Cognitive-self consciousness and metacognitive beliefs: Stress sensitization in individuals at ultra-high risk of developing psychosis

OBJECTIVE

Metacognitive beliefs (MCB) may guide information and attention processes, increasing affective and symptomatic reactions to stressful events. Cognitive self-consciousness (CSC; i.e., a preoccupation with one's thoughts) may increase awareness of MCB, potentially triggering the onset of psychotic symptoms. This study tested the hypotheses that (1), MCB would moderate affective and symptomatic reactions to stress in individuals at ultra-high risk (UHR) of developing psychosis, and (2), greater CSC would precede worsening in psychotic symptoms in individuals with strong MCB.

METHOD

Twenty-seven individuals at UHR of developing psychosis completed a self-report diary when prompted by an electronic wristwatch several times each day for 6 days (experience sampling).

RESULTS

MCB moderated the association between affective, but not symptomatic, responses to social stress. CSC preceded the subsequent occurrence of hallucinations in individuals who reported strong beliefs about the need to control their thoughts.

CONCLUSIONS

The data suggest that MCB sensitize an individual to social stressors. CSC may represent times where an individual is aware that their thoughts are uncontrollable, and therefore contradicting their MCB, motivating them to make an external attribution. The findings have implications for improving the effectiveness of interventions for people experiencing hallucinations.

An siRNA screen identifies RSK1 as a key modulator of lung cancer metastasis

We performed a kinome-wide siRNA screen and identified 70 kinases altering cell migration in A549 lung cancer cells. In particular, ribosomal S6 kinase 1 (RSK1) silencing increased, whereas RSK2 and RSK4 downregulation inhibited cell motility. In a secondary collagen-based three-dimensional invasion screen, 38 of our hits cross-validated, including RSK1 and RSK4. In two further lung cancer cell lines, RSK1 but not RSK4 silencing showed identical modulation of cell motility. We therefore selected RSK1 for further investigation. Bioinformatic analysis followed by co-immunoprecipitation-based validation revealed that the actin regulators VASP and Mena interact with RSK1. Moreover, RSK1 phosphorylated VASP on T278, a site regulating its binding to actin. In addition, silencing of RSK1 enhanced the metastatic potential of these cells in vivo using a zebrafish model. Finally, we investigated the relevance of this finding in human lung cancer samples. In isogenically matched tissue, RSK1 was reduced in metastatic versus primary lung cancer lesions. Moreover, patients with RSK1-negative lung tumours showed increased number of metastases. Our results suggest that the findings of our high-throughput in vitro screen can reliably identify relevant clinical targets and as a proof of principle, RSK1 may provide a biomarker for metastasis in lung cancer patients.

Abnormal cortisol awakening response predicts worse cognitive function in patients with first-episode psychosis

BACKGROUND

Cognitive impairment, particularly in memory and executive function, is a core feature of psychosis. Moreover, psychosis is characterized by a more prominent history of stress exposure, and by dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis. In turn, stress exposure and abnormal levels of the main HPA axis hormone cortisol are associated with cognitive impairments in a variety of clinical and experimental samples; however, this association has never been examined in first-episode psychosis (FEP).

METHOD

In this study, 30 FEP patients and 26 controls completed assessment of the HPA axis (cortisol awakening response and cortisol levels during the day), perceived stress, recent life events, history of childhood trauma, and cognitive function. The neuropsychological battery comprised general cognitive function, verbal and non-verbal memory, executive function, perception, visuospatial abilities, processing speed, and general knowledge.

RESULTS

Patients performed significantly worse on all cognitive domains compared to controls. In patients only, a more blunted cortisol awakening response (that is, more abnormal) was associated with a more severe deficit in verbal memory and processing speed. In controls only, higher levels of perceived stress and more recent life events were associated with a worse performance in executive function and perception and visuospatial abilities.

CONCLUSIONS

These data support a role for the HPA axis, as measured by cortisol awakening response, in modulating cognitive function in patients with psychosis; however, this association does not seem to be related to the increased exposure to psychosocial stressors described in these patients.

Adaptive-predictive organ localization (a-POLO) in the clinic: Updated results in hypofractionated bladder radiotherapy

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Background: The A-POLO strategy allows the optimal 'plan of the day' to be selected online for radiotherapy (RT) delivery. The methodology is implemented in a phase II study of patients with muscle-invasive bladder cancer who are not suitable for cystectomy/daily RT and are receiving hypofractionated RT.

Methods: Planning scans were performed at 0 and 30 minutes post void (CT0 and CT30). Three conformal plans were created (small, intermediate, large) ( Table ). Patients were prescribed 6Gy weekly for 5–6 weeks. A pre-RT cone beam CT (CBCT) scan and online set-up correction were performed. The plan giving the optimal target coverage was selected by 2 observers. Offline plan selection was also carried out by an independent observer. A post-RT CBCT was acquired to calculate the percentage of the CTV covered by 95% of the dose (V95). The mean A- POLO volume was compared to our previous institutional standard PTV (1.5cm isotropic margins) (PTViso). Outcome data were collected.

Results: A total of 77 RT fractions were delivered to 14 patients. The small plan was delivered for 38 (49%) fractions and the large for 6 (8%) fractions. The concordance rate between online and offline plan selection was 71/77 (92%). The mean CTV V95 was 99% (patient mean range 97–100%). The mean time between the pre- and post-treatment CBCT was 15 minutes. The mean reduction between PTViso and mean A-POLO PTV was 42% (range 16– 59%). 2 patients had grade (G) 3 (CTCv3.0) treatment-related acute toxicity. There have been no treatment-related G4 acute or G3 late toxicities. With a median follow-up of 7.3 months 10 patients are alive with 8 disease free (1 local and 1 distant relapse).

Conclusions: Implementation of A-POLO RT is feasible, well tolerated, and associated with good concordance in 'plan of the day' selection. An individualized treatment plan can be delivered with each fraction to achieve a reduction in PTV compared to PTViso with maintenance of target coverage.

[Table: see text]

No significant financial relationships to disclose.

Planning outcomes and acute toxicity of intensity-modulated radiotherapy (IMRT) for treatment of bladder and pelvic lymph nodes

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Background: We implemented an IMRT protocol for simultaneous treatment of bladder and pelvic lymph nodes (LN) and report the planning outcomes and acute toxicity of patients treated using this technique.

Methods: 13 patients were treated with a 5-field step and shoot IMRT technique. Inclusion criteria were: radiological evidence of pelvic LN metastases; stage T3/T4; high risk pathology or post-cystectomy with persistent/recurrent disease. Anisotropic margins were applied to the whole bladder CTV (0.5 cm laterally/inferiorly, 1 cm posteriorly, 1.5 cm superiorly/anteriorly) to create PTV1. 0.5 cm margins were applied to the pelvic LN CTV to create PTV2. PTVs 1/2 were prescribed 52 Gy in 32 fractions. 1 cm margins were applied to the involved bladder to create PTV3 (prescribed 64Gy). 0.5 cm margins were applied to the involved LN volumes to create PTV4 (prescribed 60 Gy). Post cystectomy patients were planned using PTVs 2/4 only. Dose volume histograms for organs at risk (rectum, femoral heads and other bowel) were calculated and compared with local dose constraints. Acute toxicity was assessed according to common toxicity criteria v3.0 and recorded weekly during treatment. Treatment verification was performed by cone beam CT.

Results: All treatment plans achieved target coverage of > 95% volume to > 95% prescription dose for each PTV. All patients achieved rectal and femoral head dose constraints. 2 patients did not meet V45 other bowel constraints but proceeded with treatment as all other dose limits were achieved. At the time of abstract submission 13 patients had completed treatment. 2 were treated for relapse post-cystectomy and did not have GU toxicities recorded. Maximum experienced acute toxicities were recorded. 9/11 patients experienced acute GU toxicity (G1=3, G2=1, G3=5). 6/13 patients experienced acute GI toxicity (G1=3, G2=3). 9/13 patients developed other acute toxicities (G1=7, G2=2). No patients developed ≥G3 non-GU toxicity.

Conclusions: Bladder and pelvic LN IMRT allows patients with high risk locoregional bladder cancer to meet preset dose constraints, appears feasible and has a comparable rate of acute toxicity to conventional bladder-only radiotherapy treatment.

No significant financial relationships to disclose.

A robust MRI-compatible system to facilitate highly accurate stereotactic administration of therapeutic agents to targets within the brain of a large animal model

Achieving accurate intracranial electrode or catheter placement is critical in clinical practice in order to maximise the efficacy of deep brain stimulation and drug delivery respectively as well as to minimise side-effects. We have developed a highly accurate and robust method for MRI-guided, stereotactic delivery of catheters and electrodes to deep target structures in the brain of pigs. This study outlines the development of this equipment and animal model. Specifically this system enables reliable head immobilisation, acquisition of high-resolution MR images, precise co-registration of MRI and stereotactic spaces and overall rigidity to facilitate accurate burr hole-generation and catheter implantation.

To demonstrate the utility of this system, in this study a total of twelve catheters were implanted into the putamen of six Large White Landrace pigs. All implants were accurately placed into the putamen. Target accuracy had a mean Euclidean distance of 0.623 mm (standard deviation of 0.33 mm). This method has allowed us to accurately insert fine cannulae, suitable for the administration of therapeutic agents by convection-enhanced delivery (CED), into the brain of pigs. This study provides summary evidence of a robust system for catheter implantation into the brain of a large animal model. We are currently using this stereotactic system, implantation procedure and animal model to develop catheter-based drug delivery systems that will be translated into human clinical trials, as well as to model the distribution of therapeutic agents administered by CED over large volumes of brain.