Assignment of the absolute configuration at the sulfur atom of thioridazine metabolites by the analysis of their chiroptical properties: the case of thioridazine 2-sulfoxide.

Thioridazine (THD) is a commonly prescribed phenotiazine neuroleptic drug, which is extensively biotransformed in the organism producing as main metabolites sulfoxides and a sulfone by sulfur oxidation. Significant differences have been observed in the activity of the THD enantiomers as well as for its main metabolites, and enantioselectivity phenomena have been proved in the metabolic pathway. Here the assignment of the absolute configuration at the sulfur atom of enantiomeric THD-2-sulfoxide (THD-2-SO) has been carried out by circular dichroism (CD) spectroscopy. The stereoisomers were separated by HPLC on Chiralpak AS column, recording the CD spectra for the two collected enantiomeric fractions. The theoretical electronic CD spectrum has been obtained by the TDDFT/B3LYP/6-31G*, as Boltzmann averaging of the contributions calculated for the most stable conformations of the drug. The comparison of the simulated and experimental spectra allowed the absolute configuration at the sulfur atom of the four THD-2-SO stereoisomers to be assigned. The developed method should be useful for a reliable correlation between stereochemistry and activity and/or toxicity.

Surface tension of calcium hydroxide associated with different substances

Estudou-se a tensão superficial do hidróxido de cálcio associado a diferentes substâncias (água destilada deionizada, paramonoclorofenol canforado, digluconato de clorexidina 2%, Otosporin, sulfato éter lauril sódio 3%, furacin, PMC furacin) usando tensiômetro. O modelo experimental consistiu na aplicação de uma força para separar um anel de platina imerso na superfície das substâncias, exercido por um tensiômetro. Considerando a metodologia aplicada, pode-se concluir: a água destilada isolada ou associada com o hidróxido de cálcio apresenta alta tensão superficial (70,00 e 68,40 dinas/cm); hidróxido de cálcio associado ao detergente aniônico mostrou baixa tensão superficial (31,60 dinas/cm); paramonoclorofenol canforado mais hidróxido de cálcio apresentou baixa tensão superficial (37,50 dinas/cm); clorexidina 2% associada com hidróxido de cálcio mostrou um alto valor de tensão superficial (58,00 dinas/cm); Otosporin mais hidróxido de cálcio mostrou baixa tensão superficial (35,40 dinas/cm); paramonoclorofenol furacin misturado com hidróxido de cálcio apresentou tensão superficial igual a 45,50 dinas/cm; hipoclorito de sódio apresentou alta tensão superficial (75,00 dinas/cm).

Surface tension of calcium hydroxide associated with different substances.

The purpose of this study was to evaluate the surface tension of calcium hydroxide (CH) associated with different substances (deionized distilled water, camphorated paramonochlorophenol, 2% chlorhexidine digluconate, Otosporin, 3% sodium lauryl ether sulphate; Furacin, PMC Furacin) using tensiometer. The action of the substances studied on the dentinal structure enhances the property of surface tension. This method consists in the application of force to separate a platinum ring immersed in the substances. Thus, torsion was applied to the screw until the platinum ring separated during substances testing. Considering the methodology applied, the following can be concluded: distilled water alone or associated with CH presented a high surface tension (70.00 and 68.40 dynes/cm); calcium hydroxide in association with anionic detergent showed low surface tension (31.60 dynes/cm); camphorated paramonochlorophenol plus CH presented low surface tension (37.50 dynes/cm); 2% chlorhexidine associated with calcium hydroxide showed high surface tension values (58.00 dynes/cm); Otosporin plus calcium hydroxide showed low surface tension (35.40 dynes/cm); paramonochlorophenol Furacin mixed with calcium hydroxide presented surface tension equal to 45.50 dynes/cm; sodium hypochlorite presented high surface tension (75.00 dynes/cm). Antimicrobial agents more indicated in endodontics, i.e. CH, chlorhexidine and hypochlorite, presented the highest surface tension.

Insulin-like effects of Bauhinia forficata aqueous extract upon Tityus serrulatus scorpion envenoming.

Scorpion envenoming causes an intense autonomic discharge, leading to a massive release of neurotransmitters, giving rise to several pathophysiological effects. In this work we report the effects of a Bauhinia forficata aqueous extract (BfAE) upon hyperglycemia, glycogenolysis, increase of plasma catecholamines, lethality and changes in serum insulin and plasma electrolytes induced by Tityus serrulatus scorpion venom (TSV). We compare them with the effects of the regular insulin therapy. The following treatments were performed: TSV (500 microg/kg, i.p.); BfAE (1g/kg, p.o.), 24, 12 and 1 h before and immediately after TSV or saline and insulin in a single dose (1.5 IU/kg, s.c.) after TSV. BfAE reduces the fast hyperglycemia induced by TSV, but it is deprived of hypoglycemic activity. The extract also did not reduce either the intense glycogenolysis or the release of catecholamines and did not stimulate the release of endogenous insulin, although causing changes in the electrolyte plasma levels similarly to insulin. Although BfAE and insulin antagonize some effects of TSV, they should be avoided in the treatment of Tityus serrulatus envenoming, since they enhance the lethality of the venom.

Evaluation of solubility, disintegration, and dimensional alterations of a glass ionomer root canal sealer.

The aim of this study was to evaluate the glass ionomer cement Ketac-Endo (K) compared with Endofill (E), N-Rickert (N), and Sealer 26 (S) in terms of disintegration, solubility, and dimensional alteration properties, based on ADA Specification No 57. For dimensional alterations, 12-mm high cylindric specimens measuring 6 mm in diameter were prepared and left to stand for a period corresponding to three times the setting time. These specimens were immersed in 30 ml of deionized distilled water after measuring their length with a caliper. Thirty days later, the sample was removed from the container, dried and measured again for length to determine the percent of dimensional alteration. For solubility and disintegration, 1.5-mm thick cement samples measuring 20 mm in diameter were prepared and left to stand for a period corresponding to three times the setting time. The samples were weighed and immersed in 50 ml of deionized distilled water. After seven days, the samples were removed, dried and weighed again to determine the mass loss of each sample, expressed as percentage of original mass. This was considered to correspond to solubility and disintegration of cement. The results were: dimensional alteration: E (+0.14), K (-0.24), N (+0.23), S (+3.26); for disintegration and solubility: E (3.90), K (9.90), N (3.00), S (0.25). We concluded that the dimensional alteration of all cements conformed to ADA standards; Endofill and Ketac-Endo sealers presented higher values for disintegration and solubility than ADA recommendations. Obturating a root canal with a sealer that presents low disintegration and low contraction could minimize the penetration of fluids into the root canal system, thus sealing the space hermetically.

Evaluation of solubility, disintegration, and dimensional alterations of a glass ionomer root canal sealer

The aim of this study was to evaluate the glass ionomer cement Ketac-Endo (K) compared with Endofill (E), N-Rickert (N), and Sealer 26 (S) in terms of disintegration, solubility, and dimensional alteration properties, based on ADA Specification No 57. For dimensional alterations, 12-mm high cylindric specimens measuring 6 mm in diameter were prepared and left to stand for a period corresponding to three times the setting time. These specimens were immersed in 30 ml of deionized distilled water after measuring their length with a caliper. Thirty days later, the sample was removed from the container, dried and measured again for length to determine the percent of dimensional alteration. For solubility and disintegration, 1.5-mm thick cement samples measuring 20 mm in diameter were prepared and left to stand for a period corresponding to three times the setting time. The samples were weighed and immersed in 50 ml of deionized distilled water. After seven days, the samples were removed, dried and weighed again to determine the mass loss of each sample, expressed as percentage of original mass. This was considered to correspond to solubility and disintegration of cement. The results were: dimensional alteration: E (+0.14), K (-0.24), N (+0.23), S (+3.26); for disintegration and solubility: E (3.90), K (9.90), N (3.00), S (0.25). We concluded that the dimensional alteration of all cements conformed to ADA standards; Endofill and Ketac-Endo sealers presented higher values for disintegration and solubility than ADA recommendations. Obturating a root canal with a sealer that presents low disintegration and low contraction could minimize the penetration of fluids into the root canal system, thus sealing the space hermetically

Análise qualitativa da presença de mercúrio em cápsulas de amálgama utilizadas / Qualitative analysis of mercury presence in utilized amalgam capsule

Analisou-se quantitativamente a presença ou ausência de resíduos de mercúrio em cápsulas pré-dosadas de amálgama de marcas Degussa, Permite SDI, SSWHITE (Velvalloy Plus) e Vigodent (Pratic NG2) já utilizadas. Utilizou-se para tanto, testes provenientes da química analítica denominado análise por via úmida. Concluiu-se que a cápsula da marca Degussa apresentou resultados negativos e as demais cápsulas testadas apresentaram resultados positivos para a presença de resíduos de mercúrio

Solvent action of sodium hypochlorite on bovine pulp and physico-chemical properties of resulting liquid / Ação solvente da solução de hipoclorito de sódio sobre o tecido pulpar bovino e as propriedades físico-quimica do líquido resultante

Estudou-se, in vitro, a ação solvente de quatro concentrações da solução de hipoclorito de sódio (0,5, 1,0, 2,5 e 5,0 por cento) sobre o tecido pulpar bovino, o teor de cloro residual, pH e a tensão superficial antes e após a dissolução. Um fragmento do tecido pulpar bovino era submerso na solução de hipoclorito de sódio que circulava em um aparato composto de uma bomba peristáltica e uma seringa Luer Lok e anotava-se o tempo até a total dissolução deste fragmento. De acordo com a metodologia empregada e com os resultados obtidos concluiu-se que: quanto maior a concentração da solução de hipoclorito de sódio maior a velocidade de dissolução do tecido pulpar, todas as soluções de hipoclorito de sódio apresentaram redução do pH e da tensão superficial após os testes de dissolução e as soluções de maior concentração apresentam menor consumo de cloro para a realização da dissolução tecidual

The influence of different grades of rosins and hydrogenated resins on the powder-liquid ratio of grossman cements / A influência de diferentes graus de resinas e resinas hidrogenadas em líquido-pó razão de cimentos Grossman

In this study, the effect of different grades of rosin and hydrogenated resin on the setting time of Grossman cement was evaluated. The experiments were carried following the American Dental Association Specification number 57 for root canal sealers. For this analysis, different Grossman cement powders were preparedusing different grades of rosin (X, WW and WG) and hydrogenated resin (Staybelite and Staybelite ester 10). The pH and electrical conductance of the different grades of rosin and hydrogenated resin were evaluated. The phisicochemical properties of the Grossman cements obtained with the differnt grades of rosin and hydrogenated resins interfere in the powder-liquid ratio of the cements. The sealers obtained with the hydrogenated resin showed a higher powder-liquid ratio

Evaluation of chelating action of EDTA in association with dakin's solution / Avaliação da ação quelante do EDTA em associação com a solução de Dakin

Three methods were used to study the chelating effect of EDTA, associated or not with 0.5 percent sodium hypochlorite (Dakin's solution). The results showed that: 1) aqueous EDTA, associated or not with Dakin's solution, is capable of chelating metallic ions; 2) EDTA and EDTA + Dakin's solution are capable of chelating calcium ions; 3) aqueous EDTA, as well as EDTA + Dakin's solution, decalcify dentin, decreasing its Vicker's microhardness; 4) the chelating action of EDTA is not inactivated when associated with Dakin's solution

Tensäo superficial de algumas soluçöes irrigantes de canais radiculares / Surface tension of root canal irrigating solution

Estudou-se a tensäo superficial de várias soluçöes auxiliares de instrumentaçäo de canais radiculares por meio do método da ascensäo capilar. O Lauril sulfato de sódio a 0.1 por cento apresentou a mais baixa tensäo superficial das soluçöes estudadas. A associaçäo de tensoativos ao EDTA reduz sensivelmente sua tensäo superficial. O líquido de Dakin apresenta uma tensäo superficial de 31,34 din/cm, que o posiciona como uma boa soluçäo de contato

Verificaçäo do teor de cloro ativo de diferentes marcas de líquido de Dakin encontrados no mercado / Determination of active chloride content in different comercial brands of Dakin's fluid

Verificou-se por meio da titulometria, o teor de cloro ativo, de 16 marcas de líquido de Dakin encontrada no mercado. Das amostras testadas, 6 estavam com teor de cloro ativo aceitável, ou seja , entre 0.64 a 0.40 por cento. Dez amostras apresentavam-se com teor de cloro abaixo de 0.40 por cento. A embalagem em plástico foi a predominante e entre elas, as transparentes