Effects of different selenium sources on duodenum and jejunum tight junction network and growth performance of broilers in a model of fluorine-induced chronic oxidative stress.

The protective effects and underlying molecular mechanisms of sodium selenite (SS) and selenomethionine (SM) against chronic oxidative stress-induced duodenum and jejunum tight junction (TJ) network disturbance and growth inhibition of broilers were investigated in the current experiment. At the age of 1 d, 720 Lingnan Yellow broiler chicks were allocated to 4 experimental diets (with 6 replicates per diet and 30 birds per replicate) and offered either a control diet (fluorine [F] 23 mg/kg, control [CoN] group) or test diets (800 mg/kg F, high F [HF] group; 800 mg/kg F+0.15 mg selenium [Se]/kg as SS [SS group] or SM [SM group]) for 56 d. The results showed that HF group could induce chronic oxidative stress and subsequently increased (P < 0.05) proinflammatory cytokines levels of duodenum and jejunum in comparison with the CoN group. Increased proinflammatory cytokines levels of HF group promoted myosin light chain kinase (MLCK) transcription, thus leading to a decrease (P < 0.05) in TJ proteins expression of duodenum and jejunum when compared with the CoN group. A reduction of TJ proteins expression destroyed the TJ structures in the HF group, which in turn increased intestinal mucosal permeability of duodenum and jejunum and ultimately induced growth inhibition of broilers. Dietary Se supplementation could ameliorate HF-induced duodenum and jejunum TJ network impairment and growth retardation of broilers, potentially by increasing (P < 0.05) the glutathione peroxidase and thioredoxin reductase activities, reducing (P < 0.05) the reactive oxygen species and malondialdehyde levels, regulating the secretion of proinflammatory cytokines, and mediating the transcription level of MLCK in the duodenum and jejunum. Additionally, our data also suggested that the protective effects of SM were superior to those of SS. This study will provide a theoretical basis for developing SM into an efficient protective agent for intestinal mucosal barrier in poultry.

The Effects of Calcium, Magnesium, Phosphorus, Fluoride, and Lead on Bone Tissue.

Bones are metabolically active organs. Their reconstruction is crucial for the proper functioning of the skeletal system during bone growth and remodeling, fracture healing, and maintaining calcium-phosphorus homeostasis. The bone metabolism and tissue properties are influenced by trace elements that may act either indirectly through the regulation of macromineral metabolism, or directly by affecting osteoblast and osteoclast proliferation or activity, or through becoming part of the bone mineral matrix. This study analyzes the skeletal impact of macroelements (calcium, magnesium, phosphorus), microelements (fluorine), and heavy metals (lead), and discusses the concentration of each of these elements in the various bone tissues.

Do Only Calcium and Vitamin D Matter? Micronutrients in the Diet of Inflammatory Bowel Diseases Patients and the Risk of Osteoporosis.

Osteoporosis is one of the most common extraintestinal complications among patients suffering from inflammatory bowel diseases. The role of vitamin D and calcium in the prevention of a decreased bone mineral density is well known, although other nutrients, including micronutrients, are also of extreme importance. Despite the fact that zinc, copper, selenium, iron, cadmium, silicon and fluorine have not been frequently discussed with regard to the prevention of osteoporosis, it is possible that a deficiency or excess of the abovementioned elements may affect bone mineralization. Additionally, the risk of malnutrition, which is common in patients with ulcerative colitis or Crohn's disease, as well as the composition of gut microbiota, may be associated with micronutrients status.

Staphylococcus aureus Prosthetic Joint Infection Is Prevented by a Fluorine- and Phosphorus-Doped Nanostructured Ti-6Al-4V Alloy Loaded With Gentamicin and Vancomycin.

Prosthetic joint infection (PJI) is one of the most devastating complications in orthopedic surgery. One approach used to prevent PJI is local antibiotic therapy. This study evaluates the antibiotic release, in vitro cytocompatibility and in vivo effectiveness in preventing PJI caused by Staphylococcus aureus (S. aureus) of the fluorine- and phosphorus-doped, bottle-shaped, nanostructured (bNT) Ti-6Al-4V alloy loaded with a mixture of gentamicin and vancomycin (GV). We evaluated bNT Ti-6Al-4V loading with a mixture of GV, measuring the release of these antibiotics using high-performance liquid chromatography. Further, we describe bNT Ti-6Al-4V GV cytocompatibility and its efficacy against S. aureus using an in vivo rabbit model. GV was released from bNT Ti-6Al-4V following a Boltzmann non-linear model and maximum release values were obtained at 240 min for both antibiotics. The cell proliferation of MCT3T3-E1 osteoblastic cells significantly increased at 48 (28%) and 168 h (68%), as did the matrix mineralization (52%) of these cells and the gene expression of three of the most important markers related to bone differentiation (more than threefold for VEGF and BGLAP, and 65% for RunX) on bNT Ti-6Al-4V GV compared with control. In vivo study results show that bNT Ti-6Al-4V GV can prevent S. aureus PJI according to histopathological and microbiological results. According to our results, bNT Ti-6Al-4V loaded with a mixture of GV using the soaking method is a promising biomaterial with favorable cytocompatibility and osteointegration, demonstrating local bactericidal properties against S. aureus. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:588-597, 2020.

[Electronic probe analysis of enamel remineralization effect of casein phosphopeptide-amorphous calcium phosphate promoted by different concentrations of fluorine].

Objective: To evaluate the remineralization effect and mechanism of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) with different concentrations of fluorine on demineralized enamel using electronic probe. Methods: Extracted premolar teeth for orthodontic purpose were immersed into lactic acid gel to prepare artificial white spot lesions (10 teeth in each group). Then the specimens were randomly assigned to three groups: Control group, with 5% of the CPP-ACP+deionized water; Group A with 5% CPP-ACP+500 mg/L F(-) and Group B with 5% CPP-ACP+900 mg/L F(-). The teeth in each group were soaked in different solutions for 4 days and then were measured using electron probe tester. The changes of contents among the three groups were compared. Results: No statistically significant difference in the percentage of fluorine was found in the control group before and after treatment (P=0.06), and the difference in the percentage of fluorine quality in the other two groups was statistically significant (P<0.05). Statistically significant difference was found between calcium oxide and phosphorus peroxide in the three groups before and after mineralization (P<0.05). The percentage change of fluorine mass in group B [(0.107±0.035)%] was significantly greater than that in group A [(0.057±0.038)%] (P<0.05), while fluorine mass in group A was significantly greater than that in control group [(0.013±0.019)%] (P<0.05). In group A and group B, the change in quality of calcium oxide and phosphorus peroxide was significantly greater than that in control group (P<0.05), while no significant difference was found between group A and group B (P>0.05). Conclusions: The addition of fluorine in CPP-ACP increased the transport and penetration of calcium, phosphorus and fluorine on enamel surface.

Evaluation of bacterial flora composition on teeth and periodontal tissues in patients in treatment with rapid palatal expander.

Patients in treatment with rapid palatal expander (RPE) require professional assistance and more meticulous instructions on oral hygiene, since this appliance predisposes to gingivitis and caries. The aim of this work is to analyse the variability of the oral microbial flora found in patients in treatment with RPE with occlusal acrylic splint. It was also investigated whether the association of an antimicrobial mouthwash was useful during orthodontic treatment or whether regular and specific home oral hygiene manoeuvres were sufficient to maintain a good plaque control. The last goal was to highlight which of the different mouthwashes was the most effective in reducing the bacterial load. The patients were divided into 3 test groups and each one of them had a different mouthwash (chlorhexidine and sodium fluoride, fluorine, essential oils) randomly assigned. There was also a control group. Plaque samples were analysed through cultural analysis and PCR from T0 to T4 (8 months). Chlorhexidine mouthwash reduces the bacterial count by 96.08%, the fluorine by 94.50% and the essential oils by 95.74%. The results of the three mouthwashes are superimposable and although chlorhexidine gives the highest rate of bacteria reduction, its side effects lead the authors to prefer the essential oils.

Dietary High Fluorine Alters Intestinal Microbiota in Broiler Chickens.

This study investigated the effects of dietary high fluorine on ileal and cecal microbiota in broiler chickens. Two hundred eighty 1-day-old broiler chickens were randomly assigned to four groups and raised for 42 days. The control group was fed a corn-soybean basal diet (fluorine 22.6 mg/kg). The other three groups were fed the same basal diet, but supplemented with 400, 800, and 1200 mg/kg fluorine (high fluorine groups I, II, and III), administered in the form of sodium fluoride. The microbiota of ileal and cecal digesta was assessed with plate counts and polymerase chain reaction-based denaturing gradient gel electrophoresis (PCR-DGGE). It was found that, compared with those in the control group, the counts of Lactobacillus spp. and Bifidobacterium spp. were markedly decreased (P < 0.01 or P < 0.05), whereas the counts of Escherichia coli and Enterococcus spp. were significantly increased (P < 0.01 or P < 0.05) in the high fluorine groups II and III. PCR-DGGE analysis showed that the number of DGGE bands, similarity, and Shannon index of ileal and cecal bacteria were markedly reduced in the high fluorine groups II and III from 21 to 42 days. Sequencing analysis revealed that the composition of the intestinal microbiota was altered in the high fluorine groups. In conclusion, dietary fluorine in the range of 800-1200 mg/kg obviously altered the bacterial counts, and the diversity and composition of intestinal microbiota in broiler chickens, a finding which implies that dietary high fluorine can disrupt the natural balance and structure of the intestinal microbiota.

Significance of αThr-349 in the catalytic sites of Escherichia coli ATP synthase.

This paper describes the role of α-subunit VISIT-DG sequence residue αThr-349 in the catalytic sites of Escherichia coli F1Fo ATP synthase. X-ray structures show the highly conserved αThr-349 in the proximity (2.68 Å) of the conserved phosphate binding residue ßR182 in the phosphate binding subdomain. αT349A, -D, -Q, and -R mutations caused 90-100-fold losses of oxidative phosphorylation and reduced ATPase activity of F1Fo in membranes. Double mutation αT349R/ßR182A was able to partially compensate for the absence of known phosphate binding residue ßR182. Azide, fluoroaluminate, and fluoroscandium caused insignificant inhibition of αT349A, -D, and -Q mutants, slight inhibition of the αT349R mutant, partial inhibition of the αT349R/ßR182A double mutant, and complete inhibition of the wild type. Whereas NBD-Cl (7-chloro-4-nitrobenzo-2-oxa-1,3-diazole) inhibited wild-type ATPase and its αT349A, -D, -R, and -Q mutants essentially completely, ßR182A ATPase and double mutant αT349A/ßR182A were inhibited partially. Inhibition characteristics supported the conclusion that NBD-Cl reacts in ßE (empty) catalytic sites, as shown previously by X-ray structure analysis. Phosphate protected against NBD-Cl inhibition in the wild type, αT349R, and double mutant αT349R/ßR182A but not in αT349A, αT349D, or αT349Q. The results demonstrate that αThr-349 is a supplementary residue involved in phosphate binding and transition state stabilization in ATP synthase catalytic sites through its interaction with ßR182.

Suppressive effects of dietary high fluorine on the intestinal development in broilers.

Fluoride (F) is a well-recognized hazardous substance. Ingested F initially acts locally on the intestines. The small intestine plays a critical role in the digestion, absorption, and defense. In this study, therefore, we investigated the effects of fluorine on the intestinal development by light microscopy, transmission electron microscopy, and histochemistry. A total of 280 one-day-old avian broilers were randomly divided into four groups and fed on a corn-soybean basal diet as control diet (fluorine, 22.6 mg/kg) or the same basal diet supplemented with 400, 800, and 1,200 mg/kg fluorine (high fluorine groups I, II, and III) in the form of sodium fluoride for 42 days. The results showed that the intestinal gross, histological, and ultrastructural changes were observed in the high fluorine groups II and III. Meanwhile, the intestinal length, weight, viscera index, villus height, crypt depth, villus height to crypt depth ratio, diameter, muscle layer thickness, and goblet cell numbers were significantly lower (p < 0.01 or p < 0.05), and the intestinal diameter to villus height ratio was markedly higher (p < 0.01 or p < 0.05) in the high fluorine groups II and III than those in control group. In conclusion, dietary fluorine in the range of 800-1,200 mg/kg obviously altered the aforementioned parameters of the intestines, implying that the intestinal development was suppressed and the intestinal functions, such as digestion, absorption, defense, or osmoregulation were impaired in broilers.

The association between cytokines and intestinal mucosal immunity among broilers fed on diets supplemented with fluorine.

Fluorine (F) bioaccumulation has been reported in the organs and tissues of organisms, including intestine. The intestinal mucosa is very important to the immune development. Meanwhile, cytokines are present in the normal intestinal mucosal and play an important role in the immune function. Thus, changes of the cytokine contents are related to the state of intestinal mucosal immunity. In this study, we investigated the changes in contents of cytokines such as interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-6 (IL-6), interferon gamma (IFN-γ), and tumor necrosis factor-alpha (TNF-α) induced by dietary high F in the mucosa of different parts of intestines (duodenum, jejunum, and ileum) by enzyme-linked immunosorbent assay. A total of 280 one-day-old healthy avian broilers were randomly divided into four groups and fed on a corn-soybean basal diet as control diet (F 22.6 mg/kg) or the same basal diet supplemented with 400, 800, and 1,200 mg F/kg (high F groups I, II, and III) in the form of sodium fluoride for 42 days. The experimental data showed that the contents of IL-2, IL-4, IL-6, IFN-γ, and TNF-α in the intestinal mucosa were significantly decreased in the high F groups II and III when compared with those of the control group from 14 to 42 days of age. It was concluded that dietary F in the range of 800-1,200 mg/kg significantly reduced the contents of aforementioned cytokines in the intestinal mucosa of broilers, which could impact the function of intestinal mucosal immunity through the pathways that decreased the lymphocyte population and/or lymphocyte activation.

Novel heteroaromatic organofluorine inhibitors of fructose-1,6-bisphosphatase.

A broad group of compounds including substituted pyrazoles, pyrroles, indoles, and carbazoles were screened to identify potential inhibitor lead compounds of fructose-1,6-bisphosphatase (FBPase). Best inhibitors are (1H-indol-1-yl)(4-(trifluoromethyl)phenyl)methanone, ethyl 3-(3,5-dimethyl-1H-pyrrol-2-yl)-4,4,4-trifluoro-3-hydroxybutanoate, 3,5-diphenyl-1-(3-(trifluoromethyl) phenyl)-1H-pyrazole, and ethyl 3,3,3-trifluoro-2-hydroxy-2-(1-methyl-1H-indol-3-yl)propanoate. The IC50 values (3.1, 4.8, 6.1, and 11.9 microM) were comparable to that of AMP, the natural inhibitor of murine FBPase (IC50 of 4.0 microM). Docking programs were utilized to interpret the experiments.

Fluorinated natural products with clinical significance.

The modification of natural products in an effort to alter their biochemical capacity is a common technique utilized by synthetic and medicinal chemists. Fluorine substitution imparts unique and advantageous physiochemical properties that can be shrewdly employed to constructively alter pharmacological agents. The adornment of natural products with fluorine has proven beneficial in several examples. This overview discusses several of the most relevant fluorinated natural products under current examination.

Synthesis and biological activity of novel 4,4-difluorobenzazepine derivatives as non-peptide antagonists of the arginine vasopressin V1A receptor.

To find potent and selective antagonists of the arginine vasopressin (AVP) V1A receptor, optimization studies of compounds structurally related to (Z)-N-{4'-[(4,4-difluoro-5-carbamoylmethylidene-2,3,4,5-tetrahydro-1H-1-benzazepin-1-yl)carbonyl]phenyl}carboxamide were performed. The synthesis and pharmacological properties of these compounds are described. We first investigated the effect of the carboxamide moiety, and found that a 2-methylfuran-3-carbonyl group at this position increased V1A binding affinity and selectivity for the V1A receptor versus the V2 receptor. The amino group of the 5-carbamoylmethylidene moiety was also examined, and a 4-piperidinopiperidino group was found to be optimal at this position. The hemifumarate of compound 12l (YM218) was shown to exhibit potent binding affinity, V1A receptor selectivity, and in vivo antagonist activity.

In vitro advanced antimycobacterial screening of cobalt(II) and copper(II) complexes of fluorinated isonicotinoylhydrazones.

The in vitro antimycobacterial activity of cobalt(II) and copper(II) complexes of some fluorinated isonicotinoylhydrazones was evaluated in a TB-infected macrophage model; all metalcomplexes exhibited excellent activity against Mycobacterium tuberculosis Erdman growing within macrophages, at concentrations much lower than in culture media. Moreover complexes 1b and 2a displayed EC(99) values lower than that of the parent-drug, isoniazid. In addition, all tested metalchelates significantly inhibited the growth of single-drug-resistant M. tuberculosis strains; complexes 1a and 2a also possessed moderate activity against Mycobacterium avium complex.

Noninvasive measurements of capecitabine metabolism in bladder tumors overexpressing thymidine phosphorylase by fluorine-19 magnetic resonance spectroscopy.

PURPOSE: Previous studies have shown that tumor response to capecitabine strongly correlates with tumor thymidine phosphorylase (TP). The aims of our study were to (a). investigate the pharmacological role of TP by measuring the pharmacokinetics (PK) of capecitabine in a human bladder tumor model that was characterized by the overexpression of TP and (b). develop the use of PK measurements for capecitabine by fluorine-19 magnetic resonance spectroscopy as a noninvasive surrogate marker for determining TP levels in tumors and for predicting tumor response to capecitabine in patients. EXPERIMENTAL DESIGN: TP overexpressing (2T10) and control tumors were grown s.c. in nude mice. Mice were given a dose of capecitabine or 5'-deoxy-5-fluorouridine (5'DFUR). (19)F tumor spectra were acquired for determination of rate constants of capecitabine breakdown and buildup and subsequent breakdown of intermediates, 5'-deoxy-5-fluorocytidine (5'DFCR) and 5'DFUR. The rate constant of 5'DFUR breakdown was also evaluated. RESULTS: The rate constant of breakdown of intermediates was significantly faster in 2T10 tumors than controls (P < 0.003). No significant differences in the rate of capecitabine breakdown or intermediate buildup were observed. The rate constant of 5'DFUR breakdown in the 2T10 tumors was doubled compared with controls (P < 0.001). CONCLUSIONS: This study confirmed the expected pathway of capecitabine metabolism and showed that the level of TP was related to the rate of 5'DFUR conversion. Using in vivo fluorine-19 magnetic resonance spectroscopy to mea-sure the PK of capecitabine and its intermediate metabolites in tumors may provide a noninvasive surrogate method for determining TP levels in tumors and for predicting tumor response to capecitabine in patients.

Utilisation of different phosphorus sources in relation to their fluorine content for broilers and layers.

1. The relative utilisation of different phosphorus sources in relation to their fluorine (F) content was studied in commercial broilers (5 to 40 d) and White Leghorn layers (252 to 364 d). The phosphorus (P) sources tested were bonemeal (BM), low fluorine (LFRP) and high fluorine (HFRP) rock phosphates and a commercial mineral mixture (CMM). The P sources were incorporated in broiler and layer diets by replacing dicalcium phosphate (DCP) on a P basis. 2. The F contents of diets based on BM, LFRP, CMM and HFRP were 53, 365, 622 and 1383 mg/kg in the broiler experiment and 34, 242, 437 and 967 mg/kg in the layer experiment, respectively. F was not detected in DCP based diets. 3. In broilers, body weight gain, food intake, gain: food, P retention and serum inorganic P content on P sources (BM and LFRP) containing F up to 365 mg/kg diet were similar to those on DCP. Body weight gain, food intake, serum calcium and inorganic P contents and retention of P were depressed in groups fed on CMM and HFRP, which may have been due to the toxic effects of F (622 and 1383 mg/kg) present in diets based on these P sources. 4. Bone ash and its P content were not affected by feeding diets containing F up to 1383 mg/kg from various P sources. The amount of F deposited in tibia increased significantly with increases in dietary F concentration. 5. In layers, egg production and food intake were not affected by F up to 437 mg/kg in diets containing BM, LFRP or CMM as the sole source of supplemental P. Egg production and food intake were depressed significantly in layers given the diet containing 967 mg F/kg from HFRP. 6. Egg mass: food, egg weight, shell quality (shell thickness and shell weight) and serum calcium and inorganic P levels were not affected by F up to 967 mg/kg in diets containing different P sources. 7. It may be concluded that the performance of broilers and layers was not affected by feeding various P supplements with dietary levels of F up to 365 and 437 mg/kg, respectively. The reduced performance in broilers and layers observed with some of the P sources may have been due to poor availability of P and/or toxic effects of F (622 and 967 mg/kg, respectively).

Estudos histológico-morfométricos e microrradiográficos de costelas de bovinos suplementados com fosfato de rocha / Morphologic-morphometrical and microradiographical studies on ribs of cattle supplemented with rock phosphate

O objetivo do presente trabalho foi o de avaliar, através de técnicas especializadas, as possíveis alterações ósseas produzidas em bovinos em decorrência da ingestão prolongada de diferentes níveis de flúor contido no fosfato de rocha de Tapira utilizado como fonte suplementar de fósforo. No primeiro experimento bovinos confinados ingeriram, durante 6 meses, quantidades variáveis (63 e 128g/dia) de fosfato de Tapira contendo 1.3% de flúor. No segundo experimento, bovinos em pastos de Brachiaria decumbens ingeriram, durante 33 meses, misturas minerais contendo diferentes níveis de fosfato de rocha de Tapira. No terceiro experimento, novilhas com idade inicial média de 14 meses ingeriram mistura mineral com fosfato de Tapira até a quinta lactação inclusivamente. Através de exames histológicos, morfométricos e microrradiográficos das amostras de costelas, não se observaram alterações da normalidade óssea, bem como não foram registradas diferenças entre amostras provenientes de diferentes tratamentos. Tais achados permitem inferir que, do ponto de vista de alterações ósseas, o fosfato de rocha de Tapira pode ser utilizado como fonte suplementar de fósforo para bovinos, nas dosagens, períodos e manejos alimentares estudados, sem risco de produzir alterações patológicas nos esqueleto dos animais

Mechanism of the mitogenic effect of fluoride on osteoblast-like cells: evidences for a G protein-dependent tyrosine phosphorylation process.

Recent results indicate that a fluoroalumino complex (AlFx) is probably the molecule responsible for the mitogenic effect of fluoride in MC3T3-E1 osteoblast-like cells. Initial analysis suggested that a tyrosine phosphorylation (tyr phos) process similar to that induced by thrombin and activation of the p42 MAP kinase (ERK 2) mediate this cellular response. In the present study, the signaling mechanism activated by AlFx was further investigated. The results indicated that AlFx dose-dependently enhanced the tyr phos of the cell adhesion proteins FAK and paxillin, as well as of the adaptor molecules p46shc, p52shc, and p66shc and their association with GRB2. Pretreatment of MC3T3-E1 cells with cytochalasin D completely prevented FAK and paxillin tyr phos without any alteration in the tyr phos of Shc proteins and activation of ERK2 induced by AlFx. This observation suggests that in confluent MC3T3-E1 cells, there is no link between the activation of FAK induced by AlFx and the stimulation of ERK2. Pretreatment of the cells with pertussis toxin inhibited Shc phosphorylation, activation of ERK2, and markedly reduced cell replication induced by AlFx. This toxin also significantly reduced the stimulation of Pi transport activity induced by AlFx in these cells. Alteration in tyr phos induced by AlFx was not associated with any detectable inhibition of tyrosine phosphatase activity in MC3T3-E1 cell homogenates, suggesting that enhanced tyr phos induced by AlFx probably resulted from activation of a tyrosine kinase. In conclusion, the results of this study suggest that the mitogenic effect of fluoride in MC3T3-E1 osteoblast-like cells is mediated by the activation of a pertussis toxin-sensitive Gi/o protein and suggest an important role for these heterotrimeric G proteins in controlling the growth and differentiation of bone-forming cells.