Influencia de la enfermedad psiquiátrica previa en la evolución de los pacientes sometidos a cirugía bariátrica

IntroductionPresurgical evaluation of patients undergoing bariatric surgery includes, among others, a psychological/psychiatric evaluation. Psychiatric disorders that did not contraindicate surgery may persist and influence on weight loss and postoperative clinical course, hindering the success of the procedure. The aim of our study was to analyze the postoperative evolution of our series of patients with and without psychiatric symptoms before surgery.Patients and methodsRetrospective analysis of 109 patients undergoing bariatric surgery with duodenal switch from 2003 to 2008 (follow up > 6 months). We studied weight changes, immediate and delayed complications of surgery and nutritional deficiencies in post-surgical follow-up in patients with previous psychiatric disorders (group 1, n = 17) compared with patients without psychiatric disorders (group 2, n = 92).ResultsPatients in group 1 showed a greater tendency for weight gain. They regained a 9,4% of the initial excess weight lost between 18 months after surgery and 36 months after surgery, while patients in group 2 regained only 0.2% in the same period (p < 0.05). There was no difference in immediate surgical complications (5/17 vs 25/92 patients). The mean incidence of late surgical complications was 0.71 per patient in group 1 and 0.22 complications per patient in group 2 (p = 0.02). 52.9% of patients in group 1 had at least one late complication compared to 19,6% of patients in group 2 (p = 0.003). The three most common complications in patients with previous psychiatric disorders were chronic diarrhea, vomits and malnutrition. The presence of nutritional deficiencies were common in both groups, mainly soluble vitamins, iron and zinc. During postoperative follow-up, we found 3.1 ± 1.6 nutritional deficiencies per patient in group 1 and 2.5 ± 1.7 in group 2 (p = 0.04). More than three nutritional deficiencies were found in 8 patients in group 1 (52.9%) compared to 23 patients in group 2 (25%) (p = 0.03).ConclusionsThe presence of previous psychiatric disorders may be a predictor of a less positive outcome in morbidly obese patients who undergo bariatric surgery.     

Electrical signals during nectar sucking in the carpenter ant Camponotus mus

Ants of the same size can vary their intake rate of a given sucrose solution depending on the colony's needs for carbohydrates. As this capacity has not yet been described for another insect, the question of how they can do that was the focus of our work. When viscosity and ant-morphometry remain constant, changes in intake rate can only be attributed to the sucking forces. The aim of this study was to analyze the nectar sucking activity in the ant Camponotus mus. Feeding behavior seems to be under motivational control; therefore, we developed a non-invasive experimental device. We recorded the electrical signal generated during nectar feeding by offering ants sucrose solutions of different concentrations (from 10%w/w to 70%w/w). The signal frequency was between 2 and 12 peaks/s. We could distinguish two different patterns of electrical signal during feeding depending on the solution concentration. Only the more concentrated solutions reached frequencies higher than 7 peaks/s and the signal performance was quite irregular. For the other concentrations (10%, 30% and 50%), signal frequencies were lower than 6 peaks/s and the signal pattern was sinusoidal, regular and decreased with intake in all cases. We discuss the possible implications of these two signal patterns.     

Phenotypic plasticity with respect to salt stress response by Lotus glaber: the role of its AM fungal and rhizobial symbionts

Our hypothesis is that Lotus glaber (a glycophytic species, highly tolerant to saline-alkaline soils) displays a plastic root phenotypic response to soil salinity that may be influenced by mycorrhizal and rhizobial microorganisms. Uninoculated plants and plants colonised by Glomus intraradices or Mesorhizobium loti were exposed to either 150 or 0 mM NaCl. General plant growth and root architectural parameters (morphology and topology) were measured and phenotypic plasticity determined at the end of the salt treatment period. Two genotypes differing in their salt tolerance capacity were used in this study. G. intraradices and M. loti reduced the total biomass of non-salinised, sensitive plants, but they did not affect that of corresponding tolerant ones. Root morphology of sensitive plants was greatly affected by salinity, whereas mycorrhiza establishment counteracted salinity effects. Under both saline conditions, the external link length and the internal link length of mycorrhizal salt-sensitive plants were higher than those of uninoculated control and rhizobial treatments. The topological trend (TT) was strongly influenced by genotype x symbiosis interaction. Under non-saline conditions, nodulated root systems of the sensitive plant genotype had a more herringbone architecture than corresponding uninoculated ones. At 150 mM NaCl, nodulated root systems of tolerant plants were more dichotomous and those of the corresponding sensitive genotype more herringbone in architecture. Notwithstanding the absence of a link between TTs and variations in plant growth, it is possible to predict a dissimilar adaptation of plants with different TTs. Root colonisation by either symbiotic microorganisms reduced the level of root phenotypic plasticity in the sensitive plant genotype. We conclude that root plasticity could be part of the general mechanism of L. glaber salt tolerance only in the case of non-symbiotic plants.     

Structure-antifungal activity relationship of His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH2 and analogues

The synthesis, in vitro evaluation and conformational study of His-Phe-Arg-Trp-Gly-Lys-Pro-Val-NH(2) and analogues acting as antifungal agents are reported. Among them, His-Phe-Lys-Trp-Gly-Arg-Phe-Val-NH(2) exhibited a moderate but significant antifungal activity against Cryptococcus neoformans, Candida albicans and Candida tropicalis. A theoretical study allows us to propose a biologically relevant conformation for these octapeptides acting as antifungal agents. In addition, these theoretical calculations allow us to determine the minimal structural requirements to produce the antifungal response and can provide a guide for the design of compounds with this biological activity.     

Furoxan-, alkylnitrate-derivatives and related compounds as anti-trypanosomatid agents: mechanism of action studies

A series of over a hundred furoxans, alkylnitrates and related compounds were studied as growth inhibitors of the two major kinetoplastids of Latin America, Trypanosoma cruziand Leishmania spp., in in vitro assays. The most active compounds showed 50% inhibitory doses of the same order of that of Nifurtimox and Miltefosine, reference drugs used to treat Chagas Disease and Leishmaniasis respectively. Among the studied compounds derivative 4, presenting excellent inhibitory activity against the tryposmastigote and amastigote forms of T. cruzi, has emerged as a lead compound. Mechanism of action seems to involve mitochondrial dehydrogenases as a distinct effect with respect to Nifurtimox. Excreted metabolites, studied by NMR, showed a significant decrease in succinate, confirming the observed effect on the mitochrondrial dehydrogenases.     

Metabolic responses to red/far-red ratio and ontogeny show poor correlation with the growth rate of sunflower stems

In sparse canopies, low red to far-red (R/FR) ratios reach only vertically-oriented stems, which respond with faster rates of extension. It is shown here that this signal also promotes stem dry matter accumulation in sunflower (Helianthus annuus) but not in mustard (Sinapis alba L.). Physically blocking internode extension growth also blocked internode recovery of labelled carbon fed to the leaves, indicating that increased carbon accumulation is partially a consequence of increased extension growth in sunflower. However, low R/FR also promoted carbon accumulation in the lower section of the internode, where extension growth was unaffected. Although the levels of many soluble metabolites and of cell-wall carbohydrates increased in the stem in response to low R/FR, allowing conservation of their concentration, sucrose was present at a lower concentration under low R/FR. This change is anticipated to favour carbon unloading from the stem phloem. Low R/FR also reduced the levels of selected fatty acids, fatty acid alcohols, and sterols. Compared with the lower section, the upper section of the internode showed higher levels of organic acids, amino acids, fatty acids, and sterols. It is concluded that the promotion of stem extension growth by low R/FR ratios causes increased dry matter gain in sunflower internodes by a mechanism that is largely independent of changes in metabolism, since, whilst both low R/FR and ontogeny alter the metabolic profile, the changes do not correlate with the observed growth responses.