171 research outputs found

    Functional characterization of a 28-Kilobase Catabolic Island from Pseudomonas sp. Strain M1 involved in biotransformation of β-Myrcene and related plant-derived volatiles

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    Pseudomonas sp. strain M1 is able to mineralize highly hydrophobic and recalcitrant compounds, such as benzene, phenol, and their methylated/halogenated derivatives, as well as the backbone of several monoterpenes. The ability to use such a spectrum of compounds as the sole carbon source is, most probably, associated with a genetic background evolved under different environmental constraints. The outstanding performance of strain M1 regarding β-myrcene catabolism was elucidated in this work, with a focus on the biocatalytical potential of the β-myrcene-associated core code, comprised in a 28-kb genomic island (GI), predicted to be organized in 8 transcriptional units. Functional characterization of this locus with promoter probes and analytical approaches validated the genetic organization predictedin silicoand associated the β-myrcene-induced promoter activity to the production of β-myrcene derivatives. Notably, by using a whole-genome mutagenesis strategy, different genotypes of the 28-kb GI were generated, resulting in the identification of a novel putative β-myrcene hydroxylase, responsible for the initial oxidation of β-myrcene into myrcen-8-ol, and a sensor-like regulatory protein, whose inactivation abolished themyr + trait of M1 cells. Moreover, it was demonstrated that the range of monoterpene substrates of the M1 enzymatic repertoire, besides β-myrcene, also includes other acyclic (e.g., β-linalool) and cyclic [e.g.,R-(+)-limonene and (-)-β-pinene] molecules. Our findings are the cornerstone for following metabolic engineering approaches and hint at a major role of the 28-kb GI in the biotransformation of a broad monoterpene backbone spectrum for its future biotechnological applications.IMPORTANCEInformation regarding microbial systems able to biotransform monoterpenes, especially β-myrcene, is limited and focused mainly on nonsystematic metabolite identification. Complete and detailed knowledge at the genetic, protein, metabolite, and regulatory levels is essential in order to set a model organism or a catabolic system as a biotechnology tool. Moreover, molecular characterization of reported systems is scarce, almost nonexistent, limiting advances in the development of optimized cell factories with strategies based on the new generation of metabolic engineering platforms. This study provides new insights into the intricate molecular functionalities associated with β-myrcene catabolism inPseudomonas, envisaging the production of a molecular knowledge base about the underlying catalytic and regulatory mechanisms of plant-derived volatile catabolic pathways.Vectors from the Standard European Vector Architecture (SEVA) library and pBAM1 used in this work were kindly provided by Victor de Lorenzo (CNB-CSIC, Madrid, Spain). This work was supported by the strategic program UID/BIA/04050/2013 (POCI-01- 0145-FEDER-007569) funded by national funds through the FCT I.P. and by the ERDF through the COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI) and through a Ph.D. grant (grant SFRH/BD/76894/2011) to P.S.-C.info:eu-repo/semantics/publishedVersio

    Domestic cats (Felis silvestris catus) do not show signs of secure attachment to their owners

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    The Ainsworth Strange Situation Test (SST) has been widely used to demonstrate that the bond between both children and dogs to their primary carer typically meets the requirements of a secure attachment (i.e. the carer being perceived as a focus of safety and security in otherwise threatening environments), and has been adapted for cats with a similar claim made. However methodological problems in this latter research make the claim that the cat-owner bond is typically a secure attachment, operationally definable by its behaviour in the SST, questionable. We therefore developed an adapted version of the SST with the necessary methodological controls which include a full counterbalance of the procedure. A cross-over design experiment with 20 cat-owner pairs (10 each undertaking one of the two versions of the SST first) and continuous focal sampling was used to record the duration of a range of behavioural states expressed by the cats that might be useful for assessing secure attachment. Since data were not normally distributed, non-parametric analyses were used on those behaviours shown to be reliable across the two versions of the test (which excluded much cat behaviour). Although cats vocalised more when the owner rather the stranger left the cat with the other individual, there was no other evidence consistent with the interpretation of the bond between a cat and its owner meeting the requirements of a secure attachment. These results are consistent with the view that adult cats are typically quite autonomous, even in their social relationships, and not necessarily dependent on others to provide a sense of security and safety. It is concluded that alternative methods need to be developed to characterise the normal psychological features of the cat-owner bond

    State rumination predicts inhibitory control failures and dysregulation of default, salience, and cognitive control networks in youth at risk of depressive relapse: Findings from the RuMeChange trial.

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    This is the final version. Available from Elsevier via the DOI in this record. This is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record Background: Trait rumination is a habitual response to negative experiences that can emerge during adolescence, increasing risk of depression. Trait rumination is correlated with poor inhibitory control (IC) and altered default mode network (DMN) and cognitive control network (CCN) engagement. Provoking state rumination in high ruminating youth permits investigation of rumination and IC at the neural level, highlighting potential treatment targets. Methods: Fifty-three high-ruminating youth were cued with an unresolved goal that provoked state rumination, then completed a modified Sustained Attention to Response Task (SART) that measures IC (commissions on no-go trials) in a functional MRI study. Thought probes measured state rumination about that unresolved goal and task-focused thoughts during the SART. Results: Greater state rumination during the SART was correlated with more IC failures. CCN engagement increased during rumination (relative to task-focus), including left dorsolateral prefrontal cortex and dorsal-medial prefrontal cortex. Relative to successful response suppression, DMN engagement increased during IC failures amongst individuals with higher state and trait rumination. Exploratory analyses suggested more bothersome unresolved goals predicted higher left DLPFC activation during rumination. Limitations: The correlational research design did not permit a direct contrast of causal accounts of the relationship between rumination and IC. Conclusions: State rumination was associated with impaired IC and disrupted modulation of DMN and CCN. Increased CCN engagement during rumination suggested effortful suppression of negative thoughts, and this was greater for more bothersome unresolved goals. Relative task disengagement was observed during rumination-related errors. DMN-CCN dysregulation in high-ruminating youth may be an important treatment target.National Institute of Mental Healt

    Self-injury in adolescence is associated with greater behavioral risk avoidance, not risk-taking.

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    This is the final version. Available from MDPI via the DOI in this record. Data Availability Statement: The study is registered on clinicaltrials.gov (NCT03859297), which will be updated with the published protocol and the study results and associated publications. Deidentified data and results will be submitted to the National Database for Clinical Trials Related to Mental Illness (NDCT).Strategies to link impulsivity and self-injurious behaviors (SIBs) show highly variable results, and may differ depending on the impulsivity measure used. To better understand this lack of consistency, we investigated correlations between self-report and behavioral impulsivity, inhibitory control, SIBs, and rumination. We included participants aged 13-17 years with either current or remitted psychopathology who have (n = 31) and who do not have (n = 14) a history of SIBs. Participants completed self-report measures of impulsivity, the Rumination Responsiveness Scale (RRS), and two behavioral measures of impulsivity: the Balloon Analogue Risk Task (BART) and Parametric Go/No-Go (PGNG). Lifetime SIBs were positively associated with self-reported impulsivity, specifically positive and negative urgency. However, individuals with greater lifetime SIBs demonstrated greater risk aversion (lower impulsivity) as measured by the BART, whereas there was no relation between lifetime SIBs and PGNG performance. There was no relation between rumination and behavioral impulsivity, although greater rumination was associated with higher negative urgency. Future research examining the role of SIBs in the context of active versus remitted psychopathology is warranted. Because most adolescents were remitted from major depressive disorder at the time of study, follow-up studies can determine if lower risk-taking may aid individuals with more prior SIBs to achieve and maintain a remitted state.National Institute of Mental Health (NIMH

    Rumination-Focused Cognitive Behavioral Therapy Reduces Rumination and Targeted Cross-network Connectivity in Youth With a History of Depression: Replication in a Preregistered Randomized Clinical Trial

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    This is the final version. Available from Elsevier via the DOI in this record. Background: Rumination-focused cognitive behavioral therapy (RF-CBT) is designed to reduce depressive rumination or the habitual tendency to dwell on experiences in a repetitive, negative, passive, and global manner. RF-CBT uses functional analysis, experiential exercises, and repeated practice to identify and change the ruminative habit. This preregistered randomized clinical trial (NCT03859297, R61) is a preregistered replication of initial work. We hypothesized a concurrent reduction of both self-reported rumination and cross-network connectivity between the left posterior cingulate cortex and right inferior frontal and inferior temporal gyri. Methods: Seventy-six youths with a history of depression and elevated rumination were randomized to 10 to 14 sessions of RF-CBT (n = 39; 34 completers) or treatment as usual (n = 37; 28 completers). Intent-to-treat analyses assessed pre-post change in rumination response scale and in functional connectivity assessed using two 5 minute, 12 second runs of resting-state functional magnetic resonance imaging. Results: We replicated previous findings: a significant reduction in rumination response scale and a reduction in left posterior cingulate cortex to right inferior frontal gyrus/inferior temporal gyrus connectivity in participants who received RF-CBT compared with those who received treatment as usual. Reductions were large (z change = 0.84; 0.73, respectively [ps < .05]). Conclusions: This adolescent clinical trial further demonstrates that depressive rumination is a brain-based mechanism that is modifiable via RF-CBT. Here, we replicated that RF-CBT reduces cross-network connectivity, a possible mechanism by which rumination becomes less frequent, intense, and automatic. This National Institute of Mental Health-funded fast-fail study continues to the R33 phase during which treatment-specific effects of RF-CBT will be compared with relaxation therapy.National Institute of Mental HealthHuntsman Mental Health Institut

    Natural Form of Noncytolytic Flexible Human Fc as a Long-Acting Carrier of Agonistic Ligand, Erythropoietin

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    Human IgG1 Fc has been widely used as a bioconjugate, but exhibits shortcomings, such as antibody- and complement-mediated cytotoxicity as well as decreased bioactivity, when applied to agonistic proteins. Here, we constructed a nonimmunogenic, noncytolytic and flexible hybrid Fc (hyFc) consisting of IgD and IgG4, and tested its function using erythropoietin (EPO) conjugate, EPO-hyFc. Despite low amino acid homology (20.5%) between IgD Fc and IgG4 Fc, EPO-hyFc retained “Y-shaped” structure and repeated intravenous administrations of EPO-hyFc into monkeys did not generate EPO-hyFc-specific antibody responses. Furthermore, EPO-hyFc could not bind to FcγR I and C1q in contrast to EPO-IgG1 Fc. In addition, EPO-hyFc exhibited better in vitro bioactivity and in vivo bioactivity in rats than EPO-IgG1 Fc, presumably due to the high flexibility of IgD. Moreover, the mean serum half-life of EPO-hyFc(H), a high sialic acid content form of EPO-hyFc, was approximately 2-fold longer than that of the heavily glycosylated EPO, darbepoetin alfa, in rats. More importantly, subcutaneous injection of EPO-hyFc(H) not only induced a significantly greater elevation of serum hemoglobin levels than darbepoetin alfa in both normal rats and cisplatin-induced anemic rats, but also displayed a delayed time to maximal serum level and twice final area-under-the-curve (AUClast). Taken together, hyFc might be a more attractive Fc conjugate for agonistic proteins/peptides than IgG1 Fc due to its capability to elongate their half-lives without inducing host effector functions and hindering bioactivity of fused molecules. Additionally, a head-to-head comparison demonstrated that hyFc-fusion strategy more effectively improved the in vivo bioactivity of EPO than the hyperglycosylation approach

    Emotion regulation

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    Synonyms: emotional control; emotion-related self-regulation; stress-regulation; mood-regulation; affect-regulation; emotional intelligence Definition: Emotion regulation refers to the conscious or unconscious processes of monitoring, evaluating, modulating, and managing emotional experiences and expression of emotion in terms of intensity, form, and duration of feelings, emotion-related physiological states and behaviors

    Ginseng and ginkgo biloba effects on cognition as modulated by cardiovascular reactivity: a randomised trial

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    Background There is some evidence to suggest that ginseng and Ginkgo biloba can improve cognitive performance, however, very little is known about the mechanisms associated with such improvement. Here, we tested whether cardiovascular reactivity to a task is associated with cognitive improvement. Methodology/Principal findings Using a double-blind, placebo controlled, crossover design, participants (N = 24) received two doses of Panax Ginseng (500, 1000 mg) or Ginkgo Biloba (120, 240 mg) (N = 24), and underwent a series of cognitive tests while systolic, diastolic, and heart rate readings were taken. Ginkgo Biloba improved aspects of executive functioning (Stroop and Berg tasks) in females but not in males. Ginseng had no effect on cognition. Ginkgo biloba in females reversed the initial (i.e. placebo) increase in cardiovascular reactivity (systolic and diastolic readings increased compared to baseline) to cognitive tasks. This effect (reversal) was most notable after those tasks (Stroop and Iowa) that elicited the greatest cardiovascular reactivity during placebo. In males, although ginkgo also decreased cardiovascular readings, it did so from an initial (placebo) blunted response (i.e. decrease or no change from baseline) to cognitive tasks. Ginseng, on the contrary, increased cardiovascular readings compared to placebo. Conclusions/Significance These results suggest that cardiovascular reactivity may be a mechanism by which ginkgo but not ginseng, in females is associated with certain forms of cognitive improvement

    An overlooked connection: serotonergic mediation of estrogen-related physiology and pathology

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    BACKGROUND: In humans, serotonin has typically been investigated as a neurotransmitter. However, serotonin also functions as a hormone across animal phyla, including those lacking an organized central nervous system. This hormonal action allows serotonin to have physiological consequences in systems outside the central nervous system. Fluctuations in estrogen levels over the lifespan and during ovarian cycles cause predictable changes in serotonin systems in female mammals. DISCUSSION: We hypothesize that some of the physiological effects attributed to estrogen may be a consequence of estrogen-related changes in serotonin efficacy and receptor distribution. Here, we integrate data from endocrinology, molecular biology, neuroscience, and epidemiology to propose that serotonin may mediate the effects of estrogen. In the central nervous system, estrogen influences pain transmission, headache, dizziness, nausea, and depression, all of which are known to be a consequence of serotonergic signaling. Outside of the central nervous system, estrogen produces changes in bone density, vascular function, and immune cell self-recognition and activation that are consistent with serotonin's effects. For breast cancer risk, our hypothesis predicts heretofore unexplained observations of the opposing effects of obesity pre- and post-menopause and the increase following treatment with hormone replacement therapy using medroxyprogesterone. SUMMARY: Serotonergic mediation of estrogen has important clinical implications and warrants further evaluation
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