Effects of QMix and ethylenediaminetetraacetic acid on decalcification and erosion of root canal dentin.

The aim of this study was to evaluate the effect of initial NaOCl on the decalcification and erosion ability of EDTA and QMix. Sixty-maxillary-incisors were bisected longitudinally and the tooth-halves were used. The experiment was conducted in two-sets.

A new, fast and sensitive method for the determination of trace amounts of nitrite using differential pulse polarography.

Nitrite salts of sodium or potassium are being used for the protection of meat products. They provide color and taste of meat and they protect against clostridia. On the other hand, nitrite ions can interact with amines to form nitrosamines which are known as carcinogenic substances.

Preparation and properties of a new solid state arsenate As(V) ion selective electrode and its application.

In this study a new solid-state ion selective electrode which is easy to prepare and sensitive to arsenate ion concentration is prepared. The solid salts used in the electrode composition were Cu2S, Ag3AsO4 and Ag2S. The principal component of the electrode was Ag3AsO4.

Preparation and properties of a new solid state borate ion selective electrode and its application.

A new borate ion selective electrode using solid salts of Ag(3)BO(3), Ag(2)S and Cu(2)S has been developed. Detailed information is provided concerning the composition, working pH and conditioning of the electrode. An analytically useful potential change occurred from 1×10(-6) to 1×10(-1) M borate ion.

Preparation of a new solid state fluoride ion selective electrode and application.

A new solid state fluoride ion selective electrode composed of 70% Ag(2)S, 10% Cu(2)S and 20% CaF(2) has been developed. An analytically useful potential change occurred, from 1x10(-6) to 1x10(-1)M fluoride ion. The slope of the linear portion (1x10(-1)-1x10(-5)M) was about 26+/-2mV/10-fold concentration changes in fluoride.

Nucleophilic attack by bromide ions as a first step of conversion of Se(VI) to Se(IV).

Numerous commonly used analytical methods allow only determination of a total amount of selenium in a given sample. Electroanalytical methods as well as those based on hydride generation or on formation of piazselenol allow only determination of Se(IV). To determine Se(VI) by these procedures, present alone or in mixtures with Se(IV), it is first necessary to convert Se(VI) to Se(IV).

Interference between selenium and some trace elements during polarographic studies and its elimination.

When selenite was added into solutions of some ions such as copper, lead, cadmium, zinc, chromium and arsenic their DPP peak decreased. This kind of interference was observed in all acids and in wide range of pH values, causing at least 50% error when both ions (the ion present and selenite) were in similar quantities. It was found that this interference was not taking place at pH 8.

Preparation and application of a new glucose sensor based on iodide ion selective electrode.

An electrode for glucose has been prepared by using an iodide selective electrode with the glucose oxidase enzyme. The iodide selective electrode used was prepared from 10% TDMAI and PVC according our previous study. The enzyme was immobilized on the iodide electrode by holding it at pH 7 phosphate buffer for 10min at room temperature.

A new and direct method for the trace element determination in cauliflower by differential pulse polarography.

Using the DPP polarograms of wet digested cauliflower sample in acetate buffer at pH values of 2, 4 and 6, Fe, Zn, Mo, Se, Cr, Cd, Pb, Ti and Cu quantities were determined. The best separation and determination conditions for Zn, Se and Mo was pH 2; for Cr, Zn, Mo and As was pH 4; for Pb pH 6, for Ti, Cu and Fe was pH 6-7 EDTA, for Cd pH 2 EDTA and for lead pH 6, all in acetate buffer. The trace element ranges for cauliflowers from two different seasons were (first figure for winter, the second for summer) for Se 120-250mugg(-1), Fe 70-85mugg(-1), Cu 320-150mugg(-1), Ti 90-120mugg(-1), Cr 130-630mugg(-1), Zn 90-550mugg(-1), Mo 170-230mugg(-1), Cd 20mugg(-1) (in winter) and Pb 130-300mugg(-1) in dry sample.

Differential pulse polarographic determination of selenium(IV) in whole blood using the catalytic hydrogen wave.

The selenium content in blood was determined using the hydrogen catalytic peak. This peak at -1.1 V was obtained in the presence of selenium and molybdenum at pH values of 1-4 in different buffers.

Polarographic and voltammetric behavior of selenious acid and its use in analysis.

Solution chemistry of Se(IV), in particular the acid-base properties, salt and complex formation, chemical reduction and reaction of Se(IV) with organic and inorganic sulfur compounds are briefly summarized. The electrochemical reduction of Se(IV) on dropping and stationary mercury electrodes is dealt with in some detail. The effects of antecedent acid-base equilibria and of consecutive reactions of the reduction product, Se(2-), adsorption of their products, and effects of added metal ions are discussed.

Differential pulse polarographic determination of trace selenium(IV) and molybdenum(VI) using the catalytic hydrogen wave.

In the presence of selenium(IV) and molybdenum(VI) a new polarographic peak appears which corresponds to a hydrogen catalytic wave. By differential pulse polarography a single, sharp peak at about -1.1 V is obtained, allowing trace determination of selenium(IV) and molybdenum(VI) in the range 1x10(-6)-5.

Preparation and properties of solid state selenite ion selective electrodes and their applications.

A new selenite ion selective electrode using solid salts of Ag(2)Se and Cu(2)S has been developed. Detailed information is provided concerning the composition, working pH and conditioning of the electrode. The change of potential with concentration is found to be linear in the range of 10(-5)-10(-2) M, the slope of the linear portion is 28 mV/10-fold change in selenite concentration.

A new selenite selective membrane electrode and its application.

A new membrane ion selective electrode sensitive to selenite ion has been developed. The electrode consisted of 1,2-phenylenediamine selen complex PIS (piaselenol) as the active material, PVC or SR (silicon rubber) as membrane matrix and DBF (dibutylphtalate) as plasticizer. This electrode showed linear response for selenite ion in the 10(-5)-10(-1)M concentration range.

Simultaneous determination of selenium and lead in whole blood samples by differential pulse polarography.

The polarographic reduction of lead in the presence of selenite gives rise to an additional peak corresponding to the reduction of lead (Pb) on adsorbed selenium (Se) on mercury at -0.33 V. The selenium and lead content can be determined using this peak by the addition of a known amount of one of these ions first and then the second ion.

Direct and indirect methods for the determination of vitamin K3 using differential pulse polarography and application to pharmaceuticals.

Two methods for the determination of vitamin K(3) have been developed. Vitamin K(3) in its oxidized form is determined by direct and indirect methods. Its standard solution was prepared by the indirect method using Ti(III) as reducing agent.

Determination of trace sulfite by direct and indirect methods using differential pulse polarography.

Sulfite determination plays an important role since it is used in some food stuff as protecting agent. The objective of this study was to develop a new and simple method for the determination of sulfite so that it can be used in routine food analysis. A differential pulse polarographic (DPP) method has been used for this purpose since the results obtained with this method are very reproducible and the instrument used is not expensive.

Naltrexone in the treatment of alcohol dependence: a Canadian trial.

Objectives: Alcohol dependence is a prevalent psychiatric disorder affecting approximately 12% of the adult population at some point in their lifetime. Psychosocial treatments are associated with only modest success rates. The first Canadian clinical trial with naltrexone, an opiate antagonist, was conducted to evaluate its safety and usefulness as an adjunctive treatment in the management of alcohol dependence.

Comparative abuse liability of intravenously administered remifentanil and fentanyl.

Remifentanil is a short-acting, esterase-metabolized opioid analgesic. This study compared the abuse liability of remifentanil with that of fentanyl and placebo in a randomized, double-blind, crossover study. Twelve recreational users of opioids received increasing doses of remifentanil (0.

Efficacy of dexfenfluramine in the treatment of alcohol dependence.

Background: A substantial body of evidence supports a role for serotonin in modulating alcohol intake, which suggests that this neurotransmitter represents a promising target for pharmacotherapy development for alcohol use disorders. Dexfenfluramine. a serotonin releaser and reuptake inhibitor, decreases alcohol self-administration by rats.

Cytochrome P450 2D6 and treatment of codeine dependence.

Oral opioid analgesics such as codeine are used extensively worldwide and are frequently misused. Codeine is a substrate of CYP2D6, a genetically polymorphic P450 enzyme, and is metabolized to the more potent drug morphine. CYP2D6 activity can be inhibited by fluoxetine, and the inhibition of morphine formation may help individuals reduce their use of codeine.

Attenuation of the euphoric effects of cocaine by the dopamine D1/D5 antagonist ecopipam (SCH 39166).

Background: The subjective and reinforcing effects of cocaine in humans are associated with the enhancement of endogenous dopamine function in the mesolimbic system. This study examined the role of dopamine D1-like receptors in the behavioral and mood effects of cocaine by evaluating the effects of the selective D1/D5 antagonist ecopipam (SCH 39166) on subjective responses to intravenous cocaine in 11 subjects with cocaine dependence as defined by DSM-IV.

Methods: Subjects were pretreated in a randomized double-blind fashion with either placebo or 10 mg, 25 mg, or 100 mg of ecopipam orally on 4 separate occasions.

Long-term codeine use is associated with depressive symptoms.

A community survey was conducted among long-term (>6 months) users of codeine-containing products to characterize chronic use of these extensively consumed medications. Respondents recruited through newspaper advertisements completed a mailed questionnaire. Three hundred thirty-nine completed questionnaires were obtained, yielding a response rate of 70%.

Characteristics of dependent and nondependent regular users of codeine.

Although codeine is a widely used medication, the problems of codeine abuse and dependence have not been well-studied. This study characterized regular codeine users (using at least 3 days per week for 6 months, excluding those using codeine for the treatment of cancer pain) through a self-completed questionnaire. Recruitment through newspaper advertisements resulted in a total of 339 eligible questionnaires.

A controlled trial of ondansetron, a 5-HT3 antagonist, in benzodiazepine discontinuation.

Serotonin is implicated in the etiology of anxiety disorders and in the anxiolytic actions of benzodiazepines. Preclinical studies with 5-HT3 receptor antagonists, including ondansetron, show they have anxiolytic properties and that ondansetron suppresses withdrawal anxiety after abrupt discontinuation of chronic benzodiazepine treatment. We evaluated the efficacy of ondansetron as an adjunctive medication in the discontinuation of benzodiazepines in long-term users.