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Biochemical, microbiologic, and clinical comparisons between two dentifrices that contain different mixtures of sugar alcohols.

It has been customary to think that in a dentifrice only a few of its ingredients would be active and have clinically significant effects on dental caries, oral hygiene, and the levels of caries-inducive microorganisms or harmful plaque metabolic products. Therefore, most of the emphasis has been placed on the type of fluorine compounds, abrasives, or similar dentifrice ingredients. This study shows that such common dentifrice components as the humectants, which contribute to the texture, rheologic characteristics, and shelf life of the product, also may affect the type of dental plaque grown on the tooth surfaces between toothbrushings or during long-term neglect of toothbrushing or of oral hygiene. Commonly used humectants include sorbitol, a sugar alcohol of the hexitol type, which is used often in sugarless candies. This study showed that when sorbitol in a dentifrice was replaced by xylitol, a sugar alcohol of the pentitol type, the dental plaque of human subjects contained more ammonia and significantly less bacterial polysaccharides. It is accepted generally that ammonia neutralizes plaque acids and that bacterial polysaccharides are involved in promoting caries. Xylitol-containing dentifrice also reduced the saliva levels of S mutans. The results further indicated that if sorbitol and xylitol could be compared in a short-term dentifrice study that relied on subjective and coarse plaque determinations only, no differences between those dentifrices would be found necessarily. To demonstrate the differences between the experimental dentifrices used in this study, it was necessary to analyze specific plaque components and the salivary levels of S mutans.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

[Quantification and visualization of oxygen partial pressure in vivo by 19F NMR imaging of perfluorocarbons].

Due to the high solubility of molecular oxygen in perfluorocabons (PFC), this class of fluorinated compounds has gained wide-spread interest for its biomedical application as temporary blood substitutes and as radiosensitizers. Since the observation that the NMR spin-lattice relaxation times (T1) of some 19F PFC resonances are sensitive to oxygen tension (pO2), this paramagnetic effect has been used to non-invasively probe pO2 in vivo. In this study, combined 19F/1H NMR image data of Copenhagen rats after PFC application were evaluated with the software package MATLAB. The analysis of the 19F NMR data resulted in image matrices with calculated T1 values in each pixel. By using a calibration curve, the corresponding pO2 values were computed. Color overlays of pO2 contour lines on T1-weighted 1H images show a good anatomical-functional correspondence.

Animals↗

Artificial O2 carriers: status in 2005.

Donor blood is a limited resource and its transfusion is associated with significant adverse effects. Therefore, alternatives have been searched, the ultimate being artificial oxygen (O2) carriers. There are two main groups of artificial O2 carriers: hemoglobin based and perfluorocarbon emulsions. The hemoglobin molecule in hemoglobin based artificial O2 carriers needs to be stabilized to prevent dissociation of the alpha2beta2-hemoglobin tetramer into alphabeta-dimers in order to prolong intravascular retention and to eliminate nephrotoxicity. Other modifications serve to decrease O2 affinity in order to improve O2 off-loading to tissues. In addition, polyethylene glycol may be surface conjugated to increase molecular size. Finally, certain products are polymerized to increase the hemoglobin concentration at physiologic colloid oncotic pressure. Perfluorocarbons are carbon-fluorine compounds characterized by a high gas dissolving capacity for O2 and CO2 and chemical and biologic inertness. Perfluorocarbons are not miscible with water and therefore need to be brought into emulsion for intravenous application. Development, product specification, physiologic effects, efficacy to decrease the need for donor blood in surgery and side effects of the following products are described: Diaspirin cross-linked hemoglobin (HemAssist), human recombinant hemoglobin (rHb1.1 and rHb2.0), polymerized bovine hemoglobin-based O2 carrier (HBOC-201), human polymerized hemoglobin (PolyHeme), hemoglobin raffimer (Hemolink), maleimide-activated polyethylene glycol-modified hemoglobin (MP4) and perflubron emulsion (Oxygent). In addition, enzyme cross-linked poly-hemoglobin, hemoglobin containing vesicles (nano-dimension artificial red blood cells) and an allosteric modifier (RSR13) are discussed. The most advanced products are in clinical phase III trials but no product has achieved market approval yet in the US, Europe or Canada.

Allosteric Regulation↗

Engineering of nanoemulsions for drug delivery.

Nanoemulsions, usually spherical, are a group of dispersed particles used for pharmaceutical and biomedical aids and vehicles that show great promise for the future of cosmetics, diagnostics, drug therapies and biotechnologies. They exist in a wide variety of forms that are dictated by the particle components. Nanoemulsions are generally considered to be in the size range of less than and around 100 nm in diameter. The particles can exist as water-in-oil and oil-in-water forms, where the core of the particle is either water or oil, respectively. More complex variations also exist but these are often larger. The longer-term properties of the particle are dependent on the composition of the adsorbed material lying at the dispersed droplet interface with the dispersion medium. This has an impact on the partitioning and extraction of droplet contents. Thermodynamically stable particles are characterized by having a very low surface tension and this produces a very large surface area. Nanoemulsions can also include small meta-stable very small-scale emulsions; here the surface properties and chemistry can strongly influence behaviour. Processing, storage and formulation composition can also have an impact on the longevity of a pharmaceutical preparation. Some revolutionary new nanoemulsion droplets based on fluorinated compounds are finding a number of widespread biomedical roles and applications. Developments in nanoemulsion technology are likely to lead to a much greater use of this medium in future pharmaceuticals.

Animals↗

[The caries prevention campaign in the Canton of Zürich during 1962-1974 along with a statistical result report from the first 8 years].

In November 1962, a caries prophylactic campaign was inaugurated in the canton of Zurich. At the end of 1965, two thirds of the communities, 115 of 171, had introduced already toothbrushing with fluorine compounds at school, under supervision. The following years though did not bring notable increase in participation of the remaining communities. Here are the main results of the campaign: -reduction of dental caries in the permanent dentition by 45 to 50% (fig. 2) -reduction of dental caries on cuspid and incisor teeth and on the buccal and lingual surfaces of lateral teeth by about 80% -reduction of first molar extractions (fig. 5) -massive reduction of the number of untreated carious teeth (table VI) -better condition of the deciduous dentition (fig. 6, 7) -reduction in the incidence of gingival inflammations (table VII, fig. 8) -reduction of the supra- and subgingival calculus deposits. It is deduced from the discussion that supervised toothbrushing with fluorides, the spread of fluoridated toothpastes, and in a lesser degree--the fluoridation of table salt are a certain cause for the massive improvement of juvenile dentitions. It is still uncertain whether the avoidance of sugar containing snacks have also contributed to the favourable result. The reduction of gingival inflammations can only be explained by the improved home care. It cannot be proven if this has also an influence upon caries incidence.

Adolescent↗

Comparison of [18 F]fluorocholine and [18 F]fluorodeoxyglucose for positron emission tomography of androgen dependent and androgen independent prostate cancer.

PURPOSE: Positron emission tomography (PET) imaging is used for the metabolic evaluation of cancer. [18F]fluorodeoxyglucose (FDG) is commonly used as a radiotracer but its low cellular uptake rate in prostate cancer limits its usefulness. We evaluated the novel choline analog [18F]fluorocholine (FCH) for detecting androgen dependent and androgen independent prostate cancer, and its metastases. MATERIALS AND METHODS: The cellular uptake of FCH and FDG was compared in cultured prostate cancer cells (LNCaP and PC-3). FCH and FDG were injected into nude mice xenografts (CWR-22 and PC-3) and radiotracer uptake in various organs were evaluated. Patients with androgen dependent (9) and independent (9) prostate cancer were studied by FCH and FDG PET. RESULTS: FCH uptake was 849% and 60% greater than FDG uptake in androgen dependent (LNCaP) and independent (PC-3) cells, respectively. The addition of hemicholinium-3 (5 mM.) 30 minutes before radiotracer administration inhibited FCH uptake by 79% and 70% in LNCaP and PC-3 cells, respectively, whereas FDG uptake was not significantly affected. Although nude mice xenografts showed that FDG uptake was equal to or greater than FCH uptake, clinical imaging in patients demonstrated 2 to 4-fold higher uptake of FCH in those with androgen and androgen independent prostate carcinoma (p <0.001). More lesions were detected by FCH than by FDG in primary tumors, osseous metastases and soft tissue metastases. CONCLUSIONS: In vitro data demonstrated greater FCH than FDG uptake in androgen dependent (LNCaP) and androgen independent (PC-3) prostate cancer cells. Although the murine xenograft data showed greater accumulation of FDG than FCH in PC-3 tumors, PET in humans showed that FCH was better than FDG for detecting primary and metastatic prostate cancer. Overall the data from this study suggest that FCH is preferable to FDG for PET of prostate carcinoma and support the need for future validation studies in a larger number of subjects.

Animals↗

[Trace analysis for drugs and poisons in human tissues].

Despite continuous developments of analytical techniques in terms of sensitivity and accuracy, uncountable increase in number of chemical substances are brought into the field of forensic sciences to be analyzed. Based on the idea that progress in analytical technique to cope with the change of situation is always required, a research team including 10 members was organized to set up the most advanced methods at present to analyze the important drugs and poisons in biological materials for forensic purposes. Stimulant drugs such as methamphetamine and amphetamine were studied on the improvement of extraction procedure prior to mass spectrometric analysis. A conventional solvent extraction method was replaced by an extraction technique using Extrelut column. The technical procedure was simplified and the accuracy of measurement was improved. The changes in CO-Hb concentration in the whole blood in storage was examined with regard to the lapse of time and temperature, where a differential spectrophotometry was used. Useful information could be obtained from practical aspects. Analytical conditions of gas chromatography were revised on volatiles including alcohols, especially as to column conditions. The use of capillary column was recommended for sensitivity and peak separation. The optimum conditions for detecting barbiturates in the blood were examined. The combination of Sep-pak C18 cartridge with a capillary column for gas chromatography using nitrogen phosphorus detection was found preferable. Mass spectrometry of various kinds of local anesthetics was studied. Quantitative analysis of the drugs was examined on gas chromatography with a surface ionization detector. Three types of insecticides including organophosphorus, chlorinated and fluorine compounds were analyzed by gas chromatography/mass spectrometry in order to establish a sensitive and selective method. The detection limits, calibration and reproducibility were examined. Herbicide, paraquat, was examined on the sensitivity, recovery, required time and costs in connection with methods of pretreatment and analytical procedure. A secondary spectrophotometry was found useful practically. Antimony in biological tissues was analyzed, using a flameless atomic absorption spectrometer with carbon tube atomizer. The time for analysis was reduced, and sensitivity was improved. Immunoassay method was examined from general aspects on drugs and hormones. Using antibodies specific to haptens, the dynamics of such antigens as drugs and hormones in the body tissues were observed. Interfering substances at the time of toxicological analysis were checked in order to obtain reliable information. Exact identification was found possible by using gas chromatography/mass spectrometry. As described above, the research was made from the practical aspects of forensic toxicology, and meaningful results could be obtained from each study.

Animals↗

[Clinical-radiological parallel control of a longitudinal study of the anti-caries effect of aminofluoride applied locally for 7 years in a double-blind test].

The determination of anticarious effects of topically administered fluorine compounds is usually based on short-time cross-sectional or longitudinal studies. In a comparison made for a period of more than seven years the anticarious effects of amine fluorides administered to selected groups of test subjects have been studied under controlled clinical experimental conditions.

Child↗

[Combined effect of agonists and antagonists of the membranes channels on hemodynamic indices in rats with normal blood pressure and spontaneous hypertension].

It has been investigated the influence of synthesized in Institute of Organic Chemistry NA of Science fluorinated Compound "C" on haemodynamic indexes of normotensive (Wistar) and hypertensive (SHR) rats. Molecules of Compound 'C' contain the blocker of calcium channels foridon and the potassium channels activator flocalin. It was shown that separately used foridon (0.5 mg/kg) and flocalin (which has dose-depended effect) evoke hypertensive reaction, decreasing the total peripheral resistance. They differently affect the systolic blood volume (foridon decreases and flocalin increases) but do not change the heart rate. Compound "C" (0.5 mg/kg) decreases arterial pressure and total peripheral vessels resistance, decreases heart rate and increases systolic blood volume. In hypertensive animals these effects were more pronounced in comparison with normotensive animals.

Animals↗

[Content of fluoride in hair and hoofs of wild boars and deer from Western Pomerania as a bioindicator of environmental pollution].

The aim of this study was to assess the fluoride content in hair and hoofs of wild boars and deer from Western Pomerania (Poland). Fluoride content was determined with the Orion 96-09 fluoroselective electrode. The highest content of fluoride (13.39 microg/g d.m.) was found in hair of wild boars from the city of Stargard Szczeciński. The lowest fluoride content was in the control group of boars from the city of Pyrzyce (8.41 microg/g d.m.) and Myślibórz (6.11 microg/g d.m.). It was concluded that biomonitoring of fluoride accumulation in hair and hoofs may be useful for the assessment of environmental pollution with fluorine compounds.

Animals↗

[Congenital developmental defects in children and environmental pollution].

In one of the southern regions of the Ukraine, analysis was made over the recent three years of the genetic monitoring data on the incidence and structure of congenital developmental abnormalities in the newborn as related to the status of environmental pollution (the content of dust, carbon black, carbon and nitrogen oxides, nitrogen and sulfur dioxides, hydrogen sulfide, formaldehyde, phenol, fluorine compounds in the atmospheric air; the content of toxic chemicals and pesticides in foods, soil, water and feeds) as well as to the radiation situation. In the region under study, areas with varying degree of environmental pollution were distinguished. That was mainly done in terms of the characteristics of the atmospheric air and (to a less degree) varying annual dose of external radiation on conversion to one inhabitant. Analysis of the genetic monitoring has demonstrated the prevalence of congenital abnormalities, in the genesis of which the mutation component was of paramount importance, to be significantly higher in an ecologically unsafe area. The data obtained can be used in the regional programs aimed at the improvement of the environment, a reduction of the influence of exogenous risk factors implicated in the formation of congenital developmental abnormalities in children.

Abnormalities, Drug-Induced↗

[The condition of the eye in electrolytic shop workers in a Tadzhik aluminum plant suffering from autonomovascular dystonia].

Examinations of 1000 workers of electrolysis shops at the Tadjik aluminum plant have shown that, along with the physical factors of electrolysis process, excessive concentrations of fluorine compounds, surpassing the maximum permissible levels, essentially contribute to the development of ocular abnormalities. Comparison of ophthalmic morbidity rate and structure in the workers suffering from arterial hypertension has demonstrated that systemic diseases and ocular conditions develop irrespectively of each other. Vascular disorders in the retina and the hemo- and hydrodynamic characteristics of ocular function, detected in the patients with systemic arterial hypertension, indicate a common trigger mechanism of such disorders, depending on the endogenous effects of physical and chemical factors of aluminum production.

Adult↗

[Micromorphology of dentine in rats with chronic exposure to ammonium fluoride].

Wistar rats were exposed chronically to ammonium fluoride in a toxicological chamber where the concentration of fluoride ions was 0.0016 mg/m3 of air. The exposure lasted 6 hours daily five times weekly. The animals were sacrificed after 3.6 and 9 months of the experiment. Histological preparations were made from upper incisors with surrounding tissues. Microscopic examination demonstrated striation of dentine in the teeth, of these animals, which was due to development of decalcification bands. This type of changes was observed also by other authors and it is regarded as a characteristic feature of dentine damage by fluorine compounds.

Ammonium Compounds↗

In vivo metabolism of 3-deoxy-3-fluoro-D-glucose.

Recent studies have demonstrated that 3-deoxy-3-fluoro-D-glucose (3-FG) is metabolized to 3-deoxy-3-fluoro-D-sorbitol (3-FS), via aldose reductase, and 3-deoxy-3-fluoro-D-fructose (3-FF), via the sorbitol dehydrogenase reaction with 3-FS, in rat cerebral tissue (Kwee, I. L., Nakada, T., and Card, P. J. (1987) J. Neurochem. 49, 428-433). However, the biochemistry of 3-FG in other mammalian organs has not been investigated making the application of 3-FG as a metabolic tracer uncertain. To address this issue we investigated 3-FG metabolism and distribution in isolated cell lines and in rabbit tissues in vivo with 19F NMR and gas chromatography-mass spectrometry. In general, the production of 3-FS is well correlated with the known distribution of aldose reductase in all the systems studied. Further metabolism of 3-FS to 3-FF was verified to occur in cerebral tissue. Surprisingly, two new fluorinated compounds were found in the liver and kidney cortex. These compounds are identified as 3-deoxy-3-fluoro-D-gluconic acid, which is produced via glucose dehydrogenase activity on 3-FG, and 3-deoxy-3-fluoro-D-gluconate-6-phosphate. Based on enzyme studies, it is argued that the 3-deoxy-3-fluoro-D-gluconate-6-phosphate is derived directly from 3-deoxy-3-fluoro-D-gluconic acid and not as a product of pentose phosphate activity. Direct oxidation and reduction are the major metabolic routes of 3-FG, not metabolism through glycolysis or the pentose phosphate shunt. Thus, 3-FG metabolism coupled with 19F NMR appears to be very useful for monitoring aldose reductase and glucose dehydrogenase activity in vivo.

Aldehyde Reductase↗

[Hygienic evaluation of proposed materials for an oxygen-converter plant].

The proposed article presents results of a hygienic assessment of a converter shop project at a metallurgic plant. Labour conditions in similar metallurgic plants in the country were studied at the preliminary sanitary control stage. 81 per cent of the sanitary authorities' reclamations were met, including dust discharge control measures, out-flowing gases purification, decrease of fluorine compounds discharge measures, etc.

Air Pollutants, Occupational↗

[Chronic effects of fluorides on the pituitary-thyroid system in industrial workers].

Radioimmunologic study of thyrotropin and thyroid hormones in the blood of those engaged in fluorine production showed moderate functional changes of the hypophysis-thyroid gland system, not accompanied by clinical manifestations of hypo- or hyperthyreosis and caused by disorders of the regulatory chain and fluorine impact on thyroid hormones' metabolism at the level of target cells. Elevation of calcitonin concentration in workers' blood indicated stimulation of thyroid gland parafollicular cells. Phase states in the hypophysis-thyroid gland system were detected along with the dependence of some hormones' concentration on the duration of workers' contact with fluorine compounds and the stage of fluorosis.

Adult↗