Fine tuning of magnetite nanoparticle size distribution using dissymmetric potential pulses in the presence of biocompatible surfactants and the electrochemical characterization of the nanoparticles.

The effects of varying the surfactant concentration and the anodic pulse potential on the properties and electrochemical behaviors of magnetite nanoparticles were investigated. The nanoparticles were synthesized with an electrochemical method based on applying dissymmetric potential pulses, which offers the advantage that can be used to tune the particle size distribution very precisely in the range of 10 to 50 nm. Under the conditions studied, the surfactant concentration directly affects the size distribution, with higher concentrations producing narrower distributions. Linear voltammetry was used to characterize the electrochemical behavior of the synthesized nanoparticles in both the anodic and cathodic regions, which are attributed to the oxidation of Fe(2+) and the reduction of Fe(3+); these species are part of the spinel structure of magnetite. Electrochemical impedance spectroscopy data indicated that the reduction and oxidation reactions of the nanoparticles are not controlled by the mass transport step, but by the charge transfer step. The sample with the highest saturation magnetization was that synthesized in the presence of polyethylene glycol.

Influenza vaccine: development of a novel intranasal and subcutaneous recombinant adjuvant.

The synthetic peptide GK-1, derived from Taenia crassiceps, enhances the protection induced by human influenza vaccine in both young and aged mice. Herein, the adjuvant properties of GK-1 fused to the pVIII protein of a heat-inactivated phagemid vector (FGK1) when co-administered with the influenza vaccine were assessed, to evaluate its feasibility as a low-cost adjuvant. In mice, FGK1 significantly increased the expected IgG and IgA anti-influenza antibody levels both in sera and in bronchoalveolar fluids when intranasally or subcutaneously co-administered with influenza vaccine. Single-dose pig co-immunization with FGK1 and influenza vaccine induced serum levels of IgG anti-influenza antibodies similar to those elicited by a two-dose immunization with the influenza vaccine alone. Preclinical evaluation of FGK1 with the influenza vaccine is currently in progress, in order to recommend its use for veterinary purposes.

Pre-exposure to infectious hypodermal and haematopoietic necrosis virus or to inactivated white spot syndrome virus (WSSV) confers protection against WSSV in Penaeus vannamei (Boone) post-larvae.

Larvae and post-larvae of Penaeus vannamei (Boone) were submitted to primary challenge with infectious hypodermal and haematopoietic necrosis virus (IHHNV) or formalin-inactivated white spot syndrome virus (WSSV). Survival rate and viral load were evaluated after secondary per os challenge with WSSV at post-larval stage 45 (PL45). Only shrimp treated with inactivated WSSV at PL35 or with IHHNV infection at nauplius 5, zoea 1 and PL22 were alive (4.7% and 4%, respectively) at 10 days post-infection (p.i.). Moreover, at 9 days p.i. there was 100% mortality in all remaining treatments, while there was 94% mortality in shrimp treated with inactivated WSSV at PL35 and 95% mortality in shrimp previously treated with IHHNV at N5, Z1 and PL22. Based on viral genome copy quantification by real-time PCR, surviving shrimp previously challenged with IHHNV at PL22 contained the lowest load of WSSV (0-1x10(3) copies microg-1 of DNA). In addition, surviving shrimp previously exposed to inactivated WSSV at PL35 also contained few WSSV (0-2x10(3) copies microg-1 of DNA). Consequently, pre-exposure to either IHHNV or inactivated WSSV resulted in slower WSSV replication and delayed mortality. This evidence suggests a protective role of IHHNV as an interfering virus, while protection obtained by inactivated WSSV might result from non-specific antiviral immune response.

[Nutritional evaluation of women admitted for pregnancy complications]. / Evaluación nutricional de las embarazadas ingresadas en la sala de gestantes patológicas.

A descriptive, cross-sectional and prospective study of 558 pregnant women was conducted. 998 gravidae admitted at the Eastern Hospital in Santiago de Cuba during the first trimester of 1995 were taken as a sample. The nursing work was analyzed, as well as the correct advising given to the pregnant patients and to those who had already delivered in order to evaluate their nutritional status. The following characteristics of the sample were considered: age, educational level, parity, weight gain during pregnancy and at the end of it, and gestational age at delivery. Most of the pregnant women were between 18 and 35 years and had attained a senior high school level. There was a predominance of parity 0-2. It was proved that the nutritional status is related to weight and size. Maternal weight gain during pregnancy was positive.

PIP: A prospective study was conducted in early 1995 to evaluate the nutritional status of pregnant women admitted to the gestational pathology service of the Eastern Hospital in Santiago, Cuba. 98 of the 558 women admitted were randomly selected for study. 86 were of normal weight, 8 were underweight, and 4 were overweight. 50% of the underweight women and 6% of those of normal weight had 3 or more children. At the end of the pregnancy, 6 of the 8 underweight women and 3 of the 4 overweight women had corrected their weight. 75% of underweight women and 25% of overweight women gained 12 kg or more during the pregnancy. There were no premature deliveries in the series. The adequate weight gain of most of the women demonstrates the importance of the work of nurses in providing nutrition education.