High-resolution structure of an atypical α-phosphoglucomutase related to eukaryotic phosphomannomutases

The first structure of a bacterial α-phosphoglucomutase with an overall fold similar to eukaryotic phosphomannomutases is reported. Unlike most α-phosphoglucomutases within the α-D-phosphohexomutase superfamily, it belongs to subclass IIb of the haloacid dehalogenase superfamily (HADSF). It catalyzes the reversible conversion of α-glucose 1-phosphate to glucose 6-phosphate. The crystal structure of α-phosphoglucomutase from Lactococcus lactis (APGM) was determined at 1.5 Å resolution and contains a sulfate and a glycerol bound at the enzyme active site that partially mimic the substrate. A dimeric form of APGM is present in the crystal and in solution, an arrangement that may be functionally relevant. The catalytic mechanism of APGM and its strict specificity towards α-glucose 1-phosphate are discussed.Diamond Light Source

Obstructive sleep apnea representations, self-efficacy and family coping regarding APAP adherence: a longitudinal study

Adherence is still an important issue considering new advances in Obstructive Sleep Apnea (OSA) treatment, as automatic positive airway pressure (APAP). The aim of the present study was to identify and explore relationships between identified predictors of adherence, over time. After overnight sleep study and OSA diagnosis and during a six-month APAP treatment period, a total of 153 patients underwent a three time psychological protocol evaluation. Generalized estimating equations were applied to analyzed repeated measurements in the same individuals. Results show that 40% of patients were poorly adherent and 60% were adherent after six months of treatment. The results confirmed a predictive value of age, self-efficacy, decisional balance index and health-related quality of life (HRQoL) in APAP adherence. Furthermore, the results revealed an interaction between time and illness cognitive representations, and self-efficacy and family coping, in explaining adherence patterns over time. Therefore, understanding the causality of theoretically derived constructs is crucial to predict the continuity of APAP adherence.Fundação para a Ciência e Tecnologia (FCT

PACAP system evolution and its role in melanophore function in teleost fish skin

Pituitary adenylate cyclase-activating polypeptide (PACAP) administered to tilapia melanophores ex-vivo causes significant pigment aggregation and this is a newly identified function for this peptide in fish. The G-protein coupled receptors (GPCRs), adcyap1r1a (encoding Pac1a) and vipr2a (encoding Vpac2a), are the only receptors in melanophores with appreciable levels of expression and are significantly (p < 0.05) down-regulated in the absence of light. Vpac2a is activated exclusively by peptide histidine isoleucine (PHI), which suggests that Pac1a mediates the melanin aggregating effect of PACAP on melanophores. Paradoxically activation of Pac1a with PACAP caused a rise in cAMP, which in fish melanophores is associated with melanin dispersion. We hypothesise that the duplicate adcyap1ra and vipr2a genes in teleosts have acquired a specific role in skin and that the melanin aggregating effect of PACAP results from the interaction of Pac1a with Ramp that attenuates cAMP-dependent PKA activity and favours the Ca(2+)/Calmodulin dependent pathway.info:eu-repo/semantics/publishedVersio

Psychological morbidity, illness representations, and quality of life in female and male patients with obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS) is a sleep-related breathing disorder that affects both women and men. The aim of this study was to characterize and investigate the differences in terms of anxiety, depression, illness perception, and quality of life between female and male OSAS patients from a total of 111 patients (33 women and 78 men) who were recently diagnosed with OSAS in an outpatient clinic of a University Hospital in Portugal. They underwent a standardized protocol that included evaluation to assess of psychological morbidity (anxiety and depression – Hospital Anxiety and Depression Scale), illness representations (Brief Illness Perception Questionnaire), and quality of life (Sleep Apnea Quality of Life Index). The most significant differences between female and male OSAS patients result of apnea/hypopnea index (AHI), after controlling for body mass index (p 5 0.05); anxiety (p ¼ 0.000) and depression (p 5 0.005); consequences (p 5 0.005), identity (p ¼ 0.000), coherence (p 5 0.01), and emotional representation (p 5 0.005) of OSAS; and for daily functioning (p ¼ 0.000), emotional (p ¼ 0.001), and symptoms (p 5 0.05) domains of quality of life. Data suggest that women revealed more psychological morbidity associated with OSAS. Therefore, it seems extremely important to look at women as potential patients for sleep apnea and avoid looking up for a pattern of symptoms that rely on men as a norm to which women are compared.Fundação para a Ciência e a Tecnologia (FCT

Temperature responsiveness of gilthead sea bream bone; an in vitro and in vivo approach

This study aimed to characterize the molecules involved in osteogenesis in seabream and establish using in vitro/in vivo approaches the responsiveness of selected key genes to temperature. The impact of a temperature drop from 23 to 13 degrees C was evaluated in juvenile fish thermally imprinted during embryogenesis. Both, in vitro/in vivo, Fib1a, appeared important in the first stages of bone formation, and Col1A1, ON and OP, in regulating matrix production and mineralization. OCN mRNA levels were up-regulated in the final larval stages when mineralization was more intense. Moreover, temperature-dependent differential gene expression was observed, with lower transcript levels in the larvae at 18 degrees C relative to those at 22 degrees C, suggesting bone formation was enhanced in the latter group. Results revealed that thermal imprinting affected the long-term regulation of osteogenesis. Specifically, juveniles under the low and low-to-high-temperature regimes had reduced levels of OCN when challenged, indicative of impaired bone development. In contrast, gene expression in fish from the high and high-to-low-temperature treatments was unchanged, suggesting imprinting may have a protective effect. Overall, the present study revealed that thermal imprinting modulates bone development in seabream larvae, and demonstrated the utility of the in vitro MSC culture as a reliable tool to investigate fish osteogenesis."Ministerio de Economia y Competitividad" (MINECO) [BES-2015-074654]; Portuguese Science Foundation (FCT) [SFRH/BPD/111512/2015, SFRH/BD/81625/2011]; MINECO, Spain [AGL2010-17324, AGL2014-57974-R]; "Generalitat de Catalunya" (XRAq); Generalitat de Catalunya [2014SGR-01371]; FCT, Portugal [CCMAR/Multi/04326/2013]; European Union [LIFECYCLE EU-FP7 222719]info:eu-repo/semantics/publishedVersio

Influence of temperature and humidity manipulation on chicken embryonic development

BACKGROUND: Temperature and relative humidity (RH) are very important factors affecting embryo development, hatchability, and posthatch performance. This study aimed at characterizing embryonic metabolic and behavioural response to a harsh incubation environment generated by manipulations (elevations and drops) in these two key factors. This study was aimed at establishing patterns of metabolic and behavioural response, as well as mortality and the development of malformations, all of which can potentially be used in monitoring incubating operations and diagnosing problems with faulty equipment. RESULTS: Of all the parameters monitored throughout embryonic development the ones shown to be most affected were: albumen-weight to egg-weight ratio (AR); yolk-weight to egg-weight ratio (YR); embryo-weight to egg-weight ratio (ER); heart rate (HR); voluntary movements per minute (VMM); mortality rates; malformation prevalence and type. The most significant changes in the evolution of AR and YR throughout incubation involved delay and reduction in the amplitude of the expected drop in albumen and yolk levels, reflecting lower nutrient consumption by the embryo. ER tended to grow more slowly and remain lower than the established normal, especially in embryos challenged with temperature treatments. HR and VMM were considered to be strong indicators of embryonic stress, as all treatments applied resulted in elevated heart rate and decreased embryo movement. Mortality rates for both temperature-related treatments were higher during the first four days of incubation. Changes in relative humidity have produced less radical effects on mortality. Malformation rates were higher for embryos subjected to high incubation temperatures and were most prominently related to the abdominal wall, head, skull and limbs. Overall, manipulations in environmental (incubator) temperature during incubation produced more drastic changes in embryo development than humidity-related manipulations, especially where mortality and malformation rates were concerned. CONCLUSIONS: This paper describes changes in embryonic metabolism and behaviour, as well as in mortality and malformation rates, in response to manipulations in environmental temperature and relative humidity. Together with further studies, these patterns may prove helpful in the diagnosis of equipment malfunctions relating to temperature or relative humidity

Transcriptome of Quercus suber challenged by drought, salinity, and oxidative stresses

Comunicação em painelThe cork oak (Quercus suber) forest (the “montado”) is a unique and emblematic resource for Portugal, due to its ecological, socio-economic significance, and the commercial value of cork. Plant abiotic stresses, particularly reduced water availability and extreme temperatures, are substantial constraints to agricultural and agro-forestry production. In the particular case of cork oak, the damaging land-use policies, the climate change, and imposition of abiotic stresses related with high light intensities have been threatening the cork oak forests. The adaptation to abiotic stresses comprises a series of morphological, physiological, biochemical and molecular changes controlled by complex molecular networks. Recent advances in increasing plant tolerance were achieved after the identification of specific genes suited for plant genetic engineering. However, as abiotic stress is commonly present in the field as a combination of different stresses, the complex plant response mechanisms are far from being elucidated. This work is part of a coordinated effort to uncover the transcriptome of Q. suber and attention was paid to the identification of expressed sequence tags (ESTs) involved in responses to distinct abiotic stress challenges, namely drought, salt and oxidative stresses.This work was supported by the FCT project SOBREIRO/0033/200

Saccharomyces cerevisiae and Dekkera bruxellensis interactions in alcoholic fermentations: growth and 4-ethylphenol production

The yeast Dekkera/Brettanomyces bruxellensis can cause enormous economic losses both in wine industry and fuel-ethanol processes due to production of phenolic off-flavour compounds and low ethanol productivities. In winemaking this microbial hazard is usually tackled by the use of chemical preservatives such as sulphur dioxide. In spite of this, D. bruxellensis strains are frequently found in wines at low levels (ca 103 cells/ml) where they can metabolise residual sugars producing phenolic off-flavours compounds, such as 4-ethyl phenol. In the present work we investigated S. cerevisiae and D. bruxellensis interactions during alcoholic fermentations and evaluated the effectiveness of antimicrobial peptides secreted by S. cerevisiae to prevent growth of the main wine spoilage yeast and the production of 4-ethylphenol. Several fermentations were performed with single cultures of D. bruxellensis and mixed cultures of S. cerevisiae and D. bruxellensis, both in synthetic grape juice (SGJ) and grape must. Yeast growth (culturability and viability) and fermentation performance (i.e. sugars consumption, ethanol and 4-ethylphenol production) of those fermentations was accessed by different methods, namely by florescence in situ hybridization and flow cytometry. Results showed that S. cerevisiae significantly reduced the growth of D. bruxellensis and the production of 4-ethylphenol both in SGJ and grape must fermentations performed with mixed cultures. Moreover, our work also showed that antimicrobial peptides secreted by S. cerevisiae are effective to prevent growth of D. bruxellensis and production of phenolic off-flavor compounds in wine