An overview of cytokines and heat shock response in polytraumatized patients

Early after injury, local tissue damage induces a local and systemic inflammatory response that activates the immune system and leads to the development of systemic inflammatory response syndrome (SIRS). This post-traumatic response often results in uncontrolled release of inflammatory mediators and over-activation of the immune system, which occasionally results in multiple organ dysfunction syndrome (MODS). In parallel, a state of immunosuppression develops. This counter-regulating suppression of different cellular and humoral immune functions has been termed “compensatory anti-inflammatory response syndrome (CARS).” Both SIRS and CARS occur simultaneously even in the initial phase after injury. Pro- and anti-inflammatory cytokines have been suggested to play a major role in development of SIRS, although the degree of involvement of the different cytokines is quite disparate. While TNF-α and IL-1β are quite irrelevant for predicting organ dysfunction, IL-6 is the parameter that best predicts mortality. The hyperinflammatory state seems to be the cause of post-traumatic immunosuppression and heat shock proteins (HSPs), which have been proposed as one of the endogenous stimuli for the deterioration of the immune system acting as danger-associated molecular patterns (DAMPs). Extracellular HSPA1A released from injured tissues increase up to ten times immediately after trauma and even more in patients with MODS. It has powerful immune properties that could contribute to post-traumatic immunosuppression through several mechanisms that have been previously described, so HSPs could represent trauma-associated immunomodulatory mediators. For this reason, HSPA1A has been suggested to be a helpful early prognostic biomarker of trauma after severe injury: serial quantification of serum HSPA1A and anti-Hsp70 concentrations in the first hours after trauma is proposed to be used as a predictive biomarker of MODS and immunosuppression development in polytraumatized patients.     

Sigmodontine rodents diversified in South America prior to the complete rise of the Panamanian Isthmus

The extant distribution of sigmodontine rodents encompasses most of the New World, and the majority of the species in this subfamily inhabit South America. Nevertheless, the basal lineages of the Sigmodontinae are distributed in North and Central America, and the fossil record indicates a North American origin. This evidence has produced contentious theories concerning the evolution of these rodents. The dispute usually stems from a disagreement about the way in which sigmodontines reached South America, which was an isolated landmass during most of the Cenozoic. Fundamentally, the debate is associated with the role of Panamanian Isthmus formation and the Great American Biotic Interchange (GABI) in the diversification of the clade. An early hypothesis implies that sigmodontines arrived in South America before the complete rise of the Panamanian Isthmus, whereas a late hypothesis directly correlates the diversification of the lineage with this event. To address this question, we have sequenced nuclear and mitochondrial sequences, as well as the first Sigmodontinae mitochondrial genomes (Akodon montensis and Wiedomys cerradensis) and performed a Bayesian dating analysis. Our results showed that the most recent common ancestor of the subfamily lived at approximately 15 Ma. Although the diversification of sigmodontines was not associated with the complete rise of the Panamanian Isthmus, we cannot exclude the hypothesis that this event played a relevant role in the evolution of the lineage during the Miocene.     

The Santa Pola saltern as a model for studying the microbiota of hypersaline environments

Multi-pond salterns constitute an excellent model for the study of the microbial diversity and ecology of hypersaline environments, showing a wide range of salt concentrations, from seawater to salt saturation. Accumulated studies on the Santa Pola (Alicante, Spain) multi-pond solar saltern during the last 35 years include culture-dependent and culture-independent molecular methods and metagenomics more recently. These approaches have permitted to determine in depth the microbial diversity of the ponds with intermediate salinities (from 10 % salts) up to salt saturation, with haloarchaea and bacteria as the two main dominant groups. In this review, we describe the main results obtained using the different methodologies, the most relevant contributions for understanding the ecology of these extreme environments and the future perspectives for such studies.     

Multiple sensitive estimation and optimal sample size allocation in the item sum technique

For surveys of sensitive issues in life sciences, statistical procedures can be used to reduce nonresponse and social desirability response bias. Both of these phenomena provoke nonsampling errors that are difficult to deal with and can seriously flaw the validity of the analyses. The item sum technique (IST) is a very recent indirect questioning method derived from the item count technique that seeks to procure more reliable responses on quantitative items than direct questioning while preserving respondents' anonymity. This article addresses two important questions concerning the IST: (i) its implementation when two or more sensitive variables are investigated and efficient estimates of their unknown population means are required; (ii) the determination of the optimal sample size to achieve minimum variance estimates. These aspects are of great relevance for survey practitioners engaged in sensitive research and, to the best of our knowledge, were not studied so far. In this article, theoretical results for multiple estimation and optimal allocation are obtained under a generic sampling design and then particularized to simple random sampling and stratified sampling designs. Theoretical considerations are integrated with a number of simulation studies based on data from two real surveys and conducted to ascertain the efficiency gain derived from optimal allocation in different situations. One of the surveys concerns cannabis consumption among university students. Our findings highlight some methodological advances that can be obtained in life sciences IST surveys when optimal allocation is achieved.     

Soil microbial communities drive the resistance of ecosystem multifunctionality to global change in drylands across the globe

The relationship between soil microbial communities and the resistance of multiple ecosystem functions linked to C, N and P cycling (multifunctionality resistance) to global change has never been assessed globally in natural ecosystems. We collected soils from 59 dryland ecosystems worldwide to investigate the importance of microbial communities as predictor of multifunctionality resistance to climate change and nitrogen fertilisation. Multifunctionality had a lower resistance to wetting–drying cycles than to warming or N deposition. Multifunctionality resistance was regulated by changes in microbial composition (relative abundance of phylotypes) but not by richness, total abundance of fungi and bacteria or the fungal: bacterial ratio. Our results suggest that positive effects of particular microbial taxa on multifunctionality resistance could potentially be controlled by altering soil pH. Together, our work demonstrates strong links between microbial community composition and multifunctionality resistance in dryland soils from six continents, and provides insights into the importance of microbial community composition for buffering effects of global change in drylands worldwide.     

Biotechnologically relevant enzymes and proteins

The mold Aspergillus giganteus produces a basic, low molecular weight protein showing antifungal properties against economically important plant pathogens, the AFP (Antifungal Protein). In this study, we investigated the mechanisms by which AFP exerts its antifungal activity against Magnaporthe grisea. M. grisea is the causal agent of rice blast, one of the most devastating diseases of cultivated rice worldwide. AFP was purified from the extracellular medium of A. giganteus cultures. The AFP protein was found to induce membrane permeabilization in M. grisea cells. Electron microscopy studies revealed severe cellular degradation and damage of plasma membranes in AFP-treated fungal cells. AFP however failed to induce membrane permeabilization on rice or human HeLa cells. Furthermore, AFP enters the fungal cell and targets to the nucleus, as revealed by co-localization experiments of Alexa-labeled AFP with the SYTOX Green dye. Finally, AFP binds to nucleic acids, including M. grisea DNA. Our results suggest that the combination of fungal cell permeabilization, cell-penetrating ability and nucleic acid-binding activity of AFP determines its potent antifungal activity against M. grisea. These results are discussed in relation to the potential of the AFP protein to enhance crop protection against fungal diseases.     

Diagnostic accuracy, effectiveness and cost for cognitive impairment and dementia screening of three short cognitive tests applicable to illiterates

Background

Illiteracy, a universal problem, limits the utilization of the most widely used short cognitive tests. Our objective was to assess and compare the effectiveness and cost for cognitive impairment (CI) and dementia (DEM) screening of three short cognitive tests applicable to illiterates.

Methods

Phase III diagnostic test evaluation study was performed during one year in four Primary Care centers, prospectively including individuals with suspicion of CI or DEM. All underwent the Eurotest, Memory Alteration Test (M@T), and Phototest, applied in a balanced manner. Clinical, functional, and cognitive studies were independently performed in a blinded fashion in a Cognitive Behavioral Neurology Unit, and the gold standard diagnosis was established by consensus of expert neurologists on the basis of these results. Effectiveness of tests was assessed as the proportion of correct diagnoses (diagnostic accuracy [DA]) and the kappa index of concordance (k) with respect to gold standard diagnoses. Costs were based on public prices at the time and hospital accounts.

Results

The study included 139 individuals: 47 with DEM, 36 with CI, and 56 without CI. No significant differences in effectiveness were found among the tests. For DEM screening: Eurotest (k = 0.71 [0.59–0.83], DA = 0.87 [0.80–0.92]), M@T (k = 0.72 [0.60–0.84], DA = 0.87 [0.80–0.92]), Phototest (k = 0.70 [0.57–0.82], DA = 0.86 [0.79–0.91]). For CI screening: Eurotest (k = 0.67 [0.55–0.79]; DA = 0.83 [0.76–0.89]), M@T (k = 0.52 [0.37–0.67]; DA = 0.80 [0.72–0.86]), Phototest (k = 0.59 [0.46–0.72]; DA = 0.79 [0.71–0.86]). There were no differences in the cost of DEM screening, but the cost of CI screening was significantly higher with M@T (330.7±177.1€, mean±sd) than with Eurotest (294.1±195.0€) or Phototest (296.0±196.5€). Application time was shorter with Phototest (2.8±0.8 min) than with Eurotest (7.1±1.8 min) or M@T (6.8±2.2 min).

Conclusions

Eurotest, M@T, and Phototest are equally effective. Eurotest and Phototest are both less expensive options but Phototest is the most efficient, requiring the shortest application time.     

Cationic polyelectrolytes-lipases complexes formation as tool for recovery of these enzymes from their natural sources

In the present paper the formation of complexes between positively charge polyelectrolyte (polyethyleneimine and chitosan) and Candida rugosa lipase from a crude extract and porcine lipase from pancreas commercial homogenate preparations were analyzed. The solubility of lipases-cationic polyelectrolytes formation was dependent on: polyelectrolyte densities electrical charge, polyelectrolyte and enzyme concentrations and salts present in the solution. The lipase was recovered from the non-soluble complex by adding of NaCl at a given pH. Although the polyelectrolytes did not affect lipase biological activity, both of them produced good enzyme recovery (>90%); however, purification factors were low. This methodology appears to be a good previous prepurification and concentration method, using, low-cost polymers, allows the design of a purification method where the protein of interest is present in a large volume with respect to the small amount of polyelectrolyte added.