Exploring new compounds for functional imaging using a crayfish (Procambarus clarkia) aggression paradigm.

Covalently bonding multiple fluorine atom tags to the precursors of monoamines could provide compounds for functional imaging. Theoretically, the fluorine atoms can produce detectible signal if concentrated in vesicles inside neurons. Prior to committing more costly resources to the project, evidence was sought for uptake of the molecules into neurons in living organisms. Two 19F tag configurations of seven or nine atoms were investigated. Crayfish aggression provided a paradigm for obtaining preliminary data on the scarce new molecules. After establishing that 5-hydroxytryptophan (5-HTP) elicited serotonin-like effects, the fluorine tagged versions (PF-5-HTP) were investigated; then, the elevated aggression produced by these precursors to serotonin was blocked by coadministering fluoxetine. Treatment order effects and interrater reliability of the behavioral inventory were evaluated. Preliminary evidence that these imaging compounds are taken up into neurons obtained by studying crayfish behavior later found support using more sophisticated neuroscience techniques.

Fluorosis y deporte. A propósito de un caso / Fluorosis and sport. By the way of a case

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Pérdida de flúor en piezas dentarias permanentes expuestas a refrescos: estudio comparativo in vitro / Fluor loss in permanent teeth exposed to beverages: comparative study in vitro

Introducción: La exposición a refrescos y zumos de frutas se encuentra en constante aumento, siendo su principal característica la elevada acidez que presentan. Con estas alteraciones del equilibrio oral, la perdida mineral de la estructura dentaria es muy frecuente. Nuestro objetivo fue identificar la cantidad de flúor perdido de una pieza dentaria y comparar el efecto de dos bebidas presentes en el mercado. Metodología: Se formaron dos grupos con 15 premolares cada uno, extraídos por indicación de ortodoncia; las piezas no presentaban patologías clínicas. El experimento consistió en la aplicación de un amortiguador de fuerza iónica para posteriormente llevarlo a una curva de calibración. Luego con un pH metro (ORION, modelo 920 A) se obtuvo los datos de pH de las bebidas; luego, durante 30 minutos se sumergió en la respectiva bebida para que con el electrodo se obtuviera los resultados de flúor presente. Se realizo la prueba estadística T test para muestras independientes. Resultados: cada vez más estudios confirman el impacto de los ácidos en la cavidad oral y su papel en la erosión dentaria. En nuestro estudio se aprecio un pH de 3,1 para la bebida de naranja y 2,5 para la bebida cola. Además arrojo diferencia significativa de la pérdida de flúor según la bebida aplicada (p<0,0001).Conclusión: existe una importante pérdida de flúor de las piezas dentarias cuando se aplica una bebida ácida así como también existe diferencia significativa en el efecto de bebidas ácidas con solo 0,6 pH de diferencia (AU)

Introduction: The exposure of soft drinks and fruit juices is constantly increasing and the main caracteristic of these beverages is the high acidity. This alteration of oral balance causes a more frequent loss of dental minerals. Our main objective was to identify the quantity loss of fluor of a tooth and compare this effect caused by two different kinds of soft drinks. Methodology: 30 bicuspids were put in two different groups, 15 in each, extracted by ortodontics indication The tooth did not have evidence of clinical pathology. The experiment consisted in applying an ionic buffer, and later put the results in a calibration curve. So with a pH-Meter (Orion, model 920 a) the pH value was obtained. Then the tooth was submerged for 30 minutes in the soft drink and with the electrode the result of the presente quantity of fluor was obtained. The statistic T-test for independent proof where done. Results: more and more research confirm the impact of the acid in the mouth and its role in dental erosion. In our research the pH value of the orange drink was 3.1 and the value for the coke drink was 2.5. Otherwise it shows a statistic difference of the loss of fluor by the different drinks (p<0.0001). Conclusion: An important loss of fluor occurs in the tooth when it gets in contact with an acid drink, as it also occurs a significant difference in the effect of acid drinks with a variation of 0.6 pH (AU)

Qualitative microanalysis of ions and ultrastructural changes in dentin exposed to laser irradiation and to metal salts solution.

BACKGROUND AND OBJECTIVES: This study evaluated the ultrastructural changes in dentin after treatment with the Nd:YAG laser and/or metal salt solutions and verified the presence of Sn++, Sr++, and F- in dentin structure. STUDY DESIGNS/MATERIALS AND METHODS: Sixty dentin disks were randomly divided into groups (n = 10): (I) control (no treatment), (II) Nd:YAG (1.5 W, 100 mJ, 15 Hz, 125 J/cm2), (III) 10% SnF2 aqueous solution for 30 minutes, (IV) Nd:YAG+10% SnF2 aqueous solution for 30 minutes, (V) 10% SrCl2 toothpaste for 30 minutes, (VI) Nd:YAG+10% SrCl2 toothpaste for 30 minutes. Then, all samples were prepared for scanning electron microscopy (SEM) and the samples from Groups I to IV for the energy dispersive X-ray microanalysis (EDX). RESULTS: SEM evaluation revealed occluded dentinal tubules and a dentin surface altered by the laser irradiation. The EDX microanalysis revealed Sn++ at a depth of 250 microm in Group IV and not deeper than 100 microm in Group III. In Group V, Sr++ was not deeper than 50 microm, but it could be detected at a depth of 500 microm in Group VI. F- was found only in Group IV. CONCLUSIONS: Ultrastructural changes caused by laser irradiation can increase dentin uptake of Sn++, Sr++, and F-.

[Osteoporosis and mineral intake].

For prevention against the development of osteoporosis and related fractures, the importance of sufficient intake of calcium and vitamin D has been increasingly recognized. However, due to increasing intake of calcium, the relative intake of magnesium and trace elements, such as zinc and copper has been relatively decreasing and thus been focused in recent years. On this article, we will give an outline of the importance of magnesium and trace elements in the regulation of bone metabolism.

Relación entre los esfuerzos de compresión simple y cantidad de flúor en el tejido óseo / Relationship between simple compressive stresses and fluoride in bone tissue

Se investigó la relación que existe entre la cantidad de flúor en hueso y la resistencia a la compresión simple del mismo. Se analizaron 12 muestras de la quinta costilla humana extraidos de cadáveres frescos de no más de 24 horas de fallecidos en el Instituto de Medicina Legal de Medellin. Los cadáveres seleccionados debian tener datos completos de: edad, sexo, lugar de residencia, y una historia médica referida por sus familiares, en la que no presentara antecedentes de enfermedades sistémicas; posteriormente se investigó si en los respectivos sitios de residencia se utilizaba la fluorízación del agua. Los valores de flúor se determinaron con el método descrito por Alhava en 1980, y la resistencia a la comprensión simple se determino mediante el método descrito por Franke (1976). En los resultados finales no se obtuvieron diferencias estadísticamente significativas entre el contenido de flúor de las muestras óseas y la resistencia a la compresión de las mismas.

The relationship between the amount of fluoride in bone and its resistance to simple compression was investigated. 12 samples were analized from the 5th ribofhuman beings taken from fresh corpse with no more than 24 hours after death, in the Legal Medicine Institute of Medellín. The chosen corpses should have complete data concerning: age, sex, place of residence (address) and aclinical history refered by its relatives, and it couldn't present any previous sistemic illness; subsequently a research in their diferent places of residence was done, to investigate if the water used contained fluoride. The importance of fluoride was determined with the method described by Alhavain 1980, and the resistance to simple compression was determinated throughout the method described by Franke (1976). In the final results no statisticaly significant differences were obtained between the amount of fluoride in the bone sample and its resistance to compression.

New quinolones: pharmacology, pharmacokinetics, and dosing in patients with renal insufficiency.

Despite similarities in their chemical structures, the new fluoroquinolones differ greatly in the extent to which renal clearance contributes to their elimination. On the opposite ends of this spectrum are ofloxacin, which is almost entirely eliminated by the kidney as unmodified drug, and pefloxacin, which undergoes extensive biotransformation. Dosage adjustments in patients with renal insufficiency therefore are recommended for ofloxacin, but, on the basis of currently available data, adjustments do not appear to be required for pefloxacin. Both renal clearance of unmodified drug and metabolic transformation contribute substantially to the elimination of norfloxacin and ciprofloxacin. Because of the great antimicrobial potency of the new fluoroquinolones, it should be possible to employ them in the treatment of urinary tract infections caused by highly susceptible bacteria even in patients with marked impairment of renal function.

An appraisal of the newer trace elements.

For an element to be considered essential it should satisfy three criteria: (1) it must be present in living matter; (2) it must be able to interact with living systems; (3) a dietary deficiency must consistently result in a reduction of a biological function, preventable or reversible by physiological amounts of the element. Ideally, essentiality should be established in more than one species and confirmed in more than one laboratory. Since 1970, vanadium, fluorine, silicon, nickel and arsenic have been shown to meet all the criteria listed above, and evidence from one laboratory has indicated that tin may have an essential biological role in the laboratory rat. A review is presented of the evidence on which the essentiality of these elements has been established and, when known, an indication of their biochemical functions. The possible significance of these 'newer' trace elements to the health of man and animals is discussed.

Fluorine: an essential element for good dental health.

Universal water fluoridation will have a positive impact on the oral health of the nation. The ultimate goal is to have every individual's teeth last a lifetime. Fluoridation of community water supplies provides the best cost containment public health measure known for improving the dental health of the nation's citizens.