Microstructural Analysis of Cancellous Bone in Fluorosis Rats.

Skeletal fluorosis likely alters bone structural properties on the cortical and cancellous tissue levels in view that fluorine ion replaces bone mineral composition. Our previous study showed high bone turnover occurred in cortical bone of skeletal fluorosis. Therefore, this study further analyzed the microstructure of cancellous bone in fluorosis rats. Rats were randomly assigned into three groups: the control, low-dose fluoride group (10 mgF-/kg·day), and high-dose fluoride group (20 mgF-/kg·day). Rats were orally administered with fluoride for 1, 2, and 3 months of periods. The trabecular bone parameters of tibia were detected with micro CT and analyzed with software. The activities of glutathione peroxidase (GPX), superoxide dismutase (SOD), and the content of malondialdehyde (MDA) in serum were measured. Results showed that severity of dental fluorosis rose with the increase of dose and prolongation of fluoride exposure. Meantime, the poorer connectivity and less trabecular bone network were observed in cancellous bone of rats treated with fluoride. Data analysis indicated that fluoride treatment significantly decreased bone volume and connectivity degree, but amplified trabecular space in 1 and 2 months of periods. Intriguingly, trabecular thickness significantly decreased in 1-month high-dose fluoride group, but returned to the control in 3 months of period. Fluoride treatment mainly inhibited the GPX activity and increased the MDA level to activate oxidative stress. This study confirmed that excessive fluoride impaired cancellous bone and caused redox imbalance.

Effects of Different Doses of Calcium on the Mitochondrial Apoptotic Pathway and Rho/ROCK Signaling Pathway in the Bone of Fluorosis Rats.

For this study, we investigate more deeply the effect calcium (Ca) develops on the mechanism underlying fluoride-triggered osteocyte apoptosis. We detected the morphology of osteocytes by HE staining, mitochondrial microstructure by using the transmission electron microscope, and the biochemical indexes related to bone metabolism and the expression of apoptosis-related genes. These results showed that NaF brought out the reduced osteocytes and ruptured mitochondrial outer membrane, with a significantly increased StrACP activity by 10.414 IU/L at the 4th week (P < 0.05), markedly upregulating the mRNA expression of Bax, Cyto-C, Apaf-1, caspase-7, ROCK-1, BMP-2, and BGP (P < 0.01), as well as caspase-6 (P < 0.05), while downregulating Bcl-2 by 61.3% (P < 0.01). Through immunohistochemical analysis, we also found that NaF notably increased the protein expression of ROCK-1 (P < 0.05) and Cyto-C, BMP-2, and BGP (P < 0.01), suggesting that NaF triggered the activation of the mitochondrial apoptotic pathway and Rho/ROCK signaling pathway. Nevertheless, 1% Ca supplementation in diet notably enhanced the mRNA expression of Bcl-2 by 39.3% (P < 0.01), thus blocking the increment of the expression of mitochondrial apoptotic pathway-related genes and ROCK-1. Meanwhile, Ca could attenuate the StrACP activity by 10.741 IU/L at the 4th week (P < 0.05) and protect the integrity of the mitochondrial outer membrane. These findings strongly suggest that 1% Ca abated the mitochondrial apoptosis pathway by increasing the anti-apoptotic gene Bcl-2 expression, and effectively inhibited the hyper-activation of ROCK-1, dually protecting the structural integrity of the mitochondrial outer membrane and maintaining normal cellular metabolic function.

Calcium relieves fluoride-induced bone damage through the PI3K/AKT pathway.

Bone is the main target of fluorosis, and it has been perfectly elaborated that a moderate dosage of calcium (Ca) can alleviate bone fluorosis. However, whether Ca can alleviate fluorosis through the phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT) signaling pathway has not yet been reported. Hence, we evaluated the histopathological structure, the imbalance of the biochemical index of bone metabolism, and the expression levels of PI3K/AKT apoptosis signaling pathway-related genes in rats treated with sodium fluoride (NaF, F) and/or calcium carbonate (CaCO3) for 120 days. Our results suggest that 100 mg L-1 NaF induced histopathological injury as alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (StrACP) activity increased, with a decrease in the serum Ca levels (p < 0.05). Moreover, the results of qRT-PCR and western blotting showed that F increased the expression levels of transglutaminase 2 (TGM2), focal adhesion kinase (FAK), PI3K, AKT, forkhead box O1 (Foxo1), Bcl-2 interacting mediator of cell death (BIM), Bcl2-associated x protein (Bax) and Caspase 3 (p < 0.05, p < 0.01). It also decreased the expression of AnnexinA5 (Anxa5), 3'-phosphoinositide-dependent kinase 1 (PDK1) and B-cell lymphoma-2 (Bcl-2) (p < 0.05, p < 0.01), which finally activated the PI3K/AKT pathway. On the other hand, CaCO3 supplementation reversed the histopathological injury along with the levels of ALP, StrACP and serum Ca, alleviating the gene expression levels of PI3K/AKT pathway-related markers. Altogether, we can conclude that CaCO3 supplementation mitigated F-induced bone damage via the PI3K/AKT signaling pathway.

[Separation and identification of differential protein in rat's bone with fluorosis and calcium supplementation intervention].

In order to explore the mechanisms underlying the calcium alleviating fluorosis at protein level, we made an attempt to establish fluorosis and calcium supplementation rat models to isolate and identify bone differential proteins. The bone proteins of different groups were compared by two-dimensional electrophoresis (2-DE) and mass spectrometry (MALDI-TOF MS), and analyzed by gene ontology annotation, pathway enrichment and interaction networks. The 17 proteins were identified in the fluorosis group (F) and the fluorosis calcium supplement group (F+Ca), including type I collagen (Col1a1), actin (Actb), protein glutamine transferase 2 (Tgm2), compared with the control group (C). These differential proteins are enriched in 38 bone metabolic pathways such as focal adhesion, PI3K-Akt signaling pathway, and AMPK signaling pathway. And the functions of these proteins are mainly related to cytoskeleton, energy metabolism, substance transport, ion channel, and apoptosis. Therefore, it is speculated that calcium may alleviate the fluoride-induced bone damage by regulating the focal adhesion, PI3K-Akt, AMPK and other signaling pathway, but the specific mechanism needs further research.

Separation and identification of differential protein in rat's bone with fluorosis and calcium supplementation intervention / 生物工程学报

In order to explore the mechanisms underlying the calcium alleviating fluorosis at protein level, we made an attempt to establish fluorosis and calcium supplementation rat models to isolate and identify bone differential proteins. The bone proteins of different groups were compared by two-dimensional electrophoresis (2-DE) and mass spectrometry (MALDI-TOF MS), and analyzed by gene ontology annotation, pathway enrichment and interaction networks. The 17 proteins were identified in the fluorosis group (F) and the fluorosis calcium supplement group (F+Ca), including type I collagen (Col1a1), actin (Actb), protein glutamine transferase 2 (Tgm2), compared with the control group (C). These differential proteins are enriched in 38 bone metabolic pathways such as focal adhesion, PI3K-Akt signaling pathway, and AMPK signaling pathway. And the functions of these proteins are mainly related to cytoskeleton, energy metabolism, substance transport, ion channel, and apoptosis. Therefore, it is speculated that calcium may alleviate the fluoride-induced bone damage by regulating the focal adhesion, PI3K-Akt, AMPK and other signaling pathway, but the specific mechanism needs further research.

Effects of Supplemental Epigallocatechin Gallate in the Diet of Broilers Exposed to Fluoride Intoxication.

We evaluated the effects of dietary epigallocatechin gallate (EGCG) on the performance, biochemical parameters, and liver histopathology of fluoride-intoxicated broiler chickens. In total, 160 1-day-old male broiler chicks (Ross PM3 strain) were collected and assigned to four groups (40 animals each), with four replicates. The control group received a basal diet; the F group received 800 mg/kg fluoride; the EGCG group received 400 mg/kg EGCG; and the EGCG+F group received 400 mg/kg EGCG and 800 mg/kg fluoride. The live weight (LW) of F-treated chicks was significantly lower than that of the controls. In the F-treated groups, feed intake (FI) and LW values were lower, but the feed conversion ratio (FCR) was higher than those of the controls. The ratio of heart weight to LW was found to be the highest in the F-treated groups. Alkaline phosphatase (ALP), aspartate aminotransferase (AST), and total oxidant status (TOS) levels in the F-treated groups were significantly higher, whereas the increase in total cholesterol levels was insignificant than those in the control group. In the EGCG+F group, AST, total cholesterol, and TOS levels decreased to a level comparable to those in the control group. Histopathological evaluation revealed that there were mild changes in the portal region in the EGCG+F group; additionally, there was an improvement in liver morphology in the EGCG+F group compared to that in the F group. Thus, EGCG has potent antioxidant and regenerative effects that can ameliorate the detrimental effects of fluoride toxicity on blood parameters and the liver.

Rescuing fluoride-induced damages in liver with gamma aminobutyric acid.

Fluorine poisoning affects human health all over the world and an urgent task is to develop alleviative medicine to recover or ameliorate the damages to the body. Here we studied the effects of gamma-aminobutyric acid (GABA), a liver protector reported previously, on fluoride-induced damage in the mouse liver. Through microscope imaging of the liver tissue, TUNEL immunostaining, real-time RT-PCR, enzyme immunoassay and colorimetric method, we found that GABA supplementation prevented the metabolic toxicity caused by fluoride treatment in mice. This detoxification was reflected by the reduced oxidative stress and apoptosis, enhanced neuron protection and liver function. Collectively, this study provided evidence of the beneficial effects of GABA supplement on liver damage, implicating its therapeutic potential in fluorosis.

[Effect of magnesium and selenium on the expression of matrix metalloproteinases-20 and kallikrein 4 in fluorosis mice].

OBJECTIVE: To study the effect of magnesium/selenium on the expression of matrix metalloproteinases-20(MMP-20) and kallikrein 4(KLK4) during fluorosis in mice and to explore the formation mechanism of dental fluorosis. METHODS: Eighty SPF male ICR mice were randomly divided into 8 groups according to body weight: control group, magnesium group, selenium group, magnesium-selenium group, fluoride group, magnesium-fluorine group, selenium-fluorine group and magnesium-selenium-fluorine group. Mice in control, magnesium, selenium and magnesium-selenium groups were fed double steamed water, and mice in the other four groups were feddouble steamed water with 50 mg/L F(-). Mice in control and fluoride groups were fed conventionally. Mice in magnesium and magnesium-fluorine groups were fed conventionally by adding MgSO4·7H2O 162.5 mg/kg. Mice in selenium and selenium-fluorine groups were fed conventionally by adding Na2SeO3·5H2O 2 mg/kg. Mice in magnesium-selenium and magnesium-selenium-fluorine groups were fed conventionally by adding MgSO4·7 H2O 162.5 mg/kg + Na2SeO3·5H2O 2 mg/kg. Incisor specimens were obtained after the mice were put into death when they were 42 days. The expressions of MMP-20 and KLK4 were observed by using immunohisto-chemicalstain. RESULTS: The meangray value of MMP-20 of fluoride group(133.1±10.3) was significantly higher than that of control group(116.8±10.0), magnesium group (113.6 ± 9.6), magnesium-selenium group(108.2 ± 15.2), magnesium-fluorine group(111.1 ± 8.1) and magnesium-selenium-fluorine group(108.2 ± 11.0), respectively(F=3.864, P<0.05). The mean gray value of MMP-20 of magnesium-selenium-fluorine group(108.2±11.0) was significantly lower than that of selenium group(125.4 ± 7.9), fluoride group (133.1 ± 10.3) and selenium-fluorine group(126.2 ± 2.8), respectively(F= 3.864, P<0.05). The mean gray value of KLK4 of magnesium-selenium group(117.2±11.7) was significantly lower than others(137.3±7.9 of control group, 144.2±7.7 of magnesium group, 138.9±13.3 of selenium group, 149.7 ± 12.4 of fluoride group, 148.9 ± 7.5 of magnesium-fluorine group, 140.6 ± 17.0 of selenium-fluorine group and 140.7 ± 7.3 of magnesium-selenium-fluorine group, F=3.668, P<0.05). In factorial analysis of fluorosis mice, magnesium had effect on the expression of MMP-20(F=42.613, P<0.05), selenium had effect on the expression of KLK4(F=6.649, P<0.05). CONCLUSIONS: The excessive fluoride could inhibit the expressions of MMP-20. The excessive fluoride hadno significant influence on the expression of KLK4. Magnesium and selenium had antagonistic effect on the dental fluorosis.

Maize purple plant pigment protects against fluoride-induced oxidative damage of liver and kidney in rats.

Anthocyanins are polyphenols and well known for their biological antioxidative benefits. Maize purple plant pigment (MPPP) extracted and separated from maize purple plant is rich in anthocyanins. In the present study, MPPP was used to alleviate the adverse effects generated by fluoride on liver and kidney in rats. The results showed that the ultrastructure of the liver and kidney in fluoride treated rats displayed shrinkage of nuclear and cell volume, swollen mitochondria and endoplasmic reticulum and vacuols formation in the liver and kidney cells. MPPP significantly attenuated these fluoride-induced pathological changes. The MDA levels in serum and liver tissue of fluoride alone treated group were significantly higher than those of the control group (p < 0.05). The presence of 5 g/kg MPPP in the diet reduced the elevation of MDA levels in blood and liver, and increased the SOD and GSH-Px activities in kidney and GSH level in liver and kidney compared with the fluoride alone treated group (p < 0.05). In addition, MPPP alleviated the decrease of Bcl-2 protein expression and the increase of Bax protein expression induced by fluoride. This study demonstrated the protective role of MPPP against fluoride-induced oxidative stress in liver and kidney of rats.

[Dermal and inhalation poisoning. Rare guests in our intensive care units?]. / Dermale und inhalative Intoxikationen. Seltene Gäste auf unseren Intensivstationen?

Patients with dermal and inhalation poisoning are uncommon in intensive care treatment. We describe the diagnostics and specific toxicological treatment of patients with hydrofluoric acid burns. For inhalation poisoning, we focus on smoke inhalation, especially the management of cyanide and carbon monoxide poisoning. Special attention is given to the use of hyperbaric oxygenation for the treatment of carbon monoxide poisoning.

[Intervention of selenium on liver impairment induced by chronic fluorosis in rats].

OBJECTIVE: To further explore the intervention of selenium on liver impairment induced by chronic fluorosis in rats. METHODS: Animals were divided into 8 groups and treated by different programs (In the 4 prevention groups, 0, 0.375, 0.75 and 1.5 mg/L sodium selenite solution were given for 6 months and then 50mg/L fluoride solution for another 6 months. In the 4 treatment groups, 50mg/L fluoride solution was given for 6 months and then 0, 0.375, 0.75 and 1. 5mg/L sodium selenite solution for another 6 months). The pathological change of liver was observed. The activities of GSH-Px, SOD, the level of MDA and the expression of NF-kappaB in liver were also determined. RESULTS: In the prevention groups, the activity of GSH-Px in the LSe-F and MSe-F groups was higher than the noSe-F control group (P < 0.05). The activity of SOD in the LSe-F group was higher than the noSe-F control group (P < 0.05). The MDA levels in LSe-F, MSe-F and HSe-F groups were lower than the noSe-F control group (P < 0.05). In the treatment groups, the activity of GSH-Px in the F-LSe and F-HSe groups was higher than the F-noSe control group (P < 0.05). The activity of SOD in the F-MSe group was higher than the F-noSe control group (P < 0.05). The MDA levels in the F-LSe, F-MSe and F-HSe groups were lower than the F-noSe control group (P < 0.05). CONCLUSION: There were a certain effects of selenium intervention on liver impairment induced by chronic fluorosis in rats. The preventive effect of selenium was better than the therapeutic effect, and the level of 0.375 mg/L Na2SeO3 was considered as the optimal concentration for the prevention of liver impairment induced by chronic fluorosis under this experimental condition.

Combined subchronic fluoride-lead intoxication and its attenuation with the help of a complex of bioprotectors.

BACKGROUND: Combined toxicity of lead and fluoride has been studied insufficiently, and there is no known information about attempts to inhibit it with any bioprotectors. METHODS: Lead acetate and sodium fluoride, administered separately or in combination, were injected i.p. to rats at isoeffective sublethal doses 3 times a week for 6 weeks. Some of the rats were exposed to the same combination against the background of oral administration of a bioprotector complex (BPC) comprising pectin, glutamate, and multivitamin/multimineral preparations. Following exposure, functional and biochemical indices and histopathological examinations of the femur of exposed and control rats were evaluated for signs of toxicity. RESULTS: We have shown that with regard to a number of effects on the organism level the combined toxicity of lead and fluoride may be evaluated as additive or even superadditive, but lead reduces fluoride accumulation in the bone, and pathological changes in the bone tissue proved to be less marked for combined exposure compared with separate exposures. The BPC has been demonstrated to attenuate a range of the combined harmful effects of lead and fluoride, including those on the bone tissue. CONCLUSIONS: In spite of the fact that fluoride and lead may reciprocally attenuate their harmful effects on the bone tissue in case of combined exposure, they prove to be more toxic for soft tissues just in combination than when administered separately. The development of combined intoxication may be substantially inhibited by means of the tested set of innocuous biologically active agents.

[Effect of fluoride on expression of CaN mRNA and protein in bone tissue of rats].

OBJECTIVE: To investigate the changes of mRNA and protein expression of CaN in the bone of rats with chronic fluorosis, and the mechanism of skeletal fluorosis. METHODS: Thirty-six SD rats were divided into three groups (12 in each group, half male and half female selected according to body weight): control, low-dose and high-dose fluorosis groups. Controls were fed tap water (NaF < 0.5 mg/L), experimental animals in the low- or high-dose groups were fed water containing NaF of 5.0 and 50.0 mg/L, respectively. The rats were sacrificed after 6 months of treatment with fluoride. The serum was kept for testing bone metabolic marker bone gla protein (BGP) by enzyme-linked immunosorbent assay (ELISA), the protein and mRNA levels of CaN in distal femur of the rats with chronic flurosis were assessed by immunohistochemistry and in-situ hybridization. RESULTS: The levels of BGP (1.99 ± 0.62, 2.38 ± 0.16)µg/L in the low- or high-dose fluorosis groups were higher than that in the control group (0.15 ± 0.03) µg/L; and the high fluorosis group showed higher level than the low fluorosis group (all P < 0.05). Compared to the control group (131.11 ± 1.95, 111.82 ± 2.39), the protein and mRNA levels of CaN were higher in the low- or high-dose fluorosis groups (142.69 ± 1.17, 157.54 ± 1.88 and 121.28 ± 3.27, 134.63 ± 3.19, respectively), and the high fluorosis group showed higher levels than the low fluorosis group (all P < 0.05). CONCLUSIONS: BGP content could be used as a bone metabolic index in endemic fluorosis disease. Fluoride might up-regulate the mRNA and protein expression of CaN, and the changes in CaN level may be involved in the increase of the bone turnover and could be one of the pathogenetic factors in fluorosis.

Effect of fluoride on expression of CaN mRNA and protein in bone tissue of rats / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the changes of mRNA and protein expression of CaN in the bone of rats with chronic fluorosis, and the mechanism of skeletal fluorosis.</p><p><b>METHODS</b>Thirty-six SD rats were divided into three groups (12 in each group, half male and half female selected according to body weight): control, low-dose and high-dose fluorosis groups. Controls were fed tap water (NaF < 0.5 mg/L), experimental animals in the low- or high-dose groups were fed water containing NaF of 5.0 and 50.0 mg/L, respectively. The rats were sacrificed after 6 months of treatment with fluoride. The serum was kept for testing bone metabolic marker bone gla protein (BGP) by enzyme-linked immunosorbent assay (ELISA), the protein and mRNA levels of CaN in distal femur of the rats with chronic flurosis were assessed by immunohistochemistry and in-situ hybridization.</p><p><b>RESULTS</b>The levels of BGP (1.99 ± 0.62, 2.38 ± 0.16)µg/L in the low- or high-dose fluorosis groups were higher than that in the control group (0.15 ± 0.03) µg/L; and the high fluorosis group showed higher level than the low fluorosis group (all P < 0.05). Compared to the control group (131.11 ± 1.95, 111.82 ± 2.39), the protein and mRNA levels of CaN were higher in the low- or high-dose fluorosis groups (142.69 ± 1.17, 157.54 ± 1.88 and 121.28 ± 3.27, 134.63 ± 3.19, respectively), and the high fluorosis group showed higher levels than the low fluorosis group (all P < 0.05).</p><p><b>CONCLUSIONS</b>BGP content could be used as a bone metabolic index in endemic fluorosis disease. Fluoride might up-regulate the mRNA and protein expression of CaN, and the changes in CaN level may be involved in the increase of the bone turnover and could be one of the pathogenetic factors in fluorosis.</p>

Intervention of selenium on chronic fluorosis-induced injury of blood antioxidant capacity in rats.

This study was conducted to further explore the effects of selenium on the blood antioxidant capacity in rats exposed to fluoride to find out the optimal dosage level of selenium. Animals were divided into prevention sequence (Selenium → NaF, water → NaF) and treatment sequence (NaF → Selenium, NaF → water) (sodium fluoride 50 mg/L; sodium selenite 0.375, 0.75, 1.5 mg/L). The exposure time was 12 months. Then, the fluidity of erythrocyte membrane by electron spin resonance was analyzed, and the blood was collected for GSH-Px and SOD activity, total antioxidant capacity (T-AOC) and uric acid assay, sialic acid and MDA content. The results showed that, compared with control group, GSH-Px activity and T-AOC level increased significantly (P < 0.05), and SOD activity was raised in varying degrees in prevention and treatment groups, respectively. Uric acid level was up-regulated, but no significant differences were observed (P > 0.05). The fluidity of erythrocyte membrane showed significant increase (P < 0.05). As evident in this study, when the dose of selenium was 0.75 mg/L, all the activities of antioxidant enzymes increased significantly in prevention sequence; but in treatment sequence, the optimum intervention concentration was 1.5 mg/L. On the basis of results, the preventive effect of selenium was superior to treatment effect on the oxidative stress induced by an overdose of fluoride.

Antioxidant and ACE enhancing potential of Pankajakasthuri in fluoride toxicity: an in vitro study on mammalian lungs.

Fluoride toxicity occurs due to high concentrations of fluoride in water sources or anthropogenic causes. The aim of the present study was to investigate the effects of an Ayurvedic drug--Pankajakasthuri (PK)--in relation to fluoride-induced toxicity in mammalian lungs. The results indicated that sodium fluoride increased lipid peroxidation and decreased enzymatic and non-enzymatic antioxidants in a concentration-dependent manner in lungs. The antioxidant potential of the lungs was suppressed maximally at 10 ppm fluoride concentration and PK at all three dose levels (i.e., 100, 200 and 300 µl) decreased fluoride induced lipid peroxidation (p < 0.05) and increased the levels of total ascorbic acid, superoxide dismutase, catalase, reduced glutathione, glutathione peroxidase and FRAP values significantly (p < 0.05) in a dose-dependent manner. When PK was examined for its effects on angiotensin-converting enzyme (ACE) activity, in fluoride-induced toxicity, the ACE activity was found to increase (p < 0.0001) in lung homogenates with all three doses. This study indicates that PK, an Ayurvedic drug, improves mammalian lung function by increasing antioxidant potential and ACE activity under the conditions of fluoride toxicity.

Skeletal fluorosis due to excessive tea and toothpaste consumption.

We describe the case of a 53-year-old woman who presented with a metatarsal fracture and was found to have a bone mineral density (BMD) T-score of +11 in the lumbar spine and +7.6 in the hip. Subsequent investigation revealed very high serum, urine and tissue fluoride levels, associated with excessive tea and toothpaste consumption. The case emphasises the need to exclude fluorosis in individuals with unexpectedly high BMD levels.

Comparative study of p38 MAPK signal transduction pathway of peripheral blood mononuclear cells from patients with coal-combustion-type fluorosis with and without high hair selenium levels.

Coal-combustion-type fluorosis has only been reported in China and its pathogenesis has not been fully understood. Fluoride causes chronic toxic effects and selenium modulates cellular activities through signal transduction in human cells. The present study enrolled three groups of subjects with well-defined serum and urine fluoride and hair selenium: high fluoride+high selenium group, high fluoride group and normal control group. The expressions of p38, NF-kB p65, caspase-3 and p53 genes at both protein and mRNA levels in peripheral blood mononuclear cells (PBMCs) were determined by Western blotting and quantitative real-time RT-PCR, respectively. The results showed that the expressions of p38, NF-kB p65, and caspase-3 protein in high fluoride group were higher than those in the other two groups. The mRNA level of NF-kB p65 and caspase-3 was significantly higher in high fluoride+high selenium group than control and lower than high fluoride group. The mRNA and protein level of p53 was significantly higher in high fluoride+high selenium group than that in other two groups. These results suggest that selenium may influence the protein and gene expression associated with p38 signal transduction pathway and up-regulate p53 expression in PBMCs from patients with coal-combustion-type fluorosis.

Selenium increases expression of HSP70 and antioxidant enzymes to lessen oxidative damage in Fincoal-type fluorosis.

Fincoal type fluorosis has only been reported from China, but its pathogenesis is unclear. Many people believe that fluorosis is associated with oxidative stress. Oxidative stress can be reduced at higher selenium (Se) level. Heat shock protein (HSP70) is the most conserved and induced against different stressors. The aim of this study is to detect the expression of HSP70 in fluorosis patients and explore the role of Se in fluorosis protection. The subjects were divided into four groups: "High Se + F group" (n = 50), "High F group" (n = 50), "High Se group" (n = 20) and "Control group" (n = 46). Expression of HSP70 was evaluated by Western blotting and real-time PCR techniques. The concentration of fluoride, content of Se in hair, activity of antioxidant enzymes (GSH-Px, SOD, CAT) and content of malondialdehyde (MDA) were determined. The relative amount of HSP70 gene transcription was significantly higher in "High Se + F group" than the other groups. The same results were found for expression of HSP70 protein to beta-actin ratio. There was a significant difference between "High Se + F group" and "High F group" regarding MDA content and glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and catalase (CAT) activity. These results suggest that oxidative stress plays an important role in the pathogenesis of the Fincoal type fluorosis and it can be reduced at higher Se level.

Growth, feed efficiency and blood profile of buffalo calves consuming high levels of fluoride: growth and blood metabolites in buffaloes fed high fluoride.

Twelve male buffalo calves of 10 to 12 months of age were divided into 3 groups of four each. They were fed wheat straw+concentrate mixture +3 Kg greens. The chemical composition of the diet was same in all the three groups except fluoride which was added (as NaF) in concentrate mixture of group B and C to make the final fluoride concentration 30 ppm and 60 ppm respectively. The animals were kept on scheduled diet for a period of 90 days. Body weights were recorded at the start of the experiment and at fortnightly interval thereafter. Analysis of data revealed that the dry matter intake decreased non significantly in group B and C as compared to control group. A significant decrease in serum calcium and a significant increase in phosphorus concentration were observed in group C animals. A significant increase was observed in alkaline phosphatase activity in group C animals. A non significant decrease was observed in T4 values in group C animals. On the basis of these results it could be concluded that fluoride in the diet of buffalo calves @ 30 ppm is a safe level whereas 60 ppm has affected the blood metabolites.