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PubMedDate not supplied

[Biochemical mechanisms of fluorine action].

Biochemical mechanisms of fluorine ion action accounting for the biological role and significance of fluorine for vital activity of the organism are investigated. Results of these investigations are generalized. This trace element is shown to participate at least in two vitally important systems of the organism: the adenylate cyclase system which accounts for the cell response to neuroendocrinological information and the immune protection system providing antimicrobic resistance. Available data permit considering that cytotoxic fluorine action is based on the ability to hinder protein synthesis in eukaryotes and to stimulate peroxidation processes of biomembrane lipids. Inorganic fluorine compounds are recommended to be used with the treatment-and-prophylactic purpose for certain pathologic states, associated with its insufficient or excessive arrival into the organism.

Adenylyl Cyclases↗
PubMed1985

[Ototoxic factors requiring consideration in the diagnosis of occupational hearing loss].

In the practice of diagnosing occupational deafness resulting from noise effects of factors determining workers' hearing, such as living conditions, working conditions, nutritional and other habits, diseases and their therapy, are often neglected. Discussed in the paper are the significance and ototoxic effects of such factors as: aminoglycoside antibiotics, diuretics, salicylic acid derivatives, fenacetin, quinine, fluorine compounds, cytotoxic drugs, chemical compounds other than drugs (carbon monoxide, carbon disulphide, lead, organic solvents), ethyl alcohol, diseases (abdominal typhus, bacillary dysentery, diphtheria, brucellosis, epidemic parotiditis, poliomyelitis, rubella, aural shingles, syphilis, diabetes mellitus, chronic renopathies, hypothyroidism, serologic conflict, pigmentary retinitis). Exposure to intense noise is more and more frequently juxtaposed with the impact of the mentioned factors. If industrial physicians get aware of this association the prevention of deafness and reliability of treatment may be largely promoted.

Anti-Bacterial Agents↗
PubMed1985

[Evaluation of the effect of the work environment on the state of the oral cavity].

2439 men and employed in 4 industrial plants of Szczecin area had their masticatory system examined. Onto the cards prepared for electronic data processing the information has been written on: oral cavity caries (IMF), oral mucosa membrane, periodontium, parafunction and T.M.J. dysfunction. The main exposure factors of those plants have been determined, namely: welding gas, aromatic hydrocarbons, fluorine compounds, and copper dusts. The IMF values, oral hygiene, periodontal diseases as well as the TMJ-dysfunction in the test workers have been found to be approximately similar to the relevant values of other populations and to vary with sex, age or poor hygienic conditions. On the other hand, the prevalence of oral leukoplakia and parafunction seems to be dependent on the working environment.

Adult↗
PubMed1971

Inhibition of contact sensitivity in the mouse by topical application of corticosteroids.

1. Topical application of oxazolone to the ears of mice previously sensitized to this hapten resulted in a marked increase in ear weight 24 h later.2. Topical application of hydrocortisone, betamethasone 17-valerate, fluocinolone acetonide or triamcinolone acetonide inhibited this response in a dose dependent manner.3. The free alcohols of the three fluorinated compounds were only weakly active.4. Activity in this model was truly local. Oral administration of hydrocortisone or fluocinolone acetonide at doses comparable to those used topically failed to inhibit the ear swelling.5. Some steroids with poor anti-inflammatory properties had no significant effect.

Adrenal Cortex Hormones↗
PubMed1984

Correlation between chemical structure, receptor binding, and biological activity of some novel, highly active, 16 alpha, 17 alpha-acetal-substituted glucocorticoids.

The affinity for the glucocorticoid receptor in rat skeletal muscle of some glucocorticoids with a new type of 16 alpha, 17 alpha-acetal substituent has been estimated and correlated to the glucocorticoid activities in three in vivo systems in rats. Budesonide (an approximately 1:1 mixture of the C(22) epimers of 11 beta, 21-dihydroxy-16 alpha, 17 alpha-[(22R,S)-propylmethylenedioxy]-pregna-1,4-diene-3,20-dione) and the isolated (22R)- and (22S)-epimers bound to the same binding site as the potent glucocorticoids dexamethasone (DEX) or triamcinolone 16 alpha, 17 alpha-acetonide (TA), but with even higher affinity than DEX or TA, despite the lack of a 9 alpha-fluoro atom in budesonide and its epimers. The (22R)-epimer was twice as active as the (22S)-epimer, 4 times more active than TA, and 14 times more active than DEX. The introduction of a 9 alpha-fluoro atom slightly decreased the binding affinity of the (22R)-epimer of budesonide, in contrast to the positive effect of 9 alpha-fluorination of, e.g., 16 alpha, 17 alpha-acetonides. The negative influence of 9 alpha-fluorination of the (22R)-epimer was partially reversed in the 6 alpha, 9 alpha-difluorinated (22R)-epimer. Nevertheless, the fluorinated compounds were more active than DEX and TA (8 and 11 times more active than DEX, and 2 and 3 times more active than TA, in case of the 9 alpha-fluoro- and 6 alpha, 9 alpha-difluoro-derivatives of the (22R)-epimer, respectively). Budesonide is metabolized mainly to 16 alpha-hydroxyprednisolone (11 beta, 16 alpha, 17 alpha, 21-tetrahydroxy-pregna-1,4-diene-3,20-dione) and 6 beta-hydroxy-budesonide. Both metabolites were very weak competitors for the ligand-binding sites on the receptor (3% and 6% of the affinity of DEX, respectively). The affinity for the receptor in vitro was closely correlated to the topical glucocorticoid activity in vivo for the 12 steroids compared (r = 0.98; R = 0.98), which supports the contention that in vitro tests for receptor affinity are useful when screening for agonists among steroids with the present type of structures. The results on receptor-ligand interaction are in accordance with X-ray crystallographic data available for some steroids.

Animals↗
PubMed1981

Reduction of tumorigenicity and of dihydrodiol formation by fluorine substitution in the angular rings of dibenzo(a,i)pyrene.

The tumor-initiating activities on mouse skin and in vitro metabolism of dibenzo(a,i)pyrene, 2-fluorodibenzo(a,i)pyrene, 3-fluorodibenzo(a,i)pyrene, and 2, 10-difluorodibenzo(a,i)pyrene were compared. After an initiating dose of 500 micrograms, followed by promotion with tetradecanoylphorbol acetate, dibenzo(a,i)pyrene induced skin tumors in 85% of the mice and caused 5.8 skin tumors/mouse. The corresponding tumorigenic activities for the fluorinated compounds were: 2-fluorodibenzo(a,i)pyrene (85%; 1.7 tumors/mouse); 3-fluorodibenzo(a,i)pyrene (80%; 3.1 tumors/mouse); and 2,10-difluorodibenzo(a,i)pyrene (10%; 0.1 tumors/mouse). After an initiating dose of 100 micrograms, only dibenzo(a,i)pyrene showed significant tumor-initiating activity. 3,4-Dihydro-3,4-dihydroxydibenzo(a,i)pyrene was identified as a metabolite of dibenzo(a,i)pyrene formed by the 9000 X g supernatant from the livers of Aroclor 1254-pretreated rats. Another dihydrodiol was tentatively identified as 1,2-dihydro-1,2-dihydroxydibenzo(a,i)pyrene. The formation of these angular ring dihdrodiols was inhibited in the metabolism of 2-fluorodibenzo(a,i)pyrene and 3-fluorodibenzo(a,i)pyrene. Angular ring dihydrodiols were not detected in the metabolism of 2,10-difluorodibenzo(a,i)pyrene. These results suggest that an angular ring dihydrodiol, 3,4-dihydro-3,4-dihydroxydibenzo(a,i)pyrene, which can form a bay-region dihydrodiol epoxide, may be a proximate carcinogen of dibenzo(a,i)pyrene.

Animals↗
PubMed1980

Detection and partial characterization of glucocorticoid-binding components in hepatic metastases of human bronchial and gastric carcinoid tumors.

Metastases of human carcinoid tumors of bronchial and gastric origin have been analysed for glucocorticoid receptors using the fluorinated compound [3H] dexamethasone. In both tumors high concentrations of glucocorticoid-binding components were detected which based on several physicochemical characteristics were identified as glucocorticoid receptors in nature. The apparent dissociation constant of the dexamethasone-binder complex was found to be 1.8 x 10(-8) mol/l for the bronchial and 2.8 x 10(-8) mol/l for the gastric carcinoid tumor. Sedimentation in sucrose gradients disclosed the binding components to be macromolecules, sedimenting at about 7.S. By agar gel electrophoresis the molecular species binding dexamethasone were found to exhibit the same electrophoretic mobility as glucocorticoid receptors from well-known target organs. The ligand specificity for binding to these components indicated a requirement of active glucocorticoids as well as anti-glucocorticoids. A regulatory function of glucocorticoids in serotonin biosyntheses is discussed, which may be of potential clinical significance.

Binding, Competitive↗
PubMed1980

[Effect of contamination of drinking water with sodium fluoride on the alkaline phosphatase activity of peripheral granulocytes in the rat].

During a 4-week administration of water contaminated with sodium fluoride in doses of 20 mg/kg of body weight and above, decreased activity of granulocytes alkaline phosphatase and increased count of leucocytes in peripheral blood were found. This may be indicative of a toxic effect of high doses of sodium fluoride on the leucocytic system. Thus, observation of those parameters in people and animals from the area surrounding the factories, contaminated by fluorine compounds, seems advisable.

Alkaline Phosphatase↗
PubMed1995

[Modification of the ortho-route in Pseudomonas putida strain 87: purification and properties of dienlactone hydrolase].

Dienelactone hydrolase (DLH) was purified to electrophoretic homogeneity from the biomass of the Pseudomonas putida strain 87 grown on 3-chlorobenzoate. The specific activity of the purified enzyme is 50.5 U./mg of protein. The enzyme is a monomer with a molecular mass of 22 kDa, has a pH optimum at 7.6 and is active within a broad temperature range (20-45 degrees C). The enzyme activity is inhibited by pCMB (which requires up to two equivalents of the reagent) but not by EDTA. The Vmax values of DLH for trans-dienelactone and 2-chlorodienelactone are practically identical (247.9 and 247 u./mg, respectively) and exceeded two fold that for cis-dienelactone. However, the Km for 2-chlorodienelactone is two times as high as that for trans-dienelactone (6.9 and 14.2 microM, respectively). A comparison of physico-chemical and kinetic properties of P. putida 87 DLH with those of the enzymes responsible for the decomposition of chlorinated and fluorinated compounds revealed that the enzyme can be assigned to the third group, i.e., the DLH-modified ortho-cleavage path way characteristic of gram-negative bacteria.

Carboxylic Ester Hydrolases↗
PubMed1995

[19F-MR imaging of transplanted tumor: perfluorochemicals as a fluorine tumor imaging agent].

PURPOSE: The purpose of our study was to detect tumor selectively using 19F-magnetic resonance imaging (MRI) and to assess Fluosol-DA, a perfluorochemical emulsion, as a tumor imaging agent for 19F-MRI. MATERIALS AND METHODS: SCC VII cells were transplanted in the right leg of mice. After 6 days, Fluosol-DA was administrated intravenously (40 ml/kg). 19F-MR imaging was performed on a Bruker CSI Omega 2 at 4.7 Tesla using a homemade volume coil. RESULTS: In vitro, the concentration and 19F signal intensity of FDA showed a very high correlation (r = 0.9997). Detection on MRI was possible at a concentration of 2%. In vivo, images of 19F in SCC VII tumors were achieved in animals 2 days after the administration of FDA. CONCLUSION: Our study confirms the feasibility of 19F-MR in vivo imaging of tumors using the fluorine compound FDA.

Animals↗
PubMed1993

[Interaction of fluoride with milk constituents].

Fluoride concentrations have been studied in cow milk stemming from regions variably influenced by fluorine pollution. It was disclosed that fluoride concentration in the milk of cows grazing on areas with a high degree of environmental contamination by fluorine compounds was about three-fold higher as compared to the control group. Fluoride distribution was evaluated in milk, in which the protein sediment got separated from the whey. The said distribution was found to be equal in both of the milk constituents. Due to the decomposition of whey into the whey proteins sediment and the remaining solution, an answer was obtained to the question of which part of whey fluoride appeared in the ionized form (80%). Studying the binding of fluoride by isolating and purifying the fraction of milk proteins at various pH, it was revealed that alpha-lactalbumin bound fluoride at 3.9 pH. Because of limited caseins solubility at that pH, there was no possibility to find out whether they bound fluoride ions. At fresh milk pH, the caseins exist in the anionic form and as such they are unable to bind fluoride independently. The binding of fluoride with milk lipids was investigated and it was ascertained that about 11% of fluoride being introduced into milk were bound to lipid constituent. The study covered also the influence of fluoride ions on the magnitude of the optic polarization angle of aqueous lactose solutions in different concentrations. That angle undergoes diminution in comparison with solutions not polluted by fluoride. Fluoride concentration was defined in some milk formulas of Polish production designed for infants. They exceed, depending on the kind of formulas, 20-70 fold the average fluoride concentration evidenced in human milk. Thus, the differences in fluoride supplied to infants, fed by breast and artificially, are very great.

Animals↗
PubMed1995

[The effectiveness of perfluorotributylamine/pluronic F-68 stem-emulsion (FC43se) against xenograft rejection in the guinea pig-to-rat model].

The administration of perfluorotributylamine/pluronic F-68 stem-emulsion (FC43se), a fluorine compound emulsion, to a rodent discordant xeno-transplantation (dXT) model led to the discovery of the inhibitory effect of this compound against hyperacute rejection (HAR). When a guinea pig heart was transplanted to a rat administered with FC43se (10 microliters/g body weight), rhythmic beating was maintained for 1110 +/- 111.1 min (mean +/- SD; n = 8) whereas the untreated heart continued to beat for 15.5 +/- 6.6 min (mean +/- SD; n = 8). After 720 min of re-beating; pathologic changes observed in the untreated group, such as multiple thrombosis in the coronary vessels, were not observed in the FC43se-administered group by light and electron microscopic examination, and endothelial cells were well preserved. On the other hand, scattered necroses of the myocardium were observed and lymphocytic infiltration was demonstrated in the interstitium. We concluded that FC43se possessed a HAR inhibitory effect by inhibiting thrombus formation in the xeno-graft heart. Using this model, we speculated that action in the vessels of the graft heart (intravascular HAR) caused thrombus formation in the vessels. On the other hand, extravascular HAR causes myocardial necrosis more slowly, not resulting in cardiac arrest in the short term.

Acute Disease↗
PubMedDate not supplied

[The role of physical balneological factors in the treatment of occupational diseases].

The authors review the results obtained in the treatment of some occupational diseases using physical factors. In osteoarthritis patients exposed to fluorine compounds good results were achieved at employment of decimeter-wave therapy combined with mud applications or sulfurated hydrogen baths. Patients with scapulohumeral periarthritis benefited from combination of EHF therapy with alternating magnetic field. Initial lead intoxication was effectively treated with magnetotherapy. Subjects with vascular pathology occupationally exposed to high temperature responded to magnetolaser impact on reflexogenic regions of the heart.

Balneology↗
PubMed1998

Evolving role of oral chemotherapy for the treatment of patients with neoplasms.

The past 20 years has seen an increasing trend toward the use of oral chemotherapy for the treatment of patients with a variety of malignancies. The advantages of oral chemotherapy include lower treatment cost, compared with that of intravenous (i.v.) administration, and more convenient treatment for patients. Several oral drugs are now used routinely for cancer treatment, and others are under investigation. Hormonal agents, such as tamoxifen, flutamide, and megestrol acetate, and antimetabolites, such as hydroxyurea, which are available only in oral formulation, have proven both safe and efficacious. Several other oral drugs, including etoposide and cyclophosphamide, have been shown to be useful and often as effective as their i.v. formulations, and more data on the bioavailability of these agents have become available. In addition, several new and promising oral agents (platinum compounds, fluorinated pyrimidines, topoisomerase I inhibitors, and others) are likely to be introduced into clinical practice in the near future. It is possible that eventually, oral combination chemotherapy will be an accepted and standard approach for the treatment of patients with many types of cancer.

Administration, Oral↗
PubMed1992

High performance liquid chromatography of nucleic acids and the related compounds on a fluorinated silica gel column.

Separations of nucleic acids and the related compounds were investigated by HPLC on a new fluorinated bonded silica gel column. Polyadenylate (Poly (A)) enzymatic partial hydrolysate sample and the mixture of various polynucleotide samples were sufficiently separated by the reversed-phase mode using a gradient elution with aqueous ammonium acetate/acetonitrile system. Mixed-mode separation on the fluorinated bonded phase coated with a tert-alkylammonium salt was also examined for the separation of the various polynucleotides including tRNAs.

Chromatography, High Pressure Liquid↗
PubMed2005

Fluorinated diaryl sulfides as serotonin transporter ligands: synthesis, structure-activity relationship study, and in vivo evaluation of fluorine-18-labeled compounds as PET imaging agents.

A series of new, fluorine-containing substituted diphenyl sulfides was synthesized to serve as candidate ligands for positron emission tomography (PET) imaging of the serotonin transporter (SERT) and to further probe the structure-activity relationship (SAR) of this class of compounds. Candidate compounds were assayed for their affinities to the monoamine transporters (SERT, norepinephrine transporter (NET), and dopamine transporter (DAT)) in competitive binding experiments in vitro using cloned human transporters. From these in vitro assays, four compounds (7c-f) were chosen for further evaluation. All four compounds have nanomolar affinity for SERT (K(i) 1.46 nM, 1.04 nM,1.83 nM, and 3.58 nM for 7c, 7d, 7e, and 7f, respectively). The F-18-labeled compounds, 16 and 18a-c, were prepared via a two-step radiosynthesis. Biodistribution studies in rats indicated that the F-18-labeled compounds localized in brain regions with high concentrations of SERT. Furthermore, competition experiments demonstrated that the binding of these radioligands in the rat brain was saturable, specific, and selective to SERT. Specific binding in the rat hypothalamus peaked at 5.6 for ligand 16 and 4.4 for 18b at 90 min after radioactivity administration. For ligand 18a, this same ratio was 8.4 at 120 min postinjection, while compound 18c displayed a lower specific binding ratio of 2.4. In summary, four F-18-labeled ligands were prepared and evaluated as candidate PET imaging agents for SERT. Among these four ligands, three appear to be promising radioligands suitable for the labeling of SERT in vivo, with 18a providing a higher specific binding in vivo than 16 or 18b.

Animals↗
PubMed2001

Ion-induced manipulation of photochemical pathways in crown ether compounds based on fluorinated oligophenylenevinylenes: the border between ultrafast photoswitches and photoproduced nanomaterials.

The photochemical and photophysical properties of the crown ethers trans,trans-1,4-bis[2-(3',4'-benzo 15-crown 5)ethenyl]-2,3,5,6-tetrafluorobenzene (1) and trans,trans-1,4-bis[2-(3',4'-benzo 18-crown 6) ethenyl]-2,3,5,6-tetrafluorobenzene (2) were investigated in the absence and presence of groups I and II metal ions. The photophysical methods used include steady state flurescence, uv spectroscopy, and ultrafast transient absorption spectroscopy. Both compounds showed solvatochromic behavior, due to intramolecular charge transfer state formation, and efficient fluorescence in polar solvents. Photophysical behavior was dependent on the metal ion. The addition of metal ions that completely fit into the crown ether cavity resulted in significant blue shifts in the fluorescence emission spectra (chemosensing properties). Partially fitting ions changed the fluorescence spectra slightly. Transient absorption measurements revealed fast and slow decay components with time constants of 10-20 and 500-600 ps for all fitting ions, respectively. The latter is assigned to a trans-cis photoisomerization process, which decreased in efficiency in the presence of partially fitting ions, i.e., increasing ion size. Steady state irradiation showed clear evidence of a change in the absorption spectra. Trans-cis photoisomerization and [2 + 2] photocycloaddition were found to compete with fluorescence. The ions Li+, Na+, and Ca2+, which fit into the cavity, direct the photoisomerization. Larger ions (K+, Rb+, Sr2+ and Ba2+) that partially fit the cavity cause photocycloaddition. Quantum yields of the photoreaction are between 0.1 and 0.3. Analysis of the photo-product obtained for the 1-Sr2+ system revealed a compound with a molecular weight of nanosize dimension, which was equivalent to seven mass units of 1. The higher molecular weight product was formed due to alternately stacked supramolecular assemblies.

Crystallization↗