Direct bonding brackets: unfilled versus unfilled/filled resins.

The clinical and clinical/laboratorial performance of unfilled/filled and only unfilled resins for direct bonding of orthodontic brackets were evaluated. In the clinical part, brackets were bonded using both techniques in alternate quadrants of eleven patients of the Orthodontic Clinic, State University of Rio de Janeiro. A total of 118 teeth, 59 in each group, were tested and bond failure frequencies were recorded for six months. For the clinical/laboratory part, upper and lower premolars to be extracted for orthodontic reasons, were selected. Thirty-two brackets were bonded in vivo--16 using unfilled/filled and 16 using only unfilled resins--and the teeth were kept in the mouth for two months. After extraction, the teeth were secured in plastic rings and an Universal Instron Machine was used to debond the brackets. No statistically significant differences were observed for clinical failure rates, nor for laboratory debonding strength between the two techniques. Failures occurred preponderantly at the bracket/resin interface, so that most of the resin remained bonded to the enamel surface on both groups.

Zinc tolerance modulation in Myracrodruon urundeuva plants.

We investigated Zn tolerance and related tolerance mechanisms of Myracrodruon urundeuva by evaluating the growth (biomass production, pigment content, and photosynthetic activity) and antioxidant systems (redox potential and antioxidant enzyme activities) of seedlings exposed to increasing Zn doses. Plants were grown for 120 days in substrates with 0, 50, 80, 120 and 200 mg Zn kg(-1) and demonstrated Zn-tolerance. Zn doses greater than 80 mg Zn kg(-1) were phytotoxic but not lethal, and Zn toxicity under these conditions was imposed by oxidative stress caused by hydrogen peroxide (H2O2) accumulation and related lipid peroxidation. Zn tolerance in M. urundeuva is linked to the activity of antioxidant systems in their leaves that are modulated by that metal: both superoxide dismutase (SOD) and catalase (CAT) were always higher in the presence of Zn; lower Zn doses stimulated ascorbate peroxidase (APX) and glutathione reductase (GR) activities, but enzyme activity was inhibited at high doses; APX appeared to be the main peroxidase in H2O2 scavenging as stimulated guaiacol peroxidase (GPX) activity was not sufficient to avoid H2O2 accumulation at higher Zn doses; the modulation of APX and GR activities was linked to changes in the redox status of leaves.

Use of immunoblotting assay improves the sensitivity of paracoccidioidomycosis diagnosis

The purpose of this work was to evaluate two serological assays: double immunodiffusion (DI) and immunoblotting (IB) in immunodiagnosis of paracoccidioidomycosis (PCM). We evaluated by IB assay 23 sera samples from patients with clinical confirmation of PCM, all of them with negative DI results against culture filtrate from Paracoccidioides brasiliensis isolate 113. For IB, as well as for comparative DI assay, we employed soluble components of the cell wall outer surface (SCCWOS) from P. brasiliensis isolate 113 cultivated at 36°C in Fava-Neto's agar medium for 5 and 10 days. Among the 20 sera samples analyzed by DI, 13 (65 percent) were negative and 7 (35 percent) were positive against SCCWOS obtained on the 5th and 10th days. By IB assay, 95.4 percent and 100 percent of sera reacted against gp43 and gp70 present in SCCWOS from the 5th day and 95.6 percent recognized these fractions when evaluated against SCCWOS from the 10th day. Our results demonstrated that the use of an immunoenzymatic assay significantly improves the sensitivity of PCM immunodiagnosis and also suggests that at least two serological tests for antibody detection should be adopted in cases of questionable diagnosis.

Utilização de ciclodextrinas na formação de complexos de inclusão de interesse farmacêutico / Use of cyclodextrins to form inclusion complexes of pharmaceutical interest

As ciclodextrinas (CDs) constituem uma nova classe de excipientes farmacêuticos com capacidade para formar complexos de inclusão reversíveis com moléculas apolares. A habilidade das CDs em encapsular fármacos tem conseguido melhoras na biodisponibilidade, estabilidade e segurança de inúmeras fórmulas farmacêuticas atualmente comercializadas. Esta revisão bibliográfica compila os principais procedimentos empregados para a obtenção de complexos de inclusão em solução e em estado sólido utilizando CDs, discutindo seus diferentes aspectos. As técnicas utilizadas para caracterização e controle são analisadas criticamente quanto a suas aportações e limitações. Os aspectos relacionados à sua utilização pela indústria farmacêutica também são abordados

Cyclodextrins (CDs) have found application in a new family of pharmaceutical excipients with the ability to form reversible inclusion complexes with non-polar molecules. CDs capable of encapsulating drugs have led to improvements in the bioavailability, stability and safety of several dosage forms on the market. The main procedures employed to produce CD inclusion complexes, both in dissolved and solid forms, are brought together in this review of the literature and several aspects of these methods are examined. The techniques used in research and quality control of CD formulations are analysed critically with respect to their particular features and limitations. Aspects of their use in the drugs industry are also discussed.

Ecdisteróide e iridóide glicosilado de Vitex gardneriana Schauer (Verbenaceae) / Ecdysteroid and iridoid glycoside from Vitex gardneriana Schauer (Verbenaceae)

O extrato metanólico das cascas do caule de Vitex gardneriana Schauer forneceu o ecdisteróide, 20-hidroxi-ecdisona e o iridóide glicosilado, aucubina. As estruturas foram caracterizadas por métodos químicos e espectroscópicos.

The methanolic extract of the stem bark of Vitex gardneriana Schauer afforded the ecdysteroid, 20-hydroxy-ecdysone and the iridoid glycoside, aucubin. Their structures were established on the basis of chemical and spectroscopic studies.