Abstract
The clastogenic potential of sodium fluoride was determined both in vitro (using cultured human lymphocytes) and in vivo (using the rat bone-marrow micronucleus test). The incidence of chromosome aberrations in human lymphocyte cultures exposed to 20 or 40 micrograms/ml sodium fluoride (3 and 9% respectively) was significantly increased compared with control cultures (0.5%). However, the incidence of micronucleated polychromatic erythrocytes in male AP rats dosed 1000 mg/kg NaF (the maximum tolerated dose over 24 h) or 500 mg/kg NaF was similar to that in the animals dosed distilled water (vehicle control). Thus, sodium fluoride is clastogenic in vitro but not in vivo.
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Effects of different concentrations of fluoride in oral mucosal cells in albino rats
INTRODUCTION: Fluoride has been described to be physiologically essential for the normal development and growth of human beings. However, it is well known that excessive fluoride causes skeletal, nonskeletal and dental complications. Therefore, outlining the cytogenetic effects induced by fluorosis is necessary. OBJECTIVES: To evaluate the cytomorphology of exfoliated oral mucosal
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DNA damage, apoptosis and cell cycle changes induced by fluoride in rat oral mucosal cells and hepatocytes
AIM: To study the effect of fluoride on oxidative stress, DNA damage and apoptosis as well as cell cycle of rat oral mucosal cells and hepatocytes. METHODS: Ten male SD rats weighing 80-120 g were randomly divided into control group and fluoride group, 5 animals each group. The animals in
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The influence of atmospheric hydrogen fluoride on the frequency of sex-linked recessive lethals and sterility in Drosophila Melanogaster
The influence of hydrogen fluoride as an atmospheric contaminant was investigated in the Oregon-r strain of Drosophila melanogaster. Two principal parameters of mutagenicity were used: sex-linked recessive lethals and sterility. The flies were subjected to various levels of HF in fumigation chambers. Sex-linked recessive lethal mutation frequency increasd at each level
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Sister chromatid exchanges: a study in fluorotic individuals of North Gujurat
The purpose of this preliminary investigation was to compare the genotoxic effect of fluoride in human individuals directly exposed to high concentrations of drinking water fluoride (1.95 to 2.2 ppm) with those in individuals exposed to concentrations (0.6 to 1.0 ppm) within the WHO permissible limit. Sister chromatid exchanges (SCE)
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Chronic fluoride exposure does not cause detrimental, extraskeletal effects in nutritionally deficient rats
On the basis of observations that endemic fluorosis occurs more often in malnourished populations, a series of studies tested the hypothesis that deficient dietary intake of calcium, protein or energy affects fluoride metabolism so that the margin of safe fluoride exposure may be reduced. The objective of the investigation was
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A Critique of Gelberg's Study on Fluoride/Osteosarcoma in New York
The case-control study by Gelberg, published first as a PhD dissertation and then later in two peer-reviewed journals, may represent the most substantive study on fluoride/osteosarcoma previous to Bassin’s 2001 analysis. In assessing Gelberg’s data, we were at first struck by the existence of several notable errors in both the thesis and papers. While these errors do raise questions about the study, our primary concern with Gelberg’s work relates to the methods she used to analyze her data.
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NTP Bioassay on Fluoride/Cancer (1990)
In 1977, the U.S. Congress requested that animal studies be conducted to determine if fluoride can cause cancer. The result of the Congressional request was an extensive animal study conducted in the 1980s by the National Toxicology Program (NTP) and published in 1990. The main finding of NTP's study was a dose-dependent increase in osteosarcoma (bone cancer) among the fluoride-treated male rats.
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Fluoride & Osteosarcoma: A Timeline
Several human epidemiological studies have found an association between fluoride in drinking water and the occurrence of osteosarcoma (bone cancer) in young males. These studies are consistent with the National Toxicology Program's (NTP) cancer bioassay which found that fluoride-treated male rats had an dose-dependent increase in osteosarcoma. Although a number of studies have failed to detect an association between fluoride and osteosarcoma, none of these studies have measured the risk of fluoride at specific windows in time, which based on recent results, is the critical question with respect to fluoride and osteosarcoma.
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Micronucleus and Sister Chromatid Exchange Frequency in Endemic Fluorosis
The rise of sister chromatid exchange (SCE) and micronucleus (MN) in the peripheral blood lymphocytes of the fluorine-intoxicated patients indicates that fluorine is a mutagenic agent which can cause DNA and chromosomal damage.
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Fluoride's Mutagenicity: In vivo Studies
Consistent with dozens of in vitro studies, a number of in vivo studies, in both humans and animals, have found evidence of fluoride-induced genetic damage. In particular, research on humans exposed to high levels of fluoride have found increased levels of "sister chromatid exchange" (SCE). As noted in one study: "In
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