RESUMEN
Oral tolerance (OT) is characterized as a peripheral immune tolerance form, in which, mature lymphocytes in lymphoid tissues associated with mucosa, become non-functional or hypo responsive due to prior oral administration of antigen. OT is an important immunological phenomenon due to its therapeutic potential in inflammatory processes and others diseases. Here we evaluated leukotriene role in the induction of OT, as well as, the production of cytokines IL-5 and IFN-γ in leukotriene deficient animals (knock-out). Our results suggested that even in the presence of OT and leukotrienes absence, cytokine IFN-γ remains being secreted, which gives us an indication of immune system specificity and also that IFN-γ participates in various immune processes.
RESUMEN
BACKGROUND: Aluminum loading can reach toxic levels depending on the amount of aluminum intake in intravenous solutions (IV). Premature infants are at a higher risk of aluminum toxicity because of their reduced urinary aluminum elimination. All steps involved in the preparation of intravenous solutions for premature neonates in intensive care units were evaluated to determine to what degree, if any, they increased the aluminum load and should be considered when assessing the daily aluminum intake (<5 mcg/kg) established by the U.S. Food and Drug Administration (FDA). METHODS: Products and medical devices used for the IV administration of solutions to preterm neonates were analyzed for their aluminum content. Commercial formulations, bags after compounding, and medications before and after their preparation, as well as infusion sets (including burettes) and syringes, were evaluated for their contribution to the aluminum levels in the final solution. The determination was carried out by atomic absorption spectrometry. RESULTS: Currently available products used to prepare parenteral nutrition solutions as well as injectable medications usually administered to premature neonates present aluminum contamination. Bags, burettes, and syringes were also contaminated by aluminum to some degree, which may be leached during use. CONCLUSIONS: Commercial products are the main source of aluminum in parenteral nutrition; nevertheless, manipulation, containers, and administration sets increased aluminum levels by about 40%. Because this is a significant rate, these sources should be taken into account when calculating the amount of aluminum delivered to the patient in order to comply with FDA standards.