Lead Exposure: A Contributing Cause of the Current Breast Cancer Epidemic in Nigerian Women

Breast cancer incidence in Nigerian women has significantly increased during the past three decades in parallel with the rapid industrialization of that country. This suggested that the associated widespread contamination of the soil and of the water supplies by lead (Pb) and other industrial metals was a major contributing cause. Because of its many domestic, industrial, and automotive uses, Pb is of particular concern as it has been shown to promote the development of mammary tumors in murine mammary tumor virus-infected female C3H mice at levels as low of 0.5 ppm Pb in the drinking water. Lead belongs to the group of selenium-antagonistic elements that interact with selenium (Se), abolishing its anti-carcinogenic effect. Lead on chronic, low-level exposure in addition also accelerates tumor growth rates. Higher levels of Pb were found in blood and head hair samples of newly diagnosed patients with breast cancer, all with infiltrating ductal carcinoma, the most common form of breast cancer in Nigeria, seen at Obafemi Awolowo University, than in cancer-free controls from the same area. Evidence for interactions between Pb and Se was obtained from blood, hair, and tumor biopsy tissue analyses. Furthermore, the Pb levels in hair samples of the patients were directly correlated with the volumes of their tumors, in accord with the tumor growth-promoting effects of Pb. Conversely, Se levels in hair and blood were inversely correlated with the tumor volumes, consistent with the anti-proliferative effects of Se. Several other elements, e.g., Cd, Hg, Cr, Sn, and As, were detected in the scalp hair of the patients and the controls, although at significantly lower levels than those of Pb. However, correlation calculations revealed them also to interact with Se, suggesting that only a fraction of the Se in organs and tissues is actually present in bioactive forms. In metal-exposed subjects, a state of latent Se deficiency may exist, resulting in depressed immune functions and increased cancer susceptibility. Evidence is presented to show that Pb and other metals also interact with iodine, another vitally important essential trace element believed to protect against breast cancer development. Public health programs aiming at lowering the breast cancer risk of Nigerian women thus will have to include effective measures to protect the population from exposures to Pb and other industrial metals that are presently contaminating the environment and the water supplies

The mediating role of self/everyday creativity and depression on the relationship between creative personality traits and problematic social media use among emerging adults

Personality is one of the important contributory factors in the development of problematic technology use. The purpose of the present study was to investigate the direct and indirect associations of creative personality traits with problematic social media use via self/everyday creativity, depression, and loneliness. A total of 460 Turkish emerging adults aged between 18 and 26 years (61% female) were surveyed. Findings indicated that (i) task-orientedness was indirectly associated with problematic social media use via self/everyday creativity, (ii) self-confidence was directly and indirectly associated with problematic social media use via self/everyday creativity and depression, (iii) risk-taking was indirectly associated with problematic social media use via depression, and (iv) self/everyday creativity and depression were directly associated with problematic social media use. The present study is the first to suggest that creative personality traits (i.e., task-orientedness, self-confidence, and risk-taking) and self/everyday creativity are associated with problematic social media use and that these factors should be taken into account when considering the etiology of problematic social media use

Absence of interference of serum IgGs from patients with breast cancer and thyroid autoimmunity on the function of human iodide symporter gene stably transfected in CHO cells

The cause of the association between breast cancer (BC) and thyroid autoimmunity is still unknown. Na+/I- symporter (NIS) is highly expressed in BC cells, and previous studies demonstrated that iodine content in BC is lower than in remote normal breast tissue, suggesting a disorder of iodide uptake in BC. In this study, we evaluated the presence of putative serum autoantibodies able to block the function of NIS in BC patients with thyroid autoimmunity. IgGs were obtained from: a) 11 patients with BC and high antithyroglobulin (TgAb) and antithyroperoxidase (TPOAb) autoantibodies serum concentration; b) 34 patients with Hashimoto's thyroiditis (HT) (1 was euthyroid, 4 had subclinical hypothyroidism and 29 were overtly hypothyroid); c) 15 control subjects. The biological activity of NIS was studied using a chinese hamster ovary (CHO) cell line stably expressing NIS (NIS-CHO). The course of iodide accumulation in NIS-CHO was studied after addition of Na125 I in culture medium. The accumulation of iodide linearly increased between 2 and 10 min, reaching a plateau at 45 min. The preincubation of NIS-CHO with IgGs purified from sera of BC with the highest levels of TPOAb and TgAb caused an inhibition of iodine uptake of no more than 5%. Similar results were obtained using IgGs purified from patients with HT and control subjects. Our data showed no interference of autoantibodies on iodine uptake in patients with BC and thyroid autoimmunity and the very low percentage of inhibition of iodine uptake cannot explain the lower content of iodine in BC tissue

Acute iodine deficiency induces a transient VEGF dependent microvascular response in mammary glands involving HIF-1, ROS and mTOR.

Iodine deficiency (ID), which affects almost two billion people worldwide, is associated with breast pathologies such as fibrosis in human and induces breast atypia in animal models. Because ID induces vascular activation in the thyroid, another iodide-uptaking organ, and as breast is also sensitive to ID, we aimed to characterize ID-induced effects on the breast microvasculature in vivo and in two different breast cell lines in vitro. Virgin and lactating NMRI mice received an iodide-deficient diet and a Na/I symporter inhibitor for one to 20 days. Some mice were treated with vascular endothelial growth factor A (VEGF) or VEGF receptors inhibitors. In vitro, ID was induced in MCF7 and MCF12A cells by replacing the iodide containing medium by an iodide-deficient medium. In vivo, VEGF expression was increased following ID in mammary tissues. Consequently, ID induced a transient increase in mammary gland blood flow, measured after anesthesia, in virgin and lactating mice, which was repressed by VEGF or VEGF receptor inhibitors. In MCF7 cells, ID induced a transient increase in reactive oxygen species (ROS), followed by an increase in hypoxia-inducible factor-1α (HIF-1α) protein and VEGF mRNA expression. Antioxidant N-acetylcysteine and mammalian target of rapamycin (mTOR) inhibitor blocked ID-induced HIF-1α protein increase and VEGF transcription. However, mTOR activity was not inhibited by N-acetylcysteine. Similar responses were observed in MCF12A cells. These data indicate that ID activates the canonical VEGF pathway and mTOR in breast tissues, which provides new insights to better understand the correlation between ID, vascular activation and breast pathologies

Women's perceived work environment after stress-related rehabilitation: experiences from the ReDO project.

The study aimed to investigate (a) if women's perceptions of their work environment changed during a 16-week rehabilitation period and at a 12-month follow-up; (b) whether such changes were related to outcomes in terms of return to work, well-being and valued occupations