Bingyun Li

Harbin Medical University, Charbin, Heilongjiang Sheng, China

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Publications (6)16.74 Total impact

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    ABSTRACT: Residents living in fluorosis areas generally experienced long-term exposure to excessive fluoride in drinking water. The adverse effects of high fluoride levels on the nervous system have been studied; however, the effect of fluoride exposure on cognitive functions of elderly people in fluorosis areas is rarely reported. This study was aimed to find out the potential risk factors of cognitive impairment among elderly people who lived in fluorosis areas of China. A total of 511 subjects, aged 60 years or above, were investigated in fluorosis areas of Heilongjiang Province, Inner Mongolia Autonomous Region, Qinghai Province, and Xinjiang Uygur Autonomous Region. The Mini-Mental State Examination (MMSE) was used to examine cognitive functions of the study subjects. Based on the MMSE scores, the study subjects were divided into normal group and cognitive impairment group that consisted of mild, moderate, and severe groups. Multivariable logistic regression showed that a higher risk of cognitive impairment was associated with increased age and decreased education levels. Multiple linear regression analysis revealed that MMSE scores were negatively associated with serum homocysteine (Hcy) levels. However, both urinary fluoride and serum Hcy levels in the normal group were not the lowest among the four groups. Spearman’s correlation analysis showed that urinary fluoride levels were positively correlated with serum Hcy (r s = 0.209, P < 0.01). Our study suggests that people with cognitive impairment in fluorosis areas have elevated serum Hcy levels, which was positively correlated with urinary fluoride concentrations. A certain low dose of fluoride intake may play a potential protective rather than harmful role in cognitive functions; however, high fluoride exposure is a potential risk factor for cognitive impairment.
    No preview · Article · Nov 2015 · Biological Trace Element Research
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    ABSTRACT: Background: Brick tea type fluorosis is a public health concern in the north-west area of China. The association between SNPs of genes influencing bone mass and fluorosis has attracted attention, but the association of SNPs with the risk of brick-tea type of fluorosis has not been reported. Objective: To investigate the modifying roles of GSTP1 rs1695 polymorphisms on this association. Methods: A cross-sectional study was conducted. Brick-tea water was tested by the standard of GB1996-2005 (China). Urinary fluoride was tested by the standard of WS/T 89-2006 (China). Skeletal fluorosis was diagnosed by X-ray, the part we scheduled was forearm, shank, and pelvic, then diagnosed the skeletal fluorosis by the standard of WS/192-2008 (China). Gene polymorphism was tested by Sequenom MassARRAY system. Result: The prevalence rate in different ethnical participants was different: Tibetan individuals had the highest prevalence rate of skeletal fluorosis. There were significant differences in genotype frequencies of GSTP1 Rs1695 among different ethnical participants (p<0.001): Tibetan, Mongolian and Han subjects with homozygous wild type (GSTP1-AA) genotype were numerically higher than Kazakh and Russian subjects (p<0.001). Compared to Tibetan participants who carried homozygous A allele of GSTP1 Rs1695, Tibetan participants who carried G allele had a significantly decreased risk of skeletal fluorosis (OR = 0.558 [95% CI, 0.326-0.955]). For Kazakh participants, a decreased risk of skeletal fluorosis among carriers of the G allele was limited to non high-loaded fluoride status (OR = 0. 166 [95% CI, 0.035-0.780] vs. OR = 1.478 [95% CI, 0.866-2.552] in participants with high-loaded fluoride status). Neither SNP-IF nor SNP-age for GSTP1 Rs1695 was observed. Conclusion: The prevalence rate of the brick tea type fluorosis might have ethnic difference. For Tibetan individuals, who had the highest prevalence rate, G allele of GSTP1 Rs1695 might be a protective factor for brick tea type skeletal fluorosis.
    Preview · Article · Jun 2015 · PLoS ONE
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    ABSTRACT: Over the past two decades, fluoride effects on osteoclasts have been evaluated; however, its molecular mechanisms remain unclear. In this study, we investigated the effect of fluoride on osteoclast formation, function, and regulation using osteoclasts formed from mice bone marrow macrophages treated with the receptor activator of NF-κB ligand and macrophage colony-stimulating factor. Our data showed that fluoride levels ≤ 8 mg/L had no effect on osteoclast formation; however, it significantly reduced osteoclast resorption at 0.5 mg/L. Fluoride activity on bone resorption occurred through the inhibition of nuclear factor of active T cells (NFAT) c1 expression. Furthermore, the expression of its downstream genes, including the dendritic cell-specific transmembrane protein, c-Src, the d2 isoform of vacuolar (H+) ATPase v0 domain, matrix metalloproteinase 9, and cathepsin K were decreased, leading to impaired osteoclast acidification, reduced secretion of proteolytic enzymes, and decreased bone resorption. In summary, our results suggested that fluoride has different roles in osteoclast formation and function. Fluoride ≤ 8 mg/L did not impact osteoclast formation; however, it significantly decreased the resorption activity of newly formed osteoclasts. The molecular mechanism of fluoride action may involve inhibition of NFATc1 and its downstream genes. © 2012 Wiley Periodicals, Inc. Environ Toxicol, 2012.
    No preview · Article · May 2014 · Environmental Toxicology
  • Hui Liu · Yanhui Gao · Liyan Sun · Mang Li · Bingyun Li · Dianjun Sun
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    ABSTRACT: Cross-sectional analysis was conducted to access the relationships between developing carotid artery atherosclerosis through consuming high fluoride in drinking water and its possible mechanism, using the baseline data collected from 585 study subjects. In the cross sectional analysis, subjects were divided into four groups based on the concentrations of fluoride in their drinking water. The range of fluoride concentrations was: normal group (less than 1.20mg/L), mild group (1.21-2.00mg/L), moderate group (2.01-3.00mg/L), and high concentration group (more than 3.01mg/L). The prevalence rate of carotid artery atherosclerosis in the subjects in each group was found to be 16.13%, 27.22%, 27.10%, and 29.69%, respectively. Significant difference between the prevalence of carotid artery atherosclerosis in the mild, moderate and high fluoride exposure group and in the normal group was observed (P<0.05). In addition, it was found that elevated intercellular cell adhesion molecule-1 (ICAM-1) and reduced glutathione peroxidases (GPx) was associated with carotid artery atherosclerosis in fluoride endemic areas. The findings of the research study revealed a significant positive relationship between excess fluoride exposure from drinking water and prevalence of carotid artery atherosclerosis in adults living in fluoride endemic areas. The possible mechanism was the excess fluoride induced the decreasing level of GPx causing the systemic inflammation and endothelial activation by oxidative stress.
    No preview · Article · Aug 2013 · International journal of hygiene and environmental health
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    ABSTRACT: In this study, the relationships between high water fluoride exposure and essential hypertension as well as plasma ET-1 levels were investigated. A total of 487 residents aged 40 to 75 were randomly recruited from eight villages in Zhaozhou County from Heilongjiang Province in China and were divided into 4 groups according to the concentrations of fluoride in their water. Consumption levels of drinking water fluoride for normal, mild, moderate, and high exposure groups were 0.84±0.26mg/L, 1.55±0.22mg/L, 2.49±0.30mg/L, and 4.06±1.15mg/L, respectively. The prevalence of hypertension in each group was 20.16%, 24.54%, 32.30%, and 49.23%, respectively. There were significant differences between all the groups; namely, with the increase in water fluoride concentrations, the risk of essential hypertension in adults grows in a concentration-dependent manner. Significant differences were observed in the plasma ET-1 levels between the different groups (P<0.0001). In the multivariable logistic regression model, high water fluoride concentrations (F(-)≥3.01mg/L, OR(4/1)=2.84), age (OR(3/1)=2.63), and BMI (OR(2/1)=2.40, OR(3/1)=6.03) were closely associated with essential hypertension. In other words, the study not only confirmed the relationship between excess fluoride intake and essential hypertension in adults, but it also demonstrated that high levels of fluoride exposure in drinking water could increase plasma ET-1 levels in subjects living in fluoride endemic areas.
    No preview · Article · Dec 2012 · Science of The Total Environment
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    ABSTRACT: Receptor activator of nuclear factor kappa-B ligand (RANKL) acting on osteoblasts is an essential cytokine for osteoclast formation. Recent studies have shown that fluoride (F) can stimulate RANKL expression of osteoblasts. However, the effect of F under various levels of RANKL on osteoclast formation is not clear. In this study, stem cell technology was used to observe the effect of F on osteoclast formation at different levels of treatment with RANKL. Our results show that F significantly inhibits the formation of osteoclasts treated with 50 ng/mL RANKL. The number of osteoclasts in the 0.5 mg/L F group fell to about 60% of the control group with no further significant change at the higher fluoride concentrations used (2 and 8 mg/L). On the other hand, F had no effect on the formation of osteoclasts treated with 100 ng/mL RANKL. In fact, the number of osteoclasts formed at 100 ng/mL RANKL was significantly higher than at the 50 ng/mL RANKL level. However, F significantly decreased the activity of osteoclast bone resorption even at a low level of 0.5 mg/L F, and the higher the F concentration was, the lower the activity of bone resorption became. Therefore we conclude that the main effect of F on osteoclasts was the inhibition of their capacity for bone resorption, thus resulting in osteosclerosis as the major clinical manifestation in patients with skeletal fluorosis.
    Full-text · Article · Apr 2012 · Fluoride