Interplay between iron homeostasis and the osmotic stress response in the halophilic bacterium Chromohalobacter salexigens.

In this study, the connection between iron homeostasis and the osmostress response in the halophile Chromohalobacter salexigens was investigated. A decrease in the requirement for both iron and histidine and a lower level of siderophore synthesis were observed at high salinity, and these findings were correlated with a lower protein content in salt-stressed cells. A six-gene operon (cfuABC-fur-hisI-orf6 operon) located downstream of the ectABC ectoine synthesis genes was characterized. A fur strain (in which the ferric iron uptake regulator Fur was affected) had the Mn resistance phenotype typical of fur mutants, was deregulated for siderophore production, and displayed delayed growth under iron limitation conditions, indicating that fur encodes a functional iron regulator. hisI was essential for histidine synthesis, which in turn was necessary for siderophore production. Fur boxes were found in the promoters of the cfuABC-fur-hisI-orf6 and ectABC operons, suggesting that Fur directly interacts with DNA in these regions. Fur mediated the osmoregulated inhibition of cfuABC-fur-hisI-orf6 operon expression by iron and functioned as a positive regulator of the ectABC genes under high-salinity conditions, linking the salt stress response with iron homeostasis. Excess iron led to a higher cytoplasmic hydroxyectoine content, suggesting that hydroxyectoine protects against the oxidative stress caused by iron better than ectoine. This study provides the first evidence of involvement of the iron homeostasis regulator Fur as part of the complex circuit that controls the response to osmotic stress in halophilic bacteria.

Treatment of advanced laryngeal cancer and quality of life. Systematic review. / Tratamiento del cáncer de laringe avanzado y calidad de vida. Revisión sistemática.

INTRODUCTION AND OBJECTIVES: The objective was the comparison of the quality of life in patients with advanced laryngeal cancer treated with organ preservation versus surgical treatment. METHODS: We performed a systematic review in the databases MedLine, EMBASE, and PubMed (2014 1991) and Web of Science (2012 - 2014). The search terms were: Laryngeal cancer, organ preservation, chemotherapy, laryngectomy, treatment outcomes and quality of life. Systematic reviews, meta-analysis, reports of health technology assessment and comparative studies with control group, published in Spanish, French or English were included. The selection and quality assessment was made by two researchers. The criteria of the Cochrane Collaboration were used to assess the risk of bias and Scottish Intercollegiate Guidelines Network (SIGN) for the level of evidence. RESULTS: Of the 208 studies identified in the search, three were included a clinical trial and two observational studies, with a total of 211 patients. Quality and level of evidence was low. The results were contradictory, on occasion they favoured surgery, and on other occasions chemotherapy, but in general there were no statistical differences between the treatments. The studies were heterogeneous, with different methodology, undersized, limitations in quality with high risk of bias and use of different measurement scales. CONCLUSIONS: There are not enough studies of quality to establish differences in the quality of life in patients with advanced laryngeal cancer according to the treatment received.

[Methodological guideline for the efficacy and safety assessment of new pharmaceuticals: implementation of EUnetHTA's recommendations]. / Guía metodológica para la evaluación de la eficacia y la seguridad de nuevos fármacos: implementación de las recomendaciones de EUnetHTA.

The European network for Health Technology Assessment (EUnetHTA) is the network of public health technology assessment (HTA) agencies and entities from across the EU. In this context, the HTA Core Model®, has been developed. The Andalusian Agency for Health Technology Assessment (AETSA) is a member of the Spanish HTA Network and EUnetHTA collaboration In addition, AETSA participates in the new EUnetHTA Joint Action 3 (JA, 2016-2019). Furthermore, AETSA works on pharmaceutical assessments. Part of this work involves drafting therapeutic positioning reports (TPRs) on drugs that have recently been granted marketing authorisation, which is overseen by the Spanish Agency of Medicines and Medical Devices (AEMPS). AETSA contributes by drafting "Evidence synthesis reports: pharmaceuticals" in which a rapid comparative efficacy and safety assessment is performed for drugs for which a TPR will be created. To create this type of report, AETSA follows its own methodological guideline based on EUnetHTA guidelines and the HTA Core Model®. In this paper, the methodology that AETSA has developed to create the guideline for "Evidence synthesis reports: pharmaceuticals" is described. The structure of the report itself is also presented.

Osmoprotection of Salmonella enterica serovar Typhimurium by Ngamma-acetyldiaminobutyrate, the precursor of the compatible solute ectoine.

N(gamma)-acetyl-2,4-diaminobutyrate (NADA), the precursor of the compatible solute ectoine, was shown to function as an osmoprotectant for the non-halophilic bacterium Salmonella enterica serovar Typhimurium. The addition of NADA-containing extracts of an ectoine synthase mutant of the broad salt-growing halophile Chromohalobacter salexigens DSM 3043(T) could alleviate the inhibitory effects of high salinity in S. enterica, which lacks the ectoine biosynthetic pathway. NADA, purified from extracts of the mutant, protected S. enterica against salinity stress. This osmoprotective effect was slightly lower than that of ectoine, but more potent than that of hydroxyectoine. Accumulation of purified NADA by S. enterica was demonstrated by (13)C-NMR spectroscopy and HPLC analysis. In addition, it was shown that NADA was taken up by S. enterica via the ProP and ProU transport systems, which are known to transport glycine betaine and proline. This finding provides evidence that these permeases can recognize a diaminoacid that carries an unsubstituted alpha-amino group. This is the first time that NADA has been connected with osmoprotective functions in non-halophilic bacteria.

The ectD gene, which is involved in the synthesis of the compatible solute hydroxyectoine, is essential for thermoprotection of the halophilic bacterium Chromohalobacter salexigens.

The halophilic bacterium Chromohalobacter salexigens synthesizes and accumulates compatible solutes in response to salt and temperature stress. (13)C-nuclear magnetic resonance analysis of cells grown in minimal medium at the limiting temperature of 45 degrees C revealed the presence of hydroxyectoine, ectoine, glutamate, trehalose (not present in cells grown at 37 degrees C), and the ectoine precursor, Ngamma-acetyldiaminobutyric acid. High-performance liquid chromatography analyses showed that the levels of ectoine and hydroxyectoine were maximal during the stationary phase of growth. Accumulation of hydroxyectoine was up-regulated by salinity and temperature, whereas accumulation of ectoine was up-regulated by salinity and down-regulated by temperature. The ectD gene, which is involved in the conversion of ectoine to hydroxyectoine, was isolated as part of a DNA region that also contains a gene whose product belongs to the AraC-XylS family of transcriptional activators. Orthologs of ectD were found within the sequenced genomes of members of the proteobacteria, firmicutes, and actinobacteria, and their products were grouped into the ectoine hydroxylase subfamily, which was shown to belong to the superfamily of Fe(II)- and 2-oxoglutarate-dependent oxygenases. Analysis of the ectoine and hydroxyectoine contents of an ectABC ectD mutant strain fed with 1 mM ectoine or hydroxyectoine demonstrated that ectD is required for the main ectoine hydroxylase activity in C. salexigens. Although in minimal medium at 37 degrees C the wild-type strain grew with 0.5 to 3.0 M NaCl, with optimal growth at 1.5 M NaCl, at 45 degrees C it could not cope with the lowest (0.75 M NaCl) or the highest (3.0 M NaCl) salinity, and it grew optimally at 2.5 M NaCl. The ectD mutation caused a growth defect at 45 degrees C in minimal medium with 1.5 to 2.5 M NaCl, but it did not affect growth at 37 degrees C at any salinity tested. With 2.5 M NaCl, the ectD mutant synthesized 38% (at 37 degrees C) and 15% (at 45 degrees C) of the hydroxyectoine produced by the wild-type strain. All of these data reveal that hydroxyectoine synthesis mediated by the ectD gene is thermoregulated and essential for thermoprotection of C. salexigens.