132 research outputs found

    A novel targeted/untargeted GC-Orbitrap metabolomics methodology applied to Candida albicans and Staphylococcus aureus biofilms

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    Introduction: Combined infections from Candida albicans and Staphylococcus aureus are a leading cause of death in the developed world. Evidence suggests that Candida enhances the virulence of Staphylococcus—hyphae penetrate through tissue barriers, while S. aureus tightly associates with the hyphae to obtain entry to the host organism. Indeed, in a biofilm state, C. albicans enhances the antimicrobial resistance characteristics of S. aureus. The association of these microorganisms is also associated with significantly increased morbidity and mortality. Due to this tight association we hypothesised that metabolic effects were also in evidence. Objectives: To explore the interaction, we used a novel GC-Orbitrap-based mass spectrometer, the Q Exactive GC, which combines the high peak capacity and chromatographic resolution of gas chromatography with the sub-ppm mass accuracy of an Orbitrap system. This allows the capability to leverage the widely available electron ionisation libraries for untargeted applications, along with expanding accurate mass libraries and targeted matches based around authentic standards. Methods: Optimised C. albicans and S. aureus mono- and co-cultured biofilms were analysed using the new instrument in addition to the fresh and spent bacterial growth media. Results: The targeted analysis experiment was based around 36 sugars and sugar phosphates, 22 amino acids and five organic acids. Untargeted analysis resulted in the detection of 465 features from fresh and spent medium and 405 from biofilm samples. Three significantly changing compounds that matched to high scoring library fragment patterns were chosen for validation. Conclusion: Evaluation of the results demonstrates that the Q Exactive GC is suitable for metabolomics analysis using a targeted/untargeted methodology. Many of the results were as expected: e.g. rapid consumption of glucose and fructose from the medium regardless of the cell type. Modulation of sugar-phosphate levels also suggest that the pentose phosphate pathway could be enhanced in the cells from co-cultured biofilms. Untargeted metabolomics results suggested significant production of cell-wall biosynthesis components and the consumption of non-proteinaceous amino-acids

    The projected degradation of subtropical coral assemblages by recurrent thermal stress

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    1. Subtropical coral assemblages are threatened by similar extreme thermal stress events to their tropical counterparts. Yet, the mid‐ and long‐term thermal stress responses of corals in subtropical environments remain largely unquantified, limiting our capacity to predict their future viability. 2. The annual survival, growth and recruitment of 311 individual corals within the Solitary Islands Marine Park (Australia) was recorded over a 3‐year period (2016–2018), including the 2015/2016 thermal stress event. These data were used to parameterise integral projection models quantifying the effect of thermal stress within a subtropical coral assemblage. Stochastic simulations were also applied to evaluate the implications of recurrent thermal stress scenarios predicted by four different Representative Concentration Pathways. 3. We report differential shifts in population growth rates (λ) among coral populations during both stress and non‐stress periods, confirming contrasting bleaching responses among taxa. However, even during non‐stress periods, the observed dynamics for all taxa were unable to maintain current community composition, highlighting the need for external recruitment sources to support the community structure. 4. Across all coral taxa, projected stochastic growth rates (λs) were found to be lowest under higher emissions scenarios. Correspondingly, predicted increases in recurrent thermal stress regimes may accelerate the loss of coral coverage, species diversity and structural complexity within subtropical regions. 5. We suggest that these trends are primarily due to the susceptibility of subtropical specialists and endemic species, such as Pocillopora aliciae, to thermal stress. Similarly, the viability of many tropical coral populations at higher latitudes is highly dependent on the persistence of up‐current tropical systems. As such, the inherent dynamics of subtropical coral populations appear unable to support their future persistence under unprecedented thermal disturbance scenarios

    The contribution of metacognitions and attentional control to decisional procrastination

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    Earlier research has implicated metacognitions and attentional control in procrastination and self-regulatory failure. This study tested several hypotheses: (1) that metacognitions would be positively correlated with decisional procrastination; (2) that attentional control would be negatively correlated with decisional procrastination; (3) that metacognitions would be negatively correlated with attentional control; and (4) that metacognitions and attentional control would predict decisional procrastination when controlling for negative affect. One hundred and twenty-nine participants completed the Depression Anxiety Stress Scale 21, the Meta-Cognitions Questionnaire 30, the Attentional Control Scale, and the Decisional Procrastination Scale. Significant relationships were found between all three attentional control factors (focusing, shifting, and flexible control of thought) and two metacognitions factors (negative beliefs concerning thoughts about uncontrollability and danger, and cognitive confidence). Results also revealed that decisional procrastination was significantly associated with negative affect, all measured metacognitions factors, and all attentional control factors. In the final step of a hierarchical regression analysis only stress, cognitive confidence, and attention shifting were independent predictors of decisional procrastination. Overall these findings support the hypotheses and are consistent with the Self-Regulatory Executive Function model of psychological dysfunction. The implications of these findings are discussed

    Recent advances in studies of polymicrobial interactions in oral biofilms

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    The oral cavity supports a complex and finely balanced consortium of microbial species, many of which cooperate within structured biofilms. These communities develop through multitudinous synergistic and antagonistic interspecies relationships. Changes in the dynamics of oral microbial populations are associated with the transition from healthy teeth and gums to dental caries, gingivitis and periodontitis. Understanding the ecology of oral biofilm communities, and how different species communicate within a given host, will inform new strategies for treatment and prevention of oral diseases. Advances in sequencing technologies have fuelled an increasing trend towards global genomic and proteomic approaches to determine the key factors that initiate oral diseases. Whilst metabolic profiling seeks to identify phenotypic changes of whole microbial communities, transcriptomic studies are exploring their complex interactions with each other and the host. This review discusses the most recent in vitro and in vivo studies of interspecies interactions within polymicrobial oral biofilms

    Uterus Bicornis Bicollis, Imperforate Hemivagina and Ipsilateral Renal Agenesis: Case Report and Literature Review

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    We present a case of a patient with Uterus bicornis bicollis, imperforate hemivagina and ipsilateral renal agenesis. This group of congenital malformations is often asymptomatic until puberty, when it presents as cyclic dysmenorrhoea, leucorrhoea or a pelvic mass. Magnetic resonance imaging is becoming the preferred modality for delineation of uterine malformations. When congenital abnormalities of the reproductive tract are encountered, a search should also be made for renal anomalies. Patients with Uterus bicornis bicollis and unilateral imperforate vagina are often seen with pain severe enough to mimic an acute abdomen. It is important to keep this unusual congenital malformation in mind in the differential diagnosis of vaginal discharge, pelvic mass and/or abdominopelvic pain in young women so as to avoid inappropriate surgical procedures. "Útero Bicorne Bicollis, Hemivagina Imperforada, y Agenesia Renal Ipsilateral: Reporte de Caso y Revisión de la Literatura" RESUMEN Presentamos el caso de una paciente con útero bicorne bicollis, hemivagina imperforada, y agenesia renal ipsilateral. Este grupo de malformaciones congénitas es a menudo asintomático hasta la pubertad, cuando se presenta en forma de dismenorrea cíclica, leucorrea, o una masa pélvica. La imagen por resonancia magnética se está convirtiendo en la modalidad preferida para delinear las malformaciones uterinas. Cuando se encuentran anormalidades del aparato reproductor, debe realizarse también una investigación en busca de anomalías renales. A los pacientes con útero bicorne bicollis y vagina imperforada se les ve a menudo con dolores suficientemente severos como para parecer un abdomen agudo. Es importante tener en mente esta inusual malformación congénita en el diagnóstico diferencial del flujo vaginal, la masa pélvica y/o el dolor pélvico-abdominal en las mujeres jóvenes, a fin de evitar procedimientos quirúrgicos inadecuados

    Laparoscopic Cervicoisthmic Cerclage for the Treatment of Cervical Incompetence

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    Cervical insufficiency/incompetence occurs in 0.5−1% of all pregnancies, often resulting in significant pregnancy lost. Three women with a history of second trimester miscarriages after failed transvaginal cervical cerclages were reviewed. A laparoscopic cervicoisthmic cerclage (LCC) was placed before pregnancy without any intra-operative or postoperative complications. Two patients have since de-livered live babies at term by Caesarean section. This small case series supports the conclusion that LCC is a safe and cost-effective procedure in properly selected patients. Laparoscopic cervicoisthmic cerclage costs less, is less invasive, has fewer complications and should replace the traditional laparo-tomy technique. Keywords: Cervicoisthmic cerclage, laparoscopy, miscarriages. "Cerclaje Cérvico-ístmico Laparoscópico en el Tratamiento de la Incompetencia Cervical" RESUMEN La insuficiencia/incompetencia cervical ocurre en 0.5-1% de todos los embarazos, trayendo a menudo como consecuencia una pérdida significativa de embarazos. Se revisaron los casos de tres mujeres con una historia de abortos en el segundo trimestre después de cerclajes cervicales transvaginales fallidos. Un cerclaje cérvico-ístmico laparoscópico (CCL) se realizó antes del embarazo sin ninguna complicación intraoperatoria o postoperatoria. Desde entonces, dos pacientes han parido bebés vivos a término por cesárea. Esta pequeña serie de casos sustenta la conclusión de que el CCL es un procedimiento seguro y costo-efectivo en pacientes propiamente seleccionados. El cerclaje cérvico-ístmico laparoscópico cuesta menos, es menos invasivo, tiene menos complicaciones, y debe reemplazar la técnica de laparotomía tradicional. Palabras claves: Cerclaje cérvico-ístmico, laparoscopía, aborto
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