ABSTRACT
Oil/water emulsions, containing liquid crystals, were developed employing Andiroba oil, PEG-12 Dimethicone and Crodafos CES. It was evaluated the influence of silicone surfactants on the emulsions stability and on the formation of liquid crystalline phases and therefore, physicochemical characteristics, such as rheology and zeta potential, were evaluated. Emulsions were prepared by the emulsions phase inversion method. All the formulations presented lamellar liquid crystalline phases. The PEG-12 Dimethicone addition did not change microscopically the liquid crystalline phases. The emulsions containing silicone demonstrated lower viscosity than those without the additive. This is an important feature, as the silicone did not change the rheological profile; however, the addition of silicone still can be used as a viscosity controller. The formulations had their viscosity increased 15 and 150 days after their preparation. This characteristic shows that the emulsions have their organization increased along the storing time. In the analysis of zeta potential, we could verify that all formulations presented negative values between -39.7 and -70.0 mV. Within this range of values, the emulsion physical stability is high (Fig. 10). It was concluded that the addition of PEG-12 Dimethicone kept the liquid crystalline phase of the emulsion obtained with Crodafos CES, influencing in a positive way in the system stability.
ABSTRACT
UNLABELLED: During 1986 the authors came across two cases of brain abscess among children with congenital heart disease followed at the Pediatric Cardiology Service and decided to evaluate their global experience on the subject. In a retrospective study of 860 infants and children with cyanotic congenital heart disease and final diagnosis, there were four cases complicated with brain abscess. The following items were evaluated: prevalence of the complication, type of congenital heart disease, date and age at the diagnosis of brain abscess, diagnostic methods, neurosurgical treatment and results. The main findings were: all patients were above two years of age and had noncorrected cyanotic congenital heart disease belonging to the classic high risk group; the first two cases had been treated in other institutions and only scanty information was available; two recent cases had early diagnosis on CAT scan followed by neurosurgical treatment. All children survived. CONCLUSIONS: brain abscess is a rare but severe complication occurring in patients with noncorrected cyanotic congenital heart disease above two years of age; whenever prevention turns impossible, early diagnosis and treatment provide good short term and long term results. A multidisciplinar approach with full cooperation is advocated.
