal Compositum® > Katalysatoren® > Traumeel® > Coenzyme Compositum®. In the advanced cancer patients, the homoeopathic preparation significantly increased NKCs cytotoxic activity (p < 0·05). The homoeopathic complex preparations tested in this study can be used as an adjuvant immunotherapy in advanced cancer patients.

The role of catechols and free radicals in benzene toxicity: an oxidative DNA damage pathway

Benzene is a widespread volatile compound and an environmental contaminant. Since it causes important toxic effects in workers exposed to low levels, long-term exposure to this compound has been extensively studied. Leukemia, blood disorders, bone marrow depression, and some types of cancer are directly related to benzene-initiated toxicity. Bioactivation of benzene can lead to the formation of hazardous metabolites such as phenol, hydroquinone, and catechol. Catechol forms semiquinones and reactive quinones that are presumed to play an important role in the generation of reactive oxygen species (ROS). ROS formation can directly induce single and double strand breaks in the DNA, oxidized nucleotides, and hyper-recombination, and consequently produces deleterious genetic changes. In this review, we have addressed the cytotoxic effects of benzene and its main metabolite, catechol, focusing on the oxidative pathway and further DNA damage.