Microtubule end-on attachment maturation regulates Mps1 association with its kinetochore receptor

Faithful chromosome segregation requires that sister chromatids establish bi-oriented kinetochore-microtubule attachments. The spindle assembly checkpoint (SAC) prevents premature anaphase onset with incomplete attachments. However, how microtubule attachment and checkpoint signaling are coordinated remains unclear. The conserved kinase Mps1 initiates SAC signaling by localizing transiently to kinetochores in prometaphase and is released upon bi-orientation. Using biochemistry, structure predictions, and cellular assays, we shed light on this dynamic behavior in Saccharomyces cerevisiae. A conserved N-terminal segment of Mps1 binds the neck region of Ndc80:Nuf2, the main microtubule receptor of kinetochores. Mutational disruption of this interface, located at the backside of the paired CH domains and opposite the microtubule-binding site, prevents Mps1 localization, eliminates SAC signaling, and impairs growth. The same interface of Ndc80:Nuf2 binds the microtubule-associated Dam1 complex. We demonstrate that the error correction kinase Ipl1/Aurora B controls the competition between Dam1 and Mps1 for the same binding site. Thus, binding of the Dam1 complex to Ndc80:Nuf2 may release Mps1 from the kinetochore to promote anaphase onset.

Predictors of paranoia in the daily lives of people with non-affective psychosis and non-clinical controls: A systematic review of intensive longitudinal studies

BACKGROUND AND OBJECTIVES

Worrying, self-esteem, sleep problems, anomalous internal experiences, reasoning biases, and interpersonal sensitivity are associated with paranoia. However, no review has examined whether these variables function as predictors of paranoia in everyday life. The present systematic review of intensive longitudinal studies (e.g., experience sampling) examined contemporaneous and time-lagged associations between paranoia and each candidate mechanism in individuals with non-affective psychosis and controls (pre-registration: https://osf.io/uwr9d).

METHODS

We searched electronic databases, PsyArXiv, and reference lists for studies published since 1994.

RESULTS

Of n = 5,918 results, n = 54 fulfilled inclusion criteria (n = 43 datasets). Most studies examined individuals with non-affective psychosis (n = 34). Strong evidence emerged for negative affect (subsumed under 'anomalous internal experiences') and sleep problems. For self-esteem, results suggest contemporaneous and lagged effects on paranoia but associations are likely driven by between-person variance. The low number of studies (n = 2 studies each) allowed no conclusions regarding worrying and reasoning biases. Findings on interpersonal sensitivity, which should be interpreted with caution because of the predictor's conceptual overlap with paranoia, indicate contemporaneous effects whereas time-lagged and within-person associations could not be judged due to insufficient data.

LIMITATIONS

The present review used a narrative data-synthetization and it did not cover outcomes such as hallucinations.

CONCLUSIONS

Despite convincing evidence for affect and sleep problems, it remains unclear whether affective states are precursors or also consequences of paranoia (vicious circle), and which of the actigraphy measures (sleep time, -efficiency, -fragmentation, etc.) best predicts paranoia.

Multivalent Molecular Tweezers Disrupt the Essential NDC80 Interaction with Microtubules

Binding of microtubule filaments by the conserved Ndc80 protein is required for kinetochore-microtubule attachments in cells and the successful distribution of the genetic material during cell division. The reversible inhibition of microtubule binding is an important aspect of the physiological error correction process. Small molecule inhibitors of protein-protein interactions involving Ndc80 are therefore highly desirable, both for mechanistic studies of chromosome segregation and also for their potential therapeutic value. Here, we report on a novel strategy to develop rationally designed inhibitors of the Ndc80 Calponin-homology domain using Supramolecular Chemistry. With a multiple-click approach, lysine-specific molecular tweezers were assembled to form covalently fused dimers to pentamers with a different overall size and preorganization/stiffness. We identified two dimers and a trimer as efficient Ndc80 CH-domain binders and have shown that they disrupt the interaction between Ndc80 and microtubules at low micromolar concentrations without affecting microtubule dynamics. NMR spectroscopy allowed us to identify the biologically important lysine residues 160 and 204 as preferred tweezer interaction sites. Enhanced sampling molecular dynamics simulations provided a rationale for the binding mode of multivalent tweezers and the role of pre-organization and secondary interactions in targeting multiple lysine residues across a protein surface.

Subsea permafrost organic carbon stocks are large and of dominantly low reactivity

Subsea permafrost carbon pools below the Arctic shelf seas are a major unknown in the global carbon cycle. We combine a numerical model of sedimentation and permafrost evolution with simplified carbon turnover to estimate accumulation and microbial decomposition of organic matter on the pan-Arctic shelf over the past four glacial cycles. We find that Arctic shelf permafrost is a globally important long-term carbon sink storing 2822 (1518-4982) Pg OC, double the amount stored in lowland permafrost. Although currently thawing, prior microbial decomposition and organic matter aging limit decomposition rates to less than 48 Tg OC/yr (25-85) constraining emissions due to thaw and suggesting that the large permafrost shelf carbon pool is largely insensitive to thaw. We identify an urgent need to reduce uncertainty in rates of microbial decomposition of organic matter in cold and saline subaquatic environments. Large emissions of methane more likely derive from older and deeper sources than from organic matter in thawing permafrost.

Systematic analysis of microtubule plus-end networks defines EB-cargo complexes critical for mitosis in budding yeast

Microtubules are ubiquitous cytoskeletal polymers with essential functions in chromosome segregation, intracellular transport and cellular morphogenesis. End-binding proteins (EBs) form the nodes of intricate microtubule plus-end interaction networks. Which EB binding partners are most critical for cell division, and how cells organize a microtubule cytoskeleton in the absence of an EB protein, are open questions. Here, we perform a detailed analysis of deletion and point mutants of the budding yeast EB protein Bim1. We demonstrate that Bim1 executes its key mitotic functions as part of two cargo complexes - Bim1-Kar9 in the cytoplasm and Bim1-Bik1-Cik1-Kar3 in the nucleus. The latter complex acts during initial metaphase spindle assembly and supports tension establishment and sister chromatid bi-orientation. We demonstrate that engineered plus-end targeting of Cik1-Kar3 and overexpression of the microtubule crosslinker Ase1 restore distinct aspects of the bim1Δ spindle phenotype. In addition to defining key Bim1-cargo complexes our study also characterizes redundant mechanisms that allow cells to proliferate in the absence of Bim1. [Media: see text] [Media: see text] [Media: see text] [Media: see text].

Negative expectations regarding interpersonal interactions in daily life are associated with subclinical depressive symptoms in a student sample: A prospective experience sampling study

Dysfunctional expectations and interpersonal problems are associated with depression, so we measured expected emotions towards interaction partners and compared them with actual emotions. We hypothesized that, between persons, individuals with higher subclinical depression would display stronger, more stable, and less accurate negative expectations. Within persons, we hypothesized that momentary negative expectations would predict subsequent negative affect. Fifty-three students completed 6 days of Experience Sampling, consisting of one morning expectation-assessment (9 am), three assessments on actual interpersonal emotions (1 pm, 5 pm, 9 pm), and six random affect-assessments. We regressed expected emotions, experienced emotions, expectation fluctuations, and expectation violations on subclinical depression. Using mixed model analyses, we further examined whether negative expectations preceded negative affect, and whether expectation violations preceded adjustments of expectations. Higher subclinical depression predicted more negative expectations. Within persons, worse-than-expected interpersonal interactions preceded negative affect whereas better-than-expected interactions preceded reductions of negative expectations. Despite problems with skewed data, our approach appears well-suited to examine interpersonal expectations in vivo.

Motive-Oriented, Personalized, Internet-Based Interventions for Depression: Nonclinical Experimental Study

Background

The low level of adherence in internet-based self-help interventions for depression suggests that in many existing programs, the motivational fit between the program and the user is unsatisfactory (eg, the user seeks autonomy, but the program provides directive guidance). Personalized, motive-oriented, self-help interventions could enable participants who interact with a program and its contents to have more engaging and less aversive experiences and thus increase adherence.

Objective

In an experimental study with a nonclinical analogue sample, we aimed to test the hypotheses that a better motivational person-program fit is linked with higher anticipated adherence, working alliance, and satisfaction with the program.

Methods

Motivational person-program fit was examined with respect to the 2 contrasting motives being autonomous and being supported. The hypotheses were tested by specifically varying the motivational person-program fit in a nonclinical sample (N=55), where participants were asked to work on, and subsequently evaluate, a limited set of individual pages of a self-help program with guidance (in the form of text messages) for depression. The sections of the self-help program were redesigned to either particularly address the autonomy motive or the support motive. For the quasi-experimental variation of the motivational person-program characteristics, we divided the 55 participants into 2 groups (autonomy group: n=27, 49%; support group: n=28, 51%) by screening method (using the Inventory of Approach and Avoidance Motivation), corresponding to the 2 motives. Both groups evaluated (in randomized order) 2 excerpts of the program—one that matched their motive (fit) and one that was contrary to it (no fit). Immediately after the evaluation of each excerpt, anticipated adherence, working alliance, and treatment satisfaction were assessed.

Results

Regarding being supported, the satisfaction with or violation of this motive had an impact on (optimal) anticipated adherence as well as working alliance and satisfaction with the intervention; a congruent person-program fit resulted in significantly higher anticipated adherence (t₂₇=3.00; P=.006), working alliance (t₂₇=3.20; P=.003), and satisfaction (t₂₇=2.86; P=.008) than a noncongruent fit. However, a similar impact could not be found for the motive being autonomous. Several correlations were found that supported our hypotheses (eg, for the congruent person-program fit autonomy motive and autonomy group, support satisfaction negatively correlated with optimal anticipated adherence).

Conclusions

This first experimental study gives reason to assume that motive orientation may have a positive influence on adherence, working alliance, and satisfaction in internet-based self-help interventions for depression and other mental disorders. Future studies should conduct randomized controlled trials with clinical samples and assess clinical outcomes.

Emergence and assessment of interpersonal experience and behavior in a nonverbal, generative, game-like paradigm

Dominance, hostility and autonomy are interpersonal phenomena that emerge from the complex dyadic interplay of two individuals reciprocally influencing each other. Assessing the complexity of interpersonal interactions usually involves its reduction, for example with self-report and observer-rated measures informed by the structural analysis of social behavior (SASB). In contrast, letting individuals generate a complex stream of interpersonal experience and behavior from moment to moment is an empirical approach not yet usual in interpersonal theory. In the present study, we developed and evaluated an interpersonal, generative paradigm that allows participants to interact nonverbally and spontaneously with a computer-controlled other player in real-time without the need for introspection or the capacity to verbalize potentially implicit interpersonal processes. In the game-like paradigm, participants use the keyboard to take over objects such as a handcar to move autonomously around and encounter interfering or freedom granting artificial other players. We expected that participants (1) experience the nonverbal so-called game mechanics of the paradigm as interpersonal in nature, (2) behave towards the other players in an interpersonally complementary way, and (3) are influenced by their own trait interpersonal expectations. During the paradigm, 40 participants appraised the majority of the game mechanics and computer-controlled other players as intended. Also, interpersonal traits affected the spontaneous behavior towards artificial characters. These findings corroborate the feasibility and validity of a generative assessment of interpersonal dynamics beyond self-reports and observer ratings. The paradigm paves the way for the empirical testing of formal, computational models of dyadic interaction.

Insight and the number of completed modules predict a reduction of positive symptoms in an Internet-based intervention for people with psychosis

Emerging evidence suggests that Internet-based interventions for people with psychosis (ICBTp) are feasible and efficacious. However, predictors of adherence and treatment outcomes are largely unknown. To narrow this research gap, we conducted secondary analyses on data from a randomized controlled trial, which evaluated an eight-week ICBTp intervention targeting topics, such as voice hearing, mindfulness, and others. In n = 100 participants with psychosis, we aimed at identifying sociodemographic, psychopathological, and treatment-related predictor variables of post-treatment symptoms and adherence (i.e., at least four completed modules). We followed a two-stage approach. First, we conducted regression analyses to examine the effect of single candidate predictors on post-treatment symptoms as well as adherence. Subsequently, we selected variables that met a significance threshold of p < .1 and entered them into linear and logistic multiple regression models. Whereas no variable was able to predict adherence, the number of completed modules was negatively associated with self-reported delusion severity at post-treatment. Additionally, higher pre-treatment insight predicted fewer hallucinations after treatment. Because this was one of the first studies to investigate predictors in ICBTp, more research is needed to customize future interventions to the needs of users.

Phospho-regulated Bim1/EB1 interactions trigger Dam1c ring assembly at the budding yeast outer kinetochore

Kinetochores form the link between chromosomes and microtubules of the mitotic spindle. The heterodecameric Dam1 complex (Dam1c) is a major component of the Saccharomyces cerevisiae outer kinetochore, assembling into 3 MDa‐sized microtubule‐embracing rings, but how ring assembly is specifically initiated in vivo remains to be understood. Here, we describe a molecular pathway that provides local control of ring assembly during the establishment of sister kinetochore bi‐orientation. We show that Dam1c and the general microtubule plus end‐associated protein (+TIP) Bim1/EB1 form a stable complex depending on a conserved motif in the Duo1 subunit of Dam1c. EM analyses reveal that Bim1 crosslinks protrusion domains of adjacent Dam1c heterodecamers and promotes the formation of oligomers with defined curvature. Disruption of the Dam1c‐Bim1 interaction impairs kinetochore localization of Dam1c in metaphase and delays mitosis. Phosphorylation promotes Dam1c‐Bim1 binding by relieving an intramolecular inhibition of the Dam1 C‐terminus. In addition, Bim1 recruits Bik1/CLIP‐170 to Dam1c and induces formation of full rings even in the absence of microtubules. Our data help to explain how new kinetochore end‐on attachments are formed during the process of attachment error correction.

Cdc4 phospho-degrons allow differential regulation of Ame1CENP-U protein stability across the cell cycle

Kinetochores are multi-subunit protein assemblies that link chromosomes to microtubules of the mitotic and meiotic spindle. It is still poorly understood how efficient, centromere-dependent kinetochore assembly is accomplished from hundreds of individual protein building blocks in a cell cycle-dependent manner. Here, by combining comprehensive phosphorylation analysis of native Ctf19^CCAN subunits with biochemical and functional assays in the model system budding yeast, we demonstrate that Cdk1 phosphorylation activates phospho-degrons on the essential subunit Ame1^CENP-U, which are recognized by the E3 ubiquitin ligase complex SCF-Cdc4. Gradual phosphorylation of degron motifs culminates in M-phase and targets the protein for degradation. Binding of the Mtw1^Mis12 complex shields the proximal phospho-degron, protecting kinetochore-bound Ame1 from the degradation machinery. Artificially increasing degron strength partially suppresses the temperature sensitivity of a cdc4 mutant, while overexpression of Ame1-Okp1 is toxic in SCF mutants, demonstrating the physiological importance of this mechanism. We propose that phospho-regulated clearance of excess CCAN subunits facilitates efficient centromere-dependent kinetochore assembly. Our results suggest a novel strategy for how phospho-degrons can be used to regulate the assembly of multi-subunit complexes.

A randomized controlled trial on a self-guided Internet-based intervention for gambling problems

The majority of individuals with problematic and pathological gambling remain untreated, and treatment barriers are high. Internet-based interventions can help to address existing barriers, and first studies suggest their potential for this target group. Within a randomized controlled trial (N = 150) with two assessment times (baseline and post-intervention), we aimed to investigate the feasibility, acceptance, and effectiveness of a self-guided Internet-based intervention targeted at gambling problems. We expected a significant reduction in gambling symptoms (primary outcome) and depressive symptoms as well gambling-specific dysfunctional thoughts (secondary outcomes) in the intervention group (IG) compared to a wait-list control group with access to treatment-as-usual (control group, CG) after the intervention period of 8 weeks. Results of the complete cases, per protocol, intention-to-treat (ITT), and frequent user analyses showed significant improvements in both groups for primary and secondary outcomes but no significant between-group differences (ITT primary outcome, F(1,147) = .11, p = .739, ηp2 < .001). Moderation analyses indicated that individuals in the IG with higher gambling and depressive symptoms, older age, and comorbid anxiety symptoms showed significant improvement relative to the CG. The intervention was positively evaluated (e.g., 96.5% rated the program as useful). Possible reasons for the nonsignificant between-group differences are discussed. Future studies should include follow-up assessments and larger samples to address limitations of the present study.

Trial Registration ClinicalTrials.gov (NCT03372226), http://clinicaltrials.gov/ct2/show/NCT03372226, date of registration (13/12/2017).

The EB1-Kinesin-14 complex is required for efficient metaphase spindle assembly and kinetochore bi-orientation

Kinesin-14s are conserved molecular motors required for high-fidelity chromosome segregation, but their specific contributions to spindle function have not been fully defined. Here, we show that key functions of budding yeast Kinesin-14 Cik1-Kar3 are accomplished in a complex with Bim1 (yeast EB1). Genetic complementation of mitotic phenotypes identifies a novel KLTF peptide motif in the Cik1 N-terminus. We show that this motif is one element of a tripartite binding interface required to form a high-affinity Bim1–Cik1-Kar3 complex. Lack of Bim1-binding by Cik1-Kar3 delays cells in mitosis and impairs microtubule bundle organization and dynamics. Conversely, constitutive targeting of Cik1-Kar3 to microtubule plus ends induces the formation of nuclear microtubule bundles. Cells lacking the Bim1–Cik1-Kar3 complex rely on the conserved microtubule bundler Ase1/PRC1 for metaphase spindle organization, and simultaneous loss of plus-end targeted Kar3 and Ase1 is lethal. Our results reveal the contributions of an EB1–Kinesin-14 complex for spindle formation as a prerequisite for efficient kinetochore clustering and bi-orientation.

Sleep problems and worrying precede psychotic symptoms during an online intervention for psychosis

OBJECTIVE

Experience sampling assessments (multiple assessments per day for approximately one week) indicate that positive symptoms fluctuate over time in psychosis. Precursors, such as sleep problems or worrying, predict these fluctuations. To date, it remains unclear whether the same precursors predict symptom variability also during treatment in an online intervention for psychosis, using assessments lying temporally further apart.

METHODS

Participants completed brief intermediate online self-report assessments on their computers (up to every 7 days during a 2-month waiting period and up to twice every 6 days during a 2-month intervention period) within a randomized controlled trial. We monitored the course of paranoia, auditory verbal hallucinations, and their theory-driven precursors worrying, negative affect, self-esteem, self-reported cognitive biases, and quality of sleep in n = 124 participants (M = 10.32 assessments per participant; SD = 6.07). We tested group differences regarding the course of the composite of precursors, group differences regarding the effect of the composite on subsequent momentary psychotic symptoms, and the effect of each individual precursor on subsequent psychotic symptoms, using (lagged) linear mixed models.

RESULTS

The course composite precursors over time and their lagged effect on subsequent momentary psychotic symptoms did not differ between groups. During the intervention, increased worrying and decreased quality of sleep preceded heightened momentary psychotic symptoms.

CONCLUSION

The regression-based design does not allow drawing causal conclusions. However, worrying and sleep problems likely represent underlying mechanisms of psychotic symptom variability during online psychosis treatment, indicating that experience sampling findings from everyday life generalize to interventions with assessments lying several days apart.

PRACTITIONER POINTS

Worrying and sleep problems represent important mechanisms of symptom fluctuations during an online intervention for people with psychosis. Our findings further support the notion that worrying and sleep problems are important treatment targets in psychological interventions for people with psychosis. Momentary levels of worrying and quality of sleep can signal subsequent fluctuations of psychotic symptom severity so practitioners should monitor these variables during treatment. Worrying seems to predict subsequent paranoia specifically during treatment whereas quality of sleep predicts both paranoia and auditory verbal hallucinations.

Unguided Internet-based cognitive-behavioral therapy for obsessive-compulsive disorder: A randomized controlled trial

BACKGROUND

Many individuals with obsessive-compulsive disorder (OCD) do not receive professional treatment due to various idiosyncratic barriers. Internet-based cognitive-behavioral therapy (iCBT) is increasingly used to narrow treatment gaps, but the efficacy of such interventions without guidance of therapists has not been well studied. This study evaluated the efficacy of an unguided iCBT that includes third-wave approaches for the treatment of OCD symptoms.

METHODS

A total of 128 individuals with self-reported OCD symptoms were randomly allocated to either an intervention group (unguided iCBT) or to a care-as-usual (CAU) control group following an anonymous baseline assessment via an online survey. Eight weeks after inclusion, a reassessment was carried out online. The Yale-Brown Obsessive-Compulsive Scale served as the primary outcome parameter for detecting symptom changes in the per-protocol sample with at least 60 minutes utilization.

RESULTS

The iCBT group showed a significantly stronger reduction of OCD symptoms with a medium effect size (η²_p  = 0.06) compared with the control condition. This effect was moderated by the general frequency of Internet usage (η²_p  = 0.08); the more time per day users spent online, the less they benefited from the intervention. Secondary outcomes revealed (1) a medium effect size on self-esteem (η²_p  = 0.06); (2) no statistically significant effects on quality of life, depression symptoms, impulsivity, or social insecurity; and (3) good acceptability of the intervention.

CONCLUSIONS

The current study provides evidence that unguided iCBT for OCD may be a viable option for individuals who experience treatment barriers. As non-compliance remains a challenge, this topic needs further research.

Internet-based self-help for psychosis: Findings from a randomized controlled trial

OBJECTIVE

Cognitive-behavioral therapy (CBT) for psychosis is recommended in many national guidelines, but dissemination into routine health care remains poor. This study tests whether an 8-week, CBT-oriented, Internet-based intervention (IBI) for people with psychosis is feasible, effective, and safe compared to care as usual.

METHOD

A sample of 101 people diagnosed with schizophrenia-spectrum disorders (age: M = 40.0, SD = 9.60; sex: 58% female) was randomly assigned to either an IBI for psychosis or a wait-list control condition. The primary outcome was a composite score of the positive factor of the Positive and Negative Syndrome Scale, the Launay Slade Hallucination Scale, and the paranoia checklist (clinicaltrials.gov, NCT02974400).

RESULTS

The composite score of psychotic symptom severity decreased more in the IBI condition than in the wait-list condition, reflected in the significant interaction of Time × Condition, F(1, 87.28) = 4.04, p = .047, dbetween = 0.24, 95% CI [-0.15, 0.63]. In the combined sample of participants who received immediate or delayed access to the intervention, the outcome improved further during the 6-month follow up period with a significant main effect of time, F(1, 69.35) = 9.59, p = .003, d = -0.37, 95% CI [-0.66, -0.07]. Participants were satisfied with the intervention (89%), and many used the intervention as defined per protocol (52%; at least four completed modules). Adverse events were infrequent (4.9%).

CONCLUSIONS

Internet-based, CBT-oriented interventions provide an add-on effect to care as usual and have the potential to narrow the psychological treatment gap in psychosis. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Auto-inhibition of Mif2/CENP-C ensures centromere-dependent kinetochore assembly in budding yeast

Kinetochores are chromatin‐bound multi‐protein complexes that allow high‐fidelity chromosome segregation during mitosis and meiosis. Kinetochore assembly is exclusively initiated at chromatin containing Cse4/CENP‐A nucleosomes. The molecular mechanisms ensuring that subcomplexes assemble efficiently into kinetochores only at centromeres, but not anywhere else, are incompletely understood. Here, we combine biochemical and genetic experiments to demonstrate that auto‐inhibition of the conserved kinetochore subunit Mif2/CENP‐C contributes to preventing unscheduled kinetochore assembly in budding yeast cells. We show that wild‐type Mif2 is attenuated in its ability to bind a key downstream component in the assembly pathway, the Mtw1 complex, and that addition of Cse4 nucleosomes overcomes this inhibition. By exchanging the N‐terminus of Mif2 with its functional counterpart from Ame1/CENP‐U, we have created a Mif2 mutant which bypasses the Cse4 requirement for Mtw1 binding in vitro, thereby shortcutting kinetochore assembly. Expression of this Mif2 mutant in cells leads to mis‐localization of the Mtw1 complex and causes pronounced chromosome segregation defects. We propose that auto‐inhibition of Mif2/CENP‐C constitutes a key concept underlying the molecular logic of kinetochore assembly.

Brief Web-Based Intervention for Depression: Randomized Controlled Trial on Behavioral Activation

Background

Web-based interventions have been shown to be effective for the treatment of depression. However, interventions are often complex and include a variety of elements, making it difficult to identify the most effective component(s).

Objective

The aim of this pilot study was to shed light on mechanisms in the online treatment of depression by comparing a single-module, fully automated intervention for depression (internet-based behavioral activation [iBA]) to a nonoverlapping active control intervention and a nonactive control group.

Methods

We assessed 104 people with at least mild depressive symptoms (Patient Health Questionnaire-9, >4) via the internet at baseline (t₀) and 2 weeks (t₁) and 4 weeks (t₂) later. After the t₀ assessment, participants were randomly allocated to one of three groups: (1) iBA (n=37), (2) active control using a brief internet-based mindfulness intervention (iMBI, n=32), or (3) care as usual (CAU, n=35). The primary outcome was improvement in depressive symptoms, as measured using the Patient Health Questionnaire-9. Secondary parameters included changes in activity, dysfunctional attitudes, and quality of life

Results

While groups did not differ regarding the change in depression from t₀ to t₁ (η_p²=.007, P=.746) or t₀ to t₂ (η_p²=.008, P=.735), iBA was associated with a larger decrease in dysfunctional attitudes from t₀ to t₂ in comparison to CAU (η_p²=.053, P=.04) and a larger increase in activity from t₀ to t₁ than the pooled control groups (η_p²=.060, P=.02). A change in depression from t₀ to t₂ was mediated by a change in activity from t₀ to t₁. At t₁, 22% (6/27) of the participants in the iBA group and 12% (3/25) of the participants in the iMBI group indicated that they did not use the intervention.

Conclusions

Although we did not find support for the short-term efficacy of the single-module iBA regarding depression, long-term effects are still conceivable, potentially initiated by changes in secondary outcomes. Future studies should use a longer intervention and follow-up interval.

Trial Registration

DKRS (#DRKS00011562)

Mindfulness Mediates the Effect of a Psychological Online Intervention for Psychosis on Self-Reported Hallucinations: A Secondary Analysis of Voice Hearers From the EviBaS Trial

BACKGROUND

Psychological online interventions (POIs) could represent a promising approach to narrow the treatment gap in psychosis but it remains unclear whether improving mindfulness functions as a mechanism of change in POIs. For the present study, we examined if mindfulness mediates the effect of a comprehensive POI on distressing (auditory) hallucinations.

METHODS

We conducted a secondary analysis on voice hearers (n = 55) from a randomized controlled trial evaluating a POI for psychosis (EviBaS; trial registration NCT02974400, clinicaltrials.gov). The POI includes a module on mindfulness and we only considered POI participants in our analyses who completed the mindfulness module (n = 16).

RESULTS

Participants who completed the mindfulness module reported higher mindfulness (p = 0.015) and lower hallucinations (p = 0.001) at post assessment, compared to controls, but there was no effect on distress by voices (p = 0.598). Mindfulness mediated the POI's effect on hallucinations (b = -1.618, LLCI = -3.747, ULCI = -0.054) but not on distress by voices (b = -0.057, LLCI = -0.640, ULCI = 0.915).

LIMITATIONS AND DISCUSSION

Completion of the mindfulness module was not randomized. Hence, we cannot draw causal inferences. Even if we assumed causality, it remains unclear which contents of the POI could have resulted in increased mindfulness and reduced hallucinations, as participants completed other modules as well. In addition, confounding variables could explain the mediation and the sample size was small. Nonetheless, the overall pattern of results indicates that the POI is likely to improve mindfulness, and that increased mindfulness could partially explain the POI's efficacy.

Diminishing Effects After Recurrent Use of Self-Guided Internet-Based Interventions in Depression: Randomized Controlled Trial

Background

Self-guided internet-based interventions have several advantages over guided interventions and are generally effective in treating psychiatric symptoms.

Objective

We aimed to investigate whether the use of a new self-guided internet-based intervention (MOOD) would lead to a significant reduction in depressive symptoms compared with a care-as-usual (CAU) control group in a sample of individuals with depressive symptoms, most of whom had already used a different self-guided internet-based intervention in a previous trial.

Methods

A total of 125 individuals were randomized to the intervention condition (MOOD) and received access to the intervention for a period of six weeks or a CAU group. After six weeks, all participants were invited to take part in the post assessment. The Beck Depression Inventory-II served as the primary outcome.

Results

Both intention-to-treat as well as per-protocol analyses indicated that the depressive symptomatology decreased in both conditions but showed no advantage for those who had used MOOD. Subsequent moderation analyses suggested that those individuals who had less experience with psychotherapy benefitted to a greater extent compared with those with more experience.

Conclusions

Self-guided internet-based interventions are deemed a suitable first-step approach to the treatment of depression. However, our results indicate that they are more efficacious in those with less psychotherapy experience.

Trial Registration

ClinicalTrials.gov NCT03795480; http://clinicaltrials.gov/ct2/show/NCT03795480

A self-guided Internet-based intervention for individuals with gambling problems: study protocol for a randomized controlled trial

Background

Only a small fraction of individuals with pathological or problematic gambling seek professional help despite available evidence-based treatments such as cognitive behavioral therapy (CBT). Anonymous Internet-based interventions may help to overcome treatment barriers. Results of a pilot study using an Internet-based intervention for depression in a sample of individuals with problematic or pathological gambling behavior show that both depressive and gambling-related symptomatology can be reduced with a generic depression program compared with a wait-list control group. Based on encouraging results of the pilot study, we developed a low-threshold, anonymous and cost-free online self-help program (“Restart”) to test whether a program tailored to the needs of gamblers yields better results compared to the effects of the intervention evaluated in the pilot study. The online self-help program is based on CBT, targeting emotional problems and gambling-related symptoms and is accompanied by a smartphone application to sustain treatment benefits.

Method

A randomized controlled trial with two conditions (intervention group and wait-list control group), two assessment times (reassessment after 8 weeks) and a total of 136 participants is planned. The primary outcome will be change in pathological gambling measured with the Pathological Gambling Adaptation of Yale-Brown Obsessive-Compulsive Scale from pre to post intervention. The change in depressive symptoms (assessed with the Patient Health Questionnaire - 9 depression module) and gambling-related dysfunctional thoughts (assessed with the Gambling Attitudes and Beliefs Survey) will represent secondary outcomes. The intervention includes modules on debt management, impulse control, gambling-specific cognitive biases, self-esteem, social competence, sleep hygiene, mindfulness and positive activities.

Discussion

This study is one of the first investigations of Internet-based self-help programs in a sample of problematic gamblers. Self-guided Internet-based interventions represent a promising possibility to narrow the existing treatment gap while saving expensive and scarce resources (e.g., psychotherapists). The expected findings will add substantial knowledge in the development of effective Internet-based treatments for individuals with gambling problems. The empirical and clinical implications (e.g., broader use and promotion of such interventions in the future) and the limitations of the study will be discussed.

Trial registration

ClinicalTrials.gov, NCT03372226. Registered on 13 December 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3176-z) contains supplementary material, which is available to authorized users.

Maintaining Delusional Beliefs to Satisfy and Protect Psychological Needs

Abstract. Affiliation, control, and self-esteem are psychological needs that human beings attempt to satisfy and protect ( Epstein, 2003 ; Grawe, 2004 ). From a motivational perspective, behaviors, attentional and cognitive biases as well as symptoms can have an instrumental function for need satisfaction and protection ( Caspar, 2011 ). In this opinion paper, we elaborate the idea that the maintenance of delusions could be a motivated process. This approach helps to view the maintenance of delusional beliefs as a purposeful, yet mostly nonconscious, and not completely adaptive attempt to satisfy and protect psychological needs. Conclusions for case formulations, therapy planning, and therapeutic relationship building are drawn within the framework of cognitive-behavioral therapy for psychosis. In addition, limitations of the approach and future research avenues are discussed.

An internet-based intervention for people with psychosis (EviBaS): study protocol for a randomized controlled trial

BACKGROUND

Evidence shows that internet-based self-help interventions are effective in reducing symptoms for a wide range of mental disorders. To date, online interventions treating psychotic disorders have been scarce, even though psychosis is among the most burdensome disorders worldwide. Furthermore, the implementation of cognitive-behavioral therapy (CBT) for psychosis in routine health care is challenging. Internet-based interventions could narrow this treatment gap. Thus, a comprehensive CBT-based online self-help intervention for people with psychosis has been developed. The aim of this study is the evaluation of the feasibility and efficacy of the intervention compared with a waiting list control group.

METHODS

The intervention includes modules on delusion, voice hearing, social competence, mindfulness, and seven other domains. Participants are guided through the program by a personal moderator. Usage can be amended by an optional smartphone app. In this randomized controlled trial, participants are allocated to a waiting list or an intervention of eight weeks. Change in positive psychotic symptoms of both groups will be compared (primary outcome) and predictors of treatment effects will be assessed.

DISCUSSION

To our knowledge, this project is one of the first large-scale investigations of an internet-based intervention for people with psychosis. It may thus be a further step to broaden treatment options for people suffering from this disorder.

TRIAL REGISTRATION

NCT02974400 (clinicaltrials.gov), date of registration: November 28th 2016.

Metacognitive Training Online

Abstract. Psychological interventions such as cognitive-behavioral therapy and metacognitive training (MCT) have proven to be effective treatments for schizophrenia, but only a small number of patients actually gain access to them. Internet-based interventions are effective, but hardly explored for schizophrenia. This pilot study created an Online-MCT to investigate the feasibility, efficacy, and possible negative effects of the program. Fifteen patients participated in this uncontrolled study. During the 6-week intervention phase, two-thirds of participants completed the whole program. Only 6.1 % of all possible negative effects were strongly agreed to. Symptom severity did not change significantly, but 80 % of participants were (very) satisfied with the program, suggesting that internet-based interventions could help reduce the gap in psychological treatments of schizophrenia.

Embracing Psychosis: A Cognitive Insight Intervention Improves Personal Narratives and Meaning-Making in Patients With Schizophrenia

Schizophrenia is a complex psychiatric disorder with unknown and presumably heterogeneous etiology. While the disorder can have various outcomes, research is predominantly "deficit-oriented" emphasizing the hardship that the disorder inflicts on sufferers as well as their families and society. Beyond symptom reduction, imparting patients with hope and meaning in life is increasingly considered an important treatment target, which may raise self-esteem, and reduce self-stigma and suicidal ideation. The present study compared a psychotherapeutic treatment aimed at improving cognitive insight, individualized metacognitive intervention (MCT+), with an active control in order to elucidate if personal meaning-making and hope can be improved in patients with psychosis across time. A total of 92 patients were randomized to either individualized metacognitive therapy (MCT+) or CogPack (neuropsychological training) and followed up for up to 6 months. The "Subjective Sense in Psychosis Questionnaire" (SUSE) was administered which covers different salutogenetic vs pathogenetic views of the disorder, valence of symptom experiences and the consequences of psychosis. Patients in the MCT+ group showed a significant positive shift in attitudes towards the consequences of their illness over time relative to patients in the active control condition. There was some evidence that MCT+ also enhanced meaning-making. The perceived negative consequences of psychosis were highly correlated with depression and low self-esteem, as well as suicidality. The study shows that a cognitive insight training can improve meaning-making in patients and help them come to terms with their diagnosis.

Structural and functional differences between porcine brain and budding yeast microtubules

The cytoskeleton of eukaryotic cells relies on microtubules to perform many essential functions. We have previously shown that, in spite of the overall conservation in sequence and structure of tubulin subunits across species, there are differences between mammalian and budding yeast microtubules with likely functional consequences for the cell. Here we expand our structural and function comparison of yeast and porcine microtubules to show different distribution of protofilament number in microtubules assembled in vitro from these two species. The different geometry at lateral contacts between protofilaments is likely due to a more polar interface in yeast. We also find that yeast tubulin forms longer and less curved oligomers in solution, suggesting stronger tubulin:tubulin interactions along the protofilament. Finally, we observed species-specific plus-end tracking activity for EB proteins: yeast Bim1 tracked yeast but not mammalian MTs, and human EB1 tracked mammalian but not yeast MTs. These findings further demonstrate that subtle sequence differences in tubulin sequence can have significant structural and functional consequences in microtubule structure and behavior.

Untangling the complex relationships between symptoms of schizophrenia and emotion dynamics in daily life: Findings from an experience sampling pilot study

The unfolding of emotions over time (i.e., emotion dynamics) has been characterized by baseline, intraindividual variability and regulatory tendency (return time to baseline after deflection). Mounting evidence suggests that compared to healthy individuals, individuals with schizophrenia are characterized by a more negatively valenced baseline and a higher intraindividual variability. However, the regulatory tendency has not been investigated in schizophrenia so far. We hypothesize that the severity of positive symptoms is linked to increased emotional variability and that the severity of negative symptoms is associated with an increased regulatory tendency. Fifteen individuals diagnosed with schizophrenia took part in this pilot experience sampling study and reported their emotional state ten times a day. The dynamics of valence and arousal and their relationship with symptomatology were estimated with the DynAffect model. Regulatory tendency in valence and arousal was positively associated with negative symptom severity and negatively associated with positive symptom severity. However, the severity of positive symptoms was not credibly associated with the variability of valence. The study only partly corroborates findings on increased stress reactivity in schizophrenia, which might be due to the small sample size. However, results suggest that negative symptoms could stem from over-regulated emotion dynamics, which may impede goal-directed behavior.

Comparison of fMRI paradigms assessing visuospatial processing: Robustness and reproducibility

The development of brain imaging techniques, in particular functional magnetic resonance imaging (fMRI), made it possible to non-invasively study the hemispheric lateralization of cognitive brain functions in large cohorts. Comprehensive models of hemispheric lateralization are, however, still missing and should not only account for the hemispheric specialization of individual brain functions, but also for the interactions among different lateralized cognitive processes (e.g., language and visuospatial processing). This calls for robust and reliable paradigms to study hemispheric lateralization for various cognitive functions. While numerous reliable imaging paradigms have been developed for language, which represents the most prominent left-lateralized brain function, the reliability of imaging paradigms investigating typically right-lateralized brain functions, such as visuospatial processing, has received comparatively less attention. In the present study, we aimed to establish an fMRI paradigm that robustly and reliably identifies right-hemispheric activation evoked by visuospatial processing in individual subjects. In a first study, we therefore compared three frequently used paradigms for assessing visuospatial processing and evaluated their utility to robustly detect right-lateralized brain activity on a single-subject level. In a second study, we then assessed the test-retest reliability of the so-called Landmark task–the paradigm that yielded the most robust results in study 1. At the single-voxel level, we found poor reliability of the brain activation underlying visuospatial attention. This suggests that poor signal-to-noise ratios can become a limiting factor for test-retest reliability. This represents a common detriment of fMRI paradigms investigating visuospatial attention in general and therefore highlights the need for careful considerations of both the possibilities and limitations of the respective fMRI paradigm–in particular, when being interested in effects at the single-voxel level. Notably, however, when focusing on the reliability of measures of hemispheric lateralization (which was the main goal of study 2), we show that hemispheric dominance (quantified by the lateralization index, LI, with |LI| >0.4) of the evoked activation could be robustly determined in more than 62% and, if considering only two categories (i.e., left, right), in more than 93% of our subjects. Furthermore, the reliability of the lateralization strength (LI) was “fair” to “good”. In conclusion, our results suggest that the degree of right-hemispheric dominance during visuospatial processing can be reliably determined using the Landmark task, both at the group and single-subject level, while at the same time stressing the need for future refinements of experimental paradigms and more sophisticated fMRI data acquisition techniques.

Molecular basis for inner kinetochore configuration through RWD domain-peptide interactions

Kinetochores are dynamic cellular structures that connect chromosomes to microtubules. They form from multi‐protein assemblies that are evolutionarily conserved between yeasts and humans. One of these assemblies—COMA—consists of subunits Ame1^CENP‐U, Ctf19^CENP‐P, Mcm21^CENP‐O and Okp1^CENP‐Q. A description of COMA molecular organization has so far been missing. We defined the subunit topology of COMA, bound with inner kinetochore proteins Nkp1 and Nkp2, from the yeast Kluyveromyces lactis, with nanoflow electrospray ionization mass spectrometry, and mapped intermolecular contacts with hydrogen‐deuterium exchange coupled to mass spectrometry. Our data suggest that the essential Okp1 subunit is a multi‐segmented nexus with distinct binding sites for Ame1, Nkp1‐Nkp2 and Ctf19‐Mcm21. Our crystal structure of the Ctf19‐Mcm21 RWD domains bound with Okp1 shows the molecular contacts of this important inner kinetochore joint. The Ctf19‐Mcm21 binding motif in Okp1 configures a branch of mitotic inner kinetochores, by tethering Ctf19‐Mcm21 and Chl4^CENP‐N‐Iml3^CENP‐L. Absence of this motif results in dependence on the mitotic checkpoint for viability.

Internet interventions for depression: new developments

A wide range of Internet interventions, mostly grounded in methods of cognitive behavioral therapy, have been developed and tested for several mental disorders. The evidence to date shows that these interventions are effective in reducing symptoms of depression. Metaanalyses report small-to-medium effect sizes when Internet interventions are delivered as stand-alone self-help interventions (d=0.25-0.36), and medium-to-large effect sizes when delivered as therapist-guided interventions (d=0.58-0.78), both compared with usual care. Only a minority of people suffering from depression receive adequate treatment, and Internet interventions might help bridge the large treatment gap. This review summarizes the current body of evidence and highlights pros and cons of Internet interventions. It also outlines how they could be implemented in mental health care systems and points out unresolved questions, as well as future directions, in this research field.

TORC1 signaling exerts spatial control over microtubule dynamics by promoting nuclear export of Stu2

TORC1 regulates microtubule (MT) dynamics in budding yeast, but the key downstream effectors are unknown. van der Vaart et al. show that TORC1 activity before mitosis promotes phosphorylation of the MT polymerase Stu2 near a nuclear export signal, which leads to the nuclear export of Stu2 and reduced nuclear MT growth.

The target of rapamycin complex 1 (TORC1) is a highly conserved multiprotein complex that functions in many cellular processes, including cell growth and cell cycle progression. In this study, we define a novel role for TORC1 as a critical regulator of nuclear microtubule (MT) dynamics in the budding yeast Saccharomyces cerevisiae. This activity requires interactions between EB1 and CLIP-170 plus end–tracking protein (+TIP) family members with the TORC1 subunit Kog1/Raptor, which in turn allow the TORC1 proximal kinase Sch9/S6K1 to regulate the MT polymerase Stu2/XMAP215. Sch9-dependent phosphorylation of Stu2 adjacent to a nuclear export signal prevents nuclear accumulation of Stu2 before cells enter mitosis. Mutants impaired in +TIP–TORC1 interactions or Stu2 nuclear export show increased nuclear but not cytoplasmic MT length and display nuclear fusion, spindle positioning, and elongation kinetics defects. Our results reveal key mechanisms by which TORC1 signaling controls Stu2 localization and thereby contributes to proper MT cytoskeletal organization in interphase and mitosis.

Do depressive symptoms predict paranoia or vice versa?

BACKGROUND AND OBJECTIVES

Affective versus nonaffective psychoses are today no longer regarded as mutually exclusive disorders. Theorists have recently highlighted the role of affective symptoms in the formation of paranoid beliefs, particularly negative beliefs about the self, interpersonal sensitivity, sleep disturbances, and worrying, which exist along a continuum in the general population. For the present study, we tested the bidirectional causal relationships between paranoia and affect.

METHOD

A large population sample (N = 2,357) was examined at three time-points (baseline, six months, two years) as to the severity of subclinical paranoid beliefs (Paranoia Checklist, PCL) and depressive symptoms (Patient Health Questionnaire-9, PHQ-9). Worrying and avoidance were measured with items from the Maladaptive and Adaptive Coping Style Questionnaire (MAX).

RESULTS

Depression and paranoid symptoms were strongly cross-sectionally related (r = 0.69) and showed high stability (r > 0.72). Depressive symptoms at T2 predicted paranoid symptoms at T3 (beta = 0.16; no significant relationship from T1 to T2), whereas paranoid symptoms predicted depressive symptoms from T1 to T2 (beta = 0.09; no significant relationship from T2 to T3).

LIMITATIONS

Results should be replicated in a sample of paranoid patients, as risk factors for subclinical versus manifest paranoia may differ. Some constructs were measured with single items derived from a new scale.

CONCLUSIONS

The predictive association of depression to subsequent paranoia was small and confined to the long interval from T2 to T3. Treatments should target both paranoia and depression - irrespective of their causal relationship - particularly as patients with psychosis consider treatment of their emotional problems a priority.

Structural differences between yeast and mammalian microtubules revealed by cryo-EM

Yeast MTs do not appear to undergo the lattice compaction seen in mammalian MTs upon GTP hydrolysis. Binding of the +TIP Bim1, both between and within αβ-tubulin dimers, causes compaction of yeast MTs and their rapid disassembly.

Microtubules are polymers of αβ-tubulin heterodimers essential for all eukaryotes. Despite sequence conservation, there are significant structural differences between microtubules assembled in vitro from mammalian or budding yeast tubulin. Yeast MTs were not observed to undergo compaction at the interdimer interface as seen for mammalian microtubules upon GTP hydrolysis. Lack of compaction might reflect slower GTP hydrolysis or a different degree of allosteric coupling in the lattice. The microtubule plus end–tracking protein Bim1 binds yeast microtubules both between αβ-tubulin heterodimers, as seen for other organisms, and within tubulin dimers, but binds mammalian tubulin only at interdimer contacts. At the concentrations used in cryo-electron microscopy, Bim1 causes the compaction of yeast microtubules and induces their rapid disassembly. Our studies demonstrate structural differences between yeast and mammalian microtubules that likely underlie their differing polymerization dynamics. These differences may reflect adaptations to the demands of different cell size or range of physiological growth temperatures.

[Early recognition of cancerous lesions in the mouth and oropharynx: Automated evaluation of hyperspectral image stacks]

BACKGROUND

Early detection of cancerous lesions is still crucial for a patient's prognosis. Although diagnostic access to the oral cavity and oropharynx is comparably easy, the incidence of resulting disease remains high. This is due to the fact that in many cases, malignity is recognized too late on a purely visual basis. Previously, we discussed the application of hyperspectral imaging for early detection of precancerous and cancerous lesions of the larynx. This time, we evaluate the method in the oral cavity and oropharynx.

MATERIALS AND METHODS

In 85 patients scheduled for endoscopy, hyperspectral imaging was performed. We used a rigid 0-degree endoscope, a light-adjustable monochromator, and a hyperspectral camera. For evaluation of the method, 3 patients were chosen exemplarily. Training sites from physiological and cancerous tissues were marked. Hyperspectral data from 1 patient were used to train a classifier, which was then used for automatic detection of precancerous and cancerous lesions in another 2 patients.

RESULTS

Intraoperative hyperspectral imaging was performed without any problems. Classification showed sensitivities of 61 and 43%, and a specificity of 100%.

CONCLUSION

This proof-of-concept study underscores the high potential of hyperspectral imaging for early recognition of cancer in the mouth and oropharynx. Besides a better prognosis for cancer patients, this approach could lead to higher cost efficiency in the health system.

Cognitive emotion regulation in patients with schizophrenia: Evidence for effective reappraisal and distraction

Negative emotions trigger psychotic symptoms, according to a growing body of evidence. Thus, there is a need for effective emotion regulation in schizophrenia. Reappraisal is an effective, cognitive emotion regulation strategy in healthy individuals. However, it is an open research question whether individuals with schizophrenia have difficulties in successfully applying reappraisal. This study experimentally tests the efficacy of reappraisal compared to distraction in patients with schizophrenia and non-clinical controls. An experimental design with group as between-subject factor (non-clinical controls versus patients with schizophrenia) and emotion regulation during anxiety induction as within-subject factor (reappraisal, distraction, no regulation). Seventeen patients with schizophrenia and 27 healthy participants were instructed to respond to anxiety-inducing stimuli by either using reappraisal, distraction or by just watching. Both reappraisal and distraction were effective in down-regulating anxiety, compared to no regulation. The main effect of group and the interaction of emotion regulation condition and group were not significant indicating that the efficacy of both cognitive emotion regulation strategies was independent of group. Patients with schizophrenia are able to apply reappraisal successfully under experimental conditions. Conclusions are limited by the small sample size of this pilot study. Clinical implications for cognitive behavioral therapy for psychosis are discussed.

Motive-oriented therapeutic relationship building for patients diagnosed with schizophrenia

Treatment options for patients with schizophrenia demand further improvement. One way to achieve this improvement is the translation of findings from basic research into new specific interventions. Beyond that, addressing the therapy relationship has the potential to enhance both pharmacological and non-pharmacological treatments. This paper introduces motive-oriented therapeutic relationship (MOTR) building for schizophrenia. MOTR enables therapists to proactively adapt to their patient’s needs and to prevent problematic behaviors. For example, a patient might consider medication as helpful in principle, but the rejection of medication might be one of his few remaining means for his acceptable motive to stay autonomous despite hospitalization. A therapist who is motive-oriented proactively offers many degrees of freedom to this patient in order to satisfy his need for autonomy and to weaken the motivational basis for not taking medication. MOTR makes use of findings from basic and psychotherapy research and is generic in this respect, but at the same time guides therapeutic action precisely and flexibly in a patient oriented way.

Metacognition-augmented cognitive remediation training reduces jumping to conclusions and overconfidence but not neurocognitive deficits in psychosis

The majority of patients with schizophrenia display neurocognitive deficits (e.g., memory impairment) as well as inflated cognitive biases (e.g., jumping to conclusions). Both cognitive domains are implicated in the pathogenesis of the disorder and are known to compromise functional outcome. At present, there is a dearth of effective treatment options. A total of 90 patients with schizophrenia were recruited online (a diagnosis of schizophrenia had been confirmed in a large subgroup during a previous hospital admission). Subsequent to a baseline assessment encompassing psychopathology, self-reported cognition as well as objective memory and reasoning tests, patients were randomized to one of three conditions: standard cognitive remediation (mybraintraining), metacognition-augmented cognition remediation (CR) condition (variant of mybraintraining which encouraged patients to reduce speed of decision-making and attenuate response confidence when participants made high-confidence judgements and hasty incorrect decisions) and a waitlist control group. Patients were retested after 6 weeks and again 3 months after the second assessment. Groups did not differ on psychopathology and neurocognitive parameters at any timepoint. However, at follow-up the metacognitive-augmented CR group displayed a significant reduction on jumping to conclusions and overconfidence. Treatment adherence correlated with a reduction of depression; gains in the training exercises from the standard mybraintraining condition were correlated with improved objective memory performance. The study suggests that metacognition-augmented CR may ameliorate cognitive biases but not neurocognition. The study ties in well with prior research showing that neurocognitive dysfunctions are rather resistant to change; the failure to detect significant improvement of CR or metacognition-augmented CR on psychopathology and neurocognition over time may partly be attributed to a number of methodological limitations of our study (low psychopathology and chronicity of participants, low “dosage,” narrow range of tests, self-report psychopathology scales).

Non-catalytic motor domains enable processive movement and functional diversification of the kinesin-14 Kar3

Motor proteins of the conserved kinesin-14 family have important roles in mitotic spindle organization and chromosome segregation. Previous studies have indicated that kinesin-14 motors are non-processive enzymes, working in the context of multi-motor ensembles that collectively organize microtubule networks. In this study, we show that the yeast kinesin-14 Kar3 generates processive movement as a heterodimer with the non-motor proteins Cik1 or Vik1. By analyzing the single-molecule properties of engineered motors, we demonstrate that the non-catalytic domain has a key role in the motility mechanism by acting as a 'foothold' that allows Kar3 to bias translocation towards the minus end. This mechanism rivals the speed and run length of conventional motors, can support transport of the Ndc80 complex in vitro and is critical for Kar3 function in vivo. Our findings provide an example for a non-conventional translocation mechanism and can explain how Kar3 substitutes for key functions of Dynein in the yeast nucleus.

A cooperative mechanism drives budding yeast kinetochore assembly downstream of CENP-A

During kinetochore assembly in budding yeast, the key steps of CENP-A recognition and outer kinetochore recruitment are executed through different yeast CCAN subunits, potentially protecting against inappropriate kinetochore assembly.

Kinetochores are megadalton-sized protein complexes that mediate chromosome–microtubule interactions in eukaryotes. How kinetochore assembly is triggered specifically on centromeric chromatin is poorly understood. Here we use biochemical reconstitution experiments alongside genetic and structural analysis to delineate the contributions of centromere-associated proteins to kinetochore assembly in yeast. We show that the conserved kinetochore subunits Ame1^CENP-U and Okp1^CENP-Q form a DNA-binding complex that associates with the microtubule-binding KMN network via a short Mtw1 recruitment motif in the N terminus of Ame1. Point mutations in the Ame1 motif disrupt kinetochore function by preventing KMN assembly on chromatin. Ame1–Okp1 directly associates with the centromere protein C (CENP-C) homologue Mif2 to form a cooperative binding platform for outer kinetochore assembly. Our results indicate that the key assembly steps, CENP-A recognition and outer kinetochore recruitment, are executed through different yeast constitutive centromere-associated network subunits. This two-step mechanism may protect against inappropriate kinetochore assembly similar to rate-limiting nucleation steps used by cytoskeletal polymers.

"Uno, nessuno e centomila": the different faces of the budding yeast kinetochore

"One, no one and one hundred thousand" is a masterpiece of Italian literature, written by Luigi Pirandello. The central theme is that in each individual there are multiple personalities, since one's perception of one's self differs from the view of others. As a consequence, a unique identity does not exist, but rather one hundred thousand. This concept can be very well applied to the kinetochore, one of the largest macromolecular complexes conserved in eukaryotes. The kinetochore is essential during cell division and fulfills different sophisticated functions, including linking chromosomes to spindle microtubules and delaying anaphase onset in case of incorrect bi-orientation. In order to perform these tasks, the kinetochore shapes its structure by recruiting different subunits, such as the components of the spindle assembly checkpoint (SAC) or the monopolin complex during meiosis. It also modifies its internal organization by rearranging intramolecular connections and acquiring a distinct identity at different time points of cell division. In this review, we describe recent insights into the changes in composition and configuration of the kinetochore in mitosis and meiosis, focusing on the kinetochore of Saccharomyces cerevisiae.

Who stays, who benefits? Predicting dropout and change in cognitive behaviour therapy for psychosis

This study investigates the predictors of outcome in a secondary analysis of dropout and completer data from a randomized controlled effectiveness trial comparing CBTp to a wait-list group (Lincoln et al., 2012). Eighty patients with DSM-IV psychotic disorders seeking outpatient treatment were included. Predictors were assessed at baseline. Symptom outcome was assessed at post-treatment and at 1-year follow-up. The predictor×group interactions indicate that a longer duration of disorder predicted less improvement in negative symptoms in the CBTp but not in the wait-list group whereas jumping-to-conclusions was associated with poorer outcome only in the wait-list group. There were no CBTp specific predictors of improvement in positive symptoms. However, in the combined sample (immediate CBTp+the delayed CBTp group) baseline variables predicted significant amounts of positive and negative symptom variance at post-therapy and 1-year follow-up after controlling for pre-treatment symptoms. Lack of insight and low social functioning were the main predictors of drop-out, contributing to a prediction accuracy of 87%. The findings indicate that higher baseline symptom severity, poorer functioning, neurocognitive deficits, reasoning biases and comorbidity pose no barrier to improvement during CBTp. However, in line with previous predictor-research, the findings imply that patients need to receive treatment earlier.