Se investigó la actividad antioxidante de alfa-tocoferol, delta-tocoferol, ácido cítrico y palmitato de ascorbilo en aceite de girasol con su conteniendo natural de tocoferol. La efectividad de los ...mismos fue analizada a través de la medida de la estabilidad oxidativa en Rancimat y el seguimiento de la oxidación con el almacenamiento a diferentes temperaturas. Las muestras extraídas periódicamente de la estufa fueron sometidas a los siguientes análisis: índice de peróxidos, valor de p-anisidina, contenido y distribución de compuestos polares y contenido residual de tocoferol natural. La efectividad de cada antioxidante resultó fuertemente dependiente de la temperatura y método de ensayo. Mientras el ácido ascórbico resultó ser el antioxidante más efectivo según el índice de estabilidad oxidativa medido en el equipo Rancimat, el delta-tocoferol fue el antioxidante más efectivo en las experiencias de almacenamiento.
The antioxidant activity of alpha- and delta-tocopherol, citric acid, ascorbic acid and ascorbyl palmitate was investigated in sunflower oil containing naturally occurring tocopherol. The effectiveness of natural antioxidants in sunflower oil was monitored by the accelerated oxidative stability test Rancimat and oxidation development during storage under different conditions. Samples in storage experiments were periodically removed and analyzed for peroxide value, p-anisidine value, total content and distribution of polar compounds, and residual naturally occurring tocopherol. The effectiveness of each antioxidant was strongly dependent on temperature and the testing method. While ascorbic acid appears to be the most effective antioxidant according to the Rancimat oxidative stability index, delta-tocopherol shows improved performance when considering storage experiments.
One hundred sixty patients who underwent a percutaneous intervention for treatment of in-stent restenosis were evaluated on clinical follow-up to determine the predictors of reintervention, and also ...to compare rotational atherectomy with repeat percutaneous transluminal coronary angioplasty (PTCA) for this condition. Current smoking and saphenous vein graft location were the independent predictors of target vessel revascularization (TVR), and there was no difference in the rate of TVR between rotational atherectomy and re-PTCA.
Various techniques of reconstruction have been developed to improve the cosmetic and functional status of the abdominal wall in the prune-belly syndrome. We describe a new extraperitoneal plication ...technique of abdominoplasty that is simplified in comparison to other established procedures in that it obviates the need for a fascial incision and/or entrance into the peritoneal cavity in patients who do not require a concurrent intra-abdominal procedure.
Since 1980 this technique of abdominoplasty has been performed in 13 patients 9 months to 11 years old (mean age 3.8) at 2 institutions. Seven patients underwent surgery before age 2.5 years. Abdominal wall reconstruction was performed as an isolated extraperitoneal procedure in 5 patients, while 8 had concomitant procedures performed with the abdominoplasty, including bilateral Fowler-Stephens orchiopexy in 7, ureteral reconstruction/reimplantation in 5, excision of urachal diverticulum or cyst in 2, reduction cystoplasty in 1 and Tenckhoff catheter placement in 1.
In all cases the cosmetic result was excellent and satisfactory to patients, parents and surgeons. Since the first procedure was performed 17 years ago, only 1 patient has returned with abdominal wall laxity or bulging in the area of repair.
Our method of abdominal wall reconstruction in the prune-belly syndrome produces a cosmetically excellent and durable result. In contrast to other techniques of abdominoplasty, the need for a fascial incision and/or entrance into the peritoneal cavity is avoided. We believe that this modified procedure offers distinct technical and anatomical advantages over other existing techniques.
Acridine orange (AO), dinitrobenzoic acid (DNB), bromocresol green (BCG), bromophenol blue (BPB), and methylene blue (MB) were chosen as model aromatic compounds of different polarity, charge, and ...solubility in water to examine the effects of solute properties on hydrophobic adsorption. These compounds show strict structural similarities to some herbicides and other potential xenobiotic pollutants and exhibit distinct absorption maxima in the visible region, which allows for their easy determination. A well-decomposed peat (medisaprist) at four different stages of drying was used to determine compound adsorption/desorption influences based on the degree of hydrophobicity and charge density of an organic surface. Adsorption and desorption isotherms were investigated using the batch equilibration method and determining the concentration of free chemicals by UV-Vis spectrophotometry. AO had a high tendency of adsorption and was strongly sorbed on peat samples that had been air-dried for 12 months. The lower Freundlich coefficient values found for MB when compared with AO at all the drying stages of the peat indicated that electrostatic attraction has a secondary contribution to sorption. On the contrary, the higher energy that must be spent to break solute-solvent interactions in the case of charged or polar molecules is one of the main factors in determining the position of the equilibrium. For a given solute, K
f
values varied with the degree of hydrophobicity and the charge density of the surface, but again solute-solvent interactions appear to be much more important in the overall energy balance of hydrophobic pollutants than the electrostatic sorbate-sorbent interactions. A change in the solution pH does not improve the adsorption of the relatively polar DNB molecule, but sorption increases strongly for BCG and BPB when these molecules are in non-dissociated forms. The larger increase in BPB sorption observed on H
+
saturated peat suggests that the degree of interaction increases with the suppression of the negative charge, but charge repulsion has a small effect in preventing adsorption of molecules bearing hydrophobic groups such as BCG. Desorption results differed depending on the chemical structure of the compound examined. For example, with AO there was no desorption from the more hydrophobic peat surfaces. A negative hysteresis was observed for DNB; the magnitude of hysteresis, evaluated using the ratio of Freundlich coefficients for adsorption and desorption, increased with the drying stage of the sorbent and was larger on oven-dried samples.
Twenty-seven subjects with moderate asthma at the time of diagnosis, well controlled under regular fluticasone propionate (FP) (250 μg b.i.d.) for 6 months at least, were randomized to receive in ...double-blind fashion: FP 125 μg b.i.d. (Group 1) or FP 50 μg b.i.d. (Group 2) or placebo (Group 3) for 3 months or until symptom recurrence. Daily symptom score and peak expiratory flow were monitored. At the beginning and at the end of the study, subjects underwent methacholine challenge and sputum induction. Recurrence of symptoms occurred shortly after randomization in all subjects receiving placebo. None from Group 1 or 2 experienced symptom recurrence during the study. No significant difference in clinical and functional data, and in sputum eosinophil percentages was observed between the beginning and the end of the study in both Groups 1 and 2. Subjects from Group 3 showed a significant increase of sputum eosinophils (
P<0.05) and a significant decrease in provocative dose of methacholine (
P<0.05) when asthma symptoms recurred. Therefore, very low doses of FP (50 μg b.i.d.) are effective in maintaining for 3 months a good control of the disease in asthmatics already stable under high-dose fluticasone, considering both clinical and functional outcomes and markers of airway inflammation.
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